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Linux 5.5.2
[linux/fpc-iii.git] / fs / btrfs / inode.c
blobc70baafb2a3920ced47005c3d60b11c07c89af88
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6 #include <linux/kernel.h>
7 #include <linux/bio.h>
8 #include <linux/buffer_head.h>
9 #include <linux/file.h>
10 #include <linux/fs.h>
11 #include <linux/pagemap.h>
12 #include <linux/highmem.h>
13 #include <linux/time.h>
14 #include <linux/init.h>
15 #include <linux/string.h>
16 #include <linux/backing-dev.h>
17 #include <linux/writeback.h>
18 #include <linux/compat.h>
19 #include <linux/xattr.h>
20 #include <linux/posix_acl.h>
21 #include <linux/falloc.h>
22 #include <linux/slab.h>
23 #include <linux/ratelimit.h>
24 #include <linux/btrfs.h>
25 #include <linux/blkdev.h>
26 #include <linux/posix_acl_xattr.h>
27 #include <linux/uio.h>
28 #include <linux/magic.h>
29 #include <linux/iversion.h>
30 #include <linux/swap.h>
31 #include <linux/sched/mm.h>
32 #include <asm/unaligned.h>
33 #include "misc.h"
34 #include "ctree.h"
35 #include "disk-io.h"
36 #include "transaction.h"
37 #include "btrfs_inode.h"
38 #include "print-tree.h"
39 #include "ordered-data.h"
40 #include "xattr.h"
41 #include "tree-log.h"
42 #include "volumes.h"
43 #include "compression.h"
44 #include "locking.h"
45 #include "free-space-cache.h"
46 #include "inode-map.h"
47 #include "backref.h"
48 #include "props.h"
49 #include "qgroup.h"
50 #include "delalloc-space.h"
51 #include "block-group.h"
52
53 struct btrfs_iget_args {
54 struct btrfs_key *location;
55 struct btrfs_root *root;
56 };
57
58 struct btrfs_dio_data {
59 u64 reserve;
60 u64 unsubmitted_oe_range_start;
61 u64 unsubmitted_oe_range_end;
62 int overwrite;
63 };
64
65 static const struct inode_operations btrfs_dir_inode_operations;
66 static const struct inode_operations btrfs_symlink_inode_operations;
67 static const struct inode_operations btrfs_dir_ro_inode_operations;
68 static const struct inode_operations btrfs_special_inode_operations;
69 static const struct inode_operations btrfs_file_inode_operations;
70 static const struct address_space_operations btrfs_aops;
71 static const struct file_operations btrfs_dir_file_operations;
72 static const struct extent_io_ops btrfs_extent_io_ops;
73
74 static struct kmem_cache *btrfs_inode_cachep;
75 struct kmem_cache *btrfs_trans_handle_cachep;
76 struct kmem_cache *btrfs_path_cachep;
77 struct kmem_cache *btrfs_free_space_cachep;
78 struct kmem_cache *btrfs_free_space_bitmap_cachep;
79
80 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
81 static int btrfs_truncate(struct inode *inode, bool skip_writeback);
82 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
83 static noinline int cow_file_range(struct inode *inode,
84 struct page *locked_page,
85 u64 start, u64 end, int *page_started,
86 unsigned long *nr_written, int unlock);
87 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
88 u64 orig_start, u64 block_start,
89 u64 block_len, u64 orig_block_len,
90 u64 ram_bytes, int compress_type,
91 int type);
92
93 static void __endio_write_update_ordered(struct inode *inode,
94 const u64 offset, const u64 bytes,
95 const bool uptodate);
96
97 /*
98 * Cleanup all submitted ordered extents in specified range to handle errors
99 * from the btrfs_run_delalloc_range() callback.
100 *
101 * NOTE: caller must ensure that when an error happens, it can not call
102 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
103 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
104 * to be released, which we want to happen only when finishing the ordered
105 * extent (btrfs_finish_ordered_io()).
106 */
107 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
108 struct page *locked_page,
109 u64 offset, u64 bytes)
110 {
111 unsigned long index = offset >> PAGE_SHIFT;
112 unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
113 u64 page_start = page_offset(locked_page);
114 u64 page_end = page_start + PAGE_SIZE - 1;
115
116 struct page *page;
117
118 while (index <= end_index) {
119 page = find_get_page(inode->i_mapping, index);
120 index++;
121 if (!page)
122 continue;
123 ClearPagePrivate2(page);
124 put_page(page);
125 }
126
127 /*
128 * In case this page belongs to the delalloc range being instantiated
129 * then skip it, since the first page of a range is going to be
130 * properly cleaned up by the caller of run_delalloc_range
131 */
132 if (page_start >= offset && page_end <= (offset + bytes - 1)) {
133 offset += PAGE_SIZE;
134 bytes -= PAGE_SIZE;
135 }
136
137 return __endio_write_update_ordered(inode, offset, bytes, false);
138 }
139
140 static int btrfs_dirty_inode(struct inode *inode);
141
142 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
143 void btrfs_test_inode_set_ops(struct inode *inode)
144 {
145 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
146 }
147 #endif
148
149 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
150 struct inode *inode, struct inode *dir,
151 const struct qstr *qstr)
152 {
153 int err;
154
155 err = btrfs_init_acl(trans, inode, dir);
156 if (!err)
157 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
158 return err;
159 }
160
161 /*
162 * this does all the hard work for inserting an inline extent into
163 * the btree. The caller should have done a btrfs_drop_extents so that
164 * no overlapping inline items exist in the btree
165 */
166 static int insert_inline_extent(struct btrfs_trans_handle *trans,
167 struct btrfs_path *path, int extent_inserted,
168 struct btrfs_root *root, struct inode *inode,
169 u64 start, size_t size, size_t compressed_size,
170 int compress_type,
171 struct page **compressed_pages)
172 {
173 struct extent_buffer *leaf;
174 struct page *page = NULL;
175 char *kaddr;
176 unsigned long ptr;
177 struct btrfs_file_extent_item *ei;
178 int ret;
179 size_t cur_size = size;
180 unsigned long offset;
181
182 ASSERT((compressed_size > 0 && compressed_pages) ||
183 (compressed_size == 0 && !compressed_pages));
184
185 if (compressed_size && compressed_pages)
186 cur_size = compressed_size;
187
188 inode_add_bytes(inode, size);
189
190 if (!extent_inserted) {
191 struct btrfs_key key;
192 size_t datasize;
193
194 key.objectid = btrfs_ino(BTRFS_I(inode));
195 key.offset = start;
196 key.type = BTRFS_EXTENT_DATA_KEY;
197
198 datasize = btrfs_file_extent_calc_inline_size(cur_size);
199 path->leave_spinning = 1;
200 ret = btrfs_insert_empty_item(trans, root, path, &key,
201 datasize);
202 if (ret)
203 goto fail;
204 }
205 leaf = path->nodes[0];
206 ei = btrfs_item_ptr(leaf, path->slots[0],
207 struct btrfs_file_extent_item);
208 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
209 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
210 btrfs_set_file_extent_encryption(leaf, ei, 0);
211 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
212 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
213 ptr = btrfs_file_extent_inline_start(ei);
214
215 if (compress_type != BTRFS_COMPRESS_NONE) {
216 struct page *cpage;
217 int i = 0;
218 while (compressed_size > 0) {
219 cpage = compressed_pages[i];
220 cur_size = min_t(unsigned long, compressed_size,
221 PAGE_SIZE);
222
223 kaddr = kmap_atomic(cpage);
224 write_extent_buffer(leaf, kaddr, ptr, cur_size);
225 kunmap_atomic(kaddr);
226
227 i++;
228 ptr += cur_size;
229 compressed_size -= cur_size;
230 }
231 btrfs_set_file_extent_compression(leaf, ei,
232 compress_type);
233 } else {
234 page = find_get_page(inode->i_mapping,
235 start >> PAGE_SHIFT);
236 btrfs_set_file_extent_compression(leaf, ei, 0);
237 kaddr = kmap_atomic(page);
238 offset = offset_in_page(start);
239 write_extent_buffer(leaf, kaddr + offset, ptr, size);
240 kunmap_atomic(kaddr);
241 put_page(page);
242 }
243 btrfs_mark_buffer_dirty(leaf);
244 btrfs_release_path(path);
245
246 /*
247 * we're an inline extent, so nobody can
248 * extend the file past i_size without locking
249 * a page we already have locked.
250 *
251 * We must do any isize and inode updates
252 * before we unlock the pages. Otherwise we
253 * could end up racing with unlink.
254 */
255 BTRFS_I(inode)->disk_i_size = inode->i_size;
256 ret = btrfs_update_inode(trans, root, inode);
257
258 fail:
259 return ret;
260 }
261
262
263 /*
264 * conditionally insert an inline extent into the file. This
265 * does the checks required to make sure the data is small enough
266 * to fit as an inline extent.
267 */
268 static noinline int cow_file_range_inline(struct inode *inode, u64 start,
269 u64 end, size_t compressed_size,
270 int compress_type,
271 struct page **compressed_pages)
272 {
273 struct btrfs_root *root = BTRFS_I(inode)->root;
274 struct btrfs_fs_info *fs_info = root->fs_info;
275 struct btrfs_trans_handle *trans;
276 u64 isize = i_size_read(inode);
277 u64 actual_end = min(end + 1, isize);
278 u64 inline_len = actual_end - start;
279 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
280 u64 data_len = inline_len;
281 int ret;
282 struct btrfs_path *path;
283 int extent_inserted = 0;
284 u32 extent_item_size;
285
286 if (compressed_size)
287 data_len = compressed_size;
288
289 if (start > 0 ||
290 actual_end > fs_info->sectorsize ||
291 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
292 (!compressed_size &&
293 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
294 end + 1 < isize ||
295 data_len > fs_info->max_inline) {
296 return 1;
297 }
298
299 path = btrfs_alloc_path();
300 if (!path)
301 return -ENOMEM;
302
303 trans = btrfs_join_transaction(root);
304 if (IS_ERR(trans)) {
305 btrfs_free_path(path);
306 return PTR_ERR(trans);
307 }
308 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
309
310 if (compressed_size && compressed_pages)
311 extent_item_size = btrfs_file_extent_calc_inline_size(
312 compressed_size);
313 else
314 extent_item_size = btrfs_file_extent_calc_inline_size(
315 inline_len);
316
317 ret = __btrfs_drop_extents(trans, root, inode, path,
318 start, aligned_end, NULL,
319 1, 1, extent_item_size, &extent_inserted);
320 if (ret) {
321 btrfs_abort_transaction(trans, ret);
322 goto out;
323 }
324
325 if (isize > actual_end)
326 inline_len = min_t(u64, isize, actual_end);
327 ret = insert_inline_extent(trans, path, extent_inserted,
328 root, inode, start,
329 inline_len, compressed_size,
330 compress_type, compressed_pages);
331 if (ret && ret != -ENOSPC) {
332 btrfs_abort_transaction(trans, ret);
333 goto out;
334 } else if (ret == -ENOSPC) {
335 ret = 1;
336 goto out;
337 }
338
339 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
340 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
341 out:
342 /*
343 * Don't forget to free the reserved space, as for inlined extent
344 * it won't count as data extent, free them directly here.
345 * And at reserve time, it's always aligned to page size, so
346 * just free one page here.
347 */
348 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
349 btrfs_free_path(path);
350 btrfs_end_transaction(trans);
351 return ret;
352 }
353
354 struct async_extent {
355 u64 start;
356 u64 ram_size;
357 u64 compressed_size;
358 struct page **pages;
359 unsigned long nr_pages;
360 int compress_type;
361 struct list_head list;
362 };
363
364 struct async_chunk {
365 struct inode *inode;
366 struct page *locked_page;
367 u64 start;
368 u64 end;
369 unsigned int write_flags;
370 struct list_head extents;
371 struct cgroup_subsys_state *blkcg_css;
372 struct btrfs_work work;
373 atomic_t *pending;
374 };
375
376 struct async_cow {
377 /* Number of chunks in flight; must be first in the structure */
378 atomic_t num_chunks;
379 struct async_chunk chunks[];
380 };
381
382 static noinline int add_async_extent(struct async_chunk *cow,
383 u64 start, u64 ram_size,
384 u64 compressed_size,
385 struct page **pages,
386 unsigned long nr_pages,
387 int compress_type)
388 {
389 struct async_extent *async_extent;
390
391 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
392 BUG_ON(!async_extent); /* -ENOMEM */
393 async_extent->start = start;
394 async_extent->ram_size = ram_size;
395 async_extent->compressed_size = compressed_size;
396 async_extent->pages = pages;
397 async_extent->nr_pages = nr_pages;
398 async_extent->compress_type = compress_type;
399 list_add_tail(&async_extent->list, &cow->extents);
400 return 0;
401 }
402
403 /*
404 * Check if the inode has flags compatible with compression
405 */
406 static inline bool inode_can_compress(struct inode *inode)
407 {
408 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW ||
409 BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
410 return false;
411 return true;
412 }
413
414 /*
415 * Check if the inode needs to be submitted to compression, based on mount
416 * options, defragmentation, properties or heuristics.
417 */
418 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
419 {
420 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
421
422 if (!inode_can_compress(inode)) {
423 WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
424 KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
425 btrfs_ino(BTRFS_I(inode)));
426 return 0;
427 }
428 /* force compress */
429 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
430 return 1;
431 /* defrag ioctl */
432 if (BTRFS_I(inode)->defrag_compress)
433 return 1;
434 /* bad compression ratios */
435 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
436 return 0;
437 if (btrfs_test_opt(fs_info, COMPRESS) ||
438 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
439 BTRFS_I(inode)->prop_compress)
440 return btrfs_compress_heuristic(inode, start, end);
441 return 0;
442 }
443
444 static inline void inode_should_defrag(struct btrfs_inode *inode,
445 u64 start, u64 end, u64 num_bytes, u64 small_write)
446 {
447 /* If this is a small write inside eof, kick off a defrag */
448 if (num_bytes < small_write &&
449 (start > 0 || end + 1 < inode->disk_i_size))
450 btrfs_add_inode_defrag(NULL, inode);
451 }
452
453 /*
454 * we create compressed extents in two phases. The first
455 * phase compresses a range of pages that have already been
456 * locked (both pages and state bits are locked).
457 *
458 * This is done inside an ordered work queue, and the compression
459 * is spread across many cpus. The actual IO submission is step
460 * two, and the ordered work queue takes care of making sure that
461 * happens in the same order things were put onto the queue by
462 * writepages and friends.
463 *
464 * If this code finds it can't get good compression, it puts an
465 * entry onto the work queue to write the uncompressed bytes. This
466 * makes sure that both compressed inodes and uncompressed inodes
467 * are written in the same order that the flusher thread sent them
468 * down.
469 */
470 static noinline int compress_file_range(struct async_chunk *async_chunk)
471 {
472 struct inode *inode = async_chunk->inode;
473 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
474 u64 blocksize = fs_info->sectorsize;
475 u64 start = async_chunk->start;
476 u64 end = async_chunk->end;
477 u64 actual_end;
478 u64 i_size;
479 int ret = 0;
480 struct page **pages = NULL;
481 unsigned long nr_pages;
482 unsigned long total_compressed = 0;
483 unsigned long total_in = 0;
484 int i;
485 int will_compress;
486 int compress_type = fs_info->compress_type;
487 int compressed_extents = 0;
488 int redirty = 0;
489
490 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
491 SZ_16K);
492
493 /*
494 * We need to save i_size before now because it could change in between
495 * us evaluating the size and assigning it. This is because we lock and
496 * unlock the page in truncate and fallocate, and then modify the i_size
497 * later on.
498 *
499 * The barriers are to emulate READ_ONCE, remove that once i_size_read
500 * does that for us.
501 */
502 barrier();
503 i_size = i_size_read(inode);
504 barrier();
505 actual_end = min_t(u64, i_size, end + 1);
506 again:
507 will_compress = 0;
508 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
509 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
510 nr_pages = min_t(unsigned long, nr_pages,
511 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
512
513 /*
514 * we don't want to send crud past the end of i_size through
515 * compression, that's just a waste of CPU time. So, if the
516 * end of the file is before the start of our current
517 * requested range of bytes, we bail out to the uncompressed
518 * cleanup code that can deal with all of this.
519 *
520 * It isn't really the fastest way to fix things, but this is a
521 * very uncommon corner.
522 */
523 if (actual_end <= start)
524 goto cleanup_and_bail_uncompressed;
525
526 total_compressed = actual_end - start;
527
528 /*
529 * skip compression for a small file range(<=blocksize) that
530 * isn't an inline extent, since it doesn't save disk space at all.
531 */
532 if (total_compressed <= blocksize &&
533 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
534 goto cleanup_and_bail_uncompressed;
535
536 total_compressed = min_t(unsigned long, total_compressed,
537 BTRFS_MAX_UNCOMPRESSED);
538 total_in = 0;
539 ret = 0;
540
541 /*
542 * we do compression for mount -o compress and when the
543 * inode has not been flagged as nocompress. This flag can
544 * change at any time if we discover bad compression ratios.
545 */
546 if (inode_need_compress(inode, start, end)) {
547 WARN_ON(pages);
548 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
549 if (!pages) {
550 /* just bail out to the uncompressed code */
551 nr_pages = 0;
552 goto cont;
553 }
554
555 if (BTRFS_I(inode)->defrag_compress)
556 compress_type = BTRFS_I(inode)->defrag_compress;
557 else if (BTRFS_I(inode)->prop_compress)
558 compress_type = BTRFS_I(inode)->prop_compress;
559
560 /*
561 * we need to call clear_page_dirty_for_io on each
562 * page in the range. Otherwise applications with the file
563 * mmap'd can wander in and change the page contents while
564 * we are compressing them.
565 *
566 * If the compression fails for any reason, we set the pages
567 * dirty again later on.
568 *
569 * Note that the remaining part is redirtied, the start pointer
570 * has moved, the end is the original one.
571 */
572 if (!redirty) {
573 extent_range_clear_dirty_for_io(inode, start, end);
574 redirty = 1;
575 }
576
577 /* Compression level is applied here and only here */
578 ret = btrfs_compress_pages(
579 compress_type | (fs_info->compress_level << 4),
580 inode->i_mapping, start,
581 pages,
582 &nr_pages,
583 &total_in,
584 &total_compressed);
585
586 if (!ret) {
587 unsigned long offset = offset_in_page(total_compressed);
588 struct page *page = pages[nr_pages - 1];
589 char *kaddr;
590
591 /* zero the tail end of the last page, we might be
592 * sending it down to disk
593 */
594 if (offset) {
595 kaddr = kmap_atomic(page);
596 memset(kaddr + offset, 0,
597 PAGE_SIZE - offset);
598 kunmap_atomic(kaddr);
599 }
600 will_compress = 1;
601 }
602 }
603 cont:
604 if (start == 0) {
605 /* lets try to make an inline extent */
606 if (ret || total_in < actual_end) {
607 /* we didn't compress the entire range, try
608 * to make an uncompressed inline extent.
609 */
610 ret = cow_file_range_inline(inode, start, end, 0,
611 BTRFS_COMPRESS_NONE, NULL);
612 } else {
613 /* try making a compressed inline extent */
614 ret = cow_file_range_inline(inode, start, end,
615 total_compressed,
616 compress_type, pages);
617 }
618 if (ret <= 0) {
619 unsigned long clear_flags = EXTENT_DELALLOC |
620 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
621 EXTENT_DO_ACCOUNTING;
622 unsigned long page_error_op;
623
624 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
625
626 /*
627 * inline extent creation worked or returned error,
628 * we don't need to create any more async work items.
629 * Unlock and free up our temp pages.
630 *
631 * We use DO_ACCOUNTING here because we need the
632 * delalloc_release_metadata to be done _after_ we drop
633 * our outstanding extent for clearing delalloc for this
634 * range.
635 */
636 extent_clear_unlock_delalloc(inode, start, end, NULL,
637 clear_flags,
638 PAGE_UNLOCK |
639 PAGE_CLEAR_DIRTY |
640 PAGE_SET_WRITEBACK |
641 page_error_op |
642 PAGE_END_WRITEBACK);
643
644 for (i = 0; i < nr_pages; i++) {
645 WARN_ON(pages[i]->mapping);
646 put_page(pages[i]);
647 }
648 kfree(pages);
649
650 return 0;
651 }
652 }
653
654 if (will_compress) {
655 /*
656 * we aren't doing an inline extent round the compressed size
657 * up to a block size boundary so the allocator does sane
658 * things
659 */
660 total_compressed = ALIGN(total_compressed, blocksize);
661
662 /*
663 * one last check to make sure the compression is really a
664 * win, compare the page count read with the blocks on disk,
665 * compression must free at least one sector size
666 */
667 total_in = ALIGN(total_in, PAGE_SIZE);
668 if (total_compressed + blocksize <= total_in) {
669 compressed_extents++;
670
671 /*
672 * The async work queues will take care of doing actual
673 * allocation on disk for these compressed pages, and
674 * will submit them to the elevator.
675 */
676 add_async_extent(async_chunk, start, total_in,
677 total_compressed, pages, nr_pages,
678 compress_type);
679
680 if (start + total_in < end) {
681 start += total_in;
682 pages = NULL;
683 cond_resched();
684 goto again;
685 }
686 return compressed_extents;
687 }
688 }
689 if (pages) {
690 /*
691 * the compression code ran but failed to make things smaller,
692 * free any pages it allocated and our page pointer array
693 */
694 for (i = 0; i < nr_pages; i++) {
695 WARN_ON(pages[i]->mapping);
696 put_page(pages[i]);
697 }
698 kfree(pages);
699 pages = NULL;
700 total_compressed = 0;
701 nr_pages = 0;
702
703 /* flag the file so we don't compress in the future */
704 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
705 !(BTRFS_I(inode)->prop_compress)) {
706 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
707 }
708 }
709 cleanup_and_bail_uncompressed:
710 /*
711 * No compression, but we still need to write the pages in the file
712 * we've been given so far. redirty the locked page if it corresponds
713 * to our extent and set things up for the async work queue to run
714 * cow_file_range to do the normal delalloc dance.
715 */
716 if (async_chunk->locked_page &&
717 (page_offset(async_chunk->locked_page) >= start &&
718 page_offset(async_chunk->locked_page)) <= end) {
719 __set_page_dirty_nobuffers(async_chunk->locked_page);
720 /* unlocked later on in the async handlers */
721 }
722
723 if (redirty)
724 extent_range_redirty_for_io(inode, start, end);
725 add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
726 BTRFS_COMPRESS_NONE);
727 compressed_extents++;
728
729 return compressed_extents;
730 }
731
732 static void free_async_extent_pages(struct async_extent *async_extent)
733 {
734 int i;
735
736 if (!async_extent->pages)
737 return;
738
739 for (i = 0; i < async_extent->nr_pages; i++) {
740 WARN_ON(async_extent->pages[i]->mapping);
741 put_page(async_extent->pages[i]);
742 }
743 kfree(async_extent->pages);
744 async_extent->nr_pages = 0;
745 async_extent->pages = NULL;
746 }
747
748 /*
749 * phase two of compressed writeback. This is the ordered portion
750 * of the code, which only gets called in the order the work was
751 * queued. We walk all the async extents created by compress_file_range
752 * and send them down to the disk.
753 */
754 static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
755 {
756 struct inode *inode = async_chunk->inode;
757 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
758 struct async_extent *async_extent;
759 u64 alloc_hint = 0;
760 struct btrfs_key ins;
761 struct extent_map *em;
762 struct btrfs_root *root = BTRFS_I(inode)->root;
763 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
764 int ret = 0;
765
766 again:
767 while (!list_empty(&async_chunk->extents)) {
768 async_extent = list_entry(async_chunk->extents.next,
769 struct async_extent, list);
770 list_del(&async_extent->list);
771
772 retry:
773 lock_extent(io_tree, async_extent->start,
774 async_extent->start + async_extent->ram_size - 1);
775 /* did the compression code fall back to uncompressed IO? */
776 if (!async_extent->pages) {
777 int page_started = 0;
778 unsigned long nr_written = 0;
779
780 /* allocate blocks */
781 ret = cow_file_range(inode, async_chunk->locked_page,
782 async_extent->start,
783 async_extent->start +
784 async_extent->ram_size - 1,
785 &page_started, &nr_written, 0);
786
787 /* JDM XXX */
788
789 /*
790 * if page_started, cow_file_range inserted an
791 * inline extent and took care of all the unlocking
792 * and IO for us. Otherwise, we need to submit
793 * all those pages down to the drive.
794 */
795 if (!page_started && !ret)
796 extent_write_locked_range(inode,
797 async_extent->start,
798 async_extent->start +
799 async_extent->ram_size - 1,
800 WB_SYNC_ALL);
801 else if (ret && async_chunk->locked_page)
802 unlock_page(async_chunk->locked_page);
803 kfree(async_extent);
804 cond_resched();
805 continue;
806 }
807
808 ret = btrfs_reserve_extent(root, async_extent->ram_size,
809 async_extent->compressed_size,
810 async_extent->compressed_size,
811 0, alloc_hint, &ins, 1, 1);
812 if (ret) {
813 free_async_extent_pages(async_extent);
814
815 if (ret == -ENOSPC) {
816 unlock_extent(io_tree, async_extent->start,
817 async_extent->start +
818 async_extent->ram_size - 1);
819
820 /*
821 * we need to redirty the pages if we decide to
822 * fallback to uncompressed IO, otherwise we
823 * will not submit these pages down to lower
824 * layers.
825 */
826 extent_range_redirty_for_io(inode,
827 async_extent->start,
828 async_extent->start +
829 async_extent->ram_size - 1);
830
831 goto retry;
832 }
833 goto out_free;
834 }
835 /*
836 * here we're doing allocation and writeback of the
837 * compressed pages
838 */
839 em = create_io_em(inode, async_extent->start,
840 async_extent->ram_size, /* len */
841 async_extent->start, /* orig_start */
842 ins.objectid, /* block_start */
843 ins.offset, /* block_len */
844 ins.offset, /* orig_block_len */
845 async_extent->ram_size, /* ram_bytes */
846 async_extent->compress_type,
847 BTRFS_ORDERED_COMPRESSED);
848 if (IS_ERR(em))
849 /* ret value is not necessary due to void function */
850 goto out_free_reserve;
851 free_extent_map(em);
852
853 ret = btrfs_add_ordered_extent_compress(inode,
854 async_extent->start,
855 ins.objectid,
856 async_extent->ram_size,
857 ins.offset,
858 BTRFS_ORDERED_COMPRESSED,
859 async_extent->compress_type);
860 if (ret) {
861 btrfs_drop_extent_cache(BTRFS_I(inode),
862 async_extent->start,
863 async_extent->start +
864 async_extent->ram_size - 1, 0);
865 goto out_free_reserve;
866 }
867 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
868
869 /*
870 * clear dirty, set writeback and unlock the pages.
871 */
872 extent_clear_unlock_delalloc(inode, async_extent->start,
873 async_extent->start +
874 async_extent->ram_size - 1,
875 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
876 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
877 PAGE_SET_WRITEBACK);
878 if (btrfs_submit_compressed_write(inode,
879 async_extent->start,
880 async_extent->ram_size,
881 ins.objectid,
882 ins.offset, async_extent->pages,
883 async_extent->nr_pages,
884 async_chunk->write_flags,
885 async_chunk->blkcg_css)) {
886 struct page *p = async_extent->pages[0];
887 const u64 start = async_extent->start;
888 const u64 end = start + async_extent->ram_size - 1;
889
890 p->mapping = inode->i_mapping;
891 btrfs_writepage_endio_finish_ordered(p, start, end, 0);
892
893 p->mapping = NULL;
894 extent_clear_unlock_delalloc(inode, start, end,
895 NULL, 0,
896 PAGE_END_WRITEBACK |
897 PAGE_SET_ERROR);
898 free_async_extent_pages(async_extent);
899 }
900 alloc_hint = ins.objectid + ins.offset;
901 kfree(async_extent);
902 cond_resched();
903 }
904 return;
905 out_free_reserve:
906 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
907 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
908 out_free:
909 extent_clear_unlock_delalloc(inode, async_extent->start,
910 async_extent->start +
911 async_extent->ram_size - 1,
912 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
913 EXTENT_DELALLOC_NEW |
914 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
915 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
916 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
917 PAGE_SET_ERROR);
918 free_async_extent_pages(async_extent);
919 kfree(async_extent);
920 goto again;
921 }
922
923 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
924 u64 num_bytes)
925 {
926 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
927 struct extent_map *em;
928 u64 alloc_hint = 0;
929
930 read_lock(&em_tree->lock);
931 em = search_extent_mapping(em_tree, start, num_bytes);
932 if (em) {
933 /*
934 * if block start isn't an actual block number then find the
935 * first block in this inode and use that as a hint. If that
936 * block is also bogus then just don't worry about it.
937 */
938 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
939 free_extent_map(em);
940 em = search_extent_mapping(em_tree, 0, 0);
941 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
942 alloc_hint = em->block_start;
943 if (em)
944 free_extent_map(em);
945 } else {
946 alloc_hint = em->block_start;
947 free_extent_map(em);
948 }
949 }
950 read_unlock(&em_tree->lock);
951
952 return alloc_hint;
953 }
954
955 /*
956 * when extent_io.c finds a delayed allocation range in the file,
957 * the call backs end up in this code. The basic idea is to
958 * allocate extents on disk for the range, and create ordered data structs
959 * in ram to track those extents.
960 *
961 * locked_page is the page that writepage had locked already. We use
962 * it to make sure we don't do extra locks or unlocks.
963 *
964 * *page_started is set to one if we unlock locked_page and do everything
965 * required to start IO on it. It may be clean and already done with
966 * IO when we return.
967 */
968 static noinline int cow_file_range(struct inode *inode,
969 struct page *locked_page,
970 u64 start, u64 end, int *page_started,
971 unsigned long *nr_written, int unlock)
972 {
973 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
974 struct btrfs_root *root = BTRFS_I(inode)->root;
975 u64 alloc_hint = 0;
976 u64 num_bytes;
977 unsigned long ram_size;
978 u64 cur_alloc_size = 0;
979 u64 blocksize = fs_info->sectorsize;
980 struct btrfs_key ins;
981 struct extent_map *em;
982 unsigned clear_bits;
983 unsigned long page_ops;
984 bool extent_reserved = false;
985 int ret = 0;
986
987 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
988 WARN_ON_ONCE(1);
989 ret = -EINVAL;
990 goto out_unlock;
991 }
992
993 num_bytes = ALIGN(end - start + 1, blocksize);
994 num_bytes = max(blocksize, num_bytes);
995 ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
996
997 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
998
999 if (start == 0) {
1000 /* lets try to make an inline extent */
1001 ret = cow_file_range_inline(inode, start, end, 0,
1002 BTRFS_COMPRESS_NONE, NULL);
1003 if (ret == 0) {
1004 /*
1005 * We use DO_ACCOUNTING here because we need the
1006 * delalloc_release_metadata to be run _after_ we drop
1007 * our outstanding extent for clearing delalloc for this
1008 * range.
1009 */
1010 extent_clear_unlock_delalloc(inode, start, end, NULL,
1011 EXTENT_LOCKED | EXTENT_DELALLOC |
1012 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
1013 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1014 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1015 PAGE_END_WRITEBACK);
1016 *nr_written = *nr_written +
1017 (end - start + PAGE_SIZE) / PAGE_SIZE;
1018 *page_started = 1;
1019 goto out;
1020 } else if (ret < 0) {
1021 goto out_unlock;
1022 }
1023 }
1024
1025 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
1026 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1027 start + num_bytes - 1, 0);
1028
1029 while (num_bytes > 0) {
1030 cur_alloc_size = num_bytes;
1031 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1032 fs_info->sectorsize, 0, alloc_hint,
1033 &ins, 1, 1);
1034 if (ret < 0)
1035 goto out_unlock;
1036 cur_alloc_size = ins.offset;
1037 extent_reserved = true;
1038
1039 ram_size = ins.offset;
1040 em = create_io_em(inode, start, ins.offset, /* len */
1041 start, /* orig_start */
1042 ins.objectid, /* block_start */
1043 ins.offset, /* block_len */
1044 ins.offset, /* orig_block_len */
1045 ram_size, /* ram_bytes */
1046 BTRFS_COMPRESS_NONE, /* compress_type */
1047 BTRFS_ORDERED_REGULAR /* type */);
1048 if (IS_ERR(em)) {
1049 ret = PTR_ERR(em);
1050 goto out_reserve;
1051 }
1052 free_extent_map(em);
1053
1054 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1055 ram_size, cur_alloc_size, 0);
1056 if (ret)
1057 goto out_drop_extent_cache;
1058
1059 if (root->root_key.objectid ==
1060 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1061 ret = btrfs_reloc_clone_csums(inode, start,
1062 cur_alloc_size);
1063 /*
1064 * Only drop cache here, and process as normal.
1065 *
1066 * We must not allow extent_clear_unlock_delalloc()
1067 * at out_unlock label to free meta of this ordered
1068 * extent, as its meta should be freed by
1069 * btrfs_finish_ordered_io().
1070 *
1071 * So we must continue until @start is increased to
1072 * skip current ordered extent.
1073 */
1074 if (ret)
1075 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1076 start + ram_size - 1, 0);
1077 }
1078
1079 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1080
1081 /* we're not doing compressed IO, don't unlock the first
1082 * page (which the caller expects to stay locked), don't
1083 * clear any dirty bits and don't set any writeback bits
1084 *
1085 * Do set the Private2 bit so we know this page was properly
1086 * setup for writepage
1087 */
1088 page_ops = unlock ? PAGE_UNLOCK : 0;
1089 page_ops |= PAGE_SET_PRIVATE2;
1090
1091 extent_clear_unlock_delalloc(inode, start,
1092 start + ram_size - 1,
1093 locked_page,
1094 EXTENT_LOCKED | EXTENT_DELALLOC,
1095 page_ops);
1096 if (num_bytes < cur_alloc_size)
1097 num_bytes = 0;
1098 else
1099 num_bytes -= cur_alloc_size;
1100 alloc_hint = ins.objectid + ins.offset;
1101 start += cur_alloc_size;
1102 extent_reserved = false;
1103
1104 /*
1105 * btrfs_reloc_clone_csums() error, since start is increased
1106 * extent_clear_unlock_delalloc() at out_unlock label won't
1107 * free metadata of current ordered extent, we're OK to exit.
1108 */
1109 if (ret)
1110 goto out_unlock;
1111 }
1112 out:
1113 return ret;
1114
1115 out_drop_extent_cache:
1116 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1117 out_reserve:
1118 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1119 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1120 out_unlock:
1121 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1122 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1123 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1124 PAGE_END_WRITEBACK;
1125 /*
1126 * If we reserved an extent for our delalloc range (or a subrange) and
1127 * failed to create the respective ordered extent, then it means that
1128 * when we reserved the extent we decremented the extent's size from
1129 * the data space_info's bytes_may_use counter and incremented the
1130 * space_info's bytes_reserved counter by the same amount. We must make
1131 * sure extent_clear_unlock_delalloc() does not try to decrement again
1132 * the data space_info's bytes_may_use counter, therefore we do not pass
1133 * it the flag EXTENT_CLEAR_DATA_RESV.
1134 */
1135 if (extent_reserved) {
1136 extent_clear_unlock_delalloc(inode, start,
1137 start + cur_alloc_size,
1138 locked_page,
1139 clear_bits,
1140 page_ops);
1141 start += cur_alloc_size;
1142 if (start >= end)
1143 goto out;
1144 }
1145 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1146 clear_bits | EXTENT_CLEAR_DATA_RESV,
1147 page_ops);
1148 goto out;
1149 }
1150
1151 /*
1152 * work queue call back to started compression on a file and pages
1153 */
1154 static noinline void async_cow_start(struct btrfs_work *work)
1155 {
1156 struct async_chunk *async_chunk;
1157 int compressed_extents;
1158
1159 async_chunk = container_of(work, struct async_chunk, work);
1160
1161 compressed_extents = compress_file_range(async_chunk);
1162 if (compressed_extents == 0) {
1163 btrfs_add_delayed_iput(async_chunk->inode);
1164 async_chunk->inode = NULL;
1165 }
1166 }
1167
1168 /*
1169 * work queue call back to submit previously compressed pages
1170 */
1171 static noinline void async_cow_submit(struct btrfs_work *work)
1172 {
1173 struct async_chunk *async_chunk = container_of(work, struct async_chunk,
1174 work);
1175 struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
1176 unsigned long nr_pages;
1177
1178 nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
1179 PAGE_SHIFT;
1180
1181 /* atomic_sub_return implies a barrier */
1182 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1183 5 * SZ_1M)
1184 cond_wake_up_nomb(&fs_info->async_submit_wait);
1185
1186 /*
1187 * ->inode could be NULL if async_chunk_start has failed to compress,
1188 * in which case we don't have anything to submit, yet we need to
1189 * always adjust ->async_delalloc_pages as its paired with the init
1190 * happening in cow_file_range_async
1191 */
1192 if (async_chunk->inode)
1193 submit_compressed_extents(async_chunk);
1194 }
1195
1196 static noinline void async_cow_free(struct btrfs_work *work)
1197 {
1198 struct async_chunk *async_chunk;
1199
1200 async_chunk = container_of(work, struct async_chunk, work);
1201 if (async_chunk->inode)
1202 btrfs_add_delayed_iput(async_chunk->inode);
1203 if (async_chunk->blkcg_css)
1204 css_put(async_chunk->blkcg_css);
1205 /*
1206 * Since the pointer to 'pending' is at the beginning of the array of
1207 * async_chunk's, freeing it ensures the whole array has been freed.
1208 */
1209 if (atomic_dec_and_test(async_chunk->pending))
1210 kvfree(async_chunk->pending);
1211 }
1212
1213 static int cow_file_range_async(struct inode *inode,
1214 struct writeback_control *wbc,
1215 struct page *locked_page,
1216 u64 start, u64 end, int *page_started,
1217 unsigned long *nr_written)
1218 {
1219 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1220 struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc);
1221 struct async_cow *ctx;
1222 struct async_chunk *async_chunk;
1223 unsigned long nr_pages;
1224 u64 cur_end;
1225 u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
1226 int i;
1227 bool should_compress;
1228 unsigned nofs_flag;
1229 const unsigned int write_flags = wbc_to_write_flags(wbc);
1230
1231 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
1232
1233 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1234 !btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
1235 num_chunks = 1;
1236 should_compress = false;
1237 } else {
1238 should_compress = true;
1239 }
1240
1241 nofs_flag = memalloc_nofs_save();
1242 ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
1243 memalloc_nofs_restore(nofs_flag);
1244
1245 if (!ctx) {
1246 unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
1247 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
1248 EXTENT_DO_ACCOUNTING;
1249 unsigned long page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1250 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
1251 PAGE_SET_ERROR;
1252
1253 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1254 clear_bits, page_ops);
1255 return -ENOMEM;
1256 }
1257
1258 async_chunk = ctx->chunks;
1259 atomic_set(&ctx->num_chunks, num_chunks);
1260
1261 for (i = 0; i < num_chunks; i++) {
1262 if (should_compress)
1263 cur_end = min(end, start + SZ_512K - 1);
1264 else
1265 cur_end = end;
1266
1267 /*
1268 * igrab is called higher up in the call chain, take only the
1269 * lightweight reference for the callback lifetime
1270 */
1271 ihold(inode);
1272 async_chunk[i].pending = &ctx->num_chunks;
1273 async_chunk[i].inode = inode;
1274 async_chunk[i].start = start;
1275 async_chunk[i].end = cur_end;
1276 async_chunk[i].write_flags = write_flags;
1277 INIT_LIST_HEAD(&async_chunk[i].extents);
1278
1279 /*
1280 * The locked_page comes all the way from writepage and its
1281 * the original page we were actually given. As we spread
1282 * this large delalloc region across multiple async_chunk
1283 * structs, only the first struct needs a pointer to locked_page
1284 *
1285 * This way we don't need racey decisions about who is supposed
1286 * to unlock it.
1287 */
1288 if (locked_page) {
1289 /*
1290 * Depending on the compressibility, the pages might or
1291 * might not go through async. We want all of them to
1292 * be accounted against wbc once. Let's do it here
1293 * before the paths diverge. wbc accounting is used
1294 * only for foreign writeback detection and doesn't
1295 * need full accuracy. Just account the whole thing
1296 * against the first page.
1297 */
1298 wbc_account_cgroup_owner(wbc, locked_page,
1299 cur_end - start);
1300 async_chunk[i].locked_page = locked_page;
1301 locked_page = NULL;
1302 } else {
1303 async_chunk[i].locked_page = NULL;
1304 }
1305
1306 if (blkcg_css != blkcg_root_css) {
1307 css_get(blkcg_css);
1308 async_chunk[i].blkcg_css = blkcg_css;
1309 } else {
1310 async_chunk[i].blkcg_css = NULL;
1311 }
1312
1313 btrfs_init_work(&async_chunk[i].work, async_cow_start,
1314 async_cow_submit, async_cow_free);
1315
1316 nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
1317 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1318
1319 btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
1320
1321 *nr_written += nr_pages;
1322 start = cur_end + 1;
1323 }
1324 *page_started = 1;
1325 return 0;
1326 }
1327
1328 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1329 u64 bytenr, u64 num_bytes)
1330 {
1331 int ret;
1332 struct btrfs_ordered_sum *sums;
1333 LIST_HEAD(list);
1334
1335 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1336 bytenr + num_bytes - 1, &list, 0);
1337 if (ret == 0 && list_empty(&list))
1338 return 0;
1339
1340 while (!list_empty(&list)) {
1341 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1342 list_del(&sums->list);
1343 kfree(sums);
1344 }
1345 if (ret < 0)
1346 return ret;
1347 return 1;
1348 }
1349
1350 /*
1351 * when nowcow writeback call back. This checks for snapshots or COW copies
1352 * of the extents that exist in the file, and COWs the file as required.
1353 *
1354 * If no cow copies or snapshots exist, we write directly to the existing
1355 * blocks on disk
1356 */
1357 static noinline int run_delalloc_nocow(struct inode *inode,
1358 struct page *locked_page,
1359 const u64 start, const u64 end,
1360 int *page_started, int force,
1361 unsigned long *nr_written)
1362 {
1363 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1364 struct btrfs_root *root = BTRFS_I(inode)->root;
1365 struct btrfs_path *path;
1366 u64 cow_start = (u64)-1;
1367 u64 cur_offset = start;
1368 int ret;
1369 bool check_prev = true;
1370 const bool freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
1371 u64 ino = btrfs_ino(BTRFS_I(inode));
1372 bool nocow = false;
1373 u64 disk_bytenr = 0;
1374
1375 path = btrfs_alloc_path();
1376 if (!path) {
1377 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1378 EXTENT_LOCKED | EXTENT_DELALLOC |
1379 EXTENT_DO_ACCOUNTING |
1380 EXTENT_DEFRAG, PAGE_UNLOCK |
1381 PAGE_CLEAR_DIRTY |
1382 PAGE_SET_WRITEBACK |
1383 PAGE_END_WRITEBACK);
1384 return -ENOMEM;
1385 }
1386
1387 while (1) {
1388 struct btrfs_key found_key;
1389 struct btrfs_file_extent_item *fi;
1390 struct extent_buffer *leaf;
1391 u64 extent_end;
1392 u64 extent_offset;
1393 u64 num_bytes = 0;
1394 u64 disk_num_bytes;
1395 u64 ram_bytes;
1396 int extent_type;
1397
1398 nocow = false;
1399
1400 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1401 cur_offset, 0);
1402 if (ret < 0)
1403 goto error;
1404
1405 /*
1406 * If there is no extent for our range when doing the initial
1407 * search, then go back to the previous slot as it will be the
1408 * one containing the search offset
1409 */
1410 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1411 leaf = path->nodes[0];
1412 btrfs_item_key_to_cpu(leaf, &found_key,
1413 path->slots[0] - 1);
1414 if (found_key.objectid == ino &&
1415 found_key.type == BTRFS_EXTENT_DATA_KEY)
1416 path->slots[0]--;
1417 }
1418 check_prev = false;
1419 next_slot:
1420 /* Go to next leaf if we have exhausted the current one */
1421 leaf = path->nodes[0];
1422 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1423 ret = btrfs_next_leaf(root, path);
1424 if (ret < 0) {
1425 if (cow_start != (u64)-1)
1426 cur_offset = cow_start;
1427 goto error;
1428 }
1429 if (ret > 0)
1430 break;
1431 leaf = path->nodes[0];
1432 }
1433
1434 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1435
1436 /* Didn't find anything for our INO */
1437 if (found_key.objectid > ino)
1438 break;
1439 /*
1440 * Keep searching until we find an EXTENT_ITEM or there are no
1441 * more extents for this inode
1442 */
1443 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1444 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1445 path->slots[0]++;
1446 goto next_slot;
1447 }
1448
1449 /* Found key is not EXTENT_DATA_KEY or starts after req range */
1450 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1451 found_key.offset > end)
1452 break;
1453
1454 /*
1455 * If the found extent starts after requested offset, then
1456 * adjust extent_end to be right before this extent begins
1457 */
1458 if (found_key.offset > cur_offset) {
1459 extent_end = found_key.offset;
1460 extent_type = 0;
1461 goto out_check;
1462 }
1463
1464 /*
1465 * Found extent which begins before our range and potentially
1466 * intersect it
1467 */
1468 fi = btrfs_item_ptr(leaf, path->slots[0],
1469 struct btrfs_file_extent_item);
1470 extent_type = btrfs_file_extent_type(leaf, fi);
1471
1472 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1473 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1474 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1475 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1476 extent_offset = btrfs_file_extent_offset(leaf, fi);
1477 extent_end = found_key.offset +
1478 btrfs_file_extent_num_bytes(leaf, fi);
1479 disk_num_bytes =
1480 btrfs_file_extent_disk_num_bytes(leaf, fi);
1481 /*
1482 * If the extent we got ends before our current offset,
1483 * skip to the next extent.
1484 */
1485 if (extent_end <= cur_offset) {
1486 path->slots[0]++;
1487 goto next_slot;
1488 }
1489 /* Skip holes */
1490 if (disk_bytenr == 0)
1491 goto out_check;
1492 /* Skip compressed/encrypted/encoded extents */
1493 if (btrfs_file_extent_compression(leaf, fi) ||
1494 btrfs_file_extent_encryption(leaf, fi) ||
1495 btrfs_file_extent_other_encoding(leaf, fi))
1496 goto out_check;
1497 /*
1498 * If extent is created before the last volume's snapshot
1499 * this implies the extent is shared, hence we can't do
1500 * nocow. This is the same check as in
1501 * btrfs_cross_ref_exist but without calling
1502 * btrfs_search_slot.
1503 */
1504 if (!freespace_inode &&
1505 btrfs_file_extent_generation(leaf, fi) <=
1506 btrfs_root_last_snapshot(&root->root_item))
1507 goto out_check;
1508 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1509 goto out_check;
1510 /* If extent is RO, we must COW it */
1511 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1512 goto out_check;
1513 ret = btrfs_cross_ref_exist(root, ino,
1514 found_key.offset -
1515 extent_offset, disk_bytenr);
1516 if (ret) {
1517 /*
1518 * ret could be -EIO if the above fails to read
1519 * metadata.
1520 */
1521 if (ret < 0) {
1522 if (cow_start != (u64)-1)
1523 cur_offset = cow_start;
1524 goto error;
1525 }
1526
1527 WARN_ON_ONCE(freespace_inode);
1528 goto out_check;
1529 }
1530 disk_bytenr += extent_offset;
1531 disk_bytenr += cur_offset - found_key.offset;
1532 num_bytes = min(end + 1, extent_end) - cur_offset;
1533 /*
1534 * If there are pending snapshots for this root, we
1535 * fall into common COW way
1536 */
1537 if (!freespace_inode && atomic_read(&root->snapshot_force_cow))
1538 goto out_check;
1539 /*
1540 * force cow if csum exists in the range.
1541 * this ensure that csum for a given extent are
1542 * either valid or do not exist.
1543 */
1544 ret = csum_exist_in_range(fs_info, disk_bytenr,
1545 num_bytes);
1546 if (ret) {
1547 /*
1548 * ret could be -EIO if the above fails to read
1549 * metadata.
1550 */
1551 if (ret < 0) {
1552 if (cow_start != (u64)-1)
1553 cur_offset = cow_start;
1554 goto error;
1555 }
1556 WARN_ON_ONCE(freespace_inode);
1557 goto out_check;
1558 }
1559 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
1560 goto out_check;
1561 nocow = true;
1562 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1563 extent_end = found_key.offset + ram_bytes;
1564 extent_end = ALIGN(extent_end, fs_info->sectorsize);
1565 /* Skip extents outside of our requested range */
1566 if (extent_end <= start) {
1567 path->slots[0]++;
1568 goto next_slot;
1569 }
1570 } else {
1571 /* If this triggers then we have a memory corruption */
1572 BUG();
1573 }
1574 out_check:
1575 /*
1576 * If nocow is false then record the beginning of the range
1577 * that needs to be COWed
1578 */
1579 if (!nocow) {
1580 if (cow_start == (u64)-1)
1581 cow_start = cur_offset;
1582 cur_offset = extent_end;
1583 if (cur_offset > end)
1584 break;
1585 path->slots[0]++;
1586 goto next_slot;
1587 }
1588
1589 btrfs_release_path(path);
1590
1591 /*
1592 * COW range from cow_start to found_key.offset - 1. As the key
1593 * will contain the beginning of the first extent that can be
1594 * NOCOW, following one which needs to be COW'ed
1595 */
1596 if (cow_start != (u64)-1) {
1597 ret = cow_file_range(inode, locked_page,
1598 cow_start, found_key.offset - 1,
1599 page_started, nr_written, 1);
1600 if (ret) {
1601 if (nocow)
1602 btrfs_dec_nocow_writers(fs_info,
1603 disk_bytenr);
1604 goto error;
1605 }
1606 cow_start = (u64)-1;
1607 }
1608
1609 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1610 u64 orig_start = found_key.offset - extent_offset;
1611 struct extent_map *em;
1612
1613 em = create_io_em(inode, cur_offset, num_bytes,
1614 orig_start,
1615 disk_bytenr, /* block_start */
1616 num_bytes, /* block_len */
1617 disk_num_bytes, /* orig_block_len */
1618 ram_bytes, BTRFS_COMPRESS_NONE,
1619 BTRFS_ORDERED_PREALLOC);
1620 if (IS_ERR(em)) {
1621 if (nocow)
1622 btrfs_dec_nocow_writers(fs_info,
1623 disk_bytenr);
1624 ret = PTR_ERR(em);
1625 goto error;
1626 }
1627 free_extent_map(em);
1628 ret = btrfs_add_ordered_extent(inode, cur_offset,
1629 disk_bytenr, num_bytes,
1630 num_bytes,
1631 BTRFS_ORDERED_PREALLOC);
1632 if (ret) {
1633 btrfs_drop_extent_cache(BTRFS_I(inode),
1634 cur_offset,
1635 cur_offset + num_bytes - 1,
1636 0);
1637 goto error;
1638 }
1639 } else {
1640 ret = btrfs_add_ordered_extent(inode, cur_offset,
1641 disk_bytenr, num_bytes,
1642 num_bytes,
1643 BTRFS_ORDERED_NOCOW);
1644 if (ret)
1645 goto error;
1646 }
1647
1648 if (nocow)
1649 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1650 nocow = false;
1651
1652 if (root->root_key.objectid ==
1653 BTRFS_DATA_RELOC_TREE_OBJECTID)
1654 /*
1655 * Error handled later, as we must prevent
1656 * extent_clear_unlock_delalloc() in error handler
1657 * from freeing metadata of created ordered extent.
1658 */
1659 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1660 num_bytes);
1661
1662 extent_clear_unlock_delalloc(inode, cur_offset,
1663 cur_offset + num_bytes - 1,
1664 locked_page, EXTENT_LOCKED |
1665 EXTENT_DELALLOC |
1666 EXTENT_CLEAR_DATA_RESV,
1667 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1668
1669 cur_offset = extent_end;
1670
1671 /*
1672 * btrfs_reloc_clone_csums() error, now we're OK to call error
1673 * handler, as metadata for created ordered extent will only
1674 * be freed by btrfs_finish_ordered_io().
1675 */
1676 if (ret)
1677 goto error;
1678 if (cur_offset > end)
1679 break;
1680 }
1681 btrfs_release_path(path);
1682
1683 if (cur_offset <= end && cow_start == (u64)-1)
1684 cow_start = cur_offset;
1685
1686 if (cow_start != (u64)-1) {
1687 cur_offset = end;
1688 ret = cow_file_range(inode, locked_page, cow_start, end,
1689 page_started, nr_written, 1);
1690 if (ret)
1691 goto error;
1692 }
1693
1694 error:
1695 if (nocow)
1696 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1697
1698 if (ret && cur_offset < end)
1699 extent_clear_unlock_delalloc(inode, cur_offset, end,
1700 locked_page, EXTENT_LOCKED |
1701 EXTENT_DELALLOC | EXTENT_DEFRAG |
1702 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1703 PAGE_CLEAR_DIRTY |
1704 PAGE_SET_WRITEBACK |
1705 PAGE_END_WRITEBACK);
1706 btrfs_free_path(path);
1707 return ret;
1708 }
1709
1710 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1711 {
1712
1713 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1714 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1715 return 0;
1716
1717 /*
1718 * @defrag_bytes is a hint value, no spinlock held here,
1719 * if is not zero, it means the file is defragging.
1720 * Force cow if given extent needs to be defragged.
1721 */
1722 if (BTRFS_I(inode)->defrag_bytes &&
1723 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1724 EXTENT_DEFRAG, 0, NULL))
1725 return 1;
1726
1727 return 0;
1728 }
1729
1730 /*
1731 * Function to process delayed allocation (create CoW) for ranges which are
1732 * being touched for the first time.
1733 */
1734 int btrfs_run_delalloc_range(struct inode *inode, struct page *locked_page,
1735 u64 start, u64 end, int *page_started, unsigned long *nr_written,
1736 struct writeback_control *wbc)
1737 {
1738 int ret;
1739 int force_cow = need_force_cow(inode, start, end);
1740
1741 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1742 ret = run_delalloc_nocow(inode, locked_page, start, end,
1743 page_started, 1, nr_written);
1744 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1745 ret = run_delalloc_nocow(inode, locked_page, start, end,
1746 page_started, 0, nr_written);
1747 } else if (!inode_can_compress(inode) ||
1748 !inode_need_compress(inode, start, end)) {
1749 ret = cow_file_range(inode, locked_page, start, end,
1750 page_started, nr_written, 1);
1751 } else {
1752 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1753 &BTRFS_I(inode)->runtime_flags);
1754 ret = cow_file_range_async(inode, wbc, locked_page, start, end,
1755 page_started, nr_written);
1756 }
1757 if (ret)
1758 btrfs_cleanup_ordered_extents(inode, locked_page, start,
1759 end - start + 1);
1760 return ret;
1761 }
1762
1763 void btrfs_split_delalloc_extent(struct inode *inode,
1764 struct extent_state *orig, u64 split)
1765 {
1766 u64 size;
1767
1768 /* not delalloc, ignore it */
1769 if (!(orig->state & EXTENT_DELALLOC))
1770 return;
1771
1772 size = orig->end - orig->start + 1;
1773 if (size > BTRFS_MAX_EXTENT_SIZE) {
1774 u32 num_extents;
1775 u64 new_size;
1776
1777 /*
1778 * See the explanation in btrfs_merge_delalloc_extent, the same
1779 * applies here, just in reverse.
1780 */
1781 new_size = orig->end - split + 1;
1782 num_extents = count_max_extents(new_size);
1783 new_size = split - orig->start;
1784 num_extents += count_max_extents(new_size);
1785 if (count_max_extents(size) >= num_extents)
1786 return;
1787 }
1788
1789 spin_lock(&BTRFS_I(inode)->lock);
1790 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1791 spin_unlock(&BTRFS_I(inode)->lock);
1792 }
1793
1794 /*
1795 * Handle merged delayed allocation extents so we can keep track of new extents
1796 * that are just merged onto old extents, such as when we are doing sequential
1797 * writes, so we can properly account for the metadata space we'll need.
1798 */
1799 void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
1800 struct extent_state *other)
1801 {
1802 u64 new_size, old_size;
1803 u32 num_extents;
1804
1805 /* not delalloc, ignore it */
1806 if (!(other->state & EXTENT_DELALLOC))
1807 return;
1808
1809 if (new->start > other->start)
1810 new_size = new->end - other->start + 1;
1811 else
1812 new_size = other->end - new->start + 1;
1813
1814 /* we're not bigger than the max, unreserve the space and go */
1815 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1816 spin_lock(&BTRFS_I(inode)->lock);
1817 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1818 spin_unlock(&BTRFS_I(inode)->lock);
1819 return;
1820 }
1821
1822 /*
1823 * We have to add up either side to figure out how many extents were
1824 * accounted for before we merged into one big extent. If the number of
1825 * extents we accounted for is <= the amount we need for the new range
1826 * then we can return, otherwise drop. Think of it like this
1827 *
1828 * [ 4k][MAX_SIZE]
1829 *
1830 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1831 * need 2 outstanding extents, on one side we have 1 and the other side
1832 * we have 1 so they are == and we can return. But in this case
1833 *
1834 * [MAX_SIZE+4k][MAX_SIZE+4k]
1835 *
1836 * Each range on their own accounts for 2 extents, but merged together
1837 * they are only 3 extents worth of accounting, so we need to drop in
1838 * this case.
1839 */
1840 old_size = other->end - other->start + 1;
1841 num_extents = count_max_extents(old_size);
1842 old_size = new->end - new->start + 1;
1843 num_extents += count_max_extents(old_size);
1844 if (count_max_extents(new_size) >= num_extents)
1845 return;
1846
1847 spin_lock(&BTRFS_I(inode)->lock);
1848 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1849 spin_unlock(&BTRFS_I(inode)->lock);
1850 }
1851
1852 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1853 struct inode *inode)
1854 {
1855 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1856
1857 spin_lock(&root->delalloc_lock);
1858 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1859 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1860 &root->delalloc_inodes);
1861 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1862 &BTRFS_I(inode)->runtime_flags);
1863 root->nr_delalloc_inodes++;
1864 if (root->nr_delalloc_inodes == 1) {
1865 spin_lock(&fs_info->delalloc_root_lock);
1866 BUG_ON(!list_empty(&root->delalloc_root));
1867 list_add_tail(&root->delalloc_root,
1868 &fs_info->delalloc_roots);
1869 spin_unlock(&fs_info->delalloc_root_lock);
1870 }
1871 }
1872 spin_unlock(&root->delalloc_lock);
1873 }
1874
1875
1876 void __btrfs_del_delalloc_inode(struct btrfs_root *root,
1877 struct btrfs_inode *inode)
1878 {
1879 struct btrfs_fs_info *fs_info = root->fs_info;
1880
1881 if (!list_empty(&inode->delalloc_inodes)) {
1882 list_del_init(&inode->delalloc_inodes);
1883 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1884 &inode->runtime_flags);
1885 root->nr_delalloc_inodes--;
1886 if (!root->nr_delalloc_inodes) {
1887 ASSERT(list_empty(&root->delalloc_inodes));
1888 spin_lock(&fs_info->delalloc_root_lock);
1889 BUG_ON(list_empty(&root->delalloc_root));
1890 list_del_init(&root->delalloc_root);
1891 spin_unlock(&fs_info->delalloc_root_lock);
1892 }
1893 }
1894 }
1895
1896 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1897 struct btrfs_inode *inode)
1898 {
1899 spin_lock(&root->delalloc_lock);
1900 __btrfs_del_delalloc_inode(root, inode);
1901 spin_unlock(&root->delalloc_lock);
1902 }
1903
1904 /*
1905 * Properly track delayed allocation bytes in the inode and to maintain the
1906 * list of inodes that have pending delalloc work to be done.
1907 */
1908 void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
1909 unsigned *bits)
1910 {
1911 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1912
1913 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1914 WARN_ON(1);
1915 /*
1916 * set_bit and clear bit hooks normally require _irqsave/restore
1917 * but in this case, we are only testing for the DELALLOC
1918 * bit, which is only set or cleared with irqs on
1919 */
1920 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1921 struct btrfs_root *root = BTRFS_I(inode)->root;
1922 u64 len = state->end + 1 - state->start;
1923 u32 num_extents = count_max_extents(len);
1924 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1925
1926 spin_lock(&BTRFS_I(inode)->lock);
1927 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1928 spin_unlock(&BTRFS_I(inode)->lock);
1929
1930 /* For sanity tests */
1931 if (btrfs_is_testing(fs_info))
1932 return;
1933
1934 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1935 fs_info->delalloc_batch);
1936 spin_lock(&BTRFS_I(inode)->lock);
1937 BTRFS_I(inode)->delalloc_bytes += len;
1938 if (*bits & EXTENT_DEFRAG)
1939 BTRFS_I(inode)->defrag_bytes += len;
1940 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1941 &BTRFS_I(inode)->runtime_flags))
1942 btrfs_add_delalloc_inodes(root, inode);
1943 spin_unlock(&BTRFS_I(inode)->lock);
1944 }
1945
1946 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1947 (*bits & EXTENT_DELALLOC_NEW)) {
1948 spin_lock(&BTRFS_I(inode)->lock);
1949 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1950 state->start;
1951 spin_unlock(&BTRFS_I(inode)->lock);
1952 }
1953 }
1954
1955 /*
1956 * Once a range is no longer delalloc this function ensures that proper
1957 * accounting happens.
1958 */
1959 void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
1960 struct extent_state *state, unsigned *bits)
1961 {
1962 struct btrfs_inode *inode = BTRFS_I(vfs_inode);
1963 struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
1964 u64 len = state->end + 1 - state->start;
1965 u32 num_extents = count_max_extents(len);
1966
1967 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1968 spin_lock(&inode->lock);
1969 inode->defrag_bytes -= len;
1970 spin_unlock(&inode->lock);
1971 }
1972
1973 /*
1974 * set_bit and clear bit hooks normally require _irqsave/restore
1975 * but in this case, we are only testing for the DELALLOC
1976 * bit, which is only set or cleared with irqs on
1977 */
1978 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1979 struct btrfs_root *root = inode->root;
1980 bool do_list = !btrfs_is_free_space_inode(inode);
1981
1982 spin_lock(&inode->lock);
1983 btrfs_mod_outstanding_extents(inode, -num_extents);
1984 spin_unlock(&inode->lock);
1985
1986 /*
1987 * We don't reserve metadata space for space cache inodes so we
1988 * don't need to call delalloc_release_metadata if there is an
1989 * error.
1990 */
1991 if (*bits & EXTENT_CLEAR_META_RESV &&
1992 root != fs_info->tree_root)
1993 btrfs_delalloc_release_metadata(inode, len, false);
1994
1995 /* For sanity tests. */
1996 if (btrfs_is_testing(fs_info))
1997 return;
1998
1999 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
2000 do_list && !(state->state & EXTENT_NORESERVE) &&
2001 (*bits & EXTENT_CLEAR_DATA_RESV))
2002 btrfs_free_reserved_data_space_noquota(
2003 &inode->vfs_inode,
2004 state->start, len);
2005
2006 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
2007 fs_info->delalloc_batch);
2008 spin_lock(&inode->lock);
2009 inode->delalloc_bytes -= len;
2010 if (do_list && inode->delalloc_bytes == 0 &&
2011 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
2012 &inode->runtime_flags))
2013 btrfs_del_delalloc_inode(root, inode);
2014 spin_unlock(&inode->lock);
2015 }
2016
2017 if ((state->state & EXTENT_DELALLOC_NEW) &&
2018 (*bits & EXTENT_DELALLOC_NEW)) {
2019 spin_lock(&inode->lock);
2020 ASSERT(inode->new_delalloc_bytes >= len);
2021 inode->new_delalloc_bytes -= len;
2022 spin_unlock(&inode->lock);
2023 }
2024 }
2025
2026 /*
2027 * btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit
2028 * in a chunk's stripe. This function ensures that bios do not span a
2029 * stripe/chunk
2030 *
2031 * @page - The page we are about to add to the bio
2032 * @size - size we want to add to the bio
2033 * @bio - bio we want to ensure is smaller than a stripe
2034 * @bio_flags - flags of the bio
2035 *
2036 * return 1 if page cannot be added to the bio
2037 * return 0 if page can be added to the bio
2038 * return error otherwise
2039 */
2040 int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
2041 unsigned long bio_flags)
2042 {
2043 struct inode *inode = page->mapping->host;
2044 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2045 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
2046 u64 length = 0;
2047 u64 map_length;
2048 int ret;
2049 struct btrfs_io_geometry geom;
2050
2051 if (bio_flags & EXTENT_BIO_COMPRESSED)
2052 return 0;
2053
2054 length = bio->bi_iter.bi_size;
2055 map_length = length;
2056 ret = btrfs_get_io_geometry(fs_info, btrfs_op(bio), logical, map_length,
2057 &geom);
2058 if (ret < 0)
2059 return ret;
2060
2061 if (geom.len < length + size)
2062 return 1;
2063 return 0;
2064 }
2065
2066 /*
2067 * in order to insert checksums into the metadata in large chunks,
2068 * we wait until bio submission time. All the pages in the bio are
2069 * checksummed and sums are attached onto the ordered extent record.
2070 *
2071 * At IO completion time the cums attached on the ordered extent record
2072 * are inserted into the btree
2073 */
2074 static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
2075 u64 bio_offset)
2076 {
2077 struct inode *inode = private_data;
2078 blk_status_t ret = 0;
2079
2080 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2081 BUG_ON(ret); /* -ENOMEM */
2082 return 0;
2083 }
2084
2085 /*
2086 * extent_io.c submission hook. This does the right thing for csum calculation
2087 * on write, or reading the csums from the tree before a read.
2088 *
2089 * Rules about async/sync submit,
2090 * a) read: sync submit
2091 *
2092 * b) write without checksum: sync submit
2093 *
2094 * c) write with checksum:
2095 * c-1) if bio is issued by fsync: sync submit
2096 * (sync_writers != 0)
2097 *
2098 * c-2) if root is reloc root: sync submit
2099 * (only in case of buffered IO)
2100 *
2101 * c-3) otherwise: async submit
2102 */
2103 static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
2104 int mirror_num,
2105 unsigned long bio_flags)
2106
2107 {
2108 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2109 struct btrfs_root *root = BTRFS_I(inode)->root;
2110 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
2111 blk_status_t ret = 0;
2112 int skip_sum;
2113 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
2114
2115 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
2116
2117 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
2118 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
2119
2120 if (bio_op(bio) != REQ_OP_WRITE) {
2121 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
2122 if (ret)
2123 goto out;
2124
2125 if (bio_flags & EXTENT_BIO_COMPRESSED) {
2126 ret = btrfs_submit_compressed_read(inode, bio,
2127 mirror_num,
2128 bio_flags);
2129 goto out;
2130 } else if (!skip_sum) {
2131 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
2132 if (ret)
2133 goto out;
2134 }
2135 goto mapit;
2136 } else if (async && !skip_sum) {
2137 /* csum items have already been cloned */
2138 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2139 goto mapit;
2140 /* we're doing a write, do the async checksumming */
2141 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
2142 0, inode, btrfs_submit_bio_start);
2143 goto out;
2144 } else if (!skip_sum) {
2145 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2146 if (ret)
2147 goto out;
2148 }
2149
2150 mapit:
2151 ret = btrfs_map_bio(fs_info, bio, mirror_num);
2152
2153 out:
2154 if (ret) {
2155 bio->bi_status = ret;
2156 bio_endio(bio);
2157 }
2158 return ret;
2159 }
2160
2161 /*
2162 * given a list of ordered sums record them in the inode. This happens
2163 * at IO completion time based on sums calculated at bio submission time.
2164 */
2165 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2166 struct inode *inode, struct list_head *list)
2167 {
2168 struct btrfs_ordered_sum *sum;
2169 int ret;
2170
2171 list_for_each_entry(sum, list, list) {
2172 trans->adding_csums = true;
2173 ret = btrfs_csum_file_blocks(trans,
2174 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2175 trans->adding_csums = false;
2176 if (ret)
2177 return ret;
2178 }
2179 return 0;
2180 }
2181
2182 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2183 unsigned int extra_bits,
2184 struct extent_state **cached_state)
2185 {
2186 WARN_ON(PAGE_ALIGNED(end));
2187 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2188 extra_bits, cached_state);
2189 }
2190
2191 /* see btrfs_writepage_start_hook for details on why this is required */
2192 struct btrfs_writepage_fixup {
2193 struct page *page;
2194 struct btrfs_work work;
2195 };
2196
2197 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2198 {
2199 struct btrfs_writepage_fixup *fixup;
2200 struct btrfs_ordered_extent *ordered;
2201 struct extent_state *cached_state = NULL;
2202 struct extent_changeset *data_reserved = NULL;
2203 struct page *page;
2204 struct inode *inode;
2205 u64 page_start;
2206 u64 page_end;
2207 int ret;
2208
2209 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2210 page = fixup->page;
2211 again:
2212 lock_page(page);
2213 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2214 ClearPageChecked(page);
2215 goto out_page;
2216 }
2217
2218 inode = page->mapping->host;
2219 page_start = page_offset(page);
2220 page_end = page_offset(page) + PAGE_SIZE - 1;
2221
2222 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2223 &cached_state);
2224
2225 /* already ordered? We're done */
2226 if (PagePrivate2(page))
2227 goto out;
2228
2229 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2230 PAGE_SIZE);
2231 if (ordered) {
2232 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2233 page_end, &cached_state);
2234 unlock_page(page);
2235 btrfs_start_ordered_extent(inode, ordered, 1);
2236 btrfs_put_ordered_extent(ordered);
2237 goto again;
2238 }
2239
2240 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2241 PAGE_SIZE);
2242 if (ret) {
2243 mapping_set_error(page->mapping, ret);
2244 end_extent_writepage(page, ret, page_start, page_end);
2245 ClearPageChecked(page);
2246 goto out;
2247 }
2248
2249 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2250 &cached_state);
2251 if (ret) {
2252 mapping_set_error(page->mapping, ret);
2253 end_extent_writepage(page, ret, page_start, page_end);
2254 ClearPageChecked(page);
2255 goto out_reserved;
2256 }
2257
2258 ClearPageChecked(page);
2259 set_page_dirty(page);
2260 out_reserved:
2261 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
2262 if (ret)
2263 btrfs_delalloc_release_space(inode, data_reserved, page_start,
2264 PAGE_SIZE, true);
2265 out:
2266 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2267 &cached_state);
2268 out_page:
2269 unlock_page(page);
2270 put_page(page);
2271 kfree(fixup);
2272 extent_changeset_free(data_reserved);
2273 }
2274
2275 /*
2276 * There are a few paths in the higher layers of the kernel that directly
2277 * set the page dirty bit without asking the filesystem if it is a
2278 * good idea. This causes problems because we want to make sure COW
2279 * properly happens and the data=ordered rules are followed.
2280 *
2281 * In our case any range that doesn't have the ORDERED bit set
2282 * hasn't been properly setup for IO. We kick off an async process
2283 * to fix it up. The async helper will wait for ordered extents, set
2284 * the delalloc bit and make it safe to write the page.
2285 */
2286 int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end)
2287 {
2288 struct inode *inode = page->mapping->host;
2289 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2290 struct btrfs_writepage_fixup *fixup;
2291
2292 /* this page is properly in the ordered list */
2293 if (TestClearPagePrivate2(page))
2294 return 0;
2295
2296 if (PageChecked(page))
2297 return -EAGAIN;
2298
2299 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2300 if (!fixup)
2301 return -EAGAIN;
2302
2303 SetPageChecked(page);
2304 get_page(page);
2305 btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
2306 fixup->page = page;
2307 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2308 return -EBUSY;
2309 }
2310
2311 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2312 struct inode *inode, u64 file_pos,
2313 u64 disk_bytenr, u64 disk_num_bytes,
2314 u64 num_bytes, u64 ram_bytes,
2315 u8 compression, u8 encryption,
2316 u16 other_encoding, int extent_type)
2317 {
2318 struct btrfs_root *root = BTRFS_I(inode)->root;
2319 struct btrfs_file_extent_item *fi;
2320 struct btrfs_path *path;
2321 struct extent_buffer *leaf;
2322 struct btrfs_key ins;
2323 u64 qg_released;
2324 int extent_inserted = 0;
2325 int ret;
2326
2327 path = btrfs_alloc_path();
2328 if (!path)
2329 return -ENOMEM;
2330
2331 /*
2332 * we may be replacing one extent in the tree with another.
2333 * The new extent is pinned in the extent map, and we don't want
2334 * to drop it from the cache until it is completely in the btree.
2335 *
2336 * So, tell btrfs_drop_extents to leave this extent in the cache.
2337 * the caller is expected to unpin it and allow it to be merged
2338 * with the others.
2339 */
2340 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2341 file_pos + num_bytes, NULL, 0,
2342 1, sizeof(*fi), &extent_inserted);
2343 if (ret)
2344 goto out;
2345
2346 if (!extent_inserted) {
2347 ins.objectid = btrfs_ino(BTRFS_I(inode));
2348 ins.offset = file_pos;
2349 ins.type = BTRFS_EXTENT_DATA_KEY;
2350
2351 path->leave_spinning = 1;
2352 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2353 sizeof(*fi));
2354 if (ret)
2355 goto out;
2356 }
2357 leaf = path->nodes[0];
2358 fi = btrfs_item_ptr(leaf, path->slots[0],
2359 struct btrfs_file_extent_item);
2360 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2361 btrfs_set_file_extent_type(leaf, fi, extent_type);
2362 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2363 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2364 btrfs_set_file_extent_offset(leaf, fi, 0);
2365 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2366 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2367 btrfs_set_file_extent_compression(leaf, fi, compression);
2368 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2369 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2370
2371 btrfs_mark_buffer_dirty(leaf);
2372 btrfs_release_path(path);
2373
2374 inode_add_bytes(inode, num_bytes);
2375
2376 ins.objectid = disk_bytenr;
2377 ins.offset = disk_num_bytes;
2378 ins.type = BTRFS_EXTENT_ITEM_KEY;
2379
2380 /*
2381 * Release the reserved range from inode dirty range map, as it is
2382 * already moved into delayed_ref_head
2383 */
2384 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2385 if (ret < 0)
2386 goto out;
2387 qg_released = ret;
2388 ret = btrfs_alloc_reserved_file_extent(trans, root,
2389 btrfs_ino(BTRFS_I(inode)),
2390 file_pos, qg_released, &ins);
2391 out:
2392 btrfs_free_path(path);
2393
2394 return ret;
2395 }
2396
2397 /* snapshot-aware defrag */
2398 struct sa_defrag_extent_backref {
2399 struct rb_node node;
2400 struct old_sa_defrag_extent *old;
2401 u64 root_id;
2402 u64 inum;
2403 u64 file_pos;
2404 u64 extent_offset;
2405 u64 num_bytes;
2406 u64 generation;
2407 };
2408
2409 struct old_sa_defrag_extent {
2410 struct list_head list;
2411 struct new_sa_defrag_extent *new;
2412
2413 u64 extent_offset;
2414 u64 bytenr;
2415 u64 offset;
2416 u64 len;
2417 int count;
2418 };
2419
2420 struct new_sa_defrag_extent {
2421 struct rb_root root;
2422 struct list_head head;
2423 struct btrfs_path *path;
2424 struct inode *inode;
2425 u64 file_pos;
2426 u64 len;
2427 u64 bytenr;
2428 u64 disk_len;
2429 u8 compress_type;
2430 };
2431
2432 static int backref_comp(struct sa_defrag_extent_backref *b1,
2433 struct sa_defrag_extent_backref *b2)
2434 {
2435 if (b1->root_id < b2->root_id)
2436 return -1;
2437 else if (b1->root_id > b2->root_id)
2438 return 1;
2439
2440 if (b1->inum < b2->inum)
2441 return -1;
2442 else if (b1->inum > b2->inum)
2443 return 1;
2444
2445 if (b1->file_pos < b2->file_pos)
2446 return -1;
2447 else if (b1->file_pos > b2->file_pos)
2448 return 1;
2449
2450 /*
2451 * [------------------------------] ===> (a range of space)
2452 * |<--->| |<---->| =============> (fs/file tree A)
2453 * |<---------------------------->| ===> (fs/file tree B)
2454 *
2455 * A range of space can refer to two file extents in one tree while
2456 * refer to only one file extent in another tree.
2457 *
2458 * So we may process a disk offset more than one time(two extents in A)
2459 * and locate at the same extent(one extent in B), then insert two same
2460 * backrefs(both refer to the extent in B).
2461 */
2462 return 0;
2463 }
2464
2465 static void backref_insert(struct rb_root *root,
2466 struct sa_defrag_extent_backref *backref)
2467 {
2468 struct rb_node **p = &root->rb_node;
2469 struct rb_node *parent = NULL;
2470 struct sa_defrag_extent_backref *entry;
2471 int ret;
2472
2473 while (*p) {
2474 parent = *p;
2475 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2476
2477 ret = backref_comp(backref, entry);
2478 if (ret < 0)
2479 p = &(*p)->rb_left;
2480 else
2481 p = &(*p)->rb_right;
2482 }
2483
2484 rb_link_node(&backref->node, parent, p);
2485 rb_insert_color(&backref->node, root);
2486 }
2487
2488 /*
2489 * Note the backref might has changed, and in this case we just return 0.
2490 */
2491 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2492 void *ctx)
2493 {
2494 struct btrfs_file_extent_item *extent;
2495 struct old_sa_defrag_extent *old = ctx;
2496 struct new_sa_defrag_extent *new = old->new;
2497 struct btrfs_path *path = new->path;
2498 struct btrfs_key key;
2499 struct btrfs_root *root;
2500 struct sa_defrag_extent_backref *backref;
2501 struct extent_buffer *leaf;
2502 struct inode *inode = new->inode;
2503 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2504 int slot;
2505 int ret;
2506 u64 extent_offset;
2507 u64 num_bytes;
2508
2509 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2510 inum == btrfs_ino(BTRFS_I(inode)))
2511 return 0;
2512
2513 key.objectid = root_id;
2514 key.type = BTRFS_ROOT_ITEM_KEY;
2515 key.offset = (u64)-1;
2516
2517 root = btrfs_read_fs_root_no_name(fs_info, &key);
2518 if (IS_ERR(root)) {
2519 if (PTR_ERR(root) == -ENOENT)
2520 return 0;
2521 WARN_ON(1);
2522 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2523 inum, offset, root_id);
2524 return PTR_ERR(root);
2525 }
2526
2527 key.objectid = inum;
2528 key.type = BTRFS_EXTENT_DATA_KEY;
2529 if (offset > (u64)-1 << 32)
2530 key.offset = 0;
2531 else
2532 key.offset = offset;
2533
2534 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2535 if (WARN_ON(ret < 0))
2536 return ret;
2537 ret = 0;
2538
2539 while (1) {
2540 cond_resched();
2541
2542 leaf = path->nodes[0];
2543 slot = path->slots[0];
2544
2545 if (slot >= btrfs_header_nritems(leaf)) {
2546 ret = btrfs_next_leaf(root, path);
2547 if (ret < 0) {
2548 goto out;
2549 } else if (ret > 0) {
2550 ret = 0;
2551 goto out;
2552 }
2553 continue;
2554 }
2555
2556 path->slots[0]++;
2557
2558 btrfs_item_key_to_cpu(leaf, &key, slot);
2559
2560 if (key.objectid > inum)
2561 goto out;
2562
2563 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2564 continue;
2565
2566 extent = btrfs_item_ptr(leaf, slot,
2567 struct btrfs_file_extent_item);
2568
2569 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2570 continue;
2571
2572 /*
2573 * 'offset' refers to the exact key.offset,
2574 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2575 * (key.offset - extent_offset).
2576 */
2577 if (key.offset != offset)
2578 continue;
2579
2580 extent_offset = btrfs_file_extent_offset(leaf, extent);
2581 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2582
2583 if (extent_offset >= old->extent_offset + old->offset +
2584 old->len || extent_offset + num_bytes <=
2585 old->extent_offset + old->offset)
2586 continue;
2587 break;
2588 }
2589
2590 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2591 if (!backref) {
2592 ret = -ENOENT;
2593 goto out;
2594 }
2595
2596 backref->root_id = root_id;
2597 backref->inum = inum;
2598 backref->file_pos = offset;
2599 backref->num_bytes = num_bytes;
2600 backref->extent_offset = extent_offset;
2601 backref->generation = btrfs_file_extent_generation(leaf, extent);
2602 backref->old = old;
2603 backref_insert(&new->root, backref);
2604 old->count++;
2605 out:
2606 btrfs_release_path(path);
2607 WARN_ON(ret);
2608 return ret;
2609 }
2610
2611 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2612 struct new_sa_defrag_extent *new)
2613 {
2614 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2615 struct old_sa_defrag_extent *old, *tmp;
2616 int ret;
2617
2618 new->path = path;
2619
2620 list_for_each_entry_safe(old, tmp, &new->head, list) {
2621 ret = iterate_inodes_from_logical(old->bytenr +
2622 old->extent_offset, fs_info,
2623 path, record_one_backref,
2624 old, false);
2625 if (ret < 0 && ret != -ENOENT)
2626 return false;
2627
2628 /* no backref to be processed for this extent */
2629 if (!old->count) {
2630 list_del(&old->list);
2631 kfree(old);
2632 }
2633 }
2634
2635 if (list_empty(&new->head))
2636 return false;
2637
2638 return true;
2639 }
2640
2641 static int relink_is_mergable(struct extent_buffer *leaf,
2642 struct btrfs_file_extent_item *fi,
2643 struct new_sa_defrag_extent *new)
2644 {
2645 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2646 return 0;
2647
2648 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2649 return 0;
2650
2651 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2652 return 0;
2653
2654 if (btrfs_file_extent_encryption(leaf, fi) ||
2655 btrfs_file_extent_other_encoding(leaf, fi))
2656 return 0;
2657
2658 return 1;
2659 }
2660
2661 /*
2662 * Note the backref might has changed, and in this case we just return 0.
2663 */
2664 static noinline int relink_extent_backref(struct btrfs_path *path,
2665 struct sa_defrag_extent_backref *prev,
2666 struct sa_defrag_extent_backref *backref)
2667 {
2668 struct btrfs_file_extent_item *extent;
2669 struct btrfs_file_extent_item *item;
2670 struct btrfs_ordered_extent *ordered;
2671 struct btrfs_trans_handle *trans;
2672 struct btrfs_ref ref = { 0 };
2673 struct btrfs_root *root;
2674 struct btrfs_key key;
2675 struct extent_buffer *leaf;
2676 struct old_sa_defrag_extent *old = backref->old;
2677 struct new_sa_defrag_extent *new = old->new;
2678 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2679 struct inode *inode;
2680 struct extent_state *cached = NULL;
2681 int ret = 0;
2682 u64 start;
2683 u64 len;
2684 u64 lock_start;
2685 u64 lock_end;
2686 bool merge = false;
2687 int index;
2688
2689 if (prev && prev->root_id == backref->root_id &&
2690 prev->inum == backref->inum &&
2691 prev->file_pos + prev->num_bytes == backref->file_pos)
2692 merge = true;
2693
2694 /* step 1: get root */
2695 key.objectid = backref->root_id;
2696 key.type = BTRFS_ROOT_ITEM_KEY;
2697 key.offset = (u64)-1;
2698
2699 index = srcu_read_lock(&fs_info->subvol_srcu);
2700
2701 root = btrfs_read_fs_root_no_name(fs_info, &key);
2702 if (IS_ERR(root)) {
2703 srcu_read_unlock(&fs_info->subvol_srcu, index);
2704 if (PTR_ERR(root) == -ENOENT)
2705 return 0;
2706 return PTR_ERR(root);
2707 }
2708
2709 if (btrfs_root_readonly(root)) {
2710 srcu_read_unlock(&fs_info->subvol_srcu, index);
2711 return 0;
2712 }
2713
2714 /* step 2: get inode */
2715 key.objectid = backref->inum;
2716 key.type = BTRFS_INODE_ITEM_KEY;
2717 key.offset = 0;
2718
2719 inode = btrfs_iget(fs_info->sb, &key, root);
2720 if (IS_ERR(inode)) {
2721 srcu_read_unlock(&fs_info->subvol_srcu, index);
2722 return 0;
2723 }
2724
2725 srcu_read_unlock(&fs_info->subvol_srcu, index);
2726
2727 /* step 3: relink backref */
2728 lock_start = backref->file_pos;
2729 lock_end = backref->file_pos + backref->num_bytes - 1;
2730 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2731 &cached);
2732
2733 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2734 if (ordered) {
2735 btrfs_put_ordered_extent(ordered);
2736 goto out_unlock;
2737 }
2738
2739 trans = btrfs_join_transaction(root);
2740 if (IS_ERR(trans)) {
2741 ret = PTR_ERR(trans);
2742 goto out_unlock;
2743 }
2744
2745 key.objectid = backref->inum;
2746 key.type = BTRFS_EXTENT_DATA_KEY;
2747 key.offset = backref->file_pos;
2748
2749 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2750 if (ret < 0) {
2751 goto out_free_path;
2752 } else if (ret > 0) {
2753 ret = 0;
2754 goto out_free_path;
2755 }
2756
2757 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2758 struct btrfs_file_extent_item);
2759
2760 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2761 backref->generation)
2762 goto out_free_path;
2763
2764 btrfs_release_path(path);
2765
2766 start = backref->file_pos;
2767 if (backref->extent_offset < old->extent_offset + old->offset)
2768 start += old->extent_offset + old->offset -
2769 backref->extent_offset;
2770
2771 len = min(backref->extent_offset + backref->num_bytes,
2772 old->extent_offset + old->offset + old->len);
2773 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2774
2775 ret = btrfs_drop_extents(trans, root, inode, start,
2776 start + len, 1);
2777 if (ret)
2778 goto out_free_path;
2779 again:
2780 key.objectid = btrfs_ino(BTRFS_I(inode));
2781 key.type = BTRFS_EXTENT_DATA_KEY;
2782 key.offset = start;
2783
2784 path->leave_spinning = 1;
2785 if (merge) {
2786 struct btrfs_file_extent_item *fi;
2787 u64 extent_len;
2788 struct btrfs_key found_key;
2789
2790 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2791 if (ret < 0)
2792 goto out_free_path;
2793
2794 path->slots[0]--;
2795 leaf = path->nodes[0];
2796 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2797
2798 fi = btrfs_item_ptr(leaf, path->slots[0],
2799 struct btrfs_file_extent_item);
2800 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2801
2802 if (extent_len + found_key.offset == start &&
2803 relink_is_mergable(leaf, fi, new)) {
2804 btrfs_set_file_extent_num_bytes(leaf, fi,
2805 extent_len + len);
2806 btrfs_mark_buffer_dirty(leaf);
2807 inode_add_bytes(inode, len);
2808
2809 ret = 1;
2810 goto out_free_path;
2811 } else {
2812 merge = false;
2813 btrfs_release_path(path);
2814 goto again;
2815 }
2816 }
2817
2818 ret = btrfs_insert_empty_item(trans, root, path, &key,
2819 sizeof(*extent));
2820 if (ret) {
2821 btrfs_abort_transaction(trans, ret);
2822 goto out_free_path;
2823 }
2824
2825 leaf = path->nodes[0];
2826 item = btrfs_item_ptr(leaf, path->slots[0],
2827 struct btrfs_file_extent_item);
2828 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2829 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2830 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2831 btrfs_set_file_extent_num_bytes(leaf, item, len);
2832 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2833 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2834 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2835 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2836 btrfs_set_file_extent_encryption(leaf, item, 0);
2837 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2838
2839 btrfs_mark_buffer_dirty(leaf);
2840 inode_add_bytes(inode, len);
2841 btrfs_release_path(path);
2842
2843 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, new->bytenr,
2844 new->disk_len, 0);
2845 btrfs_init_data_ref(&ref, backref->root_id, backref->inum,
2846 new->file_pos); /* start - extent_offset */
2847 ret = btrfs_inc_extent_ref(trans, &ref);
2848 if (ret) {
2849 btrfs_abort_transaction(trans, ret);
2850 goto out_free_path;
2851 }
2852
2853 ret = 1;
2854 out_free_path:
2855 btrfs_release_path(path);
2856 path->leave_spinning = 0;
2857 btrfs_end_transaction(trans);
2858 out_unlock:
2859 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2860 &cached);
2861 iput(inode);
2862 return ret;
2863 }
2864
2865 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2866 {
2867 struct old_sa_defrag_extent *old, *tmp;
2868
2869 if (!new)
2870 return;
2871
2872 list_for_each_entry_safe(old, tmp, &new->head, list) {
2873 kfree(old);
2874 }
2875 kfree(new);
2876 }
2877
2878 static void relink_file_extents(struct new_sa_defrag_extent *new)
2879 {
2880 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2881 struct btrfs_path *path;
2882 struct sa_defrag_extent_backref *backref;
2883 struct sa_defrag_extent_backref *prev = NULL;
2884 struct rb_node *node;
2885 int ret;
2886
2887 path = btrfs_alloc_path();
2888 if (!path)
2889 return;
2890
2891 if (!record_extent_backrefs(path, new)) {
2892 btrfs_free_path(path);
2893 goto out;
2894 }
2895 btrfs_release_path(path);
2896
2897 while (1) {
2898 node = rb_first(&new->root);
2899 if (!node)
2900 break;
2901 rb_erase(node, &new->root);
2902
2903 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2904
2905 ret = relink_extent_backref(path, prev, backref);
2906 WARN_ON(ret < 0);
2907
2908 kfree(prev);
2909
2910 if (ret == 1)
2911 prev = backref;
2912 else
2913 prev = NULL;
2914 cond_resched();
2915 }
2916 kfree(prev);
2917
2918 btrfs_free_path(path);
2919 out:
2920 free_sa_defrag_extent(new);
2921
2922 atomic_dec(&fs_info->defrag_running);
2923 wake_up(&fs_info->transaction_wait);
2924 }
2925
2926 static struct new_sa_defrag_extent *
2927 record_old_file_extents(struct inode *inode,
2928 struct btrfs_ordered_extent *ordered)
2929 {
2930 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2931 struct btrfs_root *root = BTRFS_I(inode)->root;
2932 struct btrfs_path *path;
2933 struct btrfs_key key;
2934 struct old_sa_defrag_extent *old;
2935 struct new_sa_defrag_extent *new;
2936 int ret;
2937
2938 new = kmalloc(sizeof(*new), GFP_NOFS);
2939 if (!new)
2940 return NULL;
2941
2942 new->inode = inode;
2943 new->file_pos = ordered->file_offset;
2944 new->len = ordered->len;
2945 new->bytenr = ordered->start;
2946 new->disk_len = ordered->disk_len;
2947 new->compress_type = ordered->compress_type;
2948 new->root = RB_ROOT;
2949 INIT_LIST_HEAD(&new->head);
2950
2951 path = btrfs_alloc_path();
2952 if (!path)
2953 goto out_kfree;
2954
2955 key.objectid = btrfs_ino(BTRFS_I(inode));
2956 key.type = BTRFS_EXTENT_DATA_KEY;
2957 key.offset = new->file_pos;
2958
2959 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2960 if (ret < 0)
2961 goto out_free_path;
2962 if (ret > 0 && path->slots[0] > 0)
2963 path->slots[0]--;
2964
2965 /* find out all the old extents for the file range */
2966 while (1) {
2967 struct btrfs_file_extent_item *extent;
2968 struct extent_buffer *l;
2969 int slot;
2970 u64 num_bytes;
2971 u64 offset;
2972 u64 end;
2973 u64 disk_bytenr;
2974 u64 extent_offset;
2975
2976 l = path->nodes[0];
2977 slot = path->slots[0];
2978
2979 if (slot >= btrfs_header_nritems(l)) {
2980 ret = btrfs_next_leaf(root, path);
2981 if (ret < 0)
2982 goto out_free_path;
2983 else if (ret > 0)
2984 break;
2985 continue;
2986 }
2987
2988 btrfs_item_key_to_cpu(l, &key, slot);
2989
2990 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2991 break;
2992 if (key.type != BTRFS_EXTENT_DATA_KEY)
2993 break;
2994 if (key.offset >= new->file_pos + new->len)
2995 break;
2996
2997 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2998
2999 num_bytes = btrfs_file_extent_num_bytes(l, extent);
3000 if (key.offset + num_bytes < new->file_pos)
3001 goto next;
3002
3003 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
3004 if (!disk_bytenr)
3005 goto next;
3006
3007 extent_offset = btrfs_file_extent_offset(l, extent);
3008
3009 old = kmalloc(sizeof(*old), GFP_NOFS);
3010 if (!old)
3011 goto out_free_path;
3012
3013 offset = max(new->file_pos, key.offset);
3014 end = min(new->file_pos + new->len, key.offset + num_bytes);
3015
3016 old->bytenr = disk_bytenr;
3017 old->extent_offset = extent_offset;
3018 old->offset = offset - key.offset;
3019 old->len = end - offset;
3020 old->new = new;
3021 old->count = 0;
3022 list_add_tail(&old->list, &new->head);
3023 next:
3024 path->slots[0]++;
3025 cond_resched();
3026 }
3027
3028 btrfs_free_path(path);
3029 atomic_inc(&fs_info->defrag_running);
3030
3031 return new;
3032
3033 out_free_path:
3034 btrfs_free_path(path);
3035 out_kfree:
3036 free_sa_defrag_extent(new);
3037 return NULL;
3038 }
3039
3040 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
3041 u64 start, u64 len)
3042 {
3043 struct btrfs_block_group *cache;
3044
3045 cache = btrfs_lookup_block_group(fs_info, start);
3046 ASSERT(cache);
3047
3048 spin_lock(&cache->lock);
3049 cache->delalloc_bytes -= len;
3050 spin_unlock(&cache->lock);
3051
3052 btrfs_put_block_group(cache);
3053 }
3054
3055 /* as ordered data IO finishes, this gets called so we can finish
3056 * an ordered extent if the range of bytes in the file it covers are
3057 * fully written.
3058 */
3059 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
3060 {
3061 struct inode *inode = ordered_extent->inode;
3062 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3063 struct btrfs_root *root = BTRFS_I(inode)->root;
3064 struct btrfs_trans_handle *trans = NULL;
3065 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3066 struct extent_state *cached_state = NULL;
3067 struct new_sa_defrag_extent *new = NULL;
3068 int compress_type = 0;
3069 int ret = 0;
3070 u64 logical_len = ordered_extent->len;
3071 bool freespace_inode;
3072 bool truncated = false;
3073 bool range_locked = false;
3074 bool clear_new_delalloc_bytes = false;
3075 bool clear_reserved_extent = true;
3076
3077 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3078 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
3079 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
3080 clear_new_delalloc_bytes = true;
3081
3082 freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
3083
3084 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
3085 ret = -EIO;
3086 goto out;
3087 }
3088
3089 btrfs_free_io_failure_record(BTRFS_I(inode),
3090 ordered_extent->file_offset,
3091 ordered_extent->file_offset +
3092 ordered_extent->len - 1);
3093
3094 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
3095 truncated = true;
3096 logical_len = ordered_extent->truncated_len;
3097 /* Truncated the entire extent, don't bother adding */
3098 if (!logical_len)
3099 goto out;
3100 }
3101
3102 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
3103 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
3104
3105 /*
3106 * For mwrite(mmap + memset to write) case, we still reserve
3107 * space for NOCOW range.
3108 * As NOCOW won't cause a new delayed ref, just free the space
3109 */
3110 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3111 ordered_extent->len);
3112 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3113 if (freespace_inode)
3114 trans = btrfs_join_transaction_spacecache(root);
3115 else
3116 trans = btrfs_join_transaction(root);
3117 if (IS_ERR(trans)) {
3118 ret = PTR_ERR(trans);
3119 trans = NULL;
3120 goto out;
3121 }
3122 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3123 ret = btrfs_update_inode_fallback(trans, root, inode);
3124 if (ret) /* -ENOMEM or corruption */
3125 btrfs_abort_transaction(trans, ret);
3126 goto out;
3127 }
3128
3129 range_locked = true;
3130 lock_extent_bits(io_tree, ordered_extent->file_offset,
3131 ordered_extent->file_offset + ordered_extent->len - 1,
3132 &cached_state);
3133
3134 ret = test_range_bit(io_tree, ordered_extent->file_offset,
3135 ordered_extent->file_offset + ordered_extent->len - 1,
3136 EXTENT_DEFRAG, 0, cached_state);
3137 if (ret) {
3138 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
3139 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
3140 /* the inode is shared */
3141 new = record_old_file_extents(inode, ordered_extent);
3142
3143 clear_extent_bit(io_tree, ordered_extent->file_offset,
3144 ordered_extent->file_offset + ordered_extent->len - 1,
3145 EXTENT_DEFRAG, 0, 0, &cached_state);
3146 }
3147
3148 if (freespace_inode)
3149 trans = btrfs_join_transaction_spacecache(root);
3150 else
3151 trans = btrfs_join_transaction(root);
3152 if (IS_ERR(trans)) {
3153 ret = PTR_ERR(trans);
3154 trans = NULL;
3155 goto out;
3156 }
3157
3158 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3159
3160 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3161 compress_type = ordered_extent->compress_type;
3162 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3163 BUG_ON(compress_type);
3164 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3165 ordered_extent->len);
3166 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3167 ordered_extent->file_offset,
3168 ordered_extent->file_offset +
3169 logical_len);
3170 } else {
3171 BUG_ON(root == fs_info->tree_root);
3172 ret = insert_reserved_file_extent(trans, inode,
3173 ordered_extent->file_offset,
3174 ordered_extent->start,
3175 ordered_extent->disk_len,
3176 logical_len, logical_len,
3177 compress_type, 0, 0,
3178 BTRFS_FILE_EXTENT_REG);
3179 if (!ret) {
3180 clear_reserved_extent = false;
3181 btrfs_release_delalloc_bytes(fs_info,
3182 ordered_extent->start,
3183 ordered_extent->disk_len);
3184 }
3185 }
3186 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3187 ordered_extent->file_offset, ordered_extent->len,
3188 trans->transid);
3189 if (ret < 0) {
3190 btrfs_abort_transaction(trans, ret);
3191 goto out;
3192 }
3193
3194 ret = add_pending_csums(trans, inode, &ordered_extent->list);
3195 if (ret) {
3196 btrfs_abort_transaction(trans, ret);
3197 goto out;
3198 }
3199
3200 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3201 ret = btrfs_update_inode_fallback(trans, root, inode);
3202 if (ret) { /* -ENOMEM or corruption */
3203 btrfs_abort_transaction(trans, ret);
3204 goto out;
3205 }
3206 ret = 0;
3207 out:
3208 if (range_locked || clear_new_delalloc_bytes) {
3209 unsigned int clear_bits = 0;
3210
3211 if (range_locked)
3212 clear_bits |= EXTENT_LOCKED;
3213 if (clear_new_delalloc_bytes)
3214 clear_bits |= EXTENT_DELALLOC_NEW;
3215 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3216 ordered_extent->file_offset,
3217 ordered_extent->file_offset +
3218 ordered_extent->len - 1,
3219 clear_bits,
3220 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3221 0, &cached_state);
3222 }
3223
3224 if (trans)
3225 btrfs_end_transaction(trans);
3226
3227 if (ret || truncated) {
3228 u64 start, end;
3229
3230 if (truncated)
3231 start = ordered_extent->file_offset + logical_len;
3232 else
3233 start = ordered_extent->file_offset;
3234 end = ordered_extent->file_offset + ordered_extent->len - 1;
3235 clear_extent_uptodate(io_tree, start, end, NULL);
3236
3237 /* Drop the cache for the part of the extent we didn't write. */
3238 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3239
3240 /*
3241 * If the ordered extent had an IOERR or something else went
3242 * wrong we need to return the space for this ordered extent
3243 * back to the allocator. We only free the extent in the
3244 * truncated case if we didn't write out the extent at all.
3245 *
3246 * If we made it past insert_reserved_file_extent before we
3247 * errored out then we don't need to do this as the accounting
3248 * has already been done.
3249 */
3250 if ((ret || !logical_len) &&
3251 clear_reserved_extent &&
3252 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3253 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3254 btrfs_free_reserved_extent(fs_info,
3255 ordered_extent->start,
3256 ordered_extent->disk_len, 1);
3257 }
3258
3259
3260 /*
3261 * This needs to be done to make sure anybody waiting knows we are done
3262 * updating everything for this ordered extent.
3263 */
3264 btrfs_remove_ordered_extent(inode, ordered_extent);
3265
3266 /* for snapshot-aware defrag */
3267 if (new) {
3268 if (ret) {
3269 free_sa_defrag_extent(new);
3270 atomic_dec(&fs_info->defrag_running);
3271 } else {
3272 relink_file_extents(new);
3273 }
3274 }
3275
3276 /* once for us */
3277 btrfs_put_ordered_extent(ordered_extent);
3278 /* once for the tree */
3279 btrfs_put_ordered_extent(ordered_extent);
3280
3281 return ret;
3282 }
3283
3284 static void finish_ordered_fn(struct btrfs_work *work)
3285 {
3286 struct btrfs_ordered_extent *ordered_extent;
3287 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3288 btrfs_finish_ordered_io(ordered_extent);
3289 }
3290
3291 void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
3292 u64 end, int uptodate)
3293 {
3294 struct inode *inode = page->mapping->host;
3295 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3296 struct btrfs_ordered_extent *ordered_extent = NULL;
3297 struct btrfs_workqueue *wq;
3298
3299 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3300
3301 ClearPagePrivate2(page);
3302 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3303 end - start + 1, uptodate))
3304 return;
3305
3306 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
3307 wq = fs_info->endio_freespace_worker;
3308 else
3309 wq = fs_info->endio_write_workers;
3310
3311 btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL);
3312 btrfs_queue_work(wq, &ordered_extent->work);
3313 }
3314
3315 static int __readpage_endio_check(struct inode *inode,
3316 struct btrfs_io_bio *io_bio,
3317 int icsum, struct page *page,
3318 int pgoff, u64 start, size_t len)
3319 {
3320 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3321 SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
3322 char *kaddr;
3323 u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
3324 u8 *csum_expected;
3325 u8 csum[BTRFS_CSUM_SIZE];
3326
3327 csum_expected = ((u8 *)io_bio->csum) + icsum * csum_size;
3328
3329 kaddr = kmap_atomic(page);
3330 shash->tfm = fs_info->csum_shash;
3331
3332 crypto_shash_init(shash);
3333 crypto_shash_update(shash, kaddr + pgoff, len);
3334 crypto_shash_final(shash, csum);
3335
3336 if (memcmp(csum, csum_expected, csum_size))
3337 goto zeroit;
3338
3339 kunmap_atomic(kaddr);
3340 return 0;
3341 zeroit:
3342 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3343 io_bio->mirror_num);
3344 memset(kaddr + pgoff, 1, len);
3345 flush_dcache_page(page);
3346 kunmap_atomic(kaddr);
3347 return -EIO;
3348 }
3349
3350 /*
3351 * when reads are done, we need to check csums to verify the data is correct
3352 * if there's a match, we allow the bio to finish. If not, the code in
3353 * extent_io.c will try to find good copies for us.
3354 */
3355 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3356 u64 phy_offset, struct page *page,
3357 u64 start, u64 end, int mirror)
3358 {
3359 size_t offset = start - page_offset(page);
3360 struct inode *inode = page->mapping->host;
3361 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3362 struct btrfs_root *root = BTRFS_I(inode)->root;
3363
3364 if (PageChecked(page)) {
3365 ClearPageChecked(page);
3366 return 0;
3367 }
3368
3369 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3370 return 0;
3371
3372 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3373 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3374 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3375 return 0;
3376 }
3377
3378 phy_offset >>= inode->i_sb->s_blocksize_bits;
3379 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3380 start, (size_t)(end - start + 1));
3381 }
3382
3383 /*
3384 * btrfs_add_delayed_iput - perform a delayed iput on @inode
3385 *
3386 * @inode: The inode we want to perform iput on
3387 *
3388 * This function uses the generic vfs_inode::i_count to track whether we should
3389 * just decrement it (in case it's > 1) or if this is the last iput then link
3390 * the inode to the delayed iput machinery. Delayed iputs are processed at
3391 * transaction commit time/superblock commit/cleaner kthread.
3392 */
3393 void btrfs_add_delayed_iput(struct inode *inode)
3394 {
3395 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3396 struct btrfs_inode *binode = BTRFS_I(inode);
3397
3398 if (atomic_add_unless(&inode->i_count, -1, 1))
3399 return;
3400
3401 atomic_inc(&fs_info->nr_delayed_iputs);
3402 spin_lock(&fs_info->delayed_iput_lock);
3403 ASSERT(list_empty(&binode->delayed_iput));
3404 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3405 spin_unlock(&fs_info->delayed_iput_lock);
3406 if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
3407 wake_up_process(fs_info->cleaner_kthread);
3408 }
3409
3410 static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
3411 struct btrfs_inode *inode)
3412 {
3413 list_del_init(&inode->delayed_iput);
3414 spin_unlock(&fs_info->delayed_iput_lock);
3415 iput(&inode->vfs_inode);
3416 if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
3417 wake_up(&fs_info->delayed_iputs_wait);
3418 spin_lock(&fs_info->delayed_iput_lock);
3419 }
3420
3421 static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
3422 struct btrfs_inode *inode)
3423 {
3424 if (!list_empty(&inode->delayed_iput)) {
3425 spin_lock(&fs_info->delayed_iput_lock);
3426 if (!list_empty(&inode->delayed_iput))
3427 run_delayed_iput_locked(fs_info, inode);
3428 spin_unlock(&fs_info->delayed_iput_lock);
3429 }
3430 }
3431
3432 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3433 {
3434
3435 spin_lock(&fs_info->delayed_iput_lock);
3436 while (!list_empty(&fs_info->delayed_iputs)) {
3437 struct btrfs_inode *inode;
3438
3439 inode = list_first_entry(&fs_info->delayed_iputs,
3440 struct btrfs_inode, delayed_iput);
3441 run_delayed_iput_locked(fs_info, inode);
3442 }
3443 spin_unlock(&fs_info->delayed_iput_lock);
3444 }
3445
3446 /**
3447 * btrfs_wait_on_delayed_iputs - wait on the delayed iputs to be done running
3448 * @fs_info - the fs_info for this fs
3449 * @return - EINTR if we were killed, 0 if nothing's pending
3450 *
3451 * This will wait on any delayed iputs that are currently running with KILLABLE
3452 * set. Once they are all done running we will return, unless we are killed in
3453 * which case we return EINTR. This helps in user operations like fallocate etc
3454 * that might get blocked on the iputs.
3455 */
3456 int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info)
3457 {
3458 int ret = wait_event_killable(fs_info->delayed_iputs_wait,
3459 atomic_read(&fs_info->nr_delayed_iputs) == 0);
3460 if (ret)
3461 return -EINTR;
3462 return 0;
3463 }
3464
3465 /*
3466 * This creates an orphan entry for the given inode in case something goes wrong
3467 * in the middle of an unlink.
3468 */
3469 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3470 struct btrfs_inode *inode)
3471 {
3472 int ret;
3473
3474 ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode));
3475 if (ret && ret != -EEXIST) {
3476 btrfs_abort_transaction(trans, ret);
3477 return ret;
3478 }
3479
3480 return 0;
3481 }
3482
3483 /*
3484 * We have done the delete so we can go ahead and remove the orphan item for
3485 * this particular inode.
3486 */
3487 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3488 struct btrfs_inode *inode)
3489 {
3490 return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode));
3491 }
3492
3493 /*
3494 * this cleans up any orphans that may be left on the list from the last use
3495 * of this root.
3496 */
3497 int btrfs_orphan_cleanup(struct btrfs_root *root)
3498 {
3499 struct btrfs_fs_info *fs_info = root->fs_info;
3500 struct btrfs_path *path;
3501 struct extent_buffer *leaf;
3502 struct btrfs_key key, found_key;
3503 struct btrfs_trans_handle *trans;
3504 struct inode *inode;
3505 u64 last_objectid = 0;
3506 int ret = 0, nr_unlink = 0;
3507
3508 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3509 return 0;
3510
3511 path = btrfs_alloc_path();
3512 if (!path) {
3513 ret = -ENOMEM;
3514 goto out;
3515 }
3516 path->reada = READA_BACK;
3517
3518 key.objectid = BTRFS_ORPHAN_OBJECTID;
3519 key.type = BTRFS_ORPHAN_ITEM_KEY;
3520 key.offset = (u64)-1;
3521
3522 while (1) {
3523 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3524 if (ret < 0)
3525 goto out;
3526
3527 /*
3528 * if ret == 0 means we found what we were searching for, which
3529 * is weird, but possible, so only screw with path if we didn't
3530 * find the key and see if we have stuff that matches
3531 */
3532 if (ret > 0) {
3533 ret = 0;
3534 if (path->slots[0] == 0)
3535 break;
3536 path->slots[0]--;
3537 }
3538
3539 /* pull out the item */
3540 leaf = path->nodes[0];
3541 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3542
3543 /* make sure the item matches what we want */
3544 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3545 break;
3546 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3547 break;
3548
3549 /* release the path since we're done with it */
3550 btrfs_release_path(path);
3551
3552 /*
3553 * this is where we are basically btrfs_lookup, without the
3554 * crossing root thing. we store the inode number in the
3555 * offset of the orphan item.
3556 */
3557
3558 if (found_key.offset == last_objectid) {
3559 btrfs_err(fs_info,
3560 "Error removing orphan entry, stopping orphan cleanup");
3561 ret = -EINVAL;
3562 goto out;
3563 }
3564
3565 last_objectid = found_key.offset;
3566
3567 found_key.objectid = found_key.offset;
3568 found_key.type = BTRFS_INODE_ITEM_KEY;
3569 found_key.offset = 0;
3570 inode = btrfs_iget(fs_info->sb, &found_key, root);
3571 ret = PTR_ERR_OR_ZERO(inode);
3572 if (ret && ret != -ENOENT)
3573 goto out;
3574
3575 if (ret == -ENOENT && root == fs_info->tree_root) {
3576 struct btrfs_root *dead_root;
3577 struct btrfs_fs_info *fs_info = root->fs_info;
3578 int is_dead_root = 0;
3579
3580 /*
3581 * this is an orphan in the tree root. Currently these
3582 * could come from 2 sources:
3583 * a) a snapshot deletion in progress
3584 * b) a free space cache inode
3585 * We need to distinguish those two, as the snapshot
3586 * orphan must not get deleted.
3587 * find_dead_roots already ran before us, so if this
3588 * is a snapshot deletion, we should find the root
3589 * in the dead_roots list
3590 */
3591 spin_lock(&fs_info->trans_lock);
3592 list_for_each_entry(dead_root, &fs_info->dead_roots,
3593 root_list) {
3594 if (dead_root->root_key.objectid ==
3595 found_key.objectid) {
3596 is_dead_root = 1;
3597 break;
3598 }
3599 }
3600 spin_unlock(&fs_info->trans_lock);
3601 if (is_dead_root) {
3602 /* prevent this orphan from being found again */
3603 key.offset = found_key.objectid - 1;
3604 continue;
3605 }
3606
3607 }
3608
3609 /*
3610 * If we have an inode with links, there are a couple of
3611 * possibilities. Old kernels (before v3.12) used to create an
3612 * orphan item for truncate indicating that there were possibly
3613 * extent items past i_size that needed to be deleted. In v3.12,
3614 * truncate was changed to update i_size in sync with the extent
3615 * items, but the (useless) orphan item was still created. Since
3616 * v4.18, we don't create the orphan item for truncate at all.
3617 *
3618 * So, this item could mean that we need to do a truncate, but
3619 * only if this filesystem was last used on a pre-v3.12 kernel
3620 * and was not cleanly unmounted. The odds of that are quite
3621 * slim, and it's a pain to do the truncate now, so just delete
3622 * the orphan item.
3623 *
3624 * It's also possible that this orphan item was supposed to be
3625 * deleted but wasn't. The inode number may have been reused,
3626 * but either way, we can delete the orphan item.
3627 */
3628 if (ret == -ENOENT || inode->i_nlink) {
3629 if (!ret)
3630 iput(inode);
3631 trans = btrfs_start_transaction(root, 1);
3632 if (IS_ERR(trans)) {
3633 ret = PTR_ERR(trans);
3634 goto out;
3635 }
3636 btrfs_debug(fs_info, "auto deleting %Lu",
3637 found_key.objectid);
3638 ret = btrfs_del_orphan_item(trans, root,
3639 found_key.objectid);
3640 btrfs_end_transaction(trans);
3641 if (ret)
3642 goto out;
3643 continue;
3644 }
3645
3646 nr_unlink++;
3647
3648 /* this will do delete_inode and everything for us */
3649 iput(inode);
3650 }
3651 /* release the path since we're done with it */
3652 btrfs_release_path(path);
3653
3654 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3655
3656 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3657 trans = btrfs_join_transaction(root);
3658 if (!IS_ERR(trans))
3659 btrfs_end_transaction(trans);
3660 }
3661
3662 if (nr_unlink)
3663 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3664
3665 out:
3666 if (ret)
3667 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3668 btrfs_free_path(path);
3669 return ret;
3670 }
3671
3672 /*
3673 * very simple check to peek ahead in the leaf looking for xattrs. If we
3674 * don't find any xattrs, we know there can't be any acls.
3675 *
3676 * slot is the slot the inode is in, objectid is the objectid of the inode
3677 */
3678 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3679 int slot, u64 objectid,
3680 int *first_xattr_slot)
3681 {
3682 u32 nritems = btrfs_header_nritems(leaf);
3683 struct btrfs_key found_key;
3684 static u64 xattr_access = 0;
3685 static u64 xattr_default = 0;
3686 int scanned = 0;
3687
3688 if (!xattr_access) {
3689 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3690 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3691 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3692 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3693 }
3694
3695 slot++;
3696 *first_xattr_slot = -1;
3697 while (slot < nritems) {
3698 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3699
3700 /* we found a different objectid, there must not be acls */
3701 if (found_key.objectid != objectid)
3702 return 0;
3703
3704 /* we found an xattr, assume we've got an acl */
3705 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3706 if (*first_xattr_slot == -1)
3707 *first_xattr_slot = slot;
3708 if (found_key.offset == xattr_access ||
3709 found_key.offset == xattr_default)
3710 return 1;
3711 }
3712
3713 /*
3714 * we found a key greater than an xattr key, there can't
3715 * be any acls later on
3716 */
3717 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3718 return 0;
3719
3720 slot++;
3721 scanned++;
3722
3723 /*
3724 * it goes inode, inode backrefs, xattrs, extents,
3725 * so if there are a ton of hard links to an inode there can
3726 * be a lot of backrefs. Don't waste time searching too hard,
3727 * this is just an optimization
3728 */
3729 if (scanned >= 8)
3730 break;
3731 }
3732 /* we hit the end of the leaf before we found an xattr or
3733 * something larger than an xattr. We have to assume the inode
3734 * has acls
3735 */
3736 if (*first_xattr_slot == -1)
3737 *first_xattr_slot = slot;
3738 return 1;
3739 }
3740
3741 /*
3742 * read an inode from the btree into the in-memory inode
3743 */
3744 static int btrfs_read_locked_inode(struct inode *inode,
3745 struct btrfs_path *in_path)
3746 {
3747 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3748 struct btrfs_path *path = in_path;
3749 struct extent_buffer *leaf;
3750 struct btrfs_inode_item *inode_item;
3751 struct btrfs_root *root = BTRFS_I(inode)->root;
3752 struct btrfs_key location;
3753 unsigned long ptr;
3754 int maybe_acls;
3755 u32 rdev;
3756 int ret;
3757 bool filled = false;
3758 int first_xattr_slot;
3759
3760 ret = btrfs_fill_inode(inode, &rdev);
3761 if (!ret)
3762 filled = true;
3763
3764 if (!path) {
3765 path = btrfs_alloc_path();
3766 if (!path)
3767 return -ENOMEM;
3768 }
3769
3770 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3771
3772 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3773 if (ret) {
3774 if (path != in_path)
3775 btrfs_free_path(path);
3776 return ret;
3777 }
3778
3779 leaf = path->nodes[0];
3780
3781 if (filled)
3782 goto cache_index;
3783
3784 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3785 struct btrfs_inode_item);
3786 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3787 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3788 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3789 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3790 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3791
3792 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3793 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3794
3795 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3796 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3797
3798 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3799 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3800
3801 BTRFS_I(inode)->i_otime.tv_sec =
3802 btrfs_timespec_sec(leaf, &inode_item->otime);
3803 BTRFS_I(inode)->i_otime.tv_nsec =
3804 btrfs_timespec_nsec(leaf, &inode_item->otime);
3805
3806 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3807 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3808 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3809
3810 inode_set_iversion_queried(inode,
3811 btrfs_inode_sequence(leaf, inode_item));
3812 inode->i_generation = BTRFS_I(inode)->generation;
3813 inode->i_rdev = 0;
3814 rdev = btrfs_inode_rdev(leaf, inode_item);
3815
3816 BTRFS_I(inode)->index_cnt = (u64)-1;
3817 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3818
3819 cache_index:
3820 /*
3821 * If we were modified in the current generation and evicted from memory
3822 * and then re-read we need to do a full sync since we don't have any
3823 * idea about which extents were modified before we were evicted from
3824 * cache.
3825 *
3826 * This is required for both inode re-read from disk and delayed inode
3827 * in delayed_nodes_tree.
3828 */
3829 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3830 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3831 &BTRFS_I(inode)->runtime_flags);
3832
3833 /*
3834 * We don't persist the id of the transaction where an unlink operation
3835 * against the inode was last made. So here we assume the inode might
3836 * have been evicted, and therefore the exact value of last_unlink_trans
3837 * lost, and set it to last_trans to avoid metadata inconsistencies
3838 * between the inode and its parent if the inode is fsync'ed and the log
3839 * replayed. For example, in the scenario:
3840 *
3841 * touch mydir/foo
3842 * ln mydir/foo mydir/bar
3843 * sync
3844 * unlink mydir/bar
3845 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3846 * xfs_io -c fsync mydir/foo
3847 * <power failure>
3848 * mount fs, triggers fsync log replay
3849 *
3850 * We must make sure that when we fsync our inode foo we also log its
3851 * parent inode, otherwise after log replay the parent still has the
3852 * dentry with the "bar" name but our inode foo has a link count of 1
3853 * and doesn't have an inode ref with the name "bar" anymore.
3854 *
3855 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3856 * but it guarantees correctness at the expense of occasional full
3857 * transaction commits on fsync if our inode is a directory, or if our
3858 * inode is not a directory, logging its parent unnecessarily.
3859 */
3860 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3861
3862 path->slots[0]++;
3863 if (inode->i_nlink != 1 ||
3864 path->slots[0] >= btrfs_header_nritems(leaf))
3865 goto cache_acl;
3866
3867 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3868 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3869 goto cache_acl;
3870
3871 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3872 if (location.type == BTRFS_INODE_REF_KEY) {
3873 struct btrfs_inode_ref *ref;
3874
3875 ref = (struct btrfs_inode_ref *)ptr;
3876 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3877 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3878 struct btrfs_inode_extref *extref;
3879
3880 extref = (struct btrfs_inode_extref *)ptr;
3881 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3882 extref);
3883 }
3884 cache_acl:
3885 /*
3886 * try to precache a NULL acl entry for files that don't have
3887 * any xattrs or acls
3888 */
3889 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3890 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3891 if (first_xattr_slot != -1) {
3892 path->slots[0] = first_xattr_slot;
3893 ret = btrfs_load_inode_props(inode, path);
3894 if (ret)
3895 btrfs_err(fs_info,
3896 "error loading props for ino %llu (root %llu): %d",
3897 btrfs_ino(BTRFS_I(inode)),
3898 root->root_key.objectid, ret);
3899 }
3900 if (path != in_path)
3901 btrfs_free_path(path);
3902
3903 if (!maybe_acls)
3904 cache_no_acl(inode);
3905
3906 switch (inode->i_mode & S_IFMT) {
3907 case S_IFREG:
3908 inode->i_mapping->a_ops = &btrfs_aops;
3909 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3910 inode->i_fop = &btrfs_file_operations;
3911 inode->i_op = &btrfs_file_inode_operations;
3912 break;
3913 case S_IFDIR:
3914 inode->i_fop = &btrfs_dir_file_operations;
3915 inode->i_op = &btrfs_dir_inode_operations;
3916 break;
3917 case S_IFLNK:
3918 inode->i_op = &btrfs_symlink_inode_operations;
3919 inode_nohighmem(inode);
3920 inode->i_mapping->a_ops = &btrfs_aops;
3921 break;
3922 default:
3923 inode->i_op = &btrfs_special_inode_operations;
3924 init_special_inode(inode, inode->i_mode, rdev);
3925 break;
3926 }
3927
3928 btrfs_sync_inode_flags_to_i_flags(inode);
3929 return 0;
3930 }
3931
3932 /*
3933 * given a leaf and an inode, copy the inode fields into the leaf
3934 */
3935 static void fill_inode_item(struct btrfs_trans_handle *trans,
3936 struct extent_buffer *leaf,
3937 struct btrfs_inode_item *item,
3938 struct inode *inode)
3939 {
3940 struct btrfs_map_token token;
3941
3942 btrfs_init_map_token(&token, leaf);
3943
3944 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3945 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3946 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3947 &token);
3948 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3949 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3950
3951 btrfs_set_token_timespec_sec(leaf, &item->atime,
3952 inode->i_atime.tv_sec, &token);
3953 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3954 inode->i_atime.tv_nsec, &token);
3955
3956 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3957 inode->i_mtime.tv_sec, &token);
3958 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3959 inode->i_mtime.tv_nsec, &token);
3960
3961 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3962 inode->i_ctime.tv_sec, &token);
3963 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3964 inode->i_ctime.tv_nsec, &token);
3965
3966 btrfs_set_token_timespec_sec(leaf, &item->otime,
3967 BTRFS_I(inode)->i_otime.tv_sec, &token);
3968 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3969 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3970
3971 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3972 &token);
3973 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3974 &token);
3975 btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
3976 &token);
3977 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3978 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3979 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3980 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3981 }
3982
3983 /*
3984 * copy everything in the in-memory inode into the btree.
3985 */
3986 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3987 struct btrfs_root *root, struct inode *inode)
3988 {
3989 struct btrfs_inode_item *inode_item;
3990 struct btrfs_path *path;
3991 struct extent_buffer *leaf;
3992 int ret;
3993
3994 path = btrfs_alloc_path();
3995 if (!path)
3996 return -ENOMEM;
3997
3998 path->leave_spinning = 1;
3999 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
4000 1);
4001 if (ret) {
4002 if (ret > 0)
4003 ret = -ENOENT;
4004 goto failed;
4005 }
4006
4007 leaf = path->nodes[0];
4008 inode_item = btrfs_item_ptr(leaf, path->slots[0],
4009 struct btrfs_inode_item);
4010
4011 fill_inode_item(trans, leaf, inode_item, inode);
4012 btrfs_mark_buffer_dirty(leaf);
4013 btrfs_set_inode_last_trans(trans, inode);
4014 ret = 0;
4015 failed:
4016 btrfs_free_path(path);
4017 return ret;
4018 }
4019
4020 /*
4021 * copy everything in the in-memory inode into the btree.
4022 */
4023 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
4024 struct btrfs_root *root, struct inode *inode)
4025 {
4026 struct btrfs_fs_info *fs_info = root->fs_info;
4027 int ret;
4028
4029 /*
4030 * If the inode is a free space inode, we can deadlock during commit
4031 * if we put it into the delayed code.
4032 *
4033 * The data relocation inode should also be directly updated
4034 * without delay
4035 */
4036 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
4037 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4038 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4039 btrfs_update_root_times(trans, root);
4040
4041 ret = btrfs_delayed_update_inode(trans, root, inode);
4042 if (!ret)
4043 btrfs_set_inode_last_trans(trans, inode);
4044 return ret;
4045 }
4046
4047 return btrfs_update_inode_item(trans, root, inode);
4048 }
4049
4050 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4051 struct btrfs_root *root,
4052 struct inode *inode)
4053 {
4054 int ret;
4055
4056 ret = btrfs_update_inode(trans, root, inode);
4057 if (ret == -ENOSPC)
4058 return btrfs_update_inode_item(trans, root, inode);
4059 return ret;
4060 }
4061
4062 /*
4063 * unlink helper that gets used here in inode.c and in the tree logging
4064 * recovery code. It remove a link in a directory with a given name, and
4065 * also drops the back refs in the inode to the directory
4066 */
4067 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4068 struct btrfs_root *root,
4069 struct btrfs_inode *dir,
4070 struct btrfs_inode *inode,
4071 const char *name, int name_len)
4072 {
4073 struct btrfs_fs_info *fs_info = root->fs_info;
4074 struct btrfs_path *path;
4075 int ret = 0;
4076 struct btrfs_dir_item *di;
4077 u64 index;
4078 u64 ino = btrfs_ino(inode);
4079 u64 dir_ino = btrfs_ino(dir);
4080
4081 path = btrfs_alloc_path();
4082 if (!path) {
4083 ret = -ENOMEM;
4084 goto out;
4085 }
4086
4087 path->leave_spinning = 1;
4088 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4089 name, name_len, -1);
4090 if (IS_ERR_OR_NULL(di)) {
4091 ret = di ? PTR_ERR(di) : -ENOENT;
4092 goto err;
4093 }
4094 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4095 if (ret)
4096 goto err;
4097 btrfs_release_path(path);
4098
4099 /*
4100 * If we don't have dir index, we have to get it by looking up
4101 * the inode ref, since we get the inode ref, remove it directly,
4102 * it is unnecessary to do delayed deletion.
4103 *
4104 * But if we have dir index, needn't search inode ref to get it.
4105 * Since the inode ref is close to the inode item, it is better
4106 * that we delay to delete it, and just do this deletion when
4107 * we update the inode item.
4108 */
4109 if (inode->dir_index) {
4110 ret = btrfs_delayed_delete_inode_ref(inode);
4111 if (!ret) {
4112 index = inode->dir_index;
4113 goto skip_backref;
4114 }
4115 }
4116
4117 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4118 dir_ino, &index);
4119 if (ret) {
4120 btrfs_info(fs_info,
4121 "failed to delete reference to %.*s, inode %llu parent %llu",
4122 name_len, name, ino, dir_ino);
4123 btrfs_abort_transaction(trans, ret);
4124 goto err;
4125 }
4126 skip_backref:
4127 ret = btrfs_delete_delayed_dir_index(trans, dir, index);
4128 if (ret) {
4129 btrfs_abort_transaction(trans, ret);
4130 goto err;
4131 }
4132
4133 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4134 dir_ino);
4135 if (ret != 0 && ret != -ENOENT) {
4136 btrfs_abort_transaction(trans, ret);
4137 goto err;
4138 }
4139
4140 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4141 index);
4142 if (ret == -ENOENT)
4143 ret = 0;
4144 else if (ret)
4145 btrfs_abort_transaction(trans, ret);
4146
4147 /*
4148 * If we have a pending delayed iput we could end up with the final iput
4149 * being run in btrfs-cleaner context. If we have enough of these built
4150 * up we can end up burning a lot of time in btrfs-cleaner without any
4151 * way to throttle the unlinks. Since we're currently holding a ref on
4152 * the inode we can run the delayed iput here without any issues as the
4153 * final iput won't be done until after we drop the ref we're currently
4154 * holding.
4155 */
4156 btrfs_run_delayed_iput(fs_info, inode);
4157 err:
4158 btrfs_free_path(path);
4159 if (ret)
4160 goto out;
4161
4162 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4163 inode_inc_iversion(&inode->vfs_inode);
4164 inode_inc_iversion(&dir->vfs_inode);
4165 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4166 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4167 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4168 out:
4169 return ret;
4170 }
4171
4172 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4173 struct btrfs_root *root,
4174 struct btrfs_inode *dir, struct btrfs_inode *inode,
4175 const char *name, int name_len)
4176 {
4177 int ret;
4178 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4179 if (!ret) {
4180 drop_nlink(&inode->vfs_inode);
4181 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4182 }
4183 return ret;
4184 }
4185
4186 /*
4187 * helper to start transaction for unlink and rmdir.
4188 *
4189 * unlink and rmdir are special in btrfs, they do not always free space, so
4190 * if we cannot make our reservations the normal way try and see if there is
4191 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4192 * allow the unlink to occur.
4193 */
4194 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4195 {
4196 struct btrfs_root *root = BTRFS_I(dir)->root;
4197
4198 /*
4199 * 1 for the possible orphan item
4200 * 1 for the dir item
4201 * 1 for the dir index
4202 * 1 for the inode ref
4203 * 1 for the inode
4204 */
4205 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4206 }
4207
4208 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4209 {
4210 struct btrfs_root *root = BTRFS_I(dir)->root;
4211 struct btrfs_trans_handle *trans;
4212 struct inode *inode = d_inode(dentry);
4213 int ret;
4214
4215 trans = __unlink_start_trans(dir);
4216 if (IS_ERR(trans))
4217 return PTR_ERR(trans);
4218
4219 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4220 0);
4221
4222 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4223 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4224 dentry->d_name.len);
4225 if (ret)
4226 goto out;
4227
4228 if (inode->i_nlink == 0) {
4229 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4230 if (ret)
4231 goto out;
4232 }
4233
4234 out:
4235 btrfs_end_transaction(trans);
4236 btrfs_btree_balance_dirty(root->fs_info);
4237 return ret;
4238 }
4239
4240 static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4241 struct inode *dir, struct dentry *dentry)
4242 {
4243 struct btrfs_root *root = BTRFS_I(dir)->root;
4244 struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
4245 struct btrfs_path *path;
4246 struct extent_buffer *leaf;
4247 struct btrfs_dir_item *di;
4248 struct btrfs_key key;
4249 const char *name = dentry->d_name.name;
4250 int name_len = dentry->d_name.len;
4251 u64 index;
4252 int ret;
4253 u64 objectid;
4254 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4255
4256 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
4257 objectid = inode->root->root_key.objectid;
4258 } else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
4259 objectid = inode->location.objectid;
4260 } else {
4261 WARN_ON(1);
4262 return -EINVAL;
4263 }
4264
4265 path = btrfs_alloc_path();
4266 if (!path)
4267 return -ENOMEM;
4268
4269 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4270 name, name_len, -1);
4271 if (IS_ERR_OR_NULL(di)) {
4272 ret = di ? PTR_ERR(di) : -ENOENT;
4273 goto out;
4274 }
4275
4276 leaf = path->nodes[0];
4277 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4278 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4279 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4280 if (ret) {
4281 btrfs_abort_transaction(trans, ret);
4282 goto out;
4283 }
4284 btrfs_release_path(path);
4285
4286 /*
4287 * This is a placeholder inode for a subvolume we didn't have a
4288 * reference to at the time of the snapshot creation. In the meantime
4289 * we could have renamed the real subvol link into our snapshot, so
4290 * depending on btrfs_del_root_ref to return -ENOENT here is incorret.
4291 * Instead simply lookup the dir_index_item for this entry so we can
4292 * remove it. Otherwise we know we have a ref to the root and we can
4293 * call btrfs_del_root_ref, and it _shouldn't_ fail.
4294 */
4295 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
4296 di = btrfs_search_dir_index_item(root, path, dir_ino,
4297 name, name_len);
4298 if (IS_ERR_OR_NULL(di)) {
4299 if (!di)
4300 ret = -ENOENT;
4301 else
4302 ret = PTR_ERR(di);
4303 btrfs_abort_transaction(trans, ret);
4304 goto out;
4305 }
4306
4307 leaf = path->nodes[0];
4308 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4309 index = key.offset;
4310 btrfs_release_path(path);
4311 } else {
4312 ret = btrfs_del_root_ref(trans, objectid,
4313 root->root_key.objectid, dir_ino,
4314 &index, name, name_len);
4315 if (ret) {
4316 btrfs_abort_transaction(trans, ret);
4317 goto out;
4318 }
4319 }
4320
4321 ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index);
4322 if (ret) {
4323 btrfs_abort_transaction(trans, ret);
4324 goto out;
4325 }
4326
4327 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4328 inode_inc_iversion(dir);
4329 dir->i_mtime = dir->i_ctime = current_time(dir);
4330 ret = btrfs_update_inode_fallback(trans, root, dir);
4331 if (ret)
4332 btrfs_abort_transaction(trans, ret);
4333 out:
4334 btrfs_free_path(path);
4335 return ret;
4336 }
4337
4338 /*
4339 * Helper to check if the subvolume references other subvolumes or if it's
4340 * default.
4341 */
4342 static noinline int may_destroy_subvol(struct btrfs_root *root)
4343 {
4344 struct btrfs_fs_info *fs_info = root->fs_info;
4345 struct btrfs_path *path;
4346 struct btrfs_dir_item *di;
4347 struct btrfs_key key;
4348 u64 dir_id;
4349 int ret;
4350
4351 path = btrfs_alloc_path();
4352 if (!path)
4353 return -ENOMEM;
4354
4355 /* Make sure this root isn't set as the default subvol */
4356 dir_id = btrfs_super_root_dir(fs_info->super_copy);
4357 di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
4358 dir_id, "default", 7, 0);
4359 if (di && !IS_ERR(di)) {
4360 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
4361 if (key.objectid == root->root_key.objectid) {
4362 ret = -EPERM;
4363 btrfs_err(fs_info,
4364 "deleting default subvolume %llu is not allowed",
4365 key.objectid);
4366 goto out;
4367 }
4368 btrfs_release_path(path);
4369 }
4370
4371 key.objectid = root->root_key.objectid;
4372 key.type = BTRFS_ROOT_REF_KEY;
4373 key.offset = (u64)-1;
4374
4375 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
4376 if (ret < 0)
4377 goto out;
4378 BUG_ON(ret == 0);
4379
4380 ret = 0;
4381 if (path->slots[0] > 0) {
4382 path->slots[0]--;
4383 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
4384 if (key.objectid == root->root_key.objectid &&
4385 key.type == BTRFS_ROOT_REF_KEY)
4386 ret = -ENOTEMPTY;
4387 }
4388 out:
4389 btrfs_free_path(path);
4390 return ret;
4391 }
4392
4393 /* Delete all dentries for inodes belonging to the root */
4394 static void btrfs_prune_dentries(struct btrfs_root *root)
4395 {
4396 struct btrfs_fs_info *fs_info = root->fs_info;
4397 struct rb_node *node;
4398 struct rb_node *prev;
4399 struct btrfs_inode *entry;
4400 struct inode *inode;
4401 u64 objectid = 0;
4402
4403 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
4404 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
4405
4406 spin_lock(&root->inode_lock);
4407 again:
4408 node = root->inode_tree.rb_node;
4409 prev = NULL;
4410 while (node) {
4411 prev = node;
4412 entry = rb_entry(node, struct btrfs_inode, rb_node);
4413
4414 if (objectid < btrfs_ino(entry))
4415 node = node->rb_left;
4416 else if (objectid > btrfs_ino(entry))
4417 node = node->rb_right;
4418 else
4419 break;
4420 }
4421 if (!node) {
4422 while (prev) {
4423 entry = rb_entry(prev, struct btrfs_inode, rb_node);
4424 if (objectid <= btrfs_ino(entry)) {
4425 node = prev;
4426 break;
4427 }
4428 prev = rb_next(prev);
4429 }
4430 }
4431 while (node) {
4432 entry = rb_entry(node, struct btrfs_inode, rb_node);
4433 objectid = btrfs_ino(entry) + 1;
4434 inode = igrab(&entry->vfs_inode);
4435 if (inode) {
4436 spin_unlock(&root->inode_lock);
4437 if (atomic_read(&inode->i_count) > 1)
4438 d_prune_aliases(inode);
4439 /*
4440 * btrfs_drop_inode will have it removed from the inode
4441 * cache when its usage count hits zero.
4442 */
4443 iput(inode);
4444 cond_resched();
4445 spin_lock(&root->inode_lock);
4446 goto again;
4447 }
4448
4449 if (cond_resched_lock(&root->inode_lock))
4450 goto again;
4451
4452 node = rb_next(node);
4453 }
4454 spin_unlock(&root->inode_lock);
4455 }
4456
4457 int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
4458 {
4459 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
4460 struct btrfs_root *root = BTRFS_I(dir)->root;
4461 struct inode *inode = d_inode(dentry);
4462 struct btrfs_root *dest = BTRFS_I(inode)->root;
4463 struct btrfs_trans_handle *trans;
4464 struct btrfs_block_rsv block_rsv;
4465 u64 root_flags;
4466 int ret;
4467 int err;
4468
4469 /*
4470 * Don't allow to delete a subvolume with send in progress. This is
4471 * inside the inode lock so the error handling that has to drop the bit
4472 * again is not run concurrently.
4473 */
4474 spin_lock(&dest->root_item_lock);
4475 if (dest->send_in_progress) {
4476 spin_unlock(&dest->root_item_lock);
4477 btrfs_warn(fs_info,
4478 "attempt to delete subvolume %llu during send",
4479 dest->root_key.objectid);
4480 return -EPERM;
4481 }
4482 root_flags = btrfs_root_flags(&dest->root_item);
4483 btrfs_set_root_flags(&dest->root_item,
4484 root_flags | BTRFS_ROOT_SUBVOL_DEAD);
4485 spin_unlock(&dest->root_item_lock);
4486
4487 down_write(&fs_info->subvol_sem);
4488
4489 err = may_destroy_subvol(dest);
4490 if (err)
4491 goto out_up_write;
4492
4493 btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
4494 /*
4495 * One for dir inode,
4496 * two for dir entries,
4497 * two for root ref/backref.
4498 */
4499 err = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
4500 if (err)
4501 goto out_up_write;
4502
4503 trans = btrfs_start_transaction(root, 0);
4504 if (IS_ERR(trans)) {
4505 err = PTR_ERR(trans);
4506 goto out_release;
4507 }
4508 trans->block_rsv = &block_rsv;
4509 trans->bytes_reserved = block_rsv.size;
4510
4511 btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
4512
4513 ret = btrfs_unlink_subvol(trans, dir, dentry);
4514 if (ret) {
4515 err = ret;
4516 btrfs_abort_transaction(trans, ret);
4517 goto out_end_trans;
4518 }
4519
4520 btrfs_record_root_in_trans(trans, dest);
4521
4522 memset(&dest->root_item.drop_progress, 0,
4523 sizeof(dest->root_item.drop_progress));
4524 dest->root_item.drop_level = 0;
4525 btrfs_set_root_refs(&dest->root_item, 0);
4526
4527 if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
4528 ret = btrfs_insert_orphan_item(trans,
4529 fs_info->tree_root,
4530 dest->root_key.objectid);
4531 if (ret) {
4532 btrfs_abort_transaction(trans, ret);
4533 err = ret;
4534 goto out_end_trans;
4535 }
4536 }
4537
4538 ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid,
4539 BTRFS_UUID_KEY_SUBVOL,
4540 dest->root_key.objectid);
4541 if (ret && ret != -ENOENT) {
4542 btrfs_abort_transaction(trans, ret);
4543 err = ret;
4544 goto out_end_trans;
4545 }
4546 if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
4547 ret = btrfs_uuid_tree_remove(trans,
4548 dest->root_item.received_uuid,
4549 BTRFS_UUID_KEY_RECEIVED_SUBVOL,
4550 dest->root_key.objectid);
4551 if (ret && ret != -ENOENT) {
4552 btrfs_abort_transaction(trans, ret);
4553 err = ret;
4554 goto out_end_trans;
4555 }
4556 }
4557
4558 out_end_trans:
4559 trans->block_rsv = NULL;
4560 trans->bytes_reserved = 0;
4561 ret = btrfs_end_transaction(trans);
4562 if (ret && !err)
4563 err = ret;
4564 inode->i_flags |= S_DEAD;
4565 out_release:
4566 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
4567 out_up_write:
4568 up_write(&fs_info->subvol_sem);
4569 if (err) {
4570 spin_lock(&dest->root_item_lock);
4571 root_flags = btrfs_root_flags(&dest->root_item);
4572 btrfs_set_root_flags(&dest->root_item,
4573 root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
4574 spin_unlock(&dest->root_item_lock);
4575 } else {
4576 d_invalidate(dentry);
4577 btrfs_prune_dentries(dest);
4578 ASSERT(dest->send_in_progress == 0);
4579
4580 /* the last ref */
4581 if (dest->ino_cache_inode) {
4582 iput(dest->ino_cache_inode);
4583 dest->ino_cache_inode = NULL;
4584 }
4585 }
4586
4587 return err;
4588 }
4589
4590 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4591 {
4592 struct inode *inode = d_inode(dentry);
4593 int err = 0;
4594 struct btrfs_root *root = BTRFS_I(dir)->root;
4595 struct btrfs_trans_handle *trans;
4596 u64 last_unlink_trans;
4597
4598 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4599 return -ENOTEMPTY;
4600 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4601 return btrfs_delete_subvolume(dir, dentry);
4602
4603 trans = __unlink_start_trans(dir);
4604 if (IS_ERR(trans))
4605 return PTR_ERR(trans);
4606
4607 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4608 err = btrfs_unlink_subvol(trans, dir, dentry);
4609 goto out;
4610 }
4611
4612 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4613 if (err)
4614 goto out;
4615
4616 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4617
4618 /* now the directory is empty */
4619 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4620 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4621 dentry->d_name.len);
4622 if (!err) {
4623 btrfs_i_size_write(BTRFS_I(inode), 0);
4624 /*
4625 * Propagate the last_unlink_trans value of the deleted dir to
4626 * its parent directory. This is to prevent an unrecoverable
4627 * log tree in the case we do something like this:
4628 * 1) create dir foo
4629 * 2) create snapshot under dir foo
4630 * 3) delete the snapshot
4631 * 4) rmdir foo
4632 * 5) mkdir foo
4633 * 6) fsync foo or some file inside foo
4634 */
4635 if (last_unlink_trans >= trans->transid)
4636 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4637 }
4638 out:
4639 btrfs_end_transaction(trans);
4640 btrfs_btree_balance_dirty(root->fs_info);
4641
4642 return err;
4643 }
4644
4645 /*
4646 * Return this if we need to call truncate_block for the last bit of the
4647 * truncate.
4648 */
4649 #define NEED_TRUNCATE_BLOCK 1
4650
4651 /*
4652 * this can truncate away extent items, csum items and directory items.
4653 * It starts at a high offset and removes keys until it can't find
4654 * any higher than new_size
4655 *
4656 * csum items that cross the new i_size are truncated to the new size
4657 * as well.
4658 *
4659 * min_type is the minimum key type to truncate down to. If set to 0, this
4660 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4661 */
4662 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4663 struct btrfs_root *root,
4664 struct inode *inode,
4665 u64 new_size, u32 min_type)
4666 {
4667 struct btrfs_fs_info *fs_info = root->fs_info;
4668 struct btrfs_path *path;
4669 struct extent_buffer *leaf;
4670 struct btrfs_file_extent_item *fi;
4671 struct btrfs_key key;
4672 struct btrfs_key found_key;
4673 u64 extent_start = 0;
4674 u64 extent_num_bytes = 0;
4675 u64 extent_offset = 0;
4676 u64 item_end = 0;
4677 u64 last_size = new_size;
4678 u32 found_type = (u8)-1;
4679 int found_extent;
4680 int del_item;
4681 int pending_del_nr = 0;
4682 int pending_del_slot = 0;
4683 int extent_type = -1;
4684 int ret;
4685 u64 ino = btrfs_ino(BTRFS_I(inode));
4686 u64 bytes_deleted = 0;
4687 bool be_nice = false;
4688 bool should_throttle = false;
4689
4690 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4691
4692 /*
4693 * for non-free space inodes and ref cows, we want to back off from
4694 * time to time
4695 */
4696 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4697 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4698 be_nice = true;
4699
4700 path = btrfs_alloc_path();
4701 if (!path)
4702 return -ENOMEM;
4703 path->reada = READA_BACK;
4704
4705 /*
4706 * We want to drop from the next block forward in case this new size is
4707 * not block aligned since we will be keeping the last block of the
4708 * extent just the way it is.
4709 */
4710 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4711 root == fs_info->tree_root)
4712 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4713 fs_info->sectorsize),
4714 (u64)-1, 0);
4715
4716 /*
4717 * This function is also used to drop the items in the log tree before
4718 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4719 * it is used to drop the logged items. So we shouldn't kill the delayed
4720 * items.
4721 */
4722 if (min_type == 0 && root == BTRFS_I(inode)->root)
4723 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4724
4725 key.objectid = ino;
4726 key.offset = (u64)-1;
4727 key.type = (u8)-1;
4728
4729 search_again:
4730 /*
4731 * with a 16K leaf size and 128MB extents, you can actually queue
4732 * up a huge file in a single leaf. Most of the time that
4733 * bytes_deleted is > 0, it will be huge by the time we get here
4734 */
4735 if (be_nice && bytes_deleted > SZ_32M &&
4736 btrfs_should_end_transaction(trans)) {
4737 ret = -EAGAIN;
4738 goto out;
4739 }
4740
4741 path->leave_spinning = 1;
4742 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4743 if (ret < 0)
4744 goto out;
4745
4746 if (ret > 0) {
4747 ret = 0;
4748 /* there are no items in the tree for us to truncate, we're
4749 * done
4750 */
4751 if (path->slots[0] == 0)
4752 goto out;
4753 path->slots[0]--;
4754 }
4755
4756 while (1) {
4757 fi = NULL;
4758 leaf = path->nodes[0];
4759 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4760 found_type = found_key.type;
4761
4762 if (found_key.objectid != ino)
4763 break;
4764
4765 if (found_type < min_type)
4766 break;
4767
4768 item_end = found_key.offset;
4769 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4770 fi = btrfs_item_ptr(leaf, path->slots[0],
4771 struct btrfs_file_extent_item);
4772 extent_type = btrfs_file_extent_type(leaf, fi);
4773 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4774 item_end +=
4775 btrfs_file_extent_num_bytes(leaf, fi);
4776
4777 trace_btrfs_truncate_show_fi_regular(
4778 BTRFS_I(inode), leaf, fi,
4779 found_key.offset);
4780 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4781 item_end += btrfs_file_extent_ram_bytes(leaf,
4782 fi);
4783
4784 trace_btrfs_truncate_show_fi_inline(
4785 BTRFS_I(inode), leaf, fi, path->slots[0],
4786 found_key.offset);
4787 }
4788 item_end--;
4789 }
4790 if (found_type > min_type) {
4791 del_item = 1;
4792 } else {
4793 if (item_end < new_size)
4794 break;
4795 if (found_key.offset >= new_size)
4796 del_item = 1;
4797 else
4798 del_item = 0;
4799 }
4800 found_extent = 0;
4801 /* FIXME, shrink the extent if the ref count is only 1 */
4802 if (found_type != BTRFS_EXTENT_DATA_KEY)
4803 goto delete;
4804
4805 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4806 u64 num_dec;
4807 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4808 if (!del_item) {
4809 u64 orig_num_bytes =
4810 btrfs_file_extent_num_bytes(leaf, fi);
4811 extent_num_bytes = ALIGN(new_size -
4812 found_key.offset,
4813 fs_info->sectorsize);
4814 btrfs_set_file_extent_num_bytes(leaf, fi,
4815 extent_num_bytes);
4816 num_dec = (orig_num_bytes -
4817 extent_num_bytes);
4818 if (test_bit(BTRFS_ROOT_REF_COWS,
4819 &root->state) &&
4820 extent_start != 0)
4821 inode_sub_bytes(inode, num_dec);
4822 btrfs_mark_buffer_dirty(leaf);
4823 } else {
4824 extent_num_bytes =
4825 btrfs_file_extent_disk_num_bytes(leaf,
4826 fi);
4827 extent_offset = found_key.offset -
4828 btrfs_file_extent_offset(leaf, fi);
4829
4830 /* FIXME blocksize != 4096 */
4831 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4832 if (extent_start != 0) {
4833 found_extent = 1;
4834 if (test_bit(BTRFS_ROOT_REF_COWS,
4835 &root->state))
4836 inode_sub_bytes(inode, num_dec);
4837 }
4838 }
4839 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4840 /*
4841 * we can't truncate inline items that have had
4842 * special encodings
4843 */
4844 if (!del_item &&
4845 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4846 btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4847 btrfs_file_extent_compression(leaf, fi) == 0) {
4848 u32 size = (u32)(new_size - found_key.offset);
4849
4850 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4851 size = btrfs_file_extent_calc_inline_size(size);
4852 btrfs_truncate_item(path, size, 1);
4853 } else if (!del_item) {
4854 /*
4855 * We have to bail so the last_size is set to
4856 * just before this extent.
4857 */
4858 ret = NEED_TRUNCATE_BLOCK;
4859 break;
4860 }
4861
4862 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4863 inode_sub_bytes(inode, item_end + 1 - new_size);
4864 }
4865 delete:
4866 if (del_item)
4867 last_size = found_key.offset;
4868 else
4869 last_size = new_size;
4870 if (del_item) {
4871 if (!pending_del_nr) {
4872 /* no pending yet, add ourselves */
4873 pending_del_slot = path->slots[0];
4874 pending_del_nr = 1;
4875 } else if (pending_del_nr &&
4876 path->slots[0] + 1 == pending_del_slot) {
4877 /* hop on the pending chunk */
4878 pending_del_nr++;
4879 pending_del_slot = path->slots[0];
4880 } else {
4881 BUG();
4882 }
4883 } else {
4884 break;
4885 }
4886 should_throttle = false;
4887
4888 if (found_extent &&
4889 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4890 root == fs_info->tree_root)) {
4891 struct btrfs_ref ref = { 0 };
4892
4893 btrfs_set_path_blocking(path);
4894 bytes_deleted += extent_num_bytes;
4895
4896 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF,
4897 extent_start, extent_num_bytes, 0);
4898 ref.real_root = root->root_key.objectid;
4899 btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
4900 ino, extent_offset);
4901 ret = btrfs_free_extent(trans, &ref);
4902 if (ret) {
4903 btrfs_abort_transaction(trans, ret);
4904 break;
4905 }
4906 if (be_nice) {
4907 if (btrfs_should_throttle_delayed_refs(trans))
4908 should_throttle = true;
4909 }
4910 }
4911
4912 if (found_type == BTRFS_INODE_ITEM_KEY)
4913 break;
4914
4915 if (path->slots[0] == 0 ||
4916 path->slots[0] != pending_del_slot ||
4917 should_throttle) {
4918 if (pending_del_nr) {
4919 ret = btrfs_del_items(trans, root, path,
4920 pending_del_slot,
4921 pending_del_nr);
4922 if (ret) {
4923 btrfs_abort_transaction(trans, ret);
4924 break;
4925 }
4926 pending_del_nr = 0;
4927 }
4928 btrfs_release_path(path);
4929
4930 /*
4931 * We can generate a lot of delayed refs, so we need to
4932 * throttle every once and a while and make sure we're
4933 * adding enough space to keep up with the work we are
4934 * generating. Since we hold a transaction here we
4935 * can't flush, and we don't want to FLUSH_LIMIT because
4936 * we could have generated too many delayed refs to
4937 * actually allocate, so just bail if we're short and
4938 * let the normal reservation dance happen higher up.
4939 */
4940 if (should_throttle) {
4941 ret = btrfs_delayed_refs_rsv_refill(fs_info,
4942 BTRFS_RESERVE_NO_FLUSH);
4943 if (ret) {
4944 ret = -EAGAIN;
4945 break;
4946 }
4947 }
4948 goto search_again;
4949 } else {
4950 path->slots[0]--;
4951 }
4952 }
4953 out:
4954 if (ret >= 0 && pending_del_nr) {
4955 int err;
4956
4957 err = btrfs_del_items(trans, root, path, pending_del_slot,
4958 pending_del_nr);
4959 if (err) {
4960 btrfs_abort_transaction(trans, err);
4961 ret = err;
4962 }
4963 }
4964 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4965 ASSERT(last_size >= new_size);
4966 if (!ret && last_size > new_size)
4967 last_size = new_size;
4968 btrfs_ordered_update_i_size(inode, last_size, NULL);
4969 }
4970
4971 btrfs_free_path(path);
4972 return ret;
4973 }
4974
4975 /*
4976 * btrfs_truncate_block - read, zero a chunk and write a block
4977 * @inode - inode that we're zeroing
4978 * @from - the offset to start zeroing
4979 * @len - the length to zero, 0 to zero the entire range respective to the
4980 * offset
4981 * @front - zero up to the offset instead of from the offset on
4982 *
4983 * This will find the block for the "from" offset and cow the block and zero the
4984 * part we want to zero. This is used with truncate and hole punching.
4985 */
4986 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4987 int front)
4988 {
4989 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4990 struct address_space *mapping = inode->i_mapping;
4991 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4992 struct btrfs_ordered_extent *ordered;
4993 struct extent_state *cached_state = NULL;
4994 struct extent_changeset *data_reserved = NULL;
4995 char *kaddr;
4996 u32 blocksize = fs_info->sectorsize;
4997 pgoff_t index = from >> PAGE_SHIFT;
4998 unsigned offset = from & (blocksize - 1);
4999 struct page *page;
5000 gfp_t mask = btrfs_alloc_write_mask(mapping);
5001 int ret = 0;
5002 u64 block_start;
5003 u64 block_end;
5004
5005 if (IS_ALIGNED(offset, blocksize) &&
5006 (!len || IS_ALIGNED(len, blocksize)))
5007 goto out;
5008
5009 block_start = round_down(from, blocksize);
5010 block_end = block_start + blocksize - 1;
5011
5012 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
5013 block_start, blocksize);
5014 if (ret)
5015 goto out;
5016
5017 again:
5018 page = find_or_create_page(mapping, index, mask);
5019 if (!page) {
5020 btrfs_delalloc_release_space(inode, data_reserved,
5021 block_start, blocksize, true);
5022 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
5023 ret = -ENOMEM;
5024 goto out;
5025 }
5026
5027 if (!PageUptodate(page)) {
5028 ret = btrfs_readpage(NULL, page);
5029 lock_page(page);
5030 if (page->mapping != mapping) {
5031 unlock_page(page);
5032 put_page(page);
5033 goto again;
5034 }
5035 if (!PageUptodate(page)) {
5036 ret = -EIO;
5037 goto out_unlock;
5038 }
5039 }
5040 wait_on_page_writeback(page);
5041
5042 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
5043 set_page_extent_mapped(page);
5044
5045 ordered = btrfs_lookup_ordered_extent(inode, block_start);
5046 if (ordered) {
5047 unlock_extent_cached(io_tree, block_start, block_end,
5048 &cached_state);
5049 unlock_page(page);
5050 put_page(page);
5051 btrfs_start_ordered_extent(inode, ordered, 1);
5052 btrfs_put_ordered_extent(ordered);
5053 goto again;
5054 }
5055
5056 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
5057 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
5058 0, 0, &cached_state);
5059
5060 ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
5061 &cached_state);
5062 if (ret) {
5063 unlock_extent_cached(io_tree, block_start, block_end,
5064 &cached_state);
5065 goto out_unlock;
5066 }
5067
5068 if (offset != blocksize) {
5069 if (!len)
5070 len = blocksize - offset;
5071 kaddr = kmap(page);
5072 if (front)
5073 memset(kaddr + (block_start - page_offset(page)),
5074 0, offset);
5075 else
5076 memset(kaddr + (block_start - page_offset(page)) + offset,
5077 0, len);
5078 flush_dcache_page(page);
5079 kunmap(page);
5080 }
5081 ClearPageChecked(page);
5082 set_page_dirty(page);
5083 unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
5084
5085 out_unlock:
5086 if (ret)
5087 btrfs_delalloc_release_space(inode, data_reserved, block_start,
5088 blocksize, true);
5089 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
5090 unlock_page(page);
5091 put_page(page);
5092 out:
5093 extent_changeset_free(data_reserved);
5094 return ret;
5095 }
5096
5097 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
5098 u64 offset, u64 len)
5099 {
5100 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5101 struct btrfs_trans_handle *trans;
5102 int ret;
5103
5104 /*
5105 * Still need to make sure the inode looks like it's been updated so
5106 * that any holes get logged if we fsync.
5107 */
5108 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
5109 BTRFS_I(inode)->last_trans = fs_info->generation;
5110 BTRFS_I(inode)->last_sub_trans = root->log_transid;
5111 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
5112 return 0;
5113 }
5114
5115 /*
5116 * 1 - for the one we're dropping
5117 * 1 - for the one we're adding
5118 * 1 - for updating the inode.
5119 */
5120 trans = btrfs_start_transaction(root, 3);
5121 if (IS_ERR(trans))
5122 return PTR_ERR(trans);
5123
5124 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
5125 if (ret) {
5126 btrfs_abort_transaction(trans, ret);
5127 btrfs_end_transaction(trans);
5128 return ret;
5129 }
5130
5131 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
5132 offset, 0, 0, len, 0, len, 0, 0, 0);
5133 if (ret)
5134 btrfs_abort_transaction(trans, ret);
5135 else
5136 btrfs_update_inode(trans, root, inode);
5137 btrfs_end_transaction(trans);
5138 return ret;
5139 }
5140
5141 /*
5142 * This function puts in dummy file extents for the area we're creating a hole
5143 * for. So if we are truncating this file to a larger size we need to insert
5144 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
5145 * the range between oldsize and size
5146 */
5147 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
5148 {
5149 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5150 struct btrfs_root *root = BTRFS_I(inode)->root;
5151 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5152 struct extent_map *em = NULL;
5153 struct extent_state *cached_state = NULL;
5154 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5155 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
5156 u64 block_end = ALIGN(size, fs_info->sectorsize);
5157 u64 last_byte;
5158 u64 cur_offset;
5159 u64 hole_size;
5160 int err = 0;
5161
5162 /*
5163 * If our size started in the middle of a block we need to zero out the
5164 * rest of the block before we expand the i_size, otherwise we could
5165 * expose stale data.
5166 */
5167 err = btrfs_truncate_block(inode, oldsize, 0, 0);
5168 if (err)
5169 return err;
5170
5171 if (size <= hole_start)
5172 return 0;
5173
5174 btrfs_lock_and_flush_ordered_range(io_tree, BTRFS_I(inode), hole_start,
5175 block_end - 1, &cached_state);
5176 cur_offset = hole_start;
5177 while (1) {
5178 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
5179 block_end - cur_offset, 0);
5180 if (IS_ERR(em)) {
5181 err = PTR_ERR(em);
5182 em = NULL;
5183 break;
5184 }
5185 last_byte = min(extent_map_end(em), block_end);
5186 last_byte = ALIGN(last_byte, fs_info->sectorsize);
5187 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
5188 struct extent_map *hole_em;
5189 hole_size = last_byte - cur_offset;
5190
5191 err = maybe_insert_hole(root, inode, cur_offset,
5192 hole_size);
5193 if (err)
5194 break;
5195 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
5196 cur_offset + hole_size - 1, 0);
5197 hole_em = alloc_extent_map();
5198 if (!hole_em) {
5199 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
5200 &BTRFS_I(inode)->runtime_flags);
5201 goto next;
5202 }
5203 hole_em->start = cur_offset;
5204 hole_em->len = hole_size;
5205 hole_em->orig_start = cur_offset;
5206
5207 hole_em->block_start = EXTENT_MAP_HOLE;
5208 hole_em->block_len = 0;
5209 hole_em->orig_block_len = 0;
5210 hole_em->ram_bytes = hole_size;
5211 hole_em->compress_type = BTRFS_COMPRESS_NONE;
5212 hole_em->generation = fs_info->generation;
5213
5214 while (1) {
5215 write_lock(&em_tree->lock);
5216 err = add_extent_mapping(em_tree, hole_em, 1);
5217 write_unlock(&em_tree->lock);
5218 if (err != -EEXIST)
5219 break;
5220 btrfs_drop_extent_cache(BTRFS_I(inode),
5221 cur_offset,
5222 cur_offset +
5223 hole_size - 1, 0);
5224 }
5225 free_extent_map(hole_em);
5226 }
5227 next:
5228 free_extent_map(em);
5229 em = NULL;
5230 cur_offset = last_byte;
5231 if (cur_offset >= block_end)
5232 break;
5233 }
5234 free_extent_map(em);
5235 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
5236 return err;
5237 }
5238
5239 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5240 {
5241 struct btrfs_root *root = BTRFS_I(inode)->root;
5242 struct btrfs_trans_handle *trans;
5243 loff_t oldsize = i_size_read(inode);
5244 loff_t newsize = attr->ia_size;
5245 int mask = attr->ia_valid;
5246 int ret;
5247
5248 /*
5249 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5250 * special case where we need to update the times despite not having
5251 * these flags set. For all other operations the VFS set these flags
5252 * explicitly if it wants a timestamp update.
5253 */
5254 if (newsize != oldsize) {
5255 inode_inc_iversion(inode);
5256 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5257 inode->i_ctime = inode->i_mtime =
5258 current_time(inode);
5259 }
5260
5261 if (newsize > oldsize) {
5262 /*
5263 * Don't do an expanding truncate while snapshotting is ongoing.
5264 * This is to ensure the snapshot captures a fully consistent
5265 * state of this file - if the snapshot captures this expanding
5266 * truncation, it must capture all writes that happened before
5267 * this truncation.
5268 */
5269 btrfs_wait_for_snapshot_creation(root);
5270 ret = btrfs_cont_expand(inode, oldsize, newsize);
5271 if (ret) {
5272 btrfs_end_write_no_snapshotting(root);
5273 return ret;
5274 }
5275
5276 trans = btrfs_start_transaction(root, 1);
5277 if (IS_ERR(trans)) {
5278 btrfs_end_write_no_snapshotting(root);
5279 return PTR_ERR(trans);
5280 }
5281
5282 i_size_write(inode, newsize);
5283 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5284 pagecache_isize_extended(inode, oldsize, newsize);
5285 ret = btrfs_update_inode(trans, root, inode);
5286 btrfs_end_write_no_snapshotting(root);
5287 btrfs_end_transaction(trans);
5288 } else {
5289
5290 /*
5291 * We're truncating a file that used to have good data down to
5292 * zero. Make sure it gets into the ordered flush list so that
5293 * any new writes get down to disk quickly.
5294 */
5295 if (newsize == 0)
5296 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5297 &BTRFS_I(inode)->runtime_flags);
5298
5299 truncate_setsize(inode, newsize);
5300
5301 /* Disable nonlocked read DIO to avoid the endless truncate */
5302 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5303 inode_dio_wait(inode);
5304 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5305
5306 ret = btrfs_truncate(inode, newsize == oldsize);
5307 if (ret && inode->i_nlink) {
5308 int err;
5309
5310 /*
5311 * Truncate failed, so fix up the in-memory size. We
5312 * adjusted disk_i_size down as we removed extents, so
5313 * wait for disk_i_size to be stable and then update the
5314 * in-memory size to match.
5315 */
5316 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5317 if (err)
5318 return err;
5319 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5320 }
5321 }
5322
5323 return ret;
5324 }
5325
5326 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5327 {
5328 struct inode *inode = d_inode(dentry);
5329 struct btrfs_root *root = BTRFS_I(inode)->root;
5330 int err;
5331
5332 if (btrfs_root_readonly(root))
5333 return -EROFS;
5334
5335 err = setattr_prepare(dentry, attr);
5336 if (err)
5337 return err;
5338
5339 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5340 err = btrfs_setsize(inode, attr);
5341 if (err)
5342 return err;
5343 }
5344
5345 if (attr->ia_valid) {
5346 setattr_copy(inode, attr);
5347 inode_inc_iversion(inode);
5348 err = btrfs_dirty_inode(inode);
5349
5350 if (!err && attr->ia_valid & ATTR_MODE)
5351 err = posix_acl_chmod(inode, inode->i_mode);
5352 }
5353
5354 return err;
5355 }
5356
5357 /*
5358 * While truncating the inode pages during eviction, we get the VFS calling
5359 * btrfs_invalidatepage() against each page of the inode. This is slow because
5360 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5361 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5362 * extent_state structures over and over, wasting lots of time.
5363 *
5364 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5365 * those expensive operations on a per page basis and do only the ordered io
5366 * finishing, while we release here the extent_map and extent_state structures,
5367 * without the excessive merging and splitting.
5368 */
5369 static void evict_inode_truncate_pages(struct inode *inode)
5370 {
5371 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5372 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5373 struct rb_node *node;
5374
5375 ASSERT(inode->i_state & I_FREEING);
5376 truncate_inode_pages_final(&inode->i_data);
5377
5378 write_lock(&map_tree->lock);
5379 while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) {
5380 struct extent_map *em;
5381
5382 node = rb_first_cached(&map_tree->map);
5383 em = rb_entry(node, struct extent_map, rb_node);
5384 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5385 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5386 remove_extent_mapping(map_tree, em);
5387 free_extent_map(em);
5388 if (need_resched()) {
5389 write_unlock(&map_tree->lock);
5390 cond_resched();
5391 write_lock(&map_tree->lock);
5392 }
5393 }
5394 write_unlock(&map_tree->lock);
5395
5396 /*
5397 * Keep looping until we have no more ranges in the io tree.
5398 * We can have ongoing bios started by readpages (called from readahead)
5399 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5400 * still in progress (unlocked the pages in the bio but did not yet
5401 * unlocked the ranges in the io tree). Therefore this means some
5402 * ranges can still be locked and eviction started because before
5403 * submitting those bios, which are executed by a separate task (work
5404 * queue kthread), inode references (inode->i_count) were not taken
5405 * (which would be dropped in the end io callback of each bio).
5406 * Therefore here we effectively end up waiting for those bios and
5407 * anyone else holding locked ranges without having bumped the inode's
5408 * reference count - if we don't do it, when they access the inode's
5409 * io_tree to unlock a range it may be too late, leading to an
5410 * use-after-free issue.
5411 */
5412 spin_lock(&io_tree->lock);
5413 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5414 struct extent_state *state;
5415 struct extent_state *cached_state = NULL;
5416 u64 start;
5417 u64 end;
5418 unsigned state_flags;
5419
5420 node = rb_first(&io_tree->state);
5421 state = rb_entry(node, struct extent_state, rb_node);
5422 start = state->start;
5423 end = state->end;
5424 state_flags = state->state;
5425 spin_unlock(&io_tree->lock);
5426
5427 lock_extent_bits(io_tree, start, end, &cached_state);
5428
5429 /*
5430 * If still has DELALLOC flag, the extent didn't reach disk,
5431 * and its reserved space won't be freed by delayed_ref.
5432 * So we need to free its reserved space here.
5433 * (Refer to comment in btrfs_invalidatepage, case 2)
5434 *
5435 * Note, end is the bytenr of last byte, so we need + 1 here.
5436 */
5437 if (state_flags & EXTENT_DELALLOC)
5438 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5439
5440 clear_extent_bit(io_tree, start, end,
5441 EXTENT_LOCKED | EXTENT_DELALLOC |
5442 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
5443 &cached_state);
5444
5445 cond_resched();
5446 spin_lock(&io_tree->lock);
5447 }
5448 spin_unlock(&io_tree->lock);
5449 }
5450
5451 static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
5452 struct btrfs_block_rsv *rsv)
5453 {
5454 struct btrfs_fs_info *fs_info = root->fs_info;
5455 struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
5456 struct btrfs_trans_handle *trans;
5457 u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1);
5458 int ret;
5459
5460 /*
5461 * Eviction should be taking place at some place safe because of our
5462 * delayed iputs. However the normal flushing code will run delayed
5463 * iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock.
5464 *
5465 * We reserve the delayed_refs_extra here again because we can't use
5466 * btrfs_start_transaction(root, 0) for the same deadlocky reason as
5467 * above. We reserve our extra bit here because we generate a ton of
5468 * delayed refs activity by truncating.
5469 *
5470 * If we cannot make our reservation we'll attempt to steal from the
5471 * global reserve, because we really want to be able to free up space.
5472 */
5473 ret = btrfs_block_rsv_refill(root, rsv, rsv->size + delayed_refs_extra,
5474 BTRFS_RESERVE_FLUSH_EVICT);
5475 if (ret) {
5476 /*
5477 * Try to steal from the global reserve if there is space for
5478 * it.
5479 */
5480 if (btrfs_check_space_for_delayed_refs(fs_info) ||
5481 btrfs_block_rsv_migrate(global_rsv, rsv, rsv->size, 0)) {
5482 btrfs_warn(fs_info,
5483 "could not allocate space for delete; will truncate on mount");
5484 return ERR_PTR(-ENOSPC);
5485 }
5486 delayed_refs_extra = 0;
5487 }
5488
5489 trans = btrfs_join_transaction(root);
5490 if (IS_ERR(trans))
5491 return trans;
5492
5493 if (delayed_refs_extra) {
5494 trans->block_rsv = &fs_info->trans_block_rsv;
5495 trans->bytes_reserved = delayed_refs_extra;
5496 btrfs_block_rsv_migrate(rsv, trans->block_rsv,
5497 delayed_refs_extra, 1);
5498 }
5499 return trans;
5500 }
5501
5502 void btrfs_evict_inode(struct inode *inode)
5503 {
5504 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5505 struct btrfs_trans_handle *trans;
5506 struct btrfs_root *root = BTRFS_I(inode)->root;
5507 struct btrfs_block_rsv *rsv;
5508 int ret;
5509
5510 trace_btrfs_inode_evict(inode);
5511
5512 if (!root) {
5513 clear_inode(inode);
5514 return;
5515 }
5516
5517 evict_inode_truncate_pages(inode);
5518
5519 if (inode->i_nlink &&
5520 ((btrfs_root_refs(&root->root_item) != 0 &&
5521 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5522 btrfs_is_free_space_inode(BTRFS_I(inode))))
5523 goto no_delete;
5524
5525 if (is_bad_inode(inode))
5526 goto no_delete;
5527
5528 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5529
5530 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
5531 goto no_delete;
5532
5533 if (inode->i_nlink > 0) {
5534 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5535 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5536 goto no_delete;
5537 }
5538
5539 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5540 if (ret)
5541 goto no_delete;
5542
5543 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5544 if (!rsv)
5545 goto no_delete;
5546 rsv->size = btrfs_calc_metadata_size(fs_info, 1);
5547 rsv->failfast = 1;
5548
5549 btrfs_i_size_write(BTRFS_I(inode), 0);
5550
5551 while (1) {
5552 trans = evict_refill_and_join(root, rsv);
5553 if (IS_ERR(trans))
5554 goto free_rsv;
5555
5556 trans->block_rsv = rsv;
5557
5558 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5559 trans->block_rsv = &fs_info->trans_block_rsv;
5560 btrfs_end_transaction(trans);
5561 btrfs_btree_balance_dirty(fs_info);
5562 if (ret && ret != -ENOSPC && ret != -EAGAIN)
5563 goto free_rsv;
5564 else if (!ret)
5565 break;
5566 }
5567
5568 /*
5569 * Errors here aren't a big deal, it just means we leave orphan items in
5570 * the tree. They will be cleaned up on the next mount. If the inode
5571 * number gets reused, cleanup deletes the orphan item without doing
5572 * anything, and unlink reuses the existing orphan item.
5573 *
5574 * If it turns out that we are dropping too many of these, we might want
5575 * to add a mechanism for retrying these after a commit.
5576 */
5577 trans = evict_refill_and_join(root, rsv);
5578 if (!IS_ERR(trans)) {
5579 trans->block_rsv = rsv;
5580 btrfs_orphan_del(trans, BTRFS_I(inode));
5581 trans->block_rsv = &fs_info->trans_block_rsv;
5582 btrfs_end_transaction(trans);
5583 }
5584
5585 if (!(root == fs_info->tree_root ||
5586 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5587 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5588
5589 free_rsv:
5590 btrfs_free_block_rsv(fs_info, rsv);
5591 no_delete:
5592 /*
5593 * If we didn't successfully delete, the orphan item will still be in
5594 * the tree and we'll retry on the next mount. Again, we might also want
5595 * to retry these periodically in the future.
5596 */
5597 btrfs_remove_delayed_node(BTRFS_I(inode));
5598 clear_inode(inode);
5599 }
5600
5601 /*
5602 * Return the key found in the dir entry in the location pointer, fill @type
5603 * with BTRFS_FT_*, and return 0.
5604 *
5605 * If no dir entries were found, returns -ENOENT.
5606 * If found a corrupted location in dir entry, returns -EUCLEAN.
5607 */
5608 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5609 struct btrfs_key *location, u8 *type)
5610 {
5611 const char *name = dentry->d_name.name;
5612 int namelen = dentry->d_name.len;
5613 struct btrfs_dir_item *di;
5614 struct btrfs_path *path;
5615 struct btrfs_root *root = BTRFS_I(dir)->root;
5616 int ret = 0;
5617
5618 path = btrfs_alloc_path();
5619 if (!path)
5620 return -ENOMEM;
5621
5622 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5623 name, namelen, 0);
5624 if (IS_ERR_OR_NULL(di)) {
5625 ret = di ? PTR_ERR(di) : -ENOENT;
5626 goto out;
5627 }
5628
5629 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5630 if (location->type != BTRFS_INODE_ITEM_KEY &&
5631 location->type != BTRFS_ROOT_ITEM_KEY) {
5632 ret = -EUCLEAN;
5633 btrfs_warn(root->fs_info,
5634 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5635 __func__, name, btrfs_ino(BTRFS_I(dir)),
5636 location->objectid, location->type, location->offset);
5637 }
5638 if (!ret)
5639 *type = btrfs_dir_type(path->nodes[0], di);
5640 out:
5641 btrfs_free_path(path);
5642 return ret;
5643 }
5644
5645 /*
5646 * when we hit a tree root in a directory, the btrfs part of the inode
5647 * needs to be changed to reflect the root directory of the tree root. This
5648 * is kind of like crossing a mount point.
5649 */
5650 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5651 struct inode *dir,
5652 struct dentry *dentry,
5653 struct btrfs_key *location,
5654 struct btrfs_root **sub_root)
5655 {
5656 struct btrfs_path *path;
5657 struct btrfs_root *new_root;
5658 struct btrfs_root_ref *ref;
5659 struct extent_buffer *leaf;
5660 struct btrfs_key key;
5661 int ret;
5662 int err = 0;
5663
5664 path = btrfs_alloc_path();
5665 if (!path) {
5666 err = -ENOMEM;
5667 goto out;
5668 }
5669
5670 err = -ENOENT;
5671 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5672 key.type = BTRFS_ROOT_REF_KEY;
5673 key.offset = location->objectid;
5674
5675 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5676 if (ret) {
5677 if (ret < 0)
5678 err = ret;
5679 goto out;
5680 }
5681
5682 leaf = path->nodes[0];
5683 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5684 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5685 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5686 goto out;
5687
5688 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5689 (unsigned long)(ref + 1),
5690 dentry->d_name.len);
5691 if (ret)
5692 goto out;
5693
5694 btrfs_release_path(path);
5695
5696 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5697 if (IS_ERR(new_root)) {
5698 err = PTR_ERR(new_root);
5699 goto out;
5700 }
5701
5702 *sub_root = new_root;
5703 location->objectid = btrfs_root_dirid(&new_root->root_item);
5704 location->type = BTRFS_INODE_ITEM_KEY;
5705 location->offset = 0;
5706 err = 0;
5707 out:
5708 btrfs_free_path(path);
5709 return err;
5710 }
5711
5712 static void inode_tree_add(struct inode *inode)
5713 {
5714 struct btrfs_root *root = BTRFS_I(inode)->root;
5715 struct btrfs_inode *entry;
5716 struct rb_node **p;
5717 struct rb_node *parent;
5718 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5719 u64 ino = btrfs_ino(BTRFS_I(inode));
5720
5721 if (inode_unhashed(inode))
5722 return;
5723 parent = NULL;
5724 spin_lock(&root->inode_lock);
5725 p = &root->inode_tree.rb_node;
5726 while (*p) {
5727 parent = *p;
5728 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5729
5730 if (ino < btrfs_ino(entry))
5731 p = &parent->rb_left;
5732 else if (ino > btrfs_ino(entry))
5733 p = &parent->rb_right;
5734 else {
5735 WARN_ON(!(entry->vfs_inode.i_state &
5736 (I_WILL_FREE | I_FREEING)));
5737 rb_replace_node(parent, new, &root->inode_tree);
5738 RB_CLEAR_NODE(parent);
5739 spin_unlock(&root->inode_lock);
5740 return;
5741 }
5742 }
5743 rb_link_node(new, parent, p);
5744 rb_insert_color(new, &root->inode_tree);
5745 spin_unlock(&root->inode_lock);
5746 }
5747
5748 static void inode_tree_del(struct inode *inode)
5749 {
5750 struct btrfs_root *root = BTRFS_I(inode)->root;
5751 int empty = 0;
5752
5753 spin_lock(&root->inode_lock);
5754 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5755 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5756 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5757 empty = RB_EMPTY_ROOT(&root->inode_tree);
5758 }
5759 spin_unlock(&root->inode_lock);
5760
5761 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5762 spin_lock(&root->inode_lock);
5763 empty = RB_EMPTY_ROOT(&root->inode_tree);
5764 spin_unlock(&root->inode_lock);
5765 if (empty)
5766 btrfs_add_dead_root(root);
5767 }
5768 }
5769
5770
5771 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5772 {
5773 struct btrfs_iget_args *args = p;
5774 inode->i_ino = args->location->objectid;
5775 memcpy(&BTRFS_I(inode)->location, args->location,
5776 sizeof(*args->location));
5777 BTRFS_I(inode)->root = args->root;
5778 return 0;
5779 }
5780
5781 static int btrfs_find_actor(struct inode *inode, void *opaque)
5782 {
5783 struct btrfs_iget_args *args = opaque;
5784 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5785 args->root == BTRFS_I(inode)->root;
5786 }
5787
5788 static struct inode *btrfs_iget_locked(struct super_block *s,
5789 struct btrfs_key *location,
5790 struct btrfs_root *root)
5791 {
5792 struct inode *inode;
5793 struct btrfs_iget_args args;
5794 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5795
5796 args.location = location;
5797 args.root = root;
5798
5799 inode = iget5_locked(s, hashval, btrfs_find_actor,
5800 btrfs_init_locked_inode,
5801 (void *)&args);
5802 return inode;
5803 }
5804
5805 /*
5806 * Get an inode object given its location and corresponding root.
5807 * Path can be preallocated to prevent recursing back to iget through
5808 * allocator. NULL is also valid but may require an additional allocation
5809 * later.
5810 */
5811 struct inode *btrfs_iget_path(struct super_block *s, struct btrfs_key *location,
5812 struct btrfs_root *root, struct btrfs_path *path)
5813 {
5814 struct inode *inode;
5815
5816 inode = btrfs_iget_locked(s, location, root);
5817 if (!inode)
5818 return ERR_PTR(-ENOMEM);
5819
5820 if (inode->i_state & I_NEW) {
5821 int ret;
5822
5823 ret = btrfs_read_locked_inode(inode, path);
5824 if (!ret) {
5825 inode_tree_add(inode);
5826 unlock_new_inode(inode);
5827 } else {
5828 iget_failed(inode);
5829 /*
5830 * ret > 0 can come from btrfs_search_slot called by
5831 * btrfs_read_locked_inode, this means the inode item
5832 * was not found.
5833 */
5834 if (ret > 0)
5835 ret = -ENOENT;
5836 inode = ERR_PTR(ret);
5837 }
5838 }
5839
5840 return inode;
5841 }
5842
5843 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5844 struct btrfs_root *root)
5845 {
5846 return btrfs_iget_path(s, location, root, NULL);
5847 }
5848
5849 static struct inode *new_simple_dir(struct super_block *s,
5850 struct btrfs_key *key,
5851 struct btrfs_root *root)
5852 {
5853 struct inode *inode = new_inode(s);
5854
5855 if (!inode)
5856 return ERR_PTR(-ENOMEM);
5857
5858 BTRFS_I(inode)->root = root;
5859 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5860 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5861
5862 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5863 inode->i_op = &btrfs_dir_ro_inode_operations;
5864 inode->i_opflags &= ~IOP_XATTR;
5865 inode->i_fop = &simple_dir_operations;
5866 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5867 inode->i_mtime = current_time(inode);
5868 inode->i_atime = inode->i_mtime;
5869 inode->i_ctime = inode->i_mtime;
5870 BTRFS_I(inode)->i_otime = inode->i_mtime;
5871
5872 return inode;
5873 }
5874
5875 static inline u8 btrfs_inode_type(struct inode *inode)
5876 {
5877 /*
5878 * Compile-time asserts that generic FT_* types still match
5879 * BTRFS_FT_* types
5880 */
5881 BUILD_BUG_ON(BTRFS_FT_UNKNOWN != FT_UNKNOWN);
5882 BUILD_BUG_ON(BTRFS_FT_REG_FILE != FT_REG_FILE);
5883 BUILD_BUG_ON(BTRFS_FT_DIR != FT_DIR);
5884 BUILD_BUG_ON(BTRFS_FT_CHRDEV != FT_CHRDEV);
5885 BUILD_BUG_ON(BTRFS_FT_BLKDEV != FT_BLKDEV);
5886 BUILD_BUG_ON(BTRFS_FT_FIFO != FT_FIFO);
5887 BUILD_BUG_ON(BTRFS_FT_SOCK != FT_SOCK);
5888 BUILD_BUG_ON(BTRFS_FT_SYMLINK != FT_SYMLINK);
5889
5890 return fs_umode_to_ftype(inode->i_mode);
5891 }
5892
5893 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5894 {
5895 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5896 struct inode *inode;
5897 struct btrfs_root *root = BTRFS_I(dir)->root;
5898 struct btrfs_root *sub_root = root;
5899 struct btrfs_key location;
5900 u8 di_type = 0;
5901 int index;
5902 int ret = 0;
5903
5904 if (dentry->d_name.len > BTRFS_NAME_LEN)
5905 return ERR_PTR(-ENAMETOOLONG);
5906
5907 ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
5908 if (ret < 0)
5909 return ERR_PTR(ret);
5910
5911 if (location.type == BTRFS_INODE_ITEM_KEY) {
5912 inode = btrfs_iget(dir->i_sb, &location, root);
5913 if (IS_ERR(inode))
5914 return inode;
5915
5916 /* Do extra check against inode mode with di_type */
5917 if (btrfs_inode_type(inode) != di_type) {
5918 btrfs_crit(fs_info,
5919 "inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
5920 inode->i_mode, btrfs_inode_type(inode),
5921 di_type);
5922 iput(inode);
5923 return ERR_PTR(-EUCLEAN);
5924 }
5925 return inode;
5926 }
5927
5928 index = srcu_read_lock(&fs_info->subvol_srcu);
5929 ret = fixup_tree_root_location(fs_info, dir, dentry,
5930 &location, &sub_root);
5931 if (ret < 0) {
5932 if (ret != -ENOENT)
5933 inode = ERR_PTR(ret);
5934 else
5935 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5936 } else {
5937 inode = btrfs_iget(dir->i_sb, &location, sub_root);
5938 }
5939 srcu_read_unlock(&fs_info->subvol_srcu, index);
5940
5941 if (!IS_ERR(inode) && root != sub_root) {
5942 down_read(&fs_info->cleanup_work_sem);
5943 if (!sb_rdonly(inode->i_sb))
5944 ret = btrfs_orphan_cleanup(sub_root);
5945 up_read(&fs_info->cleanup_work_sem);
5946 if (ret) {
5947 iput(inode);
5948 inode = ERR_PTR(ret);
5949 }
5950 }
5951
5952 return inode;
5953 }
5954
5955 static int btrfs_dentry_delete(const struct dentry *dentry)
5956 {
5957 struct btrfs_root *root;
5958 struct inode *inode = d_inode(dentry);
5959
5960 if (!inode && !IS_ROOT(dentry))
5961 inode = d_inode(dentry->d_parent);
5962
5963 if (inode) {
5964 root = BTRFS_I(inode)->root;
5965 if (btrfs_root_refs(&root->root_item) == 0)
5966 return 1;
5967
5968 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5969 return 1;
5970 }
5971 return 0;
5972 }
5973
5974 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5975 unsigned int flags)
5976 {
5977 struct inode *inode = btrfs_lookup_dentry(dir, dentry);
5978
5979 if (inode == ERR_PTR(-ENOENT))
5980 inode = NULL;
5981 return d_splice_alias(inode, dentry);
5982 }
5983
5984 /*
5985 * All this infrastructure exists because dir_emit can fault, and we are holding
5986 * the tree lock when doing readdir. For now just allocate a buffer and copy
5987 * our information into that, and then dir_emit from the buffer. This is
5988 * similar to what NFS does, only we don't keep the buffer around in pagecache
5989 * because I'm afraid I'll mess that up. Long term we need to make filldir do
5990 * copy_to_user_inatomic so we don't have to worry about page faulting under the
5991 * tree lock.
5992 */
5993 static int btrfs_opendir(struct inode *inode, struct file *file)
5994 {
5995 struct btrfs_file_private *private;
5996
5997 private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5998 if (!private)
5999 return -ENOMEM;
6000 private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
6001 if (!private->filldir_buf) {
6002 kfree(private);
6003 return -ENOMEM;
6004 }
6005 file->private_data = private;
6006 return 0;
6007 }
6008
6009 struct dir_entry {
6010 u64 ino;
6011 u64 offset;
6012 unsigned type;
6013 int name_len;
6014 };
6015
6016 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
6017 {
6018 while (entries--) {
6019 struct dir_entry *entry = addr;
6020 char *name = (char *)(entry + 1);
6021
6022 ctx->pos = get_unaligned(&entry->offset);
6023 if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
6024 get_unaligned(&entry->ino),
6025 get_unaligned(&entry->type)))
6026 return 1;
6027 addr += sizeof(struct dir_entry) +
6028 get_unaligned(&entry->name_len);
6029 ctx->pos++;
6030 }
6031 return 0;
6032 }
6033
6034 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
6035 {
6036 struct inode *inode = file_inode(file);
6037 struct btrfs_root *root = BTRFS_I(inode)->root;
6038 struct btrfs_file_private *private = file->private_data;
6039 struct btrfs_dir_item *di;
6040 struct btrfs_key key;
6041 struct btrfs_key found_key;
6042 struct btrfs_path *path;
6043 void *addr;
6044 struct list_head ins_list;
6045 struct list_head del_list;
6046 int ret;
6047 struct extent_buffer *leaf;
6048 int slot;
6049 char *name_ptr;
6050 int name_len;
6051 int entries = 0;
6052 int total_len = 0;
6053 bool put = false;
6054 struct btrfs_key location;
6055
6056 if (!dir_emit_dots(file, ctx))
6057 return 0;
6058
6059 path = btrfs_alloc_path();
6060 if (!path)
6061 return -ENOMEM;
6062
6063 addr = private->filldir_buf;
6064 path->reada = READA_FORWARD;
6065
6066 INIT_LIST_HEAD(&ins_list);
6067 INIT_LIST_HEAD(&del_list);
6068 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
6069
6070 again:
6071 key.type = BTRFS_DIR_INDEX_KEY;
6072 key.offset = ctx->pos;
6073 key.objectid = btrfs_ino(BTRFS_I(inode));
6074
6075 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6076 if (ret < 0)
6077 goto err;
6078
6079 while (1) {
6080 struct dir_entry *entry;
6081
6082 leaf = path->nodes[0];
6083 slot = path->slots[0];
6084 if (slot >= btrfs_header_nritems(leaf)) {
6085 ret = btrfs_next_leaf(root, path);
6086 if (ret < 0)
6087 goto err;
6088 else if (ret > 0)
6089 break;
6090 continue;
6091 }
6092
6093 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6094
6095 if (found_key.objectid != key.objectid)
6096 break;
6097 if (found_key.type != BTRFS_DIR_INDEX_KEY)
6098 break;
6099 if (found_key.offset < ctx->pos)
6100 goto next;
6101 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
6102 goto next;
6103 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
6104 name_len = btrfs_dir_name_len(leaf, di);
6105 if ((total_len + sizeof(struct dir_entry) + name_len) >=
6106 PAGE_SIZE) {
6107 btrfs_release_path(path);
6108 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6109 if (ret)
6110 goto nopos;
6111 addr = private->filldir_buf;
6112 entries = 0;
6113 total_len = 0;
6114 goto again;
6115 }
6116
6117 entry = addr;
6118 put_unaligned(name_len, &entry->name_len);
6119 name_ptr = (char *)(entry + 1);
6120 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6121 name_len);
6122 put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)),
6123 &entry->type);
6124 btrfs_dir_item_key_to_cpu(leaf, di, &location);
6125 put_unaligned(location.objectid, &entry->ino);
6126 put_unaligned(found_key.offset, &entry->offset);
6127 entries++;
6128 addr += sizeof(struct dir_entry) + name_len;
6129 total_len += sizeof(struct dir_entry) + name_len;
6130 next:
6131 path->slots[0]++;
6132 }
6133 btrfs_release_path(path);
6134
6135 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6136 if (ret)
6137 goto nopos;
6138
6139 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6140 if (ret)
6141 goto nopos;
6142
6143 /*
6144 * Stop new entries from being returned after we return the last
6145 * entry.
6146 *
6147 * New directory entries are assigned a strictly increasing
6148 * offset. This means that new entries created during readdir
6149 * are *guaranteed* to be seen in the future by that readdir.
6150 * This has broken buggy programs which operate on names as
6151 * they're returned by readdir. Until we re-use freed offsets
6152 * we have this hack to stop new entries from being returned
6153 * under the assumption that they'll never reach this huge
6154 * offset.
6155 *
6156 * This is being careful not to overflow 32bit loff_t unless the
6157 * last entry requires it because doing so has broken 32bit apps
6158 * in the past.
6159 */
6160 if (ctx->pos >= INT_MAX)
6161 ctx->pos = LLONG_MAX;
6162 else
6163 ctx->pos = INT_MAX;
6164 nopos:
6165 ret = 0;
6166 err:
6167 if (put)
6168 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6169 btrfs_free_path(path);
6170 return ret;
6171 }
6172
6173 /*
6174 * This is somewhat expensive, updating the tree every time the
6175 * inode changes. But, it is most likely to find the inode in cache.
6176 * FIXME, needs more benchmarking...there are no reasons other than performance
6177 * to keep or drop this code.
6178 */
6179 static int btrfs_dirty_inode(struct inode *inode)
6180 {
6181 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6182 struct btrfs_root *root = BTRFS_I(inode)->root;
6183 struct btrfs_trans_handle *trans;
6184 int ret;
6185
6186 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6187 return 0;
6188
6189 trans = btrfs_join_transaction(root);
6190 if (IS_ERR(trans))
6191 return PTR_ERR(trans);
6192
6193 ret = btrfs_update_inode(trans, root, inode);
6194 if (ret && ret == -ENOSPC) {
6195 /* whoops, lets try again with the full transaction */
6196 btrfs_end_transaction(trans);
6197 trans = btrfs_start_transaction(root, 1);
6198 if (IS_ERR(trans))
6199 return PTR_ERR(trans);
6200
6201 ret = btrfs_update_inode(trans, root, inode);
6202 }
6203 btrfs_end_transaction(trans);
6204 if (BTRFS_I(inode)->delayed_node)
6205 btrfs_balance_delayed_items(fs_info);
6206
6207 return ret;
6208 }
6209
6210 /*
6211 * This is a copy of file_update_time. We need this so we can return error on
6212 * ENOSPC for updating the inode in the case of file write and mmap writes.
6213 */
6214 static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
6215 int flags)
6216 {
6217 struct btrfs_root *root = BTRFS_I(inode)->root;
6218 bool dirty = flags & ~S_VERSION;
6219
6220 if (btrfs_root_readonly(root))
6221 return -EROFS;
6222
6223 if (flags & S_VERSION)
6224 dirty |= inode_maybe_inc_iversion(inode, dirty);
6225 if (flags & S_CTIME)
6226 inode->i_ctime = *now;
6227 if (flags & S_MTIME)
6228 inode->i_mtime = *now;
6229 if (flags & S_ATIME)
6230 inode->i_atime = *now;
6231 return dirty ? btrfs_dirty_inode(inode) : 0;
6232 }
6233
6234 /*
6235 * find the highest existing sequence number in a directory
6236 * and then set the in-memory index_cnt variable to reflect
6237 * free sequence numbers
6238 */
6239 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6240 {
6241 struct btrfs_root *root = inode->root;
6242 struct btrfs_key key, found_key;
6243 struct btrfs_path *path;
6244 struct extent_buffer *leaf;
6245 int ret;
6246
6247 key.objectid = btrfs_ino(inode);
6248 key.type = BTRFS_DIR_INDEX_KEY;
6249 key.offset = (u64)-1;
6250
6251 path = btrfs_alloc_path();
6252 if (!path)
6253 return -ENOMEM;
6254
6255 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6256 if (ret < 0)
6257 goto out;
6258 /* FIXME: we should be able to handle this */
6259 if (ret == 0)
6260 goto out;
6261 ret = 0;
6262
6263 /*
6264 * MAGIC NUMBER EXPLANATION:
6265 * since we search a directory based on f_pos we have to start at 2
6266 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6267 * else has to start at 2
6268 */
6269 if (path->slots[0] == 0) {
6270 inode->index_cnt = 2;
6271 goto out;
6272 }
6273
6274 path->slots[0]--;
6275
6276 leaf = path->nodes[0];
6277 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6278
6279 if (found_key.objectid != btrfs_ino(inode) ||
6280 found_key.type != BTRFS_DIR_INDEX_KEY) {
6281 inode->index_cnt = 2;
6282 goto out;
6283 }
6284
6285 inode->index_cnt = found_key.offset + 1;
6286 out:
6287 btrfs_free_path(path);
6288 return ret;
6289 }
6290
6291 /*
6292 * helper to find a free sequence number in a given directory. This current
6293 * code is very simple, later versions will do smarter things in the btree
6294 */
6295 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6296 {
6297 int ret = 0;
6298
6299 if (dir->index_cnt == (u64)-1) {
6300 ret = btrfs_inode_delayed_dir_index_count(dir);
6301 if (ret) {
6302 ret = btrfs_set_inode_index_count(dir);
6303 if (ret)
6304 return ret;
6305 }
6306 }
6307
6308 *index = dir->index_cnt;
6309 dir->index_cnt++;
6310
6311 return ret;
6312 }
6313
6314 static int btrfs_insert_inode_locked(struct inode *inode)
6315 {
6316 struct btrfs_iget_args args;
6317 args.location = &BTRFS_I(inode)->location;
6318 args.root = BTRFS_I(inode)->root;
6319
6320 return insert_inode_locked4(inode,
6321 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6322 btrfs_find_actor, &args);
6323 }
6324
6325 /*
6326 * Inherit flags from the parent inode.
6327 *
6328 * Currently only the compression flags and the cow flags are inherited.
6329 */
6330 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6331 {
6332 unsigned int flags;
6333
6334 if (!dir)
6335 return;
6336
6337 flags = BTRFS_I(dir)->flags;
6338
6339 if (flags & BTRFS_INODE_NOCOMPRESS) {
6340 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6341 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6342 } else if (flags & BTRFS_INODE_COMPRESS) {
6343 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6344 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6345 }
6346
6347 if (flags & BTRFS_INODE_NODATACOW) {
6348 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6349 if (S_ISREG(inode->i_mode))
6350 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6351 }
6352
6353 btrfs_sync_inode_flags_to_i_flags(inode);
6354 }
6355
6356 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6357 struct btrfs_root *root,
6358 struct inode *dir,
6359 const char *name, int name_len,
6360 u64 ref_objectid, u64 objectid,
6361 umode_t mode, u64 *index)
6362 {
6363 struct btrfs_fs_info *fs_info = root->fs_info;
6364 struct inode *inode;
6365 struct btrfs_inode_item *inode_item;
6366 struct btrfs_key *location;
6367 struct btrfs_path *path;
6368 struct btrfs_inode_ref *ref;
6369 struct btrfs_key key[2];
6370 u32 sizes[2];
6371 int nitems = name ? 2 : 1;
6372 unsigned long ptr;
6373 unsigned int nofs_flag;
6374 int ret;
6375
6376 path = btrfs_alloc_path();
6377 if (!path)
6378 return ERR_PTR(-ENOMEM);
6379
6380 nofs_flag = memalloc_nofs_save();
6381 inode = new_inode(fs_info->sb);
6382 memalloc_nofs_restore(nofs_flag);
6383 if (!inode) {
6384 btrfs_free_path(path);
6385 return ERR_PTR(-ENOMEM);
6386 }
6387
6388 /*
6389 * O_TMPFILE, set link count to 0, so that after this point,
6390 * we fill in an inode item with the correct link count.
6391 */
6392 if (!name)
6393 set_nlink(inode, 0);
6394
6395 /*
6396 * we have to initialize this early, so we can reclaim the inode
6397 * number if we fail afterwards in this function.
6398 */
6399 inode->i_ino = objectid;
6400
6401 if (dir && name) {
6402 trace_btrfs_inode_request(dir);
6403
6404 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6405 if (ret) {
6406 btrfs_free_path(path);
6407 iput(inode);
6408 return ERR_PTR(ret);
6409 }
6410 } else if (dir) {
6411 *index = 0;
6412 }
6413 /*
6414 * index_cnt is ignored for everything but a dir,
6415 * btrfs_set_inode_index_count has an explanation for the magic
6416 * number
6417 */
6418 BTRFS_I(inode)->index_cnt = 2;
6419 BTRFS_I(inode)->dir_index = *index;
6420 BTRFS_I(inode)->root = root;
6421 BTRFS_I(inode)->generation = trans->transid;
6422 inode->i_generation = BTRFS_I(inode)->generation;
6423
6424 /*
6425 * We could have gotten an inode number from somebody who was fsynced
6426 * and then removed in this same transaction, so let's just set full
6427 * sync since it will be a full sync anyway and this will blow away the
6428 * old info in the log.
6429 */
6430 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6431
6432 key[0].objectid = objectid;
6433 key[0].type = BTRFS_INODE_ITEM_KEY;
6434 key[0].offset = 0;
6435
6436 sizes[0] = sizeof(struct btrfs_inode_item);
6437
6438 if (name) {
6439 /*
6440 * Start new inodes with an inode_ref. This is slightly more
6441 * efficient for small numbers of hard links since they will
6442 * be packed into one item. Extended refs will kick in if we
6443 * add more hard links than can fit in the ref item.
6444 */
6445 key[1].objectid = objectid;
6446 key[1].type = BTRFS_INODE_REF_KEY;
6447 key[1].offset = ref_objectid;
6448
6449 sizes[1] = name_len + sizeof(*ref);
6450 }
6451
6452 location = &BTRFS_I(inode)->location;
6453 location->objectid = objectid;
6454 location->offset = 0;
6455 location->type = BTRFS_INODE_ITEM_KEY;
6456
6457 ret = btrfs_insert_inode_locked(inode);
6458 if (ret < 0) {
6459 iput(inode);
6460 goto fail;
6461 }
6462
6463 path->leave_spinning = 1;
6464 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6465 if (ret != 0)
6466 goto fail_unlock;
6467
6468 inode_init_owner(inode, dir, mode);
6469 inode_set_bytes(inode, 0);
6470
6471 inode->i_mtime = current_time(inode);
6472 inode->i_atime = inode->i_mtime;
6473 inode->i_ctime = inode->i_mtime;
6474 BTRFS_I(inode)->i_otime = inode->i_mtime;
6475
6476 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6477 struct btrfs_inode_item);
6478 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6479 sizeof(*inode_item));
6480 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6481
6482 if (name) {
6483 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6484 struct btrfs_inode_ref);
6485 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6486 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6487 ptr = (unsigned long)(ref + 1);
6488 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6489 }
6490
6491 btrfs_mark_buffer_dirty(path->nodes[0]);
6492 btrfs_free_path(path);
6493
6494 btrfs_inherit_iflags(inode, dir);
6495
6496 if (S_ISREG(mode)) {
6497 if (btrfs_test_opt(fs_info, NODATASUM))
6498 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6499 if (btrfs_test_opt(fs_info, NODATACOW))
6500 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6501 BTRFS_INODE_NODATASUM;
6502 }
6503
6504 inode_tree_add(inode);
6505
6506 trace_btrfs_inode_new(inode);
6507 btrfs_set_inode_last_trans(trans, inode);
6508
6509 btrfs_update_root_times(trans, root);
6510
6511 ret = btrfs_inode_inherit_props(trans, inode, dir);
6512 if (ret)
6513 btrfs_err(fs_info,
6514 "error inheriting props for ino %llu (root %llu): %d",
6515 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6516
6517 return inode;
6518
6519 fail_unlock:
6520 discard_new_inode(inode);
6521 fail:
6522 if (dir && name)
6523 BTRFS_I(dir)->index_cnt--;
6524 btrfs_free_path(path);
6525 return ERR_PTR(ret);
6526 }
6527
6528 /*
6529 * utility function to add 'inode' into 'parent_inode' with
6530 * a give name and a given sequence number.
6531 * if 'add_backref' is true, also insert a backref from the
6532 * inode to the parent directory.
6533 */
6534 int btrfs_add_link(struct btrfs_trans_handle *trans,
6535 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6536 const char *name, int name_len, int add_backref, u64 index)
6537 {
6538 int ret = 0;
6539 struct btrfs_key key;
6540 struct btrfs_root *root = parent_inode->root;
6541 u64 ino = btrfs_ino(inode);
6542 u64 parent_ino = btrfs_ino(parent_inode);
6543
6544 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6545 memcpy(&key, &inode->root->root_key, sizeof(key));
6546 } else {
6547 key.objectid = ino;
6548 key.type = BTRFS_INODE_ITEM_KEY;
6549 key.offset = 0;
6550 }
6551
6552 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6553 ret = btrfs_add_root_ref(trans, key.objectid,
6554 root->root_key.objectid, parent_ino,
6555 index, name, name_len);
6556 } else if (add_backref) {
6557 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6558 parent_ino, index);
6559 }
6560
6561 /* Nothing to clean up yet */
6562 if (ret)
6563 return ret;
6564
6565 ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key,
6566 btrfs_inode_type(&inode->vfs_inode), index);
6567 if (ret == -EEXIST || ret == -EOVERFLOW)
6568 goto fail_dir_item;
6569 else if (ret) {
6570 btrfs_abort_transaction(trans, ret);
6571 return ret;
6572 }
6573
6574 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6575 name_len * 2);
6576 inode_inc_iversion(&parent_inode->vfs_inode);
6577 /*
6578 * If we are replaying a log tree, we do not want to update the mtime
6579 * and ctime of the parent directory with the current time, since the
6580 * log replay procedure is responsible for setting them to their correct
6581 * values (the ones it had when the fsync was done).
6582 */
6583 if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
6584 struct timespec64 now = current_time(&parent_inode->vfs_inode);
6585
6586 parent_inode->vfs_inode.i_mtime = now;
6587 parent_inode->vfs_inode.i_ctime = now;
6588 }
6589 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6590 if (ret)
6591 btrfs_abort_transaction(trans, ret);
6592 return ret;
6593
6594 fail_dir_item:
6595 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6596 u64 local_index;
6597 int err;
6598 err = btrfs_del_root_ref(trans, key.objectid,
6599 root->root_key.objectid, parent_ino,
6600 &local_index, name, name_len);
6601 if (err)
6602 btrfs_abort_transaction(trans, err);
6603 } else if (add_backref) {
6604 u64 local_index;
6605 int err;
6606
6607 err = btrfs_del_inode_ref(trans, root, name, name_len,
6608 ino, parent_ino, &local_index);
6609 if (err)
6610 btrfs_abort_transaction(trans, err);
6611 }
6612
6613 /* Return the original error code */
6614 return ret;
6615 }
6616
6617 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6618 struct btrfs_inode *dir, struct dentry *dentry,
6619 struct btrfs_inode *inode, int backref, u64 index)
6620 {
6621 int err = btrfs_add_link(trans, dir, inode,
6622 dentry->d_name.name, dentry->d_name.len,
6623 backref, index);
6624 if (err > 0)
6625 err = -EEXIST;
6626 return err;
6627 }
6628
6629 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6630 umode_t mode, dev_t rdev)
6631 {
6632 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6633 struct btrfs_trans_handle *trans;
6634 struct btrfs_root *root = BTRFS_I(dir)->root;
6635 struct inode *inode = NULL;
6636 int err;
6637 u64 objectid;
6638 u64 index = 0;
6639
6640 /*
6641 * 2 for inode item and ref
6642 * 2 for dir items
6643 * 1 for xattr if selinux is on
6644 */
6645 trans = btrfs_start_transaction(root, 5);
6646 if (IS_ERR(trans))
6647 return PTR_ERR(trans);
6648
6649 err = btrfs_find_free_ino(root, &objectid);
6650 if (err)
6651 goto out_unlock;
6652
6653 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6654 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6655 mode, &index);
6656 if (IS_ERR(inode)) {
6657 err = PTR_ERR(inode);
6658 inode = NULL;
6659 goto out_unlock;
6660 }
6661
6662 /*
6663 * If the active LSM wants to access the inode during
6664 * d_instantiate it needs these. Smack checks to see
6665 * if the filesystem supports xattrs by looking at the
6666 * ops vector.
6667 */
6668 inode->i_op = &btrfs_special_inode_operations;
6669 init_special_inode(inode, inode->i_mode, rdev);
6670
6671 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6672 if (err)
6673 goto out_unlock;
6674
6675 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6676 0, index);
6677 if (err)
6678 goto out_unlock;
6679
6680 btrfs_update_inode(trans, root, inode);
6681 d_instantiate_new(dentry, inode);
6682
6683 out_unlock:
6684 btrfs_end_transaction(trans);
6685 btrfs_btree_balance_dirty(fs_info);
6686 if (err && inode) {
6687 inode_dec_link_count(inode);
6688 discard_new_inode(inode);
6689 }
6690 return err;
6691 }
6692
6693 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6694 umode_t mode, bool excl)
6695 {
6696 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6697 struct btrfs_trans_handle *trans;
6698 struct btrfs_root *root = BTRFS_I(dir)->root;
6699 struct inode *inode = NULL;
6700 int err;
6701 u64 objectid;
6702 u64 index = 0;
6703
6704 /*
6705 * 2 for inode item and ref
6706 * 2 for dir items
6707 * 1 for xattr if selinux is on
6708 */
6709 trans = btrfs_start_transaction(root, 5);
6710 if (IS_ERR(trans))
6711 return PTR_ERR(trans);
6712
6713 err = btrfs_find_free_ino(root, &objectid);
6714 if (err)
6715 goto out_unlock;
6716
6717 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6718 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6719 mode, &index);
6720 if (IS_ERR(inode)) {
6721 err = PTR_ERR(inode);
6722 inode = NULL;
6723 goto out_unlock;
6724 }
6725 /*
6726 * If the active LSM wants to access the inode during
6727 * d_instantiate it needs these. Smack checks to see
6728 * if the filesystem supports xattrs by looking at the
6729 * ops vector.
6730 */
6731 inode->i_fop = &btrfs_file_operations;
6732 inode->i_op = &btrfs_file_inode_operations;
6733 inode->i_mapping->a_ops = &btrfs_aops;
6734
6735 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6736 if (err)
6737 goto out_unlock;
6738
6739 err = btrfs_update_inode(trans, root, inode);
6740 if (err)
6741 goto out_unlock;
6742
6743 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6744 0, index);
6745 if (err)
6746 goto out_unlock;
6747
6748 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6749 d_instantiate_new(dentry, inode);
6750
6751 out_unlock:
6752 btrfs_end_transaction(trans);
6753 if (err && inode) {
6754 inode_dec_link_count(inode);
6755 discard_new_inode(inode);
6756 }
6757 btrfs_btree_balance_dirty(fs_info);
6758 return err;
6759 }
6760
6761 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6762 struct dentry *dentry)
6763 {
6764 struct btrfs_trans_handle *trans = NULL;
6765 struct btrfs_root *root = BTRFS_I(dir)->root;
6766 struct inode *inode = d_inode(old_dentry);
6767 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6768 u64 index;
6769 int err;
6770 int drop_inode = 0;
6771
6772 /* do not allow sys_link's with other subvols of the same device */
6773 if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
6774 return -EXDEV;
6775
6776 if (inode->i_nlink >= BTRFS_LINK_MAX)
6777 return -EMLINK;
6778
6779 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6780 if (err)
6781 goto fail;
6782
6783 /*
6784 * 2 items for inode and inode ref
6785 * 2 items for dir items
6786 * 1 item for parent inode
6787 * 1 item for orphan item deletion if O_TMPFILE
6788 */
6789 trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
6790 if (IS_ERR(trans)) {
6791 err = PTR_ERR(trans);
6792 trans = NULL;
6793 goto fail;
6794 }
6795
6796 /* There are several dir indexes for this inode, clear the cache. */
6797 BTRFS_I(inode)->dir_index = 0ULL;
6798 inc_nlink(inode);
6799 inode_inc_iversion(inode);
6800 inode->i_ctime = current_time(inode);
6801 ihold(inode);
6802 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6803
6804 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6805 1, index);
6806
6807 if (err) {
6808 drop_inode = 1;
6809 } else {
6810 struct dentry *parent = dentry->d_parent;
6811 int ret;
6812
6813 err = btrfs_update_inode(trans, root, inode);
6814 if (err)
6815 goto fail;
6816 if (inode->i_nlink == 1) {
6817 /*
6818 * If new hard link count is 1, it's a file created
6819 * with open(2) O_TMPFILE flag.
6820 */
6821 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6822 if (err)
6823 goto fail;
6824 }
6825 d_instantiate(dentry, inode);
6826 ret = btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent,
6827 true, NULL);
6828 if (ret == BTRFS_NEED_TRANS_COMMIT) {
6829 err = btrfs_commit_transaction(trans);
6830 trans = NULL;
6831 }
6832 }
6833
6834 fail:
6835 if (trans)
6836 btrfs_end_transaction(trans);
6837 if (drop_inode) {
6838 inode_dec_link_count(inode);
6839 iput(inode);
6840 }
6841 btrfs_btree_balance_dirty(fs_info);
6842 return err;
6843 }
6844
6845 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6846 {
6847 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6848 struct inode *inode = NULL;
6849 struct btrfs_trans_handle *trans;
6850 struct btrfs_root *root = BTRFS_I(dir)->root;
6851 int err = 0;
6852 u64 objectid = 0;
6853 u64 index = 0;
6854
6855 /*
6856 * 2 items for inode and ref
6857 * 2 items for dir items
6858 * 1 for xattr if selinux is on
6859 */
6860 trans = btrfs_start_transaction(root, 5);
6861 if (IS_ERR(trans))
6862 return PTR_ERR(trans);
6863
6864 err = btrfs_find_free_ino(root, &objectid);
6865 if (err)
6866 goto out_fail;
6867
6868 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6869 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6870 S_IFDIR | mode, &index);
6871 if (IS_ERR(inode)) {
6872 err = PTR_ERR(inode);
6873 inode = NULL;
6874 goto out_fail;
6875 }
6876
6877 /* these must be set before we unlock the inode */
6878 inode->i_op = &btrfs_dir_inode_operations;
6879 inode->i_fop = &btrfs_dir_file_operations;
6880
6881 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6882 if (err)
6883 goto out_fail;
6884
6885 btrfs_i_size_write(BTRFS_I(inode), 0);
6886 err = btrfs_update_inode(trans, root, inode);
6887 if (err)
6888 goto out_fail;
6889
6890 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6891 dentry->d_name.name,
6892 dentry->d_name.len, 0, index);
6893 if (err)
6894 goto out_fail;
6895
6896 d_instantiate_new(dentry, inode);
6897
6898 out_fail:
6899 btrfs_end_transaction(trans);
6900 if (err && inode) {
6901 inode_dec_link_count(inode);
6902 discard_new_inode(inode);
6903 }
6904 btrfs_btree_balance_dirty(fs_info);
6905 return err;
6906 }
6907
6908 static noinline int uncompress_inline(struct btrfs_path *path,
6909 struct page *page,
6910 size_t pg_offset, u64 extent_offset,
6911 struct btrfs_file_extent_item *item)
6912 {
6913 int ret;
6914 struct extent_buffer *leaf = path->nodes[0];
6915 char *tmp;
6916 size_t max_size;
6917 unsigned long inline_size;
6918 unsigned long ptr;
6919 int compress_type;
6920
6921 WARN_ON(pg_offset != 0);
6922 compress_type = btrfs_file_extent_compression(leaf, item);
6923 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6924 inline_size = btrfs_file_extent_inline_item_len(leaf,
6925 btrfs_item_nr(path->slots[0]));
6926 tmp = kmalloc(inline_size, GFP_NOFS);
6927 if (!tmp)
6928 return -ENOMEM;
6929 ptr = btrfs_file_extent_inline_start(item);
6930
6931 read_extent_buffer(leaf, tmp, ptr, inline_size);
6932
6933 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6934 ret = btrfs_decompress(compress_type, tmp, page,
6935 extent_offset, inline_size, max_size);
6936
6937 /*
6938 * decompression code contains a memset to fill in any space between the end
6939 * of the uncompressed data and the end of max_size in case the decompressed
6940 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6941 * the end of an inline extent and the beginning of the next block, so we
6942 * cover that region here.
6943 */
6944
6945 if (max_size + pg_offset < PAGE_SIZE) {
6946 char *map = kmap(page);
6947 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6948 kunmap(page);
6949 }
6950 kfree(tmp);
6951 return ret;
6952 }
6953
6954 /*
6955 * a bit scary, this does extent mapping from logical file offset to the disk.
6956 * the ugly parts come from merging extents from the disk with the in-ram
6957 * representation. This gets more complex because of the data=ordered code,
6958 * where the in-ram extents might be locked pending data=ordered completion.
6959 *
6960 * This also copies inline extents directly into the page.
6961 */
6962 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6963 struct page *page,
6964 size_t pg_offset, u64 start, u64 len,
6965 int create)
6966 {
6967 struct btrfs_fs_info *fs_info = inode->root->fs_info;
6968 int ret;
6969 int err = 0;
6970 u64 extent_start = 0;
6971 u64 extent_end = 0;
6972 u64 objectid = btrfs_ino(inode);
6973 int extent_type = -1;
6974 struct btrfs_path *path = NULL;
6975 struct btrfs_root *root = inode->root;
6976 struct btrfs_file_extent_item *item;
6977 struct extent_buffer *leaf;
6978 struct btrfs_key found_key;
6979 struct extent_map *em = NULL;
6980 struct extent_map_tree *em_tree = &inode->extent_tree;
6981 struct extent_io_tree *io_tree = &inode->io_tree;
6982 const bool new_inline = !page || create;
6983
6984 read_lock(&em_tree->lock);
6985 em = lookup_extent_mapping(em_tree, start, len);
6986 read_unlock(&em_tree->lock);
6987
6988 if (em) {
6989 if (em->start > start || em->start + em->len <= start)
6990 free_extent_map(em);
6991 else if (em->block_start == EXTENT_MAP_INLINE && page)
6992 free_extent_map(em);
6993 else
6994 goto out;
6995 }
6996 em = alloc_extent_map();
6997 if (!em) {
6998 err = -ENOMEM;
6999 goto out;
7000 }
7001 em->start = EXTENT_MAP_HOLE;
7002 em->orig_start = EXTENT_MAP_HOLE;
7003 em->len = (u64)-1;
7004 em->block_len = (u64)-1;
7005
7006 path = btrfs_alloc_path();
7007 if (!path) {
7008 err = -ENOMEM;
7009 goto out;
7010 }
7011
7012 /* Chances are we'll be called again, so go ahead and do readahead */
7013 path->reada = READA_FORWARD;
7014
7015 /*
7016 * Unless we're going to uncompress the inline extent, no sleep would
7017 * happen.
7018 */
7019 path->leave_spinning = 1;
7020
7021 ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
7022 if (ret < 0) {
7023 err = ret;
7024 goto out;
7025 } else if (ret > 0) {
7026 if (path->slots[0] == 0)
7027 goto not_found;
7028 path->slots[0]--;
7029 }
7030
7031 leaf = path->nodes[0];
7032 item = btrfs_item_ptr(leaf, path->slots[0],
7033 struct btrfs_file_extent_item);
7034 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7035 if (found_key.objectid != objectid ||
7036 found_key.type != BTRFS_EXTENT_DATA_KEY) {
7037 /*
7038 * If we backup past the first extent we want to move forward
7039 * and see if there is an extent in front of us, otherwise we'll
7040 * say there is a hole for our whole search range which can
7041 * cause problems.
7042 */
7043 extent_end = start;
7044 goto next;
7045 }
7046
7047 extent_type = btrfs_file_extent_type(leaf, item);
7048 extent_start = found_key.offset;
7049 if (extent_type == BTRFS_FILE_EXTENT_REG ||
7050 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
7051 /* Only regular file could have regular/prealloc extent */
7052 if (!S_ISREG(inode->vfs_inode.i_mode)) {
7053 ret = -EUCLEAN;
7054 btrfs_crit(fs_info,
7055 "regular/prealloc extent found for non-regular inode %llu",
7056 btrfs_ino(inode));
7057 goto out;
7058 }
7059 extent_end = extent_start +
7060 btrfs_file_extent_num_bytes(leaf, item);
7061
7062 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
7063 extent_start);
7064 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
7065 size_t size;
7066
7067 size = btrfs_file_extent_ram_bytes(leaf, item);
7068 extent_end = ALIGN(extent_start + size,
7069 fs_info->sectorsize);
7070
7071 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
7072 path->slots[0],
7073 extent_start);
7074 }
7075 next:
7076 if (start >= extent_end) {
7077 path->slots[0]++;
7078 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7079 ret = btrfs_next_leaf(root, path);
7080 if (ret < 0) {
7081 err = ret;
7082 goto out;
7083 } else if (ret > 0) {
7084 goto not_found;
7085 }
7086 leaf = path->nodes[0];
7087 }
7088 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7089 if (found_key.objectid != objectid ||
7090 found_key.type != BTRFS_EXTENT_DATA_KEY)
7091 goto not_found;
7092 if (start + len <= found_key.offset)
7093 goto not_found;
7094 if (start > found_key.offset)
7095 goto next;
7096
7097 /* New extent overlaps with existing one */
7098 em->start = start;
7099 em->orig_start = start;
7100 em->len = found_key.offset - start;
7101 em->block_start = EXTENT_MAP_HOLE;
7102 goto insert;
7103 }
7104
7105 btrfs_extent_item_to_extent_map(inode, path, item,
7106 new_inline, em);
7107
7108 if (extent_type == BTRFS_FILE_EXTENT_REG ||
7109 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
7110 goto insert;
7111 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
7112 unsigned long ptr;
7113 char *map;
7114 size_t size;
7115 size_t extent_offset;
7116 size_t copy_size;
7117
7118 if (new_inline)
7119 goto out;
7120
7121 size = btrfs_file_extent_ram_bytes(leaf, item);
7122 extent_offset = page_offset(page) + pg_offset - extent_start;
7123 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7124 size - extent_offset);
7125 em->start = extent_start + extent_offset;
7126 em->len = ALIGN(copy_size, fs_info->sectorsize);
7127 em->orig_block_len = em->len;
7128 em->orig_start = em->start;
7129 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7130
7131 btrfs_set_path_blocking(path);
7132 if (!PageUptodate(page)) {
7133 if (btrfs_file_extent_compression(leaf, item) !=
7134 BTRFS_COMPRESS_NONE) {
7135 ret = uncompress_inline(path, page, pg_offset,
7136 extent_offset, item);
7137 if (ret) {
7138 err = ret;
7139 goto out;
7140 }
7141 } else {
7142 map = kmap(page);
7143 read_extent_buffer(leaf, map + pg_offset, ptr,
7144 copy_size);
7145 if (pg_offset + copy_size < PAGE_SIZE) {
7146 memset(map + pg_offset + copy_size, 0,
7147 PAGE_SIZE - pg_offset -
7148 copy_size);
7149 }
7150 kunmap(page);
7151 }
7152 flush_dcache_page(page);
7153 }
7154 set_extent_uptodate(io_tree, em->start,
7155 extent_map_end(em) - 1, NULL, GFP_NOFS);
7156 goto insert;
7157 }
7158 not_found:
7159 em->start = start;
7160 em->orig_start = start;
7161 em->len = len;
7162 em->block_start = EXTENT_MAP_HOLE;
7163 insert:
7164 btrfs_release_path(path);
7165 if (em->start > start || extent_map_end(em) <= start) {
7166 btrfs_err(fs_info,
7167 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7168 em->start, em->len, start, len);
7169 err = -EIO;
7170 goto out;
7171 }
7172
7173 err = 0;
7174 write_lock(&em_tree->lock);
7175 err = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
7176 write_unlock(&em_tree->lock);
7177 out:
7178 btrfs_free_path(path);
7179
7180 trace_btrfs_get_extent(root, inode, em);
7181
7182 if (err) {
7183 free_extent_map(em);
7184 return ERR_PTR(err);
7185 }
7186 BUG_ON(!em); /* Error is always set */
7187 return em;
7188 }
7189
7190 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7191 u64 start, u64 len)
7192 {
7193 struct extent_map *em;
7194 struct extent_map *hole_em = NULL;
7195 u64 delalloc_start = start;
7196 u64 end;
7197 u64 delalloc_len;
7198 u64 delalloc_end;
7199 int err = 0;
7200
7201 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7202 if (IS_ERR(em))
7203 return em;
7204 /*
7205 * If our em maps to:
7206 * - a hole or
7207 * - a pre-alloc extent,
7208 * there might actually be delalloc bytes behind it.
7209 */
7210 if (em->block_start != EXTENT_MAP_HOLE &&
7211 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7212 return em;
7213 else
7214 hole_em = em;
7215
7216 /* check to see if we've wrapped (len == -1 or similar) */
7217 end = start + len;
7218 if (end < start)
7219 end = (u64)-1;
7220 else
7221 end -= 1;
7222
7223 em = NULL;
7224
7225 /* ok, we didn't find anything, lets look for delalloc */
7226 delalloc_len = count_range_bits(&inode->io_tree, &delalloc_start,
7227 end, len, EXTENT_DELALLOC, 1);
7228 delalloc_end = delalloc_start + delalloc_len;
7229 if (delalloc_end < delalloc_start)
7230 delalloc_end = (u64)-1;
7231
7232 /*
7233 * We didn't find anything useful, return the original results from
7234 * get_extent()
7235 */
7236 if (delalloc_start > end || delalloc_end <= start) {
7237 em = hole_em;
7238 hole_em = NULL;
7239 goto out;
7240 }
7241
7242 /*
7243 * Adjust the delalloc_start to make sure it doesn't go backwards from
7244 * the start they passed in
7245 */
7246 delalloc_start = max(start, delalloc_start);
7247 delalloc_len = delalloc_end - delalloc_start;
7248
7249 if (delalloc_len > 0) {
7250 u64 hole_start;
7251 u64 hole_len;
7252 const u64 hole_end = extent_map_end(hole_em);
7253
7254 em = alloc_extent_map();
7255 if (!em) {
7256 err = -ENOMEM;
7257 goto out;
7258 }
7259
7260 ASSERT(hole_em);
7261 /*
7262 * When btrfs_get_extent can't find anything it returns one
7263 * huge hole
7264 *
7265 * Make sure what it found really fits our range, and adjust to
7266 * make sure it is based on the start from the caller
7267 */
7268 if (hole_end <= start || hole_em->start > end) {
7269 free_extent_map(hole_em);
7270 hole_em = NULL;
7271 } else {
7272 hole_start = max(hole_em->start, start);
7273 hole_len = hole_end - hole_start;
7274 }
7275
7276 if (hole_em && delalloc_start > hole_start) {
7277 /*
7278 * Our hole starts before our delalloc, so we have to
7279 * return just the parts of the hole that go until the
7280 * delalloc starts
7281 */
7282 em->len = min(hole_len, delalloc_start - hole_start);
7283 em->start = hole_start;
7284 em->orig_start = hole_start;
7285 /*
7286 * Don't adjust block start at all, it is fixed at
7287 * EXTENT_MAP_HOLE
7288 */
7289 em->block_start = hole_em->block_start;
7290 em->block_len = hole_len;
7291 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7292 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7293 } else {
7294 /*
7295 * Hole is out of passed range or it starts after
7296 * delalloc range
7297 */
7298 em->start = delalloc_start;
7299 em->len = delalloc_len;
7300 em->orig_start = delalloc_start;
7301 em->block_start = EXTENT_MAP_DELALLOC;
7302 em->block_len = delalloc_len;
7303 }
7304 } else {
7305 return hole_em;
7306 }
7307 out:
7308
7309 free_extent_map(hole_em);
7310 if (err) {
7311 free_extent_map(em);
7312 return ERR_PTR(err);
7313 }
7314 return em;
7315 }
7316
7317 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7318 const u64 start,
7319 const u64 len,
7320 const u64 orig_start,
7321 const u64 block_start,
7322 const u64 block_len,
7323 const u64 orig_block_len,
7324 const u64 ram_bytes,
7325 const int type)
7326 {
7327 struct extent_map *em = NULL;
7328 int ret;
7329
7330 if (type != BTRFS_ORDERED_NOCOW) {
7331 em = create_io_em(inode, start, len, orig_start,
7332 block_start, block_len, orig_block_len,
7333 ram_bytes,
7334 BTRFS_COMPRESS_NONE, /* compress_type */
7335 type);
7336 if (IS_ERR(em))
7337 goto out;
7338 }
7339 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7340 len, block_len, type);
7341 if (ret) {
7342 if (em) {
7343 free_extent_map(em);
7344 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7345 start + len - 1, 0);
7346 }
7347 em = ERR_PTR(ret);
7348 }
7349 out:
7350
7351 return em;
7352 }
7353
7354 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7355 u64 start, u64 len)
7356 {
7357 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7358 struct btrfs_root *root = BTRFS_I(inode)->root;
7359 struct extent_map *em;
7360 struct btrfs_key ins;
7361 u64 alloc_hint;
7362 int ret;
7363
7364 alloc_hint = get_extent_allocation_hint(inode, start, len);
7365 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7366 0, alloc_hint, &ins, 1, 1);
7367 if (ret)
7368 return ERR_PTR(ret);
7369
7370 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7371 ins.objectid, ins.offset, ins.offset,
7372 ins.offset, BTRFS_ORDERED_REGULAR);
7373 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7374 if (IS_ERR(em))
7375 btrfs_free_reserved_extent(fs_info, ins.objectid,
7376 ins.offset, 1);
7377
7378 return em;
7379 }
7380
7381 /*
7382 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7383 * block must be cow'd
7384 */
7385 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7386 u64 *orig_start, u64 *orig_block_len,
7387 u64 *ram_bytes)
7388 {
7389 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7390 struct btrfs_path *path;
7391 int ret;
7392 struct extent_buffer *leaf;
7393 struct btrfs_root *root = BTRFS_I(inode)->root;
7394 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7395 struct btrfs_file_extent_item *fi;
7396 struct btrfs_key key;
7397 u64 disk_bytenr;
7398 u64 backref_offset;
7399 u64 extent_end;
7400 u64 num_bytes;
7401 int slot;
7402 int found_type;
7403 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7404
7405 path = btrfs_alloc_path();
7406 if (!path)
7407 return -ENOMEM;
7408
7409 ret = btrfs_lookup_file_extent(NULL, root, path,
7410 btrfs_ino(BTRFS_I(inode)), offset, 0);
7411 if (ret < 0)
7412 goto out;
7413
7414 slot = path->slots[0];
7415 if (ret == 1) {
7416 if (slot == 0) {
7417 /* can't find the item, must cow */
7418 ret = 0;
7419 goto out;
7420 }
7421 slot--;
7422 }
7423 ret = 0;
7424 leaf = path->nodes[0];
7425 btrfs_item_key_to_cpu(leaf, &key, slot);
7426 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7427 key.type != BTRFS_EXTENT_DATA_KEY) {
7428 /* not our file or wrong item type, must cow */
7429 goto out;
7430 }
7431
7432 if (key.offset > offset) {
7433 /* Wrong offset, must cow */
7434 goto out;
7435 }
7436
7437 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7438 found_type = btrfs_file_extent_type(leaf, fi);
7439 if (found_type != BTRFS_FILE_EXTENT_REG &&
7440 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7441 /* not a regular extent, must cow */
7442 goto out;
7443 }
7444
7445 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7446 goto out;
7447
7448 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7449 if (extent_end <= offset)
7450 goto out;
7451
7452 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7453 if (disk_bytenr == 0)
7454 goto out;
7455
7456 if (btrfs_file_extent_compression(leaf, fi) ||
7457 btrfs_file_extent_encryption(leaf, fi) ||
7458 btrfs_file_extent_other_encoding(leaf, fi))
7459 goto out;
7460
7461 /*
7462 * Do the same check as in btrfs_cross_ref_exist but without the
7463 * unnecessary search.
7464 */
7465 if (btrfs_file_extent_generation(leaf, fi) <=
7466 btrfs_root_last_snapshot(&root->root_item))
7467 goto out;
7468
7469 backref_offset = btrfs_file_extent_offset(leaf, fi);
7470
7471 if (orig_start) {
7472 *orig_start = key.offset - backref_offset;
7473 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7474 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7475 }
7476
7477 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7478 goto out;
7479
7480 num_bytes = min(offset + *len, extent_end) - offset;
7481 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7482 u64 range_end;
7483
7484 range_end = round_up(offset + num_bytes,
7485 root->fs_info->sectorsize) - 1;
7486 ret = test_range_bit(io_tree, offset, range_end,
7487 EXTENT_DELALLOC, 0, NULL);
7488 if (ret) {
7489 ret = -EAGAIN;
7490 goto out;
7491 }
7492 }
7493
7494 btrfs_release_path(path);
7495
7496 /*
7497 * look for other files referencing this extent, if we
7498 * find any we must cow
7499 */
7500
7501 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7502 key.offset - backref_offset, disk_bytenr);
7503 if (ret) {
7504 ret = 0;
7505 goto out;
7506 }
7507
7508 /*
7509 * adjust disk_bytenr and num_bytes to cover just the bytes
7510 * in this extent we are about to write. If there
7511 * are any csums in that range we have to cow in order
7512 * to keep the csums correct
7513 */
7514 disk_bytenr += backref_offset;
7515 disk_bytenr += offset - key.offset;
7516 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7517 goto out;
7518 /*
7519 * all of the above have passed, it is safe to overwrite this extent
7520 * without cow
7521 */
7522 *len = num_bytes;
7523 ret = 1;
7524 out:
7525 btrfs_free_path(path);
7526 return ret;
7527 }
7528
7529 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7530 struct extent_state **cached_state, int writing)
7531 {
7532 struct btrfs_ordered_extent *ordered;
7533 int ret = 0;
7534
7535 while (1) {
7536 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7537 cached_state);
7538 /*
7539 * We're concerned with the entire range that we're going to be
7540 * doing DIO to, so we need to make sure there's no ordered
7541 * extents in this range.
7542 */
7543 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7544 lockend - lockstart + 1);
7545
7546 /*
7547 * We need to make sure there are no buffered pages in this
7548 * range either, we could have raced between the invalidate in
7549 * generic_file_direct_write and locking the extent. The
7550 * invalidate needs to happen so that reads after a write do not
7551 * get stale data.
7552 */
7553 if (!ordered &&
7554 (!writing || !filemap_range_has_page(inode->i_mapping,
7555 lockstart, lockend)))
7556 break;
7557
7558 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7559 cached_state);
7560
7561 if (ordered) {
7562 /*
7563 * If we are doing a DIO read and the ordered extent we
7564 * found is for a buffered write, we can not wait for it
7565 * to complete and retry, because if we do so we can
7566 * deadlock with concurrent buffered writes on page
7567 * locks. This happens only if our DIO read covers more
7568 * than one extent map, if at this point has already
7569 * created an ordered extent for a previous extent map
7570 * and locked its range in the inode's io tree, and a
7571 * concurrent write against that previous extent map's
7572 * range and this range started (we unlock the ranges
7573 * in the io tree only when the bios complete and
7574 * buffered writes always lock pages before attempting
7575 * to lock range in the io tree).
7576 */
7577 if (writing ||
7578 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7579 btrfs_start_ordered_extent(inode, ordered, 1);
7580 else
7581 ret = -ENOTBLK;
7582 btrfs_put_ordered_extent(ordered);
7583 } else {
7584 /*
7585 * We could trigger writeback for this range (and wait
7586 * for it to complete) and then invalidate the pages for
7587 * this range (through invalidate_inode_pages2_range()),
7588 * but that can lead us to a deadlock with a concurrent
7589 * call to readpages() (a buffered read or a defrag call
7590 * triggered a readahead) on a page lock due to an
7591 * ordered dio extent we created before but did not have
7592 * yet a corresponding bio submitted (whence it can not
7593 * complete), which makes readpages() wait for that
7594 * ordered extent to complete while holding a lock on
7595 * that page.
7596 */
7597 ret = -ENOTBLK;
7598 }
7599
7600 if (ret)
7601 break;
7602
7603 cond_resched();
7604 }
7605
7606 return ret;
7607 }
7608
7609 /* The callers of this must take lock_extent() */
7610 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7611 u64 orig_start, u64 block_start,
7612 u64 block_len, u64 orig_block_len,
7613 u64 ram_bytes, int compress_type,
7614 int type)
7615 {
7616 struct extent_map_tree *em_tree;
7617 struct extent_map *em;
7618 int ret;
7619
7620 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7621 type == BTRFS_ORDERED_COMPRESSED ||
7622 type == BTRFS_ORDERED_NOCOW ||
7623 type == BTRFS_ORDERED_REGULAR);
7624
7625 em_tree = &BTRFS_I(inode)->extent_tree;
7626 em = alloc_extent_map();
7627 if (!em)
7628 return ERR_PTR(-ENOMEM);
7629
7630 em->start = start;
7631 em->orig_start = orig_start;
7632 em->len = len;
7633 em->block_len = block_len;
7634 em->block_start = block_start;
7635 em->orig_block_len = orig_block_len;
7636 em->ram_bytes = ram_bytes;
7637 em->generation = -1;
7638 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7639 if (type == BTRFS_ORDERED_PREALLOC) {
7640 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7641 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7642 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7643 em->compress_type = compress_type;
7644 }
7645
7646 do {
7647 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7648 em->start + em->len - 1, 0);
7649 write_lock(&em_tree->lock);
7650 ret = add_extent_mapping(em_tree, em, 1);
7651 write_unlock(&em_tree->lock);
7652 /*
7653 * The caller has taken lock_extent(), who could race with us
7654 * to add em?
7655 */
7656 } while (ret == -EEXIST);
7657
7658 if (ret) {
7659 free_extent_map(em);
7660 return ERR_PTR(ret);
7661 }
7662
7663 /* em got 2 refs now, callers needs to do free_extent_map once. */
7664 return em;
7665 }
7666
7667
7668 static int btrfs_get_blocks_direct_read(struct extent_map *em,
7669 struct buffer_head *bh_result,
7670 struct inode *inode,
7671 u64 start, u64 len)
7672 {
7673 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7674
7675 if (em->block_start == EXTENT_MAP_HOLE ||
7676 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7677 return -ENOENT;
7678
7679 len = min(len, em->len - (start - em->start));
7680
7681 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7682 inode->i_blkbits;
7683 bh_result->b_size = len;
7684 bh_result->b_bdev = fs_info->fs_devices->latest_bdev;
7685 set_buffer_mapped(bh_result);
7686
7687 return 0;
7688 }
7689
7690 static int btrfs_get_blocks_direct_write(struct extent_map **map,
7691 struct buffer_head *bh_result,
7692 struct inode *inode,
7693 struct btrfs_dio_data *dio_data,
7694 u64 start, u64 len)
7695 {
7696 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7697 struct extent_map *em = *map;
7698 int ret = 0;
7699
7700 /*
7701 * We don't allocate a new extent in the following cases
7702 *
7703 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7704 * existing extent.
7705 * 2) The extent is marked as PREALLOC. We're good to go here and can
7706 * just use the extent.
7707 *
7708 */
7709 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7710 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7711 em->block_start != EXTENT_MAP_HOLE)) {
7712 int type;
7713 u64 block_start, orig_start, orig_block_len, ram_bytes;
7714
7715 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7716 type = BTRFS_ORDERED_PREALLOC;
7717 else
7718 type = BTRFS_ORDERED_NOCOW;
7719 len = min(len, em->len - (start - em->start));
7720 block_start = em->block_start + (start - em->start);
7721
7722 if (can_nocow_extent(inode, start, &len, &orig_start,
7723 &orig_block_len, &ram_bytes) == 1 &&
7724 btrfs_inc_nocow_writers(fs_info, block_start)) {
7725 struct extent_map *em2;
7726
7727 em2 = btrfs_create_dio_extent(inode, start, len,
7728 orig_start, block_start,
7729 len, orig_block_len,
7730 ram_bytes, type);
7731 btrfs_dec_nocow_writers(fs_info, block_start);
7732 if (type == BTRFS_ORDERED_PREALLOC) {
7733 free_extent_map(em);
7734 *map = em = em2;
7735 }
7736
7737 if (em2 && IS_ERR(em2)) {
7738 ret = PTR_ERR(em2);
7739 goto out;
7740 }
7741 /*
7742 * For inode marked NODATACOW or extent marked PREALLOC,
7743 * use the existing or preallocated extent, so does not
7744 * need to adjust btrfs_space_info's bytes_may_use.
7745 */
7746 btrfs_free_reserved_data_space_noquota(inode, start,
7747 len);
7748 goto skip_cow;
7749 }
7750 }
7751
7752 /* this will cow the extent */
7753 len = bh_result->b_size;
7754 free_extent_map(em);
7755 *map = em = btrfs_new_extent_direct(inode, start, len);
7756 if (IS_ERR(em)) {
7757 ret = PTR_ERR(em);
7758 goto out;
7759 }
7760
7761 len = min(len, em->len - (start - em->start));
7762
7763 skip_cow:
7764 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7765 inode->i_blkbits;
7766 bh_result->b_size = len;
7767 bh_result->b_bdev = fs_info->fs_devices->latest_bdev;
7768 set_buffer_mapped(bh_result);
7769
7770 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7771 set_buffer_new(bh_result);
7772
7773 /*
7774 * Need to update the i_size under the extent lock so buffered
7775 * readers will get the updated i_size when we unlock.
7776 */
7777 if (!dio_data->overwrite && start + len > i_size_read(inode))
7778 i_size_write(inode, start + len);
7779
7780 WARN_ON(dio_data->reserve < len);
7781 dio_data->reserve -= len;
7782 dio_data->unsubmitted_oe_range_end = start + len;
7783 current->journal_info = dio_data;
7784 out:
7785 return ret;
7786 }
7787
7788 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7789 struct buffer_head *bh_result, int create)
7790 {
7791 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7792 struct extent_map *em;
7793 struct extent_state *cached_state = NULL;
7794 struct btrfs_dio_data *dio_data = NULL;
7795 u64 start = iblock << inode->i_blkbits;
7796 u64 lockstart, lockend;
7797 u64 len = bh_result->b_size;
7798 int ret = 0;
7799
7800 if (!create)
7801 len = min_t(u64, len, fs_info->sectorsize);
7802
7803 lockstart = start;
7804 lockend = start + len - 1;
7805
7806 if (current->journal_info) {
7807 /*
7808 * Need to pull our outstanding extents and set journal_info to NULL so
7809 * that anything that needs to check if there's a transaction doesn't get
7810 * confused.
7811 */
7812 dio_data = current->journal_info;
7813 current->journal_info = NULL;
7814 }
7815
7816 /*
7817 * If this errors out it's because we couldn't invalidate pagecache for
7818 * this range and we need to fallback to buffered.
7819 */
7820 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7821 create)) {
7822 ret = -ENOTBLK;
7823 goto err;
7824 }
7825
7826 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7827 if (IS_ERR(em)) {
7828 ret = PTR_ERR(em);
7829 goto unlock_err;
7830 }
7831
7832 /*
7833 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7834 * io. INLINE is special, and we could probably kludge it in here, but
7835 * it's still buffered so for safety lets just fall back to the generic
7836 * buffered path.
7837 *
7838 * For COMPRESSED we _have_ to read the entire extent in so we can
7839 * decompress it, so there will be buffering required no matter what we
7840 * do, so go ahead and fallback to buffered.
7841 *
7842 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7843 * to buffered IO. Don't blame me, this is the price we pay for using
7844 * the generic code.
7845 */
7846 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7847 em->block_start == EXTENT_MAP_INLINE) {
7848 free_extent_map(em);
7849 ret = -ENOTBLK;
7850 goto unlock_err;
7851 }
7852
7853 if (create) {
7854 ret = btrfs_get_blocks_direct_write(&em, bh_result, inode,
7855 dio_data, start, len);
7856 if (ret < 0)
7857 goto unlock_err;
7858
7859 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
7860 lockend, &cached_state);
7861 } else {
7862 ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
7863 start, len);
7864 /* Can be negative only if we read from a hole */
7865 if (ret < 0) {
7866 ret = 0;
7867 free_extent_map(em);
7868 goto unlock_err;
7869 }
7870 /*
7871 * We need to unlock only the end area that we aren't using.
7872 * The rest is going to be unlocked by the endio routine.
7873 */
7874 lockstart = start + bh_result->b_size;
7875 if (lockstart < lockend) {
7876 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
7877 lockstart, lockend, &cached_state);
7878 } else {
7879 free_extent_state(cached_state);
7880 }
7881 }
7882
7883 free_extent_map(em);
7884
7885 return 0;
7886
7887 unlock_err:
7888 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7889 &cached_state);
7890 err:
7891 if (dio_data)
7892 current->journal_info = dio_data;
7893 return ret;
7894 }
7895
7896 static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7897 struct bio *bio,
7898 int mirror_num)
7899 {
7900 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7901 blk_status_t ret;
7902
7903 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7904
7905 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7906 if (ret)
7907 return ret;
7908
7909 ret = btrfs_map_bio(fs_info, bio, mirror_num);
7910
7911 return ret;
7912 }
7913
7914 static int btrfs_check_dio_repairable(struct inode *inode,
7915 struct bio *failed_bio,
7916 struct io_failure_record *failrec,
7917 int failed_mirror)
7918 {
7919 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7920 int num_copies;
7921
7922 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7923 if (num_copies == 1) {
7924 /*
7925 * we only have a single copy of the data, so don't bother with
7926 * all the retry and error correction code that follows. no
7927 * matter what the error is, it is very likely to persist.
7928 */
7929 btrfs_debug(fs_info,
7930 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7931 num_copies, failrec->this_mirror, failed_mirror);
7932 return 0;
7933 }
7934
7935 failrec->failed_mirror = failed_mirror;
7936 failrec->this_mirror++;
7937 if (failrec->this_mirror == failed_mirror)
7938 failrec->this_mirror++;
7939
7940 if (failrec->this_mirror > num_copies) {
7941 btrfs_debug(fs_info,
7942 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7943 num_copies, failrec->this_mirror, failed_mirror);
7944 return 0;
7945 }
7946
7947 return 1;
7948 }
7949
7950 static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
7951 struct page *page, unsigned int pgoff,
7952 u64 start, u64 end, int failed_mirror,
7953 bio_end_io_t *repair_endio, void *repair_arg)
7954 {
7955 struct io_failure_record *failrec;
7956 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7957 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
7958 struct bio *bio;
7959 int isector;
7960 unsigned int read_mode = 0;
7961 int segs;
7962 int ret;
7963 blk_status_t status;
7964 struct bio_vec bvec;
7965
7966 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7967
7968 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7969 if (ret)
7970 return errno_to_blk_status(ret);
7971
7972 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7973 failed_mirror);
7974 if (!ret) {
7975 free_io_failure(failure_tree, io_tree, failrec);
7976 return BLK_STS_IOERR;
7977 }
7978
7979 segs = bio_segments(failed_bio);
7980 bio_get_first_bvec(failed_bio, &bvec);
7981 if (segs > 1 ||
7982 (bvec.bv_len > btrfs_inode_sectorsize(inode)))
7983 read_mode |= REQ_FAILFAST_DEV;
7984
7985 isector = start - btrfs_io_bio(failed_bio)->logical;
7986 isector >>= inode->i_sb->s_blocksize_bits;
7987 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7988 pgoff, isector, repair_endio, repair_arg);
7989 bio->bi_opf = REQ_OP_READ | read_mode;
7990
7991 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7992 "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
7993 read_mode, failrec->this_mirror, failrec->in_validation);
7994
7995 status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7996 if (status) {
7997 free_io_failure(failure_tree, io_tree, failrec);
7998 bio_put(bio);
7999 }
8000
8001 return status;
8002 }
8003
8004 struct btrfs_retry_complete {
8005 struct completion done;
8006 struct inode *inode;
8007 u64 start;
8008 int uptodate;
8009 };
8010
8011 static void btrfs_retry_endio_nocsum(struct bio *bio)
8012 {
8013 struct btrfs_retry_complete *done = bio->bi_private;
8014 struct inode *inode = done->inode;
8015 struct bio_vec *bvec;
8016 struct extent_io_tree *io_tree, *failure_tree;
8017 struct bvec_iter_all iter_all;
8018
8019 if (bio->bi_status)
8020 goto end;
8021
8022 ASSERT(bio->bi_vcnt == 1);
8023 io_tree = &BTRFS_I(inode)->io_tree;
8024 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8025 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
8026
8027 done->uptodate = 1;
8028 ASSERT(!bio_flagged(bio, BIO_CLONED));
8029 bio_for_each_segment_all(bvec, bio, iter_all)
8030 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
8031 io_tree, done->start, bvec->bv_page,
8032 btrfs_ino(BTRFS_I(inode)), 0);
8033 end:
8034 complete(&done->done);
8035 bio_put(bio);
8036 }
8037
8038 static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
8039 struct btrfs_io_bio *io_bio)
8040 {
8041 struct btrfs_fs_info *fs_info;
8042 struct bio_vec bvec;
8043 struct bvec_iter iter;
8044 struct btrfs_retry_complete done;
8045 u64 start;
8046 unsigned int pgoff;
8047 u32 sectorsize;
8048 int nr_sectors;
8049 blk_status_t ret;
8050 blk_status_t err = BLK_STS_OK;
8051
8052 fs_info = BTRFS_I(inode)->root->fs_info;
8053 sectorsize = fs_info->sectorsize;
8054
8055 start = io_bio->logical;
8056 done.inode = inode;
8057 io_bio->bio.bi_iter = io_bio->iter;
8058
8059 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8060 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8061 pgoff = bvec.bv_offset;
8062
8063 next_block_or_try_again:
8064 done.uptodate = 0;
8065 done.start = start;
8066 init_completion(&done.done);
8067
8068 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8069 pgoff, start, start + sectorsize - 1,
8070 io_bio->mirror_num,
8071 btrfs_retry_endio_nocsum, &done);
8072 if (ret) {
8073 err = ret;
8074 goto next;
8075 }
8076
8077 wait_for_completion_io(&done.done);
8078
8079 if (!done.uptodate) {
8080 /* We might have another mirror, so try again */
8081 goto next_block_or_try_again;
8082 }
8083
8084 next:
8085 start += sectorsize;
8086
8087 nr_sectors--;
8088 if (nr_sectors) {
8089 pgoff += sectorsize;
8090 ASSERT(pgoff < PAGE_SIZE);
8091 goto next_block_or_try_again;
8092 }
8093 }
8094
8095 return err;
8096 }
8097
8098 static void btrfs_retry_endio(struct bio *bio)
8099 {
8100 struct btrfs_retry_complete *done = bio->bi_private;
8101 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8102 struct extent_io_tree *io_tree, *failure_tree;
8103 struct inode *inode = done->inode;
8104 struct bio_vec *bvec;
8105 int uptodate;
8106 int ret;
8107 int i = 0;
8108 struct bvec_iter_all iter_all;
8109
8110 if (bio->bi_status)
8111 goto end;
8112
8113 uptodate = 1;
8114
8115 ASSERT(bio->bi_vcnt == 1);
8116 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
8117
8118 io_tree = &BTRFS_I(inode)->io_tree;
8119 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8120
8121 ASSERT(!bio_flagged(bio, BIO_CLONED));
8122 bio_for_each_segment_all(bvec, bio, iter_all) {
8123 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8124 bvec->bv_offset, done->start,
8125 bvec->bv_len);
8126 if (!ret)
8127 clean_io_failure(BTRFS_I(inode)->root->fs_info,
8128 failure_tree, io_tree, done->start,
8129 bvec->bv_page,
8130 btrfs_ino(BTRFS_I(inode)),
8131 bvec->bv_offset);
8132 else
8133 uptodate = 0;
8134 i++;
8135 }
8136
8137 done->uptodate = uptodate;
8138 end:
8139 complete(&done->done);
8140 bio_put(bio);
8141 }
8142
8143 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8144 struct btrfs_io_bio *io_bio, blk_status_t err)
8145 {
8146 struct btrfs_fs_info *fs_info;
8147 struct bio_vec bvec;
8148 struct bvec_iter iter;
8149 struct btrfs_retry_complete done;
8150 u64 start;
8151 u64 offset = 0;
8152 u32 sectorsize;
8153 int nr_sectors;
8154 unsigned int pgoff;
8155 int csum_pos;
8156 bool uptodate = (err == 0);
8157 int ret;
8158 blk_status_t status;
8159
8160 fs_info = BTRFS_I(inode)->root->fs_info;
8161 sectorsize = fs_info->sectorsize;
8162
8163 err = BLK_STS_OK;
8164 start = io_bio->logical;
8165 done.inode = inode;
8166 io_bio->bio.bi_iter = io_bio->iter;
8167
8168 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8169 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8170
8171 pgoff = bvec.bv_offset;
8172 next_block:
8173 if (uptodate) {
8174 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8175 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8176 bvec.bv_page, pgoff, start, sectorsize);
8177 if (likely(!ret))
8178 goto next;
8179 }
8180 try_again:
8181 done.uptodate = 0;
8182 done.start = start;
8183 init_completion(&done.done);
8184
8185 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8186 pgoff, start, start + sectorsize - 1,
8187 io_bio->mirror_num, btrfs_retry_endio,
8188 &done);
8189 if (status) {
8190 err = status;
8191 goto next;
8192 }
8193
8194 wait_for_completion_io(&done.done);
8195
8196 if (!done.uptodate) {
8197 /* We might have another mirror, so try again */
8198 goto try_again;
8199 }
8200 next:
8201 offset += sectorsize;
8202 start += sectorsize;
8203
8204 ASSERT(nr_sectors);
8205
8206 nr_sectors--;
8207 if (nr_sectors) {
8208 pgoff += sectorsize;
8209 ASSERT(pgoff < PAGE_SIZE);
8210 goto next_block;
8211 }
8212 }
8213
8214 return err;
8215 }
8216
8217 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8218 struct btrfs_io_bio *io_bio, blk_status_t err)
8219 {
8220 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8221
8222 if (skip_csum) {
8223 if (unlikely(err))
8224 return __btrfs_correct_data_nocsum(inode, io_bio);
8225 else
8226 return BLK_STS_OK;
8227 } else {
8228 return __btrfs_subio_endio_read(inode, io_bio, err);
8229 }
8230 }
8231
8232 static void btrfs_endio_direct_read(struct bio *bio)
8233 {
8234 struct btrfs_dio_private *dip = bio->bi_private;
8235 struct inode *inode = dip->inode;
8236 struct bio *dio_bio;
8237 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8238 blk_status_t err = bio->bi_status;
8239
8240 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8241 err = btrfs_subio_endio_read(inode, io_bio, err);
8242
8243 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8244 dip->logical_offset + dip->bytes - 1);
8245 dio_bio = dip->dio_bio;
8246
8247 kfree(dip);
8248
8249 dio_bio->bi_status = err;
8250 dio_end_io(dio_bio);
8251 btrfs_io_bio_free_csum(io_bio);
8252 bio_put(bio);
8253 }
8254
8255 static void __endio_write_update_ordered(struct inode *inode,
8256 const u64 offset, const u64 bytes,
8257 const bool uptodate)
8258 {
8259 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8260 struct btrfs_ordered_extent *ordered = NULL;
8261 struct btrfs_workqueue *wq;
8262 u64 ordered_offset = offset;
8263 u64 ordered_bytes = bytes;
8264 u64 last_offset;
8265
8266 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
8267 wq = fs_info->endio_freespace_worker;
8268 else
8269 wq = fs_info->endio_write_workers;
8270
8271 while (ordered_offset < offset + bytes) {
8272 last_offset = ordered_offset;
8273 if (btrfs_dec_test_first_ordered_pending(inode, &ordered,
8274 &ordered_offset,
8275 ordered_bytes,
8276 uptodate)) {
8277 btrfs_init_work(&ordered->work, finish_ordered_fn, NULL,
8278 NULL);
8279 btrfs_queue_work(wq, &ordered->work);
8280 }
8281 /*
8282 * If btrfs_dec_test_ordered_pending does not find any ordered
8283 * extent in the range, we can exit.
8284 */
8285 if (ordered_offset == last_offset)
8286 return;
8287 /*
8288 * Our bio might span multiple ordered extents. In this case
8289 * we keep going until we have accounted the whole dio.
8290 */
8291 if (ordered_offset < offset + bytes) {
8292 ordered_bytes = offset + bytes - ordered_offset;
8293 ordered = NULL;
8294 }
8295 }
8296 }
8297
8298 static void btrfs_endio_direct_write(struct bio *bio)
8299 {
8300 struct btrfs_dio_private *dip = bio->bi_private;
8301 struct bio *dio_bio = dip->dio_bio;
8302
8303 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8304 dip->bytes, !bio->bi_status);
8305
8306 kfree(dip);
8307
8308 dio_bio->bi_status = bio->bi_status;
8309 dio_end_io(dio_bio);
8310 bio_put(bio);
8311 }
8312
8313 static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
8314 struct bio *bio, u64 offset)
8315 {
8316 struct inode *inode = private_data;
8317 blk_status_t ret;
8318 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8319 BUG_ON(ret); /* -ENOMEM */
8320 return 0;
8321 }
8322
8323 static void btrfs_end_dio_bio(struct bio *bio)
8324 {
8325 struct btrfs_dio_private *dip = bio->bi_private;
8326 blk_status_t err = bio->bi_status;
8327
8328 if (err)
8329 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8330 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8331 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8332 bio->bi_opf,
8333 (unsigned long long)bio->bi_iter.bi_sector,
8334 bio->bi_iter.bi_size, err);
8335
8336 if (dip->subio_endio)
8337 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8338
8339 if (err) {
8340 /*
8341 * We want to perceive the errors flag being set before
8342 * decrementing the reference count. We don't need a barrier
8343 * since atomic operations with a return value are fully
8344 * ordered as per atomic_t.txt
8345 */
8346 dip->errors = 1;
8347 }
8348
8349 /* if there are more bios still pending for this dio, just exit */
8350 if (!atomic_dec_and_test(&dip->pending_bios))
8351 goto out;
8352
8353 if (dip->errors) {
8354 bio_io_error(dip->orig_bio);
8355 } else {
8356 dip->dio_bio->bi_status = BLK_STS_OK;
8357 bio_endio(dip->orig_bio);
8358 }
8359 out:
8360 bio_put(bio);
8361 }
8362
8363 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8364 struct btrfs_dio_private *dip,
8365 struct bio *bio,
8366 u64 file_offset)
8367 {
8368 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8369 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8370 blk_status_t ret;
8371
8372 /*
8373 * We load all the csum data we need when we submit
8374 * the first bio to reduce the csum tree search and
8375 * contention.
8376 */
8377 if (dip->logical_offset == file_offset) {
8378 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8379 file_offset);
8380 if (ret)
8381 return ret;
8382 }
8383
8384 if (bio == dip->orig_bio)
8385 return 0;
8386
8387 file_offset -= dip->logical_offset;
8388 file_offset >>= inode->i_sb->s_blocksize_bits;
8389 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8390
8391 return 0;
8392 }
8393
8394 static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
8395 struct inode *inode, u64 file_offset, int async_submit)
8396 {
8397 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8398 struct btrfs_dio_private *dip = bio->bi_private;
8399 bool write = bio_op(bio) == REQ_OP_WRITE;
8400 blk_status_t ret;
8401
8402 /* Check btrfs_submit_bio_hook() for rules about async submit. */
8403 if (async_submit)
8404 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8405
8406 if (!write) {
8407 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8408 if (ret)
8409 goto err;
8410 }
8411
8412 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8413 goto map;
8414
8415 if (write && async_submit) {
8416 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8417 file_offset, inode,
8418 btrfs_submit_bio_start_direct_io);
8419 goto err;
8420 } else if (write) {
8421 /*
8422 * If we aren't doing async submit, calculate the csum of the
8423 * bio now.
8424 */
8425 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8426 if (ret)
8427 goto err;
8428 } else {
8429 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8430 file_offset);
8431 if (ret)
8432 goto err;
8433 }
8434 map:
8435 ret = btrfs_map_bio(fs_info, bio, 0);
8436 err:
8437 return ret;
8438 }
8439
8440 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8441 {
8442 struct inode *inode = dip->inode;
8443 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8444 struct bio *bio;
8445 struct bio *orig_bio = dip->orig_bio;
8446 u64 start_sector = orig_bio->bi_iter.bi_sector;
8447 u64 file_offset = dip->logical_offset;
8448 int async_submit = 0;
8449 u64 submit_len;
8450 int clone_offset = 0;
8451 int clone_len;
8452 int ret;
8453 blk_status_t status;
8454 struct btrfs_io_geometry geom;
8455
8456 submit_len = orig_bio->bi_iter.bi_size;
8457 ret = btrfs_get_io_geometry(fs_info, btrfs_op(orig_bio),
8458 start_sector << 9, submit_len, &geom);
8459 if (ret)
8460 return -EIO;
8461
8462 if (geom.len >= submit_len) {
8463 bio = orig_bio;
8464 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8465 goto submit;
8466 }
8467
8468 /* async crcs make it difficult to collect full stripe writes. */
8469 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8470 async_submit = 0;
8471 else
8472 async_submit = 1;
8473
8474 /* bio split */
8475 ASSERT(geom.len <= INT_MAX);
8476 atomic_inc(&dip->pending_bios);
8477 do {
8478 clone_len = min_t(int, submit_len, geom.len);
8479
8480 /*
8481 * This will never fail as it's passing GPF_NOFS and
8482 * the allocation is backed by btrfs_bioset.
8483 */
8484 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8485 clone_len);
8486 bio->bi_private = dip;
8487 bio->bi_end_io = btrfs_end_dio_bio;
8488 btrfs_io_bio(bio)->logical = file_offset;
8489
8490 ASSERT(submit_len >= clone_len);
8491 submit_len -= clone_len;
8492 if (submit_len == 0)
8493 break;
8494
8495 /*
8496 * Increase the count before we submit the bio so we know
8497 * the end IO handler won't happen before we increase the
8498 * count. Otherwise, the dip might get freed before we're
8499 * done setting it up.
8500 */
8501 atomic_inc(&dip->pending_bios);
8502
8503 status = btrfs_submit_dio_bio(bio, inode, file_offset,
8504 async_submit);
8505 if (status) {
8506 bio_put(bio);
8507 atomic_dec(&dip->pending_bios);
8508 goto out_err;
8509 }
8510
8511 clone_offset += clone_len;
8512 start_sector += clone_len >> 9;
8513 file_offset += clone_len;
8514
8515 ret = btrfs_get_io_geometry(fs_info, btrfs_op(orig_bio),
8516 start_sector << 9, submit_len, &geom);
8517 if (ret)
8518 goto out_err;
8519 } while (submit_len > 0);
8520
8521 submit:
8522 status = btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8523 if (!status)
8524 return 0;
8525
8526 bio_put(bio);
8527 out_err:
8528 dip->errors = 1;
8529 /*
8530 * Before atomic variable goto zero, we must make sure dip->errors is
8531 * perceived to be set. This ordering is ensured by the fact that an
8532 * atomic operations with a return value are fully ordered as per
8533 * atomic_t.txt
8534 */
8535 if (atomic_dec_and_test(&dip->pending_bios))
8536 bio_io_error(dip->orig_bio);
8537
8538 /* bio_end_io() will handle error, so we needn't return it */
8539 return 0;
8540 }
8541
8542 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8543 loff_t file_offset)
8544 {
8545 struct btrfs_dio_private *dip = NULL;
8546 struct bio *bio = NULL;
8547 struct btrfs_io_bio *io_bio;
8548 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8549 int ret = 0;
8550
8551 bio = btrfs_bio_clone(dio_bio);
8552
8553 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8554 if (!dip) {
8555 ret = -ENOMEM;
8556 goto free_ordered;
8557 }
8558
8559 dip->private = dio_bio->bi_private;
8560 dip->inode = inode;
8561 dip->logical_offset = file_offset;
8562 dip->bytes = dio_bio->bi_iter.bi_size;
8563 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8564 bio->bi_private = dip;
8565 dip->orig_bio = bio;
8566 dip->dio_bio = dio_bio;
8567 atomic_set(&dip->pending_bios, 0);
8568 io_bio = btrfs_io_bio(bio);
8569 io_bio->logical = file_offset;
8570
8571 if (write) {
8572 bio->bi_end_io = btrfs_endio_direct_write;
8573 } else {
8574 bio->bi_end_io = btrfs_endio_direct_read;
8575 dip->subio_endio = btrfs_subio_endio_read;
8576 }
8577
8578 /*
8579 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8580 * even if we fail to submit a bio, because in such case we do the
8581 * corresponding error handling below and it must not be done a second
8582 * time by btrfs_direct_IO().
8583 */
8584 if (write) {
8585 struct btrfs_dio_data *dio_data = current->journal_info;
8586
8587 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8588 dip->bytes;
8589 dio_data->unsubmitted_oe_range_start =
8590 dio_data->unsubmitted_oe_range_end;
8591 }
8592
8593 ret = btrfs_submit_direct_hook(dip);
8594 if (!ret)
8595 return;
8596
8597 btrfs_io_bio_free_csum(io_bio);
8598
8599 free_ordered:
8600 /*
8601 * If we arrived here it means either we failed to submit the dip
8602 * or we either failed to clone the dio_bio or failed to allocate the
8603 * dip. If we cloned the dio_bio and allocated the dip, we can just
8604 * call bio_endio against our io_bio so that we get proper resource
8605 * cleanup if we fail to submit the dip, otherwise, we must do the
8606 * same as btrfs_endio_direct_[write|read] because we can't call these
8607 * callbacks - they require an allocated dip and a clone of dio_bio.
8608 */
8609 if (bio && dip) {
8610 bio_io_error(bio);
8611 /*
8612 * The end io callbacks free our dip, do the final put on bio
8613 * and all the cleanup and final put for dio_bio (through
8614 * dio_end_io()).
8615 */
8616 dip = NULL;
8617 bio = NULL;
8618 } else {
8619 if (write)
8620 __endio_write_update_ordered(inode,
8621 file_offset,
8622 dio_bio->bi_iter.bi_size,
8623 false);
8624 else
8625 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8626 file_offset + dio_bio->bi_iter.bi_size - 1);
8627
8628 dio_bio->bi_status = BLK_STS_IOERR;
8629 /*
8630 * Releases and cleans up our dio_bio, no need to bio_put()
8631 * nor bio_endio()/bio_io_error() against dio_bio.
8632 */
8633 dio_end_io(dio_bio);
8634 }
8635 if (bio)
8636 bio_put(bio);
8637 kfree(dip);
8638 }
8639
8640 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8641 const struct iov_iter *iter, loff_t offset)
8642 {
8643 int seg;
8644 int i;
8645 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8646 ssize_t retval = -EINVAL;
8647
8648 if (offset & blocksize_mask)
8649 goto out;
8650
8651 if (iov_iter_alignment(iter) & blocksize_mask)
8652 goto out;
8653
8654 /* If this is a write we don't need to check anymore */
8655 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8656 return 0;
8657 /*
8658 * Check to make sure we don't have duplicate iov_base's in this
8659 * iovec, if so return EINVAL, otherwise we'll get csum errors
8660 * when reading back.
8661 */
8662 for (seg = 0; seg < iter->nr_segs; seg++) {
8663 for (i = seg + 1; i < iter->nr_segs; i++) {
8664 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8665 goto out;
8666 }
8667 }
8668 retval = 0;
8669 out:
8670 return retval;
8671 }
8672
8673 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8674 {
8675 struct file *file = iocb->ki_filp;
8676 struct inode *inode = file->f_mapping->host;
8677 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8678 struct btrfs_dio_data dio_data = { 0 };
8679 struct extent_changeset *data_reserved = NULL;
8680 loff_t offset = iocb->ki_pos;
8681 size_t count = 0;
8682 int flags = 0;
8683 bool wakeup = true;
8684 bool relock = false;
8685 ssize_t ret;
8686
8687 if (check_direct_IO(fs_info, iter, offset))
8688 return 0;
8689
8690 inode_dio_begin(inode);
8691
8692 /*
8693 * The generic stuff only does filemap_write_and_wait_range, which
8694 * isn't enough if we've written compressed pages to this area, so
8695 * we need to flush the dirty pages again to make absolutely sure
8696 * that any outstanding dirty pages are on disk.
8697 */
8698 count = iov_iter_count(iter);
8699 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8700 &BTRFS_I(inode)->runtime_flags))
8701 filemap_fdatawrite_range(inode->i_mapping, offset,
8702 offset + count - 1);
8703
8704 if (iov_iter_rw(iter) == WRITE) {
8705 /*
8706 * If the write DIO is beyond the EOF, we need update
8707 * the isize, but it is protected by i_mutex. So we can
8708 * not unlock the i_mutex at this case.
8709 */
8710 if (offset + count <= inode->i_size) {
8711 dio_data.overwrite = 1;
8712 inode_unlock(inode);
8713 relock = true;
8714 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8715 ret = -EAGAIN;
8716 goto out;
8717 }
8718 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8719 offset, count);
8720 if (ret)
8721 goto out;
8722
8723 /*
8724 * We need to know how many extents we reserved so that we can
8725 * do the accounting properly if we go over the number we
8726 * originally calculated. Abuse current->journal_info for this.
8727 */
8728 dio_data.reserve = round_up(count,
8729 fs_info->sectorsize);
8730 dio_data.unsubmitted_oe_range_start = (u64)offset;
8731 dio_data.unsubmitted_oe_range_end = (u64)offset;
8732 current->journal_info = &dio_data;
8733 down_read(&BTRFS_I(inode)->dio_sem);
8734 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8735 &BTRFS_I(inode)->runtime_flags)) {
8736 inode_dio_end(inode);
8737 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8738 wakeup = false;
8739 }
8740
8741 ret = __blockdev_direct_IO(iocb, inode,
8742 fs_info->fs_devices->latest_bdev,
8743 iter, btrfs_get_blocks_direct, NULL,
8744 btrfs_submit_direct, flags);
8745 if (iov_iter_rw(iter) == WRITE) {
8746 up_read(&BTRFS_I(inode)->dio_sem);
8747 current->journal_info = NULL;
8748 if (ret < 0 && ret != -EIOCBQUEUED) {
8749 if (dio_data.reserve)
8750 btrfs_delalloc_release_space(inode, data_reserved,
8751 offset, dio_data.reserve, true);
8752 /*
8753 * On error we might have left some ordered extents
8754 * without submitting corresponding bios for them, so
8755 * cleanup them up to avoid other tasks getting them
8756 * and waiting for them to complete forever.
8757 */
8758 if (dio_data.unsubmitted_oe_range_start <
8759 dio_data.unsubmitted_oe_range_end)
8760 __endio_write_update_ordered(inode,
8761 dio_data.unsubmitted_oe_range_start,
8762 dio_data.unsubmitted_oe_range_end -
8763 dio_data.unsubmitted_oe_range_start,
8764 false);
8765 } else if (ret >= 0 && (size_t)ret < count)
8766 btrfs_delalloc_release_space(inode, data_reserved,
8767 offset, count - (size_t)ret, true);
8768 btrfs_delalloc_release_extents(BTRFS_I(inode), count);
8769 }
8770 out:
8771 if (wakeup)
8772 inode_dio_end(inode);
8773 if (relock)
8774 inode_lock(inode);
8775
8776 extent_changeset_free(data_reserved);
8777 return ret;
8778 }
8779
8780 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8781
8782 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8783 __u64 start, __u64 len)
8784 {
8785 int ret;
8786
8787 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8788 if (ret)
8789 return ret;
8790
8791 return extent_fiemap(inode, fieinfo, start, len);
8792 }
8793
8794 int btrfs_readpage(struct file *file, struct page *page)
8795 {
8796 struct extent_io_tree *tree;
8797 tree = &BTRFS_I(page->mapping->host)->io_tree;
8798 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8799 }
8800
8801 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8802 {
8803 struct inode *inode = page->mapping->host;
8804 int ret;
8805
8806 if (current->flags & PF_MEMALLOC) {
8807 redirty_page_for_writepage(wbc, page);
8808 unlock_page(page);
8809 return 0;
8810 }
8811
8812 /*
8813 * If we are under memory pressure we will call this directly from the
8814 * VM, we need to make sure we have the inode referenced for the ordered
8815 * extent. If not just return like we didn't do anything.
8816 */
8817 if (!igrab(inode)) {
8818 redirty_page_for_writepage(wbc, page);
8819 return AOP_WRITEPAGE_ACTIVATE;
8820 }
8821 ret = extent_write_full_page(page, wbc);
8822 btrfs_add_delayed_iput(inode);
8823 return ret;
8824 }
8825
8826 static int btrfs_writepages(struct address_space *mapping,
8827 struct writeback_control *wbc)
8828 {
8829 return extent_writepages(mapping, wbc);
8830 }
8831
8832 static int
8833 btrfs_readpages(struct file *file, struct address_space *mapping,
8834 struct list_head *pages, unsigned nr_pages)
8835 {
8836 return extent_readpages(mapping, pages, nr_pages);
8837 }
8838
8839 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8840 {
8841 int ret = try_release_extent_mapping(page, gfp_flags);
8842 if (ret == 1) {
8843 ClearPagePrivate(page);
8844 set_page_private(page, 0);
8845 put_page(page);
8846 }
8847 return ret;
8848 }
8849
8850 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8851 {
8852 if (PageWriteback(page) || PageDirty(page))
8853 return 0;
8854 return __btrfs_releasepage(page, gfp_flags);
8855 }
8856
8857 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8858 unsigned int length)
8859 {
8860 struct inode *inode = page->mapping->host;
8861 struct extent_io_tree *tree;
8862 struct btrfs_ordered_extent *ordered;
8863 struct extent_state *cached_state = NULL;
8864 u64 page_start = page_offset(page);
8865 u64 page_end = page_start + PAGE_SIZE - 1;
8866 u64 start;
8867 u64 end;
8868 int inode_evicting = inode->i_state & I_FREEING;
8869
8870 /*
8871 * we have the page locked, so new writeback can't start,
8872 * and the dirty bit won't be cleared while we are here.
8873 *
8874 * Wait for IO on this page so that we can safely clear
8875 * the PagePrivate2 bit and do ordered accounting
8876 */
8877 wait_on_page_writeback(page);
8878
8879 tree = &BTRFS_I(inode)->io_tree;
8880 if (offset) {
8881 btrfs_releasepage(page, GFP_NOFS);
8882 return;
8883 }
8884
8885 if (!inode_evicting)
8886 lock_extent_bits(tree, page_start, page_end, &cached_state);
8887 again:
8888 start = page_start;
8889 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8890 page_end - start + 1);
8891 if (ordered) {
8892 end = min(page_end, ordered->file_offset + ordered->len - 1);
8893 /*
8894 * IO on this page will never be started, so we need
8895 * to account for any ordered extents now
8896 */
8897 if (!inode_evicting)
8898 clear_extent_bit(tree, start, end,
8899 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
8900 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8901 EXTENT_DEFRAG, 1, 0, &cached_state);
8902 /*
8903 * whoever cleared the private bit is responsible
8904 * for the finish_ordered_io
8905 */
8906 if (TestClearPagePrivate2(page)) {
8907 struct btrfs_ordered_inode_tree *tree;
8908 u64 new_len;
8909
8910 tree = &BTRFS_I(inode)->ordered_tree;
8911
8912 spin_lock_irq(&tree->lock);
8913 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8914 new_len = start - ordered->file_offset;
8915 if (new_len < ordered->truncated_len)
8916 ordered->truncated_len = new_len;
8917 spin_unlock_irq(&tree->lock);
8918
8919 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8920 start,
8921 end - start + 1, 1))
8922 btrfs_finish_ordered_io(ordered);
8923 }
8924 btrfs_put_ordered_extent(ordered);
8925 if (!inode_evicting) {
8926 cached_state = NULL;
8927 lock_extent_bits(tree, start, end,
8928 &cached_state);
8929 }
8930
8931 start = end + 1;
8932 if (start < page_end)
8933 goto again;
8934 }
8935
8936 /*
8937 * Qgroup reserved space handler
8938 * Page here will be either
8939 * 1) Already written to disk
8940 * In this case, its reserved space is released from data rsv map
8941 * and will be freed by delayed_ref handler finally.
8942 * So even we call qgroup_free_data(), it won't decrease reserved
8943 * space.
8944 * 2) Not written to disk
8945 * This means the reserved space should be freed here. However,
8946 * if a truncate invalidates the page (by clearing PageDirty)
8947 * and the page is accounted for while allocating extent
8948 * in btrfs_check_data_free_space() we let delayed_ref to
8949 * free the entire extent.
8950 */
8951 if (PageDirty(page))
8952 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
8953 if (!inode_evicting) {
8954 clear_extent_bit(tree, page_start, page_end, EXTENT_LOCKED |
8955 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
8956 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
8957 &cached_state);
8958
8959 __btrfs_releasepage(page, GFP_NOFS);
8960 }
8961
8962 ClearPageChecked(page);
8963 if (PagePrivate(page)) {
8964 ClearPagePrivate(page);
8965 set_page_private(page, 0);
8966 put_page(page);
8967 }
8968 }
8969
8970 /*
8971 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8972 * called from a page fault handler when a page is first dirtied. Hence we must
8973 * be careful to check for EOF conditions here. We set the page up correctly
8974 * for a written page which means we get ENOSPC checking when writing into
8975 * holes and correct delalloc and unwritten extent mapping on filesystems that
8976 * support these features.
8977 *
8978 * We are not allowed to take the i_mutex here so we have to play games to
8979 * protect against truncate races as the page could now be beyond EOF. Because
8980 * truncate_setsize() writes the inode size before removing pages, once we have
8981 * the page lock we can determine safely if the page is beyond EOF. If it is not
8982 * beyond EOF, then the page is guaranteed safe against truncation until we
8983 * unlock the page.
8984 */
8985 vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
8986 {
8987 struct page *page = vmf->page;
8988 struct inode *inode = file_inode(vmf->vma->vm_file);
8989 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8990 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8991 struct btrfs_ordered_extent *ordered;
8992 struct extent_state *cached_state = NULL;
8993 struct extent_changeset *data_reserved = NULL;
8994 char *kaddr;
8995 unsigned long zero_start;
8996 loff_t size;
8997 vm_fault_t ret;
8998 int ret2;
8999 int reserved = 0;
9000 u64 reserved_space;
9001 u64 page_start;
9002 u64 page_end;
9003 u64 end;
9004
9005 reserved_space = PAGE_SIZE;
9006
9007 sb_start_pagefault(inode->i_sb);
9008 page_start = page_offset(page);
9009 page_end = page_start + PAGE_SIZE - 1;
9010 end = page_end;
9011
9012 /*
9013 * Reserving delalloc space after obtaining the page lock can lead to
9014 * deadlock. For example, if a dirty page is locked by this function
9015 * and the call to btrfs_delalloc_reserve_space() ends up triggering
9016 * dirty page write out, then the btrfs_writepage() function could
9017 * end up waiting indefinitely to get a lock on the page currently
9018 * being processed by btrfs_page_mkwrite() function.
9019 */
9020 ret2 = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
9021 reserved_space);
9022 if (!ret2) {
9023 ret2 = file_update_time(vmf->vma->vm_file);
9024 reserved = 1;
9025 }
9026 if (ret2) {
9027 ret = vmf_error(ret2);
9028 if (reserved)
9029 goto out;
9030 goto out_noreserve;
9031 }
9032
9033 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9034 again:
9035 lock_page(page);
9036 size = i_size_read(inode);
9037
9038 if ((page->mapping != inode->i_mapping) ||
9039 (page_start >= size)) {
9040 /* page got truncated out from underneath us */
9041 goto out_unlock;
9042 }
9043 wait_on_page_writeback(page);
9044
9045 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9046 set_page_extent_mapped(page);
9047
9048 /*
9049 * we can't set the delalloc bits if there are pending ordered
9050 * extents. Drop our locks and wait for them to finish
9051 */
9052 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
9053 PAGE_SIZE);
9054 if (ordered) {
9055 unlock_extent_cached(io_tree, page_start, page_end,
9056 &cached_state);
9057 unlock_page(page);
9058 btrfs_start_ordered_extent(inode, ordered, 1);
9059 btrfs_put_ordered_extent(ordered);
9060 goto again;
9061 }
9062
9063 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9064 reserved_space = round_up(size - page_start,
9065 fs_info->sectorsize);
9066 if (reserved_space < PAGE_SIZE) {
9067 end = page_start + reserved_space - 1;
9068 btrfs_delalloc_release_space(inode, data_reserved,
9069 page_start, PAGE_SIZE - reserved_space,
9070 true);
9071 }
9072 }
9073
9074 /*
9075 * page_mkwrite gets called when the page is firstly dirtied after it's
9076 * faulted in, but write(2) could also dirty a page and set delalloc
9077 * bits, thus in this case for space account reason, we still need to
9078 * clear any delalloc bits within this page range since we have to
9079 * reserve data&meta space before lock_page() (see above comments).
9080 */
9081 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9082 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
9083 EXTENT_DEFRAG, 0, 0, &cached_state);
9084
9085 ret2 = btrfs_set_extent_delalloc(inode, page_start, end, 0,
9086 &cached_state);
9087 if (ret2) {
9088 unlock_extent_cached(io_tree, page_start, page_end,
9089 &cached_state);
9090 ret = VM_FAULT_SIGBUS;
9091 goto out_unlock;
9092 }
9093 ret2 = 0;
9094
9095 /* page is wholly or partially inside EOF */
9096 if (page_start + PAGE_SIZE > size)
9097 zero_start = offset_in_page(size);
9098 else
9099 zero_start = PAGE_SIZE;
9100
9101 if (zero_start != PAGE_SIZE) {
9102 kaddr = kmap(page);
9103 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9104 flush_dcache_page(page);
9105 kunmap(page);
9106 }
9107 ClearPageChecked(page);
9108 set_page_dirty(page);
9109 SetPageUptodate(page);
9110
9111 BTRFS_I(inode)->last_trans = fs_info->generation;
9112 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9113 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9114
9115 unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
9116
9117 if (!ret2) {
9118 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9119 sb_end_pagefault(inode->i_sb);
9120 extent_changeset_free(data_reserved);
9121 return VM_FAULT_LOCKED;
9122 }
9123
9124 out_unlock:
9125 unlock_page(page);
9126 out:
9127 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9128 btrfs_delalloc_release_space(inode, data_reserved, page_start,
9129 reserved_space, (ret != 0));
9130 out_noreserve:
9131 sb_end_pagefault(inode->i_sb);
9132 extent_changeset_free(data_reserved);
9133 return ret;
9134 }
9135
9136 static int btrfs_truncate(struct inode *inode, bool skip_writeback)
9137 {
9138 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9139 struct btrfs_root *root = BTRFS_I(inode)->root;
9140 struct btrfs_block_rsv *rsv;
9141 int ret;
9142 struct btrfs_trans_handle *trans;
9143 u64 mask = fs_info->sectorsize - 1;
9144 u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
9145
9146 if (!skip_writeback) {
9147 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9148 (u64)-1);
9149 if (ret)
9150 return ret;
9151 }
9152
9153 /*
9154 * Yes ladies and gentlemen, this is indeed ugly. We have a couple of
9155 * things going on here:
9156 *
9157 * 1) We need to reserve space to update our inode.
9158 *
9159 * 2) We need to have something to cache all the space that is going to
9160 * be free'd up by the truncate operation, but also have some slack
9161 * space reserved in case it uses space during the truncate (thank you
9162 * very much snapshotting).
9163 *
9164 * And we need these to be separate. The fact is we can use a lot of
9165 * space doing the truncate, and we have no earthly idea how much space
9166 * we will use, so we need the truncate reservation to be separate so it
9167 * doesn't end up using space reserved for updating the inode. We also
9168 * need to be able to stop the transaction and start a new one, which
9169 * means we need to be able to update the inode several times, and we
9170 * have no idea of knowing how many times that will be, so we can't just
9171 * reserve 1 item for the entirety of the operation, so that has to be
9172 * done separately as well.
9173 *
9174 * So that leaves us with
9175 *
9176 * 1) rsv - for the truncate reservation, which we will steal from the
9177 * transaction reservation.
9178 * 2) fs_info->trans_block_rsv - this will have 1 items worth left for
9179 * updating the inode.
9180 */
9181 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9182 if (!rsv)
9183 return -ENOMEM;
9184 rsv->size = min_size;
9185 rsv->failfast = 1;
9186
9187 /*
9188 * 1 for the truncate slack space
9189 * 1 for updating the inode.
9190 */
9191 trans = btrfs_start_transaction(root, 2);
9192 if (IS_ERR(trans)) {
9193 ret = PTR_ERR(trans);
9194 goto out;
9195 }
9196
9197 /* Migrate the slack space for the truncate to our reserve */
9198 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9199 min_size, false);
9200 BUG_ON(ret);
9201
9202 /*
9203 * So if we truncate and then write and fsync we normally would just
9204 * write the extents that changed, which is a problem if we need to
9205 * first truncate that entire inode. So set this flag so we write out
9206 * all of the extents in the inode to the sync log so we're completely
9207 * safe.
9208 */
9209 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9210 trans->block_rsv = rsv;
9211
9212 while (1) {
9213 ret = btrfs_truncate_inode_items(trans, root, inode,
9214 inode->i_size,
9215 BTRFS_EXTENT_DATA_KEY);
9216 trans->block_rsv = &fs_info->trans_block_rsv;
9217 if (ret != -ENOSPC && ret != -EAGAIN)
9218 break;
9219
9220 ret = btrfs_update_inode(trans, root, inode);
9221 if (ret)
9222 break;
9223
9224 btrfs_end_transaction(trans);
9225 btrfs_btree_balance_dirty(fs_info);
9226
9227 trans = btrfs_start_transaction(root, 2);
9228 if (IS_ERR(trans)) {
9229 ret = PTR_ERR(trans);
9230 trans = NULL;
9231 break;
9232 }
9233
9234 btrfs_block_rsv_release(fs_info, rsv, -1);
9235 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9236 rsv, min_size, false);
9237 BUG_ON(ret); /* shouldn't happen */
9238 trans->block_rsv = rsv;
9239 }
9240
9241 /*
9242 * We can't call btrfs_truncate_block inside a trans handle as we could
9243 * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9244 * we've truncated everything except the last little bit, and can do
9245 * btrfs_truncate_block and then update the disk_i_size.
9246 */
9247 if (ret == NEED_TRUNCATE_BLOCK) {
9248 btrfs_end_transaction(trans);
9249 btrfs_btree_balance_dirty(fs_info);
9250
9251 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9252 if (ret)
9253 goto out;
9254 trans = btrfs_start_transaction(root, 1);
9255 if (IS_ERR(trans)) {
9256 ret = PTR_ERR(trans);
9257 goto out;
9258 }
9259 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9260 }
9261
9262 if (trans) {
9263 int ret2;
9264
9265 trans->block_rsv = &fs_info->trans_block_rsv;
9266 ret2 = btrfs_update_inode(trans, root, inode);
9267 if (ret2 && !ret)
9268 ret = ret2;
9269
9270 ret2 = btrfs_end_transaction(trans);
9271 if (ret2 && !ret)
9272 ret = ret2;
9273 btrfs_btree_balance_dirty(fs_info);
9274 }
9275 out:
9276 btrfs_free_block_rsv(fs_info, rsv);
9277
9278 return ret;
9279 }
9280
9281 /*
9282 * create a new subvolume directory/inode (helper for the ioctl).
9283 */
9284 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9285 struct btrfs_root *new_root,
9286 struct btrfs_root *parent_root,
9287 u64 new_dirid)
9288 {
9289 struct inode *inode;
9290 int err;
9291 u64 index = 0;
9292
9293 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9294 new_dirid, new_dirid,
9295 S_IFDIR | (~current_umask() & S_IRWXUGO),
9296 &index);
9297 if (IS_ERR(inode))
9298 return PTR_ERR(inode);
9299 inode->i_op = &btrfs_dir_inode_operations;
9300 inode->i_fop = &btrfs_dir_file_operations;
9301
9302 set_nlink(inode, 1);
9303 btrfs_i_size_write(BTRFS_I(inode), 0);
9304 unlock_new_inode(inode);
9305
9306 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9307 if (err)
9308 btrfs_err(new_root->fs_info,
9309 "error inheriting subvolume %llu properties: %d",
9310 new_root->root_key.objectid, err);
9311
9312 err = btrfs_update_inode(trans, new_root, inode);
9313
9314 iput(inode);
9315 return err;
9316 }
9317
9318 struct inode *btrfs_alloc_inode(struct super_block *sb)
9319 {
9320 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9321 struct btrfs_inode *ei;
9322 struct inode *inode;
9323
9324 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
9325 if (!ei)
9326 return NULL;
9327
9328 ei->root = NULL;
9329 ei->generation = 0;
9330 ei->last_trans = 0;
9331 ei->last_sub_trans = 0;
9332 ei->logged_trans = 0;
9333 ei->delalloc_bytes = 0;
9334 ei->new_delalloc_bytes = 0;
9335 ei->defrag_bytes = 0;
9336 ei->disk_i_size = 0;
9337 ei->flags = 0;
9338 ei->csum_bytes = 0;
9339 ei->index_cnt = (u64)-1;
9340 ei->dir_index = 0;
9341 ei->last_unlink_trans = 0;
9342 ei->last_log_commit = 0;
9343
9344 spin_lock_init(&ei->lock);
9345 ei->outstanding_extents = 0;
9346 if (sb->s_magic != BTRFS_TEST_MAGIC)
9347 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9348 BTRFS_BLOCK_RSV_DELALLOC);
9349 ei->runtime_flags = 0;
9350 ei->prop_compress = BTRFS_COMPRESS_NONE;
9351 ei->defrag_compress = BTRFS_COMPRESS_NONE;
9352
9353 ei->delayed_node = NULL;
9354
9355 ei->i_otime.tv_sec = 0;
9356 ei->i_otime.tv_nsec = 0;
9357
9358 inode = &ei->vfs_inode;
9359 extent_map_tree_init(&ei->extent_tree);
9360 extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO, inode);
9361 extent_io_tree_init(fs_info, &ei->io_failure_tree,
9362 IO_TREE_INODE_IO_FAILURE, inode);
9363 ei->io_tree.track_uptodate = true;
9364 ei->io_failure_tree.track_uptodate = true;
9365 atomic_set(&ei->sync_writers, 0);
9366 mutex_init(&ei->log_mutex);
9367 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9368 INIT_LIST_HEAD(&ei->delalloc_inodes);
9369 INIT_LIST_HEAD(&ei->delayed_iput);
9370 RB_CLEAR_NODE(&ei->rb_node);
9371 init_rwsem(&ei->dio_sem);
9372
9373 return inode;
9374 }
9375
9376 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9377 void btrfs_test_destroy_inode(struct inode *inode)
9378 {
9379 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9380 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9381 }
9382 #endif
9383
9384 void btrfs_free_inode(struct inode *inode)
9385 {
9386 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9387 }
9388
9389 void btrfs_destroy_inode(struct inode *inode)
9390 {
9391 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9392 struct btrfs_ordered_extent *ordered;
9393 struct btrfs_root *root = BTRFS_I(inode)->root;
9394
9395 WARN_ON(!hlist_empty(&inode->i_dentry));
9396 WARN_ON(inode->i_data.nrpages);
9397 WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9398 WARN_ON(BTRFS_I(inode)->block_rsv.size);
9399 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9400 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9401 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9402 WARN_ON(BTRFS_I(inode)->csum_bytes);
9403 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9404
9405 /*
9406 * This can happen where we create an inode, but somebody else also
9407 * created the same inode and we need to destroy the one we already
9408 * created.
9409 */
9410 if (!root)
9411 return;
9412
9413 while (1) {
9414 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9415 if (!ordered)
9416 break;
9417 else {
9418 btrfs_err(fs_info,
9419 "found ordered extent %llu %llu on inode cleanup",
9420 ordered->file_offset, ordered->len);
9421 btrfs_remove_ordered_extent(inode, ordered);
9422 btrfs_put_ordered_extent(ordered);
9423 btrfs_put_ordered_extent(ordered);
9424 }
9425 }
9426 btrfs_qgroup_check_reserved_leak(inode);
9427 inode_tree_del(inode);
9428 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9429 }
9430
9431 int btrfs_drop_inode(struct inode *inode)
9432 {
9433 struct btrfs_root *root = BTRFS_I(inode)->root;
9434
9435 if (root == NULL)
9436 return 1;
9437
9438 /* the snap/subvol tree is on deleting */
9439 if (btrfs_root_refs(&root->root_item) == 0)
9440 return 1;
9441 else
9442 return generic_drop_inode(inode);
9443 }
9444
9445 static void init_once(void *foo)
9446 {
9447 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9448
9449 inode_init_once(&ei->vfs_inode);
9450 }
9451
9452 void __cold btrfs_destroy_cachep(void)
9453 {
9454 /*
9455 * Make sure all delayed rcu free inodes are flushed before we
9456 * destroy cache.
9457 */
9458 rcu_barrier();
9459 kmem_cache_destroy(btrfs_inode_cachep);
9460 kmem_cache_destroy(btrfs_trans_handle_cachep);
9461 kmem_cache_destroy(btrfs_path_cachep);
9462 kmem_cache_destroy(btrfs_free_space_cachep);
9463 kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
9464 }
9465
9466 int __init btrfs_init_cachep(void)
9467 {
9468 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9469 sizeof(struct btrfs_inode), 0,
9470 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9471 init_once);
9472 if (!btrfs_inode_cachep)
9473 goto fail;
9474
9475 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9476 sizeof(struct btrfs_trans_handle), 0,
9477 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9478 if (!btrfs_trans_handle_cachep)
9479 goto fail;
9480
9481 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9482 sizeof(struct btrfs_path), 0,
9483 SLAB_MEM_SPREAD, NULL);
9484 if (!btrfs_path_cachep)
9485 goto fail;
9486
9487 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9488 sizeof(struct btrfs_free_space), 0,
9489 SLAB_MEM_SPREAD, NULL);
9490 if (!btrfs_free_space_cachep)
9491 goto fail;
9492
9493 btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
9494 PAGE_SIZE, PAGE_SIZE,
9495 SLAB_RED_ZONE, NULL);
9496 if (!btrfs_free_space_bitmap_cachep)
9497 goto fail;
9498
9499 return 0;
9500 fail:
9501 btrfs_destroy_cachep();
9502 return -ENOMEM;
9503 }
9504
9505 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9506 u32 request_mask, unsigned int flags)
9507 {
9508 u64 delalloc_bytes;
9509 struct inode *inode = d_inode(path->dentry);
9510 u32 blocksize = inode->i_sb->s_blocksize;
9511 u32 bi_flags = BTRFS_I(inode)->flags;
9512
9513 stat->result_mask |= STATX_BTIME;
9514 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9515 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9516 if (bi_flags & BTRFS_INODE_APPEND)
9517 stat->attributes |= STATX_ATTR_APPEND;
9518 if (bi_flags & BTRFS_INODE_COMPRESS)
9519 stat->attributes |= STATX_ATTR_COMPRESSED;
9520 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9521 stat->attributes |= STATX_ATTR_IMMUTABLE;
9522 if (bi_flags & BTRFS_INODE_NODUMP)
9523 stat->attributes |= STATX_ATTR_NODUMP;
9524
9525 stat->attributes_mask |= (STATX_ATTR_APPEND |
9526 STATX_ATTR_COMPRESSED |
9527 STATX_ATTR_IMMUTABLE |
9528 STATX_ATTR_NODUMP);
9529
9530 generic_fillattr(inode, stat);
9531 stat->dev = BTRFS_I(inode)->root->anon_dev;
9532
9533 spin_lock(&BTRFS_I(inode)->lock);
9534 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9535 spin_unlock(&BTRFS_I(inode)->lock);
9536 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9537 ALIGN(delalloc_bytes, blocksize)) >> 9;
9538 return 0;
9539 }
9540
9541 static int btrfs_rename_exchange(struct inode *old_dir,
9542 struct dentry *old_dentry,
9543 struct inode *new_dir,
9544 struct dentry *new_dentry)
9545 {
9546 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9547 struct btrfs_trans_handle *trans;
9548 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9549 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9550 struct inode *new_inode = new_dentry->d_inode;
9551 struct inode *old_inode = old_dentry->d_inode;
9552 struct timespec64 ctime = current_time(old_inode);
9553 struct dentry *parent;
9554 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9555 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9556 u64 old_idx = 0;
9557 u64 new_idx = 0;
9558 int ret;
9559 bool root_log_pinned = false;
9560 bool dest_log_pinned = false;
9561 struct btrfs_log_ctx ctx_root;
9562 struct btrfs_log_ctx ctx_dest;
9563 bool sync_log_root = false;
9564 bool sync_log_dest = false;
9565 bool commit_transaction = false;
9566
9567 /* we only allow rename subvolume link between subvolumes */
9568 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9569 return -EXDEV;
9570
9571 btrfs_init_log_ctx(&ctx_root, old_inode);
9572 btrfs_init_log_ctx(&ctx_dest, new_inode);
9573
9574 /* close the race window with snapshot create/destroy ioctl */
9575 if (old_ino == BTRFS_FIRST_FREE_OBJECTID ||
9576 new_ino == BTRFS_FIRST_FREE_OBJECTID)
9577 down_read(&fs_info->subvol_sem);
9578
9579 /*
9580 * We want to reserve the absolute worst case amount of items. So if
9581 * both inodes are subvols and we need to unlink them then that would
9582 * require 4 item modifications, but if they are both normal inodes it
9583 * would require 5 item modifications, so we'll assume their normal
9584 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9585 * should cover the worst case number of items we'll modify.
9586 */
9587 trans = btrfs_start_transaction(root, 12);
9588 if (IS_ERR(trans)) {
9589 ret = PTR_ERR(trans);
9590 goto out_notrans;
9591 }
9592
9593 if (dest != root)
9594 btrfs_record_root_in_trans(trans, dest);
9595
9596 /*
9597 * We need to find a free sequence number both in the source and
9598 * in the destination directory for the exchange.
9599 */
9600 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9601 if (ret)
9602 goto out_fail;
9603 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9604 if (ret)
9605 goto out_fail;
9606
9607 BTRFS_I(old_inode)->dir_index = 0ULL;
9608 BTRFS_I(new_inode)->dir_index = 0ULL;
9609
9610 /* Reference for the source. */
9611 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9612 /* force full log commit if subvolume involved. */
9613 btrfs_set_log_full_commit(trans);
9614 } else {
9615 btrfs_pin_log_trans(root);
9616 root_log_pinned = true;
9617 ret = btrfs_insert_inode_ref(trans, dest,
9618 new_dentry->d_name.name,
9619 new_dentry->d_name.len,
9620 old_ino,
9621 btrfs_ino(BTRFS_I(new_dir)),
9622 old_idx);
9623 if (ret)
9624 goto out_fail;
9625 }
9626
9627 /* And now for the dest. */
9628 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9629 /* force full log commit if subvolume involved. */
9630 btrfs_set_log_full_commit(trans);
9631 } else {
9632 btrfs_pin_log_trans(dest);
9633 dest_log_pinned = true;
9634 ret = btrfs_insert_inode_ref(trans, root,
9635 old_dentry->d_name.name,
9636 old_dentry->d_name.len,
9637 new_ino,
9638 btrfs_ino(BTRFS_I(old_dir)),
9639 new_idx);
9640 if (ret)
9641 goto out_fail;
9642 }
9643
9644 /* Update inode version and ctime/mtime. */
9645 inode_inc_iversion(old_dir);
9646 inode_inc_iversion(new_dir);
9647 inode_inc_iversion(old_inode);
9648 inode_inc_iversion(new_inode);
9649 old_dir->i_ctime = old_dir->i_mtime = ctime;
9650 new_dir->i_ctime = new_dir->i_mtime = ctime;
9651 old_inode->i_ctime = ctime;
9652 new_inode->i_ctime = ctime;
9653
9654 if (old_dentry->d_parent != new_dentry->d_parent) {
9655 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9656 BTRFS_I(old_inode), 1);
9657 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9658 BTRFS_I(new_inode), 1);
9659 }
9660
9661 /* src is a subvolume */
9662 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9663 ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
9664 } else { /* src is an inode */
9665 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9666 BTRFS_I(old_dentry->d_inode),
9667 old_dentry->d_name.name,
9668 old_dentry->d_name.len);
9669 if (!ret)
9670 ret = btrfs_update_inode(trans, root, old_inode);
9671 }
9672 if (ret) {
9673 btrfs_abort_transaction(trans, ret);
9674 goto out_fail;
9675 }
9676
9677 /* dest is a subvolume */
9678 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9679 ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
9680 } else { /* dest is an inode */
9681 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9682 BTRFS_I(new_dentry->d_inode),
9683 new_dentry->d_name.name,
9684 new_dentry->d_name.len);
9685 if (!ret)
9686 ret = btrfs_update_inode(trans, dest, new_inode);
9687 }
9688 if (ret) {
9689 btrfs_abort_transaction(trans, ret);
9690 goto out_fail;
9691 }
9692
9693 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9694 new_dentry->d_name.name,
9695 new_dentry->d_name.len, 0, old_idx);
9696 if (ret) {
9697 btrfs_abort_transaction(trans, ret);
9698 goto out_fail;
9699 }
9700
9701 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9702 old_dentry->d_name.name,
9703 old_dentry->d_name.len, 0, new_idx);
9704 if (ret) {
9705 btrfs_abort_transaction(trans, ret);
9706 goto out_fail;
9707 }
9708
9709 if (old_inode->i_nlink == 1)
9710 BTRFS_I(old_inode)->dir_index = old_idx;
9711 if (new_inode->i_nlink == 1)
9712 BTRFS_I(new_inode)->dir_index = new_idx;
9713
9714 if (root_log_pinned) {
9715 parent = new_dentry->d_parent;
9716 ret = btrfs_log_new_name(trans, BTRFS_I(old_inode),
9717 BTRFS_I(old_dir), parent,
9718 false, &ctx_root);
9719 if (ret == BTRFS_NEED_LOG_SYNC)
9720 sync_log_root = true;
9721 else if (ret == BTRFS_NEED_TRANS_COMMIT)
9722 commit_transaction = true;
9723 ret = 0;
9724 btrfs_end_log_trans(root);
9725 root_log_pinned = false;
9726 }
9727 if (dest_log_pinned) {
9728 if (!commit_transaction) {
9729 parent = old_dentry->d_parent;
9730 ret = btrfs_log_new_name(trans, BTRFS_I(new_inode),
9731 BTRFS_I(new_dir), parent,
9732 false, &ctx_dest);
9733 if (ret == BTRFS_NEED_LOG_SYNC)
9734 sync_log_dest = true;
9735 else if (ret == BTRFS_NEED_TRANS_COMMIT)
9736 commit_transaction = true;
9737 ret = 0;
9738 }
9739 btrfs_end_log_trans(dest);
9740 dest_log_pinned = false;
9741 }
9742 out_fail:
9743 /*
9744 * If we have pinned a log and an error happened, we unpin tasks
9745 * trying to sync the log and force them to fallback to a transaction
9746 * commit if the log currently contains any of the inodes involved in
9747 * this rename operation (to ensure we do not persist a log with an
9748 * inconsistent state for any of these inodes or leading to any
9749 * inconsistencies when replayed). If the transaction was aborted, the
9750 * abortion reason is propagated to userspace when attempting to commit
9751 * the transaction. If the log does not contain any of these inodes, we
9752 * allow the tasks to sync it.
9753 */
9754 if (ret && (root_log_pinned || dest_log_pinned)) {
9755 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9756 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9757 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9758 (new_inode &&
9759 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9760 btrfs_set_log_full_commit(trans);
9761
9762 if (root_log_pinned) {
9763 btrfs_end_log_trans(root);
9764 root_log_pinned = false;
9765 }
9766 if (dest_log_pinned) {
9767 btrfs_end_log_trans(dest);
9768 dest_log_pinned = false;
9769 }
9770 }
9771 if (!ret && sync_log_root && !commit_transaction) {
9772 ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root,
9773 &ctx_root);
9774 if (ret)
9775 commit_transaction = true;
9776 }
9777 if (!ret && sync_log_dest && !commit_transaction) {
9778 ret = btrfs_sync_log(trans, BTRFS_I(new_inode)->root,
9779 &ctx_dest);
9780 if (ret)
9781 commit_transaction = true;
9782 }
9783 if (commit_transaction) {
9784 /*
9785 * We may have set commit_transaction when logging the new name
9786 * in the destination root, in which case we left the source
9787 * root context in the list of log contextes. So make sure we
9788 * remove it to avoid invalid memory accesses, since the context
9789 * was allocated in our stack frame.
9790 */
9791 if (sync_log_root) {
9792 mutex_lock(&root->log_mutex);
9793 list_del_init(&ctx_root.list);
9794 mutex_unlock(&root->log_mutex);
9795 }
9796 ret = btrfs_commit_transaction(trans);
9797 } else {
9798 int ret2;
9799
9800 ret2 = btrfs_end_transaction(trans);
9801 ret = ret ? ret : ret2;
9802 }
9803 out_notrans:
9804 if (new_ino == BTRFS_FIRST_FREE_OBJECTID ||
9805 old_ino == BTRFS_FIRST_FREE_OBJECTID)
9806 up_read(&fs_info->subvol_sem);
9807
9808 ASSERT(list_empty(&ctx_root.list));
9809 ASSERT(list_empty(&ctx_dest.list));
9810
9811 return ret;
9812 }
9813
9814 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9815 struct btrfs_root *root,
9816 struct inode *dir,
9817 struct dentry *dentry)
9818 {
9819 int ret;
9820 struct inode *inode;
9821 u64 objectid;
9822 u64 index;
9823
9824 ret = btrfs_find_free_ino(root, &objectid);
9825 if (ret)
9826 return ret;
9827
9828 inode = btrfs_new_inode(trans, root, dir,
9829 dentry->d_name.name,
9830 dentry->d_name.len,
9831 btrfs_ino(BTRFS_I(dir)),
9832 objectid,
9833 S_IFCHR | WHITEOUT_MODE,
9834 &index);
9835
9836 if (IS_ERR(inode)) {
9837 ret = PTR_ERR(inode);
9838 return ret;
9839 }
9840
9841 inode->i_op = &btrfs_special_inode_operations;
9842 init_special_inode(inode, inode->i_mode,
9843 WHITEOUT_DEV);
9844
9845 ret = btrfs_init_inode_security(trans, inode, dir,
9846 &dentry->d_name);
9847 if (ret)
9848 goto out;
9849
9850 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9851 BTRFS_I(inode), 0, index);
9852 if (ret)
9853 goto out;
9854
9855 ret = btrfs_update_inode(trans, root, inode);
9856 out:
9857 unlock_new_inode(inode);
9858 if (ret)
9859 inode_dec_link_count(inode);
9860 iput(inode);
9861
9862 return ret;
9863 }
9864
9865 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9866 struct inode *new_dir, struct dentry *new_dentry,
9867 unsigned int flags)
9868 {
9869 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9870 struct btrfs_trans_handle *trans;
9871 unsigned int trans_num_items;
9872 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9873 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9874 struct inode *new_inode = d_inode(new_dentry);
9875 struct inode *old_inode = d_inode(old_dentry);
9876 u64 index = 0;
9877 int ret;
9878 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9879 bool log_pinned = false;
9880 struct btrfs_log_ctx ctx;
9881 bool sync_log = false;
9882 bool commit_transaction = false;
9883
9884 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9885 return -EPERM;
9886
9887 /* we only allow rename subvolume link between subvolumes */
9888 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9889 return -EXDEV;
9890
9891 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9892 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9893 return -ENOTEMPTY;
9894
9895 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9896 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9897 return -ENOTEMPTY;
9898
9899
9900 /* check for collisions, even if the name isn't there */
9901 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9902 new_dentry->d_name.name,
9903 new_dentry->d_name.len);
9904
9905 if (ret) {
9906 if (ret == -EEXIST) {
9907 /* we shouldn't get
9908 * eexist without a new_inode */
9909 if (WARN_ON(!new_inode)) {
9910 return ret;
9911 }
9912 } else {
9913 /* maybe -EOVERFLOW */
9914 return ret;
9915 }
9916 }
9917 ret = 0;
9918
9919 /*
9920 * we're using rename to replace one file with another. Start IO on it
9921 * now so we don't add too much work to the end of the transaction
9922 */
9923 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9924 filemap_flush(old_inode->i_mapping);
9925
9926 /* close the racy window with snapshot create/destroy ioctl */
9927 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9928 down_read(&fs_info->subvol_sem);
9929 /*
9930 * We want to reserve the absolute worst case amount of items. So if
9931 * both inodes are subvols and we need to unlink them then that would
9932 * require 4 item modifications, but if they are both normal inodes it
9933 * would require 5 item modifications, so we'll assume they are normal
9934 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9935 * should cover the worst case number of items we'll modify.
9936 * If our rename has the whiteout flag, we need more 5 units for the
9937 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9938 * when selinux is enabled).
9939 */
9940 trans_num_items = 11;
9941 if (flags & RENAME_WHITEOUT)
9942 trans_num_items += 5;
9943 trans = btrfs_start_transaction(root, trans_num_items);
9944 if (IS_ERR(trans)) {
9945 ret = PTR_ERR(trans);
9946 goto out_notrans;
9947 }
9948
9949 if (dest != root)
9950 btrfs_record_root_in_trans(trans, dest);
9951
9952 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9953 if (ret)
9954 goto out_fail;
9955
9956 BTRFS_I(old_inode)->dir_index = 0ULL;
9957 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9958 /* force full log commit if subvolume involved. */
9959 btrfs_set_log_full_commit(trans);
9960 } else {
9961 btrfs_pin_log_trans(root);
9962 log_pinned = true;
9963 ret = btrfs_insert_inode_ref(trans, dest,
9964 new_dentry->d_name.name,
9965 new_dentry->d_name.len,
9966 old_ino,
9967 btrfs_ino(BTRFS_I(new_dir)), index);
9968 if (ret)
9969 goto out_fail;
9970 }
9971
9972 inode_inc_iversion(old_dir);
9973 inode_inc_iversion(new_dir);
9974 inode_inc_iversion(old_inode);
9975 old_dir->i_ctime = old_dir->i_mtime =
9976 new_dir->i_ctime = new_dir->i_mtime =
9977 old_inode->i_ctime = current_time(old_dir);
9978
9979 if (old_dentry->d_parent != new_dentry->d_parent)
9980 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9981 BTRFS_I(old_inode), 1);
9982
9983 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9984 ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
9985 } else {
9986 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9987 BTRFS_I(d_inode(old_dentry)),
9988 old_dentry->d_name.name,
9989 old_dentry->d_name.len);
9990 if (!ret)
9991 ret = btrfs_update_inode(trans, root, old_inode);
9992 }
9993 if (ret) {
9994 btrfs_abort_transaction(trans, ret);
9995 goto out_fail;
9996 }
9997
9998 if (new_inode) {
9999 inode_inc_iversion(new_inode);
10000 new_inode->i_ctime = current_time(new_inode);
10001 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
10002 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
10003 ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
10004 BUG_ON(new_inode->i_nlink == 0);
10005 } else {
10006 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
10007 BTRFS_I(d_inode(new_dentry)),
10008 new_dentry->d_name.name,
10009 new_dentry->d_name.len);
10010 }
10011 if (!ret && new_inode->i_nlink == 0)
10012 ret = btrfs_orphan_add(trans,
10013 BTRFS_I(d_inode(new_dentry)));
10014 if (ret) {
10015 btrfs_abort_transaction(trans, ret);
10016 goto out_fail;
10017 }
10018 }
10019
10020 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
10021 new_dentry->d_name.name,
10022 new_dentry->d_name.len, 0, index);
10023 if (ret) {
10024 btrfs_abort_transaction(trans, ret);
10025 goto out_fail;
10026 }
10027
10028 if (old_inode->i_nlink == 1)
10029 BTRFS_I(old_inode)->dir_index = index;
10030
10031 if (log_pinned) {
10032 struct dentry *parent = new_dentry->d_parent;
10033
10034 btrfs_init_log_ctx(&ctx, old_inode);
10035 ret = btrfs_log_new_name(trans, BTRFS_I(old_inode),
10036 BTRFS_I(old_dir), parent,
10037 false, &ctx);
10038 if (ret == BTRFS_NEED_LOG_SYNC)
10039 sync_log = true;
10040 else if (ret == BTRFS_NEED_TRANS_COMMIT)
10041 commit_transaction = true;
10042 ret = 0;
10043 btrfs_end_log_trans(root);
10044 log_pinned = false;
10045 }
10046
10047 if (flags & RENAME_WHITEOUT) {
10048 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
10049 old_dentry);
10050
10051 if (ret) {
10052 btrfs_abort_transaction(trans, ret);
10053 goto out_fail;
10054 }
10055 }
10056 out_fail:
10057 /*
10058 * If we have pinned the log and an error happened, we unpin tasks
10059 * trying to sync the log and force them to fallback to a transaction
10060 * commit if the log currently contains any of the inodes involved in
10061 * this rename operation (to ensure we do not persist a log with an
10062 * inconsistent state for any of these inodes or leading to any
10063 * inconsistencies when replayed). If the transaction was aborted, the
10064 * abortion reason is propagated to userspace when attempting to commit
10065 * the transaction. If the log does not contain any of these inodes, we
10066 * allow the tasks to sync it.
10067 */
10068 if (ret && log_pinned) {
10069 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
10070 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
10071 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
10072 (new_inode &&
10073 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
10074 btrfs_set_log_full_commit(trans);
10075
10076 btrfs_end_log_trans(root);
10077 log_pinned = false;
10078 }
10079 if (!ret && sync_log) {
10080 ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root, &ctx);
10081 if (ret)
10082 commit_transaction = true;
10083 }
10084 if (commit_transaction) {
10085 ret = btrfs_commit_transaction(trans);
10086 } else {
10087 int ret2;
10088
10089 ret2 = btrfs_end_transaction(trans);
10090 ret = ret ? ret : ret2;
10091 }
10092 out_notrans:
10093 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10094 up_read(&fs_info->subvol_sem);
10095
10096 return ret;
10097 }
10098
10099 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
10100 struct inode *new_dir, struct dentry *new_dentry,
10101 unsigned int flags)
10102 {
10103 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
10104 return -EINVAL;
10105
10106 if (flags & RENAME_EXCHANGE)
10107 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
10108 new_dentry);
10109
10110 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10111 }
10112
10113 struct btrfs_delalloc_work {
10114 struct inode *inode;
10115 struct completion completion;
10116 struct list_head list;
10117 struct btrfs_work work;
10118 };
10119
10120 static void btrfs_run_delalloc_work(struct btrfs_work *work)
10121 {
10122 struct btrfs_delalloc_work *delalloc_work;
10123 struct inode *inode;
10124
10125 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10126 work);
10127 inode = delalloc_work->inode;
10128 filemap_flush(inode->i_mapping);
10129 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10130 &BTRFS_I(inode)->runtime_flags))
10131 filemap_flush(inode->i_mapping);
10132
10133 iput(inode);
10134 complete(&delalloc_work->completion);
10135 }
10136
10137 static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
10138 {
10139 struct btrfs_delalloc_work *work;
10140
10141 work = kmalloc(sizeof(*work), GFP_NOFS);
10142 if (!work)
10143 return NULL;
10144
10145 init_completion(&work->completion);
10146 INIT_LIST_HEAD(&work->list);
10147 work->inode = inode;
10148 btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
10149
10150 return work;
10151 }
10152
10153 /*
10154 * some fairly slow code that needs optimization. This walks the list
10155 * of all the inodes with pending delalloc and forces them to disk.
10156 */
10157 static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
10158 {
10159 struct btrfs_inode *binode;
10160 struct inode *inode;
10161 struct btrfs_delalloc_work *work, *next;
10162 struct list_head works;
10163 struct list_head splice;
10164 int ret = 0;
10165
10166 INIT_LIST_HEAD(&works);
10167 INIT_LIST_HEAD(&splice);
10168
10169 mutex_lock(&root->delalloc_mutex);
10170 spin_lock(&root->delalloc_lock);
10171 list_splice_init(&root->delalloc_inodes, &splice);
10172 while (!list_empty(&splice)) {
10173 binode = list_entry(splice.next, struct btrfs_inode,
10174 delalloc_inodes);
10175
10176 list_move_tail(&binode->delalloc_inodes,
10177 &root->delalloc_inodes);
10178 inode = igrab(&binode->vfs_inode);
10179 if (!inode) {
10180 cond_resched_lock(&root->delalloc_lock);
10181 continue;
10182 }
10183 spin_unlock(&root->delalloc_lock);
10184
10185 if (snapshot)
10186 set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
10187 &binode->runtime_flags);
10188 work = btrfs_alloc_delalloc_work(inode);
10189 if (!work) {
10190 iput(inode);
10191 ret = -ENOMEM;
10192 goto out;
10193 }
10194 list_add_tail(&work->list, &works);
10195 btrfs_queue_work(root->fs_info->flush_workers,
10196 &work->work);
10197 ret++;
10198 if (nr != -1 && ret >= nr)
10199 goto out;
10200 cond_resched();
10201 spin_lock(&root->delalloc_lock);
10202 }
10203 spin_unlock(&root->delalloc_lock);
10204
10205 out:
10206 list_for_each_entry_safe(work, next, &works, list) {
10207 list_del_init(&work->list);
10208 wait_for_completion(&work->completion);
10209 kfree(work);
10210 }
10211
10212 if (!list_empty(&splice)) {
10213 spin_lock(&root->delalloc_lock);
10214 list_splice_tail(&splice, &root->delalloc_inodes);
10215 spin_unlock(&root->delalloc_lock);
10216 }
10217 mutex_unlock(&root->delalloc_mutex);
10218 return ret;
10219 }
10220
10221 int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
10222 {
10223 struct btrfs_fs_info *fs_info = root->fs_info;
10224 int ret;
10225
10226 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10227 return -EROFS;
10228
10229 ret = start_delalloc_inodes(root, -1, true);
10230 if (ret > 0)
10231 ret = 0;
10232 return ret;
10233 }
10234
10235 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr)
10236 {
10237 struct btrfs_root *root;
10238 struct list_head splice;
10239 int ret;
10240
10241 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10242 return -EROFS;
10243
10244 INIT_LIST_HEAD(&splice);
10245
10246 mutex_lock(&fs_info->delalloc_root_mutex);
10247 spin_lock(&fs_info->delalloc_root_lock);
10248 list_splice_init(&fs_info->delalloc_roots, &splice);
10249 while (!list_empty(&splice) && nr) {
10250 root = list_first_entry(&splice, struct btrfs_root,
10251 delalloc_root);
10252 root = btrfs_grab_fs_root(root);
10253 BUG_ON(!root);
10254 list_move_tail(&root->delalloc_root,
10255 &fs_info->delalloc_roots);
10256 spin_unlock(&fs_info->delalloc_root_lock);
10257
10258 ret = start_delalloc_inodes(root, nr, false);
10259 btrfs_put_fs_root(root);
10260 if (ret < 0)
10261 goto out;
10262
10263 if (nr != -1) {
10264 nr -= ret;
10265 WARN_ON(nr < 0);
10266 }
10267 spin_lock(&fs_info->delalloc_root_lock);
10268 }
10269 spin_unlock(&fs_info->delalloc_root_lock);
10270
10271 ret = 0;
10272 out:
10273 if (!list_empty(&splice)) {
10274 spin_lock(&fs_info->delalloc_root_lock);
10275 list_splice_tail(&splice, &fs_info->delalloc_roots);
10276 spin_unlock(&fs_info->delalloc_root_lock);
10277 }
10278 mutex_unlock(&fs_info->delalloc_root_mutex);
10279 return ret;
10280 }
10281
10282 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10283 const char *symname)
10284 {
10285 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10286 struct btrfs_trans_handle *trans;
10287 struct btrfs_root *root = BTRFS_I(dir)->root;
10288 struct btrfs_path *path;
10289 struct btrfs_key key;
10290 struct inode *inode = NULL;
10291 int err;
10292 u64 objectid;
10293 u64 index = 0;
10294 int name_len;
10295 int datasize;
10296 unsigned long ptr;
10297 struct btrfs_file_extent_item *ei;
10298 struct extent_buffer *leaf;
10299
10300 name_len = strlen(symname);
10301 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10302 return -ENAMETOOLONG;
10303
10304 /*
10305 * 2 items for inode item and ref
10306 * 2 items for dir items
10307 * 1 item for updating parent inode item
10308 * 1 item for the inline extent item
10309 * 1 item for xattr if selinux is on
10310 */
10311 trans = btrfs_start_transaction(root, 7);
10312 if (IS_ERR(trans))
10313 return PTR_ERR(trans);
10314
10315 err = btrfs_find_free_ino(root, &objectid);
10316 if (err)
10317 goto out_unlock;
10318
10319 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10320 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10321 objectid, S_IFLNK|S_IRWXUGO, &index);
10322 if (IS_ERR(inode)) {
10323 err = PTR_ERR(inode);
10324 inode = NULL;
10325 goto out_unlock;
10326 }
10327
10328 /*
10329 * If the active LSM wants to access the inode during
10330 * d_instantiate it needs these. Smack checks to see
10331 * if the filesystem supports xattrs by looking at the
10332 * ops vector.
10333 */
10334 inode->i_fop = &btrfs_file_operations;
10335 inode->i_op = &btrfs_file_inode_operations;
10336 inode->i_mapping->a_ops = &btrfs_aops;
10337 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10338
10339 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10340 if (err)
10341 goto out_unlock;
10342
10343 path = btrfs_alloc_path();
10344 if (!path) {
10345 err = -ENOMEM;
10346 goto out_unlock;
10347 }
10348 key.objectid = btrfs_ino(BTRFS_I(inode));
10349 key.offset = 0;
10350 key.type = BTRFS_EXTENT_DATA_KEY;
10351 datasize = btrfs_file_extent_calc_inline_size(name_len);
10352 err = btrfs_insert_empty_item(trans, root, path, &key,
10353 datasize);
10354 if (err) {
10355 btrfs_free_path(path);
10356 goto out_unlock;
10357 }
10358 leaf = path->nodes[0];
10359 ei = btrfs_item_ptr(leaf, path->slots[0],
10360 struct btrfs_file_extent_item);
10361 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10362 btrfs_set_file_extent_type(leaf, ei,
10363 BTRFS_FILE_EXTENT_INLINE);
10364 btrfs_set_file_extent_encryption(leaf, ei, 0);
10365 btrfs_set_file_extent_compression(leaf, ei, 0);
10366 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10367 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10368
10369 ptr = btrfs_file_extent_inline_start(ei);
10370 write_extent_buffer(leaf, symname, ptr, name_len);
10371 btrfs_mark_buffer_dirty(leaf);
10372 btrfs_free_path(path);
10373
10374 inode->i_op = &btrfs_symlink_inode_operations;
10375 inode_nohighmem(inode);
10376 inode_set_bytes(inode, name_len);
10377 btrfs_i_size_write(BTRFS_I(inode), name_len);
10378 err = btrfs_update_inode(trans, root, inode);
10379 /*
10380 * Last step, add directory indexes for our symlink inode. This is the
10381 * last step to avoid extra cleanup of these indexes if an error happens
10382 * elsewhere above.
10383 */
10384 if (!err)
10385 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10386 BTRFS_I(inode), 0, index);
10387 if (err)
10388 goto out_unlock;
10389
10390 d_instantiate_new(dentry, inode);
10391
10392 out_unlock:
10393 btrfs_end_transaction(trans);
10394 if (err && inode) {
10395 inode_dec_link_count(inode);
10396 discard_new_inode(inode);
10397 }
10398 btrfs_btree_balance_dirty(fs_info);
10399 return err;
10400 }
10401
10402 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10403 u64 start, u64 num_bytes, u64 min_size,
10404 loff_t actual_len, u64 *alloc_hint,
10405 struct btrfs_trans_handle *trans)
10406 {
10407 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10408 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10409 struct extent_map *em;
10410 struct btrfs_root *root = BTRFS_I(inode)->root;
10411 struct btrfs_key ins;
10412 u64 cur_offset = start;
10413 u64 i_size;
10414 u64 cur_bytes;
10415 u64 last_alloc = (u64)-1;
10416 int ret = 0;
10417 bool own_trans = true;
10418 u64 end = start + num_bytes - 1;
10419
10420 if (trans)
10421 own_trans = false;
10422 while (num_bytes > 0) {
10423 if (own_trans) {
10424 trans = btrfs_start_transaction(root, 3);
10425 if (IS_ERR(trans)) {
10426 ret = PTR_ERR(trans);
10427 break;
10428 }
10429 }
10430
10431 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10432 cur_bytes = max(cur_bytes, min_size);
10433 /*
10434 * If we are severely fragmented we could end up with really
10435 * small allocations, so if the allocator is returning small
10436 * chunks lets make its job easier by only searching for those
10437 * sized chunks.
10438 */
10439 cur_bytes = min(cur_bytes, last_alloc);
10440 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10441 min_size, 0, *alloc_hint, &ins, 1, 0);
10442 if (ret) {
10443 if (own_trans)
10444 btrfs_end_transaction(trans);
10445 break;
10446 }
10447 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10448
10449 last_alloc = ins.offset;
10450 ret = insert_reserved_file_extent(trans, inode,
10451 cur_offset, ins.objectid,
10452 ins.offset, ins.offset,
10453 ins.offset, 0, 0, 0,
10454 BTRFS_FILE_EXTENT_PREALLOC);
10455 if (ret) {
10456 btrfs_free_reserved_extent(fs_info, ins.objectid,
10457 ins.offset, 0);
10458 btrfs_abort_transaction(trans, ret);
10459 if (own_trans)
10460 btrfs_end_transaction(trans);
10461 break;
10462 }
10463
10464 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10465 cur_offset + ins.offset -1, 0);
10466
10467 em = alloc_extent_map();
10468 if (!em) {
10469 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10470 &BTRFS_I(inode)->runtime_flags);
10471 goto next;
10472 }
10473
10474 em->start = cur_offset;
10475 em->orig_start = cur_offset;
10476 em->len = ins.offset;
10477 em->block_start = ins.objectid;
10478 em->block_len = ins.offset;
10479 em->orig_block_len = ins.offset;
10480 em->ram_bytes = ins.offset;
10481 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10482 em->generation = trans->transid;
10483
10484 while (1) {
10485 write_lock(&em_tree->lock);
10486 ret = add_extent_mapping(em_tree, em, 1);
10487 write_unlock(&em_tree->lock);
10488 if (ret != -EEXIST)
10489 break;
10490 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10491 cur_offset + ins.offset - 1,
10492 0);
10493 }
10494 free_extent_map(em);
10495 next:
10496 num_bytes -= ins.offset;
10497 cur_offset += ins.offset;
10498 *alloc_hint = ins.objectid + ins.offset;
10499
10500 inode_inc_iversion(inode);
10501 inode->i_ctime = current_time(inode);
10502 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10503 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10504 (actual_len > inode->i_size) &&
10505 (cur_offset > inode->i_size)) {
10506 if (cur_offset > actual_len)
10507 i_size = actual_len;
10508 else
10509 i_size = cur_offset;
10510 i_size_write(inode, i_size);
10511 btrfs_ordered_update_i_size(inode, i_size, NULL);
10512 }
10513
10514 ret = btrfs_update_inode(trans, root, inode);
10515
10516 if (ret) {
10517 btrfs_abort_transaction(trans, ret);
10518 if (own_trans)
10519 btrfs_end_transaction(trans);
10520 break;
10521 }
10522
10523 if (own_trans)
10524 btrfs_end_transaction(trans);
10525 }
10526 if (cur_offset < end)
10527 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10528 end - cur_offset + 1);
10529 return ret;
10530 }
10531
10532 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10533 u64 start, u64 num_bytes, u64 min_size,
10534 loff_t actual_len, u64 *alloc_hint)
10535 {
10536 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10537 min_size, actual_len, alloc_hint,
10538 NULL);
10539 }
10540
10541 int btrfs_prealloc_file_range_trans(struct inode *inode,
10542 struct btrfs_trans_handle *trans, int mode,
10543 u64 start, u64 num_bytes, u64 min_size,
10544 loff_t actual_len, u64 *alloc_hint)
10545 {
10546 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10547 min_size, actual_len, alloc_hint, trans);
10548 }
10549
10550 static int btrfs_set_page_dirty(struct page *page)
10551 {
10552 return __set_page_dirty_nobuffers(page);
10553 }
10554
10555 static int btrfs_permission(struct inode *inode, int mask)
10556 {
10557 struct btrfs_root *root = BTRFS_I(inode)->root;
10558 umode_t mode = inode->i_mode;
10559
10560 if (mask & MAY_WRITE &&
10561 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10562 if (btrfs_root_readonly(root))
10563 return -EROFS;
10564 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10565 return -EACCES;
10566 }
10567 return generic_permission(inode, mask);
10568 }
10569
10570 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10571 {
10572 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10573 struct btrfs_trans_handle *trans;
10574 struct btrfs_root *root = BTRFS_I(dir)->root;
10575 struct inode *inode = NULL;
10576 u64 objectid;
10577 u64 index;
10578 int ret = 0;
10579
10580 /*
10581 * 5 units required for adding orphan entry
10582 */
10583 trans = btrfs_start_transaction(root, 5);
10584 if (IS_ERR(trans))
10585 return PTR_ERR(trans);
10586
10587 ret = btrfs_find_free_ino(root, &objectid);
10588 if (ret)
10589 goto out;
10590
10591 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10592 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10593 if (IS_ERR(inode)) {
10594 ret = PTR_ERR(inode);
10595 inode = NULL;
10596 goto out;
10597 }
10598
10599 inode->i_fop = &btrfs_file_operations;
10600 inode->i_op = &btrfs_file_inode_operations;
10601
10602 inode->i_mapping->a_ops = &btrfs_aops;
10603 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10604
10605 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10606 if (ret)
10607 goto out;
10608
10609 ret = btrfs_update_inode(trans, root, inode);
10610 if (ret)
10611 goto out;
10612 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10613 if (ret)
10614 goto out;
10615
10616 /*
10617 * We set number of links to 0 in btrfs_new_inode(), and here we set
10618 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10619 * through:
10620 *
10621 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10622 */
10623 set_nlink(inode, 1);
10624 d_tmpfile(dentry, inode);
10625 unlock_new_inode(inode);
10626 mark_inode_dirty(inode);
10627 out:
10628 btrfs_end_transaction(trans);
10629 if (ret && inode)
10630 discard_new_inode(inode);
10631 btrfs_btree_balance_dirty(fs_info);
10632 return ret;
10633 }
10634
10635 void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
10636 {
10637 struct inode *inode = tree->private_data;
10638 unsigned long index = start >> PAGE_SHIFT;
10639 unsigned long end_index = end >> PAGE_SHIFT;
10640 struct page *page;
10641
10642 while (index <= end_index) {
10643 page = find_get_page(inode->i_mapping, index);
10644 ASSERT(page); /* Pages should be in the extent_io_tree */
10645 set_page_writeback(page);
10646 put_page(page);
10647 index++;
10648 }
10649 }
10650
10651 #ifdef CONFIG_SWAP
10652 /*
10653 * Add an entry indicating a block group or device which is pinned by a
10654 * swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
10655 * negative errno on failure.
10656 */
10657 static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
10658 bool is_block_group)
10659 {
10660 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
10661 struct btrfs_swapfile_pin *sp, *entry;
10662 struct rb_node **p;
10663 struct rb_node *parent = NULL;
10664
10665 sp = kmalloc(sizeof(*sp), GFP_NOFS);
10666 if (!sp)
10667 return -ENOMEM;
10668 sp->ptr = ptr;
10669 sp->inode = inode;
10670 sp->is_block_group = is_block_group;
10671
10672 spin_lock(&fs_info->swapfile_pins_lock);
10673 p = &fs_info->swapfile_pins.rb_node;
10674 while (*p) {
10675 parent = *p;
10676 entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
10677 if (sp->ptr < entry->ptr ||
10678 (sp->ptr == entry->ptr && sp->inode < entry->inode)) {
10679 p = &(*p)->rb_left;
10680 } else if (sp->ptr > entry->ptr ||
10681 (sp->ptr == entry->ptr && sp->inode > entry->inode)) {
10682 p = &(*p)->rb_right;
10683 } else {
10684 spin_unlock(&fs_info->swapfile_pins_lock);
10685 kfree(sp);
10686 return 1;
10687 }
10688 }
10689 rb_link_node(&sp->node, parent, p);
10690 rb_insert_color(&sp->node, &fs_info->swapfile_pins);
10691 spin_unlock(&fs_info->swapfile_pins_lock);
10692 return 0;
10693 }
10694
10695 /* Free all of the entries pinned by this swapfile. */
10696 static void btrfs_free_swapfile_pins(struct inode *inode)
10697 {
10698 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
10699 struct btrfs_swapfile_pin *sp;
10700 struct rb_node *node, *next;
10701
10702 spin_lock(&fs_info->swapfile_pins_lock);
10703 node = rb_first(&fs_info->swapfile_pins);
10704 while (node) {
10705 next = rb_next(node);
10706 sp = rb_entry(node, struct btrfs_swapfile_pin, node);
10707 if (sp->inode == inode) {
10708 rb_erase(&sp->node, &fs_info->swapfile_pins);
10709 if (sp->is_block_group)
10710 btrfs_put_block_group(sp->ptr);
10711 kfree(sp);
10712 }
10713 node = next;
10714 }
10715 spin_unlock(&fs_info->swapfile_pins_lock);
10716 }
10717
10718 struct btrfs_swap_info {
10719 u64 start;
10720 u64 block_start;
10721 u64 block_len;
10722 u64 lowest_ppage;
10723 u64 highest_ppage;
10724 unsigned long nr_pages;
10725 int nr_extents;
10726 };
10727
10728 static int btrfs_add_swap_extent(struct swap_info_struct *sis,
10729 struct btrfs_swap_info *bsi)
10730 {
10731 unsigned long nr_pages;
10732 u64 first_ppage, first_ppage_reported, next_ppage;
10733 int ret;
10734
10735 first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
10736 next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
10737 PAGE_SIZE) >> PAGE_SHIFT;
10738
10739 if (first_ppage >= next_ppage)
10740 return 0;
10741 nr_pages = next_ppage - first_ppage;
10742
10743 first_ppage_reported = first_ppage;
10744 if (bsi->start == 0)
10745 first_ppage_reported++;
10746 if (bsi->lowest_ppage > first_ppage_reported)
10747 bsi->lowest_ppage = first_ppage_reported;
10748 if (bsi->highest_ppage < (next_ppage - 1))
10749 bsi->highest_ppage = next_ppage - 1;
10750
10751 ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
10752 if (ret < 0)
10753 return ret;
10754 bsi->nr_extents += ret;
10755 bsi->nr_pages += nr_pages;
10756 return 0;
10757 }
10758
10759 static void btrfs_swap_deactivate(struct file *file)
10760 {
10761 struct inode *inode = file_inode(file);
10762
10763 btrfs_free_swapfile_pins(inode);
10764 atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
10765 }
10766
10767 static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
10768 sector_t *span)
10769 {
10770 struct inode *inode = file_inode(file);
10771 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
10772 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
10773 struct extent_state *cached_state = NULL;
10774 struct extent_map *em = NULL;
10775 struct btrfs_device *device = NULL;
10776 struct btrfs_swap_info bsi = {
10777 .lowest_ppage = (sector_t)-1ULL,
10778 };
10779 int ret = 0;
10780 u64 isize;
10781 u64 start;
10782
10783 /*
10784 * If the swap file was just created, make sure delalloc is done. If the
10785 * file changes again after this, the user is doing something stupid and
10786 * we don't really care.
10787 */
10788 ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
10789 if (ret)
10790 return ret;
10791
10792 /*
10793 * The inode is locked, so these flags won't change after we check them.
10794 */
10795 if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
10796 btrfs_warn(fs_info, "swapfile must not be compressed");
10797 return -EINVAL;
10798 }
10799 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
10800 btrfs_warn(fs_info, "swapfile must not be copy-on-write");
10801 return -EINVAL;
10802 }
10803 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
10804 btrfs_warn(fs_info, "swapfile must not be checksummed");
10805 return -EINVAL;
10806 }
10807
10808 /*
10809 * Balance or device remove/replace/resize can move stuff around from
10810 * under us. The EXCL_OP flag makes sure they aren't running/won't run
10811 * concurrently while we are mapping the swap extents, and
10812 * fs_info->swapfile_pins prevents them from running while the swap file
10813 * is active and moving the extents. Note that this also prevents a
10814 * concurrent device add which isn't actually necessary, but it's not
10815 * really worth the trouble to allow it.
10816 */
10817 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
10818 btrfs_warn(fs_info,
10819 "cannot activate swapfile while exclusive operation is running");
10820 return -EBUSY;
10821 }
10822 /*
10823 * Snapshots can create extents which require COW even if NODATACOW is
10824 * set. We use this counter to prevent snapshots. We must increment it
10825 * before walking the extents because we don't want a concurrent
10826 * snapshot to run after we've already checked the extents.
10827 */
10828 atomic_inc(&BTRFS_I(inode)->root->nr_swapfiles);
10829
10830 isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
10831
10832 lock_extent_bits(io_tree, 0, isize - 1, &cached_state);
10833 start = 0;
10834 while (start < isize) {
10835 u64 logical_block_start, physical_block_start;
10836 struct btrfs_block_group *bg;
10837 u64 len = isize - start;
10838
10839 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
10840 if (IS_ERR(em)) {
10841 ret = PTR_ERR(em);
10842 goto out;
10843 }
10844
10845 if (em->block_start == EXTENT_MAP_HOLE) {
10846 btrfs_warn(fs_info, "swapfile must not have holes");
10847 ret = -EINVAL;
10848 goto out;
10849 }
10850 if (em->block_start == EXTENT_MAP_INLINE) {
10851 /*
10852 * It's unlikely we'll ever actually find ourselves
10853 * here, as a file small enough to fit inline won't be
10854 * big enough to store more than the swap header, but in
10855 * case something changes in the future, let's catch it
10856 * here rather than later.
10857 */
10858 btrfs_warn(fs_info, "swapfile must not be inline");
10859 ret = -EINVAL;
10860 goto out;
10861 }
10862 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
10863 btrfs_warn(fs_info, "swapfile must not be compressed");
10864 ret = -EINVAL;
10865 goto out;
10866 }
10867
10868 logical_block_start = em->block_start + (start - em->start);
10869 len = min(len, em->len - (start - em->start));
10870 free_extent_map(em);
10871 em = NULL;
10872
10873 ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL);
10874 if (ret < 0) {
10875 goto out;
10876 } else if (ret) {
10877 ret = 0;
10878 } else {
10879 btrfs_warn(fs_info,
10880 "swapfile must not be copy-on-write");
10881 ret = -EINVAL;
10882 goto out;
10883 }
10884
10885 em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
10886 if (IS_ERR(em)) {
10887 ret = PTR_ERR(em);
10888 goto out;
10889 }
10890
10891 if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
10892 btrfs_warn(fs_info,
10893 "swapfile must have single data profile");
10894 ret = -EINVAL;
10895 goto out;
10896 }
10897
10898 if (device == NULL) {
10899 device = em->map_lookup->stripes[0].dev;
10900 ret = btrfs_add_swapfile_pin(inode, device, false);
10901 if (ret == 1)
10902 ret = 0;
10903 else if (ret)
10904 goto out;
10905 } else if (device != em->map_lookup->stripes[0].dev) {
10906 btrfs_warn(fs_info, "swapfile must be on one device");
10907 ret = -EINVAL;
10908 goto out;
10909 }
10910
10911 physical_block_start = (em->map_lookup->stripes[0].physical +
10912 (logical_block_start - em->start));
10913 len = min(len, em->len - (logical_block_start - em->start));
10914 free_extent_map(em);
10915 em = NULL;
10916
10917 bg = btrfs_lookup_block_group(fs_info, logical_block_start);
10918 if (!bg) {
10919 btrfs_warn(fs_info,
10920 "could not find block group containing swapfile");
10921 ret = -EINVAL;
10922 goto out;
10923 }
10924
10925 ret = btrfs_add_swapfile_pin(inode, bg, true);
10926 if (ret) {
10927 btrfs_put_block_group(bg);
10928 if (ret == 1)
10929 ret = 0;
10930 else
10931 goto out;
10932 }
10933
10934 if (bsi.block_len &&
10935 bsi.block_start + bsi.block_len == physical_block_start) {
10936 bsi.block_len += len;
10937 } else {
10938 if (bsi.block_len) {
10939 ret = btrfs_add_swap_extent(sis, &bsi);
10940 if (ret)
10941 goto out;
10942 }
10943 bsi.start = start;
10944 bsi.block_start = physical_block_start;
10945 bsi.block_len = len;
10946 }
10947
10948 start += len;
10949 }
10950
10951 if (bsi.block_len)
10952 ret = btrfs_add_swap_extent(sis, &bsi);
10953
10954 out:
10955 if (!IS_ERR_OR_NULL(em))
10956 free_extent_map(em);
10957
10958 unlock_extent_cached(io_tree, 0, isize - 1, &cached_state);
10959
10960 if (ret)
10961 btrfs_swap_deactivate(file);
10962
10963 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
10964
10965 if (ret)
10966 return ret;
10967
10968 if (device)
10969 sis->bdev = device->bdev;
10970 *span = bsi.highest_ppage - bsi.lowest_ppage + 1;
10971 sis->max = bsi.nr_pages;
10972 sis->pages = bsi.nr_pages - 1;
10973 sis->highest_bit = bsi.nr_pages - 1;
10974 return bsi.nr_extents;
10975 }
10976 #else
10977 static void btrfs_swap_deactivate(struct file *file)
10978 {
10979 }
10980
10981 static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
10982 sector_t *span)
10983 {
10984 return -EOPNOTSUPP;
10985 }
10986 #endif
10987
10988 static const struct inode_operations btrfs_dir_inode_operations = {
10989 .getattr = btrfs_getattr,
10990 .lookup = btrfs_lookup,
10991 .create = btrfs_create,
10992 .unlink = btrfs_unlink,
10993 .link = btrfs_link,
10994 .mkdir = btrfs_mkdir,
10995 .rmdir = btrfs_rmdir,
10996 .rename = btrfs_rename2,
10997 .symlink = btrfs_symlink,
10998 .setattr = btrfs_setattr,
10999 .mknod = btrfs_mknod,
11000 .listxattr = btrfs_listxattr,
11001 .permission = btrfs_permission,
11002 .get_acl = btrfs_get_acl,
11003 .set_acl = btrfs_set_acl,
11004 .update_time = btrfs_update_time,
11005 .tmpfile = btrfs_tmpfile,
11006 };
11007 static const struct inode_operations btrfs_dir_ro_inode_operations = {
11008 .lookup = btrfs_lookup,
11009 .permission = btrfs_permission,
11010 .update_time = btrfs_update_time,
11011 };
11012
11013 static const struct file_operations btrfs_dir_file_operations = {
11014 .llseek = generic_file_llseek,
11015 .read = generic_read_dir,
11016 .iterate_shared = btrfs_real_readdir,
11017 .open = btrfs_opendir,
11018 .unlocked_ioctl = btrfs_ioctl,
11019 #ifdef CONFIG_COMPAT
11020 .compat_ioctl = btrfs_compat_ioctl,
11021 #endif
11022 .release = btrfs_release_file,
11023 .fsync = btrfs_sync_file,
11024 };
11025
11026 static const struct extent_io_ops btrfs_extent_io_ops = {
11027 /* mandatory callbacks */
11028 .submit_bio_hook = btrfs_submit_bio_hook,
11029 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
11030 };
11031
11032 /*
11033 * btrfs doesn't support the bmap operation because swapfiles
11034 * use bmap to make a mapping of extents in the file. They assume
11035 * these extents won't change over the life of the file and they
11036 * use the bmap result to do IO directly to the drive.
11037 *
11038 * the btrfs bmap call would return logical addresses that aren't
11039 * suitable for IO and they also will change frequently as COW
11040 * operations happen. So, swapfile + btrfs == corruption.
11041 *
11042 * For now we're avoiding this by dropping bmap.
11043 */
11044 static const struct address_space_operations btrfs_aops = {
11045 .readpage = btrfs_readpage,
11046 .writepage = btrfs_writepage,
11047 .writepages = btrfs_writepages,
11048 .readpages = btrfs_readpages,
11049 .direct_IO = btrfs_direct_IO,
11050 .invalidatepage = btrfs_invalidatepage,
11051 .releasepage = btrfs_releasepage,
11052 .set_page_dirty = btrfs_set_page_dirty,
11053 .error_remove_page = generic_error_remove_page,
11054 .swap_activate = btrfs_swap_activate,
11055 .swap_deactivate = btrfs_swap_deactivate,
11056 };
11057
11058 static const struct inode_operations btrfs_file_inode_operations = {
11059 .getattr = btrfs_getattr,
11060 .setattr = btrfs_setattr,
11061 .listxattr = btrfs_listxattr,
11062 .permission = btrfs_permission,
11063 .fiemap = btrfs_fiemap,
11064 .get_acl = btrfs_get_acl,
11065 .set_acl = btrfs_set_acl,
11066 .update_time = btrfs_update_time,
11067 };
11068 static const struct inode_operations btrfs_special_inode_operations = {
11069 .getattr = btrfs_getattr,
11070 .setattr = btrfs_setattr,
11071 .permission = btrfs_permission,
11072 .listxattr = btrfs_listxattr,
11073 .get_acl = btrfs_get_acl,
11074 .set_acl = btrfs_set_acl,
11075 .update_time = btrfs_update_time,
11076 };
11077 static const struct inode_operations btrfs_symlink_inode_operations = {
11078 .get_link = page_get_link,
11079 .getattr = btrfs_getattr,
11080 .setattr = btrfs_setattr,
11081 .permission = btrfs_permission,
11082 .listxattr = btrfs_listxattr,
11083 .update_time = btrfs_update_time,
11084 };
11085
11086 const struct dentry_operations btrfs_dentry_operations = {
11087 .d_delete = btrfs_dentry_delete,
11088 };
Linux with added FPC-III support