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Merge tag 'xtensa-20180225' of git://github.com/jcmvbkbc/linux-xtensa
[cris-mirror.git] / fs / btrfs / inode.c
bloba79299a89b7d0285328e29cecaaff51ff82c5be7
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/bio.h>
21 #include <linux/buffer_head.h>
22 #include <linux/file.h>
23 #include <linux/fs.h>
24 #include <linux/pagemap.h>
25 #include <linux/highmem.h>
26 #include <linux/time.h>
27 #include <linux/init.h>
28 #include <linux/string.h>
29 #include <linux/backing-dev.h>
30 #include <linux/mpage.h>
31 #include <linux/swap.h>
32 #include <linux/writeback.h>
33 #include <linux/compat.h>
34 #include <linux/bit_spinlock.h>
35 #include <linux/xattr.h>
36 #include <linux/posix_acl.h>
37 #include <linux/falloc.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
40 #include <linux/mount.h>
41 #include <linux/btrfs.h>
42 #include <linux/blkdev.h>
43 #include <linux/posix_acl_xattr.h>
44 #include <linux/uio.h>
45 #include <linux/magic.h>
46 #include <linux/iversion.h>
47 #include "ctree.h"
48 #include "disk-io.h"
49 #include "transaction.h"
50 #include "btrfs_inode.h"
51 #include "print-tree.h"
52 #include "ordered-data.h"
53 #include "xattr.h"
54 #include "tree-log.h"
55 #include "volumes.h"
56 #include "compression.h"
57 #include "locking.h"
58 #include "free-space-cache.h"
59 #include "inode-map.h"
60 #include "backref.h"
61 #include "hash.h"
62 #include "props.h"
63 #include "qgroup.h"
64 #include "dedupe.h"
65
66 struct btrfs_iget_args {
67 struct btrfs_key *location;
68 struct btrfs_root *root;
69 };
70
71 struct btrfs_dio_data {
72 u64 reserve;
73 u64 unsubmitted_oe_range_start;
74 u64 unsubmitted_oe_range_end;
75 int overwrite;
76 };
77
78 static const struct inode_operations btrfs_dir_inode_operations;
79 static const struct inode_operations btrfs_symlink_inode_operations;
80 static const struct inode_operations btrfs_dir_ro_inode_operations;
81 static const struct inode_operations btrfs_special_inode_operations;
82 static const struct inode_operations btrfs_file_inode_operations;
83 static const struct address_space_operations btrfs_aops;
84 static const struct address_space_operations btrfs_symlink_aops;
85 static const struct file_operations btrfs_dir_file_operations;
86 static const struct extent_io_ops btrfs_extent_io_ops;
87
88 static struct kmem_cache *btrfs_inode_cachep;
89 struct kmem_cache *btrfs_trans_handle_cachep;
90 struct kmem_cache *btrfs_path_cachep;
91 struct kmem_cache *btrfs_free_space_cachep;
92
93 #define S_SHIFT 12
94 static const unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
95 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
96 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
97 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
98 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
99 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
100 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
101 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
102 };
103
104 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
105 static int btrfs_truncate(struct inode *inode);
106 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
107 static noinline int cow_file_range(struct inode *inode,
108 struct page *locked_page,
109 u64 start, u64 end, u64 delalloc_end,
110 int *page_started, unsigned long *nr_written,
111 int unlock, struct btrfs_dedupe_hash *hash);
112 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
113 u64 orig_start, u64 block_start,
114 u64 block_len, u64 orig_block_len,
115 u64 ram_bytes, int compress_type,
116 int type);
117
118 static void __endio_write_update_ordered(struct inode *inode,
119 const u64 offset, const u64 bytes,
120 const bool uptodate);
121
122 /*
123 * Cleanup all submitted ordered extents in specified range to handle errors
124 * from the fill_dellaloc() callback.
125 *
126 * NOTE: caller must ensure that when an error happens, it can not call
127 * extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
128 * and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
129 * to be released, which we want to happen only when finishing the ordered
130 * extent (btrfs_finish_ordered_io()). Also note that the caller of the
131 * fill_delalloc() callback already does proper cleanup for the first page of
132 * the range, that is, it invokes the callback writepage_end_io_hook() for the
133 * range of the first page.
134 */
135 static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
136 const u64 offset,
137 const u64 bytes)
138 {
139 unsigned long index = offset >> PAGE_SHIFT;
140 unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
141 struct page *page;
142
143 while (index <= end_index) {
144 page = find_get_page(inode->i_mapping, index);
145 index++;
146 if (!page)
147 continue;
148 ClearPagePrivate2(page);
149 put_page(page);
150 }
151 return __endio_write_update_ordered(inode, offset + PAGE_SIZE,
152 bytes - PAGE_SIZE, false);
153 }
154
155 static int btrfs_dirty_inode(struct inode *inode);
156
157 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
158 void btrfs_test_inode_set_ops(struct inode *inode)
159 {
160 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
161 }
162 #endif
163
164 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
165 struct inode *inode, struct inode *dir,
166 const struct qstr *qstr)
167 {
168 int err;
169
170 err = btrfs_init_acl(trans, inode, dir);
171 if (!err)
172 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
173 return err;
174 }
175
176 /*
177 * this does all the hard work for inserting an inline extent into
178 * the btree. The caller should have done a btrfs_drop_extents so that
179 * no overlapping inline items exist in the btree
180 */
181 static int insert_inline_extent(struct btrfs_trans_handle *trans,
182 struct btrfs_path *path, int extent_inserted,
183 struct btrfs_root *root, struct inode *inode,
184 u64 start, size_t size, size_t compressed_size,
185 int compress_type,
186 struct page **compressed_pages)
187 {
188 struct extent_buffer *leaf;
189 struct page *page = NULL;
190 char *kaddr;
191 unsigned long ptr;
192 struct btrfs_file_extent_item *ei;
193 int ret;
194 size_t cur_size = size;
195 unsigned long offset;
196
197 if (compressed_size && compressed_pages)
198 cur_size = compressed_size;
199
200 inode_add_bytes(inode, size);
201
202 if (!extent_inserted) {
203 struct btrfs_key key;
204 size_t datasize;
205
206 key.objectid = btrfs_ino(BTRFS_I(inode));
207 key.offset = start;
208 key.type = BTRFS_EXTENT_DATA_KEY;
209
210 datasize = btrfs_file_extent_calc_inline_size(cur_size);
211 path->leave_spinning = 1;
212 ret = btrfs_insert_empty_item(trans, root, path, &key,
213 datasize);
214 if (ret)
215 goto fail;
216 }
217 leaf = path->nodes[0];
218 ei = btrfs_item_ptr(leaf, path->slots[0],
219 struct btrfs_file_extent_item);
220 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
221 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
222 btrfs_set_file_extent_encryption(leaf, ei, 0);
223 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
224 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
225 ptr = btrfs_file_extent_inline_start(ei);
226
227 if (compress_type != BTRFS_COMPRESS_NONE) {
228 struct page *cpage;
229 int i = 0;
230 while (compressed_size > 0) {
231 cpage = compressed_pages[i];
232 cur_size = min_t(unsigned long, compressed_size,
233 PAGE_SIZE);
234
235 kaddr = kmap_atomic(cpage);
236 write_extent_buffer(leaf, kaddr, ptr, cur_size);
237 kunmap_atomic(kaddr);
238
239 i++;
240 ptr += cur_size;
241 compressed_size -= cur_size;
242 }
243 btrfs_set_file_extent_compression(leaf, ei,
244 compress_type);
245 } else {
246 page = find_get_page(inode->i_mapping,
247 start >> PAGE_SHIFT);
248 btrfs_set_file_extent_compression(leaf, ei, 0);
249 kaddr = kmap_atomic(page);
250 offset = start & (PAGE_SIZE - 1);
251 write_extent_buffer(leaf, kaddr + offset, ptr, size);
252 kunmap_atomic(kaddr);
253 put_page(page);
254 }
255 btrfs_mark_buffer_dirty(leaf);
256 btrfs_release_path(path);
257
258 /*
259 * we're an inline extent, so nobody can
260 * extend the file past i_size without locking
261 * a page we already have locked.
262 *
263 * We must do any isize and inode updates
264 * before we unlock the pages. Otherwise we
265 * could end up racing with unlink.
266 */
267 BTRFS_I(inode)->disk_i_size = inode->i_size;
268 ret = btrfs_update_inode(trans, root, inode);
269
270 fail:
271 return ret;
272 }
273
274
275 /*
276 * conditionally insert an inline extent into the file. This
277 * does the checks required to make sure the data is small enough
278 * to fit as an inline extent.
279 */
280 static noinline int cow_file_range_inline(struct btrfs_root *root,
281 struct inode *inode, u64 start,
282 u64 end, size_t compressed_size,
283 int compress_type,
284 struct page **compressed_pages)
285 {
286 struct btrfs_fs_info *fs_info = root->fs_info;
287 struct btrfs_trans_handle *trans;
288 u64 isize = i_size_read(inode);
289 u64 actual_end = min(end + 1, isize);
290 u64 inline_len = actual_end - start;
291 u64 aligned_end = ALIGN(end, fs_info->sectorsize);
292 u64 data_len = inline_len;
293 int ret;
294 struct btrfs_path *path;
295 int extent_inserted = 0;
296 u32 extent_item_size;
297
298 if (compressed_size)
299 data_len = compressed_size;
300
301 if (start > 0 ||
302 actual_end > fs_info->sectorsize ||
303 data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
304 (!compressed_size &&
305 (actual_end & (fs_info->sectorsize - 1)) == 0) ||
306 end + 1 < isize ||
307 data_len > fs_info->max_inline) {
308 return 1;
309 }
310
311 path = btrfs_alloc_path();
312 if (!path)
313 return -ENOMEM;
314
315 trans = btrfs_join_transaction(root);
316 if (IS_ERR(trans)) {
317 btrfs_free_path(path);
318 return PTR_ERR(trans);
319 }
320 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
321
322 if (compressed_size && compressed_pages)
323 extent_item_size = btrfs_file_extent_calc_inline_size(
324 compressed_size);
325 else
326 extent_item_size = btrfs_file_extent_calc_inline_size(
327 inline_len);
328
329 ret = __btrfs_drop_extents(trans, root, inode, path,
330 start, aligned_end, NULL,
331 1, 1, extent_item_size, &extent_inserted);
332 if (ret) {
333 btrfs_abort_transaction(trans, ret);
334 goto out;
335 }
336
337 if (isize > actual_end)
338 inline_len = min_t(u64, isize, actual_end);
339 ret = insert_inline_extent(trans, path, extent_inserted,
340 root, inode, start,
341 inline_len, compressed_size,
342 compress_type, compressed_pages);
343 if (ret && ret != -ENOSPC) {
344 btrfs_abort_transaction(trans, ret);
345 goto out;
346 } else if (ret == -ENOSPC) {
347 ret = 1;
348 goto out;
349 }
350
351 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
352 btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
353 out:
354 /*
355 * Don't forget to free the reserved space, as for inlined extent
356 * it won't count as data extent, free them directly here.
357 * And at reserve time, it's always aligned to page size, so
358 * just free one page here.
359 */
360 btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
361 btrfs_free_path(path);
362 btrfs_end_transaction(trans);
363 return ret;
364 }
365
366 struct async_extent {
367 u64 start;
368 u64 ram_size;
369 u64 compressed_size;
370 struct page **pages;
371 unsigned long nr_pages;
372 int compress_type;
373 struct list_head list;
374 };
375
376 struct async_cow {
377 struct inode *inode;
378 struct btrfs_root *root;
379 struct page *locked_page;
380 u64 start;
381 u64 end;
382 unsigned int write_flags;
383 struct list_head extents;
384 struct btrfs_work work;
385 };
386
387 static noinline int add_async_extent(struct async_cow *cow,
388 u64 start, u64 ram_size,
389 u64 compressed_size,
390 struct page **pages,
391 unsigned long nr_pages,
392 int compress_type)
393 {
394 struct async_extent *async_extent;
395
396 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
397 BUG_ON(!async_extent); /* -ENOMEM */
398 async_extent->start = start;
399 async_extent->ram_size = ram_size;
400 async_extent->compressed_size = compressed_size;
401 async_extent->pages = pages;
402 async_extent->nr_pages = nr_pages;
403 async_extent->compress_type = compress_type;
404 list_add_tail(&async_extent->list, &cow->extents);
405 return 0;
406 }
407
408 static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
409 {
410 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
411
412 /* force compress */
413 if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
414 return 1;
415 /* defrag ioctl */
416 if (BTRFS_I(inode)->defrag_compress)
417 return 1;
418 /* bad compression ratios */
419 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
420 return 0;
421 if (btrfs_test_opt(fs_info, COMPRESS) ||
422 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
423 BTRFS_I(inode)->prop_compress)
424 return btrfs_compress_heuristic(inode, start, end);
425 return 0;
426 }
427
428 static inline void inode_should_defrag(struct btrfs_inode *inode,
429 u64 start, u64 end, u64 num_bytes, u64 small_write)
430 {
431 /* If this is a small write inside eof, kick off a defrag */
432 if (num_bytes < small_write &&
433 (start > 0 || end + 1 < inode->disk_i_size))
434 btrfs_add_inode_defrag(NULL, inode);
435 }
436
437 /*
438 * we create compressed extents in two phases. The first
439 * phase compresses a range of pages that have already been
440 * locked (both pages and state bits are locked).
441 *
442 * This is done inside an ordered work queue, and the compression
443 * is spread across many cpus. The actual IO submission is step
444 * two, and the ordered work queue takes care of making sure that
445 * happens in the same order things were put onto the queue by
446 * writepages and friends.
447 *
448 * If this code finds it can't get good compression, it puts an
449 * entry onto the work queue to write the uncompressed bytes. This
450 * makes sure that both compressed inodes and uncompressed inodes
451 * are written in the same order that the flusher thread sent them
452 * down.
453 */
454 static noinline void compress_file_range(struct inode *inode,
455 struct page *locked_page,
456 u64 start, u64 end,
457 struct async_cow *async_cow,
458 int *num_added)
459 {
460 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
461 struct btrfs_root *root = BTRFS_I(inode)->root;
462 u64 blocksize = fs_info->sectorsize;
463 u64 actual_end;
464 u64 isize = i_size_read(inode);
465 int ret = 0;
466 struct page **pages = NULL;
467 unsigned long nr_pages;
468 unsigned long total_compressed = 0;
469 unsigned long total_in = 0;
470 int i;
471 int will_compress;
472 int compress_type = fs_info->compress_type;
473 int redirty = 0;
474
475 inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
476 SZ_16K);
477
478 actual_end = min_t(u64, isize, end + 1);
479 again:
480 will_compress = 0;
481 nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
482 BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
483 nr_pages = min_t(unsigned long, nr_pages,
484 BTRFS_MAX_COMPRESSED / PAGE_SIZE);
485
486 /*
487 * we don't want to send crud past the end of i_size through
488 * compression, that's just a waste of CPU time. So, if the
489 * end of the file is before the start of our current
490 * requested range of bytes, we bail out to the uncompressed
491 * cleanup code that can deal with all of this.
492 *
493 * It isn't really the fastest way to fix things, but this is a
494 * very uncommon corner.
495 */
496 if (actual_end <= start)
497 goto cleanup_and_bail_uncompressed;
498
499 total_compressed = actual_end - start;
500
501 /*
502 * skip compression for a small file range(<=blocksize) that
503 * isn't an inline extent, since it doesn't save disk space at all.
504 */
505 if (total_compressed <= blocksize &&
506 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
507 goto cleanup_and_bail_uncompressed;
508
509 total_compressed = min_t(unsigned long, total_compressed,
510 BTRFS_MAX_UNCOMPRESSED);
511 total_in = 0;
512 ret = 0;
513
514 /*
515 * we do compression for mount -o compress and when the
516 * inode has not been flagged as nocompress. This flag can
517 * change at any time if we discover bad compression ratios.
518 */
519 if (inode_need_compress(inode, start, end)) {
520 WARN_ON(pages);
521 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
522 if (!pages) {
523 /* just bail out to the uncompressed code */
524 goto cont;
525 }
526
527 if (BTRFS_I(inode)->defrag_compress)
528 compress_type = BTRFS_I(inode)->defrag_compress;
529 else if (BTRFS_I(inode)->prop_compress)
530 compress_type = BTRFS_I(inode)->prop_compress;
531
532 /*
533 * we need to call clear_page_dirty_for_io on each
534 * page in the range. Otherwise applications with the file
535 * mmap'd can wander in and change the page contents while
536 * we are compressing them.
537 *
538 * If the compression fails for any reason, we set the pages
539 * dirty again later on.
540 *
541 * Note that the remaining part is redirtied, the start pointer
542 * has moved, the end is the original one.
543 */
544 if (!redirty) {
545 extent_range_clear_dirty_for_io(inode, start, end);
546 redirty = 1;
547 }
548
549 /* Compression level is applied here and only here */
550 ret = btrfs_compress_pages(
551 compress_type | (fs_info->compress_level << 4),
552 inode->i_mapping, start,
553 pages,
554 &nr_pages,
555 &total_in,
556 &total_compressed);
557
558 if (!ret) {
559 unsigned long offset = total_compressed &
560 (PAGE_SIZE - 1);
561 struct page *page = pages[nr_pages - 1];
562 char *kaddr;
563
564 /* zero the tail end of the last page, we might be
565 * sending it down to disk
566 */
567 if (offset) {
568 kaddr = kmap_atomic(page);
569 memset(kaddr + offset, 0,
570 PAGE_SIZE - offset);
571 kunmap_atomic(kaddr);
572 }
573 will_compress = 1;
574 }
575 }
576 cont:
577 if (start == 0) {
578 /* lets try to make an inline extent */
579 if (ret || total_in < actual_end) {
580 /* we didn't compress the entire range, try
581 * to make an uncompressed inline extent.
582 */
583 ret = cow_file_range_inline(root, inode, start, end,
584 0, BTRFS_COMPRESS_NONE, NULL);
585 } else {
586 /* try making a compressed inline extent */
587 ret = cow_file_range_inline(root, inode, start, end,
588 total_compressed,
589 compress_type, pages);
590 }
591 if (ret <= 0) {
592 unsigned long clear_flags = EXTENT_DELALLOC |
593 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
594 EXTENT_DO_ACCOUNTING;
595 unsigned long page_error_op;
596
597 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
598
599 /*
600 * inline extent creation worked or returned error,
601 * we don't need to create any more async work items.
602 * Unlock and free up our temp pages.
603 *
604 * We use DO_ACCOUNTING here because we need the
605 * delalloc_release_metadata to be done _after_ we drop
606 * our outstanding extent for clearing delalloc for this
607 * range.
608 */
609 extent_clear_unlock_delalloc(inode, start, end, end,
610 NULL, clear_flags,
611 PAGE_UNLOCK |
612 PAGE_CLEAR_DIRTY |
613 PAGE_SET_WRITEBACK |
614 page_error_op |
615 PAGE_END_WRITEBACK);
616 goto free_pages_out;
617 }
618 }
619
620 if (will_compress) {
621 /*
622 * we aren't doing an inline extent round the compressed size
623 * up to a block size boundary so the allocator does sane
624 * things
625 */
626 total_compressed = ALIGN(total_compressed, blocksize);
627
628 /*
629 * one last check to make sure the compression is really a
630 * win, compare the page count read with the blocks on disk,
631 * compression must free at least one sector size
632 */
633 total_in = ALIGN(total_in, PAGE_SIZE);
634 if (total_compressed + blocksize <= total_in) {
635 *num_added += 1;
636
637 /*
638 * The async work queues will take care of doing actual
639 * allocation on disk for these compressed pages, and
640 * will submit them to the elevator.
641 */
642 add_async_extent(async_cow, start, total_in,
643 total_compressed, pages, nr_pages,
644 compress_type);
645
646 if (start + total_in < end) {
647 start += total_in;
648 pages = NULL;
649 cond_resched();
650 goto again;
651 }
652 return;
653 }
654 }
655 if (pages) {
656 /*
657 * the compression code ran but failed to make things smaller,
658 * free any pages it allocated and our page pointer array
659 */
660 for (i = 0; i < nr_pages; i++) {
661 WARN_ON(pages[i]->mapping);
662 put_page(pages[i]);
663 }
664 kfree(pages);
665 pages = NULL;
666 total_compressed = 0;
667 nr_pages = 0;
668
669 /* flag the file so we don't compress in the future */
670 if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
671 !(BTRFS_I(inode)->prop_compress)) {
672 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
673 }
674 }
675 cleanup_and_bail_uncompressed:
676 /*
677 * No compression, but we still need to write the pages in the file
678 * we've been given so far. redirty the locked page if it corresponds
679 * to our extent and set things up for the async work queue to run
680 * cow_file_range to do the normal delalloc dance.
681 */
682 if (page_offset(locked_page) >= start &&
683 page_offset(locked_page) <= end)
684 __set_page_dirty_nobuffers(locked_page);
685 /* unlocked later on in the async handlers */
686
687 if (redirty)
688 extent_range_redirty_for_io(inode, start, end);
689 add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0,
690 BTRFS_COMPRESS_NONE);
691 *num_added += 1;
692
693 return;
694
695 free_pages_out:
696 for (i = 0; i < nr_pages; i++) {
697 WARN_ON(pages[i]->mapping);
698 put_page(pages[i]);
699 }
700 kfree(pages);
701 }
702
703 static void free_async_extent_pages(struct async_extent *async_extent)
704 {
705 int i;
706
707 if (!async_extent->pages)
708 return;
709
710 for (i = 0; i < async_extent->nr_pages; i++) {
711 WARN_ON(async_extent->pages[i]->mapping);
712 put_page(async_extent->pages[i]);
713 }
714 kfree(async_extent->pages);
715 async_extent->nr_pages = 0;
716 async_extent->pages = NULL;
717 }
718
719 /*
720 * phase two of compressed writeback. This is the ordered portion
721 * of the code, which only gets called in the order the work was
722 * queued. We walk all the async extents created by compress_file_range
723 * and send them down to the disk.
724 */
725 static noinline void submit_compressed_extents(struct inode *inode,
726 struct async_cow *async_cow)
727 {
728 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
729 struct async_extent *async_extent;
730 u64 alloc_hint = 0;
731 struct btrfs_key ins;
732 struct extent_map *em;
733 struct btrfs_root *root = BTRFS_I(inode)->root;
734 struct extent_io_tree *io_tree;
735 int ret = 0;
736
737 again:
738 while (!list_empty(&async_cow->extents)) {
739 async_extent = list_entry(async_cow->extents.next,
740 struct async_extent, list);
741 list_del(&async_extent->list);
742
743 io_tree = &BTRFS_I(inode)->io_tree;
744
745 retry:
746 /* did the compression code fall back to uncompressed IO? */
747 if (!async_extent->pages) {
748 int page_started = 0;
749 unsigned long nr_written = 0;
750
751 lock_extent(io_tree, async_extent->start,
752 async_extent->start +
753 async_extent->ram_size - 1);
754
755 /* allocate blocks */
756 ret = cow_file_range(inode, async_cow->locked_page,
757 async_extent->start,
758 async_extent->start +
759 async_extent->ram_size - 1,
760 async_extent->start +
761 async_extent->ram_size - 1,
762 &page_started, &nr_written, 0,
763 NULL);
764
765 /* JDM XXX */
766
767 /*
768 * if page_started, cow_file_range inserted an
769 * inline extent and took care of all the unlocking
770 * and IO for us. Otherwise, we need to submit
771 * all those pages down to the drive.
772 */
773 if (!page_started && !ret)
774 extent_write_locked_range(inode,
775 async_extent->start,
776 async_extent->start +
777 async_extent->ram_size - 1,
778 WB_SYNC_ALL);
779 else if (ret)
780 unlock_page(async_cow->locked_page);
781 kfree(async_extent);
782 cond_resched();
783 continue;
784 }
785
786 lock_extent(io_tree, async_extent->start,
787 async_extent->start + async_extent->ram_size - 1);
788
789 ret = btrfs_reserve_extent(root, async_extent->ram_size,
790 async_extent->compressed_size,
791 async_extent->compressed_size,
792 0, alloc_hint, &ins, 1, 1);
793 if (ret) {
794 free_async_extent_pages(async_extent);
795
796 if (ret == -ENOSPC) {
797 unlock_extent(io_tree, async_extent->start,
798 async_extent->start +
799 async_extent->ram_size - 1);
800
801 /*
802 * we need to redirty the pages if we decide to
803 * fallback to uncompressed IO, otherwise we
804 * will not submit these pages down to lower
805 * layers.
806 */
807 extent_range_redirty_for_io(inode,
808 async_extent->start,
809 async_extent->start +
810 async_extent->ram_size - 1);
811
812 goto retry;
813 }
814 goto out_free;
815 }
816 /*
817 * here we're doing allocation and writeback of the
818 * compressed pages
819 */
820 em = create_io_em(inode, async_extent->start,
821 async_extent->ram_size, /* len */
822 async_extent->start, /* orig_start */
823 ins.objectid, /* block_start */
824 ins.offset, /* block_len */
825 ins.offset, /* orig_block_len */
826 async_extent->ram_size, /* ram_bytes */
827 async_extent->compress_type,
828 BTRFS_ORDERED_COMPRESSED);
829 if (IS_ERR(em))
830 /* ret value is not necessary due to void function */
831 goto out_free_reserve;
832 free_extent_map(em);
833
834 ret = btrfs_add_ordered_extent_compress(inode,
835 async_extent->start,
836 ins.objectid,
837 async_extent->ram_size,
838 ins.offset,
839 BTRFS_ORDERED_COMPRESSED,
840 async_extent->compress_type);
841 if (ret) {
842 btrfs_drop_extent_cache(BTRFS_I(inode),
843 async_extent->start,
844 async_extent->start +
845 async_extent->ram_size - 1, 0);
846 goto out_free_reserve;
847 }
848 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
849
850 /*
851 * clear dirty, set writeback and unlock the pages.
852 */
853 extent_clear_unlock_delalloc(inode, async_extent->start,
854 async_extent->start +
855 async_extent->ram_size - 1,
856 async_extent->start +
857 async_extent->ram_size - 1,
858 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
859 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
860 PAGE_SET_WRITEBACK);
861 if (btrfs_submit_compressed_write(inode,
862 async_extent->start,
863 async_extent->ram_size,
864 ins.objectid,
865 ins.offset, async_extent->pages,
866 async_extent->nr_pages,
867 async_cow->write_flags)) {
868 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
869 struct page *p = async_extent->pages[0];
870 const u64 start = async_extent->start;
871 const u64 end = start + async_extent->ram_size - 1;
872
873 p->mapping = inode->i_mapping;
874 tree->ops->writepage_end_io_hook(p, start, end,
875 NULL, 0);
876 p->mapping = NULL;
877 extent_clear_unlock_delalloc(inode, start, end, end,
878 NULL, 0,
879 PAGE_END_WRITEBACK |
880 PAGE_SET_ERROR);
881 free_async_extent_pages(async_extent);
882 }
883 alloc_hint = ins.objectid + ins.offset;
884 kfree(async_extent);
885 cond_resched();
886 }
887 return;
888 out_free_reserve:
889 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
890 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
891 out_free:
892 extent_clear_unlock_delalloc(inode, async_extent->start,
893 async_extent->start +
894 async_extent->ram_size - 1,
895 async_extent->start +
896 async_extent->ram_size - 1,
897 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
898 EXTENT_DELALLOC_NEW |
899 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
900 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
901 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
902 PAGE_SET_ERROR);
903 free_async_extent_pages(async_extent);
904 kfree(async_extent);
905 goto again;
906 }
907
908 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
909 u64 num_bytes)
910 {
911 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
912 struct extent_map *em;
913 u64 alloc_hint = 0;
914
915 read_lock(&em_tree->lock);
916 em = search_extent_mapping(em_tree, start, num_bytes);
917 if (em) {
918 /*
919 * if block start isn't an actual block number then find the
920 * first block in this inode and use that as a hint. If that
921 * block is also bogus then just don't worry about it.
922 */
923 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
924 free_extent_map(em);
925 em = search_extent_mapping(em_tree, 0, 0);
926 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
927 alloc_hint = em->block_start;
928 if (em)
929 free_extent_map(em);
930 } else {
931 alloc_hint = em->block_start;
932 free_extent_map(em);
933 }
934 }
935 read_unlock(&em_tree->lock);
936
937 return alloc_hint;
938 }
939
940 /*
941 * when extent_io.c finds a delayed allocation range in the file,
942 * the call backs end up in this code. The basic idea is to
943 * allocate extents on disk for the range, and create ordered data structs
944 * in ram to track those extents.
945 *
946 * locked_page is the page that writepage had locked already. We use
947 * it to make sure we don't do extra locks or unlocks.
948 *
949 * *page_started is set to one if we unlock locked_page and do everything
950 * required to start IO on it. It may be clean and already done with
951 * IO when we return.
952 */
953 static noinline int cow_file_range(struct inode *inode,
954 struct page *locked_page,
955 u64 start, u64 end, u64 delalloc_end,
956 int *page_started, unsigned long *nr_written,
957 int unlock, struct btrfs_dedupe_hash *hash)
958 {
959 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
960 struct btrfs_root *root = BTRFS_I(inode)->root;
961 u64 alloc_hint = 0;
962 u64 num_bytes;
963 unsigned long ram_size;
964 u64 disk_num_bytes;
965 u64 cur_alloc_size = 0;
966 u64 blocksize = fs_info->sectorsize;
967 struct btrfs_key ins;
968 struct extent_map *em;
969 unsigned clear_bits;
970 unsigned long page_ops;
971 bool extent_reserved = false;
972 int ret = 0;
973
974 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
975 WARN_ON_ONCE(1);
976 ret = -EINVAL;
977 goto out_unlock;
978 }
979
980 num_bytes = ALIGN(end - start + 1, blocksize);
981 num_bytes = max(blocksize, num_bytes);
982 disk_num_bytes = num_bytes;
983
984 inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
985
986 if (start == 0) {
987 /* lets try to make an inline extent */
988 ret = cow_file_range_inline(root, inode, start, end, 0,
989 BTRFS_COMPRESS_NONE, NULL);
990 if (ret == 0) {
991 /*
992 * We use DO_ACCOUNTING here because we need the
993 * delalloc_release_metadata to be run _after_ we drop
994 * our outstanding extent for clearing delalloc for this
995 * range.
996 */
997 extent_clear_unlock_delalloc(inode, start, end,
998 delalloc_end, NULL,
999 EXTENT_LOCKED | EXTENT_DELALLOC |
1000 EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
1001 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1002 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1003 PAGE_END_WRITEBACK);
1004 *nr_written = *nr_written +
1005 (end - start + PAGE_SIZE) / PAGE_SIZE;
1006 *page_started = 1;
1007 goto out;
1008 } else if (ret < 0) {
1009 goto out_unlock;
1010 }
1011 }
1012
1013 BUG_ON(disk_num_bytes >
1014 btrfs_super_total_bytes(fs_info->super_copy));
1015
1016 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
1017 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1018 start + num_bytes - 1, 0);
1019
1020 while (disk_num_bytes > 0) {
1021 cur_alloc_size = disk_num_bytes;
1022 ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
1023 fs_info->sectorsize, 0, alloc_hint,
1024 &ins, 1, 1);
1025 if (ret < 0)
1026 goto out_unlock;
1027 cur_alloc_size = ins.offset;
1028 extent_reserved = true;
1029
1030 ram_size = ins.offset;
1031 em = create_io_em(inode, start, ins.offset, /* len */
1032 start, /* orig_start */
1033 ins.objectid, /* block_start */
1034 ins.offset, /* block_len */
1035 ins.offset, /* orig_block_len */
1036 ram_size, /* ram_bytes */
1037 BTRFS_COMPRESS_NONE, /* compress_type */
1038 BTRFS_ORDERED_REGULAR /* type */);
1039 if (IS_ERR(em))
1040 goto out_reserve;
1041 free_extent_map(em);
1042
1043 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1044 ram_size, cur_alloc_size, 0);
1045 if (ret)
1046 goto out_drop_extent_cache;
1047
1048 if (root->root_key.objectid ==
1049 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1050 ret = btrfs_reloc_clone_csums(inode, start,
1051 cur_alloc_size);
1052 /*
1053 * Only drop cache here, and process as normal.
1054 *
1055 * We must not allow extent_clear_unlock_delalloc()
1056 * at out_unlock label to free meta of this ordered
1057 * extent, as its meta should be freed by
1058 * btrfs_finish_ordered_io().
1059 *
1060 * So we must continue until @start is increased to
1061 * skip current ordered extent.
1062 */
1063 if (ret)
1064 btrfs_drop_extent_cache(BTRFS_I(inode), start,
1065 start + ram_size - 1, 0);
1066 }
1067
1068 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1069
1070 /* we're not doing compressed IO, don't unlock the first
1071 * page (which the caller expects to stay locked), don't
1072 * clear any dirty bits and don't set any writeback bits
1073 *
1074 * Do set the Private2 bit so we know this page was properly
1075 * setup for writepage
1076 */
1077 page_ops = unlock ? PAGE_UNLOCK : 0;
1078 page_ops |= PAGE_SET_PRIVATE2;
1079
1080 extent_clear_unlock_delalloc(inode, start,
1081 start + ram_size - 1,
1082 delalloc_end, locked_page,
1083 EXTENT_LOCKED | EXTENT_DELALLOC,
1084 page_ops);
1085 if (disk_num_bytes < cur_alloc_size)
1086 disk_num_bytes = 0;
1087 else
1088 disk_num_bytes -= cur_alloc_size;
1089 num_bytes -= cur_alloc_size;
1090 alloc_hint = ins.objectid + ins.offset;
1091 start += cur_alloc_size;
1092 extent_reserved = false;
1093
1094 /*
1095 * btrfs_reloc_clone_csums() error, since start is increased
1096 * extent_clear_unlock_delalloc() at out_unlock label won't
1097 * free metadata of current ordered extent, we're OK to exit.
1098 */
1099 if (ret)
1100 goto out_unlock;
1101 }
1102 out:
1103 return ret;
1104
1105 out_drop_extent_cache:
1106 btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
1107 out_reserve:
1108 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
1109 btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
1110 out_unlock:
1111 clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
1112 EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
1113 page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
1114 PAGE_END_WRITEBACK;
1115 /*
1116 * If we reserved an extent for our delalloc range (or a subrange) and
1117 * failed to create the respective ordered extent, then it means that
1118 * when we reserved the extent we decremented the extent's size from
1119 * the data space_info's bytes_may_use counter and incremented the
1120 * space_info's bytes_reserved counter by the same amount. We must make
1121 * sure extent_clear_unlock_delalloc() does not try to decrement again
1122 * the data space_info's bytes_may_use counter, therefore we do not pass
1123 * it the flag EXTENT_CLEAR_DATA_RESV.
1124 */
1125 if (extent_reserved) {
1126 extent_clear_unlock_delalloc(inode, start,
1127 start + cur_alloc_size,
1128 start + cur_alloc_size,
1129 locked_page,
1130 clear_bits,
1131 page_ops);
1132 start += cur_alloc_size;
1133 if (start >= end)
1134 goto out;
1135 }
1136 extent_clear_unlock_delalloc(inode, start, end, delalloc_end,
1137 locked_page,
1138 clear_bits | EXTENT_CLEAR_DATA_RESV,
1139 page_ops);
1140 goto out;
1141 }
1142
1143 /*
1144 * work queue call back to started compression on a file and pages
1145 */
1146 static noinline void async_cow_start(struct btrfs_work *work)
1147 {
1148 struct async_cow *async_cow;
1149 int num_added = 0;
1150 async_cow = container_of(work, struct async_cow, work);
1151
1152 compress_file_range(async_cow->inode, async_cow->locked_page,
1153 async_cow->start, async_cow->end, async_cow,
1154 &num_added);
1155 if (num_added == 0) {
1156 btrfs_add_delayed_iput(async_cow->inode);
1157 async_cow->inode = NULL;
1158 }
1159 }
1160
1161 /*
1162 * work queue call back to submit previously compressed pages
1163 */
1164 static noinline void async_cow_submit(struct btrfs_work *work)
1165 {
1166 struct btrfs_fs_info *fs_info;
1167 struct async_cow *async_cow;
1168 struct btrfs_root *root;
1169 unsigned long nr_pages;
1170
1171 async_cow = container_of(work, struct async_cow, work);
1172
1173 root = async_cow->root;
1174 fs_info = root->fs_info;
1175 nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >>
1176 PAGE_SHIFT;
1177
1178 /*
1179 * atomic_sub_return implies a barrier for waitqueue_active
1180 */
1181 if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
1182 5 * SZ_1M &&
1183 waitqueue_active(&fs_info->async_submit_wait))
1184 wake_up(&fs_info->async_submit_wait);
1185
1186 if (async_cow->inode)
1187 submit_compressed_extents(async_cow->inode, async_cow);
1188 }
1189
1190 static noinline void async_cow_free(struct btrfs_work *work)
1191 {
1192 struct async_cow *async_cow;
1193 async_cow = container_of(work, struct async_cow, work);
1194 if (async_cow->inode)
1195 btrfs_add_delayed_iput(async_cow->inode);
1196 kfree(async_cow);
1197 }
1198
1199 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1200 u64 start, u64 end, int *page_started,
1201 unsigned long *nr_written,
1202 unsigned int write_flags)
1203 {
1204 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1205 struct async_cow *async_cow;
1206 struct btrfs_root *root = BTRFS_I(inode)->root;
1207 unsigned long nr_pages;
1208 u64 cur_end;
1209
1210 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1211 1, 0, NULL);
1212 while (start < end) {
1213 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1214 BUG_ON(!async_cow); /* -ENOMEM */
1215 async_cow->inode = igrab(inode);
1216 async_cow->root = root;
1217 async_cow->locked_page = locked_page;
1218 async_cow->start = start;
1219 async_cow->write_flags = write_flags;
1220
1221 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1222 !btrfs_test_opt(fs_info, FORCE_COMPRESS))
1223 cur_end = end;
1224 else
1225 cur_end = min(end, start + SZ_512K - 1);
1226
1227 async_cow->end = cur_end;
1228 INIT_LIST_HEAD(&async_cow->extents);
1229
1230 btrfs_init_work(&async_cow->work,
1231 btrfs_delalloc_helper,
1232 async_cow_start, async_cow_submit,
1233 async_cow_free);
1234
1235 nr_pages = (cur_end - start + PAGE_SIZE) >>
1236 PAGE_SHIFT;
1237 atomic_add(nr_pages, &fs_info->async_delalloc_pages);
1238
1239 btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work);
1240
1241 *nr_written += nr_pages;
1242 start = cur_end + 1;
1243 }
1244 *page_started = 1;
1245 return 0;
1246 }
1247
1248 static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
1249 u64 bytenr, u64 num_bytes)
1250 {
1251 int ret;
1252 struct btrfs_ordered_sum *sums;
1253 LIST_HEAD(list);
1254
1255 ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
1256 bytenr + num_bytes - 1, &list, 0);
1257 if (ret == 0 && list_empty(&list))
1258 return 0;
1259
1260 while (!list_empty(&list)) {
1261 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1262 list_del(&sums->list);
1263 kfree(sums);
1264 }
1265 return 1;
1266 }
1267
1268 /*
1269 * when nowcow writeback call back. This checks for snapshots or COW copies
1270 * of the extents that exist in the file, and COWs the file as required.
1271 *
1272 * If no cow copies or snapshots exist, we write directly to the existing
1273 * blocks on disk
1274 */
1275 static noinline int run_delalloc_nocow(struct inode *inode,
1276 struct page *locked_page,
1277 u64 start, u64 end, int *page_started, int force,
1278 unsigned long *nr_written)
1279 {
1280 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1281 struct btrfs_root *root = BTRFS_I(inode)->root;
1282 struct extent_buffer *leaf;
1283 struct btrfs_path *path;
1284 struct btrfs_file_extent_item *fi;
1285 struct btrfs_key found_key;
1286 struct extent_map *em;
1287 u64 cow_start;
1288 u64 cur_offset;
1289 u64 extent_end;
1290 u64 extent_offset;
1291 u64 disk_bytenr;
1292 u64 num_bytes;
1293 u64 disk_num_bytes;
1294 u64 ram_bytes;
1295 int extent_type;
1296 int ret, err;
1297 int type;
1298 int nocow;
1299 int check_prev = 1;
1300 bool nolock;
1301 u64 ino = btrfs_ino(BTRFS_I(inode));
1302
1303 path = btrfs_alloc_path();
1304 if (!path) {
1305 extent_clear_unlock_delalloc(inode, start, end, end,
1306 locked_page,
1307 EXTENT_LOCKED | EXTENT_DELALLOC |
1308 EXTENT_DO_ACCOUNTING |
1309 EXTENT_DEFRAG, PAGE_UNLOCK |
1310 PAGE_CLEAR_DIRTY |
1311 PAGE_SET_WRITEBACK |
1312 PAGE_END_WRITEBACK);
1313 return -ENOMEM;
1314 }
1315
1316 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
1317
1318 cow_start = (u64)-1;
1319 cur_offset = start;
1320 while (1) {
1321 ret = btrfs_lookup_file_extent(NULL, root, path, ino,
1322 cur_offset, 0);
1323 if (ret < 0)
1324 goto error;
1325 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1326 leaf = path->nodes[0];
1327 btrfs_item_key_to_cpu(leaf, &found_key,
1328 path->slots[0] - 1);
1329 if (found_key.objectid == ino &&
1330 found_key.type == BTRFS_EXTENT_DATA_KEY)
1331 path->slots[0]--;
1332 }
1333 check_prev = 0;
1334 next_slot:
1335 leaf = path->nodes[0];
1336 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1337 ret = btrfs_next_leaf(root, path);
1338 if (ret < 0) {
1339 if (cow_start != (u64)-1)
1340 cur_offset = cow_start;
1341 goto error;
1342 }
1343 if (ret > 0)
1344 break;
1345 leaf = path->nodes[0];
1346 }
1347
1348 nocow = 0;
1349 disk_bytenr = 0;
1350 num_bytes = 0;
1351 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1352
1353 if (found_key.objectid > ino)
1354 break;
1355 if (WARN_ON_ONCE(found_key.objectid < ino) ||
1356 found_key.type < BTRFS_EXTENT_DATA_KEY) {
1357 path->slots[0]++;
1358 goto next_slot;
1359 }
1360 if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
1361 found_key.offset > end)
1362 break;
1363
1364 if (found_key.offset > cur_offset) {
1365 extent_end = found_key.offset;
1366 extent_type = 0;
1367 goto out_check;
1368 }
1369
1370 fi = btrfs_item_ptr(leaf, path->slots[0],
1371 struct btrfs_file_extent_item);
1372 extent_type = btrfs_file_extent_type(leaf, fi);
1373
1374 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1375 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1376 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1377 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1378 extent_offset = btrfs_file_extent_offset(leaf, fi);
1379 extent_end = found_key.offset +
1380 btrfs_file_extent_num_bytes(leaf, fi);
1381 disk_num_bytes =
1382 btrfs_file_extent_disk_num_bytes(leaf, fi);
1383 if (extent_end <= start) {
1384 path->slots[0]++;
1385 goto next_slot;
1386 }
1387 if (disk_bytenr == 0)
1388 goto out_check;
1389 if (btrfs_file_extent_compression(leaf, fi) ||
1390 btrfs_file_extent_encryption(leaf, fi) ||
1391 btrfs_file_extent_other_encoding(leaf, fi))
1392 goto out_check;
1393 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1394 goto out_check;
1395 if (btrfs_extent_readonly(fs_info, disk_bytenr))
1396 goto out_check;
1397 if (btrfs_cross_ref_exist(root, ino,
1398 found_key.offset -
1399 extent_offset, disk_bytenr))
1400 goto out_check;
1401 disk_bytenr += extent_offset;
1402 disk_bytenr += cur_offset - found_key.offset;
1403 num_bytes = min(end + 1, extent_end) - cur_offset;
1404 /*
1405 * if there are pending snapshots for this root,
1406 * we fall into common COW way.
1407 */
1408 if (!nolock) {
1409 err = btrfs_start_write_no_snapshotting(root);
1410 if (!err)
1411 goto out_check;
1412 }
1413 /*
1414 * force cow if csum exists in the range.
1415 * this ensure that csum for a given extent are
1416 * either valid or do not exist.
1417 */
1418 if (csum_exist_in_range(fs_info, disk_bytenr,
1419 num_bytes)) {
1420 if (!nolock)
1421 btrfs_end_write_no_snapshotting(root);
1422 goto out_check;
1423 }
1424 if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {
1425 if (!nolock)
1426 btrfs_end_write_no_snapshotting(root);
1427 goto out_check;
1428 }
1429 nocow = 1;
1430 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1431 extent_end = found_key.offset +
1432 btrfs_file_extent_inline_len(leaf,
1433 path->slots[0], fi);
1434 extent_end = ALIGN(extent_end,
1435 fs_info->sectorsize);
1436 } else {
1437 BUG_ON(1);
1438 }
1439 out_check:
1440 if (extent_end <= start) {
1441 path->slots[0]++;
1442 if (!nolock && nocow)
1443 btrfs_end_write_no_snapshotting(root);
1444 if (nocow)
1445 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1446 goto next_slot;
1447 }
1448 if (!nocow) {
1449 if (cow_start == (u64)-1)
1450 cow_start = cur_offset;
1451 cur_offset = extent_end;
1452 if (cur_offset > end)
1453 break;
1454 path->slots[0]++;
1455 goto next_slot;
1456 }
1457
1458 btrfs_release_path(path);
1459 if (cow_start != (u64)-1) {
1460 ret = cow_file_range(inode, locked_page,
1461 cow_start, found_key.offset - 1,
1462 end, page_started, nr_written, 1,
1463 NULL);
1464 if (ret) {
1465 if (!nolock && nocow)
1466 btrfs_end_write_no_snapshotting(root);
1467 if (nocow)
1468 btrfs_dec_nocow_writers(fs_info,
1469 disk_bytenr);
1470 goto error;
1471 }
1472 cow_start = (u64)-1;
1473 }
1474
1475 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1476 u64 orig_start = found_key.offset - extent_offset;
1477
1478 em = create_io_em(inode, cur_offset, num_bytes,
1479 orig_start,
1480 disk_bytenr, /* block_start */
1481 num_bytes, /* block_len */
1482 disk_num_bytes, /* orig_block_len */
1483 ram_bytes, BTRFS_COMPRESS_NONE,
1484 BTRFS_ORDERED_PREALLOC);
1485 if (IS_ERR(em)) {
1486 if (!nolock && nocow)
1487 btrfs_end_write_no_snapshotting(root);
1488 if (nocow)
1489 btrfs_dec_nocow_writers(fs_info,
1490 disk_bytenr);
1491 ret = PTR_ERR(em);
1492 goto error;
1493 }
1494 free_extent_map(em);
1495 }
1496
1497 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1498 type = BTRFS_ORDERED_PREALLOC;
1499 } else {
1500 type = BTRFS_ORDERED_NOCOW;
1501 }
1502
1503 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1504 num_bytes, num_bytes, type);
1505 if (nocow)
1506 btrfs_dec_nocow_writers(fs_info, disk_bytenr);
1507 BUG_ON(ret); /* -ENOMEM */
1508
1509 if (root->root_key.objectid ==
1510 BTRFS_DATA_RELOC_TREE_OBJECTID)
1511 /*
1512 * Error handled later, as we must prevent
1513 * extent_clear_unlock_delalloc() in error handler
1514 * from freeing metadata of created ordered extent.
1515 */
1516 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1517 num_bytes);
1518
1519 extent_clear_unlock_delalloc(inode, cur_offset,
1520 cur_offset + num_bytes - 1, end,
1521 locked_page, EXTENT_LOCKED |
1522 EXTENT_DELALLOC |
1523 EXTENT_CLEAR_DATA_RESV,
1524 PAGE_UNLOCK | PAGE_SET_PRIVATE2);
1525
1526 if (!nolock && nocow)
1527 btrfs_end_write_no_snapshotting(root);
1528 cur_offset = extent_end;
1529
1530 /*
1531 * btrfs_reloc_clone_csums() error, now we're OK to call error
1532 * handler, as metadata for created ordered extent will only
1533 * be freed by btrfs_finish_ordered_io().
1534 */
1535 if (ret)
1536 goto error;
1537 if (cur_offset > end)
1538 break;
1539 }
1540 btrfs_release_path(path);
1541
1542 if (cur_offset <= end && cow_start == (u64)-1) {
1543 cow_start = cur_offset;
1544 cur_offset = end;
1545 }
1546
1547 if (cow_start != (u64)-1) {
1548 ret = cow_file_range(inode, locked_page, cow_start, end, end,
1549 page_started, nr_written, 1, NULL);
1550 if (ret)
1551 goto error;
1552 }
1553
1554 error:
1555 if (ret && cur_offset < end)
1556 extent_clear_unlock_delalloc(inode, cur_offset, end, end,
1557 locked_page, EXTENT_LOCKED |
1558 EXTENT_DELALLOC | EXTENT_DEFRAG |
1559 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1560 PAGE_CLEAR_DIRTY |
1561 PAGE_SET_WRITEBACK |
1562 PAGE_END_WRITEBACK);
1563 btrfs_free_path(path);
1564 return ret;
1565 }
1566
1567 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1568 {
1569
1570 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1571 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1572 return 0;
1573
1574 /*
1575 * @defrag_bytes is a hint value, no spinlock held here,
1576 * if is not zero, it means the file is defragging.
1577 * Force cow if given extent needs to be defragged.
1578 */
1579 if (BTRFS_I(inode)->defrag_bytes &&
1580 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1581 EXTENT_DEFRAG, 0, NULL))
1582 return 1;
1583
1584 return 0;
1585 }
1586
1587 /*
1588 * extent_io.c call back to do delayed allocation processing
1589 */
1590 static int run_delalloc_range(void *private_data, struct page *locked_page,
1591 u64 start, u64 end, int *page_started,
1592 unsigned long *nr_written,
1593 struct writeback_control *wbc)
1594 {
1595 struct inode *inode = private_data;
1596 int ret;
1597 int force_cow = need_force_cow(inode, start, end);
1598 unsigned int write_flags = wbc_to_write_flags(wbc);
1599
1600 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1601 ret = run_delalloc_nocow(inode, locked_page, start, end,
1602 page_started, 1, nr_written);
1603 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1604 ret = run_delalloc_nocow(inode, locked_page, start, end,
1605 page_started, 0, nr_written);
1606 } else if (!inode_need_compress(inode, start, end)) {
1607 ret = cow_file_range(inode, locked_page, start, end, end,
1608 page_started, nr_written, 1, NULL);
1609 } else {
1610 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1611 &BTRFS_I(inode)->runtime_flags);
1612 ret = cow_file_range_async(inode, locked_page, start, end,
1613 page_started, nr_written,
1614 write_flags);
1615 }
1616 if (ret)
1617 btrfs_cleanup_ordered_extents(inode, start, end - start + 1);
1618 return ret;
1619 }
1620
1621 static void btrfs_split_extent_hook(void *private_data,
1622 struct extent_state *orig, u64 split)
1623 {
1624 struct inode *inode = private_data;
1625 u64 size;
1626
1627 /* not delalloc, ignore it */
1628 if (!(orig->state & EXTENT_DELALLOC))
1629 return;
1630
1631 size = orig->end - orig->start + 1;
1632 if (size > BTRFS_MAX_EXTENT_SIZE) {
1633 u32 num_extents;
1634 u64 new_size;
1635
1636 /*
1637 * See the explanation in btrfs_merge_extent_hook, the same
1638 * applies here, just in reverse.
1639 */
1640 new_size = orig->end - split + 1;
1641 num_extents = count_max_extents(new_size);
1642 new_size = split - orig->start;
1643 num_extents += count_max_extents(new_size);
1644 if (count_max_extents(size) >= num_extents)
1645 return;
1646 }
1647
1648 spin_lock(&BTRFS_I(inode)->lock);
1649 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1650 spin_unlock(&BTRFS_I(inode)->lock);
1651 }
1652
1653 /*
1654 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1655 * extents so we can keep track of new extents that are just merged onto old
1656 * extents, such as when we are doing sequential writes, so we can properly
1657 * account for the metadata space we'll need.
1658 */
1659 static void btrfs_merge_extent_hook(void *private_data,
1660 struct extent_state *new,
1661 struct extent_state *other)
1662 {
1663 struct inode *inode = private_data;
1664 u64 new_size, old_size;
1665 u32 num_extents;
1666
1667 /* not delalloc, ignore it */
1668 if (!(other->state & EXTENT_DELALLOC))
1669 return;
1670
1671 if (new->start > other->start)
1672 new_size = new->end - other->start + 1;
1673 else
1674 new_size = other->end - new->start + 1;
1675
1676 /* we're not bigger than the max, unreserve the space and go */
1677 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1678 spin_lock(&BTRFS_I(inode)->lock);
1679 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1680 spin_unlock(&BTRFS_I(inode)->lock);
1681 return;
1682 }
1683
1684 /*
1685 * We have to add up either side to figure out how many extents were
1686 * accounted for before we merged into one big extent. If the number of
1687 * extents we accounted for is <= the amount we need for the new range
1688 * then we can return, otherwise drop. Think of it like this
1689 *
1690 * [ 4k][MAX_SIZE]
1691 *
1692 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1693 * need 2 outstanding extents, on one side we have 1 and the other side
1694 * we have 1 so they are == and we can return. But in this case
1695 *
1696 * [MAX_SIZE+4k][MAX_SIZE+4k]
1697 *
1698 * Each range on their own accounts for 2 extents, but merged together
1699 * they are only 3 extents worth of accounting, so we need to drop in
1700 * this case.
1701 */
1702 old_size = other->end - other->start + 1;
1703 num_extents = count_max_extents(old_size);
1704 old_size = new->end - new->start + 1;
1705 num_extents += count_max_extents(old_size);
1706 if (count_max_extents(new_size) >= num_extents)
1707 return;
1708
1709 spin_lock(&BTRFS_I(inode)->lock);
1710 btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
1711 spin_unlock(&BTRFS_I(inode)->lock);
1712 }
1713
1714 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1715 struct inode *inode)
1716 {
1717 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1718
1719 spin_lock(&root->delalloc_lock);
1720 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1721 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1722 &root->delalloc_inodes);
1723 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1724 &BTRFS_I(inode)->runtime_flags);
1725 root->nr_delalloc_inodes++;
1726 if (root->nr_delalloc_inodes == 1) {
1727 spin_lock(&fs_info->delalloc_root_lock);
1728 BUG_ON(!list_empty(&root->delalloc_root));
1729 list_add_tail(&root->delalloc_root,
1730 &fs_info->delalloc_roots);
1731 spin_unlock(&fs_info->delalloc_root_lock);
1732 }
1733 }
1734 spin_unlock(&root->delalloc_lock);
1735 }
1736
1737 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1738 struct btrfs_inode *inode)
1739 {
1740 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1741
1742 spin_lock(&root->delalloc_lock);
1743 if (!list_empty(&inode->delalloc_inodes)) {
1744 list_del_init(&inode->delalloc_inodes);
1745 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1746 &inode->runtime_flags);
1747 root->nr_delalloc_inodes--;
1748 if (!root->nr_delalloc_inodes) {
1749 spin_lock(&fs_info->delalloc_root_lock);
1750 BUG_ON(list_empty(&root->delalloc_root));
1751 list_del_init(&root->delalloc_root);
1752 spin_unlock(&fs_info->delalloc_root_lock);
1753 }
1754 }
1755 spin_unlock(&root->delalloc_lock);
1756 }
1757
1758 /*
1759 * extent_io.c set_bit_hook, used to track delayed allocation
1760 * bytes in this file, and to maintain the list of inodes that
1761 * have pending delalloc work to be done.
1762 */
1763 static void btrfs_set_bit_hook(void *private_data,
1764 struct extent_state *state, unsigned *bits)
1765 {
1766 struct inode *inode = private_data;
1767
1768 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1769
1770 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1771 WARN_ON(1);
1772 /*
1773 * set_bit and clear bit hooks normally require _irqsave/restore
1774 * but in this case, we are only testing for the DELALLOC
1775 * bit, which is only set or cleared with irqs on
1776 */
1777 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1778 struct btrfs_root *root = BTRFS_I(inode)->root;
1779 u64 len = state->end + 1 - state->start;
1780 u32 num_extents = count_max_extents(len);
1781 bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
1782
1783 spin_lock(&BTRFS_I(inode)->lock);
1784 btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
1785 spin_unlock(&BTRFS_I(inode)->lock);
1786
1787 /* For sanity tests */
1788 if (btrfs_is_testing(fs_info))
1789 return;
1790
1791 percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
1792 fs_info->delalloc_batch);
1793 spin_lock(&BTRFS_I(inode)->lock);
1794 BTRFS_I(inode)->delalloc_bytes += len;
1795 if (*bits & EXTENT_DEFRAG)
1796 BTRFS_I(inode)->defrag_bytes += len;
1797 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1798 &BTRFS_I(inode)->runtime_flags))
1799 btrfs_add_delalloc_inodes(root, inode);
1800 spin_unlock(&BTRFS_I(inode)->lock);
1801 }
1802
1803 if (!(state->state & EXTENT_DELALLOC_NEW) &&
1804 (*bits & EXTENT_DELALLOC_NEW)) {
1805 spin_lock(&BTRFS_I(inode)->lock);
1806 BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
1807 state->start;
1808 spin_unlock(&BTRFS_I(inode)->lock);
1809 }
1810 }
1811
1812 /*
1813 * extent_io.c clear_bit_hook, see set_bit_hook for why
1814 */
1815 static void btrfs_clear_bit_hook(void *private_data,
1816 struct extent_state *state,
1817 unsigned *bits)
1818 {
1819 struct btrfs_inode *inode = BTRFS_I((struct inode *)private_data);
1820 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1821 u64 len = state->end + 1 - state->start;
1822 u32 num_extents = count_max_extents(len);
1823
1824 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
1825 spin_lock(&inode->lock);
1826 inode->defrag_bytes -= len;
1827 spin_unlock(&inode->lock);
1828 }
1829
1830 /*
1831 * set_bit and clear bit hooks normally require _irqsave/restore
1832 * but in this case, we are only testing for the DELALLOC
1833 * bit, which is only set or cleared with irqs on
1834 */
1835 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1836 struct btrfs_root *root = inode->root;
1837 bool do_list = !btrfs_is_free_space_inode(inode);
1838
1839 spin_lock(&inode->lock);
1840 btrfs_mod_outstanding_extents(inode, -num_extents);
1841 spin_unlock(&inode->lock);
1842
1843 /*
1844 * We don't reserve metadata space for space cache inodes so we
1845 * don't need to call dellalloc_release_metadata if there is an
1846 * error.
1847 */
1848 if (*bits & EXTENT_CLEAR_META_RESV &&
1849 root != fs_info->tree_root)
1850 btrfs_delalloc_release_metadata(inode, len);
1851
1852 /* For sanity tests. */
1853 if (btrfs_is_testing(fs_info))
1854 return;
1855
1856 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
1857 do_list && !(state->state & EXTENT_NORESERVE) &&
1858 (*bits & EXTENT_CLEAR_DATA_RESV))
1859 btrfs_free_reserved_data_space_noquota(
1860 &inode->vfs_inode,
1861 state->start, len);
1862
1863 percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
1864 fs_info->delalloc_batch);
1865 spin_lock(&inode->lock);
1866 inode->delalloc_bytes -= len;
1867 if (do_list && inode->delalloc_bytes == 0 &&
1868 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1869 &inode->runtime_flags))
1870 btrfs_del_delalloc_inode(root, inode);
1871 spin_unlock(&inode->lock);
1872 }
1873
1874 if ((state->state & EXTENT_DELALLOC_NEW) &&
1875 (*bits & EXTENT_DELALLOC_NEW)) {
1876 spin_lock(&inode->lock);
1877 ASSERT(inode->new_delalloc_bytes >= len);
1878 inode->new_delalloc_bytes -= len;
1879 spin_unlock(&inode->lock);
1880 }
1881 }
1882
1883 /*
1884 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1885 * we don't create bios that span stripes or chunks
1886 *
1887 * return 1 if page cannot be merged to bio
1888 * return 0 if page can be merged to bio
1889 * return error otherwise
1890 */
1891 int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
1892 size_t size, struct bio *bio,
1893 unsigned long bio_flags)
1894 {
1895 struct inode *inode = page->mapping->host;
1896 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1897 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1898 u64 length = 0;
1899 u64 map_length;
1900 int ret;
1901
1902 if (bio_flags & EXTENT_BIO_COMPRESSED)
1903 return 0;
1904
1905 length = bio->bi_iter.bi_size;
1906 map_length = length;
1907 ret = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length,
1908 NULL, 0);
1909 if (ret < 0)
1910 return ret;
1911 if (map_length < length + size)
1912 return 1;
1913 return 0;
1914 }
1915
1916 /*
1917 * in order to insert checksums into the metadata in large chunks,
1918 * we wait until bio submission time. All the pages in the bio are
1919 * checksummed and sums are attached onto the ordered extent record.
1920 *
1921 * At IO completion time the cums attached on the ordered extent record
1922 * are inserted into the btree
1923 */
1924 static blk_status_t __btrfs_submit_bio_start(void *private_data, struct bio *bio,
1925 int mirror_num, unsigned long bio_flags,
1926 u64 bio_offset)
1927 {
1928 struct inode *inode = private_data;
1929 blk_status_t ret = 0;
1930
1931 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
1932 BUG_ON(ret); /* -ENOMEM */
1933 return 0;
1934 }
1935
1936 /*
1937 * in order to insert checksums into the metadata in large chunks,
1938 * we wait until bio submission time. All the pages in the bio are
1939 * checksummed and sums are attached onto the ordered extent record.
1940 *
1941 * At IO completion time the cums attached on the ordered extent record
1942 * are inserted into the btree
1943 */
1944 static blk_status_t __btrfs_submit_bio_done(void *private_data, struct bio *bio,
1945 int mirror_num, unsigned long bio_flags,
1946 u64 bio_offset)
1947 {
1948 struct inode *inode = private_data;
1949 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1950 blk_status_t ret;
1951
1952 ret = btrfs_map_bio(fs_info, bio, mirror_num, 1);
1953 if (ret) {
1954 bio->bi_status = ret;
1955 bio_endio(bio);
1956 }
1957 return ret;
1958 }
1959
1960 /*
1961 * extent_io.c submission hook. This does the right thing for csum calculation
1962 * on write, or reading the csums from the tree before a read.
1963 *
1964 * Rules about async/sync submit,
1965 * a) read: sync submit
1966 *
1967 * b) write without checksum: sync submit
1968 *
1969 * c) write with checksum:
1970 * c-1) if bio is issued by fsync: sync submit
1971 * (sync_writers != 0)
1972 *
1973 * c-2) if root is reloc root: sync submit
1974 * (only in case of buffered IO)
1975 *
1976 * c-3) otherwise: async submit
1977 */
1978 static blk_status_t btrfs_submit_bio_hook(void *private_data, struct bio *bio,
1979 int mirror_num, unsigned long bio_flags,
1980 u64 bio_offset)
1981 {
1982 struct inode *inode = private_data;
1983 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1984 struct btrfs_root *root = BTRFS_I(inode)->root;
1985 enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
1986 blk_status_t ret = 0;
1987 int skip_sum;
1988 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1989
1990 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1991
1992 if (btrfs_is_free_space_inode(BTRFS_I(inode)))
1993 metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
1994
1995 if (bio_op(bio) != REQ_OP_WRITE) {
1996 ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
1997 if (ret)
1998 goto out;
1999
2000 if (bio_flags & EXTENT_BIO_COMPRESSED) {
2001 ret = btrfs_submit_compressed_read(inode, bio,
2002 mirror_num,
2003 bio_flags);
2004 goto out;
2005 } else if (!skip_sum) {
2006 ret = btrfs_lookup_bio_sums(inode, bio, NULL);
2007 if (ret)
2008 goto out;
2009 }
2010 goto mapit;
2011 } else if (async && !skip_sum) {
2012 /* csum items have already been cloned */
2013 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
2014 goto mapit;
2015 /* we're doing a write, do the async checksumming */
2016 ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
2017 bio_offset, inode,
2018 __btrfs_submit_bio_start,
2019 __btrfs_submit_bio_done);
2020 goto out;
2021 } else if (!skip_sum) {
2022 ret = btrfs_csum_one_bio(inode, bio, 0, 0);
2023 if (ret)
2024 goto out;
2025 }
2026
2027 mapit:
2028 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
2029
2030 out:
2031 if (ret) {
2032 bio->bi_status = ret;
2033 bio_endio(bio);
2034 }
2035 return ret;
2036 }
2037
2038 /*
2039 * given a list of ordered sums record them in the inode. This happens
2040 * at IO completion time based on sums calculated at bio submission time.
2041 */
2042 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
2043 struct inode *inode, struct list_head *list)
2044 {
2045 struct btrfs_ordered_sum *sum;
2046
2047 list_for_each_entry(sum, list, list) {
2048 trans->adding_csums = true;
2049 btrfs_csum_file_blocks(trans,
2050 BTRFS_I(inode)->root->fs_info->csum_root, sum);
2051 trans->adding_csums = false;
2052 }
2053 return 0;
2054 }
2055
2056 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
2057 unsigned int extra_bits,
2058 struct extent_state **cached_state, int dedupe)
2059 {
2060 WARN_ON((end & (PAGE_SIZE - 1)) == 0);
2061 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
2062 extra_bits, cached_state);
2063 }
2064
2065 /* see btrfs_writepage_start_hook for details on why this is required */
2066 struct btrfs_writepage_fixup {
2067 struct page *page;
2068 struct btrfs_work work;
2069 };
2070
2071 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
2072 {
2073 struct btrfs_writepage_fixup *fixup;
2074 struct btrfs_ordered_extent *ordered;
2075 struct extent_state *cached_state = NULL;
2076 struct extent_changeset *data_reserved = NULL;
2077 struct page *page;
2078 struct inode *inode;
2079 u64 page_start;
2080 u64 page_end;
2081 int ret;
2082
2083 fixup = container_of(work, struct btrfs_writepage_fixup, work);
2084 page = fixup->page;
2085 again:
2086 lock_page(page);
2087 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
2088 ClearPageChecked(page);
2089 goto out_page;
2090 }
2091
2092 inode = page->mapping->host;
2093 page_start = page_offset(page);
2094 page_end = page_offset(page) + PAGE_SIZE - 1;
2095
2096 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
2097 &cached_state);
2098
2099 /* already ordered? We're done */
2100 if (PagePrivate2(page))
2101 goto out;
2102
2103 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
2104 PAGE_SIZE);
2105 if (ordered) {
2106 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
2107 page_end, &cached_state);
2108 unlock_page(page);
2109 btrfs_start_ordered_extent(inode, ordered, 1);
2110 btrfs_put_ordered_extent(ordered);
2111 goto again;
2112 }
2113
2114 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
2115 PAGE_SIZE);
2116 if (ret) {
2117 mapping_set_error(page->mapping, ret);
2118 end_extent_writepage(page, ret, page_start, page_end);
2119 ClearPageChecked(page);
2120 goto out;
2121 }
2122
2123 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
2124 &cached_state, 0);
2125 if (ret) {
2126 mapping_set_error(page->mapping, ret);
2127 end_extent_writepage(page, ret, page_start, page_end);
2128 ClearPageChecked(page);
2129 goto out;
2130 }
2131
2132 ClearPageChecked(page);
2133 set_page_dirty(page);
2134 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
2135 out:
2136 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2137 &cached_state);
2138 out_page:
2139 unlock_page(page);
2140 put_page(page);
2141 kfree(fixup);
2142 extent_changeset_free(data_reserved);
2143 }
2144
2145 /*
2146 * There are a few paths in the higher layers of the kernel that directly
2147 * set the page dirty bit without asking the filesystem if it is a
2148 * good idea. This causes problems because we want to make sure COW
2149 * properly happens and the data=ordered rules are followed.
2150 *
2151 * In our case any range that doesn't have the ORDERED bit set
2152 * hasn't been properly setup for IO. We kick off an async process
2153 * to fix it up. The async helper will wait for ordered extents, set
2154 * the delalloc bit and make it safe to write the page.
2155 */
2156 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2157 {
2158 struct inode *inode = page->mapping->host;
2159 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2160 struct btrfs_writepage_fixup *fixup;
2161
2162 /* this page is properly in the ordered list */
2163 if (TestClearPagePrivate2(page))
2164 return 0;
2165
2166 if (PageChecked(page))
2167 return -EAGAIN;
2168
2169 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2170 if (!fixup)
2171 return -EAGAIN;
2172
2173 SetPageChecked(page);
2174 get_page(page);
2175 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2176 btrfs_writepage_fixup_worker, NULL, NULL);
2177 fixup->page = page;
2178 btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
2179 return -EBUSY;
2180 }
2181
2182 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2183 struct inode *inode, u64 file_pos,
2184 u64 disk_bytenr, u64 disk_num_bytes,
2185 u64 num_bytes, u64 ram_bytes,
2186 u8 compression, u8 encryption,
2187 u16 other_encoding, int extent_type)
2188 {
2189 struct btrfs_root *root = BTRFS_I(inode)->root;
2190 struct btrfs_file_extent_item *fi;
2191 struct btrfs_path *path;
2192 struct extent_buffer *leaf;
2193 struct btrfs_key ins;
2194 u64 qg_released;
2195 int extent_inserted = 0;
2196 int ret;
2197
2198 path = btrfs_alloc_path();
2199 if (!path)
2200 return -ENOMEM;
2201
2202 /*
2203 * we may be replacing one extent in the tree with another.
2204 * The new extent is pinned in the extent map, and we don't want
2205 * to drop it from the cache until it is completely in the btree.
2206 *
2207 * So, tell btrfs_drop_extents to leave this extent in the cache.
2208 * the caller is expected to unpin it and allow it to be merged
2209 * with the others.
2210 */
2211 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2212 file_pos + num_bytes, NULL, 0,
2213 1, sizeof(*fi), &extent_inserted);
2214 if (ret)
2215 goto out;
2216
2217 if (!extent_inserted) {
2218 ins.objectid = btrfs_ino(BTRFS_I(inode));
2219 ins.offset = file_pos;
2220 ins.type = BTRFS_EXTENT_DATA_KEY;
2221
2222 path->leave_spinning = 1;
2223 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2224 sizeof(*fi));
2225 if (ret)
2226 goto out;
2227 }
2228 leaf = path->nodes[0];
2229 fi = btrfs_item_ptr(leaf, path->slots[0],
2230 struct btrfs_file_extent_item);
2231 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2232 btrfs_set_file_extent_type(leaf, fi, extent_type);
2233 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2234 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2235 btrfs_set_file_extent_offset(leaf, fi, 0);
2236 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2237 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2238 btrfs_set_file_extent_compression(leaf, fi, compression);
2239 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2240 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2241
2242 btrfs_mark_buffer_dirty(leaf);
2243 btrfs_release_path(path);
2244
2245 inode_add_bytes(inode, num_bytes);
2246
2247 ins.objectid = disk_bytenr;
2248 ins.offset = disk_num_bytes;
2249 ins.type = BTRFS_EXTENT_ITEM_KEY;
2250
2251 /*
2252 * Release the reserved range from inode dirty range map, as it is
2253 * already moved into delayed_ref_head
2254 */
2255 ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
2256 if (ret < 0)
2257 goto out;
2258 qg_released = ret;
2259 ret = btrfs_alloc_reserved_file_extent(trans, root,
2260 btrfs_ino(BTRFS_I(inode)),
2261 file_pos, qg_released, &ins);
2262 out:
2263 btrfs_free_path(path);
2264
2265 return ret;
2266 }
2267
2268 /* snapshot-aware defrag */
2269 struct sa_defrag_extent_backref {
2270 struct rb_node node;
2271 struct old_sa_defrag_extent *old;
2272 u64 root_id;
2273 u64 inum;
2274 u64 file_pos;
2275 u64 extent_offset;
2276 u64 num_bytes;
2277 u64 generation;
2278 };
2279
2280 struct old_sa_defrag_extent {
2281 struct list_head list;
2282 struct new_sa_defrag_extent *new;
2283
2284 u64 extent_offset;
2285 u64 bytenr;
2286 u64 offset;
2287 u64 len;
2288 int count;
2289 };
2290
2291 struct new_sa_defrag_extent {
2292 struct rb_root root;
2293 struct list_head head;
2294 struct btrfs_path *path;
2295 struct inode *inode;
2296 u64 file_pos;
2297 u64 len;
2298 u64 bytenr;
2299 u64 disk_len;
2300 u8 compress_type;
2301 };
2302
2303 static int backref_comp(struct sa_defrag_extent_backref *b1,
2304 struct sa_defrag_extent_backref *b2)
2305 {
2306 if (b1->root_id < b2->root_id)
2307 return -1;
2308 else if (b1->root_id > b2->root_id)
2309 return 1;
2310
2311 if (b1->inum < b2->inum)
2312 return -1;
2313 else if (b1->inum > b2->inum)
2314 return 1;
2315
2316 if (b1->file_pos < b2->file_pos)
2317 return -1;
2318 else if (b1->file_pos > b2->file_pos)
2319 return 1;
2320
2321 /*
2322 * [------------------------------] ===> (a range of space)
2323 * |<--->| |<---->| =============> (fs/file tree A)
2324 * |<---------------------------->| ===> (fs/file tree B)
2325 *
2326 * A range of space can refer to two file extents in one tree while
2327 * refer to only one file extent in another tree.
2328 *
2329 * So we may process a disk offset more than one time(two extents in A)
2330 * and locate at the same extent(one extent in B), then insert two same
2331 * backrefs(both refer to the extent in B).
2332 */
2333 return 0;
2334 }
2335
2336 static void backref_insert(struct rb_root *root,
2337 struct sa_defrag_extent_backref *backref)
2338 {
2339 struct rb_node **p = &root->rb_node;
2340 struct rb_node *parent = NULL;
2341 struct sa_defrag_extent_backref *entry;
2342 int ret;
2343
2344 while (*p) {
2345 parent = *p;
2346 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2347
2348 ret = backref_comp(backref, entry);
2349 if (ret < 0)
2350 p = &(*p)->rb_left;
2351 else
2352 p = &(*p)->rb_right;
2353 }
2354
2355 rb_link_node(&backref->node, parent, p);
2356 rb_insert_color(&backref->node, root);
2357 }
2358
2359 /*
2360 * Note the backref might has changed, and in this case we just return 0.
2361 */
2362 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2363 void *ctx)
2364 {
2365 struct btrfs_file_extent_item *extent;
2366 struct old_sa_defrag_extent *old = ctx;
2367 struct new_sa_defrag_extent *new = old->new;
2368 struct btrfs_path *path = new->path;
2369 struct btrfs_key key;
2370 struct btrfs_root *root;
2371 struct sa_defrag_extent_backref *backref;
2372 struct extent_buffer *leaf;
2373 struct inode *inode = new->inode;
2374 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2375 int slot;
2376 int ret;
2377 u64 extent_offset;
2378 u64 num_bytes;
2379
2380 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2381 inum == btrfs_ino(BTRFS_I(inode)))
2382 return 0;
2383
2384 key.objectid = root_id;
2385 key.type = BTRFS_ROOT_ITEM_KEY;
2386 key.offset = (u64)-1;
2387
2388 root = btrfs_read_fs_root_no_name(fs_info, &key);
2389 if (IS_ERR(root)) {
2390 if (PTR_ERR(root) == -ENOENT)
2391 return 0;
2392 WARN_ON(1);
2393 btrfs_debug(fs_info, "inum=%llu, offset=%llu, root_id=%llu",
2394 inum, offset, root_id);
2395 return PTR_ERR(root);
2396 }
2397
2398 key.objectid = inum;
2399 key.type = BTRFS_EXTENT_DATA_KEY;
2400 if (offset > (u64)-1 << 32)
2401 key.offset = 0;
2402 else
2403 key.offset = offset;
2404
2405 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2406 if (WARN_ON(ret < 0))
2407 return ret;
2408 ret = 0;
2409
2410 while (1) {
2411 cond_resched();
2412
2413 leaf = path->nodes[0];
2414 slot = path->slots[0];
2415
2416 if (slot >= btrfs_header_nritems(leaf)) {
2417 ret = btrfs_next_leaf(root, path);
2418 if (ret < 0) {
2419 goto out;
2420 } else if (ret > 0) {
2421 ret = 0;
2422 goto out;
2423 }
2424 continue;
2425 }
2426
2427 path->slots[0]++;
2428
2429 btrfs_item_key_to_cpu(leaf, &key, slot);
2430
2431 if (key.objectid > inum)
2432 goto out;
2433
2434 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2435 continue;
2436
2437 extent = btrfs_item_ptr(leaf, slot,
2438 struct btrfs_file_extent_item);
2439
2440 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2441 continue;
2442
2443 /*
2444 * 'offset' refers to the exact key.offset,
2445 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2446 * (key.offset - extent_offset).
2447 */
2448 if (key.offset != offset)
2449 continue;
2450
2451 extent_offset = btrfs_file_extent_offset(leaf, extent);
2452 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2453
2454 if (extent_offset >= old->extent_offset + old->offset +
2455 old->len || extent_offset + num_bytes <=
2456 old->extent_offset + old->offset)
2457 continue;
2458 break;
2459 }
2460
2461 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2462 if (!backref) {
2463 ret = -ENOENT;
2464 goto out;
2465 }
2466
2467 backref->root_id = root_id;
2468 backref->inum = inum;
2469 backref->file_pos = offset;
2470 backref->num_bytes = num_bytes;
2471 backref->extent_offset = extent_offset;
2472 backref->generation = btrfs_file_extent_generation(leaf, extent);
2473 backref->old = old;
2474 backref_insert(&new->root, backref);
2475 old->count++;
2476 out:
2477 btrfs_release_path(path);
2478 WARN_ON(ret);
2479 return ret;
2480 }
2481
2482 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2483 struct new_sa_defrag_extent *new)
2484 {
2485 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2486 struct old_sa_defrag_extent *old, *tmp;
2487 int ret;
2488
2489 new->path = path;
2490
2491 list_for_each_entry_safe(old, tmp, &new->head, list) {
2492 ret = iterate_inodes_from_logical(old->bytenr +
2493 old->extent_offset, fs_info,
2494 path, record_one_backref,
2495 old, false);
2496 if (ret < 0 && ret != -ENOENT)
2497 return false;
2498
2499 /* no backref to be processed for this extent */
2500 if (!old->count) {
2501 list_del(&old->list);
2502 kfree(old);
2503 }
2504 }
2505
2506 if (list_empty(&new->head))
2507 return false;
2508
2509 return true;
2510 }
2511
2512 static int relink_is_mergable(struct extent_buffer *leaf,
2513 struct btrfs_file_extent_item *fi,
2514 struct new_sa_defrag_extent *new)
2515 {
2516 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2517 return 0;
2518
2519 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2520 return 0;
2521
2522 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2523 return 0;
2524
2525 if (btrfs_file_extent_encryption(leaf, fi) ||
2526 btrfs_file_extent_other_encoding(leaf, fi))
2527 return 0;
2528
2529 return 1;
2530 }
2531
2532 /*
2533 * Note the backref might has changed, and in this case we just return 0.
2534 */
2535 static noinline int relink_extent_backref(struct btrfs_path *path,
2536 struct sa_defrag_extent_backref *prev,
2537 struct sa_defrag_extent_backref *backref)
2538 {
2539 struct btrfs_file_extent_item *extent;
2540 struct btrfs_file_extent_item *item;
2541 struct btrfs_ordered_extent *ordered;
2542 struct btrfs_trans_handle *trans;
2543 struct btrfs_root *root;
2544 struct btrfs_key key;
2545 struct extent_buffer *leaf;
2546 struct old_sa_defrag_extent *old = backref->old;
2547 struct new_sa_defrag_extent *new = old->new;
2548 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2549 struct inode *inode;
2550 struct extent_state *cached = NULL;
2551 int ret = 0;
2552 u64 start;
2553 u64 len;
2554 u64 lock_start;
2555 u64 lock_end;
2556 bool merge = false;
2557 int index;
2558
2559 if (prev && prev->root_id == backref->root_id &&
2560 prev->inum == backref->inum &&
2561 prev->file_pos + prev->num_bytes == backref->file_pos)
2562 merge = true;
2563
2564 /* step 1: get root */
2565 key.objectid = backref->root_id;
2566 key.type = BTRFS_ROOT_ITEM_KEY;
2567 key.offset = (u64)-1;
2568
2569 index = srcu_read_lock(&fs_info->subvol_srcu);
2570
2571 root = btrfs_read_fs_root_no_name(fs_info, &key);
2572 if (IS_ERR(root)) {
2573 srcu_read_unlock(&fs_info->subvol_srcu, index);
2574 if (PTR_ERR(root) == -ENOENT)
2575 return 0;
2576 return PTR_ERR(root);
2577 }
2578
2579 if (btrfs_root_readonly(root)) {
2580 srcu_read_unlock(&fs_info->subvol_srcu, index);
2581 return 0;
2582 }
2583
2584 /* step 2: get inode */
2585 key.objectid = backref->inum;
2586 key.type = BTRFS_INODE_ITEM_KEY;
2587 key.offset = 0;
2588
2589 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2590 if (IS_ERR(inode)) {
2591 srcu_read_unlock(&fs_info->subvol_srcu, index);
2592 return 0;
2593 }
2594
2595 srcu_read_unlock(&fs_info->subvol_srcu, index);
2596
2597 /* step 3: relink backref */
2598 lock_start = backref->file_pos;
2599 lock_end = backref->file_pos + backref->num_bytes - 1;
2600 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2601 &cached);
2602
2603 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2604 if (ordered) {
2605 btrfs_put_ordered_extent(ordered);
2606 goto out_unlock;
2607 }
2608
2609 trans = btrfs_join_transaction(root);
2610 if (IS_ERR(trans)) {
2611 ret = PTR_ERR(trans);
2612 goto out_unlock;
2613 }
2614
2615 key.objectid = backref->inum;
2616 key.type = BTRFS_EXTENT_DATA_KEY;
2617 key.offset = backref->file_pos;
2618
2619 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2620 if (ret < 0) {
2621 goto out_free_path;
2622 } else if (ret > 0) {
2623 ret = 0;
2624 goto out_free_path;
2625 }
2626
2627 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2628 struct btrfs_file_extent_item);
2629
2630 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2631 backref->generation)
2632 goto out_free_path;
2633
2634 btrfs_release_path(path);
2635
2636 start = backref->file_pos;
2637 if (backref->extent_offset < old->extent_offset + old->offset)
2638 start += old->extent_offset + old->offset -
2639 backref->extent_offset;
2640
2641 len = min(backref->extent_offset + backref->num_bytes,
2642 old->extent_offset + old->offset + old->len);
2643 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2644
2645 ret = btrfs_drop_extents(trans, root, inode, start,
2646 start + len, 1);
2647 if (ret)
2648 goto out_free_path;
2649 again:
2650 key.objectid = btrfs_ino(BTRFS_I(inode));
2651 key.type = BTRFS_EXTENT_DATA_KEY;
2652 key.offset = start;
2653
2654 path->leave_spinning = 1;
2655 if (merge) {
2656 struct btrfs_file_extent_item *fi;
2657 u64 extent_len;
2658 struct btrfs_key found_key;
2659
2660 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2661 if (ret < 0)
2662 goto out_free_path;
2663
2664 path->slots[0]--;
2665 leaf = path->nodes[0];
2666 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2667
2668 fi = btrfs_item_ptr(leaf, path->slots[0],
2669 struct btrfs_file_extent_item);
2670 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2671
2672 if (extent_len + found_key.offset == start &&
2673 relink_is_mergable(leaf, fi, new)) {
2674 btrfs_set_file_extent_num_bytes(leaf, fi,
2675 extent_len + len);
2676 btrfs_mark_buffer_dirty(leaf);
2677 inode_add_bytes(inode, len);
2678
2679 ret = 1;
2680 goto out_free_path;
2681 } else {
2682 merge = false;
2683 btrfs_release_path(path);
2684 goto again;
2685 }
2686 }
2687
2688 ret = btrfs_insert_empty_item(trans, root, path, &key,
2689 sizeof(*extent));
2690 if (ret) {
2691 btrfs_abort_transaction(trans, ret);
2692 goto out_free_path;
2693 }
2694
2695 leaf = path->nodes[0];
2696 item = btrfs_item_ptr(leaf, path->slots[0],
2697 struct btrfs_file_extent_item);
2698 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2699 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2700 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2701 btrfs_set_file_extent_num_bytes(leaf, item, len);
2702 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2703 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2704 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2705 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2706 btrfs_set_file_extent_encryption(leaf, item, 0);
2707 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2708
2709 btrfs_mark_buffer_dirty(leaf);
2710 inode_add_bytes(inode, len);
2711 btrfs_release_path(path);
2712
2713 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2714 new->disk_len, 0,
2715 backref->root_id, backref->inum,
2716 new->file_pos); /* start - extent_offset */
2717 if (ret) {
2718 btrfs_abort_transaction(trans, ret);
2719 goto out_free_path;
2720 }
2721
2722 ret = 1;
2723 out_free_path:
2724 btrfs_release_path(path);
2725 path->leave_spinning = 0;
2726 btrfs_end_transaction(trans);
2727 out_unlock:
2728 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2729 &cached);
2730 iput(inode);
2731 return ret;
2732 }
2733
2734 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2735 {
2736 struct old_sa_defrag_extent *old, *tmp;
2737
2738 if (!new)
2739 return;
2740
2741 list_for_each_entry_safe(old, tmp, &new->head, list) {
2742 kfree(old);
2743 }
2744 kfree(new);
2745 }
2746
2747 static void relink_file_extents(struct new_sa_defrag_extent *new)
2748 {
2749 struct btrfs_fs_info *fs_info = btrfs_sb(new->inode->i_sb);
2750 struct btrfs_path *path;
2751 struct sa_defrag_extent_backref *backref;
2752 struct sa_defrag_extent_backref *prev = NULL;
2753 struct inode *inode;
2754 struct btrfs_root *root;
2755 struct rb_node *node;
2756 int ret;
2757
2758 inode = new->inode;
2759 root = BTRFS_I(inode)->root;
2760
2761 path = btrfs_alloc_path();
2762 if (!path)
2763 return;
2764
2765 if (!record_extent_backrefs(path, new)) {
2766 btrfs_free_path(path);
2767 goto out;
2768 }
2769 btrfs_release_path(path);
2770
2771 while (1) {
2772 node = rb_first(&new->root);
2773 if (!node)
2774 break;
2775 rb_erase(node, &new->root);
2776
2777 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2778
2779 ret = relink_extent_backref(path, prev, backref);
2780 WARN_ON(ret < 0);
2781
2782 kfree(prev);
2783
2784 if (ret == 1)
2785 prev = backref;
2786 else
2787 prev = NULL;
2788 cond_resched();
2789 }
2790 kfree(prev);
2791
2792 btrfs_free_path(path);
2793 out:
2794 free_sa_defrag_extent(new);
2795
2796 atomic_dec(&fs_info->defrag_running);
2797 wake_up(&fs_info->transaction_wait);
2798 }
2799
2800 static struct new_sa_defrag_extent *
2801 record_old_file_extents(struct inode *inode,
2802 struct btrfs_ordered_extent *ordered)
2803 {
2804 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2805 struct btrfs_root *root = BTRFS_I(inode)->root;
2806 struct btrfs_path *path;
2807 struct btrfs_key key;
2808 struct old_sa_defrag_extent *old;
2809 struct new_sa_defrag_extent *new;
2810 int ret;
2811
2812 new = kmalloc(sizeof(*new), GFP_NOFS);
2813 if (!new)
2814 return NULL;
2815
2816 new->inode = inode;
2817 new->file_pos = ordered->file_offset;
2818 new->len = ordered->len;
2819 new->bytenr = ordered->start;
2820 new->disk_len = ordered->disk_len;
2821 new->compress_type = ordered->compress_type;
2822 new->root = RB_ROOT;
2823 INIT_LIST_HEAD(&new->head);
2824
2825 path = btrfs_alloc_path();
2826 if (!path)
2827 goto out_kfree;
2828
2829 key.objectid = btrfs_ino(BTRFS_I(inode));
2830 key.type = BTRFS_EXTENT_DATA_KEY;
2831 key.offset = new->file_pos;
2832
2833 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2834 if (ret < 0)
2835 goto out_free_path;
2836 if (ret > 0 && path->slots[0] > 0)
2837 path->slots[0]--;
2838
2839 /* find out all the old extents for the file range */
2840 while (1) {
2841 struct btrfs_file_extent_item *extent;
2842 struct extent_buffer *l;
2843 int slot;
2844 u64 num_bytes;
2845 u64 offset;
2846 u64 end;
2847 u64 disk_bytenr;
2848 u64 extent_offset;
2849
2850 l = path->nodes[0];
2851 slot = path->slots[0];
2852
2853 if (slot >= btrfs_header_nritems(l)) {
2854 ret = btrfs_next_leaf(root, path);
2855 if (ret < 0)
2856 goto out_free_path;
2857 else if (ret > 0)
2858 break;
2859 continue;
2860 }
2861
2862 btrfs_item_key_to_cpu(l, &key, slot);
2863
2864 if (key.objectid != btrfs_ino(BTRFS_I(inode)))
2865 break;
2866 if (key.type != BTRFS_EXTENT_DATA_KEY)
2867 break;
2868 if (key.offset >= new->file_pos + new->len)
2869 break;
2870
2871 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2872
2873 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2874 if (key.offset + num_bytes < new->file_pos)
2875 goto next;
2876
2877 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2878 if (!disk_bytenr)
2879 goto next;
2880
2881 extent_offset = btrfs_file_extent_offset(l, extent);
2882
2883 old = kmalloc(sizeof(*old), GFP_NOFS);
2884 if (!old)
2885 goto out_free_path;
2886
2887 offset = max(new->file_pos, key.offset);
2888 end = min(new->file_pos + new->len, key.offset + num_bytes);
2889
2890 old->bytenr = disk_bytenr;
2891 old->extent_offset = extent_offset;
2892 old->offset = offset - key.offset;
2893 old->len = end - offset;
2894 old->new = new;
2895 old->count = 0;
2896 list_add_tail(&old->list, &new->head);
2897 next:
2898 path->slots[0]++;
2899 cond_resched();
2900 }
2901
2902 btrfs_free_path(path);
2903 atomic_inc(&fs_info->defrag_running);
2904
2905 return new;
2906
2907 out_free_path:
2908 btrfs_free_path(path);
2909 out_kfree:
2910 free_sa_defrag_extent(new);
2911 return NULL;
2912 }
2913
2914 static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
2915 u64 start, u64 len)
2916 {
2917 struct btrfs_block_group_cache *cache;
2918
2919 cache = btrfs_lookup_block_group(fs_info, start);
2920 ASSERT(cache);
2921
2922 spin_lock(&cache->lock);
2923 cache->delalloc_bytes -= len;
2924 spin_unlock(&cache->lock);
2925
2926 btrfs_put_block_group(cache);
2927 }
2928
2929 /* as ordered data IO finishes, this gets called so we can finish
2930 * an ordered extent if the range of bytes in the file it covers are
2931 * fully written.
2932 */
2933 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2934 {
2935 struct inode *inode = ordered_extent->inode;
2936 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2937 struct btrfs_root *root = BTRFS_I(inode)->root;
2938 struct btrfs_trans_handle *trans = NULL;
2939 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2940 struct extent_state *cached_state = NULL;
2941 struct new_sa_defrag_extent *new = NULL;
2942 int compress_type = 0;
2943 int ret = 0;
2944 u64 logical_len = ordered_extent->len;
2945 bool nolock;
2946 bool truncated = false;
2947 bool range_locked = false;
2948 bool clear_new_delalloc_bytes = false;
2949
2950 if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2951 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
2952 !test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
2953 clear_new_delalloc_bytes = true;
2954
2955 nolock = btrfs_is_free_space_inode(BTRFS_I(inode));
2956
2957 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2958 ret = -EIO;
2959 goto out;
2960 }
2961
2962 btrfs_free_io_failure_record(BTRFS_I(inode),
2963 ordered_extent->file_offset,
2964 ordered_extent->file_offset +
2965 ordered_extent->len - 1);
2966
2967 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2968 truncated = true;
2969 logical_len = ordered_extent->truncated_len;
2970 /* Truncated the entire extent, don't bother adding */
2971 if (!logical_len)
2972 goto out;
2973 }
2974
2975 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2976 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2977
2978 /*
2979 * For mwrite(mmap + memset to write) case, we still reserve
2980 * space for NOCOW range.
2981 * As NOCOW won't cause a new delayed ref, just free the space
2982 */
2983 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
2984 ordered_extent->len);
2985 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2986 if (nolock)
2987 trans = btrfs_join_transaction_nolock(root);
2988 else
2989 trans = btrfs_join_transaction(root);
2990 if (IS_ERR(trans)) {
2991 ret = PTR_ERR(trans);
2992 trans = NULL;
2993 goto out;
2994 }
2995 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
2996 ret = btrfs_update_inode_fallback(trans, root, inode);
2997 if (ret) /* -ENOMEM or corruption */
2998 btrfs_abort_transaction(trans, ret);
2999 goto out;
3000 }
3001
3002 range_locked = true;
3003 lock_extent_bits(io_tree, ordered_extent->file_offset,
3004 ordered_extent->file_offset + ordered_extent->len - 1,
3005 &cached_state);
3006
3007 ret = test_range_bit(io_tree, ordered_extent->file_offset,
3008 ordered_extent->file_offset + ordered_extent->len - 1,
3009 EXTENT_DEFRAG, 0, cached_state);
3010 if (ret) {
3011 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
3012 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
3013 /* the inode is shared */
3014 new = record_old_file_extents(inode, ordered_extent);
3015
3016 clear_extent_bit(io_tree, ordered_extent->file_offset,
3017 ordered_extent->file_offset + ordered_extent->len - 1,
3018 EXTENT_DEFRAG, 0, 0, &cached_state);
3019 }
3020
3021 if (nolock)
3022 trans = btrfs_join_transaction_nolock(root);
3023 else
3024 trans = btrfs_join_transaction(root);
3025 if (IS_ERR(trans)) {
3026 ret = PTR_ERR(trans);
3027 trans = NULL;
3028 goto out;
3029 }
3030
3031 trans->block_rsv = &BTRFS_I(inode)->block_rsv;
3032
3033 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
3034 compress_type = ordered_extent->compress_type;
3035 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
3036 BUG_ON(compress_type);
3037 btrfs_qgroup_free_data(inode, NULL, ordered_extent->file_offset,
3038 ordered_extent->len);
3039 ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
3040 ordered_extent->file_offset,
3041 ordered_extent->file_offset +
3042 logical_len);
3043 } else {
3044 BUG_ON(root == fs_info->tree_root);
3045 ret = insert_reserved_file_extent(trans, inode,
3046 ordered_extent->file_offset,
3047 ordered_extent->start,
3048 ordered_extent->disk_len,
3049 logical_len, logical_len,
3050 compress_type, 0, 0,
3051 BTRFS_FILE_EXTENT_REG);
3052 if (!ret)
3053 btrfs_release_delalloc_bytes(fs_info,
3054 ordered_extent->start,
3055 ordered_extent->disk_len);
3056 }
3057 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
3058 ordered_extent->file_offset, ordered_extent->len,
3059 trans->transid);
3060 if (ret < 0) {
3061 btrfs_abort_transaction(trans, ret);
3062 goto out;
3063 }
3064
3065 add_pending_csums(trans, inode, &ordered_extent->list);
3066
3067 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
3068 ret = btrfs_update_inode_fallback(trans, root, inode);
3069 if (ret) { /* -ENOMEM or corruption */
3070 btrfs_abort_transaction(trans, ret);
3071 goto out;
3072 }
3073 ret = 0;
3074 out:
3075 if (range_locked || clear_new_delalloc_bytes) {
3076 unsigned int clear_bits = 0;
3077
3078 if (range_locked)
3079 clear_bits |= EXTENT_LOCKED;
3080 if (clear_new_delalloc_bytes)
3081 clear_bits |= EXTENT_DELALLOC_NEW;
3082 clear_extent_bit(&BTRFS_I(inode)->io_tree,
3083 ordered_extent->file_offset,
3084 ordered_extent->file_offset +
3085 ordered_extent->len - 1,
3086 clear_bits,
3087 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
3088 0, &cached_state);
3089 }
3090
3091 if (trans)
3092 btrfs_end_transaction(trans);
3093
3094 if (ret || truncated) {
3095 u64 start, end;
3096
3097 if (truncated)
3098 start = ordered_extent->file_offset + logical_len;
3099 else
3100 start = ordered_extent->file_offset;
3101 end = ordered_extent->file_offset + ordered_extent->len - 1;
3102 clear_extent_uptodate(io_tree, start, end, NULL);
3103
3104 /* Drop the cache for the part of the extent we didn't write. */
3105 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3106
3107 /*
3108 * If the ordered extent had an IOERR or something else went
3109 * wrong we need to return the space for this ordered extent
3110 * back to the allocator. We only free the extent in the
3111 * truncated case if we didn't write out the extent at all.
3112 */
3113 if ((ret || !logical_len) &&
3114 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
3115 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
3116 btrfs_free_reserved_extent(fs_info,
3117 ordered_extent->start,
3118 ordered_extent->disk_len, 1);
3119 }
3120
3121
3122 /*
3123 * This needs to be done to make sure anybody waiting knows we are done
3124 * updating everything for this ordered extent.
3125 */
3126 btrfs_remove_ordered_extent(inode, ordered_extent);
3127
3128 /* for snapshot-aware defrag */
3129 if (new) {
3130 if (ret) {
3131 free_sa_defrag_extent(new);
3132 atomic_dec(&fs_info->defrag_running);
3133 } else {
3134 relink_file_extents(new);
3135 }
3136 }
3137
3138 /* once for us */
3139 btrfs_put_ordered_extent(ordered_extent);
3140 /* once for the tree */
3141 btrfs_put_ordered_extent(ordered_extent);
3142
3143 return ret;
3144 }
3145
3146 static void finish_ordered_fn(struct btrfs_work *work)
3147 {
3148 struct btrfs_ordered_extent *ordered_extent;
3149 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
3150 btrfs_finish_ordered_io(ordered_extent);
3151 }
3152
3153 static void btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
3154 struct extent_state *state, int uptodate)
3155 {
3156 struct inode *inode = page->mapping->host;
3157 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3158 struct btrfs_ordered_extent *ordered_extent = NULL;
3159 struct btrfs_workqueue *wq;
3160 btrfs_work_func_t func;
3161
3162 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
3163
3164 ClearPagePrivate2(page);
3165 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
3166 end - start + 1, uptodate))
3167 return;
3168
3169 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
3170 wq = fs_info->endio_freespace_worker;
3171 func = btrfs_freespace_write_helper;
3172 } else {
3173 wq = fs_info->endio_write_workers;
3174 func = btrfs_endio_write_helper;
3175 }
3176
3177 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3178 NULL);
3179 btrfs_queue_work(wq, &ordered_extent->work);
3180 }
3181
3182 static int __readpage_endio_check(struct inode *inode,
3183 struct btrfs_io_bio *io_bio,
3184 int icsum, struct page *page,
3185 int pgoff, u64 start, size_t len)
3186 {
3187 char *kaddr;
3188 u32 csum_expected;
3189 u32 csum = ~(u32)0;
3190
3191 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3192
3193 kaddr = kmap_atomic(page);
3194 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3195 btrfs_csum_final(csum, (u8 *)&csum);
3196 if (csum != csum_expected)
3197 goto zeroit;
3198
3199 kunmap_atomic(kaddr);
3200 return 0;
3201 zeroit:
3202 btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
3203 io_bio->mirror_num);
3204 memset(kaddr + pgoff, 1, len);
3205 flush_dcache_page(page);
3206 kunmap_atomic(kaddr);
3207 return -EIO;
3208 }
3209
3210 /*
3211 * when reads are done, we need to check csums to verify the data is correct
3212 * if there's a match, we allow the bio to finish. If not, the code in
3213 * extent_io.c will try to find good copies for us.
3214 */
3215 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3216 u64 phy_offset, struct page *page,
3217 u64 start, u64 end, int mirror)
3218 {
3219 size_t offset = start - page_offset(page);
3220 struct inode *inode = page->mapping->host;
3221 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3222 struct btrfs_root *root = BTRFS_I(inode)->root;
3223
3224 if (PageChecked(page)) {
3225 ClearPageChecked(page);
3226 return 0;
3227 }
3228
3229 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3230 return 0;
3231
3232 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3233 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3234 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
3235 return 0;
3236 }
3237
3238 phy_offset >>= inode->i_sb->s_blocksize_bits;
3239 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3240 start, (size_t)(end - start + 1));
3241 }
3242
3243 void btrfs_add_delayed_iput(struct inode *inode)
3244 {
3245 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3246 struct btrfs_inode *binode = BTRFS_I(inode);
3247
3248 if (atomic_add_unless(&inode->i_count, -1, 1))
3249 return;
3250
3251 spin_lock(&fs_info->delayed_iput_lock);
3252 if (binode->delayed_iput_count == 0) {
3253 ASSERT(list_empty(&binode->delayed_iput));
3254 list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
3255 } else {
3256 binode->delayed_iput_count++;
3257 }
3258 spin_unlock(&fs_info->delayed_iput_lock);
3259 }
3260
3261 void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
3262 {
3263
3264 spin_lock(&fs_info->delayed_iput_lock);
3265 while (!list_empty(&fs_info->delayed_iputs)) {
3266 struct btrfs_inode *inode;
3267
3268 inode = list_first_entry(&fs_info->delayed_iputs,
3269 struct btrfs_inode, delayed_iput);
3270 if (inode->delayed_iput_count) {
3271 inode->delayed_iput_count--;
3272 list_move_tail(&inode->delayed_iput,
3273 &fs_info->delayed_iputs);
3274 } else {
3275 list_del_init(&inode->delayed_iput);
3276 }
3277 spin_unlock(&fs_info->delayed_iput_lock);
3278 iput(&inode->vfs_inode);
3279 spin_lock(&fs_info->delayed_iput_lock);
3280 }
3281 spin_unlock(&fs_info->delayed_iput_lock);
3282 }
3283
3284 /*
3285 * This is called in transaction commit time. If there are no orphan
3286 * files in the subvolume, it removes orphan item and frees block_rsv
3287 * structure.
3288 */
3289 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3290 struct btrfs_root *root)
3291 {
3292 struct btrfs_fs_info *fs_info = root->fs_info;
3293 struct btrfs_block_rsv *block_rsv;
3294 int ret;
3295
3296 if (atomic_read(&root->orphan_inodes) ||
3297 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3298 return;
3299
3300 spin_lock(&root->orphan_lock);
3301 if (atomic_read(&root->orphan_inodes)) {
3302 spin_unlock(&root->orphan_lock);
3303 return;
3304 }
3305
3306 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3307 spin_unlock(&root->orphan_lock);
3308 return;
3309 }
3310
3311 block_rsv = root->orphan_block_rsv;
3312 root->orphan_block_rsv = NULL;
3313 spin_unlock(&root->orphan_lock);
3314
3315 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3316 btrfs_root_refs(&root->root_item) > 0) {
3317 ret = btrfs_del_orphan_item(trans, fs_info->tree_root,
3318 root->root_key.objectid);
3319 if (ret)
3320 btrfs_abort_transaction(trans, ret);
3321 else
3322 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3323 &root->state);
3324 }
3325
3326 if (block_rsv) {
3327 WARN_ON(block_rsv->size > 0);
3328 btrfs_free_block_rsv(fs_info, block_rsv);
3329 }
3330 }
3331
3332 /*
3333 * This creates an orphan entry for the given inode in case something goes
3334 * wrong in the middle of an unlink/truncate.
3335 *
3336 * NOTE: caller of this function should reserve 5 units of metadata for
3337 * this function.
3338 */
3339 int btrfs_orphan_add(struct btrfs_trans_handle *trans,
3340 struct btrfs_inode *inode)
3341 {
3342 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
3343 struct btrfs_root *root = inode->root;
3344 struct btrfs_block_rsv *block_rsv = NULL;
3345 int reserve = 0;
3346 int insert = 0;
3347 int ret;
3348
3349 if (!root->orphan_block_rsv) {
3350 block_rsv = btrfs_alloc_block_rsv(fs_info,
3351 BTRFS_BLOCK_RSV_TEMP);
3352 if (!block_rsv)
3353 return -ENOMEM;
3354 }
3355
3356 spin_lock(&root->orphan_lock);
3357 if (!root->orphan_block_rsv) {
3358 root->orphan_block_rsv = block_rsv;
3359 } else if (block_rsv) {
3360 btrfs_free_block_rsv(fs_info, block_rsv);
3361 block_rsv = NULL;
3362 }
3363
3364 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3365 &inode->runtime_flags)) {
3366 #if 0
3367 /*
3368 * For proper ENOSPC handling, we should do orphan
3369 * cleanup when mounting. But this introduces backward
3370 * compatibility issue.
3371 */
3372 if (!xchg(&root->orphan_item_inserted, 1))
3373 insert = 2;
3374 else
3375 insert = 1;
3376 #endif
3377 insert = 1;
3378 atomic_inc(&root->orphan_inodes);
3379 }
3380
3381 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3382 &inode->runtime_flags))
3383 reserve = 1;
3384 spin_unlock(&root->orphan_lock);
3385
3386 /* grab metadata reservation from transaction handle */
3387 if (reserve) {
3388 ret = btrfs_orphan_reserve_metadata(trans, inode);
3389 ASSERT(!ret);
3390 if (ret) {
3391 /*
3392 * dec doesn't need spin_lock as ->orphan_block_rsv
3393 * would be released only if ->orphan_inodes is
3394 * zero.
3395 */
3396 atomic_dec(&root->orphan_inodes);
3397 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3398 &inode->runtime_flags);
3399 if (insert)
3400 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3401 &inode->runtime_flags);
3402 return ret;
3403 }
3404 }
3405
3406 /* insert an orphan item to track this unlinked/truncated file */
3407 if (insert >= 1) {
3408 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3409 if (ret) {
3410 if (reserve) {
3411 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3412 &inode->runtime_flags);
3413 btrfs_orphan_release_metadata(inode);
3414 }
3415 /*
3416 * btrfs_orphan_commit_root may race with us and set
3417 * ->orphan_block_rsv to zero, in order to avoid that,
3418 * decrease ->orphan_inodes after everything is done.
3419 */
3420 atomic_dec(&root->orphan_inodes);
3421 if (ret != -EEXIST) {
3422 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3423 &inode->runtime_flags);
3424 btrfs_abort_transaction(trans, ret);
3425 return ret;
3426 }
3427 }
3428 ret = 0;
3429 }
3430
3431 /* insert an orphan item to track subvolume contains orphan files */
3432 if (insert >= 2) {
3433 ret = btrfs_insert_orphan_item(trans, fs_info->tree_root,
3434 root->root_key.objectid);
3435 if (ret && ret != -EEXIST) {
3436 btrfs_abort_transaction(trans, ret);
3437 return ret;
3438 }
3439 }
3440 return 0;
3441 }
3442
3443 /*
3444 * We have done the truncate/delete so we can go ahead and remove the orphan
3445 * item for this particular inode.
3446 */
3447 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3448 struct btrfs_inode *inode)
3449 {
3450 struct btrfs_root *root = inode->root;
3451 int delete_item = 0;
3452 int ret = 0;
3453
3454 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3455 &inode->runtime_flags))
3456 delete_item = 1;
3457
3458 if (delete_item && trans)
3459 ret = btrfs_del_orphan_item(trans, root, btrfs_ino(inode));
3460
3461 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3462 &inode->runtime_flags))
3463 btrfs_orphan_release_metadata(inode);
3464
3465 /*
3466 * btrfs_orphan_commit_root may race with us and set ->orphan_block_rsv
3467 * to zero, in order to avoid that, decrease ->orphan_inodes after
3468 * everything is done.
3469 */
3470 if (delete_item)
3471 atomic_dec(&root->orphan_inodes);
3472
3473 return ret;
3474 }
3475
3476 /*
3477 * this cleans up any orphans that may be left on the list from the last use
3478 * of this root.
3479 */
3480 int btrfs_orphan_cleanup(struct btrfs_root *root)
3481 {
3482 struct btrfs_fs_info *fs_info = root->fs_info;
3483 struct btrfs_path *path;
3484 struct extent_buffer *leaf;
3485 struct btrfs_key key, found_key;
3486 struct btrfs_trans_handle *trans;
3487 struct inode *inode;
3488 u64 last_objectid = 0;
3489 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3490
3491 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3492 return 0;
3493
3494 path = btrfs_alloc_path();
3495 if (!path) {
3496 ret = -ENOMEM;
3497 goto out;
3498 }
3499 path->reada = READA_BACK;
3500
3501 key.objectid = BTRFS_ORPHAN_OBJECTID;
3502 key.type = BTRFS_ORPHAN_ITEM_KEY;
3503 key.offset = (u64)-1;
3504
3505 while (1) {
3506 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3507 if (ret < 0)
3508 goto out;
3509
3510 /*
3511 * if ret == 0 means we found what we were searching for, which
3512 * is weird, but possible, so only screw with path if we didn't
3513 * find the key and see if we have stuff that matches
3514 */
3515 if (ret > 0) {
3516 ret = 0;
3517 if (path->slots[0] == 0)
3518 break;
3519 path->slots[0]--;
3520 }
3521
3522 /* pull out the item */
3523 leaf = path->nodes[0];
3524 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3525
3526 /* make sure the item matches what we want */
3527 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3528 break;
3529 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3530 break;
3531
3532 /* release the path since we're done with it */
3533 btrfs_release_path(path);
3534
3535 /*
3536 * this is where we are basically btrfs_lookup, without the
3537 * crossing root thing. we store the inode number in the
3538 * offset of the orphan item.
3539 */
3540
3541 if (found_key.offset == last_objectid) {
3542 btrfs_err(fs_info,
3543 "Error removing orphan entry, stopping orphan cleanup");
3544 ret = -EINVAL;
3545 goto out;
3546 }
3547
3548 last_objectid = found_key.offset;
3549
3550 found_key.objectid = found_key.offset;
3551 found_key.type = BTRFS_INODE_ITEM_KEY;
3552 found_key.offset = 0;
3553 inode = btrfs_iget(fs_info->sb, &found_key, root, NULL);
3554 ret = PTR_ERR_OR_ZERO(inode);
3555 if (ret && ret != -ENOENT)
3556 goto out;
3557
3558 if (ret == -ENOENT && root == fs_info->tree_root) {
3559 struct btrfs_root *dead_root;
3560 struct btrfs_fs_info *fs_info = root->fs_info;
3561 int is_dead_root = 0;
3562
3563 /*
3564 * this is an orphan in the tree root. Currently these
3565 * could come from 2 sources:
3566 * a) a snapshot deletion in progress
3567 * b) a free space cache inode
3568 * We need to distinguish those two, as the snapshot
3569 * orphan must not get deleted.
3570 * find_dead_roots already ran before us, so if this
3571 * is a snapshot deletion, we should find the root
3572 * in the dead_roots list
3573 */
3574 spin_lock(&fs_info->trans_lock);
3575 list_for_each_entry(dead_root, &fs_info->dead_roots,
3576 root_list) {
3577 if (dead_root->root_key.objectid ==
3578 found_key.objectid) {
3579 is_dead_root = 1;
3580 break;
3581 }
3582 }
3583 spin_unlock(&fs_info->trans_lock);
3584 if (is_dead_root) {
3585 /* prevent this orphan from being found again */
3586 key.offset = found_key.objectid - 1;
3587 continue;
3588 }
3589 }
3590 /*
3591 * Inode is already gone but the orphan item is still there,
3592 * kill the orphan item.
3593 */
3594 if (ret == -ENOENT) {
3595 trans = btrfs_start_transaction(root, 1);
3596 if (IS_ERR(trans)) {
3597 ret = PTR_ERR(trans);
3598 goto out;
3599 }
3600 btrfs_debug(fs_info, "auto deleting %Lu",
3601 found_key.objectid);
3602 ret = btrfs_del_orphan_item(trans, root,
3603 found_key.objectid);
3604 btrfs_end_transaction(trans);
3605 if (ret)
3606 goto out;
3607 continue;
3608 }
3609
3610 /*
3611 * add this inode to the orphan list so btrfs_orphan_del does
3612 * the proper thing when we hit it
3613 */
3614 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3615 &BTRFS_I(inode)->runtime_flags);
3616 atomic_inc(&root->orphan_inodes);
3617
3618 /* if we have links, this was a truncate, lets do that */
3619 if (inode->i_nlink) {
3620 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3621 iput(inode);
3622 continue;
3623 }
3624 nr_truncate++;
3625
3626 /* 1 for the orphan item deletion. */
3627 trans = btrfs_start_transaction(root, 1);
3628 if (IS_ERR(trans)) {
3629 iput(inode);
3630 ret = PTR_ERR(trans);
3631 goto out;
3632 }
3633 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
3634 btrfs_end_transaction(trans);
3635 if (ret) {
3636 iput(inode);
3637 goto out;
3638 }
3639
3640 ret = btrfs_truncate(inode);
3641 if (ret)
3642 btrfs_orphan_del(NULL, BTRFS_I(inode));
3643 } else {
3644 nr_unlink++;
3645 }
3646
3647 /* this will do delete_inode and everything for us */
3648 iput(inode);
3649 if (ret)
3650 goto out;
3651 }
3652 /* release the path since we're done with it */
3653 btrfs_release_path(path);
3654
3655 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3656
3657 if (root->orphan_block_rsv)
3658 btrfs_block_rsv_release(fs_info, root->orphan_block_rsv,
3659 (u64)-1);
3660
3661 if (root->orphan_block_rsv ||
3662 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3663 trans = btrfs_join_transaction(root);
3664 if (!IS_ERR(trans))
3665 btrfs_end_transaction(trans);
3666 }
3667
3668 if (nr_unlink)
3669 btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
3670 if (nr_truncate)
3671 btrfs_debug(fs_info, "truncated %d orphans", nr_truncate);
3672
3673 out:
3674 if (ret)
3675 btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
3676 btrfs_free_path(path);
3677 return ret;
3678 }
3679
3680 /*
3681 * very simple check to peek ahead in the leaf looking for xattrs. If we
3682 * don't find any xattrs, we know there can't be any acls.
3683 *
3684 * slot is the slot the inode is in, objectid is the objectid of the inode
3685 */
3686 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3687 int slot, u64 objectid,
3688 int *first_xattr_slot)
3689 {
3690 u32 nritems = btrfs_header_nritems(leaf);
3691 struct btrfs_key found_key;
3692 static u64 xattr_access = 0;
3693 static u64 xattr_default = 0;
3694 int scanned = 0;
3695
3696 if (!xattr_access) {
3697 xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
3698 strlen(XATTR_NAME_POSIX_ACL_ACCESS));
3699 xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
3700 strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
3701 }
3702
3703 slot++;
3704 *first_xattr_slot = -1;
3705 while (slot < nritems) {
3706 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3707
3708 /* we found a different objectid, there must not be acls */
3709 if (found_key.objectid != objectid)
3710 return 0;
3711
3712 /* we found an xattr, assume we've got an acl */
3713 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3714 if (*first_xattr_slot == -1)
3715 *first_xattr_slot = slot;
3716 if (found_key.offset == xattr_access ||
3717 found_key.offset == xattr_default)
3718 return 1;
3719 }
3720
3721 /*
3722 * we found a key greater than an xattr key, there can't
3723 * be any acls later on
3724 */
3725 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3726 return 0;
3727
3728 slot++;
3729 scanned++;
3730
3731 /*
3732 * it goes inode, inode backrefs, xattrs, extents,
3733 * so if there are a ton of hard links to an inode there can
3734 * be a lot of backrefs. Don't waste time searching too hard,
3735 * this is just an optimization
3736 */
3737 if (scanned >= 8)
3738 break;
3739 }
3740 /* we hit the end of the leaf before we found an xattr or
3741 * something larger than an xattr. We have to assume the inode
3742 * has acls
3743 */
3744 if (*first_xattr_slot == -1)
3745 *first_xattr_slot = slot;
3746 return 1;
3747 }
3748
3749 /*
3750 * read an inode from the btree into the in-memory inode
3751 */
3752 static int btrfs_read_locked_inode(struct inode *inode)
3753 {
3754 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3755 struct btrfs_path *path;
3756 struct extent_buffer *leaf;
3757 struct btrfs_inode_item *inode_item;
3758 struct btrfs_root *root = BTRFS_I(inode)->root;
3759 struct btrfs_key location;
3760 unsigned long ptr;
3761 int maybe_acls;
3762 u32 rdev;
3763 int ret;
3764 bool filled = false;
3765 int first_xattr_slot;
3766
3767 ret = btrfs_fill_inode(inode, &rdev);
3768 if (!ret)
3769 filled = true;
3770
3771 path = btrfs_alloc_path();
3772 if (!path) {
3773 ret = -ENOMEM;
3774 goto make_bad;
3775 }
3776
3777 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3778
3779 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3780 if (ret) {
3781 if (ret > 0)
3782 ret = -ENOENT;
3783 goto make_bad;
3784 }
3785
3786 leaf = path->nodes[0];
3787
3788 if (filled)
3789 goto cache_index;
3790
3791 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3792 struct btrfs_inode_item);
3793 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3794 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3795 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3796 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3797 btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
3798
3799 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3800 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3801
3802 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3803 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3804
3805 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3806 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3807
3808 BTRFS_I(inode)->i_otime.tv_sec =
3809 btrfs_timespec_sec(leaf, &inode_item->otime);
3810 BTRFS_I(inode)->i_otime.tv_nsec =
3811 btrfs_timespec_nsec(leaf, &inode_item->otime);
3812
3813 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3814 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3815 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3816
3817 inode_set_iversion_queried(inode,
3818 btrfs_inode_sequence(leaf, inode_item));
3819 inode->i_generation = BTRFS_I(inode)->generation;
3820 inode->i_rdev = 0;
3821 rdev = btrfs_inode_rdev(leaf, inode_item);
3822
3823 BTRFS_I(inode)->index_cnt = (u64)-1;
3824 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3825
3826 cache_index:
3827 /*
3828 * If we were modified in the current generation and evicted from memory
3829 * and then re-read we need to do a full sync since we don't have any
3830 * idea about which extents were modified before we were evicted from
3831 * cache.
3832 *
3833 * This is required for both inode re-read from disk and delayed inode
3834 * in delayed_nodes_tree.
3835 */
3836 if (BTRFS_I(inode)->last_trans == fs_info->generation)
3837 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3838 &BTRFS_I(inode)->runtime_flags);
3839
3840 /*
3841 * We don't persist the id of the transaction where an unlink operation
3842 * against the inode was last made. So here we assume the inode might
3843 * have been evicted, and therefore the exact value of last_unlink_trans
3844 * lost, and set it to last_trans to avoid metadata inconsistencies
3845 * between the inode and its parent if the inode is fsync'ed and the log
3846 * replayed. For example, in the scenario:
3847 *
3848 * touch mydir/foo
3849 * ln mydir/foo mydir/bar
3850 * sync
3851 * unlink mydir/bar
3852 * echo 2 > /proc/sys/vm/drop_caches # evicts inode
3853 * xfs_io -c fsync mydir/foo
3854 * <power failure>
3855 * mount fs, triggers fsync log replay
3856 *
3857 * We must make sure that when we fsync our inode foo we also log its
3858 * parent inode, otherwise after log replay the parent still has the
3859 * dentry with the "bar" name but our inode foo has a link count of 1
3860 * and doesn't have an inode ref with the name "bar" anymore.
3861 *
3862 * Setting last_unlink_trans to last_trans is a pessimistic approach,
3863 * but it guarantees correctness at the expense of occasional full
3864 * transaction commits on fsync if our inode is a directory, or if our
3865 * inode is not a directory, logging its parent unnecessarily.
3866 */
3867 BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
3868
3869 path->slots[0]++;
3870 if (inode->i_nlink != 1 ||
3871 path->slots[0] >= btrfs_header_nritems(leaf))
3872 goto cache_acl;
3873
3874 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3875 if (location.objectid != btrfs_ino(BTRFS_I(inode)))
3876 goto cache_acl;
3877
3878 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3879 if (location.type == BTRFS_INODE_REF_KEY) {
3880 struct btrfs_inode_ref *ref;
3881
3882 ref = (struct btrfs_inode_ref *)ptr;
3883 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3884 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3885 struct btrfs_inode_extref *extref;
3886
3887 extref = (struct btrfs_inode_extref *)ptr;
3888 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3889 extref);
3890 }
3891 cache_acl:
3892 /*
3893 * try to precache a NULL acl entry for files that don't have
3894 * any xattrs or acls
3895 */
3896 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3897 btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
3898 if (first_xattr_slot != -1) {
3899 path->slots[0] = first_xattr_slot;
3900 ret = btrfs_load_inode_props(inode, path);
3901 if (ret)
3902 btrfs_err(fs_info,
3903 "error loading props for ino %llu (root %llu): %d",
3904 btrfs_ino(BTRFS_I(inode)),
3905 root->root_key.objectid, ret);
3906 }
3907 btrfs_free_path(path);
3908
3909 if (!maybe_acls)
3910 cache_no_acl(inode);
3911
3912 switch (inode->i_mode & S_IFMT) {
3913 case S_IFREG:
3914 inode->i_mapping->a_ops = &btrfs_aops;
3915 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3916 inode->i_fop = &btrfs_file_operations;
3917 inode->i_op = &btrfs_file_inode_operations;
3918 break;
3919 case S_IFDIR:
3920 inode->i_fop = &btrfs_dir_file_operations;
3921 inode->i_op = &btrfs_dir_inode_operations;
3922 break;
3923 case S_IFLNK:
3924 inode->i_op = &btrfs_symlink_inode_operations;
3925 inode_nohighmem(inode);
3926 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3927 break;
3928 default:
3929 inode->i_op = &btrfs_special_inode_operations;
3930 init_special_inode(inode, inode->i_mode, rdev);
3931 break;
3932 }
3933
3934 btrfs_update_iflags(inode);
3935 return 0;
3936
3937 make_bad:
3938 btrfs_free_path(path);
3939 make_bad_inode(inode);
3940 return ret;
3941 }
3942
3943 /*
3944 * given a leaf and an inode, copy the inode fields into the leaf
3945 */
3946 static void fill_inode_item(struct btrfs_trans_handle *trans,
3947 struct extent_buffer *leaf,
3948 struct btrfs_inode_item *item,
3949 struct inode *inode)
3950 {
3951 struct btrfs_map_token token;
3952
3953 btrfs_init_map_token(&token);
3954
3955 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3956 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3957 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3958 &token);
3959 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3960 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3961
3962 btrfs_set_token_timespec_sec(leaf, &item->atime,
3963 inode->i_atime.tv_sec, &token);
3964 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3965 inode->i_atime.tv_nsec, &token);
3966
3967 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3968 inode->i_mtime.tv_sec, &token);
3969 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3970 inode->i_mtime.tv_nsec, &token);
3971
3972 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3973 inode->i_ctime.tv_sec, &token);
3974 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3975 inode->i_ctime.tv_nsec, &token);
3976
3977 btrfs_set_token_timespec_sec(leaf, &item->otime,
3978 BTRFS_I(inode)->i_otime.tv_sec, &token);
3979 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3980 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3981
3982 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3983 &token);
3984 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3985 &token);
3986 btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
3987 &token);
3988 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3989 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3990 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3991 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3992 }
3993
3994 /*
3995 * copy everything in the in-memory inode into the btree.
3996 */
3997 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3998 struct btrfs_root *root, struct inode *inode)
3999 {
4000 struct btrfs_inode_item *inode_item;
4001 struct btrfs_path *path;
4002 struct extent_buffer *leaf;
4003 int ret;
4004
4005 path = btrfs_alloc_path();
4006 if (!path)
4007 return -ENOMEM;
4008
4009 path->leave_spinning = 1;
4010 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
4011 1);
4012 if (ret) {
4013 if (ret > 0)
4014 ret = -ENOENT;
4015 goto failed;
4016 }
4017
4018 leaf = path->nodes[0];
4019 inode_item = btrfs_item_ptr(leaf, path->slots[0],
4020 struct btrfs_inode_item);
4021
4022 fill_inode_item(trans, leaf, inode_item, inode);
4023 btrfs_mark_buffer_dirty(leaf);
4024 btrfs_set_inode_last_trans(trans, inode);
4025 ret = 0;
4026 failed:
4027 btrfs_free_path(path);
4028 return ret;
4029 }
4030
4031 /*
4032 * copy everything in the in-memory inode into the btree.
4033 */
4034 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
4035 struct btrfs_root *root, struct inode *inode)
4036 {
4037 struct btrfs_fs_info *fs_info = root->fs_info;
4038 int ret;
4039
4040 /*
4041 * If the inode is a free space inode, we can deadlock during commit
4042 * if we put it into the delayed code.
4043 *
4044 * The data relocation inode should also be directly updated
4045 * without delay
4046 */
4047 if (!btrfs_is_free_space_inode(BTRFS_I(inode))
4048 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
4049 && !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
4050 btrfs_update_root_times(trans, root);
4051
4052 ret = btrfs_delayed_update_inode(trans, root, inode);
4053 if (!ret)
4054 btrfs_set_inode_last_trans(trans, inode);
4055 return ret;
4056 }
4057
4058 return btrfs_update_inode_item(trans, root, inode);
4059 }
4060
4061 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
4062 struct btrfs_root *root,
4063 struct inode *inode)
4064 {
4065 int ret;
4066
4067 ret = btrfs_update_inode(trans, root, inode);
4068 if (ret == -ENOSPC)
4069 return btrfs_update_inode_item(trans, root, inode);
4070 return ret;
4071 }
4072
4073 /*
4074 * unlink helper that gets used here in inode.c and in the tree logging
4075 * recovery code. It remove a link in a directory with a given name, and
4076 * also drops the back refs in the inode to the directory
4077 */
4078 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4079 struct btrfs_root *root,
4080 struct btrfs_inode *dir,
4081 struct btrfs_inode *inode,
4082 const char *name, int name_len)
4083 {
4084 struct btrfs_fs_info *fs_info = root->fs_info;
4085 struct btrfs_path *path;
4086 int ret = 0;
4087 struct extent_buffer *leaf;
4088 struct btrfs_dir_item *di;
4089 struct btrfs_key key;
4090 u64 index;
4091 u64 ino = btrfs_ino(inode);
4092 u64 dir_ino = btrfs_ino(dir);
4093
4094 path = btrfs_alloc_path();
4095 if (!path) {
4096 ret = -ENOMEM;
4097 goto out;
4098 }
4099
4100 path->leave_spinning = 1;
4101 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4102 name, name_len, -1);
4103 if (IS_ERR(di)) {
4104 ret = PTR_ERR(di);
4105 goto err;
4106 }
4107 if (!di) {
4108 ret = -ENOENT;
4109 goto err;
4110 }
4111 leaf = path->nodes[0];
4112 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4113 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4114 if (ret)
4115 goto err;
4116 btrfs_release_path(path);
4117
4118 /*
4119 * If we don't have dir index, we have to get it by looking up
4120 * the inode ref, since we get the inode ref, remove it directly,
4121 * it is unnecessary to do delayed deletion.
4122 *
4123 * But if we have dir index, needn't search inode ref to get it.
4124 * Since the inode ref is close to the inode item, it is better
4125 * that we delay to delete it, and just do this deletion when
4126 * we update the inode item.
4127 */
4128 if (inode->dir_index) {
4129 ret = btrfs_delayed_delete_inode_ref(inode);
4130 if (!ret) {
4131 index = inode->dir_index;
4132 goto skip_backref;
4133 }
4134 }
4135
4136 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
4137 dir_ino, &index);
4138 if (ret) {
4139 btrfs_info(fs_info,
4140 "failed to delete reference to %.*s, inode %llu parent %llu",
4141 name_len, name, ino, dir_ino);
4142 btrfs_abort_transaction(trans, ret);
4143 goto err;
4144 }
4145 skip_backref:
4146 ret = btrfs_delete_delayed_dir_index(trans, fs_info, dir, index);
4147 if (ret) {
4148 btrfs_abort_transaction(trans, ret);
4149 goto err;
4150 }
4151
4152 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
4153 dir_ino);
4154 if (ret != 0 && ret != -ENOENT) {
4155 btrfs_abort_transaction(trans, ret);
4156 goto err;
4157 }
4158
4159 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
4160 index);
4161 if (ret == -ENOENT)
4162 ret = 0;
4163 else if (ret)
4164 btrfs_abort_transaction(trans, ret);
4165 err:
4166 btrfs_free_path(path);
4167 if (ret)
4168 goto out;
4169
4170 btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
4171 inode_inc_iversion(&inode->vfs_inode);
4172 inode_inc_iversion(&dir->vfs_inode);
4173 inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
4174 dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
4175 ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
4176 out:
4177 return ret;
4178 }
4179
4180 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
4181 struct btrfs_root *root,
4182 struct btrfs_inode *dir, struct btrfs_inode *inode,
4183 const char *name, int name_len)
4184 {
4185 int ret;
4186 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
4187 if (!ret) {
4188 drop_nlink(&inode->vfs_inode);
4189 ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
4190 }
4191 return ret;
4192 }
4193
4194 /*
4195 * helper to start transaction for unlink and rmdir.
4196 *
4197 * unlink and rmdir are special in btrfs, they do not always free space, so
4198 * if we cannot make our reservations the normal way try and see if there is
4199 * plenty of slack room in the global reserve to migrate, otherwise we cannot
4200 * allow the unlink to occur.
4201 */
4202 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
4203 {
4204 struct btrfs_root *root = BTRFS_I(dir)->root;
4205
4206 /*
4207 * 1 for the possible orphan item
4208 * 1 for the dir item
4209 * 1 for the dir index
4210 * 1 for the inode ref
4211 * 1 for the inode
4212 */
4213 return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
4214 }
4215
4216 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4217 {
4218 struct btrfs_root *root = BTRFS_I(dir)->root;
4219 struct btrfs_trans_handle *trans;
4220 struct inode *inode = d_inode(dentry);
4221 int ret;
4222
4223 trans = __unlink_start_trans(dir);
4224 if (IS_ERR(trans))
4225 return PTR_ERR(trans);
4226
4227 btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
4228 0);
4229
4230 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4231 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4232 dentry->d_name.len);
4233 if (ret)
4234 goto out;
4235
4236 if (inode->i_nlink == 0) {
4237 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
4238 if (ret)
4239 goto out;
4240 }
4241
4242 out:
4243 btrfs_end_transaction(trans);
4244 btrfs_btree_balance_dirty(root->fs_info);
4245 return ret;
4246 }
4247
4248 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4249 struct btrfs_root *root,
4250 struct inode *dir, u64 objectid,
4251 const char *name, int name_len)
4252 {
4253 struct btrfs_fs_info *fs_info = root->fs_info;
4254 struct btrfs_path *path;
4255 struct extent_buffer *leaf;
4256 struct btrfs_dir_item *di;
4257 struct btrfs_key key;
4258 u64 index;
4259 int ret;
4260 u64 dir_ino = btrfs_ino(BTRFS_I(dir));
4261
4262 path = btrfs_alloc_path();
4263 if (!path)
4264 return -ENOMEM;
4265
4266 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4267 name, name_len, -1);
4268 if (IS_ERR_OR_NULL(di)) {
4269 if (!di)
4270 ret = -ENOENT;
4271 else
4272 ret = PTR_ERR(di);
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 ret = btrfs_del_root_ref(trans, fs_info, objectid,
4287 root->root_key.objectid, dir_ino,
4288 &index, name, name_len);
4289 if (ret < 0) {
4290 if (ret != -ENOENT) {
4291 btrfs_abort_transaction(trans, ret);
4292 goto out;
4293 }
4294 di = btrfs_search_dir_index_item(root, path, dir_ino,
4295 name, name_len);
4296 if (IS_ERR_OR_NULL(di)) {
4297 if (!di)
4298 ret = -ENOENT;
4299 else
4300 ret = PTR_ERR(di);
4301 btrfs_abort_transaction(trans, ret);
4302 goto out;
4303 }
4304
4305 leaf = path->nodes[0];
4306 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4307 btrfs_release_path(path);
4308 index = key.offset;
4309 }
4310 btrfs_release_path(path);
4311
4312 ret = btrfs_delete_delayed_dir_index(trans, fs_info, BTRFS_I(dir), index);
4313 if (ret) {
4314 btrfs_abort_transaction(trans, ret);
4315 goto out;
4316 }
4317
4318 btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
4319 inode_inc_iversion(dir);
4320 dir->i_mtime = dir->i_ctime = current_time(dir);
4321 ret = btrfs_update_inode_fallback(trans, root, dir);
4322 if (ret)
4323 btrfs_abort_transaction(trans, ret);
4324 out:
4325 btrfs_free_path(path);
4326 return ret;
4327 }
4328
4329 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4330 {
4331 struct inode *inode = d_inode(dentry);
4332 int err = 0;
4333 struct btrfs_root *root = BTRFS_I(dir)->root;
4334 struct btrfs_trans_handle *trans;
4335 u64 last_unlink_trans;
4336
4337 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4338 return -ENOTEMPTY;
4339 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
4340 return -EPERM;
4341
4342 trans = __unlink_start_trans(dir);
4343 if (IS_ERR(trans))
4344 return PTR_ERR(trans);
4345
4346 if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4347 err = btrfs_unlink_subvol(trans, root, dir,
4348 BTRFS_I(inode)->location.objectid,
4349 dentry->d_name.name,
4350 dentry->d_name.len);
4351 goto out;
4352 }
4353
4354 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4355 if (err)
4356 goto out;
4357
4358 last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
4359
4360 /* now the directory is empty */
4361 err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
4362 BTRFS_I(d_inode(dentry)), dentry->d_name.name,
4363 dentry->d_name.len);
4364 if (!err) {
4365 btrfs_i_size_write(BTRFS_I(inode), 0);
4366 /*
4367 * Propagate the last_unlink_trans value of the deleted dir to
4368 * its parent directory. This is to prevent an unrecoverable
4369 * log tree in the case we do something like this:
4370 * 1) create dir foo
4371 * 2) create snapshot under dir foo
4372 * 3) delete the snapshot
4373 * 4) rmdir foo
4374 * 5) mkdir foo
4375 * 6) fsync foo or some file inside foo
4376 */
4377 if (last_unlink_trans >= trans->transid)
4378 BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
4379 }
4380 out:
4381 btrfs_end_transaction(trans);
4382 btrfs_btree_balance_dirty(root->fs_info);
4383
4384 return err;
4385 }
4386
4387 static int truncate_space_check(struct btrfs_trans_handle *trans,
4388 struct btrfs_root *root,
4389 u64 bytes_deleted)
4390 {
4391 struct btrfs_fs_info *fs_info = root->fs_info;
4392 int ret;
4393
4394 /*
4395 * This is only used to apply pressure to the enospc system, we don't
4396 * intend to use this reservation at all.
4397 */
4398 bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted);
4399 bytes_deleted *= fs_info->nodesize;
4400 ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv,
4401 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4402 if (!ret) {
4403 trace_btrfs_space_reservation(fs_info, "transaction",
4404 trans->transid,
4405 bytes_deleted, 1);
4406 trans->bytes_reserved += bytes_deleted;
4407 }
4408 return ret;
4409
4410 }
4411
4412 /*
4413 * Return this if we need to call truncate_block for the last bit of the
4414 * truncate.
4415 */
4416 #define NEED_TRUNCATE_BLOCK 1
4417
4418 /*
4419 * this can truncate away extent items, csum items and directory items.
4420 * It starts at a high offset and removes keys until it can't find
4421 * any higher than new_size
4422 *
4423 * csum items that cross the new i_size are truncated to the new size
4424 * as well.
4425 *
4426 * min_type is the minimum key type to truncate down to. If set to 0, this
4427 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4428 */
4429 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4430 struct btrfs_root *root,
4431 struct inode *inode,
4432 u64 new_size, u32 min_type)
4433 {
4434 struct btrfs_fs_info *fs_info = root->fs_info;
4435 struct btrfs_path *path;
4436 struct extent_buffer *leaf;
4437 struct btrfs_file_extent_item *fi;
4438 struct btrfs_key key;
4439 struct btrfs_key found_key;
4440 u64 extent_start = 0;
4441 u64 extent_num_bytes = 0;
4442 u64 extent_offset = 0;
4443 u64 item_end = 0;
4444 u64 last_size = new_size;
4445 u32 found_type = (u8)-1;
4446 int found_extent;
4447 int del_item;
4448 int pending_del_nr = 0;
4449 int pending_del_slot = 0;
4450 int extent_type = -1;
4451 int ret;
4452 int err = 0;
4453 u64 ino = btrfs_ino(BTRFS_I(inode));
4454 u64 bytes_deleted = 0;
4455 bool be_nice = false;
4456 bool should_throttle = false;
4457 bool should_end = false;
4458
4459 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4460
4461 /*
4462 * for non-free space inodes and ref cows, we want to back off from
4463 * time to time
4464 */
4465 if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
4466 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4467 be_nice = true;
4468
4469 path = btrfs_alloc_path();
4470 if (!path)
4471 return -ENOMEM;
4472 path->reada = READA_BACK;
4473
4474 /*
4475 * We want to drop from the next block forward in case this new size is
4476 * not block aligned since we will be keeping the last block of the
4477 * extent just the way it is.
4478 */
4479 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4480 root == fs_info->tree_root)
4481 btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
4482 fs_info->sectorsize),
4483 (u64)-1, 0);
4484
4485 /*
4486 * This function is also used to drop the items in the log tree before
4487 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4488 * it is used to drop the loged items. So we shouldn't kill the delayed
4489 * items.
4490 */
4491 if (min_type == 0 && root == BTRFS_I(inode)->root)
4492 btrfs_kill_delayed_inode_items(BTRFS_I(inode));
4493
4494 key.objectid = ino;
4495 key.offset = (u64)-1;
4496 key.type = (u8)-1;
4497
4498 search_again:
4499 /*
4500 * with a 16K leaf size and 128MB extents, you can actually queue
4501 * up a huge file in a single leaf. Most of the time that
4502 * bytes_deleted is > 0, it will be huge by the time we get here
4503 */
4504 if (be_nice && bytes_deleted > SZ_32M) {
4505 if (btrfs_should_end_transaction(trans)) {
4506 err = -EAGAIN;
4507 goto error;
4508 }
4509 }
4510
4511
4512 path->leave_spinning = 1;
4513 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4514 if (ret < 0) {
4515 err = ret;
4516 goto out;
4517 }
4518
4519 if (ret > 0) {
4520 /* there are no items in the tree for us to truncate, we're
4521 * done
4522 */
4523 if (path->slots[0] == 0)
4524 goto out;
4525 path->slots[0]--;
4526 }
4527
4528 while (1) {
4529 fi = NULL;
4530 leaf = path->nodes[0];
4531 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4532 found_type = found_key.type;
4533
4534 if (found_key.objectid != ino)
4535 break;
4536
4537 if (found_type < min_type)
4538 break;
4539
4540 item_end = found_key.offset;
4541 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4542 fi = btrfs_item_ptr(leaf, path->slots[0],
4543 struct btrfs_file_extent_item);
4544 extent_type = btrfs_file_extent_type(leaf, fi);
4545 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4546 item_end +=
4547 btrfs_file_extent_num_bytes(leaf, fi);
4548
4549 trace_btrfs_truncate_show_fi_regular(
4550 BTRFS_I(inode), leaf, fi,
4551 found_key.offset);
4552 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4553 item_end += btrfs_file_extent_inline_len(leaf,
4554 path->slots[0], fi);
4555
4556 trace_btrfs_truncate_show_fi_inline(
4557 BTRFS_I(inode), leaf, fi, path->slots[0],
4558 found_key.offset);
4559 }
4560 item_end--;
4561 }
4562 if (found_type > min_type) {
4563 del_item = 1;
4564 } else {
4565 if (item_end < new_size)
4566 break;
4567 if (found_key.offset >= new_size)
4568 del_item = 1;
4569 else
4570 del_item = 0;
4571 }
4572 found_extent = 0;
4573 /* FIXME, shrink the extent if the ref count is only 1 */
4574 if (found_type != BTRFS_EXTENT_DATA_KEY)
4575 goto delete;
4576
4577 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4578 u64 num_dec;
4579 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4580 if (!del_item) {
4581 u64 orig_num_bytes =
4582 btrfs_file_extent_num_bytes(leaf, fi);
4583 extent_num_bytes = ALIGN(new_size -
4584 found_key.offset,
4585 fs_info->sectorsize);
4586 btrfs_set_file_extent_num_bytes(leaf, fi,
4587 extent_num_bytes);
4588 num_dec = (orig_num_bytes -
4589 extent_num_bytes);
4590 if (test_bit(BTRFS_ROOT_REF_COWS,
4591 &root->state) &&
4592 extent_start != 0)
4593 inode_sub_bytes(inode, num_dec);
4594 btrfs_mark_buffer_dirty(leaf);
4595 } else {
4596 extent_num_bytes =
4597 btrfs_file_extent_disk_num_bytes(leaf,
4598 fi);
4599 extent_offset = found_key.offset -
4600 btrfs_file_extent_offset(leaf, fi);
4601
4602 /* FIXME blocksize != 4096 */
4603 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4604 if (extent_start != 0) {
4605 found_extent = 1;
4606 if (test_bit(BTRFS_ROOT_REF_COWS,
4607 &root->state))
4608 inode_sub_bytes(inode, num_dec);
4609 }
4610 }
4611 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4612 /*
4613 * we can't truncate inline items that have had
4614 * special encodings
4615 */
4616 if (!del_item &&
4617 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4618 btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
4619 btrfs_file_extent_compression(leaf, fi) == 0) {
4620 u32 size = (u32)(new_size - found_key.offset);
4621
4622 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4623 size = btrfs_file_extent_calc_inline_size(size);
4624 btrfs_truncate_item(root->fs_info, path, size, 1);
4625 } else if (!del_item) {
4626 /*
4627 * We have to bail so the last_size is set to
4628 * just before this extent.
4629 */
4630 err = NEED_TRUNCATE_BLOCK;
4631 break;
4632 }
4633
4634 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4635 inode_sub_bytes(inode, item_end + 1 - new_size);
4636 }
4637 delete:
4638 if (del_item)
4639 last_size = found_key.offset;
4640 else
4641 last_size = new_size;
4642 if (del_item) {
4643 if (!pending_del_nr) {
4644 /* no pending yet, add ourselves */
4645 pending_del_slot = path->slots[0];
4646 pending_del_nr = 1;
4647 } else if (pending_del_nr &&
4648 path->slots[0] + 1 == pending_del_slot) {
4649 /* hop on the pending chunk */
4650 pending_del_nr++;
4651 pending_del_slot = path->slots[0];
4652 } else {
4653 BUG();
4654 }
4655 } else {
4656 break;
4657 }
4658 should_throttle = false;
4659
4660 if (found_extent &&
4661 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4662 root == fs_info->tree_root)) {
4663 btrfs_set_path_blocking(path);
4664 bytes_deleted += extent_num_bytes;
4665 ret = btrfs_free_extent(trans, root, extent_start,
4666 extent_num_bytes, 0,
4667 btrfs_header_owner(leaf),
4668 ino, extent_offset);
4669 BUG_ON(ret);
4670 if (btrfs_should_throttle_delayed_refs(trans, fs_info))
4671 btrfs_async_run_delayed_refs(fs_info,
4672 trans->delayed_ref_updates * 2,
4673 trans->transid, 0);
4674 if (be_nice) {
4675 if (truncate_space_check(trans, root,
4676 extent_num_bytes)) {
4677 should_end = true;
4678 }
4679 if (btrfs_should_throttle_delayed_refs(trans,
4680 fs_info))
4681 should_throttle = true;
4682 }
4683 }
4684
4685 if (found_type == BTRFS_INODE_ITEM_KEY)
4686 break;
4687
4688 if (path->slots[0] == 0 ||
4689 path->slots[0] != pending_del_slot ||
4690 should_throttle || should_end) {
4691 if (pending_del_nr) {
4692 ret = btrfs_del_items(trans, root, path,
4693 pending_del_slot,
4694 pending_del_nr);
4695 if (ret) {
4696 btrfs_abort_transaction(trans, ret);
4697 goto error;
4698 }
4699 pending_del_nr = 0;
4700 }
4701 btrfs_release_path(path);
4702 if (should_throttle) {
4703 unsigned long updates = trans->delayed_ref_updates;
4704 if (updates) {
4705 trans->delayed_ref_updates = 0;
4706 ret = btrfs_run_delayed_refs(trans,
4707 fs_info,
4708 updates * 2);
4709 if (ret && !err)
4710 err = ret;
4711 }
4712 }
4713 /*
4714 * if we failed to refill our space rsv, bail out
4715 * and let the transaction restart
4716 */
4717 if (should_end) {
4718 err = -EAGAIN;
4719 goto error;
4720 }
4721 goto search_again;
4722 } else {
4723 path->slots[0]--;
4724 }
4725 }
4726 out:
4727 if (pending_del_nr) {
4728 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4729 pending_del_nr);
4730 if (ret)
4731 btrfs_abort_transaction(trans, ret);
4732 }
4733 error:
4734 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
4735 ASSERT(last_size >= new_size);
4736 if (!err && last_size > new_size)
4737 last_size = new_size;
4738 btrfs_ordered_update_i_size(inode, last_size, NULL);
4739 }
4740
4741 btrfs_free_path(path);
4742
4743 if (be_nice && bytes_deleted > SZ_32M) {
4744 unsigned long updates = trans->delayed_ref_updates;
4745 if (updates) {
4746 trans->delayed_ref_updates = 0;
4747 ret = btrfs_run_delayed_refs(trans, fs_info,
4748 updates * 2);
4749 if (ret && !err)
4750 err = ret;
4751 }
4752 }
4753 return err;
4754 }
4755
4756 /*
4757 * btrfs_truncate_block - read, zero a chunk and write a block
4758 * @inode - inode that we're zeroing
4759 * @from - the offset to start zeroing
4760 * @len - the length to zero, 0 to zero the entire range respective to the
4761 * offset
4762 * @front - zero up to the offset instead of from the offset on
4763 *
4764 * This will find the block for the "from" offset and cow the block and zero the
4765 * part we want to zero. This is used with truncate and hole punching.
4766 */
4767 int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
4768 int front)
4769 {
4770 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4771 struct address_space *mapping = inode->i_mapping;
4772 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4773 struct btrfs_ordered_extent *ordered;
4774 struct extent_state *cached_state = NULL;
4775 struct extent_changeset *data_reserved = NULL;
4776 char *kaddr;
4777 u32 blocksize = fs_info->sectorsize;
4778 pgoff_t index = from >> PAGE_SHIFT;
4779 unsigned offset = from & (blocksize - 1);
4780 struct page *page;
4781 gfp_t mask = btrfs_alloc_write_mask(mapping);
4782 int ret = 0;
4783 u64 block_start;
4784 u64 block_end;
4785
4786 if (IS_ALIGNED(offset, blocksize) &&
4787 (!len || IS_ALIGNED(len, blocksize)))
4788 goto out;
4789
4790 block_start = round_down(from, blocksize);
4791 block_end = block_start + blocksize - 1;
4792
4793 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
4794 block_start, blocksize);
4795 if (ret)
4796 goto out;
4797
4798 again:
4799 page = find_or_create_page(mapping, index, mask);
4800 if (!page) {
4801 btrfs_delalloc_release_space(inode, data_reserved,
4802 block_start, blocksize);
4803 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
4804 ret = -ENOMEM;
4805 goto out;
4806 }
4807
4808 if (!PageUptodate(page)) {
4809 ret = btrfs_readpage(NULL, page);
4810 lock_page(page);
4811 if (page->mapping != mapping) {
4812 unlock_page(page);
4813 put_page(page);
4814 goto again;
4815 }
4816 if (!PageUptodate(page)) {
4817 ret = -EIO;
4818 goto out_unlock;
4819 }
4820 }
4821 wait_on_page_writeback(page);
4822
4823 lock_extent_bits(io_tree, block_start, block_end, &cached_state);
4824 set_page_extent_mapped(page);
4825
4826 ordered = btrfs_lookup_ordered_extent(inode, block_start);
4827 if (ordered) {
4828 unlock_extent_cached(io_tree, block_start, block_end,
4829 &cached_state);
4830 unlock_page(page);
4831 put_page(page);
4832 btrfs_start_ordered_extent(inode, ordered, 1);
4833 btrfs_put_ordered_extent(ordered);
4834 goto again;
4835 }
4836
4837 clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
4838 EXTENT_DIRTY | EXTENT_DELALLOC |
4839 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4840 0, 0, &cached_state);
4841
4842 ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
4843 &cached_state, 0);
4844 if (ret) {
4845 unlock_extent_cached(io_tree, block_start, block_end,
4846 &cached_state);
4847 goto out_unlock;
4848 }
4849
4850 if (offset != blocksize) {
4851 if (!len)
4852 len = blocksize - offset;
4853 kaddr = kmap(page);
4854 if (front)
4855 memset(kaddr + (block_start - page_offset(page)),
4856 0, offset);
4857 else
4858 memset(kaddr + (block_start - page_offset(page)) + offset,
4859 0, len);
4860 flush_dcache_page(page);
4861 kunmap(page);
4862 }
4863 ClearPageChecked(page);
4864 set_page_dirty(page);
4865 unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
4866
4867 out_unlock:
4868 if (ret)
4869 btrfs_delalloc_release_space(inode, data_reserved, block_start,
4870 blocksize);
4871 btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
4872 unlock_page(page);
4873 put_page(page);
4874 out:
4875 extent_changeset_free(data_reserved);
4876 return ret;
4877 }
4878
4879 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4880 u64 offset, u64 len)
4881 {
4882 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4883 struct btrfs_trans_handle *trans;
4884 int ret;
4885
4886 /*
4887 * Still need to make sure the inode looks like it's been updated so
4888 * that any holes get logged if we fsync.
4889 */
4890 if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
4891 BTRFS_I(inode)->last_trans = fs_info->generation;
4892 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4893 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4894 return 0;
4895 }
4896
4897 /*
4898 * 1 - for the one we're dropping
4899 * 1 - for the one we're adding
4900 * 1 - for updating the inode.
4901 */
4902 trans = btrfs_start_transaction(root, 3);
4903 if (IS_ERR(trans))
4904 return PTR_ERR(trans);
4905
4906 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4907 if (ret) {
4908 btrfs_abort_transaction(trans, ret);
4909 btrfs_end_transaction(trans);
4910 return ret;
4911 }
4912
4913 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
4914 offset, 0, 0, len, 0, len, 0, 0, 0);
4915 if (ret)
4916 btrfs_abort_transaction(trans, ret);
4917 else
4918 btrfs_update_inode(trans, root, inode);
4919 btrfs_end_transaction(trans);
4920 return ret;
4921 }
4922
4923 /*
4924 * This function puts in dummy file extents for the area we're creating a hole
4925 * for. So if we are truncating this file to a larger size we need to insert
4926 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4927 * the range between oldsize and size
4928 */
4929 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4930 {
4931 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4932 struct btrfs_root *root = BTRFS_I(inode)->root;
4933 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4934 struct extent_map *em = NULL;
4935 struct extent_state *cached_state = NULL;
4936 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4937 u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
4938 u64 block_end = ALIGN(size, fs_info->sectorsize);
4939 u64 last_byte;
4940 u64 cur_offset;
4941 u64 hole_size;
4942 int err = 0;
4943
4944 /*
4945 * If our size started in the middle of a block we need to zero out the
4946 * rest of the block before we expand the i_size, otherwise we could
4947 * expose stale data.
4948 */
4949 err = btrfs_truncate_block(inode, oldsize, 0, 0);
4950 if (err)
4951 return err;
4952
4953 if (size <= hole_start)
4954 return 0;
4955
4956 while (1) {
4957 struct btrfs_ordered_extent *ordered;
4958
4959 lock_extent_bits(io_tree, hole_start, block_end - 1,
4960 &cached_state);
4961 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), hole_start,
4962 block_end - hole_start);
4963 if (!ordered)
4964 break;
4965 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4966 &cached_state);
4967 btrfs_start_ordered_extent(inode, ordered, 1);
4968 btrfs_put_ordered_extent(ordered);
4969 }
4970
4971 cur_offset = hole_start;
4972 while (1) {
4973 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
4974 block_end - cur_offset, 0);
4975 if (IS_ERR(em)) {
4976 err = PTR_ERR(em);
4977 em = NULL;
4978 break;
4979 }
4980 last_byte = min(extent_map_end(em), block_end);
4981 last_byte = ALIGN(last_byte, fs_info->sectorsize);
4982 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4983 struct extent_map *hole_em;
4984 hole_size = last_byte - cur_offset;
4985
4986 err = maybe_insert_hole(root, inode, cur_offset,
4987 hole_size);
4988 if (err)
4989 break;
4990 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
4991 cur_offset + hole_size - 1, 0);
4992 hole_em = alloc_extent_map();
4993 if (!hole_em) {
4994 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4995 &BTRFS_I(inode)->runtime_flags);
4996 goto next;
4997 }
4998 hole_em->start = cur_offset;
4999 hole_em->len = hole_size;
5000 hole_em->orig_start = cur_offset;
5001
5002 hole_em->block_start = EXTENT_MAP_HOLE;
5003 hole_em->block_len = 0;
5004 hole_em->orig_block_len = 0;
5005 hole_em->ram_bytes = hole_size;
5006 hole_em->bdev = fs_info->fs_devices->latest_bdev;
5007 hole_em->compress_type = BTRFS_COMPRESS_NONE;
5008 hole_em->generation = fs_info->generation;
5009
5010 while (1) {
5011 write_lock(&em_tree->lock);
5012 err = add_extent_mapping(em_tree, hole_em, 1);
5013 write_unlock(&em_tree->lock);
5014 if (err != -EEXIST)
5015 break;
5016 btrfs_drop_extent_cache(BTRFS_I(inode),
5017 cur_offset,
5018 cur_offset +
5019 hole_size - 1, 0);
5020 }
5021 free_extent_map(hole_em);
5022 }
5023 next:
5024 free_extent_map(em);
5025 em = NULL;
5026 cur_offset = last_byte;
5027 if (cur_offset >= block_end)
5028 break;
5029 }
5030 free_extent_map(em);
5031 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
5032 return err;
5033 }
5034
5035 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
5036 {
5037 struct btrfs_root *root = BTRFS_I(inode)->root;
5038 struct btrfs_trans_handle *trans;
5039 loff_t oldsize = i_size_read(inode);
5040 loff_t newsize = attr->ia_size;
5041 int mask = attr->ia_valid;
5042 int ret;
5043
5044 /*
5045 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
5046 * special case where we need to update the times despite not having
5047 * these flags set. For all other operations the VFS set these flags
5048 * explicitly if it wants a timestamp update.
5049 */
5050 if (newsize != oldsize) {
5051 inode_inc_iversion(inode);
5052 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
5053 inode->i_ctime = inode->i_mtime =
5054 current_time(inode);
5055 }
5056
5057 if (newsize > oldsize) {
5058 /*
5059 * Don't do an expanding truncate while snapshotting is ongoing.
5060 * This is to ensure the snapshot captures a fully consistent
5061 * state of this file - if the snapshot captures this expanding
5062 * truncation, it must capture all writes that happened before
5063 * this truncation.
5064 */
5065 btrfs_wait_for_snapshot_creation(root);
5066 ret = btrfs_cont_expand(inode, oldsize, newsize);
5067 if (ret) {
5068 btrfs_end_write_no_snapshotting(root);
5069 return ret;
5070 }
5071
5072 trans = btrfs_start_transaction(root, 1);
5073 if (IS_ERR(trans)) {
5074 btrfs_end_write_no_snapshotting(root);
5075 return PTR_ERR(trans);
5076 }
5077
5078 i_size_write(inode, newsize);
5079 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
5080 pagecache_isize_extended(inode, oldsize, newsize);
5081 ret = btrfs_update_inode(trans, root, inode);
5082 btrfs_end_write_no_snapshotting(root);
5083 btrfs_end_transaction(trans);
5084 } else {
5085
5086 /*
5087 * We're truncating a file that used to have good data down to
5088 * zero. Make sure it gets into the ordered flush list so that
5089 * any new writes get down to disk quickly.
5090 */
5091 if (newsize == 0)
5092 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
5093 &BTRFS_I(inode)->runtime_flags);
5094
5095 /*
5096 * 1 for the orphan item we're going to add
5097 * 1 for the orphan item deletion.
5098 */
5099 trans = btrfs_start_transaction(root, 2);
5100 if (IS_ERR(trans))
5101 return PTR_ERR(trans);
5102
5103 /*
5104 * We need to do this in case we fail at _any_ point during the
5105 * actual truncate. Once we do the truncate_setsize we could
5106 * invalidate pages which forces any outstanding ordered io to
5107 * be instantly completed which will give us extents that need
5108 * to be truncated. If we fail to get an orphan inode down we
5109 * could have left over extents that were never meant to live,
5110 * so we need to guarantee from this point on that everything
5111 * will be consistent.
5112 */
5113 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
5114 btrfs_end_transaction(trans);
5115 if (ret)
5116 return ret;
5117
5118 /* we don't support swapfiles, so vmtruncate shouldn't fail */
5119 truncate_setsize(inode, newsize);
5120
5121 /* Disable nonlocked read DIO to avoid the end less truncate */
5122 btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
5123 inode_dio_wait(inode);
5124 btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
5125
5126 ret = btrfs_truncate(inode);
5127 if (ret && inode->i_nlink) {
5128 int err;
5129
5130 /* To get a stable disk_i_size */
5131 err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
5132 if (err) {
5133 btrfs_orphan_del(NULL, BTRFS_I(inode));
5134 return err;
5135 }
5136
5137 /*
5138 * failed to truncate, disk_i_size is only adjusted down
5139 * as we remove extents, so it should represent the true
5140 * size of the inode, so reset the in memory size and
5141 * delete our orphan entry.
5142 */
5143 trans = btrfs_join_transaction(root);
5144 if (IS_ERR(trans)) {
5145 btrfs_orphan_del(NULL, BTRFS_I(inode));
5146 return ret;
5147 }
5148 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
5149 err = btrfs_orphan_del(trans, BTRFS_I(inode));
5150 if (err)
5151 btrfs_abort_transaction(trans, err);
5152 btrfs_end_transaction(trans);
5153 }
5154 }
5155
5156 return ret;
5157 }
5158
5159 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
5160 {
5161 struct inode *inode = d_inode(dentry);
5162 struct btrfs_root *root = BTRFS_I(inode)->root;
5163 int err;
5164
5165 if (btrfs_root_readonly(root))
5166 return -EROFS;
5167
5168 err = setattr_prepare(dentry, attr);
5169 if (err)
5170 return err;
5171
5172 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
5173 err = btrfs_setsize(inode, attr);
5174 if (err)
5175 return err;
5176 }
5177
5178 if (attr->ia_valid) {
5179 setattr_copy(inode, attr);
5180 inode_inc_iversion(inode);
5181 err = btrfs_dirty_inode(inode);
5182
5183 if (!err && attr->ia_valid & ATTR_MODE)
5184 err = posix_acl_chmod(inode, inode->i_mode);
5185 }
5186
5187 return err;
5188 }
5189
5190 /*
5191 * While truncating the inode pages during eviction, we get the VFS calling
5192 * btrfs_invalidatepage() against each page of the inode. This is slow because
5193 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
5194 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
5195 * extent_state structures over and over, wasting lots of time.
5196 *
5197 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
5198 * those expensive operations on a per page basis and do only the ordered io
5199 * finishing, while we release here the extent_map and extent_state structures,
5200 * without the excessive merging and splitting.
5201 */
5202 static void evict_inode_truncate_pages(struct inode *inode)
5203 {
5204 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5205 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
5206 struct rb_node *node;
5207
5208 ASSERT(inode->i_state & I_FREEING);
5209 truncate_inode_pages_final(&inode->i_data);
5210
5211 write_lock(&map_tree->lock);
5212 while (!RB_EMPTY_ROOT(&map_tree->map)) {
5213 struct extent_map *em;
5214
5215 node = rb_first(&map_tree->map);
5216 em = rb_entry(node, struct extent_map, rb_node);
5217 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
5218 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
5219 remove_extent_mapping(map_tree, em);
5220 free_extent_map(em);
5221 if (need_resched()) {
5222 write_unlock(&map_tree->lock);
5223 cond_resched();
5224 write_lock(&map_tree->lock);
5225 }
5226 }
5227 write_unlock(&map_tree->lock);
5228
5229 /*
5230 * Keep looping until we have no more ranges in the io tree.
5231 * We can have ongoing bios started by readpages (called from readahead)
5232 * that have their endio callback (extent_io.c:end_bio_extent_readpage)
5233 * still in progress (unlocked the pages in the bio but did not yet
5234 * unlocked the ranges in the io tree). Therefore this means some
5235 * ranges can still be locked and eviction started because before
5236 * submitting those bios, which are executed by a separate task (work
5237 * queue kthread), inode references (inode->i_count) were not taken
5238 * (which would be dropped in the end io callback of each bio).
5239 * Therefore here we effectively end up waiting for those bios and
5240 * anyone else holding locked ranges without having bumped the inode's
5241 * reference count - if we don't do it, when they access the inode's
5242 * io_tree to unlock a range it may be too late, leading to an
5243 * use-after-free issue.
5244 */
5245 spin_lock(&io_tree->lock);
5246 while (!RB_EMPTY_ROOT(&io_tree->state)) {
5247 struct extent_state *state;
5248 struct extent_state *cached_state = NULL;
5249 u64 start;
5250 u64 end;
5251
5252 node = rb_first(&io_tree->state);
5253 state = rb_entry(node, struct extent_state, rb_node);
5254 start = state->start;
5255 end = state->end;
5256 spin_unlock(&io_tree->lock);
5257
5258 lock_extent_bits(io_tree, start, end, &cached_state);
5259
5260 /*
5261 * If still has DELALLOC flag, the extent didn't reach disk,
5262 * and its reserved space won't be freed by delayed_ref.
5263 * So we need to free its reserved space here.
5264 * (Refer to comment in btrfs_invalidatepage, case 2)
5265 *
5266 * Note, end is the bytenr of last byte, so we need + 1 here.
5267 */
5268 if (state->state & EXTENT_DELALLOC)
5269 btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
5270
5271 clear_extent_bit(io_tree, start, end,
5272 EXTENT_LOCKED | EXTENT_DIRTY |
5273 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5274 EXTENT_DEFRAG, 1, 1, &cached_state);
5275
5276 cond_resched();
5277 spin_lock(&io_tree->lock);
5278 }
5279 spin_unlock(&io_tree->lock);
5280 }
5281
5282 void btrfs_evict_inode(struct inode *inode)
5283 {
5284 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5285 struct btrfs_trans_handle *trans;
5286 struct btrfs_root *root = BTRFS_I(inode)->root;
5287 struct btrfs_block_rsv *rsv, *global_rsv;
5288 int steal_from_global = 0;
5289 u64 min_size;
5290 int ret;
5291
5292 trace_btrfs_inode_evict(inode);
5293
5294 if (!root) {
5295 clear_inode(inode);
5296 return;
5297 }
5298
5299 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
5300
5301 evict_inode_truncate_pages(inode);
5302
5303 if (inode->i_nlink &&
5304 ((btrfs_root_refs(&root->root_item) != 0 &&
5305 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5306 btrfs_is_free_space_inode(BTRFS_I(inode))))
5307 goto no_delete;
5308
5309 if (is_bad_inode(inode)) {
5310 btrfs_orphan_del(NULL, BTRFS_I(inode));
5311 goto no_delete;
5312 }
5313 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5314 if (!special_file(inode->i_mode))
5315 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5316
5317 btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
5318
5319 if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
5320 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5321 &BTRFS_I(inode)->runtime_flags));
5322 goto no_delete;
5323 }
5324
5325 if (inode->i_nlink > 0) {
5326 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5327 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5328 goto no_delete;
5329 }
5330
5331 ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
5332 if (ret) {
5333 btrfs_orphan_del(NULL, BTRFS_I(inode));
5334 goto no_delete;
5335 }
5336
5337 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
5338 if (!rsv) {
5339 btrfs_orphan_del(NULL, BTRFS_I(inode));
5340 goto no_delete;
5341 }
5342 rsv->size = min_size;
5343 rsv->failfast = 1;
5344 global_rsv = &fs_info->global_block_rsv;
5345
5346 btrfs_i_size_write(BTRFS_I(inode), 0);
5347
5348 /*
5349 * This is a bit simpler than btrfs_truncate since we've already
5350 * reserved our space for our orphan item in the unlink, so we just
5351 * need to reserve some slack space in case we add bytes and update
5352 * inode item when doing the truncate.
5353 */
5354 while (1) {
5355 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5356 BTRFS_RESERVE_FLUSH_LIMIT);
5357
5358 /*
5359 * Try and steal from the global reserve since we will
5360 * likely not use this space anyway, we want to try as
5361 * hard as possible to get this to work.
5362 */
5363 if (ret)
5364 steal_from_global++;
5365 else
5366 steal_from_global = 0;
5367 ret = 0;
5368
5369 /*
5370 * steal_from_global == 0: we reserved stuff, hooray!
5371 * steal_from_global == 1: we didn't reserve stuff, boo!
5372 * steal_from_global == 2: we've committed, still not a lot of
5373 * room but maybe we'll have room in the global reserve this
5374 * time.
5375 * steal_from_global == 3: abandon all hope!
5376 */
5377 if (steal_from_global > 2) {
5378 btrfs_warn(fs_info,
5379 "Could not get space for a delete, will truncate on mount %d",
5380 ret);
5381 btrfs_orphan_del(NULL, BTRFS_I(inode));
5382 btrfs_free_block_rsv(fs_info, rsv);
5383 goto no_delete;
5384 }
5385
5386 trans = btrfs_join_transaction(root);
5387 if (IS_ERR(trans)) {
5388 btrfs_orphan_del(NULL, BTRFS_I(inode));
5389 btrfs_free_block_rsv(fs_info, rsv);
5390 goto no_delete;
5391 }
5392
5393 /*
5394 * We can't just steal from the global reserve, we need to make
5395 * sure there is room to do it, if not we need to commit and try
5396 * again.
5397 */
5398 if (steal_from_global) {
5399 if (!btrfs_check_space_for_delayed_refs(trans, fs_info))
5400 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5401 min_size, 0);
5402 else
5403 ret = -ENOSPC;
5404 }
5405
5406 /*
5407 * Couldn't steal from the global reserve, we have too much
5408 * pending stuff built up, commit the transaction and try it
5409 * again.
5410 */
5411 if (ret) {
5412 ret = btrfs_commit_transaction(trans);
5413 if (ret) {
5414 btrfs_orphan_del(NULL, BTRFS_I(inode));
5415 btrfs_free_block_rsv(fs_info, rsv);
5416 goto no_delete;
5417 }
5418 continue;
5419 } else {
5420 steal_from_global = 0;
5421 }
5422
5423 trans->block_rsv = rsv;
5424
5425 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5426 if (ret != -ENOSPC && ret != -EAGAIN)
5427 break;
5428
5429 trans->block_rsv = &fs_info->trans_block_rsv;
5430 btrfs_end_transaction(trans);
5431 trans = NULL;
5432 btrfs_btree_balance_dirty(fs_info);
5433 }
5434
5435 btrfs_free_block_rsv(fs_info, rsv);
5436
5437 /*
5438 * Errors here aren't a big deal, it just means we leave orphan items
5439 * in the tree. They will be cleaned up on the next mount.
5440 */
5441 if (ret == 0) {
5442 trans->block_rsv = root->orphan_block_rsv;
5443 btrfs_orphan_del(trans, BTRFS_I(inode));
5444 } else {
5445 btrfs_orphan_del(NULL, BTRFS_I(inode));
5446 }
5447
5448 trans->block_rsv = &fs_info->trans_block_rsv;
5449 if (!(root == fs_info->tree_root ||
5450 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5451 btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
5452
5453 btrfs_end_transaction(trans);
5454 btrfs_btree_balance_dirty(fs_info);
5455 no_delete:
5456 btrfs_remove_delayed_node(BTRFS_I(inode));
5457 clear_inode(inode);
5458 }
5459
5460 /*
5461 * this returns the key found in the dir entry in the location pointer.
5462 * If no dir entries were found, location->objectid is 0.
5463 */
5464 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5465 struct btrfs_key *location)
5466 {
5467 const char *name = dentry->d_name.name;
5468 int namelen = dentry->d_name.len;
5469 struct btrfs_dir_item *di;
5470 struct btrfs_path *path;
5471 struct btrfs_root *root = BTRFS_I(dir)->root;
5472 int ret = 0;
5473
5474 path = btrfs_alloc_path();
5475 if (!path)
5476 return -ENOMEM;
5477
5478 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
5479 name, namelen, 0);
5480 if (IS_ERR(di))
5481 ret = PTR_ERR(di);
5482
5483 if (IS_ERR_OR_NULL(di))
5484 goto out_err;
5485
5486 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5487 if (location->type != BTRFS_INODE_ITEM_KEY &&
5488 location->type != BTRFS_ROOT_ITEM_KEY) {
5489 btrfs_warn(root->fs_info,
5490 "%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
5491 __func__, name, btrfs_ino(BTRFS_I(dir)),
5492 location->objectid, location->type, location->offset);
5493 goto out_err;
5494 }
5495 out:
5496 btrfs_free_path(path);
5497 return ret;
5498 out_err:
5499 location->objectid = 0;
5500 goto out;
5501 }
5502
5503 /*
5504 * when we hit a tree root in a directory, the btrfs part of the inode
5505 * needs to be changed to reflect the root directory of the tree root. This
5506 * is kind of like crossing a mount point.
5507 */
5508 static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
5509 struct inode *dir,
5510 struct dentry *dentry,
5511 struct btrfs_key *location,
5512 struct btrfs_root **sub_root)
5513 {
5514 struct btrfs_path *path;
5515 struct btrfs_root *new_root;
5516 struct btrfs_root_ref *ref;
5517 struct extent_buffer *leaf;
5518 struct btrfs_key key;
5519 int ret;
5520 int err = 0;
5521
5522 path = btrfs_alloc_path();
5523 if (!path) {
5524 err = -ENOMEM;
5525 goto out;
5526 }
5527
5528 err = -ENOENT;
5529 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5530 key.type = BTRFS_ROOT_REF_KEY;
5531 key.offset = location->objectid;
5532
5533 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
5534 if (ret) {
5535 if (ret < 0)
5536 err = ret;
5537 goto out;
5538 }
5539
5540 leaf = path->nodes[0];
5541 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5542 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
5543 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5544 goto out;
5545
5546 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5547 (unsigned long)(ref + 1),
5548 dentry->d_name.len);
5549 if (ret)
5550 goto out;
5551
5552 btrfs_release_path(path);
5553
5554 new_root = btrfs_read_fs_root_no_name(fs_info, location);
5555 if (IS_ERR(new_root)) {
5556 err = PTR_ERR(new_root);
5557 goto out;
5558 }
5559
5560 *sub_root = new_root;
5561 location->objectid = btrfs_root_dirid(&new_root->root_item);
5562 location->type = BTRFS_INODE_ITEM_KEY;
5563 location->offset = 0;
5564 err = 0;
5565 out:
5566 btrfs_free_path(path);
5567 return err;
5568 }
5569
5570 static void inode_tree_add(struct inode *inode)
5571 {
5572 struct btrfs_root *root = BTRFS_I(inode)->root;
5573 struct btrfs_inode *entry;
5574 struct rb_node **p;
5575 struct rb_node *parent;
5576 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5577 u64 ino = btrfs_ino(BTRFS_I(inode));
5578
5579 if (inode_unhashed(inode))
5580 return;
5581 parent = NULL;
5582 spin_lock(&root->inode_lock);
5583 p = &root->inode_tree.rb_node;
5584 while (*p) {
5585 parent = *p;
5586 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5587
5588 if (ino < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5589 p = &parent->rb_left;
5590 else if (ino > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5591 p = &parent->rb_right;
5592 else {
5593 WARN_ON(!(entry->vfs_inode.i_state &
5594 (I_WILL_FREE | I_FREEING)));
5595 rb_replace_node(parent, new, &root->inode_tree);
5596 RB_CLEAR_NODE(parent);
5597 spin_unlock(&root->inode_lock);
5598 return;
5599 }
5600 }
5601 rb_link_node(new, parent, p);
5602 rb_insert_color(new, &root->inode_tree);
5603 spin_unlock(&root->inode_lock);
5604 }
5605
5606 static void inode_tree_del(struct inode *inode)
5607 {
5608 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5609 struct btrfs_root *root = BTRFS_I(inode)->root;
5610 int empty = 0;
5611
5612 spin_lock(&root->inode_lock);
5613 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5614 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5615 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5616 empty = RB_EMPTY_ROOT(&root->inode_tree);
5617 }
5618 spin_unlock(&root->inode_lock);
5619
5620 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5621 synchronize_srcu(&fs_info->subvol_srcu);
5622 spin_lock(&root->inode_lock);
5623 empty = RB_EMPTY_ROOT(&root->inode_tree);
5624 spin_unlock(&root->inode_lock);
5625 if (empty)
5626 btrfs_add_dead_root(root);
5627 }
5628 }
5629
5630 void btrfs_invalidate_inodes(struct btrfs_root *root)
5631 {
5632 struct btrfs_fs_info *fs_info = root->fs_info;
5633 struct rb_node *node;
5634 struct rb_node *prev;
5635 struct btrfs_inode *entry;
5636 struct inode *inode;
5637 u64 objectid = 0;
5638
5639 if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
5640 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5641
5642 spin_lock(&root->inode_lock);
5643 again:
5644 node = root->inode_tree.rb_node;
5645 prev = NULL;
5646 while (node) {
5647 prev = node;
5648 entry = rb_entry(node, struct btrfs_inode, rb_node);
5649
5650 if (objectid < btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5651 node = node->rb_left;
5652 else if (objectid > btrfs_ino(BTRFS_I(&entry->vfs_inode)))
5653 node = node->rb_right;
5654 else
5655 break;
5656 }
5657 if (!node) {
5658 while (prev) {
5659 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5660 if (objectid <= btrfs_ino(BTRFS_I(&entry->vfs_inode))) {
5661 node = prev;
5662 break;
5663 }
5664 prev = rb_next(prev);
5665 }
5666 }
5667 while (node) {
5668 entry = rb_entry(node, struct btrfs_inode, rb_node);
5669 objectid = btrfs_ino(BTRFS_I(&entry->vfs_inode)) + 1;
5670 inode = igrab(&entry->vfs_inode);
5671 if (inode) {
5672 spin_unlock(&root->inode_lock);
5673 if (atomic_read(&inode->i_count) > 1)
5674 d_prune_aliases(inode);
5675 /*
5676 * btrfs_drop_inode will have it removed from
5677 * the inode cache when its usage count
5678 * hits zero.
5679 */
5680 iput(inode);
5681 cond_resched();
5682 spin_lock(&root->inode_lock);
5683 goto again;
5684 }
5685
5686 if (cond_resched_lock(&root->inode_lock))
5687 goto again;
5688
5689 node = rb_next(node);
5690 }
5691 spin_unlock(&root->inode_lock);
5692 }
5693
5694 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5695 {
5696 struct btrfs_iget_args *args = p;
5697 inode->i_ino = args->location->objectid;
5698 memcpy(&BTRFS_I(inode)->location, args->location,
5699 sizeof(*args->location));
5700 BTRFS_I(inode)->root = args->root;
5701 return 0;
5702 }
5703
5704 static int btrfs_find_actor(struct inode *inode, void *opaque)
5705 {
5706 struct btrfs_iget_args *args = opaque;
5707 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5708 args->root == BTRFS_I(inode)->root;
5709 }
5710
5711 static struct inode *btrfs_iget_locked(struct super_block *s,
5712 struct btrfs_key *location,
5713 struct btrfs_root *root)
5714 {
5715 struct inode *inode;
5716 struct btrfs_iget_args args;
5717 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5718
5719 args.location = location;
5720 args.root = root;
5721
5722 inode = iget5_locked(s, hashval, btrfs_find_actor,
5723 btrfs_init_locked_inode,
5724 (void *)&args);
5725 return inode;
5726 }
5727
5728 /* Get an inode object given its location and corresponding root.
5729 * Returns in *is_new if the inode was read from disk
5730 */
5731 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5732 struct btrfs_root *root, int *new)
5733 {
5734 struct inode *inode;
5735
5736 inode = btrfs_iget_locked(s, location, root);
5737 if (!inode)
5738 return ERR_PTR(-ENOMEM);
5739
5740 if (inode->i_state & I_NEW) {
5741 int ret;
5742
5743 ret = btrfs_read_locked_inode(inode);
5744 if (!is_bad_inode(inode)) {
5745 inode_tree_add(inode);
5746 unlock_new_inode(inode);
5747 if (new)
5748 *new = 1;
5749 } else {
5750 unlock_new_inode(inode);
5751 iput(inode);
5752 ASSERT(ret < 0);
5753 inode = ERR_PTR(ret < 0 ? ret : -ESTALE);
5754 }
5755 }
5756
5757 return inode;
5758 }
5759
5760 static struct inode *new_simple_dir(struct super_block *s,
5761 struct btrfs_key *key,
5762 struct btrfs_root *root)
5763 {
5764 struct inode *inode = new_inode(s);
5765
5766 if (!inode)
5767 return ERR_PTR(-ENOMEM);
5768
5769 BTRFS_I(inode)->root = root;
5770 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5771 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5772
5773 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5774 inode->i_op = &btrfs_dir_ro_inode_operations;
5775 inode->i_opflags &= ~IOP_XATTR;
5776 inode->i_fop = &simple_dir_operations;
5777 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5778 inode->i_mtime = current_time(inode);
5779 inode->i_atime = inode->i_mtime;
5780 inode->i_ctime = inode->i_mtime;
5781 BTRFS_I(inode)->i_otime = inode->i_mtime;
5782
5783 return inode;
5784 }
5785
5786 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5787 {
5788 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
5789 struct inode *inode;
5790 struct btrfs_root *root = BTRFS_I(dir)->root;
5791 struct btrfs_root *sub_root = root;
5792 struct btrfs_key location;
5793 int index;
5794 int ret = 0;
5795
5796 if (dentry->d_name.len > BTRFS_NAME_LEN)
5797 return ERR_PTR(-ENAMETOOLONG);
5798
5799 ret = btrfs_inode_by_name(dir, dentry, &location);
5800 if (ret < 0)
5801 return ERR_PTR(ret);
5802
5803 if (location.objectid == 0)
5804 return ERR_PTR(-ENOENT);
5805
5806 if (location.type == BTRFS_INODE_ITEM_KEY) {
5807 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5808 return inode;
5809 }
5810
5811 index = srcu_read_lock(&fs_info->subvol_srcu);
5812 ret = fixup_tree_root_location(fs_info, dir, dentry,
5813 &location, &sub_root);
5814 if (ret < 0) {
5815 if (ret != -ENOENT)
5816 inode = ERR_PTR(ret);
5817 else
5818 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5819 } else {
5820 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5821 }
5822 srcu_read_unlock(&fs_info->subvol_srcu, index);
5823
5824 if (!IS_ERR(inode) && root != sub_root) {
5825 down_read(&fs_info->cleanup_work_sem);
5826 if (!sb_rdonly(inode->i_sb))
5827 ret = btrfs_orphan_cleanup(sub_root);
5828 up_read(&fs_info->cleanup_work_sem);
5829 if (ret) {
5830 iput(inode);
5831 inode = ERR_PTR(ret);
5832 }
5833 }
5834
5835 return inode;
5836 }
5837
5838 static int btrfs_dentry_delete(const struct dentry *dentry)
5839 {
5840 struct btrfs_root *root;
5841 struct inode *inode = d_inode(dentry);
5842
5843 if (!inode && !IS_ROOT(dentry))
5844 inode = d_inode(dentry->d_parent);
5845
5846 if (inode) {
5847 root = BTRFS_I(inode)->root;
5848 if (btrfs_root_refs(&root->root_item) == 0)
5849 return 1;
5850
5851 if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5852 return 1;
5853 }
5854 return 0;
5855 }
5856
5857 static void btrfs_dentry_release(struct dentry *dentry)
5858 {
5859 kfree(dentry->d_fsdata);
5860 }
5861
5862 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5863 unsigned int flags)
5864 {
5865 struct inode *inode;
5866
5867 inode = btrfs_lookup_dentry(dir, dentry);
5868 if (IS_ERR(inode)) {
5869 if (PTR_ERR(inode) == -ENOENT)
5870 inode = NULL;
5871 else
5872 return ERR_CAST(inode);
5873 }
5874
5875 return d_splice_alias(inode, dentry);
5876 }
5877
5878 unsigned char btrfs_filetype_table[] = {
5879 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5880 };
5881
5882 /*
5883 * All this infrastructure exists because dir_emit can fault, and we are holding
5884 * the tree lock when doing readdir. For now just allocate a buffer and copy
5885 * our information into that, and then dir_emit from the buffer. This is
5886 * similar to what NFS does, only we don't keep the buffer around in pagecache
5887 * because I'm afraid I'll mess that up. Long term we need to make filldir do
5888 * copy_to_user_inatomic so we don't have to worry about page faulting under the
5889 * tree lock.
5890 */
5891 static int btrfs_opendir(struct inode *inode, struct file *file)
5892 {
5893 struct btrfs_file_private *private;
5894
5895 private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
5896 if (!private)
5897 return -ENOMEM;
5898 private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
5899 if (!private->filldir_buf) {
5900 kfree(private);
5901 return -ENOMEM;
5902 }
5903 file->private_data = private;
5904 return 0;
5905 }
5906
5907 struct dir_entry {
5908 u64 ino;
5909 u64 offset;
5910 unsigned type;
5911 int name_len;
5912 };
5913
5914 static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
5915 {
5916 while (entries--) {
5917 struct dir_entry *entry = addr;
5918 char *name = (char *)(entry + 1);
5919
5920 ctx->pos = entry->offset;
5921 if (!dir_emit(ctx, name, entry->name_len, entry->ino,
5922 entry->type))
5923 return 1;
5924 addr += sizeof(struct dir_entry) + entry->name_len;
5925 ctx->pos++;
5926 }
5927 return 0;
5928 }
5929
5930 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5931 {
5932 struct inode *inode = file_inode(file);
5933 struct btrfs_root *root = BTRFS_I(inode)->root;
5934 struct btrfs_file_private *private = file->private_data;
5935 struct btrfs_dir_item *di;
5936 struct btrfs_key key;
5937 struct btrfs_key found_key;
5938 struct btrfs_path *path;
5939 void *addr;
5940 struct list_head ins_list;
5941 struct list_head del_list;
5942 int ret;
5943 struct extent_buffer *leaf;
5944 int slot;
5945 char *name_ptr;
5946 int name_len;
5947 int entries = 0;
5948 int total_len = 0;
5949 bool put = false;
5950 struct btrfs_key location;
5951
5952 if (!dir_emit_dots(file, ctx))
5953 return 0;
5954
5955 path = btrfs_alloc_path();
5956 if (!path)
5957 return -ENOMEM;
5958
5959 addr = private->filldir_buf;
5960 path->reada = READA_FORWARD;
5961
5962 INIT_LIST_HEAD(&ins_list);
5963 INIT_LIST_HEAD(&del_list);
5964 put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
5965
5966 again:
5967 key.type = BTRFS_DIR_INDEX_KEY;
5968 key.offset = ctx->pos;
5969 key.objectid = btrfs_ino(BTRFS_I(inode));
5970
5971 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5972 if (ret < 0)
5973 goto err;
5974
5975 while (1) {
5976 struct dir_entry *entry;
5977
5978 leaf = path->nodes[0];
5979 slot = path->slots[0];
5980 if (slot >= btrfs_header_nritems(leaf)) {
5981 ret = btrfs_next_leaf(root, path);
5982 if (ret < 0)
5983 goto err;
5984 else if (ret > 0)
5985 break;
5986 continue;
5987 }
5988
5989 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5990
5991 if (found_key.objectid != key.objectid)
5992 break;
5993 if (found_key.type != BTRFS_DIR_INDEX_KEY)
5994 break;
5995 if (found_key.offset < ctx->pos)
5996 goto next;
5997 if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
5998 goto next;
5999 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
6000 name_len = btrfs_dir_name_len(leaf, di);
6001 if ((total_len + sizeof(struct dir_entry) + name_len) >=
6002 PAGE_SIZE) {
6003 btrfs_release_path(path);
6004 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6005 if (ret)
6006 goto nopos;
6007 addr = private->filldir_buf;
6008 entries = 0;
6009 total_len = 0;
6010 goto again;
6011 }
6012
6013 entry = addr;
6014 entry->name_len = name_len;
6015 name_ptr = (char *)(entry + 1);
6016 read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
6017 name_len);
6018 entry->type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
6019 btrfs_dir_item_key_to_cpu(leaf, di, &location);
6020 entry->ino = location.objectid;
6021 entry->offset = found_key.offset;
6022 entries++;
6023 addr += sizeof(struct dir_entry) + name_len;
6024 total_len += sizeof(struct dir_entry) + name_len;
6025 next:
6026 path->slots[0]++;
6027 }
6028 btrfs_release_path(path);
6029
6030 ret = btrfs_filldir(private->filldir_buf, entries, ctx);
6031 if (ret)
6032 goto nopos;
6033
6034 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
6035 if (ret)
6036 goto nopos;
6037
6038 /*
6039 * Stop new entries from being returned after we return the last
6040 * entry.
6041 *
6042 * New directory entries are assigned a strictly increasing
6043 * offset. This means that new entries created during readdir
6044 * are *guaranteed* to be seen in the future by that readdir.
6045 * This has broken buggy programs which operate on names as
6046 * they're returned by readdir. Until we re-use freed offsets
6047 * we have this hack to stop new entries from being returned
6048 * under the assumption that they'll never reach this huge
6049 * offset.
6050 *
6051 * This is being careful not to overflow 32bit loff_t unless the
6052 * last entry requires it because doing so has broken 32bit apps
6053 * in the past.
6054 */
6055 if (ctx->pos >= INT_MAX)
6056 ctx->pos = LLONG_MAX;
6057 else
6058 ctx->pos = INT_MAX;
6059 nopos:
6060 ret = 0;
6061 err:
6062 if (put)
6063 btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
6064 btrfs_free_path(path);
6065 return ret;
6066 }
6067
6068 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
6069 {
6070 struct btrfs_root *root = BTRFS_I(inode)->root;
6071 struct btrfs_trans_handle *trans;
6072 int ret = 0;
6073 bool nolock = false;
6074
6075 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6076 return 0;
6077
6078 if (btrfs_fs_closing(root->fs_info) &&
6079 btrfs_is_free_space_inode(BTRFS_I(inode)))
6080 nolock = true;
6081
6082 if (wbc->sync_mode == WB_SYNC_ALL) {
6083 if (nolock)
6084 trans = btrfs_join_transaction_nolock(root);
6085 else
6086 trans = btrfs_join_transaction(root);
6087 if (IS_ERR(trans))
6088 return PTR_ERR(trans);
6089 ret = btrfs_commit_transaction(trans);
6090 }
6091 return ret;
6092 }
6093
6094 /*
6095 * This is somewhat expensive, updating the tree every time the
6096 * inode changes. But, it is most likely to find the inode in cache.
6097 * FIXME, needs more benchmarking...there are no reasons other than performance
6098 * to keep or drop this code.
6099 */
6100 static int btrfs_dirty_inode(struct inode *inode)
6101 {
6102 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6103 struct btrfs_root *root = BTRFS_I(inode)->root;
6104 struct btrfs_trans_handle *trans;
6105 int ret;
6106
6107 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
6108 return 0;
6109
6110 trans = btrfs_join_transaction(root);
6111 if (IS_ERR(trans))
6112 return PTR_ERR(trans);
6113
6114 ret = btrfs_update_inode(trans, root, inode);
6115 if (ret && ret == -ENOSPC) {
6116 /* whoops, lets try again with the full transaction */
6117 btrfs_end_transaction(trans);
6118 trans = btrfs_start_transaction(root, 1);
6119 if (IS_ERR(trans))
6120 return PTR_ERR(trans);
6121
6122 ret = btrfs_update_inode(trans, root, inode);
6123 }
6124 btrfs_end_transaction(trans);
6125 if (BTRFS_I(inode)->delayed_node)
6126 btrfs_balance_delayed_items(fs_info);
6127
6128 return ret;
6129 }
6130
6131 /*
6132 * This is a copy of file_update_time. We need this so we can return error on
6133 * ENOSPC for updating the inode in the case of file write and mmap writes.
6134 */
6135 static int btrfs_update_time(struct inode *inode, struct timespec *now,
6136 int flags)
6137 {
6138 struct btrfs_root *root = BTRFS_I(inode)->root;
6139 bool dirty = flags & ~S_VERSION;
6140
6141 if (btrfs_root_readonly(root))
6142 return -EROFS;
6143
6144 if (flags & S_VERSION)
6145 dirty |= inode_maybe_inc_iversion(inode, dirty);
6146 if (flags & S_CTIME)
6147 inode->i_ctime = *now;
6148 if (flags & S_MTIME)
6149 inode->i_mtime = *now;
6150 if (flags & S_ATIME)
6151 inode->i_atime = *now;
6152 return dirty ? btrfs_dirty_inode(inode) : 0;
6153 }
6154
6155 /*
6156 * find the highest existing sequence number in a directory
6157 * and then set the in-memory index_cnt variable to reflect
6158 * free sequence numbers
6159 */
6160 static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
6161 {
6162 struct btrfs_root *root = inode->root;
6163 struct btrfs_key key, found_key;
6164 struct btrfs_path *path;
6165 struct extent_buffer *leaf;
6166 int ret;
6167
6168 key.objectid = btrfs_ino(inode);
6169 key.type = BTRFS_DIR_INDEX_KEY;
6170 key.offset = (u64)-1;
6171
6172 path = btrfs_alloc_path();
6173 if (!path)
6174 return -ENOMEM;
6175
6176 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6177 if (ret < 0)
6178 goto out;
6179 /* FIXME: we should be able to handle this */
6180 if (ret == 0)
6181 goto out;
6182 ret = 0;
6183
6184 /*
6185 * MAGIC NUMBER EXPLANATION:
6186 * since we search a directory based on f_pos we have to start at 2
6187 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
6188 * else has to start at 2
6189 */
6190 if (path->slots[0] == 0) {
6191 inode->index_cnt = 2;
6192 goto out;
6193 }
6194
6195 path->slots[0]--;
6196
6197 leaf = path->nodes[0];
6198 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6199
6200 if (found_key.objectid != btrfs_ino(inode) ||
6201 found_key.type != BTRFS_DIR_INDEX_KEY) {
6202 inode->index_cnt = 2;
6203 goto out;
6204 }
6205
6206 inode->index_cnt = found_key.offset + 1;
6207 out:
6208 btrfs_free_path(path);
6209 return ret;
6210 }
6211
6212 /*
6213 * helper to find a free sequence number in a given directory. This current
6214 * code is very simple, later versions will do smarter things in the btree
6215 */
6216 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
6217 {
6218 int ret = 0;
6219
6220 if (dir->index_cnt == (u64)-1) {
6221 ret = btrfs_inode_delayed_dir_index_count(dir);
6222 if (ret) {
6223 ret = btrfs_set_inode_index_count(dir);
6224 if (ret)
6225 return ret;
6226 }
6227 }
6228
6229 *index = dir->index_cnt;
6230 dir->index_cnt++;
6231
6232 return ret;
6233 }
6234
6235 static int btrfs_insert_inode_locked(struct inode *inode)
6236 {
6237 struct btrfs_iget_args args;
6238 args.location = &BTRFS_I(inode)->location;
6239 args.root = BTRFS_I(inode)->root;
6240
6241 return insert_inode_locked4(inode,
6242 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
6243 btrfs_find_actor, &args);
6244 }
6245
6246 /*
6247 * Inherit flags from the parent inode.
6248 *
6249 * Currently only the compression flags and the cow flags are inherited.
6250 */
6251 static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
6252 {
6253 unsigned int flags;
6254
6255 if (!dir)
6256 return;
6257
6258 flags = BTRFS_I(dir)->flags;
6259
6260 if (flags & BTRFS_INODE_NOCOMPRESS) {
6261 BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
6262 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
6263 } else if (flags & BTRFS_INODE_COMPRESS) {
6264 BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
6265 BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
6266 }
6267
6268 if (flags & BTRFS_INODE_NODATACOW) {
6269 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
6270 if (S_ISREG(inode->i_mode))
6271 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6272 }
6273
6274 btrfs_update_iflags(inode);
6275 }
6276
6277 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
6278 struct btrfs_root *root,
6279 struct inode *dir,
6280 const char *name, int name_len,
6281 u64 ref_objectid, u64 objectid,
6282 umode_t mode, u64 *index)
6283 {
6284 struct btrfs_fs_info *fs_info = root->fs_info;
6285 struct inode *inode;
6286 struct btrfs_inode_item *inode_item;
6287 struct btrfs_key *location;
6288 struct btrfs_path *path;
6289 struct btrfs_inode_ref *ref;
6290 struct btrfs_key key[2];
6291 u32 sizes[2];
6292 int nitems = name ? 2 : 1;
6293 unsigned long ptr;
6294 int ret;
6295
6296 path = btrfs_alloc_path();
6297 if (!path)
6298 return ERR_PTR(-ENOMEM);
6299
6300 inode = new_inode(fs_info->sb);
6301 if (!inode) {
6302 btrfs_free_path(path);
6303 return ERR_PTR(-ENOMEM);
6304 }
6305
6306 /*
6307 * O_TMPFILE, set link count to 0, so that after this point,
6308 * we fill in an inode item with the correct link count.
6309 */
6310 if (!name)
6311 set_nlink(inode, 0);
6312
6313 /*
6314 * we have to initialize this early, so we can reclaim the inode
6315 * number if we fail afterwards in this function.
6316 */
6317 inode->i_ino = objectid;
6318
6319 if (dir && name) {
6320 trace_btrfs_inode_request(dir);
6321
6322 ret = btrfs_set_inode_index(BTRFS_I(dir), index);
6323 if (ret) {
6324 btrfs_free_path(path);
6325 iput(inode);
6326 return ERR_PTR(ret);
6327 }
6328 } else if (dir) {
6329 *index = 0;
6330 }
6331 /*
6332 * index_cnt is ignored for everything but a dir,
6333 * btrfs_set_inode_index_count has an explanation for the magic
6334 * number
6335 */
6336 BTRFS_I(inode)->index_cnt = 2;
6337 BTRFS_I(inode)->dir_index = *index;
6338 BTRFS_I(inode)->root = root;
6339 BTRFS_I(inode)->generation = trans->transid;
6340 inode->i_generation = BTRFS_I(inode)->generation;
6341
6342 /*
6343 * We could have gotten an inode number from somebody who was fsynced
6344 * and then removed in this same transaction, so let's just set full
6345 * sync since it will be a full sync anyway and this will blow away the
6346 * old info in the log.
6347 */
6348 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6349
6350 key[0].objectid = objectid;
6351 key[0].type = BTRFS_INODE_ITEM_KEY;
6352 key[0].offset = 0;
6353
6354 sizes[0] = sizeof(struct btrfs_inode_item);
6355
6356 if (name) {
6357 /*
6358 * Start new inodes with an inode_ref. This is slightly more
6359 * efficient for small numbers of hard links since they will
6360 * be packed into one item. Extended refs will kick in if we
6361 * add more hard links than can fit in the ref item.
6362 */
6363 key[1].objectid = objectid;
6364 key[1].type = BTRFS_INODE_REF_KEY;
6365 key[1].offset = ref_objectid;
6366
6367 sizes[1] = name_len + sizeof(*ref);
6368 }
6369
6370 location = &BTRFS_I(inode)->location;
6371 location->objectid = objectid;
6372 location->offset = 0;
6373 location->type = BTRFS_INODE_ITEM_KEY;
6374
6375 ret = btrfs_insert_inode_locked(inode);
6376 if (ret < 0)
6377 goto fail;
6378
6379 path->leave_spinning = 1;
6380 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6381 if (ret != 0)
6382 goto fail_unlock;
6383
6384 inode_init_owner(inode, dir, mode);
6385 inode_set_bytes(inode, 0);
6386
6387 inode->i_mtime = current_time(inode);
6388 inode->i_atime = inode->i_mtime;
6389 inode->i_ctime = inode->i_mtime;
6390 BTRFS_I(inode)->i_otime = inode->i_mtime;
6391
6392 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6393 struct btrfs_inode_item);
6394 memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
6395 sizeof(*inode_item));
6396 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6397
6398 if (name) {
6399 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6400 struct btrfs_inode_ref);
6401 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6402 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6403 ptr = (unsigned long)(ref + 1);
6404 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6405 }
6406
6407 btrfs_mark_buffer_dirty(path->nodes[0]);
6408 btrfs_free_path(path);
6409
6410 btrfs_inherit_iflags(inode, dir);
6411
6412 if (S_ISREG(mode)) {
6413 if (btrfs_test_opt(fs_info, NODATASUM))
6414 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6415 if (btrfs_test_opt(fs_info, NODATACOW))
6416 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6417 BTRFS_INODE_NODATASUM;
6418 }
6419
6420 inode_tree_add(inode);
6421
6422 trace_btrfs_inode_new(inode);
6423 btrfs_set_inode_last_trans(trans, inode);
6424
6425 btrfs_update_root_times(trans, root);
6426
6427 ret = btrfs_inode_inherit_props(trans, inode, dir);
6428 if (ret)
6429 btrfs_err(fs_info,
6430 "error inheriting props for ino %llu (root %llu): %d",
6431 btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
6432
6433 return inode;
6434
6435 fail_unlock:
6436 unlock_new_inode(inode);
6437 fail:
6438 if (dir && name)
6439 BTRFS_I(dir)->index_cnt--;
6440 btrfs_free_path(path);
6441 iput(inode);
6442 return ERR_PTR(ret);
6443 }
6444
6445 static inline u8 btrfs_inode_type(struct inode *inode)
6446 {
6447 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6448 }
6449
6450 /*
6451 * utility function to add 'inode' into 'parent_inode' with
6452 * a give name and a given sequence number.
6453 * if 'add_backref' is true, also insert a backref from the
6454 * inode to the parent directory.
6455 */
6456 int btrfs_add_link(struct btrfs_trans_handle *trans,
6457 struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
6458 const char *name, int name_len, int add_backref, u64 index)
6459 {
6460 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6461 int ret = 0;
6462 struct btrfs_key key;
6463 struct btrfs_root *root = parent_inode->root;
6464 u64 ino = btrfs_ino(inode);
6465 u64 parent_ino = btrfs_ino(parent_inode);
6466
6467 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6468 memcpy(&key, &inode->root->root_key, sizeof(key));
6469 } else {
6470 key.objectid = ino;
6471 key.type = BTRFS_INODE_ITEM_KEY;
6472 key.offset = 0;
6473 }
6474
6475 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6476 ret = btrfs_add_root_ref(trans, fs_info, key.objectid,
6477 root->root_key.objectid, parent_ino,
6478 index, name, name_len);
6479 } else if (add_backref) {
6480 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6481 parent_ino, index);
6482 }
6483
6484 /* Nothing to clean up yet */
6485 if (ret)
6486 return ret;
6487
6488 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6489 parent_inode, &key,
6490 btrfs_inode_type(&inode->vfs_inode), index);
6491 if (ret == -EEXIST || ret == -EOVERFLOW)
6492 goto fail_dir_item;
6493 else if (ret) {
6494 btrfs_abort_transaction(trans, ret);
6495 return ret;
6496 }
6497
6498 btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
6499 name_len * 2);
6500 inode_inc_iversion(&parent_inode->vfs_inode);
6501 parent_inode->vfs_inode.i_mtime = parent_inode->vfs_inode.i_ctime =
6502 current_time(&parent_inode->vfs_inode);
6503 ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
6504 if (ret)
6505 btrfs_abort_transaction(trans, ret);
6506 return ret;
6507
6508 fail_dir_item:
6509 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6510 u64 local_index;
6511 int err;
6512 err = btrfs_del_root_ref(trans, fs_info, key.objectid,
6513 root->root_key.objectid, parent_ino,
6514 &local_index, name, name_len);
6515
6516 } else if (add_backref) {
6517 u64 local_index;
6518 int err;
6519
6520 err = btrfs_del_inode_ref(trans, root, name, name_len,
6521 ino, parent_ino, &local_index);
6522 }
6523 return ret;
6524 }
6525
6526 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6527 struct btrfs_inode *dir, struct dentry *dentry,
6528 struct btrfs_inode *inode, int backref, u64 index)
6529 {
6530 int err = btrfs_add_link(trans, dir, inode,
6531 dentry->d_name.name, dentry->d_name.len,
6532 backref, index);
6533 if (err > 0)
6534 err = -EEXIST;
6535 return err;
6536 }
6537
6538 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6539 umode_t mode, dev_t rdev)
6540 {
6541 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6542 struct btrfs_trans_handle *trans;
6543 struct btrfs_root *root = BTRFS_I(dir)->root;
6544 struct inode *inode = NULL;
6545 int err;
6546 int drop_inode = 0;
6547 u64 objectid;
6548 u64 index = 0;
6549
6550 /*
6551 * 2 for inode item and ref
6552 * 2 for dir items
6553 * 1 for xattr if selinux is on
6554 */
6555 trans = btrfs_start_transaction(root, 5);
6556 if (IS_ERR(trans))
6557 return PTR_ERR(trans);
6558
6559 err = btrfs_find_free_ino(root, &objectid);
6560 if (err)
6561 goto out_unlock;
6562
6563 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6564 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6565 mode, &index);
6566 if (IS_ERR(inode)) {
6567 err = PTR_ERR(inode);
6568 goto out_unlock;
6569 }
6570
6571 /*
6572 * If the active LSM wants to access the inode during
6573 * d_instantiate it needs these. Smack checks to see
6574 * if the filesystem supports xattrs by looking at the
6575 * ops vector.
6576 */
6577 inode->i_op = &btrfs_special_inode_operations;
6578 init_special_inode(inode, inode->i_mode, rdev);
6579
6580 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6581 if (err)
6582 goto out_unlock_inode;
6583
6584 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6585 0, index);
6586 if (err) {
6587 goto out_unlock_inode;
6588 } else {
6589 btrfs_update_inode(trans, root, inode);
6590 unlock_new_inode(inode);
6591 d_instantiate(dentry, inode);
6592 }
6593
6594 out_unlock:
6595 btrfs_end_transaction(trans);
6596 btrfs_btree_balance_dirty(fs_info);
6597 if (drop_inode) {
6598 inode_dec_link_count(inode);
6599 iput(inode);
6600 }
6601 return err;
6602
6603 out_unlock_inode:
6604 drop_inode = 1;
6605 unlock_new_inode(inode);
6606 goto out_unlock;
6607
6608 }
6609
6610 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6611 umode_t mode, bool excl)
6612 {
6613 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6614 struct btrfs_trans_handle *trans;
6615 struct btrfs_root *root = BTRFS_I(dir)->root;
6616 struct inode *inode = NULL;
6617 int drop_inode_on_err = 0;
6618 int err;
6619 u64 objectid;
6620 u64 index = 0;
6621
6622 /*
6623 * 2 for inode item and ref
6624 * 2 for dir items
6625 * 1 for xattr if selinux is on
6626 */
6627 trans = btrfs_start_transaction(root, 5);
6628 if (IS_ERR(trans))
6629 return PTR_ERR(trans);
6630
6631 err = btrfs_find_free_ino(root, &objectid);
6632 if (err)
6633 goto out_unlock;
6634
6635 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6636 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6637 mode, &index);
6638 if (IS_ERR(inode)) {
6639 err = PTR_ERR(inode);
6640 goto out_unlock;
6641 }
6642 drop_inode_on_err = 1;
6643 /*
6644 * If the active LSM wants to access the inode during
6645 * d_instantiate it needs these. Smack checks to see
6646 * if the filesystem supports xattrs by looking at the
6647 * ops vector.
6648 */
6649 inode->i_fop = &btrfs_file_operations;
6650 inode->i_op = &btrfs_file_inode_operations;
6651 inode->i_mapping->a_ops = &btrfs_aops;
6652
6653 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6654 if (err)
6655 goto out_unlock_inode;
6656
6657 err = btrfs_update_inode(trans, root, inode);
6658 if (err)
6659 goto out_unlock_inode;
6660
6661 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6662 0, index);
6663 if (err)
6664 goto out_unlock_inode;
6665
6666 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6667 unlock_new_inode(inode);
6668 d_instantiate(dentry, inode);
6669
6670 out_unlock:
6671 btrfs_end_transaction(trans);
6672 if (err && drop_inode_on_err) {
6673 inode_dec_link_count(inode);
6674 iput(inode);
6675 }
6676 btrfs_btree_balance_dirty(fs_info);
6677 return err;
6678
6679 out_unlock_inode:
6680 unlock_new_inode(inode);
6681 goto out_unlock;
6682
6683 }
6684
6685 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6686 struct dentry *dentry)
6687 {
6688 struct btrfs_trans_handle *trans = NULL;
6689 struct btrfs_root *root = BTRFS_I(dir)->root;
6690 struct inode *inode = d_inode(old_dentry);
6691 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
6692 u64 index;
6693 int err;
6694 int drop_inode = 0;
6695
6696 /* do not allow sys_link's with other subvols of the same device */
6697 if (root->objectid != BTRFS_I(inode)->root->objectid)
6698 return -EXDEV;
6699
6700 if (inode->i_nlink >= BTRFS_LINK_MAX)
6701 return -EMLINK;
6702
6703 err = btrfs_set_inode_index(BTRFS_I(dir), &index);
6704 if (err)
6705 goto fail;
6706
6707 /*
6708 * 2 items for inode and inode ref
6709 * 2 items for dir items
6710 * 1 item for parent inode
6711 */
6712 trans = btrfs_start_transaction(root, 5);
6713 if (IS_ERR(trans)) {
6714 err = PTR_ERR(trans);
6715 trans = NULL;
6716 goto fail;
6717 }
6718
6719 /* There are several dir indexes for this inode, clear the cache. */
6720 BTRFS_I(inode)->dir_index = 0ULL;
6721 inc_nlink(inode);
6722 inode_inc_iversion(inode);
6723 inode->i_ctime = current_time(inode);
6724 ihold(inode);
6725 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6726
6727 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
6728 1, index);
6729
6730 if (err) {
6731 drop_inode = 1;
6732 } else {
6733 struct dentry *parent = dentry->d_parent;
6734 err = btrfs_update_inode(trans, root, inode);
6735 if (err)
6736 goto fail;
6737 if (inode->i_nlink == 1) {
6738 /*
6739 * If new hard link count is 1, it's a file created
6740 * with open(2) O_TMPFILE flag.
6741 */
6742 err = btrfs_orphan_del(trans, BTRFS_I(inode));
6743 if (err)
6744 goto fail;
6745 }
6746 d_instantiate(dentry, inode);
6747 btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
6748 }
6749
6750 fail:
6751 if (trans)
6752 btrfs_end_transaction(trans);
6753 if (drop_inode) {
6754 inode_dec_link_count(inode);
6755 iput(inode);
6756 }
6757 btrfs_btree_balance_dirty(fs_info);
6758 return err;
6759 }
6760
6761 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6762 {
6763 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
6764 struct inode *inode = NULL;
6765 struct btrfs_trans_handle *trans;
6766 struct btrfs_root *root = BTRFS_I(dir)->root;
6767 int err = 0;
6768 int drop_on_err = 0;
6769 u64 objectid = 0;
6770 u64 index = 0;
6771
6772 /*
6773 * 2 items for inode and ref
6774 * 2 items for dir items
6775 * 1 for xattr if selinux is on
6776 */
6777 trans = btrfs_start_transaction(root, 5);
6778 if (IS_ERR(trans))
6779 return PTR_ERR(trans);
6780
6781 err = btrfs_find_free_ino(root, &objectid);
6782 if (err)
6783 goto out_fail;
6784
6785 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6786 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
6787 S_IFDIR | mode, &index);
6788 if (IS_ERR(inode)) {
6789 err = PTR_ERR(inode);
6790 goto out_fail;
6791 }
6792
6793 drop_on_err = 1;
6794 /* these must be set before we unlock the inode */
6795 inode->i_op = &btrfs_dir_inode_operations;
6796 inode->i_fop = &btrfs_dir_file_operations;
6797
6798 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6799 if (err)
6800 goto out_fail_inode;
6801
6802 btrfs_i_size_write(BTRFS_I(inode), 0);
6803 err = btrfs_update_inode(trans, root, inode);
6804 if (err)
6805 goto out_fail_inode;
6806
6807 err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
6808 dentry->d_name.name,
6809 dentry->d_name.len, 0, index);
6810 if (err)
6811 goto out_fail_inode;
6812
6813 d_instantiate(dentry, inode);
6814 /*
6815 * mkdir is special. We're unlocking after we call d_instantiate
6816 * to avoid a race with nfsd calling d_instantiate.
6817 */
6818 unlock_new_inode(inode);
6819 drop_on_err = 0;
6820
6821 out_fail:
6822 btrfs_end_transaction(trans);
6823 if (drop_on_err) {
6824 inode_dec_link_count(inode);
6825 iput(inode);
6826 }
6827 btrfs_btree_balance_dirty(fs_info);
6828 return err;
6829
6830 out_fail_inode:
6831 unlock_new_inode(inode);
6832 goto out_fail;
6833 }
6834
6835 static noinline int uncompress_inline(struct btrfs_path *path,
6836 struct page *page,
6837 size_t pg_offset, u64 extent_offset,
6838 struct btrfs_file_extent_item *item)
6839 {
6840 int ret;
6841 struct extent_buffer *leaf = path->nodes[0];
6842 char *tmp;
6843 size_t max_size;
6844 unsigned long inline_size;
6845 unsigned long ptr;
6846 int compress_type;
6847
6848 WARN_ON(pg_offset != 0);
6849 compress_type = btrfs_file_extent_compression(leaf, item);
6850 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6851 inline_size = btrfs_file_extent_inline_item_len(leaf,
6852 btrfs_item_nr(path->slots[0]));
6853 tmp = kmalloc(inline_size, GFP_NOFS);
6854 if (!tmp)
6855 return -ENOMEM;
6856 ptr = btrfs_file_extent_inline_start(item);
6857
6858 read_extent_buffer(leaf, tmp, ptr, inline_size);
6859
6860 max_size = min_t(unsigned long, PAGE_SIZE, max_size);
6861 ret = btrfs_decompress(compress_type, tmp, page,
6862 extent_offset, inline_size, max_size);
6863
6864 /*
6865 * decompression code contains a memset to fill in any space between the end
6866 * of the uncompressed data and the end of max_size in case the decompressed
6867 * data ends up shorter than ram_bytes. That doesn't cover the hole between
6868 * the end of an inline extent and the beginning of the next block, so we
6869 * cover that region here.
6870 */
6871
6872 if (max_size + pg_offset < PAGE_SIZE) {
6873 char *map = kmap(page);
6874 memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
6875 kunmap(page);
6876 }
6877 kfree(tmp);
6878 return ret;
6879 }
6880
6881 /*
6882 * a bit scary, this does extent mapping from logical file offset to the disk.
6883 * the ugly parts come from merging extents from the disk with the in-ram
6884 * representation. This gets more complex because of the data=ordered code,
6885 * where the in-ram extents might be locked pending data=ordered completion.
6886 *
6887 * This also copies inline extents directly into the page.
6888 */
6889 struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
6890 struct page *page,
6891 size_t pg_offset, u64 start, u64 len,
6892 int create)
6893 {
6894 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
6895 int ret;
6896 int err = 0;
6897 u64 extent_start = 0;
6898 u64 extent_end = 0;
6899 u64 objectid = btrfs_ino(inode);
6900 u32 found_type;
6901 struct btrfs_path *path = NULL;
6902 struct btrfs_root *root = inode->root;
6903 struct btrfs_file_extent_item *item;
6904 struct extent_buffer *leaf;
6905 struct btrfs_key found_key;
6906 struct extent_map *em = NULL;
6907 struct extent_map_tree *em_tree = &inode->extent_tree;
6908 struct extent_io_tree *io_tree = &inode->io_tree;
6909 const bool new_inline = !page || create;
6910
6911 read_lock(&em_tree->lock);
6912 em = lookup_extent_mapping(em_tree, start, len);
6913 if (em)
6914 em->bdev = fs_info->fs_devices->latest_bdev;
6915 read_unlock(&em_tree->lock);
6916
6917 if (em) {
6918 if (em->start > start || em->start + em->len <= start)
6919 free_extent_map(em);
6920 else if (em->block_start == EXTENT_MAP_INLINE && page)
6921 free_extent_map(em);
6922 else
6923 goto out;
6924 }
6925 em = alloc_extent_map();
6926 if (!em) {
6927 err = -ENOMEM;
6928 goto out;
6929 }
6930 em->bdev = fs_info->fs_devices->latest_bdev;
6931 em->start = EXTENT_MAP_HOLE;
6932 em->orig_start = EXTENT_MAP_HOLE;
6933 em->len = (u64)-1;
6934 em->block_len = (u64)-1;
6935
6936 if (!path) {
6937 path = btrfs_alloc_path();
6938 if (!path) {
6939 err = -ENOMEM;
6940 goto out;
6941 }
6942 /*
6943 * Chances are we'll be called again, so go ahead and do
6944 * readahead
6945 */
6946 path->reada = READA_FORWARD;
6947 }
6948
6949 ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
6950 if (ret < 0) {
6951 err = ret;
6952 goto out;
6953 }
6954
6955 if (ret != 0) {
6956 if (path->slots[0] == 0)
6957 goto not_found;
6958 path->slots[0]--;
6959 }
6960
6961 leaf = path->nodes[0];
6962 item = btrfs_item_ptr(leaf, path->slots[0],
6963 struct btrfs_file_extent_item);
6964 /* are we inside the extent that was found? */
6965 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6966 found_type = found_key.type;
6967 if (found_key.objectid != objectid ||
6968 found_type != BTRFS_EXTENT_DATA_KEY) {
6969 /*
6970 * If we backup past the first extent we want to move forward
6971 * and see if there is an extent in front of us, otherwise we'll
6972 * say there is a hole for our whole search range which can
6973 * cause problems.
6974 */
6975 extent_end = start;
6976 goto next;
6977 }
6978
6979 found_type = btrfs_file_extent_type(leaf, item);
6980 extent_start = found_key.offset;
6981 if (found_type == BTRFS_FILE_EXTENT_REG ||
6982 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6983 extent_end = extent_start +
6984 btrfs_file_extent_num_bytes(leaf, item);
6985
6986 trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
6987 extent_start);
6988 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6989 size_t size;
6990 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6991 extent_end = ALIGN(extent_start + size,
6992 fs_info->sectorsize);
6993
6994 trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
6995 path->slots[0],
6996 extent_start);
6997 }
6998 next:
6999 if (start >= extent_end) {
7000 path->slots[0]++;
7001 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
7002 ret = btrfs_next_leaf(root, path);
7003 if (ret < 0) {
7004 err = ret;
7005 goto out;
7006 }
7007 if (ret > 0)
7008 goto not_found;
7009 leaf = path->nodes[0];
7010 }
7011 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
7012 if (found_key.objectid != objectid ||
7013 found_key.type != BTRFS_EXTENT_DATA_KEY)
7014 goto not_found;
7015 if (start + len <= found_key.offset)
7016 goto not_found;
7017 if (start > found_key.offset)
7018 goto next;
7019 em->start = start;
7020 em->orig_start = start;
7021 em->len = found_key.offset - start;
7022 goto not_found_em;
7023 }
7024
7025 btrfs_extent_item_to_extent_map(inode, path, item,
7026 new_inline, em);
7027
7028 if (found_type == BTRFS_FILE_EXTENT_REG ||
7029 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7030 goto insert;
7031 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
7032 unsigned long ptr;
7033 char *map;
7034 size_t size;
7035 size_t extent_offset;
7036 size_t copy_size;
7037
7038 if (new_inline)
7039 goto out;
7040
7041 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
7042 extent_offset = page_offset(page) + pg_offset - extent_start;
7043 copy_size = min_t(u64, PAGE_SIZE - pg_offset,
7044 size - extent_offset);
7045 em->start = extent_start + extent_offset;
7046 em->len = ALIGN(copy_size, fs_info->sectorsize);
7047 em->orig_block_len = em->len;
7048 em->orig_start = em->start;
7049 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
7050 if (!PageUptodate(page)) {
7051 if (btrfs_file_extent_compression(leaf, item) !=
7052 BTRFS_COMPRESS_NONE) {
7053 ret = uncompress_inline(path, page, pg_offset,
7054 extent_offset, item);
7055 if (ret) {
7056 err = ret;
7057 goto out;
7058 }
7059 } else {
7060 map = kmap(page);
7061 read_extent_buffer(leaf, map + pg_offset, ptr,
7062 copy_size);
7063 if (pg_offset + copy_size < PAGE_SIZE) {
7064 memset(map + pg_offset + copy_size, 0,
7065 PAGE_SIZE - pg_offset -
7066 copy_size);
7067 }
7068 kunmap(page);
7069 }
7070 flush_dcache_page(page);
7071 }
7072 set_extent_uptodate(io_tree, em->start,
7073 extent_map_end(em) - 1, NULL, GFP_NOFS);
7074 goto insert;
7075 }
7076 not_found:
7077 em->start = start;
7078 em->orig_start = start;
7079 em->len = len;
7080 not_found_em:
7081 em->block_start = EXTENT_MAP_HOLE;
7082 insert:
7083 btrfs_release_path(path);
7084 if (em->start > start || extent_map_end(em) <= start) {
7085 btrfs_err(fs_info,
7086 "bad extent! em: [%llu %llu] passed [%llu %llu]",
7087 em->start, em->len, start, len);
7088 err = -EIO;
7089 goto out;
7090 }
7091
7092 err = 0;
7093 write_lock(&em_tree->lock);
7094 err = btrfs_add_extent_mapping(em_tree, &em, start, len);
7095 write_unlock(&em_tree->lock);
7096 out:
7097
7098 trace_btrfs_get_extent(root, inode, em);
7099
7100 btrfs_free_path(path);
7101 if (err) {
7102 free_extent_map(em);
7103 return ERR_PTR(err);
7104 }
7105 BUG_ON(!em); /* Error is always set */
7106 return em;
7107 }
7108
7109 struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
7110 struct page *page,
7111 size_t pg_offset, u64 start, u64 len,
7112 int create)
7113 {
7114 struct extent_map *em;
7115 struct extent_map *hole_em = NULL;
7116 u64 range_start = start;
7117 u64 end;
7118 u64 found;
7119 u64 found_end;
7120 int err = 0;
7121
7122 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
7123 if (IS_ERR(em))
7124 return em;
7125 /*
7126 * If our em maps to:
7127 * - a hole or
7128 * - a pre-alloc extent,
7129 * there might actually be delalloc bytes behind it.
7130 */
7131 if (em->block_start != EXTENT_MAP_HOLE &&
7132 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7133 return em;
7134 else
7135 hole_em = em;
7136
7137 /* check to see if we've wrapped (len == -1 or similar) */
7138 end = start + len;
7139 if (end < start)
7140 end = (u64)-1;
7141 else
7142 end -= 1;
7143
7144 em = NULL;
7145
7146 /* ok, we didn't find anything, lets look for delalloc */
7147 found = count_range_bits(&inode->io_tree, &range_start,
7148 end, len, EXTENT_DELALLOC, 1);
7149 found_end = range_start + found;
7150 if (found_end < range_start)
7151 found_end = (u64)-1;
7152
7153 /*
7154 * we didn't find anything useful, return
7155 * the original results from get_extent()
7156 */
7157 if (range_start > end || found_end <= start) {
7158 em = hole_em;
7159 hole_em = NULL;
7160 goto out;
7161 }
7162
7163 /* adjust the range_start to make sure it doesn't
7164 * go backwards from the start they passed in
7165 */
7166 range_start = max(start, range_start);
7167 found = found_end - range_start;
7168
7169 if (found > 0) {
7170 u64 hole_start = start;
7171 u64 hole_len = len;
7172
7173 em = alloc_extent_map();
7174 if (!em) {
7175 err = -ENOMEM;
7176 goto out;
7177 }
7178 /*
7179 * when btrfs_get_extent can't find anything it
7180 * returns one huge hole
7181 *
7182 * make sure what it found really fits our range, and
7183 * adjust to make sure it is based on the start from
7184 * the caller
7185 */
7186 if (hole_em) {
7187 u64 calc_end = extent_map_end(hole_em);
7188
7189 if (calc_end <= start || (hole_em->start > end)) {
7190 free_extent_map(hole_em);
7191 hole_em = NULL;
7192 } else {
7193 hole_start = max(hole_em->start, start);
7194 hole_len = calc_end - hole_start;
7195 }
7196 }
7197 em->bdev = NULL;
7198 if (hole_em && range_start > hole_start) {
7199 /* our hole starts before our delalloc, so we
7200 * have to return just the parts of the hole
7201 * that go until the delalloc starts
7202 */
7203 em->len = min(hole_len,
7204 range_start - hole_start);
7205 em->start = hole_start;
7206 em->orig_start = hole_start;
7207 /*
7208 * don't adjust block start at all,
7209 * it is fixed at EXTENT_MAP_HOLE
7210 */
7211 em->block_start = hole_em->block_start;
7212 em->block_len = hole_len;
7213 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
7214 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
7215 } else {
7216 em->start = range_start;
7217 em->len = found;
7218 em->orig_start = range_start;
7219 em->block_start = EXTENT_MAP_DELALLOC;
7220 em->block_len = found;
7221 }
7222 } else {
7223 return hole_em;
7224 }
7225 out:
7226
7227 free_extent_map(hole_em);
7228 if (err) {
7229 free_extent_map(em);
7230 return ERR_PTR(err);
7231 }
7232 return em;
7233 }
7234
7235 static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
7236 const u64 start,
7237 const u64 len,
7238 const u64 orig_start,
7239 const u64 block_start,
7240 const u64 block_len,
7241 const u64 orig_block_len,
7242 const u64 ram_bytes,
7243 const int type)
7244 {
7245 struct extent_map *em = NULL;
7246 int ret;
7247
7248 if (type != BTRFS_ORDERED_NOCOW) {
7249 em = create_io_em(inode, start, len, orig_start,
7250 block_start, block_len, orig_block_len,
7251 ram_bytes,
7252 BTRFS_COMPRESS_NONE, /* compress_type */
7253 type);
7254 if (IS_ERR(em))
7255 goto out;
7256 }
7257 ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
7258 len, block_len, type);
7259 if (ret) {
7260 if (em) {
7261 free_extent_map(em);
7262 btrfs_drop_extent_cache(BTRFS_I(inode), start,
7263 start + len - 1, 0);
7264 }
7265 em = ERR_PTR(ret);
7266 }
7267 out:
7268
7269 return em;
7270 }
7271
7272 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7273 u64 start, u64 len)
7274 {
7275 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7276 struct btrfs_root *root = BTRFS_I(inode)->root;
7277 struct extent_map *em;
7278 struct btrfs_key ins;
7279 u64 alloc_hint;
7280 int ret;
7281
7282 alloc_hint = get_extent_allocation_hint(inode, start, len);
7283 ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
7284 0, alloc_hint, &ins, 1, 1);
7285 if (ret)
7286 return ERR_PTR(ret);
7287
7288 em = btrfs_create_dio_extent(inode, start, ins.offset, start,
7289 ins.objectid, ins.offset, ins.offset,
7290 ins.offset, BTRFS_ORDERED_REGULAR);
7291 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
7292 if (IS_ERR(em))
7293 btrfs_free_reserved_extent(fs_info, ins.objectid,
7294 ins.offset, 1);
7295
7296 return em;
7297 }
7298
7299 /*
7300 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7301 * block must be cow'd
7302 */
7303 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7304 u64 *orig_start, u64 *orig_block_len,
7305 u64 *ram_bytes)
7306 {
7307 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7308 struct btrfs_path *path;
7309 int ret;
7310 struct extent_buffer *leaf;
7311 struct btrfs_root *root = BTRFS_I(inode)->root;
7312 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7313 struct btrfs_file_extent_item *fi;
7314 struct btrfs_key key;
7315 u64 disk_bytenr;
7316 u64 backref_offset;
7317 u64 extent_end;
7318 u64 num_bytes;
7319 int slot;
7320 int found_type;
7321 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7322
7323 path = btrfs_alloc_path();
7324 if (!path)
7325 return -ENOMEM;
7326
7327 ret = btrfs_lookup_file_extent(NULL, root, path,
7328 btrfs_ino(BTRFS_I(inode)), offset, 0);
7329 if (ret < 0)
7330 goto out;
7331
7332 slot = path->slots[0];
7333 if (ret == 1) {
7334 if (slot == 0) {
7335 /* can't find the item, must cow */
7336 ret = 0;
7337 goto out;
7338 }
7339 slot--;
7340 }
7341 ret = 0;
7342 leaf = path->nodes[0];
7343 btrfs_item_key_to_cpu(leaf, &key, slot);
7344 if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
7345 key.type != BTRFS_EXTENT_DATA_KEY) {
7346 /* not our file or wrong item type, must cow */
7347 goto out;
7348 }
7349
7350 if (key.offset > offset) {
7351 /* Wrong offset, must cow */
7352 goto out;
7353 }
7354
7355 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7356 found_type = btrfs_file_extent_type(leaf, fi);
7357 if (found_type != BTRFS_FILE_EXTENT_REG &&
7358 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7359 /* not a regular extent, must cow */
7360 goto out;
7361 }
7362
7363 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7364 goto out;
7365
7366 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7367 if (extent_end <= offset)
7368 goto out;
7369
7370 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7371 if (disk_bytenr == 0)
7372 goto out;
7373
7374 if (btrfs_file_extent_compression(leaf, fi) ||
7375 btrfs_file_extent_encryption(leaf, fi) ||
7376 btrfs_file_extent_other_encoding(leaf, fi))
7377 goto out;
7378
7379 backref_offset = btrfs_file_extent_offset(leaf, fi);
7380
7381 if (orig_start) {
7382 *orig_start = key.offset - backref_offset;
7383 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7384 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7385 }
7386
7387 if (btrfs_extent_readonly(fs_info, disk_bytenr))
7388 goto out;
7389
7390 num_bytes = min(offset + *len, extent_end) - offset;
7391 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7392 u64 range_end;
7393
7394 range_end = round_up(offset + num_bytes,
7395 root->fs_info->sectorsize) - 1;
7396 ret = test_range_bit(io_tree, offset, range_end,
7397 EXTENT_DELALLOC, 0, NULL);
7398 if (ret) {
7399 ret = -EAGAIN;
7400 goto out;
7401 }
7402 }
7403
7404 btrfs_release_path(path);
7405
7406 /*
7407 * look for other files referencing this extent, if we
7408 * find any we must cow
7409 */
7410
7411 ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
7412 key.offset - backref_offset, disk_bytenr);
7413 if (ret) {
7414 ret = 0;
7415 goto out;
7416 }
7417
7418 /*
7419 * adjust disk_bytenr and num_bytes to cover just the bytes
7420 * in this extent we are about to write. If there
7421 * are any csums in that range we have to cow in order
7422 * to keep the csums correct
7423 */
7424 disk_bytenr += backref_offset;
7425 disk_bytenr += offset - key.offset;
7426 if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
7427 goto out;
7428 /*
7429 * all of the above have passed, it is safe to overwrite this extent
7430 * without cow
7431 */
7432 *len = num_bytes;
7433 ret = 1;
7434 out:
7435 btrfs_free_path(path);
7436 return ret;
7437 }
7438
7439 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7440 {
7441 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7442 bool found = false;
7443 void **pagep = NULL;
7444 struct page *page = NULL;
7445 unsigned long start_idx;
7446 unsigned long end_idx;
7447
7448 start_idx = start >> PAGE_SHIFT;
7449
7450 /*
7451 * end is the last byte in the last page. end == start is legal
7452 */
7453 end_idx = end >> PAGE_SHIFT;
7454
7455 rcu_read_lock();
7456
7457 /* Most of the code in this while loop is lifted from
7458 * find_get_page. It's been modified to begin searching from a
7459 * page and return just the first page found in that range. If the
7460 * found idx is less than or equal to the end idx then we know that
7461 * a page exists. If no pages are found or if those pages are
7462 * outside of the range then we're fine (yay!) */
7463 while (page == NULL &&
7464 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7465 page = radix_tree_deref_slot(pagep);
7466 if (unlikely(!page))
7467 break;
7468
7469 if (radix_tree_exception(page)) {
7470 if (radix_tree_deref_retry(page)) {
7471 page = NULL;
7472 continue;
7473 }
7474 /*
7475 * Otherwise, shmem/tmpfs must be storing a swap entry
7476 * here as an exceptional entry: so return it without
7477 * attempting to raise page count.
7478 */
7479 page = NULL;
7480 break; /* TODO: Is this relevant for this use case? */
7481 }
7482
7483 if (!page_cache_get_speculative(page)) {
7484 page = NULL;
7485 continue;
7486 }
7487
7488 /*
7489 * Has the page moved?
7490 * This is part of the lockless pagecache protocol. See
7491 * include/linux/pagemap.h for details.
7492 */
7493 if (unlikely(page != *pagep)) {
7494 put_page(page);
7495 page = NULL;
7496 }
7497 }
7498
7499 if (page) {
7500 if (page->index <= end_idx)
7501 found = true;
7502 put_page(page);
7503 }
7504
7505 rcu_read_unlock();
7506 return found;
7507 }
7508
7509 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7510 struct extent_state **cached_state, int writing)
7511 {
7512 struct btrfs_ordered_extent *ordered;
7513 int ret = 0;
7514
7515 while (1) {
7516 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7517 cached_state);
7518 /*
7519 * We're concerned with the entire range that we're going to be
7520 * doing DIO to, so we need to make sure there's no ordered
7521 * extents in this range.
7522 */
7523 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
7524 lockend - lockstart + 1);
7525
7526 /*
7527 * We need to make sure there are no buffered pages in this
7528 * range either, we could have raced between the invalidate in
7529 * generic_file_direct_write and locking the extent. The
7530 * invalidate needs to happen so that reads after a write do not
7531 * get stale data.
7532 */
7533 if (!ordered &&
7534 (!writing ||
7535 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7536 break;
7537
7538 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7539 cached_state);
7540
7541 if (ordered) {
7542 /*
7543 * If we are doing a DIO read and the ordered extent we
7544 * found is for a buffered write, we can not wait for it
7545 * to complete and retry, because if we do so we can
7546 * deadlock with concurrent buffered writes on page
7547 * locks. This happens only if our DIO read covers more
7548 * than one extent map, if at this point has already
7549 * created an ordered extent for a previous extent map
7550 * and locked its range in the inode's io tree, and a
7551 * concurrent write against that previous extent map's
7552 * range and this range started (we unlock the ranges
7553 * in the io tree only when the bios complete and
7554 * buffered writes always lock pages before attempting
7555 * to lock range in the io tree).
7556 */
7557 if (writing ||
7558 test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
7559 btrfs_start_ordered_extent(inode, ordered, 1);
7560 else
7561 ret = -ENOTBLK;
7562 btrfs_put_ordered_extent(ordered);
7563 } else {
7564 /*
7565 * We could trigger writeback for this range (and wait
7566 * for it to complete) and then invalidate the pages for
7567 * this range (through invalidate_inode_pages2_range()),
7568 * but that can lead us to a deadlock with a concurrent
7569 * call to readpages() (a buffered read or a defrag call
7570 * triggered a readahead) on a page lock due to an
7571 * ordered dio extent we created before but did not have
7572 * yet a corresponding bio submitted (whence it can not
7573 * complete), which makes readpages() wait for that
7574 * ordered extent to complete while holding a lock on
7575 * that page.
7576 */
7577 ret = -ENOTBLK;
7578 }
7579
7580 if (ret)
7581 break;
7582
7583 cond_resched();
7584 }
7585
7586 return ret;
7587 }
7588
7589 /* The callers of this must take lock_extent() */
7590 static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
7591 u64 orig_start, u64 block_start,
7592 u64 block_len, u64 orig_block_len,
7593 u64 ram_bytes, int compress_type,
7594 int type)
7595 {
7596 struct extent_map_tree *em_tree;
7597 struct extent_map *em;
7598 struct btrfs_root *root = BTRFS_I(inode)->root;
7599 int ret;
7600
7601 ASSERT(type == BTRFS_ORDERED_PREALLOC ||
7602 type == BTRFS_ORDERED_COMPRESSED ||
7603 type == BTRFS_ORDERED_NOCOW ||
7604 type == BTRFS_ORDERED_REGULAR);
7605
7606 em_tree = &BTRFS_I(inode)->extent_tree;
7607 em = alloc_extent_map();
7608 if (!em)
7609 return ERR_PTR(-ENOMEM);
7610
7611 em->start = start;
7612 em->orig_start = orig_start;
7613 em->len = len;
7614 em->block_len = block_len;
7615 em->block_start = block_start;
7616 em->bdev = root->fs_info->fs_devices->latest_bdev;
7617 em->orig_block_len = orig_block_len;
7618 em->ram_bytes = ram_bytes;
7619 em->generation = -1;
7620 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7621 if (type == BTRFS_ORDERED_PREALLOC) {
7622 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7623 } else if (type == BTRFS_ORDERED_COMPRESSED) {
7624 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
7625 em->compress_type = compress_type;
7626 }
7627
7628 do {
7629 btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
7630 em->start + em->len - 1, 0);
7631 write_lock(&em_tree->lock);
7632 ret = add_extent_mapping(em_tree, em, 1);
7633 write_unlock(&em_tree->lock);
7634 /*
7635 * The caller has taken lock_extent(), who could race with us
7636 * to add em?
7637 */
7638 } while (ret == -EEXIST);
7639
7640 if (ret) {
7641 free_extent_map(em);
7642 return ERR_PTR(ret);
7643 }
7644
7645 /* em got 2 refs now, callers needs to do free_extent_map once. */
7646 return em;
7647 }
7648
7649 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7650 struct buffer_head *bh_result, int create)
7651 {
7652 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7653 struct extent_map *em;
7654 struct extent_state *cached_state = NULL;
7655 struct btrfs_dio_data *dio_data = NULL;
7656 u64 start = iblock << inode->i_blkbits;
7657 u64 lockstart, lockend;
7658 u64 len = bh_result->b_size;
7659 int unlock_bits = EXTENT_LOCKED;
7660 int ret = 0;
7661
7662 if (create)
7663 unlock_bits |= EXTENT_DIRTY;
7664 else
7665 len = min_t(u64, len, fs_info->sectorsize);
7666
7667 lockstart = start;
7668 lockend = start + len - 1;
7669
7670 if (current->journal_info) {
7671 /*
7672 * Need to pull our outstanding extents and set journal_info to NULL so
7673 * that anything that needs to check if there's a transaction doesn't get
7674 * confused.
7675 */
7676 dio_data = current->journal_info;
7677 current->journal_info = NULL;
7678 }
7679
7680 /*
7681 * If this errors out it's because we couldn't invalidate pagecache for
7682 * this range and we need to fallback to buffered.
7683 */
7684 if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
7685 create)) {
7686 ret = -ENOTBLK;
7687 goto err;
7688 }
7689
7690 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
7691 if (IS_ERR(em)) {
7692 ret = PTR_ERR(em);
7693 goto unlock_err;
7694 }
7695
7696 /*
7697 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7698 * io. INLINE is special, and we could probably kludge it in here, but
7699 * it's still buffered so for safety lets just fall back to the generic
7700 * buffered path.
7701 *
7702 * For COMPRESSED we _have_ to read the entire extent in so we can
7703 * decompress it, so there will be buffering required no matter what we
7704 * do, so go ahead and fallback to buffered.
7705 *
7706 * We return -ENOTBLK because that's what makes DIO go ahead and go back
7707 * to buffered IO. Don't blame me, this is the price we pay for using
7708 * the generic code.
7709 */
7710 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7711 em->block_start == EXTENT_MAP_INLINE) {
7712 free_extent_map(em);
7713 ret = -ENOTBLK;
7714 goto unlock_err;
7715 }
7716
7717 /* Just a good old fashioned hole, return */
7718 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7719 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7720 free_extent_map(em);
7721 goto unlock_err;
7722 }
7723
7724 /*
7725 * We don't allocate a new extent in the following cases
7726 *
7727 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7728 * existing extent.
7729 * 2) The extent is marked as PREALLOC. We're good to go here and can
7730 * just use the extent.
7731 *
7732 */
7733 if (!create) {
7734 len = min(len, em->len - (start - em->start));
7735 lockstart = start + len;
7736 goto unlock;
7737 }
7738
7739 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7740 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7741 em->block_start != EXTENT_MAP_HOLE)) {
7742 int type;
7743 u64 block_start, orig_start, orig_block_len, ram_bytes;
7744
7745 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7746 type = BTRFS_ORDERED_PREALLOC;
7747 else
7748 type = BTRFS_ORDERED_NOCOW;
7749 len = min(len, em->len - (start - em->start));
7750 block_start = em->block_start + (start - em->start);
7751
7752 if (can_nocow_extent(inode, start, &len, &orig_start,
7753 &orig_block_len, &ram_bytes) == 1 &&
7754 btrfs_inc_nocow_writers(fs_info, block_start)) {
7755 struct extent_map *em2;
7756
7757 em2 = btrfs_create_dio_extent(inode, start, len,
7758 orig_start, block_start,
7759 len, orig_block_len,
7760 ram_bytes, type);
7761 btrfs_dec_nocow_writers(fs_info, block_start);
7762 if (type == BTRFS_ORDERED_PREALLOC) {
7763 free_extent_map(em);
7764 em = em2;
7765 }
7766 if (em2 && IS_ERR(em2)) {
7767 ret = PTR_ERR(em2);
7768 goto unlock_err;
7769 }
7770 /*
7771 * For inode marked NODATACOW or extent marked PREALLOC,
7772 * use the existing or preallocated extent, so does not
7773 * need to adjust btrfs_space_info's bytes_may_use.
7774 */
7775 btrfs_free_reserved_data_space_noquota(inode,
7776 start, len);
7777 goto unlock;
7778 }
7779 }
7780
7781 /*
7782 * this will cow the extent, reset the len in case we changed
7783 * it above
7784 */
7785 len = bh_result->b_size;
7786 free_extent_map(em);
7787 em = btrfs_new_extent_direct(inode, start, len);
7788 if (IS_ERR(em)) {
7789 ret = PTR_ERR(em);
7790 goto unlock_err;
7791 }
7792 len = min(len, em->len - (start - em->start));
7793 unlock:
7794 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7795 inode->i_blkbits;
7796 bh_result->b_size = len;
7797 bh_result->b_bdev = em->bdev;
7798 set_buffer_mapped(bh_result);
7799 if (create) {
7800 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7801 set_buffer_new(bh_result);
7802
7803 /*
7804 * Need to update the i_size under the extent lock so buffered
7805 * readers will get the updated i_size when we unlock.
7806 */
7807 if (!dio_data->overwrite && start + len > i_size_read(inode))
7808 i_size_write(inode, start + len);
7809
7810 WARN_ON(dio_data->reserve < len);
7811 dio_data->reserve -= len;
7812 dio_data->unsubmitted_oe_range_end = start + len;
7813 current->journal_info = dio_data;
7814 }
7815
7816 /*
7817 * In the case of write we need to clear and unlock the entire range,
7818 * in the case of read we need to unlock only the end area that we
7819 * aren't using if there is any left over space.
7820 */
7821 if (lockstart < lockend) {
7822 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7823 lockend, unlock_bits, 1, 0,
7824 &cached_state);
7825 } else {
7826 free_extent_state(cached_state);
7827 }
7828
7829 free_extent_map(em);
7830
7831 return 0;
7832
7833 unlock_err:
7834 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7835 unlock_bits, 1, 0, &cached_state);
7836 err:
7837 if (dio_data)
7838 current->journal_info = dio_data;
7839 return ret;
7840 }
7841
7842 static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
7843 struct bio *bio,
7844 int mirror_num)
7845 {
7846 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7847 blk_status_t ret;
7848
7849 BUG_ON(bio_op(bio) == REQ_OP_WRITE);
7850
7851 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
7852 if (ret)
7853 return ret;
7854
7855 ret = btrfs_map_bio(fs_info, bio, mirror_num, 0);
7856
7857 return ret;
7858 }
7859
7860 static int btrfs_check_dio_repairable(struct inode *inode,
7861 struct bio *failed_bio,
7862 struct io_failure_record *failrec,
7863 int failed_mirror)
7864 {
7865 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
7866 int num_copies;
7867
7868 num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
7869 if (num_copies == 1) {
7870 /*
7871 * we only have a single copy of the data, so don't bother with
7872 * all the retry and error correction code that follows. no
7873 * matter what the error is, it is very likely to persist.
7874 */
7875 btrfs_debug(fs_info,
7876 "Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
7877 num_copies, failrec->this_mirror, failed_mirror);
7878 return 0;
7879 }
7880
7881 failrec->failed_mirror = failed_mirror;
7882 failrec->this_mirror++;
7883 if (failrec->this_mirror == failed_mirror)
7884 failrec->this_mirror++;
7885
7886 if (failrec->this_mirror > num_copies) {
7887 btrfs_debug(fs_info,
7888 "Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
7889 num_copies, failrec->this_mirror, failed_mirror);
7890 return 0;
7891 }
7892
7893 return 1;
7894 }
7895
7896 static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
7897 struct page *page, unsigned int pgoff,
7898 u64 start, u64 end, int failed_mirror,
7899 bio_end_io_t *repair_endio, void *repair_arg)
7900 {
7901 struct io_failure_record *failrec;
7902 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7903 struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
7904 struct bio *bio;
7905 int isector;
7906 unsigned int read_mode = 0;
7907 int segs;
7908 int ret;
7909 blk_status_t status;
7910 struct bio_vec bvec;
7911
7912 BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
7913
7914 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7915 if (ret)
7916 return errno_to_blk_status(ret);
7917
7918 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7919 failed_mirror);
7920 if (!ret) {
7921 free_io_failure(failure_tree, io_tree, failrec);
7922 return BLK_STS_IOERR;
7923 }
7924
7925 segs = bio_segments(failed_bio);
7926 bio_get_first_bvec(failed_bio, &bvec);
7927 if (segs > 1 ||
7928 (bvec.bv_len > btrfs_inode_sectorsize(inode)))
7929 read_mode |= REQ_FAILFAST_DEV;
7930
7931 isector = start - btrfs_io_bio(failed_bio)->logical;
7932 isector >>= inode->i_sb->s_blocksize_bits;
7933 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7934 pgoff, isector, repair_endio, repair_arg);
7935 bio_set_op_attrs(bio, REQ_OP_READ, read_mode);
7936
7937 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7938 "repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
7939 read_mode, failrec->this_mirror, failrec->in_validation);
7940
7941 status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
7942 if (status) {
7943 free_io_failure(failure_tree, io_tree, failrec);
7944 bio_put(bio);
7945 }
7946
7947 return status;
7948 }
7949
7950 struct btrfs_retry_complete {
7951 struct completion done;
7952 struct inode *inode;
7953 u64 start;
7954 int uptodate;
7955 };
7956
7957 static void btrfs_retry_endio_nocsum(struct bio *bio)
7958 {
7959 struct btrfs_retry_complete *done = bio->bi_private;
7960 struct inode *inode = done->inode;
7961 struct bio_vec *bvec;
7962 struct extent_io_tree *io_tree, *failure_tree;
7963 int i;
7964
7965 if (bio->bi_status)
7966 goto end;
7967
7968 ASSERT(bio->bi_vcnt == 1);
7969 io_tree = &BTRFS_I(inode)->io_tree;
7970 failure_tree = &BTRFS_I(inode)->io_failure_tree;
7971 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
7972
7973 done->uptodate = 1;
7974 ASSERT(!bio_flagged(bio, BIO_CLONED));
7975 bio_for_each_segment_all(bvec, bio, i)
7976 clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
7977 io_tree, done->start, bvec->bv_page,
7978 btrfs_ino(BTRFS_I(inode)), 0);
7979 end:
7980 complete(&done->done);
7981 bio_put(bio);
7982 }
7983
7984 static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
7985 struct btrfs_io_bio *io_bio)
7986 {
7987 struct btrfs_fs_info *fs_info;
7988 struct bio_vec bvec;
7989 struct bvec_iter iter;
7990 struct btrfs_retry_complete done;
7991 u64 start;
7992 unsigned int pgoff;
7993 u32 sectorsize;
7994 int nr_sectors;
7995 blk_status_t ret;
7996 blk_status_t err = BLK_STS_OK;
7997
7998 fs_info = BTRFS_I(inode)->root->fs_info;
7999 sectorsize = fs_info->sectorsize;
8000
8001 start = io_bio->logical;
8002 done.inode = inode;
8003 io_bio->bio.bi_iter = io_bio->iter;
8004
8005 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8006 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8007 pgoff = bvec.bv_offset;
8008
8009 next_block_or_try_again:
8010 done.uptodate = 0;
8011 done.start = start;
8012 init_completion(&done.done);
8013
8014 ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8015 pgoff, start, start + sectorsize - 1,
8016 io_bio->mirror_num,
8017 btrfs_retry_endio_nocsum, &done);
8018 if (ret) {
8019 err = ret;
8020 goto next;
8021 }
8022
8023 wait_for_completion_io(&done.done);
8024
8025 if (!done.uptodate) {
8026 /* We might have another mirror, so try again */
8027 goto next_block_or_try_again;
8028 }
8029
8030 next:
8031 start += sectorsize;
8032
8033 nr_sectors--;
8034 if (nr_sectors) {
8035 pgoff += sectorsize;
8036 ASSERT(pgoff < PAGE_SIZE);
8037 goto next_block_or_try_again;
8038 }
8039 }
8040
8041 return err;
8042 }
8043
8044 static void btrfs_retry_endio(struct bio *bio)
8045 {
8046 struct btrfs_retry_complete *done = bio->bi_private;
8047 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8048 struct extent_io_tree *io_tree, *failure_tree;
8049 struct inode *inode = done->inode;
8050 struct bio_vec *bvec;
8051 int uptodate;
8052 int ret;
8053 int i;
8054
8055 if (bio->bi_status)
8056 goto end;
8057
8058 uptodate = 1;
8059
8060 ASSERT(bio->bi_vcnt == 1);
8061 ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
8062
8063 io_tree = &BTRFS_I(inode)->io_tree;
8064 failure_tree = &BTRFS_I(inode)->io_failure_tree;
8065
8066 ASSERT(!bio_flagged(bio, BIO_CLONED));
8067 bio_for_each_segment_all(bvec, bio, i) {
8068 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
8069 bvec->bv_offset, done->start,
8070 bvec->bv_len);
8071 if (!ret)
8072 clean_io_failure(BTRFS_I(inode)->root->fs_info,
8073 failure_tree, io_tree, done->start,
8074 bvec->bv_page,
8075 btrfs_ino(BTRFS_I(inode)),
8076 bvec->bv_offset);
8077 else
8078 uptodate = 0;
8079 }
8080
8081 done->uptodate = uptodate;
8082 end:
8083 complete(&done->done);
8084 bio_put(bio);
8085 }
8086
8087 static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
8088 struct btrfs_io_bio *io_bio, blk_status_t err)
8089 {
8090 struct btrfs_fs_info *fs_info;
8091 struct bio_vec bvec;
8092 struct bvec_iter iter;
8093 struct btrfs_retry_complete done;
8094 u64 start;
8095 u64 offset = 0;
8096 u32 sectorsize;
8097 int nr_sectors;
8098 unsigned int pgoff;
8099 int csum_pos;
8100 bool uptodate = (err == 0);
8101 int ret;
8102 blk_status_t status;
8103
8104 fs_info = BTRFS_I(inode)->root->fs_info;
8105 sectorsize = fs_info->sectorsize;
8106
8107 err = BLK_STS_OK;
8108 start = io_bio->logical;
8109 done.inode = inode;
8110 io_bio->bio.bi_iter = io_bio->iter;
8111
8112 bio_for_each_segment(bvec, &io_bio->bio, iter) {
8113 nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
8114
8115 pgoff = bvec.bv_offset;
8116 next_block:
8117 if (uptodate) {
8118 csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
8119 ret = __readpage_endio_check(inode, io_bio, csum_pos,
8120 bvec.bv_page, pgoff, start, sectorsize);
8121 if (likely(!ret))
8122 goto next;
8123 }
8124 try_again:
8125 done.uptodate = 0;
8126 done.start = start;
8127 init_completion(&done.done);
8128
8129 status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
8130 pgoff, start, start + sectorsize - 1,
8131 io_bio->mirror_num, btrfs_retry_endio,
8132 &done);
8133 if (status) {
8134 err = status;
8135 goto next;
8136 }
8137
8138 wait_for_completion_io(&done.done);
8139
8140 if (!done.uptodate) {
8141 /* We might have another mirror, so try again */
8142 goto try_again;
8143 }
8144 next:
8145 offset += sectorsize;
8146 start += sectorsize;
8147
8148 ASSERT(nr_sectors);
8149
8150 nr_sectors--;
8151 if (nr_sectors) {
8152 pgoff += sectorsize;
8153 ASSERT(pgoff < PAGE_SIZE);
8154 goto next_block;
8155 }
8156 }
8157
8158 return err;
8159 }
8160
8161 static blk_status_t btrfs_subio_endio_read(struct inode *inode,
8162 struct btrfs_io_bio *io_bio, blk_status_t err)
8163 {
8164 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8165
8166 if (skip_csum) {
8167 if (unlikely(err))
8168 return __btrfs_correct_data_nocsum(inode, io_bio);
8169 else
8170 return BLK_STS_OK;
8171 } else {
8172 return __btrfs_subio_endio_read(inode, io_bio, err);
8173 }
8174 }
8175
8176 static void btrfs_endio_direct_read(struct bio *bio)
8177 {
8178 struct btrfs_dio_private *dip = bio->bi_private;
8179 struct inode *inode = dip->inode;
8180 struct bio *dio_bio;
8181 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8182 blk_status_t err = bio->bi_status;
8183
8184 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
8185 err = btrfs_subio_endio_read(inode, io_bio, err);
8186
8187 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
8188 dip->logical_offset + dip->bytes - 1);
8189 dio_bio = dip->dio_bio;
8190
8191 kfree(dip);
8192
8193 dio_bio->bi_status = err;
8194 dio_end_io(dio_bio);
8195
8196 if (io_bio->end_io)
8197 io_bio->end_io(io_bio, blk_status_to_errno(err));
8198 bio_put(bio);
8199 }
8200
8201 static void __endio_write_update_ordered(struct inode *inode,
8202 const u64 offset, const u64 bytes,
8203 const bool uptodate)
8204 {
8205 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8206 struct btrfs_ordered_extent *ordered = NULL;
8207 struct btrfs_workqueue *wq;
8208 btrfs_work_func_t func;
8209 u64 ordered_offset = offset;
8210 u64 ordered_bytes = bytes;
8211 u64 last_offset;
8212 int ret;
8213
8214 if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
8215 wq = fs_info->endio_freespace_worker;
8216 func = btrfs_freespace_write_helper;
8217 } else {
8218 wq = fs_info->endio_write_workers;
8219 func = btrfs_endio_write_helper;
8220 }
8221
8222 again:
8223 last_offset = ordered_offset;
8224 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
8225 &ordered_offset,
8226 ordered_bytes,
8227 uptodate);
8228 if (!ret)
8229 goto out_test;
8230
8231 btrfs_init_work(&ordered->work, func, finish_ordered_fn, NULL, NULL);
8232 btrfs_queue_work(wq, &ordered->work);
8233 out_test:
8234 /*
8235 * If btrfs_dec_test_ordered_pending does not find any ordered extent
8236 * in the range, we can exit.
8237 */
8238 if (ordered_offset == last_offset)
8239 return;
8240 /*
8241 * our bio might span multiple ordered extents. If we haven't
8242 * completed the accounting for the whole dio, go back and try again
8243 */
8244 if (ordered_offset < offset + bytes) {
8245 ordered_bytes = offset + bytes - ordered_offset;
8246 ordered = NULL;
8247 goto again;
8248 }
8249 }
8250
8251 static void btrfs_endio_direct_write(struct bio *bio)
8252 {
8253 struct btrfs_dio_private *dip = bio->bi_private;
8254 struct bio *dio_bio = dip->dio_bio;
8255
8256 __endio_write_update_ordered(dip->inode, dip->logical_offset,
8257 dip->bytes, !bio->bi_status);
8258
8259 kfree(dip);
8260
8261 dio_bio->bi_status = bio->bi_status;
8262 dio_end_io(dio_bio);
8263 bio_put(bio);
8264 }
8265
8266 static blk_status_t __btrfs_submit_bio_start_direct_io(void *private_data,
8267 struct bio *bio, int mirror_num,
8268 unsigned long bio_flags, u64 offset)
8269 {
8270 struct inode *inode = private_data;
8271 blk_status_t ret;
8272 ret = btrfs_csum_one_bio(inode, bio, offset, 1);
8273 BUG_ON(ret); /* -ENOMEM */
8274 return 0;
8275 }
8276
8277 static void btrfs_end_dio_bio(struct bio *bio)
8278 {
8279 struct btrfs_dio_private *dip = bio->bi_private;
8280 blk_status_t err = bio->bi_status;
8281
8282 if (err)
8283 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
8284 "direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
8285 btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
8286 bio->bi_opf,
8287 (unsigned long long)bio->bi_iter.bi_sector,
8288 bio->bi_iter.bi_size, err);
8289
8290 if (dip->subio_endio)
8291 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
8292
8293 if (err) {
8294 dip->errors = 1;
8295
8296 /*
8297 * before atomic variable goto zero, we must make sure
8298 * dip->errors is perceived to be set.
8299 */
8300 smp_mb__before_atomic();
8301 }
8302
8303 /* if there are more bios still pending for this dio, just exit */
8304 if (!atomic_dec_and_test(&dip->pending_bios))
8305 goto out;
8306
8307 if (dip->errors) {
8308 bio_io_error(dip->orig_bio);
8309 } else {
8310 dip->dio_bio->bi_status = BLK_STS_OK;
8311 bio_endio(dip->orig_bio);
8312 }
8313 out:
8314 bio_put(bio);
8315 }
8316
8317 static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
8318 struct btrfs_dio_private *dip,
8319 struct bio *bio,
8320 u64 file_offset)
8321 {
8322 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
8323 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
8324 blk_status_t ret;
8325
8326 /*
8327 * We load all the csum data we need when we submit
8328 * the first bio to reduce the csum tree search and
8329 * contention.
8330 */
8331 if (dip->logical_offset == file_offset) {
8332 ret = btrfs_lookup_bio_sums_dio(inode, dip->orig_bio,
8333 file_offset);
8334 if (ret)
8335 return ret;
8336 }
8337
8338 if (bio == dip->orig_bio)
8339 return 0;
8340
8341 file_offset -= dip->logical_offset;
8342 file_offset >>= inode->i_sb->s_blocksize_bits;
8343 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
8344
8345 return 0;
8346 }
8347
8348 static inline blk_status_t
8349 __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode, u64 file_offset,
8350 int async_submit)
8351 {
8352 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8353 struct btrfs_dio_private *dip = bio->bi_private;
8354 bool write = bio_op(bio) == REQ_OP_WRITE;
8355 blk_status_t ret;
8356
8357 /* Check btrfs_submit_bio_hook() for rules about async submit. */
8358 if (async_submit)
8359 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
8360
8361 if (!write) {
8362 ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
8363 if (ret)
8364 goto err;
8365 }
8366
8367 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
8368 goto map;
8369
8370 if (write && async_submit) {
8371 ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
8372 file_offset, inode,
8373 __btrfs_submit_bio_start_direct_io,
8374 __btrfs_submit_bio_done);
8375 goto err;
8376 } else if (write) {
8377 /*
8378 * If we aren't doing async submit, calculate the csum of the
8379 * bio now.
8380 */
8381 ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
8382 if (ret)
8383 goto err;
8384 } else {
8385 ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
8386 file_offset);
8387 if (ret)
8388 goto err;
8389 }
8390 map:
8391 ret = btrfs_map_bio(fs_info, bio, 0, 0);
8392 err:
8393 return ret;
8394 }
8395
8396 static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
8397 {
8398 struct inode *inode = dip->inode;
8399 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8400 struct bio *bio;
8401 struct bio *orig_bio = dip->orig_bio;
8402 u64 start_sector = orig_bio->bi_iter.bi_sector;
8403 u64 file_offset = dip->logical_offset;
8404 u64 map_length;
8405 int async_submit = 0;
8406 u64 submit_len;
8407 int clone_offset = 0;
8408 int clone_len;
8409 int ret;
8410 blk_status_t status;
8411
8412 map_length = orig_bio->bi_iter.bi_size;
8413 submit_len = map_length;
8414 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio), start_sector << 9,
8415 &map_length, NULL, 0);
8416 if (ret)
8417 return -EIO;
8418
8419 if (map_length >= submit_len) {
8420 bio = orig_bio;
8421 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8422 goto submit;
8423 }
8424
8425 /* async crcs make it difficult to collect full stripe writes. */
8426 if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8427 async_submit = 0;
8428 else
8429 async_submit = 1;
8430
8431 /* bio split */
8432 ASSERT(map_length <= INT_MAX);
8433 atomic_inc(&dip->pending_bios);
8434 do {
8435 clone_len = min_t(int, submit_len, map_length);
8436
8437 /*
8438 * This will never fail as it's passing GPF_NOFS and
8439 * the allocation is backed by btrfs_bioset.
8440 */
8441 bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
8442 clone_len);
8443 bio->bi_private = dip;
8444 bio->bi_end_io = btrfs_end_dio_bio;
8445 btrfs_io_bio(bio)->logical = file_offset;
8446
8447 ASSERT(submit_len >= clone_len);
8448 submit_len -= clone_len;
8449 if (submit_len == 0)
8450 break;
8451
8452 /*
8453 * Increase the count before we submit the bio so we know
8454 * the end IO handler won't happen before we increase the
8455 * count. Otherwise, the dip might get freed before we're
8456 * done setting it up.
8457 */
8458 atomic_inc(&dip->pending_bios);
8459
8460 status = __btrfs_submit_dio_bio(bio, inode, file_offset,
8461 async_submit);
8462 if (status) {
8463 bio_put(bio);
8464 atomic_dec(&dip->pending_bios);
8465 goto out_err;
8466 }
8467
8468 clone_offset += clone_len;
8469 start_sector += clone_len >> 9;
8470 file_offset += clone_len;
8471
8472 map_length = submit_len;
8473 ret = btrfs_map_block(fs_info, btrfs_op(orig_bio),
8474 start_sector << 9, &map_length, NULL, 0);
8475 if (ret)
8476 goto out_err;
8477 } while (submit_len > 0);
8478
8479 submit:
8480 status = __btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
8481 if (!status)
8482 return 0;
8483
8484 bio_put(bio);
8485 out_err:
8486 dip->errors = 1;
8487 /*
8488 * before atomic variable goto zero, we must
8489 * make sure dip->errors is perceived to be set.
8490 */
8491 smp_mb__before_atomic();
8492 if (atomic_dec_and_test(&dip->pending_bios))
8493 bio_io_error(dip->orig_bio);
8494
8495 /* bio_end_io() will handle error, so we needn't return it */
8496 return 0;
8497 }
8498
8499 static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
8500 loff_t file_offset)
8501 {
8502 struct btrfs_dio_private *dip = NULL;
8503 struct bio *bio = NULL;
8504 struct btrfs_io_bio *io_bio;
8505 bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
8506 int ret = 0;
8507
8508 bio = btrfs_bio_clone(dio_bio);
8509
8510 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8511 if (!dip) {
8512 ret = -ENOMEM;
8513 goto free_ordered;
8514 }
8515
8516 dip->private = dio_bio->bi_private;
8517 dip->inode = inode;
8518 dip->logical_offset = file_offset;
8519 dip->bytes = dio_bio->bi_iter.bi_size;
8520 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8521 bio->bi_private = dip;
8522 dip->orig_bio = bio;
8523 dip->dio_bio = dio_bio;
8524 atomic_set(&dip->pending_bios, 0);
8525 io_bio = btrfs_io_bio(bio);
8526 io_bio->logical = file_offset;
8527
8528 if (write) {
8529 bio->bi_end_io = btrfs_endio_direct_write;
8530 } else {
8531 bio->bi_end_io = btrfs_endio_direct_read;
8532 dip->subio_endio = btrfs_subio_endio_read;
8533 }
8534
8535 /*
8536 * Reset the range for unsubmitted ordered extents (to a 0 length range)
8537 * even if we fail to submit a bio, because in such case we do the
8538 * corresponding error handling below and it must not be done a second
8539 * time by btrfs_direct_IO().
8540 */
8541 if (write) {
8542 struct btrfs_dio_data *dio_data = current->journal_info;
8543
8544 dio_data->unsubmitted_oe_range_end = dip->logical_offset +
8545 dip->bytes;
8546 dio_data->unsubmitted_oe_range_start =
8547 dio_data->unsubmitted_oe_range_end;
8548 }
8549
8550 ret = btrfs_submit_direct_hook(dip);
8551 if (!ret)
8552 return;
8553
8554 if (io_bio->end_io)
8555 io_bio->end_io(io_bio, ret);
8556
8557 free_ordered:
8558 /*
8559 * If we arrived here it means either we failed to submit the dip
8560 * or we either failed to clone the dio_bio or failed to allocate the
8561 * dip. If we cloned the dio_bio and allocated the dip, we can just
8562 * call bio_endio against our io_bio so that we get proper resource
8563 * cleanup if we fail to submit the dip, otherwise, we must do the
8564 * same as btrfs_endio_direct_[write|read] because we can't call these
8565 * callbacks - they require an allocated dip and a clone of dio_bio.
8566 */
8567 if (bio && dip) {
8568 bio_io_error(bio);
8569 /*
8570 * The end io callbacks free our dip, do the final put on bio
8571 * and all the cleanup and final put for dio_bio (through
8572 * dio_end_io()).
8573 */
8574 dip = NULL;
8575 bio = NULL;
8576 } else {
8577 if (write)
8578 __endio_write_update_ordered(inode,
8579 file_offset,
8580 dio_bio->bi_iter.bi_size,
8581 false);
8582 else
8583 unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
8584 file_offset + dio_bio->bi_iter.bi_size - 1);
8585
8586 dio_bio->bi_status = BLK_STS_IOERR;
8587 /*
8588 * Releases and cleans up our dio_bio, no need to bio_put()
8589 * nor bio_endio()/bio_io_error() against dio_bio.
8590 */
8591 dio_end_io(dio_bio);
8592 }
8593 if (bio)
8594 bio_put(bio);
8595 kfree(dip);
8596 }
8597
8598 static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
8599 const struct iov_iter *iter, loff_t offset)
8600 {
8601 int seg;
8602 int i;
8603 unsigned int blocksize_mask = fs_info->sectorsize - 1;
8604 ssize_t retval = -EINVAL;
8605
8606 if (offset & blocksize_mask)
8607 goto out;
8608
8609 if (iov_iter_alignment(iter) & blocksize_mask)
8610 goto out;
8611
8612 /* If this is a write we don't need to check anymore */
8613 if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
8614 return 0;
8615 /*
8616 * Check to make sure we don't have duplicate iov_base's in this
8617 * iovec, if so return EINVAL, otherwise we'll get csum errors
8618 * when reading back.
8619 */
8620 for (seg = 0; seg < iter->nr_segs; seg++) {
8621 for (i = seg + 1; i < iter->nr_segs; i++) {
8622 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8623 goto out;
8624 }
8625 }
8626 retval = 0;
8627 out:
8628 return retval;
8629 }
8630
8631 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
8632 {
8633 struct file *file = iocb->ki_filp;
8634 struct inode *inode = file->f_mapping->host;
8635 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8636 struct btrfs_dio_data dio_data = { 0 };
8637 struct extent_changeset *data_reserved = NULL;
8638 loff_t offset = iocb->ki_pos;
8639 size_t count = 0;
8640 int flags = 0;
8641 bool wakeup = true;
8642 bool relock = false;
8643 ssize_t ret;
8644
8645 if (check_direct_IO(fs_info, iter, offset))
8646 return 0;
8647
8648 inode_dio_begin(inode);
8649
8650 /*
8651 * The generic stuff only does filemap_write_and_wait_range, which
8652 * isn't enough if we've written compressed pages to this area, so
8653 * we need to flush the dirty pages again to make absolutely sure
8654 * that any outstanding dirty pages are on disk.
8655 */
8656 count = iov_iter_count(iter);
8657 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8658 &BTRFS_I(inode)->runtime_flags))
8659 filemap_fdatawrite_range(inode->i_mapping, offset,
8660 offset + count - 1);
8661
8662 if (iov_iter_rw(iter) == WRITE) {
8663 /*
8664 * If the write DIO is beyond the EOF, we need update
8665 * the isize, but it is protected by i_mutex. So we can
8666 * not unlock the i_mutex at this case.
8667 */
8668 if (offset + count <= inode->i_size) {
8669 dio_data.overwrite = 1;
8670 inode_unlock(inode);
8671 relock = true;
8672 } else if (iocb->ki_flags & IOCB_NOWAIT) {
8673 ret = -EAGAIN;
8674 goto out;
8675 }
8676 ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
8677 offset, count);
8678 if (ret)
8679 goto out;
8680
8681 /*
8682 * We need to know how many extents we reserved so that we can
8683 * do the accounting properly if we go over the number we
8684 * originally calculated. Abuse current->journal_info for this.
8685 */
8686 dio_data.reserve = round_up(count,
8687 fs_info->sectorsize);
8688 dio_data.unsubmitted_oe_range_start = (u64)offset;
8689 dio_data.unsubmitted_oe_range_end = (u64)offset;
8690 current->journal_info = &dio_data;
8691 down_read(&BTRFS_I(inode)->dio_sem);
8692 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8693 &BTRFS_I(inode)->runtime_flags)) {
8694 inode_dio_end(inode);
8695 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8696 wakeup = false;
8697 }
8698
8699 ret = __blockdev_direct_IO(iocb, inode,
8700 fs_info->fs_devices->latest_bdev,
8701 iter, btrfs_get_blocks_direct, NULL,
8702 btrfs_submit_direct, flags);
8703 if (iov_iter_rw(iter) == WRITE) {
8704 up_read(&BTRFS_I(inode)->dio_sem);
8705 current->journal_info = NULL;
8706 if (ret < 0 && ret != -EIOCBQUEUED) {
8707 if (dio_data.reserve)
8708 btrfs_delalloc_release_space(inode, data_reserved,
8709 offset, dio_data.reserve);
8710 /*
8711 * On error we might have left some ordered extents
8712 * without submitting corresponding bios for them, so
8713 * cleanup them up to avoid other tasks getting them
8714 * and waiting for them to complete forever.
8715 */
8716 if (dio_data.unsubmitted_oe_range_start <
8717 dio_data.unsubmitted_oe_range_end)
8718 __endio_write_update_ordered(inode,
8719 dio_data.unsubmitted_oe_range_start,
8720 dio_data.unsubmitted_oe_range_end -
8721 dio_data.unsubmitted_oe_range_start,
8722 false);
8723 } else if (ret >= 0 && (size_t)ret < count)
8724 btrfs_delalloc_release_space(inode, data_reserved,
8725 offset, count - (size_t)ret);
8726 btrfs_delalloc_release_extents(BTRFS_I(inode), count);
8727 }
8728 out:
8729 if (wakeup)
8730 inode_dio_end(inode);
8731 if (relock)
8732 inode_lock(inode);
8733
8734 extent_changeset_free(data_reserved);
8735 return ret;
8736 }
8737
8738 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8739
8740 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8741 __u64 start, __u64 len)
8742 {
8743 int ret;
8744
8745 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8746 if (ret)
8747 return ret;
8748
8749 return extent_fiemap(inode, fieinfo, start, len);
8750 }
8751
8752 int btrfs_readpage(struct file *file, struct page *page)
8753 {
8754 struct extent_io_tree *tree;
8755 tree = &BTRFS_I(page->mapping->host)->io_tree;
8756 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8757 }
8758
8759 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8760 {
8761 struct inode *inode = page->mapping->host;
8762 int ret;
8763
8764 if (current->flags & PF_MEMALLOC) {
8765 redirty_page_for_writepage(wbc, page);
8766 unlock_page(page);
8767 return 0;
8768 }
8769
8770 /*
8771 * If we are under memory pressure we will call this directly from the
8772 * VM, we need to make sure we have the inode referenced for the ordered
8773 * extent. If not just return like we didn't do anything.
8774 */
8775 if (!igrab(inode)) {
8776 redirty_page_for_writepage(wbc, page);
8777 return AOP_WRITEPAGE_ACTIVATE;
8778 }
8779 ret = extent_write_full_page(page, wbc);
8780 btrfs_add_delayed_iput(inode);
8781 return ret;
8782 }
8783
8784 static int btrfs_writepages(struct address_space *mapping,
8785 struct writeback_control *wbc)
8786 {
8787 struct extent_io_tree *tree;
8788
8789 tree = &BTRFS_I(mapping->host)->io_tree;
8790 return extent_writepages(tree, mapping, wbc);
8791 }
8792
8793 static int
8794 btrfs_readpages(struct file *file, struct address_space *mapping,
8795 struct list_head *pages, unsigned nr_pages)
8796 {
8797 struct extent_io_tree *tree;
8798 tree = &BTRFS_I(mapping->host)->io_tree;
8799 return extent_readpages(tree, mapping, pages, nr_pages);
8800 }
8801 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8802 {
8803 struct extent_io_tree *tree;
8804 struct extent_map_tree *map;
8805 int ret;
8806
8807 tree = &BTRFS_I(page->mapping->host)->io_tree;
8808 map = &BTRFS_I(page->mapping->host)->extent_tree;
8809 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8810 if (ret == 1) {
8811 ClearPagePrivate(page);
8812 set_page_private(page, 0);
8813 put_page(page);
8814 }
8815 return ret;
8816 }
8817
8818 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8819 {
8820 if (PageWriteback(page) || PageDirty(page))
8821 return 0;
8822 return __btrfs_releasepage(page, gfp_flags);
8823 }
8824
8825 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8826 unsigned int length)
8827 {
8828 struct inode *inode = page->mapping->host;
8829 struct extent_io_tree *tree;
8830 struct btrfs_ordered_extent *ordered;
8831 struct extent_state *cached_state = NULL;
8832 u64 page_start = page_offset(page);
8833 u64 page_end = page_start + PAGE_SIZE - 1;
8834 u64 start;
8835 u64 end;
8836 int inode_evicting = inode->i_state & I_FREEING;
8837
8838 /*
8839 * we have the page locked, so new writeback can't start,
8840 * and the dirty bit won't be cleared while we are here.
8841 *
8842 * Wait for IO on this page so that we can safely clear
8843 * the PagePrivate2 bit and do ordered accounting
8844 */
8845 wait_on_page_writeback(page);
8846
8847 tree = &BTRFS_I(inode)->io_tree;
8848 if (offset) {
8849 btrfs_releasepage(page, GFP_NOFS);
8850 return;
8851 }
8852
8853 if (!inode_evicting)
8854 lock_extent_bits(tree, page_start, page_end, &cached_state);
8855 again:
8856 start = page_start;
8857 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
8858 page_end - start + 1);
8859 if (ordered) {
8860 end = min(page_end, ordered->file_offset + ordered->len - 1);
8861 /*
8862 * IO on this page will never be started, so we need
8863 * to account for any ordered extents now
8864 */
8865 if (!inode_evicting)
8866 clear_extent_bit(tree, start, end,
8867 EXTENT_DIRTY | EXTENT_DELALLOC |
8868 EXTENT_DELALLOC_NEW |
8869 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8870 EXTENT_DEFRAG, 1, 0, &cached_state);
8871 /*
8872 * whoever cleared the private bit is responsible
8873 * for the finish_ordered_io
8874 */
8875 if (TestClearPagePrivate2(page)) {
8876 struct btrfs_ordered_inode_tree *tree;
8877 u64 new_len;
8878
8879 tree = &BTRFS_I(inode)->ordered_tree;
8880
8881 spin_lock_irq(&tree->lock);
8882 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8883 new_len = start - ordered->file_offset;
8884 if (new_len < ordered->truncated_len)
8885 ordered->truncated_len = new_len;
8886 spin_unlock_irq(&tree->lock);
8887
8888 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8889 start,
8890 end - start + 1, 1))
8891 btrfs_finish_ordered_io(ordered);
8892 }
8893 btrfs_put_ordered_extent(ordered);
8894 if (!inode_evicting) {
8895 cached_state = NULL;
8896 lock_extent_bits(tree, start, end,
8897 &cached_state);
8898 }
8899
8900 start = end + 1;
8901 if (start < page_end)
8902 goto again;
8903 }
8904
8905 /*
8906 * Qgroup reserved space handler
8907 * Page here will be either
8908 * 1) Already written to disk
8909 * In this case, its reserved space is released from data rsv map
8910 * and will be freed by delayed_ref handler finally.
8911 * So even we call qgroup_free_data(), it won't decrease reserved
8912 * space.
8913 * 2) Not written to disk
8914 * This means the reserved space should be freed here. However,
8915 * if a truncate invalidates the page (by clearing PageDirty)
8916 * and the page is accounted for while allocating extent
8917 * in btrfs_check_data_free_space() we let delayed_ref to
8918 * free the entire extent.
8919 */
8920 if (PageDirty(page))
8921 btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
8922 if (!inode_evicting) {
8923 clear_extent_bit(tree, page_start, page_end,
8924 EXTENT_LOCKED | EXTENT_DIRTY |
8925 EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
8926 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
8927 &cached_state);
8928
8929 __btrfs_releasepage(page, GFP_NOFS);
8930 }
8931
8932 ClearPageChecked(page);
8933 if (PagePrivate(page)) {
8934 ClearPagePrivate(page);
8935 set_page_private(page, 0);
8936 put_page(page);
8937 }
8938 }
8939
8940 /*
8941 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8942 * called from a page fault handler when a page is first dirtied. Hence we must
8943 * be careful to check for EOF conditions here. We set the page up correctly
8944 * for a written page which means we get ENOSPC checking when writing into
8945 * holes and correct delalloc and unwritten extent mapping on filesystems that
8946 * support these features.
8947 *
8948 * We are not allowed to take the i_mutex here so we have to play games to
8949 * protect against truncate races as the page could now be beyond EOF. Because
8950 * vmtruncate() writes the inode size before removing pages, once we have the
8951 * page lock we can determine safely if the page is beyond EOF. If it is not
8952 * beyond EOF, then the page is guaranteed safe against truncation until we
8953 * unlock the page.
8954 */
8955 int btrfs_page_mkwrite(struct vm_fault *vmf)
8956 {
8957 struct page *page = vmf->page;
8958 struct inode *inode = file_inode(vmf->vma->vm_file);
8959 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
8960 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8961 struct btrfs_ordered_extent *ordered;
8962 struct extent_state *cached_state = NULL;
8963 struct extent_changeset *data_reserved = NULL;
8964 char *kaddr;
8965 unsigned long zero_start;
8966 loff_t size;
8967 int ret;
8968 int reserved = 0;
8969 u64 reserved_space;
8970 u64 page_start;
8971 u64 page_end;
8972 u64 end;
8973
8974 reserved_space = PAGE_SIZE;
8975
8976 sb_start_pagefault(inode->i_sb);
8977 page_start = page_offset(page);
8978 page_end = page_start + PAGE_SIZE - 1;
8979 end = page_end;
8980
8981 /*
8982 * Reserving delalloc space after obtaining the page lock can lead to
8983 * deadlock. For example, if a dirty page is locked by this function
8984 * and the call to btrfs_delalloc_reserve_space() ends up triggering
8985 * dirty page write out, then the btrfs_writepage() function could
8986 * end up waiting indefinitely to get a lock on the page currently
8987 * being processed by btrfs_page_mkwrite() function.
8988 */
8989 ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
8990 reserved_space);
8991 if (!ret) {
8992 ret = file_update_time(vmf->vma->vm_file);
8993 reserved = 1;
8994 }
8995 if (ret) {
8996 if (ret == -ENOMEM)
8997 ret = VM_FAULT_OOM;
8998 else /* -ENOSPC, -EIO, etc */
8999 ret = VM_FAULT_SIGBUS;
9000 if (reserved)
9001 goto out;
9002 goto out_noreserve;
9003 }
9004
9005 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
9006 again:
9007 lock_page(page);
9008 size = i_size_read(inode);
9009
9010 if ((page->mapping != inode->i_mapping) ||
9011 (page_start >= size)) {
9012 /* page got truncated out from underneath us */
9013 goto out_unlock;
9014 }
9015 wait_on_page_writeback(page);
9016
9017 lock_extent_bits(io_tree, page_start, page_end, &cached_state);
9018 set_page_extent_mapped(page);
9019
9020 /*
9021 * we can't set the delalloc bits if there are pending ordered
9022 * extents. Drop our locks and wait for them to finish
9023 */
9024 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
9025 PAGE_SIZE);
9026 if (ordered) {
9027 unlock_extent_cached(io_tree, page_start, page_end,
9028 &cached_state);
9029 unlock_page(page);
9030 btrfs_start_ordered_extent(inode, ordered, 1);
9031 btrfs_put_ordered_extent(ordered);
9032 goto again;
9033 }
9034
9035 if (page->index == ((size - 1) >> PAGE_SHIFT)) {
9036 reserved_space = round_up(size - page_start,
9037 fs_info->sectorsize);
9038 if (reserved_space < PAGE_SIZE) {
9039 end = page_start + reserved_space - 1;
9040 btrfs_delalloc_release_space(inode, data_reserved,
9041 page_start, PAGE_SIZE - reserved_space);
9042 }
9043 }
9044
9045 /*
9046 * page_mkwrite gets called when the page is firstly dirtied after it's
9047 * faulted in, but write(2) could also dirty a page and set delalloc
9048 * bits, thus in this case for space account reason, we still need to
9049 * clear any delalloc bits within this page range since we have to
9050 * reserve data&meta space before lock_page() (see above comments).
9051 */
9052 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
9053 EXTENT_DIRTY | EXTENT_DELALLOC |
9054 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
9055 0, 0, &cached_state);
9056
9057 ret = btrfs_set_extent_delalloc(inode, page_start, end, 0,
9058 &cached_state, 0);
9059 if (ret) {
9060 unlock_extent_cached(io_tree, page_start, page_end,
9061 &cached_state);
9062 ret = VM_FAULT_SIGBUS;
9063 goto out_unlock;
9064 }
9065 ret = 0;
9066
9067 /* page is wholly or partially inside EOF */
9068 if (page_start + PAGE_SIZE > size)
9069 zero_start = size & ~PAGE_MASK;
9070 else
9071 zero_start = PAGE_SIZE;
9072
9073 if (zero_start != PAGE_SIZE) {
9074 kaddr = kmap(page);
9075 memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
9076 flush_dcache_page(page);
9077 kunmap(page);
9078 }
9079 ClearPageChecked(page);
9080 set_page_dirty(page);
9081 SetPageUptodate(page);
9082
9083 BTRFS_I(inode)->last_trans = fs_info->generation;
9084 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
9085 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
9086
9087 unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
9088
9089 out_unlock:
9090 if (!ret) {
9091 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9092 sb_end_pagefault(inode->i_sb);
9093 extent_changeset_free(data_reserved);
9094 return VM_FAULT_LOCKED;
9095 }
9096 unlock_page(page);
9097 out:
9098 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
9099 btrfs_delalloc_release_space(inode, data_reserved, page_start,
9100 reserved_space);
9101 out_noreserve:
9102 sb_end_pagefault(inode->i_sb);
9103 extent_changeset_free(data_reserved);
9104 return ret;
9105 }
9106
9107 static int btrfs_truncate(struct inode *inode)
9108 {
9109 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9110 struct btrfs_root *root = BTRFS_I(inode)->root;
9111 struct btrfs_block_rsv *rsv;
9112 int ret = 0;
9113 int err = 0;
9114 struct btrfs_trans_handle *trans;
9115 u64 mask = fs_info->sectorsize - 1;
9116 u64 min_size = btrfs_calc_trunc_metadata_size(fs_info, 1);
9117
9118 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
9119 (u64)-1);
9120 if (ret)
9121 return ret;
9122
9123 /*
9124 * Yes ladies and gentlemen, this is indeed ugly. The fact is we have
9125 * 3 things going on here
9126 *
9127 * 1) We need to reserve space for our orphan item and the space to
9128 * delete our orphan item. Lord knows we don't want to have a dangling
9129 * orphan item because we didn't reserve space to remove it.
9130 *
9131 * 2) We need to reserve space to update our inode.
9132 *
9133 * 3) We need to have something to cache all the space that is going to
9134 * be free'd up by the truncate operation, but also have some slack
9135 * space reserved in case it uses space during the truncate (thank you
9136 * very much snapshotting).
9137 *
9138 * And we need these to all be separate. The fact is we can use a lot of
9139 * space doing the truncate, and we have no earthly idea how much space
9140 * we will use, so we need the truncate reservation to be separate so it
9141 * doesn't end up using space reserved for updating the inode or
9142 * removing the orphan item. We also need to be able to stop the
9143 * transaction and start a new one, which means we need to be able to
9144 * update the inode several times, and we have no idea of knowing how
9145 * many times that will be, so we can't just reserve 1 item for the
9146 * entirety of the operation, so that has to be done separately as well.
9147 * Then there is the orphan item, which does indeed need to be held on
9148 * to for the whole operation, and we need nobody to touch this reserved
9149 * space except the orphan code.
9150 *
9151 * So that leaves us with
9152 *
9153 * 1) root->orphan_block_rsv - for the orphan deletion.
9154 * 2) rsv - for the truncate reservation, which we will steal from the
9155 * transaction reservation.
9156 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
9157 * updating the inode.
9158 */
9159 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
9160 if (!rsv)
9161 return -ENOMEM;
9162 rsv->size = min_size;
9163 rsv->failfast = 1;
9164
9165 /*
9166 * 1 for the truncate slack space
9167 * 1 for updating the inode.
9168 */
9169 trans = btrfs_start_transaction(root, 2);
9170 if (IS_ERR(trans)) {
9171 err = PTR_ERR(trans);
9172 goto out;
9173 }
9174
9175 /* Migrate the slack space for the truncate to our reserve */
9176 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
9177 min_size, 0);
9178 BUG_ON(ret);
9179
9180 /*
9181 * So if we truncate and then write and fsync we normally would just
9182 * write the extents that changed, which is a problem if we need to
9183 * first truncate that entire inode. So set this flag so we write out
9184 * all of the extents in the inode to the sync log so we're completely
9185 * safe.
9186 */
9187 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
9188 trans->block_rsv = rsv;
9189
9190 while (1) {
9191 ret = btrfs_truncate_inode_items(trans, root, inode,
9192 inode->i_size,
9193 BTRFS_EXTENT_DATA_KEY);
9194 trans->block_rsv = &fs_info->trans_block_rsv;
9195 if (ret != -ENOSPC && ret != -EAGAIN) {
9196 err = ret;
9197 break;
9198 }
9199
9200 ret = btrfs_update_inode(trans, root, inode);
9201 if (ret) {
9202 err = ret;
9203 break;
9204 }
9205
9206 btrfs_end_transaction(trans);
9207 btrfs_btree_balance_dirty(fs_info);
9208
9209 trans = btrfs_start_transaction(root, 2);
9210 if (IS_ERR(trans)) {
9211 ret = err = PTR_ERR(trans);
9212 trans = NULL;
9213 break;
9214 }
9215
9216 btrfs_block_rsv_release(fs_info, rsv, -1);
9217 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
9218 rsv, min_size, 0);
9219 BUG_ON(ret); /* shouldn't happen */
9220 trans->block_rsv = rsv;
9221 }
9222
9223 /*
9224 * We can't call btrfs_truncate_block inside a trans handle as we could
9225 * deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
9226 * we've truncated everything except the last little bit, and can do
9227 * btrfs_truncate_block and then update the disk_i_size.
9228 */
9229 if (ret == NEED_TRUNCATE_BLOCK) {
9230 btrfs_end_transaction(trans);
9231 btrfs_btree_balance_dirty(fs_info);
9232
9233 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
9234 if (ret)
9235 goto out;
9236 trans = btrfs_start_transaction(root, 1);
9237 if (IS_ERR(trans)) {
9238 ret = PTR_ERR(trans);
9239 goto out;
9240 }
9241 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
9242 }
9243
9244 if (ret == 0 && inode->i_nlink > 0) {
9245 trans->block_rsv = root->orphan_block_rsv;
9246 ret = btrfs_orphan_del(trans, BTRFS_I(inode));
9247 if (ret)
9248 err = ret;
9249 }
9250
9251 if (trans) {
9252 trans->block_rsv = &fs_info->trans_block_rsv;
9253 ret = btrfs_update_inode(trans, root, inode);
9254 if (ret && !err)
9255 err = ret;
9256
9257 ret = btrfs_end_transaction(trans);
9258 btrfs_btree_balance_dirty(fs_info);
9259 }
9260 out:
9261 btrfs_free_block_rsv(fs_info, rsv);
9262
9263 if (ret && !err)
9264 err = ret;
9265
9266 return err;
9267 }
9268
9269 /*
9270 * create a new subvolume directory/inode (helper for the ioctl).
9271 */
9272 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
9273 struct btrfs_root *new_root,
9274 struct btrfs_root *parent_root,
9275 u64 new_dirid)
9276 {
9277 struct inode *inode;
9278 int err;
9279 u64 index = 0;
9280
9281 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
9282 new_dirid, new_dirid,
9283 S_IFDIR | (~current_umask() & S_IRWXUGO),
9284 &index);
9285 if (IS_ERR(inode))
9286 return PTR_ERR(inode);
9287 inode->i_op = &btrfs_dir_inode_operations;
9288 inode->i_fop = &btrfs_dir_file_operations;
9289
9290 set_nlink(inode, 1);
9291 btrfs_i_size_write(BTRFS_I(inode), 0);
9292 unlock_new_inode(inode);
9293
9294 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
9295 if (err)
9296 btrfs_err(new_root->fs_info,
9297 "error inheriting subvolume %llu properties: %d",
9298 new_root->root_key.objectid, err);
9299
9300 err = btrfs_update_inode(trans, new_root, inode);
9301
9302 iput(inode);
9303 return err;
9304 }
9305
9306 struct inode *btrfs_alloc_inode(struct super_block *sb)
9307 {
9308 struct btrfs_fs_info *fs_info = btrfs_sb(sb);
9309 struct btrfs_inode *ei;
9310 struct inode *inode;
9311
9312 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
9313 if (!ei)
9314 return NULL;
9315
9316 ei->root = NULL;
9317 ei->generation = 0;
9318 ei->last_trans = 0;
9319 ei->last_sub_trans = 0;
9320 ei->logged_trans = 0;
9321 ei->delalloc_bytes = 0;
9322 ei->new_delalloc_bytes = 0;
9323 ei->defrag_bytes = 0;
9324 ei->disk_i_size = 0;
9325 ei->flags = 0;
9326 ei->csum_bytes = 0;
9327 ei->index_cnt = (u64)-1;
9328 ei->dir_index = 0;
9329 ei->last_unlink_trans = 0;
9330 ei->last_log_commit = 0;
9331 ei->delayed_iput_count = 0;
9332
9333 spin_lock_init(&ei->lock);
9334 ei->outstanding_extents = 0;
9335 if (sb->s_magic != BTRFS_TEST_MAGIC)
9336 btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
9337 BTRFS_BLOCK_RSV_DELALLOC);
9338 ei->runtime_flags = 0;
9339 ei->prop_compress = BTRFS_COMPRESS_NONE;
9340 ei->defrag_compress = BTRFS_COMPRESS_NONE;
9341
9342 ei->delayed_node = NULL;
9343
9344 ei->i_otime.tv_sec = 0;
9345 ei->i_otime.tv_nsec = 0;
9346
9347 inode = &ei->vfs_inode;
9348 extent_map_tree_init(&ei->extent_tree);
9349 extent_io_tree_init(&ei->io_tree, inode);
9350 extent_io_tree_init(&ei->io_failure_tree, inode);
9351 ei->io_tree.track_uptodate = 1;
9352 ei->io_failure_tree.track_uptodate = 1;
9353 atomic_set(&ei->sync_writers, 0);
9354 mutex_init(&ei->log_mutex);
9355 mutex_init(&ei->delalloc_mutex);
9356 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
9357 INIT_LIST_HEAD(&ei->delalloc_inodes);
9358 INIT_LIST_HEAD(&ei->delayed_iput);
9359 RB_CLEAR_NODE(&ei->rb_node);
9360 init_rwsem(&ei->dio_sem);
9361
9362 return inode;
9363 }
9364
9365 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
9366 void btrfs_test_destroy_inode(struct inode *inode)
9367 {
9368 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9369 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9370 }
9371 #endif
9372
9373 static void btrfs_i_callback(struct rcu_head *head)
9374 {
9375 struct inode *inode = container_of(head, struct inode, i_rcu);
9376 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
9377 }
9378
9379 void btrfs_destroy_inode(struct inode *inode)
9380 {
9381 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
9382 struct btrfs_ordered_extent *ordered;
9383 struct btrfs_root *root = BTRFS_I(inode)->root;
9384
9385 WARN_ON(!hlist_empty(&inode->i_dentry));
9386 WARN_ON(inode->i_data.nrpages);
9387 WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
9388 WARN_ON(BTRFS_I(inode)->block_rsv.size);
9389 WARN_ON(BTRFS_I(inode)->outstanding_extents);
9390 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
9391 WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
9392 WARN_ON(BTRFS_I(inode)->csum_bytes);
9393 WARN_ON(BTRFS_I(inode)->defrag_bytes);
9394
9395 /*
9396 * This can happen where we create an inode, but somebody else also
9397 * created the same inode and we need to destroy the one we already
9398 * created.
9399 */
9400 if (!root)
9401 goto free;
9402
9403 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
9404 &BTRFS_I(inode)->runtime_flags)) {
9405 btrfs_info(fs_info, "inode %llu still on the orphan list",
9406 btrfs_ino(BTRFS_I(inode)));
9407 atomic_dec(&root->orphan_inodes);
9408 }
9409
9410 while (1) {
9411 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
9412 if (!ordered)
9413 break;
9414 else {
9415 btrfs_err(fs_info,
9416 "found ordered extent %llu %llu on inode cleanup",
9417 ordered->file_offset, ordered->len);
9418 btrfs_remove_ordered_extent(inode, ordered);
9419 btrfs_put_ordered_extent(ordered);
9420 btrfs_put_ordered_extent(ordered);
9421 }
9422 }
9423 btrfs_qgroup_check_reserved_leak(inode);
9424 inode_tree_del(inode);
9425 btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
9426 free:
9427 call_rcu(&inode->i_rcu, btrfs_i_callback);
9428 }
9429
9430 int btrfs_drop_inode(struct inode *inode)
9431 {
9432 struct btrfs_root *root = BTRFS_I(inode)->root;
9433
9434 if (root == NULL)
9435 return 1;
9436
9437 /* the snap/subvol tree is on deleting */
9438 if (btrfs_root_refs(&root->root_item) == 0)
9439 return 1;
9440 else
9441 return generic_drop_inode(inode);
9442 }
9443
9444 static void init_once(void *foo)
9445 {
9446 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
9447
9448 inode_init_once(&ei->vfs_inode);
9449 }
9450
9451 void btrfs_destroy_cachep(void)
9452 {
9453 /*
9454 * Make sure all delayed rcu free inodes are flushed before we
9455 * destroy cache.
9456 */
9457 rcu_barrier();
9458 kmem_cache_destroy(btrfs_inode_cachep);
9459 kmem_cache_destroy(btrfs_trans_handle_cachep);
9460 kmem_cache_destroy(btrfs_path_cachep);
9461 kmem_cache_destroy(btrfs_free_space_cachep);
9462 }
9463
9464 int __init btrfs_init_cachep(void)
9465 {
9466 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
9467 sizeof(struct btrfs_inode), 0,
9468 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
9469 init_once);
9470 if (!btrfs_inode_cachep)
9471 goto fail;
9472
9473 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
9474 sizeof(struct btrfs_trans_handle), 0,
9475 SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
9476 if (!btrfs_trans_handle_cachep)
9477 goto fail;
9478
9479 btrfs_path_cachep = kmem_cache_create("btrfs_path",
9480 sizeof(struct btrfs_path), 0,
9481 SLAB_MEM_SPREAD, NULL);
9482 if (!btrfs_path_cachep)
9483 goto fail;
9484
9485 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
9486 sizeof(struct btrfs_free_space), 0,
9487 SLAB_MEM_SPREAD, NULL);
9488 if (!btrfs_free_space_cachep)
9489 goto fail;
9490
9491 return 0;
9492 fail:
9493 btrfs_destroy_cachep();
9494 return -ENOMEM;
9495 }
9496
9497 static int btrfs_getattr(const struct path *path, struct kstat *stat,
9498 u32 request_mask, unsigned int flags)
9499 {
9500 u64 delalloc_bytes;
9501 struct inode *inode = d_inode(path->dentry);
9502 u32 blocksize = inode->i_sb->s_blocksize;
9503 u32 bi_flags = BTRFS_I(inode)->flags;
9504
9505 stat->result_mask |= STATX_BTIME;
9506 stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
9507 stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
9508 if (bi_flags & BTRFS_INODE_APPEND)
9509 stat->attributes |= STATX_ATTR_APPEND;
9510 if (bi_flags & BTRFS_INODE_COMPRESS)
9511 stat->attributes |= STATX_ATTR_COMPRESSED;
9512 if (bi_flags & BTRFS_INODE_IMMUTABLE)
9513 stat->attributes |= STATX_ATTR_IMMUTABLE;
9514 if (bi_flags & BTRFS_INODE_NODUMP)
9515 stat->attributes |= STATX_ATTR_NODUMP;
9516
9517 stat->attributes_mask |= (STATX_ATTR_APPEND |
9518 STATX_ATTR_COMPRESSED |
9519 STATX_ATTR_IMMUTABLE |
9520 STATX_ATTR_NODUMP);
9521
9522 generic_fillattr(inode, stat);
9523 stat->dev = BTRFS_I(inode)->root->anon_dev;
9524
9525 spin_lock(&BTRFS_I(inode)->lock);
9526 delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
9527 spin_unlock(&BTRFS_I(inode)->lock);
9528 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9529 ALIGN(delalloc_bytes, blocksize)) >> 9;
9530 return 0;
9531 }
9532
9533 static int btrfs_rename_exchange(struct inode *old_dir,
9534 struct dentry *old_dentry,
9535 struct inode *new_dir,
9536 struct dentry *new_dentry)
9537 {
9538 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9539 struct btrfs_trans_handle *trans;
9540 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9541 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9542 struct inode *new_inode = new_dentry->d_inode;
9543 struct inode *old_inode = old_dentry->d_inode;
9544 struct timespec ctime = current_time(old_inode);
9545 struct dentry *parent;
9546 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9547 u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
9548 u64 old_idx = 0;
9549 u64 new_idx = 0;
9550 u64 root_objectid;
9551 int ret;
9552 bool root_log_pinned = false;
9553 bool dest_log_pinned = false;
9554
9555 /* we only allow rename subvolume link between subvolumes */
9556 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9557 return -EXDEV;
9558
9559 /* close the race window with snapshot create/destroy ioctl */
9560 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9561 down_read(&fs_info->subvol_sem);
9562 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9563 down_read(&fs_info->subvol_sem);
9564
9565 /*
9566 * We want to reserve the absolute worst case amount of items. So if
9567 * both inodes are subvols and we need to unlink them then that would
9568 * require 4 item modifications, but if they are both normal inodes it
9569 * would require 5 item modifications, so we'll assume their normal
9570 * inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
9571 * should cover the worst case number of items we'll modify.
9572 */
9573 trans = btrfs_start_transaction(root, 12);
9574 if (IS_ERR(trans)) {
9575 ret = PTR_ERR(trans);
9576 goto out_notrans;
9577 }
9578
9579 /*
9580 * We need to find a free sequence number both in the source and
9581 * in the destination directory for the exchange.
9582 */
9583 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
9584 if (ret)
9585 goto out_fail;
9586 ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
9587 if (ret)
9588 goto out_fail;
9589
9590 BTRFS_I(old_inode)->dir_index = 0ULL;
9591 BTRFS_I(new_inode)->dir_index = 0ULL;
9592
9593 /* Reference for the source. */
9594 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9595 /* force full log commit if subvolume involved. */
9596 btrfs_set_log_full_commit(fs_info, trans);
9597 } else {
9598 btrfs_pin_log_trans(root);
9599 root_log_pinned = true;
9600 ret = btrfs_insert_inode_ref(trans, dest,
9601 new_dentry->d_name.name,
9602 new_dentry->d_name.len,
9603 old_ino,
9604 btrfs_ino(BTRFS_I(new_dir)),
9605 old_idx);
9606 if (ret)
9607 goto out_fail;
9608 }
9609
9610 /* And now for the dest. */
9611 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9612 /* force full log commit if subvolume involved. */
9613 btrfs_set_log_full_commit(fs_info, trans);
9614 } else {
9615 btrfs_pin_log_trans(dest);
9616 dest_log_pinned = true;
9617 ret = btrfs_insert_inode_ref(trans, root,
9618 old_dentry->d_name.name,
9619 old_dentry->d_name.len,
9620 new_ino,
9621 btrfs_ino(BTRFS_I(old_dir)),
9622 new_idx);
9623 if (ret)
9624 goto out_fail;
9625 }
9626
9627 /* Update inode version and ctime/mtime. */
9628 inode_inc_iversion(old_dir);
9629 inode_inc_iversion(new_dir);
9630 inode_inc_iversion(old_inode);
9631 inode_inc_iversion(new_inode);
9632 old_dir->i_ctime = old_dir->i_mtime = ctime;
9633 new_dir->i_ctime = new_dir->i_mtime = ctime;
9634 old_inode->i_ctime = ctime;
9635 new_inode->i_ctime = ctime;
9636
9637 if (old_dentry->d_parent != new_dentry->d_parent) {
9638 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9639 BTRFS_I(old_inode), 1);
9640 btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
9641 BTRFS_I(new_inode), 1);
9642 }
9643
9644 /* src is a subvolume */
9645 if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
9646 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9647 ret = btrfs_unlink_subvol(trans, root, old_dir,
9648 root_objectid,
9649 old_dentry->d_name.name,
9650 old_dentry->d_name.len);
9651 } else { /* src is an inode */
9652 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9653 BTRFS_I(old_dentry->d_inode),
9654 old_dentry->d_name.name,
9655 old_dentry->d_name.len);
9656 if (!ret)
9657 ret = btrfs_update_inode(trans, root, old_inode);
9658 }
9659 if (ret) {
9660 btrfs_abort_transaction(trans, ret);
9661 goto out_fail;
9662 }
9663
9664 /* dest is a subvolume */
9665 if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
9666 root_objectid = BTRFS_I(new_inode)->root->root_key.objectid;
9667 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9668 root_objectid,
9669 new_dentry->d_name.name,
9670 new_dentry->d_name.len);
9671 } else { /* dest is an inode */
9672 ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9673 BTRFS_I(new_dentry->d_inode),
9674 new_dentry->d_name.name,
9675 new_dentry->d_name.len);
9676 if (!ret)
9677 ret = btrfs_update_inode(trans, dest, new_inode);
9678 }
9679 if (ret) {
9680 btrfs_abort_transaction(trans, ret);
9681 goto out_fail;
9682 }
9683
9684 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9685 new_dentry->d_name.name,
9686 new_dentry->d_name.len, 0, old_idx);
9687 if (ret) {
9688 btrfs_abort_transaction(trans, ret);
9689 goto out_fail;
9690 }
9691
9692 ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
9693 old_dentry->d_name.name,
9694 old_dentry->d_name.len, 0, new_idx);
9695 if (ret) {
9696 btrfs_abort_transaction(trans, ret);
9697 goto out_fail;
9698 }
9699
9700 if (old_inode->i_nlink == 1)
9701 BTRFS_I(old_inode)->dir_index = old_idx;
9702 if (new_inode->i_nlink == 1)
9703 BTRFS_I(new_inode)->dir_index = new_idx;
9704
9705 if (root_log_pinned) {
9706 parent = new_dentry->d_parent;
9707 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9708 parent);
9709 btrfs_end_log_trans(root);
9710 root_log_pinned = false;
9711 }
9712 if (dest_log_pinned) {
9713 parent = old_dentry->d_parent;
9714 btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
9715 parent);
9716 btrfs_end_log_trans(dest);
9717 dest_log_pinned = false;
9718 }
9719 out_fail:
9720 /*
9721 * If we have pinned a log and an error happened, we unpin tasks
9722 * trying to sync the log and force them to fallback to a transaction
9723 * commit if the log currently contains any of the inodes involved in
9724 * this rename operation (to ensure we do not persist a log with an
9725 * inconsistent state for any of these inodes or leading to any
9726 * inconsistencies when replayed). If the transaction was aborted, the
9727 * abortion reason is propagated to userspace when attempting to commit
9728 * the transaction. If the log does not contain any of these inodes, we
9729 * allow the tasks to sync it.
9730 */
9731 if (ret && (root_log_pinned || dest_log_pinned)) {
9732 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
9733 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
9734 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
9735 (new_inode &&
9736 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
9737 btrfs_set_log_full_commit(fs_info, trans);
9738
9739 if (root_log_pinned) {
9740 btrfs_end_log_trans(root);
9741 root_log_pinned = false;
9742 }
9743 if (dest_log_pinned) {
9744 btrfs_end_log_trans(dest);
9745 dest_log_pinned = false;
9746 }
9747 }
9748 ret = btrfs_end_transaction(trans);
9749 out_notrans:
9750 if (new_ino == BTRFS_FIRST_FREE_OBJECTID)
9751 up_read(&fs_info->subvol_sem);
9752 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9753 up_read(&fs_info->subvol_sem);
9754
9755 return ret;
9756 }
9757
9758 static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
9759 struct btrfs_root *root,
9760 struct inode *dir,
9761 struct dentry *dentry)
9762 {
9763 int ret;
9764 struct inode *inode;
9765 u64 objectid;
9766 u64 index;
9767
9768 ret = btrfs_find_free_ino(root, &objectid);
9769 if (ret)
9770 return ret;
9771
9772 inode = btrfs_new_inode(trans, root, dir,
9773 dentry->d_name.name,
9774 dentry->d_name.len,
9775 btrfs_ino(BTRFS_I(dir)),
9776 objectid,
9777 S_IFCHR | WHITEOUT_MODE,
9778 &index);
9779
9780 if (IS_ERR(inode)) {
9781 ret = PTR_ERR(inode);
9782 return ret;
9783 }
9784
9785 inode->i_op = &btrfs_special_inode_operations;
9786 init_special_inode(inode, inode->i_mode,
9787 WHITEOUT_DEV);
9788
9789 ret = btrfs_init_inode_security(trans, inode, dir,
9790 &dentry->d_name);
9791 if (ret)
9792 goto out;
9793
9794 ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
9795 BTRFS_I(inode), 0, index);
9796 if (ret)
9797 goto out;
9798
9799 ret = btrfs_update_inode(trans, root, inode);
9800 out:
9801 unlock_new_inode(inode);
9802 if (ret)
9803 inode_dec_link_count(inode);
9804 iput(inode);
9805
9806 return ret;
9807 }
9808
9809 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9810 struct inode *new_dir, struct dentry *new_dentry,
9811 unsigned int flags)
9812 {
9813 struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
9814 struct btrfs_trans_handle *trans;
9815 unsigned int trans_num_items;
9816 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9817 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9818 struct inode *new_inode = d_inode(new_dentry);
9819 struct inode *old_inode = d_inode(old_dentry);
9820 u64 index = 0;
9821 u64 root_objectid;
9822 int ret;
9823 u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
9824 bool log_pinned = false;
9825
9826 if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9827 return -EPERM;
9828
9829 /* we only allow rename subvolume link between subvolumes */
9830 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9831 return -EXDEV;
9832
9833 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9834 (new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
9835 return -ENOTEMPTY;
9836
9837 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9838 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9839 return -ENOTEMPTY;
9840
9841
9842 /* check for collisions, even if the name isn't there */
9843 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9844 new_dentry->d_name.name,
9845 new_dentry->d_name.len);
9846
9847 if (ret) {
9848 if (ret == -EEXIST) {
9849 /* we shouldn't get
9850 * eexist without a new_inode */
9851 if (WARN_ON(!new_inode)) {
9852 return ret;
9853 }
9854 } else {
9855 /* maybe -EOVERFLOW */
9856 return ret;
9857 }
9858 }
9859 ret = 0;
9860
9861 /*
9862 * we're using rename to replace one file with another. Start IO on it
9863 * now so we don't add too much work to the end of the transaction
9864 */
9865 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9866 filemap_flush(old_inode->i_mapping);
9867
9868 /* close the racy window with snapshot create/destroy ioctl */
9869 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9870 down_read(&fs_info->subvol_sem);
9871 /*
9872 * We want to reserve the absolute worst case amount of items. So if
9873 * both inodes are subvols and we need to unlink them then that would
9874 * require 4 item modifications, but if they are both normal inodes it
9875 * would require 5 item modifications, so we'll assume they are normal
9876 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9877 * should cover the worst case number of items we'll modify.
9878 * If our rename has the whiteout flag, we need more 5 units for the
9879 * new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
9880 * when selinux is enabled).
9881 */
9882 trans_num_items = 11;
9883 if (flags & RENAME_WHITEOUT)
9884 trans_num_items += 5;
9885 trans = btrfs_start_transaction(root, trans_num_items);
9886 if (IS_ERR(trans)) {
9887 ret = PTR_ERR(trans);
9888 goto out_notrans;
9889 }
9890
9891 if (dest != root)
9892 btrfs_record_root_in_trans(trans, dest);
9893
9894 ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
9895 if (ret)
9896 goto out_fail;
9897
9898 BTRFS_I(old_inode)->dir_index = 0ULL;
9899 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9900 /* force full log commit if subvolume involved. */
9901 btrfs_set_log_full_commit(fs_info, trans);
9902 } else {
9903 btrfs_pin_log_trans(root);
9904 log_pinned = true;
9905 ret = btrfs_insert_inode_ref(trans, dest,
9906 new_dentry->d_name.name,
9907 new_dentry->d_name.len,
9908 old_ino,
9909 btrfs_ino(BTRFS_I(new_dir)), index);
9910 if (ret)
9911 goto out_fail;
9912 }
9913
9914 inode_inc_iversion(old_dir);
9915 inode_inc_iversion(new_dir);
9916 inode_inc_iversion(old_inode);
9917 old_dir->i_ctime = old_dir->i_mtime =
9918 new_dir->i_ctime = new_dir->i_mtime =
9919 old_inode->i_ctime = current_time(old_dir);
9920
9921 if (old_dentry->d_parent != new_dentry->d_parent)
9922 btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
9923 BTRFS_I(old_inode), 1);
9924
9925 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9926 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9927 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9928 old_dentry->d_name.name,
9929 old_dentry->d_name.len);
9930 } else {
9931 ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
9932 BTRFS_I(d_inode(old_dentry)),
9933 old_dentry->d_name.name,
9934 old_dentry->d_name.len);
9935 if (!ret)
9936 ret = btrfs_update_inode(trans, root, old_inode);
9937 }
9938 if (ret) {
9939 btrfs_abort_transaction(trans, ret);
9940 goto out_fail;
9941 }
9942
9943 if (new_inode) {
9944 inode_inc_iversion(new_inode);
9945 new_inode->i_ctime = current_time(new_inode);
9946 if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
9947 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9948 root_objectid = BTRFS_I(new_inode)->location.objectid;
9949 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9950 root_objectid,
9951 new_dentry->d_name.name,
9952 new_dentry->d_name.len);
9953 BUG_ON(new_inode->i_nlink == 0);
9954 } else {
9955 ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
9956 BTRFS_I(d_inode(new_dentry)),
9957 new_dentry->d_name.name,
9958 new_dentry->d_name.len);
9959 }
9960 if (!ret && new_inode->i_nlink == 0)
9961 ret = btrfs_orphan_add(trans,
9962 BTRFS_I(d_inode(new_dentry)));
9963 if (ret) {
9964 btrfs_abort_transaction(trans, ret);
9965 goto out_fail;
9966 }
9967 }
9968
9969 ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
9970 new_dentry->d_name.name,
9971 new_dentry->d_name.len, 0, index);
9972 if (ret) {
9973 btrfs_abort_transaction(trans, ret);
9974 goto out_fail;
9975 }
9976
9977 if (old_inode->i_nlink == 1)
9978 BTRFS_I(old_inode)->dir_index = index;
9979
9980 if (log_pinned) {
9981 struct dentry *parent = new_dentry->d_parent;
9982
9983 btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
9984 parent);
9985 btrfs_end_log_trans(root);
9986 log_pinned = false;
9987 }
9988
9989 if (flags & RENAME_WHITEOUT) {
9990 ret = btrfs_whiteout_for_rename(trans, root, old_dir,
9991 old_dentry);
9992
9993 if (ret) {
9994 btrfs_abort_transaction(trans, ret);
9995 goto out_fail;
9996 }
9997 }
9998 out_fail:
9999 /*
10000 * If we have pinned the log and an error happened, we unpin tasks
10001 * trying to sync the log and force them to fallback to a transaction
10002 * commit if the log currently contains any of the inodes involved in
10003 * this rename operation (to ensure we do not persist a log with an
10004 * inconsistent state for any of these inodes or leading to any
10005 * inconsistencies when replayed). If the transaction was aborted, the
10006 * abortion reason is propagated to userspace when attempting to commit
10007 * the transaction. If the log does not contain any of these inodes, we
10008 * allow the tasks to sync it.
10009 */
10010 if (ret && log_pinned) {
10011 if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
10012 btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
10013 btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
10014 (new_inode &&
10015 btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
10016 btrfs_set_log_full_commit(fs_info, trans);
10017
10018 btrfs_end_log_trans(root);
10019 log_pinned = false;
10020 }
10021 btrfs_end_transaction(trans);
10022 out_notrans:
10023 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
10024 up_read(&fs_info->subvol_sem);
10025
10026 return ret;
10027 }
10028
10029 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
10030 struct inode *new_dir, struct dentry *new_dentry,
10031 unsigned int flags)
10032 {
10033 if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
10034 return -EINVAL;
10035
10036 if (flags & RENAME_EXCHANGE)
10037 return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
10038 new_dentry);
10039
10040 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
10041 }
10042
10043 static void btrfs_run_delalloc_work(struct btrfs_work *work)
10044 {
10045 struct btrfs_delalloc_work *delalloc_work;
10046 struct inode *inode;
10047
10048 delalloc_work = container_of(work, struct btrfs_delalloc_work,
10049 work);
10050 inode = delalloc_work->inode;
10051 filemap_flush(inode->i_mapping);
10052 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
10053 &BTRFS_I(inode)->runtime_flags))
10054 filemap_flush(inode->i_mapping);
10055
10056 if (delalloc_work->delay_iput)
10057 btrfs_add_delayed_iput(inode);
10058 else
10059 iput(inode);
10060 complete(&delalloc_work->completion);
10061 }
10062
10063 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
10064 int delay_iput)
10065 {
10066 struct btrfs_delalloc_work *work;
10067
10068 work = kmalloc(sizeof(*work), GFP_NOFS);
10069 if (!work)
10070 return NULL;
10071
10072 init_completion(&work->completion);
10073 INIT_LIST_HEAD(&work->list);
10074 work->inode = inode;
10075 work->delay_iput = delay_iput;
10076 WARN_ON_ONCE(!inode);
10077 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
10078 btrfs_run_delalloc_work, NULL, NULL);
10079
10080 return work;
10081 }
10082
10083 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
10084 {
10085 wait_for_completion(&work->completion);
10086 kfree(work);
10087 }
10088
10089 /*
10090 * some fairly slow code that needs optimization. This walks the list
10091 * of all the inodes with pending delalloc and forces them to disk.
10092 */
10093 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
10094 int nr)
10095 {
10096 struct btrfs_inode *binode;
10097 struct inode *inode;
10098 struct btrfs_delalloc_work *work, *next;
10099 struct list_head works;
10100 struct list_head splice;
10101 int ret = 0;
10102
10103 INIT_LIST_HEAD(&works);
10104 INIT_LIST_HEAD(&splice);
10105
10106 mutex_lock(&root->delalloc_mutex);
10107 spin_lock(&root->delalloc_lock);
10108 list_splice_init(&root->delalloc_inodes, &splice);
10109 while (!list_empty(&splice)) {
10110 binode = list_entry(splice.next, struct btrfs_inode,
10111 delalloc_inodes);
10112
10113 list_move_tail(&binode->delalloc_inodes,
10114 &root->delalloc_inodes);
10115 inode = igrab(&binode->vfs_inode);
10116 if (!inode) {
10117 cond_resched_lock(&root->delalloc_lock);
10118 continue;
10119 }
10120 spin_unlock(&root->delalloc_lock);
10121
10122 work = btrfs_alloc_delalloc_work(inode, delay_iput);
10123 if (!work) {
10124 if (delay_iput)
10125 btrfs_add_delayed_iput(inode);
10126 else
10127 iput(inode);
10128 ret = -ENOMEM;
10129 goto out;
10130 }
10131 list_add_tail(&work->list, &works);
10132 btrfs_queue_work(root->fs_info->flush_workers,
10133 &work->work);
10134 ret++;
10135 if (nr != -1 && ret >= nr)
10136 goto out;
10137 cond_resched();
10138 spin_lock(&root->delalloc_lock);
10139 }
10140 spin_unlock(&root->delalloc_lock);
10141
10142 out:
10143 list_for_each_entry_safe(work, next, &works, list) {
10144 list_del_init(&work->list);
10145 btrfs_wait_and_free_delalloc_work(work);
10146 }
10147
10148 if (!list_empty_careful(&splice)) {
10149 spin_lock(&root->delalloc_lock);
10150 list_splice_tail(&splice, &root->delalloc_inodes);
10151 spin_unlock(&root->delalloc_lock);
10152 }
10153 mutex_unlock(&root->delalloc_mutex);
10154 return ret;
10155 }
10156
10157 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
10158 {
10159 struct btrfs_fs_info *fs_info = root->fs_info;
10160 int ret;
10161
10162 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10163 return -EROFS;
10164
10165 ret = __start_delalloc_inodes(root, delay_iput, -1);
10166 if (ret > 0)
10167 ret = 0;
10168 return ret;
10169 }
10170
10171 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
10172 int nr)
10173 {
10174 struct btrfs_root *root;
10175 struct list_head splice;
10176 int ret;
10177
10178 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
10179 return -EROFS;
10180
10181 INIT_LIST_HEAD(&splice);
10182
10183 mutex_lock(&fs_info->delalloc_root_mutex);
10184 spin_lock(&fs_info->delalloc_root_lock);
10185 list_splice_init(&fs_info->delalloc_roots, &splice);
10186 while (!list_empty(&splice) && nr) {
10187 root = list_first_entry(&splice, struct btrfs_root,
10188 delalloc_root);
10189 root = btrfs_grab_fs_root(root);
10190 BUG_ON(!root);
10191 list_move_tail(&root->delalloc_root,
10192 &fs_info->delalloc_roots);
10193 spin_unlock(&fs_info->delalloc_root_lock);
10194
10195 ret = __start_delalloc_inodes(root, delay_iput, nr);
10196 btrfs_put_fs_root(root);
10197 if (ret < 0)
10198 goto out;
10199
10200 if (nr != -1) {
10201 nr -= ret;
10202 WARN_ON(nr < 0);
10203 }
10204 spin_lock(&fs_info->delalloc_root_lock);
10205 }
10206 spin_unlock(&fs_info->delalloc_root_lock);
10207
10208 ret = 0;
10209 out:
10210 if (!list_empty_careful(&splice)) {
10211 spin_lock(&fs_info->delalloc_root_lock);
10212 list_splice_tail(&splice, &fs_info->delalloc_roots);
10213 spin_unlock(&fs_info->delalloc_root_lock);
10214 }
10215 mutex_unlock(&fs_info->delalloc_root_mutex);
10216 return ret;
10217 }
10218
10219 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
10220 const char *symname)
10221 {
10222 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10223 struct btrfs_trans_handle *trans;
10224 struct btrfs_root *root = BTRFS_I(dir)->root;
10225 struct btrfs_path *path;
10226 struct btrfs_key key;
10227 struct inode *inode = NULL;
10228 int err;
10229 int drop_inode = 0;
10230 u64 objectid;
10231 u64 index = 0;
10232 int name_len;
10233 int datasize;
10234 unsigned long ptr;
10235 struct btrfs_file_extent_item *ei;
10236 struct extent_buffer *leaf;
10237
10238 name_len = strlen(symname);
10239 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
10240 return -ENAMETOOLONG;
10241
10242 /*
10243 * 2 items for inode item and ref
10244 * 2 items for dir items
10245 * 1 item for updating parent inode item
10246 * 1 item for the inline extent item
10247 * 1 item for xattr if selinux is on
10248 */
10249 trans = btrfs_start_transaction(root, 7);
10250 if (IS_ERR(trans))
10251 return PTR_ERR(trans);
10252
10253 err = btrfs_find_free_ino(root, &objectid);
10254 if (err)
10255 goto out_unlock;
10256
10257 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
10258 dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
10259 objectid, S_IFLNK|S_IRWXUGO, &index);
10260 if (IS_ERR(inode)) {
10261 err = PTR_ERR(inode);
10262 goto out_unlock;
10263 }
10264
10265 /*
10266 * If the active LSM wants to access the inode during
10267 * d_instantiate it needs these. Smack checks to see
10268 * if the filesystem supports xattrs by looking at the
10269 * ops vector.
10270 */
10271 inode->i_fop = &btrfs_file_operations;
10272 inode->i_op = &btrfs_file_inode_operations;
10273 inode->i_mapping->a_ops = &btrfs_aops;
10274 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10275
10276 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
10277 if (err)
10278 goto out_unlock_inode;
10279
10280 path = btrfs_alloc_path();
10281 if (!path) {
10282 err = -ENOMEM;
10283 goto out_unlock_inode;
10284 }
10285 key.objectid = btrfs_ino(BTRFS_I(inode));
10286 key.offset = 0;
10287 key.type = BTRFS_EXTENT_DATA_KEY;
10288 datasize = btrfs_file_extent_calc_inline_size(name_len);
10289 err = btrfs_insert_empty_item(trans, root, path, &key,
10290 datasize);
10291 if (err) {
10292 btrfs_free_path(path);
10293 goto out_unlock_inode;
10294 }
10295 leaf = path->nodes[0];
10296 ei = btrfs_item_ptr(leaf, path->slots[0],
10297 struct btrfs_file_extent_item);
10298 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
10299 btrfs_set_file_extent_type(leaf, ei,
10300 BTRFS_FILE_EXTENT_INLINE);
10301 btrfs_set_file_extent_encryption(leaf, ei, 0);
10302 btrfs_set_file_extent_compression(leaf, ei, 0);
10303 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
10304 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
10305
10306 ptr = btrfs_file_extent_inline_start(ei);
10307 write_extent_buffer(leaf, symname, ptr, name_len);
10308 btrfs_mark_buffer_dirty(leaf);
10309 btrfs_free_path(path);
10310
10311 inode->i_op = &btrfs_symlink_inode_operations;
10312 inode_nohighmem(inode);
10313 inode->i_mapping->a_ops = &btrfs_symlink_aops;
10314 inode_set_bytes(inode, name_len);
10315 btrfs_i_size_write(BTRFS_I(inode), name_len);
10316 err = btrfs_update_inode(trans, root, inode);
10317 /*
10318 * Last step, add directory indexes for our symlink inode. This is the
10319 * last step to avoid extra cleanup of these indexes if an error happens
10320 * elsewhere above.
10321 */
10322 if (!err)
10323 err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
10324 BTRFS_I(inode), 0, index);
10325 if (err) {
10326 drop_inode = 1;
10327 goto out_unlock_inode;
10328 }
10329
10330 unlock_new_inode(inode);
10331 d_instantiate(dentry, inode);
10332
10333 out_unlock:
10334 btrfs_end_transaction(trans);
10335 if (drop_inode) {
10336 inode_dec_link_count(inode);
10337 iput(inode);
10338 }
10339 btrfs_btree_balance_dirty(fs_info);
10340 return err;
10341
10342 out_unlock_inode:
10343 drop_inode = 1;
10344 unlock_new_inode(inode);
10345 goto out_unlock;
10346 }
10347
10348 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
10349 u64 start, u64 num_bytes, u64 min_size,
10350 loff_t actual_len, u64 *alloc_hint,
10351 struct btrfs_trans_handle *trans)
10352 {
10353 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
10354 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
10355 struct extent_map *em;
10356 struct btrfs_root *root = BTRFS_I(inode)->root;
10357 struct btrfs_key ins;
10358 u64 cur_offset = start;
10359 u64 i_size;
10360 u64 cur_bytes;
10361 u64 last_alloc = (u64)-1;
10362 int ret = 0;
10363 bool own_trans = true;
10364 u64 end = start + num_bytes - 1;
10365
10366 if (trans)
10367 own_trans = false;
10368 while (num_bytes > 0) {
10369 if (own_trans) {
10370 trans = btrfs_start_transaction(root, 3);
10371 if (IS_ERR(trans)) {
10372 ret = PTR_ERR(trans);
10373 break;
10374 }
10375 }
10376
10377 cur_bytes = min_t(u64, num_bytes, SZ_256M);
10378 cur_bytes = max(cur_bytes, min_size);
10379 /*
10380 * If we are severely fragmented we could end up with really
10381 * small allocations, so if the allocator is returning small
10382 * chunks lets make its job easier by only searching for those
10383 * sized chunks.
10384 */
10385 cur_bytes = min(cur_bytes, last_alloc);
10386 ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
10387 min_size, 0, *alloc_hint, &ins, 1, 0);
10388 if (ret) {
10389 if (own_trans)
10390 btrfs_end_transaction(trans);
10391 break;
10392 }
10393 btrfs_dec_block_group_reservations(fs_info, ins.objectid);
10394
10395 last_alloc = ins.offset;
10396 ret = insert_reserved_file_extent(trans, inode,
10397 cur_offset, ins.objectid,
10398 ins.offset, ins.offset,
10399 ins.offset, 0, 0, 0,
10400 BTRFS_FILE_EXTENT_PREALLOC);
10401 if (ret) {
10402 btrfs_free_reserved_extent(fs_info, ins.objectid,
10403 ins.offset, 0);
10404 btrfs_abort_transaction(trans, ret);
10405 if (own_trans)
10406 btrfs_end_transaction(trans);
10407 break;
10408 }
10409
10410 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10411 cur_offset + ins.offset -1, 0);
10412
10413 em = alloc_extent_map();
10414 if (!em) {
10415 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
10416 &BTRFS_I(inode)->runtime_flags);
10417 goto next;
10418 }
10419
10420 em->start = cur_offset;
10421 em->orig_start = cur_offset;
10422 em->len = ins.offset;
10423 em->block_start = ins.objectid;
10424 em->block_len = ins.offset;
10425 em->orig_block_len = ins.offset;
10426 em->ram_bytes = ins.offset;
10427 em->bdev = fs_info->fs_devices->latest_bdev;
10428 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
10429 em->generation = trans->transid;
10430
10431 while (1) {
10432 write_lock(&em_tree->lock);
10433 ret = add_extent_mapping(em_tree, em, 1);
10434 write_unlock(&em_tree->lock);
10435 if (ret != -EEXIST)
10436 break;
10437 btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
10438 cur_offset + ins.offset - 1,
10439 0);
10440 }
10441 free_extent_map(em);
10442 next:
10443 num_bytes -= ins.offset;
10444 cur_offset += ins.offset;
10445 *alloc_hint = ins.objectid + ins.offset;
10446
10447 inode_inc_iversion(inode);
10448 inode->i_ctime = current_time(inode);
10449 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
10450 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
10451 (actual_len > inode->i_size) &&
10452 (cur_offset > inode->i_size)) {
10453 if (cur_offset > actual_len)
10454 i_size = actual_len;
10455 else
10456 i_size = cur_offset;
10457 i_size_write(inode, i_size);
10458 btrfs_ordered_update_i_size(inode, i_size, NULL);
10459 }
10460
10461 ret = btrfs_update_inode(trans, root, inode);
10462
10463 if (ret) {
10464 btrfs_abort_transaction(trans, ret);
10465 if (own_trans)
10466 btrfs_end_transaction(trans);
10467 break;
10468 }
10469
10470 if (own_trans)
10471 btrfs_end_transaction(trans);
10472 }
10473 if (cur_offset < end)
10474 btrfs_free_reserved_data_space(inode, NULL, cur_offset,
10475 end - cur_offset + 1);
10476 return ret;
10477 }
10478
10479 int btrfs_prealloc_file_range(struct inode *inode, int mode,
10480 u64 start, u64 num_bytes, u64 min_size,
10481 loff_t actual_len, u64 *alloc_hint)
10482 {
10483 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10484 min_size, actual_len, alloc_hint,
10485 NULL);
10486 }
10487
10488 int btrfs_prealloc_file_range_trans(struct inode *inode,
10489 struct btrfs_trans_handle *trans, int mode,
10490 u64 start, u64 num_bytes, u64 min_size,
10491 loff_t actual_len, u64 *alloc_hint)
10492 {
10493 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
10494 min_size, actual_len, alloc_hint, trans);
10495 }
10496
10497 static int btrfs_set_page_dirty(struct page *page)
10498 {
10499 return __set_page_dirty_nobuffers(page);
10500 }
10501
10502 static int btrfs_permission(struct inode *inode, int mask)
10503 {
10504 struct btrfs_root *root = BTRFS_I(inode)->root;
10505 umode_t mode = inode->i_mode;
10506
10507 if (mask & MAY_WRITE &&
10508 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
10509 if (btrfs_root_readonly(root))
10510 return -EROFS;
10511 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
10512 return -EACCES;
10513 }
10514 return generic_permission(inode, mask);
10515 }
10516
10517 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
10518 {
10519 struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
10520 struct btrfs_trans_handle *trans;
10521 struct btrfs_root *root = BTRFS_I(dir)->root;
10522 struct inode *inode = NULL;
10523 u64 objectid;
10524 u64 index;
10525 int ret = 0;
10526
10527 /*
10528 * 5 units required for adding orphan entry
10529 */
10530 trans = btrfs_start_transaction(root, 5);
10531 if (IS_ERR(trans))
10532 return PTR_ERR(trans);
10533
10534 ret = btrfs_find_free_ino(root, &objectid);
10535 if (ret)
10536 goto out;
10537
10538 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
10539 btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
10540 if (IS_ERR(inode)) {
10541 ret = PTR_ERR(inode);
10542 inode = NULL;
10543 goto out;
10544 }
10545
10546 inode->i_fop = &btrfs_file_operations;
10547 inode->i_op = &btrfs_file_inode_operations;
10548
10549 inode->i_mapping->a_ops = &btrfs_aops;
10550 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
10551
10552 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
10553 if (ret)
10554 goto out_inode;
10555
10556 ret = btrfs_update_inode(trans, root, inode);
10557 if (ret)
10558 goto out_inode;
10559 ret = btrfs_orphan_add(trans, BTRFS_I(inode));
10560 if (ret)
10561 goto out_inode;
10562
10563 /*
10564 * We set number of links to 0 in btrfs_new_inode(), and here we set
10565 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
10566 * through:
10567 *
10568 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
10569 */
10570 set_nlink(inode, 1);
10571 unlock_new_inode(inode);
10572 d_tmpfile(dentry, inode);
10573 mark_inode_dirty(inode);
10574
10575 out:
10576 btrfs_end_transaction(trans);
10577 if (ret)
10578 iput(inode);
10579 btrfs_btree_balance_dirty(fs_info);
10580 return ret;
10581
10582 out_inode:
10583 unlock_new_inode(inode);
10584 goto out;
10585
10586 }
10587
10588 __attribute__((const))
10589 static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror)
10590 {
10591 return -EAGAIN;
10592 }
10593
10594 static struct btrfs_fs_info *iotree_fs_info(void *private_data)
10595 {
10596 struct inode *inode = private_data;
10597 return btrfs_sb(inode->i_sb);
10598 }
10599
10600 static void btrfs_check_extent_io_range(void *private_data, const char *caller,
10601 u64 start, u64 end)
10602 {
10603 struct inode *inode = private_data;
10604 u64 isize;
10605
10606 isize = i_size_read(inode);
10607 if (end >= PAGE_SIZE && (end % 2) == 0 && end != isize - 1) {
10608 btrfs_debug_rl(BTRFS_I(inode)->root->fs_info,
10609 "%s: ino %llu isize %llu odd range [%llu,%llu]",
10610 caller, btrfs_ino(BTRFS_I(inode)), isize, start, end);
10611 }
10612 }
10613
10614 void btrfs_set_range_writeback(void *private_data, u64 start, u64 end)
10615 {
10616 struct inode *inode = private_data;
10617 unsigned long index = start >> PAGE_SHIFT;
10618 unsigned long end_index = end >> PAGE_SHIFT;
10619 struct page *page;
10620
10621 while (index <= end_index) {
10622 page = find_get_page(inode->i_mapping, index);
10623 ASSERT(page); /* Pages should be in the extent_io_tree */
10624 set_page_writeback(page);
10625 put_page(page);
10626 index++;
10627 }
10628 }
10629
10630 static const struct inode_operations btrfs_dir_inode_operations = {
10631 .getattr = btrfs_getattr,
10632 .lookup = btrfs_lookup,
10633 .create = btrfs_create,
10634 .unlink = btrfs_unlink,
10635 .link = btrfs_link,
10636 .mkdir = btrfs_mkdir,
10637 .rmdir = btrfs_rmdir,
10638 .rename = btrfs_rename2,
10639 .symlink = btrfs_symlink,
10640 .setattr = btrfs_setattr,
10641 .mknod = btrfs_mknod,
10642 .listxattr = btrfs_listxattr,
10643 .permission = btrfs_permission,
10644 .get_acl = btrfs_get_acl,
10645 .set_acl = btrfs_set_acl,
10646 .update_time = btrfs_update_time,
10647 .tmpfile = btrfs_tmpfile,
10648 };
10649 static const struct inode_operations btrfs_dir_ro_inode_operations = {
10650 .lookup = btrfs_lookup,
10651 .permission = btrfs_permission,
10652 .update_time = btrfs_update_time,
10653 };
10654
10655 static const struct file_operations btrfs_dir_file_operations = {
10656 .llseek = generic_file_llseek,
10657 .read = generic_read_dir,
10658 .iterate_shared = btrfs_real_readdir,
10659 .open = btrfs_opendir,
10660 .unlocked_ioctl = btrfs_ioctl,
10661 #ifdef CONFIG_COMPAT
10662 .compat_ioctl = btrfs_compat_ioctl,
10663 #endif
10664 .release = btrfs_release_file,
10665 .fsync = btrfs_sync_file,
10666 };
10667
10668 static const struct extent_io_ops btrfs_extent_io_ops = {
10669 /* mandatory callbacks */
10670 .submit_bio_hook = btrfs_submit_bio_hook,
10671 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
10672 .merge_bio_hook = btrfs_merge_bio_hook,
10673 .readpage_io_failed_hook = btrfs_readpage_io_failed_hook,
10674 .tree_fs_info = iotree_fs_info,
10675 .set_range_writeback = btrfs_set_range_writeback,
10676
10677 /* optional callbacks */
10678 .fill_delalloc = run_delalloc_range,
10679 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
10680 .writepage_start_hook = btrfs_writepage_start_hook,
10681 .set_bit_hook = btrfs_set_bit_hook,
10682 .clear_bit_hook = btrfs_clear_bit_hook,
10683 .merge_extent_hook = btrfs_merge_extent_hook,
10684 .split_extent_hook = btrfs_split_extent_hook,
10685 .check_extent_io_range = btrfs_check_extent_io_range,
10686 };
10687
10688 /*
10689 * btrfs doesn't support the bmap operation because swapfiles
10690 * use bmap to make a mapping of extents in the file. They assume
10691 * these extents won't change over the life of the file and they
10692 * use the bmap result to do IO directly to the drive.
10693 *
10694 * the btrfs bmap call would return logical addresses that aren't
10695 * suitable for IO and they also will change frequently as COW
10696 * operations happen. So, swapfile + btrfs == corruption.
10697 *
10698 * For now we're avoiding this by dropping bmap.
10699 */
10700 static const struct address_space_operations btrfs_aops = {
10701 .readpage = btrfs_readpage,
10702 .writepage = btrfs_writepage,
10703 .writepages = btrfs_writepages,
10704 .readpages = btrfs_readpages,
10705 .direct_IO = btrfs_direct_IO,
10706 .invalidatepage = btrfs_invalidatepage,
10707 .releasepage = btrfs_releasepage,
10708 .set_page_dirty = btrfs_set_page_dirty,
10709 .error_remove_page = generic_error_remove_page,
10710 };
10711
10712 static const struct address_space_operations btrfs_symlink_aops = {
10713 .readpage = btrfs_readpage,
10714 .writepage = btrfs_writepage,
10715 .invalidatepage = btrfs_invalidatepage,
10716 .releasepage = btrfs_releasepage,
10717 };
10718
10719 static const struct inode_operations btrfs_file_inode_operations = {
10720 .getattr = btrfs_getattr,
10721 .setattr = btrfs_setattr,
10722 .listxattr = btrfs_listxattr,
10723 .permission = btrfs_permission,
10724 .fiemap = btrfs_fiemap,
10725 .get_acl = btrfs_get_acl,
10726 .set_acl = btrfs_set_acl,
10727 .update_time = btrfs_update_time,
10728 };
10729 static const struct inode_operations btrfs_special_inode_operations = {
10730 .getattr = btrfs_getattr,
10731 .setattr = btrfs_setattr,
10732 .permission = btrfs_permission,
10733 .listxattr = btrfs_listxattr,
10734 .get_acl = btrfs_get_acl,
10735 .set_acl = btrfs_set_acl,
10736 .update_time = btrfs_update_time,
10737 };
10738 static const struct inode_operations btrfs_symlink_inode_operations = {
10739 .get_link = page_get_link,
10740 .getattr = btrfs_getattr,
10741 .setattr = btrfs_setattr,
10742 .permission = btrfs_permission,
10743 .listxattr = btrfs_listxattr,
10744 .update_time = btrfs_update_time,
10745 };
10746
10747 const struct dentry_operations btrfs_dentry_operations = {
10748 .d_delete = btrfs_dentry_delete,
10749 .d_release = btrfs_dentry_release,
10750 };
CRIS linux kernel tree