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proc: Allow creating permanently empty directories that serve as mount points
[linux/fpc-iii.git] / fs / btrfs / inode.c
blob8bb013672aee061e81eb03fcba6d51db9cd169af
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/statfs.h>
34 #include <linux/compat.h>
35 #include <linux/bit_spinlock.h>
36 #include <linux/xattr.h>
37 #include <linux/posix_acl.h>
38 #include <linux/falloc.h>
39 #include <linux/slab.h>
40 #include <linux/ratelimit.h>
41 #include <linux/mount.h>
42 #include <linux/btrfs.h>
43 #include <linux/blkdev.h>
44 #include <linux/posix_acl_xattr.h>
45 #include <linux/uio.h>
46 #include "ctree.h"
47 #include "disk-io.h"
48 #include "transaction.h"
49 #include "btrfs_inode.h"
50 #include "print-tree.h"
51 #include "ordered-data.h"
52 #include "xattr.h"
53 #include "tree-log.h"
54 #include "volumes.h"
55 #include "compression.h"
56 #include "locking.h"
57 #include "free-space-cache.h"
58 #include "inode-map.h"
59 #include "backref.h"
60 #include "hash.h"
61 #include "props.h"
62 #include "qgroup.h"
63
64 struct btrfs_iget_args {
65 struct btrfs_key *location;
66 struct btrfs_root *root;
67 };
68
69 static const struct inode_operations btrfs_dir_inode_operations;
70 static const struct inode_operations btrfs_symlink_inode_operations;
71 static const struct inode_operations btrfs_dir_ro_inode_operations;
72 static const struct inode_operations btrfs_special_inode_operations;
73 static const struct inode_operations btrfs_file_inode_operations;
74 static const struct address_space_operations btrfs_aops;
75 static const struct address_space_operations btrfs_symlink_aops;
76 static const struct file_operations btrfs_dir_file_operations;
77 static struct extent_io_ops btrfs_extent_io_ops;
78
79 static struct kmem_cache *btrfs_inode_cachep;
80 static struct kmem_cache *btrfs_delalloc_work_cachep;
81 struct kmem_cache *btrfs_trans_handle_cachep;
82 struct kmem_cache *btrfs_transaction_cachep;
83 struct kmem_cache *btrfs_path_cachep;
84 struct kmem_cache *btrfs_free_space_cachep;
85
86 #define S_SHIFT 12
87 static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
88 [S_IFREG >> S_SHIFT] = BTRFS_FT_REG_FILE,
89 [S_IFDIR >> S_SHIFT] = BTRFS_FT_DIR,
90 [S_IFCHR >> S_SHIFT] = BTRFS_FT_CHRDEV,
91 [S_IFBLK >> S_SHIFT] = BTRFS_FT_BLKDEV,
92 [S_IFIFO >> S_SHIFT] = BTRFS_FT_FIFO,
93 [S_IFSOCK >> S_SHIFT] = BTRFS_FT_SOCK,
94 [S_IFLNK >> S_SHIFT] = BTRFS_FT_SYMLINK,
95 };
96
97 static int btrfs_setsize(struct inode *inode, struct iattr *attr);
98 static int btrfs_truncate(struct inode *inode);
99 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
100 static noinline int cow_file_range(struct inode *inode,
101 struct page *locked_page,
102 u64 start, u64 end, int *page_started,
103 unsigned long *nr_written, int unlock);
104 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
105 u64 len, u64 orig_start,
106 u64 block_start, u64 block_len,
107 u64 orig_block_len, u64 ram_bytes,
108 int type);
109
110 static int btrfs_dirty_inode(struct inode *inode);
111
112 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
113 void btrfs_test_inode_set_ops(struct inode *inode)
114 {
115 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
116 }
117 #endif
118
119 static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
120 struct inode *inode, struct inode *dir,
121 const struct qstr *qstr)
122 {
123 int err;
124
125 err = btrfs_init_acl(trans, inode, dir);
126 if (!err)
127 err = btrfs_xattr_security_init(trans, inode, dir, qstr);
128 return err;
129 }
130
131 /*
132 * this does all the hard work for inserting an inline extent into
133 * the btree. The caller should have done a btrfs_drop_extents so that
134 * no overlapping inline items exist in the btree
135 */
136 static int insert_inline_extent(struct btrfs_trans_handle *trans,
137 struct btrfs_path *path, int extent_inserted,
138 struct btrfs_root *root, struct inode *inode,
139 u64 start, size_t size, size_t compressed_size,
140 int compress_type,
141 struct page **compressed_pages)
142 {
143 struct extent_buffer *leaf;
144 struct page *page = NULL;
145 char *kaddr;
146 unsigned long ptr;
147 struct btrfs_file_extent_item *ei;
148 int err = 0;
149 int ret;
150 size_t cur_size = size;
151 unsigned long offset;
152
153 if (compressed_size && compressed_pages)
154 cur_size = compressed_size;
155
156 inode_add_bytes(inode, size);
157
158 if (!extent_inserted) {
159 struct btrfs_key key;
160 size_t datasize;
161
162 key.objectid = btrfs_ino(inode);
163 key.offset = start;
164 key.type = BTRFS_EXTENT_DATA_KEY;
165
166 datasize = btrfs_file_extent_calc_inline_size(cur_size);
167 path->leave_spinning = 1;
168 ret = btrfs_insert_empty_item(trans, root, path, &key,
169 datasize);
170 if (ret) {
171 err = ret;
172 goto fail;
173 }
174 }
175 leaf = path->nodes[0];
176 ei = btrfs_item_ptr(leaf, path->slots[0],
177 struct btrfs_file_extent_item);
178 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
179 btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
180 btrfs_set_file_extent_encryption(leaf, ei, 0);
181 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
182 btrfs_set_file_extent_ram_bytes(leaf, ei, size);
183 ptr = btrfs_file_extent_inline_start(ei);
184
185 if (compress_type != BTRFS_COMPRESS_NONE) {
186 struct page *cpage;
187 int i = 0;
188 while (compressed_size > 0) {
189 cpage = compressed_pages[i];
190 cur_size = min_t(unsigned long, compressed_size,
191 PAGE_CACHE_SIZE);
192
193 kaddr = kmap_atomic(cpage);
194 write_extent_buffer(leaf, kaddr, ptr, cur_size);
195 kunmap_atomic(kaddr);
196
197 i++;
198 ptr += cur_size;
199 compressed_size -= cur_size;
200 }
201 btrfs_set_file_extent_compression(leaf, ei,
202 compress_type);
203 } else {
204 page = find_get_page(inode->i_mapping,
205 start >> PAGE_CACHE_SHIFT);
206 btrfs_set_file_extent_compression(leaf, ei, 0);
207 kaddr = kmap_atomic(page);
208 offset = start & (PAGE_CACHE_SIZE - 1);
209 write_extent_buffer(leaf, kaddr + offset, ptr, size);
210 kunmap_atomic(kaddr);
211 page_cache_release(page);
212 }
213 btrfs_mark_buffer_dirty(leaf);
214 btrfs_release_path(path);
215
216 /*
217 * we're an inline extent, so nobody can
218 * extend the file past i_size without locking
219 * a page we already have locked.
220 *
221 * We must do any isize and inode updates
222 * before we unlock the pages. Otherwise we
223 * could end up racing with unlink.
224 */
225 BTRFS_I(inode)->disk_i_size = inode->i_size;
226 ret = btrfs_update_inode(trans, root, inode);
227
228 return ret;
229 fail:
230 return err;
231 }
232
233
234 /*
235 * conditionally insert an inline extent into the file. This
236 * does the checks required to make sure the data is small enough
237 * to fit as an inline extent.
238 */
239 static noinline int cow_file_range_inline(struct btrfs_root *root,
240 struct inode *inode, u64 start,
241 u64 end, size_t compressed_size,
242 int compress_type,
243 struct page **compressed_pages)
244 {
245 struct btrfs_trans_handle *trans;
246 u64 isize = i_size_read(inode);
247 u64 actual_end = min(end + 1, isize);
248 u64 inline_len = actual_end - start;
249 u64 aligned_end = ALIGN(end, root->sectorsize);
250 u64 data_len = inline_len;
251 int ret;
252 struct btrfs_path *path;
253 int extent_inserted = 0;
254 u32 extent_item_size;
255
256 if (compressed_size)
257 data_len = compressed_size;
258
259 if (start > 0 ||
260 actual_end > PAGE_CACHE_SIZE ||
261 data_len > BTRFS_MAX_INLINE_DATA_SIZE(root) ||
262 (!compressed_size &&
263 (actual_end & (root->sectorsize - 1)) == 0) ||
264 end + 1 < isize ||
265 data_len > root->fs_info->max_inline) {
266 return 1;
267 }
268
269 path = btrfs_alloc_path();
270 if (!path)
271 return -ENOMEM;
272
273 trans = btrfs_join_transaction(root);
274 if (IS_ERR(trans)) {
275 btrfs_free_path(path);
276 return PTR_ERR(trans);
277 }
278 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
279
280 if (compressed_size && compressed_pages)
281 extent_item_size = btrfs_file_extent_calc_inline_size(
282 compressed_size);
283 else
284 extent_item_size = btrfs_file_extent_calc_inline_size(
285 inline_len);
286
287 ret = __btrfs_drop_extents(trans, root, inode, path,
288 start, aligned_end, NULL,
289 1, 1, extent_item_size, &extent_inserted);
290 if (ret) {
291 btrfs_abort_transaction(trans, root, ret);
292 goto out;
293 }
294
295 if (isize > actual_end)
296 inline_len = min_t(u64, isize, actual_end);
297 ret = insert_inline_extent(trans, path, extent_inserted,
298 root, inode, start,
299 inline_len, compressed_size,
300 compress_type, compressed_pages);
301 if (ret && ret != -ENOSPC) {
302 btrfs_abort_transaction(trans, root, ret);
303 goto out;
304 } else if (ret == -ENOSPC) {
305 ret = 1;
306 goto out;
307 }
308
309 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
310 btrfs_delalloc_release_metadata(inode, end + 1 - start);
311 btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
312 out:
313 btrfs_free_path(path);
314 btrfs_end_transaction(trans, root);
315 return ret;
316 }
317
318 struct async_extent {
319 u64 start;
320 u64 ram_size;
321 u64 compressed_size;
322 struct page **pages;
323 unsigned long nr_pages;
324 int compress_type;
325 struct list_head list;
326 };
327
328 struct async_cow {
329 struct inode *inode;
330 struct btrfs_root *root;
331 struct page *locked_page;
332 u64 start;
333 u64 end;
334 struct list_head extents;
335 struct btrfs_work work;
336 };
337
338 static noinline int add_async_extent(struct async_cow *cow,
339 u64 start, u64 ram_size,
340 u64 compressed_size,
341 struct page **pages,
342 unsigned long nr_pages,
343 int compress_type)
344 {
345 struct async_extent *async_extent;
346
347 async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
348 BUG_ON(!async_extent); /* -ENOMEM */
349 async_extent->start = start;
350 async_extent->ram_size = ram_size;
351 async_extent->compressed_size = compressed_size;
352 async_extent->pages = pages;
353 async_extent->nr_pages = nr_pages;
354 async_extent->compress_type = compress_type;
355 list_add_tail(&async_extent->list, &cow->extents);
356 return 0;
357 }
358
359 static inline int inode_need_compress(struct inode *inode)
360 {
361 struct btrfs_root *root = BTRFS_I(inode)->root;
362
363 /* force compress */
364 if (btrfs_test_opt(root, FORCE_COMPRESS))
365 return 1;
366 /* bad compression ratios */
367 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
368 return 0;
369 if (btrfs_test_opt(root, COMPRESS) ||
370 BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
371 BTRFS_I(inode)->force_compress)
372 return 1;
373 return 0;
374 }
375
376 /*
377 * we create compressed extents in two phases. The first
378 * phase compresses a range of pages that have already been
379 * locked (both pages and state bits are locked).
380 *
381 * This is done inside an ordered work queue, and the compression
382 * is spread across many cpus. The actual IO submission is step
383 * two, and the ordered work queue takes care of making sure that
384 * happens in the same order things were put onto the queue by
385 * writepages and friends.
386 *
387 * If this code finds it can't get good compression, it puts an
388 * entry onto the work queue to write the uncompressed bytes. This
389 * makes sure that both compressed inodes and uncompressed inodes
390 * are written in the same order that the flusher thread sent them
391 * down.
392 */
393 static noinline void compress_file_range(struct inode *inode,
394 struct page *locked_page,
395 u64 start, u64 end,
396 struct async_cow *async_cow,
397 int *num_added)
398 {
399 struct btrfs_root *root = BTRFS_I(inode)->root;
400 u64 num_bytes;
401 u64 blocksize = root->sectorsize;
402 u64 actual_end;
403 u64 isize = i_size_read(inode);
404 int ret = 0;
405 struct page **pages = NULL;
406 unsigned long nr_pages;
407 unsigned long nr_pages_ret = 0;
408 unsigned long total_compressed = 0;
409 unsigned long total_in = 0;
410 unsigned long max_compressed = 128 * 1024;
411 unsigned long max_uncompressed = 128 * 1024;
412 int i;
413 int will_compress;
414 int compress_type = root->fs_info->compress_type;
415 int redirty = 0;
416
417 /* if this is a small write inside eof, kick off a defrag */
418 if ((end - start + 1) < 16 * 1024 &&
419 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
420 btrfs_add_inode_defrag(NULL, inode);
421
422 actual_end = min_t(u64, isize, end + 1);
423 again:
424 will_compress = 0;
425 nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
426 nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
427
428 /*
429 * we don't want to send crud past the end of i_size through
430 * compression, that's just a waste of CPU time. So, if the
431 * end of the file is before the start of our current
432 * requested range of bytes, we bail out to the uncompressed
433 * cleanup code that can deal with all of this.
434 *
435 * It isn't really the fastest way to fix things, but this is a
436 * very uncommon corner.
437 */
438 if (actual_end <= start)
439 goto cleanup_and_bail_uncompressed;
440
441 total_compressed = actual_end - start;
442
443 /*
444 * skip compression for a small file range(<=blocksize) that
445 * isn't an inline extent, since it dosen't save disk space at all.
446 */
447 if (total_compressed <= blocksize &&
448 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
449 goto cleanup_and_bail_uncompressed;
450
451 /* we want to make sure that amount of ram required to uncompress
452 * an extent is reasonable, so we limit the total size in ram
453 * of a compressed extent to 128k. This is a crucial number
454 * because it also controls how easily we can spread reads across
455 * cpus for decompression.
456 *
457 * We also want to make sure the amount of IO required to do
458 * a random read is reasonably small, so we limit the size of
459 * a compressed extent to 128k.
460 */
461 total_compressed = min(total_compressed, max_uncompressed);
462 num_bytes = ALIGN(end - start + 1, blocksize);
463 num_bytes = max(blocksize, num_bytes);
464 total_in = 0;
465 ret = 0;
466
467 /*
468 * we do compression for mount -o compress and when the
469 * inode has not been flagged as nocompress. This flag can
470 * change at any time if we discover bad compression ratios.
471 */
472 if (inode_need_compress(inode)) {
473 WARN_ON(pages);
474 pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
475 if (!pages) {
476 /* just bail out to the uncompressed code */
477 goto cont;
478 }
479
480 if (BTRFS_I(inode)->force_compress)
481 compress_type = BTRFS_I(inode)->force_compress;
482
483 /*
484 * we need to call clear_page_dirty_for_io on each
485 * page in the range. Otherwise applications with the file
486 * mmap'd can wander in and change the page contents while
487 * we are compressing them.
488 *
489 * If the compression fails for any reason, we set the pages
490 * dirty again later on.
491 */
492 extent_range_clear_dirty_for_io(inode, start, end);
493 redirty = 1;
494 ret = btrfs_compress_pages(compress_type,
495 inode->i_mapping, start,
496 total_compressed, pages,
497 nr_pages, &nr_pages_ret,
498 &total_in,
499 &total_compressed,
500 max_compressed);
501
502 if (!ret) {
503 unsigned long offset = total_compressed &
504 (PAGE_CACHE_SIZE - 1);
505 struct page *page = pages[nr_pages_ret - 1];
506 char *kaddr;
507
508 /* zero the tail end of the last page, we might be
509 * sending it down to disk
510 */
511 if (offset) {
512 kaddr = kmap_atomic(page);
513 memset(kaddr + offset, 0,
514 PAGE_CACHE_SIZE - offset);
515 kunmap_atomic(kaddr);
516 }
517 will_compress = 1;
518 }
519 }
520 cont:
521 if (start == 0) {
522 /* lets try to make an inline extent */
523 if (ret || total_in < (actual_end - start)) {
524 /* we didn't compress the entire range, try
525 * to make an uncompressed inline extent.
526 */
527 ret = cow_file_range_inline(root, inode, start, end,
528 0, 0, NULL);
529 } else {
530 /* try making a compressed inline extent */
531 ret = cow_file_range_inline(root, inode, start, end,
532 total_compressed,
533 compress_type, pages);
534 }
535 if (ret <= 0) {
536 unsigned long clear_flags = EXTENT_DELALLOC |
537 EXTENT_DEFRAG;
538 unsigned long page_error_op;
539
540 clear_flags |= (ret < 0) ? EXTENT_DO_ACCOUNTING : 0;
541 page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
542
543 /*
544 * inline extent creation worked or returned error,
545 * we don't need to create any more async work items.
546 * Unlock and free up our temp pages.
547 */
548 extent_clear_unlock_delalloc(inode, start, end, NULL,
549 clear_flags, PAGE_UNLOCK |
550 PAGE_CLEAR_DIRTY |
551 PAGE_SET_WRITEBACK |
552 page_error_op |
553 PAGE_END_WRITEBACK);
554 goto free_pages_out;
555 }
556 }
557
558 if (will_compress) {
559 /*
560 * we aren't doing an inline extent round the compressed size
561 * up to a block size boundary so the allocator does sane
562 * things
563 */
564 total_compressed = ALIGN(total_compressed, blocksize);
565
566 /*
567 * one last check to make sure the compression is really a
568 * win, compare the page count read with the blocks on disk
569 */
570 total_in = ALIGN(total_in, PAGE_CACHE_SIZE);
571 if (total_compressed >= total_in) {
572 will_compress = 0;
573 } else {
574 num_bytes = total_in;
575 }
576 }
577 if (!will_compress && pages) {
578 /*
579 * the compression code ran but failed to make things smaller,
580 * free any pages it allocated and our page pointer array
581 */
582 for (i = 0; i < nr_pages_ret; i++) {
583 WARN_ON(pages[i]->mapping);
584 page_cache_release(pages[i]);
585 }
586 kfree(pages);
587 pages = NULL;
588 total_compressed = 0;
589 nr_pages_ret = 0;
590
591 /* flag the file so we don't compress in the future */
592 if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
593 !(BTRFS_I(inode)->force_compress)) {
594 BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
595 }
596 }
597 if (will_compress) {
598 *num_added += 1;
599
600 /* the async work queues will take care of doing actual
601 * allocation on disk for these compressed pages,
602 * and will submit them to the elevator.
603 */
604 add_async_extent(async_cow, start, num_bytes,
605 total_compressed, pages, nr_pages_ret,
606 compress_type);
607
608 if (start + num_bytes < end) {
609 start += num_bytes;
610 pages = NULL;
611 cond_resched();
612 goto again;
613 }
614 } else {
615 cleanup_and_bail_uncompressed:
616 /*
617 * No compression, but we still need to write the pages in
618 * the file we've been given so far. redirty the locked
619 * page if it corresponds to our extent and set things up
620 * for the async work queue to run cow_file_range to do
621 * the normal delalloc dance
622 */
623 if (page_offset(locked_page) >= start &&
624 page_offset(locked_page) <= end) {
625 __set_page_dirty_nobuffers(locked_page);
626 /* unlocked later on in the async handlers */
627 }
628 if (redirty)
629 extent_range_redirty_for_io(inode, start, end);
630 add_async_extent(async_cow, start, end - start + 1,
631 0, NULL, 0, BTRFS_COMPRESS_NONE);
632 *num_added += 1;
633 }
634
635 return;
636
637 free_pages_out:
638 for (i = 0; i < nr_pages_ret; i++) {
639 WARN_ON(pages[i]->mapping);
640 page_cache_release(pages[i]);
641 }
642 kfree(pages);
643 }
644
645 static void free_async_extent_pages(struct async_extent *async_extent)
646 {
647 int i;
648
649 if (!async_extent->pages)
650 return;
651
652 for (i = 0; i < async_extent->nr_pages; i++) {
653 WARN_ON(async_extent->pages[i]->mapping);
654 page_cache_release(async_extent->pages[i]);
655 }
656 kfree(async_extent->pages);
657 async_extent->nr_pages = 0;
658 async_extent->pages = NULL;
659 }
660
661 /*
662 * phase two of compressed writeback. This is the ordered portion
663 * of the code, which only gets called in the order the work was
664 * queued. We walk all the async extents created by compress_file_range
665 * and send them down to the disk.
666 */
667 static noinline void submit_compressed_extents(struct inode *inode,
668 struct async_cow *async_cow)
669 {
670 struct async_extent *async_extent;
671 u64 alloc_hint = 0;
672 struct btrfs_key ins;
673 struct extent_map *em;
674 struct btrfs_root *root = BTRFS_I(inode)->root;
675 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
676 struct extent_io_tree *io_tree;
677 int ret = 0;
678
679 again:
680 while (!list_empty(&async_cow->extents)) {
681 async_extent = list_entry(async_cow->extents.next,
682 struct async_extent, list);
683 list_del(&async_extent->list);
684
685 io_tree = &BTRFS_I(inode)->io_tree;
686
687 retry:
688 /* did the compression code fall back to uncompressed IO? */
689 if (!async_extent->pages) {
690 int page_started = 0;
691 unsigned long nr_written = 0;
692
693 lock_extent(io_tree, async_extent->start,
694 async_extent->start +
695 async_extent->ram_size - 1);
696
697 /* allocate blocks */
698 ret = cow_file_range(inode, async_cow->locked_page,
699 async_extent->start,
700 async_extent->start +
701 async_extent->ram_size - 1,
702 &page_started, &nr_written, 0);
703
704 /* JDM XXX */
705
706 /*
707 * if page_started, cow_file_range inserted an
708 * inline extent and took care of all the unlocking
709 * and IO for us. Otherwise, we need to submit
710 * all those pages down to the drive.
711 */
712 if (!page_started && !ret)
713 extent_write_locked_range(io_tree,
714 inode, async_extent->start,
715 async_extent->start +
716 async_extent->ram_size - 1,
717 btrfs_get_extent,
718 WB_SYNC_ALL);
719 else if (ret)
720 unlock_page(async_cow->locked_page);
721 kfree(async_extent);
722 cond_resched();
723 continue;
724 }
725
726 lock_extent(io_tree, async_extent->start,
727 async_extent->start + async_extent->ram_size - 1);
728
729 ret = btrfs_reserve_extent(root,
730 async_extent->compressed_size,
731 async_extent->compressed_size,
732 0, alloc_hint, &ins, 1, 1);
733 if (ret) {
734 free_async_extent_pages(async_extent);
735
736 if (ret == -ENOSPC) {
737 unlock_extent(io_tree, async_extent->start,
738 async_extent->start +
739 async_extent->ram_size - 1);
740
741 /*
742 * we need to redirty the pages if we decide to
743 * fallback to uncompressed IO, otherwise we
744 * will not submit these pages down to lower
745 * layers.
746 */
747 extent_range_redirty_for_io(inode,
748 async_extent->start,
749 async_extent->start +
750 async_extent->ram_size - 1);
751
752 goto retry;
753 }
754 goto out_free;
755 }
756 /*
757 * here we're doing allocation and writeback of the
758 * compressed pages
759 */
760 btrfs_drop_extent_cache(inode, async_extent->start,
761 async_extent->start +
762 async_extent->ram_size - 1, 0);
763
764 em = alloc_extent_map();
765 if (!em) {
766 ret = -ENOMEM;
767 goto out_free_reserve;
768 }
769 em->start = async_extent->start;
770 em->len = async_extent->ram_size;
771 em->orig_start = em->start;
772 em->mod_start = em->start;
773 em->mod_len = em->len;
774
775 em->block_start = ins.objectid;
776 em->block_len = ins.offset;
777 em->orig_block_len = ins.offset;
778 em->ram_bytes = async_extent->ram_size;
779 em->bdev = root->fs_info->fs_devices->latest_bdev;
780 em->compress_type = async_extent->compress_type;
781 set_bit(EXTENT_FLAG_PINNED, &em->flags);
782 set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
783 em->generation = -1;
784
785 while (1) {
786 write_lock(&em_tree->lock);
787 ret = add_extent_mapping(em_tree, em, 1);
788 write_unlock(&em_tree->lock);
789 if (ret != -EEXIST) {
790 free_extent_map(em);
791 break;
792 }
793 btrfs_drop_extent_cache(inode, async_extent->start,
794 async_extent->start +
795 async_extent->ram_size - 1, 0);
796 }
797
798 if (ret)
799 goto out_free_reserve;
800
801 ret = btrfs_add_ordered_extent_compress(inode,
802 async_extent->start,
803 ins.objectid,
804 async_extent->ram_size,
805 ins.offset,
806 BTRFS_ORDERED_COMPRESSED,
807 async_extent->compress_type);
808 if (ret) {
809 btrfs_drop_extent_cache(inode, async_extent->start,
810 async_extent->start +
811 async_extent->ram_size - 1, 0);
812 goto out_free_reserve;
813 }
814
815 /*
816 * clear dirty, set writeback and unlock the pages.
817 */
818 extent_clear_unlock_delalloc(inode, async_extent->start,
819 async_extent->start +
820 async_extent->ram_size - 1,
821 NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
822 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
823 PAGE_SET_WRITEBACK);
824 ret = btrfs_submit_compressed_write(inode,
825 async_extent->start,
826 async_extent->ram_size,
827 ins.objectid,
828 ins.offset, async_extent->pages,
829 async_extent->nr_pages);
830 if (ret) {
831 struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
832 struct page *p = async_extent->pages[0];
833 const u64 start = async_extent->start;
834 const u64 end = start + async_extent->ram_size - 1;
835
836 p->mapping = inode->i_mapping;
837 tree->ops->writepage_end_io_hook(p, start, end,
838 NULL, 0);
839 p->mapping = NULL;
840 extent_clear_unlock_delalloc(inode, start, end, NULL, 0,
841 PAGE_END_WRITEBACK |
842 PAGE_SET_ERROR);
843 free_async_extent_pages(async_extent);
844 }
845 alloc_hint = ins.objectid + ins.offset;
846 kfree(async_extent);
847 cond_resched();
848 }
849 return;
850 out_free_reserve:
851 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
852 out_free:
853 extent_clear_unlock_delalloc(inode, async_extent->start,
854 async_extent->start +
855 async_extent->ram_size - 1,
856 NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
857 EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
858 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
859 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
860 PAGE_SET_ERROR);
861 free_async_extent_pages(async_extent);
862 kfree(async_extent);
863 goto again;
864 }
865
866 static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
867 u64 num_bytes)
868 {
869 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
870 struct extent_map *em;
871 u64 alloc_hint = 0;
872
873 read_lock(&em_tree->lock);
874 em = search_extent_mapping(em_tree, start, num_bytes);
875 if (em) {
876 /*
877 * if block start isn't an actual block number then find the
878 * first block in this inode and use that as a hint. If that
879 * block is also bogus then just don't worry about it.
880 */
881 if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
882 free_extent_map(em);
883 em = search_extent_mapping(em_tree, 0, 0);
884 if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
885 alloc_hint = em->block_start;
886 if (em)
887 free_extent_map(em);
888 } else {
889 alloc_hint = em->block_start;
890 free_extent_map(em);
891 }
892 }
893 read_unlock(&em_tree->lock);
894
895 return alloc_hint;
896 }
897
898 /*
899 * when extent_io.c finds a delayed allocation range in the file,
900 * the call backs end up in this code. The basic idea is to
901 * allocate extents on disk for the range, and create ordered data structs
902 * in ram to track those extents.
903 *
904 * locked_page is the page that writepage had locked already. We use
905 * it to make sure we don't do extra locks or unlocks.
906 *
907 * *page_started is set to one if we unlock locked_page and do everything
908 * required to start IO on it. It may be clean and already done with
909 * IO when we return.
910 */
911 static noinline int cow_file_range(struct inode *inode,
912 struct page *locked_page,
913 u64 start, u64 end, int *page_started,
914 unsigned long *nr_written,
915 int unlock)
916 {
917 struct btrfs_root *root = BTRFS_I(inode)->root;
918 u64 alloc_hint = 0;
919 u64 num_bytes;
920 unsigned long ram_size;
921 u64 disk_num_bytes;
922 u64 cur_alloc_size;
923 u64 blocksize = root->sectorsize;
924 struct btrfs_key ins;
925 struct extent_map *em;
926 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
927 int ret = 0;
928
929 if (btrfs_is_free_space_inode(inode)) {
930 WARN_ON_ONCE(1);
931 ret = -EINVAL;
932 goto out_unlock;
933 }
934
935 num_bytes = ALIGN(end - start + 1, blocksize);
936 num_bytes = max(blocksize, num_bytes);
937 disk_num_bytes = num_bytes;
938
939 /* if this is a small write inside eof, kick off defrag */
940 if (num_bytes < 64 * 1024 &&
941 (start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
942 btrfs_add_inode_defrag(NULL, inode);
943
944 if (start == 0) {
945 /* lets try to make an inline extent */
946 ret = cow_file_range_inline(root, inode, start, end, 0, 0,
947 NULL);
948 if (ret == 0) {
949 extent_clear_unlock_delalloc(inode, start, end, NULL,
950 EXTENT_LOCKED | EXTENT_DELALLOC |
951 EXTENT_DEFRAG, PAGE_UNLOCK |
952 PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
953 PAGE_END_WRITEBACK);
954
955 *nr_written = *nr_written +
956 (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
957 *page_started = 1;
958 goto out;
959 } else if (ret < 0) {
960 goto out_unlock;
961 }
962 }
963
964 BUG_ON(disk_num_bytes >
965 btrfs_super_total_bytes(root->fs_info->super_copy));
966
967 alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
968 btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);
969
970 while (disk_num_bytes > 0) {
971 unsigned long op;
972
973 cur_alloc_size = disk_num_bytes;
974 ret = btrfs_reserve_extent(root, cur_alloc_size,
975 root->sectorsize, 0, alloc_hint,
976 &ins, 1, 1);
977 if (ret < 0)
978 goto out_unlock;
979
980 em = alloc_extent_map();
981 if (!em) {
982 ret = -ENOMEM;
983 goto out_reserve;
984 }
985 em->start = start;
986 em->orig_start = em->start;
987 ram_size = ins.offset;
988 em->len = ins.offset;
989 em->mod_start = em->start;
990 em->mod_len = em->len;
991
992 em->block_start = ins.objectid;
993 em->block_len = ins.offset;
994 em->orig_block_len = ins.offset;
995 em->ram_bytes = ram_size;
996 em->bdev = root->fs_info->fs_devices->latest_bdev;
997 set_bit(EXTENT_FLAG_PINNED, &em->flags);
998 em->generation = -1;
999
1000 while (1) {
1001 write_lock(&em_tree->lock);
1002 ret = add_extent_mapping(em_tree, em, 1);
1003 write_unlock(&em_tree->lock);
1004 if (ret != -EEXIST) {
1005 free_extent_map(em);
1006 break;
1007 }
1008 btrfs_drop_extent_cache(inode, start,
1009 start + ram_size - 1, 0);
1010 }
1011 if (ret)
1012 goto out_reserve;
1013
1014 cur_alloc_size = ins.offset;
1015 ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
1016 ram_size, cur_alloc_size, 0);
1017 if (ret)
1018 goto out_drop_extent_cache;
1019
1020 if (root->root_key.objectid ==
1021 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1022 ret = btrfs_reloc_clone_csums(inode, start,
1023 cur_alloc_size);
1024 if (ret)
1025 goto out_drop_extent_cache;
1026 }
1027
1028 if (disk_num_bytes < cur_alloc_size)
1029 break;
1030
1031 /* we're not doing compressed IO, don't unlock the first
1032 * page (which the caller expects to stay locked), don't
1033 * clear any dirty bits and don't set any writeback bits
1034 *
1035 * Do set the Private2 bit so we know this page was properly
1036 * setup for writepage
1037 */
1038 op = unlock ? PAGE_UNLOCK : 0;
1039 op |= PAGE_SET_PRIVATE2;
1040
1041 extent_clear_unlock_delalloc(inode, start,
1042 start + ram_size - 1, locked_page,
1043 EXTENT_LOCKED | EXTENT_DELALLOC,
1044 op);
1045 disk_num_bytes -= cur_alloc_size;
1046 num_bytes -= cur_alloc_size;
1047 alloc_hint = ins.objectid + ins.offset;
1048 start += cur_alloc_size;
1049 }
1050 out:
1051 return ret;
1052
1053 out_drop_extent_cache:
1054 btrfs_drop_extent_cache(inode, start, start + ram_size - 1, 0);
1055 out_reserve:
1056 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
1057 out_unlock:
1058 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1059 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
1060 EXTENT_DELALLOC | EXTENT_DEFRAG,
1061 PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
1062 PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK);
1063 goto out;
1064 }
1065
1066 /*
1067 * work queue call back to started compression on a file and pages
1068 */
1069 static noinline void async_cow_start(struct btrfs_work *work)
1070 {
1071 struct async_cow *async_cow;
1072 int num_added = 0;
1073 async_cow = container_of(work, struct async_cow, work);
1074
1075 compress_file_range(async_cow->inode, async_cow->locked_page,
1076 async_cow->start, async_cow->end, async_cow,
1077 &num_added);
1078 if (num_added == 0) {
1079 btrfs_add_delayed_iput(async_cow->inode);
1080 async_cow->inode = NULL;
1081 }
1082 }
1083
1084 /*
1085 * work queue call back to submit previously compressed pages
1086 */
1087 static noinline void async_cow_submit(struct btrfs_work *work)
1088 {
1089 struct async_cow *async_cow;
1090 struct btrfs_root *root;
1091 unsigned long nr_pages;
1092
1093 async_cow = container_of(work, struct async_cow, work);
1094
1095 root = async_cow->root;
1096 nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
1097 PAGE_CACHE_SHIFT;
1098
1099 if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
1100 5 * 1024 * 1024 &&
1101 waitqueue_active(&root->fs_info->async_submit_wait))
1102 wake_up(&root->fs_info->async_submit_wait);
1103
1104 if (async_cow->inode)
1105 submit_compressed_extents(async_cow->inode, async_cow);
1106 }
1107
1108 static noinline void async_cow_free(struct btrfs_work *work)
1109 {
1110 struct async_cow *async_cow;
1111 async_cow = container_of(work, struct async_cow, work);
1112 if (async_cow->inode)
1113 btrfs_add_delayed_iput(async_cow->inode);
1114 kfree(async_cow);
1115 }
1116
1117 static int cow_file_range_async(struct inode *inode, struct page *locked_page,
1118 u64 start, u64 end, int *page_started,
1119 unsigned long *nr_written)
1120 {
1121 struct async_cow *async_cow;
1122 struct btrfs_root *root = BTRFS_I(inode)->root;
1123 unsigned long nr_pages;
1124 u64 cur_end;
1125 int limit = 10 * 1024 * 1024;
1126
1127 clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
1128 1, 0, NULL, GFP_NOFS);
1129 while (start < end) {
1130 async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
1131 BUG_ON(!async_cow); /* -ENOMEM */
1132 async_cow->inode = igrab(inode);
1133 async_cow->root = root;
1134 async_cow->locked_page = locked_page;
1135 async_cow->start = start;
1136
1137 if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
1138 !btrfs_test_opt(root, FORCE_COMPRESS))
1139 cur_end = end;
1140 else
1141 cur_end = min(end, start + 512 * 1024 - 1);
1142
1143 async_cow->end = cur_end;
1144 INIT_LIST_HEAD(&async_cow->extents);
1145
1146 btrfs_init_work(&async_cow->work,
1147 btrfs_delalloc_helper,
1148 async_cow_start, async_cow_submit,
1149 async_cow_free);
1150
1151 nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
1152 PAGE_CACHE_SHIFT;
1153 atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);
1154
1155 btrfs_queue_work(root->fs_info->delalloc_workers,
1156 &async_cow->work);
1157
1158 if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
1159 wait_event(root->fs_info->async_submit_wait,
1160 (atomic_read(&root->fs_info->async_delalloc_pages) <
1161 limit));
1162 }
1163
1164 while (atomic_read(&root->fs_info->async_submit_draining) &&
1165 atomic_read(&root->fs_info->async_delalloc_pages)) {
1166 wait_event(root->fs_info->async_submit_wait,
1167 (atomic_read(&root->fs_info->async_delalloc_pages) ==
1168 0));
1169 }
1170
1171 *nr_written += nr_pages;
1172 start = cur_end + 1;
1173 }
1174 *page_started = 1;
1175 return 0;
1176 }
1177
1178 static noinline int csum_exist_in_range(struct btrfs_root *root,
1179 u64 bytenr, u64 num_bytes)
1180 {
1181 int ret;
1182 struct btrfs_ordered_sum *sums;
1183 LIST_HEAD(list);
1184
1185 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
1186 bytenr + num_bytes - 1, &list, 0);
1187 if (ret == 0 && list_empty(&list))
1188 return 0;
1189
1190 while (!list_empty(&list)) {
1191 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
1192 list_del(&sums->list);
1193 kfree(sums);
1194 }
1195 return 1;
1196 }
1197
1198 /*
1199 * when nowcow writeback call back. This checks for snapshots or COW copies
1200 * of the extents that exist in the file, and COWs the file as required.
1201 *
1202 * If no cow copies or snapshots exist, we write directly to the existing
1203 * blocks on disk
1204 */
1205 static noinline int run_delalloc_nocow(struct inode *inode,
1206 struct page *locked_page,
1207 u64 start, u64 end, int *page_started, int force,
1208 unsigned long *nr_written)
1209 {
1210 struct btrfs_root *root = BTRFS_I(inode)->root;
1211 struct btrfs_trans_handle *trans;
1212 struct extent_buffer *leaf;
1213 struct btrfs_path *path;
1214 struct btrfs_file_extent_item *fi;
1215 struct btrfs_key found_key;
1216 u64 cow_start;
1217 u64 cur_offset;
1218 u64 extent_end;
1219 u64 extent_offset;
1220 u64 disk_bytenr;
1221 u64 num_bytes;
1222 u64 disk_num_bytes;
1223 u64 ram_bytes;
1224 int extent_type;
1225 int ret, err;
1226 int type;
1227 int nocow;
1228 int check_prev = 1;
1229 bool nolock;
1230 u64 ino = btrfs_ino(inode);
1231
1232 path = btrfs_alloc_path();
1233 if (!path) {
1234 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1235 EXTENT_LOCKED | EXTENT_DELALLOC |
1236 EXTENT_DO_ACCOUNTING |
1237 EXTENT_DEFRAG, PAGE_UNLOCK |
1238 PAGE_CLEAR_DIRTY |
1239 PAGE_SET_WRITEBACK |
1240 PAGE_END_WRITEBACK);
1241 return -ENOMEM;
1242 }
1243
1244 nolock = btrfs_is_free_space_inode(inode);
1245
1246 if (nolock)
1247 trans = btrfs_join_transaction_nolock(root);
1248 else
1249 trans = btrfs_join_transaction(root);
1250
1251 if (IS_ERR(trans)) {
1252 extent_clear_unlock_delalloc(inode, start, end, locked_page,
1253 EXTENT_LOCKED | EXTENT_DELALLOC |
1254 EXTENT_DO_ACCOUNTING |
1255 EXTENT_DEFRAG, PAGE_UNLOCK |
1256 PAGE_CLEAR_DIRTY |
1257 PAGE_SET_WRITEBACK |
1258 PAGE_END_WRITEBACK);
1259 btrfs_free_path(path);
1260 return PTR_ERR(trans);
1261 }
1262
1263 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1264
1265 cow_start = (u64)-1;
1266 cur_offset = start;
1267 while (1) {
1268 ret = btrfs_lookup_file_extent(trans, root, path, ino,
1269 cur_offset, 0);
1270 if (ret < 0)
1271 goto error;
1272 if (ret > 0 && path->slots[0] > 0 && check_prev) {
1273 leaf = path->nodes[0];
1274 btrfs_item_key_to_cpu(leaf, &found_key,
1275 path->slots[0] - 1);
1276 if (found_key.objectid == ino &&
1277 found_key.type == BTRFS_EXTENT_DATA_KEY)
1278 path->slots[0]--;
1279 }
1280 check_prev = 0;
1281 next_slot:
1282 leaf = path->nodes[0];
1283 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
1284 ret = btrfs_next_leaf(root, path);
1285 if (ret < 0)
1286 goto error;
1287 if (ret > 0)
1288 break;
1289 leaf = path->nodes[0];
1290 }
1291
1292 nocow = 0;
1293 disk_bytenr = 0;
1294 num_bytes = 0;
1295 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
1296
1297 if (found_key.objectid > ino ||
1298 found_key.type > BTRFS_EXTENT_DATA_KEY ||
1299 found_key.offset > end)
1300 break;
1301
1302 if (found_key.offset > cur_offset) {
1303 extent_end = found_key.offset;
1304 extent_type = 0;
1305 goto out_check;
1306 }
1307
1308 fi = btrfs_item_ptr(leaf, path->slots[0],
1309 struct btrfs_file_extent_item);
1310 extent_type = btrfs_file_extent_type(leaf, fi);
1311
1312 ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
1313 if (extent_type == BTRFS_FILE_EXTENT_REG ||
1314 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1315 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1316 extent_offset = btrfs_file_extent_offset(leaf, fi);
1317 extent_end = found_key.offset +
1318 btrfs_file_extent_num_bytes(leaf, fi);
1319 disk_num_bytes =
1320 btrfs_file_extent_disk_num_bytes(leaf, fi);
1321 if (extent_end <= start) {
1322 path->slots[0]++;
1323 goto next_slot;
1324 }
1325 if (disk_bytenr == 0)
1326 goto out_check;
1327 if (btrfs_file_extent_compression(leaf, fi) ||
1328 btrfs_file_extent_encryption(leaf, fi) ||
1329 btrfs_file_extent_other_encoding(leaf, fi))
1330 goto out_check;
1331 if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
1332 goto out_check;
1333 if (btrfs_extent_readonly(root, disk_bytenr))
1334 goto out_check;
1335 if (btrfs_cross_ref_exist(trans, root, ino,
1336 found_key.offset -
1337 extent_offset, disk_bytenr))
1338 goto out_check;
1339 disk_bytenr += extent_offset;
1340 disk_bytenr += cur_offset - found_key.offset;
1341 num_bytes = min(end + 1, extent_end) - cur_offset;
1342 /*
1343 * if there are pending snapshots for this root,
1344 * we fall into common COW way.
1345 */
1346 if (!nolock) {
1347 err = btrfs_start_write_no_snapshoting(root);
1348 if (!err)
1349 goto out_check;
1350 }
1351 /*
1352 * force cow if csum exists in the range.
1353 * this ensure that csum for a given extent are
1354 * either valid or do not exist.
1355 */
1356 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
1357 goto out_check;
1358 nocow = 1;
1359 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
1360 extent_end = found_key.offset +
1361 btrfs_file_extent_inline_len(leaf,
1362 path->slots[0], fi);
1363 extent_end = ALIGN(extent_end, root->sectorsize);
1364 } else {
1365 BUG_ON(1);
1366 }
1367 out_check:
1368 if (extent_end <= start) {
1369 path->slots[0]++;
1370 if (!nolock && nocow)
1371 btrfs_end_write_no_snapshoting(root);
1372 goto next_slot;
1373 }
1374 if (!nocow) {
1375 if (cow_start == (u64)-1)
1376 cow_start = cur_offset;
1377 cur_offset = extent_end;
1378 if (cur_offset > end)
1379 break;
1380 path->slots[0]++;
1381 goto next_slot;
1382 }
1383
1384 btrfs_release_path(path);
1385 if (cow_start != (u64)-1) {
1386 ret = cow_file_range(inode, locked_page,
1387 cow_start, found_key.offset - 1,
1388 page_started, nr_written, 1);
1389 if (ret) {
1390 if (!nolock && nocow)
1391 btrfs_end_write_no_snapshoting(root);
1392 goto error;
1393 }
1394 cow_start = (u64)-1;
1395 }
1396
1397 if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
1398 struct extent_map *em;
1399 struct extent_map_tree *em_tree;
1400 em_tree = &BTRFS_I(inode)->extent_tree;
1401 em = alloc_extent_map();
1402 BUG_ON(!em); /* -ENOMEM */
1403 em->start = cur_offset;
1404 em->orig_start = found_key.offset - extent_offset;
1405 em->len = num_bytes;
1406 em->block_len = num_bytes;
1407 em->block_start = disk_bytenr;
1408 em->orig_block_len = disk_num_bytes;
1409 em->ram_bytes = ram_bytes;
1410 em->bdev = root->fs_info->fs_devices->latest_bdev;
1411 em->mod_start = em->start;
1412 em->mod_len = em->len;
1413 set_bit(EXTENT_FLAG_PINNED, &em->flags);
1414 set_bit(EXTENT_FLAG_FILLING, &em->flags);
1415 em->generation = -1;
1416 while (1) {
1417 write_lock(&em_tree->lock);
1418 ret = add_extent_mapping(em_tree, em, 1);
1419 write_unlock(&em_tree->lock);
1420 if (ret != -EEXIST) {
1421 free_extent_map(em);
1422 break;
1423 }
1424 btrfs_drop_extent_cache(inode, em->start,
1425 em->start + em->len - 1, 0);
1426 }
1427 type = BTRFS_ORDERED_PREALLOC;
1428 } else {
1429 type = BTRFS_ORDERED_NOCOW;
1430 }
1431
1432 ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
1433 num_bytes, num_bytes, type);
1434 BUG_ON(ret); /* -ENOMEM */
1435
1436 if (root->root_key.objectid ==
1437 BTRFS_DATA_RELOC_TREE_OBJECTID) {
1438 ret = btrfs_reloc_clone_csums(inode, cur_offset,
1439 num_bytes);
1440 if (ret) {
1441 if (!nolock && nocow)
1442 btrfs_end_write_no_snapshoting(root);
1443 goto error;
1444 }
1445 }
1446
1447 extent_clear_unlock_delalloc(inode, cur_offset,
1448 cur_offset + num_bytes - 1,
1449 locked_page, EXTENT_LOCKED |
1450 EXTENT_DELALLOC, PAGE_UNLOCK |
1451 PAGE_SET_PRIVATE2);
1452 if (!nolock && nocow)
1453 btrfs_end_write_no_snapshoting(root);
1454 cur_offset = extent_end;
1455 if (cur_offset > end)
1456 break;
1457 }
1458 btrfs_release_path(path);
1459
1460 if (cur_offset <= end && cow_start == (u64)-1) {
1461 cow_start = cur_offset;
1462 cur_offset = end;
1463 }
1464
1465 if (cow_start != (u64)-1) {
1466 ret = cow_file_range(inode, locked_page, cow_start, end,
1467 page_started, nr_written, 1);
1468 if (ret)
1469 goto error;
1470 }
1471
1472 error:
1473 err = btrfs_end_transaction(trans, root);
1474 if (!ret)
1475 ret = err;
1476
1477 if (ret && cur_offset < end)
1478 extent_clear_unlock_delalloc(inode, cur_offset, end,
1479 locked_page, EXTENT_LOCKED |
1480 EXTENT_DELALLOC | EXTENT_DEFRAG |
1481 EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
1482 PAGE_CLEAR_DIRTY |
1483 PAGE_SET_WRITEBACK |
1484 PAGE_END_WRITEBACK);
1485 btrfs_free_path(path);
1486 return ret;
1487 }
1488
1489 static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
1490 {
1491
1492 if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
1493 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
1494 return 0;
1495
1496 /*
1497 * @defrag_bytes is a hint value, no spinlock held here,
1498 * if is not zero, it means the file is defragging.
1499 * Force cow if given extent needs to be defragged.
1500 */
1501 if (BTRFS_I(inode)->defrag_bytes &&
1502 test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
1503 EXTENT_DEFRAG, 0, NULL))
1504 return 1;
1505
1506 return 0;
1507 }
1508
1509 /*
1510 * extent_io.c call back to do delayed allocation processing
1511 */
1512 static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1513 u64 start, u64 end, int *page_started,
1514 unsigned long *nr_written)
1515 {
1516 int ret;
1517 int force_cow = need_force_cow(inode, start, end);
1518
1519 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
1520 ret = run_delalloc_nocow(inode, locked_page, start, end,
1521 page_started, 1, nr_written);
1522 } else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
1523 ret = run_delalloc_nocow(inode, locked_page, start, end,
1524 page_started, 0, nr_written);
1525 } else if (!inode_need_compress(inode)) {
1526 ret = cow_file_range(inode, locked_page, start, end,
1527 page_started, nr_written, 1);
1528 } else {
1529 set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1530 &BTRFS_I(inode)->runtime_flags);
1531 ret = cow_file_range_async(inode, locked_page, start, end,
1532 page_started, nr_written);
1533 }
1534 return ret;
1535 }
1536
1537 static void btrfs_split_extent_hook(struct inode *inode,
1538 struct extent_state *orig, u64 split)
1539 {
1540 u64 size;
1541
1542 /* not delalloc, ignore it */
1543 if (!(orig->state & EXTENT_DELALLOC))
1544 return;
1545
1546 size = orig->end - orig->start + 1;
1547 if (size > BTRFS_MAX_EXTENT_SIZE) {
1548 u64 num_extents;
1549 u64 new_size;
1550
1551 /*
1552 * See the explanation in btrfs_merge_extent_hook, the same
1553 * applies here, just in reverse.
1554 */
1555 new_size = orig->end - split + 1;
1556 num_extents = div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1557 BTRFS_MAX_EXTENT_SIZE);
1558 new_size = split - orig->start;
1559 num_extents += div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1560 BTRFS_MAX_EXTENT_SIZE);
1561 if (div64_u64(size + BTRFS_MAX_EXTENT_SIZE - 1,
1562 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1563 return;
1564 }
1565
1566 spin_lock(&BTRFS_I(inode)->lock);
1567 BTRFS_I(inode)->outstanding_extents++;
1568 spin_unlock(&BTRFS_I(inode)->lock);
1569 }
1570
1571 /*
1572 * extent_io.c merge_extent_hook, used to track merged delayed allocation
1573 * extents so we can keep track of new extents that are just merged onto old
1574 * extents, such as when we are doing sequential writes, so we can properly
1575 * account for the metadata space we'll need.
1576 */
1577 static void btrfs_merge_extent_hook(struct inode *inode,
1578 struct extent_state *new,
1579 struct extent_state *other)
1580 {
1581 u64 new_size, old_size;
1582 u64 num_extents;
1583
1584 /* not delalloc, ignore it */
1585 if (!(other->state & EXTENT_DELALLOC))
1586 return;
1587
1588 if (new->start > other->start)
1589 new_size = new->end - other->start + 1;
1590 else
1591 new_size = other->end - new->start + 1;
1592
1593 /* we're not bigger than the max, unreserve the space and go */
1594 if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
1595 spin_lock(&BTRFS_I(inode)->lock);
1596 BTRFS_I(inode)->outstanding_extents--;
1597 spin_unlock(&BTRFS_I(inode)->lock);
1598 return;
1599 }
1600
1601 /*
1602 * We have to add up either side to figure out how many extents were
1603 * accounted for before we merged into one big extent. If the number of
1604 * extents we accounted for is <= the amount we need for the new range
1605 * then we can return, otherwise drop. Think of it like this
1606 *
1607 * [ 4k][MAX_SIZE]
1608 *
1609 * So we've grown the extent by a MAX_SIZE extent, this would mean we
1610 * need 2 outstanding extents, on one side we have 1 and the other side
1611 * we have 1 so they are == and we can return. But in this case
1612 *
1613 * [MAX_SIZE+4k][MAX_SIZE+4k]
1614 *
1615 * Each range on their own accounts for 2 extents, but merged together
1616 * they are only 3 extents worth of accounting, so we need to drop in
1617 * this case.
1618 */
1619 old_size = other->end - other->start + 1;
1620 num_extents = div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1621 BTRFS_MAX_EXTENT_SIZE);
1622 old_size = new->end - new->start + 1;
1623 num_extents += div64_u64(old_size + BTRFS_MAX_EXTENT_SIZE - 1,
1624 BTRFS_MAX_EXTENT_SIZE);
1625
1626 if (div64_u64(new_size + BTRFS_MAX_EXTENT_SIZE - 1,
1627 BTRFS_MAX_EXTENT_SIZE) >= num_extents)
1628 return;
1629
1630 spin_lock(&BTRFS_I(inode)->lock);
1631 BTRFS_I(inode)->outstanding_extents--;
1632 spin_unlock(&BTRFS_I(inode)->lock);
1633 }
1634
1635 static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
1636 struct inode *inode)
1637 {
1638 spin_lock(&root->delalloc_lock);
1639 if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1640 list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
1641 &root->delalloc_inodes);
1642 set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1643 &BTRFS_I(inode)->runtime_flags);
1644 root->nr_delalloc_inodes++;
1645 if (root->nr_delalloc_inodes == 1) {
1646 spin_lock(&root->fs_info->delalloc_root_lock);
1647 BUG_ON(!list_empty(&root->delalloc_root));
1648 list_add_tail(&root->delalloc_root,
1649 &root->fs_info->delalloc_roots);
1650 spin_unlock(&root->fs_info->delalloc_root_lock);
1651 }
1652 }
1653 spin_unlock(&root->delalloc_lock);
1654 }
1655
1656 static void btrfs_del_delalloc_inode(struct btrfs_root *root,
1657 struct inode *inode)
1658 {
1659 spin_lock(&root->delalloc_lock);
1660 if (!list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1661 list_del_init(&BTRFS_I(inode)->delalloc_inodes);
1662 clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1663 &BTRFS_I(inode)->runtime_flags);
1664 root->nr_delalloc_inodes--;
1665 if (!root->nr_delalloc_inodes) {
1666 spin_lock(&root->fs_info->delalloc_root_lock);
1667 BUG_ON(list_empty(&root->delalloc_root));
1668 list_del_init(&root->delalloc_root);
1669 spin_unlock(&root->fs_info->delalloc_root_lock);
1670 }
1671 }
1672 spin_unlock(&root->delalloc_lock);
1673 }
1674
1675 /*
1676 * extent_io.c set_bit_hook, used to track delayed allocation
1677 * bytes in this file, and to maintain the list of inodes that
1678 * have pending delalloc work to be done.
1679 */
1680 static void btrfs_set_bit_hook(struct inode *inode,
1681 struct extent_state *state, unsigned *bits)
1682 {
1683
1684 if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
1685 WARN_ON(1);
1686 /*
1687 * set_bit and clear bit hooks normally require _irqsave/restore
1688 * but in this case, we are only testing for the DELALLOC
1689 * bit, which is only set or cleared with irqs on
1690 */
1691 if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1692 struct btrfs_root *root = BTRFS_I(inode)->root;
1693 u64 len = state->end + 1 - state->start;
1694 bool do_list = !btrfs_is_free_space_inode(inode);
1695
1696 if (*bits & EXTENT_FIRST_DELALLOC) {
1697 *bits &= ~EXTENT_FIRST_DELALLOC;
1698 } else {
1699 spin_lock(&BTRFS_I(inode)->lock);
1700 BTRFS_I(inode)->outstanding_extents++;
1701 spin_unlock(&BTRFS_I(inode)->lock);
1702 }
1703
1704 /* For sanity tests */
1705 if (btrfs_test_is_dummy_root(root))
1706 return;
1707
1708 __percpu_counter_add(&root->fs_info->delalloc_bytes, len,
1709 root->fs_info->delalloc_batch);
1710 spin_lock(&BTRFS_I(inode)->lock);
1711 BTRFS_I(inode)->delalloc_bytes += len;
1712 if (*bits & EXTENT_DEFRAG)
1713 BTRFS_I(inode)->defrag_bytes += len;
1714 if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1715 &BTRFS_I(inode)->runtime_flags))
1716 btrfs_add_delalloc_inodes(root, inode);
1717 spin_unlock(&BTRFS_I(inode)->lock);
1718 }
1719 }
1720
1721 /*
1722 * extent_io.c clear_bit_hook, see set_bit_hook for why
1723 */
1724 static void btrfs_clear_bit_hook(struct inode *inode,
1725 struct extent_state *state,
1726 unsigned *bits)
1727 {
1728 u64 len = state->end + 1 - state->start;
1729 u64 num_extents = div64_u64(len + BTRFS_MAX_EXTENT_SIZE -1,
1730 BTRFS_MAX_EXTENT_SIZE);
1731
1732 spin_lock(&BTRFS_I(inode)->lock);
1733 if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG))
1734 BTRFS_I(inode)->defrag_bytes -= len;
1735 spin_unlock(&BTRFS_I(inode)->lock);
1736
1737 /*
1738 * set_bit and clear bit hooks normally require _irqsave/restore
1739 * but in this case, we are only testing for the DELALLOC
1740 * bit, which is only set or cleared with irqs on
1741 */
1742 if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1743 struct btrfs_root *root = BTRFS_I(inode)->root;
1744 bool do_list = !btrfs_is_free_space_inode(inode);
1745
1746 if (*bits & EXTENT_FIRST_DELALLOC) {
1747 *bits &= ~EXTENT_FIRST_DELALLOC;
1748 } else if (!(*bits & EXTENT_DO_ACCOUNTING)) {
1749 spin_lock(&BTRFS_I(inode)->lock);
1750 BTRFS_I(inode)->outstanding_extents -= num_extents;
1751 spin_unlock(&BTRFS_I(inode)->lock);
1752 }
1753
1754 /*
1755 * We don't reserve metadata space for space cache inodes so we
1756 * don't need to call dellalloc_release_metadata if there is an
1757 * error.
1758 */
1759 if (*bits & EXTENT_DO_ACCOUNTING &&
1760 root != root->fs_info->tree_root)
1761 btrfs_delalloc_release_metadata(inode, len);
1762
1763 /* For sanity tests. */
1764 if (btrfs_test_is_dummy_root(root))
1765 return;
1766
1767 if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
1768 && do_list && !(state->state & EXTENT_NORESERVE))
1769 btrfs_free_reserved_data_space(inode, len);
1770
1771 __percpu_counter_add(&root->fs_info->delalloc_bytes, -len,
1772 root->fs_info->delalloc_batch);
1773 spin_lock(&BTRFS_I(inode)->lock);
1774 BTRFS_I(inode)->delalloc_bytes -= len;
1775 if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1776 test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
1777 &BTRFS_I(inode)->runtime_flags))
1778 btrfs_del_delalloc_inode(root, inode);
1779 spin_unlock(&BTRFS_I(inode)->lock);
1780 }
1781 }
1782
1783 /*
1784 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
1785 * we don't create bios that span stripes or chunks
1786 */
1787 int btrfs_merge_bio_hook(int rw, struct page *page, unsigned long offset,
1788 size_t size, struct bio *bio,
1789 unsigned long bio_flags)
1790 {
1791 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
1792 u64 logical = (u64)bio->bi_iter.bi_sector << 9;
1793 u64 length = 0;
1794 u64 map_length;
1795 int ret;
1796
1797 if (bio_flags & EXTENT_BIO_COMPRESSED)
1798 return 0;
1799
1800 length = bio->bi_iter.bi_size;
1801 map_length = length;
1802 ret = btrfs_map_block(root->fs_info, rw, logical,
1803 &map_length, NULL, 0);
1804 /* Will always return 0 with map_multi == NULL */
1805 BUG_ON(ret < 0);
1806 if (map_length < length + size)
1807 return 1;
1808 return 0;
1809 }
1810
1811 /*
1812 * in order to insert checksums into the metadata in large chunks,
1813 * we wait until bio submission time. All the pages in the bio are
1814 * checksummed and sums are attached onto the ordered extent record.
1815 *
1816 * At IO completion time the cums attached on the ordered extent record
1817 * are inserted into the btree
1818 */
1819 static int __btrfs_submit_bio_start(struct inode *inode, int rw,
1820 struct bio *bio, int mirror_num,
1821 unsigned long bio_flags,
1822 u64 bio_offset)
1823 {
1824 struct btrfs_root *root = BTRFS_I(inode)->root;
1825 int ret = 0;
1826
1827 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1828 BUG_ON(ret); /* -ENOMEM */
1829 return 0;
1830 }
1831
1832 /*
1833 * in order to insert checksums into the metadata in large chunks,
1834 * we wait until bio submission time. All the pages in the bio are
1835 * checksummed and sums are attached onto the ordered extent record.
1836 *
1837 * At IO completion time the cums attached on the ordered extent record
1838 * are inserted into the btree
1839 */
1840 static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1841 int mirror_num, unsigned long bio_flags,
1842 u64 bio_offset)
1843 {
1844 struct btrfs_root *root = BTRFS_I(inode)->root;
1845 int ret;
1846
1847 ret = btrfs_map_bio(root, rw, bio, mirror_num, 1);
1848 if (ret)
1849 bio_endio(bio, ret);
1850 return ret;
1851 }
1852
1853 /*
1854 * extent_io.c submission hook. This does the right thing for csum calculation
1855 * on write, or reading the csums from the tree before a read
1856 */
1857 static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1858 int mirror_num, unsigned long bio_flags,
1859 u64 bio_offset)
1860 {
1861 struct btrfs_root *root = BTRFS_I(inode)->root;
1862 int ret = 0;
1863 int skip_sum;
1864 int metadata = 0;
1865 int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
1866
1867 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1868
1869 if (btrfs_is_free_space_inode(inode))
1870 metadata = 2;
1871
1872 if (!(rw & REQ_WRITE)) {
1873 ret = btrfs_bio_wq_end_io(root->fs_info, bio, metadata);
1874 if (ret)
1875 goto out;
1876
1877 if (bio_flags & EXTENT_BIO_COMPRESSED) {
1878 ret = btrfs_submit_compressed_read(inode, bio,
1879 mirror_num,
1880 bio_flags);
1881 goto out;
1882 } else if (!skip_sum) {
1883 ret = btrfs_lookup_bio_sums(root, inode, bio, NULL);
1884 if (ret)
1885 goto out;
1886 }
1887 goto mapit;
1888 } else if (async && !skip_sum) {
1889 /* csum items have already been cloned */
1890 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
1891 goto mapit;
1892 /* we're doing a write, do the async checksumming */
1893 ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1894 inode, rw, bio, mirror_num,
1895 bio_flags, bio_offset,
1896 __btrfs_submit_bio_start,
1897 __btrfs_submit_bio_done);
1898 goto out;
1899 } else if (!skip_sum) {
1900 ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1901 if (ret)
1902 goto out;
1903 }
1904
1905 mapit:
1906 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
1907
1908 out:
1909 if (ret < 0)
1910 bio_endio(bio, ret);
1911 return ret;
1912 }
1913
1914 /*
1915 * given a list of ordered sums record them in the inode. This happens
1916 * at IO completion time based on sums calculated at bio submission time.
1917 */
1918 static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1919 struct inode *inode, u64 file_offset,
1920 struct list_head *list)
1921 {
1922 struct btrfs_ordered_sum *sum;
1923
1924 list_for_each_entry(sum, list, list) {
1925 trans->adding_csums = 1;
1926 btrfs_csum_file_blocks(trans,
1927 BTRFS_I(inode)->root->fs_info->csum_root, sum);
1928 trans->adding_csums = 0;
1929 }
1930 return 0;
1931 }
1932
1933 int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
1934 struct extent_state **cached_state)
1935 {
1936 WARN_ON((end & (PAGE_CACHE_SIZE - 1)) == 0);
1937 return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1938 cached_state, GFP_NOFS);
1939 }
1940
1941 /* see btrfs_writepage_start_hook for details on why this is required */
1942 struct btrfs_writepage_fixup {
1943 struct page *page;
1944 struct btrfs_work work;
1945 };
1946
1947 static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1948 {
1949 struct btrfs_writepage_fixup *fixup;
1950 struct btrfs_ordered_extent *ordered;
1951 struct extent_state *cached_state = NULL;
1952 struct page *page;
1953 struct inode *inode;
1954 u64 page_start;
1955 u64 page_end;
1956 int ret;
1957
1958 fixup = container_of(work, struct btrfs_writepage_fixup, work);
1959 page = fixup->page;
1960 again:
1961 lock_page(page);
1962 if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
1963 ClearPageChecked(page);
1964 goto out_page;
1965 }
1966
1967 inode = page->mapping->host;
1968 page_start = page_offset(page);
1969 page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;
1970
1971 lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
1972 &cached_state);
1973
1974 /* already ordered? We're done */
1975 if (PagePrivate2(page))
1976 goto out;
1977
1978 ordered = btrfs_lookup_ordered_extent(inode, page_start);
1979 if (ordered) {
1980 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
1981 page_end, &cached_state, GFP_NOFS);
1982 unlock_page(page);
1983 btrfs_start_ordered_extent(inode, ordered, 1);
1984 btrfs_put_ordered_extent(ordered);
1985 goto again;
1986 }
1987
1988 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
1989 if (ret) {
1990 mapping_set_error(page->mapping, ret);
1991 end_extent_writepage(page, ret, page_start, page_end);
1992 ClearPageChecked(page);
1993 goto out;
1994 }
1995
1996 btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1997 ClearPageChecked(page);
1998 set_page_dirty(page);
1999 out:
2000 unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
2001 &cached_state, GFP_NOFS);
2002 out_page:
2003 unlock_page(page);
2004 page_cache_release(page);
2005 kfree(fixup);
2006 }
2007
2008 /*
2009 * There are a few paths in the higher layers of the kernel that directly
2010 * set the page dirty bit without asking the filesystem if it is a
2011 * good idea. This causes problems because we want to make sure COW
2012 * properly happens and the data=ordered rules are followed.
2013 *
2014 * In our case any range that doesn't have the ORDERED bit set
2015 * hasn't been properly setup for IO. We kick off an async process
2016 * to fix it up. The async helper will wait for ordered extents, set
2017 * the delalloc bit and make it safe to write the page.
2018 */
2019 static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
2020 {
2021 struct inode *inode = page->mapping->host;
2022 struct btrfs_writepage_fixup *fixup;
2023 struct btrfs_root *root = BTRFS_I(inode)->root;
2024
2025 /* this page is properly in the ordered list */
2026 if (TestClearPagePrivate2(page))
2027 return 0;
2028
2029 if (PageChecked(page))
2030 return -EAGAIN;
2031
2032 fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
2033 if (!fixup)
2034 return -EAGAIN;
2035
2036 SetPageChecked(page);
2037 page_cache_get(page);
2038 btrfs_init_work(&fixup->work, btrfs_fixup_helper,
2039 btrfs_writepage_fixup_worker, NULL, NULL);
2040 fixup->page = page;
2041 btrfs_queue_work(root->fs_info->fixup_workers, &fixup->work);
2042 return -EBUSY;
2043 }
2044
2045 static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
2046 struct inode *inode, u64 file_pos,
2047 u64 disk_bytenr, u64 disk_num_bytes,
2048 u64 num_bytes, u64 ram_bytes,
2049 u8 compression, u8 encryption,
2050 u16 other_encoding, int extent_type)
2051 {
2052 struct btrfs_root *root = BTRFS_I(inode)->root;
2053 struct btrfs_file_extent_item *fi;
2054 struct btrfs_path *path;
2055 struct extent_buffer *leaf;
2056 struct btrfs_key ins;
2057 int extent_inserted = 0;
2058 int ret;
2059
2060 path = btrfs_alloc_path();
2061 if (!path)
2062 return -ENOMEM;
2063
2064 /*
2065 * we may be replacing one extent in the tree with another.
2066 * The new extent is pinned in the extent map, and we don't want
2067 * to drop it from the cache until it is completely in the btree.
2068 *
2069 * So, tell btrfs_drop_extents to leave this extent in the cache.
2070 * the caller is expected to unpin it and allow it to be merged
2071 * with the others.
2072 */
2073 ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
2074 file_pos + num_bytes, NULL, 0,
2075 1, sizeof(*fi), &extent_inserted);
2076 if (ret)
2077 goto out;
2078
2079 if (!extent_inserted) {
2080 ins.objectid = btrfs_ino(inode);
2081 ins.offset = file_pos;
2082 ins.type = BTRFS_EXTENT_DATA_KEY;
2083
2084 path->leave_spinning = 1;
2085 ret = btrfs_insert_empty_item(trans, root, path, &ins,
2086 sizeof(*fi));
2087 if (ret)
2088 goto out;
2089 }
2090 leaf = path->nodes[0];
2091 fi = btrfs_item_ptr(leaf, path->slots[0],
2092 struct btrfs_file_extent_item);
2093 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2094 btrfs_set_file_extent_type(leaf, fi, extent_type);
2095 btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
2096 btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
2097 btrfs_set_file_extent_offset(leaf, fi, 0);
2098 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2099 btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
2100 btrfs_set_file_extent_compression(leaf, fi, compression);
2101 btrfs_set_file_extent_encryption(leaf, fi, encryption);
2102 btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
2103
2104 btrfs_mark_buffer_dirty(leaf);
2105 btrfs_release_path(path);
2106
2107 inode_add_bytes(inode, num_bytes);
2108
2109 ins.objectid = disk_bytenr;
2110 ins.offset = disk_num_bytes;
2111 ins.type = BTRFS_EXTENT_ITEM_KEY;
2112 ret = btrfs_alloc_reserved_file_extent(trans, root,
2113 root->root_key.objectid,
2114 btrfs_ino(inode), file_pos, &ins);
2115 out:
2116 btrfs_free_path(path);
2117
2118 return ret;
2119 }
2120
2121 /* snapshot-aware defrag */
2122 struct sa_defrag_extent_backref {
2123 struct rb_node node;
2124 struct old_sa_defrag_extent *old;
2125 u64 root_id;
2126 u64 inum;
2127 u64 file_pos;
2128 u64 extent_offset;
2129 u64 num_bytes;
2130 u64 generation;
2131 };
2132
2133 struct old_sa_defrag_extent {
2134 struct list_head list;
2135 struct new_sa_defrag_extent *new;
2136
2137 u64 extent_offset;
2138 u64 bytenr;
2139 u64 offset;
2140 u64 len;
2141 int count;
2142 };
2143
2144 struct new_sa_defrag_extent {
2145 struct rb_root root;
2146 struct list_head head;
2147 struct btrfs_path *path;
2148 struct inode *inode;
2149 u64 file_pos;
2150 u64 len;
2151 u64 bytenr;
2152 u64 disk_len;
2153 u8 compress_type;
2154 };
2155
2156 static int backref_comp(struct sa_defrag_extent_backref *b1,
2157 struct sa_defrag_extent_backref *b2)
2158 {
2159 if (b1->root_id < b2->root_id)
2160 return -1;
2161 else if (b1->root_id > b2->root_id)
2162 return 1;
2163
2164 if (b1->inum < b2->inum)
2165 return -1;
2166 else if (b1->inum > b2->inum)
2167 return 1;
2168
2169 if (b1->file_pos < b2->file_pos)
2170 return -1;
2171 else if (b1->file_pos > b2->file_pos)
2172 return 1;
2173
2174 /*
2175 * [------------------------------] ===> (a range of space)
2176 * |<--->| |<---->| =============> (fs/file tree A)
2177 * |<---------------------------->| ===> (fs/file tree B)
2178 *
2179 * A range of space can refer to two file extents in one tree while
2180 * refer to only one file extent in another tree.
2181 *
2182 * So we may process a disk offset more than one time(two extents in A)
2183 * and locate at the same extent(one extent in B), then insert two same
2184 * backrefs(both refer to the extent in B).
2185 */
2186 return 0;
2187 }
2188
2189 static void backref_insert(struct rb_root *root,
2190 struct sa_defrag_extent_backref *backref)
2191 {
2192 struct rb_node **p = &root->rb_node;
2193 struct rb_node *parent = NULL;
2194 struct sa_defrag_extent_backref *entry;
2195 int ret;
2196
2197 while (*p) {
2198 parent = *p;
2199 entry = rb_entry(parent, struct sa_defrag_extent_backref, node);
2200
2201 ret = backref_comp(backref, entry);
2202 if (ret < 0)
2203 p = &(*p)->rb_left;
2204 else
2205 p = &(*p)->rb_right;
2206 }
2207
2208 rb_link_node(&backref->node, parent, p);
2209 rb_insert_color(&backref->node, root);
2210 }
2211
2212 /*
2213 * Note the backref might has changed, and in this case we just return 0.
2214 */
2215 static noinline int record_one_backref(u64 inum, u64 offset, u64 root_id,
2216 void *ctx)
2217 {
2218 struct btrfs_file_extent_item *extent;
2219 struct btrfs_fs_info *fs_info;
2220 struct old_sa_defrag_extent *old = ctx;
2221 struct new_sa_defrag_extent *new = old->new;
2222 struct btrfs_path *path = new->path;
2223 struct btrfs_key key;
2224 struct btrfs_root *root;
2225 struct sa_defrag_extent_backref *backref;
2226 struct extent_buffer *leaf;
2227 struct inode *inode = new->inode;
2228 int slot;
2229 int ret;
2230 u64 extent_offset;
2231 u64 num_bytes;
2232
2233 if (BTRFS_I(inode)->root->root_key.objectid == root_id &&
2234 inum == btrfs_ino(inode))
2235 return 0;
2236
2237 key.objectid = root_id;
2238 key.type = BTRFS_ROOT_ITEM_KEY;
2239 key.offset = (u64)-1;
2240
2241 fs_info = BTRFS_I(inode)->root->fs_info;
2242 root = btrfs_read_fs_root_no_name(fs_info, &key);
2243 if (IS_ERR(root)) {
2244 if (PTR_ERR(root) == -ENOENT)
2245 return 0;
2246 WARN_ON(1);
2247 pr_debug("inum=%llu, offset=%llu, root_id=%llu\n",
2248 inum, offset, root_id);
2249 return PTR_ERR(root);
2250 }
2251
2252 key.objectid = inum;
2253 key.type = BTRFS_EXTENT_DATA_KEY;
2254 if (offset > (u64)-1 << 32)
2255 key.offset = 0;
2256 else
2257 key.offset = offset;
2258
2259 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2260 if (WARN_ON(ret < 0))
2261 return ret;
2262 ret = 0;
2263
2264 while (1) {
2265 cond_resched();
2266
2267 leaf = path->nodes[0];
2268 slot = path->slots[0];
2269
2270 if (slot >= btrfs_header_nritems(leaf)) {
2271 ret = btrfs_next_leaf(root, path);
2272 if (ret < 0) {
2273 goto out;
2274 } else if (ret > 0) {
2275 ret = 0;
2276 goto out;
2277 }
2278 continue;
2279 }
2280
2281 path->slots[0]++;
2282
2283 btrfs_item_key_to_cpu(leaf, &key, slot);
2284
2285 if (key.objectid > inum)
2286 goto out;
2287
2288 if (key.objectid < inum || key.type != BTRFS_EXTENT_DATA_KEY)
2289 continue;
2290
2291 extent = btrfs_item_ptr(leaf, slot,
2292 struct btrfs_file_extent_item);
2293
2294 if (btrfs_file_extent_disk_bytenr(leaf, extent) != old->bytenr)
2295 continue;
2296
2297 /*
2298 * 'offset' refers to the exact key.offset,
2299 * NOT the 'offset' field in btrfs_extent_data_ref, ie.
2300 * (key.offset - extent_offset).
2301 */
2302 if (key.offset != offset)
2303 continue;
2304
2305 extent_offset = btrfs_file_extent_offset(leaf, extent);
2306 num_bytes = btrfs_file_extent_num_bytes(leaf, extent);
2307
2308 if (extent_offset >= old->extent_offset + old->offset +
2309 old->len || extent_offset + num_bytes <=
2310 old->extent_offset + old->offset)
2311 continue;
2312 break;
2313 }
2314
2315 backref = kmalloc(sizeof(*backref), GFP_NOFS);
2316 if (!backref) {
2317 ret = -ENOENT;
2318 goto out;
2319 }
2320
2321 backref->root_id = root_id;
2322 backref->inum = inum;
2323 backref->file_pos = offset;
2324 backref->num_bytes = num_bytes;
2325 backref->extent_offset = extent_offset;
2326 backref->generation = btrfs_file_extent_generation(leaf, extent);
2327 backref->old = old;
2328 backref_insert(&new->root, backref);
2329 old->count++;
2330 out:
2331 btrfs_release_path(path);
2332 WARN_ON(ret);
2333 return ret;
2334 }
2335
2336 static noinline bool record_extent_backrefs(struct btrfs_path *path,
2337 struct new_sa_defrag_extent *new)
2338 {
2339 struct btrfs_fs_info *fs_info = BTRFS_I(new->inode)->root->fs_info;
2340 struct old_sa_defrag_extent *old, *tmp;
2341 int ret;
2342
2343 new->path = path;
2344
2345 list_for_each_entry_safe(old, tmp, &new->head, list) {
2346 ret = iterate_inodes_from_logical(old->bytenr +
2347 old->extent_offset, fs_info,
2348 path, record_one_backref,
2349 old);
2350 if (ret < 0 && ret != -ENOENT)
2351 return false;
2352
2353 /* no backref to be processed for this extent */
2354 if (!old->count) {
2355 list_del(&old->list);
2356 kfree(old);
2357 }
2358 }
2359
2360 if (list_empty(&new->head))
2361 return false;
2362
2363 return true;
2364 }
2365
2366 static int relink_is_mergable(struct extent_buffer *leaf,
2367 struct btrfs_file_extent_item *fi,
2368 struct new_sa_defrag_extent *new)
2369 {
2370 if (btrfs_file_extent_disk_bytenr(leaf, fi) != new->bytenr)
2371 return 0;
2372
2373 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2374 return 0;
2375
2376 if (btrfs_file_extent_compression(leaf, fi) != new->compress_type)
2377 return 0;
2378
2379 if (btrfs_file_extent_encryption(leaf, fi) ||
2380 btrfs_file_extent_other_encoding(leaf, fi))
2381 return 0;
2382
2383 return 1;
2384 }
2385
2386 /*
2387 * Note the backref might has changed, and in this case we just return 0.
2388 */
2389 static noinline int relink_extent_backref(struct btrfs_path *path,
2390 struct sa_defrag_extent_backref *prev,
2391 struct sa_defrag_extent_backref *backref)
2392 {
2393 struct btrfs_file_extent_item *extent;
2394 struct btrfs_file_extent_item *item;
2395 struct btrfs_ordered_extent *ordered;
2396 struct btrfs_trans_handle *trans;
2397 struct btrfs_fs_info *fs_info;
2398 struct btrfs_root *root;
2399 struct btrfs_key key;
2400 struct extent_buffer *leaf;
2401 struct old_sa_defrag_extent *old = backref->old;
2402 struct new_sa_defrag_extent *new = old->new;
2403 struct inode *src_inode = new->inode;
2404 struct inode *inode;
2405 struct extent_state *cached = NULL;
2406 int ret = 0;
2407 u64 start;
2408 u64 len;
2409 u64 lock_start;
2410 u64 lock_end;
2411 bool merge = false;
2412 int index;
2413
2414 if (prev && prev->root_id == backref->root_id &&
2415 prev->inum == backref->inum &&
2416 prev->file_pos + prev->num_bytes == backref->file_pos)
2417 merge = true;
2418
2419 /* step 1: get root */
2420 key.objectid = backref->root_id;
2421 key.type = BTRFS_ROOT_ITEM_KEY;
2422 key.offset = (u64)-1;
2423
2424 fs_info = BTRFS_I(src_inode)->root->fs_info;
2425 index = srcu_read_lock(&fs_info->subvol_srcu);
2426
2427 root = btrfs_read_fs_root_no_name(fs_info, &key);
2428 if (IS_ERR(root)) {
2429 srcu_read_unlock(&fs_info->subvol_srcu, index);
2430 if (PTR_ERR(root) == -ENOENT)
2431 return 0;
2432 return PTR_ERR(root);
2433 }
2434
2435 if (btrfs_root_readonly(root)) {
2436 srcu_read_unlock(&fs_info->subvol_srcu, index);
2437 return 0;
2438 }
2439
2440 /* step 2: get inode */
2441 key.objectid = backref->inum;
2442 key.type = BTRFS_INODE_ITEM_KEY;
2443 key.offset = 0;
2444
2445 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
2446 if (IS_ERR(inode)) {
2447 srcu_read_unlock(&fs_info->subvol_srcu, index);
2448 return 0;
2449 }
2450
2451 srcu_read_unlock(&fs_info->subvol_srcu, index);
2452
2453 /* step 3: relink backref */
2454 lock_start = backref->file_pos;
2455 lock_end = backref->file_pos + backref->num_bytes - 1;
2456 lock_extent_bits(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2457 0, &cached);
2458
2459 ordered = btrfs_lookup_first_ordered_extent(inode, lock_end);
2460 if (ordered) {
2461 btrfs_put_ordered_extent(ordered);
2462 goto out_unlock;
2463 }
2464
2465 trans = btrfs_join_transaction(root);
2466 if (IS_ERR(trans)) {
2467 ret = PTR_ERR(trans);
2468 goto out_unlock;
2469 }
2470
2471 key.objectid = backref->inum;
2472 key.type = BTRFS_EXTENT_DATA_KEY;
2473 key.offset = backref->file_pos;
2474
2475 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2476 if (ret < 0) {
2477 goto out_free_path;
2478 } else if (ret > 0) {
2479 ret = 0;
2480 goto out_free_path;
2481 }
2482
2483 extent = btrfs_item_ptr(path->nodes[0], path->slots[0],
2484 struct btrfs_file_extent_item);
2485
2486 if (btrfs_file_extent_generation(path->nodes[0], extent) !=
2487 backref->generation)
2488 goto out_free_path;
2489
2490 btrfs_release_path(path);
2491
2492 start = backref->file_pos;
2493 if (backref->extent_offset < old->extent_offset + old->offset)
2494 start += old->extent_offset + old->offset -
2495 backref->extent_offset;
2496
2497 len = min(backref->extent_offset + backref->num_bytes,
2498 old->extent_offset + old->offset + old->len);
2499 len -= max(backref->extent_offset, old->extent_offset + old->offset);
2500
2501 ret = btrfs_drop_extents(trans, root, inode, start,
2502 start + len, 1);
2503 if (ret)
2504 goto out_free_path;
2505 again:
2506 key.objectid = btrfs_ino(inode);
2507 key.type = BTRFS_EXTENT_DATA_KEY;
2508 key.offset = start;
2509
2510 path->leave_spinning = 1;
2511 if (merge) {
2512 struct btrfs_file_extent_item *fi;
2513 u64 extent_len;
2514 struct btrfs_key found_key;
2515
2516 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2517 if (ret < 0)
2518 goto out_free_path;
2519
2520 path->slots[0]--;
2521 leaf = path->nodes[0];
2522 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
2523
2524 fi = btrfs_item_ptr(leaf, path->slots[0],
2525 struct btrfs_file_extent_item);
2526 extent_len = btrfs_file_extent_num_bytes(leaf, fi);
2527
2528 if (extent_len + found_key.offset == start &&
2529 relink_is_mergable(leaf, fi, new)) {
2530 btrfs_set_file_extent_num_bytes(leaf, fi,
2531 extent_len + len);
2532 btrfs_mark_buffer_dirty(leaf);
2533 inode_add_bytes(inode, len);
2534
2535 ret = 1;
2536 goto out_free_path;
2537 } else {
2538 merge = false;
2539 btrfs_release_path(path);
2540 goto again;
2541 }
2542 }
2543
2544 ret = btrfs_insert_empty_item(trans, root, path, &key,
2545 sizeof(*extent));
2546 if (ret) {
2547 btrfs_abort_transaction(trans, root, ret);
2548 goto out_free_path;
2549 }
2550
2551 leaf = path->nodes[0];
2552 item = btrfs_item_ptr(leaf, path->slots[0],
2553 struct btrfs_file_extent_item);
2554 btrfs_set_file_extent_disk_bytenr(leaf, item, new->bytenr);
2555 btrfs_set_file_extent_disk_num_bytes(leaf, item, new->disk_len);
2556 btrfs_set_file_extent_offset(leaf, item, start - new->file_pos);
2557 btrfs_set_file_extent_num_bytes(leaf, item, len);
2558 btrfs_set_file_extent_ram_bytes(leaf, item, new->len);
2559 btrfs_set_file_extent_generation(leaf, item, trans->transid);
2560 btrfs_set_file_extent_type(leaf, item, BTRFS_FILE_EXTENT_REG);
2561 btrfs_set_file_extent_compression(leaf, item, new->compress_type);
2562 btrfs_set_file_extent_encryption(leaf, item, 0);
2563 btrfs_set_file_extent_other_encoding(leaf, item, 0);
2564
2565 btrfs_mark_buffer_dirty(leaf);
2566 inode_add_bytes(inode, len);
2567 btrfs_release_path(path);
2568
2569 ret = btrfs_inc_extent_ref(trans, root, new->bytenr,
2570 new->disk_len, 0,
2571 backref->root_id, backref->inum,
2572 new->file_pos, 0); /* start - extent_offset */
2573 if (ret) {
2574 btrfs_abort_transaction(trans, root, ret);
2575 goto out_free_path;
2576 }
2577
2578 ret = 1;
2579 out_free_path:
2580 btrfs_release_path(path);
2581 path->leave_spinning = 0;
2582 btrfs_end_transaction(trans, root);
2583 out_unlock:
2584 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lock_start, lock_end,
2585 &cached, GFP_NOFS);
2586 iput(inode);
2587 return ret;
2588 }
2589
2590 static void free_sa_defrag_extent(struct new_sa_defrag_extent *new)
2591 {
2592 struct old_sa_defrag_extent *old, *tmp;
2593
2594 if (!new)
2595 return;
2596
2597 list_for_each_entry_safe(old, tmp, &new->head, list) {
2598 list_del(&old->list);
2599 kfree(old);
2600 }
2601 kfree(new);
2602 }
2603
2604 static void relink_file_extents(struct new_sa_defrag_extent *new)
2605 {
2606 struct btrfs_path *path;
2607 struct sa_defrag_extent_backref *backref;
2608 struct sa_defrag_extent_backref *prev = NULL;
2609 struct inode *inode;
2610 struct btrfs_root *root;
2611 struct rb_node *node;
2612 int ret;
2613
2614 inode = new->inode;
2615 root = BTRFS_I(inode)->root;
2616
2617 path = btrfs_alloc_path();
2618 if (!path)
2619 return;
2620
2621 if (!record_extent_backrefs(path, new)) {
2622 btrfs_free_path(path);
2623 goto out;
2624 }
2625 btrfs_release_path(path);
2626
2627 while (1) {
2628 node = rb_first(&new->root);
2629 if (!node)
2630 break;
2631 rb_erase(node, &new->root);
2632
2633 backref = rb_entry(node, struct sa_defrag_extent_backref, node);
2634
2635 ret = relink_extent_backref(path, prev, backref);
2636 WARN_ON(ret < 0);
2637
2638 kfree(prev);
2639
2640 if (ret == 1)
2641 prev = backref;
2642 else
2643 prev = NULL;
2644 cond_resched();
2645 }
2646 kfree(prev);
2647
2648 btrfs_free_path(path);
2649 out:
2650 free_sa_defrag_extent(new);
2651
2652 atomic_dec(&root->fs_info->defrag_running);
2653 wake_up(&root->fs_info->transaction_wait);
2654 }
2655
2656 static struct new_sa_defrag_extent *
2657 record_old_file_extents(struct inode *inode,
2658 struct btrfs_ordered_extent *ordered)
2659 {
2660 struct btrfs_root *root = BTRFS_I(inode)->root;
2661 struct btrfs_path *path;
2662 struct btrfs_key key;
2663 struct old_sa_defrag_extent *old;
2664 struct new_sa_defrag_extent *new;
2665 int ret;
2666
2667 new = kmalloc(sizeof(*new), GFP_NOFS);
2668 if (!new)
2669 return NULL;
2670
2671 new->inode = inode;
2672 new->file_pos = ordered->file_offset;
2673 new->len = ordered->len;
2674 new->bytenr = ordered->start;
2675 new->disk_len = ordered->disk_len;
2676 new->compress_type = ordered->compress_type;
2677 new->root = RB_ROOT;
2678 INIT_LIST_HEAD(&new->head);
2679
2680 path = btrfs_alloc_path();
2681 if (!path)
2682 goto out_kfree;
2683
2684 key.objectid = btrfs_ino(inode);
2685 key.type = BTRFS_EXTENT_DATA_KEY;
2686 key.offset = new->file_pos;
2687
2688 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2689 if (ret < 0)
2690 goto out_free_path;
2691 if (ret > 0 && path->slots[0] > 0)
2692 path->slots[0]--;
2693
2694 /* find out all the old extents for the file range */
2695 while (1) {
2696 struct btrfs_file_extent_item *extent;
2697 struct extent_buffer *l;
2698 int slot;
2699 u64 num_bytes;
2700 u64 offset;
2701 u64 end;
2702 u64 disk_bytenr;
2703 u64 extent_offset;
2704
2705 l = path->nodes[0];
2706 slot = path->slots[0];
2707
2708 if (slot >= btrfs_header_nritems(l)) {
2709 ret = btrfs_next_leaf(root, path);
2710 if (ret < 0)
2711 goto out_free_path;
2712 else if (ret > 0)
2713 break;
2714 continue;
2715 }
2716
2717 btrfs_item_key_to_cpu(l, &key, slot);
2718
2719 if (key.objectid != btrfs_ino(inode))
2720 break;
2721 if (key.type != BTRFS_EXTENT_DATA_KEY)
2722 break;
2723 if (key.offset >= new->file_pos + new->len)
2724 break;
2725
2726 extent = btrfs_item_ptr(l, slot, struct btrfs_file_extent_item);
2727
2728 num_bytes = btrfs_file_extent_num_bytes(l, extent);
2729 if (key.offset + num_bytes < new->file_pos)
2730 goto next;
2731
2732 disk_bytenr = btrfs_file_extent_disk_bytenr(l, extent);
2733 if (!disk_bytenr)
2734 goto next;
2735
2736 extent_offset = btrfs_file_extent_offset(l, extent);
2737
2738 old = kmalloc(sizeof(*old), GFP_NOFS);
2739 if (!old)
2740 goto out_free_path;
2741
2742 offset = max(new->file_pos, key.offset);
2743 end = min(new->file_pos + new->len, key.offset + num_bytes);
2744
2745 old->bytenr = disk_bytenr;
2746 old->extent_offset = extent_offset;
2747 old->offset = offset - key.offset;
2748 old->len = end - offset;
2749 old->new = new;
2750 old->count = 0;
2751 list_add_tail(&old->list, &new->head);
2752 next:
2753 path->slots[0]++;
2754 cond_resched();
2755 }
2756
2757 btrfs_free_path(path);
2758 atomic_inc(&root->fs_info->defrag_running);
2759
2760 return new;
2761
2762 out_free_path:
2763 btrfs_free_path(path);
2764 out_kfree:
2765 free_sa_defrag_extent(new);
2766 return NULL;
2767 }
2768
2769 static void btrfs_release_delalloc_bytes(struct btrfs_root *root,
2770 u64 start, u64 len)
2771 {
2772 struct btrfs_block_group_cache *cache;
2773
2774 cache = btrfs_lookup_block_group(root->fs_info, start);
2775 ASSERT(cache);
2776
2777 spin_lock(&cache->lock);
2778 cache->delalloc_bytes -= len;
2779 spin_unlock(&cache->lock);
2780
2781 btrfs_put_block_group(cache);
2782 }
2783
2784 /* as ordered data IO finishes, this gets called so we can finish
2785 * an ordered extent if the range of bytes in the file it covers are
2786 * fully written.
2787 */
2788 static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
2789 {
2790 struct inode *inode = ordered_extent->inode;
2791 struct btrfs_root *root = BTRFS_I(inode)->root;
2792 struct btrfs_trans_handle *trans = NULL;
2793 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
2794 struct extent_state *cached_state = NULL;
2795 struct new_sa_defrag_extent *new = NULL;
2796 int compress_type = 0;
2797 int ret = 0;
2798 u64 logical_len = ordered_extent->len;
2799 bool nolock;
2800 bool truncated = false;
2801
2802 nolock = btrfs_is_free_space_inode(inode);
2803
2804 if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
2805 ret = -EIO;
2806 goto out;
2807 }
2808
2809 btrfs_free_io_failure_record(inode, ordered_extent->file_offset,
2810 ordered_extent->file_offset +
2811 ordered_extent->len - 1);
2812
2813 if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
2814 truncated = true;
2815 logical_len = ordered_extent->truncated_len;
2816 /* Truncated the entire extent, don't bother adding */
2817 if (!logical_len)
2818 goto out;
2819 }
2820
2821 if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
2822 BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
2823 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2824 if (nolock)
2825 trans = btrfs_join_transaction_nolock(root);
2826 else
2827 trans = btrfs_join_transaction(root);
2828 if (IS_ERR(trans)) {
2829 ret = PTR_ERR(trans);
2830 trans = NULL;
2831 goto out;
2832 }
2833 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2834 ret = btrfs_update_inode_fallback(trans, root, inode);
2835 if (ret) /* -ENOMEM or corruption */
2836 btrfs_abort_transaction(trans, root, ret);
2837 goto out;
2838 }
2839
2840 lock_extent_bits(io_tree, ordered_extent->file_offset,
2841 ordered_extent->file_offset + ordered_extent->len - 1,
2842 0, &cached_state);
2843
2844 ret = test_range_bit(io_tree, ordered_extent->file_offset,
2845 ordered_extent->file_offset + ordered_extent->len - 1,
2846 EXTENT_DEFRAG, 1, cached_state);
2847 if (ret) {
2848 u64 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
2849 if (0 && last_snapshot >= BTRFS_I(inode)->generation)
2850 /* the inode is shared */
2851 new = record_old_file_extents(inode, ordered_extent);
2852
2853 clear_extent_bit(io_tree, ordered_extent->file_offset,
2854 ordered_extent->file_offset + ordered_extent->len - 1,
2855 EXTENT_DEFRAG, 0, 0, &cached_state, GFP_NOFS);
2856 }
2857
2858 if (nolock)
2859 trans = btrfs_join_transaction_nolock(root);
2860 else
2861 trans = btrfs_join_transaction(root);
2862 if (IS_ERR(trans)) {
2863 ret = PTR_ERR(trans);
2864 trans = NULL;
2865 goto out_unlock;
2866 }
2867
2868 trans->block_rsv = &root->fs_info->delalloc_block_rsv;
2869
2870 if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
2871 compress_type = ordered_extent->compress_type;
2872 if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
2873 BUG_ON(compress_type);
2874 ret = btrfs_mark_extent_written(trans, inode,
2875 ordered_extent->file_offset,
2876 ordered_extent->file_offset +
2877 logical_len);
2878 } else {
2879 BUG_ON(root == root->fs_info->tree_root);
2880 ret = insert_reserved_file_extent(trans, inode,
2881 ordered_extent->file_offset,
2882 ordered_extent->start,
2883 ordered_extent->disk_len,
2884 logical_len, logical_len,
2885 compress_type, 0, 0,
2886 BTRFS_FILE_EXTENT_REG);
2887 if (!ret)
2888 btrfs_release_delalloc_bytes(root,
2889 ordered_extent->start,
2890 ordered_extent->disk_len);
2891 }
2892 unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
2893 ordered_extent->file_offset, ordered_extent->len,
2894 trans->transid);
2895 if (ret < 0) {
2896 btrfs_abort_transaction(trans, root, ret);
2897 goto out_unlock;
2898 }
2899
2900 add_pending_csums(trans, inode, ordered_extent->file_offset,
2901 &ordered_extent->list);
2902
2903 btrfs_ordered_update_i_size(inode, 0, ordered_extent);
2904 ret = btrfs_update_inode_fallback(trans, root, inode);
2905 if (ret) { /* -ENOMEM or corruption */
2906 btrfs_abort_transaction(trans, root, ret);
2907 goto out_unlock;
2908 }
2909 ret = 0;
2910 out_unlock:
2911 unlock_extent_cached(io_tree, ordered_extent->file_offset,
2912 ordered_extent->file_offset +
2913 ordered_extent->len - 1, &cached_state, GFP_NOFS);
2914 out:
2915 if (root != root->fs_info->tree_root)
2916 btrfs_delalloc_release_metadata(inode, ordered_extent->len);
2917 if (trans)
2918 btrfs_end_transaction(trans, root);
2919
2920 if (ret || truncated) {
2921 u64 start, end;
2922
2923 if (truncated)
2924 start = ordered_extent->file_offset + logical_len;
2925 else
2926 start = ordered_extent->file_offset;
2927 end = ordered_extent->file_offset + ordered_extent->len - 1;
2928 clear_extent_uptodate(io_tree, start, end, NULL, GFP_NOFS);
2929
2930 /* Drop the cache for the part of the extent we didn't write. */
2931 btrfs_drop_extent_cache(inode, start, end, 0);
2932
2933 /*
2934 * If the ordered extent had an IOERR or something else went
2935 * wrong we need to return the space for this ordered extent
2936 * back to the allocator. We only free the extent in the
2937 * truncated case if we didn't write out the extent at all.
2938 */
2939 if ((ret || !logical_len) &&
2940 !test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
2941 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags))
2942 btrfs_free_reserved_extent(root, ordered_extent->start,
2943 ordered_extent->disk_len, 1);
2944 }
2945
2946
2947 /*
2948 * This needs to be done to make sure anybody waiting knows we are done
2949 * updating everything for this ordered extent.
2950 */
2951 btrfs_remove_ordered_extent(inode, ordered_extent);
2952
2953 /* for snapshot-aware defrag */
2954 if (new) {
2955 if (ret) {
2956 free_sa_defrag_extent(new);
2957 atomic_dec(&root->fs_info->defrag_running);
2958 } else {
2959 relink_file_extents(new);
2960 }
2961 }
2962
2963 /* once for us */
2964 btrfs_put_ordered_extent(ordered_extent);
2965 /* once for the tree */
2966 btrfs_put_ordered_extent(ordered_extent);
2967
2968 return ret;
2969 }
2970
2971 static void finish_ordered_fn(struct btrfs_work *work)
2972 {
2973 struct btrfs_ordered_extent *ordered_extent;
2974 ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
2975 btrfs_finish_ordered_io(ordered_extent);
2976 }
2977
2978 static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
2979 struct extent_state *state, int uptodate)
2980 {
2981 struct inode *inode = page->mapping->host;
2982 struct btrfs_root *root = BTRFS_I(inode)->root;
2983 struct btrfs_ordered_extent *ordered_extent = NULL;
2984 struct btrfs_workqueue *wq;
2985 btrfs_work_func_t func;
2986
2987 trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
2988
2989 ClearPagePrivate2(page);
2990 if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
2991 end - start + 1, uptodate))
2992 return 0;
2993
2994 if (btrfs_is_free_space_inode(inode)) {
2995 wq = root->fs_info->endio_freespace_worker;
2996 func = btrfs_freespace_write_helper;
2997 } else {
2998 wq = root->fs_info->endio_write_workers;
2999 func = btrfs_endio_write_helper;
3000 }
3001
3002 btrfs_init_work(&ordered_extent->work, func, finish_ordered_fn, NULL,
3003 NULL);
3004 btrfs_queue_work(wq, &ordered_extent->work);
3005
3006 return 0;
3007 }
3008
3009 static int __readpage_endio_check(struct inode *inode,
3010 struct btrfs_io_bio *io_bio,
3011 int icsum, struct page *page,
3012 int pgoff, u64 start, size_t len)
3013 {
3014 char *kaddr;
3015 u32 csum_expected;
3016 u32 csum = ~(u32)0;
3017 static DEFINE_RATELIMIT_STATE(_rs, DEFAULT_RATELIMIT_INTERVAL,
3018 DEFAULT_RATELIMIT_BURST);
3019
3020 csum_expected = *(((u32 *)io_bio->csum) + icsum);
3021
3022 kaddr = kmap_atomic(page);
3023 csum = btrfs_csum_data(kaddr + pgoff, csum, len);
3024 btrfs_csum_final(csum, (char *)&csum);
3025 if (csum != csum_expected)
3026 goto zeroit;
3027
3028 kunmap_atomic(kaddr);
3029 return 0;
3030 zeroit:
3031 if (__ratelimit(&_rs))
3032 btrfs_warn(BTRFS_I(inode)->root->fs_info,
3033 "csum failed ino %llu off %llu csum %u expected csum %u",
3034 btrfs_ino(inode), start, csum, csum_expected);
3035 memset(kaddr + pgoff, 1, len);
3036 flush_dcache_page(page);
3037 kunmap_atomic(kaddr);
3038 if (csum_expected == 0)
3039 return 0;
3040 return -EIO;
3041 }
3042
3043 /*
3044 * when reads are done, we need to check csums to verify the data is correct
3045 * if there's a match, we allow the bio to finish. If not, the code in
3046 * extent_io.c will try to find good copies for us.
3047 */
3048 static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
3049 u64 phy_offset, struct page *page,
3050 u64 start, u64 end, int mirror)
3051 {
3052 size_t offset = start - page_offset(page);
3053 struct inode *inode = page->mapping->host;
3054 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3055 struct btrfs_root *root = BTRFS_I(inode)->root;
3056
3057 if (PageChecked(page)) {
3058 ClearPageChecked(page);
3059 return 0;
3060 }
3061
3062 if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
3063 return 0;
3064
3065 if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
3066 test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
3067 clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
3068 GFP_NOFS);
3069 return 0;
3070 }
3071
3072 phy_offset >>= inode->i_sb->s_blocksize_bits;
3073 return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
3074 start, (size_t)(end - start + 1));
3075 }
3076
3077 struct delayed_iput {
3078 struct list_head list;
3079 struct inode *inode;
3080 };
3081
3082 /* JDM: If this is fs-wide, why can't we add a pointer to
3083 * btrfs_inode instead and avoid the allocation? */
3084 void btrfs_add_delayed_iput(struct inode *inode)
3085 {
3086 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3087 struct delayed_iput *delayed;
3088
3089 if (atomic_add_unless(&inode->i_count, -1, 1))
3090 return;
3091
3092 delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
3093 delayed->inode = inode;
3094
3095 spin_lock(&fs_info->delayed_iput_lock);
3096 list_add_tail(&delayed->list, &fs_info->delayed_iputs);
3097 spin_unlock(&fs_info->delayed_iput_lock);
3098 }
3099
3100 void btrfs_run_delayed_iputs(struct btrfs_root *root)
3101 {
3102 LIST_HEAD(list);
3103 struct btrfs_fs_info *fs_info = root->fs_info;
3104 struct delayed_iput *delayed;
3105 int empty;
3106
3107 spin_lock(&fs_info->delayed_iput_lock);
3108 empty = list_empty(&fs_info->delayed_iputs);
3109 spin_unlock(&fs_info->delayed_iput_lock);
3110 if (empty)
3111 return;
3112
3113 down_read(&fs_info->delayed_iput_sem);
3114
3115 spin_lock(&fs_info->delayed_iput_lock);
3116 list_splice_init(&fs_info->delayed_iputs, &list);
3117 spin_unlock(&fs_info->delayed_iput_lock);
3118
3119 while (!list_empty(&list)) {
3120 delayed = list_entry(list.next, struct delayed_iput, list);
3121 list_del(&delayed->list);
3122 iput(delayed->inode);
3123 kfree(delayed);
3124 }
3125
3126 up_read(&root->fs_info->delayed_iput_sem);
3127 }
3128
3129 /*
3130 * This is called in transaction commit time. If there are no orphan
3131 * files in the subvolume, it removes orphan item and frees block_rsv
3132 * structure.
3133 */
3134 void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
3135 struct btrfs_root *root)
3136 {
3137 struct btrfs_block_rsv *block_rsv;
3138 int ret;
3139
3140 if (atomic_read(&root->orphan_inodes) ||
3141 root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
3142 return;
3143
3144 spin_lock(&root->orphan_lock);
3145 if (atomic_read(&root->orphan_inodes)) {
3146 spin_unlock(&root->orphan_lock);
3147 return;
3148 }
3149
3150 if (root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE) {
3151 spin_unlock(&root->orphan_lock);
3152 return;
3153 }
3154
3155 block_rsv = root->orphan_block_rsv;
3156 root->orphan_block_rsv = NULL;
3157 spin_unlock(&root->orphan_lock);
3158
3159 if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state) &&
3160 btrfs_root_refs(&root->root_item) > 0) {
3161 ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
3162 root->root_key.objectid);
3163 if (ret)
3164 btrfs_abort_transaction(trans, root, ret);
3165 else
3166 clear_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED,
3167 &root->state);
3168 }
3169
3170 if (block_rsv) {
3171 WARN_ON(block_rsv->size > 0);
3172 btrfs_free_block_rsv(root, block_rsv);
3173 }
3174 }
3175
3176 /*
3177 * This creates an orphan entry for the given inode in case something goes
3178 * wrong in the middle of an unlink/truncate.
3179 *
3180 * NOTE: caller of this function should reserve 5 units of metadata for
3181 * this function.
3182 */
3183 int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
3184 {
3185 struct btrfs_root *root = BTRFS_I(inode)->root;
3186 struct btrfs_block_rsv *block_rsv = NULL;
3187 int reserve = 0;
3188 int insert = 0;
3189 int ret;
3190
3191 if (!root->orphan_block_rsv) {
3192 block_rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
3193 if (!block_rsv)
3194 return -ENOMEM;
3195 }
3196
3197 spin_lock(&root->orphan_lock);
3198 if (!root->orphan_block_rsv) {
3199 root->orphan_block_rsv = block_rsv;
3200 } else if (block_rsv) {
3201 btrfs_free_block_rsv(root, block_rsv);
3202 block_rsv = NULL;
3203 }
3204
3205 if (!test_and_set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3206 &BTRFS_I(inode)->runtime_flags)) {
3207 #if 0
3208 /*
3209 * For proper ENOSPC handling, we should do orphan
3210 * cleanup when mounting. But this introduces backward
3211 * compatibility issue.
3212 */
3213 if (!xchg(&root->orphan_item_inserted, 1))
3214 insert = 2;
3215 else
3216 insert = 1;
3217 #endif
3218 insert = 1;
3219 atomic_inc(&root->orphan_inodes);
3220 }
3221
3222 if (!test_and_set_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3223 &BTRFS_I(inode)->runtime_flags))
3224 reserve = 1;
3225 spin_unlock(&root->orphan_lock);
3226
3227 /* grab metadata reservation from transaction handle */
3228 if (reserve) {
3229 ret = btrfs_orphan_reserve_metadata(trans, inode);
3230 BUG_ON(ret); /* -ENOSPC in reservation; Logic error? JDM */
3231 }
3232
3233 /* insert an orphan item to track this unlinked/truncated file */
3234 if (insert >= 1) {
3235 ret = btrfs_insert_orphan_item(trans, root, btrfs_ino(inode));
3236 if (ret) {
3237 atomic_dec(&root->orphan_inodes);
3238 if (reserve) {
3239 clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3240 &BTRFS_I(inode)->runtime_flags);
3241 btrfs_orphan_release_metadata(inode);
3242 }
3243 if (ret != -EEXIST) {
3244 clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3245 &BTRFS_I(inode)->runtime_flags);
3246 btrfs_abort_transaction(trans, root, ret);
3247 return ret;
3248 }
3249 }
3250 ret = 0;
3251 }
3252
3253 /* insert an orphan item to track subvolume contains orphan files */
3254 if (insert >= 2) {
3255 ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
3256 root->root_key.objectid);
3257 if (ret && ret != -EEXIST) {
3258 btrfs_abort_transaction(trans, root, ret);
3259 return ret;
3260 }
3261 }
3262 return 0;
3263 }
3264
3265 /*
3266 * We have done the truncate/delete so we can go ahead and remove the orphan
3267 * item for this particular inode.
3268 */
3269 static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
3270 struct inode *inode)
3271 {
3272 struct btrfs_root *root = BTRFS_I(inode)->root;
3273 int delete_item = 0;
3274 int release_rsv = 0;
3275 int ret = 0;
3276
3277 spin_lock(&root->orphan_lock);
3278 if (test_and_clear_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3279 &BTRFS_I(inode)->runtime_flags))
3280 delete_item = 1;
3281
3282 if (test_and_clear_bit(BTRFS_INODE_ORPHAN_META_RESERVED,
3283 &BTRFS_I(inode)->runtime_flags))
3284 release_rsv = 1;
3285 spin_unlock(&root->orphan_lock);
3286
3287 if (delete_item) {
3288 atomic_dec(&root->orphan_inodes);
3289 if (trans)
3290 ret = btrfs_del_orphan_item(trans, root,
3291 btrfs_ino(inode));
3292 }
3293
3294 if (release_rsv)
3295 btrfs_orphan_release_metadata(inode);
3296
3297 return ret;
3298 }
3299
3300 /*
3301 * this cleans up any orphans that may be left on the list from the last use
3302 * of this root.
3303 */
3304 int btrfs_orphan_cleanup(struct btrfs_root *root)
3305 {
3306 struct btrfs_path *path;
3307 struct extent_buffer *leaf;
3308 struct btrfs_key key, found_key;
3309 struct btrfs_trans_handle *trans;
3310 struct inode *inode;
3311 u64 last_objectid = 0;
3312 int ret = 0, nr_unlink = 0, nr_truncate = 0;
3313
3314 if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
3315 return 0;
3316
3317 path = btrfs_alloc_path();
3318 if (!path) {
3319 ret = -ENOMEM;
3320 goto out;
3321 }
3322 path->reada = -1;
3323
3324 key.objectid = BTRFS_ORPHAN_OBJECTID;
3325 key.type = BTRFS_ORPHAN_ITEM_KEY;
3326 key.offset = (u64)-1;
3327
3328 while (1) {
3329 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3330 if (ret < 0)
3331 goto out;
3332
3333 /*
3334 * if ret == 0 means we found what we were searching for, which
3335 * is weird, but possible, so only screw with path if we didn't
3336 * find the key and see if we have stuff that matches
3337 */
3338 if (ret > 0) {
3339 ret = 0;
3340 if (path->slots[0] == 0)
3341 break;
3342 path->slots[0]--;
3343 }
3344
3345 /* pull out the item */
3346 leaf = path->nodes[0];
3347 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
3348
3349 /* make sure the item matches what we want */
3350 if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
3351 break;
3352 if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
3353 break;
3354
3355 /* release the path since we're done with it */
3356 btrfs_release_path(path);
3357
3358 /*
3359 * this is where we are basically btrfs_lookup, without the
3360 * crossing root thing. we store the inode number in the
3361 * offset of the orphan item.
3362 */
3363
3364 if (found_key.offset == last_objectid) {
3365 btrfs_err(root->fs_info,
3366 "Error removing orphan entry, stopping orphan cleanup");
3367 ret = -EINVAL;
3368 goto out;
3369 }
3370
3371 last_objectid = found_key.offset;
3372
3373 found_key.objectid = found_key.offset;
3374 found_key.type = BTRFS_INODE_ITEM_KEY;
3375 found_key.offset = 0;
3376 inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
3377 ret = PTR_ERR_OR_ZERO(inode);
3378 if (ret && ret != -ESTALE)
3379 goto out;
3380
3381 if (ret == -ESTALE && root == root->fs_info->tree_root) {
3382 struct btrfs_root *dead_root;
3383 struct btrfs_fs_info *fs_info = root->fs_info;
3384 int is_dead_root = 0;
3385
3386 /*
3387 * this is an orphan in the tree root. Currently these
3388 * could come from 2 sources:
3389 * a) a snapshot deletion in progress
3390 * b) a free space cache inode
3391 * We need to distinguish those two, as the snapshot
3392 * orphan must not get deleted.
3393 * find_dead_roots already ran before us, so if this
3394 * is a snapshot deletion, we should find the root
3395 * in the dead_roots list
3396 */
3397 spin_lock(&fs_info->trans_lock);
3398 list_for_each_entry(dead_root, &fs_info->dead_roots,
3399 root_list) {
3400 if (dead_root->root_key.objectid ==
3401 found_key.objectid) {
3402 is_dead_root = 1;
3403 break;
3404 }
3405 }
3406 spin_unlock(&fs_info->trans_lock);
3407 if (is_dead_root) {
3408 /* prevent this orphan from being found again */
3409 key.offset = found_key.objectid - 1;
3410 continue;
3411 }
3412 }
3413 /*
3414 * Inode is already gone but the orphan item is still there,
3415 * kill the orphan item.
3416 */
3417 if (ret == -ESTALE) {
3418 trans = btrfs_start_transaction(root, 1);
3419 if (IS_ERR(trans)) {
3420 ret = PTR_ERR(trans);
3421 goto out;
3422 }
3423 btrfs_debug(root->fs_info, "auto deleting %Lu",
3424 found_key.objectid);
3425 ret = btrfs_del_orphan_item(trans, root,
3426 found_key.objectid);
3427 btrfs_end_transaction(trans, root);
3428 if (ret)
3429 goto out;
3430 continue;
3431 }
3432
3433 /*
3434 * add this inode to the orphan list so btrfs_orphan_del does
3435 * the proper thing when we hit it
3436 */
3437 set_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
3438 &BTRFS_I(inode)->runtime_flags);
3439 atomic_inc(&root->orphan_inodes);
3440
3441 /* if we have links, this was a truncate, lets do that */
3442 if (inode->i_nlink) {
3443 if (WARN_ON(!S_ISREG(inode->i_mode))) {
3444 iput(inode);
3445 continue;
3446 }
3447 nr_truncate++;
3448
3449 /* 1 for the orphan item deletion. */
3450 trans = btrfs_start_transaction(root, 1);
3451 if (IS_ERR(trans)) {
3452 iput(inode);
3453 ret = PTR_ERR(trans);
3454 goto out;
3455 }
3456 ret = btrfs_orphan_add(trans, inode);
3457 btrfs_end_transaction(trans, root);
3458 if (ret) {
3459 iput(inode);
3460 goto out;
3461 }
3462
3463 ret = btrfs_truncate(inode);
3464 if (ret)
3465 btrfs_orphan_del(NULL, inode);
3466 } else {
3467 nr_unlink++;
3468 }
3469
3470 /* this will do delete_inode and everything for us */
3471 iput(inode);
3472 if (ret)
3473 goto out;
3474 }
3475 /* release the path since we're done with it */
3476 btrfs_release_path(path);
3477
3478 root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
3479
3480 if (root->orphan_block_rsv)
3481 btrfs_block_rsv_release(root, root->orphan_block_rsv,
3482 (u64)-1);
3483
3484 if (root->orphan_block_rsv ||
3485 test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
3486 trans = btrfs_join_transaction(root);
3487 if (!IS_ERR(trans))
3488 btrfs_end_transaction(trans, root);
3489 }
3490
3491 if (nr_unlink)
3492 btrfs_debug(root->fs_info, "unlinked %d orphans", nr_unlink);
3493 if (nr_truncate)
3494 btrfs_debug(root->fs_info, "truncated %d orphans", nr_truncate);
3495
3496 out:
3497 if (ret)
3498 btrfs_err(root->fs_info,
3499 "could not do orphan cleanup %d", ret);
3500 btrfs_free_path(path);
3501 return ret;
3502 }
3503
3504 /*
3505 * very simple check to peek ahead in the leaf looking for xattrs. If we
3506 * don't find any xattrs, we know there can't be any acls.
3507 *
3508 * slot is the slot the inode is in, objectid is the objectid of the inode
3509 */
3510 static noinline int acls_after_inode_item(struct extent_buffer *leaf,
3511 int slot, u64 objectid,
3512 int *first_xattr_slot)
3513 {
3514 u32 nritems = btrfs_header_nritems(leaf);
3515 struct btrfs_key found_key;
3516 static u64 xattr_access = 0;
3517 static u64 xattr_default = 0;
3518 int scanned = 0;
3519
3520 if (!xattr_access) {
3521 xattr_access = btrfs_name_hash(POSIX_ACL_XATTR_ACCESS,
3522 strlen(POSIX_ACL_XATTR_ACCESS));
3523 xattr_default = btrfs_name_hash(POSIX_ACL_XATTR_DEFAULT,
3524 strlen(POSIX_ACL_XATTR_DEFAULT));
3525 }
3526
3527 slot++;
3528 *first_xattr_slot = -1;
3529 while (slot < nritems) {
3530 btrfs_item_key_to_cpu(leaf, &found_key, slot);
3531
3532 /* we found a different objectid, there must not be acls */
3533 if (found_key.objectid != objectid)
3534 return 0;
3535
3536 /* we found an xattr, assume we've got an acl */
3537 if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
3538 if (*first_xattr_slot == -1)
3539 *first_xattr_slot = slot;
3540 if (found_key.offset == xattr_access ||
3541 found_key.offset == xattr_default)
3542 return 1;
3543 }
3544
3545 /*
3546 * we found a key greater than an xattr key, there can't
3547 * be any acls later on
3548 */
3549 if (found_key.type > BTRFS_XATTR_ITEM_KEY)
3550 return 0;
3551
3552 slot++;
3553 scanned++;
3554
3555 /*
3556 * it goes inode, inode backrefs, xattrs, extents,
3557 * so if there are a ton of hard links to an inode there can
3558 * be a lot of backrefs. Don't waste time searching too hard,
3559 * this is just an optimization
3560 */
3561 if (scanned >= 8)
3562 break;
3563 }
3564 /* we hit the end of the leaf before we found an xattr or
3565 * something larger than an xattr. We have to assume the inode
3566 * has acls
3567 */
3568 if (*first_xattr_slot == -1)
3569 *first_xattr_slot = slot;
3570 return 1;
3571 }
3572
3573 /*
3574 * read an inode from the btree into the in-memory inode
3575 */
3576 static void btrfs_read_locked_inode(struct inode *inode)
3577 {
3578 struct btrfs_path *path;
3579 struct extent_buffer *leaf;
3580 struct btrfs_inode_item *inode_item;
3581 struct btrfs_root *root = BTRFS_I(inode)->root;
3582 struct btrfs_key location;
3583 unsigned long ptr;
3584 int maybe_acls;
3585 u32 rdev;
3586 int ret;
3587 bool filled = false;
3588 int first_xattr_slot;
3589
3590 ret = btrfs_fill_inode(inode, &rdev);
3591 if (!ret)
3592 filled = true;
3593
3594 path = btrfs_alloc_path();
3595 if (!path)
3596 goto make_bad;
3597
3598 memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
3599
3600 ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
3601 if (ret)
3602 goto make_bad;
3603
3604 leaf = path->nodes[0];
3605
3606 if (filled)
3607 goto cache_index;
3608
3609 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3610 struct btrfs_inode_item);
3611 inode->i_mode = btrfs_inode_mode(leaf, inode_item);
3612 set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
3613 i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
3614 i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
3615 btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
3616
3617 inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
3618 inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
3619
3620 inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
3621 inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
3622
3623 inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
3624 inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
3625
3626 BTRFS_I(inode)->i_otime.tv_sec =
3627 btrfs_timespec_sec(leaf, &inode_item->otime);
3628 BTRFS_I(inode)->i_otime.tv_nsec =
3629 btrfs_timespec_nsec(leaf, &inode_item->otime);
3630
3631 inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
3632 BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
3633 BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
3634
3635 inode->i_version = btrfs_inode_sequence(leaf, inode_item);
3636 inode->i_generation = BTRFS_I(inode)->generation;
3637 inode->i_rdev = 0;
3638 rdev = btrfs_inode_rdev(leaf, inode_item);
3639
3640 BTRFS_I(inode)->index_cnt = (u64)-1;
3641 BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
3642
3643 cache_index:
3644 /*
3645 * If we were modified in the current generation and evicted from memory
3646 * and then re-read we need to do a full sync since we don't have any
3647 * idea about which extents were modified before we were evicted from
3648 * cache.
3649 *
3650 * This is required for both inode re-read from disk and delayed inode
3651 * in delayed_nodes_tree.
3652 */
3653 if (BTRFS_I(inode)->last_trans == root->fs_info->generation)
3654 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3655 &BTRFS_I(inode)->runtime_flags);
3656
3657 path->slots[0]++;
3658 if (inode->i_nlink != 1 ||
3659 path->slots[0] >= btrfs_header_nritems(leaf))
3660 goto cache_acl;
3661
3662 btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
3663 if (location.objectid != btrfs_ino(inode))
3664 goto cache_acl;
3665
3666 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
3667 if (location.type == BTRFS_INODE_REF_KEY) {
3668 struct btrfs_inode_ref *ref;
3669
3670 ref = (struct btrfs_inode_ref *)ptr;
3671 BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
3672 } else if (location.type == BTRFS_INODE_EXTREF_KEY) {
3673 struct btrfs_inode_extref *extref;
3674
3675 extref = (struct btrfs_inode_extref *)ptr;
3676 BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
3677 extref);
3678 }
3679 cache_acl:
3680 /*
3681 * try to precache a NULL acl entry for files that don't have
3682 * any xattrs or acls
3683 */
3684 maybe_acls = acls_after_inode_item(leaf, path->slots[0],
3685 btrfs_ino(inode), &first_xattr_slot);
3686 if (first_xattr_slot != -1) {
3687 path->slots[0] = first_xattr_slot;
3688 ret = btrfs_load_inode_props(inode, path);
3689 if (ret)
3690 btrfs_err(root->fs_info,
3691 "error loading props for ino %llu (root %llu): %d",
3692 btrfs_ino(inode),
3693 root->root_key.objectid, ret);
3694 }
3695 btrfs_free_path(path);
3696
3697 if (!maybe_acls)
3698 cache_no_acl(inode);
3699
3700 switch (inode->i_mode & S_IFMT) {
3701 case S_IFREG:
3702 inode->i_mapping->a_ops = &btrfs_aops;
3703 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
3704 inode->i_fop = &btrfs_file_operations;
3705 inode->i_op = &btrfs_file_inode_operations;
3706 break;
3707 case S_IFDIR:
3708 inode->i_fop = &btrfs_dir_file_operations;
3709 if (root == root->fs_info->tree_root)
3710 inode->i_op = &btrfs_dir_ro_inode_operations;
3711 else
3712 inode->i_op = &btrfs_dir_inode_operations;
3713 break;
3714 case S_IFLNK:
3715 inode->i_op = &btrfs_symlink_inode_operations;
3716 inode->i_mapping->a_ops = &btrfs_symlink_aops;
3717 break;
3718 default:
3719 inode->i_op = &btrfs_special_inode_operations;
3720 init_special_inode(inode, inode->i_mode, rdev);
3721 break;
3722 }
3723
3724 btrfs_update_iflags(inode);
3725 return;
3726
3727 make_bad:
3728 btrfs_free_path(path);
3729 make_bad_inode(inode);
3730 }
3731
3732 /*
3733 * given a leaf and an inode, copy the inode fields into the leaf
3734 */
3735 static void fill_inode_item(struct btrfs_trans_handle *trans,
3736 struct extent_buffer *leaf,
3737 struct btrfs_inode_item *item,
3738 struct inode *inode)
3739 {
3740 struct btrfs_map_token token;
3741
3742 btrfs_init_map_token(&token);
3743
3744 btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
3745 btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
3746 btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
3747 &token);
3748 btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
3749 btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
3750
3751 btrfs_set_token_timespec_sec(leaf, &item->atime,
3752 inode->i_atime.tv_sec, &token);
3753 btrfs_set_token_timespec_nsec(leaf, &item->atime,
3754 inode->i_atime.tv_nsec, &token);
3755
3756 btrfs_set_token_timespec_sec(leaf, &item->mtime,
3757 inode->i_mtime.tv_sec, &token);
3758 btrfs_set_token_timespec_nsec(leaf, &item->mtime,
3759 inode->i_mtime.tv_nsec, &token);
3760
3761 btrfs_set_token_timespec_sec(leaf, &item->ctime,
3762 inode->i_ctime.tv_sec, &token);
3763 btrfs_set_token_timespec_nsec(leaf, &item->ctime,
3764 inode->i_ctime.tv_nsec, &token);
3765
3766 btrfs_set_token_timespec_sec(leaf, &item->otime,
3767 BTRFS_I(inode)->i_otime.tv_sec, &token);
3768 btrfs_set_token_timespec_nsec(leaf, &item->otime,
3769 BTRFS_I(inode)->i_otime.tv_nsec, &token);
3770
3771 btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
3772 &token);
3773 btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
3774 &token);
3775 btrfs_set_token_inode_sequence(leaf, item, inode->i_version, &token);
3776 btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
3777 btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
3778 btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
3779 btrfs_set_token_inode_block_group(leaf, item, 0, &token);
3780 }
3781
3782 /*
3783 * copy everything in the in-memory inode into the btree.
3784 */
3785 static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
3786 struct btrfs_root *root, struct inode *inode)
3787 {
3788 struct btrfs_inode_item *inode_item;
3789 struct btrfs_path *path;
3790 struct extent_buffer *leaf;
3791 int ret;
3792
3793 path = btrfs_alloc_path();
3794 if (!path)
3795 return -ENOMEM;
3796
3797 path->leave_spinning = 1;
3798 ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
3799 1);
3800 if (ret) {
3801 if (ret > 0)
3802 ret = -ENOENT;
3803 goto failed;
3804 }
3805
3806 leaf = path->nodes[0];
3807 inode_item = btrfs_item_ptr(leaf, path->slots[0],
3808 struct btrfs_inode_item);
3809
3810 fill_inode_item(trans, leaf, inode_item, inode);
3811 btrfs_mark_buffer_dirty(leaf);
3812 btrfs_set_inode_last_trans(trans, inode);
3813 ret = 0;
3814 failed:
3815 btrfs_free_path(path);
3816 return ret;
3817 }
3818
3819 /*
3820 * copy everything in the in-memory inode into the btree.
3821 */
3822 noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
3823 struct btrfs_root *root, struct inode *inode)
3824 {
3825 int ret;
3826
3827 /*
3828 * If the inode is a free space inode, we can deadlock during commit
3829 * if we put it into the delayed code.
3830 *
3831 * The data relocation inode should also be directly updated
3832 * without delay
3833 */
3834 if (!btrfs_is_free_space_inode(inode)
3835 && root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
3836 && !root->fs_info->log_root_recovering) {
3837 btrfs_update_root_times(trans, root);
3838
3839 ret = btrfs_delayed_update_inode(trans, root, inode);
3840 if (!ret)
3841 btrfs_set_inode_last_trans(trans, inode);
3842 return ret;
3843 }
3844
3845 return btrfs_update_inode_item(trans, root, inode);
3846 }
3847
3848 noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
3849 struct btrfs_root *root,
3850 struct inode *inode)
3851 {
3852 int ret;
3853
3854 ret = btrfs_update_inode(trans, root, inode);
3855 if (ret == -ENOSPC)
3856 return btrfs_update_inode_item(trans, root, inode);
3857 return ret;
3858 }
3859
3860 /*
3861 * unlink helper that gets used here in inode.c and in the tree logging
3862 * recovery code. It remove a link in a directory with a given name, and
3863 * also drops the back refs in the inode to the directory
3864 */
3865 static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3866 struct btrfs_root *root,
3867 struct inode *dir, struct inode *inode,
3868 const char *name, int name_len)
3869 {
3870 struct btrfs_path *path;
3871 int ret = 0;
3872 struct extent_buffer *leaf;
3873 struct btrfs_dir_item *di;
3874 struct btrfs_key key;
3875 u64 index;
3876 u64 ino = btrfs_ino(inode);
3877 u64 dir_ino = btrfs_ino(dir);
3878
3879 path = btrfs_alloc_path();
3880 if (!path) {
3881 ret = -ENOMEM;
3882 goto out;
3883 }
3884
3885 path->leave_spinning = 1;
3886 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
3887 name, name_len, -1);
3888 if (IS_ERR(di)) {
3889 ret = PTR_ERR(di);
3890 goto err;
3891 }
3892 if (!di) {
3893 ret = -ENOENT;
3894 goto err;
3895 }
3896 leaf = path->nodes[0];
3897 btrfs_dir_item_key_to_cpu(leaf, di, &key);
3898 ret = btrfs_delete_one_dir_name(trans, root, path, di);
3899 if (ret)
3900 goto err;
3901 btrfs_release_path(path);
3902
3903 /*
3904 * If we don't have dir index, we have to get it by looking up
3905 * the inode ref, since we get the inode ref, remove it directly,
3906 * it is unnecessary to do delayed deletion.
3907 *
3908 * But if we have dir index, needn't search inode ref to get it.
3909 * Since the inode ref is close to the inode item, it is better
3910 * that we delay to delete it, and just do this deletion when
3911 * we update the inode item.
3912 */
3913 if (BTRFS_I(inode)->dir_index) {
3914 ret = btrfs_delayed_delete_inode_ref(inode);
3915 if (!ret) {
3916 index = BTRFS_I(inode)->dir_index;
3917 goto skip_backref;
3918 }
3919 }
3920
3921 ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
3922 dir_ino, &index);
3923 if (ret) {
3924 btrfs_info(root->fs_info,
3925 "failed to delete reference to %.*s, inode %llu parent %llu",
3926 name_len, name, ino, dir_ino);
3927 btrfs_abort_transaction(trans, root, ret);
3928 goto err;
3929 }
3930 skip_backref:
3931 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
3932 if (ret) {
3933 btrfs_abort_transaction(trans, root, ret);
3934 goto err;
3935 }
3936
3937 ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
3938 inode, dir_ino);
3939 if (ret != 0 && ret != -ENOENT) {
3940 btrfs_abort_transaction(trans, root, ret);
3941 goto err;
3942 }
3943
3944 ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
3945 dir, index);
3946 if (ret == -ENOENT)
3947 ret = 0;
3948 else if (ret)
3949 btrfs_abort_transaction(trans, root, ret);
3950 err:
3951 btrfs_free_path(path);
3952 if (ret)
3953 goto out;
3954
3955 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
3956 inode_inc_iversion(inode);
3957 inode_inc_iversion(dir);
3958 inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
3959 ret = btrfs_update_inode(trans, root, dir);
3960 out:
3961 return ret;
3962 }
3963
3964 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
3965 struct btrfs_root *root,
3966 struct inode *dir, struct inode *inode,
3967 const char *name, int name_len)
3968 {
3969 int ret;
3970 ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
3971 if (!ret) {
3972 drop_nlink(inode);
3973 ret = btrfs_update_inode(trans, root, inode);
3974 }
3975 return ret;
3976 }
3977
3978 /*
3979 * helper to start transaction for unlink and rmdir.
3980 *
3981 * unlink and rmdir are special in btrfs, they do not always free space, so
3982 * if we cannot make our reservations the normal way try and see if there is
3983 * plenty of slack room in the global reserve to migrate, otherwise we cannot
3984 * allow the unlink to occur.
3985 */
3986 static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
3987 {
3988 struct btrfs_trans_handle *trans;
3989 struct btrfs_root *root = BTRFS_I(dir)->root;
3990 int ret;
3991
3992 /*
3993 * 1 for the possible orphan item
3994 * 1 for the dir item
3995 * 1 for the dir index
3996 * 1 for the inode ref
3997 * 1 for the inode
3998 */
3999 trans = btrfs_start_transaction(root, 5);
4000 if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
4001 return trans;
4002
4003 if (PTR_ERR(trans) == -ENOSPC) {
4004 u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
4005
4006 trans = btrfs_start_transaction(root, 0);
4007 if (IS_ERR(trans))
4008 return trans;
4009 ret = btrfs_cond_migrate_bytes(root->fs_info,
4010 &root->fs_info->trans_block_rsv,
4011 num_bytes, 5);
4012 if (ret) {
4013 btrfs_end_transaction(trans, root);
4014 return ERR_PTR(ret);
4015 }
4016 trans->block_rsv = &root->fs_info->trans_block_rsv;
4017 trans->bytes_reserved = num_bytes;
4018 }
4019 return trans;
4020 }
4021
4022 static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
4023 {
4024 struct btrfs_root *root = BTRFS_I(dir)->root;
4025 struct btrfs_trans_handle *trans;
4026 struct inode *inode = d_inode(dentry);
4027 int ret;
4028
4029 trans = __unlink_start_trans(dir);
4030 if (IS_ERR(trans))
4031 return PTR_ERR(trans);
4032
4033 btrfs_record_unlink_dir(trans, dir, d_inode(dentry), 0);
4034
4035 ret = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4036 dentry->d_name.name, dentry->d_name.len);
4037 if (ret)
4038 goto out;
4039
4040 if (inode->i_nlink == 0) {
4041 ret = btrfs_orphan_add(trans, inode);
4042 if (ret)
4043 goto out;
4044 }
4045
4046 out:
4047 btrfs_end_transaction(trans, root);
4048 btrfs_btree_balance_dirty(root);
4049 return ret;
4050 }
4051
4052 int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
4053 struct btrfs_root *root,
4054 struct inode *dir, u64 objectid,
4055 const char *name, int name_len)
4056 {
4057 struct btrfs_path *path;
4058 struct extent_buffer *leaf;
4059 struct btrfs_dir_item *di;
4060 struct btrfs_key key;
4061 u64 index;
4062 int ret;
4063 u64 dir_ino = btrfs_ino(dir);
4064
4065 path = btrfs_alloc_path();
4066 if (!path)
4067 return -ENOMEM;
4068
4069 di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
4070 name, name_len, -1);
4071 if (IS_ERR_OR_NULL(di)) {
4072 if (!di)
4073 ret = -ENOENT;
4074 else
4075 ret = PTR_ERR(di);
4076 goto out;
4077 }
4078
4079 leaf = path->nodes[0];
4080 btrfs_dir_item_key_to_cpu(leaf, di, &key);
4081 WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
4082 ret = btrfs_delete_one_dir_name(trans, root, path, di);
4083 if (ret) {
4084 btrfs_abort_transaction(trans, root, ret);
4085 goto out;
4086 }
4087 btrfs_release_path(path);
4088
4089 ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
4090 objectid, root->root_key.objectid,
4091 dir_ino, &index, name, name_len);
4092 if (ret < 0) {
4093 if (ret != -ENOENT) {
4094 btrfs_abort_transaction(trans, root, ret);
4095 goto out;
4096 }
4097 di = btrfs_search_dir_index_item(root, path, dir_ino,
4098 name, name_len);
4099 if (IS_ERR_OR_NULL(di)) {
4100 if (!di)
4101 ret = -ENOENT;
4102 else
4103 ret = PTR_ERR(di);
4104 btrfs_abort_transaction(trans, root, ret);
4105 goto out;
4106 }
4107
4108 leaf = path->nodes[0];
4109 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4110 btrfs_release_path(path);
4111 index = key.offset;
4112 }
4113 btrfs_release_path(path);
4114
4115 ret = btrfs_delete_delayed_dir_index(trans, root, dir, index);
4116 if (ret) {
4117 btrfs_abort_transaction(trans, root, ret);
4118 goto out;
4119 }
4120
4121 btrfs_i_size_write(dir, dir->i_size - name_len * 2);
4122 inode_inc_iversion(dir);
4123 dir->i_mtime = dir->i_ctime = CURRENT_TIME;
4124 ret = btrfs_update_inode_fallback(trans, root, dir);
4125 if (ret)
4126 btrfs_abort_transaction(trans, root, ret);
4127 out:
4128 btrfs_free_path(path);
4129 return ret;
4130 }
4131
4132 static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
4133 {
4134 struct inode *inode = d_inode(dentry);
4135 int err = 0;
4136 struct btrfs_root *root = BTRFS_I(dir)->root;
4137 struct btrfs_trans_handle *trans;
4138
4139 if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
4140 return -ENOTEMPTY;
4141 if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID)
4142 return -EPERM;
4143
4144 trans = __unlink_start_trans(dir);
4145 if (IS_ERR(trans))
4146 return PTR_ERR(trans);
4147
4148 if (unlikely(btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
4149 err = btrfs_unlink_subvol(trans, root, dir,
4150 BTRFS_I(inode)->location.objectid,
4151 dentry->d_name.name,
4152 dentry->d_name.len);
4153 goto out;
4154 }
4155
4156 err = btrfs_orphan_add(trans, inode);
4157 if (err)
4158 goto out;
4159
4160 /* now the directory is empty */
4161 err = btrfs_unlink_inode(trans, root, dir, d_inode(dentry),
4162 dentry->d_name.name, dentry->d_name.len);
4163 if (!err)
4164 btrfs_i_size_write(inode, 0);
4165 out:
4166 btrfs_end_transaction(trans, root);
4167 btrfs_btree_balance_dirty(root);
4168
4169 return err;
4170 }
4171
4172 static int truncate_space_check(struct btrfs_trans_handle *trans,
4173 struct btrfs_root *root,
4174 u64 bytes_deleted)
4175 {
4176 int ret;
4177
4178 bytes_deleted = btrfs_csum_bytes_to_leaves(root, bytes_deleted);
4179 ret = btrfs_block_rsv_add(root, &root->fs_info->trans_block_rsv,
4180 bytes_deleted, BTRFS_RESERVE_NO_FLUSH);
4181 if (!ret)
4182 trans->bytes_reserved += bytes_deleted;
4183 return ret;
4184
4185 }
4186
4187 /*
4188 * this can truncate away extent items, csum items and directory items.
4189 * It starts at a high offset and removes keys until it can't find
4190 * any higher than new_size
4191 *
4192 * csum items that cross the new i_size are truncated to the new size
4193 * as well.
4194 *
4195 * min_type is the minimum key type to truncate down to. If set to 0, this
4196 * will kill all the items on this inode, including the INODE_ITEM_KEY.
4197 */
4198 int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
4199 struct btrfs_root *root,
4200 struct inode *inode,
4201 u64 new_size, u32 min_type)
4202 {
4203 struct btrfs_path *path;
4204 struct extent_buffer *leaf;
4205 struct btrfs_file_extent_item *fi;
4206 struct btrfs_key key;
4207 struct btrfs_key found_key;
4208 u64 extent_start = 0;
4209 u64 extent_num_bytes = 0;
4210 u64 extent_offset = 0;
4211 u64 item_end = 0;
4212 u64 last_size = (u64)-1;
4213 u32 found_type = (u8)-1;
4214 int found_extent;
4215 int del_item;
4216 int pending_del_nr = 0;
4217 int pending_del_slot = 0;
4218 int extent_type = -1;
4219 int ret;
4220 int err = 0;
4221 u64 ino = btrfs_ino(inode);
4222 u64 bytes_deleted = 0;
4223 bool be_nice = 0;
4224 bool should_throttle = 0;
4225 bool should_end = 0;
4226
4227 BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
4228
4229 /*
4230 * for non-free space inodes and ref cows, we want to back off from
4231 * time to time
4232 */
4233 if (!btrfs_is_free_space_inode(inode) &&
4234 test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4235 be_nice = 1;
4236
4237 path = btrfs_alloc_path();
4238 if (!path)
4239 return -ENOMEM;
4240 path->reada = -1;
4241
4242 /*
4243 * We want to drop from the next block forward in case this new size is
4244 * not block aligned since we will be keeping the last block of the
4245 * extent just the way it is.
4246 */
4247 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4248 root == root->fs_info->tree_root)
4249 btrfs_drop_extent_cache(inode, ALIGN(new_size,
4250 root->sectorsize), (u64)-1, 0);
4251
4252 /*
4253 * This function is also used to drop the items in the log tree before
4254 * we relog the inode, so if root != BTRFS_I(inode)->root, it means
4255 * it is used to drop the loged items. So we shouldn't kill the delayed
4256 * items.
4257 */
4258 if (min_type == 0 && root == BTRFS_I(inode)->root)
4259 btrfs_kill_delayed_inode_items(inode);
4260
4261 key.objectid = ino;
4262 key.offset = (u64)-1;
4263 key.type = (u8)-1;
4264
4265 search_again:
4266 /*
4267 * with a 16K leaf size and 128MB extents, you can actually queue
4268 * up a huge file in a single leaf. Most of the time that
4269 * bytes_deleted is > 0, it will be huge by the time we get here
4270 */
4271 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4272 if (btrfs_should_end_transaction(trans, root)) {
4273 err = -EAGAIN;
4274 goto error;
4275 }
4276 }
4277
4278
4279 path->leave_spinning = 1;
4280 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
4281 if (ret < 0) {
4282 err = ret;
4283 goto out;
4284 }
4285
4286 if (ret > 0) {
4287 /* there are no items in the tree for us to truncate, we're
4288 * done
4289 */
4290 if (path->slots[0] == 0)
4291 goto out;
4292 path->slots[0]--;
4293 }
4294
4295 while (1) {
4296 fi = NULL;
4297 leaf = path->nodes[0];
4298 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
4299 found_type = found_key.type;
4300
4301 if (found_key.objectid != ino)
4302 break;
4303
4304 if (found_type < min_type)
4305 break;
4306
4307 item_end = found_key.offset;
4308 if (found_type == BTRFS_EXTENT_DATA_KEY) {
4309 fi = btrfs_item_ptr(leaf, path->slots[0],
4310 struct btrfs_file_extent_item);
4311 extent_type = btrfs_file_extent_type(leaf, fi);
4312 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4313 item_end +=
4314 btrfs_file_extent_num_bytes(leaf, fi);
4315 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4316 item_end += btrfs_file_extent_inline_len(leaf,
4317 path->slots[0], fi);
4318 }
4319 item_end--;
4320 }
4321 if (found_type > min_type) {
4322 del_item = 1;
4323 } else {
4324 if (item_end < new_size)
4325 break;
4326 if (found_key.offset >= new_size)
4327 del_item = 1;
4328 else
4329 del_item = 0;
4330 }
4331 found_extent = 0;
4332 /* FIXME, shrink the extent if the ref count is only 1 */
4333 if (found_type != BTRFS_EXTENT_DATA_KEY)
4334 goto delete;
4335
4336 if (del_item)
4337 last_size = found_key.offset;
4338 else
4339 last_size = new_size;
4340
4341 if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
4342 u64 num_dec;
4343 extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
4344 if (!del_item) {
4345 u64 orig_num_bytes =
4346 btrfs_file_extent_num_bytes(leaf, fi);
4347 extent_num_bytes = ALIGN(new_size -
4348 found_key.offset,
4349 root->sectorsize);
4350 btrfs_set_file_extent_num_bytes(leaf, fi,
4351 extent_num_bytes);
4352 num_dec = (orig_num_bytes -
4353 extent_num_bytes);
4354 if (test_bit(BTRFS_ROOT_REF_COWS,
4355 &root->state) &&
4356 extent_start != 0)
4357 inode_sub_bytes(inode, num_dec);
4358 btrfs_mark_buffer_dirty(leaf);
4359 } else {
4360 extent_num_bytes =
4361 btrfs_file_extent_disk_num_bytes(leaf,
4362 fi);
4363 extent_offset = found_key.offset -
4364 btrfs_file_extent_offset(leaf, fi);
4365
4366 /* FIXME blocksize != 4096 */
4367 num_dec = btrfs_file_extent_num_bytes(leaf, fi);
4368 if (extent_start != 0) {
4369 found_extent = 1;
4370 if (test_bit(BTRFS_ROOT_REF_COWS,
4371 &root->state))
4372 inode_sub_bytes(inode, num_dec);
4373 }
4374 }
4375 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
4376 /*
4377 * we can't truncate inline items that have had
4378 * special encodings
4379 */
4380 if (!del_item &&
4381 btrfs_file_extent_compression(leaf, fi) == 0 &&
4382 btrfs_file_extent_encryption(leaf, fi) == 0 &&
4383 btrfs_file_extent_other_encoding(leaf, fi) == 0) {
4384 u32 size = new_size - found_key.offset;
4385
4386 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
4387 inode_sub_bytes(inode, item_end + 1 -
4388 new_size);
4389
4390 /*
4391 * update the ram bytes to properly reflect
4392 * the new size of our item
4393 */
4394 btrfs_set_file_extent_ram_bytes(leaf, fi, size);
4395 size =
4396 btrfs_file_extent_calc_inline_size(size);
4397 btrfs_truncate_item(root, path, size, 1);
4398 } else if (test_bit(BTRFS_ROOT_REF_COWS,
4399 &root->state)) {
4400 inode_sub_bytes(inode, item_end + 1 -
4401 found_key.offset);
4402 }
4403 }
4404 delete:
4405 if (del_item) {
4406 if (!pending_del_nr) {
4407 /* no pending yet, add ourselves */
4408 pending_del_slot = path->slots[0];
4409 pending_del_nr = 1;
4410 } else if (pending_del_nr &&
4411 path->slots[0] + 1 == pending_del_slot) {
4412 /* hop on the pending chunk */
4413 pending_del_nr++;
4414 pending_del_slot = path->slots[0];
4415 } else {
4416 BUG();
4417 }
4418 } else {
4419 break;
4420 }
4421 should_throttle = 0;
4422
4423 if (found_extent &&
4424 (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
4425 root == root->fs_info->tree_root)) {
4426 btrfs_set_path_blocking(path);
4427 bytes_deleted += extent_num_bytes;
4428 ret = btrfs_free_extent(trans, root, extent_start,
4429 extent_num_bytes, 0,
4430 btrfs_header_owner(leaf),
4431 ino, extent_offset, 0);
4432 BUG_ON(ret);
4433 if (btrfs_should_throttle_delayed_refs(trans, root))
4434 btrfs_async_run_delayed_refs(root,
4435 trans->delayed_ref_updates * 2, 0);
4436 if (be_nice) {
4437 if (truncate_space_check(trans, root,
4438 extent_num_bytes)) {
4439 should_end = 1;
4440 }
4441 if (btrfs_should_throttle_delayed_refs(trans,
4442 root)) {
4443 should_throttle = 1;
4444 }
4445 }
4446 }
4447
4448 if (found_type == BTRFS_INODE_ITEM_KEY)
4449 break;
4450
4451 if (path->slots[0] == 0 ||
4452 path->slots[0] != pending_del_slot ||
4453 should_throttle || should_end) {
4454 if (pending_del_nr) {
4455 ret = btrfs_del_items(trans, root, path,
4456 pending_del_slot,
4457 pending_del_nr);
4458 if (ret) {
4459 btrfs_abort_transaction(trans,
4460 root, ret);
4461 goto error;
4462 }
4463 pending_del_nr = 0;
4464 }
4465 btrfs_release_path(path);
4466 if (should_throttle) {
4467 unsigned long updates = trans->delayed_ref_updates;
4468 if (updates) {
4469 trans->delayed_ref_updates = 0;
4470 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4471 if (ret && !err)
4472 err = ret;
4473 }
4474 }
4475 /*
4476 * if we failed to refill our space rsv, bail out
4477 * and let the transaction restart
4478 */
4479 if (should_end) {
4480 err = -EAGAIN;
4481 goto error;
4482 }
4483 goto search_again;
4484 } else {
4485 path->slots[0]--;
4486 }
4487 }
4488 out:
4489 if (pending_del_nr) {
4490 ret = btrfs_del_items(trans, root, path, pending_del_slot,
4491 pending_del_nr);
4492 if (ret)
4493 btrfs_abort_transaction(trans, root, ret);
4494 }
4495 error:
4496 if (last_size != (u64)-1 &&
4497 root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
4498 btrfs_ordered_update_i_size(inode, last_size, NULL);
4499
4500 btrfs_free_path(path);
4501
4502 if (be_nice && bytes_deleted > 32 * 1024 * 1024) {
4503 unsigned long updates = trans->delayed_ref_updates;
4504 if (updates) {
4505 trans->delayed_ref_updates = 0;
4506 ret = btrfs_run_delayed_refs(trans, root, updates * 2);
4507 if (ret && !err)
4508 err = ret;
4509 }
4510 }
4511 return err;
4512 }
4513
4514 /*
4515 * btrfs_truncate_page - read, zero a chunk and write a page
4516 * @inode - inode that we're zeroing
4517 * @from - the offset to start zeroing
4518 * @len - the length to zero, 0 to zero the entire range respective to the
4519 * offset
4520 * @front - zero up to the offset instead of from the offset on
4521 *
4522 * This will find the page for the "from" offset and cow the page and zero the
4523 * part we want to zero. This is used with truncate and hole punching.
4524 */
4525 int btrfs_truncate_page(struct inode *inode, loff_t from, loff_t len,
4526 int front)
4527 {
4528 struct address_space *mapping = inode->i_mapping;
4529 struct btrfs_root *root = BTRFS_I(inode)->root;
4530 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4531 struct btrfs_ordered_extent *ordered;
4532 struct extent_state *cached_state = NULL;
4533 char *kaddr;
4534 u32 blocksize = root->sectorsize;
4535 pgoff_t index = from >> PAGE_CACHE_SHIFT;
4536 unsigned offset = from & (PAGE_CACHE_SIZE-1);
4537 struct page *page;
4538 gfp_t mask = btrfs_alloc_write_mask(mapping);
4539 int ret = 0;
4540 u64 page_start;
4541 u64 page_end;
4542
4543 if ((offset & (blocksize - 1)) == 0 &&
4544 (!len || ((len & (blocksize - 1)) == 0)))
4545 goto out;
4546 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
4547 if (ret)
4548 goto out;
4549
4550 again:
4551 page = find_or_create_page(mapping, index, mask);
4552 if (!page) {
4553 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4554 ret = -ENOMEM;
4555 goto out;
4556 }
4557
4558 page_start = page_offset(page);
4559 page_end = page_start + PAGE_CACHE_SIZE - 1;
4560
4561 if (!PageUptodate(page)) {
4562 ret = btrfs_readpage(NULL, page);
4563 lock_page(page);
4564 if (page->mapping != mapping) {
4565 unlock_page(page);
4566 page_cache_release(page);
4567 goto again;
4568 }
4569 if (!PageUptodate(page)) {
4570 ret = -EIO;
4571 goto out_unlock;
4572 }
4573 }
4574 wait_on_page_writeback(page);
4575
4576 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
4577 set_page_extent_mapped(page);
4578
4579 ordered = btrfs_lookup_ordered_extent(inode, page_start);
4580 if (ordered) {
4581 unlock_extent_cached(io_tree, page_start, page_end,
4582 &cached_state, GFP_NOFS);
4583 unlock_page(page);
4584 page_cache_release(page);
4585 btrfs_start_ordered_extent(inode, ordered, 1);
4586 btrfs_put_ordered_extent(ordered);
4587 goto again;
4588 }
4589
4590 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
4591 EXTENT_DIRTY | EXTENT_DELALLOC |
4592 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
4593 0, 0, &cached_state, GFP_NOFS);
4594
4595 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
4596 &cached_state);
4597 if (ret) {
4598 unlock_extent_cached(io_tree, page_start, page_end,
4599 &cached_state, GFP_NOFS);
4600 goto out_unlock;
4601 }
4602
4603 if (offset != PAGE_CACHE_SIZE) {
4604 if (!len)
4605 len = PAGE_CACHE_SIZE - offset;
4606 kaddr = kmap(page);
4607 if (front)
4608 memset(kaddr, 0, offset);
4609 else
4610 memset(kaddr + offset, 0, len);
4611 flush_dcache_page(page);
4612 kunmap(page);
4613 }
4614 ClearPageChecked(page);
4615 set_page_dirty(page);
4616 unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
4617 GFP_NOFS);
4618
4619 out_unlock:
4620 if (ret)
4621 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
4622 unlock_page(page);
4623 page_cache_release(page);
4624 out:
4625 return ret;
4626 }
4627
4628 static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
4629 u64 offset, u64 len)
4630 {
4631 struct btrfs_trans_handle *trans;
4632 int ret;
4633
4634 /*
4635 * Still need to make sure the inode looks like it's been updated so
4636 * that any holes get logged if we fsync.
4637 */
4638 if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) {
4639 BTRFS_I(inode)->last_trans = root->fs_info->generation;
4640 BTRFS_I(inode)->last_sub_trans = root->log_transid;
4641 BTRFS_I(inode)->last_log_commit = root->last_log_commit;
4642 return 0;
4643 }
4644
4645 /*
4646 * 1 - for the one we're dropping
4647 * 1 - for the one we're adding
4648 * 1 - for updating the inode.
4649 */
4650 trans = btrfs_start_transaction(root, 3);
4651 if (IS_ERR(trans))
4652 return PTR_ERR(trans);
4653
4654 ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
4655 if (ret) {
4656 btrfs_abort_transaction(trans, root, ret);
4657 btrfs_end_transaction(trans, root);
4658 return ret;
4659 }
4660
4661 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
4662 0, 0, len, 0, len, 0, 0, 0);
4663 if (ret)
4664 btrfs_abort_transaction(trans, root, ret);
4665 else
4666 btrfs_update_inode(trans, root, inode);
4667 btrfs_end_transaction(trans, root);
4668 return ret;
4669 }
4670
4671 /*
4672 * This function puts in dummy file extents for the area we're creating a hole
4673 * for. So if we are truncating this file to a larger size we need to insert
4674 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
4675 * the range between oldsize and size
4676 */
4677 int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
4678 {
4679 struct btrfs_root *root = BTRFS_I(inode)->root;
4680 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4681 struct extent_map *em = NULL;
4682 struct extent_state *cached_state = NULL;
4683 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4684 u64 hole_start = ALIGN(oldsize, root->sectorsize);
4685 u64 block_end = ALIGN(size, root->sectorsize);
4686 u64 last_byte;
4687 u64 cur_offset;
4688 u64 hole_size;
4689 int err = 0;
4690
4691 /*
4692 * If our size started in the middle of a page we need to zero out the
4693 * rest of the page before we expand the i_size, otherwise we could
4694 * expose stale data.
4695 */
4696 err = btrfs_truncate_page(inode, oldsize, 0, 0);
4697 if (err)
4698 return err;
4699
4700 if (size <= hole_start)
4701 return 0;
4702
4703 while (1) {
4704 struct btrfs_ordered_extent *ordered;
4705
4706 lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
4707 &cached_state);
4708 ordered = btrfs_lookup_ordered_range(inode, hole_start,
4709 block_end - hole_start);
4710 if (!ordered)
4711 break;
4712 unlock_extent_cached(io_tree, hole_start, block_end - 1,
4713 &cached_state, GFP_NOFS);
4714 btrfs_start_ordered_extent(inode, ordered, 1);
4715 btrfs_put_ordered_extent(ordered);
4716 }
4717
4718 cur_offset = hole_start;
4719 while (1) {
4720 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
4721 block_end - cur_offset, 0);
4722 if (IS_ERR(em)) {
4723 err = PTR_ERR(em);
4724 em = NULL;
4725 break;
4726 }
4727 last_byte = min(extent_map_end(em), block_end);
4728 last_byte = ALIGN(last_byte , root->sectorsize);
4729 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
4730 struct extent_map *hole_em;
4731 hole_size = last_byte - cur_offset;
4732
4733 err = maybe_insert_hole(root, inode, cur_offset,
4734 hole_size);
4735 if (err)
4736 break;
4737 btrfs_drop_extent_cache(inode, cur_offset,
4738 cur_offset + hole_size - 1, 0);
4739 hole_em = alloc_extent_map();
4740 if (!hole_em) {
4741 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
4742 &BTRFS_I(inode)->runtime_flags);
4743 goto next;
4744 }
4745 hole_em->start = cur_offset;
4746 hole_em->len = hole_size;
4747 hole_em->orig_start = cur_offset;
4748
4749 hole_em->block_start = EXTENT_MAP_HOLE;
4750 hole_em->block_len = 0;
4751 hole_em->orig_block_len = 0;
4752 hole_em->ram_bytes = hole_size;
4753 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
4754 hole_em->compress_type = BTRFS_COMPRESS_NONE;
4755 hole_em->generation = root->fs_info->generation;
4756
4757 while (1) {
4758 write_lock(&em_tree->lock);
4759 err = add_extent_mapping(em_tree, hole_em, 1);
4760 write_unlock(&em_tree->lock);
4761 if (err != -EEXIST)
4762 break;
4763 btrfs_drop_extent_cache(inode, cur_offset,
4764 cur_offset +
4765 hole_size - 1, 0);
4766 }
4767 free_extent_map(hole_em);
4768 }
4769 next:
4770 free_extent_map(em);
4771 em = NULL;
4772 cur_offset = last_byte;
4773 if (cur_offset >= block_end)
4774 break;
4775 }
4776 free_extent_map(em);
4777 unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
4778 GFP_NOFS);
4779 return err;
4780 }
4781
4782 static int wait_snapshoting_atomic_t(atomic_t *a)
4783 {
4784 schedule();
4785 return 0;
4786 }
4787
4788 static void wait_for_snapshot_creation(struct btrfs_root *root)
4789 {
4790 while (true) {
4791 int ret;
4792
4793 ret = btrfs_start_write_no_snapshoting(root);
4794 if (ret)
4795 break;
4796 wait_on_atomic_t(&root->will_be_snapshoted,
4797 wait_snapshoting_atomic_t,
4798 TASK_UNINTERRUPTIBLE);
4799 }
4800 }
4801
4802 static int btrfs_setsize(struct inode *inode, struct iattr *attr)
4803 {
4804 struct btrfs_root *root = BTRFS_I(inode)->root;
4805 struct btrfs_trans_handle *trans;
4806 loff_t oldsize = i_size_read(inode);
4807 loff_t newsize = attr->ia_size;
4808 int mask = attr->ia_valid;
4809 int ret;
4810
4811 /*
4812 * The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
4813 * special case where we need to update the times despite not having
4814 * these flags set. For all other operations the VFS set these flags
4815 * explicitly if it wants a timestamp update.
4816 */
4817 if (newsize != oldsize) {
4818 inode_inc_iversion(inode);
4819 if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
4820 inode->i_ctime = inode->i_mtime =
4821 current_fs_time(inode->i_sb);
4822 }
4823
4824 if (newsize > oldsize) {
4825 truncate_pagecache(inode, newsize);
4826 /*
4827 * Don't do an expanding truncate while snapshoting is ongoing.
4828 * This is to ensure the snapshot captures a fully consistent
4829 * state of this file - if the snapshot captures this expanding
4830 * truncation, it must capture all writes that happened before
4831 * this truncation.
4832 */
4833 wait_for_snapshot_creation(root);
4834 ret = btrfs_cont_expand(inode, oldsize, newsize);
4835 if (ret) {
4836 btrfs_end_write_no_snapshoting(root);
4837 return ret;
4838 }
4839
4840 trans = btrfs_start_transaction(root, 1);
4841 if (IS_ERR(trans)) {
4842 btrfs_end_write_no_snapshoting(root);
4843 return PTR_ERR(trans);
4844 }
4845
4846 i_size_write(inode, newsize);
4847 btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
4848 ret = btrfs_update_inode(trans, root, inode);
4849 btrfs_end_write_no_snapshoting(root);
4850 btrfs_end_transaction(trans, root);
4851 } else {
4852
4853 /*
4854 * We're truncating a file that used to have good data down to
4855 * zero. Make sure it gets into the ordered flush list so that
4856 * any new writes get down to disk quickly.
4857 */
4858 if (newsize == 0)
4859 set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
4860 &BTRFS_I(inode)->runtime_flags);
4861
4862 /*
4863 * 1 for the orphan item we're going to add
4864 * 1 for the orphan item deletion.
4865 */
4866 trans = btrfs_start_transaction(root, 2);
4867 if (IS_ERR(trans))
4868 return PTR_ERR(trans);
4869
4870 /*
4871 * We need to do this in case we fail at _any_ point during the
4872 * actual truncate. Once we do the truncate_setsize we could
4873 * invalidate pages which forces any outstanding ordered io to
4874 * be instantly completed which will give us extents that need
4875 * to be truncated. If we fail to get an orphan inode down we
4876 * could have left over extents that were never meant to live,
4877 * so we need to garuntee from this point on that everything
4878 * will be consistent.
4879 */
4880 ret = btrfs_orphan_add(trans, inode);
4881 btrfs_end_transaction(trans, root);
4882 if (ret)
4883 return ret;
4884
4885 /* we don't support swapfiles, so vmtruncate shouldn't fail */
4886 truncate_setsize(inode, newsize);
4887
4888 /* Disable nonlocked read DIO to avoid the end less truncate */
4889 btrfs_inode_block_unlocked_dio(inode);
4890 inode_dio_wait(inode);
4891 btrfs_inode_resume_unlocked_dio(inode);
4892
4893 ret = btrfs_truncate(inode);
4894 if (ret && inode->i_nlink) {
4895 int err;
4896
4897 /*
4898 * failed to truncate, disk_i_size is only adjusted down
4899 * as we remove extents, so it should represent the true
4900 * size of the inode, so reset the in memory size and
4901 * delete our orphan entry.
4902 */
4903 trans = btrfs_join_transaction(root);
4904 if (IS_ERR(trans)) {
4905 btrfs_orphan_del(NULL, inode);
4906 return ret;
4907 }
4908 i_size_write(inode, BTRFS_I(inode)->disk_i_size);
4909 err = btrfs_orphan_del(trans, inode);
4910 if (err)
4911 btrfs_abort_transaction(trans, root, err);
4912 btrfs_end_transaction(trans, root);
4913 }
4914 }
4915
4916 return ret;
4917 }
4918
4919 static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
4920 {
4921 struct inode *inode = d_inode(dentry);
4922 struct btrfs_root *root = BTRFS_I(inode)->root;
4923 int err;
4924
4925 if (btrfs_root_readonly(root))
4926 return -EROFS;
4927
4928 err = inode_change_ok(inode, attr);
4929 if (err)
4930 return err;
4931
4932 if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
4933 err = btrfs_setsize(inode, attr);
4934 if (err)
4935 return err;
4936 }
4937
4938 if (attr->ia_valid) {
4939 setattr_copy(inode, attr);
4940 inode_inc_iversion(inode);
4941 err = btrfs_dirty_inode(inode);
4942
4943 if (!err && attr->ia_valid & ATTR_MODE)
4944 err = posix_acl_chmod(inode, inode->i_mode);
4945 }
4946
4947 return err;
4948 }
4949
4950 /*
4951 * While truncating the inode pages during eviction, we get the VFS calling
4952 * btrfs_invalidatepage() against each page of the inode. This is slow because
4953 * the calls to btrfs_invalidatepage() result in a huge amount of calls to
4954 * lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
4955 * extent_state structures over and over, wasting lots of time.
4956 *
4957 * Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
4958 * those expensive operations on a per page basis and do only the ordered io
4959 * finishing, while we release here the extent_map and extent_state structures,
4960 * without the excessive merging and splitting.
4961 */
4962 static void evict_inode_truncate_pages(struct inode *inode)
4963 {
4964 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4965 struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
4966 struct rb_node *node;
4967
4968 ASSERT(inode->i_state & I_FREEING);
4969 truncate_inode_pages_final(&inode->i_data);
4970
4971 write_lock(&map_tree->lock);
4972 while (!RB_EMPTY_ROOT(&map_tree->map)) {
4973 struct extent_map *em;
4974
4975 node = rb_first(&map_tree->map);
4976 em = rb_entry(node, struct extent_map, rb_node);
4977 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
4978 clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
4979 remove_extent_mapping(map_tree, em);
4980 free_extent_map(em);
4981 if (need_resched()) {
4982 write_unlock(&map_tree->lock);
4983 cond_resched();
4984 write_lock(&map_tree->lock);
4985 }
4986 }
4987 write_unlock(&map_tree->lock);
4988
4989 spin_lock(&io_tree->lock);
4990 while (!RB_EMPTY_ROOT(&io_tree->state)) {
4991 struct extent_state *state;
4992 struct extent_state *cached_state = NULL;
4993
4994 node = rb_first(&io_tree->state);
4995 state = rb_entry(node, struct extent_state, rb_node);
4996 atomic_inc(&state->refs);
4997 spin_unlock(&io_tree->lock);
4998
4999 lock_extent_bits(io_tree, state->start, state->end,
5000 0, &cached_state);
5001 clear_extent_bit(io_tree, state->start, state->end,
5002 EXTENT_LOCKED | EXTENT_DIRTY |
5003 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
5004 EXTENT_DEFRAG, 1, 1,
5005 &cached_state, GFP_NOFS);
5006 free_extent_state(state);
5007
5008 cond_resched();
5009 spin_lock(&io_tree->lock);
5010 }
5011 spin_unlock(&io_tree->lock);
5012 }
5013
5014 void btrfs_evict_inode(struct inode *inode)
5015 {
5016 struct btrfs_trans_handle *trans;
5017 struct btrfs_root *root = BTRFS_I(inode)->root;
5018 struct btrfs_block_rsv *rsv, *global_rsv;
5019 int steal_from_global = 0;
5020 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
5021 int ret;
5022
5023 trace_btrfs_inode_evict(inode);
5024
5025 evict_inode_truncate_pages(inode);
5026
5027 if (inode->i_nlink &&
5028 ((btrfs_root_refs(&root->root_item) != 0 &&
5029 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
5030 btrfs_is_free_space_inode(inode)))
5031 goto no_delete;
5032
5033 if (is_bad_inode(inode)) {
5034 btrfs_orphan_del(NULL, inode);
5035 goto no_delete;
5036 }
5037 /* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
5038 btrfs_wait_ordered_range(inode, 0, (u64)-1);
5039
5040 btrfs_free_io_failure_record(inode, 0, (u64)-1);
5041
5042 if (root->fs_info->log_root_recovering) {
5043 BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
5044 &BTRFS_I(inode)->runtime_flags));
5045 goto no_delete;
5046 }
5047
5048 if (inode->i_nlink > 0) {
5049 BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
5050 root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
5051 goto no_delete;
5052 }
5053
5054 ret = btrfs_commit_inode_delayed_inode(inode);
5055 if (ret) {
5056 btrfs_orphan_del(NULL, inode);
5057 goto no_delete;
5058 }
5059
5060 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
5061 if (!rsv) {
5062 btrfs_orphan_del(NULL, inode);
5063 goto no_delete;
5064 }
5065 rsv->size = min_size;
5066 rsv->failfast = 1;
5067 global_rsv = &root->fs_info->global_block_rsv;
5068
5069 btrfs_i_size_write(inode, 0);
5070
5071 /*
5072 * This is a bit simpler than btrfs_truncate since we've already
5073 * reserved our space for our orphan item in the unlink, so we just
5074 * need to reserve some slack space in case we add bytes and update
5075 * inode item when doing the truncate.
5076 */
5077 while (1) {
5078 ret = btrfs_block_rsv_refill(root, rsv, min_size,
5079 BTRFS_RESERVE_FLUSH_LIMIT);
5080
5081 /*
5082 * Try and steal from the global reserve since we will
5083 * likely not use this space anyway, we want to try as
5084 * hard as possible to get this to work.
5085 */
5086 if (ret)
5087 steal_from_global++;
5088 else
5089 steal_from_global = 0;
5090 ret = 0;
5091
5092 /*
5093 * steal_from_global == 0: we reserved stuff, hooray!
5094 * steal_from_global == 1: we didn't reserve stuff, boo!
5095 * steal_from_global == 2: we've committed, still not a lot of
5096 * room but maybe we'll have room in the global reserve this
5097 * time.
5098 * steal_from_global == 3: abandon all hope!
5099 */
5100 if (steal_from_global > 2) {
5101 btrfs_warn(root->fs_info,
5102 "Could not get space for a delete, will truncate on mount %d",
5103 ret);
5104 btrfs_orphan_del(NULL, inode);
5105 btrfs_free_block_rsv(root, rsv);
5106 goto no_delete;
5107 }
5108
5109 trans = btrfs_join_transaction(root);
5110 if (IS_ERR(trans)) {
5111 btrfs_orphan_del(NULL, inode);
5112 btrfs_free_block_rsv(root, rsv);
5113 goto no_delete;
5114 }
5115
5116 /*
5117 * We can't just steal from the global reserve, we need tomake
5118 * sure there is room to do it, if not we need to commit and try
5119 * again.
5120 */
5121 if (steal_from_global) {
5122 if (!btrfs_check_space_for_delayed_refs(trans, root))
5123 ret = btrfs_block_rsv_migrate(global_rsv, rsv,
5124 min_size);
5125 else
5126 ret = -ENOSPC;
5127 }
5128
5129 /*
5130 * Couldn't steal from the global reserve, we have too much
5131 * pending stuff built up, commit the transaction and try it
5132 * again.
5133 */
5134 if (ret) {
5135 ret = btrfs_commit_transaction(trans, root);
5136 if (ret) {
5137 btrfs_orphan_del(NULL, inode);
5138 btrfs_free_block_rsv(root, rsv);
5139 goto no_delete;
5140 }
5141 continue;
5142 } else {
5143 steal_from_global = 0;
5144 }
5145
5146 trans->block_rsv = rsv;
5147
5148 ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
5149 if (ret != -ENOSPC && ret != -EAGAIN)
5150 break;
5151
5152 trans->block_rsv = &root->fs_info->trans_block_rsv;
5153 btrfs_end_transaction(trans, root);
5154 trans = NULL;
5155 btrfs_btree_balance_dirty(root);
5156 }
5157
5158 btrfs_free_block_rsv(root, rsv);
5159
5160 /*
5161 * Errors here aren't a big deal, it just means we leave orphan items
5162 * in the tree. They will be cleaned up on the next mount.
5163 */
5164 if (ret == 0) {
5165 trans->block_rsv = root->orphan_block_rsv;
5166 btrfs_orphan_del(trans, inode);
5167 } else {
5168 btrfs_orphan_del(NULL, inode);
5169 }
5170
5171 trans->block_rsv = &root->fs_info->trans_block_rsv;
5172 if (!(root == root->fs_info->tree_root ||
5173 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
5174 btrfs_return_ino(root, btrfs_ino(inode));
5175
5176 btrfs_end_transaction(trans, root);
5177 btrfs_btree_balance_dirty(root);
5178 no_delete:
5179 btrfs_remove_delayed_node(inode);
5180 clear_inode(inode);
5181 return;
5182 }
5183
5184 /*
5185 * this returns the key found in the dir entry in the location pointer.
5186 * If no dir entries were found, location->objectid is 0.
5187 */
5188 static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
5189 struct btrfs_key *location)
5190 {
5191 const char *name = dentry->d_name.name;
5192 int namelen = dentry->d_name.len;
5193 struct btrfs_dir_item *di;
5194 struct btrfs_path *path;
5195 struct btrfs_root *root = BTRFS_I(dir)->root;
5196 int ret = 0;
5197
5198 path = btrfs_alloc_path();
5199 if (!path)
5200 return -ENOMEM;
5201
5202 di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(dir), name,
5203 namelen, 0);
5204 if (IS_ERR(di))
5205 ret = PTR_ERR(di);
5206
5207 if (IS_ERR_OR_NULL(di))
5208 goto out_err;
5209
5210 btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
5211 out:
5212 btrfs_free_path(path);
5213 return ret;
5214 out_err:
5215 location->objectid = 0;
5216 goto out;
5217 }
5218
5219 /*
5220 * when we hit a tree root in a directory, the btrfs part of the inode
5221 * needs to be changed to reflect the root directory of the tree root. This
5222 * is kind of like crossing a mount point.
5223 */
5224 static int fixup_tree_root_location(struct btrfs_root *root,
5225 struct inode *dir,
5226 struct dentry *dentry,
5227 struct btrfs_key *location,
5228 struct btrfs_root **sub_root)
5229 {
5230 struct btrfs_path *path;
5231 struct btrfs_root *new_root;
5232 struct btrfs_root_ref *ref;
5233 struct extent_buffer *leaf;
5234 struct btrfs_key key;
5235 int ret;
5236 int err = 0;
5237
5238 path = btrfs_alloc_path();
5239 if (!path) {
5240 err = -ENOMEM;
5241 goto out;
5242 }
5243
5244 err = -ENOENT;
5245 key.objectid = BTRFS_I(dir)->root->root_key.objectid;
5246 key.type = BTRFS_ROOT_REF_KEY;
5247 key.offset = location->objectid;
5248
5249 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, path,
5250 0, 0);
5251 if (ret) {
5252 if (ret < 0)
5253 err = ret;
5254 goto out;
5255 }
5256
5257 leaf = path->nodes[0];
5258 ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
5259 if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(dir) ||
5260 btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
5261 goto out;
5262
5263 ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
5264 (unsigned long)(ref + 1),
5265 dentry->d_name.len);
5266 if (ret)
5267 goto out;
5268
5269 btrfs_release_path(path);
5270
5271 new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
5272 if (IS_ERR(new_root)) {
5273 err = PTR_ERR(new_root);
5274 goto out;
5275 }
5276
5277 *sub_root = new_root;
5278 location->objectid = btrfs_root_dirid(&new_root->root_item);
5279 location->type = BTRFS_INODE_ITEM_KEY;
5280 location->offset = 0;
5281 err = 0;
5282 out:
5283 btrfs_free_path(path);
5284 return err;
5285 }
5286
5287 static void inode_tree_add(struct inode *inode)
5288 {
5289 struct btrfs_root *root = BTRFS_I(inode)->root;
5290 struct btrfs_inode *entry;
5291 struct rb_node **p;
5292 struct rb_node *parent;
5293 struct rb_node *new = &BTRFS_I(inode)->rb_node;
5294 u64 ino = btrfs_ino(inode);
5295
5296 if (inode_unhashed(inode))
5297 return;
5298 parent = NULL;
5299 spin_lock(&root->inode_lock);
5300 p = &root->inode_tree.rb_node;
5301 while (*p) {
5302 parent = *p;
5303 entry = rb_entry(parent, struct btrfs_inode, rb_node);
5304
5305 if (ino < btrfs_ino(&entry->vfs_inode))
5306 p = &parent->rb_left;
5307 else if (ino > btrfs_ino(&entry->vfs_inode))
5308 p = &parent->rb_right;
5309 else {
5310 WARN_ON(!(entry->vfs_inode.i_state &
5311 (I_WILL_FREE | I_FREEING)));
5312 rb_replace_node(parent, new, &root->inode_tree);
5313 RB_CLEAR_NODE(parent);
5314 spin_unlock(&root->inode_lock);
5315 return;
5316 }
5317 }
5318 rb_link_node(new, parent, p);
5319 rb_insert_color(new, &root->inode_tree);
5320 spin_unlock(&root->inode_lock);
5321 }
5322
5323 static void inode_tree_del(struct inode *inode)
5324 {
5325 struct btrfs_root *root = BTRFS_I(inode)->root;
5326 int empty = 0;
5327
5328 spin_lock(&root->inode_lock);
5329 if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
5330 rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
5331 RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
5332 empty = RB_EMPTY_ROOT(&root->inode_tree);
5333 }
5334 spin_unlock(&root->inode_lock);
5335
5336 if (empty && btrfs_root_refs(&root->root_item) == 0) {
5337 synchronize_srcu(&root->fs_info->subvol_srcu);
5338 spin_lock(&root->inode_lock);
5339 empty = RB_EMPTY_ROOT(&root->inode_tree);
5340 spin_unlock(&root->inode_lock);
5341 if (empty)
5342 btrfs_add_dead_root(root);
5343 }
5344 }
5345
5346 void btrfs_invalidate_inodes(struct btrfs_root *root)
5347 {
5348 struct rb_node *node;
5349 struct rb_node *prev;
5350 struct btrfs_inode *entry;
5351 struct inode *inode;
5352 u64 objectid = 0;
5353
5354 if (!test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
5355 WARN_ON(btrfs_root_refs(&root->root_item) != 0);
5356
5357 spin_lock(&root->inode_lock);
5358 again:
5359 node = root->inode_tree.rb_node;
5360 prev = NULL;
5361 while (node) {
5362 prev = node;
5363 entry = rb_entry(node, struct btrfs_inode, rb_node);
5364
5365 if (objectid < btrfs_ino(&entry->vfs_inode))
5366 node = node->rb_left;
5367 else if (objectid > btrfs_ino(&entry->vfs_inode))
5368 node = node->rb_right;
5369 else
5370 break;
5371 }
5372 if (!node) {
5373 while (prev) {
5374 entry = rb_entry(prev, struct btrfs_inode, rb_node);
5375 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
5376 node = prev;
5377 break;
5378 }
5379 prev = rb_next(prev);
5380 }
5381 }
5382 while (node) {
5383 entry = rb_entry(node, struct btrfs_inode, rb_node);
5384 objectid = btrfs_ino(&entry->vfs_inode) + 1;
5385 inode = igrab(&entry->vfs_inode);
5386 if (inode) {
5387 spin_unlock(&root->inode_lock);
5388 if (atomic_read(&inode->i_count) > 1)
5389 d_prune_aliases(inode);
5390 /*
5391 * btrfs_drop_inode will have it removed from
5392 * the inode cache when its usage count
5393 * hits zero.
5394 */
5395 iput(inode);
5396 cond_resched();
5397 spin_lock(&root->inode_lock);
5398 goto again;
5399 }
5400
5401 if (cond_resched_lock(&root->inode_lock))
5402 goto again;
5403
5404 node = rb_next(node);
5405 }
5406 spin_unlock(&root->inode_lock);
5407 }
5408
5409 static int btrfs_init_locked_inode(struct inode *inode, void *p)
5410 {
5411 struct btrfs_iget_args *args = p;
5412 inode->i_ino = args->location->objectid;
5413 memcpy(&BTRFS_I(inode)->location, args->location,
5414 sizeof(*args->location));
5415 BTRFS_I(inode)->root = args->root;
5416 return 0;
5417 }
5418
5419 static int btrfs_find_actor(struct inode *inode, void *opaque)
5420 {
5421 struct btrfs_iget_args *args = opaque;
5422 return args->location->objectid == BTRFS_I(inode)->location.objectid &&
5423 args->root == BTRFS_I(inode)->root;
5424 }
5425
5426 static struct inode *btrfs_iget_locked(struct super_block *s,
5427 struct btrfs_key *location,
5428 struct btrfs_root *root)
5429 {
5430 struct inode *inode;
5431 struct btrfs_iget_args args;
5432 unsigned long hashval = btrfs_inode_hash(location->objectid, root);
5433
5434 args.location = location;
5435 args.root = root;
5436
5437 inode = iget5_locked(s, hashval, btrfs_find_actor,
5438 btrfs_init_locked_inode,
5439 (void *)&args);
5440 return inode;
5441 }
5442
5443 /* Get an inode object given its location and corresponding root.
5444 * Returns in *is_new if the inode was read from disk
5445 */
5446 struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
5447 struct btrfs_root *root, int *new)
5448 {
5449 struct inode *inode;
5450
5451 inode = btrfs_iget_locked(s, location, root);
5452 if (!inode)
5453 return ERR_PTR(-ENOMEM);
5454
5455 if (inode->i_state & I_NEW) {
5456 btrfs_read_locked_inode(inode);
5457 if (!is_bad_inode(inode)) {
5458 inode_tree_add(inode);
5459 unlock_new_inode(inode);
5460 if (new)
5461 *new = 1;
5462 } else {
5463 unlock_new_inode(inode);
5464 iput(inode);
5465 inode = ERR_PTR(-ESTALE);
5466 }
5467 }
5468
5469 return inode;
5470 }
5471
5472 static struct inode *new_simple_dir(struct super_block *s,
5473 struct btrfs_key *key,
5474 struct btrfs_root *root)
5475 {
5476 struct inode *inode = new_inode(s);
5477
5478 if (!inode)
5479 return ERR_PTR(-ENOMEM);
5480
5481 BTRFS_I(inode)->root = root;
5482 memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
5483 set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
5484
5485 inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
5486 inode->i_op = &btrfs_dir_ro_inode_operations;
5487 inode->i_fop = &simple_dir_operations;
5488 inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
5489 inode->i_mtime = CURRENT_TIME;
5490 inode->i_atime = inode->i_mtime;
5491 inode->i_ctime = inode->i_mtime;
5492 BTRFS_I(inode)->i_otime = inode->i_mtime;
5493
5494 return inode;
5495 }
5496
5497 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
5498 {
5499 struct inode *inode;
5500 struct btrfs_root *root = BTRFS_I(dir)->root;
5501 struct btrfs_root *sub_root = root;
5502 struct btrfs_key location;
5503 int index;
5504 int ret = 0;
5505
5506 if (dentry->d_name.len > BTRFS_NAME_LEN)
5507 return ERR_PTR(-ENAMETOOLONG);
5508
5509 ret = btrfs_inode_by_name(dir, dentry, &location);
5510 if (ret < 0)
5511 return ERR_PTR(ret);
5512
5513 if (location.objectid == 0)
5514 return ERR_PTR(-ENOENT);
5515
5516 if (location.type == BTRFS_INODE_ITEM_KEY) {
5517 inode = btrfs_iget(dir->i_sb, &location, root, NULL);
5518 return inode;
5519 }
5520
5521 BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);
5522
5523 index = srcu_read_lock(&root->fs_info->subvol_srcu);
5524 ret = fixup_tree_root_location(root, dir, dentry,
5525 &location, &sub_root);
5526 if (ret < 0) {
5527 if (ret != -ENOENT)
5528 inode = ERR_PTR(ret);
5529 else
5530 inode = new_simple_dir(dir->i_sb, &location, sub_root);
5531 } else {
5532 inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
5533 }
5534 srcu_read_unlock(&root->fs_info->subvol_srcu, index);
5535
5536 if (!IS_ERR(inode) && root != sub_root) {
5537 down_read(&root->fs_info->cleanup_work_sem);
5538 if (!(inode->i_sb->s_flags & MS_RDONLY))
5539 ret = btrfs_orphan_cleanup(sub_root);
5540 up_read(&root->fs_info->cleanup_work_sem);
5541 if (ret) {
5542 iput(inode);
5543 inode = ERR_PTR(ret);
5544 }
5545 }
5546
5547 return inode;
5548 }
5549
5550 static int btrfs_dentry_delete(const struct dentry *dentry)
5551 {
5552 struct btrfs_root *root;
5553 struct inode *inode = d_inode(dentry);
5554
5555 if (!inode && !IS_ROOT(dentry))
5556 inode = d_inode(dentry->d_parent);
5557
5558 if (inode) {
5559 root = BTRFS_I(inode)->root;
5560 if (btrfs_root_refs(&root->root_item) == 0)
5561 return 1;
5562
5563 if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
5564 return 1;
5565 }
5566 return 0;
5567 }
5568
5569 static void btrfs_dentry_release(struct dentry *dentry)
5570 {
5571 kfree(dentry->d_fsdata);
5572 }
5573
5574 static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
5575 unsigned int flags)
5576 {
5577 struct inode *inode;
5578
5579 inode = btrfs_lookup_dentry(dir, dentry);
5580 if (IS_ERR(inode)) {
5581 if (PTR_ERR(inode) == -ENOENT)
5582 inode = NULL;
5583 else
5584 return ERR_CAST(inode);
5585 }
5586
5587 return d_splice_alias(inode, dentry);
5588 }
5589
5590 unsigned char btrfs_filetype_table[] = {
5591 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
5592 };
5593
5594 static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
5595 {
5596 struct inode *inode = file_inode(file);
5597 struct btrfs_root *root = BTRFS_I(inode)->root;
5598 struct btrfs_item *item;
5599 struct btrfs_dir_item *di;
5600 struct btrfs_key key;
5601 struct btrfs_key found_key;
5602 struct btrfs_path *path;
5603 struct list_head ins_list;
5604 struct list_head del_list;
5605 int ret;
5606 struct extent_buffer *leaf;
5607 int slot;
5608 unsigned char d_type;
5609 int over = 0;
5610 u32 di_cur;
5611 u32 di_total;
5612 u32 di_len;
5613 int key_type = BTRFS_DIR_INDEX_KEY;
5614 char tmp_name[32];
5615 char *name_ptr;
5616 int name_len;
5617 int is_curr = 0; /* ctx->pos points to the current index? */
5618
5619 /* FIXME, use a real flag for deciding about the key type */
5620 if (root->fs_info->tree_root == root)
5621 key_type = BTRFS_DIR_ITEM_KEY;
5622
5623 if (!dir_emit_dots(file, ctx))
5624 return 0;
5625
5626 path = btrfs_alloc_path();
5627 if (!path)
5628 return -ENOMEM;
5629
5630 path->reada = 1;
5631
5632 if (key_type == BTRFS_DIR_INDEX_KEY) {
5633 INIT_LIST_HEAD(&ins_list);
5634 INIT_LIST_HEAD(&del_list);
5635 btrfs_get_delayed_items(inode, &ins_list, &del_list);
5636 }
5637
5638 key.type = key_type;
5639 key.offset = ctx->pos;
5640 key.objectid = btrfs_ino(inode);
5641
5642 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5643 if (ret < 0)
5644 goto err;
5645
5646 while (1) {
5647 leaf = path->nodes[0];
5648 slot = path->slots[0];
5649 if (slot >= btrfs_header_nritems(leaf)) {
5650 ret = btrfs_next_leaf(root, path);
5651 if (ret < 0)
5652 goto err;
5653 else if (ret > 0)
5654 break;
5655 continue;
5656 }
5657
5658 item = btrfs_item_nr(slot);
5659 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5660
5661 if (found_key.objectid != key.objectid)
5662 break;
5663 if (found_key.type != key_type)
5664 break;
5665 if (found_key.offset < ctx->pos)
5666 goto next;
5667 if (key_type == BTRFS_DIR_INDEX_KEY &&
5668 btrfs_should_delete_dir_index(&del_list,
5669 found_key.offset))
5670 goto next;
5671
5672 ctx->pos = found_key.offset;
5673 is_curr = 1;
5674
5675 di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
5676 di_cur = 0;
5677 di_total = btrfs_item_size(leaf, item);
5678
5679 while (di_cur < di_total) {
5680 struct btrfs_key location;
5681
5682 if (verify_dir_item(root, leaf, di))
5683 break;
5684
5685 name_len = btrfs_dir_name_len(leaf, di);
5686 if (name_len <= sizeof(tmp_name)) {
5687 name_ptr = tmp_name;
5688 } else {
5689 name_ptr = kmalloc(name_len, GFP_NOFS);
5690 if (!name_ptr) {
5691 ret = -ENOMEM;
5692 goto err;
5693 }
5694 }
5695 read_extent_buffer(leaf, name_ptr,
5696 (unsigned long)(di + 1), name_len);
5697
5698 d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
5699 btrfs_dir_item_key_to_cpu(leaf, di, &location);
5700
5701
5702 /* is this a reference to our own snapshot? If so
5703 * skip it.
5704 *
5705 * In contrast to old kernels, we insert the snapshot's
5706 * dir item and dir index after it has been created, so
5707 * we won't find a reference to our own snapshot. We
5708 * still keep the following code for backward
5709 * compatibility.
5710 */
5711 if (location.type == BTRFS_ROOT_ITEM_KEY &&
5712 location.objectid == root->root_key.objectid) {
5713 over = 0;
5714 goto skip;
5715 }
5716 over = !dir_emit(ctx, name_ptr, name_len,
5717 location.objectid, d_type);
5718
5719 skip:
5720 if (name_ptr != tmp_name)
5721 kfree(name_ptr);
5722
5723 if (over)
5724 goto nopos;
5725 di_len = btrfs_dir_name_len(leaf, di) +
5726 btrfs_dir_data_len(leaf, di) + sizeof(*di);
5727 di_cur += di_len;
5728 di = (struct btrfs_dir_item *)((char *)di + di_len);
5729 }
5730 next:
5731 path->slots[0]++;
5732 }
5733
5734 if (key_type == BTRFS_DIR_INDEX_KEY) {
5735 if (is_curr)
5736 ctx->pos++;
5737 ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
5738 if (ret)
5739 goto nopos;
5740 }
5741
5742 /* Reached end of directory/root. Bump pos past the last item. */
5743 ctx->pos++;
5744
5745 /*
5746 * Stop new entries from being returned after we return the last
5747 * entry.
5748 *
5749 * New directory entries are assigned a strictly increasing
5750 * offset. This means that new entries created during readdir
5751 * are *guaranteed* to be seen in the future by that readdir.
5752 * This has broken buggy programs which operate on names as
5753 * they're returned by readdir. Until we re-use freed offsets
5754 * we have this hack to stop new entries from being returned
5755 * under the assumption that they'll never reach this huge
5756 * offset.
5757 *
5758 * This is being careful not to overflow 32bit loff_t unless the
5759 * last entry requires it because doing so has broken 32bit apps
5760 * in the past.
5761 */
5762 if (key_type == BTRFS_DIR_INDEX_KEY) {
5763 if (ctx->pos >= INT_MAX)
5764 ctx->pos = LLONG_MAX;
5765 else
5766 ctx->pos = INT_MAX;
5767 }
5768 nopos:
5769 ret = 0;
5770 err:
5771 if (key_type == BTRFS_DIR_INDEX_KEY)
5772 btrfs_put_delayed_items(&ins_list, &del_list);
5773 btrfs_free_path(path);
5774 return ret;
5775 }
5776
5777 int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
5778 {
5779 struct btrfs_root *root = BTRFS_I(inode)->root;
5780 struct btrfs_trans_handle *trans;
5781 int ret = 0;
5782 bool nolock = false;
5783
5784 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5785 return 0;
5786
5787 if (btrfs_fs_closing(root->fs_info) && btrfs_is_free_space_inode(inode))
5788 nolock = true;
5789
5790 if (wbc->sync_mode == WB_SYNC_ALL) {
5791 if (nolock)
5792 trans = btrfs_join_transaction_nolock(root);
5793 else
5794 trans = btrfs_join_transaction(root);
5795 if (IS_ERR(trans))
5796 return PTR_ERR(trans);
5797 ret = btrfs_commit_transaction(trans, root);
5798 }
5799 return ret;
5800 }
5801
5802 /*
5803 * This is somewhat expensive, updating the tree every time the
5804 * inode changes. But, it is most likely to find the inode in cache.
5805 * FIXME, needs more benchmarking...there are no reasons other than performance
5806 * to keep or drop this code.
5807 */
5808 static int btrfs_dirty_inode(struct inode *inode)
5809 {
5810 struct btrfs_root *root = BTRFS_I(inode)->root;
5811 struct btrfs_trans_handle *trans;
5812 int ret;
5813
5814 if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
5815 return 0;
5816
5817 trans = btrfs_join_transaction(root);
5818 if (IS_ERR(trans))
5819 return PTR_ERR(trans);
5820
5821 ret = btrfs_update_inode(trans, root, inode);
5822 if (ret && ret == -ENOSPC) {
5823 /* whoops, lets try again with the full transaction */
5824 btrfs_end_transaction(trans, root);
5825 trans = btrfs_start_transaction(root, 1);
5826 if (IS_ERR(trans))
5827 return PTR_ERR(trans);
5828
5829 ret = btrfs_update_inode(trans, root, inode);
5830 }
5831 btrfs_end_transaction(trans, root);
5832 if (BTRFS_I(inode)->delayed_node)
5833 btrfs_balance_delayed_items(root);
5834
5835 return ret;
5836 }
5837
5838 /*
5839 * This is a copy of file_update_time. We need this so we can return error on
5840 * ENOSPC for updating the inode in the case of file write and mmap writes.
5841 */
5842 static int btrfs_update_time(struct inode *inode, struct timespec *now,
5843 int flags)
5844 {
5845 struct btrfs_root *root = BTRFS_I(inode)->root;
5846
5847 if (btrfs_root_readonly(root))
5848 return -EROFS;
5849
5850 if (flags & S_VERSION)
5851 inode_inc_iversion(inode);
5852 if (flags & S_CTIME)
5853 inode->i_ctime = *now;
5854 if (flags & S_MTIME)
5855 inode->i_mtime = *now;
5856 if (flags & S_ATIME)
5857 inode->i_atime = *now;
5858 return btrfs_dirty_inode(inode);
5859 }
5860
5861 /*
5862 * find the highest existing sequence number in a directory
5863 * and then set the in-memory index_cnt variable to reflect
5864 * free sequence numbers
5865 */
5866 static int btrfs_set_inode_index_count(struct inode *inode)
5867 {
5868 struct btrfs_root *root = BTRFS_I(inode)->root;
5869 struct btrfs_key key, found_key;
5870 struct btrfs_path *path;
5871 struct extent_buffer *leaf;
5872 int ret;
5873
5874 key.objectid = btrfs_ino(inode);
5875 key.type = BTRFS_DIR_INDEX_KEY;
5876 key.offset = (u64)-1;
5877
5878 path = btrfs_alloc_path();
5879 if (!path)
5880 return -ENOMEM;
5881
5882 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5883 if (ret < 0)
5884 goto out;
5885 /* FIXME: we should be able to handle this */
5886 if (ret == 0)
5887 goto out;
5888 ret = 0;
5889
5890 /*
5891 * MAGIC NUMBER EXPLANATION:
5892 * since we search a directory based on f_pos we have to start at 2
5893 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
5894 * else has to start at 2
5895 */
5896 if (path->slots[0] == 0) {
5897 BTRFS_I(inode)->index_cnt = 2;
5898 goto out;
5899 }
5900
5901 path->slots[0]--;
5902
5903 leaf = path->nodes[0];
5904 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
5905
5906 if (found_key.objectid != btrfs_ino(inode) ||
5907 found_key.type != BTRFS_DIR_INDEX_KEY) {
5908 BTRFS_I(inode)->index_cnt = 2;
5909 goto out;
5910 }
5911
5912 BTRFS_I(inode)->index_cnt = found_key.offset + 1;
5913 out:
5914 btrfs_free_path(path);
5915 return ret;
5916 }
5917
5918 /*
5919 * helper to find a free sequence number in a given directory. This current
5920 * code is very simple, later versions will do smarter things in the btree
5921 */
5922 int btrfs_set_inode_index(struct inode *dir, u64 *index)
5923 {
5924 int ret = 0;
5925
5926 if (BTRFS_I(dir)->index_cnt == (u64)-1) {
5927 ret = btrfs_inode_delayed_dir_index_count(dir);
5928 if (ret) {
5929 ret = btrfs_set_inode_index_count(dir);
5930 if (ret)
5931 return ret;
5932 }
5933 }
5934
5935 *index = BTRFS_I(dir)->index_cnt;
5936 BTRFS_I(dir)->index_cnt++;
5937
5938 return ret;
5939 }
5940
5941 static int btrfs_insert_inode_locked(struct inode *inode)
5942 {
5943 struct btrfs_iget_args args;
5944 args.location = &BTRFS_I(inode)->location;
5945 args.root = BTRFS_I(inode)->root;
5946
5947 return insert_inode_locked4(inode,
5948 btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
5949 btrfs_find_actor, &args);
5950 }
5951
5952 static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
5953 struct btrfs_root *root,
5954 struct inode *dir,
5955 const char *name, int name_len,
5956 u64 ref_objectid, u64 objectid,
5957 umode_t mode, u64 *index)
5958 {
5959 struct inode *inode;
5960 struct btrfs_inode_item *inode_item;
5961 struct btrfs_key *location;
5962 struct btrfs_path *path;
5963 struct btrfs_inode_ref *ref;
5964 struct btrfs_key key[2];
5965 u32 sizes[2];
5966 int nitems = name ? 2 : 1;
5967 unsigned long ptr;
5968 int ret;
5969
5970 path = btrfs_alloc_path();
5971 if (!path)
5972 return ERR_PTR(-ENOMEM);
5973
5974 inode = new_inode(root->fs_info->sb);
5975 if (!inode) {
5976 btrfs_free_path(path);
5977 return ERR_PTR(-ENOMEM);
5978 }
5979
5980 /*
5981 * O_TMPFILE, set link count to 0, so that after this point,
5982 * we fill in an inode item with the correct link count.
5983 */
5984 if (!name)
5985 set_nlink(inode, 0);
5986
5987 /*
5988 * we have to initialize this early, so we can reclaim the inode
5989 * number if we fail afterwards in this function.
5990 */
5991 inode->i_ino = objectid;
5992
5993 if (dir && name) {
5994 trace_btrfs_inode_request(dir);
5995
5996 ret = btrfs_set_inode_index(dir, index);
5997 if (ret) {
5998 btrfs_free_path(path);
5999 iput(inode);
6000 return ERR_PTR(ret);
6001 }
6002 } else if (dir) {
6003 *index = 0;
6004 }
6005 /*
6006 * index_cnt is ignored for everything but a dir,
6007 * btrfs_get_inode_index_count has an explanation for the magic
6008 * number
6009 */
6010 BTRFS_I(inode)->index_cnt = 2;
6011 BTRFS_I(inode)->dir_index = *index;
6012 BTRFS_I(inode)->root = root;
6013 BTRFS_I(inode)->generation = trans->transid;
6014 inode->i_generation = BTRFS_I(inode)->generation;
6015
6016 /*
6017 * We could have gotten an inode number from somebody who was fsynced
6018 * and then removed in this same transaction, so let's just set full
6019 * sync since it will be a full sync anyway and this will blow away the
6020 * old info in the log.
6021 */
6022 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
6023
6024 key[0].objectid = objectid;
6025 key[0].type = BTRFS_INODE_ITEM_KEY;
6026 key[0].offset = 0;
6027
6028 sizes[0] = sizeof(struct btrfs_inode_item);
6029
6030 if (name) {
6031 /*
6032 * Start new inodes with an inode_ref. This is slightly more
6033 * efficient for small numbers of hard links since they will
6034 * be packed into one item. Extended refs will kick in if we
6035 * add more hard links than can fit in the ref item.
6036 */
6037 key[1].objectid = objectid;
6038 key[1].type = BTRFS_INODE_REF_KEY;
6039 key[1].offset = ref_objectid;
6040
6041 sizes[1] = name_len + sizeof(*ref);
6042 }
6043
6044 location = &BTRFS_I(inode)->location;
6045 location->objectid = objectid;
6046 location->offset = 0;
6047 location->type = BTRFS_INODE_ITEM_KEY;
6048
6049 ret = btrfs_insert_inode_locked(inode);
6050 if (ret < 0)
6051 goto fail;
6052
6053 path->leave_spinning = 1;
6054 ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
6055 if (ret != 0)
6056 goto fail_unlock;
6057
6058 inode_init_owner(inode, dir, mode);
6059 inode_set_bytes(inode, 0);
6060
6061 inode->i_mtime = CURRENT_TIME;
6062 inode->i_atime = inode->i_mtime;
6063 inode->i_ctime = inode->i_mtime;
6064 BTRFS_I(inode)->i_otime = inode->i_mtime;
6065
6066 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
6067 struct btrfs_inode_item);
6068 memset_extent_buffer(path->nodes[0], 0, (unsigned long)inode_item,
6069 sizeof(*inode_item));
6070 fill_inode_item(trans, path->nodes[0], inode_item, inode);
6071
6072 if (name) {
6073 ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
6074 struct btrfs_inode_ref);
6075 btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
6076 btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
6077 ptr = (unsigned long)(ref + 1);
6078 write_extent_buffer(path->nodes[0], name, ptr, name_len);
6079 }
6080
6081 btrfs_mark_buffer_dirty(path->nodes[0]);
6082 btrfs_free_path(path);
6083
6084 btrfs_inherit_iflags(inode, dir);
6085
6086 if (S_ISREG(mode)) {
6087 if (btrfs_test_opt(root, NODATASUM))
6088 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
6089 if (btrfs_test_opt(root, NODATACOW))
6090 BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
6091 BTRFS_INODE_NODATASUM;
6092 }
6093
6094 inode_tree_add(inode);
6095
6096 trace_btrfs_inode_new(inode);
6097 btrfs_set_inode_last_trans(trans, inode);
6098
6099 btrfs_update_root_times(trans, root);
6100
6101 ret = btrfs_inode_inherit_props(trans, inode, dir);
6102 if (ret)
6103 btrfs_err(root->fs_info,
6104 "error inheriting props for ino %llu (root %llu): %d",
6105 btrfs_ino(inode), root->root_key.objectid, ret);
6106
6107 return inode;
6108
6109 fail_unlock:
6110 unlock_new_inode(inode);
6111 fail:
6112 if (dir && name)
6113 BTRFS_I(dir)->index_cnt--;
6114 btrfs_free_path(path);
6115 iput(inode);
6116 return ERR_PTR(ret);
6117 }
6118
6119 static inline u8 btrfs_inode_type(struct inode *inode)
6120 {
6121 return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
6122 }
6123
6124 /*
6125 * utility function to add 'inode' into 'parent_inode' with
6126 * a give name and a given sequence number.
6127 * if 'add_backref' is true, also insert a backref from the
6128 * inode to the parent directory.
6129 */
6130 int btrfs_add_link(struct btrfs_trans_handle *trans,
6131 struct inode *parent_inode, struct inode *inode,
6132 const char *name, int name_len, int add_backref, u64 index)
6133 {
6134 int ret = 0;
6135 struct btrfs_key key;
6136 struct btrfs_root *root = BTRFS_I(parent_inode)->root;
6137 u64 ino = btrfs_ino(inode);
6138 u64 parent_ino = btrfs_ino(parent_inode);
6139
6140 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6141 memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
6142 } else {
6143 key.objectid = ino;
6144 key.type = BTRFS_INODE_ITEM_KEY;
6145 key.offset = 0;
6146 }
6147
6148 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6149 ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
6150 key.objectid, root->root_key.objectid,
6151 parent_ino, index, name, name_len);
6152 } else if (add_backref) {
6153 ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
6154 parent_ino, index);
6155 }
6156
6157 /* Nothing to clean up yet */
6158 if (ret)
6159 return ret;
6160
6161 ret = btrfs_insert_dir_item(trans, root, name, name_len,
6162 parent_inode, &key,
6163 btrfs_inode_type(inode), index);
6164 if (ret == -EEXIST || ret == -EOVERFLOW)
6165 goto fail_dir_item;
6166 else if (ret) {
6167 btrfs_abort_transaction(trans, root, ret);
6168 return ret;
6169 }
6170
6171 btrfs_i_size_write(parent_inode, parent_inode->i_size +
6172 name_len * 2);
6173 inode_inc_iversion(parent_inode);
6174 parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
6175 ret = btrfs_update_inode(trans, root, parent_inode);
6176 if (ret)
6177 btrfs_abort_transaction(trans, root, ret);
6178 return ret;
6179
6180 fail_dir_item:
6181 if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
6182 u64 local_index;
6183 int err;
6184 err = btrfs_del_root_ref(trans, root->fs_info->tree_root,
6185 key.objectid, root->root_key.objectid,
6186 parent_ino, &local_index, name, name_len);
6187
6188 } else if (add_backref) {
6189 u64 local_index;
6190 int err;
6191
6192 err = btrfs_del_inode_ref(trans, root, name, name_len,
6193 ino, parent_ino, &local_index);
6194 }
6195 return ret;
6196 }
6197
6198 static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
6199 struct inode *dir, struct dentry *dentry,
6200 struct inode *inode, int backref, u64 index)
6201 {
6202 int err = btrfs_add_link(trans, dir, inode,
6203 dentry->d_name.name, dentry->d_name.len,
6204 backref, index);
6205 if (err > 0)
6206 err = -EEXIST;
6207 return err;
6208 }
6209
6210 static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
6211 umode_t mode, dev_t rdev)
6212 {
6213 struct btrfs_trans_handle *trans;
6214 struct btrfs_root *root = BTRFS_I(dir)->root;
6215 struct inode *inode = NULL;
6216 int err;
6217 int drop_inode = 0;
6218 u64 objectid;
6219 u64 index = 0;
6220
6221 if (!new_valid_dev(rdev))
6222 return -EINVAL;
6223
6224 /*
6225 * 2 for inode item and ref
6226 * 2 for dir items
6227 * 1 for xattr if selinux is on
6228 */
6229 trans = btrfs_start_transaction(root, 5);
6230 if (IS_ERR(trans))
6231 return PTR_ERR(trans);
6232
6233 err = btrfs_find_free_ino(root, &objectid);
6234 if (err)
6235 goto out_unlock;
6236
6237 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6238 dentry->d_name.len, btrfs_ino(dir), objectid,
6239 mode, &index);
6240 if (IS_ERR(inode)) {
6241 err = PTR_ERR(inode);
6242 goto out_unlock;
6243 }
6244
6245 /*
6246 * If the active LSM wants to access the inode during
6247 * d_instantiate it needs these. Smack checks to see
6248 * if the filesystem supports xattrs by looking at the
6249 * ops vector.
6250 */
6251 inode->i_op = &btrfs_special_inode_operations;
6252 init_special_inode(inode, inode->i_mode, rdev);
6253
6254 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6255 if (err)
6256 goto out_unlock_inode;
6257
6258 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6259 if (err) {
6260 goto out_unlock_inode;
6261 } else {
6262 btrfs_update_inode(trans, root, inode);
6263 unlock_new_inode(inode);
6264 d_instantiate(dentry, inode);
6265 }
6266
6267 out_unlock:
6268 btrfs_end_transaction(trans, root);
6269 btrfs_balance_delayed_items(root);
6270 btrfs_btree_balance_dirty(root);
6271 if (drop_inode) {
6272 inode_dec_link_count(inode);
6273 iput(inode);
6274 }
6275 return err;
6276
6277 out_unlock_inode:
6278 drop_inode = 1;
6279 unlock_new_inode(inode);
6280 goto out_unlock;
6281
6282 }
6283
6284 static int btrfs_create(struct inode *dir, struct dentry *dentry,
6285 umode_t mode, bool excl)
6286 {
6287 struct btrfs_trans_handle *trans;
6288 struct btrfs_root *root = BTRFS_I(dir)->root;
6289 struct inode *inode = NULL;
6290 int drop_inode_on_err = 0;
6291 int err;
6292 u64 objectid;
6293 u64 index = 0;
6294
6295 /*
6296 * 2 for inode item and ref
6297 * 2 for dir items
6298 * 1 for xattr if selinux is on
6299 */
6300 trans = btrfs_start_transaction(root, 5);
6301 if (IS_ERR(trans))
6302 return PTR_ERR(trans);
6303
6304 err = btrfs_find_free_ino(root, &objectid);
6305 if (err)
6306 goto out_unlock;
6307
6308 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6309 dentry->d_name.len, btrfs_ino(dir), objectid,
6310 mode, &index);
6311 if (IS_ERR(inode)) {
6312 err = PTR_ERR(inode);
6313 goto out_unlock;
6314 }
6315 drop_inode_on_err = 1;
6316 /*
6317 * If the active LSM wants to access the inode during
6318 * d_instantiate it needs these. Smack checks to see
6319 * if the filesystem supports xattrs by looking at the
6320 * ops vector.
6321 */
6322 inode->i_fop = &btrfs_file_operations;
6323 inode->i_op = &btrfs_file_inode_operations;
6324 inode->i_mapping->a_ops = &btrfs_aops;
6325
6326 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6327 if (err)
6328 goto out_unlock_inode;
6329
6330 err = btrfs_update_inode(trans, root, inode);
6331 if (err)
6332 goto out_unlock_inode;
6333
6334 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
6335 if (err)
6336 goto out_unlock_inode;
6337
6338 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
6339 unlock_new_inode(inode);
6340 d_instantiate(dentry, inode);
6341
6342 out_unlock:
6343 btrfs_end_transaction(trans, root);
6344 if (err && drop_inode_on_err) {
6345 inode_dec_link_count(inode);
6346 iput(inode);
6347 }
6348 btrfs_balance_delayed_items(root);
6349 btrfs_btree_balance_dirty(root);
6350 return err;
6351
6352 out_unlock_inode:
6353 unlock_new_inode(inode);
6354 goto out_unlock;
6355
6356 }
6357
6358 static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
6359 struct dentry *dentry)
6360 {
6361 struct btrfs_trans_handle *trans;
6362 struct btrfs_root *root = BTRFS_I(dir)->root;
6363 struct inode *inode = d_inode(old_dentry);
6364 u64 index;
6365 int err;
6366 int drop_inode = 0;
6367
6368 /* do not allow sys_link's with other subvols of the same device */
6369 if (root->objectid != BTRFS_I(inode)->root->objectid)
6370 return -EXDEV;
6371
6372 if (inode->i_nlink >= BTRFS_LINK_MAX)
6373 return -EMLINK;
6374
6375 err = btrfs_set_inode_index(dir, &index);
6376 if (err)
6377 goto fail;
6378
6379 /*
6380 * 2 items for inode and inode ref
6381 * 2 items for dir items
6382 * 1 item for parent inode
6383 */
6384 trans = btrfs_start_transaction(root, 5);
6385 if (IS_ERR(trans)) {
6386 err = PTR_ERR(trans);
6387 goto fail;
6388 }
6389
6390 /* There are several dir indexes for this inode, clear the cache. */
6391 BTRFS_I(inode)->dir_index = 0ULL;
6392 inc_nlink(inode);
6393 inode_inc_iversion(inode);
6394 inode->i_ctime = CURRENT_TIME;
6395 ihold(inode);
6396 set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
6397
6398 err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
6399
6400 if (err) {
6401 drop_inode = 1;
6402 } else {
6403 struct dentry *parent = dentry->d_parent;
6404 err = btrfs_update_inode(trans, root, inode);
6405 if (err)
6406 goto fail;
6407 if (inode->i_nlink == 1) {
6408 /*
6409 * If new hard link count is 1, it's a file created
6410 * with open(2) O_TMPFILE flag.
6411 */
6412 err = btrfs_orphan_del(trans, inode);
6413 if (err)
6414 goto fail;
6415 }
6416 d_instantiate(dentry, inode);
6417 btrfs_log_new_name(trans, inode, NULL, parent);
6418 }
6419
6420 btrfs_end_transaction(trans, root);
6421 btrfs_balance_delayed_items(root);
6422 fail:
6423 if (drop_inode) {
6424 inode_dec_link_count(inode);
6425 iput(inode);
6426 }
6427 btrfs_btree_balance_dirty(root);
6428 return err;
6429 }
6430
6431 static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
6432 {
6433 struct inode *inode = NULL;
6434 struct btrfs_trans_handle *trans;
6435 struct btrfs_root *root = BTRFS_I(dir)->root;
6436 int err = 0;
6437 int drop_on_err = 0;
6438 u64 objectid = 0;
6439 u64 index = 0;
6440
6441 /*
6442 * 2 items for inode and ref
6443 * 2 items for dir items
6444 * 1 for xattr if selinux is on
6445 */
6446 trans = btrfs_start_transaction(root, 5);
6447 if (IS_ERR(trans))
6448 return PTR_ERR(trans);
6449
6450 err = btrfs_find_free_ino(root, &objectid);
6451 if (err)
6452 goto out_fail;
6453
6454 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6455 dentry->d_name.len, btrfs_ino(dir), objectid,
6456 S_IFDIR | mode, &index);
6457 if (IS_ERR(inode)) {
6458 err = PTR_ERR(inode);
6459 goto out_fail;
6460 }
6461
6462 drop_on_err = 1;
6463 /* these must be set before we unlock the inode */
6464 inode->i_op = &btrfs_dir_inode_operations;
6465 inode->i_fop = &btrfs_dir_file_operations;
6466
6467 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
6468 if (err)
6469 goto out_fail_inode;
6470
6471 btrfs_i_size_write(inode, 0);
6472 err = btrfs_update_inode(trans, root, inode);
6473 if (err)
6474 goto out_fail_inode;
6475
6476 err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
6477 dentry->d_name.len, 0, index);
6478 if (err)
6479 goto out_fail_inode;
6480
6481 d_instantiate(dentry, inode);
6482 /*
6483 * mkdir is special. We're unlocking after we call d_instantiate
6484 * to avoid a race with nfsd calling d_instantiate.
6485 */
6486 unlock_new_inode(inode);
6487 drop_on_err = 0;
6488
6489 out_fail:
6490 btrfs_end_transaction(trans, root);
6491 if (drop_on_err) {
6492 inode_dec_link_count(inode);
6493 iput(inode);
6494 }
6495 btrfs_balance_delayed_items(root);
6496 btrfs_btree_balance_dirty(root);
6497 return err;
6498
6499 out_fail_inode:
6500 unlock_new_inode(inode);
6501 goto out_fail;
6502 }
6503
6504 /* Find next extent map of a given extent map, caller needs to ensure locks */
6505 static struct extent_map *next_extent_map(struct extent_map *em)
6506 {
6507 struct rb_node *next;
6508
6509 next = rb_next(&em->rb_node);
6510 if (!next)
6511 return NULL;
6512 return container_of(next, struct extent_map, rb_node);
6513 }
6514
6515 static struct extent_map *prev_extent_map(struct extent_map *em)
6516 {
6517 struct rb_node *prev;
6518
6519 prev = rb_prev(&em->rb_node);
6520 if (!prev)
6521 return NULL;
6522 return container_of(prev, struct extent_map, rb_node);
6523 }
6524
6525 /* helper for btfs_get_extent. Given an existing extent in the tree,
6526 * the existing extent is the nearest extent to map_start,
6527 * and an extent that you want to insert, deal with overlap and insert
6528 * the best fitted new extent into the tree.
6529 */
6530 static int merge_extent_mapping(struct extent_map_tree *em_tree,
6531 struct extent_map *existing,
6532 struct extent_map *em,
6533 u64 map_start)
6534 {
6535 struct extent_map *prev;
6536 struct extent_map *next;
6537 u64 start;
6538 u64 end;
6539 u64 start_diff;
6540
6541 BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
6542
6543 if (existing->start > map_start) {
6544 next = existing;
6545 prev = prev_extent_map(next);
6546 } else {
6547 prev = existing;
6548 next = next_extent_map(prev);
6549 }
6550
6551 start = prev ? extent_map_end(prev) : em->start;
6552 start = max_t(u64, start, em->start);
6553 end = next ? next->start : extent_map_end(em);
6554 end = min_t(u64, end, extent_map_end(em));
6555 start_diff = start - em->start;
6556 em->start = start;
6557 em->len = end - start;
6558 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
6559 !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
6560 em->block_start += start_diff;
6561 em->block_len -= start_diff;
6562 }
6563 return add_extent_mapping(em_tree, em, 0);
6564 }
6565
6566 static noinline int uncompress_inline(struct btrfs_path *path,
6567 struct inode *inode, struct page *page,
6568 size_t pg_offset, u64 extent_offset,
6569 struct btrfs_file_extent_item *item)
6570 {
6571 int ret;
6572 struct extent_buffer *leaf = path->nodes[0];
6573 char *tmp;
6574 size_t max_size;
6575 unsigned long inline_size;
6576 unsigned long ptr;
6577 int compress_type;
6578
6579 WARN_ON(pg_offset != 0);
6580 compress_type = btrfs_file_extent_compression(leaf, item);
6581 max_size = btrfs_file_extent_ram_bytes(leaf, item);
6582 inline_size = btrfs_file_extent_inline_item_len(leaf,
6583 btrfs_item_nr(path->slots[0]));
6584 tmp = kmalloc(inline_size, GFP_NOFS);
6585 if (!tmp)
6586 return -ENOMEM;
6587 ptr = btrfs_file_extent_inline_start(item);
6588
6589 read_extent_buffer(leaf, tmp, ptr, inline_size);
6590
6591 max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
6592 ret = btrfs_decompress(compress_type, tmp, page,
6593 extent_offset, inline_size, max_size);
6594 kfree(tmp);
6595 return ret;
6596 }
6597
6598 /*
6599 * a bit scary, this does extent mapping from logical file offset to the disk.
6600 * the ugly parts come from merging extents from the disk with the in-ram
6601 * representation. This gets more complex because of the data=ordered code,
6602 * where the in-ram extents might be locked pending data=ordered completion.
6603 *
6604 * This also copies inline extents directly into the page.
6605 */
6606
6607 struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
6608 size_t pg_offset, u64 start, u64 len,
6609 int create)
6610 {
6611 int ret;
6612 int err = 0;
6613 u64 extent_start = 0;
6614 u64 extent_end = 0;
6615 u64 objectid = btrfs_ino(inode);
6616 u32 found_type;
6617 struct btrfs_path *path = NULL;
6618 struct btrfs_root *root = BTRFS_I(inode)->root;
6619 struct btrfs_file_extent_item *item;
6620 struct extent_buffer *leaf;
6621 struct btrfs_key found_key;
6622 struct extent_map *em = NULL;
6623 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
6624 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
6625 struct btrfs_trans_handle *trans = NULL;
6626 const bool new_inline = !page || create;
6627
6628 again:
6629 read_lock(&em_tree->lock);
6630 em = lookup_extent_mapping(em_tree, start, len);
6631 if (em)
6632 em->bdev = root->fs_info->fs_devices->latest_bdev;
6633 read_unlock(&em_tree->lock);
6634
6635 if (em) {
6636 if (em->start > start || em->start + em->len <= start)
6637 free_extent_map(em);
6638 else if (em->block_start == EXTENT_MAP_INLINE && page)
6639 free_extent_map(em);
6640 else
6641 goto out;
6642 }
6643 em = alloc_extent_map();
6644 if (!em) {
6645 err = -ENOMEM;
6646 goto out;
6647 }
6648 em->bdev = root->fs_info->fs_devices->latest_bdev;
6649 em->start = EXTENT_MAP_HOLE;
6650 em->orig_start = EXTENT_MAP_HOLE;
6651 em->len = (u64)-1;
6652 em->block_len = (u64)-1;
6653
6654 if (!path) {
6655 path = btrfs_alloc_path();
6656 if (!path) {
6657 err = -ENOMEM;
6658 goto out;
6659 }
6660 /*
6661 * Chances are we'll be called again, so go ahead and do
6662 * readahead
6663 */
6664 path->reada = 1;
6665 }
6666
6667 ret = btrfs_lookup_file_extent(trans, root, path,
6668 objectid, start, trans != NULL);
6669 if (ret < 0) {
6670 err = ret;
6671 goto out;
6672 }
6673
6674 if (ret != 0) {
6675 if (path->slots[0] == 0)
6676 goto not_found;
6677 path->slots[0]--;
6678 }
6679
6680 leaf = path->nodes[0];
6681 item = btrfs_item_ptr(leaf, path->slots[0],
6682 struct btrfs_file_extent_item);
6683 /* are we inside the extent that was found? */
6684 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6685 found_type = found_key.type;
6686 if (found_key.objectid != objectid ||
6687 found_type != BTRFS_EXTENT_DATA_KEY) {
6688 /*
6689 * If we backup past the first extent we want to move forward
6690 * and see if there is an extent in front of us, otherwise we'll
6691 * say there is a hole for our whole search range which can
6692 * cause problems.
6693 */
6694 extent_end = start;
6695 goto next;
6696 }
6697
6698 found_type = btrfs_file_extent_type(leaf, item);
6699 extent_start = found_key.offset;
6700 if (found_type == BTRFS_FILE_EXTENT_REG ||
6701 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6702 extent_end = extent_start +
6703 btrfs_file_extent_num_bytes(leaf, item);
6704 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6705 size_t size;
6706 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6707 extent_end = ALIGN(extent_start + size, root->sectorsize);
6708 }
6709 next:
6710 if (start >= extent_end) {
6711 path->slots[0]++;
6712 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
6713 ret = btrfs_next_leaf(root, path);
6714 if (ret < 0) {
6715 err = ret;
6716 goto out;
6717 }
6718 if (ret > 0)
6719 goto not_found;
6720 leaf = path->nodes[0];
6721 }
6722 btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
6723 if (found_key.objectid != objectid ||
6724 found_key.type != BTRFS_EXTENT_DATA_KEY)
6725 goto not_found;
6726 if (start + len <= found_key.offset)
6727 goto not_found;
6728 if (start > found_key.offset)
6729 goto next;
6730 em->start = start;
6731 em->orig_start = start;
6732 em->len = found_key.offset - start;
6733 goto not_found_em;
6734 }
6735
6736 btrfs_extent_item_to_extent_map(inode, path, item, new_inline, em);
6737
6738 if (found_type == BTRFS_FILE_EXTENT_REG ||
6739 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
6740 goto insert;
6741 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
6742 unsigned long ptr;
6743 char *map;
6744 size_t size;
6745 size_t extent_offset;
6746 size_t copy_size;
6747
6748 if (new_inline)
6749 goto out;
6750
6751 size = btrfs_file_extent_inline_len(leaf, path->slots[0], item);
6752 extent_offset = page_offset(page) + pg_offset - extent_start;
6753 copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
6754 size - extent_offset);
6755 em->start = extent_start + extent_offset;
6756 em->len = ALIGN(copy_size, root->sectorsize);
6757 em->orig_block_len = em->len;
6758 em->orig_start = em->start;
6759 ptr = btrfs_file_extent_inline_start(item) + extent_offset;
6760 if (create == 0 && !PageUptodate(page)) {
6761 if (btrfs_file_extent_compression(leaf, item) !=
6762 BTRFS_COMPRESS_NONE) {
6763 ret = uncompress_inline(path, inode, page,
6764 pg_offset,
6765 extent_offset, item);
6766 if (ret) {
6767 err = ret;
6768 goto out;
6769 }
6770 } else {
6771 map = kmap(page);
6772 read_extent_buffer(leaf, map + pg_offset, ptr,
6773 copy_size);
6774 if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
6775 memset(map + pg_offset + copy_size, 0,
6776 PAGE_CACHE_SIZE - pg_offset -
6777 copy_size);
6778 }
6779 kunmap(page);
6780 }
6781 flush_dcache_page(page);
6782 } else if (create && PageUptodate(page)) {
6783 BUG();
6784 if (!trans) {
6785 kunmap(page);
6786 free_extent_map(em);
6787 em = NULL;
6788
6789 btrfs_release_path(path);
6790 trans = btrfs_join_transaction(root);
6791
6792 if (IS_ERR(trans))
6793 return ERR_CAST(trans);
6794 goto again;
6795 }
6796 map = kmap(page);
6797 write_extent_buffer(leaf, map + pg_offset, ptr,
6798 copy_size);
6799 kunmap(page);
6800 btrfs_mark_buffer_dirty(leaf);
6801 }
6802 set_extent_uptodate(io_tree, em->start,
6803 extent_map_end(em) - 1, NULL, GFP_NOFS);
6804 goto insert;
6805 }
6806 not_found:
6807 em->start = start;
6808 em->orig_start = start;
6809 em->len = len;
6810 not_found_em:
6811 em->block_start = EXTENT_MAP_HOLE;
6812 set_bit(EXTENT_FLAG_VACANCY, &em->flags);
6813 insert:
6814 btrfs_release_path(path);
6815 if (em->start > start || extent_map_end(em) <= start) {
6816 btrfs_err(root->fs_info, "bad extent! em: [%llu %llu] passed [%llu %llu]",
6817 em->start, em->len, start, len);
6818 err = -EIO;
6819 goto out;
6820 }
6821
6822 err = 0;
6823 write_lock(&em_tree->lock);
6824 ret = add_extent_mapping(em_tree, em, 0);
6825 /* it is possible that someone inserted the extent into the tree
6826 * while we had the lock dropped. It is also possible that
6827 * an overlapping map exists in the tree
6828 */
6829 if (ret == -EEXIST) {
6830 struct extent_map *existing;
6831
6832 ret = 0;
6833
6834 existing = search_extent_mapping(em_tree, start, len);
6835 /*
6836 * existing will always be non-NULL, since there must be
6837 * extent causing the -EEXIST.
6838 */
6839 if (start >= extent_map_end(existing) ||
6840 start <= existing->start) {
6841 /*
6842 * The existing extent map is the one nearest to
6843 * the [start, start + len) range which overlaps
6844 */
6845 err = merge_extent_mapping(em_tree, existing,
6846 em, start);
6847 free_extent_map(existing);
6848 if (err) {
6849 free_extent_map(em);
6850 em = NULL;
6851 }
6852 } else {
6853 free_extent_map(em);
6854 em = existing;
6855 err = 0;
6856 }
6857 }
6858 write_unlock(&em_tree->lock);
6859 out:
6860
6861 trace_btrfs_get_extent(root, em);
6862
6863 if (path)
6864 btrfs_free_path(path);
6865 if (trans) {
6866 ret = btrfs_end_transaction(trans, root);
6867 if (!err)
6868 err = ret;
6869 }
6870 if (err) {
6871 free_extent_map(em);
6872 return ERR_PTR(err);
6873 }
6874 BUG_ON(!em); /* Error is always set */
6875 return em;
6876 }
6877
6878 struct extent_map *btrfs_get_extent_fiemap(struct inode *inode, struct page *page,
6879 size_t pg_offset, u64 start, u64 len,
6880 int create)
6881 {
6882 struct extent_map *em;
6883 struct extent_map *hole_em = NULL;
6884 u64 range_start = start;
6885 u64 end;
6886 u64 found;
6887 u64 found_end;
6888 int err = 0;
6889
6890 em = btrfs_get_extent(inode, page, pg_offset, start, len, create);
6891 if (IS_ERR(em))
6892 return em;
6893 if (em) {
6894 /*
6895 * if our em maps to
6896 * - a hole or
6897 * - a pre-alloc extent,
6898 * there might actually be delalloc bytes behind it.
6899 */
6900 if (em->block_start != EXTENT_MAP_HOLE &&
6901 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
6902 return em;
6903 else
6904 hole_em = em;
6905 }
6906
6907 /* check to see if we've wrapped (len == -1 or similar) */
6908 end = start + len;
6909 if (end < start)
6910 end = (u64)-1;
6911 else
6912 end -= 1;
6913
6914 em = NULL;
6915
6916 /* ok, we didn't find anything, lets look for delalloc */
6917 found = count_range_bits(&BTRFS_I(inode)->io_tree, &range_start,
6918 end, len, EXTENT_DELALLOC, 1);
6919 found_end = range_start + found;
6920 if (found_end < range_start)
6921 found_end = (u64)-1;
6922
6923 /*
6924 * we didn't find anything useful, return
6925 * the original results from get_extent()
6926 */
6927 if (range_start > end || found_end <= start) {
6928 em = hole_em;
6929 hole_em = NULL;
6930 goto out;
6931 }
6932
6933 /* adjust the range_start to make sure it doesn't
6934 * go backwards from the start they passed in
6935 */
6936 range_start = max(start, range_start);
6937 found = found_end - range_start;
6938
6939 if (found > 0) {
6940 u64 hole_start = start;
6941 u64 hole_len = len;
6942
6943 em = alloc_extent_map();
6944 if (!em) {
6945 err = -ENOMEM;
6946 goto out;
6947 }
6948 /*
6949 * when btrfs_get_extent can't find anything it
6950 * returns one huge hole
6951 *
6952 * make sure what it found really fits our range, and
6953 * adjust to make sure it is based on the start from
6954 * the caller
6955 */
6956 if (hole_em) {
6957 u64 calc_end = extent_map_end(hole_em);
6958
6959 if (calc_end <= start || (hole_em->start > end)) {
6960 free_extent_map(hole_em);
6961 hole_em = NULL;
6962 } else {
6963 hole_start = max(hole_em->start, start);
6964 hole_len = calc_end - hole_start;
6965 }
6966 }
6967 em->bdev = NULL;
6968 if (hole_em && range_start > hole_start) {
6969 /* our hole starts before our delalloc, so we
6970 * have to return just the parts of the hole
6971 * that go until the delalloc starts
6972 */
6973 em->len = min(hole_len,
6974 range_start - hole_start);
6975 em->start = hole_start;
6976 em->orig_start = hole_start;
6977 /*
6978 * don't adjust block start at all,
6979 * it is fixed at EXTENT_MAP_HOLE
6980 */
6981 em->block_start = hole_em->block_start;
6982 em->block_len = hole_len;
6983 if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
6984 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
6985 } else {
6986 em->start = range_start;
6987 em->len = found;
6988 em->orig_start = range_start;
6989 em->block_start = EXTENT_MAP_DELALLOC;
6990 em->block_len = found;
6991 }
6992 } else if (hole_em) {
6993 return hole_em;
6994 }
6995 out:
6996
6997 free_extent_map(hole_em);
6998 if (err) {
6999 free_extent_map(em);
7000 return ERR_PTR(err);
7001 }
7002 return em;
7003 }
7004
7005 static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
7006 u64 start, u64 len)
7007 {
7008 struct btrfs_root *root = BTRFS_I(inode)->root;
7009 struct extent_map *em;
7010 struct btrfs_key ins;
7011 u64 alloc_hint;
7012 int ret;
7013
7014 alloc_hint = get_extent_allocation_hint(inode, start, len);
7015 ret = btrfs_reserve_extent(root, len, root->sectorsize, 0,
7016 alloc_hint, &ins, 1, 1);
7017 if (ret)
7018 return ERR_PTR(ret);
7019
7020 em = create_pinned_em(inode, start, ins.offset, start, ins.objectid,
7021 ins.offset, ins.offset, ins.offset, 0);
7022 if (IS_ERR(em)) {
7023 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7024 return em;
7025 }
7026
7027 ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
7028 ins.offset, ins.offset, 0);
7029 if (ret) {
7030 btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 1);
7031 free_extent_map(em);
7032 return ERR_PTR(ret);
7033 }
7034
7035 return em;
7036 }
7037
7038 /*
7039 * returns 1 when the nocow is safe, < 1 on error, 0 if the
7040 * block must be cow'd
7041 */
7042 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
7043 u64 *orig_start, u64 *orig_block_len,
7044 u64 *ram_bytes)
7045 {
7046 struct btrfs_trans_handle *trans;
7047 struct btrfs_path *path;
7048 int ret;
7049 struct extent_buffer *leaf;
7050 struct btrfs_root *root = BTRFS_I(inode)->root;
7051 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
7052 struct btrfs_file_extent_item *fi;
7053 struct btrfs_key key;
7054 u64 disk_bytenr;
7055 u64 backref_offset;
7056 u64 extent_end;
7057 u64 num_bytes;
7058 int slot;
7059 int found_type;
7060 bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
7061
7062 path = btrfs_alloc_path();
7063 if (!path)
7064 return -ENOMEM;
7065
7066 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(inode),
7067 offset, 0);
7068 if (ret < 0)
7069 goto out;
7070
7071 slot = path->slots[0];
7072 if (ret == 1) {
7073 if (slot == 0) {
7074 /* can't find the item, must cow */
7075 ret = 0;
7076 goto out;
7077 }
7078 slot--;
7079 }
7080 ret = 0;
7081 leaf = path->nodes[0];
7082 btrfs_item_key_to_cpu(leaf, &key, slot);
7083 if (key.objectid != btrfs_ino(inode) ||
7084 key.type != BTRFS_EXTENT_DATA_KEY) {
7085 /* not our file or wrong item type, must cow */
7086 goto out;
7087 }
7088
7089 if (key.offset > offset) {
7090 /* Wrong offset, must cow */
7091 goto out;
7092 }
7093
7094 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
7095 found_type = btrfs_file_extent_type(leaf, fi);
7096 if (found_type != BTRFS_FILE_EXTENT_REG &&
7097 found_type != BTRFS_FILE_EXTENT_PREALLOC) {
7098 /* not a regular extent, must cow */
7099 goto out;
7100 }
7101
7102 if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
7103 goto out;
7104
7105 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
7106 if (extent_end <= offset)
7107 goto out;
7108
7109 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
7110 if (disk_bytenr == 0)
7111 goto out;
7112
7113 if (btrfs_file_extent_compression(leaf, fi) ||
7114 btrfs_file_extent_encryption(leaf, fi) ||
7115 btrfs_file_extent_other_encoding(leaf, fi))
7116 goto out;
7117
7118 backref_offset = btrfs_file_extent_offset(leaf, fi);
7119
7120 if (orig_start) {
7121 *orig_start = key.offset - backref_offset;
7122 *orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
7123 *ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
7124 }
7125
7126 if (btrfs_extent_readonly(root, disk_bytenr))
7127 goto out;
7128
7129 num_bytes = min(offset + *len, extent_end) - offset;
7130 if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
7131 u64 range_end;
7132
7133 range_end = round_up(offset + num_bytes, root->sectorsize) - 1;
7134 ret = test_range_bit(io_tree, offset, range_end,
7135 EXTENT_DELALLOC, 0, NULL);
7136 if (ret) {
7137 ret = -EAGAIN;
7138 goto out;
7139 }
7140 }
7141
7142 btrfs_release_path(path);
7143
7144 /*
7145 * look for other files referencing this extent, if we
7146 * find any we must cow
7147 */
7148 trans = btrfs_join_transaction(root);
7149 if (IS_ERR(trans)) {
7150 ret = 0;
7151 goto out;
7152 }
7153
7154 ret = btrfs_cross_ref_exist(trans, root, btrfs_ino(inode),
7155 key.offset - backref_offset, disk_bytenr);
7156 btrfs_end_transaction(trans, root);
7157 if (ret) {
7158 ret = 0;
7159 goto out;
7160 }
7161
7162 /*
7163 * adjust disk_bytenr and num_bytes to cover just the bytes
7164 * in this extent we are about to write. If there
7165 * are any csums in that range we have to cow in order
7166 * to keep the csums correct
7167 */
7168 disk_bytenr += backref_offset;
7169 disk_bytenr += offset - key.offset;
7170 if (csum_exist_in_range(root, disk_bytenr, num_bytes))
7171 goto out;
7172 /*
7173 * all of the above have passed, it is safe to overwrite this extent
7174 * without cow
7175 */
7176 *len = num_bytes;
7177 ret = 1;
7178 out:
7179 btrfs_free_path(path);
7180 return ret;
7181 }
7182
7183 bool btrfs_page_exists_in_range(struct inode *inode, loff_t start, loff_t end)
7184 {
7185 struct radix_tree_root *root = &inode->i_mapping->page_tree;
7186 int found = false;
7187 void **pagep = NULL;
7188 struct page *page = NULL;
7189 int start_idx;
7190 int end_idx;
7191
7192 start_idx = start >> PAGE_CACHE_SHIFT;
7193
7194 /*
7195 * end is the last byte in the last page. end == start is legal
7196 */
7197 end_idx = end >> PAGE_CACHE_SHIFT;
7198
7199 rcu_read_lock();
7200
7201 /* Most of the code in this while loop is lifted from
7202 * find_get_page. It's been modified to begin searching from a
7203 * page and return just the first page found in that range. If the
7204 * found idx is less than or equal to the end idx then we know that
7205 * a page exists. If no pages are found or if those pages are
7206 * outside of the range then we're fine (yay!) */
7207 while (page == NULL &&
7208 radix_tree_gang_lookup_slot(root, &pagep, NULL, start_idx, 1)) {
7209 page = radix_tree_deref_slot(pagep);
7210 if (unlikely(!page))
7211 break;
7212
7213 if (radix_tree_exception(page)) {
7214 if (radix_tree_deref_retry(page)) {
7215 page = NULL;
7216 continue;
7217 }
7218 /*
7219 * Otherwise, shmem/tmpfs must be storing a swap entry
7220 * here as an exceptional entry: so return it without
7221 * attempting to raise page count.
7222 */
7223 page = NULL;
7224 break; /* TODO: Is this relevant for this use case? */
7225 }
7226
7227 if (!page_cache_get_speculative(page)) {
7228 page = NULL;
7229 continue;
7230 }
7231
7232 /*
7233 * Has the page moved?
7234 * This is part of the lockless pagecache protocol. See
7235 * include/linux/pagemap.h for details.
7236 */
7237 if (unlikely(page != *pagep)) {
7238 page_cache_release(page);
7239 page = NULL;
7240 }
7241 }
7242
7243 if (page) {
7244 if (page->index <= end_idx)
7245 found = true;
7246 page_cache_release(page);
7247 }
7248
7249 rcu_read_unlock();
7250 return found;
7251 }
7252
7253 static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
7254 struct extent_state **cached_state, int writing)
7255 {
7256 struct btrfs_ordered_extent *ordered;
7257 int ret = 0;
7258
7259 while (1) {
7260 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7261 0, cached_state);
7262 /*
7263 * We're concerned with the entire range that we're going to be
7264 * doing DIO to, so we need to make sure theres no ordered
7265 * extents in this range.
7266 */
7267 ordered = btrfs_lookup_ordered_range(inode, lockstart,
7268 lockend - lockstart + 1);
7269
7270 /*
7271 * We need to make sure there are no buffered pages in this
7272 * range either, we could have raced between the invalidate in
7273 * generic_file_direct_write and locking the extent. The
7274 * invalidate needs to happen so that reads after a write do not
7275 * get stale data.
7276 */
7277 if (!ordered &&
7278 (!writing ||
7279 !btrfs_page_exists_in_range(inode, lockstart, lockend)))
7280 break;
7281
7282 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7283 cached_state, GFP_NOFS);
7284
7285 if (ordered) {
7286 btrfs_start_ordered_extent(inode, ordered, 1);
7287 btrfs_put_ordered_extent(ordered);
7288 } else {
7289 /* Screw you mmap */
7290 ret = btrfs_fdatawrite_range(inode, lockstart, lockend);
7291 if (ret)
7292 break;
7293 ret = filemap_fdatawait_range(inode->i_mapping,
7294 lockstart,
7295 lockend);
7296 if (ret)
7297 break;
7298
7299 /*
7300 * If we found a page that couldn't be invalidated just
7301 * fall back to buffered.
7302 */
7303 ret = invalidate_inode_pages2_range(inode->i_mapping,
7304 lockstart >> PAGE_CACHE_SHIFT,
7305 lockend >> PAGE_CACHE_SHIFT);
7306 if (ret)
7307 break;
7308 }
7309
7310 cond_resched();
7311 }
7312
7313 return ret;
7314 }
7315
7316 static struct extent_map *create_pinned_em(struct inode *inode, u64 start,
7317 u64 len, u64 orig_start,
7318 u64 block_start, u64 block_len,
7319 u64 orig_block_len, u64 ram_bytes,
7320 int type)
7321 {
7322 struct extent_map_tree *em_tree;
7323 struct extent_map *em;
7324 struct btrfs_root *root = BTRFS_I(inode)->root;
7325 int ret;
7326
7327 em_tree = &BTRFS_I(inode)->extent_tree;
7328 em = alloc_extent_map();
7329 if (!em)
7330 return ERR_PTR(-ENOMEM);
7331
7332 em->start = start;
7333 em->orig_start = orig_start;
7334 em->mod_start = start;
7335 em->mod_len = len;
7336 em->len = len;
7337 em->block_len = block_len;
7338 em->block_start = block_start;
7339 em->bdev = root->fs_info->fs_devices->latest_bdev;
7340 em->orig_block_len = orig_block_len;
7341 em->ram_bytes = ram_bytes;
7342 em->generation = -1;
7343 set_bit(EXTENT_FLAG_PINNED, &em->flags);
7344 if (type == BTRFS_ORDERED_PREALLOC)
7345 set_bit(EXTENT_FLAG_FILLING, &em->flags);
7346
7347 do {
7348 btrfs_drop_extent_cache(inode, em->start,
7349 em->start + em->len - 1, 0);
7350 write_lock(&em_tree->lock);
7351 ret = add_extent_mapping(em_tree, em, 1);
7352 write_unlock(&em_tree->lock);
7353 } while (ret == -EEXIST);
7354
7355 if (ret) {
7356 free_extent_map(em);
7357 return ERR_PTR(ret);
7358 }
7359
7360 return em;
7361 }
7362
7363
7364 static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
7365 struct buffer_head *bh_result, int create)
7366 {
7367 struct extent_map *em;
7368 struct btrfs_root *root = BTRFS_I(inode)->root;
7369 struct extent_state *cached_state = NULL;
7370 u64 start = iblock << inode->i_blkbits;
7371 u64 lockstart, lockend;
7372 u64 len = bh_result->b_size;
7373 u64 *outstanding_extents = NULL;
7374 int unlock_bits = EXTENT_LOCKED;
7375 int ret = 0;
7376
7377 if (create)
7378 unlock_bits |= EXTENT_DIRTY;
7379 else
7380 len = min_t(u64, len, root->sectorsize);
7381
7382 lockstart = start;
7383 lockend = start + len - 1;
7384
7385 if (current->journal_info) {
7386 /*
7387 * Need to pull our outstanding extents and set journal_info to NULL so
7388 * that anything that needs to check if there's a transction doesn't get
7389 * confused.
7390 */
7391 outstanding_extents = current->journal_info;
7392 current->journal_info = NULL;
7393 }
7394
7395 /*
7396 * If this errors out it's because we couldn't invalidate pagecache for
7397 * this range and we need to fallback to buffered.
7398 */
7399 if (lock_extent_direct(inode, lockstart, lockend, &cached_state, create))
7400 return -ENOTBLK;
7401
7402 em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
7403 if (IS_ERR(em)) {
7404 ret = PTR_ERR(em);
7405 goto unlock_err;
7406 }
7407
7408 /*
7409 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
7410 * io. INLINE is special, and we could probably kludge it in here, but
7411 * it's still buffered so for safety lets just fall back to the generic
7412 * buffered path.
7413 *
7414 * For COMPRESSED we _have_ to read the entire extent in so we can
7415 * decompress it, so there will be buffering required no matter what we
7416 * do, so go ahead and fallback to buffered.
7417 *
7418 * We return -ENOTBLK because thats what makes DIO go ahead and go back
7419 * to buffered IO. Don't blame me, this is the price we pay for using
7420 * the generic code.
7421 */
7422 if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
7423 em->block_start == EXTENT_MAP_INLINE) {
7424 free_extent_map(em);
7425 ret = -ENOTBLK;
7426 goto unlock_err;
7427 }
7428
7429 /* Just a good old fashioned hole, return */
7430 if (!create && (em->block_start == EXTENT_MAP_HOLE ||
7431 test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
7432 free_extent_map(em);
7433 goto unlock_err;
7434 }
7435
7436 /*
7437 * We don't allocate a new extent in the following cases
7438 *
7439 * 1) The inode is marked as NODATACOW. In this case we'll just use the
7440 * existing extent.
7441 * 2) The extent is marked as PREALLOC. We're good to go here and can
7442 * just use the extent.
7443 *
7444 */
7445 if (!create) {
7446 len = min(len, em->len - (start - em->start));
7447 lockstart = start + len;
7448 goto unlock;
7449 }
7450
7451 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
7452 ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
7453 em->block_start != EXTENT_MAP_HOLE)) {
7454 int type;
7455 u64 block_start, orig_start, orig_block_len, ram_bytes;
7456
7457 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7458 type = BTRFS_ORDERED_PREALLOC;
7459 else
7460 type = BTRFS_ORDERED_NOCOW;
7461 len = min(len, em->len - (start - em->start));
7462 block_start = em->block_start + (start - em->start);
7463
7464 if (can_nocow_extent(inode, start, &len, &orig_start,
7465 &orig_block_len, &ram_bytes) == 1) {
7466 if (type == BTRFS_ORDERED_PREALLOC) {
7467 free_extent_map(em);
7468 em = create_pinned_em(inode, start, len,
7469 orig_start,
7470 block_start, len,
7471 orig_block_len,
7472 ram_bytes, type);
7473 if (IS_ERR(em)) {
7474 ret = PTR_ERR(em);
7475 goto unlock_err;
7476 }
7477 }
7478
7479 ret = btrfs_add_ordered_extent_dio(inode, start,
7480 block_start, len, len, type);
7481 if (ret) {
7482 free_extent_map(em);
7483 goto unlock_err;
7484 }
7485 goto unlock;
7486 }
7487 }
7488
7489 /*
7490 * this will cow the extent, reset the len in case we changed
7491 * it above
7492 */
7493 len = bh_result->b_size;
7494 free_extent_map(em);
7495 em = btrfs_new_extent_direct(inode, start, len);
7496 if (IS_ERR(em)) {
7497 ret = PTR_ERR(em);
7498 goto unlock_err;
7499 }
7500 len = min(len, em->len - (start - em->start));
7501 unlock:
7502 bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
7503 inode->i_blkbits;
7504 bh_result->b_size = len;
7505 bh_result->b_bdev = em->bdev;
7506 set_buffer_mapped(bh_result);
7507 if (create) {
7508 if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
7509 set_buffer_new(bh_result);
7510
7511 /*
7512 * Need to update the i_size under the extent lock so buffered
7513 * readers will get the updated i_size when we unlock.
7514 */
7515 if (start + len > i_size_read(inode))
7516 i_size_write(inode, start + len);
7517
7518 /*
7519 * If we have an outstanding_extents count still set then we're
7520 * within our reservation, otherwise we need to adjust our inode
7521 * counter appropriately.
7522 */
7523 if (*outstanding_extents) {
7524 (*outstanding_extents)--;
7525 } else {
7526 spin_lock(&BTRFS_I(inode)->lock);
7527 BTRFS_I(inode)->outstanding_extents++;
7528 spin_unlock(&BTRFS_I(inode)->lock);
7529 }
7530
7531 current->journal_info = outstanding_extents;
7532 btrfs_free_reserved_data_space(inode, len);
7533 }
7534
7535 /*
7536 * In the case of write we need to clear and unlock the entire range,
7537 * in the case of read we need to unlock only the end area that we
7538 * aren't using if there is any left over space.
7539 */
7540 if (lockstart < lockend) {
7541 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
7542 lockend, unlock_bits, 1, 0,
7543 &cached_state, GFP_NOFS);
7544 } else {
7545 free_extent_state(cached_state);
7546 }
7547
7548 free_extent_map(em);
7549
7550 return 0;
7551
7552 unlock_err:
7553 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
7554 unlock_bits, 1, 0, &cached_state, GFP_NOFS);
7555 if (outstanding_extents)
7556 current->journal_info = outstanding_extents;
7557 return ret;
7558 }
7559
7560 static inline int submit_dio_repair_bio(struct inode *inode, struct bio *bio,
7561 int rw, int mirror_num)
7562 {
7563 struct btrfs_root *root = BTRFS_I(inode)->root;
7564 int ret;
7565
7566 BUG_ON(rw & REQ_WRITE);
7567
7568 bio_get(bio);
7569
7570 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7571 BTRFS_WQ_ENDIO_DIO_REPAIR);
7572 if (ret)
7573 goto err;
7574
7575 ret = btrfs_map_bio(root, rw, bio, mirror_num, 0);
7576 err:
7577 bio_put(bio);
7578 return ret;
7579 }
7580
7581 static int btrfs_check_dio_repairable(struct inode *inode,
7582 struct bio *failed_bio,
7583 struct io_failure_record *failrec,
7584 int failed_mirror)
7585 {
7586 int num_copies;
7587
7588 num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
7589 failrec->logical, failrec->len);
7590 if (num_copies == 1) {
7591 /*
7592 * we only have a single copy of the data, so don't bother with
7593 * all the retry and error correction code that follows. no
7594 * matter what the error is, it is very likely to persist.
7595 */
7596 pr_debug("Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d\n",
7597 num_copies, failrec->this_mirror, failed_mirror);
7598 return 0;
7599 }
7600
7601 failrec->failed_mirror = failed_mirror;
7602 failrec->this_mirror++;
7603 if (failrec->this_mirror == failed_mirror)
7604 failrec->this_mirror++;
7605
7606 if (failrec->this_mirror > num_copies) {
7607 pr_debug("Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d\n",
7608 num_copies, failrec->this_mirror, failed_mirror);
7609 return 0;
7610 }
7611
7612 return 1;
7613 }
7614
7615 static int dio_read_error(struct inode *inode, struct bio *failed_bio,
7616 struct page *page, u64 start, u64 end,
7617 int failed_mirror, bio_end_io_t *repair_endio,
7618 void *repair_arg)
7619 {
7620 struct io_failure_record *failrec;
7621 struct bio *bio;
7622 int isector;
7623 int read_mode;
7624 int ret;
7625
7626 BUG_ON(failed_bio->bi_rw & REQ_WRITE);
7627
7628 ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
7629 if (ret)
7630 return ret;
7631
7632 ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
7633 failed_mirror);
7634 if (!ret) {
7635 free_io_failure(inode, failrec);
7636 return -EIO;
7637 }
7638
7639 if (failed_bio->bi_vcnt > 1)
7640 read_mode = READ_SYNC | REQ_FAILFAST_DEV;
7641 else
7642 read_mode = READ_SYNC;
7643
7644 isector = start - btrfs_io_bio(failed_bio)->logical;
7645 isector >>= inode->i_sb->s_blocksize_bits;
7646 bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
7647 0, isector, repair_endio, repair_arg);
7648 if (!bio) {
7649 free_io_failure(inode, failrec);
7650 return -EIO;
7651 }
7652
7653 btrfs_debug(BTRFS_I(inode)->root->fs_info,
7654 "Repair DIO Read Error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d\n",
7655 read_mode, failrec->this_mirror, failrec->in_validation);
7656
7657 ret = submit_dio_repair_bio(inode, bio, read_mode,
7658 failrec->this_mirror);
7659 if (ret) {
7660 free_io_failure(inode, failrec);
7661 bio_put(bio);
7662 }
7663
7664 return ret;
7665 }
7666
7667 struct btrfs_retry_complete {
7668 struct completion done;
7669 struct inode *inode;
7670 u64 start;
7671 int uptodate;
7672 };
7673
7674 static void btrfs_retry_endio_nocsum(struct bio *bio, int err)
7675 {
7676 struct btrfs_retry_complete *done = bio->bi_private;
7677 struct bio_vec *bvec;
7678 int i;
7679
7680 if (err)
7681 goto end;
7682
7683 done->uptodate = 1;
7684 bio_for_each_segment_all(bvec, bio, i)
7685 clean_io_failure(done->inode, done->start, bvec->bv_page, 0);
7686 end:
7687 complete(&done->done);
7688 bio_put(bio);
7689 }
7690
7691 static int __btrfs_correct_data_nocsum(struct inode *inode,
7692 struct btrfs_io_bio *io_bio)
7693 {
7694 struct bio_vec *bvec;
7695 struct btrfs_retry_complete done;
7696 u64 start;
7697 int i;
7698 int ret;
7699
7700 start = io_bio->logical;
7701 done.inode = inode;
7702
7703 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7704 try_again:
7705 done.uptodate = 0;
7706 done.start = start;
7707 init_completion(&done.done);
7708
7709 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7710 start + bvec->bv_len - 1,
7711 io_bio->mirror_num,
7712 btrfs_retry_endio_nocsum, &done);
7713 if (ret)
7714 return ret;
7715
7716 wait_for_completion(&done.done);
7717
7718 if (!done.uptodate) {
7719 /* We might have another mirror, so try again */
7720 goto try_again;
7721 }
7722
7723 start += bvec->bv_len;
7724 }
7725
7726 return 0;
7727 }
7728
7729 static void btrfs_retry_endio(struct bio *bio, int err)
7730 {
7731 struct btrfs_retry_complete *done = bio->bi_private;
7732 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7733 struct bio_vec *bvec;
7734 int uptodate;
7735 int ret;
7736 int i;
7737
7738 if (err)
7739 goto end;
7740
7741 uptodate = 1;
7742 bio_for_each_segment_all(bvec, bio, i) {
7743 ret = __readpage_endio_check(done->inode, io_bio, i,
7744 bvec->bv_page, 0,
7745 done->start, bvec->bv_len);
7746 if (!ret)
7747 clean_io_failure(done->inode, done->start,
7748 bvec->bv_page, 0);
7749 else
7750 uptodate = 0;
7751 }
7752
7753 done->uptodate = uptodate;
7754 end:
7755 complete(&done->done);
7756 bio_put(bio);
7757 }
7758
7759 static int __btrfs_subio_endio_read(struct inode *inode,
7760 struct btrfs_io_bio *io_bio, int err)
7761 {
7762 struct bio_vec *bvec;
7763 struct btrfs_retry_complete done;
7764 u64 start;
7765 u64 offset = 0;
7766 int i;
7767 int ret;
7768
7769 err = 0;
7770 start = io_bio->logical;
7771 done.inode = inode;
7772
7773 bio_for_each_segment_all(bvec, &io_bio->bio, i) {
7774 ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
7775 0, start, bvec->bv_len);
7776 if (likely(!ret))
7777 goto next;
7778 try_again:
7779 done.uptodate = 0;
7780 done.start = start;
7781 init_completion(&done.done);
7782
7783 ret = dio_read_error(inode, &io_bio->bio, bvec->bv_page, start,
7784 start + bvec->bv_len - 1,
7785 io_bio->mirror_num,
7786 btrfs_retry_endio, &done);
7787 if (ret) {
7788 err = ret;
7789 goto next;
7790 }
7791
7792 wait_for_completion(&done.done);
7793
7794 if (!done.uptodate) {
7795 /* We might have another mirror, so try again */
7796 goto try_again;
7797 }
7798 next:
7799 offset += bvec->bv_len;
7800 start += bvec->bv_len;
7801 }
7802
7803 return err;
7804 }
7805
7806 static int btrfs_subio_endio_read(struct inode *inode,
7807 struct btrfs_io_bio *io_bio, int err)
7808 {
7809 bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
7810
7811 if (skip_csum) {
7812 if (unlikely(err))
7813 return __btrfs_correct_data_nocsum(inode, io_bio);
7814 else
7815 return 0;
7816 } else {
7817 return __btrfs_subio_endio_read(inode, io_bio, err);
7818 }
7819 }
7820
7821 static void btrfs_endio_direct_read(struct bio *bio, int err)
7822 {
7823 struct btrfs_dio_private *dip = bio->bi_private;
7824 struct inode *inode = dip->inode;
7825 struct bio *dio_bio;
7826 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7827
7828 if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
7829 err = btrfs_subio_endio_read(inode, io_bio, err);
7830
7831 unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
7832 dip->logical_offset + dip->bytes - 1);
7833 dio_bio = dip->dio_bio;
7834
7835 kfree(dip);
7836
7837 /* If we had a csum failure make sure to clear the uptodate flag */
7838 if (err)
7839 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7840 dio_end_io(dio_bio, err);
7841
7842 if (io_bio->end_io)
7843 io_bio->end_io(io_bio, err);
7844 bio_put(bio);
7845 }
7846
7847 static void btrfs_endio_direct_write(struct bio *bio, int err)
7848 {
7849 struct btrfs_dio_private *dip = bio->bi_private;
7850 struct inode *inode = dip->inode;
7851 struct btrfs_root *root = BTRFS_I(inode)->root;
7852 struct btrfs_ordered_extent *ordered = NULL;
7853 u64 ordered_offset = dip->logical_offset;
7854 u64 ordered_bytes = dip->bytes;
7855 struct bio *dio_bio;
7856 int ret;
7857
7858 if (err)
7859 goto out_done;
7860 again:
7861 ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
7862 &ordered_offset,
7863 ordered_bytes, !err);
7864 if (!ret)
7865 goto out_test;
7866
7867 btrfs_init_work(&ordered->work, btrfs_endio_write_helper,
7868 finish_ordered_fn, NULL, NULL);
7869 btrfs_queue_work(root->fs_info->endio_write_workers,
7870 &ordered->work);
7871 out_test:
7872 /*
7873 * our bio might span multiple ordered extents. If we haven't
7874 * completed the accounting for the whole dio, go back and try again
7875 */
7876 if (ordered_offset < dip->logical_offset + dip->bytes) {
7877 ordered_bytes = dip->logical_offset + dip->bytes -
7878 ordered_offset;
7879 ordered = NULL;
7880 goto again;
7881 }
7882 out_done:
7883 dio_bio = dip->dio_bio;
7884
7885 kfree(dip);
7886
7887 /* If we had an error make sure to clear the uptodate flag */
7888 if (err)
7889 clear_bit(BIO_UPTODATE, &dio_bio->bi_flags);
7890 dio_end_io(dio_bio, err);
7891 bio_put(bio);
7892 }
7893
7894 static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
7895 struct bio *bio, int mirror_num,
7896 unsigned long bio_flags, u64 offset)
7897 {
7898 int ret;
7899 struct btrfs_root *root = BTRFS_I(inode)->root;
7900 ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
7901 BUG_ON(ret); /* -ENOMEM */
7902 return 0;
7903 }
7904
7905 static void btrfs_end_dio_bio(struct bio *bio, int err)
7906 {
7907 struct btrfs_dio_private *dip = bio->bi_private;
7908
7909 if (err)
7910 btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
7911 "direct IO failed ino %llu rw %lu sector %#Lx len %u err no %d",
7912 btrfs_ino(dip->inode), bio->bi_rw,
7913 (unsigned long long)bio->bi_iter.bi_sector,
7914 bio->bi_iter.bi_size, err);
7915
7916 if (dip->subio_endio)
7917 err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
7918
7919 if (err) {
7920 dip->errors = 1;
7921
7922 /*
7923 * before atomic variable goto zero, we must make sure
7924 * dip->errors is perceived to be set.
7925 */
7926 smp_mb__before_atomic();
7927 }
7928
7929 /* if there are more bios still pending for this dio, just exit */
7930 if (!atomic_dec_and_test(&dip->pending_bios))
7931 goto out;
7932
7933 if (dip->errors) {
7934 bio_io_error(dip->orig_bio);
7935 } else {
7936 set_bit(BIO_UPTODATE, &dip->dio_bio->bi_flags);
7937 bio_endio(dip->orig_bio, 0);
7938 }
7939 out:
7940 bio_put(bio);
7941 }
7942
7943 static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
7944 u64 first_sector, gfp_t gfp_flags)
7945 {
7946 int nr_vecs = bio_get_nr_vecs(bdev);
7947 return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
7948 }
7949
7950 static inline int btrfs_lookup_and_bind_dio_csum(struct btrfs_root *root,
7951 struct inode *inode,
7952 struct btrfs_dio_private *dip,
7953 struct bio *bio,
7954 u64 file_offset)
7955 {
7956 struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
7957 struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
7958 int ret;
7959
7960 /*
7961 * We load all the csum data we need when we submit
7962 * the first bio to reduce the csum tree search and
7963 * contention.
7964 */
7965 if (dip->logical_offset == file_offset) {
7966 ret = btrfs_lookup_bio_sums_dio(root, inode, dip->orig_bio,
7967 file_offset);
7968 if (ret)
7969 return ret;
7970 }
7971
7972 if (bio == dip->orig_bio)
7973 return 0;
7974
7975 file_offset -= dip->logical_offset;
7976 file_offset >>= inode->i_sb->s_blocksize_bits;
7977 io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
7978
7979 return 0;
7980 }
7981
7982 static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
7983 int rw, u64 file_offset, int skip_sum,
7984 int async_submit)
7985 {
7986 struct btrfs_dio_private *dip = bio->bi_private;
7987 int write = rw & REQ_WRITE;
7988 struct btrfs_root *root = BTRFS_I(inode)->root;
7989 int ret;
7990
7991 if (async_submit)
7992 async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
7993
7994 bio_get(bio);
7995
7996 if (!write) {
7997 ret = btrfs_bio_wq_end_io(root->fs_info, bio,
7998 BTRFS_WQ_ENDIO_DATA);
7999 if (ret)
8000 goto err;
8001 }
8002
8003 if (skip_sum)
8004 goto map;
8005
8006 if (write && async_submit) {
8007 ret = btrfs_wq_submit_bio(root->fs_info,
8008 inode, rw, bio, 0, 0,
8009 file_offset,
8010 __btrfs_submit_bio_start_direct_io,
8011 __btrfs_submit_bio_done);
8012 goto err;
8013 } else if (write) {
8014 /*
8015 * If we aren't doing async submit, calculate the csum of the
8016 * bio now.
8017 */
8018 ret = btrfs_csum_one_bio(root, inode, bio, file_offset, 1);
8019 if (ret)
8020 goto err;
8021 } else {
8022 ret = btrfs_lookup_and_bind_dio_csum(root, inode, dip, bio,
8023 file_offset);
8024 if (ret)
8025 goto err;
8026 }
8027 map:
8028 ret = btrfs_map_bio(root, rw, bio, 0, async_submit);
8029 err:
8030 bio_put(bio);
8031 return ret;
8032 }
8033
8034 static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
8035 int skip_sum)
8036 {
8037 struct inode *inode = dip->inode;
8038 struct btrfs_root *root = BTRFS_I(inode)->root;
8039 struct bio *bio;
8040 struct bio *orig_bio = dip->orig_bio;
8041 struct bio_vec *bvec = orig_bio->bi_io_vec;
8042 u64 start_sector = orig_bio->bi_iter.bi_sector;
8043 u64 file_offset = dip->logical_offset;
8044 u64 submit_len = 0;
8045 u64 map_length;
8046 int nr_pages = 0;
8047 int ret;
8048 int async_submit = 0;
8049
8050 map_length = orig_bio->bi_iter.bi_size;
8051 ret = btrfs_map_block(root->fs_info, rw, start_sector << 9,
8052 &map_length, NULL, 0);
8053 if (ret)
8054 return -EIO;
8055
8056 if (map_length >= orig_bio->bi_iter.bi_size) {
8057 bio = orig_bio;
8058 dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
8059 goto submit;
8060 }
8061
8062 /* async crcs make it difficult to collect full stripe writes. */
8063 if (btrfs_get_alloc_profile(root, 1) & BTRFS_BLOCK_GROUP_RAID56_MASK)
8064 async_submit = 0;
8065 else
8066 async_submit = 1;
8067
8068 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
8069 if (!bio)
8070 return -ENOMEM;
8071
8072 bio->bi_private = dip;
8073 bio->bi_end_io = btrfs_end_dio_bio;
8074 btrfs_io_bio(bio)->logical = file_offset;
8075 atomic_inc(&dip->pending_bios);
8076
8077 while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
8078 if (map_length < submit_len + bvec->bv_len ||
8079 bio_add_page(bio, bvec->bv_page, bvec->bv_len,
8080 bvec->bv_offset) < bvec->bv_len) {
8081 /*
8082 * inc the count before we submit the bio so
8083 * we know the end IO handler won't happen before
8084 * we inc the count. Otherwise, the dip might get freed
8085 * before we're done setting it up
8086 */
8087 atomic_inc(&dip->pending_bios);
8088 ret = __btrfs_submit_dio_bio(bio, inode, rw,
8089 file_offset, skip_sum,
8090 async_submit);
8091 if (ret) {
8092 bio_put(bio);
8093 atomic_dec(&dip->pending_bios);
8094 goto out_err;
8095 }
8096
8097 start_sector += submit_len >> 9;
8098 file_offset += submit_len;
8099
8100 submit_len = 0;
8101 nr_pages = 0;
8102
8103 bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
8104 start_sector, GFP_NOFS);
8105 if (!bio)
8106 goto out_err;
8107 bio->bi_private = dip;
8108 bio->bi_end_io = btrfs_end_dio_bio;
8109 btrfs_io_bio(bio)->logical = file_offset;
8110
8111 map_length = orig_bio->bi_iter.bi_size;
8112 ret = btrfs_map_block(root->fs_info, rw,
8113 start_sector << 9,
8114 &map_length, NULL, 0);
8115 if (ret) {
8116 bio_put(bio);
8117 goto out_err;
8118 }
8119 } else {
8120 submit_len += bvec->bv_len;
8121 nr_pages++;
8122 bvec++;
8123 }
8124 }
8125
8126 submit:
8127 ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
8128 async_submit);
8129 if (!ret)
8130 return 0;
8131
8132 bio_put(bio);
8133 out_err:
8134 dip->errors = 1;
8135 /*
8136 * before atomic variable goto zero, we must
8137 * make sure dip->errors is perceived to be set.
8138 */
8139 smp_mb__before_atomic();
8140 if (atomic_dec_and_test(&dip->pending_bios))
8141 bio_io_error(dip->orig_bio);
8142
8143 /* bio_end_io() will handle error, so we needn't return it */
8144 return 0;
8145 }
8146
8147 static void btrfs_submit_direct(int rw, struct bio *dio_bio,
8148 struct inode *inode, loff_t file_offset)
8149 {
8150 struct btrfs_root *root = BTRFS_I(inode)->root;
8151 struct btrfs_dio_private *dip;
8152 struct bio *io_bio;
8153 struct btrfs_io_bio *btrfs_bio;
8154 int skip_sum;
8155 int write = rw & REQ_WRITE;
8156 int ret = 0;
8157
8158 skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
8159
8160 io_bio = btrfs_bio_clone(dio_bio, GFP_NOFS);
8161 if (!io_bio) {
8162 ret = -ENOMEM;
8163 goto free_ordered;
8164 }
8165
8166 dip = kzalloc(sizeof(*dip), GFP_NOFS);
8167 if (!dip) {
8168 ret = -ENOMEM;
8169 goto free_io_bio;
8170 }
8171
8172 dip->private = dio_bio->bi_private;
8173 dip->inode = inode;
8174 dip->logical_offset = file_offset;
8175 dip->bytes = dio_bio->bi_iter.bi_size;
8176 dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
8177 io_bio->bi_private = dip;
8178 dip->orig_bio = io_bio;
8179 dip->dio_bio = dio_bio;
8180 atomic_set(&dip->pending_bios, 0);
8181 btrfs_bio = btrfs_io_bio(io_bio);
8182 btrfs_bio->logical = file_offset;
8183
8184 if (write) {
8185 io_bio->bi_end_io = btrfs_endio_direct_write;
8186 } else {
8187 io_bio->bi_end_io = btrfs_endio_direct_read;
8188 dip->subio_endio = btrfs_subio_endio_read;
8189 }
8190
8191 ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
8192 if (!ret)
8193 return;
8194
8195 if (btrfs_bio->end_io)
8196 btrfs_bio->end_io(btrfs_bio, ret);
8197 free_io_bio:
8198 bio_put(io_bio);
8199
8200 free_ordered:
8201 /*
8202 * If this is a write, we need to clean up the reserved space and kill
8203 * the ordered extent.
8204 */
8205 if (write) {
8206 struct btrfs_ordered_extent *ordered;
8207 ordered = btrfs_lookup_ordered_extent(inode, file_offset);
8208 if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
8209 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
8210 btrfs_free_reserved_extent(root, ordered->start,
8211 ordered->disk_len, 1);
8212 btrfs_put_ordered_extent(ordered);
8213 btrfs_put_ordered_extent(ordered);
8214 }
8215 bio_endio(dio_bio, ret);
8216 }
8217
8218 static ssize_t check_direct_IO(struct btrfs_root *root, struct kiocb *iocb,
8219 const struct iov_iter *iter, loff_t offset)
8220 {
8221 int seg;
8222 int i;
8223 unsigned blocksize_mask = root->sectorsize - 1;
8224 ssize_t retval = -EINVAL;
8225
8226 if (offset & blocksize_mask)
8227 goto out;
8228
8229 if (iov_iter_alignment(iter) & blocksize_mask)
8230 goto out;
8231
8232 /* If this is a write we don't need to check anymore */
8233 if (iov_iter_rw(iter) == WRITE)
8234 return 0;
8235 /*
8236 * Check to make sure we don't have duplicate iov_base's in this
8237 * iovec, if so return EINVAL, otherwise we'll get csum errors
8238 * when reading back.
8239 */
8240 for (seg = 0; seg < iter->nr_segs; seg++) {
8241 for (i = seg + 1; i < iter->nr_segs; i++) {
8242 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
8243 goto out;
8244 }
8245 }
8246 retval = 0;
8247 out:
8248 return retval;
8249 }
8250
8251 static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
8252 loff_t offset)
8253 {
8254 struct file *file = iocb->ki_filp;
8255 struct inode *inode = file->f_mapping->host;
8256 u64 outstanding_extents = 0;
8257 size_t count = 0;
8258 int flags = 0;
8259 bool wakeup = true;
8260 bool relock = false;
8261 ssize_t ret;
8262
8263 if (check_direct_IO(BTRFS_I(inode)->root, iocb, iter, offset))
8264 return 0;
8265
8266 inode_dio_begin(inode);
8267 smp_mb__after_atomic();
8268
8269 /*
8270 * The generic stuff only does filemap_write_and_wait_range, which
8271 * isn't enough if we've written compressed pages to this area, so
8272 * we need to flush the dirty pages again to make absolutely sure
8273 * that any outstanding dirty pages are on disk.
8274 */
8275 count = iov_iter_count(iter);
8276 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
8277 &BTRFS_I(inode)->runtime_flags))
8278 filemap_fdatawrite_range(inode->i_mapping, offset,
8279 offset + count - 1);
8280
8281 if (iov_iter_rw(iter) == WRITE) {
8282 /*
8283 * If the write DIO is beyond the EOF, we need update
8284 * the isize, but it is protected by i_mutex. So we can
8285 * not unlock the i_mutex at this case.
8286 */
8287 if (offset + count <= inode->i_size) {
8288 mutex_unlock(&inode->i_mutex);
8289 relock = true;
8290 }
8291 ret = btrfs_delalloc_reserve_space(inode, count);
8292 if (ret)
8293 goto out;
8294 outstanding_extents = div64_u64(count +
8295 BTRFS_MAX_EXTENT_SIZE - 1,
8296 BTRFS_MAX_EXTENT_SIZE);
8297
8298 /*
8299 * We need to know how many extents we reserved so that we can
8300 * do the accounting properly if we go over the number we
8301 * originally calculated. Abuse current->journal_info for this.
8302 */
8303 current->journal_info = &outstanding_extents;
8304 } else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
8305 &BTRFS_I(inode)->runtime_flags)) {
8306 inode_dio_end(inode);
8307 flags = DIO_LOCKING | DIO_SKIP_HOLES;
8308 wakeup = false;
8309 }
8310
8311 ret = __blockdev_direct_IO(iocb, inode,
8312 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
8313 iter, offset, btrfs_get_blocks_direct, NULL,
8314 btrfs_submit_direct, flags);
8315 if (iov_iter_rw(iter) == WRITE) {
8316 current->journal_info = NULL;
8317 if (ret < 0 && ret != -EIOCBQUEUED)
8318 btrfs_delalloc_release_space(inode, count);
8319 else if (ret >= 0 && (size_t)ret < count)
8320 btrfs_delalloc_release_space(inode,
8321 count - (size_t)ret);
8322 }
8323 out:
8324 if (wakeup)
8325 inode_dio_end(inode);
8326 if (relock)
8327 mutex_lock(&inode->i_mutex);
8328
8329 return ret;
8330 }
8331
8332 #define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
8333
8334 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
8335 __u64 start, __u64 len)
8336 {
8337 int ret;
8338
8339 ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
8340 if (ret)
8341 return ret;
8342
8343 return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent_fiemap);
8344 }
8345
8346 int btrfs_readpage(struct file *file, struct page *page)
8347 {
8348 struct extent_io_tree *tree;
8349 tree = &BTRFS_I(page->mapping->host)->io_tree;
8350 return extent_read_full_page(tree, page, btrfs_get_extent, 0);
8351 }
8352
8353 static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
8354 {
8355 struct extent_io_tree *tree;
8356
8357
8358 if (current->flags & PF_MEMALLOC) {
8359 redirty_page_for_writepage(wbc, page);
8360 unlock_page(page);
8361 return 0;
8362 }
8363 tree = &BTRFS_I(page->mapping->host)->io_tree;
8364 return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
8365 }
8366
8367 static int btrfs_writepages(struct address_space *mapping,
8368 struct writeback_control *wbc)
8369 {
8370 struct extent_io_tree *tree;
8371
8372 tree = &BTRFS_I(mapping->host)->io_tree;
8373 return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
8374 }
8375
8376 static int
8377 btrfs_readpages(struct file *file, struct address_space *mapping,
8378 struct list_head *pages, unsigned nr_pages)
8379 {
8380 struct extent_io_tree *tree;
8381 tree = &BTRFS_I(mapping->host)->io_tree;
8382 return extent_readpages(tree, mapping, pages, nr_pages,
8383 btrfs_get_extent);
8384 }
8385 static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8386 {
8387 struct extent_io_tree *tree;
8388 struct extent_map_tree *map;
8389 int ret;
8390
8391 tree = &BTRFS_I(page->mapping->host)->io_tree;
8392 map = &BTRFS_I(page->mapping->host)->extent_tree;
8393 ret = try_release_extent_mapping(map, tree, page, gfp_flags);
8394 if (ret == 1) {
8395 ClearPagePrivate(page);
8396 set_page_private(page, 0);
8397 page_cache_release(page);
8398 }
8399 return ret;
8400 }
8401
8402 static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
8403 {
8404 if (PageWriteback(page) || PageDirty(page))
8405 return 0;
8406 return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
8407 }
8408
8409 static void btrfs_invalidatepage(struct page *page, unsigned int offset,
8410 unsigned int length)
8411 {
8412 struct inode *inode = page->mapping->host;
8413 struct extent_io_tree *tree;
8414 struct btrfs_ordered_extent *ordered;
8415 struct extent_state *cached_state = NULL;
8416 u64 page_start = page_offset(page);
8417 u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
8418 int inode_evicting = inode->i_state & I_FREEING;
8419
8420 /*
8421 * we have the page locked, so new writeback can't start,
8422 * and the dirty bit won't be cleared while we are here.
8423 *
8424 * Wait for IO on this page so that we can safely clear
8425 * the PagePrivate2 bit and do ordered accounting
8426 */
8427 wait_on_page_writeback(page);
8428
8429 tree = &BTRFS_I(inode)->io_tree;
8430 if (offset) {
8431 btrfs_releasepage(page, GFP_NOFS);
8432 return;
8433 }
8434
8435 if (!inode_evicting)
8436 lock_extent_bits(tree, page_start, page_end, 0, &cached_state);
8437 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8438 if (ordered) {
8439 /*
8440 * IO on this page will never be started, so we need
8441 * to account for any ordered extents now
8442 */
8443 if (!inode_evicting)
8444 clear_extent_bit(tree, page_start, page_end,
8445 EXTENT_DIRTY | EXTENT_DELALLOC |
8446 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
8447 EXTENT_DEFRAG, 1, 0, &cached_state,
8448 GFP_NOFS);
8449 /*
8450 * whoever cleared the private bit is responsible
8451 * for the finish_ordered_io
8452 */
8453 if (TestClearPagePrivate2(page)) {
8454 struct btrfs_ordered_inode_tree *tree;
8455 u64 new_len;
8456
8457 tree = &BTRFS_I(inode)->ordered_tree;
8458
8459 spin_lock_irq(&tree->lock);
8460 set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
8461 new_len = page_start - ordered->file_offset;
8462 if (new_len < ordered->truncated_len)
8463 ordered->truncated_len = new_len;
8464 spin_unlock_irq(&tree->lock);
8465
8466 if (btrfs_dec_test_ordered_pending(inode, &ordered,
8467 page_start,
8468 PAGE_CACHE_SIZE, 1))
8469 btrfs_finish_ordered_io(ordered);
8470 }
8471 btrfs_put_ordered_extent(ordered);
8472 if (!inode_evicting) {
8473 cached_state = NULL;
8474 lock_extent_bits(tree, page_start, page_end, 0,
8475 &cached_state);
8476 }
8477 }
8478
8479 if (!inode_evicting) {
8480 clear_extent_bit(tree, page_start, page_end,
8481 EXTENT_LOCKED | EXTENT_DIRTY |
8482 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
8483 EXTENT_DEFRAG, 1, 1,
8484 &cached_state, GFP_NOFS);
8485
8486 __btrfs_releasepage(page, GFP_NOFS);
8487 }
8488
8489 ClearPageChecked(page);
8490 if (PagePrivate(page)) {
8491 ClearPagePrivate(page);
8492 set_page_private(page, 0);
8493 page_cache_release(page);
8494 }
8495 }
8496
8497 /*
8498 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
8499 * called from a page fault handler when a page is first dirtied. Hence we must
8500 * be careful to check for EOF conditions here. We set the page up correctly
8501 * for a written page which means we get ENOSPC checking when writing into
8502 * holes and correct delalloc and unwritten extent mapping on filesystems that
8503 * support these features.
8504 *
8505 * We are not allowed to take the i_mutex here so we have to play games to
8506 * protect against truncate races as the page could now be beyond EOF. Because
8507 * vmtruncate() writes the inode size before removing pages, once we have the
8508 * page lock we can determine safely if the page is beyond EOF. If it is not
8509 * beyond EOF, then the page is guaranteed safe against truncation until we
8510 * unlock the page.
8511 */
8512 int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
8513 {
8514 struct page *page = vmf->page;
8515 struct inode *inode = file_inode(vma->vm_file);
8516 struct btrfs_root *root = BTRFS_I(inode)->root;
8517 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
8518 struct btrfs_ordered_extent *ordered;
8519 struct extent_state *cached_state = NULL;
8520 char *kaddr;
8521 unsigned long zero_start;
8522 loff_t size;
8523 int ret;
8524 int reserved = 0;
8525 u64 page_start;
8526 u64 page_end;
8527
8528 sb_start_pagefault(inode->i_sb);
8529 ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
8530 if (!ret) {
8531 ret = file_update_time(vma->vm_file);
8532 reserved = 1;
8533 }
8534 if (ret) {
8535 if (ret == -ENOMEM)
8536 ret = VM_FAULT_OOM;
8537 else /* -ENOSPC, -EIO, etc */
8538 ret = VM_FAULT_SIGBUS;
8539 if (reserved)
8540 goto out;
8541 goto out_noreserve;
8542 }
8543
8544 ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
8545 again:
8546 lock_page(page);
8547 size = i_size_read(inode);
8548 page_start = page_offset(page);
8549 page_end = page_start + PAGE_CACHE_SIZE - 1;
8550
8551 if ((page->mapping != inode->i_mapping) ||
8552 (page_start >= size)) {
8553 /* page got truncated out from underneath us */
8554 goto out_unlock;
8555 }
8556 wait_on_page_writeback(page);
8557
8558 lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state);
8559 set_page_extent_mapped(page);
8560
8561 /*
8562 * we can't set the delalloc bits if there are pending ordered
8563 * extents. Drop our locks and wait for them to finish
8564 */
8565 ordered = btrfs_lookup_ordered_extent(inode, page_start);
8566 if (ordered) {
8567 unlock_extent_cached(io_tree, page_start, page_end,
8568 &cached_state, GFP_NOFS);
8569 unlock_page(page);
8570 btrfs_start_ordered_extent(inode, ordered, 1);
8571 btrfs_put_ordered_extent(ordered);
8572 goto again;
8573 }
8574
8575 /*
8576 * XXX - page_mkwrite gets called every time the page is dirtied, even
8577 * if it was already dirty, so for space accounting reasons we need to
8578 * clear any delalloc bits for the range we are fixing to save. There
8579 * is probably a better way to do this, but for now keep consistent with
8580 * prepare_pages in the normal write path.
8581 */
8582 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
8583 EXTENT_DIRTY | EXTENT_DELALLOC |
8584 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
8585 0, 0, &cached_state, GFP_NOFS);
8586
8587 ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
8588 &cached_state);
8589 if (ret) {
8590 unlock_extent_cached(io_tree, page_start, page_end,
8591 &cached_state, GFP_NOFS);
8592 ret = VM_FAULT_SIGBUS;
8593 goto out_unlock;
8594 }
8595 ret = 0;
8596
8597 /* page is wholly or partially inside EOF */
8598 if (page_start + PAGE_CACHE_SIZE > size)
8599 zero_start = size & ~PAGE_CACHE_MASK;
8600 else
8601 zero_start = PAGE_CACHE_SIZE;
8602
8603 if (zero_start != PAGE_CACHE_SIZE) {
8604 kaddr = kmap(page);
8605 memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
8606 flush_dcache_page(page);
8607 kunmap(page);
8608 }
8609 ClearPageChecked(page);
8610 set_page_dirty(page);
8611 SetPageUptodate(page);
8612
8613 BTRFS_I(inode)->last_trans = root->fs_info->generation;
8614 BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
8615 BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
8616
8617 unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
8618
8619 out_unlock:
8620 if (!ret) {
8621 sb_end_pagefault(inode->i_sb);
8622 return VM_FAULT_LOCKED;
8623 }
8624 unlock_page(page);
8625 out:
8626 btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
8627 out_noreserve:
8628 sb_end_pagefault(inode->i_sb);
8629 return ret;
8630 }
8631
8632 static int btrfs_truncate(struct inode *inode)
8633 {
8634 struct btrfs_root *root = BTRFS_I(inode)->root;
8635 struct btrfs_block_rsv *rsv;
8636 int ret = 0;
8637 int err = 0;
8638 struct btrfs_trans_handle *trans;
8639 u64 mask = root->sectorsize - 1;
8640 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
8641
8642 ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
8643 (u64)-1);
8644 if (ret)
8645 return ret;
8646
8647 /*
8648 * Yes ladies and gentelment, this is indeed ugly. The fact is we have
8649 * 3 things going on here
8650 *
8651 * 1) We need to reserve space for our orphan item and the space to
8652 * delete our orphan item. Lord knows we don't want to have a dangling
8653 * orphan item because we didn't reserve space to remove it.
8654 *
8655 * 2) We need to reserve space to update our inode.
8656 *
8657 * 3) We need to have something to cache all the space that is going to
8658 * be free'd up by the truncate operation, but also have some slack
8659 * space reserved in case it uses space during the truncate (thank you
8660 * very much snapshotting).
8661 *
8662 * And we need these to all be seperate. The fact is we can use alot of
8663 * space doing the truncate, and we have no earthly idea how much space
8664 * we will use, so we need the truncate reservation to be seperate so it
8665 * doesn't end up using space reserved for updating the inode or
8666 * removing the orphan item. We also need to be able to stop the
8667 * transaction and start a new one, which means we need to be able to
8668 * update the inode several times, and we have no idea of knowing how
8669 * many times that will be, so we can't just reserve 1 item for the
8670 * entirety of the opration, so that has to be done seperately as well.
8671 * Then there is the orphan item, which does indeed need to be held on
8672 * to for the whole operation, and we need nobody to touch this reserved
8673 * space except the orphan code.
8674 *
8675 * So that leaves us with
8676 *
8677 * 1) root->orphan_block_rsv - for the orphan deletion.
8678 * 2) rsv - for the truncate reservation, which we will steal from the
8679 * transaction reservation.
8680 * 3) fs_info->trans_block_rsv - this will have 1 items worth left for
8681 * updating the inode.
8682 */
8683 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
8684 if (!rsv)
8685 return -ENOMEM;
8686 rsv->size = min_size;
8687 rsv->failfast = 1;
8688
8689 /*
8690 * 1 for the truncate slack space
8691 * 1 for updating the inode.
8692 */
8693 trans = btrfs_start_transaction(root, 2);
8694 if (IS_ERR(trans)) {
8695 err = PTR_ERR(trans);
8696 goto out;
8697 }
8698
8699 /* Migrate the slack space for the truncate to our reserve */
8700 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
8701 min_size);
8702 BUG_ON(ret);
8703
8704 /*
8705 * So if we truncate and then write and fsync we normally would just
8706 * write the extents that changed, which is a problem if we need to
8707 * first truncate that entire inode. So set this flag so we write out
8708 * all of the extents in the inode to the sync log so we're completely
8709 * safe.
8710 */
8711 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
8712 trans->block_rsv = rsv;
8713
8714 while (1) {
8715 ret = btrfs_truncate_inode_items(trans, root, inode,
8716 inode->i_size,
8717 BTRFS_EXTENT_DATA_KEY);
8718 if (ret != -ENOSPC && ret != -EAGAIN) {
8719 err = ret;
8720 break;
8721 }
8722
8723 trans->block_rsv = &root->fs_info->trans_block_rsv;
8724 ret = btrfs_update_inode(trans, root, inode);
8725 if (ret) {
8726 err = ret;
8727 break;
8728 }
8729
8730 btrfs_end_transaction(trans, root);
8731 btrfs_btree_balance_dirty(root);
8732
8733 trans = btrfs_start_transaction(root, 2);
8734 if (IS_ERR(trans)) {
8735 ret = err = PTR_ERR(trans);
8736 trans = NULL;
8737 break;
8738 }
8739
8740 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
8741 rsv, min_size);
8742 BUG_ON(ret); /* shouldn't happen */
8743 trans->block_rsv = rsv;
8744 }
8745
8746 if (ret == 0 && inode->i_nlink > 0) {
8747 trans->block_rsv = root->orphan_block_rsv;
8748 ret = btrfs_orphan_del(trans, inode);
8749 if (ret)
8750 err = ret;
8751 }
8752
8753 if (trans) {
8754 trans->block_rsv = &root->fs_info->trans_block_rsv;
8755 ret = btrfs_update_inode(trans, root, inode);
8756 if (ret && !err)
8757 err = ret;
8758
8759 ret = btrfs_end_transaction(trans, root);
8760 btrfs_btree_balance_dirty(root);
8761 }
8762
8763 out:
8764 btrfs_free_block_rsv(root, rsv);
8765
8766 if (ret && !err)
8767 err = ret;
8768
8769 return err;
8770 }
8771
8772 /*
8773 * create a new subvolume directory/inode (helper for the ioctl).
8774 */
8775 int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
8776 struct btrfs_root *new_root,
8777 struct btrfs_root *parent_root,
8778 u64 new_dirid)
8779 {
8780 struct inode *inode;
8781 int err;
8782 u64 index = 0;
8783
8784 inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
8785 new_dirid, new_dirid,
8786 S_IFDIR | (~current_umask() & S_IRWXUGO),
8787 &index);
8788 if (IS_ERR(inode))
8789 return PTR_ERR(inode);
8790 inode->i_op = &btrfs_dir_inode_operations;
8791 inode->i_fop = &btrfs_dir_file_operations;
8792
8793 set_nlink(inode, 1);
8794 btrfs_i_size_write(inode, 0);
8795 unlock_new_inode(inode);
8796
8797 err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
8798 if (err)
8799 btrfs_err(new_root->fs_info,
8800 "error inheriting subvolume %llu properties: %d",
8801 new_root->root_key.objectid, err);
8802
8803 err = btrfs_update_inode(trans, new_root, inode);
8804
8805 iput(inode);
8806 return err;
8807 }
8808
8809 struct inode *btrfs_alloc_inode(struct super_block *sb)
8810 {
8811 struct btrfs_inode *ei;
8812 struct inode *inode;
8813
8814 ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
8815 if (!ei)
8816 return NULL;
8817
8818 ei->root = NULL;
8819 ei->generation = 0;
8820 ei->last_trans = 0;
8821 ei->last_sub_trans = 0;
8822 ei->logged_trans = 0;
8823 ei->delalloc_bytes = 0;
8824 ei->defrag_bytes = 0;
8825 ei->disk_i_size = 0;
8826 ei->flags = 0;
8827 ei->csum_bytes = 0;
8828 ei->index_cnt = (u64)-1;
8829 ei->dir_index = 0;
8830 ei->last_unlink_trans = 0;
8831 ei->last_log_commit = 0;
8832
8833 spin_lock_init(&ei->lock);
8834 ei->outstanding_extents = 0;
8835 ei->reserved_extents = 0;
8836
8837 ei->runtime_flags = 0;
8838 ei->force_compress = BTRFS_COMPRESS_NONE;
8839
8840 ei->delayed_node = NULL;
8841
8842 ei->i_otime.tv_sec = 0;
8843 ei->i_otime.tv_nsec = 0;
8844
8845 inode = &ei->vfs_inode;
8846 extent_map_tree_init(&ei->extent_tree);
8847 extent_io_tree_init(&ei->io_tree, &inode->i_data);
8848 extent_io_tree_init(&ei->io_failure_tree, &inode->i_data);
8849 ei->io_tree.track_uptodate = 1;
8850 ei->io_failure_tree.track_uptodate = 1;
8851 atomic_set(&ei->sync_writers, 0);
8852 mutex_init(&ei->log_mutex);
8853 mutex_init(&ei->delalloc_mutex);
8854 btrfs_ordered_inode_tree_init(&ei->ordered_tree);
8855 INIT_LIST_HEAD(&ei->delalloc_inodes);
8856 RB_CLEAR_NODE(&ei->rb_node);
8857
8858 return inode;
8859 }
8860
8861 #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
8862 void btrfs_test_destroy_inode(struct inode *inode)
8863 {
8864 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8865 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8866 }
8867 #endif
8868
8869 static void btrfs_i_callback(struct rcu_head *head)
8870 {
8871 struct inode *inode = container_of(head, struct inode, i_rcu);
8872 kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
8873 }
8874
8875 void btrfs_destroy_inode(struct inode *inode)
8876 {
8877 struct btrfs_ordered_extent *ordered;
8878 struct btrfs_root *root = BTRFS_I(inode)->root;
8879
8880 WARN_ON(!hlist_empty(&inode->i_dentry));
8881 WARN_ON(inode->i_data.nrpages);
8882 WARN_ON(BTRFS_I(inode)->outstanding_extents);
8883 WARN_ON(BTRFS_I(inode)->reserved_extents);
8884 WARN_ON(BTRFS_I(inode)->delalloc_bytes);
8885 WARN_ON(BTRFS_I(inode)->csum_bytes);
8886 WARN_ON(BTRFS_I(inode)->defrag_bytes);
8887
8888 /*
8889 * This can happen where we create an inode, but somebody else also
8890 * created the same inode and we need to destroy the one we already
8891 * created.
8892 */
8893 if (!root)
8894 goto free;
8895
8896 if (test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
8897 &BTRFS_I(inode)->runtime_flags)) {
8898 btrfs_info(root->fs_info, "inode %llu still on the orphan list",
8899 btrfs_ino(inode));
8900 atomic_dec(&root->orphan_inodes);
8901 }
8902
8903 while (1) {
8904 ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
8905 if (!ordered)
8906 break;
8907 else {
8908 btrfs_err(root->fs_info, "found ordered extent %llu %llu on inode cleanup",
8909 ordered->file_offset, ordered->len);
8910 btrfs_remove_ordered_extent(inode, ordered);
8911 btrfs_put_ordered_extent(ordered);
8912 btrfs_put_ordered_extent(ordered);
8913 }
8914 }
8915 inode_tree_del(inode);
8916 btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
8917 free:
8918 call_rcu(&inode->i_rcu, btrfs_i_callback);
8919 }
8920
8921 int btrfs_drop_inode(struct inode *inode)
8922 {
8923 struct btrfs_root *root = BTRFS_I(inode)->root;
8924
8925 if (root == NULL)
8926 return 1;
8927
8928 /* the snap/subvol tree is on deleting */
8929 if (btrfs_root_refs(&root->root_item) == 0)
8930 return 1;
8931 else
8932 return generic_drop_inode(inode);
8933 }
8934
8935 static void init_once(void *foo)
8936 {
8937 struct btrfs_inode *ei = (struct btrfs_inode *) foo;
8938
8939 inode_init_once(&ei->vfs_inode);
8940 }
8941
8942 void btrfs_destroy_cachep(void)
8943 {
8944 /*
8945 * Make sure all delayed rcu free inodes are flushed before we
8946 * destroy cache.
8947 */
8948 rcu_barrier();
8949 if (btrfs_inode_cachep)
8950 kmem_cache_destroy(btrfs_inode_cachep);
8951 if (btrfs_trans_handle_cachep)
8952 kmem_cache_destroy(btrfs_trans_handle_cachep);
8953 if (btrfs_transaction_cachep)
8954 kmem_cache_destroy(btrfs_transaction_cachep);
8955 if (btrfs_path_cachep)
8956 kmem_cache_destroy(btrfs_path_cachep);
8957 if (btrfs_free_space_cachep)
8958 kmem_cache_destroy(btrfs_free_space_cachep);
8959 if (btrfs_delalloc_work_cachep)
8960 kmem_cache_destroy(btrfs_delalloc_work_cachep);
8961 }
8962
8963 int btrfs_init_cachep(void)
8964 {
8965 btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
8966 sizeof(struct btrfs_inode), 0,
8967 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
8968 if (!btrfs_inode_cachep)
8969 goto fail;
8970
8971 btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
8972 sizeof(struct btrfs_trans_handle), 0,
8973 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8974 if (!btrfs_trans_handle_cachep)
8975 goto fail;
8976
8977 btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction",
8978 sizeof(struct btrfs_transaction), 0,
8979 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8980 if (!btrfs_transaction_cachep)
8981 goto fail;
8982
8983 btrfs_path_cachep = kmem_cache_create("btrfs_path",
8984 sizeof(struct btrfs_path), 0,
8985 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8986 if (!btrfs_path_cachep)
8987 goto fail;
8988
8989 btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
8990 sizeof(struct btrfs_free_space), 0,
8991 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
8992 if (!btrfs_free_space_cachep)
8993 goto fail;
8994
8995 btrfs_delalloc_work_cachep = kmem_cache_create("btrfs_delalloc_work",
8996 sizeof(struct btrfs_delalloc_work), 0,
8997 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
8998 NULL);
8999 if (!btrfs_delalloc_work_cachep)
9000 goto fail;
9001
9002 return 0;
9003 fail:
9004 btrfs_destroy_cachep();
9005 return -ENOMEM;
9006 }
9007
9008 static int btrfs_getattr(struct vfsmount *mnt,
9009 struct dentry *dentry, struct kstat *stat)
9010 {
9011 u64 delalloc_bytes;
9012 struct inode *inode = d_inode(dentry);
9013 u32 blocksize = inode->i_sb->s_blocksize;
9014
9015 generic_fillattr(inode, stat);
9016 stat->dev = BTRFS_I(inode)->root->anon_dev;
9017 stat->blksize = PAGE_CACHE_SIZE;
9018
9019 spin_lock(&BTRFS_I(inode)->lock);
9020 delalloc_bytes = BTRFS_I(inode)->delalloc_bytes;
9021 spin_unlock(&BTRFS_I(inode)->lock);
9022 stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
9023 ALIGN(delalloc_bytes, blocksize)) >> 9;
9024 return 0;
9025 }
9026
9027 static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
9028 struct inode *new_dir, struct dentry *new_dentry)
9029 {
9030 struct btrfs_trans_handle *trans;
9031 struct btrfs_root *root = BTRFS_I(old_dir)->root;
9032 struct btrfs_root *dest = BTRFS_I(new_dir)->root;
9033 struct inode *new_inode = d_inode(new_dentry);
9034 struct inode *old_inode = d_inode(old_dentry);
9035 struct timespec ctime = CURRENT_TIME;
9036 u64 index = 0;
9037 u64 root_objectid;
9038 int ret;
9039 u64 old_ino = btrfs_ino(old_inode);
9040
9041 if (btrfs_ino(new_dir) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
9042 return -EPERM;
9043
9044 /* we only allow rename subvolume link between subvolumes */
9045 if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
9046 return -EXDEV;
9047
9048 if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
9049 (new_inode && btrfs_ino(new_inode) == BTRFS_FIRST_FREE_OBJECTID))
9050 return -ENOTEMPTY;
9051
9052 if (S_ISDIR(old_inode->i_mode) && new_inode &&
9053 new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
9054 return -ENOTEMPTY;
9055
9056
9057 /* check for collisions, even if the name isn't there */
9058 ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
9059 new_dentry->d_name.name,
9060 new_dentry->d_name.len);
9061
9062 if (ret) {
9063 if (ret == -EEXIST) {
9064 /* we shouldn't get
9065 * eexist without a new_inode */
9066 if (WARN_ON(!new_inode)) {
9067 return ret;
9068 }
9069 } else {
9070 /* maybe -EOVERFLOW */
9071 return ret;
9072 }
9073 }
9074 ret = 0;
9075
9076 /*
9077 * we're using rename to replace one file with another. Start IO on it
9078 * now so we don't add too much work to the end of the transaction
9079 */
9080 if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
9081 filemap_flush(old_inode->i_mapping);
9082
9083 /* close the racy window with snapshot create/destroy ioctl */
9084 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9085 down_read(&root->fs_info->subvol_sem);
9086 /*
9087 * We want to reserve the absolute worst case amount of items. So if
9088 * both inodes are subvols and we need to unlink them then that would
9089 * require 4 item modifications, but if they are both normal inodes it
9090 * would require 5 item modifications, so we'll assume their normal
9091 * inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
9092 * should cover the worst case number of items we'll modify.
9093 */
9094 trans = btrfs_start_transaction(root, 11);
9095 if (IS_ERR(trans)) {
9096 ret = PTR_ERR(trans);
9097 goto out_notrans;
9098 }
9099
9100 if (dest != root)
9101 btrfs_record_root_in_trans(trans, dest);
9102
9103 ret = btrfs_set_inode_index(new_dir, &index);
9104 if (ret)
9105 goto out_fail;
9106
9107 BTRFS_I(old_inode)->dir_index = 0ULL;
9108 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9109 /* force full log commit if subvolume involved. */
9110 btrfs_set_log_full_commit(root->fs_info, trans);
9111 } else {
9112 ret = btrfs_insert_inode_ref(trans, dest,
9113 new_dentry->d_name.name,
9114 new_dentry->d_name.len,
9115 old_ino,
9116 btrfs_ino(new_dir), index);
9117 if (ret)
9118 goto out_fail;
9119 /*
9120 * this is an ugly little race, but the rename is required
9121 * to make sure that if we crash, the inode is either at the
9122 * old name or the new one. pinning the log transaction lets
9123 * us make sure we don't allow a log commit to come in after
9124 * we unlink the name but before we add the new name back in.
9125 */
9126 btrfs_pin_log_trans(root);
9127 }
9128
9129 inode_inc_iversion(old_dir);
9130 inode_inc_iversion(new_dir);
9131 inode_inc_iversion(old_inode);
9132 old_dir->i_ctime = old_dir->i_mtime = ctime;
9133 new_dir->i_ctime = new_dir->i_mtime = ctime;
9134 old_inode->i_ctime = ctime;
9135
9136 if (old_dentry->d_parent != new_dentry->d_parent)
9137 btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);
9138
9139 if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
9140 root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
9141 ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
9142 old_dentry->d_name.name,
9143 old_dentry->d_name.len);
9144 } else {
9145 ret = __btrfs_unlink_inode(trans, root, old_dir,
9146 d_inode(old_dentry),
9147 old_dentry->d_name.name,
9148 old_dentry->d_name.len);
9149 if (!ret)
9150 ret = btrfs_update_inode(trans, root, old_inode);
9151 }
9152 if (ret) {
9153 btrfs_abort_transaction(trans, root, ret);
9154 goto out_fail;
9155 }
9156
9157 if (new_inode) {
9158 inode_inc_iversion(new_inode);
9159 new_inode->i_ctime = CURRENT_TIME;
9160 if (unlikely(btrfs_ino(new_inode) ==
9161 BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
9162 root_objectid = BTRFS_I(new_inode)->location.objectid;
9163 ret = btrfs_unlink_subvol(trans, dest, new_dir,
9164 root_objectid,
9165 new_dentry->d_name.name,
9166 new_dentry->d_name.len);
9167 BUG_ON(new_inode->i_nlink == 0);
9168 } else {
9169 ret = btrfs_unlink_inode(trans, dest, new_dir,
9170 d_inode(new_dentry),
9171 new_dentry->d_name.name,
9172 new_dentry->d_name.len);
9173 }
9174 if (!ret && new_inode->i_nlink == 0)
9175 ret = btrfs_orphan_add(trans, d_inode(new_dentry));
9176 if (ret) {
9177 btrfs_abort_transaction(trans, root, ret);
9178 goto out_fail;
9179 }
9180 }
9181
9182 ret = btrfs_add_link(trans, new_dir, old_inode,
9183 new_dentry->d_name.name,
9184 new_dentry->d_name.len, 0, index);
9185 if (ret) {
9186 btrfs_abort_transaction(trans, root, ret);
9187 goto out_fail;
9188 }
9189
9190 if (old_inode->i_nlink == 1)
9191 BTRFS_I(old_inode)->dir_index = index;
9192
9193 if (old_ino != BTRFS_FIRST_FREE_OBJECTID) {
9194 struct dentry *parent = new_dentry->d_parent;
9195 btrfs_log_new_name(trans, old_inode, old_dir, parent);
9196 btrfs_end_log_trans(root);
9197 }
9198 out_fail:
9199 btrfs_end_transaction(trans, root);
9200 out_notrans:
9201 if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
9202 up_read(&root->fs_info->subvol_sem);
9203
9204 return ret;
9205 }
9206
9207 static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
9208 struct inode *new_dir, struct dentry *new_dentry,
9209 unsigned int flags)
9210 {
9211 if (flags & ~RENAME_NOREPLACE)
9212 return -EINVAL;
9213
9214 return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry);
9215 }
9216
9217 static void btrfs_run_delalloc_work(struct btrfs_work *work)
9218 {
9219 struct btrfs_delalloc_work *delalloc_work;
9220 struct inode *inode;
9221
9222 delalloc_work = container_of(work, struct btrfs_delalloc_work,
9223 work);
9224 inode = delalloc_work->inode;
9225 if (delalloc_work->wait) {
9226 btrfs_wait_ordered_range(inode, 0, (u64)-1);
9227 } else {
9228 filemap_flush(inode->i_mapping);
9229 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
9230 &BTRFS_I(inode)->runtime_flags))
9231 filemap_flush(inode->i_mapping);
9232 }
9233
9234 if (delalloc_work->delay_iput)
9235 btrfs_add_delayed_iput(inode);
9236 else
9237 iput(inode);
9238 complete(&delalloc_work->completion);
9239 }
9240
9241 struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode,
9242 int wait, int delay_iput)
9243 {
9244 struct btrfs_delalloc_work *work;
9245
9246 work = kmem_cache_zalloc(btrfs_delalloc_work_cachep, GFP_NOFS);
9247 if (!work)
9248 return NULL;
9249
9250 init_completion(&work->completion);
9251 INIT_LIST_HEAD(&work->list);
9252 work->inode = inode;
9253 work->wait = wait;
9254 work->delay_iput = delay_iput;
9255 WARN_ON_ONCE(!inode);
9256 btrfs_init_work(&work->work, btrfs_flush_delalloc_helper,
9257 btrfs_run_delalloc_work, NULL, NULL);
9258
9259 return work;
9260 }
9261
9262 void btrfs_wait_and_free_delalloc_work(struct btrfs_delalloc_work *work)
9263 {
9264 wait_for_completion(&work->completion);
9265 kmem_cache_free(btrfs_delalloc_work_cachep, work);
9266 }
9267
9268 /*
9269 * some fairly slow code that needs optimization. This walks the list
9270 * of all the inodes with pending delalloc and forces them to disk.
9271 */
9272 static int __start_delalloc_inodes(struct btrfs_root *root, int delay_iput,
9273 int nr)
9274 {
9275 struct btrfs_inode *binode;
9276 struct inode *inode;
9277 struct btrfs_delalloc_work *work, *next;
9278 struct list_head works;
9279 struct list_head splice;
9280 int ret = 0;
9281
9282 INIT_LIST_HEAD(&works);
9283 INIT_LIST_HEAD(&splice);
9284
9285 mutex_lock(&root->delalloc_mutex);
9286 spin_lock(&root->delalloc_lock);
9287 list_splice_init(&root->delalloc_inodes, &splice);
9288 while (!list_empty(&splice)) {
9289 binode = list_entry(splice.next, struct btrfs_inode,
9290 delalloc_inodes);
9291
9292 list_move_tail(&binode->delalloc_inodes,
9293 &root->delalloc_inodes);
9294 inode = igrab(&binode->vfs_inode);
9295 if (!inode) {
9296 cond_resched_lock(&root->delalloc_lock);
9297 continue;
9298 }
9299 spin_unlock(&root->delalloc_lock);
9300
9301 work = btrfs_alloc_delalloc_work(inode, 0, delay_iput);
9302 if (!work) {
9303 if (delay_iput)
9304 btrfs_add_delayed_iput(inode);
9305 else
9306 iput(inode);
9307 ret = -ENOMEM;
9308 goto out;
9309 }
9310 list_add_tail(&work->list, &works);
9311 btrfs_queue_work(root->fs_info->flush_workers,
9312 &work->work);
9313 ret++;
9314 if (nr != -1 && ret >= nr)
9315 goto out;
9316 cond_resched();
9317 spin_lock(&root->delalloc_lock);
9318 }
9319 spin_unlock(&root->delalloc_lock);
9320
9321 out:
9322 list_for_each_entry_safe(work, next, &works, list) {
9323 list_del_init(&work->list);
9324 btrfs_wait_and_free_delalloc_work(work);
9325 }
9326
9327 if (!list_empty_careful(&splice)) {
9328 spin_lock(&root->delalloc_lock);
9329 list_splice_tail(&splice, &root->delalloc_inodes);
9330 spin_unlock(&root->delalloc_lock);
9331 }
9332 mutex_unlock(&root->delalloc_mutex);
9333 return ret;
9334 }
9335
9336 int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
9337 {
9338 int ret;
9339
9340 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state))
9341 return -EROFS;
9342
9343 ret = __start_delalloc_inodes(root, delay_iput, -1);
9344 if (ret > 0)
9345 ret = 0;
9346 /*
9347 * the filemap_flush will queue IO into the worker threads, but
9348 * we have to make sure the IO is actually started and that
9349 * ordered extents get created before we return
9350 */
9351 atomic_inc(&root->fs_info->async_submit_draining);
9352 while (atomic_read(&root->fs_info->nr_async_submits) ||
9353 atomic_read(&root->fs_info->async_delalloc_pages)) {
9354 wait_event(root->fs_info->async_submit_wait,
9355 (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
9356 atomic_read(&root->fs_info->async_delalloc_pages) == 0));
9357 }
9358 atomic_dec(&root->fs_info->async_submit_draining);
9359 return ret;
9360 }
9361
9362 int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int delay_iput,
9363 int nr)
9364 {
9365 struct btrfs_root *root;
9366 struct list_head splice;
9367 int ret;
9368
9369 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
9370 return -EROFS;
9371
9372 INIT_LIST_HEAD(&splice);
9373
9374 mutex_lock(&fs_info->delalloc_root_mutex);
9375 spin_lock(&fs_info->delalloc_root_lock);
9376 list_splice_init(&fs_info->delalloc_roots, &splice);
9377 while (!list_empty(&splice) && nr) {
9378 root = list_first_entry(&splice, struct btrfs_root,
9379 delalloc_root);
9380 root = btrfs_grab_fs_root(root);
9381 BUG_ON(!root);
9382 list_move_tail(&root->delalloc_root,
9383 &fs_info->delalloc_roots);
9384 spin_unlock(&fs_info->delalloc_root_lock);
9385
9386 ret = __start_delalloc_inodes(root, delay_iput, nr);
9387 btrfs_put_fs_root(root);
9388 if (ret < 0)
9389 goto out;
9390
9391 if (nr != -1) {
9392 nr -= ret;
9393 WARN_ON(nr < 0);
9394 }
9395 spin_lock(&fs_info->delalloc_root_lock);
9396 }
9397 spin_unlock(&fs_info->delalloc_root_lock);
9398
9399 ret = 0;
9400 atomic_inc(&fs_info->async_submit_draining);
9401 while (atomic_read(&fs_info->nr_async_submits) ||
9402 atomic_read(&fs_info->async_delalloc_pages)) {
9403 wait_event(fs_info->async_submit_wait,
9404 (atomic_read(&fs_info->nr_async_submits) == 0 &&
9405 atomic_read(&fs_info->async_delalloc_pages) == 0));
9406 }
9407 atomic_dec(&fs_info->async_submit_draining);
9408 out:
9409 if (!list_empty_careful(&splice)) {
9410 spin_lock(&fs_info->delalloc_root_lock);
9411 list_splice_tail(&splice, &fs_info->delalloc_roots);
9412 spin_unlock(&fs_info->delalloc_root_lock);
9413 }
9414 mutex_unlock(&fs_info->delalloc_root_mutex);
9415 return ret;
9416 }
9417
9418 static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
9419 const char *symname)
9420 {
9421 struct btrfs_trans_handle *trans;
9422 struct btrfs_root *root = BTRFS_I(dir)->root;
9423 struct btrfs_path *path;
9424 struct btrfs_key key;
9425 struct inode *inode = NULL;
9426 int err;
9427 int drop_inode = 0;
9428 u64 objectid;
9429 u64 index = 0;
9430 int name_len;
9431 int datasize;
9432 unsigned long ptr;
9433 struct btrfs_file_extent_item *ei;
9434 struct extent_buffer *leaf;
9435
9436 name_len = strlen(symname);
9437 if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
9438 return -ENAMETOOLONG;
9439
9440 /*
9441 * 2 items for inode item and ref
9442 * 2 items for dir items
9443 * 1 item for xattr if selinux is on
9444 */
9445 trans = btrfs_start_transaction(root, 5);
9446 if (IS_ERR(trans))
9447 return PTR_ERR(trans);
9448
9449 err = btrfs_find_free_ino(root, &objectid);
9450 if (err)
9451 goto out_unlock;
9452
9453 inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
9454 dentry->d_name.len, btrfs_ino(dir), objectid,
9455 S_IFLNK|S_IRWXUGO, &index);
9456 if (IS_ERR(inode)) {
9457 err = PTR_ERR(inode);
9458 goto out_unlock;
9459 }
9460
9461 /*
9462 * If the active LSM wants to access the inode during
9463 * d_instantiate it needs these. Smack checks to see
9464 * if the filesystem supports xattrs by looking at the
9465 * ops vector.
9466 */
9467 inode->i_fop = &btrfs_file_operations;
9468 inode->i_op = &btrfs_file_inode_operations;
9469 inode->i_mapping->a_ops = &btrfs_aops;
9470 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9471
9472 err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
9473 if (err)
9474 goto out_unlock_inode;
9475
9476 err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
9477 if (err)
9478 goto out_unlock_inode;
9479
9480 path = btrfs_alloc_path();
9481 if (!path) {
9482 err = -ENOMEM;
9483 goto out_unlock_inode;
9484 }
9485 key.objectid = btrfs_ino(inode);
9486 key.offset = 0;
9487 key.type = BTRFS_EXTENT_DATA_KEY;
9488 datasize = btrfs_file_extent_calc_inline_size(name_len);
9489 err = btrfs_insert_empty_item(trans, root, path, &key,
9490 datasize);
9491 if (err) {
9492 btrfs_free_path(path);
9493 goto out_unlock_inode;
9494 }
9495 leaf = path->nodes[0];
9496 ei = btrfs_item_ptr(leaf, path->slots[0],
9497 struct btrfs_file_extent_item);
9498 btrfs_set_file_extent_generation(leaf, ei, trans->transid);
9499 btrfs_set_file_extent_type(leaf, ei,
9500 BTRFS_FILE_EXTENT_INLINE);
9501 btrfs_set_file_extent_encryption(leaf, ei, 0);
9502 btrfs_set_file_extent_compression(leaf, ei, 0);
9503 btrfs_set_file_extent_other_encoding(leaf, ei, 0);
9504 btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
9505
9506 ptr = btrfs_file_extent_inline_start(ei);
9507 write_extent_buffer(leaf, symname, ptr, name_len);
9508 btrfs_mark_buffer_dirty(leaf);
9509 btrfs_free_path(path);
9510
9511 inode->i_op = &btrfs_symlink_inode_operations;
9512 inode->i_mapping->a_ops = &btrfs_symlink_aops;
9513 inode_set_bytes(inode, name_len);
9514 btrfs_i_size_write(inode, name_len);
9515 err = btrfs_update_inode(trans, root, inode);
9516 if (err) {
9517 drop_inode = 1;
9518 goto out_unlock_inode;
9519 }
9520
9521 unlock_new_inode(inode);
9522 d_instantiate(dentry, inode);
9523
9524 out_unlock:
9525 btrfs_end_transaction(trans, root);
9526 if (drop_inode) {
9527 inode_dec_link_count(inode);
9528 iput(inode);
9529 }
9530 btrfs_btree_balance_dirty(root);
9531 return err;
9532
9533 out_unlock_inode:
9534 drop_inode = 1;
9535 unlock_new_inode(inode);
9536 goto out_unlock;
9537 }
9538
9539 static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
9540 u64 start, u64 num_bytes, u64 min_size,
9541 loff_t actual_len, u64 *alloc_hint,
9542 struct btrfs_trans_handle *trans)
9543 {
9544 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
9545 struct extent_map *em;
9546 struct btrfs_root *root = BTRFS_I(inode)->root;
9547 struct btrfs_key ins;
9548 u64 cur_offset = start;
9549 u64 i_size;
9550 u64 cur_bytes;
9551 int ret = 0;
9552 bool own_trans = true;
9553
9554 if (trans)
9555 own_trans = false;
9556 while (num_bytes > 0) {
9557 if (own_trans) {
9558 trans = btrfs_start_transaction(root, 3);
9559 if (IS_ERR(trans)) {
9560 ret = PTR_ERR(trans);
9561 break;
9562 }
9563 }
9564
9565 cur_bytes = min(num_bytes, 256ULL * 1024 * 1024);
9566 cur_bytes = max(cur_bytes, min_size);
9567 ret = btrfs_reserve_extent(root, cur_bytes, min_size, 0,
9568 *alloc_hint, &ins, 1, 0);
9569 if (ret) {
9570 if (own_trans)
9571 btrfs_end_transaction(trans, root);
9572 break;
9573 }
9574
9575 ret = insert_reserved_file_extent(trans, inode,
9576 cur_offset, ins.objectid,
9577 ins.offset, ins.offset,
9578 ins.offset, 0, 0, 0,
9579 BTRFS_FILE_EXTENT_PREALLOC);
9580 if (ret) {
9581 btrfs_free_reserved_extent(root, ins.objectid,
9582 ins.offset, 0);
9583 btrfs_abort_transaction(trans, root, ret);
9584 if (own_trans)
9585 btrfs_end_transaction(trans, root);
9586 break;
9587 }
9588
9589 btrfs_drop_extent_cache(inode, cur_offset,
9590 cur_offset + ins.offset -1, 0);
9591
9592 em = alloc_extent_map();
9593 if (!em) {
9594 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
9595 &BTRFS_I(inode)->runtime_flags);
9596 goto next;
9597 }
9598
9599 em->start = cur_offset;
9600 em->orig_start = cur_offset;
9601 em->len = ins.offset;
9602 em->block_start = ins.objectid;
9603 em->block_len = ins.offset;
9604 em->orig_block_len = ins.offset;
9605 em->ram_bytes = ins.offset;
9606 em->bdev = root->fs_info->fs_devices->latest_bdev;
9607 set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
9608 em->generation = trans->transid;
9609
9610 while (1) {
9611 write_lock(&em_tree->lock);
9612 ret = add_extent_mapping(em_tree, em, 1);
9613 write_unlock(&em_tree->lock);
9614 if (ret != -EEXIST)
9615 break;
9616 btrfs_drop_extent_cache(inode, cur_offset,
9617 cur_offset + ins.offset - 1,
9618 0);
9619 }
9620 free_extent_map(em);
9621 next:
9622 num_bytes -= ins.offset;
9623 cur_offset += ins.offset;
9624 *alloc_hint = ins.objectid + ins.offset;
9625
9626 inode_inc_iversion(inode);
9627 inode->i_ctime = CURRENT_TIME;
9628 BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
9629 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
9630 (actual_len > inode->i_size) &&
9631 (cur_offset > inode->i_size)) {
9632 if (cur_offset > actual_len)
9633 i_size = actual_len;
9634 else
9635 i_size = cur_offset;
9636 i_size_write(inode, i_size);
9637 btrfs_ordered_update_i_size(inode, i_size, NULL);
9638 }
9639
9640 ret = btrfs_update_inode(trans, root, inode);
9641
9642 if (ret) {
9643 btrfs_abort_transaction(trans, root, ret);
9644 if (own_trans)
9645 btrfs_end_transaction(trans, root);
9646 break;
9647 }
9648
9649 if (own_trans)
9650 btrfs_end_transaction(trans, root);
9651 }
9652 return ret;
9653 }
9654
9655 int btrfs_prealloc_file_range(struct inode *inode, int mode,
9656 u64 start, u64 num_bytes, u64 min_size,
9657 loff_t actual_len, u64 *alloc_hint)
9658 {
9659 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9660 min_size, actual_len, alloc_hint,
9661 NULL);
9662 }
9663
9664 int btrfs_prealloc_file_range_trans(struct inode *inode,
9665 struct btrfs_trans_handle *trans, int mode,
9666 u64 start, u64 num_bytes, u64 min_size,
9667 loff_t actual_len, u64 *alloc_hint)
9668 {
9669 return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
9670 min_size, actual_len, alloc_hint, trans);
9671 }
9672
9673 static int btrfs_set_page_dirty(struct page *page)
9674 {
9675 return __set_page_dirty_nobuffers(page);
9676 }
9677
9678 static int btrfs_permission(struct inode *inode, int mask)
9679 {
9680 struct btrfs_root *root = BTRFS_I(inode)->root;
9681 umode_t mode = inode->i_mode;
9682
9683 if (mask & MAY_WRITE &&
9684 (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
9685 if (btrfs_root_readonly(root))
9686 return -EROFS;
9687 if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
9688 return -EACCES;
9689 }
9690 return generic_permission(inode, mask);
9691 }
9692
9693 static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
9694 {
9695 struct btrfs_trans_handle *trans;
9696 struct btrfs_root *root = BTRFS_I(dir)->root;
9697 struct inode *inode = NULL;
9698 u64 objectid;
9699 u64 index;
9700 int ret = 0;
9701
9702 /*
9703 * 5 units required for adding orphan entry
9704 */
9705 trans = btrfs_start_transaction(root, 5);
9706 if (IS_ERR(trans))
9707 return PTR_ERR(trans);
9708
9709 ret = btrfs_find_free_ino(root, &objectid);
9710 if (ret)
9711 goto out;
9712
9713 inode = btrfs_new_inode(trans, root, dir, NULL, 0,
9714 btrfs_ino(dir), objectid, mode, &index);
9715 if (IS_ERR(inode)) {
9716 ret = PTR_ERR(inode);
9717 inode = NULL;
9718 goto out;
9719 }
9720
9721 inode->i_fop = &btrfs_file_operations;
9722 inode->i_op = &btrfs_file_inode_operations;
9723
9724 inode->i_mapping->a_ops = &btrfs_aops;
9725 BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
9726
9727 ret = btrfs_init_inode_security(trans, inode, dir, NULL);
9728 if (ret)
9729 goto out_inode;
9730
9731 ret = btrfs_update_inode(trans, root, inode);
9732 if (ret)
9733 goto out_inode;
9734 ret = btrfs_orphan_add(trans, inode);
9735 if (ret)
9736 goto out_inode;
9737
9738 /*
9739 * We set number of links to 0 in btrfs_new_inode(), and here we set
9740 * it to 1 because d_tmpfile() will issue a warning if the count is 0,
9741 * through:
9742 *
9743 * d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
9744 */
9745 set_nlink(inode, 1);
9746 unlock_new_inode(inode);
9747 d_tmpfile(dentry, inode);
9748 mark_inode_dirty(inode);
9749
9750 out:
9751 btrfs_end_transaction(trans, root);
9752 if (ret)
9753 iput(inode);
9754 btrfs_balance_delayed_items(root);
9755 btrfs_btree_balance_dirty(root);
9756 return ret;
9757
9758 out_inode:
9759 unlock_new_inode(inode);
9760 goto out;
9761
9762 }
9763
9764 /* Inspired by filemap_check_errors() */
9765 int btrfs_inode_check_errors(struct inode *inode)
9766 {
9767 int ret = 0;
9768
9769 if (test_bit(AS_ENOSPC, &inode->i_mapping->flags) &&
9770 test_and_clear_bit(AS_ENOSPC, &inode->i_mapping->flags))
9771 ret = -ENOSPC;
9772 if (test_bit(AS_EIO, &inode->i_mapping->flags) &&
9773 test_and_clear_bit(AS_EIO, &inode->i_mapping->flags))
9774 ret = -EIO;
9775
9776 return ret;
9777 }
9778
9779 static const struct inode_operations btrfs_dir_inode_operations = {
9780 .getattr = btrfs_getattr,
9781 .lookup = btrfs_lookup,
9782 .create = btrfs_create,
9783 .unlink = btrfs_unlink,
9784 .link = btrfs_link,
9785 .mkdir = btrfs_mkdir,
9786 .rmdir = btrfs_rmdir,
9787 .rename2 = btrfs_rename2,
9788 .symlink = btrfs_symlink,
9789 .setattr = btrfs_setattr,
9790 .mknod = btrfs_mknod,
9791 .setxattr = btrfs_setxattr,
9792 .getxattr = btrfs_getxattr,
9793 .listxattr = btrfs_listxattr,
9794 .removexattr = btrfs_removexattr,
9795 .permission = btrfs_permission,
9796 .get_acl = btrfs_get_acl,
9797 .set_acl = btrfs_set_acl,
9798 .update_time = btrfs_update_time,
9799 .tmpfile = btrfs_tmpfile,
9800 };
9801 static const struct inode_operations btrfs_dir_ro_inode_operations = {
9802 .lookup = btrfs_lookup,
9803 .permission = btrfs_permission,
9804 .get_acl = btrfs_get_acl,
9805 .set_acl = btrfs_set_acl,
9806 .update_time = btrfs_update_time,
9807 };
9808
9809 static const struct file_operations btrfs_dir_file_operations = {
9810 .llseek = generic_file_llseek,
9811 .read = generic_read_dir,
9812 .iterate = btrfs_real_readdir,
9813 .unlocked_ioctl = btrfs_ioctl,
9814 #ifdef CONFIG_COMPAT
9815 .compat_ioctl = btrfs_ioctl,
9816 #endif
9817 .release = btrfs_release_file,
9818 .fsync = btrfs_sync_file,
9819 };
9820
9821 static struct extent_io_ops btrfs_extent_io_ops = {
9822 .fill_delalloc = run_delalloc_range,
9823 .submit_bio_hook = btrfs_submit_bio_hook,
9824 .merge_bio_hook = btrfs_merge_bio_hook,
9825 .readpage_end_io_hook = btrfs_readpage_end_io_hook,
9826 .writepage_end_io_hook = btrfs_writepage_end_io_hook,
9827 .writepage_start_hook = btrfs_writepage_start_hook,
9828 .set_bit_hook = btrfs_set_bit_hook,
9829 .clear_bit_hook = btrfs_clear_bit_hook,
9830 .merge_extent_hook = btrfs_merge_extent_hook,
9831 .split_extent_hook = btrfs_split_extent_hook,
9832 };
9833
9834 /*
9835 * btrfs doesn't support the bmap operation because swapfiles
9836 * use bmap to make a mapping of extents in the file. They assume
9837 * these extents won't change over the life of the file and they
9838 * use the bmap result to do IO directly to the drive.
9839 *
9840 * the btrfs bmap call would return logical addresses that aren't
9841 * suitable for IO and they also will change frequently as COW
9842 * operations happen. So, swapfile + btrfs == corruption.
9843 *
9844 * For now we're avoiding this by dropping bmap.
9845 */
9846 static const struct address_space_operations btrfs_aops = {
9847 .readpage = btrfs_readpage,
9848 .writepage = btrfs_writepage,
9849 .writepages = btrfs_writepages,
9850 .readpages = btrfs_readpages,
9851 .direct_IO = btrfs_direct_IO,
9852 .invalidatepage = btrfs_invalidatepage,
9853 .releasepage = btrfs_releasepage,
9854 .set_page_dirty = btrfs_set_page_dirty,
9855 .error_remove_page = generic_error_remove_page,
9856 };
9857
9858 static const struct address_space_operations btrfs_symlink_aops = {
9859 .readpage = btrfs_readpage,
9860 .writepage = btrfs_writepage,
9861 .invalidatepage = btrfs_invalidatepage,
9862 .releasepage = btrfs_releasepage,
9863 };
9864
9865 static const struct inode_operations btrfs_file_inode_operations = {
9866 .getattr = btrfs_getattr,
9867 .setattr = btrfs_setattr,
9868 .setxattr = btrfs_setxattr,
9869 .getxattr = btrfs_getxattr,
9870 .listxattr = btrfs_listxattr,
9871 .removexattr = btrfs_removexattr,
9872 .permission = btrfs_permission,
9873 .fiemap = btrfs_fiemap,
9874 .get_acl = btrfs_get_acl,
9875 .set_acl = btrfs_set_acl,
9876 .update_time = btrfs_update_time,
9877 };
9878 static const struct inode_operations btrfs_special_inode_operations = {
9879 .getattr = btrfs_getattr,
9880 .setattr = btrfs_setattr,
9881 .permission = btrfs_permission,
9882 .setxattr = btrfs_setxattr,
9883 .getxattr = btrfs_getxattr,
9884 .listxattr = btrfs_listxattr,
9885 .removexattr = btrfs_removexattr,
9886 .get_acl = btrfs_get_acl,
9887 .set_acl = btrfs_set_acl,
9888 .update_time = btrfs_update_time,
9889 };
9890 static const struct inode_operations btrfs_symlink_inode_operations = {
9891 .readlink = generic_readlink,
9892 .follow_link = page_follow_link_light,
9893 .put_link = page_put_link,
9894 .getattr = btrfs_getattr,
9895 .setattr = btrfs_setattr,
9896 .permission = btrfs_permission,
9897 .setxattr = btrfs_setxattr,
9898 .getxattr = btrfs_getxattr,
9899 .listxattr = btrfs_listxattr,
9900 .removexattr = btrfs_removexattr,
9901 .update_time = btrfs_update_time,
9902 };
9903
9904 const struct dentry_operations btrfs_dentry_operations = {
9905 .d_delete = btrfs_dentry_delete,
9906 .d_release = btrfs_dentry_release,
9907 };
Linux with added FPC-III support