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Btrfs: fix how we deal with the pages array in the write path
[deliverable/linux.git] / fs / btrfs / file.c
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/fs.h>
20 #include <linux/pagemap.h>
21 #include <linux/highmem.h>
22 #include <linux/time.h>
23 #include <linux/init.h>
24 #include <linux/string.h>
25 #include <linux/backing-dev.h>
26 #include <linux/mpage.h>
27 #include <linux/falloc.h>
28 #include <linux/swap.h>
29 #include <linux/writeback.h>
30 #include <linux/statfs.h>
31 #include <linux/compat.h>
32 #include <linux/slab.h>
33 #include "ctree.h"
34 #include "disk-io.h"
35 #include "transaction.h"
36 #include "btrfs_inode.h"
37 #include "ioctl.h"
38 #include "print-tree.h"
39 #include "tree-log.h"
40 #include "locking.h"
41 #include "compat.h"
42
43
44 /* simple helper to fault in pages and copy. This should go away
45 * and be replaced with calls into generic code.
46 */
47 static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
48 size_t write_bytes,
49 struct page **prepared_pages,
50 struct iov_iter *i)
51 {
52 size_t copied = 0;
53 size_t total_copied = 0;
54 int pg = 0;
55 int offset = pos & (PAGE_CACHE_SIZE - 1);
56
57 while (write_bytes > 0) {
58 size_t count = min_t(size_t,
59 PAGE_CACHE_SIZE - offset, write_bytes);
60 struct page *page = prepared_pages[pg];
61 /*
62 * Copy data from userspace to the current page
63 *
64 * Disable pagefault to avoid recursive lock since
65 * the pages are already locked
66 */
67 pagefault_disable();
68 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
69 pagefault_enable();
70
71 /* Flush processor's dcache for this page */
72 flush_dcache_page(page);
73
74 /*
75 * if we get a partial write, we can end up with
76 * partially up to date pages. These add
77 * a lot of complexity, so make sure they don't
78 * happen by forcing this copy to be retried.
79 *
80 * The rest of the btrfs_file_write code will fall
81 * back to page at a time copies after we return 0.
82 */
83 if (!PageUptodate(page) && copied < count)
84 copied = 0;
85
86 iov_iter_advance(i, copied);
87 write_bytes -= copied;
88 total_copied += copied;
89
90 /* Return to btrfs_file_aio_write to fault page */
91 if (unlikely(copied == 0))
92 break;
93
94 if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
95 offset += copied;
96 } else {
97 pg++;
98 offset = 0;
99 }
100 }
101 return total_copied;
102 }
103
104 /*
105 * unlocks pages after btrfs_file_write is done with them
106 */
107 static noinline void btrfs_drop_pages(struct page **pages, size_t num_pages)
108 {
109 size_t i;
110 for (i = 0; i < num_pages; i++) {
111 /* page checked is some magic around finding pages that
112 * have been modified without going through btrfs_set_page_dirty
113 * clear it here
114 */
115 ClearPageChecked(pages[i]);
116 unlock_page(pages[i]);
117 mark_page_accessed(pages[i]);
118 page_cache_release(pages[i]);
119 }
120 }
121
122 /*
123 * after copy_from_user, pages need to be dirtied and we need to make
124 * sure holes are created between the current EOF and the start of
125 * any next extents (if required).
126 *
127 * this also makes the decision about creating an inline extent vs
128 * doing real data extents, marking pages dirty and delalloc as required.
129 */
130 static noinline int dirty_and_release_pages(struct btrfs_root *root,
131 struct file *file,
132 struct page **pages,
133 size_t num_pages,
134 loff_t pos,
135 size_t write_bytes)
136 {
137 int err = 0;
138 int i;
139 struct inode *inode = fdentry(file)->d_inode;
140 u64 num_bytes;
141 u64 start_pos;
142 u64 end_of_last_block;
143 u64 end_pos = pos + write_bytes;
144 loff_t isize = i_size_read(inode);
145
146 start_pos = pos & ~((u64)root->sectorsize - 1);
147 num_bytes = (write_bytes + pos - start_pos +
148 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
149
150 end_of_last_block = start_pos + num_bytes - 1;
151 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
152 NULL);
153 if (err)
154 return err;
155
156 for (i = 0; i < num_pages; i++) {
157 struct page *p = pages[i];
158 SetPageUptodate(p);
159 ClearPageChecked(p);
160 set_page_dirty(p);
161 }
162
163 /*
164 * we've only changed i_size in ram, and we haven't updated
165 * the disk i_size. There is no need to log the inode
166 * at this time.
167 */
168 if (end_pos > isize)
169 i_size_write(inode, end_pos);
170 return 0;
171 }
172
173 /*
174 * this drops all the extents in the cache that intersect the range
175 * [start, end]. Existing extents are split as required.
176 */
177 int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
178 int skip_pinned)
179 {
180 struct extent_map *em;
181 struct extent_map *split = NULL;
182 struct extent_map *split2 = NULL;
183 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
184 u64 len = end - start + 1;
185 int ret;
186 int testend = 1;
187 unsigned long flags;
188 int compressed = 0;
189
190 WARN_ON(end < start);
191 if (end == (u64)-1) {
192 len = (u64)-1;
193 testend = 0;
194 }
195 while (1) {
196 if (!split)
197 split = alloc_extent_map(GFP_NOFS);
198 if (!split2)
199 split2 = alloc_extent_map(GFP_NOFS);
200 BUG_ON(!split || !split2);
201
202 write_lock(&em_tree->lock);
203 em = lookup_extent_mapping(em_tree, start, len);
204 if (!em) {
205 write_unlock(&em_tree->lock);
206 break;
207 }
208 flags = em->flags;
209 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
210 if (testend && em->start + em->len >= start + len) {
211 free_extent_map(em);
212 write_unlock(&em_tree->lock);
213 break;
214 }
215 start = em->start + em->len;
216 if (testend)
217 len = start + len - (em->start + em->len);
218 free_extent_map(em);
219 write_unlock(&em_tree->lock);
220 continue;
221 }
222 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
223 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
224 remove_extent_mapping(em_tree, em);
225
226 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
227 em->start < start) {
228 split->start = em->start;
229 split->len = start - em->start;
230 split->orig_start = em->orig_start;
231 split->block_start = em->block_start;
232
233 if (compressed)
234 split->block_len = em->block_len;
235 else
236 split->block_len = split->len;
237
238 split->bdev = em->bdev;
239 split->flags = flags;
240 split->compress_type = em->compress_type;
241 ret = add_extent_mapping(em_tree, split);
242 BUG_ON(ret);
243 free_extent_map(split);
244 split = split2;
245 split2 = NULL;
246 }
247 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
248 testend && em->start + em->len > start + len) {
249 u64 diff = start + len - em->start;
250
251 split->start = start + len;
252 split->len = em->start + em->len - (start + len);
253 split->bdev = em->bdev;
254 split->flags = flags;
255 split->compress_type = em->compress_type;
256
257 if (compressed) {
258 split->block_len = em->block_len;
259 split->block_start = em->block_start;
260 split->orig_start = em->orig_start;
261 } else {
262 split->block_len = split->len;
263 split->block_start = em->block_start + diff;
264 split->orig_start = split->start;
265 }
266
267 ret = add_extent_mapping(em_tree, split);
268 BUG_ON(ret);
269 free_extent_map(split);
270 split = NULL;
271 }
272 write_unlock(&em_tree->lock);
273
274 /* once for us */
275 free_extent_map(em);
276 /* once for the tree*/
277 free_extent_map(em);
278 }
279 if (split)
280 free_extent_map(split);
281 if (split2)
282 free_extent_map(split2);
283 return 0;
284 }
285
286 /*
287 * this is very complex, but the basic idea is to drop all extents
288 * in the range start - end. hint_block is filled in with a block number
289 * that would be a good hint to the block allocator for this file.
290 *
291 * If an extent intersects the range but is not entirely inside the range
292 * it is either truncated or split. Anything entirely inside the range
293 * is deleted from the tree.
294 */
295 int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode,
296 u64 start, u64 end, u64 *hint_byte, int drop_cache)
297 {
298 struct btrfs_root *root = BTRFS_I(inode)->root;
299 struct extent_buffer *leaf;
300 struct btrfs_file_extent_item *fi;
301 struct btrfs_path *path;
302 struct btrfs_key key;
303 struct btrfs_key new_key;
304 u64 search_start = start;
305 u64 disk_bytenr = 0;
306 u64 num_bytes = 0;
307 u64 extent_offset = 0;
308 u64 extent_end = 0;
309 int del_nr = 0;
310 int del_slot = 0;
311 int extent_type;
312 int recow;
313 int ret;
314
315 if (drop_cache)
316 btrfs_drop_extent_cache(inode, start, end - 1, 0);
317
318 path = btrfs_alloc_path();
319 if (!path)
320 return -ENOMEM;
321
322 while (1) {
323 recow = 0;
324 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
325 search_start, -1);
326 if (ret < 0)
327 break;
328 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
329 leaf = path->nodes[0];
330 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
331 if (key.objectid == inode->i_ino &&
332 key.type == BTRFS_EXTENT_DATA_KEY)
333 path->slots[0]--;
334 }
335 ret = 0;
336 next_slot:
337 leaf = path->nodes[0];
338 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
339 BUG_ON(del_nr > 0);
340 ret = btrfs_next_leaf(root, path);
341 if (ret < 0)
342 break;
343 if (ret > 0) {
344 ret = 0;
345 break;
346 }
347 leaf = path->nodes[0];
348 recow = 1;
349 }
350
351 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
352 if (key.objectid > inode->i_ino ||
353 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
354 break;
355
356 fi = btrfs_item_ptr(leaf, path->slots[0],
357 struct btrfs_file_extent_item);
358 extent_type = btrfs_file_extent_type(leaf, fi);
359
360 if (extent_type == BTRFS_FILE_EXTENT_REG ||
361 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
362 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
363 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
364 extent_offset = btrfs_file_extent_offset(leaf, fi);
365 extent_end = key.offset +
366 btrfs_file_extent_num_bytes(leaf, fi);
367 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
368 extent_end = key.offset +
369 btrfs_file_extent_inline_len(leaf, fi);
370 } else {
371 WARN_ON(1);
372 extent_end = search_start;
373 }
374
375 if (extent_end <= search_start) {
376 path->slots[0]++;
377 goto next_slot;
378 }
379
380 search_start = max(key.offset, start);
381 if (recow) {
382 btrfs_release_path(root, path);
383 continue;
384 }
385
386 /*
387 * | - range to drop - |
388 * | -------- extent -------- |
389 */
390 if (start > key.offset && end < extent_end) {
391 BUG_ON(del_nr > 0);
392 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
393
394 memcpy(&new_key, &key, sizeof(new_key));
395 new_key.offset = start;
396 ret = btrfs_duplicate_item(trans, root, path,
397 &new_key);
398 if (ret == -EAGAIN) {
399 btrfs_release_path(root, path);
400 continue;
401 }
402 if (ret < 0)
403 break;
404
405 leaf = path->nodes[0];
406 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
407 struct btrfs_file_extent_item);
408 btrfs_set_file_extent_num_bytes(leaf, fi,
409 start - key.offset);
410
411 fi = btrfs_item_ptr(leaf, path->slots[0],
412 struct btrfs_file_extent_item);
413
414 extent_offset += start - key.offset;
415 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
416 btrfs_set_file_extent_num_bytes(leaf, fi,
417 extent_end - start);
418 btrfs_mark_buffer_dirty(leaf);
419
420 if (disk_bytenr > 0) {
421 ret = btrfs_inc_extent_ref(trans, root,
422 disk_bytenr, num_bytes, 0,
423 root->root_key.objectid,
424 new_key.objectid,
425 start - extent_offset);
426 BUG_ON(ret);
427 *hint_byte = disk_bytenr;
428 }
429 key.offset = start;
430 }
431 /*
432 * | ---- range to drop ----- |
433 * | -------- extent -------- |
434 */
435 if (start <= key.offset && end < extent_end) {
436 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
437
438 memcpy(&new_key, &key, sizeof(new_key));
439 new_key.offset = end;
440 btrfs_set_item_key_safe(trans, root, path, &new_key);
441
442 extent_offset += end - key.offset;
443 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
444 btrfs_set_file_extent_num_bytes(leaf, fi,
445 extent_end - end);
446 btrfs_mark_buffer_dirty(leaf);
447 if (disk_bytenr > 0) {
448 inode_sub_bytes(inode, end - key.offset);
449 *hint_byte = disk_bytenr;
450 }
451 break;
452 }
453
454 search_start = extent_end;
455 /*
456 * | ---- range to drop ----- |
457 * | -------- extent -------- |
458 */
459 if (start > key.offset && end >= extent_end) {
460 BUG_ON(del_nr > 0);
461 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
462
463 btrfs_set_file_extent_num_bytes(leaf, fi,
464 start - key.offset);
465 btrfs_mark_buffer_dirty(leaf);
466 if (disk_bytenr > 0) {
467 inode_sub_bytes(inode, extent_end - start);
468 *hint_byte = disk_bytenr;
469 }
470 if (end == extent_end)
471 break;
472
473 path->slots[0]++;
474 goto next_slot;
475 }
476
477 /*
478 * | ---- range to drop ----- |
479 * | ------ extent ------ |
480 */
481 if (start <= key.offset && end >= extent_end) {
482 if (del_nr == 0) {
483 del_slot = path->slots[0];
484 del_nr = 1;
485 } else {
486 BUG_ON(del_slot + del_nr != path->slots[0]);
487 del_nr++;
488 }
489
490 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
491 inode_sub_bytes(inode,
492 extent_end - key.offset);
493 extent_end = ALIGN(extent_end,
494 root->sectorsize);
495 } else if (disk_bytenr > 0) {
496 ret = btrfs_free_extent(trans, root,
497 disk_bytenr, num_bytes, 0,
498 root->root_key.objectid,
499 key.objectid, key.offset -
500 extent_offset);
501 BUG_ON(ret);
502 inode_sub_bytes(inode,
503 extent_end - key.offset);
504 *hint_byte = disk_bytenr;
505 }
506
507 if (end == extent_end)
508 break;
509
510 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
511 path->slots[0]++;
512 goto next_slot;
513 }
514
515 ret = btrfs_del_items(trans, root, path, del_slot,
516 del_nr);
517 BUG_ON(ret);
518
519 del_nr = 0;
520 del_slot = 0;
521
522 btrfs_release_path(root, path);
523 continue;
524 }
525
526 BUG_ON(1);
527 }
528
529 if (del_nr > 0) {
530 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
531 BUG_ON(ret);
532 }
533
534 btrfs_free_path(path);
535 return ret;
536 }
537
538 static int extent_mergeable(struct extent_buffer *leaf, int slot,
539 u64 objectid, u64 bytenr, u64 orig_offset,
540 u64 *start, u64 *end)
541 {
542 struct btrfs_file_extent_item *fi;
543 struct btrfs_key key;
544 u64 extent_end;
545
546 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
547 return 0;
548
549 btrfs_item_key_to_cpu(leaf, &key, slot);
550 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
551 return 0;
552
553 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
554 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
555 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
556 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
557 btrfs_file_extent_compression(leaf, fi) ||
558 btrfs_file_extent_encryption(leaf, fi) ||
559 btrfs_file_extent_other_encoding(leaf, fi))
560 return 0;
561
562 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
563 if ((*start && *start != key.offset) || (*end && *end != extent_end))
564 return 0;
565
566 *start = key.offset;
567 *end = extent_end;
568 return 1;
569 }
570
571 /*
572 * Mark extent in the range start - end as written.
573 *
574 * This changes extent type from 'pre-allocated' to 'regular'. If only
575 * part of extent is marked as written, the extent will be split into
576 * two or three.
577 */
578 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
579 struct inode *inode, u64 start, u64 end)
580 {
581 struct btrfs_root *root = BTRFS_I(inode)->root;
582 struct extent_buffer *leaf;
583 struct btrfs_path *path;
584 struct btrfs_file_extent_item *fi;
585 struct btrfs_key key;
586 struct btrfs_key new_key;
587 u64 bytenr;
588 u64 num_bytes;
589 u64 extent_end;
590 u64 orig_offset;
591 u64 other_start;
592 u64 other_end;
593 u64 split;
594 int del_nr = 0;
595 int del_slot = 0;
596 int recow;
597 int ret;
598
599 btrfs_drop_extent_cache(inode, start, end - 1, 0);
600
601 path = btrfs_alloc_path();
602 BUG_ON(!path);
603 again:
604 recow = 0;
605 split = start;
606 key.objectid = inode->i_ino;
607 key.type = BTRFS_EXTENT_DATA_KEY;
608 key.offset = split;
609
610 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
611 if (ret > 0 && path->slots[0] > 0)
612 path->slots[0]--;
613
614 leaf = path->nodes[0];
615 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
616 BUG_ON(key.objectid != inode->i_ino ||
617 key.type != BTRFS_EXTENT_DATA_KEY);
618 fi = btrfs_item_ptr(leaf, path->slots[0],
619 struct btrfs_file_extent_item);
620 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
621 BTRFS_FILE_EXTENT_PREALLOC);
622 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
623 BUG_ON(key.offset > start || extent_end < end);
624
625 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
626 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
627 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
628 memcpy(&new_key, &key, sizeof(new_key));
629
630 if (start == key.offset && end < extent_end) {
631 other_start = 0;
632 other_end = start;
633 if (extent_mergeable(leaf, path->slots[0] - 1,
634 inode->i_ino, bytenr, orig_offset,
635 &other_start, &other_end)) {
636 new_key.offset = end;
637 btrfs_set_item_key_safe(trans, root, path, &new_key);
638 fi = btrfs_item_ptr(leaf, path->slots[0],
639 struct btrfs_file_extent_item);
640 btrfs_set_file_extent_num_bytes(leaf, fi,
641 extent_end - end);
642 btrfs_set_file_extent_offset(leaf, fi,
643 end - orig_offset);
644 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
645 struct btrfs_file_extent_item);
646 btrfs_set_file_extent_num_bytes(leaf, fi,
647 end - other_start);
648 btrfs_mark_buffer_dirty(leaf);
649 goto out;
650 }
651 }
652
653 if (start > key.offset && end == extent_end) {
654 other_start = end;
655 other_end = 0;
656 if (extent_mergeable(leaf, path->slots[0] + 1,
657 inode->i_ino, bytenr, orig_offset,
658 &other_start, &other_end)) {
659 fi = btrfs_item_ptr(leaf, path->slots[0],
660 struct btrfs_file_extent_item);
661 btrfs_set_file_extent_num_bytes(leaf, fi,
662 start - key.offset);
663 path->slots[0]++;
664 new_key.offset = start;
665 btrfs_set_item_key_safe(trans, root, path, &new_key);
666
667 fi = btrfs_item_ptr(leaf, path->slots[0],
668 struct btrfs_file_extent_item);
669 btrfs_set_file_extent_num_bytes(leaf, fi,
670 other_end - start);
671 btrfs_set_file_extent_offset(leaf, fi,
672 start - orig_offset);
673 btrfs_mark_buffer_dirty(leaf);
674 goto out;
675 }
676 }
677
678 while (start > key.offset || end < extent_end) {
679 if (key.offset == start)
680 split = end;
681
682 new_key.offset = split;
683 ret = btrfs_duplicate_item(trans, root, path, &new_key);
684 if (ret == -EAGAIN) {
685 btrfs_release_path(root, path);
686 goto again;
687 }
688 BUG_ON(ret < 0);
689
690 leaf = path->nodes[0];
691 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
692 struct btrfs_file_extent_item);
693 btrfs_set_file_extent_num_bytes(leaf, fi,
694 split - key.offset);
695
696 fi = btrfs_item_ptr(leaf, path->slots[0],
697 struct btrfs_file_extent_item);
698
699 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
700 btrfs_set_file_extent_num_bytes(leaf, fi,
701 extent_end - split);
702 btrfs_mark_buffer_dirty(leaf);
703
704 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
705 root->root_key.objectid,
706 inode->i_ino, orig_offset);
707 BUG_ON(ret);
708
709 if (split == start) {
710 key.offset = start;
711 } else {
712 BUG_ON(start != key.offset);
713 path->slots[0]--;
714 extent_end = end;
715 }
716 recow = 1;
717 }
718
719 other_start = end;
720 other_end = 0;
721 if (extent_mergeable(leaf, path->slots[0] + 1,
722 inode->i_ino, bytenr, orig_offset,
723 &other_start, &other_end)) {
724 if (recow) {
725 btrfs_release_path(root, path);
726 goto again;
727 }
728 extent_end = other_end;
729 del_slot = path->slots[0] + 1;
730 del_nr++;
731 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
732 0, root->root_key.objectid,
733 inode->i_ino, orig_offset);
734 BUG_ON(ret);
735 }
736 other_start = 0;
737 other_end = start;
738 if (extent_mergeable(leaf, path->slots[0] - 1,
739 inode->i_ino, bytenr, orig_offset,
740 &other_start, &other_end)) {
741 if (recow) {
742 btrfs_release_path(root, path);
743 goto again;
744 }
745 key.offset = other_start;
746 del_slot = path->slots[0];
747 del_nr++;
748 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
749 0, root->root_key.objectid,
750 inode->i_ino, orig_offset);
751 BUG_ON(ret);
752 }
753 if (del_nr == 0) {
754 fi = btrfs_item_ptr(leaf, path->slots[0],
755 struct btrfs_file_extent_item);
756 btrfs_set_file_extent_type(leaf, fi,
757 BTRFS_FILE_EXTENT_REG);
758 btrfs_mark_buffer_dirty(leaf);
759 } else {
760 fi = btrfs_item_ptr(leaf, del_slot - 1,
761 struct btrfs_file_extent_item);
762 btrfs_set_file_extent_type(leaf, fi,
763 BTRFS_FILE_EXTENT_REG);
764 btrfs_set_file_extent_num_bytes(leaf, fi,
765 extent_end - key.offset);
766 btrfs_mark_buffer_dirty(leaf);
767
768 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
769 BUG_ON(ret);
770 }
771 out:
772 btrfs_free_path(path);
773 return 0;
774 }
775
776 /*
777 * on error we return an unlocked page and the error value
778 * on success we return a locked page and 0
779 */
780 static int prepare_uptodate_page(struct page *page, u64 pos)
781 {
782 int ret = 0;
783
784 if ((pos & (PAGE_CACHE_SIZE - 1)) && !PageUptodate(page)) {
785 ret = btrfs_readpage(NULL, page);
786 if (ret)
787 return ret;
788 lock_page(page);
789 if (!PageUptodate(page)) {
790 unlock_page(page);
791 return -EIO;
792 }
793 }
794 return 0;
795 }
796
797 /*
798 * this gets pages into the page cache and locks them down, it also properly
799 * waits for data=ordered extents to finish before allowing the pages to be
800 * modified.
801 */
802 static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
803 struct page **pages, size_t num_pages,
804 loff_t pos, unsigned long first_index,
805 unsigned long last_index, size_t write_bytes)
806 {
807 struct extent_state *cached_state = NULL;
808 int i;
809 unsigned long index = pos >> PAGE_CACHE_SHIFT;
810 struct inode *inode = fdentry(file)->d_inode;
811 int err = 0;
812 int faili = 0;
813 u64 start_pos;
814 u64 last_pos;
815
816 start_pos = pos & ~((u64)root->sectorsize - 1);
817 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
818
819 if (start_pos > inode->i_size) {
820 err = btrfs_cont_expand(inode, start_pos);
821 if (err)
822 return err;
823 }
824
825 again:
826 for (i = 0; i < num_pages; i++) {
827 pages[i] = grab_cache_page(inode->i_mapping, index + i);
828 if (!pages[i]) {
829 faili = i - 1;
830 err = -ENOMEM;
831 goto fail;
832 }
833
834 if (i == 0)
835 err = prepare_uptodate_page(pages[i], pos);
836 if (i == num_pages - 1)
837 err = prepare_uptodate_page(pages[i],
838 pos + write_bytes);
839 if (err) {
840 page_cache_release(pages[i]);
841 faili = i - 1;
842 goto fail;
843 }
844 wait_on_page_writeback(pages[i]);
845 }
846 err = 0;
847 if (start_pos < inode->i_size) {
848 struct btrfs_ordered_extent *ordered;
849 lock_extent_bits(&BTRFS_I(inode)->io_tree,
850 start_pos, last_pos - 1, 0, &cached_state,
851 GFP_NOFS);
852 ordered = btrfs_lookup_first_ordered_extent(inode,
853 last_pos - 1);
854 if (ordered &&
855 ordered->file_offset + ordered->len > start_pos &&
856 ordered->file_offset < last_pos) {
857 btrfs_put_ordered_extent(ordered);
858 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
859 start_pos, last_pos - 1,
860 &cached_state, GFP_NOFS);
861 for (i = 0; i < num_pages; i++) {
862 unlock_page(pages[i]);
863 page_cache_release(pages[i]);
864 }
865 btrfs_wait_ordered_range(inode, start_pos,
866 last_pos - start_pos);
867 goto again;
868 }
869 if (ordered)
870 btrfs_put_ordered_extent(ordered);
871
872 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
873 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
874 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
875 GFP_NOFS);
876 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
877 start_pos, last_pos - 1, &cached_state,
878 GFP_NOFS);
879 }
880 for (i = 0; i < num_pages; i++) {
881 clear_page_dirty_for_io(pages[i]);
882 set_page_extent_mapped(pages[i]);
883 WARN_ON(!PageLocked(pages[i]));
884 }
885 return 0;
886 fail:
887 while (faili >= 0) {
888 unlock_page(pages[faili]);
889 page_cache_release(pages[faili]);
890 faili--;
891 }
892 return err;
893
894 }
895
896 static noinline ssize_t __btrfs_buffered_write(struct file *file,
897 struct iov_iter *i,
898 loff_t pos)
899 {
900 struct inode *inode = fdentry(file)->d_inode;
901 struct btrfs_root *root = BTRFS_I(inode)->root;
902 struct page **pages = NULL;
903 unsigned long first_index;
904 unsigned long last_index;
905 size_t num_written = 0;
906 int nrptrs;
907 int ret;
908
909 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
910 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
911 (sizeof(struct page *)));
912 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
913 if (!pages)
914 return -ENOMEM;
915
916 first_index = pos >> PAGE_CACHE_SHIFT;
917 last_index = (pos + iov_iter_count(i)) >> PAGE_CACHE_SHIFT;
918
919 while (iov_iter_count(i) > 0) {
920 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
921 size_t write_bytes = min(iov_iter_count(i),
922 nrptrs * (size_t)PAGE_CACHE_SIZE -
923 offset);
924 size_t num_pages = (write_bytes + offset +
925 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
926 size_t dirty_pages;
927 size_t copied;
928
929 WARN_ON(num_pages > nrptrs);
930
931 /*
932 * Fault pages before locking them in prepare_pages
933 * to avoid recursive lock
934 */
935 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
936 ret = -EFAULT;
937 break;
938 }
939
940 ret = btrfs_delalloc_reserve_space(inode,
941 num_pages << PAGE_CACHE_SHIFT);
942 if (ret)
943 break;
944
945 /*
946 * This is going to setup the pages array with the number of
947 * pages we want, so we don't really need to worry about the
948 * contents of pages from loop to loop
949 */
950 ret = prepare_pages(root, file, pages, num_pages,
951 pos, first_index, last_index,
952 write_bytes);
953 if (ret) {
954 btrfs_delalloc_release_space(inode,
955 num_pages << PAGE_CACHE_SHIFT);
956 break;
957 }
958
959 copied = btrfs_copy_from_user(pos, num_pages,
960 write_bytes, pages, i);
961
962 /*
963 * if we have trouble faulting in the pages, fall
964 * back to one page at a time
965 */
966 if (copied < write_bytes)
967 nrptrs = 1;
968
969 if (copied == 0)
970 dirty_pages = 0;
971 else
972 dirty_pages = (copied + offset +
973 PAGE_CACHE_SIZE - 1) >>
974 PAGE_CACHE_SHIFT;
975
976 /*
977 * If we had a short copy we need to release the excess delaloc
978 * bytes we reserved. We need to increment outstanding_extents
979 * because btrfs_delalloc_release_space will decrement it, but
980 * we still have an outstanding extent for the chunk we actually
981 * managed to copy.
982 */
983 if (num_pages > dirty_pages) {
984 if (copied > 0)
985 atomic_inc(
986 &BTRFS_I(inode)->outstanding_extents);
987 btrfs_delalloc_release_space(inode,
988 (num_pages - dirty_pages) <<
989 PAGE_CACHE_SHIFT);
990 }
991
992 if (copied > 0) {
993 ret = dirty_and_release_pages(root, file, pages,
994 dirty_pages, pos,
995 copied);
996 if (ret) {
997 btrfs_delalloc_release_space(inode,
998 dirty_pages << PAGE_CACHE_SHIFT);
999 btrfs_drop_pages(pages, num_pages);
1000 break;
1001 }
1002 }
1003
1004 btrfs_drop_pages(pages, num_pages);
1005
1006 cond_resched();
1007
1008 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
1009 dirty_pages);
1010 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1011 btrfs_btree_balance_dirty(root, 1);
1012 btrfs_throttle(root);
1013
1014 pos += copied;
1015 num_written += copied;
1016 }
1017
1018 kfree(pages);
1019
1020 return num_written ? num_written : ret;
1021 }
1022
1023 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1024 const struct iovec *iov,
1025 unsigned long nr_segs, loff_t pos,
1026 loff_t *ppos, size_t count, size_t ocount)
1027 {
1028 struct file *file = iocb->ki_filp;
1029 struct inode *inode = fdentry(file)->d_inode;
1030 struct iov_iter i;
1031 ssize_t written;
1032 ssize_t written_buffered;
1033 loff_t endbyte;
1034 int err;
1035
1036 written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
1037 count, ocount);
1038
1039 /*
1040 * the generic O_DIRECT will update in-memory i_size after the
1041 * DIOs are done. But our endio handlers that update the on
1042 * disk i_size never update past the in memory i_size. So we
1043 * need one more update here to catch any additions to the
1044 * file
1045 */
1046 if (inode->i_size != BTRFS_I(inode)->disk_i_size) {
1047 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
1048 mark_inode_dirty(inode);
1049 }
1050
1051 if (written < 0 || written == count)
1052 return written;
1053
1054 pos += written;
1055 count -= written;
1056 iov_iter_init(&i, iov, nr_segs, count, written);
1057 written_buffered = __btrfs_buffered_write(file, &i, pos);
1058 if (written_buffered < 0) {
1059 err = written_buffered;
1060 goto out;
1061 }
1062 endbyte = pos + written_buffered - 1;
1063 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1064 if (err)
1065 goto out;
1066 written += written_buffered;
1067 *ppos = pos + written_buffered;
1068 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1069 endbyte >> PAGE_CACHE_SHIFT);
1070 out:
1071 return written ? written : err;
1072 }
1073
1074 static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
1075 const struct iovec *iov,
1076 unsigned long nr_segs, loff_t pos)
1077 {
1078 struct file *file = iocb->ki_filp;
1079 struct inode *inode = fdentry(file)->d_inode;
1080 struct btrfs_root *root = BTRFS_I(inode)->root;
1081 loff_t *ppos = &iocb->ki_pos;
1082 ssize_t num_written = 0;
1083 ssize_t err = 0;
1084 size_t count, ocount;
1085
1086 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1087
1088 mutex_lock(&inode->i_mutex);
1089
1090 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1091 if (err) {
1092 mutex_unlock(&inode->i_mutex);
1093 goto out;
1094 }
1095 count = ocount;
1096
1097 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1098 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1099 if (err) {
1100 mutex_unlock(&inode->i_mutex);
1101 goto out;
1102 }
1103
1104 if (count == 0) {
1105 mutex_unlock(&inode->i_mutex);
1106 goto out;
1107 }
1108
1109 err = file_remove_suid(file);
1110 if (err) {
1111 mutex_unlock(&inode->i_mutex);
1112 goto out;
1113 }
1114
1115 /*
1116 * If BTRFS flips readonly due to some impossible error
1117 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1118 * although we have opened a file as writable, we have
1119 * to stop this write operation to ensure FS consistency.
1120 */
1121 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
1122 mutex_unlock(&inode->i_mutex);
1123 err = -EROFS;
1124 goto out;
1125 }
1126
1127 file_update_time(file);
1128 BTRFS_I(inode)->sequence++;
1129
1130 if (unlikely(file->f_flags & O_DIRECT)) {
1131 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
1132 pos, ppos, count, ocount);
1133 } else {
1134 struct iov_iter i;
1135
1136 iov_iter_init(&i, iov, nr_segs, count, num_written);
1137
1138 num_written = __btrfs_buffered_write(file, &i, pos);
1139 if (num_written > 0)
1140 *ppos = pos + num_written;
1141 }
1142
1143 mutex_unlock(&inode->i_mutex);
1144
1145 /*
1146 * we want to make sure fsync finds this change
1147 * but we haven't joined a transaction running right now.
1148 *
1149 * Later on, someone is sure to update the inode and get the
1150 * real transid recorded.
1151 *
1152 * We set last_trans now to the fs_info generation + 1,
1153 * this will either be one more than the running transaction
1154 * or the generation used for the next transaction if there isn't
1155 * one running right now.
1156 */
1157 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1158 if (num_written > 0 || num_written == -EIOCBQUEUED) {
1159 err = generic_write_sync(file, pos, num_written);
1160 if (err < 0 && num_written > 0)
1161 num_written = err;
1162 }
1163 out:
1164 current->backing_dev_info = NULL;
1165 return num_written ? num_written : err;
1166 }
1167
1168 int btrfs_release_file(struct inode *inode, struct file *filp)
1169 {
1170 /*
1171 * ordered_data_close is set by settattr when we are about to truncate
1172 * a file from a non-zero size to a zero size. This tries to
1173 * flush down new bytes that may have been written if the
1174 * application were using truncate to replace a file in place.
1175 */
1176 if (BTRFS_I(inode)->ordered_data_close) {
1177 BTRFS_I(inode)->ordered_data_close = 0;
1178 btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
1179 if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
1180 filemap_flush(inode->i_mapping);
1181 }
1182 if (filp->private_data)
1183 btrfs_ioctl_trans_end(filp);
1184 return 0;
1185 }
1186
1187 /*
1188 * fsync call for both files and directories. This logs the inode into
1189 * the tree log instead of forcing full commits whenever possible.
1190 *
1191 * It needs to call filemap_fdatawait so that all ordered extent updates are
1192 * in the metadata btree are up to date for copying to the log.
1193 *
1194 * It drops the inode mutex before doing the tree log commit. This is an
1195 * important optimization for directories because holding the mutex prevents
1196 * new operations on the dir while we write to disk.
1197 */
1198 int btrfs_sync_file(struct file *file, int datasync)
1199 {
1200 struct dentry *dentry = file->f_path.dentry;
1201 struct inode *inode = dentry->d_inode;
1202 struct btrfs_root *root = BTRFS_I(inode)->root;
1203 int ret = 0;
1204 struct btrfs_trans_handle *trans;
1205
1206
1207 /* we wait first, since the writeback may change the inode */
1208 root->log_batch++;
1209 /* the VFS called filemap_fdatawrite for us */
1210 btrfs_wait_ordered_range(inode, 0, (u64)-1);
1211 root->log_batch++;
1212
1213 /*
1214 * check the transaction that last modified this inode
1215 * and see if its already been committed
1216 */
1217 if (!BTRFS_I(inode)->last_trans)
1218 goto out;
1219
1220 /*
1221 * if the last transaction that changed this file was before
1222 * the current transaction, we can bail out now without any
1223 * syncing
1224 */
1225 mutex_lock(&root->fs_info->trans_mutex);
1226 if (BTRFS_I(inode)->last_trans <=
1227 root->fs_info->last_trans_committed) {
1228 BTRFS_I(inode)->last_trans = 0;
1229 mutex_unlock(&root->fs_info->trans_mutex);
1230 goto out;
1231 }
1232 mutex_unlock(&root->fs_info->trans_mutex);
1233
1234 /*
1235 * ok we haven't committed the transaction yet, lets do a commit
1236 */
1237 if (file->private_data)
1238 btrfs_ioctl_trans_end(file);
1239
1240 trans = btrfs_start_transaction(root, 0);
1241 if (IS_ERR(trans)) {
1242 ret = PTR_ERR(trans);
1243 goto out;
1244 }
1245
1246 ret = btrfs_log_dentry_safe(trans, root, dentry);
1247 if (ret < 0)
1248 goto out;
1249
1250 /* we've logged all the items and now have a consistent
1251 * version of the file in the log. It is possible that
1252 * someone will come in and modify the file, but that's
1253 * fine because the log is consistent on disk, and we
1254 * have references to all of the file's extents
1255 *
1256 * It is possible that someone will come in and log the
1257 * file again, but that will end up using the synchronization
1258 * inside btrfs_sync_log to keep things safe.
1259 */
1260 mutex_unlock(&dentry->d_inode->i_mutex);
1261
1262 if (ret != BTRFS_NO_LOG_SYNC) {
1263 if (ret > 0) {
1264 ret = btrfs_commit_transaction(trans, root);
1265 } else {
1266 ret = btrfs_sync_log(trans, root);
1267 if (ret == 0)
1268 ret = btrfs_end_transaction(trans, root);
1269 else
1270 ret = btrfs_commit_transaction(trans, root);
1271 }
1272 } else {
1273 ret = btrfs_end_transaction(trans, root);
1274 }
1275 mutex_lock(&dentry->d_inode->i_mutex);
1276 out:
1277 return ret > 0 ? -EIO : ret;
1278 }
1279
1280 static const struct vm_operations_struct btrfs_file_vm_ops = {
1281 .fault = filemap_fault,
1282 .page_mkwrite = btrfs_page_mkwrite,
1283 };
1284
1285 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1286 {
1287 struct address_space *mapping = filp->f_mapping;
1288
1289 if (!mapping->a_ops->readpage)
1290 return -ENOEXEC;
1291
1292 file_accessed(filp);
1293 vma->vm_ops = &btrfs_file_vm_ops;
1294 vma->vm_flags |= VM_CAN_NONLINEAR;
1295
1296 return 0;
1297 }
1298
1299 static long btrfs_fallocate(struct file *file, int mode,
1300 loff_t offset, loff_t len)
1301 {
1302 struct inode *inode = file->f_path.dentry->d_inode;
1303 struct extent_state *cached_state = NULL;
1304 u64 cur_offset;
1305 u64 last_byte;
1306 u64 alloc_start;
1307 u64 alloc_end;
1308 u64 alloc_hint = 0;
1309 u64 locked_end;
1310 u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
1311 struct extent_map *em;
1312 int ret;
1313
1314 alloc_start = offset & ~mask;
1315 alloc_end = (offset + len + mask) & ~mask;
1316
1317 /* We only support the FALLOC_FL_KEEP_SIZE mode */
1318 if (mode & ~FALLOC_FL_KEEP_SIZE)
1319 return -EOPNOTSUPP;
1320
1321 /*
1322 * wait for ordered IO before we have any locks. We'll loop again
1323 * below with the locks held.
1324 */
1325 btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);
1326
1327 mutex_lock(&inode->i_mutex);
1328 ret = inode_newsize_ok(inode, alloc_end);
1329 if (ret)
1330 goto out;
1331
1332 if (alloc_start > inode->i_size) {
1333 ret = btrfs_cont_expand(inode, alloc_start);
1334 if (ret)
1335 goto out;
1336 }
1337
1338 ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
1339 if (ret)
1340 goto out;
1341
1342 locked_end = alloc_end - 1;
1343 while (1) {
1344 struct btrfs_ordered_extent *ordered;
1345
1346 /* the extent lock is ordered inside the running
1347 * transaction
1348 */
1349 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
1350 locked_end, 0, &cached_state, GFP_NOFS);
1351 ordered = btrfs_lookup_first_ordered_extent(inode,
1352 alloc_end - 1);
1353 if (ordered &&
1354 ordered->file_offset + ordered->len > alloc_start &&
1355 ordered->file_offset < alloc_end) {
1356 btrfs_put_ordered_extent(ordered);
1357 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1358 alloc_start, locked_end,
1359 &cached_state, GFP_NOFS);
1360 /*
1361 * we can't wait on the range with the transaction
1362 * running or with the extent lock held
1363 */
1364 btrfs_wait_ordered_range(inode, alloc_start,
1365 alloc_end - alloc_start);
1366 } else {
1367 if (ordered)
1368 btrfs_put_ordered_extent(ordered);
1369 break;
1370 }
1371 }
1372
1373 cur_offset = alloc_start;
1374 while (1) {
1375 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
1376 alloc_end - cur_offset, 0);
1377 BUG_ON(IS_ERR(em) || !em);
1378 last_byte = min(extent_map_end(em), alloc_end);
1379 last_byte = (last_byte + mask) & ~mask;
1380 if (em->block_start == EXTENT_MAP_HOLE ||
1381 (cur_offset >= inode->i_size &&
1382 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
1383 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
1384 last_byte - cur_offset,
1385 1 << inode->i_blkbits,
1386 offset + len,
1387 &alloc_hint);
1388 if (ret < 0) {
1389 free_extent_map(em);
1390 break;
1391 }
1392 }
1393 free_extent_map(em);
1394
1395 cur_offset = last_byte;
1396 if (cur_offset >= alloc_end) {
1397 ret = 0;
1398 break;
1399 }
1400 }
1401 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
1402 &cached_state, GFP_NOFS);
1403
1404 btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
1405 out:
1406 mutex_unlock(&inode->i_mutex);
1407 return ret;
1408 }
1409
1410 const struct file_operations btrfs_file_operations = {
1411 .llseek = generic_file_llseek,
1412 .read = do_sync_read,
1413 .write = do_sync_write,
1414 .aio_read = generic_file_aio_read,
1415 .splice_read = generic_file_splice_read,
1416 .aio_write = btrfs_file_aio_write,
1417 .mmap = btrfs_file_mmap,
1418 .open = generic_file_open,
1419 .release = btrfs_release_file,
1420 .fsync = btrfs_sync_file,
1421 .fallocate = btrfs_fallocate,
1422 .unlocked_ioctl = btrfs_ioctl,
1423 #ifdef CONFIG_COMPAT
1424 .compat_ioctl = btrfs_ioctl,
1425 #endif
1426 };
Linux kernel - Deliverables
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