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xen: cleancache shim to Xen Transcendent Memory
[linux-2.6/next.git] / fs / btrfs / file.c
blobe621ea54a3fd64bcf3dae29e4f96e887b6eff95c
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)
612 goto out;
613 if (ret > 0 && path->slots[0] > 0)
614 path->slots[0]--;
615
616 leaf = path->nodes[0];
617 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
618 BUG_ON(key.objectid != inode->i_ino ||
619 key.type != BTRFS_EXTENT_DATA_KEY);
620 fi = btrfs_item_ptr(leaf, path->slots[0],
621 struct btrfs_file_extent_item);
622 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
623 BTRFS_FILE_EXTENT_PREALLOC);
624 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
625 BUG_ON(key.offset > start || extent_end < end);
626
627 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
628 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
629 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
630 memcpy(&new_key, &key, sizeof(new_key));
631
632 if (start == key.offset && end < extent_end) {
633 other_start = 0;
634 other_end = start;
635 if (extent_mergeable(leaf, path->slots[0] - 1,
636 inode->i_ino, bytenr, orig_offset,
637 &other_start, &other_end)) {
638 new_key.offset = end;
639 btrfs_set_item_key_safe(trans, root, path, &new_key);
640 fi = btrfs_item_ptr(leaf, path->slots[0],
641 struct btrfs_file_extent_item);
642 btrfs_set_file_extent_num_bytes(leaf, fi,
643 extent_end - end);
644 btrfs_set_file_extent_offset(leaf, fi,
645 end - orig_offset);
646 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
647 struct btrfs_file_extent_item);
648 btrfs_set_file_extent_num_bytes(leaf, fi,
649 end - other_start);
650 btrfs_mark_buffer_dirty(leaf);
651 goto out;
652 }
653 }
654
655 if (start > key.offset && end == extent_end) {
656 other_start = end;
657 other_end = 0;
658 if (extent_mergeable(leaf, path->slots[0] + 1,
659 inode->i_ino, bytenr, orig_offset,
660 &other_start, &other_end)) {
661 fi = btrfs_item_ptr(leaf, path->slots[0],
662 struct btrfs_file_extent_item);
663 btrfs_set_file_extent_num_bytes(leaf, fi,
664 start - key.offset);
665 path->slots[0]++;
666 new_key.offset = start;
667 btrfs_set_item_key_safe(trans, root, path, &new_key);
668
669 fi = btrfs_item_ptr(leaf, path->slots[0],
670 struct btrfs_file_extent_item);
671 btrfs_set_file_extent_num_bytes(leaf, fi,
672 other_end - start);
673 btrfs_set_file_extent_offset(leaf, fi,
674 start - orig_offset);
675 btrfs_mark_buffer_dirty(leaf);
676 goto out;
677 }
678 }
679
680 while (start > key.offset || end < extent_end) {
681 if (key.offset == start)
682 split = end;
683
684 new_key.offset = split;
685 ret = btrfs_duplicate_item(trans, root, path, &new_key);
686 if (ret == -EAGAIN) {
687 btrfs_release_path(root, path);
688 goto again;
689 }
690 BUG_ON(ret < 0);
691
692 leaf = path->nodes[0];
693 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
694 struct btrfs_file_extent_item);
695 btrfs_set_file_extent_num_bytes(leaf, fi,
696 split - key.offset);
697
698 fi = btrfs_item_ptr(leaf, path->slots[0],
699 struct btrfs_file_extent_item);
700
701 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
702 btrfs_set_file_extent_num_bytes(leaf, fi,
703 extent_end - split);
704 btrfs_mark_buffer_dirty(leaf);
705
706 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
707 root->root_key.objectid,
708 inode->i_ino, orig_offset);
709 BUG_ON(ret);
710
711 if (split == start) {
712 key.offset = start;
713 } else {
714 BUG_ON(start != key.offset);
715 path->slots[0]--;
716 extent_end = end;
717 }
718 recow = 1;
719 }
720
721 other_start = end;
722 other_end = 0;
723 if (extent_mergeable(leaf, path->slots[0] + 1,
724 inode->i_ino, bytenr, orig_offset,
725 &other_start, &other_end)) {
726 if (recow) {
727 btrfs_release_path(root, path);
728 goto again;
729 }
730 extent_end = other_end;
731 del_slot = path->slots[0] + 1;
732 del_nr++;
733 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
734 0, root->root_key.objectid,
735 inode->i_ino, orig_offset);
736 BUG_ON(ret);
737 }
738 other_start = 0;
739 other_end = start;
740 if (extent_mergeable(leaf, path->slots[0] - 1,
741 inode->i_ino, bytenr, orig_offset,
742 &other_start, &other_end)) {
743 if (recow) {
744 btrfs_release_path(root, path);
745 goto again;
746 }
747 key.offset = other_start;
748 del_slot = path->slots[0];
749 del_nr++;
750 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
751 0, root->root_key.objectid,
752 inode->i_ino, orig_offset);
753 BUG_ON(ret);
754 }
755 if (del_nr == 0) {
756 fi = btrfs_item_ptr(leaf, path->slots[0],
757 struct btrfs_file_extent_item);
758 btrfs_set_file_extent_type(leaf, fi,
759 BTRFS_FILE_EXTENT_REG);
760 btrfs_mark_buffer_dirty(leaf);
761 } else {
762 fi = btrfs_item_ptr(leaf, del_slot - 1,
763 struct btrfs_file_extent_item);
764 btrfs_set_file_extent_type(leaf, fi,
765 BTRFS_FILE_EXTENT_REG);
766 btrfs_set_file_extent_num_bytes(leaf, fi,
767 extent_end - key.offset);
768 btrfs_mark_buffer_dirty(leaf);
769
770 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
771 BUG_ON(ret);
772 }
773 out:
774 btrfs_free_path(path);
775 return 0;
776 }
777
778 /*
779 * on error we return an unlocked page and the error value
780 * on success we return a locked page and 0
781 */
782 static int prepare_uptodate_page(struct page *page, u64 pos)
783 {
784 int ret = 0;
785
786 if ((pos & (PAGE_CACHE_SIZE - 1)) && !PageUptodate(page)) {
787 ret = btrfs_readpage(NULL, page);
788 if (ret)
789 return ret;
790 lock_page(page);
791 if (!PageUptodate(page)) {
792 unlock_page(page);
793 return -EIO;
794 }
795 }
796 return 0;
797 }
798
799 /*
800 * this gets pages into the page cache and locks them down, it also properly
801 * waits for data=ordered extents to finish before allowing the pages to be
802 * modified.
803 */
804 static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
805 struct page **pages, size_t num_pages,
806 loff_t pos, unsigned long first_index,
807 unsigned long last_index, size_t write_bytes)
808 {
809 struct extent_state *cached_state = NULL;
810 int i;
811 unsigned long index = pos >> PAGE_CACHE_SHIFT;
812 struct inode *inode = fdentry(file)->d_inode;
813 int err = 0;
814 int faili = 0;
815 u64 start_pos;
816 u64 last_pos;
817
818 start_pos = pos & ~((u64)root->sectorsize - 1);
819 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
820
821 if (start_pos > inode->i_size) {
822 err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
823 if (err)
824 return err;
825 }
826
827 again:
828 for (i = 0; i < num_pages; i++) {
829 pages[i] = grab_cache_page(inode->i_mapping, index + i);
830 if (!pages[i]) {
831 faili = i - 1;
832 err = -ENOMEM;
833 goto fail;
834 }
835
836 if (i == 0)
837 err = prepare_uptodate_page(pages[i], pos);
838 if (i == num_pages - 1)
839 err = prepare_uptodate_page(pages[i],
840 pos + write_bytes);
841 if (err) {
842 page_cache_release(pages[i]);
843 faili = i - 1;
844 goto fail;
845 }
846 wait_on_page_writeback(pages[i]);
847 }
848 err = 0;
849 if (start_pos < inode->i_size) {
850 struct btrfs_ordered_extent *ordered;
851 lock_extent_bits(&BTRFS_I(inode)->io_tree,
852 start_pos, last_pos - 1, 0, &cached_state,
853 GFP_NOFS);
854 ordered = btrfs_lookup_first_ordered_extent(inode,
855 last_pos - 1);
856 if (ordered &&
857 ordered->file_offset + ordered->len > start_pos &&
858 ordered->file_offset < last_pos) {
859 btrfs_put_ordered_extent(ordered);
860 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
861 start_pos, last_pos - 1,
862 &cached_state, GFP_NOFS);
863 for (i = 0; i < num_pages; i++) {
864 unlock_page(pages[i]);
865 page_cache_release(pages[i]);
866 }
867 btrfs_wait_ordered_range(inode, start_pos,
868 last_pos - start_pos);
869 goto again;
870 }
871 if (ordered)
872 btrfs_put_ordered_extent(ordered);
873
874 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
875 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
876 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
877 GFP_NOFS);
878 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
879 start_pos, last_pos - 1, &cached_state,
880 GFP_NOFS);
881 }
882 for (i = 0; i < num_pages; i++) {
883 clear_page_dirty_for_io(pages[i]);
884 set_page_extent_mapped(pages[i]);
885 WARN_ON(!PageLocked(pages[i]));
886 }
887 return 0;
888 fail:
889 while (faili >= 0) {
890 unlock_page(pages[faili]);
891 page_cache_release(pages[faili]);
892 faili--;
893 }
894 return err;
895
896 }
897
898 static noinline ssize_t __btrfs_buffered_write(struct file *file,
899 struct iov_iter *i,
900 loff_t pos)
901 {
902 struct inode *inode = fdentry(file)->d_inode;
903 struct btrfs_root *root = BTRFS_I(inode)->root;
904 struct page **pages = NULL;
905 unsigned long first_index;
906 unsigned long last_index;
907 size_t num_written = 0;
908 int nrptrs;
909 int ret = 0;
910
911 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
912 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
913 (sizeof(struct page *)));
914 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
915 if (!pages)
916 return -ENOMEM;
917
918 first_index = pos >> PAGE_CACHE_SHIFT;
919 last_index = (pos + iov_iter_count(i)) >> PAGE_CACHE_SHIFT;
920
921 while (iov_iter_count(i) > 0) {
922 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
923 size_t write_bytes = min(iov_iter_count(i),
924 nrptrs * (size_t)PAGE_CACHE_SIZE -
925 offset);
926 size_t num_pages = (write_bytes + offset +
927 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
928 size_t dirty_pages;
929 size_t copied;
930
931 WARN_ON(num_pages > nrptrs);
932
933 /*
934 * Fault pages before locking them in prepare_pages
935 * to avoid recursive lock
936 */
937 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
938 ret = -EFAULT;
939 break;
940 }
941
942 ret = btrfs_delalloc_reserve_space(inode,
943 num_pages << PAGE_CACHE_SHIFT);
944 if (ret)
945 break;
946
947 /*
948 * This is going to setup the pages array with the number of
949 * pages we want, so we don't really need to worry about the
950 * contents of pages from loop to loop
951 */
952 ret = prepare_pages(root, file, pages, num_pages,
953 pos, first_index, last_index,
954 write_bytes);
955 if (ret) {
956 btrfs_delalloc_release_space(inode,
957 num_pages << PAGE_CACHE_SHIFT);
958 break;
959 }
960
961 copied = btrfs_copy_from_user(pos, num_pages,
962 write_bytes, pages, i);
963
964 /*
965 * if we have trouble faulting in the pages, fall
966 * back to one page at a time
967 */
968 if (copied < write_bytes)
969 nrptrs = 1;
970
971 if (copied == 0)
972 dirty_pages = 0;
973 else
974 dirty_pages = (copied + offset +
975 PAGE_CACHE_SIZE - 1) >>
976 PAGE_CACHE_SHIFT;
977
978 /*
979 * If we had a short copy we need to release the excess delaloc
980 * bytes we reserved. We need to increment outstanding_extents
981 * because btrfs_delalloc_release_space will decrement it, but
982 * we still have an outstanding extent for the chunk we actually
983 * managed to copy.
984 */
985 if (num_pages > dirty_pages) {
986 if (copied > 0)
987 atomic_inc(
988 &BTRFS_I(inode)->outstanding_extents);
989 btrfs_delalloc_release_space(inode,
990 (num_pages - dirty_pages) <<
991 PAGE_CACHE_SHIFT);
992 }
993
994 if (copied > 0) {
995 ret = dirty_and_release_pages(root, file, pages,
996 dirty_pages, pos,
997 copied);
998 if (ret) {
999 btrfs_delalloc_release_space(inode,
1000 dirty_pages << PAGE_CACHE_SHIFT);
1001 btrfs_drop_pages(pages, num_pages);
1002 break;
1003 }
1004 }
1005
1006 btrfs_drop_pages(pages, num_pages);
1007
1008 cond_resched();
1009
1010 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
1011 dirty_pages);
1012 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1013 btrfs_btree_balance_dirty(root, 1);
1014 btrfs_throttle(root);
1015
1016 pos += copied;
1017 num_written += copied;
1018 }
1019
1020 kfree(pages);
1021
1022 return num_written ? num_written : ret;
1023 }
1024
1025 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1026 const struct iovec *iov,
1027 unsigned long nr_segs, loff_t pos,
1028 loff_t *ppos, size_t count, size_t ocount)
1029 {
1030 struct file *file = iocb->ki_filp;
1031 struct inode *inode = fdentry(file)->d_inode;
1032 struct iov_iter i;
1033 ssize_t written;
1034 ssize_t written_buffered;
1035 loff_t endbyte;
1036 int err;
1037
1038 written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
1039 count, ocount);
1040
1041 /*
1042 * the generic O_DIRECT will update in-memory i_size after the
1043 * DIOs are done. But our endio handlers that update the on
1044 * disk i_size never update past the in memory i_size. So we
1045 * need one more update here to catch any additions to the
1046 * file
1047 */
1048 if (inode->i_size != BTRFS_I(inode)->disk_i_size) {
1049 btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
1050 mark_inode_dirty(inode);
1051 }
1052
1053 if (written < 0 || written == count)
1054 return written;
1055
1056 pos += written;
1057 count -= written;
1058 iov_iter_init(&i, iov, nr_segs, count, written);
1059 written_buffered = __btrfs_buffered_write(file, &i, pos);
1060 if (written_buffered < 0) {
1061 err = written_buffered;
1062 goto out;
1063 }
1064 endbyte = pos + written_buffered - 1;
1065 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1066 if (err)
1067 goto out;
1068 written += written_buffered;
1069 *ppos = pos + written_buffered;
1070 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1071 endbyte >> PAGE_CACHE_SHIFT);
1072 out:
1073 return written ? written : err;
1074 }
1075
1076 static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
1077 const struct iovec *iov,
1078 unsigned long nr_segs, loff_t pos)
1079 {
1080 struct file *file = iocb->ki_filp;
1081 struct inode *inode = fdentry(file)->d_inode;
1082 struct btrfs_root *root = BTRFS_I(inode)->root;
1083 loff_t *ppos = &iocb->ki_pos;
1084 ssize_t num_written = 0;
1085 ssize_t err = 0;
1086 size_t count, ocount;
1087
1088 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1089
1090 mutex_lock(&inode->i_mutex);
1091
1092 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1093 if (err) {
1094 mutex_unlock(&inode->i_mutex);
1095 goto out;
1096 }
1097 count = ocount;
1098
1099 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1100 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1101 if (err) {
1102 mutex_unlock(&inode->i_mutex);
1103 goto out;
1104 }
1105
1106 if (count == 0) {
1107 mutex_unlock(&inode->i_mutex);
1108 goto out;
1109 }
1110
1111 err = file_remove_suid(file);
1112 if (err) {
1113 mutex_unlock(&inode->i_mutex);
1114 goto out;
1115 }
1116
1117 /*
1118 * If BTRFS flips readonly due to some impossible error
1119 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1120 * although we have opened a file as writable, we have
1121 * to stop this write operation to ensure FS consistency.
1122 */
1123 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
1124 mutex_unlock(&inode->i_mutex);
1125 err = -EROFS;
1126 goto out;
1127 }
1128
1129 file_update_time(file);
1130 BTRFS_I(inode)->sequence++;
1131
1132 if (unlikely(file->f_flags & O_DIRECT)) {
1133 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
1134 pos, ppos, count, ocount);
1135 } else {
1136 struct iov_iter i;
1137
1138 iov_iter_init(&i, iov, nr_segs, count, num_written);
1139
1140 num_written = __btrfs_buffered_write(file, &i, pos);
1141 if (num_written > 0)
1142 *ppos = pos + num_written;
1143 }
1144
1145 mutex_unlock(&inode->i_mutex);
1146
1147 /*
1148 * we want to make sure fsync finds this change
1149 * but we haven't joined a transaction running right now.
1150 *
1151 * Later on, someone is sure to update the inode and get the
1152 * real transid recorded.
1153 *
1154 * We set last_trans now to the fs_info generation + 1,
1155 * this will either be one more than the running transaction
1156 * or the generation used for the next transaction if there isn't
1157 * one running right now.
1158 */
1159 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1160 if (num_written > 0 || num_written == -EIOCBQUEUED) {
1161 err = generic_write_sync(file, pos, num_written);
1162 if (err < 0 && num_written > 0)
1163 num_written = err;
1164 }
1165 out:
1166 current->backing_dev_info = NULL;
1167 return num_written ? num_written : err;
1168 }
1169
1170 int btrfs_release_file(struct inode *inode, struct file *filp)
1171 {
1172 /*
1173 * ordered_data_close is set by settattr when we are about to truncate
1174 * a file from a non-zero size to a zero size. This tries to
1175 * flush down new bytes that may have been written if the
1176 * application were using truncate to replace a file in place.
1177 */
1178 if (BTRFS_I(inode)->ordered_data_close) {
1179 BTRFS_I(inode)->ordered_data_close = 0;
1180 btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
1181 if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
1182 filemap_flush(inode->i_mapping);
1183 }
1184 if (filp->private_data)
1185 btrfs_ioctl_trans_end(filp);
1186 return 0;
1187 }
1188
1189 /*
1190 * fsync call for both files and directories. This logs the inode into
1191 * the tree log instead of forcing full commits whenever possible.
1192 *
1193 * It needs to call filemap_fdatawait so that all ordered extent updates are
1194 * in the metadata btree are up to date for copying to the log.
1195 *
1196 * It drops the inode mutex before doing the tree log commit. This is an
1197 * important optimization for directories because holding the mutex prevents
1198 * new operations on the dir while we write to disk.
1199 */
1200 int btrfs_sync_file(struct file *file, int datasync)
1201 {
1202 struct dentry *dentry = file->f_path.dentry;
1203 struct inode *inode = dentry->d_inode;
1204 struct btrfs_root *root = BTRFS_I(inode)->root;
1205 int ret = 0;
1206 struct btrfs_trans_handle *trans;
1207
1208 trace_btrfs_sync_file(file, datasync);
1209
1210 /* we wait first, since the writeback may change the inode */
1211 root->log_batch++;
1212 /* the VFS called filemap_fdatawrite for us */
1213 btrfs_wait_ordered_range(inode, 0, (u64)-1);
1214 root->log_batch++;
1215
1216 /*
1217 * check the transaction that last modified this inode
1218 * and see if its already been committed
1219 */
1220 if (!BTRFS_I(inode)->last_trans)
1221 goto out;
1222
1223 /*
1224 * if the last transaction that changed this file was before
1225 * the current transaction, we can bail out now without any
1226 * syncing
1227 */
1228 mutex_lock(&root->fs_info->trans_mutex);
1229 if (BTRFS_I(inode)->last_trans <=
1230 root->fs_info->last_trans_committed) {
1231 BTRFS_I(inode)->last_trans = 0;
1232 mutex_unlock(&root->fs_info->trans_mutex);
1233 goto out;
1234 }
1235 mutex_unlock(&root->fs_info->trans_mutex);
1236
1237 /*
1238 * ok we haven't committed the transaction yet, lets do a commit
1239 */
1240 if (file->private_data)
1241 btrfs_ioctl_trans_end(file);
1242
1243 trans = btrfs_start_transaction(root, 0);
1244 if (IS_ERR(trans)) {
1245 ret = PTR_ERR(trans);
1246 goto out;
1247 }
1248
1249 ret = btrfs_log_dentry_safe(trans, root, dentry);
1250 if (ret < 0)
1251 goto out;
1252
1253 /* we've logged all the items and now have a consistent
1254 * version of the file in the log. It is possible that
1255 * someone will come in and modify the file, but that's
1256 * fine because the log is consistent on disk, and we
1257 * have references to all of the file's extents
1258 *
1259 * It is possible that someone will come in and log the
1260 * file again, but that will end up using the synchronization
1261 * inside btrfs_sync_log to keep things safe.
1262 */
1263 mutex_unlock(&dentry->d_inode->i_mutex);
1264
1265 if (ret != BTRFS_NO_LOG_SYNC) {
1266 if (ret > 0) {
1267 ret = btrfs_commit_transaction(trans, root);
1268 } else {
1269 ret = btrfs_sync_log(trans, root);
1270 if (ret == 0)
1271 ret = btrfs_end_transaction(trans, root);
1272 else
1273 ret = btrfs_commit_transaction(trans, root);
1274 }
1275 } else {
1276 ret = btrfs_end_transaction(trans, root);
1277 }
1278 mutex_lock(&dentry->d_inode->i_mutex);
1279 out:
1280 return ret > 0 ? -EIO : ret;
1281 }
1282
1283 static const struct vm_operations_struct btrfs_file_vm_ops = {
1284 .fault = filemap_fault,
1285 .page_mkwrite = btrfs_page_mkwrite,
1286 };
1287
1288 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1289 {
1290 struct address_space *mapping = filp->f_mapping;
1291
1292 if (!mapping->a_ops->readpage)
1293 return -ENOEXEC;
1294
1295 file_accessed(filp);
1296 vma->vm_ops = &btrfs_file_vm_ops;
1297 vma->vm_flags |= VM_CAN_NONLINEAR;
1298
1299 return 0;
1300 }
1301
1302 static long btrfs_fallocate(struct file *file, int mode,
1303 loff_t offset, loff_t len)
1304 {
1305 struct inode *inode = file->f_path.dentry->d_inode;
1306 struct extent_state *cached_state = NULL;
1307 u64 cur_offset;
1308 u64 last_byte;
1309 u64 alloc_start;
1310 u64 alloc_end;
1311 u64 alloc_hint = 0;
1312 u64 locked_end;
1313 u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
1314 struct extent_map *em;
1315 int ret;
1316
1317 alloc_start = offset & ~mask;
1318 alloc_end = (offset + len + mask) & ~mask;
1319
1320 /* We only support the FALLOC_FL_KEEP_SIZE mode */
1321 if (mode & ~FALLOC_FL_KEEP_SIZE)
1322 return -EOPNOTSUPP;
1323
1324 /*
1325 * wait for ordered IO before we have any locks. We'll loop again
1326 * below with the locks held.
1327 */
1328 btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);
1329
1330 mutex_lock(&inode->i_mutex);
1331 ret = inode_newsize_ok(inode, alloc_end);
1332 if (ret)
1333 goto out;
1334
1335 if (alloc_start > inode->i_size) {
1336 ret = btrfs_cont_expand(inode, i_size_read(inode),
1337 alloc_start);
1338 if (ret)
1339 goto out;
1340 }
1341
1342 ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
1343 if (ret)
1344 goto out;
1345
1346 locked_end = alloc_end - 1;
1347 while (1) {
1348 struct btrfs_ordered_extent *ordered;
1349
1350 /* the extent lock is ordered inside the running
1351 * transaction
1352 */
1353 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
1354 locked_end, 0, &cached_state, GFP_NOFS);
1355 ordered = btrfs_lookup_first_ordered_extent(inode,
1356 alloc_end - 1);
1357 if (ordered &&
1358 ordered->file_offset + ordered->len > alloc_start &&
1359 ordered->file_offset < alloc_end) {
1360 btrfs_put_ordered_extent(ordered);
1361 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1362 alloc_start, locked_end,
1363 &cached_state, GFP_NOFS);
1364 /*
1365 * we can't wait on the range with the transaction
1366 * running or with the extent lock held
1367 */
1368 btrfs_wait_ordered_range(inode, alloc_start,
1369 alloc_end - alloc_start);
1370 } else {
1371 if (ordered)
1372 btrfs_put_ordered_extent(ordered);
1373 break;
1374 }
1375 }
1376
1377 cur_offset = alloc_start;
1378 while (1) {
1379 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
1380 alloc_end - cur_offset, 0);
1381 BUG_ON(IS_ERR(em) || !em);
1382 last_byte = min(extent_map_end(em), alloc_end);
1383 last_byte = (last_byte + mask) & ~mask;
1384 if (em->block_start == EXTENT_MAP_HOLE ||
1385 (cur_offset >= inode->i_size &&
1386 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
1387 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
1388 last_byte - cur_offset,
1389 1 << inode->i_blkbits,
1390 offset + len,
1391 &alloc_hint);
1392 if (ret < 0) {
1393 free_extent_map(em);
1394 break;
1395 }
1396 }
1397 free_extent_map(em);
1398
1399 cur_offset = last_byte;
1400 if (cur_offset >= alloc_end) {
1401 ret = 0;
1402 break;
1403 }
1404 }
1405 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
1406 &cached_state, GFP_NOFS);
1407
1408 btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
1409 out:
1410 mutex_unlock(&inode->i_mutex);
1411 return ret;
1412 }
1413
1414 const struct file_operations btrfs_file_operations = {
1415 .llseek = generic_file_llseek,
1416 .read = do_sync_read,
1417 .write = do_sync_write,
1418 .aio_read = generic_file_aio_read,
1419 .splice_read = generic_file_splice_read,
1420 .aio_write = btrfs_file_aio_write,
1421 .mmap = btrfs_file_mmap,
1422 .open = generic_file_open,
1423 .release = btrfs_release_file,
1424 .fsync = btrfs_sync_file,
1425 .fallocate = btrfs_fallocate,
1426 .unlocked_ioctl = btrfs_ioctl,
1427 #ifdef CONFIG_COMPAT
1428 .compat_ioctl = btrfs_ioctl,
1429 #endif
1430 };
linux-next