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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/fs.h>
7#include <linux/pagemap.h>
8#include <linux/time.h>
9#include <linux/init.h>
10#include <linux/string.h>
11#include <linux/backing-dev.h>
12#include <linux/falloc.h>
13#include <linux/writeback.h>
14#include <linux/compat.h>
15#include <linux/slab.h>
16#include <linux/btrfs.h>
17#include <linux/uio.h>
18#include <linux/iversion.h>
19#include "ctree.h"
20#include "disk-io.h"
21#include "transaction.h"
22#include "btrfs_inode.h"
23#include "print-tree.h"
24#include "tree-log.h"
25#include "locking.h"
26#include "volumes.h"
27#include "qgroup.h"
28#include "compression.h"
29#include "delalloc-space.h"
30
31static struct kmem_cache *btrfs_inode_defrag_cachep;
32/*
33 * when auto defrag is enabled we
34 * queue up these defrag structs to remember which
35 * inodes need defragging passes
36 */
37struct inode_defrag {
38 struct rb_node rb_node;
39 /* objectid */
40 u64 ino;
41 /*
42 * transid where the defrag was added, we search for
43 * extents newer than this
44 */
45 u64 transid;
46
47 /* root objectid */
48 u64 root;
49
50 /* last offset we were able to defrag */
51 u64 last_offset;
52
53 /* if we've wrapped around back to zero once already */
54 int cycled;
55};
56
57static int __compare_inode_defrag(struct inode_defrag *defrag1,
58 struct inode_defrag *defrag2)
59{
60 if (defrag1->root > defrag2->root)
61 return 1;
62 else if (defrag1->root < defrag2->root)
63 return -1;
64 else if (defrag1->ino > defrag2->ino)
65 return 1;
66 else if (defrag1->ino < defrag2->ino)
67 return -1;
68 else
69 return 0;
70}
71
72/* pop a record for an inode into the defrag tree. The lock
73 * must be held already
74 *
75 * If you're inserting a record for an older transid than an
76 * existing record, the transid already in the tree is lowered
77 *
78 * If an existing record is found the defrag item you
79 * pass in is freed
80 */
81static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
82 struct inode_defrag *defrag)
83{
84 struct btrfs_fs_info *fs_info = inode->root->fs_info;
85 struct inode_defrag *entry;
86 struct rb_node **p;
87 struct rb_node *parent = NULL;
88 int ret;
89
90 p = &fs_info->defrag_inodes.rb_node;
91 while (*p) {
92 parent = *p;
93 entry = rb_entry(parent, struct inode_defrag, rb_node);
94
95 ret = __compare_inode_defrag(defrag, entry);
96 if (ret < 0)
97 p = &parent->rb_left;
98 else if (ret > 0)
99 p = &parent->rb_right;
100 else {
101 /* if we're reinserting an entry for
102 * an old defrag run, make sure to
103 * lower the transid of our existing record
104 */
105 if (defrag->transid < entry->transid)
106 entry->transid = defrag->transid;
107 if (defrag->last_offset > entry->last_offset)
108 entry->last_offset = defrag->last_offset;
109 return -EEXIST;
110 }
111 }
112 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
113 rb_link_node(&defrag->rb_node, parent, p);
114 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
115 return 0;
116}
117
118static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
119{
120 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
121 return 0;
122
123 if (btrfs_fs_closing(fs_info))
124 return 0;
125
126 return 1;
127}
128
129/*
130 * insert a defrag record for this inode if auto defrag is
131 * enabled
132 */
133int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
134 struct btrfs_inode *inode)
135{
136 struct btrfs_root *root = inode->root;
137 struct btrfs_fs_info *fs_info = root->fs_info;
138 struct inode_defrag *defrag;
139 u64 transid;
140 int ret;
141
142 if (!__need_auto_defrag(fs_info))
143 return 0;
144
145 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
146 return 0;
147
148 if (trans)
149 transid = trans->transid;
150 else
151 transid = inode->root->last_trans;
152
153 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
154 if (!defrag)
155 return -ENOMEM;
156
157 defrag->ino = btrfs_ino(inode);
158 defrag->transid = transid;
159 defrag->root = root->root_key.objectid;
160
161 spin_lock(&fs_info->defrag_inodes_lock);
162 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
163 /*
164 * If we set IN_DEFRAG flag and evict the inode from memory,
165 * and then re-read this inode, this new inode doesn't have
166 * IN_DEFRAG flag. At the case, we may find the existed defrag.
167 */
168 ret = __btrfs_add_inode_defrag(inode, defrag);
169 if (ret)
170 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
171 } else {
172 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
173 }
174 spin_unlock(&fs_info->defrag_inodes_lock);
175 return 0;
176}
177
178/*
179 * Requeue the defrag object. If there is a defrag object that points to
180 * the same inode in the tree, we will merge them together (by
181 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
182 */
183static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
184 struct inode_defrag *defrag)
185{
186 struct btrfs_fs_info *fs_info = inode->root->fs_info;
187 int ret;
188
189 if (!__need_auto_defrag(fs_info))
190 goto out;
191
192 /*
193 * Here we don't check the IN_DEFRAG flag, because we need merge
194 * them together.
195 */
196 spin_lock(&fs_info->defrag_inodes_lock);
197 ret = __btrfs_add_inode_defrag(inode, defrag);
198 spin_unlock(&fs_info->defrag_inodes_lock);
199 if (ret)
200 goto out;
201 return;
202out:
203 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
204}
205
206/*
207 * pick the defragable inode that we want, if it doesn't exist, we will get
208 * the next one.
209 */
210static struct inode_defrag *
211btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
212{
213 struct inode_defrag *entry = NULL;
214 struct inode_defrag tmp;
215 struct rb_node *p;
216 struct rb_node *parent = NULL;
217 int ret;
218
219 tmp.ino = ino;
220 tmp.root = root;
221
222 spin_lock(&fs_info->defrag_inodes_lock);
223 p = fs_info->defrag_inodes.rb_node;
224 while (p) {
225 parent = p;
226 entry = rb_entry(parent, struct inode_defrag, rb_node);
227
228 ret = __compare_inode_defrag(&tmp, entry);
229 if (ret < 0)
230 p = parent->rb_left;
231 else if (ret > 0)
232 p = parent->rb_right;
233 else
234 goto out;
235 }
236
237 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
238 parent = rb_next(parent);
239 if (parent)
240 entry = rb_entry(parent, struct inode_defrag, rb_node);
241 else
242 entry = NULL;
243 }
244out:
245 if (entry)
246 rb_erase(parent, &fs_info->defrag_inodes);
247 spin_unlock(&fs_info->defrag_inodes_lock);
248 return entry;
249}
250
251void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
252{
253 struct inode_defrag *defrag;
254 struct rb_node *node;
255
256 spin_lock(&fs_info->defrag_inodes_lock);
257 node = rb_first(&fs_info->defrag_inodes);
258 while (node) {
259 rb_erase(node, &fs_info->defrag_inodes);
260 defrag = rb_entry(node, struct inode_defrag, rb_node);
261 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
262
263 cond_resched_lock(&fs_info->defrag_inodes_lock);
264
265 node = rb_first(&fs_info->defrag_inodes);
266 }
267 spin_unlock(&fs_info->defrag_inodes_lock);
268}
269
270#define BTRFS_DEFRAG_BATCH 1024
271
272static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
273 struct inode_defrag *defrag)
274{
275 struct btrfs_root *inode_root;
276 struct inode *inode;
277 struct btrfs_key key;
278 struct btrfs_ioctl_defrag_range_args range;
279 int num_defrag;
280 int index;
281 int ret;
282
283 /* get the inode */
284 key.objectid = defrag->root;
285 key.type = BTRFS_ROOT_ITEM_KEY;
286 key.offset = (u64)-1;
287
288 index = srcu_read_lock(&fs_info->subvol_srcu);
289
290 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
291 if (IS_ERR(inode_root)) {
292 ret = PTR_ERR(inode_root);
293 goto cleanup;
294 }
295
296 key.objectid = defrag->ino;
297 key.type = BTRFS_INODE_ITEM_KEY;
298 key.offset = 0;
299 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
300 if (IS_ERR(inode)) {
301 ret = PTR_ERR(inode);
302 goto cleanup;
303 }
304 srcu_read_unlock(&fs_info->subvol_srcu, index);
305
306 /* do a chunk of defrag */
307 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
308 memset(&range, 0, sizeof(range));
309 range.len = (u64)-1;
310 range.start = defrag->last_offset;
311
312 sb_start_write(fs_info->sb);
313 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
314 BTRFS_DEFRAG_BATCH);
315 sb_end_write(fs_info->sb);
316 /*
317 * if we filled the whole defrag batch, there
318 * must be more work to do. Queue this defrag
319 * again
320 */
321 if (num_defrag == BTRFS_DEFRAG_BATCH) {
322 defrag->last_offset = range.start;
323 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
324 } else if (defrag->last_offset && !defrag->cycled) {
325 /*
326 * we didn't fill our defrag batch, but
327 * we didn't start at zero. Make sure we loop
328 * around to the start of the file.
329 */
330 defrag->last_offset = 0;
331 defrag->cycled = 1;
332 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
333 } else {
334 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
335 }
336
337 iput(inode);
338 return 0;
339cleanup:
340 srcu_read_unlock(&fs_info->subvol_srcu, index);
341 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
342 return ret;
343}
344
345/*
346 * run through the list of inodes in the FS that need
347 * defragging
348 */
349int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
350{
351 struct inode_defrag *defrag;
352 u64 first_ino = 0;
353 u64 root_objectid = 0;
354
355 atomic_inc(&fs_info->defrag_running);
356 while (1) {
357 /* Pause the auto defragger. */
358 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
359 &fs_info->fs_state))
360 break;
361
362 if (!__need_auto_defrag(fs_info))
363 break;
364
365 /* find an inode to defrag */
366 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
367 first_ino);
368 if (!defrag) {
369 if (root_objectid || first_ino) {
370 root_objectid = 0;
371 first_ino = 0;
372 continue;
373 } else {
374 break;
375 }
376 }
377
378 first_ino = defrag->ino + 1;
379 root_objectid = defrag->root;
380
381 __btrfs_run_defrag_inode(fs_info, defrag);
382 }
383 atomic_dec(&fs_info->defrag_running);
384
385 /*
386 * during unmount, we use the transaction_wait queue to
387 * wait for the defragger to stop
388 */
389 wake_up(&fs_info->transaction_wait);
390 return 0;
391}
392
393/* simple helper to fault in pages and copy. This should go away
394 * and be replaced with calls into generic code.
395 */
396static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
397 struct page **prepared_pages,
398 struct iov_iter *i)
399{
400 size_t copied = 0;
401 size_t total_copied = 0;
402 int pg = 0;
403 int offset = offset_in_page(pos);
404
405 while (write_bytes > 0) {
406 size_t count = min_t(size_t,
407 PAGE_SIZE - offset, write_bytes);
408 struct page *page = prepared_pages[pg];
409 /*
410 * Copy data from userspace to the current page
411 */
412 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
413
414 /* Flush processor's dcache for this page */
415 flush_dcache_page(page);
416
417 /*
418 * if we get a partial write, we can end up with
419 * partially up to date pages. These add
420 * a lot of complexity, so make sure they don't
421 * happen by forcing this copy to be retried.
422 *
423 * The rest of the btrfs_file_write code will fall
424 * back to page at a time copies after we return 0.
425 */
426 if (!PageUptodate(page) && copied < count)
427 copied = 0;
428
429 iov_iter_advance(i, copied);
430 write_bytes -= copied;
431 total_copied += copied;
432
433 /* Return to btrfs_file_write_iter to fault page */
434 if (unlikely(copied == 0))
435 break;
436
437 if (copied < PAGE_SIZE - offset) {
438 offset += copied;
439 } else {
440 pg++;
441 offset = 0;
442 }
443 }
444 return total_copied;
445}
446
447/*
448 * unlocks pages after btrfs_file_write is done with them
449 */
450static void btrfs_drop_pages(struct page **pages, size_t num_pages)
451{
452 size_t i;
453 for (i = 0; i < num_pages; i++) {
454 /* page checked is some magic around finding pages that
455 * have been modified without going through btrfs_set_page_dirty
456 * clear it here. There should be no need to mark the pages
457 * accessed as prepare_pages should have marked them accessed
458 * in prepare_pages via find_or_create_page()
459 */
460 ClearPageChecked(pages[i]);
461 unlock_page(pages[i]);
462 put_page(pages[i]);
463 }
464}
465
466static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
467 const u64 start,
468 const u64 len,
469 struct extent_state **cached_state)
470{
471 u64 search_start = start;
472 const u64 end = start + len - 1;
473
474 while (search_start < end) {
475 const u64 search_len = end - search_start + 1;
476 struct extent_map *em;
477 u64 em_len;
478 int ret = 0;
479
480 em = btrfs_get_extent(inode, NULL, 0, search_start,
481 search_len, 0);
482 if (IS_ERR(em))
483 return PTR_ERR(em);
484
485 if (em->block_start != EXTENT_MAP_HOLE)
486 goto next;
487
488 em_len = em->len;
489 if (em->start < search_start)
490 em_len -= search_start - em->start;
491 if (em_len > search_len)
492 em_len = search_len;
493
494 ret = set_extent_bit(&inode->io_tree, search_start,
495 search_start + em_len - 1,
496 EXTENT_DELALLOC_NEW,
497 NULL, cached_state, GFP_NOFS);
498next:
499 search_start = extent_map_end(em);
500 free_extent_map(em);
501 if (ret)
502 return ret;
503 }
504 return 0;
505}
506
507/*
508 * after copy_from_user, pages need to be dirtied and we need to make
509 * sure holes are created between the current EOF and the start of
510 * any next extents (if required).
511 *
512 * this also makes the decision about creating an inline extent vs
513 * doing real data extents, marking pages dirty and delalloc as required.
514 */
515int btrfs_dirty_pages(struct inode *inode, struct page **pages,
516 size_t num_pages, loff_t pos, size_t write_bytes,
517 struct extent_state **cached)
518{
519 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
520 int err = 0;
521 int i;
522 u64 num_bytes;
523 u64 start_pos;
524 u64 end_of_last_block;
525 u64 end_pos = pos + write_bytes;
526 loff_t isize = i_size_read(inode);
527 unsigned int extra_bits = 0;
528
529 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
530 num_bytes = round_up(write_bytes + pos - start_pos,
531 fs_info->sectorsize);
532
533 end_of_last_block = start_pos + num_bytes - 1;
534
535 /*
536 * The pages may have already been dirty, clear out old accounting so
537 * we can set things up properly
538 */
539 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, end_of_last_block,
540 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
541 0, 0, cached);
542
543 if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
544 if (start_pos >= isize &&
545 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) {
546 /*
547 * There can't be any extents following eof in this case
548 * so just set the delalloc new bit for the range
549 * directly.
550 */
551 extra_bits |= EXTENT_DELALLOC_NEW;
552 } else {
553 err = btrfs_find_new_delalloc_bytes(BTRFS_I(inode),
554 start_pos,
555 num_bytes, cached);
556 if (err)
557 return err;
558 }
559 }
560
561 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
562 extra_bits, cached);
563 if (err)
564 return err;
565
566 for (i = 0; i < num_pages; i++) {
567 struct page *p = pages[i];
568 SetPageUptodate(p);
569 ClearPageChecked(p);
570 set_page_dirty(p);
571 }
572
573 /*
574 * we've only changed i_size in ram, and we haven't updated
575 * the disk i_size. There is no need to log the inode
576 * at this time.
577 */
578 if (end_pos > isize)
579 i_size_write(inode, end_pos);
580 return 0;
581}
582
583/*
584 * this drops all the extents in the cache that intersect the range
585 * [start, end]. Existing extents are split as required.
586 */
587void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
588 int skip_pinned)
589{
590 struct extent_map *em;
591 struct extent_map *split = NULL;
592 struct extent_map *split2 = NULL;
593 struct extent_map_tree *em_tree = &inode->extent_tree;
594 u64 len = end - start + 1;
595 u64 gen;
596 int ret;
597 int testend = 1;
598 unsigned long flags;
599 int compressed = 0;
600 bool modified;
601
602 WARN_ON(end < start);
603 if (end == (u64)-1) {
604 len = (u64)-1;
605 testend = 0;
606 }
607 while (1) {
608 int no_splits = 0;
609
610 modified = false;
611 if (!split)
612 split = alloc_extent_map();
613 if (!split2)
614 split2 = alloc_extent_map();
615 if (!split || !split2)
616 no_splits = 1;
617
618 write_lock(&em_tree->lock);
619 em = lookup_extent_mapping(em_tree, start, len);
620 if (!em) {
621 write_unlock(&em_tree->lock);
622 break;
623 }
624 flags = em->flags;
625 gen = em->generation;
626 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
627 if (testend && em->start + em->len >= start + len) {
628 free_extent_map(em);
629 write_unlock(&em_tree->lock);
630 break;
631 }
632 start = em->start + em->len;
633 if (testend)
634 len = start + len - (em->start + em->len);
635 free_extent_map(em);
636 write_unlock(&em_tree->lock);
637 continue;
638 }
639 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
640 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
641 clear_bit(EXTENT_FLAG_LOGGING, &flags);
642 modified = !list_empty(&em->list);
643 if (no_splits)
644 goto next;
645
646 if (em->start < start) {
647 split->start = em->start;
648 split->len = start - em->start;
649
650 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
651 split->orig_start = em->orig_start;
652 split->block_start = em->block_start;
653
654 if (compressed)
655 split->block_len = em->block_len;
656 else
657 split->block_len = split->len;
658 split->orig_block_len = max(split->block_len,
659 em->orig_block_len);
660 split->ram_bytes = em->ram_bytes;
661 } else {
662 split->orig_start = split->start;
663 split->block_len = 0;
664 split->block_start = em->block_start;
665 split->orig_block_len = 0;
666 split->ram_bytes = split->len;
667 }
668
669 split->generation = gen;
670 split->bdev = em->bdev;
671 split->flags = flags;
672 split->compress_type = em->compress_type;
673 replace_extent_mapping(em_tree, em, split, modified);
674 free_extent_map(split);
675 split = split2;
676 split2 = NULL;
677 }
678 if (testend && em->start + em->len > start + len) {
679 u64 diff = start + len - em->start;
680
681 split->start = start + len;
682 split->len = em->start + em->len - (start + len);
683 split->bdev = em->bdev;
684 split->flags = flags;
685 split->compress_type = em->compress_type;
686 split->generation = gen;
687
688 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
689 split->orig_block_len = max(em->block_len,
690 em->orig_block_len);
691
692 split->ram_bytes = em->ram_bytes;
693 if (compressed) {
694 split->block_len = em->block_len;
695 split->block_start = em->block_start;
696 split->orig_start = em->orig_start;
697 } else {
698 split->block_len = split->len;
699 split->block_start = em->block_start
700 + diff;
701 split->orig_start = em->orig_start;
702 }
703 } else {
704 split->ram_bytes = split->len;
705 split->orig_start = split->start;
706 split->block_len = 0;
707 split->block_start = em->block_start;
708 split->orig_block_len = 0;
709 }
710
711 if (extent_map_in_tree(em)) {
712 replace_extent_mapping(em_tree, em, split,
713 modified);
714 } else {
715 ret = add_extent_mapping(em_tree, split,
716 modified);
717 ASSERT(ret == 0); /* Logic error */
718 }
719 free_extent_map(split);
720 split = NULL;
721 }
722next:
723 if (extent_map_in_tree(em))
724 remove_extent_mapping(em_tree, em);
725 write_unlock(&em_tree->lock);
726
727 /* once for us */
728 free_extent_map(em);
729 /* once for the tree*/
730 free_extent_map(em);
731 }
732 if (split)
733 free_extent_map(split);
734 if (split2)
735 free_extent_map(split2);
736}
737
738/*
739 * this is very complex, but the basic idea is to drop all extents
740 * in the range start - end. hint_block is filled in with a block number
741 * that would be a good hint to the block allocator for this file.
742 *
743 * If an extent intersects the range but is not entirely inside the range
744 * it is either truncated or split. Anything entirely inside the range
745 * is deleted from the tree.
746 */
747int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
748 struct btrfs_root *root, struct inode *inode,
749 struct btrfs_path *path, u64 start, u64 end,
750 u64 *drop_end, int drop_cache,
751 int replace_extent,
752 u32 extent_item_size,
753 int *key_inserted)
754{
755 struct btrfs_fs_info *fs_info = root->fs_info;
756 struct extent_buffer *leaf;
757 struct btrfs_file_extent_item *fi;
758 struct btrfs_ref ref = { 0 };
759 struct btrfs_key key;
760 struct btrfs_key new_key;
761 u64 ino = btrfs_ino(BTRFS_I(inode));
762 u64 search_start = start;
763 u64 disk_bytenr = 0;
764 u64 num_bytes = 0;
765 u64 extent_offset = 0;
766 u64 extent_end = 0;
767 u64 last_end = start;
768 int del_nr = 0;
769 int del_slot = 0;
770 int extent_type;
771 int recow;
772 int ret;
773 int modify_tree = -1;
774 int update_refs;
775 int found = 0;
776 int leafs_visited = 0;
777
778 if (drop_cache)
779 btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0);
780
781 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
782 modify_tree = 0;
783
784 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
785 root == fs_info->tree_root);
786 while (1) {
787 recow = 0;
788 ret = btrfs_lookup_file_extent(trans, root, path, ino,
789 search_start, modify_tree);
790 if (ret < 0)
791 break;
792 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
793 leaf = path->nodes[0];
794 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
795 if (key.objectid == ino &&
796 key.type == BTRFS_EXTENT_DATA_KEY)
797 path->slots[0]--;
798 }
799 ret = 0;
800 leafs_visited++;
801next_slot:
802 leaf = path->nodes[0];
803 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
804 BUG_ON(del_nr > 0);
805 ret = btrfs_next_leaf(root, path);
806 if (ret < 0)
807 break;
808 if (ret > 0) {
809 ret = 0;
810 break;
811 }
812 leafs_visited++;
813 leaf = path->nodes[0];
814 recow = 1;
815 }
816
817 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
818
819 if (key.objectid > ino)
820 break;
821 if (WARN_ON_ONCE(key.objectid < ino) ||
822 key.type < BTRFS_EXTENT_DATA_KEY) {
823 ASSERT(del_nr == 0);
824 path->slots[0]++;
825 goto next_slot;
826 }
827 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
828 break;
829
830 fi = btrfs_item_ptr(leaf, path->slots[0],
831 struct btrfs_file_extent_item);
832 extent_type = btrfs_file_extent_type(leaf, fi);
833
834 if (extent_type == BTRFS_FILE_EXTENT_REG ||
835 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
836 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
837 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
838 extent_offset = btrfs_file_extent_offset(leaf, fi);
839 extent_end = key.offset +
840 btrfs_file_extent_num_bytes(leaf, fi);
841 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
842 extent_end = key.offset +
843 btrfs_file_extent_ram_bytes(leaf, fi);
844 } else {
845 /* can't happen */
846 BUG();
847 }
848
849 /*
850 * Don't skip extent items representing 0 byte lengths. They
851 * used to be created (bug) if while punching holes we hit
852 * -ENOSPC condition. So if we find one here, just ensure we
853 * delete it, otherwise we would insert a new file extent item
854 * with the same key (offset) as that 0 bytes length file
855 * extent item in the call to setup_items_for_insert() later
856 * in this function.
857 */
858 if (extent_end == key.offset && extent_end >= search_start) {
859 last_end = extent_end;
860 goto delete_extent_item;
861 }
862
863 if (extent_end <= search_start) {
864 path->slots[0]++;
865 goto next_slot;
866 }
867
868 found = 1;
869 search_start = max(key.offset, start);
870 if (recow || !modify_tree) {
871 modify_tree = -1;
872 btrfs_release_path(path);
873 continue;
874 }
875
876 /*
877 * | - range to drop - |
878 * | -------- extent -------- |
879 */
880 if (start > key.offset && end < extent_end) {
881 BUG_ON(del_nr > 0);
882 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
883 ret = -EOPNOTSUPP;
884 break;
885 }
886
887 memcpy(&new_key, &key, sizeof(new_key));
888 new_key.offset = start;
889 ret = btrfs_duplicate_item(trans, root, path,
890 &new_key);
891 if (ret == -EAGAIN) {
892 btrfs_release_path(path);
893 continue;
894 }
895 if (ret < 0)
896 break;
897
898 leaf = path->nodes[0];
899 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
900 struct btrfs_file_extent_item);
901 btrfs_set_file_extent_num_bytes(leaf, fi,
902 start - key.offset);
903
904 fi = btrfs_item_ptr(leaf, path->slots[0],
905 struct btrfs_file_extent_item);
906
907 extent_offset += start - key.offset;
908 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
909 btrfs_set_file_extent_num_bytes(leaf, fi,
910 extent_end - start);
911 btrfs_mark_buffer_dirty(leaf);
912
913 if (update_refs && disk_bytenr > 0) {
914 btrfs_init_generic_ref(&ref,
915 BTRFS_ADD_DELAYED_REF,
916 disk_bytenr, num_bytes, 0);
917 btrfs_init_data_ref(&ref,
918 root->root_key.objectid,
919 new_key.objectid,
920 start - extent_offset);
921 ret = btrfs_inc_extent_ref(trans, &ref);
922 BUG_ON(ret); /* -ENOMEM */
923 }
924 key.offset = start;
925 }
926 /*
927 * From here on out we will have actually dropped something, so
928 * last_end can be updated.
929 */
930 last_end = extent_end;
931
932 /*
933 * | ---- range to drop ----- |
934 * | -------- extent -------- |
935 */
936 if (start <= key.offset && end < extent_end) {
937 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
938 ret = -EOPNOTSUPP;
939 break;
940 }
941
942 memcpy(&new_key, &key, sizeof(new_key));
943 new_key.offset = end;
944 btrfs_set_item_key_safe(fs_info, path, &new_key);
945
946 extent_offset += end - key.offset;
947 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
948 btrfs_set_file_extent_num_bytes(leaf, fi,
949 extent_end - end);
950 btrfs_mark_buffer_dirty(leaf);
951 if (update_refs && disk_bytenr > 0)
952 inode_sub_bytes(inode, end - key.offset);
953 break;
954 }
955
956 search_start = extent_end;
957 /*
958 * | ---- range to drop ----- |
959 * | -------- extent -------- |
960 */
961 if (start > key.offset && end >= extent_end) {
962 BUG_ON(del_nr > 0);
963 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
964 ret = -EOPNOTSUPP;
965 break;
966 }
967
968 btrfs_set_file_extent_num_bytes(leaf, fi,
969 start - key.offset);
970 btrfs_mark_buffer_dirty(leaf);
971 if (update_refs && disk_bytenr > 0)
972 inode_sub_bytes(inode, extent_end - start);
973 if (end == extent_end)
974 break;
975
976 path->slots[0]++;
977 goto next_slot;
978 }
979
980 /*
981 * | ---- range to drop ----- |
982 * | ------ extent ------ |
983 */
984 if (start <= key.offset && end >= extent_end) {
985delete_extent_item:
986 if (del_nr == 0) {
987 del_slot = path->slots[0];
988 del_nr = 1;
989 } else {
990 BUG_ON(del_slot + del_nr != path->slots[0]);
991 del_nr++;
992 }
993
994 if (update_refs &&
995 extent_type == BTRFS_FILE_EXTENT_INLINE) {
996 inode_sub_bytes(inode,
997 extent_end - key.offset);
998 extent_end = ALIGN(extent_end,
999 fs_info->sectorsize);
1000 } else if (update_refs && disk_bytenr > 0) {
1001 btrfs_init_generic_ref(&ref,
1002 BTRFS_DROP_DELAYED_REF,
1003 disk_bytenr, num_bytes, 0);
1004 btrfs_init_data_ref(&ref,
1005 root->root_key.objectid,
1006 key.objectid,
1007 key.offset - extent_offset);
1008 ret = btrfs_free_extent(trans, &ref);
1009 BUG_ON(ret); /* -ENOMEM */
1010 inode_sub_bytes(inode,
1011 extent_end - key.offset);
1012 }
1013
1014 if (end == extent_end)
1015 break;
1016
1017 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
1018 path->slots[0]++;
1019 goto next_slot;
1020 }
1021
1022 ret = btrfs_del_items(trans, root, path, del_slot,
1023 del_nr);
1024 if (ret) {
1025 btrfs_abort_transaction(trans, ret);
1026 break;
1027 }
1028
1029 del_nr = 0;
1030 del_slot = 0;
1031
1032 btrfs_release_path(path);
1033 continue;
1034 }
1035
1036 BUG();
1037 }
1038
1039 if (!ret && del_nr > 0) {
1040 /*
1041 * Set path->slots[0] to first slot, so that after the delete
1042 * if items are move off from our leaf to its immediate left or
1043 * right neighbor leafs, we end up with a correct and adjusted
1044 * path->slots[0] for our insertion (if replace_extent != 0).
1045 */
1046 path->slots[0] = del_slot;
1047 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1048 if (ret)
1049 btrfs_abort_transaction(trans, ret);
1050 }
1051
1052 leaf = path->nodes[0];
1053 /*
1054 * If btrfs_del_items() was called, it might have deleted a leaf, in
1055 * which case it unlocked our path, so check path->locks[0] matches a
1056 * write lock.
1057 */
1058 if (!ret && replace_extent && leafs_visited == 1 &&
1059 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
1060 path->locks[0] == BTRFS_WRITE_LOCK) &&
1061 btrfs_leaf_free_space(leaf) >=
1062 sizeof(struct btrfs_item) + extent_item_size) {
1063
1064 key.objectid = ino;
1065 key.type = BTRFS_EXTENT_DATA_KEY;
1066 key.offset = start;
1067 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1068 struct btrfs_key slot_key;
1069
1070 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1071 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1072 path->slots[0]++;
1073 }
1074 setup_items_for_insert(root, path, &key,
1075 &extent_item_size,
1076 extent_item_size,
1077 sizeof(struct btrfs_item) +
1078 extent_item_size, 1);
1079 *key_inserted = 1;
1080 }
1081
1082 if (!replace_extent || !(*key_inserted))
1083 btrfs_release_path(path);
1084 if (drop_end)
1085 *drop_end = found ? min(end, last_end) : end;
1086 return ret;
1087}
1088
1089int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1090 struct btrfs_root *root, struct inode *inode, u64 start,
1091 u64 end, int drop_cache)
1092{
1093 struct btrfs_path *path;
1094 int ret;
1095
1096 path = btrfs_alloc_path();
1097 if (!path)
1098 return -ENOMEM;
1099 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1100 drop_cache, 0, 0, NULL);
1101 btrfs_free_path(path);
1102 return ret;
1103}
1104
1105static int extent_mergeable(struct extent_buffer *leaf, int slot,
1106 u64 objectid, u64 bytenr, u64 orig_offset,
1107 u64 *start, u64 *end)
1108{
1109 struct btrfs_file_extent_item *fi;
1110 struct btrfs_key key;
1111 u64 extent_end;
1112
1113 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1114 return 0;
1115
1116 btrfs_item_key_to_cpu(leaf, &key, slot);
1117 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1118 return 0;
1119
1120 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1121 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1122 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1123 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1124 btrfs_file_extent_compression(leaf, fi) ||
1125 btrfs_file_extent_encryption(leaf, fi) ||
1126 btrfs_file_extent_other_encoding(leaf, fi))
1127 return 0;
1128
1129 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1130 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1131 return 0;
1132
1133 *start = key.offset;
1134 *end = extent_end;
1135 return 1;
1136}
1137
1138/*
1139 * Mark extent in the range start - end as written.
1140 *
1141 * This changes extent type from 'pre-allocated' to 'regular'. If only
1142 * part of extent is marked as written, the extent will be split into
1143 * two or three.
1144 */
1145int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1146 struct btrfs_inode *inode, u64 start, u64 end)
1147{
1148 struct btrfs_fs_info *fs_info = trans->fs_info;
1149 struct btrfs_root *root = inode->root;
1150 struct extent_buffer *leaf;
1151 struct btrfs_path *path;
1152 struct btrfs_file_extent_item *fi;
1153 struct btrfs_ref ref = { 0 };
1154 struct btrfs_key key;
1155 struct btrfs_key new_key;
1156 u64 bytenr;
1157 u64 num_bytes;
1158 u64 extent_end;
1159 u64 orig_offset;
1160 u64 other_start;
1161 u64 other_end;
1162 u64 split;
1163 int del_nr = 0;
1164 int del_slot = 0;
1165 int recow;
1166 int ret;
1167 u64 ino = btrfs_ino(inode);
1168
1169 path = btrfs_alloc_path();
1170 if (!path)
1171 return -ENOMEM;
1172again:
1173 recow = 0;
1174 split = start;
1175 key.objectid = ino;
1176 key.type = BTRFS_EXTENT_DATA_KEY;
1177 key.offset = split;
1178
1179 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1180 if (ret < 0)
1181 goto out;
1182 if (ret > 0 && path->slots[0] > 0)
1183 path->slots[0]--;
1184
1185 leaf = path->nodes[0];
1186 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1187 if (key.objectid != ino ||
1188 key.type != BTRFS_EXTENT_DATA_KEY) {
1189 ret = -EINVAL;
1190 btrfs_abort_transaction(trans, ret);
1191 goto out;
1192 }
1193 fi = btrfs_item_ptr(leaf, path->slots[0],
1194 struct btrfs_file_extent_item);
1195 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1196 ret = -EINVAL;
1197 btrfs_abort_transaction(trans, ret);
1198 goto out;
1199 }
1200 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1201 if (key.offset > start || extent_end < end) {
1202 ret = -EINVAL;
1203 btrfs_abort_transaction(trans, ret);
1204 goto out;
1205 }
1206
1207 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1208 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1209 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1210 memcpy(&new_key, &key, sizeof(new_key));
1211
1212 if (start == key.offset && end < extent_end) {
1213 other_start = 0;
1214 other_end = start;
1215 if (extent_mergeable(leaf, path->slots[0] - 1,
1216 ino, bytenr, orig_offset,
1217 &other_start, &other_end)) {
1218 new_key.offset = end;
1219 btrfs_set_item_key_safe(fs_info, path, &new_key);
1220 fi = btrfs_item_ptr(leaf, path->slots[0],
1221 struct btrfs_file_extent_item);
1222 btrfs_set_file_extent_generation(leaf, fi,
1223 trans->transid);
1224 btrfs_set_file_extent_num_bytes(leaf, fi,
1225 extent_end - end);
1226 btrfs_set_file_extent_offset(leaf, fi,
1227 end - orig_offset);
1228 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1229 struct btrfs_file_extent_item);
1230 btrfs_set_file_extent_generation(leaf, fi,
1231 trans->transid);
1232 btrfs_set_file_extent_num_bytes(leaf, fi,
1233 end - other_start);
1234 btrfs_mark_buffer_dirty(leaf);
1235 goto out;
1236 }
1237 }
1238
1239 if (start > key.offset && end == extent_end) {
1240 other_start = end;
1241 other_end = 0;
1242 if (extent_mergeable(leaf, path->slots[0] + 1,
1243 ino, bytenr, orig_offset,
1244 &other_start, &other_end)) {
1245 fi = btrfs_item_ptr(leaf, path->slots[0],
1246 struct btrfs_file_extent_item);
1247 btrfs_set_file_extent_num_bytes(leaf, fi,
1248 start - key.offset);
1249 btrfs_set_file_extent_generation(leaf, fi,
1250 trans->transid);
1251 path->slots[0]++;
1252 new_key.offset = start;
1253 btrfs_set_item_key_safe(fs_info, path, &new_key);
1254
1255 fi = btrfs_item_ptr(leaf, path->slots[0],
1256 struct btrfs_file_extent_item);
1257 btrfs_set_file_extent_generation(leaf, fi,
1258 trans->transid);
1259 btrfs_set_file_extent_num_bytes(leaf, fi,
1260 other_end - start);
1261 btrfs_set_file_extent_offset(leaf, fi,
1262 start - orig_offset);
1263 btrfs_mark_buffer_dirty(leaf);
1264 goto out;
1265 }
1266 }
1267
1268 while (start > key.offset || end < extent_end) {
1269 if (key.offset == start)
1270 split = end;
1271
1272 new_key.offset = split;
1273 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1274 if (ret == -EAGAIN) {
1275 btrfs_release_path(path);
1276 goto again;
1277 }
1278 if (ret < 0) {
1279 btrfs_abort_transaction(trans, ret);
1280 goto out;
1281 }
1282
1283 leaf = path->nodes[0];
1284 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1285 struct btrfs_file_extent_item);
1286 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1287 btrfs_set_file_extent_num_bytes(leaf, fi,
1288 split - key.offset);
1289
1290 fi = btrfs_item_ptr(leaf, path->slots[0],
1291 struct btrfs_file_extent_item);
1292
1293 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1294 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1295 btrfs_set_file_extent_num_bytes(leaf, fi,
1296 extent_end - split);
1297 btrfs_mark_buffer_dirty(leaf);
1298
1299 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
1300 num_bytes, 0);
1301 btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
1302 orig_offset);
1303 ret = btrfs_inc_extent_ref(trans, &ref);
1304 if (ret) {
1305 btrfs_abort_transaction(trans, ret);
1306 goto out;
1307 }
1308
1309 if (split == start) {
1310 key.offset = start;
1311 } else {
1312 if (start != key.offset) {
1313 ret = -EINVAL;
1314 btrfs_abort_transaction(trans, ret);
1315 goto out;
1316 }
1317 path->slots[0]--;
1318 extent_end = end;
1319 }
1320 recow = 1;
1321 }
1322
1323 other_start = end;
1324 other_end = 0;
1325 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1326 num_bytes, 0);
1327 btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset);
1328 if (extent_mergeable(leaf, path->slots[0] + 1,
1329 ino, bytenr, orig_offset,
1330 &other_start, &other_end)) {
1331 if (recow) {
1332 btrfs_release_path(path);
1333 goto again;
1334 }
1335 extent_end = other_end;
1336 del_slot = path->slots[0] + 1;
1337 del_nr++;
1338 ret = btrfs_free_extent(trans, &ref);
1339 if (ret) {
1340 btrfs_abort_transaction(trans, ret);
1341 goto out;
1342 }
1343 }
1344 other_start = 0;
1345 other_end = start;
1346 if (extent_mergeable(leaf, path->slots[0] - 1,
1347 ino, bytenr, orig_offset,
1348 &other_start, &other_end)) {
1349 if (recow) {
1350 btrfs_release_path(path);
1351 goto again;
1352 }
1353 key.offset = other_start;
1354 del_slot = path->slots[0];
1355 del_nr++;
1356 ret = btrfs_free_extent(trans, &ref);
1357 if (ret) {
1358 btrfs_abort_transaction(trans, ret);
1359 goto out;
1360 }
1361 }
1362 if (del_nr == 0) {
1363 fi = btrfs_item_ptr(leaf, path->slots[0],
1364 struct btrfs_file_extent_item);
1365 btrfs_set_file_extent_type(leaf, fi,
1366 BTRFS_FILE_EXTENT_REG);
1367 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1368 btrfs_mark_buffer_dirty(leaf);
1369 } else {
1370 fi = btrfs_item_ptr(leaf, del_slot - 1,
1371 struct btrfs_file_extent_item);
1372 btrfs_set_file_extent_type(leaf, fi,
1373 BTRFS_FILE_EXTENT_REG);
1374 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1375 btrfs_set_file_extent_num_bytes(leaf, fi,
1376 extent_end - key.offset);
1377 btrfs_mark_buffer_dirty(leaf);
1378
1379 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1380 if (ret < 0) {
1381 btrfs_abort_transaction(trans, ret);
1382 goto out;
1383 }
1384 }
1385out:
1386 btrfs_free_path(path);
1387 return 0;
1388}
1389
1390/*
1391 * on error we return an unlocked page and the error value
1392 * on success we return a locked page and 0
1393 */
1394static int prepare_uptodate_page(struct inode *inode,
1395 struct page *page, u64 pos,
1396 bool force_uptodate)
1397{
1398 int ret = 0;
1399
1400 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1401 !PageUptodate(page)) {
1402 ret = btrfs_readpage(NULL, page);
1403 if (ret)
1404 return ret;
1405 lock_page(page);
1406 if (!PageUptodate(page)) {
1407 unlock_page(page);
1408 return -EIO;
1409 }
1410 if (page->mapping != inode->i_mapping) {
1411 unlock_page(page);
1412 return -EAGAIN;
1413 }
1414 }
1415 return 0;
1416}
1417
1418/*
1419 * this just gets pages into the page cache and locks them down.
1420 */
1421static noinline int prepare_pages(struct inode *inode, struct page **pages,
1422 size_t num_pages, loff_t pos,
1423 size_t write_bytes, bool force_uptodate)
1424{
1425 int i;
1426 unsigned long index = pos >> PAGE_SHIFT;
1427 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1428 int err = 0;
1429 int faili;
1430
1431 for (i = 0; i < num_pages; i++) {
1432again:
1433 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1434 mask | __GFP_WRITE);
1435 if (!pages[i]) {
1436 faili = i - 1;
1437 err = -ENOMEM;
1438 goto fail;
1439 }
1440
1441 if (i == 0)
1442 err = prepare_uptodate_page(inode, pages[i], pos,
1443 force_uptodate);
1444 if (!err && i == num_pages - 1)
1445 err = prepare_uptodate_page(inode, pages[i],
1446 pos + write_bytes, false);
1447 if (err) {
1448 put_page(pages[i]);
1449 if (err == -EAGAIN) {
1450 err = 0;
1451 goto again;
1452 }
1453 faili = i - 1;
1454 goto fail;
1455 }
1456 wait_on_page_writeback(pages[i]);
1457 }
1458
1459 return 0;
1460fail:
1461 while (faili >= 0) {
1462 unlock_page(pages[faili]);
1463 put_page(pages[faili]);
1464 faili--;
1465 }
1466 return err;
1467
1468}
1469
1470/*
1471 * This function locks the extent and properly waits for data=ordered extents
1472 * to finish before allowing the pages to be modified if need.
1473 *
1474 * The return value:
1475 * 1 - the extent is locked
1476 * 0 - the extent is not locked, and everything is OK
1477 * -EAGAIN - need re-prepare the pages
1478 * the other < 0 number - Something wrong happens
1479 */
1480static noinline int
1481lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1482 size_t num_pages, loff_t pos,
1483 size_t write_bytes,
1484 u64 *lockstart, u64 *lockend,
1485 struct extent_state **cached_state)
1486{
1487 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1488 u64 start_pos;
1489 u64 last_pos;
1490 int i;
1491 int ret = 0;
1492
1493 start_pos = round_down(pos, fs_info->sectorsize);
1494 last_pos = start_pos
1495 + round_up(pos + write_bytes - start_pos,
1496 fs_info->sectorsize) - 1;
1497
1498 if (start_pos < inode->vfs_inode.i_size) {
1499 struct btrfs_ordered_extent *ordered;
1500
1501 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1502 cached_state);
1503 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1504 last_pos - start_pos + 1);
1505 if (ordered &&
1506 ordered->file_offset + ordered->len > start_pos &&
1507 ordered->file_offset <= last_pos) {
1508 unlock_extent_cached(&inode->io_tree, start_pos,
1509 last_pos, cached_state);
1510 for (i = 0; i < num_pages; i++) {
1511 unlock_page(pages[i]);
1512 put_page(pages[i]);
1513 }
1514 btrfs_start_ordered_extent(&inode->vfs_inode,
1515 ordered, 1);
1516 btrfs_put_ordered_extent(ordered);
1517 return -EAGAIN;
1518 }
1519 if (ordered)
1520 btrfs_put_ordered_extent(ordered);
1521
1522 *lockstart = start_pos;
1523 *lockend = last_pos;
1524 ret = 1;
1525 }
1526
1527 /*
1528 * It's possible the pages are dirty right now, but we don't want
1529 * to clean them yet because copy_from_user may catch a page fault
1530 * and we might have to fall back to one page at a time. If that
1531 * happens, we'll unlock these pages and we'd have a window where
1532 * reclaim could sneak in and drop the once-dirty page on the floor
1533 * without writing it.
1534 *
1535 * We have the pages locked and the extent range locked, so there's
1536 * no way someone can start IO on any dirty pages in this range.
1537 *
1538 * We'll call btrfs_dirty_pages() later on, and that will flip around
1539 * delalloc bits and dirty the pages as required.
1540 */
1541 for (i = 0; i < num_pages; i++) {
1542 set_page_extent_mapped(pages[i]);
1543 WARN_ON(!PageLocked(pages[i]));
1544 }
1545
1546 return ret;
1547}
1548
1549static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1550 size_t *write_bytes)
1551{
1552 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1553 struct btrfs_root *root = inode->root;
1554 u64 lockstart, lockend;
1555 u64 num_bytes;
1556 int ret;
1557
1558 ret = btrfs_start_write_no_snapshotting(root);
1559 if (!ret)
1560 return -EAGAIN;
1561
1562 lockstart = round_down(pos, fs_info->sectorsize);
1563 lockend = round_up(pos + *write_bytes,
1564 fs_info->sectorsize) - 1;
1565
1566 btrfs_lock_and_flush_ordered_range(&inode->io_tree, inode, lockstart,
1567 lockend, NULL);
1568
1569 num_bytes = lockend - lockstart + 1;
1570 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1571 NULL, NULL, NULL);
1572 if (ret <= 0) {
1573 ret = 0;
1574 btrfs_end_write_no_snapshotting(root);
1575 } else {
1576 *write_bytes = min_t(size_t, *write_bytes ,
1577 num_bytes - pos + lockstart);
1578 }
1579
1580 unlock_extent(&inode->io_tree, lockstart, lockend);
1581
1582 return ret;
1583}
1584
1585static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
1586 struct iov_iter *i)
1587{
1588 struct file *file = iocb->ki_filp;
1589 loff_t pos = iocb->ki_pos;
1590 struct inode *inode = file_inode(file);
1591 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1592 struct btrfs_root *root = BTRFS_I(inode)->root;
1593 struct page **pages = NULL;
1594 struct extent_changeset *data_reserved = NULL;
1595 u64 release_bytes = 0;
1596 u64 lockstart;
1597 u64 lockend;
1598 size_t num_written = 0;
1599 int nrptrs;
1600 int ret = 0;
1601 bool only_release_metadata = false;
1602 bool force_page_uptodate = false;
1603
1604 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1605 PAGE_SIZE / (sizeof(struct page *)));
1606 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1607 nrptrs = max(nrptrs, 8);
1608 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1609 if (!pages)
1610 return -ENOMEM;
1611
1612 while (iov_iter_count(i) > 0) {
1613 struct extent_state *cached_state = NULL;
1614 size_t offset = offset_in_page(pos);
1615 size_t sector_offset;
1616 size_t write_bytes = min(iov_iter_count(i),
1617 nrptrs * (size_t)PAGE_SIZE -
1618 offset);
1619 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1620 PAGE_SIZE);
1621 size_t reserve_bytes;
1622 size_t dirty_pages;
1623 size_t copied;
1624 size_t dirty_sectors;
1625 size_t num_sectors;
1626 int extents_locked;
1627
1628 WARN_ON(num_pages > nrptrs);
1629
1630 /*
1631 * Fault pages before locking them in prepare_pages
1632 * to avoid recursive lock
1633 */
1634 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1635 ret = -EFAULT;
1636 break;
1637 }
1638
1639 sector_offset = pos & (fs_info->sectorsize - 1);
1640 reserve_bytes = round_up(write_bytes + sector_offset,
1641 fs_info->sectorsize);
1642
1643 extent_changeset_release(data_reserved);
1644 ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
1645 write_bytes);
1646 if (ret < 0) {
1647 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1648 BTRFS_INODE_PREALLOC)) &&
1649 check_can_nocow(BTRFS_I(inode), pos,
1650 &write_bytes) > 0) {
1651 /*
1652 * For nodata cow case, no need to reserve
1653 * data space.
1654 */
1655 only_release_metadata = true;
1656 /*
1657 * our prealloc extent may be smaller than
1658 * write_bytes, so scale down.
1659 */
1660 num_pages = DIV_ROUND_UP(write_bytes + offset,
1661 PAGE_SIZE);
1662 reserve_bytes = round_up(write_bytes +
1663 sector_offset,
1664 fs_info->sectorsize);
1665 } else {
1666 break;
1667 }
1668 }
1669
1670 WARN_ON(reserve_bytes == 0);
1671 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1672 reserve_bytes);
1673 if (ret) {
1674 if (!only_release_metadata)
1675 btrfs_free_reserved_data_space(inode,
1676 data_reserved, pos,
1677 write_bytes);
1678 else
1679 btrfs_end_write_no_snapshotting(root);
1680 break;
1681 }
1682
1683 release_bytes = reserve_bytes;
1684again:
1685 /*
1686 * This is going to setup the pages array with the number of
1687 * pages we want, so we don't really need to worry about the
1688 * contents of pages from loop to loop
1689 */
1690 ret = prepare_pages(inode, pages, num_pages,
1691 pos, write_bytes,
1692 force_page_uptodate);
1693 if (ret) {
1694 btrfs_delalloc_release_extents(BTRFS_I(inode),
1695 reserve_bytes);
1696 break;
1697 }
1698
1699 extents_locked = lock_and_cleanup_extent_if_need(
1700 BTRFS_I(inode), pages,
1701 num_pages, pos, write_bytes, &lockstart,
1702 &lockend, &cached_state);
1703 if (extents_locked < 0) {
1704 if (extents_locked == -EAGAIN)
1705 goto again;
1706 btrfs_delalloc_release_extents(BTRFS_I(inode),
1707 reserve_bytes);
1708 ret = extents_locked;
1709 break;
1710 }
1711
1712 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1713
1714 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1715 dirty_sectors = round_up(copied + sector_offset,
1716 fs_info->sectorsize);
1717 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1718
1719 /*
1720 * if we have trouble faulting in the pages, fall
1721 * back to one page at a time
1722 */
1723 if (copied < write_bytes)
1724 nrptrs = 1;
1725
1726 if (copied == 0) {
1727 force_page_uptodate = true;
1728 dirty_sectors = 0;
1729 dirty_pages = 0;
1730 } else {
1731 force_page_uptodate = false;
1732 dirty_pages = DIV_ROUND_UP(copied + offset,
1733 PAGE_SIZE);
1734 }
1735
1736 if (num_sectors > dirty_sectors) {
1737 /* release everything except the sectors we dirtied */
1738 release_bytes -= dirty_sectors <<
1739 fs_info->sb->s_blocksize_bits;
1740 if (only_release_metadata) {
1741 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1742 release_bytes, true);
1743 } else {
1744 u64 __pos;
1745
1746 __pos = round_down(pos,
1747 fs_info->sectorsize) +
1748 (dirty_pages << PAGE_SHIFT);
1749 btrfs_delalloc_release_space(inode,
1750 data_reserved, __pos,
1751 release_bytes, true);
1752 }
1753 }
1754
1755 release_bytes = round_up(copied + sector_offset,
1756 fs_info->sectorsize);
1757
1758 if (copied > 0)
1759 ret = btrfs_dirty_pages(inode, pages, dirty_pages,
1760 pos, copied, &cached_state);
1761
1762 /*
1763 * If we have not locked the extent range, because the range's
1764 * start offset is >= i_size, we might still have a non-NULL
1765 * cached extent state, acquired while marking the extent range
1766 * as delalloc through btrfs_dirty_pages(). Therefore free any
1767 * possible cached extent state to avoid a memory leak.
1768 */
1769 if (extents_locked)
1770 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1771 lockstart, lockend, &cached_state);
1772 else
1773 free_extent_state(cached_state);
1774
1775 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1776 if (ret) {
1777 btrfs_drop_pages(pages, num_pages);
1778 break;
1779 }
1780
1781 release_bytes = 0;
1782 if (only_release_metadata)
1783 btrfs_end_write_no_snapshotting(root);
1784
1785 if (only_release_metadata && copied > 0) {
1786 lockstart = round_down(pos,
1787 fs_info->sectorsize);
1788 lockend = round_up(pos + copied,
1789 fs_info->sectorsize) - 1;
1790
1791 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1792 lockend, EXTENT_NORESERVE, NULL,
1793 NULL, GFP_NOFS);
1794 only_release_metadata = false;
1795 }
1796
1797 btrfs_drop_pages(pages, num_pages);
1798
1799 cond_resched();
1800
1801 balance_dirty_pages_ratelimited(inode->i_mapping);
1802 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1803 btrfs_btree_balance_dirty(fs_info);
1804
1805 pos += copied;
1806 num_written += copied;
1807 }
1808
1809 kfree(pages);
1810
1811 if (release_bytes) {
1812 if (only_release_metadata) {
1813 btrfs_end_write_no_snapshotting(root);
1814 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1815 release_bytes, true);
1816 } else {
1817 btrfs_delalloc_release_space(inode, data_reserved,
1818 round_down(pos, fs_info->sectorsize),
1819 release_bytes, true);
1820 }
1821 }
1822
1823 extent_changeset_free(data_reserved);
1824 return num_written ? num_written : ret;
1825}
1826
1827static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1828{
1829 struct file *file = iocb->ki_filp;
1830 struct inode *inode = file_inode(file);
1831 loff_t pos;
1832 ssize_t written;
1833 ssize_t written_buffered;
1834 loff_t endbyte;
1835 int err;
1836
1837 written = generic_file_direct_write(iocb, from);
1838
1839 if (written < 0 || !iov_iter_count(from))
1840 return written;
1841
1842 pos = iocb->ki_pos;
1843 written_buffered = btrfs_buffered_write(iocb, from);
1844 if (written_buffered < 0) {
1845 err = written_buffered;
1846 goto out;
1847 }
1848 /*
1849 * Ensure all data is persisted. We want the next direct IO read to be
1850 * able to read what was just written.
1851 */
1852 endbyte = pos + written_buffered - 1;
1853 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1854 if (err)
1855 goto out;
1856 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1857 if (err)
1858 goto out;
1859 written += written_buffered;
1860 iocb->ki_pos = pos + written_buffered;
1861 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1862 endbyte >> PAGE_SHIFT);
1863out:
1864 return written ? written : err;
1865}
1866
1867static void update_time_for_write(struct inode *inode)
1868{
1869 struct timespec64 now;
1870
1871 if (IS_NOCMTIME(inode))
1872 return;
1873
1874 now = current_time(inode);
1875 if (!timespec64_equal(&inode->i_mtime, &now))
1876 inode->i_mtime = now;
1877
1878 if (!timespec64_equal(&inode->i_ctime, &now))
1879 inode->i_ctime = now;
1880
1881 if (IS_I_VERSION(inode))
1882 inode_inc_iversion(inode);
1883}
1884
1885static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1886 struct iov_iter *from)
1887{
1888 struct file *file = iocb->ki_filp;
1889 struct inode *inode = file_inode(file);
1890 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1891 struct btrfs_root *root = BTRFS_I(inode)->root;
1892 u64 start_pos;
1893 u64 end_pos;
1894 ssize_t num_written = 0;
1895 const bool sync = iocb->ki_flags & IOCB_DSYNC;
1896 ssize_t err;
1897 loff_t pos;
1898 size_t count;
1899 loff_t oldsize;
1900 int clean_page = 0;
1901
1902 if (!(iocb->ki_flags & IOCB_DIRECT) &&
1903 (iocb->ki_flags & IOCB_NOWAIT))
1904 return -EOPNOTSUPP;
1905
1906 if (!inode_trylock(inode)) {
1907 if (iocb->ki_flags & IOCB_NOWAIT)
1908 return -EAGAIN;
1909 inode_lock(inode);
1910 }
1911
1912 err = generic_write_checks(iocb, from);
1913 if (err <= 0) {
1914 inode_unlock(inode);
1915 return err;
1916 }
1917
1918 pos = iocb->ki_pos;
1919 count = iov_iter_count(from);
1920 if (iocb->ki_flags & IOCB_NOWAIT) {
1921 /*
1922 * We will allocate space in case nodatacow is not set,
1923 * so bail
1924 */
1925 if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1926 BTRFS_INODE_PREALLOC)) ||
1927 check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
1928 inode_unlock(inode);
1929 return -EAGAIN;
1930 }
1931 }
1932
1933 current->backing_dev_info = inode_to_bdi(inode);
1934 err = file_remove_privs(file);
1935 if (err) {
1936 inode_unlock(inode);
1937 goto out;
1938 }
1939
1940 /*
1941 * If BTRFS flips readonly due to some impossible error
1942 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1943 * although we have opened a file as writable, we have
1944 * to stop this write operation to ensure FS consistency.
1945 */
1946 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1947 inode_unlock(inode);
1948 err = -EROFS;
1949 goto out;
1950 }
1951
1952 /*
1953 * We reserve space for updating the inode when we reserve space for the
1954 * extent we are going to write, so we will enospc out there. We don't
1955 * need to start yet another transaction to update the inode as we will
1956 * update the inode when we finish writing whatever data we write.
1957 */
1958 update_time_for_write(inode);
1959
1960 start_pos = round_down(pos, fs_info->sectorsize);
1961 oldsize = i_size_read(inode);
1962 if (start_pos > oldsize) {
1963 /* Expand hole size to cover write data, preventing empty gap */
1964 end_pos = round_up(pos + count,
1965 fs_info->sectorsize);
1966 err = btrfs_cont_expand(inode, oldsize, end_pos);
1967 if (err) {
1968 inode_unlock(inode);
1969 goto out;
1970 }
1971 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1972 clean_page = 1;
1973 }
1974
1975 if (sync)
1976 atomic_inc(&BTRFS_I(inode)->sync_writers);
1977
1978 if (iocb->ki_flags & IOCB_DIRECT) {
1979 num_written = __btrfs_direct_write(iocb, from);
1980 } else {
1981 num_written = btrfs_buffered_write(iocb, from);
1982 if (num_written > 0)
1983 iocb->ki_pos = pos + num_written;
1984 if (clean_page)
1985 pagecache_isize_extended(inode, oldsize,
1986 i_size_read(inode));
1987 }
1988
1989 inode_unlock(inode);
1990
1991 /*
1992 * We also have to set last_sub_trans to the current log transid,
1993 * otherwise subsequent syncs to a file that's been synced in this
1994 * transaction will appear to have already occurred.
1995 */
1996 spin_lock(&BTRFS_I(inode)->lock);
1997 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1998 spin_unlock(&BTRFS_I(inode)->lock);
1999 if (num_written > 0)
2000 num_written = generic_write_sync(iocb, num_written);
2001
2002 if (sync)
2003 atomic_dec(&BTRFS_I(inode)->sync_writers);
2004out:
2005 current->backing_dev_info = NULL;
2006 return num_written ? num_written : err;
2007}
2008
2009int btrfs_release_file(struct inode *inode, struct file *filp)
2010{
2011 struct btrfs_file_private *private = filp->private_data;
2012
2013 if (private && private->filldir_buf)
2014 kfree(private->filldir_buf);
2015 kfree(private);
2016 filp->private_data = NULL;
2017
2018 /*
2019 * ordered_data_close is set by setattr when we are about to truncate
2020 * a file from a non-zero size to a zero size. This tries to
2021 * flush down new bytes that may have been written if the
2022 * application were using truncate to replace a file in place.
2023 */
2024 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2025 &BTRFS_I(inode)->runtime_flags))
2026 filemap_flush(inode->i_mapping);
2027 return 0;
2028}
2029
2030static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2031{
2032 int ret;
2033 struct blk_plug plug;
2034
2035 /*
2036 * This is only called in fsync, which would do synchronous writes, so
2037 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2038 * multiple disks using raid profile, a large IO can be split to
2039 * several segments of stripe length (currently 64K).
2040 */
2041 blk_start_plug(&plug);
2042 atomic_inc(&BTRFS_I(inode)->sync_writers);
2043 ret = btrfs_fdatawrite_range(inode, start, end);
2044 atomic_dec(&BTRFS_I(inode)->sync_writers);
2045 blk_finish_plug(&plug);
2046
2047 return ret;
2048}
2049
2050/*
2051 * fsync call for both files and directories. This logs the inode into
2052 * the tree log instead of forcing full commits whenever possible.
2053 *
2054 * It needs to call filemap_fdatawait so that all ordered extent updates are
2055 * in the metadata btree are up to date for copying to the log.
2056 *
2057 * It drops the inode mutex before doing the tree log commit. This is an
2058 * important optimization for directories because holding the mutex prevents
2059 * new operations on the dir while we write to disk.
2060 */
2061int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2062{
2063 struct dentry *dentry = file_dentry(file);
2064 struct inode *inode = d_inode(dentry);
2065 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2066 struct btrfs_root *root = BTRFS_I(inode)->root;
2067 struct btrfs_trans_handle *trans;
2068 struct btrfs_log_ctx ctx;
2069 int ret = 0, err;
2070
2071 trace_btrfs_sync_file(file, datasync);
2072
2073 btrfs_init_log_ctx(&ctx, inode);
2074
2075 /*
2076 * We write the dirty pages in the range and wait until they complete
2077 * out of the ->i_mutex. If so, we can flush the dirty pages by
2078 * multi-task, and make the performance up. See
2079 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2080 */
2081 ret = start_ordered_ops(inode, start, end);
2082 if (ret)
2083 goto out;
2084
2085 inode_lock(inode);
2086
2087 /*
2088 * We take the dio_sem here because the tree log stuff can race with
2089 * lockless dio writes and get an extent map logged for an extent we
2090 * never waited on. We need it this high up for lockdep reasons.
2091 */
2092 down_write(&BTRFS_I(inode)->dio_sem);
2093
2094 atomic_inc(&root->log_batch);
2095
2096 /*
2097 * If the inode needs a full sync, make sure we use a full range to
2098 * avoid log tree corruption, due to hole detection racing with ordered
2099 * extent completion for adjacent ranges, and assertion failures during
2100 * hole detection. Do this while holding the inode lock, to avoid races
2101 * with other tasks.
2102 */
2103 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2104 &BTRFS_I(inode)->runtime_flags)) {
2105 start = 0;
2106 end = LLONG_MAX;
2107 }
2108
2109 /*
2110 * Before we acquired the inode's lock, someone may have dirtied more
2111 * pages in the target range. We need to make sure that writeback for
2112 * any such pages does not start while we are logging the inode, because
2113 * if it does, any of the following might happen when we are not doing a
2114 * full inode sync:
2115 *
2116 * 1) We log an extent after its writeback finishes but before its
2117 * checksums are added to the csum tree, leading to -EIO errors
2118 * when attempting to read the extent after a log replay.
2119 *
2120 * 2) We can end up logging an extent before its writeback finishes.
2121 * Therefore after the log replay we will have a file extent item
2122 * pointing to an unwritten extent (and no data checksums as well).
2123 *
2124 * So trigger writeback for any eventual new dirty pages and then we
2125 * wait for all ordered extents to complete below.
2126 */
2127 ret = start_ordered_ops(inode, start, end);
2128 if (ret) {
2129 inode_unlock(inode);
2130 goto out;
2131 }
2132
2133 /*
2134 * We have to do this here to avoid the priority inversion of waiting on
2135 * IO of a lower priority task while holding a transaction open.
2136 *
2137 * Also, the range length can be represented by u64, we have to do the
2138 * typecasts to avoid signed overflow if it's [0, LLONG_MAX].
2139 */
2140 ret = btrfs_wait_ordered_range(inode, start, (u64)end - (u64)start + 1);
2141 if (ret) {
2142 up_write(&BTRFS_I(inode)->dio_sem);
2143 inode_unlock(inode);
2144 goto out;
2145 }
2146 atomic_inc(&root->log_batch);
2147
2148 smp_mb();
2149 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2150 BTRFS_I(inode)->last_trans <= fs_info->last_trans_committed) {
2151 /*
2152 * We've had everything committed since the last time we were
2153 * modified so clear this flag in case it was set for whatever
2154 * reason, it's no longer relevant.
2155 */
2156 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2157 &BTRFS_I(inode)->runtime_flags);
2158 /*
2159 * An ordered extent might have started before and completed
2160 * already with io errors, in which case the inode was not
2161 * updated and we end up here. So check the inode's mapping
2162 * for any errors that might have happened since we last
2163 * checked called fsync.
2164 */
2165 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2166 up_write(&BTRFS_I(inode)->dio_sem);
2167 inode_unlock(inode);
2168 goto out;
2169 }
2170
2171 /*
2172 * We use start here because we will need to wait on the IO to complete
2173 * in btrfs_sync_log, which could require joining a transaction (for
2174 * example checking cross references in the nocow path). If we use join
2175 * here we could get into a situation where we're waiting on IO to
2176 * happen that is blocked on a transaction trying to commit. With start
2177 * we inc the extwriter counter, so we wait for all extwriters to exit
2178 * before we start blocking joiners. This comment is to keep somebody
2179 * from thinking they are super smart and changing this to
2180 * btrfs_join_transaction *cough*Josef*cough*.
2181 */
2182 trans = btrfs_start_transaction(root, 0);
2183 if (IS_ERR(trans)) {
2184 ret = PTR_ERR(trans);
2185 up_write(&BTRFS_I(inode)->dio_sem);
2186 inode_unlock(inode);
2187 goto out;
2188 }
2189
2190 ret = btrfs_log_dentry_safe(trans, dentry, start, end, &ctx);
2191 if (ret < 0) {
2192 /* Fallthrough and commit/free transaction. */
2193 ret = 1;
2194 }
2195
2196 /* we've logged all the items and now have a consistent
2197 * version of the file in the log. It is possible that
2198 * someone will come in and modify the file, but that's
2199 * fine because the log is consistent on disk, and we
2200 * have references to all of the file's extents
2201 *
2202 * It is possible that someone will come in and log the
2203 * file again, but that will end up using the synchronization
2204 * inside btrfs_sync_log to keep things safe.
2205 */
2206 up_write(&BTRFS_I(inode)->dio_sem);
2207 inode_unlock(inode);
2208
2209 if (ret != BTRFS_NO_LOG_SYNC) {
2210 if (!ret) {
2211 ret = btrfs_sync_log(trans, root, &ctx);
2212 if (!ret) {
2213 ret = btrfs_end_transaction(trans);
2214 goto out;
2215 }
2216 }
2217 ret = btrfs_commit_transaction(trans);
2218 } else {
2219 ret = btrfs_end_transaction(trans);
2220 }
2221out:
2222 ASSERT(list_empty(&ctx.list));
2223 err = file_check_and_advance_wb_err(file);
2224 if (!ret)
2225 ret = err;
2226 return ret > 0 ? -EIO : ret;
2227}
2228
2229static const struct vm_operations_struct btrfs_file_vm_ops = {
2230 .fault = filemap_fault,
2231 .map_pages = filemap_map_pages,
2232 .page_mkwrite = btrfs_page_mkwrite,
2233};
2234
2235static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2236{
2237 struct address_space *mapping = filp->f_mapping;
2238
2239 if (!mapping->a_ops->readpage)
2240 return -ENOEXEC;
2241
2242 file_accessed(filp);
2243 vma->vm_ops = &btrfs_file_vm_ops;
2244
2245 return 0;
2246}
2247
2248static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2249 int slot, u64 start, u64 end)
2250{
2251 struct btrfs_file_extent_item *fi;
2252 struct btrfs_key key;
2253
2254 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2255 return 0;
2256
2257 btrfs_item_key_to_cpu(leaf, &key, slot);
2258 if (key.objectid != btrfs_ino(inode) ||
2259 key.type != BTRFS_EXTENT_DATA_KEY)
2260 return 0;
2261
2262 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2263
2264 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2265 return 0;
2266
2267 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2268 return 0;
2269
2270 if (key.offset == end)
2271 return 1;
2272 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2273 return 1;
2274 return 0;
2275}
2276
2277static int fill_holes(struct btrfs_trans_handle *trans,
2278 struct btrfs_inode *inode,
2279 struct btrfs_path *path, u64 offset, u64 end)
2280{
2281 struct btrfs_fs_info *fs_info = trans->fs_info;
2282 struct btrfs_root *root = inode->root;
2283 struct extent_buffer *leaf;
2284 struct btrfs_file_extent_item *fi;
2285 struct extent_map *hole_em;
2286 struct extent_map_tree *em_tree = &inode->extent_tree;
2287 struct btrfs_key key;
2288 int ret;
2289
2290 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2291 goto out;
2292
2293 key.objectid = btrfs_ino(inode);
2294 key.type = BTRFS_EXTENT_DATA_KEY;
2295 key.offset = offset;
2296
2297 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2298 if (ret <= 0) {
2299 /*
2300 * We should have dropped this offset, so if we find it then
2301 * something has gone horribly wrong.
2302 */
2303 if (ret == 0)
2304 ret = -EINVAL;
2305 return ret;
2306 }
2307
2308 leaf = path->nodes[0];
2309 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2310 u64 num_bytes;
2311
2312 path->slots[0]--;
2313 fi = btrfs_item_ptr(leaf, path->slots[0],
2314 struct btrfs_file_extent_item);
2315 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2316 end - offset;
2317 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2318 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2319 btrfs_set_file_extent_offset(leaf, fi, 0);
2320 btrfs_mark_buffer_dirty(leaf);
2321 goto out;
2322 }
2323
2324 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2325 u64 num_bytes;
2326
2327 key.offset = offset;
2328 btrfs_set_item_key_safe(fs_info, path, &key);
2329 fi = btrfs_item_ptr(leaf, path->slots[0],
2330 struct btrfs_file_extent_item);
2331 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2332 offset;
2333 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2334 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2335 btrfs_set_file_extent_offset(leaf, fi, 0);
2336 btrfs_mark_buffer_dirty(leaf);
2337 goto out;
2338 }
2339 btrfs_release_path(path);
2340
2341 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2342 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2343 if (ret)
2344 return ret;
2345
2346out:
2347 btrfs_release_path(path);
2348
2349 hole_em = alloc_extent_map();
2350 if (!hole_em) {
2351 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2352 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2353 } else {
2354 hole_em->start = offset;
2355 hole_em->len = end - offset;
2356 hole_em->ram_bytes = hole_em->len;
2357 hole_em->orig_start = offset;
2358
2359 hole_em->block_start = EXTENT_MAP_HOLE;
2360 hole_em->block_len = 0;
2361 hole_em->orig_block_len = 0;
2362 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2363 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2364 hole_em->generation = trans->transid;
2365
2366 do {
2367 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2368 write_lock(&em_tree->lock);
2369 ret = add_extent_mapping(em_tree, hole_em, 1);
2370 write_unlock(&em_tree->lock);
2371 } while (ret == -EEXIST);
2372 free_extent_map(hole_em);
2373 if (ret)
2374 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2375 &inode->runtime_flags);
2376 }
2377
2378 return 0;
2379}
2380
2381/*
2382 * Find a hole extent on given inode and change start/len to the end of hole
2383 * extent.(hole/vacuum extent whose em->start <= start &&
2384 * em->start + em->len > start)
2385 * When a hole extent is found, return 1 and modify start/len.
2386 */
2387static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2388{
2389 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2390 struct extent_map *em;
2391 int ret = 0;
2392
2393 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2394 round_down(*start, fs_info->sectorsize),
2395 round_up(*len, fs_info->sectorsize), 0);
2396 if (IS_ERR(em))
2397 return PTR_ERR(em);
2398
2399 /* Hole or vacuum extent(only exists in no-hole mode) */
2400 if (em->block_start == EXTENT_MAP_HOLE) {
2401 ret = 1;
2402 *len = em->start + em->len > *start + *len ?
2403 0 : *start + *len - em->start - em->len;
2404 *start = em->start + em->len;
2405 }
2406 free_extent_map(em);
2407 return ret;
2408}
2409
2410static int btrfs_punch_hole_lock_range(struct inode *inode,
2411 const u64 lockstart,
2412 const u64 lockend,
2413 struct extent_state **cached_state)
2414{
2415 while (1) {
2416 struct btrfs_ordered_extent *ordered;
2417 int ret;
2418
2419 truncate_pagecache_range(inode, lockstart, lockend);
2420
2421 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2422 cached_state);
2423 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2424
2425 /*
2426 * We need to make sure we have no ordered extents in this range
2427 * and nobody raced in and read a page in this range, if we did
2428 * we need to try again.
2429 */
2430 if ((!ordered ||
2431 (ordered->file_offset + ordered->len <= lockstart ||
2432 ordered->file_offset > lockend)) &&
2433 !filemap_range_has_page(inode->i_mapping,
2434 lockstart, lockend)) {
2435 if (ordered)
2436 btrfs_put_ordered_extent(ordered);
2437 break;
2438 }
2439 if (ordered)
2440 btrfs_put_ordered_extent(ordered);
2441 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2442 lockend, cached_state);
2443 ret = btrfs_wait_ordered_range(inode, lockstart,
2444 lockend - lockstart + 1);
2445 if (ret)
2446 return ret;
2447 }
2448 return 0;
2449}
2450
2451static int btrfs_insert_clone_extent(struct btrfs_trans_handle *trans,
2452 struct inode *inode,
2453 struct btrfs_path *path,
2454 struct btrfs_clone_extent_info *clone_info,
2455 const u64 clone_len)
2456{
2457 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2458 struct btrfs_root *root = BTRFS_I(inode)->root;
2459 struct btrfs_file_extent_item *extent;
2460 struct extent_buffer *leaf;
2461 struct btrfs_key key;
2462 int slot;
2463 struct btrfs_ref ref = { 0 };
2464 u64 ref_offset;
2465 int ret;
2466
2467 if (clone_len == 0)
2468 return 0;
2469
2470 if (clone_info->disk_offset == 0 &&
2471 btrfs_fs_incompat(fs_info, NO_HOLES))
2472 return 0;
2473
2474 key.objectid = btrfs_ino(BTRFS_I(inode));
2475 key.type = BTRFS_EXTENT_DATA_KEY;
2476 key.offset = clone_info->file_offset;
2477 ret = btrfs_insert_empty_item(trans, root, path, &key,
2478 clone_info->item_size);
2479 if (ret)
2480 return ret;
2481 leaf = path->nodes[0];
2482 slot = path->slots[0];
2483 write_extent_buffer(leaf, clone_info->extent_buf,
2484 btrfs_item_ptr_offset(leaf, slot),
2485 clone_info->item_size);
2486 extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2487 btrfs_set_file_extent_offset(leaf, extent, clone_info->data_offset);
2488 btrfs_set_file_extent_num_bytes(leaf, extent, clone_len);
2489 btrfs_mark_buffer_dirty(leaf);
2490 btrfs_release_path(path);
2491
2492 /* If it's a hole, nothing more needs to be done. */
2493 if (clone_info->disk_offset == 0)
2494 return 0;
2495
2496 inode_add_bytes(inode, clone_len);
2497 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
2498 clone_info->disk_offset,
2499 clone_info->disk_len, 0);
2500 ref_offset = clone_info->file_offset - clone_info->data_offset;
2501 btrfs_init_data_ref(&ref, root->root_key.objectid,
2502 btrfs_ino(BTRFS_I(inode)), ref_offset);
2503 ret = btrfs_inc_extent_ref(trans, &ref);
2504
2505 return ret;
2506}
2507
2508/*
2509 * The respective range must have been previously locked, as well as the inode.
2510 * The end offset is inclusive (last byte of the range).
2511 * @clone_info is NULL for fallocate's hole punching and non-NULL for extent
2512 * cloning.
2513 * When cloning, we don't want to end up in a state where we dropped extents
2514 * without inserting a new one, so we must abort the transaction to avoid a
2515 * corruption.
2516 */
2517int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
2518 const u64 start, const u64 end,
2519 struct btrfs_clone_extent_info *clone_info,
2520 struct btrfs_trans_handle **trans_out)
2521{
2522 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2523 u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
2524 u64 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2525 struct btrfs_root *root = BTRFS_I(inode)->root;
2526 struct btrfs_trans_handle *trans = NULL;
2527 struct btrfs_block_rsv *rsv;
2528 unsigned int rsv_count;
2529 u64 cur_offset;
2530 u64 drop_end;
2531 u64 len = end - start;
2532 int ret = 0;
2533
2534 if (end <= start)
2535 return -EINVAL;
2536
2537 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2538 if (!rsv) {
2539 ret = -ENOMEM;
2540 goto out;
2541 }
2542 rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
2543 rsv->failfast = 1;
2544
2545 /*
2546 * 1 - update the inode
2547 * 1 - removing the extents in the range
2548 * 1 - adding the hole extent if no_holes isn't set or if we are cloning
2549 * an extent
2550 */
2551 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || clone_info)
2552 rsv_count = 3;
2553 else
2554 rsv_count = 2;
2555
2556 trans = btrfs_start_transaction(root, rsv_count);
2557 if (IS_ERR(trans)) {
2558 ret = PTR_ERR(trans);
2559 trans = NULL;
2560 goto out_free;
2561 }
2562
2563 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2564 min_size, false);
2565 BUG_ON(ret);
2566 trans->block_rsv = rsv;
2567
2568 cur_offset = start;
2569 while (cur_offset < end) {
2570 ret = __btrfs_drop_extents(trans, root, inode, path,
2571 cur_offset, end + 1, &drop_end,
2572 1, 0, 0, NULL);
2573 if (ret != -ENOSPC) {
2574 /*
2575 * When cloning we want to avoid transaction aborts when
2576 * nothing was done and we are attempting to clone parts
2577 * of inline extents, in such cases -EOPNOTSUPP is
2578 * returned by __btrfs_drop_extents() without having
2579 * changed anything in the file.
2580 */
2581 if (clone_info && ret && ret != -EOPNOTSUPP)
2582 btrfs_abort_transaction(trans, ret);
2583 break;
2584 }
2585
2586 trans->block_rsv = &fs_info->trans_block_rsv;
2587
2588 if (!clone_info && cur_offset < drop_end &&
2589 cur_offset < ino_size) {
2590 ret = fill_holes(trans, BTRFS_I(inode), path,
2591 cur_offset, drop_end);
2592 if (ret) {
2593 /*
2594 * If we failed then we didn't insert our hole
2595 * entries for the area we dropped, so now the
2596 * fs is corrupted, so we must abort the
2597 * transaction.
2598 */
2599 btrfs_abort_transaction(trans, ret);
2600 break;
2601 }
2602 }
2603
2604 if (clone_info) {
2605 u64 clone_len = drop_end - cur_offset;
2606
2607 ret = btrfs_insert_clone_extent(trans, inode, path,
2608 clone_info, clone_len);
2609 if (ret) {
2610 btrfs_abort_transaction(trans, ret);
2611 break;
2612 }
2613 clone_info->data_len -= clone_len;
2614 clone_info->data_offset += clone_len;
2615 clone_info->file_offset += clone_len;
2616 }
2617
2618 cur_offset = drop_end;
2619
2620 ret = btrfs_update_inode(trans, root, inode);
2621 if (ret)
2622 break;
2623
2624 btrfs_end_transaction(trans);
2625 btrfs_btree_balance_dirty(fs_info);
2626
2627 trans = btrfs_start_transaction(root, rsv_count);
2628 if (IS_ERR(trans)) {
2629 ret = PTR_ERR(trans);
2630 trans = NULL;
2631 break;
2632 }
2633
2634 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2635 rsv, min_size, false);
2636 BUG_ON(ret); /* shouldn't happen */
2637 trans->block_rsv = rsv;
2638
2639 if (!clone_info) {
2640 ret = find_first_non_hole(inode, &cur_offset, &len);
2641 if (unlikely(ret < 0))
2642 break;
2643 if (ret && !len) {
2644 ret = 0;
2645 break;
2646 }
2647 }
2648 }
2649
2650 /*
2651 * If we were cloning, force the next fsync to be a full one since we
2652 * we replaced (or just dropped in the case of cloning holes when
2653 * NO_HOLES is enabled) extents and extent maps.
2654 * This is for the sake of simplicity, and cloning into files larger
2655 * than 16Mb would force the full fsync any way (when
2656 * try_release_extent_mapping() is invoked during page cache truncation.
2657 */
2658 if (clone_info)
2659 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2660 &BTRFS_I(inode)->runtime_flags);
2661
2662 if (ret)
2663 goto out_trans;
2664
2665 trans->block_rsv = &fs_info->trans_block_rsv;
2666 /*
2667 * If we are using the NO_HOLES feature we might have had already an
2668 * hole that overlaps a part of the region [lockstart, lockend] and
2669 * ends at (or beyond) lockend. Since we have no file extent items to
2670 * represent holes, drop_end can be less than lockend and so we must
2671 * make sure we have an extent map representing the existing hole (the
2672 * call to __btrfs_drop_extents() might have dropped the existing extent
2673 * map representing the existing hole), otherwise the fast fsync path
2674 * will not record the existence of the hole region
2675 * [existing_hole_start, lockend].
2676 */
2677 if (drop_end <= end)
2678 drop_end = end + 1;
2679 /*
2680 * Don't insert file hole extent item if it's for a range beyond eof
2681 * (because it's useless) or if it represents a 0 bytes range (when
2682 * cur_offset == drop_end).
2683 */
2684 if (!clone_info && cur_offset < ino_size && cur_offset < drop_end) {
2685 ret = fill_holes(trans, BTRFS_I(inode), path,
2686 cur_offset, drop_end);
2687 if (ret) {
2688 /* Same comment as above. */
2689 btrfs_abort_transaction(trans, ret);
2690 goto out_trans;
2691 }
2692 }
2693 if (clone_info) {
2694 ret = btrfs_insert_clone_extent(trans, inode, path, clone_info,
2695 clone_info->data_len);
2696 if (ret) {
2697 btrfs_abort_transaction(trans, ret);
2698 goto out_trans;
2699 }
2700 }
2701
2702out_trans:
2703 if (!trans)
2704 goto out_free;
2705
2706 trans->block_rsv = &fs_info->trans_block_rsv;
2707 if (ret)
2708 btrfs_end_transaction(trans);
2709 else
2710 *trans_out = trans;
2711out_free:
2712 btrfs_free_block_rsv(fs_info, rsv);
2713out:
2714 return ret;
2715}
2716
2717static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2718{
2719 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2720 struct btrfs_root *root = BTRFS_I(inode)->root;
2721 struct extent_state *cached_state = NULL;
2722 struct btrfs_path *path;
2723 struct btrfs_trans_handle *trans = NULL;
2724 u64 lockstart;
2725 u64 lockend;
2726 u64 tail_start;
2727 u64 tail_len;
2728 u64 orig_start = offset;
2729 int ret = 0;
2730 bool same_block;
2731 u64 ino_size;
2732 bool truncated_block = false;
2733 bool updated_inode = false;
2734
2735 ret = btrfs_wait_ordered_range(inode, offset, len);
2736 if (ret)
2737 return ret;
2738
2739 inode_lock(inode);
2740 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2741 ret = find_first_non_hole(inode, &offset, &len);
2742 if (ret < 0)
2743 goto out_only_mutex;
2744 if (ret && !len) {
2745 /* Already in a large hole */
2746 ret = 0;
2747 goto out_only_mutex;
2748 }
2749
2750 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2751 lockend = round_down(offset + len,
2752 btrfs_inode_sectorsize(inode)) - 1;
2753 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2754 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2755 /*
2756 * We needn't truncate any block which is beyond the end of the file
2757 * because we are sure there is no data there.
2758 */
2759 /*
2760 * Only do this if we are in the same block and we aren't doing the
2761 * entire block.
2762 */
2763 if (same_block && len < fs_info->sectorsize) {
2764 if (offset < ino_size) {
2765 truncated_block = true;
2766 ret = btrfs_truncate_block(inode, offset, len, 0);
2767 } else {
2768 ret = 0;
2769 }
2770 goto out_only_mutex;
2771 }
2772
2773 /* zero back part of the first block */
2774 if (offset < ino_size) {
2775 truncated_block = true;
2776 ret = btrfs_truncate_block(inode, offset, 0, 0);
2777 if (ret) {
2778 inode_unlock(inode);
2779 return ret;
2780 }
2781 }
2782
2783 /* Check the aligned pages after the first unaligned page,
2784 * if offset != orig_start, which means the first unaligned page
2785 * including several following pages are already in holes,
2786 * the extra check can be skipped */
2787 if (offset == orig_start) {
2788 /* after truncate page, check hole again */
2789 len = offset + len - lockstart;
2790 offset = lockstart;
2791 ret = find_first_non_hole(inode, &offset, &len);
2792 if (ret < 0)
2793 goto out_only_mutex;
2794 if (ret && !len) {
2795 ret = 0;
2796 goto out_only_mutex;
2797 }
2798 lockstart = offset;
2799 }
2800
2801 /* Check the tail unaligned part is in a hole */
2802 tail_start = lockend + 1;
2803 tail_len = offset + len - tail_start;
2804 if (tail_len) {
2805 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2806 if (unlikely(ret < 0))
2807 goto out_only_mutex;
2808 if (!ret) {
2809 /* zero the front end of the last page */
2810 if (tail_start + tail_len < ino_size) {
2811 truncated_block = true;
2812 ret = btrfs_truncate_block(inode,
2813 tail_start + tail_len,
2814 0, 1);
2815 if (ret)
2816 goto out_only_mutex;
2817 }
2818 }
2819 }
2820
2821 if (lockend < lockstart) {
2822 ret = 0;
2823 goto out_only_mutex;
2824 }
2825
2826 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2827 &cached_state);
2828 if (ret)
2829 goto out_only_mutex;
2830
2831 path = btrfs_alloc_path();
2832 if (!path) {
2833 ret = -ENOMEM;
2834 goto out;
2835 }
2836
2837 ret = btrfs_punch_hole_range(inode, path, lockstart, lockend, NULL,
2838 &trans);
2839 btrfs_free_path(path);
2840 if (ret)
2841 goto out;
2842
2843 ASSERT(trans != NULL);
2844 inode_inc_iversion(inode);
2845 inode->i_mtime = inode->i_ctime = current_time(inode);
2846 ret = btrfs_update_inode(trans, root, inode);
2847 updated_inode = true;
2848 btrfs_end_transaction(trans);
2849 btrfs_btree_balance_dirty(fs_info);
2850out:
2851 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2852 &cached_state);
2853out_only_mutex:
2854 if (!updated_inode && truncated_block && !ret) {
2855 /*
2856 * If we only end up zeroing part of a page, we still need to
2857 * update the inode item, so that all the time fields are
2858 * updated as well as the necessary btrfs inode in memory fields
2859 * for detecting, at fsync time, if the inode isn't yet in the
2860 * log tree or it's there but not up to date.
2861 */
2862 struct timespec64 now = current_time(inode);
2863
2864 inode_inc_iversion(inode);
2865 inode->i_mtime = now;
2866 inode->i_ctime = now;
2867 trans = btrfs_start_transaction(root, 1);
2868 if (IS_ERR(trans)) {
2869 ret = PTR_ERR(trans);
2870 } else {
2871 int ret2;
2872
2873 ret = btrfs_update_inode(trans, root, inode);
2874 ret2 = btrfs_end_transaction(trans);
2875 if (!ret)
2876 ret = ret2;
2877 }
2878 }
2879 inode_unlock(inode);
2880 return ret;
2881}
2882
2883/* Helper structure to record which range is already reserved */
2884struct falloc_range {
2885 struct list_head list;
2886 u64 start;
2887 u64 len;
2888};
2889
2890/*
2891 * Helper function to add falloc range
2892 *
2893 * Caller should have locked the larger range of extent containing
2894 * [start, len)
2895 */
2896static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2897{
2898 struct falloc_range *prev = NULL;
2899 struct falloc_range *range = NULL;
2900
2901 if (list_empty(head))
2902 goto insert;
2903
2904 /*
2905 * As fallocate iterate by bytenr order, we only need to check
2906 * the last range.
2907 */
2908 prev = list_entry(head->prev, struct falloc_range, list);
2909 if (prev->start + prev->len == start) {
2910 prev->len += len;
2911 return 0;
2912 }
2913insert:
2914 range = kmalloc(sizeof(*range), GFP_KERNEL);
2915 if (!range)
2916 return -ENOMEM;
2917 range->start = start;
2918 range->len = len;
2919 list_add_tail(&range->list, head);
2920 return 0;
2921}
2922
2923static int btrfs_fallocate_update_isize(struct inode *inode,
2924 const u64 end,
2925 const int mode)
2926{
2927 struct btrfs_trans_handle *trans;
2928 struct btrfs_root *root = BTRFS_I(inode)->root;
2929 int ret;
2930 int ret2;
2931
2932 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
2933 return 0;
2934
2935 trans = btrfs_start_transaction(root, 1);
2936 if (IS_ERR(trans))
2937 return PTR_ERR(trans);
2938
2939 inode->i_ctime = current_time(inode);
2940 i_size_write(inode, end);
2941 btrfs_ordered_update_i_size(inode, end, NULL);
2942 ret = btrfs_update_inode(trans, root, inode);
2943 ret2 = btrfs_end_transaction(trans);
2944
2945 return ret ? ret : ret2;
2946}
2947
2948enum {
2949 RANGE_BOUNDARY_WRITTEN_EXTENT,
2950 RANGE_BOUNDARY_PREALLOC_EXTENT,
2951 RANGE_BOUNDARY_HOLE,
2952};
2953
2954static int btrfs_zero_range_check_range_boundary(struct inode *inode,
2955 u64 offset)
2956{
2957 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2958 struct extent_map *em;
2959 int ret;
2960
2961 offset = round_down(offset, sectorsize);
2962 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
2963 if (IS_ERR(em))
2964 return PTR_ERR(em);
2965
2966 if (em->block_start == EXTENT_MAP_HOLE)
2967 ret = RANGE_BOUNDARY_HOLE;
2968 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2969 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
2970 else
2971 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
2972
2973 free_extent_map(em);
2974 return ret;
2975}
2976
2977static int btrfs_zero_range(struct inode *inode,
2978 loff_t offset,
2979 loff_t len,
2980 const int mode)
2981{
2982 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2983 struct extent_map *em;
2984 struct extent_changeset *data_reserved = NULL;
2985 int ret;
2986 u64 alloc_hint = 0;
2987 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2988 u64 alloc_start = round_down(offset, sectorsize);
2989 u64 alloc_end = round_up(offset + len, sectorsize);
2990 u64 bytes_to_reserve = 0;
2991 bool space_reserved = false;
2992
2993 inode_dio_wait(inode);
2994
2995 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2996 alloc_start, alloc_end - alloc_start, 0);
2997 if (IS_ERR(em)) {
2998 ret = PTR_ERR(em);
2999 goto out;
3000 }
3001
3002 /*
3003 * Avoid hole punching and extent allocation for some cases. More cases
3004 * could be considered, but these are unlikely common and we keep things
3005 * as simple as possible for now. Also, intentionally, if the target
3006 * range contains one or more prealloc extents together with regular
3007 * extents and holes, we drop all the existing extents and allocate a
3008 * new prealloc extent, so that we get a larger contiguous disk extent.
3009 */
3010 if (em->start <= alloc_start &&
3011 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3012 const u64 em_end = em->start + em->len;
3013
3014 if (em_end >= offset + len) {
3015 /*
3016 * The whole range is already a prealloc extent,
3017 * do nothing except updating the inode's i_size if
3018 * needed.
3019 */
3020 free_extent_map(em);
3021 ret = btrfs_fallocate_update_isize(inode, offset + len,
3022 mode);
3023 goto out;
3024 }
3025 /*
3026 * Part of the range is already a prealloc extent, so operate
3027 * only on the remaining part of the range.
3028 */
3029 alloc_start = em_end;
3030 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
3031 len = offset + len - alloc_start;
3032 offset = alloc_start;
3033 alloc_hint = em->block_start + em->len;
3034 }
3035 free_extent_map(em);
3036
3037 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
3038 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
3039 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
3040 alloc_start, sectorsize, 0);
3041 if (IS_ERR(em)) {
3042 ret = PTR_ERR(em);
3043 goto out;
3044 }
3045
3046 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3047 free_extent_map(em);
3048 ret = btrfs_fallocate_update_isize(inode, offset + len,
3049 mode);
3050 goto out;
3051 }
3052 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
3053 free_extent_map(em);
3054 ret = btrfs_truncate_block(inode, offset, len, 0);
3055 if (!ret)
3056 ret = btrfs_fallocate_update_isize(inode,
3057 offset + len,
3058 mode);
3059 return ret;
3060 }
3061 free_extent_map(em);
3062 alloc_start = round_down(offset, sectorsize);
3063 alloc_end = alloc_start + sectorsize;
3064 goto reserve_space;
3065 }
3066
3067 alloc_start = round_up(offset, sectorsize);
3068 alloc_end = round_down(offset + len, sectorsize);
3069
3070 /*
3071 * For unaligned ranges, check the pages at the boundaries, they might
3072 * map to an extent, in which case we need to partially zero them, or
3073 * they might map to a hole, in which case we need our allocation range
3074 * to cover them.
3075 */
3076 if (!IS_ALIGNED(offset, sectorsize)) {
3077 ret = btrfs_zero_range_check_range_boundary(inode, offset);
3078 if (ret < 0)
3079 goto out;
3080 if (ret == RANGE_BOUNDARY_HOLE) {
3081 alloc_start = round_down(offset, sectorsize);
3082 ret = 0;
3083 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3084 ret = btrfs_truncate_block(inode, offset, 0, 0);
3085 if (ret)
3086 goto out;
3087 } else {
3088 ret = 0;
3089 }
3090 }
3091
3092 if (!IS_ALIGNED(offset + len, sectorsize)) {
3093 ret = btrfs_zero_range_check_range_boundary(inode,
3094 offset + len);
3095 if (ret < 0)
3096 goto out;
3097 if (ret == RANGE_BOUNDARY_HOLE) {
3098 alloc_end = round_up(offset + len, sectorsize);
3099 ret = 0;
3100 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3101 ret = btrfs_truncate_block(inode, offset + len, 0, 1);
3102 if (ret)
3103 goto out;
3104 } else {
3105 ret = 0;
3106 }
3107 }
3108
3109reserve_space:
3110 if (alloc_start < alloc_end) {
3111 struct extent_state *cached_state = NULL;
3112 const u64 lockstart = alloc_start;
3113 const u64 lockend = alloc_end - 1;
3114
3115 bytes_to_reserve = alloc_end - alloc_start;
3116 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3117 bytes_to_reserve);
3118 if (ret < 0)
3119 goto out;
3120 space_reserved = true;
3121 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3122 alloc_start, bytes_to_reserve);
3123 if (ret)
3124 goto out;
3125 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3126 &cached_state);
3127 if (ret)
3128 goto out;
3129 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
3130 alloc_end - alloc_start,
3131 i_blocksize(inode),
3132 offset + len, &alloc_hint);
3133 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3134 lockend, &cached_state);
3135 /* btrfs_prealloc_file_range releases reserved space on error */
3136 if (ret) {
3137 space_reserved = false;
3138 goto out;
3139 }
3140 }
3141 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
3142 out:
3143 if (ret && space_reserved)
3144 btrfs_free_reserved_data_space(inode, data_reserved,
3145 alloc_start, bytes_to_reserve);
3146 extent_changeset_free(data_reserved);
3147
3148 return ret;
3149}
3150
3151static long btrfs_fallocate(struct file *file, int mode,
3152 loff_t offset, loff_t len)
3153{
3154 struct inode *inode = file_inode(file);
3155 struct extent_state *cached_state = NULL;
3156 struct extent_changeset *data_reserved = NULL;
3157 struct falloc_range *range;
3158 struct falloc_range *tmp;
3159 struct list_head reserve_list;
3160 u64 cur_offset;
3161 u64 last_byte;
3162 u64 alloc_start;
3163 u64 alloc_end;
3164 u64 alloc_hint = 0;
3165 u64 locked_end;
3166 u64 actual_end = 0;
3167 struct extent_map *em;
3168 int blocksize = btrfs_inode_sectorsize(inode);
3169 int ret;
3170
3171 alloc_start = round_down(offset, blocksize);
3172 alloc_end = round_up(offset + len, blocksize);
3173 cur_offset = alloc_start;
3174
3175 /* Make sure we aren't being give some crap mode */
3176 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3177 FALLOC_FL_ZERO_RANGE))
3178 return -EOPNOTSUPP;
3179
3180 if (mode & FALLOC_FL_PUNCH_HOLE)
3181 return btrfs_punch_hole(inode, offset, len);
3182
3183 /*
3184 * Only trigger disk allocation, don't trigger qgroup reserve
3185 *
3186 * For qgroup space, it will be checked later.
3187 */
3188 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3189 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3190 alloc_end - alloc_start);
3191 if (ret < 0)
3192 return ret;
3193 }
3194
3195 inode_lock(inode);
3196
3197 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3198 ret = inode_newsize_ok(inode, offset + len);
3199 if (ret)
3200 goto out;
3201 }
3202
3203 /*
3204 * TODO: Move these two operations after we have checked
3205 * accurate reserved space, or fallocate can still fail but
3206 * with page truncated or size expanded.
3207 *
3208 * But that's a minor problem and won't do much harm BTW.
3209 */
3210 if (alloc_start > inode->i_size) {
3211 ret = btrfs_cont_expand(inode, i_size_read(inode),
3212 alloc_start);
3213 if (ret)
3214 goto out;
3215 } else if (offset + len > inode->i_size) {
3216 /*
3217 * If we are fallocating from the end of the file onward we
3218 * need to zero out the end of the block if i_size lands in the
3219 * middle of a block.
3220 */
3221 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
3222 if (ret)
3223 goto out;
3224 }
3225
3226 /*
3227 * wait for ordered IO before we have any locks. We'll loop again
3228 * below with the locks held.
3229 */
3230 ret = btrfs_wait_ordered_range(inode, alloc_start,
3231 alloc_end - alloc_start);
3232 if (ret)
3233 goto out;
3234
3235 if (mode & FALLOC_FL_ZERO_RANGE) {
3236 ret = btrfs_zero_range(inode, offset, len, mode);
3237 inode_unlock(inode);
3238 return ret;
3239 }
3240
3241 locked_end = alloc_end - 1;
3242 while (1) {
3243 struct btrfs_ordered_extent *ordered;
3244
3245 /* the extent lock is ordered inside the running
3246 * transaction
3247 */
3248 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3249 locked_end, &cached_state);
3250 ordered = btrfs_lookup_first_ordered_extent(inode, locked_end);
3251
3252 if (ordered &&
3253 ordered->file_offset + ordered->len > alloc_start &&
3254 ordered->file_offset < alloc_end) {
3255 btrfs_put_ordered_extent(ordered);
3256 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3257 alloc_start, locked_end,
3258 &cached_state);
3259 /*
3260 * we can't wait on the range with the transaction
3261 * running or with the extent lock held
3262 */
3263 ret = btrfs_wait_ordered_range(inode, alloc_start,
3264 alloc_end - alloc_start);
3265 if (ret)
3266 goto out;
3267 } else {
3268 if (ordered)
3269 btrfs_put_ordered_extent(ordered);
3270 break;
3271 }
3272 }
3273
3274 /* First, check if we exceed the qgroup limit */
3275 INIT_LIST_HEAD(&reserve_list);
3276 while (cur_offset < alloc_end) {
3277 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3278 alloc_end - cur_offset, 0);
3279 if (IS_ERR(em)) {
3280 ret = PTR_ERR(em);
3281 break;
3282 }
3283 last_byte = min(extent_map_end(em), alloc_end);
3284 actual_end = min_t(u64, extent_map_end(em), offset + len);
3285 last_byte = ALIGN(last_byte, blocksize);
3286 if (em->block_start == EXTENT_MAP_HOLE ||
3287 (cur_offset >= inode->i_size &&
3288 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3289 ret = add_falloc_range(&reserve_list, cur_offset,
3290 last_byte - cur_offset);
3291 if (ret < 0) {
3292 free_extent_map(em);
3293 break;
3294 }
3295 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3296 cur_offset, last_byte - cur_offset);
3297 if (ret < 0) {
3298 cur_offset = last_byte;
3299 free_extent_map(em);
3300 break;
3301 }
3302 } else {
3303 /*
3304 * Do not need to reserve unwritten extent for this
3305 * range, free reserved data space first, otherwise
3306 * it'll result in false ENOSPC error.
3307 */
3308 btrfs_free_reserved_data_space(inode, data_reserved,
3309 cur_offset, last_byte - cur_offset);
3310 }
3311 free_extent_map(em);
3312 cur_offset = last_byte;
3313 }
3314
3315 /*
3316 * If ret is still 0, means we're OK to fallocate.
3317 * Or just cleanup the list and exit.
3318 */
3319 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3320 if (!ret)
3321 ret = btrfs_prealloc_file_range(inode, mode,
3322 range->start,
3323 range->len, i_blocksize(inode),
3324 offset + len, &alloc_hint);
3325 else
3326 btrfs_free_reserved_data_space(inode,
3327 data_reserved, range->start,
3328 range->len);
3329 list_del(&range->list);
3330 kfree(range);
3331 }
3332 if (ret < 0)
3333 goto out_unlock;
3334
3335 /*
3336 * We didn't need to allocate any more space, but we still extended the
3337 * size of the file so we need to update i_size and the inode item.
3338 */
3339 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3340out_unlock:
3341 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3342 &cached_state);
3343out:
3344 inode_unlock(inode);
3345 /* Let go of our reservation. */
3346 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3347 btrfs_free_reserved_data_space(inode, data_reserved,
3348 cur_offset, alloc_end - cur_offset);
3349 extent_changeset_free(data_reserved);
3350 return ret;
3351}
3352
3353static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
3354{
3355 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3356 struct extent_map *em = NULL;
3357 struct extent_state *cached_state = NULL;
3358 u64 lockstart;
3359 u64 lockend;
3360 u64 start;
3361 u64 len;
3362 int ret = 0;
3363
3364 if (inode->i_size == 0)
3365 return -ENXIO;
3366
3367 /*
3368 * *offset can be negative, in this case we start finding DATA/HOLE from
3369 * the very start of the file.
3370 */
3371 start = max_t(loff_t, 0, *offset);
3372
3373 lockstart = round_down(start, fs_info->sectorsize);
3374 lockend = round_up(i_size_read(inode),
3375 fs_info->sectorsize);
3376 if (lockend <= lockstart)
3377 lockend = lockstart + fs_info->sectorsize;
3378 lockend--;
3379 len = lockend - lockstart + 1;
3380
3381 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3382 &cached_state);
3383
3384 while (start < inode->i_size) {
3385 em = btrfs_get_extent_fiemap(BTRFS_I(inode), start, len);
3386 if (IS_ERR(em)) {
3387 ret = PTR_ERR(em);
3388 em = NULL;
3389 break;
3390 }
3391
3392 if (whence == SEEK_HOLE &&
3393 (em->block_start == EXTENT_MAP_HOLE ||
3394 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3395 break;
3396 else if (whence == SEEK_DATA &&
3397 (em->block_start != EXTENT_MAP_HOLE &&
3398 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3399 break;
3400
3401 start = em->start + em->len;
3402 free_extent_map(em);
3403 em = NULL;
3404 cond_resched();
3405 }
3406 free_extent_map(em);
3407 if (!ret) {
3408 if (whence == SEEK_DATA && start >= inode->i_size)
3409 ret = -ENXIO;
3410 else
3411 *offset = min_t(loff_t, start, inode->i_size);
3412 }
3413 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3414 &cached_state);
3415 return ret;
3416}
3417
3418static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3419{
3420 struct inode *inode = file->f_mapping->host;
3421 int ret;
3422
3423 inode_lock(inode);
3424 switch (whence) {
3425 case SEEK_END:
3426 case SEEK_CUR:
3427 offset = generic_file_llseek(file, offset, whence);
3428 goto out;
3429 case SEEK_DATA:
3430 case SEEK_HOLE:
3431 if (offset >= i_size_read(inode)) {
3432 inode_unlock(inode);
3433 return -ENXIO;
3434 }
3435
3436 ret = find_desired_extent(inode, &offset, whence);
3437 if (ret) {
3438 inode_unlock(inode);
3439 return ret;
3440 }
3441 }
3442
3443 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3444out:
3445 inode_unlock(inode);
3446 return offset;
3447}
3448
3449static int btrfs_file_open(struct inode *inode, struct file *filp)
3450{
3451 filp->f_mode |= FMODE_NOWAIT;
3452 return generic_file_open(inode, filp);
3453}
3454
3455const struct file_operations btrfs_file_operations = {
3456 .llseek = btrfs_file_llseek,
3457 .read_iter = generic_file_read_iter,
3458 .splice_read = generic_file_splice_read,
3459 .write_iter = btrfs_file_write_iter,
3460 .mmap = btrfs_file_mmap,
3461 .open = btrfs_file_open,
3462 .release = btrfs_release_file,
3463 .fsync = btrfs_sync_file,
3464 .fallocate = btrfs_fallocate,
3465 .unlocked_ioctl = btrfs_ioctl,
3466#ifdef CONFIG_COMPAT
3467 .compat_ioctl = btrfs_compat_ioctl,
3468#endif
3469 .remap_file_range = btrfs_remap_file_range,
3470};
3471
3472void __cold btrfs_auto_defrag_exit(void)
3473{
3474 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3475}
3476
3477int __init btrfs_auto_defrag_init(void)
3478{
3479 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3480 sizeof(struct inode_defrag), 0,
3481 SLAB_MEM_SPREAD,
3482 NULL);
3483 if (!btrfs_inode_defrag_cachep)
3484 return -ENOMEM;
3485
3486 return 0;
3487}
3488
3489int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3490{
3491 int ret;
3492
3493 /*
3494 * So with compression we will find and lock a dirty page and clear the
3495 * first one as dirty, setup an async extent, and immediately return
3496 * with the entire range locked but with nobody actually marked with
3497 * writeback. So we can't just filemap_write_and_wait_range() and
3498 * expect it to work since it will just kick off a thread to do the
3499 * actual work. So we need to call filemap_fdatawrite_range _again_
3500 * since it will wait on the page lock, which won't be unlocked until
3501 * after the pages have been marked as writeback and so we're good to go
3502 * from there. We have to do this otherwise we'll miss the ordered
3503 * extents and that results in badness. Please Josef, do not think you
3504 * know better and pull this out at some point in the future, it is
3505 * right and you are wrong.
3506 */
3507 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3508 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3509 &BTRFS_I(inode)->runtime_flags))
3510 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3511
3512 return ret;
3513}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/fs.h>
7#include <linux/pagemap.h>
8#include <linux/highmem.h>
9#include <linux/time.h>
10#include <linux/init.h>
11#include <linux/string.h>
12#include <linux/backing-dev.h>
13#include <linux/mpage.h>
14#include <linux/falloc.h>
15#include <linux/swap.h>
16#include <linux/writeback.h>
17#include <linux/compat.h>
18#include <linux/slab.h>
19#include <linux/btrfs.h>
20#include <linux/uio.h>
21#include <linux/iversion.h>
22#include "ctree.h"
23#include "disk-io.h"
24#include "transaction.h"
25#include "btrfs_inode.h"
26#include "print-tree.h"
27#include "tree-log.h"
28#include "locking.h"
29#include "volumes.h"
30#include "qgroup.h"
31#include "compression.h"
32
33static struct kmem_cache *btrfs_inode_defrag_cachep;
34/*
35 * when auto defrag is enabled we
36 * queue up these defrag structs to remember which
37 * inodes need defragging passes
38 */
39struct inode_defrag {
40 struct rb_node rb_node;
41 /* objectid */
42 u64 ino;
43 /*
44 * transid where the defrag was added, we search for
45 * extents newer than this
46 */
47 u64 transid;
48
49 /* root objectid */
50 u64 root;
51
52 /* last offset we were able to defrag */
53 u64 last_offset;
54
55 /* if we've wrapped around back to zero once already */
56 int cycled;
57};
58
59static int __compare_inode_defrag(struct inode_defrag *defrag1,
60 struct inode_defrag *defrag2)
61{
62 if (defrag1->root > defrag2->root)
63 return 1;
64 else if (defrag1->root < defrag2->root)
65 return -1;
66 else if (defrag1->ino > defrag2->ino)
67 return 1;
68 else if (defrag1->ino < defrag2->ino)
69 return -1;
70 else
71 return 0;
72}
73
74/* pop a record for an inode into the defrag tree. The lock
75 * must be held already
76 *
77 * If you're inserting a record for an older transid than an
78 * existing record, the transid already in the tree is lowered
79 *
80 * If an existing record is found the defrag item you
81 * pass in is freed
82 */
83static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
84 struct inode_defrag *defrag)
85{
86 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
87 struct inode_defrag *entry;
88 struct rb_node **p;
89 struct rb_node *parent = NULL;
90 int ret;
91
92 p = &fs_info->defrag_inodes.rb_node;
93 while (*p) {
94 parent = *p;
95 entry = rb_entry(parent, struct inode_defrag, rb_node);
96
97 ret = __compare_inode_defrag(defrag, entry);
98 if (ret < 0)
99 p = &parent->rb_left;
100 else if (ret > 0)
101 p = &parent->rb_right;
102 else {
103 /* if we're reinserting an entry for
104 * an old defrag run, make sure to
105 * lower the transid of our existing record
106 */
107 if (defrag->transid < entry->transid)
108 entry->transid = defrag->transid;
109 if (defrag->last_offset > entry->last_offset)
110 entry->last_offset = defrag->last_offset;
111 return -EEXIST;
112 }
113 }
114 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
115 rb_link_node(&defrag->rb_node, parent, p);
116 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
117 return 0;
118}
119
120static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
121{
122 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
123 return 0;
124
125 if (btrfs_fs_closing(fs_info))
126 return 0;
127
128 return 1;
129}
130
131/*
132 * insert a defrag record for this inode if auto defrag is
133 * enabled
134 */
135int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
136 struct btrfs_inode *inode)
137{
138 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
139 struct btrfs_root *root = inode->root;
140 struct inode_defrag *defrag;
141 u64 transid;
142 int ret;
143
144 if (!__need_auto_defrag(fs_info))
145 return 0;
146
147 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
148 return 0;
149
150 if (trans)
151 transid = trans->transid;
152 else
153 transid = inode->root->last_trans;
154
155 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
156 if (!defrag)
157 return -ENOMEM;
158
159 defrag->ino = btrfs_ino(inode);
160 defrag->transid = transid;
161 defrag->root = root->root_key.objectid;
162
163 spin_lock(&fs_info->defrag_inodes_lock);
164 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
165 /*
166 * If we set IN_DEFRAG flag and evict the inode from memory,
167 * and then re-read this inode, this new inode doesn't have
168 * IN_DEFRAG flag. At the case, we may find the existed defrag.
169 */
170 ret = __btrfs_add_inode_defrag(inode, defrag);
171 if (ret)
172 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
173 } else {
174 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
175 }
176 spin_unlock(&fs_info->defrag_inodes_lock);
177 return 0;
178}
179
180/*
181 * Requeue the defrag object. If there is a defrag object that points to
182 * the same inode in the tree, we will merge them together (by
183 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
184 */
185static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
186 struct inode_defrag *defrag)
187{
188 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
189 int ret;
190
191 if (!__need_auto_defrag(fs_info))
192 goto out;
193
194 /*
195 * Here we don't check the IN_DEFRAG flag, because we need merge
196 * them together.
197 */
198 spin_lock(&fs_info->defrag_inodes_lock);
199 ret = __btrfs_add_inode_defrag(inode, defrag);
200 spin_unlock(&fs_info->defrag_inodes_lock);
201 if (ret)
202 goto out;
203 return;
204out:
205 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
206}
207
208/*
209 * pick the defragable inode that we want, if it doesn't exist, we will get
210 * the next one.
211 */
212static struct inode_defrag *
213btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
214{
215 struct inode_defrag *entry = NULL;
216 struct inode_defrag tmp;
217 struct rb_node *p;
218 struct rb_node *parent = NULL;
219 int ret;
220
221 tmp.ino = ino;
222 tmp.root = root;
223
224 spin_lock(&fs_info->defrag_inodes_lock);
225 p = fs_info->defrag_inodes.rb_node;
226 while (p) {
227 parent = p;
228 entry = rb_entry(parent, struct inode_defrag, rb_node);
229
230 ret = __compare_inode_defrag(&tmp, entry);
231 if (ret < 0)
232 p = parent->rb_left;
233 else if (ret > 0)
234 p = parent->rb_right;
235 else
236 goto out;
237 }
238
239 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
240 parent = rb_next(parent);
241 if (parent)
242 entry = rb_entry(parent, struct inode_defrag, rb_node);
243 else
244 entry = NULL;
245 }
246out:
247 if (entry)
248 rb_erase(parent, &fs_info->defrag_inodes);
249 spin_unlock(&fs_info->defrag_inodes_lock);
250 return entry;
251}
252
253void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
254{
255 struct inode_defrag *defrag;
256 struct rb_node *node;
257
258 spin_lock(&fs_info->defrag_inodes_lock);
259 node = rb_first(&fs_info->defrag_inodes);
260 while (node) {
261 rb_erase(node, &fs_info->defrag_inodes);
262 defrag = rb_entry(node, struct inode_defrag, rb_node);
263 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
264
265 cond_resched_lock(&fs_info->defrag_inodes_lock);
266
267 node = rb_first(&fs_info->defrag_inodes);
268 }
269 spin_unlock(&fs_info->defrag_inodes_lock);
270}
271
272#define BTRFS_DEFRAG_BATCH 1024
273
274static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
275 struct inode_defrag *defrag)
276{
277 struct btrfs_root *inode_root;
278 struct inode *inode;
279 struct btrfs_key key;
280 struct btrfs_ioctl_defrag_range_args range;
281 int num_defrag;
282 int index;
283 int ret;
284
285 /* get the inode */
286 key.objectid = defrag->root;
287 key.type = BTRFS_ROOT_ITEM_KEY;
288 key.offset = (u64)-1;
289
290 index = srcu_read_lock(&fs_info->subvol_srcu);
291
292 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
293 if (IS_ERR(inode_root)) {
294 ret = PTR_ERR(inode_root);
295 goto cleanup;
296 }
297
298 key.objectid = defrag->ino;
299 key.type = BTRFS_INODE_ITEM_KEY;
300 key.offset = 0;
301 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
302 if (IS_ERR(inode)) {
303 ret = PTR_ERR(inode);
304 goto cleanup;
305 }
306 srcu_read_unlock(&fs_info->subvol_srcu, index);
307
308 /* do a chunk of defrag */
309 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
310 memset(&range, 0, sizeof(range));
311 range.len = (u64)-1;
312 range.start = defrag->last_offset;
313
314 sb_start_write(fs_info->sb);
315 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
316 BTRFS_DEFRAG_BATCH);
317 sb_end_write(fs_info->sb);
318 /*
319 * if we filled the whole defrag batch, there
320 * must be more work to do. Queue this defrag
321 * again
322 */
323 if (num_defrag == BTRFS_DEFRAG_BATCH) {
324 defrag->last_offset = range.start;
325 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
326 } else if (defrag->last_offset && !defrag->cycled) {
327 /*
328 * we didn't fill our defrag batch, but
329 * we didn't start at zero. Make sure we loop
330 * around to the start of the file.
331 */
332 defrag->last_offset = 0;
333 defrag->cycled = 1;
334 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
335 } else {
336 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
337 }
338
339 iput(inode);
340 return 0;
341cleanup:
342 srcu_read_unlock(&fs_info->subvol_srcu, index);
343 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
344 return ret;
345}
346
347/*
348 * run through the list of inodes in the FS that need
349 * defragging
350 */
351int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
352{
353 struct inode_defrag *defrag;
354 u64 first_ino = 0;
355 u64 root_objectid = 0;
356
357 atomic_inc(&fs_info->defrag_running);
358 while (1) {
359 /* Pause the auto defragger. */
360 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
361 &fs_info->fs_state))
362 break;
363
364 if (!__need_auto_defrag(fs_info))
365 break;
366
367 /* find an inode to defrag */
368 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
369 first_ino);
370 if (!defrag) {
371 if (root_objectid || first_ino) {
372 root_objectid = 0;
373 first_ino = 0;
374 continue;
375 } else {
376 break;
377 }
378 }
379
380 first_ino = defrag->ino + 1;
381 root_objectid = defrag->root;
382
383 __btrfs_run_defrag_inode(fs_info, defrag);
384 }
385 atomic_dec(&fs_info->defrag_running);
386
387 /*
388 * during unmount, we use the transaction_wait queue to
389 * wait for the defragger to stop
390 */
391 wake_up(&fs_info->transaction_wait);
392 return 0;
393}
394
395/* simple helper to fault in pages and copy. This should go away
396 * and be replaced with calls into generic code.
397 */
398static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
399 struct page **prepared_pages,
400 struct iov_iter *i)
401{
402 size_t copied = 0;
403 size_t total_copied = 0;
404 int pg = 0;
405 int offset = pos & (PAGE_SIZE - 1);
406
407 while (write_bytes > 0) {
408 size_t count = min_t(size_t,
409 PAGE_SIZE - offset, write_bytes);
410 struct page *page = prepared_pages[pg];
411 /*
412 * Copy data from userspace to the current page
413 */
414 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
415
416 /* Flush processor's dcache for this page */
417 flush_dcache_page(page);
418
419 /*
420 * if we get a partial write, we can end up with
421 * partially up to date pages. These add
422 * a lot of complexity, so make sure they don't
423 * happen by forcing this copy to be retried.
424 *
425 * The rest of the btrfs_file_write code will fall
426 * back to page at a time copies after we return 0.
427 */
428 if (!PageUptodate(page) && copied < count)
429 copied = 0;
430
431 iov_iter_advance(i, copied);
432 write_bytes -= copied;
433 total_copied += copied;
434
435 /* Return to btrfs_file_write_iter to fault page */
436 if (unlikely(copied == 0))
437 break;
438
439 if (copied < PAGE_SIZE - offset) {
440 offset += copied;
441 } else {
442 pg++;
443 offset = 0;
444 }
445 }
446 return total_copied;
447}
448
449/*
450 * unlocks pages after btrfs_file_write is done with them
451 */
452static void btrfs_drop_pages(struct page **pages, size_t num_pages)
453{
454 size_t i;
455 for (i = 0; i < num_pages; i++) {
456 /* page checked is some magic around finding pages that
457 * have been modified without going through btrfs_set_page_dirty
458 * clear it here. There should be no need to mark the pages
459 * accessed as prepare_pages should have marked them accessed
460 * in prepare_pages via find_or_create_page()
461 */
462 ClearPageChecked(pages[i]);
463 unlock_page(pages[i]);
464 put_page(pages[i]);
465 }
466}
467
468static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
469 const u64 start,
470 const u64 len,
471 struct extent_state **cached_state)
472{
473 u64 search_start = start;
474 const u64 end = start + len - 1;
475
476 while (search_start < end) {
477 const u64 search_len = end - search_start + 1;
478 struct extent_map *em;
479 u64 em_len;
480 int ret = 0;
481
482 em = btrfs_get_extent(inode, NULL, 0, search_start,
483 search_len, 0);
484 if (IS_ERR(em))
485 return PTR_ERR(em);
486
487 if (em->block_start != EXTENT_MAP_HOLE)
488 goto next;
489
490 em_len = em->len;
491 if (em->start < search_start)
492 em_len -= search_start - em->start;
493 if (em_len > search_len)
494 em_len = search_len;
495
496 ret = set_extent_bit(&inode->io_tree, search_start,
497 search_start + em_len - 1,
498 EXTENT_DELALLOC_NEW,
499 NULL, cached_state, GFP_NOFS);
500next:
501 search_start = extent_map_end(em);
502 free_extent_map(em);
503 if (ret)
504 return ret;
505 }
506 return 0;
507}
508
509/*
510 * after copy_from_user, pages need to be dirtied and we need to make
511 * sure holes are created between the current EOF and the start of
512 * any next extents (if required).
513 *
514 * this also makes the decision about creating an inline extent vs
515 * doing real data extents, marking pages dirty and delalloc as required.
516 */
517int btrfs_dirty_pages(struct inode *inode, struct page **pages,
518 size_t num_pages, loff_t pos, size_t write_bytes,
519 struct extent_state **cached)
520{
521 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
522 int err = 0;
523 int i;
524 u64 num_bytes;
525 u64 start_pos;
526 u64 end_of_last_block;
527 u64 end_pos = pos + write_bytes;
528 loff_t isize = i_size_read(inode);
529 unsigned int extra_bits = 0;
530
531 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
532 num_bytes = round_up(write_bytes + pos - start_pos,
533 fs_info->sectorsize);
534
535 end_of_last_block = start_pos + num_bytes - 1;
536
537 if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
538 if (start_pos >= isize &&
539 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) {
540 /*
541 * There can't be any extents following eof in this case
542 * so just set the delalloc new bit for the range
543 * directly.
544 */
545 extra_bits |= EXTENT_DELALLOC_NEW;
546 } else {
547 err = btrfs_find_new_delalloc_bytes(BTRFS_I(inode),
548 start_pos,
549 num_bytes, cached);
550 if (err)
551 return err;
552 }
553 }
554
555 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
556 extra_bits, cached, 0);
557 if (err)
558 return err;
559
560 for (i = 0; i < num_pages; i++) {
561 struct page *p = pages[i];
562 SetPageUptodate(p);
563 ClearPageChecked(p);
564 set_page_dirty(p);
565 }
566
567 /*
568 * we've only changed i_size in ram, and we haven't updated
569 * the disk i_size. There is no need to log the inode
570 * at this time.
571 */
572 if (end_pos > isize)
573 i_size_write(inode, end_pos);
574 return 0;
575}
576
577/*
578 * this drops all the extents in the cache that intersect the range
579 * [start, end]. Existing extents are split as required.
580 */
581void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
582 int skip_pinned)
583{
584 struct extent_map *em;
585 struct extent_map *split = NULL;
586 struct extent_map *split2 = NULL;
587 struct extent_map_tree *em_tree = &inode->extent_tree;
588 u64 len = end - start + 1;
589 u64 gen;
590 int ret;
591 int testend = 1;
592 unsigned long flags;
593 int compressed = 0;
594 bool modified;
595
596 WARN_ON(end < start);
597 if (end == (u64)-1) {
598 len = (u64)-1;
599 testend = 0;
600 }
601 while (1) {
602 int no_splits = 0;
603
604 modified = false;
605 if (!split)
606 split = alloc_extent_map();
607 if (!split2)
608 split2 = alloc_extent_map();
609 if (!split || !split2)
610 no_splits = 1;
611
612 write_lock(&em_tree->lock);
613 em = lookup_extent_mapping(em_tree, start, len);
614 if (!em) {
615 write_unlock(&em_tree->lock);
616 break;
617 }
618 flags = em->flags;
619 gen = em->generation;
620 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
621 if (testend && em->start + em->len >= start + len) {
622 free_extent_map(em);
623 write_unlock(&em_tree->lock);
624 break;
625 }
626 start = em->start + em->len;
627 if (testend)
628 len = start + len - (em->start + em->len);
629 free_extent_map(em);
630 write_unlock(&em_tree->lock);
631 continue;
632 }
633 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
634 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
635 clear_bit(EXTENT_FLAG_LOGGING, &flags);
636 modified = !list_empty(&em->list);
637 if (no_splits)
638 goto next;
639
640 if (em->start < start) {
641 split->start = em->start;
642 split->len = start - em->start;
643
644 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
645 split->orig_start = em->orig_start;
646 split->block_start = em->block_start;
647
648 if (compressed)
649 split->block_len = em->block_len;
650 else
651 split->block_len = split->len;
652 split->orig_block_len = max(split->block_len,
653 em->orig_block_len);
654 split->ram_bytes = em->ram_bytes;
655 } else {
656 split->orig_start = split->start;
657 split->block_len = 0;
658 split->block_start = em->block_start;
659 split->orig_block_len = 0;
660 split->ram_bytes = split->len;
661 }
662
663 split->generation = gen;
664 split->bdev = em->bdev;
665 split->flags = flags;
666 split->compress_type = em->compress_type;
667 replace_extent_mapping(em_tree, em, split, modified);
668 free_extent_map(split);
669 split = split2;
670 split2 = NULL;
671 }
672 if (testend && em->start + em->len > start + len) {
673 u64 diff = start + len - em->start;
674
675 split->start = start + len;
676 split->len = em->start + em->len - (start + len);
677 split->bdev = em->bdev;
678 split->flags = flags;
679 split->compress_type = em->compress_type;
680 split->generation = gen;
681
682 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
683 split->orig_block_len = max(em->block_len,
684 em->orig_block_len);
685
686 split->ram_bytes = em->ram_bytes;
687 if (compressed) {
688 split->block_len = em->block_len;
689 split->block_start = em->block_start;
690 split->orig_start = em->orig_start;
691 } else {
692 split->block_len = split->len;
693 split->block_start = em->block_start
694 + diff;
695 split->orig_start = em->orig_start;
696 }
697 } else {
698 split->ram_bytes = split->len;
699 split->orig_start = split->start;
700 split->block_len = 0;
701 split->block_start = em->block_start;
702 split->orig_block_len = 0;
703 }
704
705 if (extent_map_in_tree(em)) {
706 replace_extent_mapping(em_tree, em, split,
707 modified);
708 } else {
709 ret = add_extent_mapping(em_tree, split,
710 modified);
711 ASSERT(ret == 0); /* Logic error */
712 }
713 free_extent_map(split);
714 split = NULL;
715 }
716next:
717 if (extent_map_in_tree(em))
718 remove_extent_mapping(em_tree, em);
719 write_unlock(&em_tree->lock);
720
721 /* once for us */
722 free_extent_map(em);
723 /* once for the tree*/
724 free_extent_map(em);
725 }
726 if (split)
727 free_extent_map(split);
728 if (split2)
729 free_extent_map(split2);
730}
731
732/*
733 * this is very complex, but the basic idea is to drop all extents
734 * in the range start - end. hint_block is filled in with a block number
735 * that would be a good hint to the block allocator for this file.
736 *
737 * If an extent intersects the range but is not entirely inside the range
738 * it is either truncated or split. Anything entirely inside the range
739 * is deleted from the tree.
740 */
741int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
742 struct btrfs_root *root, struct inode *inode,
743 struct btrfs_path *path, u64 start, u64 end,
744 u64 *drop_end, int drop_cache,
745 int replace_extent,
746 u32 extent_item_size,
747 int *key_inserted)
748{
749 struct btrfs_fs_info *fs_info = root->fs_info;
750 struct extent_buffer *leaf;
751 struct btrfs_file_extent_item *fi;
752 struct btrfs_key key;
753 struct btrfs_key new_key;
754 u64 ino = btrfs_ino(BTRFS_I(inode));
755 u64 search_start = start;
756 u64 disk_bytenr = 0;
757 u64 num_bytes = 0;
758 u64 extent_offset = 0;
759 u64 extent_end = 0;
760 u64 last_end = start;
761 int del_nr = 0;
762 int del_slot = 0;
763 int extent_type;
764 int recow;
765 int ret;
766 int modify_tree = -1;
767 int update_refs;
768 int found = 0;
769 int leafs_visited = 0;
770
771 if (drop_cache)
772 btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0);
773
774 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
775 modify_tree = 0;
776
777 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
778 root == fs_info->tree_root);
779 while (1) {
780 recow = 0;
781 ret = btrfs_lookup_file_extent(trans, root, path, ino,
782 search_start, modify_tree);
783 if (ret < 0)
784 break;
785 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
786 leaf = path->nodes[0];
787 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
788 if (key.objectid == ino &&
789 key.type == BTRFS_EXTENT_DATA_KEY)
790 path->slots[0]--;
791 }
792 ret = 0;
793 leafs_visited++;
794next_slot:
795 leaf = path->nodes[0];
796 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
797 BUG_ON(del_nr > 0);
798 ret = btrfs_next_leaf(root, path);
799 if (ret < 0)
800 break;
801 if (ret > 0) {
802 ret = 0;
803 break;
804 }
805 leafs_visited++;
806 leaf = path->nodes[0];
807 recow = 1;
808 }
809
810 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
811
812 if (key.objectid > ino)
813 break;
814 if (WARN_ON_ONCE(key.objectid < ino) ||
815 key.type < BTRFS_EXTENT_DATA_KEY) {
816 ASSERT(del_nr == 0);
817 path->slots[0]++;
818 goto next_slot;
819 }
820 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
821 break;
822
823 fi = btrfs_item_ptr(leaf, path->slots[0],
824 struct btrfs_file_extent_item);
825 extent_type = btrfs_file_extent_type(leaf, fi);
826
827 if (extent_type == BTRFS_FILE_EXTENT_REG ||
828 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
829 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
830 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
831 extent_offset = btrfs_file_extent_offset(leaf, fi);
832 extent_end = key.offset +
833 btrfs_file_extent_num_bytes(leaf, fi);
834 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
835 extent_end = key.offset +
836 btrfs_file_extent_inline_len(leaf,
837 path->slots[0], fi);
838 } else {
839 /* can't happen */
840 BUG();
841 }
842
843 /*
844 * Don't skip extent items representing 0 byte lengths. They
845 * used to be created (bug) if while punching holes we hit
846 * -ENOSPC condition. So if we find one here, just ensure we
847 * delete it, otherwise we would insert a new file extent item
848 * with the same key (offset) as that 0 bytes length file
849 * extent item in the call to setup_items_for_insert() later
850 * in this function.
851 */
852 if (extent_end == key.offset && extent_end >= search_start) {
853 last_end = extent_end;
854 goto delete_extent_item;
855 }
856
857 if (extent_end <= search_start) {
858 path->slots[0]++;
859 goto next_slot;
860 }
861
862 found = 1;
863 search_start = max(key.offset, start);
864 if (recow || !modify_tree) {
865 modify_tree = -1;
866 btrfs_release_path(path);
867 continue;
868 }
869
870 /*
871 * | - range to drop - |
872 * | -------- extent -------- |
873 */
874 if (start > key.offset && end < extent_end) {
875 BUG_ON(del_nr > 0);
876 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
877 ret = -EOPNOTSUPP;
878 break;
879 }
880
881 memcpy(&new_key, &key, sizeof(new_key));
882 new_key.offset = start;
883 ret = btrfs_duplicate_item(trans, root, path,
884 &new_key);
885 if (ret == -EAGAIN) {
886 btrfs_release_path(path);
887 continue;
888 }
889 if (ret < 0)
890 break;
891
892 leaf = path->nodes[0];
893 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
894 struct btrfs_file_extent_item);
895 btrfs_set_file_extent_num_bytes(leaf, fi,
896 start - key.offset);
897
898 fi = btrfs_item_ptr(leaf, path->slots[0],
899 struct btrfs_file_extent_item);
900
901 extent_offset += start - key.offset;
902 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
903 btrfs_set_file_extent_num_bytes(leaf, fi,
904 extent_end - start);
905 btrfs_mark_buffer_dirty(leaf);
906
907 if (update_refs && disk_bytenr > 0) {
908 ret = btrfs_inc_extent_ref(trans, root,
909 disk_bytenr, num_bytes, 0,
910 root->root_key.objectid,
911 new_key.objectid,
912 start - extent_offset);
913 BUG_ON(ret); /* -ENOMEM */
914 }
915 key.offset = start;
916 }
917 /*
918 * From here on out we will have actually dropped something, so
919 * last_end can be updated.
920 */
921 last_end = extent_end;
922
923 /*
924 * | ---- range to drop ----- |
925 * | -------- extent -------- |
926 */
927 if (start <= key.offset && end < extent_end) {
928 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
929 ret = -EOPNOTSUPP;
930 break;
931 }
932
933 memcpy(&new_key, &key, sizeof(new_key));
934 new_key.offset = end;
935 btrfs_set_item_key_safe(fs_info, path, &new_key);
936
937 extent_offset += end - key.offset;
938 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
939 btrfs_set_file_extent_num_bytes(leaf, fi,
940 extent_end - end);
941 btrfs_mark_buffer_dirty(leaf);
942 if (update_refs && disk_bytenr > 0)
943 inode_sub_bytes(inode, end - key.offset);
944 break;
945 }
946
947 search_start = extent_end;
948 /*
949 * | ---- range to drop ----- |
950 * | -------- extent -------- |
951 */
952 if (start > key.offset && end >= extent_end) {
953 BUG_ON(del_nr > 0);
954 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
955 ret = -EOPNOTSUPP;
956 break;
957 }
958
959 btrfs_set_file_extent_num_bytes(leaf, fi,
960 start - key.offset);
961 btrfs_mark_buffer_dirty(leaf);
962 if (update_refs && disk_bytenr > 0)
963 inode_sub_bytes(inode, extent_end - start);
964 if (end == extent_end)
965 break;
966
967 path->slots[0]++;
968 goto next_slot;
969 }
970
971 /*
972 * | ---- range to drop ----- |
973 * | ------ extent ------ |
974 */
975 if (start <= key.offset && end >= extent_end) {
976delete_extent_item:
977 if (del_nr == 0) {
978 del_slot = path->slots[0];
979 del_nr = 1;
980 } else {
981 BUG_ON(del_slot + del_nr != path->slots[0]);
982 del_nr++;
983 }
984
985 if (update_refs &&
986 extent_type == BTRFS_FILE_EXTENT_INLINE) {
987 inode_sub_bytes(inode,
988 extent_end - key.offset);
989 extent_end = ALIGN(extent_end,
990 fs_info->sectorsize);
991 } else if (update_refs && disk_bytenr > 0) {
992 ret = btrfs_free_extent(trans, root,
993 disk_bytenr, num_bytes, 0,
994 root->root_key.objectid,
995 key.objectid, key.offset -
996 extent_offset);
997 BUG_ON(ret); /* -ENOMEM */
998 inode_sub_bytes(inode,
999 extent_end - key.offset);
1000 }
1001
1002 if (end == extent_end)
1003 break;
1004
1005 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
1006 path->slots[0]++;
1007 goto next_slot;
1008 }
1009
1010 ret = btrfs_del_items(trans, root, path, del_slot,
1011 del_nr);
1012 if (ret) {
1013 btrfs_abort_transaction(trans, ret);
1014 break;
1015 }
1016
1017 del_nr = 0;
1018 del_slot = 0;
1019
1020 btrfs_release_path(path);
1021 continue;
1022 }
1023
1024 BUG_ON(1);
1025 }
1026
1027 if (!ret && del_nr > 0) {
1028 /*
1029 * Set path->slots[0] to first slot, so that after the delete
1030 * if items are move off from our leaf to its immediate left or
1031 * right neighbor leafs, we end up with a correct and adjusted
1032 * path->slots[0] for our insertion (if replace_extent != 0).
1033 */
1034 path->slots[0] = del_slot;
1035 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1036 if (ret)
1037 btrfs_abort_transaction(trans, ret);
1038 }
1039
1040 leaf = path->nodes[0];
1041 /*
1042 * If btrfs_del_items() was called, it might have deleted a leaf, in
1043 * which case it unlocked our path, so check path->locks[0] matches a
1044 * write lock.
1045 */
1046 if (!ret && replace_extent && leafs_visited == 1 &&
1047 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
1048 path->locks[0] == BTRFS_WRITE_LOCK) &&
1049 btrfs_leaf_free_space(fs_info, leaf) >=
1050 sizeof(struct btrfs_item) + extent_item_size) {
1051
1052 key.objectid = ino;
1053 key.type = BTRFS_EXTENT_DATA_KEY;
1054 key.offset = start;
1055 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1056 struct btrfs_key slot_key;
1057
1058 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1059 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1060 path->slots[0]++;
1061 }
1062 setup_items_for_insert(root, path, &key,
1063 &extent_item_size,
1064 extent_item_size,
1065 sizeof(struct btrfs_item) +
1066 extent_item_size, 1);
1067 *key_inserted = 1;
1068 }
1069
1070 if (!replace_extent || !(*key_inserted))
1071 btrfs_release_path(path);
1072 if (drop_end)
1073 *drop_end = found ? min(end, last_end) : end;
1074 return ret;
1075}
1076
1077int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1078 struct btrfs_root *root, struct inode *inode, u64 start,
1079 u64 end, int drop_cache)
1080{
1081 struct btrfs_path *path;
1082 int ret;
1083
1084 path = btrfs_alloc_path();
1085 if (!path)
1086 return -ENOMEM;
1087 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1088 drop_cache, 0, 0, NULL);
1089 btrfs_free_path(path);
1090 return ret;
1091}
1092
1093static int extent_mergeable(struct extent_buffer *leaf, int slot,
1094 u64 objectid, u64 bytenr, u64 orig_offset,
1095 u64 *start, u64 *end)
1096{
1097 struct btrfs_file_extent_item *fi;
1098 struct btrfs_key key;
1099 u64 extent_end;
1100
1101 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1102 return 0;
1103
1104 btrfs_item_key_to_cpu(leaf, &key, slot);
1105 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1106 return 0;
1107
1108 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1109 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1110 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1111 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1112 btrfs_file_extent_compression(leaf, fi) ||
1113 btrfs_file_extent_encryption(leaf, fi) ||
1114 btrfs_file_extent_other_encoding(leaf, fi))
1115 return 0;
1116
1117 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1118 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1119 return 0;
1120
1121 *start = key.offset;
1122 *end = extent_end;
1123 return 1;
1124}
1125
1126/*
1127 * Mark extent in the range start - end as written.
1128 *
1129 * This changes extent type from 'pre-allocated' to 'regular'. If only
1130 * part of extent is marked as written, the extent will be split into
1131 * two or three.
1132 */
1133int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1134 struct btrfs_inode *inode, u64 start, u64 end)
1135{
1136 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1137 struct btrfs_root *root = inode->root;
1138 struct extent_buffer *leaf;
1139 struct btrfs_path *path;
1140 struct btrfs_file_extent_item *fi;
1141 struct btrfs_key key;
1142 struct btrfs_key new_key;
1143 u64 bytenr;
1144 u64 num_bytes;
1145 u64 extent_end;
1146 u64 orig_offset;
1147 u64 other_start;
1148 u64 other_end;
1149 u64 split;
1150 int del_nr = 0;
1151 int del_slot = 0;
1152 int recow;
1153 int ret;
1154 u64 ino = btrfs_ino(inode);
1155
1156 path = btrfs_alloc_path();
1157 if (!path)
1158 return -ENOMEM;
1159again:
1160 recow = 0;
1161 split = start;
1162 key.objectid = ino;
1163 key.type = BTRFS_EXTENT_DATA_KEY;
1164 key.offset = split;
1165
1166 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1167 if (ret < 0)
1168 goto out;
1169 if (ret > 0 && path->slots[0] > 0)
1170 path->slots[0]--;
1171
1172 leaf = path->nodes[0];
1173 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1174 if (key.objectid != ino ||
1175 key.type != BTRFS_EXTENT_DATA_KEY) {
1176 ret = -EINVAL;
1177 btrfs_abort_transaction(trans, ret);
1178 goto out;
1179 }
1180 fi = btrfs_item_ptr(leaf, path->slots[0],
1181 struct btrfs_file_extent_item);
1182 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1183 ret = -EINVAL;
1184 btrfs_abort_transaction(trans, ret);
1185 goto out;
1186 }
1187 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1188 if (key.offset > start || extent_end < end) {
1189 ret = -EINVAL;
1190 btrfs_abort_transaction(trans, ret);
1191 goto out;
1192 }
1193
1194 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1195 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1196 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1197 memcpy(&new_key, &key, sizeof(new_key));
1198
1199 if (start == key.offset && end < extent_end) {
1200 other_start = 0;
1201 other_end = start;
1202 if (extent_mergeable(leaf, path->slots[0] - 1,
1203 ino, bytenr, orig_offset,
1204 &other_start, &other_end)) {
1205 new_key.offset = end;
1206 btrfs_set_item_key_safe(fs_info, path, &new_key);
1207 fi = btrfs_item_ptr(leaf, path->slots[0],
1208 struct btrfs_file_extent_item);
1209 btrfs_set_file_extent_generation(leaf, fi,
1210 trans->transid);
1211 btrfs_set_file_extent_num_bytes(leaf, fi,
1212 extent_end - end);
1213 btrfs_set_file_extent_offset(leaf, fi,
1214 end - orig_offset);
1215 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1216 struct btrfs_file_extent_item);
1217 btrfs_set_file_extent_generation(leaf, fi,
1218 trans->transid);
1219 btrfs_set_file_extent_num_bytes(leaf, fi,
1220 end - other_start);
1221 btrfs_mark_buffer_dirty(leaf);
1222 goto out;
1223 }
1224 }
1225
1226 if (start > key.offset && end == extent_end) {
1227 other_start = end;
1228 other_end = 0;
1229 if (extent_mergeable(leaf, path->slots[0] + 1,
1230 ino, bytenr, orig_offset,
1231 &other_start, &other_end)) {
1232 fi = btrfs_item_ptr(leaf, path->slots[0],
1233 struct btrfs_file_extent_item);
1234 btrfs_set_file_extent_num_bytes(leaf, fi,
1235 start - key.offset);
1236 btrfs_set_file_extent_generation(leaf, fi,
1237 trans->transid);
1238 path->slots[0]++;
1239 new_key.offset = start;
1240 btrfs_set_item_key_safe(fs_info, path, &new_key);
1241
1242 fi = btrfs_item_ptr(leaf, path->slots[0],
1243 struct btrfs_file_extent_item);
1244 btrfs_set_file_extent_generation(leaf, fi,
1245 trans->transid);
1246 btrfs_set_file_extent_num_bytes(leaf, fi,
1247 other_end - start);
1248 btrfs_set_file_extent_offset(leaf, fi,
1249 start - orig_offset);
1250 btrfs_mark_buffer_dirty(leaf);
1251 goto out;
1252 }
1253 }
1254
1255 while (start > key.offset || end < extent_end) {
1256 if (key.offset == start)
1257 split = end;
1258
1259 new_key.offset = split;
1260 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1261 if (ret == -EAGAIN) {
1262 btrfs_release_path(path);
1263 goto again;
1264 }
1265 if (ret < 0) {
1266 btrfs_abort_transaction(trans, ret);
1267 goto out;
1268 }
1269
1270 leaf = path->nodes[0];
1271 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1272 struct btrfs_file_extent_item);
1273 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1274 btrfs_set_file_extent_num_bytes(leaf, fi,
1275 split - key.offset);
1276
1277 fi = btrfs_item_ptr(leaf, path->slots[0],
1278 struct btrfs_file_extent_item);
1279
1280 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1281 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1282 btrfs_set_file_extent_num_bytes(leaf, fi,
1283 extent_end - split);
1284 btrfs_mark_buffer_dirty(leaf);
1285
1286 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
1287 0, root->root_key.objectid,
1288 ino, orig_offset);
1289 if (ret) {
1290 btrfs_abort_transaction(trans, ret);
1291 goto out;
1292 }
1293
1294 if (split == start) {
1295 key.offset = start;
1296 } else {
1297 if (start != key.offset) {
1298 ret = -EINVAL;
1299 btrfs_abort_transaction(trans, ret);
1300 goto out;
1301 }
1302 path->slots[0]--;
1303 extent_end = end;
1304 }
1305 recow = 1;
1306 }
1307
1308 other_start = end;
1309 other_end = 0;
1310 if (extent_mergeable(leaf, path->slots[0] + 1,
1311 ino, bytenr, orig_offset,
1312 &other_start, &other_end)) {
1313 if (recow) {
1314 btrfs_release_path(path);
1315 goto again;
1316 }
1317 extent_end = other_end;
1318 del_slot = path->slots[0] + 1;
1319 del_nr++;
1320 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1321 0, root->root_key.objectid,
1322 ino, orig_offset);
1323 if (ret) {
1324 btrfs_abort_transaction(trans, ret);
1325 goto out;
1326 }
1327 }
1328 other_start = 0;
1329 other_end = start;
1330 if (extent_mergeable(leaf, path->slots[0] - 1,
1331 ino, bytenr, orig_offset,
1332 &other_start, &other_end)) {
1333 if (recow) {
1334 btrfs_release_path(path);
1335 goto again;
1336 }
1337 key.offset = other_start;
1338 del_slot = path->slots[0];
1339 del_nr++;
1340 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1341 0, root->root_key.objectid,
1342 ino, orig_offset);
1343 if (ret) {
1344 btrfs_abort_transaction(trans, ret);
1345 goto out;
1346 }
1347 }
1348 if (del_nr == 0) {
1349 fi = btrfs_item_ptr(leaf, path->slots[0],
1350 struct btrfs_file_extent_item);
1351 btrfs_set_file_extent_type(leaf, fi,
1352 BTRFS_FILE_EXTENT_REG);
1353 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1354 btrfs_mark_buffer_dirty(leaf);
1355 } else {
1356 fi = btrfs_item_ptr(leaf, del_slot - 1,
1357 struct btrfs_file_extent_item);
1358 btrfs_set_file_extent_type(leaf, fi,
1359 BTRFS_FILE_EXTENT_REG);
1360 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1361 btrfs_set_file_extent_num_bytes(leaf, fi,
1362 extent_end - key.offset);
1363 btrfs_mark_buffer_dirty(leaf);
1364
1365 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1366 if (ret < 0) {
1367 btrfs_abort_transaction(trans, ret);
1368 goto out;
1369 }
1370 }
1371out:
1372 btrfs_free_path(path);
1373 return 0;
1374}
1375
1376/*
1377 * on error we return an unlocked page and the error value
1378 * on success we return a locked page and 0
1379 */
1380static int prepare_uptodate_page(struct inode *inode,
1381 struct page *page, u64 pos,
1382 bool force_uptodate)
1383{
1384 int ret = 0;
1385
1386 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1387 !PageUptodate(page)) {
1388 ret = btrfs_readpage(NULL, page);
1389 if (ret)
1390 return ret;
1391 lock_page(page);
1392 if (!PageUptodate(page)) {
1393 unlock_page(page);
1394 return -EIO;
1395 }
1396 if (page->mapping != inode->i_mapping) {
1397 unlock_page(page);
1398 return -EAGAIN;
1399 }
1400 }
1401 return 0;
1402}
1403
1404/*
1405 * this just gets pages into the page cache and locks them down.
1406 */
1407static noinline int prepare_pages(struct inode *inode, struct page **pages,
1408 size_t num_pages, loff_t pos,
1409 size_t write_bytes, bool force_uptodate)
1410{
1411 int i;
1412 unsigned long index = pos >> PAGE_SHIFT;
1413 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1414 int err = 0;
1415 int faili;
1416
1417 for (i = 0; i < num_pages; i++) {
1418again:
1419 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1420 mask | __GFP_WRITE);
1421 if (!pages[i]) {
1422 faili = i - 1;
1423 err = -ENOMEM;
1424 goto fail;
1425 }
1426
1427 if (i == 0)
1428 err = prepare_uptodate_page(inode, pages[i], pos,
1429 force_uptodate);
1430 if (!err && i == num_pages - 1)
1431 err = prepare_uptodate_page(inode, pages[i],
1432 pos + write_bytes, false);
1433 if (err) {
1434 put_page(pages[i]);
1435 if (err == -EAGAIN) {
1436 err = 0;
1437 goto again;
1438 }
1439 faili = i - 1;
1440 goto fail;
1441 }
1442 wait_on_page_writeback(pages[i]);
1443 }
1444
1445 return 0;
1446fail:
1447 while (faili >= 0) {
1448 unlock_page(pages[faili]);
1449 put_page(pages[faili]);
1450 faili--;
1451 }
1452 return err;
1453
1454}
1455
1456/*
1457 * This function locks the extent and properly waits for data=ordered extents
1458 * to finish before allowing the pages to be modified if need.
1459 *
1460 * The return value:
1461 * 1 - the extent is locked
1462 * 0 - the extent is not locked, and everything is OK
1463 * -EAGAIN - need re-prepare the pages
1464 * the other < 0 number - Something wrong happens
1465 */
1466static noinline int
1467lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1468 size_t num_pages, loff_t pos,
1469 size_t write_bytes,
1470 u64 *lockstart, u64 *lockend,
1471 struct extent_state **cached_state)
1472{
1473 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1474 u64 start_pos;
1475 u64 last_pos;
1476 int i;
1477 int ret = 0;
1478
1479 start_pos = round_down(pos, fs_info->sectorsize);
1480 last_pos = start_pos
1481 + round_up(pos + write_bytes - start_pos,
1482 fs_info->sectorsize) - 1;
1483
1484 if (start_pos < inode->vfs_inode.i_size) {
1485 struct btrfs_ordered_extent *ordered;
1486
1487 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1488 cached_state);
1489 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1490 last_pos - start_pos + 1);
1491 if (ordered &&
1492 ordered->file_offset + ordered->len > start_pos &&
1493 ordered->file_offset <= last_pos) {
1494 unlock_extent_cached(&inode->io_tree, start_pos,
1495 last_pos, cached_state);
1496 for (i = 0; i < num_pages; i++) {
1497 unlock_page(pages[i]);
1498 put_page(pages[i]);
1499 }
1500 btrfs_start_ordered_extent(&inode->vfs_inode,
1501 ordered, 1);
1502 btrfs_put_ordered_extent(ordered);
1503 return -EAGAIN;
1504 }
1505 if (ordered)
1506 btrfs_put_ordered_extent(ordered);
1507 clear_extent_bit(&inode->io_tree, start_pos, last_pos,
1508 EXTENT_DIRTY | EXTENT_DELALLOC |
1509 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1510 0, 0, cached_state);
1511 *lockstart = start_pos;
1512 *lockend = last_pos;
1513 ret = 1;
1514 }
1515
1516 for (i = 0; i < num_pages; i++) {
1517 if (clear_page_dirty_for_io(pages[i]))
1518 account_page_redirty(pages[i]);
1519 set_page_extent_mapped(pages[i]);
1520 WARN_ON(!PageLocked(pages[i]));
1521 }
1522
1523 return ret;
1524}
1525
1526static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1527 size_t *write_bytes)
1528{
1529 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1530 struct btrfs_root *root = inode->root;
1531 struct btrfs_ordered_extent *ordered;
1532 u64 lockstart, lockend;
1533 u64 num_bytes;
1534 int ret;
1535
1536 ret = btrfs_start_write_no_snapshotting(root);
1537 if (!ret)
1538 return -ENOSPC;
1539
1540 lockstart = round_down(pos, fs_info->sectorsize);
1541 lockend = round_up(pos + *write_bytes,
1542 fs_info->sectorsize) - 1;
1543
1544 while (1) {
1545 lock_extent(&inode->io_tree, lockstart, lockend);
1546 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1547 lockend - lockstart + 1);
1548 if (!ordered) {
1549 break;
1550 }
1551 unlock_extent(&inode->io_tree, lockstart, lockend);
1552 btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
1553 btrfs_put_ordered_extent(ordered);
1554 }
1555
1556 num_bytes = lockend - lockstart + 1;
1557 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1558 NULL, NULL, NULL);
1559 if (ret <= 0) {
1560 ret = 0;
1561 btrfs_end_write_no_snapshotting(root);
1562 } else {
1563 *write_bytes = min_t(size_t, *write_bytes ,
1564 num_bytes - pos + lockstart);
1565 }
1566
1567 unlock_extent(&inode->io_tree, lockstart, lockend);
1568
1569 return ret;
1570}
1571
1572static noinline ssize_t __btrfs_buffered_write(struct file *file,
1573 struct iov_iter *i,
1574 loff_t pos)
1575{
1576 struct inode *inode = file_inode(file);
1577 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1578 struct btrfs_root *root = BTRFS_I(inode)->root;
1579 struct page **pages = NULL;
1580 struct extent_state *cached_state = NULL;
1581 struct extent_changeset *data_reserved = NULL;
1582 u64 release_bytes = 0;
1583 u64 lockstart;
1584 u64 lockend;
1585 size_t num_written = 0;
1586 int nrptrs;
1587 int ret = 0;
1588 bool only_release_metadata = false;
1589 bool force_page_uptodate = false;
1590
1591 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1592 PAGE_SIZE / (sizeof(struct page *)));
1593 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1594 nrptrs = max(nrptrs, 8);
1595 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1596 if (!pages)
1597 return -ENOMEM;
1598
1599 while (iov_iter_count(i) > 0) {
1600 size_t offset = pos & (PAGE_SIZE - 1);
1601 size_t sector_offset;
1602 size_t write_bytes = min(iov_iter_count(i),
1603 nrptrs * (size_t)PAGE_SIZE -
1604 offset);
1605 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1606 PAGE_SIZE);
1607 size_t reserve_bytes;
1608 size_t dirty_pages;
1609 size_t copied;
1610 size_t dirty_sectors;
1611 size_t num_sectors;
1612 int extents_locked;
1613
1614 WARN_ON(num_pages > nrptrs);
1615
1616 /*
1617 * Fault pages before locking them in prepare_pages
1618 * to avoid recursive lock
1619 */
1620 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1621 ret = -EFAULT;
1622 break;
1623 }
1624
1625 sector_offset = pos & (fs_info->sectorsize - 1);
1626 reserve_bytes = round_up(write_bytes + sector_offset,
1627 fs_info->sectorsize);
1628
1629 extent_changeset_release(data_reserved);
1630 ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
1631 write_bytes);
1632 if (ret < 0) {
1633 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1634 BTRFS_INODE_PREALLOC)) &&
1635 check_can_nocow(BTRFS_I(inode), pos,
1636 &write_bytes) > 0) {
1637 /*
1638 * For nodata cow case, no need to reserve
1639 * data space.
1640 */
1641 only_release_metadata = true;
1642 /*
1643 * our prealloc extent may be smaller than
1644 * write_bytes, so scale down.
1645 */
1646 num_pages = DIV_ROUND_UP(write_bytes + offset,
1647 PAGE_SIZE);
1648 reserve_bytes = round_up(write_bytes +
1649 sector_offset,
1650 fs_info->sectorsize);
1651 } else {
1652 break;
1653 }
1654 }
1655
1656 WARN_ON(reserve_bytes == 0);
1657 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1658 reserve_bytes);
1659 if (ret) {
1660 if (!only_release_metadata)
1661 btrfs_free_reserved_data_space(inode,
1662 data_reserved, pos,
1663 write_bytes);
1664 else
1665 btrfs_end_write_no_snapshotting(root);
1666 break;
1667 }
1668
1669 release_bytes = reserve_bytes;
1670again:
1671 /*
1672 * This is going to setup the pages array with the number of
1673 * pages we want, so we don't really need to worry about the
1674 * contents of pages from loop to loop
1675 */
1676 ret = prepare_pages(inode, pages, num_pages,
1677 pos, write_bytes,
1678 force_page_uptodate);
1679 if (ret) {
1680 btrfs_delalloc_release_extents(BTRFS_I(inode),
1681 reserve_bytes, true);
1682 break;
1683 }
1684
1685 extents_locked = lock_and_cleanup_extent_if_need(
1686 BTRFS_I(inode), pages,
1687 num_pages, pos, write_bytes, &lockstart,
1688 &lockend, &cached_state);
1689 if (extents_locked < 0) {
1690 if (extents_locked == -EAGAIN)
1691 goto again;
1692 btrfs_delalloc_release_extents(BTRFS_I(inode),
1693 reserve_bytes, true);
1694 ret = extents_locked;
1695 break;
1696 }
1697
1698 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1699
1700 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1701 dirty_sectors = round_up(copied + sector_offset,
1702 fs_info->sectorsize);
1703 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1704
1705 /*
1706 * if we have trouble faulting in the pages, fall
1707 * back to one page at a time
1708 */
1709 if (copied < write_bytes)
1710 nrptrs = 1;
1711
1712 if (copied == 0) {
1713 force_page_uptodate = true;
1714 dirty_sectors = 0;
1715 dirty_pages = 0;
1716 } else {
1717 force_page_uptodate = false;
1718 dirty_pages = DIV_ROUND_UP(copied + offset,
1719 PAGE_SIZE);
1720 }
1721
1722 if (num_sectors > dirty_sectors) {
1723 /* release everything except the sectors we dirtied */
1724 release_bytes -= dirty_sectors <<
1725 fs_info->sb->s_blocksize_bits;
1726 if (only_release_metadata) {
1727 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1728 release_bytes, true);
1729 } else {
1730 u64 __pos;
1731
1732 __pos = round_down(pos,
1733 fs_info->sectorsize) +
1734 (dirty_pages << PAGE_SHIFT);
1735 btrfs_delalloc_release_space(inode,
1736 data_reserved, __pos,
1737 release_bytes, true);
1738 }
1739 }
1740
1741 release_bytes = round_up(copied + sector_offset,
1742 fs_info->sectorsize);
1743
1744 if (copied > 0)
1745 ret = btrfs_dirty_pages(inode, pages, dirty_pages,
1746 pos, copied, &cached_state);
1747 if (extents_locked)
1748 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1749 lockstart, lockend, &cached_state);
1750 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes,
1751 true);
1752 if (ret) {
1753 btrfs_drop_pages(pages, num_pages);
1754 break;
1755 }
1756
1757 release_bytes = 0;
1758 if (only_release_metadata)
1759 btrfs_end_write_no_snapshotting(root);
1760
1761 if (only_release_metadata && copied > 0) {
1762 lockstart = round_down(pos,
1763 fs_info->sectorsize);
1764 lockend = round_up(pos + copied,
1765 fs_info->sectorsize) - 1;
1766
1767 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1768 lockend, EXTENT_NORESERVE, NULL,
1769 NULL, GFP_NOFS);
1770 only_release_metadata = false;
1771 }
1772
1773 btrfs_drop_pages(pages, num_pages);
1774
1775 cond_resched();
1776
1777 balance_dirty_pages_ratelimited(inode->i_mapping);
1778 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1779 btrfs_btree_balance_dirty(fs_info);
1780
1781 pos += copied;
1782 num_written += copied;
1783 }
1784
1785 kfree(pages);
1786
1787 if (release_bytes) {
1788 if (only_release_metadata) {
1789 btrfs_end_write_no_snapshotting(root);
1790 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1791 release_bytes, true);
1792 } else {
1793 btrfs_delalloc_release_space(inode, data_reserved,
1794 round_down(pos, fs_info->sectorsize),
1795 release_bytes, true);
1796 }
1797 }
1798
1799 extent_changeset_free(data_reserved);
1800 return num_written ? num_written : ret;
1801}
1802
1803static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1804{
1805 struct file *file = iocb->ki_filp;
1806 struct inode *inode = file_inode(file);
1807 loff_t pos = iocb->ki_pos;
1808 ssize_t written;
1809 ssize_t written_buffered;
1810 loff_t endbyte;
1811 int err;
1812
1813 written = generic_file_direct_write(iocb, from);
1814
1815 if (written < 0 || !iov_iter_count(from))
1816 return written;
1817
1818 pos += written;
1819 written_buffered = __btrfs_buffered_write(file, from, pos);
1820 if (written_buffered < 0) {
1821 err = written_buffered;
1822 goto out;
1823 }
1824 /*
1825 * Ensure all data is persisted. We want the next direct IO read to be
1826 * able to read what was just written.
1827 */
1828 endbyte = pos + written_buffered - 1;
1829 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1830 if (err)
1831 goto out;
1832 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1833 if (err)
1834 goto out;
1835 written += written_buffered;
1836 iocb->ki_pos = pos + written_buffered;
1837 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1838 endbyte >> PAGE_SHIFT);
1839out:
1840 return written ? written : err;
1841}
1842
1843static void update_time_for_write(struct inode *inode)
1844{
1845 struct timespec now;
1846
1847 if (IS_NOCMTIME(inode))
1848 return;
1849
1850 now = current_time(inode);
1851 if (!timespec_equal(&inode->i_mtime, &now))
1852 inode->i_mtime = now;
1853
1854 if (!timespec_equal(&inode->i_ctime, &now))
1855 inode->i_ctime = now;
1856
1857 if (IS_I_VERSION(inode))
1858 inode_inc_iversion(inode);
1859}
1860
1861static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1862 struct iov_iter *from)
1863{
1864 struct file *file = iocb->ki_filp;
1865 struct inode *inode = file_inode(file);
1866 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1867 struct btrfs_root *root = BTRFS_I(inode)->root;
1868 u64 start_pos;
1869 u64 end_pos;
1870 ssize_t num_written = 0;
1871 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1872 ssize_t err;
1873 loff_t pos;
1874 size_t count = iov_iter_count(from);
1875 loff_t oldsize;
1876 int clean_page = 0;
1877
1878 if (!(iocb->ki_flags & IOCB_DIRECT) &&
1879 (iocb->ki_flags & IOCB_NOWAIT))
1880 return -EOPNOTSUPP;
1881
1882 if (!inode_trylock(inode)) {
1883 if (iocb->ki_flags & IOCB_NOWAIT)
1884 return -EAGAIN;
1885 inode_lock(inode);
1886 }
1887
1888 err = generic_write_checks(iocb, from);
1889 if (err <= 0) {
1890 inode_unlock(inode);
1891 return err;
1892 }
1893
1894 pos = iocb->ki_pos;
1895 if (iocb->ki_flags & IOCB_NOWAIT) {
1896 /*
1897 * We will allocate space in case nodatacow is not set,
1898 * so bail
1899 */
1900 if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1901 BTRFS_INODE_PREALLOC)) ||
1902 check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
1903 inode_unlock(inode);
1904 return -EAGAIN;
1905 }
1906 }
1907
1908 current->backing_dev_info = inode_to_bdi(inode);
1909 err = file_remove_privs(file);
1910 if (err) {
1911 inode_unlock(inode);
1912 goto out;
1913 }
1914
1915 /*
1916 * If BTRFS flips readonly due to some impossible error
1917 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1918 * although we have opened a file as writable, we have
1919 * to stop this write operation to ensure FS consistency.
1920 */
1921 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1922 inode_unlock(inode);
1923 err = -EROFS;
1924 goto out;
1925 }
1926
1927 /*
1928 * We reserve space for updating the inode when we reserve space for the
1929 * extent we are going to write, so we will enospc out there. We don't
1930 * need to start yet another transaction to update the inode as we will
1931 * update the inode when we finish writing whatever data we write.
1932 */
1933 update_time_for_write(inode);
1934
1935 start_pos = round_down(pos, fs_info->sectorsize);
1936 oldsize = i_size_read(inode);
1937 if (start_pos > oldsize) {
1938 /* Expand hole size to cover write data, preventing empty gap */
1939 end_pos = round_up(pos + count,
1940 fs_info->sectorsize);
1941 err = btrfs_cont_expand(inode, oldsize, end_pos);
1942 if (err) {
1943 inode_unlock(inode);
1944 goto out;
1945 }
1946 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1947 clean_page = 1;
1948 }
1949
1950 if (sync)
1951 atomic_inc(&BTRFS_I(inode)->sync_writers);
1952
1953 if (iocb->ki_flags & IOCB_DIRECT) {
1954 num_written = __btrfs_direct_write(iocb, from);
1955 } else {
1956 num_written = __btrfs_buffered_write(file, from, pos);
1957 if (num_written > 0)
1958 iocb->ki_pos = pos + num_written;
1959 if (clean_page)
1960 pagecache_isize_extended(inode, oldsize,
1961 i_size_read(inode));
1962 }
1963
1964 inode_unlock(inode);
1965
1966 /*
1967 * We also have to set last_sub_trans to the current log transid,
1968 * otherwise subsequent syncs to a file that's been synced in this
1969 * transaction will appear to have already occurred.
1970 */
1971 spin_lock(&BTRFS_I(inode)->lock);
1972 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1973 spin_unlock(&BTRFS_I(inode)->lock);
1974 if (num_written > 0)
1975 num_written = generic_write_sync(iocb, num_written);
1976
1977 if (sync)
1978 atomic_dec(&BTRFS_I(inode)->sync_writers);
1979out:
1980 current->backing_dev_info = NULL;
1981 return num_written ? num_written : err;
1982}
1983
1984int btrfs_release_file(struct inode *inode, struct file *filp)
1985{
1986 struct btrfs_file_private *private = filp->private_data;
1987
1988 if (private && private->filldir_buf)
1989 kfree(private->filldir_buf);
1990 kfree(private);
1991 filp->private_data = NULL;
1992
1993 /*
1994 * ordered_data_close is set by settattr when we are about to truncate
1995 * a file from a non-zero size to a zero size. This tries to
1996 * flush down new bytes that may have been written if the
1997 * application were using truncate to replace a file in place.
1998 */
1999 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2000 &BTRFS_I(inode)->runtime_flags))
2001 filemap_flush(inode->i_mapping);
2002 return 0;
2003}
2004
2005static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2006{
2007 int ret;
2008 struct blk_plug plug;
2009
2010 /*
2011 * This is only called in fsync, which would do synchronous writes, so
2012 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2013 * multiple disks using raid profile, a large IO can be split to
2014 * several segments of stripe length (currently 64K).
2015 */
2016 blk_start_plug(&plug);
2017 atomic_inc(&BTRFS_I(inode)->sync_writers);
2018 ret = btrfs_fdatawrite_range(inode, start, end);
2019 atomic_dec(&BTRFS_I(inode)->sync_writers);
2020 blk_finish_plug(&plug);
2021
2022 return ret;
2023}
2024
2025/*
2026 * fsync call for both files and directories. This logs the inode into
2027 * the tree log instead of forcing full commits whenever possible.
2028 *
2029 * It needs to call filemap_fdatawait so that all ordered extent updates are
2030 * in the metadata btree are up to date for copying to the log.
2031 *
2032 * It drops the inode mutex before doing the tree log commit. This is an
2033 * important optimization for directories because holding the mutex prevents
2034 * new operations on the dir while we write to disk.
2035 */
2036int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2037{
2038 struct dentry *dentry = file_dentry(file);
2039 struct inode *inode = d_inode(dentry);
2040 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2041 struct btrfs_root *root = BTRFS_I(inode)->root;
2042 struct btrfs_trans_handle *trans;
2043 struct btrfs_log_ctx ctx;
2044 int ret = 0, err;
2045 bool full_sync = false;
2046 u64 len;
2047
2048 /*
2049 * The range length can be represented by u64, we have to do the typecasts
2050 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
2051 */
2052 len = (u64)end - (u64)start + 1;
2053 trace_btrfs_sync_file(file, datasync);
2054
2055 btrfs_init_log_ctx(&ctx, inode);
2056
2057 /*
2058 * We write the dirty pages in the range and wait until they complete
2059 * out of the ->i_mutex. If so, we can flush the dirty pages by
2060 * multi-task, and make the performance up. See
2061 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2062 */
2063 ret = start_ordered_ops(inode, start, end);
2064 if (ret)
2065 goto out;
2066
2067 inode_lock(inode);
2068 atomic_inc(&root->log_batch);
2069 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2070 &BTRFS_I(inode)->runtime_flags);
2071 /*
2072 * We might have have had more pages made dirty after calling
2073 * start_ordered_ops and before acquiring the inode's i_mutex.
2074 */
2075 if (full_sync) {
2076 /*
2077 * For a full sync, we need to make sure any ordered operations
2078 * start and finish before we start logging the inode, so that
2079 * all extents are persisted and the respective file extent
2080 * items are in the fs/subvol btree.
2081 */
2082 ret = btrfs_wait_ordered_range(inode, start, len);
2083 } else {
2084 /*
2085 * Start any new ordered operations before starting to log the
2086 * inode. We will wait for them to finish in btrfs_sync_log().
2087 *
2088 * Right before acquiring the inode's mutex, we might have new
2089 * writes dirtying pages, which won't immediately start the
2090 * respective ordered operations - that is done through the
2091 * fill_delalloc callbacks invoked from the writepage and
2092 * writepages address space operations. So make sure we start
2093 * all ordered operations before starting to log our inode. Not
2094 * doing this means that while logging the inode, writeback
2095 * could start and invoke writepage/writepages, which would call
2096 * the fill_delalloc callbacks (cow_file_range,
2097 * submit_compressed_extents). These callbacks add first an
2098 * extent map to the modified list of extents and then create
2099 * the respective ordered operation, which means in
2100 * tree-log.c:btrfs_log_inode() we might capture all existing
2101 * ordered operations (with btrfs_get_logged_extents()) before
2102 * the fill_delalloc callback adds its ordered operation, and by
2103 * the time we visit the modified list of extent maps (with
2104 * btrfs_log_changed_extents()), we see and process the extent
2105 * map they created. We then use the extent map to construct a
2106 * file extent item for logging without waiting for the
2107 * respective ordered operation to finish - this file extent
2108 * item points to a disk location that might not have yet been
2109 * written to, containing random data - so after a crash a log
2110 * replay will make our inode have file extent items that point
2111 * to disk locations containing invalid data, as we returned
2112 * success to userspace without waiting for the respective
2113 * ordered operation to finish, because it wasn't captured by
2114 * btrfs_get_logged_extents().
2115 */
2116 ret = start_ordered_ops(inode, start, end);
2117 }
2118 if (ret) {
2119 inode_unlock(inode);
2120 goto out;
2121 }
2122 atomic_inc(&root->log_batch);
2123
2124 /*
2125 * If the last transaction that changed this file was before the current
2126 * transaction and we have the full sync flag set in our inode, we can
2127 * bail out now without any syncing.
2128 *
2129 * Note that we can't bail out if the full sync flag isn't set. This is
2130 * because when the full sync flag is set we start all ordered extents
2131 * and wait for them to fully complete - when they complete they update
2132 * the inode's last_trans field through:
2133 *
2134 * btrfs_finish_ordered_io() ->
2135 * btrfs_update_inode_fallback() ->
2136 * btrfs_update_inode() ->
2137 * btrfs_set_inode_last_trans()
2138 *
2139 * So we are sure that last_trans is up to date and can do this check to
2140 * bail out safely. For the fast path, when the full sync flag is not
2141 * set in our inode, we can not do it because we start only our ordered
2142 * extents and don't wait for them to complete (that is when
2143 * btrfs_finish_ordered_io runs), so here at this point their last_trans
2144 * value might be less than or equals to fs_info->last_trans_committed,
2145 * and setting a speculative last_trans for an inode when a buffered
2146 * write is made (such as fs_info->generation + 1 for example) would not
2147 * be reliable since after setting the value and before fsync is called
2148 * any number of transactions can start and commit (transaction kthread
2149 * commits the current transaction periodically), and a transaction
2150 * commit does not start nor waits for ordered extents to complete.
2151 */
2152 smp_mb();
2153 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2154 (full_sync && BTRFS_I(inode)->last_trans <=
2155 fs_info->last_trans_committed) ||
2156 (!btrfs_have_ordered_extents_in_range(inode, start, len) &&
2157 BTRFS_I(inode)->last_trans
2158 <= fs_info->last_trans_committed)) {
2159 /*
2160 * We've had everything committed since the last time we were
2161 * modified so clear this flag in case it was set for whatever
2162 * reason, it's no longer relevant.
2163 */
2164 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2165 &BTRFS_I(inode)->runtime_flags);
2166 /*
2167 * An ordered extent might have started before and completed
2168 * already with io errors, in which case the inode was not
2169 * updated and we end up here. So check the inode's mapping
2170 * for any errors that might have happened since we last
2171 * checked called fsync.
2172 */
2173 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2174 inode_unlock(inode);
2175 goto out;
2176 }
2177
2178 /*
2179 * We use start here because we will need to wait on the IO to complete
2180 * in btrfs_sync_log, which could require joining a transaction (for
2181 * example checking cross references in the nocow path). If we use join
2182 * here we could get into a situation where we're waiting on IO to
2183 * happen that is blocked on a transaction trying to commit. With start
2184 * we inc the extwriter counter, so we wait for all extwriters to exit
2185 * before we start blocking join'ers. This comment is to keep somebody
2186 * from thinking they are super smart and changing this to
2187 * btrfs_join_transaction *cough*Josef*cough*.
2188 */
2189 trans = btrfs_start_transaction(root, 0);
2190 if (IS_ERR(trans)) {
2191 ret = PTR_ERR(trans);
2192 inode_unlock(inode);
2193 goto out;
2194 }
2195 trans->sync = true;
2196
2197 ret = btrfs_log_dentry_safe(trans, dentry, start, end, &ctx);
2198 if (ret < 0) {
2199 /* Fallthrough and commit/free transaction. */
2200 ret = 1;
2201 }
2202
2203 /* we've logged all the items and now have a consistent
2204 * version of the file in the log. It is possible that
2205 * someone will come in and modify the file, but that's
2206 * fine because the log is consistent on disk, and we
2207 * have references to all of the file's extents
2208 *
2209 * It is possible that someone will come in and log the
2210 * file again, but that will end up using the synchronization
2211 * inside btrfs_sync_log to keep things safe.
2212 */
2213 inode_unlock(inode);
2214
2215 /*
2216 * If any of the ordered extents had an error, just return it to user
2217 * space, so that the application knows some writes didn't succeed and
2218 * can take proper action (retry for e.g.). Blindly committing the
2219 * transaction in this case, would fool userspace that everything was
2220 * successful. And we also want to make sure our log doesn't contain
2221 * file extent items pointing to extents that weren't fully written to -
2222 * just like in the non fast fsync path, where we check for the ordered
2223 * operation's error flag before writing to the log tree and return -EIO
2224 * if any of them had this flag set (btrfs_wait_ordered_range) -
2225 * therefore we need to check for errors in the ordered operations,
2226 * which are indicated by ctx.io_err.
2227 */
2228 if (ctx.io_err) {
2229 btrfs_end_transaction(trans);
2230 ret = ctx.io_err;
2231 goto out;
2232 }
2233
2234 if (ret != BTRFS_NO_LOG_SYNC) {
2235 if (!ret) {
2236 ret = btrfs_sync_log(trans, root, &ctx);
2237 if (!ret) {
2238 ret = btrfs_end_transaction(trans);
2239 goto out;
2240 }
2241 }
2242 if (!full_sync) {
2243 ret = btrfs_wait_ordered_range(inode, start, len);
2244 if (ret) {
2245 btrfs_end_transaction(trans);
2246 goto out;
2247 }
2248 }
2249 ret = btrfs_commit_transaction(trans);
2250 } else {
2251 ret = btrfs_end_transaction(trans);
2252 }
2253out:
2254 ASSERT(list_empty(&ctx.list));
2255 err = file_check_and_advance_wb_err(file);
2256 if (!ret)
2257 ret = err;
2258 return ret > 0 ? -EIO : ret;
2259}
2260
2261static const struct vm_operations_struct btrfs_file_vm_ops = {
2262 .fault = filemap_fault,
2263 .map_pages = filemap_map_pages,
2264 .page_mkwrite = btrfs_page_mkwrite,
2265};
2266
2267static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2268{
2269 struct address_space *mapping = filp->f_mapping;
2270
2271 if (!mapping->a_ops->readpage)
2272 return -ENOEXEC;
2273
2274 file_accessed(filp);
2275 vma->vm_ops = &btrfs_file_vm_ops;
2276
2277 return 0;
2278}
2279
2280static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2281 int slot, u64 start, u64 end)
2282{
2283 struct btrfs_file_extent_item *fi;
2284 struct btrfs_key key;
2285
2286 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2287 return 0;
2288
2289 btrfs_item_key_to_cpu(leaf, &key, slot);
2290 if (key.objectid != btrfs_ino(inode) ||
2291 key.type != BTRFS_EXTENT_DATA_KEY)
2292 return 0;
2293
2294 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2295
2296 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2297 return 0;
2298
2299 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2300 return 0;
2301
2302 if (key.offset == end)
2303 return 1;
2304 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2305 return 1;
2306 return 0;
2307}
2308
2309static int fill_holes(struct btrfs_trans_handle *trans,
2310 struct btrfs_inode *inode,
2311 struct btrfs_path *path, u64 offset, u64 end)
2312{
2313 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
2314 struct btrfs_root *root = inode->root;
2315 struct extent_buffer *leaf;
2316 struct btrfs_file_extent_item *fi;
2317 struct extent_map *hole_em;
2318 struct extent_map_tree *em_tree = &inode->extent_tree;
2319 struct btrfs_key key;
2320 int ret;
2321
2322 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2323 goto out;
2324
2325 key.objectid = btrfs_ino(inode);
2326 key.type = BTRFS_EXTENT_DATA_KEY;
2327 key.offset = offset;
2328
2329 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2330 if (ret <= 0) {
2331 /*
2332 * We should have dropped this offset, so if we find it then
2333 * something has gone horribly wrong.
2334 */
2335 if (ret == 0)
2336 ret = -EINVAL;
2337 return ret;
2338 }
2339
2340 leaf = path->nodes[0];
2341 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2342 u64 num_bytes;
2343
2344 path->slots[0]--;
2345 fi = btrfs_item_ptr(leaf, path->slots[0],
2346 struct btrfs_file_extent_item);
2347 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2348 end - offset;
2349 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2350 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2351 btrfs_set_file_extent_offset(leaf, fi, 0);
2352 btrfs_mark_buffer_dirty(leaf);
2353 goto out;
2354 }
2355
2356 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2357 u64 num_bytes;
2358
2359 key.offset = offset;
2360 btrfs_set_item_key_safe(fs_info, path, &key);
2361 fi = btrfs_item_ptr(leaf, path->slots[0],
2362 struct btrfs_file_extent_item);
2363 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2364 offset;
2365 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2366 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2367 btrfs_set_file_extent_offset(leaf, fi, 0);
2368 btrfs_mark_buffer_dirty(leaf);
2369 goto out;
2370 }
2371 btrfs_release_path(path);
2372
2373 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2374 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2375 if (ret)
2376 return ret;
2377
2378out:
2379 btrfs_release_path(path);
2380
2381 hole_em = alloc_extent_map();
2382 if (!hole_em) {
2383 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2384 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2385 } else {
2386 hole_em->start = offset;
2387 hole_em->len = end - offset;
2388 hole_em->ram_bytes = hole_em->len;
2389 hole_em->orig_start = offset;
2390
2391 hole_em->block_start = EXTENT_MAP_HOLE;
2392 hole_em->block_len = 0;
2393 hole_em->orig_block_len = 0;
2394 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2395 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2396 hole_em->generation = trans->transid;
2397
2398 do {
2399 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2400 write_lock(&em_tree->lock);
2401 ret = add_extent_mapping(em_tree, hole_em, 1);
2402 write_unlock(&em_tree->lock);
2403 } while (ret == -EEXIST);
2404 free_extent_map(hole_em);
2405 if (ret)
2406 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2407 &inode->runtime_flags);
2408 }
2409
2410 return 0;
2411}
2412
2413/*
2414 * Find a hole extent on given inode and change start/len to the end of hole
2415 * extent.(hole/vacuum extent whose em->start <= start &&
2416 * em->start + em->len > start)
2417 * When a hole extent is found, return 1 and modify start/len.
2418 */
2419static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2420{
2421 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2422 struct extent_map *em;
2423 int ret = 0;
2424
2425 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2426 round_down(*start, fs_info->sectorsize),
2427 round_up(*len, fs_info->sectorsize), 0);
2428 if (IS_ERR(em))
2429 return PTR_ERR(em);
2430
2431 /* Hole or vacuum extent(only exists in no-hole mode) */
2432 if (em->block_start == EXTENT_MAP_HOLE) {
2433 ret = 1;
2434 *len = em->start + em->len > *start + *len ?
2435 0 : *start + *len - em->start - em->len;
2436 *start = em->start + em->len;
2437 }
2438 free_extent_map(em);
2439 return ret;
2440}
2441
2442static int btrfs_punch_hole_lock_range(struct inode *inode,
2443 const u64 lockstart,
2444 const u64 lockend,
2445 struct extent_state **cached_state)
2446{
2447 while (1) {
2448 struct btrfs_ordered_extent *ordered;
2449 int ret;
2450
2451 truncate_pagecache_range(inode, lockstart, lockend);
2452
2453 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2454 cached_state);
2455 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2456
2457 /*
2458 * We need to make sure we have no ordered extents in this range
2459 * and nobody raced in and read a page in this range, if we did
2460 * we need to try again.
2461 */
2462 if ((!ordered ||
2463 (ordered->file_offset + ordered->len <= lockstart ||
2464 ordered->file_offset > lockend)) &&
2465 !filemap_range_has_page(inode->i_mapping,
2466 lockstart, lockend)) {
2467 if (ordered)
2468 btrfs_put_ordered_extent(ordered);
2469 break;
2470 }
2471 if (ordered)
2472 btrfs_put_ordered_extent(ordered);
2473 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2474 lockend, cached_state);
2475 ret = btrfs_wait_ordered_range(inode, lockstart,
2476 lockend - lockstart + 1);
2477 if (ret)
2478 return ret;
2479 }
2480 return 0;
2481}
2482
2483static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2484{
2485 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2486 struct btrfs_root *root = BTRFS_I(inode)->root;
2487 struct extent_state *cached_state = NULL;
2488 struct btrfs_path *path;
2489 struct btrfs_block_rsv *rsv;
2490 struct btrfs_trans_handle *trans;
2491 u64 lockstart;
2492 u64 lockend;
2493 u64 tail_start;
2494 u64 tail_len;
2495 u64 orig_start = offset;
2496 u64 cur_offset;
2497 u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
2498 u64 drop_end;
2499 int ret = 0;
2500 int err = 0;
2501 unsigned int rsv_count;
2502 bool same_block;
2503 bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES);
2504 u64 ino_size;
2505 bool truncated_block = false;
2506 bool updated_inode = false;
2507
2508 ret = btrfs_wait_ordered_range(inode, offset, len);
2509 if (ret)
2510 return ret;
2511
2512 inode_lock(inode);
2513 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2514 ret = find_first_non_hole(inode, &offset, &len);
2515 if (ret < 0)
2516 goto out_only_mutex;
2517 if (ret && !len) {
2518 /* Already in a large hole */
2519 ret = 0;
2520 goto out_only_mutex;
2521 }
2522
2523 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2524 lockend = round_down(offset + len,
2525 btrfs_inode_sectorsize(inode)) - 1;
2526 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2527 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2528 /*
2529 * We needn't truncate any block which is beyond the end of the file
2530 * because we are sure there is no data there.
2531 */
2532 /*
2533 * Only do this if we are in the same block and we aren't doing the
2534 * entire block.
2535 */
2536 if (same_block && len < fs_info->sectorsize) {
2537 if (offset < ino_size) {
2538 truncated_block = true;
2539 ret = btrfs_truncate_block(inode, offset, len, 0);
2540 } else {
2541 ret = 0;
2542 }
2543 goto out_only_mutex;
2544 }
2545
2546 /* zero back part of the first block */
2547 if (offset < ino_size) {
2548 truncated_block = true;
2549 ret = btrfs_truncate_block(inode, offset, 0, 0);
2550 if (ret) {
2551 inode_unlock(inode);
2552 return ret;
2553 }
2554 }
2555
2556 /* Check the aligned pages after the first unaligned page,
2557 * if offset != orig_start, which means the first unaligned page
2558 * including several following pages are already in holes,
2559 * the extra check can be skipped */
2560 if (offset == orig_start) {
2561 /* after truncate page, check hole again */
2562 len = offset + len - lockstart;
2563 offset = lockstart;
2564 ret = find_first_non_hole(inode, &offset, &len);
2565 if (ret < 0)
2566 goto out_only_mutex;
2567 if (ret && !len) {
2568 ret = 0;
2569 goto out_only_mutex;
2570 }
2571 lockstart = offset;
2572 }
2573
2574 /* Check the tail unaligned part is in a hole */
2575 tail_start = lockend + 1;
2576 tail_len = offset + len - tail_start;
2577 if (tail_len) {
2578 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2579 if (unlikely(ret < 0))
2580 goto out_only_mutex;
2581 if (!ret) {
2582 /* zero the front end of the last page */
2583 if (tail_start + tail_len < ino_size) {
2584 truncated_block = true;
2585 ret = btrfs_truncate_block(inode,
2586 tail_start + tail_len,
2587 0, 1);
2588 if (ret)
2589 goto out_only_mutex;
2590 }
2591 }
2592 }
2593
2594 if (lockend < lockstart) {
2595 ret = 0;
2596 goto out_only_mutex;
2597 }
2598
2599 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2600 &cached_state);
2601 if (ret) {
2602 inode_unlock(inode);
2603 goto out_only_mutex;
2604 }
2605
2606 path = btrfs_alloc_path();
2607 if (!path) {
2608 ret = -ENOMEM;
2609 goto out;
2610 }
2611
2612 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2613 if (!rsv) {
2614 ret = -ENOMEM;
2615 goto out_free;
2616 }
2617 rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
2618 rsv->failfast = 1;
2619
2620 /*
2621 * 1 - update the inode
2622 * 1 - removing the extents in the range
2623 * 1 - adding the hole extent if no_holes isn't set
2624 */
2625 rsv_count = no_holes ? 2 : 3;
2626 trans = btrfs_start_transaction(root, rsv_count);
2627 if (IS_ERR(trans)) {
2628 err = PTR_ERR(trans);
2629 goto out_free;
2630 }
2631
2632 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2633 min_size, 0);
2634 BUG_ON(ret);
2635 trans->block_rsv = rsv;
2636
2637 cur_offset = lockstart;
2638 len = lockend - cur_offset;
2639 while (cur_offset < lockend) {
2640 ret = __btrfs_drop_extents(trans, root, inode, path,
2641 cur_offset, lockend + 1,
2642 &drop_end, 1, 0, 0, NULL);
2643 if (ret != -ENOSPC)
2644 break;
2645
2646 trans->block_rsv = &fs_info->trans_block_rsv;
2647
2648 if (cur_offset < drop_end && cur_offset < ino_size) {
2649 ret = fill_holes(trans, BTRFS_I(inode), path,
2650 cur_offset, drop_end);
2651 if (ret) {
2652 /*
2653 * If we failed then we didn't insert our hole
2654 * entries for the area we dropped, so now the
2655 * fs is corrupted, so we must abort the
2656 * transaction.
2657 */
2658 btrfs_abort_transaction(trans, ret);
2659 err = ret;
2660 break;
2661 }
2662 }
2663
2664 cur_offset = drop_end;
2665
2666 ret = btrfs_update_inode(trans, root, inode);
2667 if (ret) {
2668 err = ret;
2669 break;
2670 }
2671
2672 btrfs_end_transaction(trans);
2673 btrfs_btree_balance_dirty(fs_info);
2674
2675 trans = btrfs_start_transaction(root, rsv_count);
2676 if (IS_ERR(trans)) {
2677 ret = PTR_ERR(trans);
2678 trans = NULL;
2679 break;
2680 }
2681
2682 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2683 rsv, min_size, 0);
2684 BUG_ON(ret); /* shouldn't happen */
2685 trans->block_rsv = rsv;
2686
2687 ret = find_first_non_hole(inode, &cur_offset, &len);
2688 if (unlikely(ret < 0))
2689 break;
2690 if (ret && !len) {
2691 ret = 0;
2692 break;
2693 }
2694 }
2695
2696 if (ret) {
2697 err = ret;
2698 goto out_trans;
2699 }
2700
2701 trans->block_rsv = &fs_info->trans_block_rsv;
2702 /*
2703 * If we are using the NO_HOLES feature we might have had already an
2704 * hole that overlaps a part of the region [lockstart, lockend] and
2705 * ends at (or beyond) lockend. Since we have no file extent items to
2706 * represent holes, drop_end can be less than lockend and so we must
2707 * make sure we have an extent map representing the existing hole (the
2708 * call to __btrfs_drop_extents() might have dropped the existing extent
2709 * map representing the existing hole), otherwise the fast fsync path
2710 * will not record the existence of the hole region
2711 * [existing_hole_start, lockend].
2712 */
2713 if (drop_end <= lockend)
2714 drop_end = lockend + 1;
2715 /*
2716 * Don't insert file hole extent item if it's for a range beyond eof
2717 * (because it's useless) or if it represents a 0 bytes range (when
2718 * cur_offset == drop_end).
2719 */
2720 if (cur_offset < ino_size && cur_offset < drop_end) {
2721 ret = fill_holes(trans, BTRFS_I(inode), path,
2722 cur_offset, drop_end);
2723 if (ret) {
2724 /* Same comment as above. */
2725 btrfs_abort_transaction(trans, ret);
2726 err = ret;
2727 goto out_trans;
2728 }
2729 }
2730
2731out_trans:
2732 if (!trans)
2733 goto out_free;
2734
2735 inode_inc_iversion(inode);
2736 inode->i_mtime = inode->i_ctime = current_time(inode);
2737
2738 trans->block_rsv = &fs_info->trans_block_rsv;
2739 ret = btrfs_update_inode(trans, root, inode);
2740 updated_inode = true;
2741 btrfs_end_transaction(trans);
2742 btrfs_btree_balance_dirty(fs_info);
2743out_free:
2744 btrfs_free_path(path);
2745 btrfs_free_block_rsv(fs_info, rsv);
2746out:
2747 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2748 &cached_state);
2749out_only_mutex:
2750 if (!updated_inode && truncated_block && !ret && !err) {
2751 /*
2752 * If we only end up zeroing part of a page, we still need to
2753 * update the inode item, so that all the time fields are
2754 * updated as well as the necessary btrfs inode in memory fields
2755 * for detecting, at fsync time, if the inode isn't yet in the
2756 * log tree or it's there but not up to date.
2757 */
2758 trans = btrfs_start_transaction(root, 1);
2759 if (IS_ERR(trans)) {
2760 err = PTR_ERR(trans);
2761 } else {
2762 err = btrfs_update_inode(trans, root, inode);
2763 ret = btrfs_end_transaction(trans);
2764 }
2765 }
2766 inode_unlock(inode);
2767 if (ret && !err)
2768 err = ret;
2769 return err;
2770}
2771
2772/* Helper structure to record which range is already reserved */
2773struct falloc_range {
2774 struct list_head list;
2775 u64 start;
2776 u64 len;
2777};
2778
2779/*
2780 * Helper function to add falloc range
2781 *
2782 * Caller should have locked the larger range of extent containing
2783 * [start, len)
2784 */
2785static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2786{
2787 struct falloc_range *prev = NULL;
2788 struct falloc_range *range = NULL;
2789
2790 if (list_empty(head))
2791 goto insert;
2792
2793 /*
2794 * As fallocate iterate by bytenr order, we only need to check
2795 * the last range.
2796 */
2797 prev = list_entry(head->prev, struct falloc_range, list);
2798 if (prev->start + prev->len == start) {
2799 prev->len += len;
2800 return 0;
2801 }
2802insert:
2803 range = kmalloc(sizeof(*range), GFP_KERNEL);
2804 if (!range)
2805 return -ENOMEM;
2806 range->start = start;
2807 range->len = len;
2808 list_add_tail(&range->list, head);
2809 return 0;
2810}
2811
2812static int btrfs_fallocate_update_isize(struct inode *inode,
2813 const u64 end,
2814 const int mode)
2815{
2816 struct btrfs_trans_handle *trans;
2817 struct btrfs_root *root = BTRFS_I(inode)->root;
2818 int ret;
2819 int ret2;
2820
2821 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
2822 return 0;
2823
2824 trans = btrfs_start_transaction(root, 1);
2825 if (IS_ERR(trans))
2826 return PTR_ERR(trans);
2827
2828 inode->i_ctime = current_time(inode);
2829 i_size_write(inode, end);
2830 btrfs_ordered_update_i_size(inode, end, NULL);
2831 ret = btrfs_update_inode(trans, root, inode);
2832 ret2 = btrfs_end_transaction(trans);
2833
2834 return ret ? ret : ret2;
2835}
2836
2837enum {
2838 RANGE_BOUNDARY_WRITTEN_EXTENT = 0,
2839 RANGE_BOUNDARY_PREALLOC_EXTENT = 1,
2840 RANGE_BOUNDARY_HOLE = 2,
2841};
2842
2843static int btrfs_zero_range_check_range_boundary(struct inode *inode,
2844 u64 offset)
2845{
2846 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2847 struct extent_map *em;
2848 int ret;
2849
2850 offset = round_down(offset, sectorsize);
2851 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
2852 if (IS_ERR(em))
2853 return PTR_ERR(em);
2854
2855 if (em->block_start == EXTENT_MAP_HOLE)
2856 ret = RANGE_BOUNDARY_HOLE;
2857 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2858 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
2859 else
2860 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
2861
2862 free_extent_map(em);
2863 return ret;
2864}
2865
2866static int btrfs_zero_range(struct inode *inode,
2867 loff_t offset,
2868 loff_t len,
2869 const int mode)
2870{
2871 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2872 struct extent_map *em;
2873 struct extent_changeset *data_reserved = NULL;
2874 int ret;
2875 u64 alloc_hint = 0;
2876 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2877 u64 alloc_start = round_down(offset, sectorsize);
2878 u64 alloc_end = round_up(offset + len, sectorsize);
2879 u64 bytes_to_reserve = 0;
2880 bool space_reserved = false;
2881
2882 inode_dio_wait(inode);
2883
2884 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2885 alloc_start, alloc_end - alloc_start, 0);
2886 if (IS_ERR(em)) {
2887 ret = PTR_ERR(em);
2888 goto out;
2889 }
2890
2891 /*
2892 * Avoid hole punching and extent allocation for some cases. More cases
2893 * could be considered, but these are unlikely common and we keep things
2894 * as simple as possible for now. Also, intentionally, if the target
2895 * range contains one or more prealloc extents together with regular
2896 * extents and holes, we drop all the existing extents and allocate a
2897 * new prealloc extent, so that we get a larger contiguous disk extent.
2898 */
2899 if (em->start <= alloc_start &&
2900 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
2901 const u64 em_end = em->start + em->len;
2902
2903 if (em_end >= offset + len) {
2904 /*
2905 * The whole range is already a prealloc extent,
2906 * do nothing except updating the inode's i_size if
2907 * needed.
2908 */
2909 free_extent_map(em);
2910 ret = btrfs_fallocate_update_isize(inode, offset + len,
2911 mode);
2912 goto out;
2913 }
2914 /*
2915 * Part of the range is already a prealloc extent, so operate
2916 * only on the remaining part of the range.
2917 */
2918 alloc_start = em_end;
2919 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
2920 len = offset + len - alloc_start;
2921 offset = alloc_start;
2922 alloc_hint = em->block_start + em->len;
2923 }
2924 free_extent_map(em);
2925
2926 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
2927 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
2928 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2929 alloc_start, sectorsize, 0);
2930 if (IS_ERR(em)) {
2931 ret = PTR_ERR(em);
2932 goto out;
2933 }
2934
2935 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
2936 free_extent_map(em);
2937 ret = btrfs_fallocate_update_isize(inode, offset + len,
2938 mode);
2939 goto out;
2940 }
2941 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
2942 free_extent_map(em);
2943 ret = btrfs_truncate_block(inode, offset, len, 0);
2944 if (!ret)
2945 ret = btrfs_fallocate_update_isize(inode,
2946 offset + len,
2947 mode);
2948 return ret;
2949 }
2950 free_extent_map(em);
2951 alloc_start = round_down(offset, sectorsize);
2952 alloc_end = alloc_start + sectorsize;
2953 goto reserve_space;
2954 }
2955
2956 alloc_start = round_up(offset, sectorsize);
2957 alloc_end = round_down(offset + len, sectorsize);
2958
2959 /*
2960 * For unaligned ranges, check the pages at the boundaries, they might
2961 * map to an extent, in which case we need to partially zero them, or
2962 * they might map to a hole, in which case we need our allocation range
2963 * to cover them.
2964 */
2965 if (!IS_ALIGNED(offset, sectorsize)) {
2966 ret = btrfs_zero_range_check_range_boundary(inode, offset);
2967 if (ret < 0)
2968 goto out;
2969 if (ret == RANGE_BOUNDARY_HOLE) {
2970 alloc_start = round_down(offset, sectorsize);
2971 ret = 0;
2972 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
2973 ret = btrfs_truncate_block(inode, offset, 0, 0);
2974 if (ret)
2975 goto out;
2976 } else {
2977 ret = 0;
2978 }
2979 }
2980
2981 if (!IS_ALIGNED(offset + len, sectorsize)) {
2982 ret = btrfs_zero_range_check_range_boundary(inode,
2983 offset + len);
2984 if (ret < 0)
2985 goto out;
2986 if (ret == RANGE_BOUNDARY_HOLE) {
2987 alloc_end = round_up(offset + len, sectorsize);
2988 ret = 0;
2989 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
2990 ret = btrfs_truncate_block(inode, offset + len, 0, 1);
2991 if (ret)
2992 goto out;
2993 } else {
2994 ret = 0;
2995 }
2996 }
2997
2998reserve_space:
2999 if (alloc_start < alloc_end) {
3000 struct extent_state *cached_state = NULL;
3001 const u64 lockstart = alloc_start;
3002 const u64 lockend = alloc_end - 1;
3003
3004 bytes_to_reserve = alloc_end - alloc_start;
3005 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3006 bytes_to_reserve);
3007 if (ret < 0)
3008 goto out;
3009 space_reserved = true;
3010 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3011 alloc_start, bytes_to_reserve);
3012 if (ret)
3013 goto out;
3014 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3015 &cached_state);
3016 if (ret)
3017 goto out;
3018 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
3019 alloc_end - alloc_start,
3020 i_blocksize(inode),
3021 offset + len, &alloc_hint);
3022 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3023 lockend, &cached_state);
3024 /* btrfs_prealloc_file_range releases reserved space on error */
3025 if (ret) {
3026 space_reserved = false;
3027 goto out;
3028 }
3029 }
3030 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
3031 out:
3032 if (ret && space_reserved)
3033 btrfs_free_reserved_data_space(inode, data_reserved,
3034 alloc_start, bytes_to_reserve);
3035 extent_changeset_free(data_reserved);
3036
3037 return ret;
3038}
3039
3040static long btrfs_fallocate(struct file *file, int mode,
3041 loff_t offset, loff_t len)
3042{
3043 struct inode *inode = file_inode(file);
3044 struct extent_state *cached_state = NULL;
3045 struct extent_changeset *data_reserved = NULL;
3046 struct falloc_range *range;
3047 struct falloc_range *tmp;
3048 struct list_head reserve_list;
3049 u64 cur_offset;
3050 u64 last_byte;
3051 u64 alloc_start;
3052 u64 alloc_end;
3053 u64 alloc_hint = 0;
3054 u64 locked_end;
3055 u64 actual_end = 0;
3056 struct extent_map *em;
3057 int blocksize = btrfs_inode_sectorsize(inode);
3058 int ret;
3059
3060 alloc_start = round_down(offset, blocksize);
3061 alloc_end = round_up(offset + len, blocksize);
3062 cur_offset = alloc_start;
3063
3064 /* Make sure we aren't being give some crap mode */
3065 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3066 FALLOC_FL_ZERO_RANGE))
3067 return -EOPNOTSUPP;
3068
3069 if (mode & FALLOC_FL_PUNCH_HOLE)
3070 return btrfs_punch_hole(inode, offset, len);
3071
3072 /*
3073 * Only trigger disk allocation, don't trigger qgroup reserve
3074 *
3075 * For qgroup space, it will be checked later.
3076 */
3077 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3078 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3079 alloc_end - alloc_start);
3080 if (ret < 0)
3081 return ret;
3082 }
3083
3084 inode_lock(inode);
3085
3086 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3087 ret = inode_newsize_ok(inode, offset + len);
3088 if (ret)
3089 goto out;
3090 }
3091
3092 /*
3093 * TODO: Move these two operations after we have checked
3094 * accurate reserved space, or fallocate can still fail but
3095 * with page truncated or size expanded.
3096 *
3097 * But that's a minor problem and won't do much harm BTW.
3098 */
3099 if (alloc_start > inode->i_size) {
3100 ret = btrfs_cont_expand(inode, i_size_read(inode),
3101 alloc_start);
3102 if (ret)
3103 goto out;
3104 } else if (offset + len > inode->i_size) {
3105 /*
3106 * If we are fallocating from the end of the file onward we
3107 * need to zero out the end of the block if i_size lands in the
3108 * middle of a block.
3109 */
3110 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
3111 if (ret)
3112 goto out;
3113 }
3114
3115 /*
3116 * wait for ordered IO before we have any locks. We'll loop again
3117 * below with the locks held.
3118 */
3119 ret = btrfs_wait_ordered_range(inode, alloc_start,
3120 alloc_end - alloc_start);
3121 if (ret)
3122 goto out;
3123
3124 if (mode & FALLOC_FL_ZERO_RANGE) {
3125 ret = btrfs_zero_range(inode, offset, len, mode);
3126 inode_unlock(inode);
3127 return ret;
3128 }
3129
3130 locked_end = alloc_end - 1;
3131 while (1) {
3132 struct btrfs_ordered_extent *ordered;
3133
3134 /* the extent lock is ordered inside the running
3135 * transaction
3136 */
3137 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3138 locked_end, &cached_state);
3139 ordered = btrfs_lookup_first_ordered_extent(inode, locked_end);
3140
3141 if (ordered &&
3142 ordered->file_offset + ordered->len > alloc_start &&
3143 ordered->file_offset < alloc_end) {
3144 btrfs_put_ordered_extent(ordered);
3145 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3146 alloc_start, locked_end,
3147 &cached_state);
3148 /*
3149 * we can't wait on the range with the transaction
3150 * running or with the extent lock held
3151 */
3152 ret = btrfs_wait_ordered_range(inode, alloc_start,
3153 alloc_end - alloc_start);
3154 if (ret)
3155 goto out;
3156 } else {
3157 if (ordered)
3158 btrfs_put_ordered_extent(ordered);
3159 break;
3160 }
3161 }
3162
3163 /* First, check if we exceed the qgroup limit */
3164 INIT_LIST_HEAD(&reserve_list);
3165 while (cur_offset < alloc_end) {
3166 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3167 alloc_end - cur_offset, 0);
3168 if (IS_ERR(em)) {
3169 ret = PTR_ERR(em);
3170 break;
3171 }
3172 last_byte = min(extent_map_end(em), alloc_end);
3173 actual_end = min_t(u64, extent_map_end(em), offset + len);
3174 last_byte = ALIGN(last_byte, blocksize);
3175 if (em->block_start == EXTENT_MAP_HOLE ||
3176 (cur_offset >= inode->i_size &&
3177 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3178 ret = add_falloc_range(&reserve_list, cur_offset,
3179 last_byte - cur_offset);
3180 if (ret < 0) {
3181 free_extent_map(em);
3182 break;
3183 }
3184 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3185 cur_offset, last_byte - cur_offset);
3186 if (ret < 0) {
3187 free_extent_map(em);
3188 break;
3189 }
3190 } else {
3191 /*
3192 * Do not need to reserve unwritten extent for this
3193 * range, free reserved data space first, otherwise
3194 * it'll result in false ENOSPC error.
3195 */
3196 btrfs_free_reserved_data_space(inode, data_reserved,
3197 cur_offset, last_byte - cur_offset);
3198 }
3199 free_extent_map(em);
3200 cur_offset = last_byte;
3201 }
3202
3203 /*
3204 * If ret is still 0, means we're OK to fallocate.
3205 * Or just cleanup the list and exit.
3206 */
3207 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3208 if (!ret)
3209 ret = btrfs_prealloc_file_range(inode, mode,
3210 range->start,
3211 range->len, i_blocksize(inode),
3212 offset + len, &alloc_hint);
3213 else
3214 btrfs_free_reserved_data_space(inode,
3215 data_reserved, range->start,
3216 range->len);
3217 list_del(&range->list);
3218 kfree(range);
3219 }
3220 if (ret < 0)
3221 goto out_unlock;
3222
3223 /*
3224 * We didn't need to allocate any more space, but we still extended the
3225 * size of the file so we need to update i_size and the inode item.
3226 */
3227 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3228out_unlock:
3229 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3230 &cached_state);
3231out:
3232 inode_unlock(inode);
3233 /* Let go of our reservation. */
3234 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3235 btrfs_free_reserved_data_space(inode, data_reserved,
3236 alloc_start, alloc_end - cur_offset);
3237 extent_changeset_free(data_reserved);
3238 return ret;
3239}
3240
3241static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
3242{
3243 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3244 struct extent_map *em = NULL;
3245 struct extent_state *cached_state = NULL;
3246 u64 lockstart;
3247 u64 lockend;
3248 u64 start;
3249 u64 len;
3250 int ret = 0;
3251
3252 if (inode->i_size == 0)
3253 return -ENXIO;
3254
3255 /*
3256 * *offset can be negative, in this case we start finding DATA/HOLE from
3257 * the very start of the file.
3258 */
3259 start = max_t(loff_t, 0, *offset);
3260
3261 lockstart = round_down(start, fs_info->sectorsize);
3262 lockend = round_up(i_size_read(inode),
3263 fs_info->sectorsize);
3264 if (lockend <= lockstart)
3265 lockend = lockstart + fs_info->sectorsize;
3266 lockend--;
3267 len = lockend - lockstart + 1;
3268
3269 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3270 &cached_state);
3271
3272 while (start < inode->i_size) {
3273 em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0,
3274 start, len, 0);
3275 if (IS_ERR(em)) {
3276 ret = PTR_ERR(em);
3277 em = NULL;
3278 break;
3279 }
3280
3281 if (whence == SEEK_HOLE &&
3282 (em->block_start == EXTENT_MAP_HOLE ||
3283 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3284 break;
3285 else if (whence == SEEK_DATA &&
3286 (em->block_start != EXTENT_MAP_HOLE &&
3287 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3288 break;
3289
3290 start = em->start + em->len;
3291 free_extent_map(em);
3292 em = NULL;
3293 cond_resched();
3294 }
3295 free_extent_map(em);
3296 if (!ret) {
3297 if (whence == SEEK_DATA && start >= inode->i_size)
3298 ret = -ENXIO;
3299 else
3300 *offset = min_t(loff_t, start, inode->i_size);
3301 }
3302 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3303 &cached_state);
3304 return ret;
3305}
3306
3307static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3308{
3309 struct inode *inode = file->f_mapping->host;
3310 int ret;
3311
3312 inode_lock(inode);
3313 switch (whence) {
3314 case SEEK_END:
3315 case SEEK_CUR:
3316 offset = generic_file_llseek(file, offset, whence);
3317 goto out;
3318 case SEEK_DATA:
3319 case SEEK_HOLE:
3320 if (offset >= i_size_read(inode)) {
3321 inode_unlock(inode);
3322 return -ENXIO;
3323 }
3324
3325 ret = find_desired_extent(inode, &offset, whence);
3326 if (ret) {
3327 inode_unlock(inode);
3328 return ret;
3329 }
3330 }
3331
3332 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3333out:
3334 inode_unlock(inode);
3335 return offset;
3336}
3337
3338static int btrfs_file_open(struct inode *inode, struct file *filp)
3339{
3340 filp->f_mode |= FMODE_NOWAIT;
3341 return generic_file_open(inode, filp);
3342}
3343
3344const struct file_operations btrfs_file_operations = {
3345 .llseek = btrfs_file_llseek,
3346 .read_iter = generic_file_read_iter,
3347 .splice_read = generic_file_splice_read,
3348 .write_iter = btrfs_file_write_iter,
3349 .mmap = btrfs_file_mmap,
3350 .open = btrfs_file_open,
3351 .release = btrfs_release_file,
3352 .fsync = btrfs_sync_file,
3353 .fallocate = btrfs_fallocate,
3354 .unlocked_ioctl = btrfs_ioctl,
3355#ifdef CONFIG_COMPAT
3356 .compat_ioctl = btrfs_compat_ioctl,
3357#endif
3358 .clone_file_range = btrfs_clone_file_range,
3359 .dedupe_file_range = btrfs_dedupe_file_range,
3360};
3361
3362void __cold btrfs_auto_defrag_exit(void)
3363{
3364 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3365}
3366
3367int __init btrfs_auto_defrag_init(void)
3368{
3369 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3370 sizeof(struct inode_defrag), 0,
3371 SLAB_MEM_SPREAD,
3372 NULL);
3373 if (!btrfs_inode_defrag_cachep)
3374 return -ENOMEM;
3375
3376 return 0;
3377}
3378
3379int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3380{
3381 int ret;
3382
3383 /*
3384 * So with compression we will find and lock a dirty page and clear the
3385 * first one as dirty, setup an async extent, and immediately return
3386 * with the entire range locked but with nobody actually marked with
3387 * writeback. So we can't just filemap_write_and_wait_range() and
3388 * expect it to work since it will just kick off a thread to do the
3389 * actual work. So we need to call filemap_fdatawrite_range _again_
3390 * since it will wait on the page lock, which won't be unlocked until
3391 * after the pages have been marked as writeback and so we're good to go
3392 * from there. We have to do this otherwise we'll miss the ordered
3393 * extents and that results in badness. Please Josef, do not think you
3394 * know better and pull this out at some point in the future, it is
3395 * right and you are wrong.
3396 */
3397 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3398 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3399 &BTRFS_I(inode)->runtime_flags))
3400 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3401
3402 return ret;
3403}