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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/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#include "reflink.h"
31
32static struct kmem_cache *btrfs_inode_defrag_cachep;
33/*
34 * when auto defrag is enabled we
35 * queue up these defrag structs to remember which
36 * inodes need defragging passes
37 */
38struct inode_defrag {
39 struct rb_node rb_node;
40 /* objectid */
41 u64 ino;
42 /*
43 * transid where the defrag was added, we search for
44 * extents newer than this
45 */
46 u64 transid;
47
48 /* root objectid */
49 u64 root;
50
51 /* last offset we were able to defrag */
52 u64 last_offset;
53
54 /* if we've wrapped around back to zero once already */
55 int cycled;
56};
57
58static int __compare_inode_defrag(struct inode_defrag *defrag1,
59 struct inode_defrag *defrag2)
60{
61 if (defrag1->root > defrag2->root)
62 return 1;
63 else if (defrag1->root < defrag2->root)
64 return -1;
65 else if (defrag1->ino > defrag2->ino)
66 return 1;
67 else if (defrag1->ino < defrag2->ino)
68 return -1;
69 else
70 return 0;
71}
72
73/* pop a record for an inode into the defrag tree. The lock
74 * must be held already
75 *
76 * If you're inserting a record for an older transid than an
77 * existing record, the transid already in the tree is lowered
78 *
79 * If an existing record is found the defrag item you
80 * pass in is freed
81 */
82static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
83 struct inode_defrag *defrag)
84{
85 struct btrfs_fs_info *fs_info = inode->root->fs_info;
86 struct inode_defrag *entry;
87 struct rb_node **p;
88 struct rb_node *parent = NULL;
89 int ret;
90
91 p = &fs_info->defrag_inodes.rb_node;
92 while (*p) {
93 parent = *p;
94 entry = rb_entry(parent, struct inode_defrag, rb_node);
95
96 ret = __compare_inode_defrag(defrag, entry);
97 if (ret < 0)
98 p = &parent->rb_left;
99 else if (ret > 0)
100 p = &parent->rb_right;
101 else {
102 /* if we're reinserting an entry for
103 * an old defrag run, make sure to
104 * lower the transid of our existing record
105 */
106 if (defrag->transid < entry->transid)
107 entry->transid = defrag->transid;
108 if (defrag->last_offset > entry->last_offset)
109 entry->last_offset = defrag->last_offset;
110 return -EEXIST;
111 }
112 }
113 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
114 rb_link_node(&defrag->rb_node, parent, p);
115 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
116 return 0;
117}
118
119static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
120{
121 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
122 return 0;
123
124 if (btrfs_fs_closing(fs_info))
125 return 0;
126
127 return 1;
128}
129
130/*
131 * insert a defrag record for this inode if auto defrag is
132 * enabled
133 */
134int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
135 struct btrfs_inode *inode)
136{
137 struct btrfs_root *root = inode->root;
138 struct btrfs_fs_info *fs_info = root->fs_info;
139 struct inode_defrag *defrag;
140 u64 transid;
141 int ret;
142
143 if (!__need_auto_defrag(fs_info))
144 return 0;
145
146 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
147 return 0;
148
149 if (trans)
150 transid = trans->transid;
151 else
152 transid = inode->root->last_trans;
153
154 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
155 if (!defrag)
156 return -ENOMEM;
157
158 defrag->ino = btrfs_ino(inode);
159 defrag->transid = transid;
160 defrag->root = root->root_key.objectid;
161
162 spin_lock(&fs_info->defrag_inodes_lock);
163 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
164 /*
165 * If we set IN_DEFRAG flag and evict the inode from memory,
166 * and then re-read this inode, this new inode doesn't have
167 * IN_DEFRAG flag. At the case, we may find the existed defrag.
168 */
169 ret = __btrfs_add_inode_defrag(inode, defrag);
170 if (ret)
171 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
172 } else {
173 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
174 }
175 spin_unlock(&fs_info->defrag_inodes_lock);
176 return 0;
177}
178
179/*
180 * Requeue the defrag object. If there is a defrag object that points to
181 * the same inode in the tree, we will merge them together (by
182 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
183 */
184static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
185 struct inode_defrag *defrag)
186{
187 struct btrfs_fs_info *fs_info = inode->root->fs_info;
188 int ret;
189
190 if (!__need_auto_defrag(fs_info))
191 goto out;
192
193 /*
194 * Here we don't check the IN_DEFRAG flag, because we need merge
195 * them together.
196 */
197 spin_lock(&fs_info->defrag_inodes_lock);
198 ret = __btrfs_add_inode_defrag(inode, defrag);
199 spin_unlock(&fs_info->defrag_inodes_lock);
200 if (ret)
201 goto out;
202 return;
203out:
204 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
205}
206
207/*
208 * pick the defragable inode that we want, if it doesn't exist, we will get
209 * the next one.
210 */
211static struct inode_defrag *
212btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
213{
214 struct inode_defrag *entry = NULL;
215 struct inode_defrag tmp;
216 struct rb_node *p;
217 struct rb_node *parent = NULL;
218 int ret;
219
220 tmp.ino = ino;
221 tmp.root = root;
222
223 spin_lock(&fs_info->defrag_inodes_lock);
224 p = fs_info->defrag_inodes.rb_node;
225 while (p) {
226 parent = p;
227 entry = rb_entry(parent, struct inode_defrag, rb_node);
228
229 ret = __compare_inode_defrag(&tmp, entry);
230 if (ret < 0)
231 p = parent->rb_left;
232 else if (ret > 0)
233 p = parent->rb_right;
234 else
235 goto out;
236 }
237
238 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
239 parent = rb_next(parent);
240 if (parent)
241 entry = rb_entry(parent, struct inode_defrag, rb_node);
242 else
243 entry = NULL;
244 }
245out:
246 if (entry)
247 rb_erase(parent, &fs_info->defrag_inodes);
248 spin_unlock(&fs_info->defrag_inodes_lock);
249 return entry;
250}
251
252void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
253{
254 struct inode_defrag *defrag;
255 struct rb_node *node;
256
257 spin_lock(&fs_info->defrag_inodes_lock);
258 node = rb_first(&fs_info->defrag_inodes);
259 while (node) {
260 rb_erase(node, &fs_info->defrag_inodes);
261 defrag = rb_entry(node, struct inode_defrag, rb_node);
262 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
263
264 cond_resched_lock(&fs_info->defrag_inodes_lock);
265
266 node = rb_first(&fs_info->defrag_inodes);
267 }
268 spin_unlock(&fs_info->defrag_inodes_lock);
269}
270
271#define BTRFS_DEFRAG_BATCH 1024
272
273static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
274 struct inode_defrag *defrag)
275{
276 struct btrfs_root *inode_root;
277 struct inode *inode;
278 struct btrfs_ioctl_defrag_range_args range;
279 int num_defrag;
280 int ret;
281
282 /* get the inode */
283 inode_root = btrfs_get_fs_root(fs_info, defrag->root, true);
284 if (IS_ERR(inode_root)) {
285 ret = PTR_ERR(inode_root);
286 goto cleanup;
287 }
288
289 inode = btrfs_iget(fs_info->sb, defrag->ino, inode_root);
290 btrfs_put_root(inode_root);
291 if (IS_ERR(inode)) {
292 ret = PTR_ERR(inode);
293 goto cleanup;
294 }
295
296 /* do a chunk of defrag */
297 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
298 memset(&range, 0, sizeof(range));
299 range.len = (u64)-1;
300 range.start = defrag->last_offset;
301
302 sb_start_write(fs_info->sb);
303 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
304 BTRFS_DEFRAG_BATCH);
305 sb_end_write(fs_info->sb);
306 /*
307 * if we filled the whole defrag batch, there
308 * must be more work to do. Queue this defrag
309 * again
310 */
311 if (num_defrag == BTRFS_DEFRAG_BATCH) {
312 defrag->last_offset = range.start;
313 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
314 } else if (defrag->last_offset && !defrag->cycled) {
315 /*
316 * we didn't fill our defrag batch, but
317 * we didn't start at zero. Make sure we loop
318 * around to the start of the file.
319 */
320 defrag->last_offset = 0;
321 defrag->cycled = 1;
322 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
323 } else {
324 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
325 }
326
327 iput(inode);
328 return 0;
329cleanup:
330 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
331 return ret;
332}
333
334/*
335 * run through the list of inodes in the FS that need
336 * defragging
337 */
338int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
339{
340 struct inode_defrag *defrag;
341 u64 first_ino = 0;
342 u64 root_objectid = 0;
343
344 atomic_inc(&fs_info->defrag_running);
345 while (1) {
346 /* Pause the auto defragger. */
347 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
348 &fs_info->fs_state))
349 break;
350
351 if (!__need_auto_defrag(fs_info))
352 break;
353
354 /* find an inode to defrag */
355 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
356 first_ino);
357 if (!defrag) {
358 if (root_objectid || first_ino) {
359 root_objectid = 0;
360 first_ino = 0;
361 continue;
362 } else {
363 break;
364 }
365 }
366
367 first_ino = defrag->ino + 1;
368 root_objectid = defrag->root;
369
370 __btrfs_run_defrag_inode(fs_info, defrag);
371 }
372 atomic_dec(&fs_info->defrag_running);
373
374 /*
375 * during unmount, we use the transaction_wait queue to
376 * wait for the defragger to stop
377 */
378 wake_up(&fs_info->transaction_wait);
379 return 0;
380}
381
382/* simple helper to fault in pages and copy. This should go away
383 * and be replaced with calls into generic code.
384 */
385static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
386 struct page **prepared_pages,
387 struct iov_iter *i)
388{
389 size_t copied = 0;
390 size_t total_copied = 0;
391 int pg = 0;
392 int offset = offset_in_page(pos);
393
394 while (write_bytes > 0) {
395 size_t count = min_t(size_t,
396 PAGE_SIZE - offset, write_bytes);
397 struct page *page = prepared_pages[pg];
398 /*
399 * Copy data from userspace to the current page
400 */
401 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
402
403 /* Flush processor's dcache for this page */
404 flush_dcache_page(page);
405
406 /*
407 * if we get a partial write, we can end up with
408 * partially up to date pages. These add
409 * a lot of complexity, so make sure they don't
410 * happen by forcing this copy to be retried.
411 *
412 * The rest of the btrfs_file_write code will fall
413 * back to page at a time copies after we return 0.
414 */
415 if (!PageUptodate(page) && copied < count)
416 copied = 0;
417
418 iov_iter_advance(i, copied);
419 write_bytes -= copied;
420 total_copied += copied;
421
422 /* Return to btrfs_file_write_iter to fault page */
423 if (unlikely(copied == 0))
424 break;
425
426 if (copied < PAGE_SIZE - offset) {
427 offset += copied;
428 } else {
429 pg++;
430 offset = 0;
431 }
432 }
433 return total_copied;
434}
435
436/*
437 * unlocks pages after btrfs_file_write is done with them
438 */
439static void btrfs_drop_pages(struct page **pages, size_t num_pages)
440{
441 size_t i;
442 for (i = 0; i < num_pages; i++) {
443 /* page checked is some magic around finding pages that
444 * have been modified without going through btrfs_set_page_dirty
445 * clear it here. There should be no need to mark the pages
446 * accessed as prepare_pages should have marked them accessed
447 * in prepare_pages via find_or_create_page()
448 */
449 ClearPageChecked(pages[i]);
450 unlock_page(pages[i]);
451 put_page(pages[i]);
452 }
453}
454
455static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
456 const u64 start,
457 const u64 len,
458 struct extent_state **cached_state)
459{
460 u64 search_start = start;
461 const u64 end = start + len - 1;
462
463 while (search_start < end) {
464 const u64 search_len = end - search_start + 1;
465 struct extent_map *em;
466 u64 em_len;
467 int ret = 0;
468
469 em = btrfs_get_extent(inode, NULL, 0, search_start, search_len);
470 if (IS_ERR(em))
471 return PTR_ERR(em);
472
473 if (em->block_start != EXTENT_MAP_HOLE)
474 goto next;
475
476 em_len = em->len;
477 if (em->start < search_start)
478 em_len -= search_start - em->start;
479 if (em_len > search_len)
480 em_len = search_len;
481
482 ret = set_extent_bit(&inode->io_tree, search_start,
483 search_start + em_len - 1,
484 EXTENT_DELALLOC_NEW,
485 NULL, cached_state, GFP_NOFS);
486next:
487 search_start = extent_map_end(em);
488 free_extent_map(em);
489 if (ret)
490 return ret;
491 }
492 return 0;
493}
494
495/*
496 * after copy_from_user, pages need to be dirtied and we need to make
497 * sure holes are created between the current EOF and the start of
498 * any next extents (if required).
499 *
500 * this also makes the decision about creating an inline extent vs
501 * doing real data extents, marking pages dirty and delalloc as required.
502 */
503int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
504 size_t num_pages, loff_t pos, size_t write_bytes,
505 struct extent_state **cached)
506{
507 struct btrfs_fs_info *fs_info = inode->root->fs_info;
508 int err = 0;
509 int i;
510 u64 num_bytes;
511 u64 start_pos;
512 u64 end_of_last_block;
513 u64 end_pos = pos + write_bytes;
514 loff_t isize = i_size_read(&inode->vfs_inode);
515 unsigned int extra_bits = 0;
516
517 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
518 num_bytes = round_up(write_bytes + pos - start_pos,
519 fs_info->sectorsize);
520
521 end_of_last_block = start_pos + num_bytes - 1;
522
523 /*
524 * The pages may have already been dirty, clear out old accounting so
525 * we can set things up properly
526 */
527 clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block,
528 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
529 0, 0, cached);
530
531 if (!btrfs_is_free_space_inode(inode)) {
532 if (start_pos >= isize &&
533 !(inode->flags & BTRFS_INODE_PREALLOC)) {
534 /*
535 * There can't be any extents following eof in this case
536 * so just set the delalloc new bit for the range
537 * directly.
538 */
539 extra_bits |= EXTENT_DELALLOC_NEW;
540 } else {
541 err = btrfs_find_new_delalloc_bytes(inode, start_pos,
542 num_bytes, cached);
543 if (err)
544 return err;
545 }
546 }
547
548 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
549 extra_bits, cached);
550 if (err)
551 return err;
552
553 for (i = 0; i < num_pages; i++) {
554 struct page *p = pages[i];
555 SetPageUptodate(p);
556 ClearPageChecked(p);
557 set_page_dirty(p);
558 }
559
560 /*
561 * we've only changed i_size in ram, and we haven't updated
562 * the disk i_size. There is no need to log the inode
563 * at this time.
564 */
565 if (end_pos > isize)
566 i_size_write(&inode->vfs_inode, end_pos);
567 return 0;
568}
569
570/*
571 * this drops all the extents in the cache that intersect the range
572 * [start, end]. Existing extents are split as required.
573 */
574void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
575 int skip_pinned)
576{
577 struct extent_map *em;
578 struct extent_map *split = NULL;
579 struct extent_map *split2 = NULL;
580 struct extent_map_tree *em_tree = &inode->extent_tree;
581 u64 len = end - start + 1;
582 u64 gen;
583 int ret;
584 int testend = 1;
585 unsigned long flags;
586 int compressed = 0;
587 bool modified;
588
589 WARN_ON(end < start);
590 if (end == (u64)-1) {
591 len = (u64)-1;
592 testend = 0;
593 }
594 while (1) {
595 int no_splits = 0;
596
597 modified = false;
598 if (!split)
599 split = alloc_extent_map();
600 if (!split2)
601 split2 = alloc_extent_map();
602 if (!split || !split2)
603 no_splits = 1;
604
605 write_lock(&em_tree->lock);
606 em = lookup_extent_mapping(em_tree, start, len);
607 if (!em) {
608 write_unlock(&em_tree->lock);
609 break;
610 }
611 flags = em->flags;
612 gen = em->generation;
613 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
614 if (testend && em->start + em->len >= start + len) {
615 free_extent_map(em);
616 write_unlock(&em_tree->lock);
617 break;
618 }
619 start = em->start + em->len;
620 if (testend)
621 len = start + len - (em->start + em->len);
622 free_extent_map(em);
623 write_unlock(&em_tree->lock);
624 continue;
625 }
626 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
627 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
628 clear_bit(EXTENT_FLAG_LOGGING, &flags);
629 modified = !list_empty(&em->list);
630 if (no_splits)
631 goto next;
632
633 if (em->start < start) {
634 split->start = em->start;
635 split->len = start - em->start;
636
637 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
638 split->orig_start = em->orig_start;
639 split->block_start = em->block_start;
640
641 if (compressed)
642 split->block_len = em->block_len;
643 else
644 split->block_len = split->len;
645 split->orig_block_len = max(split->block_len,
646 em->orig_block_len);
647 split->ram_bytes = em->ram_bytes;
648 } else {
649 split->orig_start = split->start;
650 split->block_len = 0;
651 split->block_start = em->block_start;
652 split->orig_block_len = 0;
653 split->ram_bytes = split->len;
654 }
655
656 split->generation = gen;
657 split->flags = flags;
658 split->compress_type = em->compress_type;
659 replace_extent_mapping(em_tree, em, split, modified);
660 free_extent_map(split);
661 split = split2;
662 split2 = NULL;
663 }
664 if (testend && em->start + em->len > start + len) {
665 u64 diff = start + len - em->start;
666
667 split->start = start + len;
668 split->len = em->start + em->len - (start + len);
669 split->flags = flags;
670 split->compress_type = em->compress_type;
671 split->generation = gen;
672
673 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
674 split->orig_block_len = max(em->block_len,
675 em->orig_block_len);
676
677 split->ram_bytes = em->ram_bytes;
678 if (compressed) {
679 split->block_len = em->block_len;
680 split->block_start = em->block_start;
681 split->orig_start = em->orig_start;
682 } else {
683 split->block_len = split->len;
684 split->block_start = em->block_start
685 + diff;
686 split->orig_start = em->orig_start;
687 }
688 } else {
689 split->ram_bytes = split->len;
690 split->orig_start = split->start;
691 split->block_len = 0;
692 split->block_start = em->block_start;
693 split->orig_block_len = 0;
694 }
695
696 if (extent_map_in_tree(em)) {
697 replace_extent_mapping(em_tree, em, split,
698 modified);
699 } else {
700 ret = add_extent_mapping(em_tree, split,
701 modified);
702 ASSERT(ret == 0); /* Logic error */
703 }
704 free_extent_map(split);
705 split = NULL;
706 }
707next:
708 if (extent_map_in_tree(em))
709 remove_extent_mapping(em_tree, em);
710 write_unlock(&em_tree->lock);
711
712 /* once for us */
713 free_extent_map(em);
714 /* once for the tree*/
715 free_extent_map(em);
716 }
717 if (split)
718 free_extent_map(split);
719 if (split2)
720 free_extent_map(split2);
721}
722
723/*
724 * this is very complex, but the basic idea is to drop all extents
725 * in the range start - end. hint_block is filled in with a block number
726 * that would be a good hint to the block allocator for this file.
727 *
728 * If an extent intersects the range but is not entirely inside the range
729 * it is either truncated or split. Anything entirely inside the range
730 * is deleted from the tree.
731 */
732int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
733 struct btrfs_root *root, struct btrfs_inode *inode,
734 struct btrfs_path *path, u64 start, u64 end,
735 u64 *drop_end, int drop_cache,
736 int replace_extent,
737 u32 extent_item_size,
738 int *key_inserted)
739{
740 struct btrfs_fs_info *fs_info = root->fs_info;
741 struct extent_buffer *leaf;
742 struct btrfs_file_extent_item *fi;
743 struct btrfs_ref ref = { 0 };
744 struct btrfs_key key;
745 struct btrfs_key new_key;
746 struct inode *vfs_inode = &inode->vfs_inode;
747 u64 ino = btrfs_ino(inode);
748 u64 search_start = start;
749 u64 disk_bytenr = 0;
750 u64 num_bytes = 0;
751 u64 extent_offset = 0;
752 u64 extent_end = 0;
753 u64 last_end = start;
754 int del_nr = 0;
755 int del_slot = 0;
756 int extent_type;
757 int recow;
758 int ret;
759 int modify_tree = -1;
760 int update_refs;
761 int found = 0;
762 int leafs_visited = 0;
763
764 if (drop_cache)
765 btrfs_drop_extent_cache(inode, start, end - 1, 0);
766
767 if (start >= inode->disk_i_size && !replace_extent)
768 modify_tree = 0;
769
770 update_refs = (test_bit(BTRFS_ROOT_SHAREABLE, &root->state) ||
771 root == fs_info->tree_root);
772 while (1) {
773 recow = 0;
774 ret = btrfs_lookup_file_extent(trans, root, path, ino,
775 search_start, modify_tree);
776 if (ret < 0)
777 break;
778 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
779 leaf = path->nodes[0];
780 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
781 if (key.objectid == ino &&
782 key.type == BTRFS_EXTENT_DATA_KEY)
783 path->slots[0]--;
784 }
785 ret = 0;
786 leafs_visited++;
787next_slot:
788 leaf = path->nodes[0];
789 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
790 BUG_ON(del_nr > 0);
791 ret = btrfs_next_leaf(root, path);
792 if (ret < 0)
793 break;
794 if (ret > 0) {
795 ret = 0;
796 break;
797 }
798 leafs_visited++;
799 leaf = path->nodes[0];
800 recow = 1;
801 }
802
803 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
804
805 if (key.objectid > ino)
806 break;
807 if (WARN_ON_ONCE(key.objectid < ino) ||
808 key.type < BTRFS_EXTENT_DATA_KEY) {
809 ASSERT(del_nr == 0);
810 path->slots[0]++;
811 goto next_slot;
812 }
813 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
814 break;
815
816 fi = btrfs_item_ptr(leaf, path->slots[0],
817 struct btrfs_file_extent_item);
818 extent_type = btrfs_file_extent_type(leaf, fi);
819
820 if (extent_type == BTRFS_FILE_EXTENT_REG ||
821 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
822 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
823 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
824 extent_offset = btrfs_file_extent_offset(leaf, fi);
825 extent_end = key.offset +
826 btrfs_file_extent_num_bytes(leaf, fi);
827 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
828 extent_end = key.offset +
829 btrfs_file_extent_ram_bytes(leaf, fi);
830 } else {
831 /* can't happen */
832 BUG();
833 }
834
835 /*
836 * Don't skip extent items representing 0 byte lengths. They
837 * used to be created (bug) if while punching holes we hit
838 * -ENOSPC condition. So if we find one here, just ensure we
839 * delete it, otherwise we would insert a new file extent item
840 * with the same key (offset) as that 0 bytes length file
841 * extent item in the call to setup_items_for_insert() later
842 * in this function.
843 */
844 if (extent_end == key.offset && extent_end >= search_start) {
845 last_end = extent_end;
846 goto delete_extent_item;
847 }
848
849 if (extent_end <= search_start) {
850 path->slots[0]++;
851 goto next_slot;
852 }
853
854 found = 1;
855 search_start = max(key.offset, start);
856 if (recow || !modify_tree) {
857 modify_tree = -1;
858 btrfs_release_path(path);
859 continue;
860 }
861
862 /*
863 * | - range to drop - |
864 * | -------- extent -------- |
865 */
866 if (start > key.offset && end < extent_end) {
867 BUG_ON(del_nr > 0);
868 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
869 ret = -EOPNOTSUPP;
870 break;
871 }
872
873 memcpy(&new_key, &key, sizeof(new_key));
874 new_key.offset = start;
875 ret = btrfs_duplicate_item(trans, root, path,
876 &new_key);
877 if (ret == -EAGAIN) {
878 btrfs_release_path(path);
879 continue;
880 }
881 if (ret < 0)
882 break;
883
884 leaf = path->nodes[0];
885 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
886 struct btrfs_file_extent_item);
887 btrfs_set_file_extent_num_bytes(leaf, fi,
888 start - key.offset);
889
890 fi = btrfs_item_ptr(leaf, path->slots[0],
891 struct btrfs_file_extent_item);
892
893 extent_offset += start - key.offset;
894 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
895 btrfs_set_file_extent_num_bytes(leaf, fi,
896 extent_end - start);
897 btrfs_mark_buffer_dirty(leaf);
898
899 if (update_refs && disk_bytenr > 0) {
900 btrfs_init_generic_ref(&ref,
901 BTRFS_ADD_DELAYED_REF,
902 disk_bytenr, num_bytes, 0);
903 btrfs_init_data_ref(&ref,
904 root->root_key.objectid,
905 new_key.objectid,
906 start - extent_offset);
907 ret = btrfs_inc_extent_ref(trans, &ref);
908 BUG_ON(ret); /* -ENOMEM */
909 }
910 key.offset = start;
911 }
912 /*
913 * From here on out we will have actually dropped something, so
914 * last_end can be updated.
915 */
916 last_end = extent_end;
917
918 /*
919 * | ---- range to drop ----- |
920 * | -------- extent -------- |
921 */
922 if (start <= key.offset && end < extent_end) {
923 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
924 ret = -EOPNOTSUPP;
925 break;
926 }
927
928 memcpy(&new_key, &key, sizeof(new_key));
929 new_key.offset = end;
930 btrfs_set_item_key_safe(fs_info, path, &new_key);
931
932 extent_offset += end - key.offset;
933 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
934 btrfs_set_file_extent_num_bytes(leaf, fi,
935 extent_end - end);
936 btrfs_mark_buffer_dirty(leaf);
937 if (update_refs && disk_bytenr > 0)
938 inode_sub_bytes(vfs_inode, end - key.offset);
939 break;
940 }
941
942 search_start = extent_end;
943 /*
944 * | ---- range to drop ----- |
945 * | -------- extent -------- |
946 */
947 if (start > key.offset && end >= extent_end) {
948 BUG_ON(del_nr > 0);
949 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
950 ret = -EOPNOTSUPP;
951 break;
952 }
953
954 btrfs_set_file_extent_num_bytes(leaf, fi,
955 start - key.offset);
956 btrfs_mark_buffer_dirty(leaf);
957 if (update_refs && disk_bytenr > 0)
958 inode_sub_bytes(vfs_inode, extent_end - start);
959 if (end == extent_end)
960 break;
961
962 path->slots[0]++;
963 goto next_slot;
964 }
965
966 /*
967 * | ---- range to drop ----- |
968 * | ------ extent ------ |
969 */
970 if (start <= key.offset && end >= extent_end) {
971delete_extent_item:
972 if (del_nr == 0) {
973 del_slot = path->slots[0];
974 del_nr = 1;
975 } else {
976 BUG_ON(del_slot + del_nr != path->slots[0]);
977 del_nr++;
978 }
979
980 if (update_refs &&
981 extent_type == BTRFS_FILE_EXTENT_INLINE) {
982 inode_sub_bytes(vfs_inode,
983 extent_end - key.offset);
984 extent_end = ALIGN(extent_end,
985 fs_info->sectorsize);
986 } else if (update_refs && disk_bytenr > 0) {
987 btrfs_init_generic_ref(&ref,
988 BTRFS_DROP_DELAYED_REF,
989 disk_bytenr, num_bytes, 0);
990 btrfs_init_data_ref(&ref,
991 root->root_key.objectid,
992 key.objectid,
993 key.offset - extent_offset);
994 ret = btrfs_free_extent(trans, &ref);
995 BUG_ON(ret); /* -ENOMEM */
996 inode_sub_bytes(vfs_inode,
997 extent_end - key.offset);
998 }
999
1000 if (end == extent_end)
1001 break;
1002
1003 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
1004 path->slots[0]++;
1005 goto next_slot;
1006 }
1007
1008 ret = btrfs_del_items(trans, root, path, del_slot,
1009 del_nr);
1010 if (ret) {
1011 btrfs_abort_transaction(trans, ret);
1012 break;
1013 }
1014
1015 del_nr = 0;
1016 del_slot = 0;
1017
1018 btrfs_release_path(path);
1019 continue;
1020 }
1021
1022 BUG();
1023 }
1024
1025 if (!ret && del_nr > 0) {
1026 /*
1027 * Set path->slots[0] to first slot, so that after the delete
1028 * if items are move off from our leaf to its immediate left or
1029 * right neighbor leafs, we end up with a correct and adjusted
1030 * path->slots[0] for our insertion (if replace_extent != 0).
1031 */
1032 path->slots[0] = del_slot;
1033 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1034 if (ret)
1035 btrfs_abort_transaction(trans, ret);
1036 }
1037
1038 leaf = path->nodes[0];
1039 /*
1040 * If btrfs_del_items() was called, it might have deleted a leaf, in
1041 * which case it unlocked our path, so check path->locks[0] matches a
1042 * write lock.
1043 */
1044 if (!ret && replace_extent && leafs_visited == 1 &&
1045 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
1046 path->locks[0] == BTRFS_WRITE_LOCK) &&
1047 btrfs_leaf_free_space(leaf) >=
1048 sizeof(struct btrfs_item) + extent_item_size) {
1049
1050 key.objectid = ino;
1051 key.type = BTRFS_EXTENT_DATA_KEY;
1052 key.offset = start;
1053 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1054 struct btrfs_key slot_key;
1055
1056 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1057 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1058 path->slots[0]++;
1059 }
1060 setup_items_for_insert(root, path, &key,
1061 &extent_item_size,
1062 extent_item_size,
1063 sizeof(struct btrfs_item) +
1064 extent_item_size, 1);
1065 *key_inserted = 1;
1066 }
1067
1068 if (!replace_extent || !(*key_inserted))
1069 btrfs_release_path(path);
1070 if (drop_end)
1071 *drop_end = found ? min(end, last_end) : end;
1072 return ret;
1073}
1074
1075int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1076 struct btrfs_root *root, struct inode *inode, u64 start,
1077 u64 end, int drop_cache)
1078{
1079 struct btrfs_path *path;
1080 int ret;
1081
1082 path = btrfs_alloc_path();
1083 if (!path)
1084 return -ENOMEM;
1085 ret = __btrfs_drop_extents(trans, root, BTRFS_I(inode), path, start,
1086 end, NULL, drop_cache, 0, 0, NULL);
1087 btrfs_free_path(path);
1088 return ret;
1089}
1090
1091static int extent_mergeable(struct extent_buffer *leaf, int slot,
1092 u64 objectid, u64 bytenr, u64 orig_offset,
1093 u64 *start, u64 *end)
1094{
1095 struct btrfs_file_extent_item *fi;
1096 struct btrfs_key key;
1097 u64 extent_end;
1098
1099 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1100 return 0;
1101
1102 btrfs_item_key_to_cpu(leaf, &key, slot);
1103 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1104 return 0;
1105
1106 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1107 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1108 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1109 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1110 btrfs_file_extent_compression(leaf, fi) ||
1111 btrfs_file_extent_encryption(leaf, fi) ||
1112 btrfs_file_extent_other_encoding(leaf, fi))
1113 return 0;
1114
1115 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1116 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1117 return 0;
1118
1119 *start = key.offset;
1120 *end = extent_end;
1121 return 1;
1122}
1123
1124/*
1125 * Mark extent in the range start - end as written.
1126 *
1127 * This changes extent type from 'pre-allocated' to 'regular'. If only
1128 * part of extent is marked as written, the extent will be split into
1129 * two or three.
1130 */
1131int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1132 struct btrfs_inode *inode, u64 start, u64 end)
1133{
1134 struct btrfs_fs_info *fs_info = trans->fs_info;
1135 struct btrfs_root *root = inode->root;
1136 struct extent_buffer *leaf;
1137 struct btrfs_path *path;
1138 struct btrfs_file_extent_item *fi;
1139 struct btrfs_ref ref = { 0 };
1140 struct btrfs_key key;
1141 struct btrfs_key new_key;
1142 u64 bytenr;
1143 u64 num_bytes;
1144 u64 extent_end;
1145 u64 orig_offset;
1146 u64 other_start;
1147 u64 other_end;
1148 u64 split;
1149 int del_nr = 0;
1150 int del_slot = 0;
1151 int recow;
1152 int ret;
1153 u64 ino = btrfs_ino(inode);
1154
1155 path = btrfs_alloc_path();
1156 if (!path)
1157 return -ENOMEM;
1158again:
1159 recow = 0;
1160 split = start;
1161 key.objectid = ino;
1162 key.type = BTRFS_EXTENT_DATA_KEY;
1163 key.offset = split;
1164
1165 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1166 if (ret < 0)
1167 goto out;
1168 if (ret > 0 && path->slots[0] > 0)
1169 path->slots[0]--;
1170
1171 leaf = path->nodes[0];
1172 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1173 if (key.objectid != ino ||
1174 key.type != BTRFS_EXTENT_DATA_KEY) {
1175 ret = -EINVAL;
1176 btrfs_abort_transaction(trans, ret);
1177 goto out;
1178 }
1179 fi = btrfs_item_ptr(leaf, path->slots[0],
1180 struct btrfs_file_extent_item);
1181 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1182 ret = -EINVAL;
1183 btrfs_abort_transaction(trans, ret);
1184 goto out;
1185 }
1186 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1187 if (key.offset > start || extent_end < end) {
1188 ret = -EINVAL;
1189 btrfs_abort_transaction(trans, ret);
1190 goto out;
1191 }
1192
1193 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1194 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1195 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1196 memcpy(&new_key, &key, sizeof(new_key));
1197
1198 if (start == key.offset && end < extent_end) {
1199 other_start = 0;
1200 other_end = start;
1201 if (extent_mergeable(leaf, path->slots[0] - 1,
1202 ino, bytenr, orig_offset,
1203 &other_start, &other_end)) {
1204 new_key.offset = end;
1205 btrfs_set_item_key_safe(fs_info, path, &new_key);
1206 fi = btrfs_item_ptr(leaf, path->slots[0],
1207 struct btrfs_file_extent_item);
1208 btrfs_set_file_extent_generation(leaf, fi,
1209 trans->transid);
1210 btrfs_set_file_extent_num_bytes(leaf, fi,
1211 extent_end - end);
1212 btrfs_set_file_extent_offset(leaf, fi,
1213 end - orig_offset);
1214 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1215 struct btrfs_file_extent_item);
1216 btrfs_set_file_extent_generation(leaf, fi,
1217 trans->transid);
1218 btrfs_set_file_extent_num_bytes(leaf, fi,
1219 end - other_start);
1220 btrfs_mark_buffer_dirty(leaf);
1221 goto out;
1222 }
1223 }
1224
1225 if (start > key.offset && end == extent_end) {
1226 other_start = end;
1227 other_end = 0;
1228 if (extent_mergeable(leaf, path->slots[0] + 1,
1229 ino, bytenr, orig_offset,
1230 &other_start, &other_end)) {
1231 fi = btrfs_item_ptr(leaf, path->slots[0],
1232 struct btrfs_file_extent_item);
1233 btrfs_set_file_extent_num_bytes(leaf, fi,
1234 start - key.offset);
1235 btrfs_set_file_extent_generation(leaf, fi,
1236 trans->transid);
1237 path->slots[0]++;
1238 new_key.offset = start;
1239 btrfs_set_item_key_safe(fs_info, path, &new_key);
1240
1241 fi = btrfs_item_ptr(leaf, path->slots[0],
1242 struct btrfs_file_extent_item);
1243 btrfs_set_file_extent_generation(leaf, fi,
1244 trans->transid);
1245 btrfs_set_file_extent_num_bytes(leaf, fi,
1246 other_end - start);
1247 btrfs_set_file_extent_offset(leaf, fi,
1248 start - orig_offset);
1249 btrfs_mark_buffer_dirty(leaf);
1250 goto out;
1251 }
1252 }
1253
1254 while (start > key.offset || end < extent_end) {
1255 if (key.offset == start)
1256 split = end;
1257
1258 new_key.offset = split;
1259 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1260 if (ret == -EAGAIN) {
1261 btrfs_release_path(path);
1262 goto again;
1263 }
1264 if (ret < 0) {
1265 btrfs_abort_transaction(trans, ret);
1266 goto out;
1267 }
1268
1269 leaf = path->nodes[0];
1270 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1271 struct btrfs_file_extent_item);
1272 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1273 btrfs_set_file_extent_num_bytes(leaf, fi,
1274 split - key.offset);
1275
1276 fi = btrfs_item_ptr(leaf, path->slots[0],
1277 struct btrfs_file_extent_item);
1278
1279 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1280 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1281 btrfs_set_file_extent_num_bytes(leaf, fi,
1282 extent_end - split);
1283 btrfs_mark_buffer_dirty(leaf);
1284
1285 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
1286 num_bytes, 0);
1287 btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
1288 orig_offset);
1289 ret = btrfs_inc_extent_ref(trans, &ref);
1290 if (ret) {
1291 btrfs_abort_transaction(trans, ret);
1292 goto out;
1293 }
1294
1295 if (split == start) {
1296 key.offset = start;
1297 } else {
1298 if (start != key.offset) {
1299 ret = -EINVAL;
1300 btrfs_abort_transaction(trans, ret);
1301 goto out;
1302 }
1303 path->slots[0]--;
1304 extent_end = end;
1305 }
1306 recow = 1;
1307 }
1308
1309 other_start = end;
1310 other_end = 0;
1311 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1312 num_bytes, 0);
1313 btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset);
1314 if (extent_mergeable(leaf, path->slots[0] + 1,
1315 ino, bytenr, orig_offset,
1316 &other_start, &other_end)) {
1317 if (recow) {
1318 btrfs_release_path(path);
1319 goto again;
1320 }
1321 extent_end = other_end;
1322 del_slot = path->slots[0] + 1;
1323 del_nr++;
1324 ret = btrfs_free_extent(trans, &ref);
1325 if (ret) {
1326 btrfs_abort_transaction(trans, ret);
1327 goto out;
1328 }
1329 }
1330 other_start = 0;
1331 other_end = start;
1332 if (extent_mergeable(leaf, path->slots[0] - 1,
1333 ino, bytenr, orig_offset,
1334 &other_start, &other_end)) {
1335 if (recow) {
1336 btrfs_release_path(path);
1337 goto again;
1338 }
1339 key.offset = other_start;
1340 del_slot = path->slots[0];
1341 del_nr++;
1342 ret = btrfs_free_extent(trans, &ref);
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 = inode->root->fs_info;
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->num_bytes > 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
1508 *lockstart = start_pos;
1509 *lockend = last_pos;
1510 ret = 1;
1511 }
1512
1513 /*
1514 * It's possible the pages are dirty right now, but we don't want
1515 * to clean them yet because copy_from_user may catch a page fault
1516 * and we might have to fall back to one page at a time. If that
1517 * happens, we'll unlock these pages and we'd have a window where
1518 * reclaim could sneak in and drop the once-dirty page on the floor
1519 * without writing it.
1520 *
1521 * We have the pages locked and the extent range locked, so there's
1522 * no way someone can start IO on any dirty pages in this range.
1523 *
1524 * We'll call btrfs_dirty_pages() later on, and that will flip around
1525 * delalloc bits and dirty the pages as required.
1526 */
1527 for (i = 0; i < num_pages; i++) {
1528 set_page_extent_mapped(pages[i]);
1529 WARN_ON(!PageLocked(pages[i]));
1530 }
1531
1532 return ret;
1533}
1534
1535static int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1536 size_t *write_bytes, bool nowait)
1537{
1538 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1539 struct btrfs_root *root = inode->root;
1540 u64 lockstart, lockend;
1541 u64 num_bytes;
1542 int ret;
1543
1544 if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
1545 return 0;
1546
1547 if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock))
1548 return -EAGAIN;
1549
1550 lockstart = round_down(pos, fs_info->sectorsize);
1551 lockend = round_up(pos + *write_bytes,
1552 fs_info->sectorsize) - 1;
1553 num_bytes = lockend - lockstart + 1;
1554
1555 if (nowait) {
1556 struct btrfs_ordered_extent *ordered;
1557
1558 if (!try_lock_extent(&inode->io_tree, lockstart, lockend))
1559 return -EAGAIN;
1560
1561 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1562 num_bytes);
1563 if (ordered) {
1564 btrfs_put_ordered_extent(ordered);
1565 ret = -EAGAIN;
1566 goto out_unlock;
1567 }
1568 } else {
1569 btrfs_lock_and_flush_ordered_range(inode, lockstart,
1570 lockend, NULL);
1571 }
1572
1573 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1574 NULL, NULL, NULL, false);
1575 if (ret <= 0) {
1576 ret = 0;
1577 if (!nowait)
1578 btrfs_drew_write_unlock(&root->snapshot_lock);
1579 } else {
1580 *write_bytes = min_t(size_t, *write_bytes ,
1581 num_bytes - pos + lockstart);
1582 }
1583out_unlock:
1584 unlock_extent(&inode->io_tree, lockstart, lockend);
1585
1586 return ret;
1587}
1588
1589static int check_nocow_nolock(struct btrfs_inode *inode, loff_t pos,
1590 size_t *write_bytes)
1591{
1592 return check_can_nocow(inode, pos, write_bytes, true);
1593}
1594
1595/*
1596 * Check if we can do nocow write into the range [@pos, @pos + @write_bytes)
1597 *
1598 * @pos: File offset
1599 * @write_bytes: The length to write, will be updated to the nocow writeable
1600 * range
1601 *
1602 * This function will flush ordered extents in the range to ensure proper
1603 * nocow checks.
1604 *
1605 * Return:
1606 * >0 and update @write_bytes if we can do nocow write
1607 * 0 if we can't do nocow write
1608 * -EAGAIN if we can't get the needed lock or there are ordered extents
1609 * for * (nowait == true) case
1610 * <0 if other error happened
1611 *
1612 * NOTE: Callers need to release the lock by btrfs_check_nocow_unlock().
1613 */
1614int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
1615 size_t *write_bytes)
1616{
1617 return check_can_nocow(inode, pos, write_bytes, false);
1618}
1619
1620void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
1621{
1622 btrfs_drew_write_unlock(&inode->root->snapshot_lock);
1623}
1624
1625static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
1626 struct iov_iter *i)
1627{
1628 struct file *file = iocb->ki_filp;
1629 loff_t pos = iocb->ki_pos;
1630 struct inode *inode = file_inode(file);
1631 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1632 struct page **pages = NULL;
1633 struct extent_changeset *data_reserved = NULL;
1634 u64 release_bytes = 0;
1635 u64 lockstart;
1636 u64 lockend;
1637 size_t num_written = 0;
1638 int nrptrs;
1639 int ret = 0;
1640 bool only_release_metadata = false;
1641 bool force_page_uptodate = false;
1642
1643 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1644 PAGE_SIZE / (sizeof(struct page *)));
1645 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1646 nrptrs = max(nrptrs, 8);
1647 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1648 if (!pages)
1649 return -ENOMEM;
1650
1651 while (iov_iter_count(i) > 0) {
1652 struct extent_state *cached_state = NULL;
1653 size_t offset = offset_in_page(pos);
1654 size_t sector_offset;
1655 size_t write_bytes = min(iov_iter_count(i),
1656 nrptrs * (size_t)PAGE_SIZE -
1657 offset);
1658 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1659 PAGE_SIZE);
1660 size_t reserve_bytes;
1661 size_t dirty_pages;
1662 size_t copied;
1663 size_t dirty_sectors;
1664 size_t num_sectors;
1665 int extents_locked;
1666
1667 WARN_ON(num_pages > nrptrs);
1668
1669 /*
1670 * Fault pages before locking them in prepare_pages
1671 * to avoid recursive lock
1672 */
1673 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1674 ret = -EFAULT;
1675 break;
1676 }
1677
1678 only_release_metadata = false;
1679 sector_offset = pos & (fs_info->sectorsize - 1);
1680 reserve_bytes = round_up(write_bytes + sector_offset,
1681 fs_info->sectorsize);
1682
1683 extent_changeset_release(data_reserved);
1684 ret = btrfs_check_data_free_space(BTRFS_I(inode),
1685 &data_reserved, pos,
1686 write_bytes);
1687 if (ret < 0) {
1688 if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,
1689 &write_bytes) > 0) {
1690 /*
1691 * For nodata cow case, no need to reserve
1692 * data space.
1693 */
1694 only_release_metadata = true;
1695 /*
1696 * our prealloc extent may be smaller than
1697 * write_bytes, so scale down.
1698 */
1699 num_pages = DIV_ROUND_UP(write_bytes + offset,
1700 PAGE_SIZE);
1701 reserve_bytes = round_up(write_bytes +
1702 sector_offset,
1703 fs_info->sectorsize);
1704 } else {
1705 break;
1706 }
1707 }
1708
1709 WARN_ON(reserve_bytes == 0);
1710 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1711 reserve_bytes);
1712 if (ret) {
1713 if (!only_release_metadata)
1714 btrfs_free_reserved_data_space(BTRFS_I(inode),
1715 data_reserved, pos,
1716 write_bytes);
1717 else
1718 btrfs_check_nocow_unlock(BTRFS_I(inode));
1719 break;
1720 }
1721
1722 release_bytes = reserve_bytes;
1723again:
1724 /*
1725 * This is going to setup the pages array with the number of
1726 * pages we want, so we don't really need to worry about the
1727 * contents of pages from loop to loop
1728 */
1729 ret = prepare_pages(inode, pages, num_pages,
1730 pos, write_bytes,
1731 force_page_uptodate);
1732 if (ret) {
1733 btrfs_delalloc_release_extents(BTRFS_I(inode),
1734 reserve_bytes);
1735 break;
1736 }
1737
1738 extents_locked = lock_and_cleanup_extent_if_need(
1739 BTRFS_I(inode), pages,
1740 num_pages, pos, write_bytes, &lockstart,
1741 &lockend, &cached_state);
1742 if (extents_locked < 0) {
1743 if (extents_locked == -EAGAIN)
1744 goto again;
1745 btrfs_delalloc_release_extents(BTRFS_I(inode),
1746 reserve_bytes);
1747 ret = extents_locked;
1748 break;
1749 }
1750
1751 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1752
1753 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1754 dirty_sectors = round_up(copied + sector_offset,
1755 fs_info->sectorsize);
1756 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1757
1758 /*
1759 * if we have trouble faulting in the pages, fall
1760 * back to one page at a time
1761 */
1762 if (copied < write_bytes)
1763 nrptrs = 1;
1764
1765 if (copied == 0) {
1766 force_page_uptodate = true;
1767 dirty_sectors = 0;
1768 dirty_pages = 0;
1769 } else {
1770 force_page_uptodate = false;
1771 dirty_pages = DIV_ROUND_UP(copied + offset,
1772 PAGE_SIZE);
1773 }
1774
1775 if (num_sectors > dirty_sectors) {
1776 /* release everything except the sectors we dirtied */
1777 release_bytes -= dirty_sectors <<
1778 fs_info->sb->s_blocksize_bits;
1779 if (only_release_metadata) {
1780 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1781 release_bytes, true);
1782 } else {
1783 u64 __pos;
1784
1785 __pos = round_down(pos,
1786 fs_info->sectorsize) +
1787 (dirty_pages << PAGE_SHIFT);
1788 btrfs_delalloc_release_space(BTRFS_I(inode),
1789 data_reserved, __pos,
1790 release_bytes, true);
1791 }
1792 }
1793
1794 release_bytes = round_up(copied + sector_offset,
1795 fs_info->sectorsize);
1796
1797 if (copied > 0)
1798 ret = btrfs_dirty_pages(BTRFS_I(inode), pages,
1799 dirty_pages, pos, copied,
1800 &cached_state);
1801
1802 /*
1803 * If we have not locked the extent range, because the range's
1804 * start offset is >= i_size, we might still have a non-NULL
1805 * cached extent state, acquired while marking the extent range
1806 * as delalloc through btrfs_dirty_pages(). Therefore free any
1807 * possible cached extent state to avoid a memory leak.
1808 */
1809 if (extents_locked)
1810 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1811 lockstart, lockend, &cached_state);
1812 else
1813 free_extent_state(cached_state);
1814
1815 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1816 if (ret) {
1817 btrfs_drop_pages(pages, num_pages);
1818 break;
1819 }
1820
1821 release_bytes = 0;
1822 if (only_release_metadata)
1823 btrfs_check_nocow_unlock(BTRFS_I(inode));
1824
1825 if (only_release_metadata && copied > 0) {
1826 lockstart = round_down(pos,
1827 fs_info->sectorsize);
1828 lockend = round_up(pos + copied,
1829 fs_info->sectorsize) - 1;
1830
1831 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1832 lockend, EXTENT_NORESERVE, NULL,
1833 NULL, GFP_NOFS);
1834 }
1835
1836 btrfs_drop_pages(pages, num_pages);
1837
1838 cond_resched();
1839
1840 balance_dirty_pages_ratelimited(inode->i_mapping);
1841
1842 pos += copied;
1843 num_written += copied;
1844 }
1845
1846 kfree(pages);
1847
1848 if (release_bytes) {
1849 if (only_release_metadata) {
1850 btrfs_check_nocow_unlock(BTRFS_I(inode));
1851 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1852 release_bytes, true);
1853 } else {
1854 btrfs_delalloc_release_space(BTRFS_I(inode),
1855 data_reserved,
1856 round_down(pos, fs_info->sectorsize),
1857 release_bytes, true);
1858 }
1859 }
1860
1861 extent_changeset_free(data_reserved);
1862 return num_written ? num_written : ret;
1863}
1864
1865static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1866{
1867 struct file *file = iocb->ki_filp;
1868 struct inode *inode = file_inode(file);
1869 loff_t pos;
1870 ssize_t written;
1871 ssize_t written_buffered;
1872 loff_t endbyte;
1873 int err;
1874
1875 written = generic_file_direct_write(iocb, from);
1876
1877 if (written < 0 || !iov_iter_count(from))
1878 return written;
1879
1880 pos = iocb->ki_pos;
1881 written_buffered = btrfs_buffered_write(iocb, from);
1882 if (written_buffered < 0) {
1883 err = written_buffered;
1884 goto out;
1885 }
1886 /*
1887 * Ensure all data is persisted. We want the next direct IO read to be
1888 * able to read what was just written.
1889 */
1890 endbyte = pos + written_buffered - 1;
1891 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1892 if (err)
1893 goto out;
1894 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1895 if (err)
1896 goto out;
1897 written += written_buffered;
1898 iocb->ki_pos = pos + written_buffered;
1899 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1900 endbyte >> PAGE_SHIFT);
1901out:
1902 return written ? written : err;
1903}
1904
1905static void update_time_for_write(struct inode *inode)
1906{
1907 struct timespec64 now;
1908
1909 if (IS_NOCMTIME(inode))
1910 return;
1911
1912 now = current_time(inode);
1913 if (!timespec64_equal(&inode->i_mtime, &now))
1914 inode->i_mtime = now;
1915
1916 if (!timespec64_equal(&inode->i_ctime, &now))
1917 inode->i_ctime = now;
1918
1919 if (IS_I_VERSION(inode))
1920 inode_inc_iversion(inode);
1921}
1922
1923static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1924 struct iov_iter *from)
1925{
1926 struct file *file = iocb->ki_filp;
1927 struct inode *inode = file_inode(file);
1928 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1929 struct btrfs_root *root = BTRFS_I(inode)->root;
1930 u64 start_pos;
1931 u64 end_pos;
1932 ssize_t num_written = 0;
1933 const bool sync = iocb->ki_flags & IOCB_DSYNC;
1934 ssize_t err;
1935 loff_t pos;
1936 size_t count;
1937 loff_t oldsize;
1938 int clean_page = 0;
1939
1940 if (!(iocb->ki_flags & IOCB_DIRECT) &&
1941 (iocb->ki_flags & IOCB_NOWAIT))
1942 return -EOPNOTSUPP;
1943
1944 if (iocb->ki_flags & IOCB_NOWAIT) {
1945 if (!inode_trylock(inode))
1946 return -EAGAIN;
1947 } else {
1948 inode_lock(inode);
1949 }
1950
1951 err = generic_write_checks(iocb, from);
1952 if (err <= 0) {
1953 inode_unlock(inode);
1954 return err;
1955 }
1956
1957 pos = iocb->ki_pos;
1958 count = iov_iter_count(from);
1959 if (iocb->ki_flags & IOCB_NOWAIT) {
1960 size_t nocow_bytes = count;
1961
1962 /*
1963 * We will allocate space in case nodatacow is not set,
1964 * so bail
1965 */
1966 if (check_nocow_nolock(BTRFS_I(inode), pos, &nocow_bytes)
1967 <= 0) {
1968 inode_unlock(inode);
1969 return -EAGAIN;
1970 }
1971 /*
1972 * There are holes in the range or parts of the range that must
1973 * be COWed (shared extents, RO block groups, etc), so just bail
1974 * out.
1975 */
1976 if (nocow_bytes < count) {
1977 inode_unlock(inode);
1978 return -EAGAIN;
1979 }
1980 }
1981
1982 current->backing_dev_info = inode_to_bdi(inode);
1983 err = file_remove_privs(file);
1984 if (err) {
1985 inode_unlock(inode);
1986 goto out;
1987 }
1988
1989 /*
1990 * If BTRFS flips readonly due to some impossible error
1991 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1992 * although we have opened a file as writable, we have
1993 * to stop this write operation to ensure FS consistency.
1994 */
1995 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1996 inode_unlock(inode);
1997 err = -EROFS;
1998 goto out;
1999 }
2000
2001 /*
2002 * We reserve space for updating the inode when we reserve space for the
2003 * extent we are going to write, so we will enospc out there. We don't
2004 * need to start yet another transaction to update the inode as we will
2005 * update the inode when we finish writing whatever data we write.
2006 */
2007 update_time_for_write(inode);
2008
2009 start_pos = round_down(pos, fs_info->sectorsize);
2010 oldsize = i_size_read(inode);
2011 if (start_pos > oldsize) {
2012 /* Expand hole size to cover write data, preventing empty gap */
2013 end_pos = round_up(pos + count,
2014 fs_info->sectorsize);
2015 err = btrfs_cont_expand(inode, oldsize, end_pos);
2016 if (err) {
2017 inode_unlock(inode);
2018 goto out;
2019 }
2020 if (start_pos > round_up(oldsize, fs_info->sectorsize))
2021 clean_page = 1;
2022 }
2023
2024 if (sync)
2025 atomic_inc(&BTRFS_I(inode)->sync_writers);
2026
2027 if (iocb->ki_flags & IOCB_DIRECT) {
2028 num_written = __btrfs_direct_write(iocb, from);
2029 } else {
2030 num_written = btrfs_buffered_write(iocb, from);
2031 if (num_written > 0)
2032 iocb->ki_pos = pos + num_written;
2033 if (clean_page)
2034 pagecache_isize_extended(inode, oldsize,
2035 i_size_read(inode));
2036 }
2037
2038 inode_unlock(inode);
2039
2040 /*
2041 * We also have to set last_sub_trans to the current log transid,
2042 * otherwise subsequent syncs to a file that's been synced in this
2043 * transaction will appear to have already occurred.
2044 */
2045 spin_lock(&BTRFS_I(inode)->lock);
2046 BTRFS_I(inode)->last_sub_trans = root->log_transid;
2047 spin_unlock(&BTRFS_I(inode)->lock);
2048 if (num_written > 0)
2049 num_written = generic_write_sync(iocb, num_written);
2050
2051 if (sync)
2052 atomic_dec(&BTRFS_I(inode)->sync_writers);
2053out:
2054 current->backing_dev_info = NULL;
2055 return num_written ? num_written : err;
2056}
2057
2058int btrfs_release_file(struct inode *inode, struct file *filp)
2059{
2060 struct btrfs_file_private *private = filp->private_data;
2061
2062 if (private && private->filldir_buf)
2063 kfree(private->filldir_buf);
2064 kfree(private);
2065 filp->private_data = NULL;
2066
2067 /*
2068 * ordered_data_close is set by setattr when we are about to truncate
2069 * a file from a non-zero size to a zero size. This tries to
2070 * flush down new bytes that may have been written if the
2071 * application were using truncate to replace a file in place.
2072 */
2073 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2074 &BTRFS_I(inode)->runtime_flags))
2075 filemap_flush(inode->i_mapping);
2076 return 0;
2077}
2078
2079static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2080{
2081 int ret;
2082 struct blk_plug plug;
2083
2084 /*
2085 * This is only called in fsync, which would do synchronous writes, so
2086 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2087 * multiple disks using raid profile, a large IO can be split to
2088 * several segments of stripe length (currently 64K).
2089 */
2090 blk_start_plug(&plug);
2091 atomic_inc(&BTRFS_I(inode)->sync_writers);
2092 ret = btrfs_fdatawrite_range(inode, start, end);
2093 atomic_dec(&BTRFS_I(inode)->sync_writers);
2094 blk_finish_plug(&plug);
2095
2096 return ret;
2097}
2098
2099/*
2100 * fsync call for both files and directories. This logs the inode into
2101 * the tree log instead of forcing full commits whenever possible.
2102 *
2103 * It needs to call filemap_fdatawait so that all ordered extent updates are
2104 * in the metadata btree are up to date for copying to the log.
2105 *
2106 * It drops the inode mutex before doing the tree log commit. This is an
2107 * important optimization for directories because holding the mutex prevents
2108 * new operations on the dir while we write to disk.
2109 */
2110int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2111{
2112 struct dentry *dentry = file_dentry(file);
2113 struct inode *inode = d_inode(dentry);
2114 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2115 struct btrfs_root *root = BTRFS_I(inode)->root;
2116 struct btrfs_trans_handle *trans;
2117 struct btrfs_log_ctx ctx;
2118 int ret = 0, err;
2119
2120 trace_btrfs_sync_file(file, datasync);
2121
2122 btrfs_init_log_ctx(&ctx, inode);
2123
2124 /*
2125 * Set the range to full if the NO_HOLES feature is not enabled.
2126 * This is to avoid missing file extent items representing holes after
2127 * replaying the log.
2128 */
2129 if (!btrfs_fs_incompat(fs_info, NO_HOLES)) {
2130 start = 0;
2131 end = LLONG_MAX;
2132 }
2133
2134 /*
2135 * We write the dirty pages in the range and wait until they complete
2136 * out of the ->i_mutex. If so, we can flush the dirty pages by
2137 * multi-task, and make the performance up. See
2138 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2139 */
2140 ret = start_ordered_ops(inode, start, end);
2141 if (ret)
2142 goto out;
2143
2144 inode_lock(inode);
2145
2146 /*
2147 * We take the dio_sem here because the tree log stuff can race with
2148 * lockless dio writes and get an extent map logged for an extent we
2149 * never waited on. We need it this high up for lockdep reasons.
2150 */
2151 down_write(&BTRFS_I(inode)->dio_sem);
2152
2153 atomic_inc(&root->log_batch);
2154
2155 /*
2156 * If the inode needs a full sync, make sure we use a full range to
2157 * avoid log tree corruption, due to hole detection racing with ordered
2158 * extent completion for adjacent ranges and races between logging and
2159 * completion of ordered extents for adjancent ranges - both races
2160 * could lead to file extent items in the log with overlapping ranges.
2161 * Do this while holding the inode lock, to avoid races with other
2162 * tasks.
2163 */
2164 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2165 &BTRFS_I(inode)->runtime_flags)) {
2166 start = 0;
2167 end = LLONG_MAX;
2168 }
2169
2170 /*
2171 * Before we acquired the inode's lock, someone may have dirtied more
2172 * pages in the target range. We need to make sure that writeback for
2173 * any such pages does not start while we are logging the inode, because
2174 * if it does, any of the following might happen when we are not doing a
2175 * full inode sync:
2176 *
2177 * 1) We log an extent after its writeback finishes but before its
2178 * checksums are added to the csum tree, leading to -EIO errors
2179 * when attempting to read the extent after a log replay.
2180 *
2181 * 2) We can end up logging an extent before its writeback finishes.
2182 * Therefore after the log replay we will have a file extent item
2183 * pointing to an unwritten extent (and no data checksums as well).
2184 *
2185 * So trigger writeback for any eventual new dirty pages and then we
2186 * wait for all ordered extents to complete below.
2187 */
2188 ret = start_ordered_ops(inode, start, end);
2189 if (ret) {
2190 up_write(&BTRFS_I(inode)->dio_sem);
2191 inode_unlock(inode);
2192 goto out;
2193 }
2194
2195 /*
2196 * We have to do this here to avoid the priority inversion of waiting on
2197 * IO of a lower priority task while holding a transaction open.
2198 *
2199 * Also, the range length can be represented by u64, we have to do the
2200 * typecasts to avoid signed overflow if it's [0, LLONG_MAX].
2201 */
2202 ret = btrfs_wait_ordered_range(inode, start, (u64)end - (u64)start + 1);
2203 if (ret) {
2204 up_write(&BTRFS_I(inode)->dio_sem);
2205 inode_unlock(inode);
2206 goto out;
2207 }
2208 atomic_inc(&root->log_batch);
2209
2210 smp_mb();
2211 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2212 BTRFS_I(inode)->last_trans <= fs_info->last_trans_committed) {
2213 /*
2214 * We've had everything committed since the last time we were
2215 * modified so clear this flag in case it was set for whatever
2216 * reason, it's no longer relevant.
2217 */
2218 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2219 &BTRFS_I(inode)->runtime_flags);
2220 /*
2221 * An ordered extent might have started before and completed
2222 * already with io errors, in which case the inode was not
2223 * updated and we end up here. So check the inode's mapping
2224 * for any errors that might have happened since we last
2225 * checked called fsync.
2226 */
2227 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2228 up_write(&BTRFS_I(inode)->dio_sem);
2229 inode_unlock(inode);
2230 goto out;
2231 }
2232
2233 /*
2234 * We use start here because we will need to wait on the IO to complete
2235 * in btrfs_sync_log, which could require joining a transaction (for
2236 * example checking cross references in the nocow path). If we use join
2237 * here we could get into a situation where we're waiting on IO to
2238 * happen that is blocked on a transaction trying to commit. With start
2239 * we inc the extwriter counter, so we wait for all extwriters to exit
2240 * before we start blocking joiners. This comment is to keep somebody
2241 * from thinking they are super smart and changing this to
2242 * btrfs_join_transaction *cough*Josef*cough*.
2243 */
2244 trans = btrfs_start_transaction(root, 0);
2245 if (IS_ERR(trans)) {
2246 ret = PTR_ERR(trans);
2247 up_write(&BTRFS_I(inode)->dio_sem);
2248 inode_unlock(inode);
2249 goto out;
2250 }
2251
2252 ret = btrfs_log_dentry_safe(trans, dentry, start, end, &ctx);
2253 if (ret < 0) {
2254 /* Fallthrough and commit/free transaction. */
2255 ret = 1;
2256 }
2257
2258 /* we've logged all the items and now have a consistent
2259 * version of the file in the log. It is possible that
2260 * someone will come in and modify the file, but that's
2261 * fine because the log is consistent on disk, and we
2262 * have references to all of the file's extents
2263 *
2264 * It is possible that someone will come in and log the
2265 * file again, but that will end up using the synchronization
2266 * inside btrfs_sync_log to keep things safe.
2267 */
2268 up_write(&BTRFS_I(inode)->dio_sem);
2269 inode_unlock(inode);
2270
2271 if (ret != BTRFS_NO_LOG_SYNC) {
2272 if (!ret) {
2273 ret = btrfs_sync_log(trans, root, &ctx);
2274 if (!ret) {
2275 ret = btrfs_end_transaction(trans);
2276 goto out;
2277 }
2278 }
2279 ret = btrfs_commit_transaction(trans);
2280 } else {
2281 ret = btrfs_end_transaction(trans);
2282 }
2283out:
2284 ASSERT(list_empty(&ctx.list));
2285 err = file_check_and_advance_wb_err(file);
2286 if (!ret)
2287 ret = err;
2288 return ret > 0 ? -EIO : ret;
2289}
2290
2291static const struct vm_operations_struct btrfs_file_vm_ops = {
2292 .fault = filemap_fault,
2293 .map_pages = filemap_map_pages,
2294 .page_mkwrite = btrfs_page_mkwrite,
2295};
2296
2297static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2298{
2299 struct address_space *mapping = filp->f_mapping;
2300
2301 if (!mapping->a_ops->readpage)
2302 return -ENOEXEC;
2303
2304 file_accessed(filp);
2305 vma->vm_ops = &btrfs_file_vm_ops;
2306
2307 return 0;
2308}
2309
2310static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2311 int slot, u64 start, u64 end)
2312{
2313 struct btrfs_file_extent_item *fi;
2314 struct btrfs_key key;
2315
2316 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2317 return 0;
2318
2319 btrfs_item_key_to_cpu(leaf, &key, slot);
2320 if (key.objectid != btrfs_ino(inode) ||
2321 key.type != BTRFS_EXTENT_DATA_KEY)
2322 return 0;
2323
2324 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2325
2326 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2327 return 0;
2328
2329 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2330 return 0;
2331
2332 if (key.offset == end)
2333 return 1;
2334 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2335 return 1;
2336 return 0;
2337}
2338
2339static int fill_holes(struct btrfs_trans_handle *trans,
2340 struct btrfs_inode *inode,
2341 struct btrfs_path *path, u64 offset, u64 end)
2342{
2343 struct btrfs_fs_info *fs_info = trans->fs_info;
2344 struct btrfs_root *root = inode->root;
2345 struct extent_buffer *leaf;
2346 struct btrfs_file_extent_item *fi;
2347 struct extent_map *hole_em;
2348 struct extent_map_tree *em_tree = &inode->extent_tree;
2349 struct btrfs_key key;
2350 int ret;
2351
2352 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2353 goto out;
2354
2355 key.objectid = btrfs_ino(inode);
2356 key.type = BTRFS_EXTENT_DATA_KEY;
2357 key.offset = offset;
2358
2359 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2360 if (ret <= 0) {
2361 /*
2362 * We should have dropped this offset, so if we find it then
2363 * something has gone horribly wrong.
2364 */
2365 if (ret == 0)
2366 ret = -EINVAL;
2367 return ret;
2368 }
2369
2370 leaf = path->nodes[0];
2371 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2372 u64 num_bytes;
2373
2374 path->slots[0]--;
2375 fi = btrfs_item_ptr(leaf, path->slots[0],
2376 struct btrfs_file_extent_item);
2377 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2378 end - offset;
2379 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2380 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2381 btrfs_set_file_extent_offset(leaf, fi, 0);
2382 btrfs_mark_buffer_dirty(leaf);
2383 goto out;
2384 }
2385
2386 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2387 u64 num_bytes;
2388
2389 key.offset = offset;
2390 btrfs_set_item_key_safe(fs_info, path, &key);
2391 fi = btrfs_item_ptr(leaf, path->slots[0],
2392 struct btrfs_file_extent_item);
2393 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2394 offset;
2395 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2396 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2397 btrfs_set_file_extent_offset(leaf, fi, 0);
2398 btrfs_mark_buffer_dirty(leaf);
2399 goto out;
2400 }
2401 btrfs_release_path(path);
2402
2403 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2404 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2405 if (ret)
2406 return ret;
2407
2408out:
2409 btrfs_release_path(path);
2410
2411 hole_em = alloc_extent_map();
2412 if (!hole_em) {
2413 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2414 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2415 } else {
2416 hole_em->start = offset;
2417 hole_em->len = end - offset;
2418 hole_em->ram_bytes = hole_em->len;
2419 hole_em->orig_start = offset;
2420
2421 hole_em->block_start = EXTENT_MAP_HOLE;
2422 hole_em->block_len = 0;
2423 hole_em->orig_block_len = 0;
2424 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2425 hole_em->generation = trans->transid;
2426
2427 do {
2428 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2429 write_lock(&em_tree->lock);
2430 ret = add_extent_mapping(em_tree, hole_em, 1);
2431 write_unlock(&em_tree->lock);
2432 } while (ret == -EEXIST);
2433 free_extent_map(hole_em);
2434 if (ret)
2435 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2436 &inode->runtime_flags);
2437 }
2438
2439 return 0;
2440}
2441
2442/*
2443 * Find a hole extent on given inode and change start/len to the end of hole
2444 * extent.(hole/vacuum extent whose em->start <= start &&
2445 * em->start + em->len > start)
2446 * When a hole extent is found, return 1 and modify start/len.
2447 */
2448static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2449{
2450 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2451 struct extent_map *em;
2452 int ret = 0;
2453
2454 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2455 round_down(*start, fs_info->sectorsize),
2456 round_up(*len, fs_info->sectorsize));
2457 if (IS_ERR(em))
2458 return PTR_ERR(em);
2459
2460 /* Hole or vacuum extent(only exists in no-hole mode) */
2461 if (em->block_start == EXTENT_MAP_HOLE) {
2462 ret = 1;
2463 *len = em->start + em->len > *start + *len ?
2464 0 : *start + *len - em->start - em->len;
2465 *start = em->start + em->len;
2466 }
2467 free_extent_map(em);
2468 return ret;
2469}
2470
2471static int btrfs_punch_hole_lock_range(struct inode *inode,
2472 const u64 lockstart,
2473 const u64 lockend,
2474 struct extent_state **cached_state)
2475{
2476 while (1) {
2477 struct btrfs_ordered_extent *ordered;
2478 int ret;
2479
2480 truncate_pagecache_range(inode, lockstart, lockend);
2481
2482 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2483 cached_state);
2484 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2485
2486 /*
2487 * We need to make sure we have no ordered extents in this range
2488 * and nobody raced in and read a page in this range, if we did
2489 * we need to try again.
2490 */
2491 if ((!ordered ||
2492 (ordered->file_offset + ordered->num_bytes <= lockstart ||
2493 ordered->file_offset > lockend)) &&
2494 !filemap_range_has_page(inode->i_mapping,
2495 lockstart, lockend)) {
2496 if (ordered)
2497 btrfs_put_ordered_extent(ordered);
2498 break;
2499 }
2500 if (ordered)
2501 btrfs_put_ordered_extent(ordered);
2502 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2503 lockend, cached_state);
2504 ret = btrfs_wait_ordered_range(inode, lockstart,
2505 lockend - lockstart + 1);
2506 if (ret)
2507 return ret;
2508 }
2509 return 0;
2510}
2511
2512static int btrfs_insert_clone_extent(struct btrfs_trans_handle *trans,
2513 struct inode *inode,
2514 struct btrfs_path *path,
2515 struct btrfs_clone_extent_info *clone_info,
2516 const u64 clone_len)
2517{
2518 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2519 struct btrfs_root *root = BTRFS_I(inode)->root;
2520 struct btrfs_file_extent_item *extent;
2521 struct extent_buffer *leaf;
2522 struct btrfs_key key;
2523 int slot;
2524 struct btrfs_ref ref = { 0 };
2525 u64 ref_offset;
2526 int ret;
2527
2528 if (clone_len == 0)
2529 return 0;
2530
2531 if (clone_info->disk_offset == 0 &&
2532 btrfs_fs_incompat(fs_info, NO_HOLES))
2533 return 0;
2534
2535 key.objectid = btrfs_ino(BTRFS_I(inode));
2536 key.type = BTRFS_EXTENT_DATA_KEY;
2537 key.offset = clone_info->file_offset;
2538 ret = btrfs_insert_empty_item(trans, root, path, &key,
2539 clone_info->item_size);
2540 if (ret)
2541 return ret;
2542 leaf = path->nodes[0];
2543 slot = path->slots[0];
2544 write_extent_buffer(leaf, clone_info->extent_buf,
2545 btrfs_item_ptr_offset(leaf, slot),
2546 clone_info->item_size);
2547 extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2548 btrfs_set_file_extent_offset(leaf, extent, clone_info->data_offset);
2549 btrfs_set_file_extent_num_bytes(leaf, extent, clone_len);
2550 btrfs_mark_buffer_dirty(leaf);
2551 btrfs_release_path(path);
2552
2553 ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode),
2554 clone_info->file_offset, clone_len);
2555 if (ret)
2556 return ret;
2557
2558 /* If it's a hole, nothing more needs to be done. */
2559 if (clone_info->disk_offset == 0)
2560 return 0;
2561
2562 inode_add_bytes(inode, clone_len);
2563 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
2564 clone_info->disk_offset,
2565 clone_info->disk_len, 0);
2566 ref_offset = clone_info->file_offset - clone_info->data_offset;
2567 btrfs_init_data_ref(&ref, root->root_key.objectid,
2568 btrfs_ino(BTRFS_I(inode)), ref_offset);
2569 ret = btrfs_inc_extent_ref(trans, &ref);
2570
2571 return ret;
2572}
2573
2574/*
2575 * The respective range must have been previously locked, as well as the inode.
2576 * The end offset is inclusive (last byte of the range).
2577 * @clone_info is NULL for fallocate's hole punching and non-NULL for extent
2578 * cloning.
2579 * When cloning, we don't want to end up in a state where we dropped extents
2580 * without inserting a new one, so we must abort the transaction to avoid a
2581 * corruption.
2582 */
2583int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
2584 const u64 start, const u64 end,
2585 struct btrfs_clone_extent_info *clone_info,
2586 struct btrfs_trans_handle **trans_out)
2587{
2588 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2589 u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
2590 u64 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2591 struct btrfs_root *root = BTRFS_I(inode)->root;
2592 struct btrfs_trans_handle *trans = NULL;
2593 struct btrfs_block_rsv *rsv;
2594 unsigned int rsv_count;
2595 u64 cur_offset;
2596 u64 drop_end;
2597 u64 len = end - start;
2598 int ret = 0;
2599
2600 if (end <= start)
2601 return -EINVAL;
2602
2603 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2604 if (!rsv) {
2605 ret = -ENOMEM;
2606 goto out;
2607 }
2608 rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
2609 rsv->failfast = 1;
2610
2611 /*
2612 * 1 - update the inode
2613 * 1 - removing the extents in the range
2614 * 1 - adding the hole extent if no_holes isn't set or if we are cloning
2615 * an extent
2616 */
2617 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || clone_info)
2618 rsv_count = 3;
2619 else
2620 rsv_count = 2;
2621
2622 trans = btrfs_start_transaction(root, rsv_count);
2623 if (IS_ERR(trans)) {
2624 ret = PTR_ERR(trans);
2625 trans = NULL;
2626 goto out_free;
2627 }
2628
2629 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2630 min_size, false);
2631 BUG_ON(ret);
2632 trans->block_rsv = rsv;
2633
2634 cur_offset = start;
2635 while (cur_offset < end) {
2636 ret = __btrfs_drop_extents(trans, root, BTRFS_I(inode), path,
2637 cur_offset, end + 1, &drop_end,
2638 1, 0, 0, NULL);
2639 if (ret != -ENOSPC) {
2640 /*
2641 * When cloning we want to avoid transaction aborts when
2642 * nothing was done and we are attempting to clone parts
2643 * of inline extents, in such cases -EOPNOTSUPP is
2644 * returned by __btrfs_drop_extents() without having
2645 * changed anything in the file.
2646 */
2647 if (clone_info && ret && ret != -EOPNOTSUPP)
2648 btrfs_abort_transaction(trans, ret);
2649 break;
2650 }
2651
2652 trans->block_rsv = &fs_info->trans_block_rsv;
2653
2654 if (!clone_info && cur_offset < drop_end &&
2655 cur_offset < ino_size) {
2656 ret = fill_holes(trans, BTRFS_I(inode), path,
2657 cur_offset, drop_end);
2658 if (ret) {
2659 /*
2660 * If we failed then we didn't insert our hole
2661 * entries for the area we dropped, so now the
2662 * fs is corrupted, so we must abort the
2663 * transaction.
2664 */
2665 btrfs_abort_transaction(trans, ret);
2666 break;
2667 }
2668 } else if (!clone_info && cur_offset < drop_end) {
2669 /*
2670 * We are past the i_size here, but since we didn't
2671 * insert holes we need to clear the mapped area so we
2672 * know to not set disk_i_size in this area until a new
2673 * file extent is inserted here.
2674 */
2675 ret = btrfs_inode_clear_file_extent_range(BTRFS_I(inode),
2676 cur_offset, drop_end - cur_offset);
2677 if (ret) {
2678 /*
2679 * We couldn't clear our area, so we could
2680 * presumably adjust up and corrupt the fs, so
2681 * we need to abort.
2682 */
2683 btrfs_abort_transaction(trans, ret);
2684 break;
2685 }
2686 }
2687
2688 if (clone_info && drop_end > clone_info->file_offset) {
2689 u64 clone_len = drop_end - clone_info->file_offset;
2690
2691 ret = btrfs_insert_clone_extent(trans, inode, path,
2692 clone_info, clone_len);
2693 if (ret) {
2694 btrfs_abort_transaction(trans, ret);
2695 break;
2696 }
2697 clone_info->data_len -= clone_len;
2698 clone_info->data_offset += clone_len;
2699 clone_info->file_offset += clone_len;
2700 }
2701
2702 cur_offset = drop_end;
2703
2704 ret = btrfs_update_inode(trans, root, inode);
2705 if (ret)
2706 break;
2707
2708 btrfs_end_transaction(trans);
2709 btrfs_btree_balance_dirty(fs_info);
2710
2711 trans = btrfs_start_transaction(root, rsv_count);
2712 if (IS_ERR(trans)) {
2713 ret = PTR_ERR(trans);
2714 trans = NULL;
2715 break;
2716 }
2717
2718 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2719 rsv, min_size, false);
2720 BUG_ON(ret); /* shouldn't happen */
2721 trans->block_rsv = rsv;
2722
2723 if (!clone_info) {
2724 ret = find_first_non_hole(inode, &cur_offset, &len);
2725 if (unlikely(ret < 0))
2726 break;
2727 if (ret && !len) {
2728 ret = 0;
2729 break;
2730 }
2731 }
2732 }
2733
2734 /*
2735 * If we were cloning, force the next fsync to be a full one since we
2736 * we replaced (or just dropped in the case of cloning holes when
2737 * NO_HOLES is enabled) extents and extent maps.
2738 * This is for the sake of simplicity, and cloning into files larger
2739 * than 16Mb would force the full fsync any way (when
2740 * try_release_extent_mapping() is invoked during page cache truncation.
2741 */
2742 if (clone_info)
2743 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2744 &BTRFS_I(inode)->runtime_flags);
2745
2746 if (ret)
2747 goto out_trans;
2748
2749 trans->block_rsv = &fs_info->trans_block_rsv;
2750 /*
2751 * If we are using the NO_HOLES feature we might have had already an
2752 * hole that overlaps a part of the region [lockstart, lockend] and
2753 * ends at (or beyond) lockend. Since we have no file extent items to
2754 * represent holes, drop_end can be less than lockend and so we must
2755 * make sure we have an extent map representing the existing hole (the
2756 * call to __btrfs_drop_extents() might have dropped the existing extent
2757 * map representing the existing hole), otherwise the fast fsync path
2758 * will not record the existence of the hole region
2759 * [existing_hole_start, lockend].
2760 */
2761 if (drop_end <= end)
2762 drop_end = end + 1;
2763 /*
2764 * Don't insert file hole extent item if it's for a range beyond eof
2765 * (because it's useless) or if it represents a 0 bytes range (when
2766 * cur_offset == drop_end).
2767 */
2768 if (!clone_info && cur_offset < ino_size && cur_offset < drop_end) {
2769 ret = fill_holes(trans, BTRFS_I(inode), path,
2770 cur_offset, drop_end);
2771 if (ret) {
2772 /* Same comment as above. */
2773 btrfs_abort_transaction(trans, ret);
2774 goto out_trans;
2775 }
2776 } else if (!clone_info && cur_offset < drop_end) {
2777 /* See the comment in the loop above for the reasoning here. */
2778 ret = btrfs_inode_clear_file_extent_range(BTRFS_I(inode),
2779 cur_offset, drop_end - cur_offset);
2780 if (ret) {
2781 btrfs_abort_transaction(trans, ret);
2782 goto out_trans;
2783 }
2784
2785 }
2786 if (clone_info) {
2787 ret = btrfs_insert_clone_extent(trans, inode, path, clone_info,
2788 clone_info->data_len);
2789 if (ret) {
2790 btrfs_abort_transaction(trans, ret);
2791 goto out_trans;
2792 }
2793 }
2794
2795out_trans:
2796 if (!trans)
2797 goto out_free;
2798
2799 trans->block_rsv = &fs_info->trans_block_rsv;
2800 if (ret)
2801 btrfs_end_transaction(trans);
2802 else
2803 *trans_out = trans;
2804out_free:
2805 btrfs_free_block_rsv(fs_info, rsv);
2806out:
2807 return ret;
2808}
2809
2810static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2811{
2812 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2813 struct btrfs_root *root = BTRFS_I(inode)->root;
2814 struct extent_state *cached_state = NULL;
2815 struct btrfs_path *path;
2816 struct btrfs_trans_handle *trans = NULL;
2817 u64 lockstart;
2818 u64 lockend;
2819 u64 tail_start;
2820 u64 tail_len;
2821 u64 orig_start = offset;
2822 int ret = 0;
2823 bool same_block;
2824 u64 ino_size;
2825 bool truncated_block = false;
2826 bool updated_inode = false;
2827
2828 ret = btrfs_wait_ordered_range(inode, offset, len);
2829 if (ret)
2830 return ret;
2831
2832 inode_lock(inode);
2833 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2834 ret = find_first_non_hole(inode, &offset, &len);
2835 if (ret < 0)
2836 goto out_only_mutex;
2837 if (ret && !len) {
2838 /* Already in a large hole */
2839 ret = 0;
2840 goto out_only_mutex;
2841 }
2842
2843 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2844 lockend = round_down(offset + len,
2845 btrfs_inode_sectorsize(inode)) - 1;
2846 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2847 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2848 /*
2849 * We needn't truncate any block which is beyond the end of the file
2850 * because we are sure there is no data there.
2851 */
2852 /*
2853 * Only do this if we are in the same block and we aren't doing the
2854 * entire block.
2855 */
2856 if (same_block && len < fs_info->sectorsize) {
2857 if (offset < ino_size) {
2858 truncated_block = true;
2859 ret = btrfs_truncate_block(inode, offset, len, 0);
2860 } else {
2861 ret = 0;
2862 }
2863 goto out_only_mutex;
2864 }
2865
2866 /* zero back part of the first block */
2867 if (offset < ino_size) {
2868 truncated_block = true;
2869 ret = btrfs_truncate_block(inode, offset, 0, 0);
2870 if (ret) {
2871 inode_unlock(inode);
2872 return ret;
2873 }
2874 }
2875
2876 /* Check the aligned pages after the first unaligned page,
2877 * if offset != orig_start, which means the first unaligned page
2878 * including several following pages are already in holes,
2879 * the extra check can be skipped */
2880 if (offset == orig_start) {
2881 /* after truncate page, check hole again */
2882 len = offset + len - lockstart;
2883 offset = lockstart;
2884 ret = find_first_non_hole(inode, &offset, &len);
2885 if (ret < 0)
2886 goto out_only_mutex;
2887 if (ret && !len) {
2888 ret = 0;
2889 goto out_only_mutex;
2890 }
2891 lockstart = offset;
2892 }
2893
2894 /* Check the tail unaligned part is in a hole */
2895 tail_start = lockend + 1;
2896 tail_len = offset + len - tail_start;
2897 if (tail_len) {
2898 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2899 if (unlikely(ret < 0))
2900 goto out_only_mutex;
2901 if (!ret) {
2902 /* zero the front end of the last page */
2903 if (tail_start + tail_len < ino_size) {
2904 truncated_block = true;
2905 ret = btrfs_truncate_block(inode,
2906 tail_start + tail_len,
2907 0, 1);
2908 if (ret)
2909 goto out_only_mutex;
2910 }
2911 }
2912 }
2913
2914 if (lockend < lockstart) {
2915 ret = 0;
2916 goto out_only_mutex;
2917 }
2918
2919 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2920 &cached_state);
2921 if (ret)
2922 goto out_only_mutex;
2923
2924 path = btrfs_alloc_path();
2925 if (!path) {
2926 ret = -ENOMEM;
2927 goto out;
2928 }
2929
2930 ret = btrfs_punch_hole_range(inode, path, lockstart, lockend, NULL,
2931 &trans);
2932 btrfs_free_path(path);
2933 if (ret)
2934 goto out;
2935
2936 ASSERT(trans != NULL);
2937 inode_inc_iversion(inode);
2938 inode->i_mtime = inode->i_ctime = current_time(inode);
2939 ret = btrfs_update_inode(trans, root, inode);
2940 updated_inode = true;
2941 btrfs_end_transaction(trans);
2942 btrfs_btree_balance_dirty(fs_info);
2943out:
2944 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2945 &cached_state);
2946out_only_mutex:
2947 if (!updated_inode && truncated_block && !ret) {
2948 /*
2949 * If we only end up zeroing part of a page, we still need to
2950 * update the inode item, so that all the time fields are
2951 * updated as well as the necessary btrfs inode in memory fields
2952 * for detecting, at fsync time, if the inode isn't yet in the
2953 * log tree or it's there but not up to date.
2954 */
2955 struct timespec64 now = current_time(inode);
2956
2957 inode_inc_iversion(inode);
2958 inode->i_mtime = now;
2959 inode->i_ctime = now;
2960 trans = btrfs_start_transaction(root, 1);
2961 if (IS_ERR(trans)) {
2962 ret = PTR_ERR(trans);
2963 } else {
2964 int ret2;
2965
2966 ret = btrfs_update_inode(trans, root, inode);
2967 ret2 = btrfs_end_transaction(trans);
2968 if (!ret)
2969 ret = ret2;
2970 }
2971 }
2972 inode_unlock(inode);
2973 return ret;
2974}
2975
2976/* Helper structure to record which range is already reserved */
2977struct falloc_range {
2978 struct list_head list;
2979 u64 start;
2980 u64 len;
2981};
2982
2983/*
2984 * Helper function to add falloc range
2985 *
2986 * Caller should have locked the larger range of extent containing
2987 * [start, len)
2988 */
2989static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2990{
2991 struct falloc_range *prev = NULL;
2992 struct falloc_range *range = NULL;
2993
2994 if (list_empty(head))
2995 goto insert;
2996
2997 /*
2998 * As fallocate iterate by bytenr order, we only need to check
2999 * the last range.
3000 */
3001 prev = list_entry(head->prev, struct falloc_range, list);
3002 if (prev->start + prev->len == start) {
3003 prev->len += len;
3004 return 0;
3005 }
3006insert:
3007 range = kmalloc(sizeof(*range), GFP_KERNEL);
3008 if (!range)
3009 return -ENOMEM;
3010 range->start = start;
3011 range->len = len;
3012 list_add_tail(&range->list, head);
3013 return 0;
3014}
3015
3016static int btrfs_fallocate_update_isize(struct inode *inode,
3017 const u64 end,
3018 const int mode)
3019{
3020 struct btrfs_trans_handle *trans;
3021 struct btrfs_root *root = BTRFS_I(inode)->root;
3022 int ret;
3023 int ret2;
3024
3025 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
3026 return 0;
3027
3028 trans = btrfs_start_transaction(root, 1);
3029 if (IS_ERR(trans))
3030 return PTR_ERR(trans);
3031
3032 inode->i_ctime = current_time(inode);
3033 i_size_write(inode, end);
3034 btrfs_inode_safe_disk_i_size_write(inode, 0);
3035 ret = btrfs_update_inode(trans, root, inode);
3036 ret2 = btrfs_end_transaction(trans);
3037
3038 return ret ? ret : ret2;
3039}
3040
3041enum {
3042 RANGE_BOUNDARY_WRITTEN_EXTENT,
3043 RANGE_BOUNDARY_PREALLOC_EXTENT,
3044 RANGE_BOUNDARY_HOLE,
3045};
3046
3047static int btrfs_zero_range_check_range_boundary(struct inode *inode,
3048 u64 offset)
3049{
3050 const u64 sectorsize = btrfs_inode_sectorsize(inode);
3051 struct extent_map *em;
3052 int ret;
3053
3054 offset = round_down(offset, sectorsize);
3055 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize);
3056 if (IS_ERR(em))
3057 return PTR_ERR(em);
3058
3059 if (em->block_start == EXTENT_MAP_HOLE)
3060 ret = RANGE_BOUNDARY_HOLE;
3061 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3062 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
3063 else
3064 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
3065
3066 free_extent_map(em);
3067 return ret;
3068}
3069
3070static int btrfs_zero_range(struct inode *inode,
3071 loff_t offset,
3072 loff_t len,
3073 const int mode)
3074{
3075 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3076 struct extent_map *em;
3077 struct extent_changeset *data_reserved = NULL;
3078 int ret;
3079 u64 alloc_hint = 0;
3080 const u64 sectorsize = btrfs_inode_sectorsize(inode);
3081 u64 alloc_start = round_down(offset, sectorsize);
3082 u64 alloc_end = round_up(offset + len, sectorsize);
3083 u64 bytes_to_reserve = 0;
3084 bool space_reserved = false;
3085
3086 inode_dio_wait(inode);
3087
3088 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start,
3089 alloc_end - alloc_start);
3090 if (IS_ERR(em)) {
3091 ret = PTR_ERR(em);
3092 goto out;
3093 }
3094
3095 /*
3096 * Avoid hole punching and extent allocation for some cases. More cases
3097 * could be considered, but these are unlikely common and we keep things
3098 * as simple as possible for now. Also, intentionally, if the target
3099 * range contains one or more prealloc extents together with regular
3100 * extents and holes, we drop all the existing extents and allocate a
3101 * new prealloc extent, so that we get a larger contiguous disk extent.
3102 */
3103 if (em->start <= alloc_start &&
3104 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3105 const u64 em_end = em->start + em->len;
3106
3107 if (em_end >= offset + len) {
3108 /*
3109 * The whole range is already a prealloc extent,
3110 * do nothing except updating the inode's i_size if
3111 * needed.
3112 */
3113 free_extent_map(em);
3114 ret = btrfs_fallocate_update_isize(inode, offset + len,
3115 mode);
3116 goto out;
3117 }
3118 /*
3119 * Part of the range is already a prealloc extent, so operate
3120 * only on the remaining part of the range.
3121 */
3122 alloc_start = em_end;
3123 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
3124 len = offset + len - alloc_start;
3125 offset = alloc_start;
3126 alloc_hint = em->block_start + em->len;
3127 }
3128 free_extent_map(em);
3129
3130 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
3131 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
3132 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start,
3133 sectorsize);
3134 if (IS_ERR(em)) {
3135 ret = PTR_ERR(em);
3136 goto out;
3137 }
3138
3139 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3140 free_extent_map(em);
3141 ret = btrfs_fallocate_update_isize(inode, offset + len,
3142 mode);
3143 goto out;
3144 }
3145 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
3146 free_extent_map(em);
3147 ret = btrfs_truncate_block(inode, offset, len, 0);
3148 if (!ret)
3149 ret = btrfs_fallocate_update_isize(inode,
3150 offset + len,
3151 mode);
3152 return ret;
3153 }
3154 free_extent_map(em);
3155 alloc_start = round_down(offset, sectorsize);
3156 alloc_end = alloc_start + sectorsize;
3157 goto reserve_space;
3158 }
3159
3160 alloc_start = round_up(offset, sectorsize);
3161 alloc_end = round_down(offset + len, sectorsize);
3162
3163 /*
3164 * For unaligned ranges, check the pages at the boundaries, they might
3165 * map to an extent, in which case we need to partially zero them, or
3166 * they might map to a hole, in which case we need our allocation range
3167 * to cover them.
3168 */
3169 if (!IS_ALIGNED(offset, sectorsize)) {
3170 ret = btrfs_zero_range_check_range_boundary(inode, offset);
3171 if (ret < 0)
3172 goto out;
3173 if (ret == RANGE_BOUNDARY_HOLE) {
3174 alloc_start = round_down(offset, sectorsize);
3175 ret = 0;
3176 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3177 ret = btrfs_truncate_block(inode, offset, 0, 0);
3178 if (ret)
3179 goto out;
3180 } else {
3181 ret = 0;
3182 }
3183 }
3184
3185 if (!IS_ALIGNED(offset + len, sectorsize)) {
3186 ret = btrfs_zero_range_check_range_boundary(inode,
3187 offset + len);
3188 if (ret < 0)
3189 goto out;
3190 if (ret == RANGE_BOUNDARY_HOLE) {
3191 alloc_end = round_up(offset + len, sectorsize);
3192 ret = 0;
3193 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3194 ret = btrfs_truncate_block(inode, offset + len, 0, 1);
3195 if (ret)
3196 goto out;
3197 } else {
3198 ret = 0;
3199 }
3200 }
3201
3202reserve_space:
3203 if (alloc_start < alloc_end) {
3204 struct extent_state *cached_state = NULL;
3205 const u64 lockstart = alloc_start;
3206 const u64 lockend = alloc_end - 1;
3207
3208 bytes_to_reserve = alloc_end - alloc_start;
3209 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3210 bytes_to_reserve);
3211 if (ret < 0)
3212 goto out;
3213 space_reserved = true;
3214 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3215 &cached_state);
3216 if (ret)
3217 goto out;
3218 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
3219 alloc_start, bytes_to_reserve);
3220 if (ret)
3221 goto out;
3222 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
3223 alloc_end - alloc_start,
3224 i_blocksize(inode),
3225 offset + len, &alloc_hint);
3226 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3227 lockend, &cached_state);
3228 /* btrfs_prealloc_file_range releases reserved space on error */
3229 if (ret) {
3230 space_reserved = false;
3231 goto out;
3232 }
3233 }
3234 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
3235 out:
3236 if (ret && space_reserved)
3237 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
3238 alloc_start, bytes_to_reserve);
3239 extent_changeset_free(data_reserved);
3240
3241 return ret;
3242}
3243
3244static long btrfs_fallocate(struct file *file, int mode,
3245 loff_t offset, loff_t len)
3246{
3247 struct inode *inode = file_inode(file);
3248 struct extent_state *cached_state = NULL;
3249 struct extent_changeset *data_reserved = NULL;
3250 struct falloc_range *range;
3251 struct falloc_range *tmp;
3252 struct list_head reserve_list;
3253 u64 cur_offset;
3254 u64 last_byte;
3255 u64 alloc_start;
3256 u64 alloc_end;
3257 u64 alloc_hint = 0;
3258 u64 locked_end;
3259 u64 actual_end = 0;
3260 struct extent_map *em;
3261 int blocksize = btrfs_inode_sectorsize(inode);
3262 int ret;
3263
3264 alloc_start = round_down(offset, blocksize);
3265 alloc_end = round_up(offset + len, blocksize);
3266 cur_offset = alloc_start;
3267
3268 /* Make sure we aren't being give some crap mode */
3269 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3270 FALLOC_FL_ZERO_RANGE))
3271 return -EOPNOTSUPP;
3272
3273 if (mode & FALLOC_FL_PUNCH_HOLE)
3274 return btrfs_punch_hole(inode, offset, len);
3275
3276 /*
3277 * Only trigger disk allocation, don't trigger qgroup reserve
3278 *
3279 * For qgroup space, it will be checked later.
3280 */
3281 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3282 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3283 alloc_end - alloc_start);
3284 if (ret < 0)
3285 return ret;
3286 }
3287
3288 inode_lock(inode);
3289
3290 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3291 ret = inode_newsize_ok(inode, offset + len);
3292 if (ret)
3293 goto out;
3294 }
3295
3296 /*
3297 * TODO: Move these two operations after we have checked
3298 * accurate reserved space, or fallocate can still fail but
3299 * with page truncated or size expanded.
3300 *
3301 * But that's a minor problem and won't do much harm BTW.
3302 */
3303 if (alloc_start > inode->i_size) {
3304 ret = btrfs_cont_expand(inode, i_size_read(inode),
3305 alloc_start);
3306 if (ret)
3307 goto out;
3308 } else if (offset + len > inode->i_size) {
3309 /*
3310 * If we are fallocating from the end of the file onward we
3311 * need to zero out the end of the block if i_size lands in the
3312 * middle of a block.
3313 */
3314 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
3315 if (ret)
3316 goto out;
3317 }
3318
3319 /*
3320 * wait for ordered IO before we have any locks. We'll loop again
3321 * below with the locks held.
3322 */
3323 ret = btrfs_wait_ordered_range(inode, alloc_start,
3324 alloc_end - alloc_start);
3325 if (ret)
3326 goto out;
3327
3328 if (mode & FALLOC_FL_ZERO_RANGE) {
3329 ret = btrfs_zero_range(inode, offset, len, mode);
3330 inode_unlock(inode);
3331 return ret;
3332 }
3333
3334 locked_end = alloc_end - 1;
3335 while (1) {
3336 struct btrfs_ordered_extent *ordered;
3337
3338 /* the extent lock is ordered inside the running
3339 * transaction
3340 */
3341 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3342 locked_end, &cached_state);
3343 ordered = btrfs_lookup_first_ordered_extent(inode, locked_end);
3344
3345 if (ordered &&
3346 ordered->file_offset + ordered->num_bytes > alloc_start &&
3347 ordered->file_offset < alloc_end) {
3348 btrfs_put_ordered_extent(ordered);
3349 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3350 alloc_start, locked_end,
3351 &cached_state);
3352 /*
3353 * we can't wait on the range with the transaction
3354 * running or with the extent lock held
3355 */
3356 ret = btrfs_wait_ordered_range(inode, alloc_start,
3357 alloc_end - alloc_start);
3358 if (ret)
3359 goto out;
3360 } else {
3361 if (ordered)
3362 btrfs_put_ordered_extent(ordered);
3363 break;
3364 }
3365 }
3366
3367 /* First, check if we exceed the qgroup limit */
3368 INIT_LIST_HEAD(&reserve_list);
3369 while (cur_offset < alloc_end) {
3370 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3371 alloc_end - cur_offset);
3372 if (IS_ERR(em)) {
3373 ret = PTR_ERR(em);
3374 break;
3375 }
3376 last_byte = min(extent_map_end(em), alloc_end);
3377 actual_end = min_t(u64, extent_map_end(em), offset + len);
3378 last_byte = ALIGN(last_byte, blocksize);
3379 if (em->block_start == EXTENT_MAP_HOLE ||
3380 (cur_offset >= inode->i_size &&
3381 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3382 ret = add_falloc_range(&reserve_list, cur_offset,
3383 last_byte - cur_offset);
3384 if (ret < 0) {
3385 free_extent_map(em);
3386 break;
3387 }
3388 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode),
3389 &data_reserved, cur_offset,
3390 last_byte - cur_offset);
3391 if (ret < 0) {
3392 cur_offset = last_byte;
3393 free_extent_map(em);
3394 break;
3395 }
3396 } else {
3397 /*
3398 * Do not need to reserve unwritten extent for this
3399 * range, free reserved data space first, otherwise
3400 * it'll result in false ENOSPC error.
3401 */
3402 btrfs_free_reserved_data_space(BTRFS_I(inode),
3403 data_reserved, cur_offset,
3404 last_byte - cur_offset);
3405 }
3406 free_extent_map(em);
3407 cur_offset = last_byte;
3408 }
3409
3410 /*
3411 * If ret is still 0, means we're OK to fallocate.
3412 * Or just cleanup the list and exit.
3413 */
3414 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3415 if (!ret)
3416 ret = btrfs_prealloc_file_range(inode, mode,
3417 range->start,
3418 range->len, i_blocksize(inode),
3419 offset + len, &alloc_hint);
3420 else
3421 btrfs_free_reserved_data_space(BTRFS_I(inode),
3422 data_reserved, range->start,
3423 range->len);
3424 list_del(&range->list);
3425 kfree(range);
3426 }
3427 if (ret < 0)
3428 goto out_unlock;
3429
3430 /*
3431 * We didn't need to allocate any more space, but we still extended the
3432 * size of the file so we need to update i_size and the inode item.
3433 */
3434 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3435out_unlock:
3436 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3437 &cached_state);
3438out:
3439 inode_unlock(inode);
3440 /* Let go of our reservation. */
3441 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3442 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
3443 cur_offset, alloc_end - cur_offset);
3444 extent_changeset_free(data_reserved);
3445 return ret;
3446}
3447
3448static loff_t find_desired_extent(struct inode *inode, loff_t offset,
3449 int whence)
3450{
3451 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3452 struct extent_map *em = NULL;
3453 struct extent_state *cached_state = NULL;
3454 loff_t i_size = inode->i_size;
3455 u64 lockstart;
3456 u64 lockend;
3457 u64 start;
3458 u64 len;
3459 int ret = 0;
3460
3461 if (i_size == 0 || offset >= i_size)
3462 return -ENXIO;
3463
3464 /*
3465 * offset can be negative, in this case we start finding DATA/HOLE from
3466 * the very start of the file.
3467 */
3468 start = max_t(loff_t, 0, offset);
3469
3470 lockstart = round_down(start, fs_info->sectorsize);
3471 lockend = round_up(i_size, fs_info->sectorsize);
3472 if (lockend <= lockstart)
3473 lockend = lockstart + fs_info->sectorsize;
3474 lockend--;
3475 len = lockend - lockstart + 1;
3476
3477 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3478 &cached_state);
3479
3480 while (start < i_size) {
3481 em = btrfs_get_extent_fiemap(BTRFS_I(inode), start, len);
3482 if (IS_ERR(em)) {
3483 ret = PTR_ERR(em);
3484 em = NULL;
3485 break;
3486 }
3487
3488 if (whence == SEEK_HOLE &&
3489 (em->block_start == EXTENT_MAP_HOLE ||
3490 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3491 break;
3492 else if (whence == SEEK_DATA &&
3493 (em->block_start != EXTENT_MAP_HOLE &&
3494 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3495 break;
3496
3497 start = em->start + em->len;
3498 free_extent_map(em);
3499 em = NULL;
3500 cond_resched();
3501 }
3502 free_extent_map(em);
3503 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3504 &cached_state);
3505 if (ret) {
3506 offset = ret;
3507 } else {
3508 if (whence == SEEK_DATA && start >= i_size)
3509 offset = -ENXIO;
3510 else
3511 offset = min_t(loff_t, start, i_size);
3512 }
3513
3514 return offset;
3515}
3516
3517static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3518{
3519 struct inode *inode = file->f_mapping->host;
3520
3521 switch (whence) {
3522 default:
3523 return generic_file_llseek(file, offset, whence);
3524 case SEEK_DATA:
3525 case SEEK_HOLE:
3526 inode_lock_shared(inode);
3527 offset = find_desired_extent(inode, offset, whence);
3528 inode_unlock_shared(inode);
3529 break;
3530 }
3531
3532 if (offset < 0)
3533 return offset;
3534
3535 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3536}
3537
3538static int btrfs_file_open(struct inode *inode, struct file *filp)
3539{
3540 filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
3541 return generic_file_open(inode, filp);
3542}
3543
3544const struct file_operations btrfs_file_operations = {
3545 .llseek = btrfs_file_llseek,
3546 .read_iter = generic_file_read_iter,
3547 .splice_read = generic_file_splice_read,
3548 .write_iter = btrfs_file_write_iter,
3549 .splice_write = iter_file_splice_write,
3550 .mmap = btrfs_file_mmap,
3551 .open = btrfs_file_open,
3552 .release = btrfs_release_file,
3553 .fsync = btrfs_sync_file,
3554 .fallocate = btrfs_fallocate,
3555 .unlocked_ioctl = btrfs_ioctl,
3556#ifdef CONFIG_COMPAT
3557 .compat_ioctl = btrfs_compat_ioctl,
3558#endif
3559 .remap_file_range = btrfs_remap_file_range,
3560};
3561
3562void __cold btrfs_auto_defrag_exit(void)
3563{
3564 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3565}
3566
3567int __init btrfs_auto_defrag_init(void)
3568{
3569 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3570 sizeof(struct inode_defrag), 0,
3571 SLAB_MEM_SPREAD,
3572 NULL);
3573 if (!btrfs_inode_defrag_cachep)
3574 return -ENOMEM;
3575
3576 return 0;
3577}
3578
3579int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3580{
3581 int ret;
3582
3583 /*
3584 * So with compression we will find and lock a dirty page and clear the
3585 * first one as dirty, setup an async extent, and immediately return
3586 * with the entire range locked but with nobody actually marked with
3587 * writeback. So we can't just filemap_write_and_wait_range() and
3588 * expect it to work since it will just kick off a thread to do the
3589 * actual work. So we need to call filemap_fdatawrite_range _again_
3590 * since it will wait on the page lock, which won't be unlocked until
3591 * after the pages have been marked as writeback and so we're good to go
3592 * from there. We have to do this otherwise we'll miss the ordered
3593 * extents and that results in badness. Please Josef, do not think you
3594 * know better and pull this out at some point in the future, it is
3595 * right and you are wrong.
3596 */
3597 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3598 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3599 &BTRFS_I(inode)->runtime_flags))
3600 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3601
3602 return ret;
3603}