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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/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/fs.h>
20#include <linux/pagemap.h>
21#include <linux/highmem.h>
22#include <linux/time.h>
23#include <linux/init.h>
24#include <linux/string.h>
25#include <linux/backing-dev.h>
26#include <linux/mpage.h>
27#include <linux/falloc.h>
28#include <linux/swap.h>
29#include <linux/writeback.h>
30#include <linux/statfs.h>
31#include <linux/compat.h>
32#include <linux/slab.h>
33#include <linux/btrfs.h>
34#include <linux/uio.h>
35#include "ctree.h"
36#include "disk-io.h"
37#include "transaction.h"
38#include "btrfs_inode.h"
39#include "print-tree.h"
40#include "tree-log.h"
41#include "locking.h"
42#include "volumes.h"
43#include "qgroup.h"
44#include "compression.h"
45
46static struct kmem_cache *btrfs_inode_defrag_cachep;
47/*
48 * when auto defrag is enabled we
49 * queue up these defrag structs to remember which
50 * inodes need defragging passes
51 */
52struct inode_defrag {
53 struct rb_node rb_node;
54 /* objectid */
55 u64 ino;
56 /*
57 * transid where the defrag was added, we search for
58 * extents newer than this
59 */
60 u64 transid;
61
62 /* root objectid */
63 u64 root;
64
65 /* last offset we were able to defrag */
66 u64 last_offset;
67
68 /* if we've wrapped around back to zero once already */
69 int cycled;
70};
71
72static int __compare_inode_defrag(struct inode_defrag *defrag1,
73 struct inode_defrag *defrag2)
74{
75 if (defrag1->root > defrag2->root)
76 return 1;
77 else if (defrag1->root < defrag2->root)
78 return -1;
79 else if (defrag1->ino > defrag2->ino)
80 return 1;
81 else if (defrag1->ino < defrag2->ino)
82 return -1;
83 else
84 return 0;
85}
86
87/* pop a record for an inode into the defrag tree. The lock
88 * must be held already
89 *
90 * If you're inserting a record for an older transid than an
91 * existing record, the transid already in the tree is lowered
92 *
93 * If an existing record is found the defrag item you
94 * pass in is freed
95 */
96static int __btrfs_add_inode_defrag(struct inode *inode,
97 struct inode_defrag *defrag)
98{
99 struct btrfs_root *root = BTRFS_I(inode)->root;
100 struct inode_defrag *entry;
101 struct rb_node **p;
102 struct rb_node *parent = NULL;
103 int ret;
104
105 p = &root->fs_info->defrag_inodes.rb_node;
106 while (*p) {
107 parent = *p;
108 entry = rb_entry(parent, struct inode_defrag, rb_node);
109
110 ret = __compare_inode_defrag(defrag, entry);
111 if (ret < 0)
112 p = &parent->rb_left;
113 else if (ret > 0)
114 p = &parent->rb_right;
115 else {
116 /* if we're reinserting an entry for
117 * an old defrag run, make sure to
118 * lower the transid of our existing record
119 */
120 if (defrag->transid < entry->transid)
121 entry->transid = defrag->transid;
122 if (defrag->last_offset > entry->last_offset)
123 entry->last_offset = defrag->last_offset;
124 return -EEXIST;
125 }
126 }
127 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
128 rb_link_node(&defrag->rb_node, parent, p);
129 rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
130 return 0;
131}
132
133static inline int __need_auto_defrag(struct btrfs_root *root)
134{
135 if (!btrfs_test_opt(root, AUTO_DEFRAG))
136 return 0;
137
138 if (btrfs_fs_closing(root->fs_info))
139 return 0;
140
141 return 1;
142}
143
144/*
145 * insert a defrag record for this inode if auto defrag is
146 * enabled
147 */
148int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
149 struct inode *inode)
150{
151 struct btrfs_root *root = BTRFS_I(inode)->root;
152 struct inode_defrag *defrag;
153 u64 transid;
154 int ret;
155
156 if (!__need_auto_defrag(root))
157 return 0;
158
159 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
160 return 0;
161
162 if (trans)
163 transid = trans->transid;
164 else
165 transid = BTRFS_I(inode)->root->last_trans;
166
167 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
168 if (!defrag)
169 return -ENOMEM;
170
171 defrag->ino = btrfs_ino(inode);
172 defrag->transid = transid;
173 defrag->root = root->root_key.objectid;
174
175 spin_lock(&root->fs_info->defrag_inodes_lock);
176 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {
177 /*
178 * If we set IN_DEFRAG flag and evict the inode from memory,
179 * and then re-read this inode, this new inode doesn't have
180 * IN_DEFRAG flag. At the case, we may find the existed defrag.
181 */
182 ret = __btrfs_add_inode_defrag(inode, defrag);
183 if (ret)
184 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
185 } else {
186 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
187 }
188 spin_unlock(&root->fs_info->defrag_inodes_lock);
189 return 0;
190}
191
192/*
193 * Requeue the defrag object. If there is a defrag object that points to
194 * the same inode in the tree, we will merge them together (by
195 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
196 */
197static void btrfs_requeue_inode_defrag(struct inode *inode,
198 struct inode_defrag *defrag)
199{
200 struct btrfs_root *root = BTRFS_I(inode)->root;
201 int ret;
202
203 if (!__need_auto_defrag(root))
204 goto out;
205
206 /*
207 * Here we don't check the IN_DEFRAG flag, because we need merge
208 * them together.
209 */
210 spin_lock(&root->fs_info->defrag_inodes_lock);
211 ret = __btrfs_add_inode_defrag(inode, defrag);
212 spin_unlock(&root->fs_info->defrag_inodes_lock);
213 if (ret)
214 goto out;
215 return;
216out:
217 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
218}
219
220/*
221 * pick the defragable inode that we want, if it doesn't exist, we will get
222 * the next one.
223 */
224static struct inode_defrag *
225btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
226{
227 struct inode_defrag *entry = NULL;
228 struct inode_defrag tmp;
229 struct rb_node *p;
230 struct rb_node *parent = NULL;
231 int ret;
232
233 tmp.ino = ino;
234 tmp.root = root;
235
236 spin_lock(&fs_info->defrag_inodes_lock);
237 p = fs_info->defrag_inodes.rb_node;
238 while (p) {
239 parent = p;
240 entry = rb_entry(parent, struct inode_defrag, rb_node);
241
242 ret = __compare_inode_defrag(&tmp, entry);
243 if (ret < 0)
244 p = parent->rb_left;
245 else if (ret > 0)
246 p = parent->rb_right;
247 else
248 goto out;
249 }
250
251 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
252 parent = rb_next(parent);
253 if (parent)
254 entry = rb_entry(parent, struct inode_defrag, rb_node);
255 else
256 entry = NULL;
257 }
258out:
259 if (entry)
260 rb_erase(parent, &fs_info->defrag_inodes);
261 spin_unlock(&fs_info->defrag_inodes_lock);
262 return entry;
263}
264
265void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
266{
267 struct inode_defrag *defrag;
268 struct rb_node *node;
269
270 spin_lock(&fs_info->defrag_inodes_lock);
271 node = rb_first(&fs_info->defrag_inodes);
272 while (node) {
273 rb_erase(node, &fs_info->defrag_inodes);
274 defrag = rb_entry(node, struct inode_defrag, rb_node);
275 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
276
277 cond_resched_lock(&fs_info->defrag_inodes_lock);
278
279 node = rb_first(&fs_info->defrag_inodes);
280 }
281 spin_unlock(&fs_info->defrag_inodes_lock);
282}
283
284#define BTRFS_DEFRAG_BATCH 1024
285
286static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
287 struct inode_defrag *defrag)
288{
289 struct btrfs_root *inode_root;
290 struct inode *inode;
291 struct btrfs_key key;
292 struct btrfs_ioctl_defrag_range_args range;
293 int num_defrag;
294 int index;
295 int ret;
296
297 /* get the inode */
298 key.objectid = defrag->root;
299 key.type = BTRFS_ROOT_ITEM_KEY;
300 key.offset = (u64)-1;
301
302 index = srcu_read_lock(&fs_info->subvol_srcu);
303
304 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
305 if (IS_ERR(inode_root)) {
306 ret = PTR_ERR(inode_root);
307 goto cleanup;
308 }
309
310 key.objectid = defrag->ino;
311 key.type = BTRFS_INODE_ITEM_KEY;
312 key.offset = 0;
313 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
314 if (IS_ERR(inode)) {
315 ret = PTR_ERR(inode);
316 goto cleanup;
317 }
318 srcu_read_unlock(&fs_info->subvol_srcu, index);
319
320 /* do a chunk of defrag */
321 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
322 memset(&range, 0, sizeof(range));
323 range.len = (u64)-1;
324 range.start = defrag->last_offset;
325
326 sb_start_write(fs_info->sb);
327 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
328 BTRFS_DEFRAG_BATCH);
329 sb_end_write(fs_info->sb);
330 /*
331 * if we filled the whole defrag batch, there
332 * must be more work to do. Queue this defrag
333 * again
334 */
335 if (num_defrag == BTRFS_DEFRAG_BATCH) {
336 defrag->last_offset = range.start;
337 btrfs_requeue_inode_defrag(inode, defrag);
338 } else if (defrag->last_offset && !defrag->cycled) {
339 /*
340 * we didn't fill our defrag batch, but
341 * we didn't start at zero. Make sure we loop
342 * around to the start of the file.
343 */
344 defrag->last_offset = 0;
345 defrag->cycled = 1;
346 btrfs_requeue_inode_defrag(inode, defrag);
347 } else {
348 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
349 }
350
351 iput(inode);
352 return 0;
353cleanup:
354 srcu_read_unlock(&fs_info->subvol_srcu, index);
355 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
356 return ret;
357}
358
359/*
360 * run through the list of inodes in the FS that need
361 * defragging
362 */
363int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
364{
365 struct inode_defrag *defrag;
366 u64 first_ino = 0;
367 u64 root_objectid = 0;
368
369 atomic_inc(&fs_info->defrag_running);
370 while (1) {
371 /* Pause the auto defragger. */
372 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
373 &fs_info->fs_state))
374 break;
375
376 if (!__need_auto_defrag(fs_info->tree_root))
377 break;
378
379 /* find an inode to defrag */
380 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
381 first_ino);
382 if (!defrag) {
383 if (root_objectid || first_ino) {
384 root_objectid = 0;
385 first_ino = 0;
386 continue;
387 } else {
388 break;
389 }
390 }
391
392 first_ino = defrag->ino + 1;
393 root_objectid = defrag->root;
394
395 __btrfs_run_defrag_inode(fs_info, defrag);
396 }
397 atomic_dec(&fs_info->defrag_running);
398
399 /*
400 * during unmount, we use the transaction_wait queue to
401 * wait for the defragger to stop
402 */
403 wake_up(&fs_info->transaction_wait);
404 return 0;
405}
406
407/* simple helper to fault in pages and copy. This should go away
408 * and be replaced with calls into generic code.
409 */
410static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
411 struct page **prepared_pages,
412 struct iov_iter *i)
413{
414 size_t copied = 0;
415 size_t total_copied = 0;
416 int pg = 0;
417 int offset = pos & (PAGE_SIZE - 1);
418
419 while (write_bytes > 0) {
420 size_t count = min_t(size_t,
421 PAGE_SIZE - offset, write_bytes);
422 struct page *page = prepared_pages[pg];
423 /*
424 * Copy data from userspace to the current page
425 */
426 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
427
428 /* Flush processor's dcache for this page */
429 flush_dcache_page(page);
430
431 /*
432 * if we get a partial write, we can end up with
433 * partially up to date pages. These add
434 * a lot of complexity, so make sure they don't
435 * happen by forcing this copy to be retried.
436 *
437 * The rest of the btrfs_file_write code will fall
438 * back to page at a time copies after we return 0.
439 */
440 if (!PageUptodate(page) && copied < count)
441 copied = 0;
442
443 iov_iter_advance(i, copied);
444 write_bytes -= copied;
445 total_copied += copied;
446
447 /* Return to btrfs_file_write_iter to fault page */
448 if (unlikely(copied == 0))
449 break;
450
451 if (copied < PAGE_SIZE - offset) {
452 offset += copied;
453 } else {
454 pg++;
455 offset = 0;
456 }
457 }
458 return total_copied;
459}
460
461/*
462 * unlocks pages after btrfs_file_write is done with them
463 */
464static void btrfs_drop_pages(struct page **pages, size_t num_pages)
465{
466 size_t i;
467 for (i = 0; i < num_pages; i++) {
468 /* page checked is some magic around finding pages that
469 * have been modified without going through btrfs_set_page_dirty
470 * clear it here. There should be no need to mark the pages
471 * accessed as prepare_pages should have marked them accessed
472 * in prepare_pages via find_or_create_page()
473 */
474 ClearPageChecked(pages[i]);
475 unlock_page(pages[i]);
476 put_page(pages[i]);
477 }
478}
479
480/*
481 * after copy_from_user, pages need to be dirtied and we need to make
482 * sure holes are created between the current EOF and the start of
483 * any next extents (if required).
484 *
485 * this also makes the decision about creating an inline extent vs
486 * doing real data extents, marking pages dirty and delalloc as required.
487 */
488int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
489 struct page **pages, size_t num_pages,
490 loff_t pos, size_t write_bytes,
491 struct extent_state **cached)
492{
493 int err = 0;
494 int i;
495 u64 num_bytes;
496 u64 start_pos;
497 u64 end_of_last_block;
498 u64 end_pos = pos + write_bytes;
499 loff_t isize = i_size_read(inode);
500
501 start_pos = pos & ~((u64)root->sectorsize - 1);
502 num_bytes = round_up(write_bytes + pos - start_pos, root->sectorsize);
503
504 end_of_last_block = start_pos + num_bytes - 1;
505 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
506 cached);
507 if (err)
508 return err;
509
510 for (i = 0; i < num_pages; i++) {
511 struct page *p = pages[i];
512 SetPageUptodate(p);
513 ClearPageChecked(p);
514 set_page_dirty(p);
515 }
516
517 /*
518 * we've only changed i_size in ram, and we haven't updated
519 * the disk i_size. There is no need to log the inode
520 * at this time.
521 */
522 if (end_pos > isize)
523 i_size_write(inode, end_pos);
524 return 0;
525}
526
527/*
528 * this drops all the extents in the cache that intersect the range
529 * [start, end]. Existing extents are split as required.
530 */
531void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
532 int skip_pinned)
533{
534 struct extent_map *em;
535 struct extent_map *split = NULL;
536 struct extent_map *split2 = NULL;
537 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
538 u64 len = end - start + 1;
539 u64 gen;
540 int ret;
541 int testend = 1;
542 unsigned long flags;
543 int compressed = 0;
544 bool modified;
545
546 WARN_ON(end < start);
547 if (end == (u64)-1) {
548 len = (u64)-1;
549 testend = 0;
550 }
551 while (1) {
552 int no_splits = 0;
553
554 modified = false;
555 if (!split)
556 split = alloc_extent_map();
557 if (!split2)
558 split2 = alloc_extent_map();
559 if (!split || !split2)
560 no_splits = 1;
561
562 write_lock(&em_tree->lock);
563 em = lookup_extent_mapping(em_tree, start, len);
564 if (!em) {
565 write_unlock(&em_tree->lock);
566 break;
567 }
568 flags = em->flags;
569 gen = em->generation;
570 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
571 if (testend && em->start + em->len >= start + len) {
572 free_extent_map(em);
573 write_unlock(&em_tree->lock);
574 break;
575 }
576 start = em->start + em->len;
577 if (testend)
578 len = start + len - (em->start + em->len);
579 free_extent_map(em);
580 write_unlock(&em_tree->lock);
581 continue;
582 }
583 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
584 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
585 clear_bit(EXTENT_FLAG_LOGGING, &flags);
586 modified = !list_empty(&em->list);
587 if (no_splits)
588 goto next;
589
590 if (em->start < start) {
591 split->start = em->start;
592 split->len = start - em->start;
593
594 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
595 split->orig_start = em->orig_start;
596 split->block_start = em->block_start;
597
598 if (compressed)
599 split->block_len = em->block_len;
600 else
601 split->block_len = split->len;
602 split->orig_block_len = max(split->block_len,
603 em->orig_block_len);
604 split->ram_bytes = em->ram_bytes;
605 } else {
606 split->orig_start = split->start;
607 split->block_len = 0;
608 split->block_start = em->block_start;
609 split->orig_block_len = 0;
610 split->ram_bytes = split->len;
611 }
612
613 split->generation = gen;
614 split->bdev = em->bdev;
615 split->flags = flags;
616 split->compress_type = em->compress_type;
617 replace_extent_mapping(em_tree, em, split, modified);
618 free_extent_map(split);
619 split = split2;
620 split2 = NULL;
621 }
622 if (testend && em->start + em->len > start + len) {
623 u64 diff = start + len - em->start;
624
625 split->start = start + len;
626 split->len = em->start + em->len - (start + len);
627 split->bdev = em->bdev;
628 split->flags = flags;
629 split->compress_type = em->compress_type;
630 split->generation = gen;
631
632 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
633 split->orig_block_len = max(em->block_len,
634 em->orig_block_len);
635
636 split->ram_bytes = em->ram_bytes;
637 if (compressed) {
638 split->block_len = em->block_len;
639 split->block_start = em->block_start;
640 split->orig_start = em->orig_start;
641 } else {
642 split->block_len = split->len;
643 split->block_start = em->block_start
644 + diff;
645 split->orig_start = em->orig_start;
646 }
647 } else {
648 split->ram_bytes = split->len;
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 }
654
655 if (extent_map_in_tree(em)) {
656 replace_extent_mapping(em_tree, em, split,
657 modified);
658 } else {
659 ret = add_extent_mapping(em_tree, split,
660 modified);
661 ASSERT(ret == 0); /* Logic error */
662 }
663 free_extent_map(split);
664 split = NULL;
665 }
666next:
667 if (extent_map_in_tree(em))
668 remove_extent_mapping(em_tree, em);
669 write_unlock(&em_tree->lock);
670
671 /* once for us */
672 free_extent_map(em);
673 /* once for the tree*/
674 free_extent_map(em);
675 }
676 if (split)
677 free_extent_map(split);
678 if (split2)
679 free_extent_map(split2);
680}
681
682/*
683 * this is very complex, but the basic idea is to drop all extents
684 * in the range start - end. hint_block is filled in with a block number
685 * that would be a good hint to the block allocator for this file.
686 *
687 * If an extent intersects the range but is not entirely inside the range
688 * it is either truncated or split. Anything entirely inside the range
689 * is deleted from the tree.
690 */
691int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
692 struct btrfs_root *root, struct inode *inode,
693 struct btrfs_path *path, u64 start, u64 end,
694 u64 *drop_end, int drop_cache,
695 int replace_extent,
696 u32 extent_item_size,
697 int *key_inserted)
698{
699 struct extent_buffer *leaf;
700 struct btrfs_file_extent_item *fi;
701 struct btrfs_key key;
702 struct btrfs_key new_key;
703 u64 ino = btrfs_ino(inode);
704 u64 search_start = start;
705 u64 disk_bytenr = 0;
706 u64 num_bytes = 0;
707 u64 extent_offset = 0;
708 u64 extent_end = 0;
709 int del_nr = 0;
710 int del_slot = 0;
711 int extent_type;
712 int recow;
713 int ret;
714 int modify_tree = -1;
715 int update_refs;
716 int found = 0;
717 int leafs_visited = 0;
718
719 if (drop_cache)
720 btrfs_drop_extent_cache(inode, start, end - 1, 0);
721
722 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
723 modify_tree = 0;
724
725 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
726 root == root->fs_info->tree_root);
727 while (1) {
728 recow = 0;
729 ret = btrfs_lookup_file_extent(trans, root, path, ino,
730 search_start, modify_tree);
731 if (ret < 0)
732 break;
733 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
734 leaf = path->nodes[0];
735 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
736 if (key.objectid == ino &&
737 key.type == BTRFS_EXTENT_DATA_KEY)
738 path->slots[0]--;
739 }
740 ret = 0;
741 leafs_visited++;
742next_slot:
743 leaf = path->nodes[0];
744 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
745 BUG_ON(del_nr > 0);
746 ret = btrfs_next_leaf(root, path);
747 if (ret < 0)
748 break;
749 if (ret > 0) {
750 ret = 0;
751 break;
752 }
753 leafs_visited++;
754 leaf = path->nodes[0];
755 recow = 1;
756 }
757
758 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
759
760 if (key.objectid > ino)
761 break;
762 if (WARN_ON_ONCE(key.objectid < ino) ||
763 key.type < BTRFS_EXTENT_DATA_KEY) {
764 ASSERT(del_nr == 0);
765 path->slots[0]++;
766 goto next_slot;
767 }
768 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
769 break;
770
771 fi = btrfs_item_ptr(leaf, path->slots[0],
772 struct btrfs_file_extent_item);
773 extent_type = btrfs_file_extent_type(leaf, fi);
774
775 if (extent_type == BTRFS_FILE_EXTENT_REG ||
776 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
777 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
778 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
779 extent_offset = btrfs_file_extent_offset(leaf, fi);
780 extent_end = key.offset +
781 btrfs_file_extent_num_bytes(leaf, fi);
782 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
783 extent_end = key.offset +
784 btrfs_file_extent_inline_len(leaf,
785 path->slots[0], fi);
786 } else {
787 /* can't happen */
788 BUG();
789 }
790
791 /*
792 * Don't skip extent items representing 0 byte lengths. They
793 * used to be created (bug) if while punching holes we hit
794 * -ENOSPC condition. So if we find one here, just ensure we
795 * delete it, otherwise we would insert a new file extent item
796 * with the same key (offset) as that 0 bytes length file
797 * extent item in the call to setup_items_for_insert() later
798 * in this function.
799 */
800 if (extent_end == key.offset && extent_end >= search_start)
801 goto delete_extent_item;
802
803 if (extent_end <= search_start) {
804 path->slots[0]++;
805 goto next_slot;
806 }
807
808 found = 1;
809 search_start = max(key.offset, start);
810 if (recow || !modify_tree) {
811 modify_tree = -1;
812 btrfs_release_path(path);
813 continue;
814 }
815
816 /*
817 * | - range to drop - |
818 * | -------- extent -------- |
819 */
820 if (start > key.offset && end < extent_end) {
821 BUG_ON(del_nr > 0);
822 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
823 ret = -EOPNOTSUPP;
824 break;
825 }
826
827 memcpy(&new_key, &key, sizeof(new_key));
828 new_key.offset = start;
829 ret = btrfs_duplicate_item(trans, root, path,
830 &new_key);
831 if (ret == -EAGAIN) {
832 btrfs_release_path(path);
833 continue;
834 }
835 if (ret < 0)
836 break;
837
838 leaf = path->nodes[0];
839 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
840 struct btrfs_file_extent_item);
841 btrfs_set_file_extent_num_bytes(leaf, fi,
842 start - key.offset);
843
844 fi = btrfs_item_ptr(leaf, path->slots[0],
845 struct btrfs_file_extent_item);
846
847 extent_offset += start - key.offset;
848 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
849 btrfs_set_file_extent_num_bytes(leaf, fi,
850 extent_end - start);
851 btrfs_mark_buffer_dirty(leaf);
852
853 if (update_refs && disk_bytenr > 0) {
854 ret = btrfs_inc_extent_ref(trans, root,
855 disk_bytenr, num_bytes, 0,
856 root->root_key.objectid,
857 new_key.objectid,
858 start - extent_offset);
859 BUG_ON(ret); /* -ENOMEM */
860 }
861 key.offset = start;
862 }
863 /*
864 * | ---- range to drop ----- |
865 * | -------- extent -------- |
866 */
867 if (start <= key.offset && end < extent_end) {
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 = end;
875 btrfs_set_item_key_safe(root->fs_info, path, &new_key);
876
877 extent_offset += end - key.offset;
878 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
879 btrfs_set_file_extent_num_bytes(leaf, fi,
880 extent_end - end);
881 btrfs_mark_buffer_dirty(leaf);
882 if (update_refs && disk_bytenr > 0)
883 inode_sub_bytes(inode, end - key.offset);
884 break;
885 }
886
887 search_start = extent_end;
888 /*
889 * | ---- range to drop ----- |
890 * | -------- extent -------- |
891 */
892 if (start > key.offset && end >= extent_end) {
893 BUG_ON(del_nr > 0);
894 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
895 ret = -EOPNOTSUPP;
896 break;
897 }
898
899 btrfs_set_file_extent_num_bytes(leaf, fi,
900 start - key.offset);
901 btrfs_mark_buffer_dirty(leaf);
902 if (update_refs && disk_bytenr > 0)
903 inode_sub_bytes(inode, extent_end - start);
904 if (end == extent_end)
905 break;
906
907 path->slots[0]++;
908 goto next_slot;
909 }
910
911 /*
912 * | ---- range to drop ----- |
913 * | ------ extent ------ |
914 */
915 if (start <= key.offset && end >= extent_end) {
916delete_extent_item:
917 if (del_nr == 0) {
918 del_slot = path->slots[0];
919 del_nr = 1;
920 } else {
921 BUG_ON(del_slot + del_nr != path->slots[0]);
922 del_nr++;
923 }
924
925 if (update_refs &&
926 extent_type == BTRFS_FILE_EXTENT_INLINE) {
927 inode_sub_bytes(inode,
928 extent_end - key.offset);
929 extent_end = ALIGN(extent_end,
930 root->sectorsize);
931 } else if (update_refs && disk_bytenr > 0) {
932 ret = btrfs_free_extent(trans, root,
933 disk_bytenr, num_bytes, 0,
934 root->root_key.objectid,
935 key.objectid, key.offset -
936 extent_offset);
937 BUG_ON(ret); /* -ENOMEM */
938 inode_sub_bytes(inode,
939 extent_end - key.offset);
940 }
941
942 if (end == extent_end)
943 break;
944
945 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
946 path->slots[0]++;
947 goto next_slot;
948 }
949
950 ret = btrfs_del_items(trans, root, path, del_slot,
951 del_nr);
952 if (ret) {
953 btrfs_abort_transaction(trans, root, ret);
954 break;
955 }
956
957 del_nr = 0;
958 del_slot = 0;
959
960 btrfs_release_path(path);
961 continue;
962 }
963
964 BUG_ON(1);
965 }
966
967 if (!ret && del_nr > 0) {
968 /*
969 * Set path->slots[0] to first slot, so that after the delete
970 * if items are move off from our leaf to its immediate left or
971 * right neighbor leafs, we end up with a correct and adjusted
972 * path->slots[0] for our insertion (if replace_extent != 0).
973 */
974 path->slots[0] = del_slot;
975 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
976 if (ret)
977 btrfs_abort_transaction(trans, root, ret);
978 }
979
980 leaf = path->nodes[0];
981 /*
982 * If btrfs_del_items() was called, it might have deleted a leaf, in
983 * which case it unlocked our path, so check path->locks[0] matches a
984 * write lock.
985 */
986 if (!ret && replace_extent && leafs_visited == 1 &&
987 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
988 path->locks[0] == BTRFS_WRITE_LOCK) &&
989 btrfs_leaf_free_space(root, leaf) >=
990 sizeof(struct btrfs_item) + extent_item_size) {
991
992 key.objectid = ino;
993 key.type = BTRFS_EXTENT_DATA_KEY;
994 key.offset = start;
995 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
996 struct btrfs_key slot_key;
997
998 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
999 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1000 path->slots[0]++;
1001 }
1002 setup_items_for_insert(root, path, &key,
1003 &extent_item_size,
1004 extent_item_size,
1005 sizeof(struct btrfs_item) +
1006 extent_item_size, 1);
1007 *key_inserted = 1;
1008 }
1009
1010 if (!replace_extent || !(*key_inserted))
1011 btrfs_release_path(path);
1012 if (drop_end)
1013 *drop_end = found ? min(end, extent_end) : end;
1014 return ret;
1015}
1016
1017int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1018 struct btrfs_root *root, struct inode *inode, u64 start,
1019 u64 end, int drop_cache)
1020{
1021 struct btrfs_path *path;
1022 int ret;
1023
1024 path = btrfs_alloc_path();
1025 if (!path)
1026 return -ENOMEM;
1027 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1028 drop_cache, 0, 0, NULL);
1029 btrfs_free_path(path);
1030 return ret;
1031}
1032
1033static int extent_mergeable(struct extent_buffer *leaf, int slot,
1034 u64 objectid, u64 bytenr, u64 orig_offset,
1035 u64 *start, u64 *end)
1036{
1037 struct btrfs_file_extent_item *fi;
1038 struct btrfs_key key;
1039 u64 extent_end;
1040
1041 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1042 return 0;
1043
1044 btrfs_item_key_to_cpu(leaf, &key, slot);
1045 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1046 return 0;
1047
1048 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1049 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1050 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1051 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1052 btrfs_file_extent_compression(leaf, fi) ||
1053 btrfs_file_extent_encryption(leaf, fi) ||
1054 btrfs_file_extent_other_encoding(leaf, fi))
1055 return 0;
1056
1057 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1058 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1059 return 0;
1060
1061 *start = key.offset;
1062 *end = extent_end;
1063 return 1;
1064}
1065
1066/*
1067 * Mark extent in the range start - end as written.
1068 *
1069 * This changes extent type from 'pre-allocated' to 'regular'. If only
1070 * part of extent is marked as written, the extent will be split into
1071 * two or three.
1072 */
1073int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1074 struct inode *inode, u64 start, u64 end)
1075{
1076 struct btrfs_root *root = BTRFS_I(inode)->root;
1077 struct extent_buffer *leaf;
1078 struct btrfs_path *path;
1079 struct btrfs_file_extent_item *fi;
1080 struct btrfs_key key;
1081 struct btrfs_key new_key;
1082 u64 bytenr;
1083 u64 num_bytes;
1084 u64 extent_end;
1085 u64 orig_offset;
1086 u64 other_start;
1087 u64 other_end;
1088 u64 split;
1089 int del_nr = 0;
1090 int del_slot = 0;
1091 int recow;
1092 int ret;
1093 u64 ino = btrfs_ino(inode);
1094
1095 path = btrfs_alloc_path();
1096 if (!path)
1097 return -ENOMEM;
1098again:
1099 recow = 0;
1100 split = start;
1101 key.objectid = ino;
1102 key.type = BTRFS_EXTENT_DATA_KEY;
1103 key.offset = split;
1104
1105 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1106 if (ret < 0)
1107 goto out;
1108 if (ret > 0 && path->slots[0] > 0)
1109 path->slots[0]--;
1110
1111 leaf = path->nodes[0];
1112 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1113 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
1114 fi = btrfs_item_ptr(leaf, path->slots[0],
1115 struct btrfs_file_extent_item);
1116 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
1117 BTRFS_FILE_EXTENT_PREALLOC);
1118 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1119 BUG_ON(key.offset > start || extent_end < end);
1120
1121 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1122 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1123 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1124 memcpy(&new_key, &key, sizeof(new_key));
1125
1126 if (start == key.offset && end < extent_end) {
1127 other_start = 0;
1128 other_end = start;
1129 if (extent_mergeable(leaf, path->slots[0] - 1,
1130 ino, bytenr, orig_offset,
1131 &other_start, &other_end)) {
1132 new_key.offset = end;
1133 btrfs_set_item_key_safe(root->fs_info, path, &new_key);
1134 fi = btrfs_item_ptr(leaf, path->slots[0],
1135 struct btrfs_file_extent_item);
1136 btrfs_set_file_extent_generation(leaf, fi,
1137 trans->transid);
1138 btrfs_set_file_extent_num_bytes(leaf, fi,
1139 extent_end - end);
1140 btrfs_set_file_extent_offset(leaf, fi,
1141 end - orig_offset);
1142 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1143 struct btrfs_file_extent_item);
1144 btrfs_set_file_extent_generation(leaf, fi,
1145 trans->transid);
1146 btrfs_set_file_extent_num_bytes(leaf, fi,
1147 end - other_start);
1148 btrfs_mark_buffer_dirty(leaf);
1149 goto out;
1150 }
1151 }
1152
1153 if (start > key.offset && end == extent_end) {
1154 other_start = end;
1155 other_end = 0;
1156 if (extent_mergeable(leaf, path->slots[0] + 1,
1157 ino, bytenr, orig_offset,
1158 &other_start, &other_end)) {
1159 fi = btrfs_item_ptr(leaf, path->slots[0],
1160 struct btrfs_file_extent_item);
1161 btrfs_set_file_extent_num_bytes(leaf, fi,
1162 start - key.offset);
1163 btrfs_set_file_extent_generation(leaf, fi,
1164 trans->transid);
1165 path->slots[0]++;
1166 new_key.offset = start;
1167 btrfs_set_item_key_safe(root->fs_info, path, &new_key);
1168
1169 fi = btrfs_item_ptr(leaf, path->slots[0],
1170 struct btrfs_file_extent_item);
1171 btrfs_set_file_extent_generation(leaf, fi,
1172 trans->transid);
1173 btrfs_set_file_extent_num_bytes(leaf, fi,
1174 other_end - start);
1175 btrfs_set_file_extent_offset(leaf, fi,
1176 start - orig_offset);
1177 btrfs_mark_buffer_dirty(leaf);
1178 goto out;
1179 }
1180 }
1181
1182 while (start > key.offset || end < extent_end) {
1183 if (key.offset == start)
1184 split = end;
1185
1186 new_key.offset = split;
1187 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1188 if (ret == -EAGAIN) {
1189 btrfs_release_path(path);
1190 goto again;
1191 }
1192 if (ret < 0) {
1193 btrfs_abort_transaction(trans, root, ret);
1194 goto out;
1195 }
1196
1197 leaf = path->nodes[0];
1198 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1199 struct btrfs_file_extent_item);
1200 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1201 btrfs_set_file_extent_num_bytes(leaf, fi,
1202 split - key.offset);
1203
1204 fi = btrfs_item_ptr(leaf, path->slots[0],
1205 struct btrfs_file_extent_item);
1206
1207 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1208 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1209 btrfs_set_file_extent_num_bytes(leaf, fi,
1210 extent_end - split);
1211 btrfs_mark_buffer_dirty(leaf);
1212
1213 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1214 root->root_key.objectid,
1215 ino, orig_offset);
1216 BUG_ON(ret); /* -ENOMEM */
1217
1218 if (split == start) {
1219 key.offset = start;
1220 } else {
1221 BUG_ON(start != key.offset);
1222 path->slots[0]--;
1223 extent_end = end;
1224 }
1225 recow = 1;
1226 }
1227
1228 other_start = end;
1229 other_end = 0;
1230 if (extent_mergeable(leaf, path->slots[0] + 1,
1231 ino, bytenr, orig_offset,
1232 &other_start, &other_end)) {
1233 if (recow) {
1234 btrfs_release_path(path);
1235 goto again;
1236 }
1237 extent_end = other_end;
1238 del_slot = path->slots[0] + 1;
1239 del_nr++;
1240 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1241 0, root->root_key.objectid,
1242 ino, orig_offset);
1243 BUG_ON(ret); /* -ENOMEM */
1244 }
1245 other_start = 0;
1246 other_end = start;
1247 if (extent_mergeable(leaf, path->slots[0] - 1,
1248 ino, bytenr, orig_offset,
1249 &other_start, &other_end)) {
1250 if (recow) {
1251 btrfs_release_path(path);
1252 goto again;
1253 }
1254 key.offset = other_start;
1255 del_slot = path->slots[0];
1256 del_nr++;
1257 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1258 0, root->root_key.objectid,
1259 ino, orig_offset);
1260 BUG_ON(ret); /* -ENOMEM */
1261 }
1262 if (del_nr == 0) {
1263 fi = btrfs_item_ptr(leaf, path->slots[0],
1264 struct btrfs_file_extent_item);
1265 btrfs_set_file_extent_type(leaf, fi,
1266 BTRFS_FILE_EXTENT_REG);
1267 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1268 btrfs_mark_buffer_dirty(leaf);
1269 } else {
1270 fi = btrfs_item_ptr(leaf, del_slot - 1,
1271 struct btrfs_file_extent_item);
1272 btrfs_set_file_extent_type(leaf, fi,
1273 BTRFS_FILE_EXTENT_REG);
1274 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1275 btrfs_set_file_extent_num_bytes(leaf, fi,
1276 extent_end - key.offset);
1277 btrfs_mark_buffer_dirty(leaf);
1278
1279 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1280 if (ret < 0) {
1281 btrfs_abort_transaction(trans, root, ret);
1282 goto out;
1283 }
1284 }
1285out:
1286 btrfs_free_path(path);
1287 return 0;
1288}
1289
1290/*
1291 * on error we return an unlocked page and the error value
1292 * on success we return a locked page and 0
1293 */
1294static int prepare_uptodate_page(struct inode *inode,
1295 struct page *page, u64 pos,
1296 bool force_uptodate)
1297{
1298 int ret = 0;
1299
1300 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1301 !PageUptodate(page)) {
1302 ret = btrfs_readpage(NULL, page);
1303 if (ret)
1304 return ret;
1305 lock_page(page);
1306 if (!PageUptodate(page)) {
1307 unlock_page(page);
1308 return -EIO;
1309 }
1310 if (page->mapping != inode->i_mapping) {
1311 unlock_page(page);
1312 return -EAGAIN;
1313 }
1314 }
1315 return 0;
1316}
1317
1318/*
1319 * this just gets pages into the page cache and locks them down.
1320 */
1321static noinline int prepare_pages(struct inode *inode, struct page **pages,
1322 size_t num_pages, loff_t pos,
1323 size_t write_bytes, bool force_uptodate)
1324{
1325 int i;
1326 unsigned long index = pos >> PAGE_SHIFT;
1327 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1328 int err = 0;
1329 int faili;
1330
1331 for (i = 0; i < num_pages; i++) {
1332again:
1333 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1334 mask | __GFP_WRITE);
1335 if (!pages[i]) {
1336 faili = i - 1;
1337 err = -ENOMEM;
1338 goto fail;
1339 }
1340
1341 if (i == 0)
1342 err = prepare_uptodate_page(inode, pages[i], pos,
1343 force_uptodate);
1344 if (!err && i == num_pages - 1)
1345 err = prepare_uptodate_page(inode, pages[i],
1346 pos + write_bytes, false);
1347 if (err) {
1348 put_page(pages[i]);
1349 if (err == -EAGAIN) {
1350 err = 0;
1351 goto again;
1352 }
1353 faili = i - 1;
1354 goto fail;
1355 }
1356 wait_on_page_writeback(pages[i]);
1357 }
1358
1359 return 0;
1360fail:
1361 while (faili >= 0) {
1362 unlock_page(pages[faili]);
1363 put_page(pages[faili]);
1364 faili--;
1365 }
1366 return err;
1367
1368}
1369
1370/*
1371 * This function locks the extent and properly waits for data=ordered extents
1372 * to finish before allowing the pages to be modified if need.
1373 *
1374 * The return value:
1375 * 1 - the extent is locked
1376 * 0 - the extent is not locked, and everything is OK
1377 * -EAGAIN - need re-prepare the pages
1378 * the other < 0 number - Something wrong happens
1379 */
1380static noinline int
1381lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
1382 size_t num_pages, loff_t pos,
1383 size_t write_bytes,
1384 u64 *lockstart, u64 *lockend,
1385 struct extent_state **cached_state)
1386{
1387 struct btrfs_root *root = BTRFS_I(inode)->root;
1388 u64 start_pos;
1389 u64 last_pos;
1390 int i;
1391 int ret = 0;
1392
1393 start_pos = round_down(pos, root->sectorsize);
1394 last_pos = start_pos
1395 + round_up(pos + write_bytes - start_pos, root->sectorsize) - 1;
1396
1397 if (start_pos < inode->i_size) {
1398 struct btrfs_ordered_extent *ordered;
1399 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1400 start_pos, last_pos, cached_state);
1401 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1402 last_pos - start_pos + 1);
1403 if (ordered &&
1404 ordered->file_offset + ordered->len > start_pos &&
1405 ordered->file_offset <= last_pos) {
1406 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1407 start_pos, last_pos,
1408 cached_state, GFP_NOFS);
1409 for (i = 0; i < num_pages; i++) {
1410 unlock_page(pages[i]);
1411 put_page(pages[i]);
1412 }
1413 btrfs_start_ordered_extent(inode, ordered, 1);
1414 btrfs_put_ordered_extent(ordered);
1415 return -EAGAIN;
1416 }
1417 if (ordered)
1418 btrfs_put_ordered_extent(ordered);
1419
1420 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1421 last_pos, EXTENT_DIRTY | EXTENT_DELALLOC |
1422 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1423 0, 0, cached_state, GFP_NOFS);
1424 *lockstart = start_pos;
1425 *lockend = last_pos;
1426 ret = 1;
1427 }
1428
1429 for (i = 0; i < num_pages; i++) {
1430 if (clear_page_dirty_for_io(pages[i]))
1431 account_page_redirty(pages[i]);
1432 set_page_extent_mapped(pages[i]);
1433 WARN_ON(!PageLocked(pages[i]));
1434 }
1435
1436 return ret;
1437}
1438
1439static noinline int check_can_nocow(struct inode *inode, loff_t pos,
1440 size_t *write_bytes)
1441{
1442 struct btrfs_root *root = BTRFS_I(inode)->root;
1443 struct btrfs_ordered_extent *ordered;
1444 u64 lockstart, lockend;
1445 u64 num_bytes;
1446 int ret;
1447
1448 ret = btrfs_start_write_no_snapshoting(root);
1449 if (!ret)
1450 return -ENOSPC;
1451
1452 lockstart = round_down(pos, root->sectorsize);
1453 lockend = round_up(pos + *write_bytes, root->sectorsize) - 1;
1454
1455 while (1) {
1456 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1457 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1458 lockend - lockstart + 1);
1459 if (!ordered) {
1460 break;
1461 }
1462 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1463 btrfs_start_ordered_extent(inode, ordered, 1);
1464 btrfs_put_ordered_extent(ordered);
1465 }
1466
1467 num_bytes = lockend - lockstart + 1;
1468 ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL);
1469 if (ret <= 0) {
1470 ret = 0;
1471 btrfs_end_write_no_snapshoting(root);
1472 } else {
1473 *write_bytes = min_t(size_t, *write_bytes ,
1474 num_bytes - pos + lockstart);
1475 }
1476
1477 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1478
1479 return ret;
1480}
1481
1482static noinline ssize_t __btrfs_buffered_write(struct file *file,
1483 struct iov_iter *i,
1484 loff_t pos)
1485{
1486 struct inode *inode = file_inode(file);
1487 struct btrfs_root *root = BTRFS_I(inode)->root;
1488 struct page **pages = NULL;
1489 struct extent_state *cached_state = NULL;
1490 u64 release_bytes = 0;
1491 u64 lockstart;
1492 u64 lockend;
1493 size_t num_written = 0;
1494 int nrptrs;
1495 int ret = 0;
1496 bool only_release_metadata = false;
1497 bool force_page_uptodate = false;
1498 bool need_unlock;
1499
1500 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1501 PAGE_SIZE / (sizeof(struct page *)));
1502 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1503 nrptrs = max(nrptrs, 8);
1504 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1505 if (!pages)
1506 return -ENOMEM;
1507
1508 while (iov_iter_count(i) > 0) {
1509 size_t offset = pos & (PAGE_SIZE - 1);
1510 size_t sector_offset;
1511 size_t write_bytes = min(iov_iter_count(i),
1512 nrptrs * (size_t)PAGE_SIZE -
1513 offset);
1514 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1515 PAGE_SIZE);
1516 size_t reserve_bytes;
1517 size_t dirty_pages;
1518 size_t copied;
1519 size_t dirty_sectors;
1520 size_t num_sectors;
1521
1522 WARN_ON(num_pages > nrptrs);
1523
1524 /*
1525 * Fault pages before locking them in prepare_pages
1526 * to avoid recursive lock
1527 */
1528 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1529 ret = -EFAULT;
1530 break;
1531 }
1532
1533 sector_offset = pos & (root->sectorsize - 1);
1534 reserve_bytes = round_up(write_bytes + sector_offset,
1535 root->sectorsize);
1536
1537 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1538 BTRFS_INODE_PREALLOC)) &&
1539 check_can_nocow(inode, pos, &write_bytes) > 0) {
1540 /*
1541 * For nodata cow case, no need to reserve
1542 * data space.
1543 */
1544 only_release_metadata = true;
1545 /*
1546 * our prealloc extent may be smaller than
1547 * write_bytes, so scale down.
1548 */
1549 num_pages = DIV_ROUND_UP(write_bytes + offset,
1550 PAGE_SIZE);
1551 reserve_bytes = round_up(write_bytes + sector_offset,
1552 root->sectorsize);
1553 goto reserve_metadata;
1554 }
1555
1556 ret = btrfs_check_data_free_space(inode, pos, write_bytes);
1557 if (ret < 0)
1558 break;
1559
1560reserve_metadata:
1561 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
1562 if (ret) {
1563 if (!only_release_metadata)
1564 btrfs_free_reserved_data_space(inode, pos,
1565 write_bytes);
1566 else
1567 btrfs_end_write_no_snapshoting(root);
1568 break;
1569 }
1570
1571 release_bytes = reserve_bytes;
1572 need_unlock = false;
1573again:
1574 /*
1575 * This is going to setup the pages array with the number of
1576 * pages we want, so we don't really need to worry about the
1577 * contents of pages from loop to loop
1578 */
1579 ret = prepare_pages(inode, pages, num_pages,
1580 pos, write_bytes,
1581 force_page_uptodate);
1582 if (ret)
1583 break;
1584
1585 ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
1586 pos, write_bytes, &lockstart,
1587 &lockend, &cached_state);
1588 if (ret < 0) {
1589 if (ret == -EAGAIN)
1590 goto again;
1591 break;
1592 } else if (ret > 0) {
1593 need_unlock = true;
1594 ret = 0;
1595 }
1596
1597 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1598
1599 /*
1600 * if we have trouble faulting in the pages, fall
1601 * back to one page at a time
1602 */
1603 if (copied < write_bytes)
1604 nrptrs = 1;
1605
1606 if (copied == 0) {
1607 force_page_uptodate = true;
1608 dirty_pages = 0;
1609 } else {
1610 force_page_uptodate = false;
1611 dirty_pages = DIV_ROUND_UP(copied + offset,
1612 PAGE_SIZE);
1613 }
1614
1615 /*
1616 * If we had a short copy we need to release the excess delaloc
1617 * bytes we reserved. We need to increment outstanding_extents
1618 * because btrfs_delalloc_release_space will decrement it, but
1619 * we still have an outstanding extent for the chunk we actually
1620 * managed to copy.
1621 */
1622 num_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
1623 reserve_bytes);
1624 dirty_sectors = round_up(copied + sector_offset,
1625 root->sectorsize);
1626 dirty_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
1627 dirty_sectors);
1628
1629 if (num_sectors > dirty_sectors) {
1630 release_bytes = (write_bytes - copied)
1631 & ~((u64)root->sectorsize - 1);
1632 if (copied > 0) {
1633 spin_lock(&BTRFS_I(inode)->lock);
1634 BTRFS_I(inode)->outstanding_extents++;
1635 spin_unlock(&BTRFS_I(inode)->lock);
1636 }
1637 if (only_release_metadata) {
1638 btrfs_delalloc_release_metadata(inode,
1639 release_bytes);
1640 } else {
1641 u64 __pos;
1642
1643 __pos = round_down(pos, root->sectorsize) +
1644 (dirty_pages << PAGE_SHIFT);
1645 btrfs_delalloc_release_space(inode, __pos,
1646 release_bytes);
1647 }
1648 }
1649
1650 release_bytes = round_up(copied + sector_offset,
1651 root->sectorsize);
1652
1653 if (copied > 0)
1654 ret = btrfs_dirty_pages(root, inode, pages,
1655 dirty_pages, pos, copied,
1656 NULL);
1657 if (need_unlock)
1658 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1659 lockstart, lockend, &cached_state,
1660 GFP_NOFS);
1661 if (ret) {
1662 btrfs_drop_pages(pages, num_pages);
1663 break;
1664 }
1665
1666 release_bytes = 0;
1667 if (only_release_metadata)
1668 btrfs_end_write_no_snapshoting(root);
1669
1670 if (only_release_metadata && copied > 0) {
1671 lockstart = round_down(pos, root->sectorsize);
1672 lockend = round_up(pos + copied, root->sectorsize) - 1;
1673
1674 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1675 lockend, EXTENT_NORESERVE, NULL,
1676 NULL, GFP_NOFS);
1677 only_release_metadata = false;
1678 }
1679
1680 btrfs_drop_pages(pages, num_pages);
1681
1682 cond_resched();
1683
1684 balance_dirty_pages_ratelimited(inode->i_mapping);
1685 if (dirty_pages < (root->nodesize >> PAGE_SHIFT) + 1)
1686 btrfs_btree_balance_dirty(root);
1687
1688 pos += copied;
1689 num_written += copied;
1690 }
1691
1692 kfree(pages);
1693
1694 if (release_bytes) {
1695 if (only_release_metadata) {
1696 btrfs_end_write_no_snapshoting(root);
1697 btrfs_delalloc_release_metadata(inode, release_bytes);
1698 } else {
1699 btrfs_delalloc_release_space(inode, pos, release_bytes);
1700 }
1701 }
1702
1703 return num_written ? num_written : ret;
1704}
1705
1706static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1707 struct iov_iter *from,
1708 loff_t pos)
1709{
1710 struct file *file = iocb->ki_filp;
1711 struct inode *inode = file_inode(file);
1712 ssize_t written;
1713 ssize_t written_buffered;
1714 loff_t endbyte;
1715 int err;
1716
1717 written = generic_file_direct_write(iocb, from, pos);
1718
1719 if (written < 0 || !iov_iter_count(from))
1720 return written;
1721
1722 pos += written;
1723 written_buffered = __btrfs_buffered_write(file, from, pos);
1724 if (written_buffered < 0) {
1725 err = written_buffered;
1726 goto out;
1727 }
1728 /*
1729 * Ensure all data is persisted. We want the next direct IO read to be
1730 * able to read what was just written.
1731 */
1732 endbyte = pos + written_buffered - 1;
1733 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1734 if (err)
1735 goto out;
1736 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1737 if (err)
1738 goto out;
1739 written += written_buffered;
1740 iocb->ki_pos = pos + written_buffered;
1741 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1742 endbyte >> PAGE_SHIFT);
1743out:
1744 return written ? written : err;
1745}
1746
1747static void update_time_for_write(struct inode *inode)
1748{
1749 struct timespec now;
1750
1751 if (IS_NOCMTIME(inode))
1752 return;
1753
1754 now = current_fs_time(inode->i_sb);
1755 if (!timespec_equal(&inode->i_mtime, &now))
1756 inode->i_mtime = now;
1757
1758 if (!timespec_equal(&inode->i_ctime, &now))
1759 inode->i_ctime = now;
1760
1761 if (IS_I_VERSION(inode))
1762 inode_inc_iversion(inode);
1763}
1764
1765static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1766 struct iov_iter *from)
1767{
1768 struct file *file = iocb->ki_filp;
1769 struct inode *inode = file_inode(file);
1770 struct btrfs_root *root = BTRFS_I(inode)->root;
1771 u64 start_pos;
1772 u64 end_pos;
1773 ssize_t num_written = 0;
1774 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1775 ssize_t err;
1776 loff_t pos;
1777 size_t count;
1778 loff_t oldsize;
1779 int clean_page = 0;
1780
1781 inode_lock(inode);
1782 err = generic_write_checks(iocb, from);
1783 if (err <= 0) {
1784 inode_unlock(inode);
1785 return err;
1786 }
1787
1788 current->backing_dev_info = inode_to_bdi(inode);
1789 err = file_remove_privs(file);
1790 if (err) {
1791 inode_unlock(inode);
1792 goto out;
1793 }
1794
1795 /*
1796 * If BTRFS flips readonly due to some impossible error
1797 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1798 * although we have opened a file as writable, we have
1799 * to stop this write operation to ensure FS consistency.
1800 */
1801 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1802 inode_unlock(inode);
1803 err = -EROFS;
1804 goto out;
1805 }
1806
1807 /*
1808 * We reserve space for updating the inode when we reserve space for the
1809 * extent we are going to write, so we will enospc out there. We don't
1810 * need to start yet another transaction to update the inode as we will
1811 * update the inode when we finish writing whatever data we write.
1812 */
1813 update_time_for_write(inode);
1814
1815 pos = iocb->ki_pos;
1816 count = iov_iter_count(from);
1817 start_pos = round_down(pos, root->sectorsize);
1818 oldsize = i_size_read(inode);
1819 if (start_pos > oldsize) {
1820 /* Expand hole size to cover write data, preventing empty gap */
1821 end_pos = round_up(pos + count, root->sectorsize);
1822 err = btrfs_cont_expand(inode, oldsize, end_pos);
1823 if (err) {
1824 inode_unlock(inode);
1825 goto out;
1826 }
1827 if (start_pos > round_up(oldsize, root->sectorsize))
1828 clean_page = 1;
1829 }
1830
1831 if (sync)
1832 atomic_inc(&BTRFS_I(inode)->sync_writers);
1833
1834 if (iocb->ki_flags & IOCB_DIRECT) {
1835 num_written = __btrfs_direct_write(iocb, from, pos);
1836 } else {
1837 num_written = __btrfs_buffered_write(file, from, pos);
1838 if (num_written > 0)
1839 iocb->ki_pos = pos + num_written;
1840 if (clean_page)
1841 pagecache_isize_extended(inode, oldsize,
1842 i_size_read(inode));
1843 }
1844
1845 inode_unlock(inode);
1846
1847 /*
1848 * We also have to set last_sub_trans to the current log transid,
1849 * otherwise subsequent syncs to a file that's been synced in this
1850 * transaction will appear to have already occurred.
1851 */
1852 spin_lock(&BTRFS_I(inode)->lock);
1853 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1854 spin_unlock(&BTRFS_I(inode)->lock);
1855 if (num_written > 0) {
1856 err = generic_write_sync(file, pos, num_written);
1857 if (err < 0)
1858 num_written = err;
1859 }
1860
1861 if (sync)
1862 atomic_dec(&BTRFS_I(inode)->sync_writers);
1863out:
1864 current->backing_dev_info = NULL;
1865 return num_written ? num_written : err;
1866}
1867
1868int btrfs_release_file(struct inode *inode, struct file *filp)
1869{
1870 if (filp->private_data)
1871 btrfs_ioctl_trans_end(filp);
1872 /*
1873 * ordered_data_close is set by settattr when we are about to truncate
1874 * a file from a non-zero size to a zero size. This tries to
1875 * flush down new bytes that may have been written if the
1876 * application were using truncate to replace a file in place.
1877 */
1878 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1879 &BTRFS_I(inode)->runtime_flags))
1880 filemap_flush(inode->i_mapping);
1881 return 0;
1882}
1883
1884static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
1885{
1886 int ret;
1887
1888 atomic_inc(&BTRFS_I(inode)->sync_writers);
1889 ret = btrfs_fdatawrite_range(inode, start, end);
1890 atomic_dec(&BTRFS_I(inode)->sync_writers);
1891
1892 return ret;
1893}
1894
1895/*
1896 * fsync call for both files and directories. This logs the inode into
1897 * the tree log instead of forcing full commits whenever possible.
1898 *
1899 * It needs to call filemap_fdatawait so that all ordered extent updates are
1900 * in the metadata btree are up to date for copying to the log.
1901 *
1902 * It drops the inode mutex before doing the tree log commit. This is an
1903 * important optimization for directories because holding the mutex prevents
1904 * new operations on the dir while we write to disk.
1905 */
1906int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1907{
1908 struct dentry *dentry = file_dentry(file);
1909 struct inode *inode = d_inode(dentry);
1910 struct btrfs_root *root = BTRFS_I(inode)->root;
1911 struct btrfs_trans_handle *trans;
1912 struct btrfs_log_ctx ctx;
1913 int ret = 0;
1914 bool full_sync = 0;
1915 u64 len;
1916
1917 /*
1918 * The range length can be represented by u64, we have to do the typecasts
1919 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
1920 */
1921 len = (u64)end - (u64)start + 1;
1922 trace_btrfs_sync_file(file, datasync);
1923
1924 /*
1925 * We write the dirty pages in the range and wait until they complete
1926 * out of the ->i_mutex. If so, we can flush the dirty pages by
1927 * multi-task, and make the performance up. See
1928 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1929 */
1930 ret = start_ordered_ops(inode, start, end);
1931 if (ret)
1932 return ret;
1933
1934 inode_lock(inode);
1935 atomic_inc(&root->log_batch);
1936 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1937 &BTRFS_I(inode)->runtime_flags);
1938 /*
1939 * We might have have had more pages made dirty after calling
1940 * start_ordered_ops and before acquiring the inode's i_mutex.
1941 */
1942 if (full_sync) {
1943 /*
1944 * For a full sync, we need to make sure any ordered operations
1945 * start and finish before we start logging the inode, so that
1946 * all extents are persisted and the respective file extent
1947 * items are in the fs/subvol btree.
1948 */
1949 ret = btrfs_wait_ordered_range(inode, start, len);
1950 } else {
1951 /*
1952 * Start any new ordered operations before starting to log the
1953 * inode. We will wait for them to finish in btrfs_sync_log().
1954 *
1955 * Right before acquiring the inode's mutex, we might have new
1956 * writes dirtying pages, which won't immediately start the
1957 * respective ordered operations - that is done through the
1958 * fill_delalloc callbacks invoked from the writepage and
1959 * writepages address space operations. So make sure we start
1960 * all ordered operations before starting to log our inode. Not
1961 * doing this means that while logging the inode, writeback
1962 * could start and invoke writepage/writepages, which would call
1963 * the fill_delalloc callbacks (cow_file_range,
1964 * submit_compressed_extents). These callbacks add first an
1965 * extent map to the modified list of extents and then create
1966 * the respective ordered operation, which means in
1967 * tree-log.c:btrfs_log_inode() we might capture all existing
1968 * ordered operations (with btrfs_get_logged_extents()) before
1969 * the fill_delalloc callback adds its ordered operation, and by
1970 * the time we visit the modified list of extent maps (with
1971 * btrfs_log_changed_extents()), we see and process the extent
1972 * map they created. We then use the extent map to construct a
1973 * file extent item for logging without waiting for the
1974 * respective ordered operation to finish - this file extent
1975 * item points to a disk location that might not have yet been
1976 * written to, containing random data - so after a crash a log
1977 * replay will make our inode have file extent items that point
1978 * to disk locations containing invalid data, as we returned
1979 * success to userspace without waiting for the respective
1980 * ordered operation to finish, because it wasn't captured by
1981 * btrfs_get_logged_extents().
1982 */
1983 ret = start_ordered_ops(inode, start, end);
1984 }
1985 if (ret) {
1986 inode_unlock(inode);
1987 goto out;
1988 }
1989 atomic_inc(&root->log_batch);
1990
1991 /*
1992 * If the last transaction that changed this file was before the current
1993 * transaction and we have the full sync flag set in our inode, we can
1994 * bail out now without any syncing.
1995 *
1996 * Note that we can't bail out if the full sync flag isn't set. This is
1997 * because when the full sync flag is set we start all ordered extents
1998 * and wait for them to fully complete - when they complete they update
1999 * the inode's last_trans field through:
2000 *
2001 * btrfs_finish_ordered_io() ->
2002 * btrfs_update_inode_fallback() ->
2003 * btrfs_update_inode() ->
2004 * btrfs_set_inode_last_trans()
2005 *
2006 * So we are sure that last_trans is up to date and can do this check to
2007 * bail out safely. For the fast path, when the full sync flag is not
2008 * set in our inode, we can not do it because we start only our ordered
2009 * extents and don't wait for them to complete (that is when
2010 * btrfs_finish_ordered_io runs), so here at this point their last_trans
2011 * value might be less than or equals to fs_info->last_trans_committed,
2012 * and setting a speculative last_trans for an inode when a buffered
2013 * write is made (such as fs_info->generation + 1 for example) would not
2014 * be reliable since after setting the value and before fsync is called
2015 * any number of transactions can start and commit (transaction kthread
2016 * commits the current transaction periodically), and a transaction
2017 * commit does not start nor waits for ordered extents to complete.
2018 */
2019 smp_mb();
2020 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
2021 (full_sync && BTRFS_I(inode)->last_trans <=
2022 root->fs_info->last_trans_committed) ||
2023 (!btrfs_have_ordered_extents_in_range(inode, start, len) &&
2024 BTRFS_I(inode)->last_trans
2025 <= root->fs_info->last_trans_committed)) {
2026 /*
2027 * We'v had everything committed since the last time we were
2028 * modified so clear this flag in case it was set for whatever
2029 * reason, it's no longer relevant.
2030 */
2031 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2032 &BTRFS_I(inode)->runtime_flags);
2033 inode_unlock(inode);
2034 goto out;
2035 }
2036
2037 /*
2038 * ok we haven't committed the transaction yet, lets do a commit
2039 */
2040 if (file->private_data)
2041 btrfs_ioctl_trans_end(file);
2042
2043 /*
2044 * We use start here because we will need to wait on the IO to complete
2045 * in btrfs_sync_log, which could require joining a transaction (for
2046 * example checking cross references in the nocow path). If we use join
2047 * here we could get into a situation where we're waiting on IO to
2048 * happen that is blocked on a transaction trying to commit. With start
2049 * we inc the extwriter counter, so we wait for all extwriters to exit
2050 * before we start blocking join'ers. This comment is to keep somebody
2051 * from thinking they are super smart and changing this to
2052 * btrfs_join_transaction *cough*Josef*cough*.
2053 */
2054 trans = btrfs_start_transaction(root, 0);
2055 if (IS_ERR(trans)) {
2056 ret = PTR_ERR(trans);
2057 inode_unlock(inode);
2058 goto out;
2059 }
2060 trans->sync = true;
2061
2062 btrfs_init_log_ctx(&ctx);
2063
2064 ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx);
2065 if (ret < 0) {
2066 /* Fallthrough and commit/free transaction. */
2067 ret = 1;
2068 }
2069
2070 /* we've logged all the items and now have a consistent
2071 * version of the file in the log. It is possible that
2072 * someone will come in and modify the file, but that's
2073 * fine because the log is consistent on disk, and we
2074 * have references to all of the file's extents
2075 *
2076 * It is possible that someone will come in and log the
2077 * file again, but that will end up using the synchronization
2078 * inside btrfs_sync_log to keep things safe.
2079 */
2080 inode_unlock(inode);
2081
2082 /*
2083 * If any of the ordered extents had an error, just return it to user
2084 * space, so that the application knows some writes didn't succeed and
2085 * can take proper action (retry for e.g.). Blindly committing the
2086 * transaction in this case, would fool userspace that everything was
2087 * successful. And we also want to make sure our log doesn't contain
2088 * file extent items pointing to extents that weren't fully written to -
2089 * just like in the non fast fsync path, where we check for the ordered
2090 * operation's error flag before writing to the log tree and return -EIO
2091 * if any of them had this flag set (btrfs_wait_ordered_range) -
2092 * therefore we need to check for errors in the ordered operations,
2093 * which are indicated by ctx.io_err.
2094 */
2095 if (ctx.io_err) {
2096 btrfs_end_transaction(trans, root);
2097 ret = ctx.io_err;
2098 goto out;
2099 }
2100
2101 if (ret != BTRFS_NO_LOG_SYNC) {
2102 if (!ret) {
2103 ret = btrfs_sync_log(trans, root, &ctx);
2104 if (!ret) {
2105 ret = btrfs_end_transaction(trans, root);
2106 goto out;
2107 }
2108 }
2109 if (!full_sync) {
2110 ret = btrfs_wait_ordered_range(inode, start, len);
2111 if (ret) {
2112 btrfs_end_transaction(trans, root);
2113 goto out;
2114 }
2115 }
2116 ret = btrfs_commit_transaction(trans, root);
2117 } else {
2118 ret = btrfs_end_transaction(trans, root);
2119 }
2120out:
2121 return ret > 0 ? -EIO : ret;
2122}
2123
2124static const struct vm_operations_struct btrfs_file_vm_ops = {
2125 .fault = filemap_fault,
2126 .map_pages = filemap_map_pages,
2127 .page_mkwrite = btrfs_page_mkwrite,
2128};
2129
2130static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2131{
2132 struct address_space *mapping = filp->f_mapping;
2133
2134 if (!mapping->a_ops->readpage)
2135 return -ENOEXEC;
2136
2137 file_accessed(filp);
2138 vma->vm_ops = &btrfs_file_vm_ops;
2139
2140 return 0;
2141}
2142
2143static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
2144 int slot, u64 start, u64 end)
2145{
2146 struct btrfs_file_extent_item *fi;
2147 struct btrfs_key key;
2148
2149 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2150 return 0;
2151
2152 btrfs_item_key_to_cpu(leaf, &key, slot);
2153 if (key.objectid != btrfs_ino(inode) ||
2154 key.type != BTRFS_EXTENT_DATA_KEY)
2155 return 0;
2156
2157 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2158
2159 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2160 return 0;
2161
2162 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2163 return 0;
2164
2165 if (key.offset == end)
2166 return 1;
2167 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2168 return 1;
2169 return 0;
2170}
2171
2172static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
2173 struct btrfs_path *path, u64 offset, u64 end)
2174{
2175 struct btrfs_root *root = BTRFS_I(inode)->root;
2176 struct extent_buffer *leaf;
2177 struct btrfs_file_extent_item *fi;
2178 struct extent_map *hole_em;
2179 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2180 struct btrfs_key key;
2181 int ret;
2182
2183 if (btrfs_fs_incompat(root->fs_info, NO_HOLES))
2184 goto out;
2185
2186 key.objectid = btrfs_ino(inode);
2187 key.type = BTRFS_EXTENT_DATA_KEY;
2188 key.offset = offset;
2189
2190 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2191 if (ret < 0)
2192 return ret;
2193 BUG_ON(!ret);
2194
2195 leaf = path->nodes[0];
2196 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
2197 u64 num_bytes;
2198
2199 path->slots[0]--;
2200 fi = btrfs_item_ptr(leaf, path->slots[0],
2201 struct btrfs_file_extent_item);
2202 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2203 end - offset;
2204 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2205 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2206 btrfs_set_file_extent_offset(leaf, fi, 0);
2207 btrfs_mark_buffer_dirty(leaf);
2208 goto out;
2209 }
2210
2211 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2212 u64 num_bytes;
2213
2214 key.offset = offset;
2215 btrfs_set_item_key_safe(root->fs_info, path, &key);
2216 fi = btrfs_item_ptr(leaf, path->slots[0],
2217 struct btrfs_file_extent_item);
2218 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2219 offset;
2220 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2221 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2222 btrfs_set_file_extent_offset(leaf, fi, 0);
2223 btrfs_mark_buffer_dirty(leaf);
2224 goto out;
2225 }
2226 btrfs_release_path(path);
2227
2228 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
2229 0, 0, end - offset, 0, end - offset,
2230 0, 0, 0);
2231 if (ret)
2232 return ret;
2233
2234out:
2235 btrfs_release_path(path);
2236
2237 hole_em = alloc_extent_map();
2238 if (!hole_em) {
2239 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2240 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2241 &BTRFS_I(inode)->runtime_flags);
2242 } else {
2243 hole_em->start = offset;
2244 hole_em->len = end - offset;
2245 hole_em->ram_bytes = hole_em->len;
2246 hole_em->orig_start = offset;
2247
2248 hole_em->block_start = EXTENT_MAP_HOLE;
2249 hole_em->block_len = 0;
2250 hole_em->orig_block_len = 0;
2251 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
2252 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2253 hole_em->generation = trans->transid;
2254
2255 do {
2256 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2257 write_lock(&em_tree->lock);
2258 ret = add_extent_mapping(em_tree, hole_em, 1);
2259 write_unlock(&em_tree->lock);
2260 } while (ret == -EEXIST);
2261 free_extent_map(hole_em);
2262 if (ret)
2263 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2264 &BTRFS_I(inode)->runtime_flags);
2265 }
2266
2267 return 0;
2268}
2269
2270/*
2271 * Find a hole extent on given inode and change start/len to the end of hole
2272 * extent.(hole/vacuum extent whose em->start <= start &&
2273 * em->start + em->len > start)
2274 * When a hole extent is found, return 1 and modify start/len.
2275 */
2276static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2277{
2278 struct extent_map *em;
2279 int ret = 0;
2280
2281 em = btrfs_get_extent(inode, NULL, 0, *start, *len, 0);
2282 if (IS_ERR_OR_NULL(em)) {
2283 if (!em)
2284 ret = -ENOMEM;
2285 else
2286 ret = PTR_ERR(em);
2287 return ret;
2288 }
2289
2290 /* Hole or vacuum extent(only exists in no-hole mode) */
2291 if (em->block_start == EXTENT_MAP_HOLE) {
2292 ret = 1;
2293 *len = em->start + em->len > *start + *len ?
2294 0 : *start + *len - em->start - em->len;
2295 *start = em->start + em->len;
2296 }
2297 free_extent_map(em);
2298 return ret;
2299}
2300
2301static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2302{
2303 struct btrfs_root *root = BTRFS_I(inode)->root;
2304 struct extent_state *cached_state = NULL;
2305 struct btrfs_path *path;
2306 struct btrfs_block_rsv *rsv;
2307 struct btrfs_trans_handle *trans;
2308 u64 lockstart;
2309 u64 lockend;
2310 u64 tail_start;
2311 u64 tail_len;
2312 u64 orig_start = offset;
2313 u64 cur_offset;
2314 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
2315 u64 drop_end;
2316 int ret = 0;
2317 int err = 0;
2318 unsigned int rsv_count;
2319 bool same_block;
2320 bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
2321 u64 ino_size;
2322 bool truncated_block = false;
2323 bool updated_inode = false;
2324
2325 ret = btrfs_wait_ordered_range(inode, offset, len);
2326 if (ret)
2327 return ret;
2328
2329 inode_lock(inode);
2330 ino_size = round_up(inode->i_size, root->sectorsize);
2331 ret = find_first_non_hole(inode, &offset, &len);
2332 if (ret < 0)
2333 goto out_only_mutex;
2334 if (ret && !len) {
2335 /* Already in a large hole */
2336 ret = 0;
2337 goto out_only_mutex;
2338 }
2339
2340 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
2341 lockend = round_down(offset + len,
2342 BTRFS_I(inode)->root->sectorsize) - 1;
2343 same_block = (BTRFS_BYTES_TO_BLKS(root->fs_info, offset))
2344 == (BTRFS_BYTES_TO_BLKS(root->fs_info, offset + len - 1));
2345 /*
2346 * We needn't truncate any block which is beyond the end of the file
2347 * because we are sure there is no data there.
2348 */
2349 /*
2350 * Only do this if we are in the same block and we aren't doing the
2351 * entire block.
2352 */
2353 if (same_block && len < root->sectorsize) {
2354 if (offset < ino_size) {
2355 truncated_block = true;
2356 ret = btrfs_truncate_block(inode, offset, len, 0);
2357 } else {
2358 ret = 0;
2359 }
2360 goto out_only_mutex;
2361 }
2362
2363 /* zero back part of the first block */
2364 if (offset < ino_size) {
2365 truncated_block = true;
2366 ret = btrfs_truncate_block(inode, offset, 0, 0);
2367 if (ret) {
2368 inode_unlock(inode);
2369 return ret;
2370 }
2371 }
2372
2373 /* Check the aligned pages after the first unaligned page,
2374 * if offset != orig_start, which means the first unaligned page
2375 * including serveral following pages are already in holes,
2376 * the extra check can be skipped */
2377 if (offset == orig_start) {
2378 /* after truncate page, check hole again */
2379 len = offset + len - lockstart;
2380 offset = lockstart;
2381 ret = find_first_non_hole(inode, &offset, &len);
2382 if (ret < 0)
2383 goto out_only_mutex;
2384 if (ret && !len) {
2385 ret = 0;
2386 goto out_only_mutex;
2387 }
2388 lockstart = offset;
2389 }
2390
2391 /* Check the tail unaligned part is in a hole */
2392 tail_start = lockend + 1;
2393 tail_len = offset + len - tail_start;
2394 if (tail_len) {
2395 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2396 if (unlikely(ret < 0))
2397 goto out_only_mutex;
2398 if (!ret) {
2399 /* zero the front end of the last page */
2400 if (tail_start + tail_len < ino_size) {
2401 truncated_block = true;
2402 ret = btrfs_truncate_block(inode,
2403 tail_start + tail_len,
2404 0, 1);
2405 if (ret)
2406 goto out_only_mutex;
2407 }
2408 }
2409 }
2410
2411 if (lockend < lockstart) {
2412 ret = 0;
2413 goto out_only_mutex;
2414 }
2415
2416 while (1) {
2417 struct btrfs_ordered_extent *ordered;
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 !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
2434 if (ordered)
2435 btrfs_put_ordered_extent(ordered);
2436 break;
2437 }
2438 if (ordered)
2439 btrfs_put_ordered_extent(ordered);
2440 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2441 lockend, &cached_state, GFP_NOFS);
2442 ret = btrfs_wait_ordered_range(inode, lockstart,
2443 lockend - lockstart + 1);
2444 if (ret) {
2445 inode_unlock(inode);
2446 return ret;
2447 }
2448 }
2449
2450 path = btrfs_alloc_path();
2451 if (!path) {
2452 ret = -ENOMEM;
2453 goto out;
2454 }
2455
2456 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2457 if (!rsv) {
2458 ret = -ENOMEM;
2459 goto out_free;
2460 }
2461 rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
2462 rsv->failfast = 1;
2463
2464 /*
2465 * 1 - update the inode
2466 * 1 - removing the extents in the range
2467 * 1 - adding the hole extent if no_holes isn't set
2468 */
2469 rsv_count = no_holes ? 2 : 3;
2470 trans = btrfs_start_transaction(root, rsv_count);
2471 if (IS_ERR(trans)) {
2472 err = PTR_ERR(trans);
2473 goto out_free;
2474 }
2475
2476 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
2477 min_size);
2478 BUG_ON(ret);
2479 trans->block_rsv = rsv;
2480
2481 cur_offset = lockstart;
2482 len = lockend - cur_offset;
2483 while (cur_offset < lockend) {
2484 ret = __btrfs_drop_extents(trans, root, inode, path,
2485 cur_offset, lockend + 1,
2486 &drop_end, 1, 0, 0, NULL);
2487 if (ret != -ENOSPC)
2488 break;
2489
2490 trans->block_rsv = &root->fs_info->trans_block_rsv;
2491
2492 if (cur_offset < ino_size) {
2493 ret = fill_holes(trans, inode, path, cur_offset,
2494 drop_end);
2495 if (ret) {
2496 err = ret;
2497 break;
2498 }
2499 }
2500
2501 cur_offset = drop_end;
2502
2503 ret = btrfs_update_inode(trans, root, inode);
2504 if (ret) {
2505 err = ret;
2506 break;
2507 }
2508
2509 btrfs_end_transaction(trans, root);
2510 btrfs_btree_balance_dirty(root);
2511
2512 trans = btrfs_start_transaction(root, rsv_count);
2513 if (IS_ERR(trans)) {
2514 ret = PTR_ERR(trans);
2515 trans = NULL;
2516 break;
2517 }
2518
2519 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
2520 rsv, min_size);
2521 BUG_ON(ret); /* shouldn't happen */
2522 trans->block_rsv = rsv;
2523
2524 ret = find_first_non_hole(inode, &cur_offset, &len);
2525 if (unlikely(ret < 0))
2526 break;
2527 if (ret && !len) {
2528 ret = 0;
2529 break;
2530 }
2531 }
2532
2533 if (ret) {
2534 err = ret;
2535 goto out_trans;
2536 }
2537
2538 trans->block_rsv = &root->fs_info->trans_block_rsv;
2539 /*
2540 * If we are using the NO_HOLES feature we might have had already an
2541 * hole that overlaps a part of the region [lockstart, lockend] and
2542 * ends at (or beyond) lockend. Since we have no file extent items to
2543 * represent holes, drop_end can be less than lockend and so we must
2544 * make sure we have an extent map representing the existing hole (the
2545 * call to __btrfs_drop_extents() might have dropped the existing extent
2546 * map representing the existing hole), otherwise the fast fsync path
2547 * will not record the existence of the hole region
2548 * [existing_hole_start, lockend].
2549 */
2550 if (drop_end <= lockend)
2551 drop_end = lockend + 1;
2552 /*
2553 * Don't insert file hole extent item if it's for a range beyond eof
2554 * (because it's useless) or if it represents a 0 bytes range (when
2555 * cur_offset == drop_end).
2556 */
2557 if (cur_offset < ino_size && cur_offset < drop_end) {
2558 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2559 if (ret) {
2560 err = ret;
2561 goto out_trans;
2562 }
2563 }
2564
2565out_trans:
2566 if (!trans)
2567 goto out_free;
2568
2569 inode_inc_iversion(inode);
2570 inode->i_mtime = inode->i_ctime = current_fs_time(inode->i_sb);
2571
2572 trans->block_rsv = &root->fs_info->trans_block_rsv;
2573 ret = btrfs_update_inode(trans, root, inode);
2574 updated_inode = true;
2575 btrfs_end_transaction(trans, root);
2576 btrfs_btree_balance_dirty(root);
2577out_free:
2578 btrfs_free_path(path);
2579 btrfs_free_block_rsv(root, rsv);
2580out:
2581 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2582 &cached_state, GFP_NOFS);
2583out_only_mutex:
2584 if (!updated_inode && truncated_block && !ret && !err) {
2585 /*
2586 * If we only end up zeroing part of a page, we still need to
2587 * update the inode item, so that all the time fields are
2588 * updated as well as the necessary btrfs inode in memory fields
2589 * for detecting, at fsync time, if the inode isn't yet in the
2590 * log tree or it's there but not up to date.
2591 */
2592 trans = btrfs_start_transaction(root, 1);
2593 if (IS_ERR(trans)) {
2594 err = PTR_ERR(trans);
2595 } else {
2596 err = btrfs_update_inode(trans, root, inode);
2597 ret = btrfs_end_transaction(trans, root);
2598 }
2599 }
2600 inode_unlock(inode);
2601 if (ret && !err)
2602 err = ret;
2603 return err;
2604}
2605
2606/* Helper structure to record which range is already reserved */
2607struct falloc_range {
2608 struct list_head list;
2609 u64 start;
2610 u64 len;
2611};
2612
2613/*
2614 * Helper function to add falloc range
2615 *
2616 * Caller should have locked the larger range of extent containing
2617 * [start, len)
2618 */
2619static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2620{
2621 struct falloc_range *prev = NULL;
2622 struct falloc_range *range = NULL;
2623
2624 if (list_empty(head))
2625 goto insert;
2626
2627 /*
2628 * As fallocate iterate by bytenr order, we only need to check
2629 * the last range.
2630 */
2631 prev = list_entry(head->prev, struct falloc_range, list);
2632 if (prev->start + prev->len == start) {
2633 prev->len += len;
2634 return 0;
2635 }
2636insert:
2637 range = kmalloc(sizeof(*range), GFP_KERNEL);
2638 if (!range)
2639 return -ENOMEM;
2640 range->start = start;
2641 range->len = len;
2642 list_add_tail(&range->list, head);
2643 return 0;
2644}
2645
2646static long btrfs_fallocate(struct file *file, int mode,
2647 loff_t offset, loff_t len)
2648{
2649 struct inode *inode = file_inode(file);
2650 struct extent_state *cached_state = NULL;
2651 struct falloc_range *range;
2652 struct falloc_range *tmp;
2653 struct list_head reserve_list;
2654 u64 cur_offset;
2655 u64 last_byte;
2656 u64 alloc_start;
2657 u64 alloc_end;
2658 u64 alloc_hint = 0;
2659 u64 locked_end;
2660 u64 actual_end = 0;
2661 struct extent_map *em;
2662 int blocksize = BTRFS_I(inode)->root->sectorsize;
2663 int ret;
2664
2665 alloc_start = round_down(offset, blocksize);
2666 alloc_end = round_up(offset + len, blocksize);
2667
2668 /* Make sure we aren't being give some crap mode */
2669 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2670 return -EOPNOTSUPP;
2671
2672 if (mode & FALLOC_FL_PUNCH_HOLE)
2673 return btrfs_punch_hole(inode, offset, len);
2674
2675 /*
2676 * Only trigger disk allocation, don't trigger qgroup reserve
2677 *
2678 * For qgroup space, it will be checked later.
2679 */
2680 ret = btrfs_alloc_data_chunk_ondemand(inode, alloc_end - alloc_start);
2681 if (ret < 0)
2682 return ret;
2683
2684 inode_lock(inode);
2685
2686 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
2687 ret = inode_newsize_ok(inode, offset + len);
2688 if (ret)
2689 goto out;
2690 }
2691
2692 /*
2693 * TODO: Move these two operations after we have checked
2694 * accurate reserved space, or fallocate can still fail but
2695 * with page truncated or size expanded.
2696 *
2697 * But that's a minor problem and won't do much harm BTW.
2698 */
2699 if (alloc_start > inode->i_size) {
2700 ret = btrfs_cont_expand(inode, i_size_read(inode),
2701 alloc_start);
2702 if (ret)
2703 goto out;
2704 } else if (offset + len > inode->i_size) {
2705 /*
2706 * If we are fallocating from the end of the file onward we
2707 * need to zero out the end of the block if i_size lands in the
2708 * middle of a block.
2709 */
2710 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
2711 if (ret)
2712 goto out;
2713 }
2714
2715 /*
2716 * wait for ordered IO before we have any locks. We'll loop again
2717 * below with the locks held.
2718 */
2719 ret = btrfs_wait_ordered_range(inode, alloc_start,
2720 alloc_end - alloc_start);
2721 if (ret)
2722 goto out;
2723
2724 locked_end = alloc_end - 1;
2725 while (1) {
2726 struct btrfs_ordered_extent *ordered;
2727
2728 /* the extent lock is ordered inside the running
2729 * transaction
2730 */
2731 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2732 locked_end, &cached_state);
2733 ordered = btrfs_lookup_first_ordered_extent(inode,
2734 alloc_end - 1);
2735 if (ordered &&
2736 ordered->file_offset + ordered->len > alloc_start &&
2737 ordered->file_offset < alloc_end) {
2738 btrfs_put_ordered_extent(ordered);
2739 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2740 alloc_start, locked_end,
2741 &cached_state, GFP_KERNEL);
2742 /*
2743 * we can't wait on the range with the transaction
2744 * running or with the extent lock held
2745 */
2746 ret = btrfs_wait_ordered_range(inode, alloc_start,
2747 alloc_end - alloc_start);
2748 if (ret)
2749 goto out;
2750 } else {
2751 if (ordered)
2752 btrfs_put_ordered_extent(ordered);
2753 break;
2754 }
2755 }
2756
2757 /* First, check if we exceed the qgroup limit */
2758 INIT_LIST_HEAD(&reserve_list);
2759 cur_offset = alloc_start;
2760 while (1) {
2761 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2762 alloc_end - cur_offset, 0);
2763 if (IS_ERR_OR_NULL(em)) {
2764 if (!em)
2765 ret = -ENOMEM;
2766 else
2767 ret = PTR_ERR(em);
2768 break;
2769 }
2770 last_byte = min(extent_map_end(em), alloc_end);
2771 actual_end = min_t(u64, extent_map_end(em), offset + len);
2772 last_byte = ALIGN(last_byte, blocksize);
2773 if (em->block_start == EXTENT_MAP_HOLE ||
2774 (cur_offset >= inode->i_size &&
2775 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2776 ret = add_falloc_range(&reserve_list, cur_offset,
2777 last_byte - cur_offset);
2778 if (ret < 0) {
2779 free_extent_map(em);
2780 break;
2781 }
2782 ret = btrfs_qgroup_reserve_data(inode, cur_offset,
2783 last_byte - cur_offset);
2784 if (ret < 0)
2785 break;
2786 }
2787 free_extent_map(em);
2788 cur_offset = last_byte;
2789 if (cur_offset >= alloc_end)
2790 break;
2791 }
2792
2793 /*
2794 * If ret is still 0, means we're OK to fallocate.
2795 * Or just cleanup the list and exit.
2796 */
2797 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
2798 if (!ret)
2799 ret = btrfs_prealloc_file_range(inode, mode,
2800 range->start,
2801 range->len, 1 << inode->i_blkbits,
2802 offset + len, &alloc_hint);
2803 list_del(&range->list);
2804 kfree(range);
2805 }
2806 if (ret < 0)
2807 goto out_unlock;
2808
2809 if (actual_end > inode->i_size &&
2810 !(mode & FALLOC_FL_KEEP_SIZE)) {
2811 struct btrfs_trans_handle *trans;
2812 struct btrfs_root *root = BTRFS_I(inode)->root;
2813
2814 /*
2815 * We didn't need to allocate any more space, but we
2816 * still extended the size of the file so we need to
2817 * update i_size and the inode item.
2818 */
2819 trans = btrfs_start_transaction(root, 1);
2820 if (IS_ERR(trans)) {
2821 ret = PTR_ERR(trans);
2822 } else {
2823 inode->i_ctime = current_fs_time(inode->i_sb);
2824 i_size_write(inode, actual_end);
2825 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2826 ret = btrfs_update_inode(trans, root, inode);
2827 if (ret)
2828 btrfs_end_transaction(trans, root);
2829 else
2830 ret = btrfs_end_transaction(trans, root);
2831 }
2832 }
2833out_unlock:
2834 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2835 &cached_state, GFP_KERNEL);
2836out:
2837 /*
2838 * As we waited the extent range, the data_rsv_map must be empty
2839 * in the range, as written data range will be released from it.
2840 * And for prealloacted extent, it will also be released when
2841 * its metadata is written.
2842 * So this is completely used as cleanup.
2843 */
2844 btrfs_qgroup_free_data(inode, alloc_start, alloc_end - alloc_start);
2845 inode_unlock(inode);
2846 /* Let go of our reservation. */
2847 btrfs_free_reserved_data_space(inode, alloc_start,
2848 alloc_end - alloc_start);
2849 return ret;
2850}
2851
2852static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2853{
2854 struct btrfs_root *root = BTRFS_I(inode)->root;
2855 struct extent_map *em = NULL;
2856 struct extent_state *cached_state = NULL;
2857 u64 lockstart;
2858 u64 lockend;
2859 u64 start;
2860 u64 len;
2861 int ret = 0;
2862
2863 if (inode->i_size == 0)
2864 return -ENXIO;
2865
2866 /*
2867 * *offset can be negative, in this case we start finding DATA/HOLE from
2868 * the very start of the file.
2869 */
2870 start = max_t(loff_t, 0, *offset);
2871
2872 lockstart = round_down(start, root->sectorsize);
2873 lockend = round_up(i_size_read(inode), root->sectorsize);
2874 if (lockend <= lockstart)
2875 lockend = lockstart + root->sectorsize;
2876 lockend--;
2877 len = lockend - lockstart + 1;
2878
2879 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2880 &cached_state);
2881
2882 while (start < inode->i_size) {
2883 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2884 if (IS_ERR(em)) {
2885 ret = PTR_ERR(em);
2886 em = NULL;
2887 break;
2888 }
2889
2890 if (whence == SEEK_HOLE &&
2891 (em->block_start == EXTENT_MAP_HOLE ||
2892 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2893 break;
2894 else if (whence == SEEK_DATA &&
2895 (em->block_start != EXTENT_MAP_HOLE &&
2896 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2897 break;
2898
2899 start = em->start + em->len;
2900 free_extent_map(em);
2901 em = NULL;
2902 cond_resched();
2903 }
2904 free_extent_map(em);
2905 if (!ret) {
2906 if (whence == SEEK_DATA && start >= inode->i_size)
2907 ret = -ENXIO;
2908 else
2909 *offset = min_t(loff_t, start, inode->i_size);
2910 }
2911 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2912 &cached_state, GFP_NOFS);
2913 return ret;
2914}
2915
2916static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2917{
2918 struct inode *inode = file->f_mapping->host;
2919 int ret;
2920
2921 inode_lock(inode);
2922 switch (whence) {
2923 case SEEK_END:
2924 case SEEK_CUR:
2925 offset = generic_file_llseek(file, offset, whence);
2926 goto out;
2927 case SEEK_DATA:
2928 case SEEK_HOLE:
2929 if (offset >= i_size_read(inode)) {
2930 inode_unlock(inode);
2931 return -ENXIO;
2932 }
2933
2934 ret = find_desired_extent(inode, &offset, whence);
2935 if (ret) {
2936 inode_unlock(inode);
2937 return ret;
2938 }
2939 }
2940
2941 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
2942out:
2943 inode_unlock(inode);
2944 return offset;
2945}
2946
2947const struct file_operations btrfs_file_operations = {
2948 .llseek = btrfs_file_llseek,
2949 .read_iter = generic_file_read_iter,
2950 .splice_read = generic_file_splice_read,
2951 .write_iter = btrfs_file_write_iter,
2952 .mmap = btrfs_file_mmap,
2953 .open = generic_file_open,
2954 .release = btrfs_release_file,
2955 .fsync = btrfs_sync_file,
2956 .fallocate = btrfs_fallocate,
2957 .unlocked_ioctl = btrfs_ioctl,
2958#ifdef CONFIG_COMPAT
2959 .compat_ioctl = btrfs_ioctl,
2960#endif
2961 .copy_file_range = btrfs_copy_file_range,
2962 .clone_file_range = btrfs_clone_file_range,
2963 .dedupe_file_range = btrfs_dedupe_file_range,
2964};
2965
2966void btrfs_auto_defrag_exit(void)
2967{
2968 kmem_cache_destroy(btrfs_inode_defrag_cachep);
2969}
2970
2971int btrfs_auto_defrag_init(void)
2972{
2973 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
2974 sizeof(struct inode_defrag), 0,
2975 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
2976 NULL);
2977 if (!btrfs_inode_defrag_cachep)
2978 return -ENOMEM;
2979
2980 return 0;
2981}
2982
2983int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
2984{
2985 int ret;
2986
2987 /*
2988 * So with compression we will find and lock a dirty page and clear the
2989 * first one as dirty, setup an async extent, and immediately return
2990 * with the entire range locked but with nobody actually marked with
2991 * writeback. So we can't just filemap_write_and_wait_range() and
2992 * expect it to work since it will just kick off a thread to do the
2993 * actual work. So we need to call filemap_fdatawrite_range _again_
2994 * since it will wait on the page lock, which won't be unlocked until
2995 * after the pages have been marked as writeback and so we're good to go
2996 * from there. We have to do this otherwise we'll miss the ordered
2997 * extents and that results in badness. Please Josef, do not think you
2998 * know better and pull this out at some point in the future, it is
2999 * right and you are wrong.
3000 */
3001 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3002 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3003 &BTRFS_I(inode)->runtime_flags))
3004 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3005
3006 return ret;
3007}