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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 <linux/fsverity.h>
20#include "ctree.h"
21#include "direct-io.h"
22#include "disk-io.h"
23#include "transaction.h"
24#include "btrfs_inode.h"
25#include "tree-log.h"
26#include "locking.h"
27#include "qgroup.h"
28#include "compression.h"
29#include "delalloc-space.h"
30#include "reflink.h"
31#include "subpage.h"
32#include "fs.h"
33#include "accessors.h"
34#include "extent-tree.h"
35#include "file-item.h"
36#include "ioctl.h"
37#include "file.h"
38#include "super.h"
39
40/*
41 * Helper to fault in page and copy. This should go away and be replaced with
42 * calls into generic code.
43 */
44static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
45 struct folio *folio, struct iov_iter *i)
46{
47 size_t copied = 0;
48 size_t total_copied = 0;
49 int offset = offset_in_page(pos);
50
51 while (write_bytes > 0) {
52 size_t count = min_t(size_t, PAGE_SIZE - offset, write_bytes);
53 /*
54 * Copy data from userspace to the current page
55 */
56 copied = copy_folio_from_iter_atomic(folio, offset, count, i);
57
58 /* Flush processor's dcache for this page */
59 flush_dcache_folio(folio);
60
61 /*
62 * if we get a partial write, we can end up with
63 * partially up to date page. These add
64 * a lot of complexity, so make sure they don't
65 * happen by forcing this copy to be retried.
66 *
67 * The rest of the btrfs_file_write code will fall
68 * back to page at a time copies after we return 0.
69 */
70 if (unlikely(copied < count)) {
71 if (!folio_test_uptodate(folio)) {
72 iov_iter_revert(i, copied);
73 copied = 0;
74 }
75 if (!copied)
76 break;
77 }
78
79 write_bytes -= copied;
80 total_copied += copied;
81 offset += copied;
82 }
83 return total_copied;
84}
85
86/*
87 * Unlock folio after btrfs_file_write() is done with it.
88 */
89static void btrfs_drop_folio(struct btrfs_fs_info *fs_info, struct folio *folio,
90 u64 pos, u64 copied)
91{
92 u64 block_start = round_down(pos, fs_info->sectorsize);
93 u64 block_len = round_up(pos + copied, fs_info->sectorsize) - block_start;
94
95 ASSERT(block_len <= U32_MAX);
96 /*
97 * Folio checked is some magic around finding folios that have been
98 * modified without going through btrfs_dirty_folio(). Clear it here.
99 * There should be no need to mark the pages accessed as
100 * prepare_one_folio() should have marked them accessed in
101 * prepare_one_folio() via find_or_create_page()
102 */
103 btrfs_folio_clamp_clear_checked(fs_info, folio, block_start, block_len);
104 folio_unlock(folio);
105 folio_put(folio);
106}
107
108/*
109 * After btrfs_copy_from_user(), update the following things for delalloc:
110 * - Mark newly dirtied folio as DELALLOC in the io tree.
111 * Used to advise which range is to be written back.
112 * - Mark modified folio as Uptodate/Dirty and not needing COW fixup
113 * - Update inode size for past EOF write
114 */
115int btrfs_dirty_folio(struct btrfs_inode *inode, struct folio *folio, loff_t pos,
116 size_t write_bytes, struct extent_state **cached, bool noreserve)
117{
118 struct btrfs_fs_info *fs_info = inode->root->fs_info;
119 int ret = 0;
120 u64 num_bytes;
121 u64 start_pos;
122 u64 end_of_last_block;
123 u64 end_pos = pos + write_bytes;
124 loff_t isize = i_size_read(&inode->vfs_inode);
125 unsigned int extra_bits = 0;
126
127 if (write_bytes == 0)
128 return 0;
129
130 if (noreserve)
131 extra_bits |= EXTENT_NORESERVE;
132
133 start_pos = round_down(pos, fs_info->sectorsize);
134 num_bytes = round_up(write_bytes + pos - start_pos,
135 fs_info->sectorsize);
136 ASSERT(num_bytes <= U32_MAX);
137 ASSERT(folio_pos(folio) <= pos &&
138 folio_pos(folio) + folio_size(folio) >= pos + write_bytes);
139
140 end_of_last_block = start_pos + num_bytes - 1;
141
142 /*
143 * The pages may have already been dirty, clear out old accounting so
144 * we can set things up properly
145 */
146 clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block,
147 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
148 cached);
149
150 ret = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
151 extra_bits, cached);
152 if (ret)
153 return ret;
154
155 btrfs_folio_clamp_set_uptodate(fs_info, folio, start_pos, num_bytes);
156 btrfs_folio_clamp_clear_checked(fs_info, folio, start_pos, num_bytes);
157 btrfs_folio_clamp_set_dirty(fs_info, folio, start_pos, num_bytes);
158
159 /*
160 * we've only changed i_size in ram, and we haven't updated
161 * the disk i_size. There is no need to log the inode
162 * at this time.
163 */
164 if (end_pos > isize)
165 i_size_write(&inode->vfs_inode, end_pos);
166 return 0;
167}
168
169/*
170 * this is very complex, but the basic idea is to drop all extents
171 * in the range start - end. hint_block is filled in with a block number
172 * that would be a good hint to the block allocator for this file.
173 *
174 * If an extent intersects the range but is not entirely inside the range
175 * it is either truncated or split. Anything entirely inside the range
176 * is deleted from the tree.
177 *
178 * Note: the VFS' inode number of bytes is not updated, it's up to the caller
179 * to deal with that. We set the field 'bytes_found' of the arguments structure
180 * with the number of allocated bytes found in the target range, so that the
181 * caller can update the inode's number of bytes in an atomic way when
182 * replacing extents in a range to avoid races with stat(2).
183 */
184int btrfs_drop_extents(struct btrfs_trans_handle *trans,
185 struct btrfs_root *root, struct btrfs_inode *inode,
186 struct btrfs_drop_extents_args *args)
187{
188 struct btrfs_fs_info *fs_info = root->fs_info;
189 struct extent_buffer *leaf;
190 struct btrfs_file_extent_item *fi;
191 struct btrfs_key key;
192 struct btrfs_key new_key;
193 u64 ino = btrfs_ino(inode);
194 u64 search_start = args->start;
195 u64 disk_bytenr = 0;
196 u64 num_bytes = 0;
197 u64 extent_offset = 0;
198 u64 extent_end = 0;
199 u64 last_end = args->start;
200 int del_nr = 0;
201 int del_slot = 0;
202 int extent_type;
203 int recow;
204 int ret;
205 int modify_tree = -1;
206 int update_refs;
207 int found = 0;
208 struct btrfs_path *path = args->path;
209
210 args->bytes_found = 0;
211 args->extent_inserted = false;
212
213 /* Must always have a path if ->replace_extent is true */
214 ASSERT(!(args->replace_extent && !args->path));
215
216 if (!path) {
217 path = btrfs_alloc_path();
218 if (!path) {
219 ret = -ENOMEM;
220 goto out;
221 }
222 }
223
224 if (args->drop_cache)
225 btrfs_drop_extent_map_range(inode, args->start, args->end - 1, false);
226
227 if (data_race(args->start >= inode->disk_i_size) && !args->replace_extent)
228 modify_tree = 0;
229
230 update_refs = (btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID);
231 while (1) {
232 recow = 0;
233 ret = btrfs_lookup_file_extent(trans, root, path, ino,
234 search_start, modify_tree);
235 if (ret < 0)
236 break;
237 if (ret > 0 && path->slots[0] > 0 && search_start == args->start) {
238 leaf = path->nodes[0];
239 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
240 if (key.objectid == ino &&
241 key.type == BTRFS_EXTENT_DATA_KEY)
242 path->slots[0]--;
243 }
244 ret = 0;
245next_slot:
246 leaf = path->nodes[0];
247 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
248 BUG_ON(del_nr > 0);
249 ret = btrfs_next_leaf(root, path);
250 if (ret < 0)
251 break;
252 if (ret > 0) {
253 ret = 0;
254 break;
255 }
256 leaf = path->nodes[0];
257 recow = 1;
258 }
259
260 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
261
262 if (key.objectid > ino)
263 break;
264 if (WARN_ON_ONCE(key.objectid < ino) ||
265 key.type < BTRFS_EXTENT_DATA_KEY) {
266 ASSERT(del_nr == 0);
267 path->slots[0]++;
268 goto next_slot;
269 }
270 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= args->end)
271 break;
272
273 fi = btrfs_item_ptr(leaf, path->slots[0],
274 struct btrfs_file_extent_item);
275 extent_type = btrfs_file_extent_type(leaf, fi);
276
277 if (extent_type == BTRFS_FILE_EXTENT_REG ||
278 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
279 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
280 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
281 extent_offset = btrfs_file_extent_offset(leaf, fi);
282 extent_end = key.offset +
283 btrfs_file_extent_num_bytes(leaf, fi);
284 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
285 extent_end = key.offset +
286 btrfs_file_extent_ram_bytes(leaf, fi);
287 } else {
288 /* can't happen */
289 BUG();
290 }
291
292 /*
293 * Don't skip extent items representing 0 byte lengths. They
294 * used to be created (bug) if while punching holes we hit
295 * -ENOSPC condition. So if we find one here, just ensure we
296 * delete it, otherwise we would insert a new file extent item
297 * with the same key (offset) as that 0 bytes length file
298 * extent item in the call to setup_items_for_insert() later
299 * in this function.
300 */
301 if (extent_end == key.offset && extent_end >= search_start) {
302 last_end = extent_end;
303 goto delete_extent_item;
304 }
305
306 if (extent_end <= search_start) {
307 path->slots[0]++;
308 goto next_slot;
309 }
310
311 found = 1;
312 search_start = max(key.offset, args->start);
313 if (recow || !modify_tree) {
314 modify_tree = -1;
315 btrfs_release_path(path);
316 continue;
317 }
318
319 /*
320 * | - range to drop - |
321 * | -------- extent -------- |
322 */
323 if (args->start > key.offset && args->end < extent_end) {
324 BUG_ON(del_nr > 0);
325 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
326 ret = -EOPNOTSUPP;
327 break;
328 }
329
330 memcpy(&new_key, &key, sizeof(new_key));
331 new_key.offset = args->start;
332 ret = btrfs_duplicate_item(trans, root, path,
333 &new_key);
334 if (ret == -EAGAIN) {
335 btrfs_release_path(path);
336 continue;
337 }
338 if (ret < 0)
339 break;
340
341 leaf = path->nodes[0];
342 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
343 struct btrfs_file_extent_item);
344 btrfs_set_file_extent_num_bytes(leaf, fi,
345 args->start - key.offset);
346
347 fi = btrfs_item_ptr(leaf, path->slots[0],
348 struct btrfs_file_extent_item);
349
350 extent_offset += args->start - key.offset;
351 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
352 btrfs_set_file_extent_num_bytes(leaf, fi,
353 extent_end - args->start);
354 btrfs_mark_buffer_dirty(trans, leaf);
355
356 if (update_refs && disk_bytenr > 0) {
357 struct btrfs_ref ref = {
358 .action = BTRFS_ADD_DELAYED_REF,
359 .bytenr = disk_bytenr,
360 .num_bytes = num_bytes,
361 .parent = 0,
362 .owning_root = btrfs_root_id(root),
363 .ref_root = btrfs_root_id(root),
364 };
365 btrfs_init_data_ref(&ref, new_key.objectid,
366 args->start - extent_offset,
367 0, false);
368 ret = btrfs_inc_extent_ref(trans, &ref);
369 if (ret) {
370 btrfs_abort_transaction(trans, ret);
371 break;
372 }
373 }
374 key.offset = args->start;
375 }
376 /*
377 * From here on out we will have actually dropped something, so
378 * last_end can be updated.
379 */
380 last_end = extent_end;
381
382 /*
383 * | ---- range to drop ----- |
384 * | -------- extent -------- |
385 */
386 if (args->start <= key.offset && args->end < extent_end) {
387 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
388 ret = -EOPNOTSUPP;
389 break;
390 }
391
392 memcpy(&new_key, &key, sizeof(new_key));
393 new_key.offset = args->end;
394 btrfs_set_item_key_safe(trans, path, &new_key);
395
396 extent_offset += args->end - key.offset;
397 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
398 btrfs_set_file_extent_num_bytes(leaf, fi,
399 extent_end - args->end);
400 btrfs_mark_buffer_dirty(trans, leaf);
401 if (update_refs && disk_bytenr > 0)
402 args->bytes_found += args->end - key.offset;
403 break;
404 }
405
406 search_start = extent_end;
407 /*
408 * | ---- range to drop ----- |
409 * | -------- extent -------- |
410 */
411 if (args->start > key.offset && args->end >= extent_end) {
412 BUG_ON(del_nr > 0);
413 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
414 ret = -EOPNOTSUPP;
415 break;
416 }
417
418 btrfs_set_file_extent_num_bytes(leaf, fi,
419 args->start - key.offset);
420 btrfs_mark_buffer_dirty(trans, leaf);
421 if (update_refs && disk_bytenr > 0)
422 args->bytes_found += extent_end - args->start;
423 if (args->end == extent_end)
424 break;
425
426 path->slots[0]++;
427 goto next_slot;
428 }
429
430 /*
431 * | ---- range to drop ----- |
432 * | ------ extent ------ |
433 */
434 if (args->start <= key.offset && args->end >= extent_end) {
435delete_extent_item:
436 if (del_nr == 0) {
437 del_slot = path->slots[0];
438 del_nr = 1;
439 } else {
440 BUG_ON(del_slot + del_nr != path->slots[0]);
441 del_nr++;
442 }
443
444 if (update_refs &&
445 extent_type == BTRFS_FILE_EXTENT_INLINE) {
446 args->bytes_found += extent_end - key.offset;
447 extent_end = ALIGN(extent_end,
448 fs_info->sectorsize);
449 } else if (update_refs && disk_bytenr > 0) {
450 struct btrfs_ref ref = {
451 .action = BTRFS_DROP_DELAYED_REF,
452 .bytenr = disk_bytenr,
453 .num_bytes = num_bytes,
454 .parent = 0,
455 .owning_root = btrfs_root_id(root),
456 .ref_root = btrfs_root_id(root),
457 };
458 btrfs_init_data_ref(&ref, key.objectid,
459 key.offset - extent_offset,
460 0, false);
461 ret = btrfs_free_extent(trans, &ref);
462 if (ret) {
463 btrfs_abort_transaction(trans, ret);
464 break;
465 }
466 args->bytes_found += extent_end - key.offset;
467 }
468
469 if (args->end == extent_end)
470 break;
471
472 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
473 path->slots[0]++;
474 goto next_slot;
475 }
476
477 ret = btrfs_del_items(trans, root, path, del_slot,
478 del_nr);
479 if (ret) {
480 btrfs_abort_transaction(trans, ret);
481 break;
482 }
483
484 del_nr = 0;
485 del_slot = 0;
486
487 btrfs_release_path(path);
488 continue;
489 }
490
491 BUG();
492 }
493
494 if (!ret && del_nr > 0) {
495 /*
496 * Set path->slots[0] to first slot, so that after the delete
497 * if items are move off from our leaf to its immediate left or
498 * right neighbor leafs, we end up with a correct and adjusted
499 * path->slots[0] for our insertion (if args->replace_extent).
500 */
501 path->slots[0] = del_slot;
502 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
503 if (ret)
504 btrfs_abort_transaction(trans, ret);
505 }
506
507 leaf = path->nodes[0];
508 /*
509 * If btrfs_del_items() was called, it might have deleted a leaf, in
510 * which case it unlocked our path, so check path->locks[0] matches a
511 * write lock.
512 */
513 if (!ret && args->replace_extent &&
514 path->locks[0] == BTRFS_WRITE_LOCK &&
515 btrfs_leaf_free_space(leaf) >=
516 sizeof(struct btrfs_item) + args->extent_item_size) {
517
518 key.objectid = ino;
519 key.type = BTRFS_EXTENT_DATA_KEY;
520 key.offset = args->start;
521 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
522 struct btrfs_key slot_key;
523
524 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
525 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
526 path->slots[0]++;
527 }
528 btrfs_setup_item_for_insert(trans, root, path, &key,
529 args->extent_item_size);
530 args->extent_inserted = true;
531 }
532
533 if (!args->path)
534 btrfs_free_path(path);
535 else if (!args->extent_inserted)
536 btrfs_release_path(path);
537out:
538 args->drop_end = found ? min(args->end, last_end) : args->end;
539
540 return ret;
541}
542
543static int extent_mergeable(struct extent_buffer *leaf, int slot,
544 u64 objectid, u64 bytenr, u64 orig_offset,
545 u64 *start, u64 *end)
546{
547 struct btrfs_file_extent_item *fi;
548 struct btrfs_key key;
549 u64 extent_end;
550
551 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
552 return 0;
553
554 btrfs_item_key_to_cpu(leaf, &key, slot);
555 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
556 return 0;
557
558 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
559 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
560 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
561 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
562 btrfs_file_extent_compression(leaf, fi) ||
563 btrfs_file_extent_encryption(leaf, fi) ||
564 btrfs_file_extent_other_encoding(leaf, fi))
565 return 0;
566
567 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
568 if ((*start && *start != key.offset) || (*end && *end != extent_end))
569 return 0;
570
571 *start = key.offset;
572 *end = extent_end;
573 return 1;
574}
575
576/*
577 * Mark extent in the range start - end as written.
578 *
579 * This changes extent type from 'pre-allocated' to 'regular'. If only
580 * part of extent is marked as written, the extent will be split into
581 * two or three.
582 */
583int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
584 struct btrfs_inode *inode, u64 start, u64 end)
585{
586 struct btrfs_root *root = inode->root;
587 struct extent_buffer *leaf;
588 struct btrfs_path *path;
589 struct btrfs_file_extent_item *fi;
590 struct btrfs_ref ref = { 0 };
591 struct btrfs_key key;
592 struct btrfs_key new_key;
593 u64 bytenr;
594 u64 num_bytes;
595 u64 extent_end;
596 u64 orig_offset;
597 u64 other_start;
598 u64 other_end;
599 u64 split;
600 int del_nr = 0;
601 int del_slot = 0;
602 int recow;
603 int ret = 0;
604 u64 ino = btrfs_ino(inode);
605
606 path = btrfs_alloc_path();
607 if (!path)
608 return -ENOMEM;
609again:
610 recow = 0;
611 split = start;
612 key.objectid = ino;
613 key.type = BTRFS_EXTENT_DATA_KEY;
614 key.offset = split;
615
616 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
617 if (ret < 0)
618 goto out;
619 if (ret > 0 && path->slots[0] > 0)
620 path->slots[0]--;
621
622 leaf = path->nodes[0];
623 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
624 if (key.objectid != ino ||
625 key.type != BTRFS_EXTENT_DATA_KEY) {
626 ret = -EINVAL;
627 btrfs_abort_transaction(trans, ret);
628 goto out;
629 }
630 fi = btrfs_item_ptr(leaf, path->slots[0],
631 struct btrfs_file_extent_item);
632 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
633 ret = -EINVAL;
634 btrfs_abort_transaction(trans, ret);
635 goto out;
636 }
637 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
638 if (key.offset > start || extent_end < end) {
639 ret = -EINVAL;
640 btrfs_abort_transaction(trans, ret);
641 goto out;
642 }
643
644 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
645 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
646 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
647 memcpy(&new_key, &key, sizeof(new_key));
648
649 if (start == key.offset && end < extent_end) {
650 other_start = 0;
651 other_end = start;
652 if (extent_mergeable(leaf, path->slots[0] - 1,
653 ino, bytenr, orig_offset,
654 &other_start, &other_end)) {
655 new_key.offset = end;
656 btrfs_set_item_key_safe(trans, path, &new_key);
657 fi = btrfs_item_ptr(leaf, path->slots[0],
658 struct btrfs_file_extent_item);
659 btrfs_set_file_extent_generation(leaf, fi,
660 trans->transid);
661 btrfs_set_file_extent_num_bytes(leaf, fi,
662 extent_end - end);
663 btrfs_set_file_extent_offset(leaf, fi,
664 end - orig_offset);
665 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
666 struct btrfs_file_extent_item);
667 btrfs_set_file_extent_generation(leaf, fi,
668 trans->transid);
669 btrfs_set_file_extent_num_bytes(leaf, fi,
670 end - other_start);
671 btrfs_mark_buffer_dirty(trans, leaf);
672 goto out;
673 }
674 }
675
676 if (start > key.offset && end == extent_end) {
677 other_start = end;
678 other_end = 0;
679 if (extent_mergeable(leaf, path->slots[0] + 1,
680 ino, bytenr, orig_offset,
681 &other_start, &other_end)) {
682 fi = btrfs_item_ptr(leaf, path->slots[0],
683 struct btrfs_file_extent_item);
684 btrfs_set_file_extent_num_bytes(leaf, fi,
685 start - key.offset);
686 btrfs_set_file_extent_generation(leaf, fi,
687 trans->transid);
688 path->slots[0]++;
689 new_key.offset = start;
690 btrfs_set_item_key_safe(trans, path, &new_key);
691
692 fi = btrfs_item_ptr(leaf, path->slots[0],
693 struct btrfs_file_extent_item);
694 btrfs_set_file_extent_generation(leaf, fi,
695 trans->transid);
696 btrfs_set_file_extent_num_bytes(leaf, fi,
697 other_end - start);
698 btrfs_set_file_extent_offset(leaf, fi,
699 start - orig_offset);
700 btrfs_mark_buffer_dirty(trans, leaf);
701 goto out;
702 }
703 }
704
705 while (start > key.offset || end < extent_end) {
706 if (key.offset == start)
707 split = end;
708
709 new_key.offset = split;
710 ret = btrfs_duplicate_item(trans, root, path, &new_key);
711 if (ret == -EAGAIN) {
712 btrfs_release_path(path);
713 goto again;
714 }
715 if (ret < 0) {
716 btrfs_abort_transaction(trans, ret);
717 goto out;
718 }
719
720 leaf = path->nodes[0];
721 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
722 struct btrfs_file_extent_item);
723 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
724 btrfs_set_file_extent_num_bytes(leaf, fi,
725 split - key.offset);
726
727 fi = btrfs_item_ptr(leaf, path->slots[0],
728 struct btrfs_file_extent_item);
729
730 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
731 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
732 btrfs_set_file_extent_num_bytes(leaf, fi,
733 extent_end - split);
734 btrfs_mark_buffer_dirty(trans, leaf);
735
736 ref.action = BTRFS_ADD_DELAYED_REF;
737 ref.bytenr = bytenr;
738 ref.num_bytes = num_bytes;
739 ref.parent = 0;
740 ref.owning_root = btrfs_root_id(root);
741 ref.ref_root = btrfs_root_id(root);
742 btrfs_init_data_ref(&ref, ino, orig_offset, 0, false);
743 ret = btrfs_inc_extent_ref(trans, &ref);
744 if (ret) {
745 btrfs_abort_transaction(trans, ret);
746 goto out;
747 }
748
749 if (split == start) {
750 key.offset = start;
751 } else {
752 if (start != key.offset) {
753 ret = -EINVAL;
754 btrfs_abort_transaction(trans, ret);
755 goto out;
756 }
757 path->slots[0]--;
758 extent_end = end;
759 }
760 recow = 1;
761 }
762
763 other_start = end;
764 other_end = 0;
765
766 ref.action = BTRFS_DROP_DELAYED_REF;
767 ref.bytenr = bytenr;
768 ref.num_bytes = num_bytes;
769 ref.parent = 0;
770 ref.owning_root = btrfs_root_id(root);
771 ref.ref_root = btrfs_root_id(root);
772 btrfs_init_data_ref(&ref, ino, orig_offset, 0, false);
773 if (extent_mergeable(leaf, path->slots[0] + 1,
774 ino, bytenr, orig_offset,
775 &other_start, &other_end)) {
776 if (recow) {
777 btrfs_release_path(path);
778 goto again;
779 }
780 extent_end = other_end;
781 del_slot = path->slots[0] + 1;
782 del_nr++;
783 ret = btrfs_free_extent(trans, &ref);
784 if (ret) {
785 btrfs_abort_transaction(trans, ret);
786 goto out;
787 }
788 }
789 other_start = 0;
790 other_end = start;
791 if (extent_mergeable(leaf, path->slots[0] - 1,
792 ino, bytenr, orig_offset,
793 &other_start, &other_end)) {
794 if (recow) {
795 btrfs_release_path(path);
796 goto again;
797 }
798 key.offset = other_start;
799 del_slot = path->slots[0];
800 del_nr++;
801 ret = btrfs_free_extent(trans, &ref);
802 if (ret) {
803 btrfs_abort_transaction(trans, ret);
804 goto out;
805 }
806 }
807 if (del_nr == 0) {
808 fi = btrfs_item_ptr(leaf, path->slots[0],
809 struct btrfs_file_extent_item);
810 btrfs_set_file_extent_type(leaf, fi,
811 BTRFS_FILE_EXTENT_REG);
812 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
813 btrfs_mark_buffer_dirty(trans, leaf);
814 } else {
815 fi = btrfs_item_ptr(leaf, del_slot - 1,
816 struct btrfs_file_extent_item);
817 btrfs_set_file_extent_type(leaf, fi,
818 BTRFS_FILE_EXTENT_REG);
819 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
820 btrfs_set_file_extent_num_bytes(leaf, fi,
821 extent_end - key.offset);
822 btrfs_mark_buffer_dirty(trans, leaf);
823
824 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
825 if (ret < 0) {
826 btrfs_abort_transaction(trans, ret);
827 goto out;
828 }
829 }
830out:
831 btrfs_free_path(path);
832 return ret;
833}
834
835/*
836 * On error return an unlocked folio and the error value
837 * On success return a locked folio and 0
838 */
839static int prepare_uptodate_folio(struct inode *inode, struct folio *folio, u64 pos,
840 u64 len, bool force_uptodate)
841{
842 u64 clamp_start = max_t(u64, pos, folio_pos(folio));
843 u64 clamp_end = min_t(u64, pos + len, folio_pos(folio) + folio_size(folio));
844 int ret = 0;
845
846 if (folio_test_uptodate(folio))
847 return 0;
848
849 if (!force_uptodate &&
850 IS_ALIGNED(clamp_start, PAGE_SIZE) &&
851 IS_ALIGNED(clamp_end, PAGE_SIZE))
852 return 0;
853
854 ret = btrfs_read_folio(NULL, folio);
855 if (ret)
856 return ret;
857 folio_lock(folio);
858 if (!folio_test_uptodate(folio)) {
859 folio_unlock(folio);
860 return -EIO;
861 }
862
863 /*
864 * Since btrfs_read_folio() will unlock the folio before it returns,
865 * there is a window where btrfs_release_folio() can be called to
866 * release the page. Here we check both inode mapping and page
867 * private to make sure the page was not released.
868 *
869 * The private flag check is essential for subpage as we need to store
870 * extra bitmap using folio private.
871 */
872 if (folio->mapping != inode->i_mapping || !folio_test_private(folio)) {
873 folio_unlock(folio);
874 return -EAGAIN;
875 }
876 return 0;
877}
878
879static gfp_t get_prepare_gfp_flags(struct inode *inode, bool nowait)
880{
881 gfp_t gfp;
882
883 gfp = btrfs_alloc_write_mask(inode->i_mapping);
884 if (nowait) {
885 gfp &= ~__GFP_DIRECT_RECLAIM;
886 gfp |= GFP_NOWAIT;
887 }
888
889 return gfp;
890}
891
892/*
893 * Get folio into the page cache and lock it.
894 */
895static noinline int prepare_one_folio(struct inode *inode, struct folio **folio_ret,
896 loff_t pos, size_t write_bytes,
897 bool force_uptodate, bool nowait)
898{
899 unsigned long index = pos >> PAGE_SHIFT;
900 gfp_t mask = get_prepare_gfp_flags(inode, nowait);
901 fgf_t fgp_flags = (nowait ? FGP_WRITEBEGIN | FGP_NOWAIT : FGP_WRITEBEGIN);
902 struct folio *folio;
903 int ret = 0;
904
905again:
906 folio = __filemap_get_folio(inode->i_mapping, index, fgp_flags, mask);
907 if (IS_ERR(folio)) {
908 if (nowait)
909 ret = -EAGAIN;
910 else
911 ret = PTR_ERR(folio);
912 return ret;
913 }
914 folio_wait_writeback(folio);
915 /* Only support page sized folio yet. */
916 ASSERT(folio_order(folio) == 0);
917 ret = set_folio_extent_mapped(folio);
918 if (ret < 0) {
919 folio_unlock(folio);
920 folio_put(folio);
921 return ret;
922 }
923 ret = prepare_uptodate_folio(inode, folio, pos, write_bytes, force_uptodate);
924 if (ret) {
925 /* The folio is already unlocked. */
926 folio_put(folio);
927 if (!nowait && ret == -EAGAIN) {
928 ret = 0;
929 goto again;
930 }
931 return ret;
932 }
933 *folio_ret = folio;
934 return 0;
935}
936
937/*
938 * Locks the extent and properly waits for data=ordered extents to finish
939 * before allowing the folios to be modified if need.
940 *
941 * Return:
942 * 1 - the extent is locked
943 * 0 - the extent is not locked, and everything is OK
944 * -EAGAIN - need to prepare the folios again
945 */
946static noinline int
947lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct folio *folio,
948 loff_t pos, size_t write_bytes,
949 u64 *lockstart, u64 *lockend, bool nowait,
950 struct extent_state **cached_state)
951{
952 struct btrfs_fs_info *fs_info = inode->root->fs_info;
953 u64 start_pos;
954 u64 last_pos;
955 int ret = 0;
956
957 start_pos = round_down(pos, fs_info->sectorsize);
958 last_pos = round_up(pos + write_bytes, fs_info->sectorsize) - 1;
959
960 if (start_pos < inode->vfs_inode.i_size) {
961 struct btrfs_ordered_extent *ordered;
962
963 if (nowait) {
964 if (!try_lock_extent(&inode->io_tree, start_pos, last_pos,
965 cached_state)) {
966 folio_unlock(folio);
967 folio_put(folio);
968 return -EAGAIN;
969 }
970 } else {
971 lock_extent(&inode->io_tree, start_pos, last_pos, cached_state);
972 }
973
974 ordered = btrfs_lookup_ordered_range(inode, start_pos,
975 last_pos - start_pos + 1);
976 if (ordered &&
977 ordered->file_offset + ordered->num_bytes > start_pos &&
978 ordered->file_offset <= last_pos) {
979 unlock_extent(&inode->io_tree, start_pos, last_pos,
980 cached_state);
981 folio_unlock(folio);
982 folio_put(folio);
983 btrfs_start_ordered_extent(ordered);
984 btrfs_put_ordered_extent(ordered);
985 return -EAGAIN;
986 }
987 if (ordered)
988 btrfs_put_ordered_extent(ordered);
989
990 *lockstart = start_pos;
991 *lockend = last_pos;
992 ret = 1;
993 }
994
995 /*
996 * We should be called after prepare_one_folio() which should have locked
997 * all pages in the range.
998 */
999 WARN_ON(!folio_test_locked(folio));
1000
1001 return ret;
1002}
1003
1004/*
1005 * Check if we can do nocow write into the range [@pos, @pos + @write_bytes)
1006 *
1007 * @pos: File offset.
1008 * @write_bytes: The length to write, will be updated to the nocow writeable
1009 * range.
1010 *
1011 * This function will flush ordered extents in the range to ensure proper
1012 * nocow checks.
1013 *
1014 * Return:
1015 * > 0 If we can nocow, and updates @write_bytes.
1016 * 0 If we can't do a nocow write.
1017 * -EAGAIN If we can't do a nocow write because snapshoting of the inode's
1018 * root is in progress.
1019 * < 0 If an error happened.
1020 *
1021 * NOTE: Callers need to call btrfs_check_nocow_unlock() if we return > 0.
1022 */
1023int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
1024 size_t *write_bytes, bool nowait)
1025{
1026 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1027 struct btrfs_root *root = inode->root;
1028 struct extent_state *cached_state = NULL;
1029 u64 lockstart, lockend;
1030 u64 num_bytes;
1031 int ret;
1032
1033 if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
1034 return 0;
1035
1036 if (!btrfs_drew_try_write_lock(&root->snapshot_lock))
1037 return -EAGAIN;
1038
1039 lockstart = round_down(pos, fs_info->sectorsize);
1040 lockend = round_up(pos + *write_bytes,
1041 fs_info->sectorsize) - 1;
1042 num_bytes = lockend - lockstart + 1;
1043
1044 if (nowait) {
1045 if (!btrfs_try_lock_ordered_range(inode, lockstart, lockend,
1046 &cached_state)) {
1047 btrfs_drew_write_unlock(&root->snapshot_lock);
1048 return -EAGAIN;
1049 }
1050 } else {
1051 btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend,
1052 &cached_state);
1053 }
1054 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1055 NULL, nowait, false);
1056 if (ret <= 0)
1057 btrfs_drew_write_unlock(&root->snapshot_lock);
1058 else
1059 *write_bytes = min_t(size_t, *write_bytes ,
1060 num_bytes - pos + lockstart);
1061 unlock_extent(&inode->io_tree, lockstart, lockend, &cached_state);
1062
1063 return ret;
1064}
1065
1066void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
1067{
1068 btrfs_drew_write_unlock(&inode->root->snapshot_lock);
1069}
1070
1071int btrfs_write_check(struct kiocb *iocb, size_t count)
1072{
1073 struct file *file = iocb->ki_filp;
1074 struct inode *inode = file_inode(file);
1075 struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
1076 loff_t pos = iocb->ki_pos;
1077 int ret;
1078 loff_t oldsize;
1079
1080 /*
1081 * Quickly bail out on NOWAIT writes if we don't have the nodatacow or
1082 * prealloc flags, as without those flags we always have to COW. We will
1083 * later check if we can really COW into the target range (using
1084 * can_nocow_extent() at btrfs_get_blocks_direct_write()).
1085 */
1086 if ((iocb->ki_flags & IOCB_NOWAIT) &&
1087 !(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
1088 return -EAGAIN;
1089
1090 ret = file_remove_privs(file);
1091 if (ret)
1092 return ret;
1093
1094 /*
1095 * We reserve space for updating the inode when we reserve space for the
1096 * extent we are going to write, so we will enospc out there. We don't
1097 * need to start yet another transaction to update the inode as we will
1098 * update the inode when we finish writing whatever data we write.
1099 */
1100 if (!IS_NOCMTIME(inode)) {
1101 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1102 inode_inc_iversion(inode);
1103 }
1104
1105 oldsize = i_size_read(inode);
1106 if (pos > oldsize) {
1107 /* Expand hole size to cover write data, preventing empty gap */
1108 loff_t end_pos = round_up(pos + count, fs_info->sectorsize);
1109
1110 ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos);
1111 if (ret)
1112 return ret;
1113 }
1114
1115 return 0;
1116}
1117
1118ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i)
1119{
1120 struct file *file = iocb->ki_filp;
1121 loff_t pos;
1122 struct inode *inode = file_inode(file);
1123 struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
1124 struct extent_changeset *data_reserved = NULL;
1125 u64 release_bytes = 0;
1126 u64 lockstart;
1127 u64 lockend;
1128 size_t num_written = 0;
1129 ssize_t ret;
1130 loff_t old_isize;
1131 unsigned int ilock_flags = 0;
1132 const bool nowait = (iocb->ki_flags & IOCB_NOWAIT);
1133 unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0);
1134 bool only_release_metadata = false;
1135
1136 if (nowait)
1137 ilock_flags |= BTRFS_ILOCK_TRY;
1138
1139 ret = btrfs_inode_lock(BTRFS_I(inode), ilock_flags);
1140 if (ret < 0)
1141 return ret;
1142
1143 /*
1144 * We can only trust the isize with inode lock held, or it can race with
1145 * other buffered writes and cause incorrect call of
1146 * pagecache_isize_extended() to overwrite existing data.
1147 */
1148 old_isize = i_size_read(inode);
1149
1150 ret = generic_write_checks(iocb, i);
1151 if (ret <= 0)
1152 goto out;
1153
1154 ret = btrfs_write_check(iocb, ret);
1155 if (ret < 0)
1156 goto out;
1157
1158 pos = iocb->ki_pos;
1159 while (iov_iter_count(i) > 0) {
1160 struct extent_state *cached_state = NULL;
1161 size_t offset = offset_in_page(pos);
1162 size_t sector_offset;
1163 size_t write_bytes = min(iov_iter_count(i), PAGE_SIZE - offset);
1164 size_t reserve_bytes;
1165 size_t copied;
1166 size_t dirty_sectors;
1167 size_t num_sectors;
1168 struct folio *folio = NULL;
1169 int extents_locked;
1170 bool force_page_uptodate = false;
1171
1172 /*
1173 * Fault pages before locking them in prepare_one_folio()
1174 * to avoid recursive lock
1175 */
1176 if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) {
1177 ret = -EFAULT;
1178 break;
1179 }
1180
1181 only_release_metadata = false;
1182 sector_offset = pos & (fs_info->sectorsize - 1);
1183
1184 extent_changeset_release(data_reserved);
1185 ret = btrfs_check_data_free_space(BTRFS_I(inode),
1186 &data_reserved, pos,
1187 write_bytes, nowait);
1188 if (ret < 0) {
1189 int can_nocow;
1190
1191 if (nowait && (ret == -ENOSPC || ret == -EAGAIN)) {
1192 ret = -EAGAIN;
1193 break;
1194 }
1195
1196 /*
1197 * If we don't have to COW at the offset, reserve
1198 * metadata only. write_bytes may get smaller than
1199 * requested here.
1200 */
1201 can_nocow = btrfs_check_nocow_lock(BTRFS_I(inode), pos,
1202 &write_bytes, nowait);
1203 if (can_nocow < 0)
1204 ret = can_nocow;
1205 if (can_nocow > 0)
1206 ret = 0;
1207 if (ret)
1208 break;
1209 only_release_metadata = true;
1210 }
1211
1212 reserve_bytes = round_up(write_bytes + sector_offset,
1213 fs_info->sectorsize);
1214 WARN_ON(reserve_bytes == 0);
1215 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1216 reserve_bytes,
1217 reserve_bytes, nowait);
1218 if (ret) {
1219 if (!only_release_metadata)
1220 btrfs_free_reserved_data_space(BTRFS_I(inode),
1221 data_reserved, pos,
1222 write_bytes);
1223 else
1224 btrfs_check_nocow_unlock(BTRFS_I(inode));
1225
1226 if (nowait && ret == -ENOSPC)
1227 ret = -EAGAIN;
1228 break;
1229 }
1230
1231 release_bytes = reserve_bytes;
1232again:
1233 ret = balance_dirty_pages_ratelimited_flags(inode->i_mapping, bdp_flags);
1234 if (ret) {
1235 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1236 break;
1237 }
1238
1239 ret = prepare_one_folio(inode, &folio, pos, write_bytes,
1240 force_page_uptodate, false);
1241 if (ret) {
1242 btrfs_delalloc_release_extents(BTRFS_I(inode),
1243 reserve_bytes);
1244 break;
1245 }
1246
1247 extents_locked = lock_and_cleanup_extent_if_need(BTRFS_I(inode),
1248 folio, pos, write_bytes, &lockstart,
1249 &lockend, nowait, &cached_state);
1250 if (extents_locked < 0) {
1251 if (!nowait && extents_locked == -EAGAIN)
1252 goto again;
1253
1254 btrfs_delalloc_release_extents(BTRFS_I(inode),
1255 reserve_bytes);
1256 ret = extents_locked;
1257 break;
1258 }
1259
1260 copied = btrfs_copy_from_user(pos, write_bytes, folio, i);
1261
1262 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1263 dirty_sectors = round_up(copied + sector_offset,
1264 fs_info->sectorsize);
1265 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1266
1267 if (copied == 0) {
1268 force_page_uptodate = true;
1269 dirty_sectors = 0;
1270 } else {
1271 force_page_uptodate = false;
1272 }
1273
1274 if (num_sectors > dirty_sectors) {
1275 /* release everything except the sectors we dirtied */
1276 release_bytes -= dirty_sectors << fs_info->sectorsize_bits;
1277 if (only_release_metadata) {
1278 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1279 release_bytes, true);
1280 } else {
1281 u64 release_start = round_up(pos + copied,
1282 fs_info->sectorsize);
1283 btrfs_delalloc_release_space(BTRFS_I(inode),
1284 data_reserved, release_start,
1285 release_bytes, true);
1286 }
1287 }
1288
1289 release_bytes = round_up(copied + sector_offset,
1290 fs_info->sectorsize);
1291
1292 ret = btrfs_dirty_folio(BTRFS_I(inode), folio, pos, copied,
1293 &cached_state, only_release_metadata);
1294
1295 /*
1296 * If we have not locked the extent range, because the range's
1297 * start offset is >= i_size, we might still have a non-NULL
1298 * cached extent state, acquired while marking the extent range
1299 * as delalloc through btrfs_dirty_page(). Therefore free any
1300 * possible cached extent state to avoid a memory leak.
1301 */
1302 if (extents_locked)
1303 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart,
1304 lockend, &cached_state);
1305 else
1306 free_extent_state(cached_state);
1307
1308 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1309 if (ret) {
1310 btrfs_drop_folio(fs_info, folio, pos, copied);
1311 break;
1312 }
1313
1314 release_bytes = 0;
1315 if (only_release_metadata)
1316 btrfs_check_nocow_unlock(BTRFS_I(inode));
1317
1318 btrfs_drop_folio(fs_info, folio, pos, copied);
1319
1320 cond_resched();
1321
1322 pos += copied;
1323 num_written += copied;
1324 }
1325
1326 if (release_bytes) {
1327 if (only_release_metadata) {
1328 btrfs_check_nocow_unlock(BTRFS_I(inode));
1329 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1330 release_bytes, true);
1331 } else {
1332 btrfs_delalloc_release_space(BTRFS_I(inode),
1333 data_reserved,
1334 round_down(pos, fs_info->sectorsize),
1335 release_bytes, true);
1336 }
1337 }
1338
1339 extent_changeset_free(data_reserved);
1340 if (num_written > 0) {
1341 pagecache_isize_extended(inode, old_isize, iocb->ki_pos);
1342 iocb->ki_pos += num_written;
1343 }
1344out:
1345 btrfs_inode_unlock(BTRFS_I(inode), ilock_flags);
1346 return num_written ? num_written : ret;
1347}
1348
1349static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from,
1350 const struct btrfs_ioctl_encoded_io_args *encoded)
1351{
1352 struct file *file = iocb->ki_filp;
1353 struct inode *inode = file_inode(file);
1354 loff_t count;
1355 ssize_t ret;
1356
1357 btrfs_inode_lock(BTRFS_I(inode), 0);
1358 count = encoded->len;
1359 ret = generic_write_checks_count(iocb, &count);
1360 if (ret == 0 && count != encoded->len) {
1361 /*
1362 * The write got truncated by generic_write_checks_count(). We
1363 * can't do a partial encoded write.
1364 */
1365 ret = -EFBIG;
1366 }
1367 if (ret || encoded->len == 0)
1368 goto out;
1369
1370 ret = btrfs_write_check(iocb, encoded->len);
1371 if (ret < 0)
1372 goto out;
1373
1374 ret = btrfs_do_encoded_write(iocb, from, encoded);
1375out:
1376 btrfs_inode_unlock(BTRFS_I(inode), 0);
1377 return ret;
1378}
1379
1380ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from,
1381 const struct btrfs_ioctl_encoded_io_args *encoded)
1382{
1383 struct file *file = iocb->ki_filp;
1384 struct btrfs_inode *inode = BTRFS_I(file_inode(file));
1385 ssize_t num_written, num_sync;
1386
1387 /*
1388 * If the fs flips readonly due to some impossible error, although we
1389 * have opened a file as writable, we have to stop this write operation
1390 * to ensure consistency.
1391 */
1392 if (BTRFS_FS_ERROR(inode->root->fs_info))
1393 return -EROFS;
1394
1395 if (encoded && (iocb->ki_flags & IOCB_NOWAIT))
1396 return -EOPNOTSUPP;
1397
1398 if (encoded) {
1399 num_written = btrfs_encoded_write(iocb, from, encoded);
1400 num_sync = encoded->len;
1401 } else if (iocb->ki_flags & IOCB_DIRECT) {
1402 num_written = btrfs_direct_write(iocb, from);
1403 num_sync = num_written;
1404 } else {
1405 num_written = btrfs_buffered_write(iocb, from);
1406 num_sync = num_written;
1407 }
1408
1409 btrfs_set_inode_last_sub_trans(inode);
1410
1411 if (num_sync > 0) {
1412 num_sync = generic_write_sync(iocb, num_sync);
1413 if (num_sync < 0)
1414 num_written = num_sync;
1415 }
1416
1417 return num_written;
1418}
1419
1420static ssize_t btrfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
1421{
1422 return btrfs_do_write_iter(iocb, from, NULL);
1423}
1424
1425int btrfs_release_file(struct inode *inode, struct file *filp)
1426{
1427 struct btrfs_file_private *private = filp->private_data;
1428
1429 if (private) {
1430 kfree(private->filldir_buf);
1431 free_extent_state(private->llseek_cached_state);
1432 kfree(private);
1433 filp->private_data = NULL;
1434 }
1435
1436 /*
1437 * Set by setattr when we are about to truncate a file from a non-zero
1438 * size to a zero size. This tries to flush down new bytes that may
1439 * have been written if the application were using truncate to replace
1440 * a file in place.
1441 */
1442 if (test_and_clear_bit(BTRFS_INODE_FLUSH_ON_CLOSE,
1443 &BTRFS_I(inode)->runtime_flags))
1444 filemap_flush(inode->i_mapping);
1445 return 0;
1446}
1447
1448static int start_ordered_ops(struct btrfs_inode *inode, loff_t start, loff_t end)
1449{
1450 int ret;
1451 struct blk_plug plug;
1452
1453 /*
1454 * This is only called in fsync, which would do synchronous writes, so
1455 * a plug can merge adjacent IOs as much as possible. Esp. in case of
1456 * multiple disks using raid profile, a large IO can be split to
1457 * several segments of stripe length (currently 64K).
1458 */
1459 blk_start_plug(&plug);
1460 ret = btrfs_fdatawrite_range(inode, start, end);
1461 blk_finish_plug(&plug);
1462
1463 return ret;
1464}
1465
1466static inline bool skip_inode_logging(const struct btrfs_log_ctx *ctx)
1467{
1468 struct btrfs_inode *inode = ctx->inode;
1469 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1470
1471 if (btrfs_inode_in_log(inode, btrfs_get_fs_generation(fs_info)) &&
1472 list_empty(&ctx->ordered_extents))
1473 return true;
1474
1475 /*
1476 * If we are doing a fast fsync we can not bail out if the inode's
1477 * last_trans is <= then the last committed transaction, because we only
1478 * update the last_trans of the inode during ordered extent completion,
1479 * and for a fast fsync we don't wait for that, we only wait for the
1480 * writeback to complete.
1481 */
1482 if (inode->last_trans <= btrfs_get_last_trans_committed(fs_info) &&
1483 (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) ||
1484 list_empty(&ctx->ordered_extents)))
1485 return true;
1486
1487 return false;
1488}
1489
1490/*
1491 * fsync call for both files and directories. This logs the inode into
1492 * the tree log instead of forcing full commits whenever possible.
1493 *
1494 * It needs to call filemap_fdatawait so that all ordered extent updates are
1495 * in the metadata btree are up to date for copying to the log.
1496 *
1497 * It drops the inode mutex before doing the tree log commit. This is an
1498 * important optimization for directories because holding the mutex prevents
1499 * new operations on the dir while we write to disk.
1500 */
1501int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1502{
1503 struct dentry *dentry = file_dentry(file);
1504 struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
1505 struct btrfs_root *root = inode->root;
1506 struct btrfs_fs_info *fs_info = root->fs_info;
1507 struct btrfs_trans_handle *trans;
1508 struct btrfs_log_ctx ctx;
1509 int ret = 0, err;
1510 u64 len;
1511 bool full_sync;
1512 bool skip_ilock = false;
1513
1514 if (current->journal_info == BTRFS_TRANS_DIO_WRITE_STUB) {
1515 skip_ilock = true;
1516 current->journal_info = NULL;
1517 btrfs_assert_inode_locked(inode);
1518 }
1519
1520 trace_btrfs_sync_file(file, datasync);
1521
1522 btrfs_init_log_ctx(&ctx, inode);
1523
1524 /*
1525 * Always set the range to a full range, otherwise we can get into
1526 * several problems, from missing file extent items to represent holes
1527 * when not using the NO_HOLES feature, to log tree corruption due to
1528 * races between hole detection during logging and completion of ordered
1529 * extents outside the range, to missing checksums due to ordered extents
1530 * for which we flushed only a subset of their pages.
1531 */
1532 start = 0;
1533 end = LLONG_MAX;
1534 len = (u64)LLONG_MAX + 1;
1535
1536 /*
1537 * We write the dirty pages in the range and wait until they complete
1538 * out of the ->i_mutex. If so, we can flush the dirty pages by
1539 * multi-task, and make the performance up. See
1540 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1541 */
1542 ret = start_ordered_ops(inode, start, end);
1543 if (ret)
1544 goto out;
1545
1546 if (skip_ilock)
1547 down_write(&inode->i_mmap_lock);
1548 else
1549 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
1550
1551 atomic_inc(&root->log_batch);
1552
1553 /*
1554 * Before we acquired the inode's lock and the mmap lock, someone may
1555 * have dirtied more pages in the target range. We need to make sure
1556 * that writeback for any such pages does not start while we are logging
1557 * the inode, because if it does, any of the following might happen when
1558 * we are not doing a full inode sync:
1559 *
1560 * 1) We log an extent after its writeback finishes but before its
1561 * checksums are added to the csum tree, leading to -EIO errors
1562 * when attempting to read the extent after a log replay.
1563 *
1564 * 2) We can end up logging an extent before its writeback finishes.
1565 * Therefore after the log replay we will have a file extent item
1566 * pointing to an unwritten extent (and no data checksums as well).
1567 *
1568 * So trigger writeback for any eventual new dirty pages and then we
1569 * wait for all ordered extents to complete below.
1570 */
1571 ret = start_ordered_ops(inode, start, end);
1572 if (ret) {
1573 if (skip_ilock)
1574 up_write(&inode->i_mmap_lock);
1575 else
1576 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
1577 goto out;
1578 }
1579
1580 /*
1581 * Always check for the full sync flag while holding the inode's lock,
1582 * to avoid races with other tasks. The flag must be either set all the
1583 * time during logging or always off all the time while logging.
1584 * We check the flag here after starting delalloc above, because when
1585 * running delalloc the full sync flag may be set if we need to drop
1586 * extra extent map ranges due to temporary memory allocation failures.
1587 */
1588 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
1589
1590 /*
1591 * We have to do this here to avoid the priority inversion of waiting on
1592 * IO of a lower priority task while holding a transaction open.
1593 *
1594 * For a full fsync we wait for the ordered extents to complete while
1595 * for a fast fsync we wait just for writeback to complete, and then
1596 * attach the ordered extents to the transaction so that a transaction
1597 * commit waits for their completion, to avoid data loss if we fsync,
1598 * the current transaction commits before the ordered extents complete
1599 * and a power failure happens right after that.
1600 *
1601 * For zoned filesystem, if a write IO uses a ZONE_APPEND command, the
1602 * logical address recorded in the ordered extent may change. We need
1603 * to wait for the IO to stabilize the logical address.
1604 */
1605 if (full_sync || btrfs_is_zoned(fs_info)) {
1606 ret = btrfs_wait_ordered_range(inode, start, len);
1607 clear_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags);
1608 } else {
1609 /*
1610 * Get our ordered extents as soon as possible to avoid doing
1611 * checksum lookups in the csum tree, and use instead the
1612 * checksums attached to the ordered extents.
1613 */
1614 btrfs_get_ordered_extents_for_logging(inode, &ctx.ordered_extents);
1615 ret = filemap_fdatawait_range(inode->vfs_inode.i_mapping, start, end);
1616 if (ret)
1617 goto out_release_extents;
1618
1619 /*
1620 * Check and clear the BTRFS_INODE_COW_WRITE_ERROR now after
1621 * starting and waiting for writeback, because for buffered IO
1622 * it may have been set during the end IO callback
1623 * (end_bbio_data_write() -> btrfs_finish_ordered_extent()) in
1624 * case an error happened and we need to wait for ordered
1625 * extents to complete so that any extent maps that point to
1626 * unwritten locations are dropped and we don't log them.
1627 */
1628 if (test_and_clear_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags))
1629 ret = btrfs_wait_ordered_range(inode, start, len);
1630 }
1631
1632 if (ret)
1633 goto out_release_extents;
1634
1635 atomic_inc(&root->log_batch);
1636
1637 if (skip_inode_logging(&ctx)) {
1638 /*
1639 * We've had everything committed since the last time we were
1640 * modified so clear this flag in case it was set for whatever
1641 * reason, it's no longer relevant.
1642 */
1643 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
1644 /*
1645 * An ordered extent might have started before and completed
1646 * already with io errors, in which case the inode was not
1647 * updated and we end up here. So check the inode's mapping
1648 * for any errors that might have happened since we last
1649 * checked called fsync.
1650 */
1651 ret = filemap_check_wb_err(inode->vfs_inode.i_mapping, file->f_wb_err);
1652 goto out_release_extents;
1653 }
1654
1655 btrfs_init_log_ctx_scratch_eb(&ctx);
1656
1657 /*
1658 * We use start here because we will need to wait on the IO to complete
1659 * in btrfs_sync_log, which could require joining a transaction (for
1660 * example checking cross references in the nocow path). If we use join
1661 * here we could get into a situation where we're waiting on IO to
1662 * happen that is blocked on a transaction trying to commit. With start
1663 * we inc the extwriter counter, so we wait for all extwriters to exit
1664 * before we start blocking joiners. This comment is to keep somebody
1665 * from thinking they are super smart and changing this to
1666 * btrfs_join_transaction *cough*Josef*cough*.
1667 */
1668 trans = btrfs_start_transaction(root, 0);
1669 if (IS_ERR(trans)) {
1670 ret = PTR_ERR(trans);
1671 goto out_release_extents;
1672 }
1673 trans->in_fsync = true;
1674
1675 ret = btrfs_log_dentry_safe(trans, dentry, &ctx);
1676 /*
1677 * Scratch eb no longer needed, release before syncing log or commit
1678 * transaction, to avoid holding unnecessary memory during such long
1679 * operations.
1680 */
1681 if (ctx.scratch_eb) {
1682 free_extent_buffer(ctx.scratch_eb);
1683 ctx.scratch_eb = NULL;
1684 }
1685 btrfs_release_log_ctx_extents(&ctx);
1686 if (ret < 0) {
1687 /* Fallthrough and commit/free transaction. */
1688 ret = BTRFS_LOG_FORCE_COMMIT;
1689 }
1690
1691 /* we've logged all the items and now have a consistent
1692 * version of the file in the log. It is possible that
1693 * someone will come in and modify the file, but that's
1694 * fine because the log is consistent on disk, and we
1695 * have references to all of the file's extents
1696 *
1697 * It is possible that someone will come in and log the
1698 * file again, but that will end up using the synchronization
1699 * inside btrfs_sync_log to keep things safe.
1700 */
1701 if (skip_ilock)
1702 up_write(&inode->i_mmap_lock);
1703 else
1704 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
1705
1706 if (ret == BTRFS_NO_LOG_SYNC) {
1707 ret = btrfs_end_transaction(trans);
1708 goto out;
1709 }
1710
1711 /* We successfully logged the inode, attempt to sync the log. */
1712 if (!ret) {
1713 ret = btrfs_sync_log(trans, root, &ctx);
1714 if (!ret) {
1715 ret = btrfs_end_transaction(trans);
1716 goto out;
1717 }
1718 }
1719
1720 /*
1721 * At this point we need to commit the transaction because we had
1722 * btrfs_need_log_full_commit() or some other error.
1723 *
1724 * If we didn't do a full sync we have to stop the trans handle, wait on
1725 * the ordered extents, start it again and commit the transaction. If
1726 * we attempt to wait on the ordered extents here we could deadlock with
1727 * something like fallocate() that is holding the extent lock trying to
1728 * start a transaction while some other thread is trying to commit the
1729 * transaction while we (fsync) are currently holding the transaction
1730 * open.
1731 */
1732 if (!full_sync) {
1733 ret = btrfs_end_transaction(trans);
1734 if (ret)
1735 goto out;
1736 ret = btrfs_wait_ordered_range(inode, start, len);
1737 if (ret)
1738 goto out;
1739
1740 /*
1741 * This is safe to use here because we're only interested in
1742 * making sure the transaction that had the ordered extents is
1743 * committed. We aren't waiting on anything past this point,
1744 * we're purely getting the transaction and committing it.
1745 */
1746 trans = btrfs_attach_transaction_barrier(root);
1747 if (IS_ERR(trans)) {
1748 ret = PTR_ERR(trans);
1749
1750 /*
1751 * We committed the transaction and there's no currently
1752 * running transaction, this means everything we care
1753 * about made it to disk and we are done.
1754 */
1755 if (ret == -ENOENT)
1756 ret = 0;
1757 goto out;
1758 }
1759 }
1760
1761 ret = btrfs_commit_transaction(trans);
1762out:
1763 free_extent_buffer(ctx.scratch_eb);
1764 ASSERT(list_empty(&ctx.list));
1765 ASSERT(list_empty(&ctx.conflict_inodes));
1766 err = file_check_and_advance_wb_err(file);
1767 if (!ret)
1768 ret = err;
1769 return ret > 0 ? -EIO : ret;
1770
1771out_release_extents:
1772 btrfs_release_log_ctx_extents(&ctx);
1773 if (skip_ilock)
1774 up_write(&inode->i_mmap_lock);
1775 else
1776 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
1777 goto out;
1778}
1779
1780/*
1781 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
1782 * called from a page fault handler when a page is first dirtied. Hence we must
1783 * be careful to check for EOF conditions here. We set the page up correctly
1784 * for a written page which means we get ENOSPC checking when writing into
1785 * holes and correct delalloc and unwritten extent mapping on filesystems that
1786 * support these features.
1787 *
1788 * We are not allowed to take the i_mutex here so we have to play games to
1789 * protect against truncate races as the page could now be beyond EOF. Because
1790 * truncate_setsize() writes the inode size before removing pages, once we have
1791 * the page lock we can determine safely if the page is beyond EOF. If it is not
1792 * beyond EOF, then the page is guaranteed safe against truncation until we
1793 * unlock the page.
1794 */
1795static vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
1796{
1797 struct page *page = vmf->page;
1798 struct folio *folio = page_folio(page);
1799 struct inode *inode = file_inode(vmf->vma->vm_file);
1800 struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
1801 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1802 struct btrfs_ordered_extent *ordered;
1803 struct extent_state *cached_state = NULL;
1804 struct extent_changeset *data_reserved = NULL;
1805 unsigned long zero_start;
1806 loff_t size;
1807 vm_fault_t ret;
1808 int ret2;
1809 int reserved = 0;
1810 u64 reserved_space;
1811 u64 page_start;
1812 u64 page_end;
1813 u64 end;
1814
1815 ASSERT(folio_order(folio) == 0);
1816
1817 reserved_space = PAGE_SIZE;
1818
1819 sb_start_pagefault(inode->i_sb);
1820 page_start = folio_pos(folio);
1821 page_end = page_start + folio_size(folio) - 1;
1822 end = page_end;
1823
1824 /*
1825 * Reserving delalloc space after obtaining the page lock can lead to
1826 * deadlock. For example, if a dirty page is locked by this function
1827 * and the call to btrfs_delalloc_reserve_space() ends up triggering
1828 * dirty page write out, then the btrfs_writepages() function could
1829 * end up waiting indefinitely to get a lock on the page currently
1830 * being processed by btrfs_page_mkwrite() function.
1831 */
1832 ret2 = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved,
1833 page_start, reserved_space);
1834 if (!ret2) {
1835 ret2 = file_update_time(vmf->vma->vm_file);
1836 reserved = 1;
1837 }
1838 if (ret2) {
1839 ret = vmf_error(ret2);
1840 if (reserved)
1841 goto out;
1842 goto out_noreserve;
1843 }
1844
1845 /* Make the VM retry the fault. */
1846 ret = VM_FAULT_NOPAGE;
1847again:
1848 down_read(&BTRFS_I(inode)->i_mmap_lock);
1849 folio_lock(folio);
1850 size = i_size_read(inode);
1851
1852 if ((folio->mapping != inode->i_mapping) ||
1853 (page_start >= size)) {
1854 /* Page got truncated out from underneath us. */
1855 goto out_unlock;
1856 }
1857 folio_wait_writeback(folio);
1858
1859 lock_extent(io_tree, page_start, page_end, &cached_state);
1860 ret2 = set_folio_extent_mapped(folio);
1861 if (ret2 < 0) {
1862 ret = vmf_error(ret2);
1863 unlock_extent(io_tree, page_start, page_end, &cached_state);
1864 goto out_unlock;
1865 }
1866
1867 /*
1868 * We can't set the delalloc bits if there are pending ordered
1869 * extents. Drop our locks and wait for them to finish.
1870 */
1871 ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start, PAGE_SIZE);
1872 if (ordered) {
1873 unlock_extent(io_tree, page_start, page_end, &cached_state);
1874 folio_unlock(folio);
1875 up_read(&BTRFS_I(inode)->i_mmap_lock);
1876 btrfs_start_ordered_extent(ordered);
1877 btrfs_put_ordered_extent(ordered);
1878 goto again;
1879 }
1880
1881 if (folio->index == ((size - 1) >> PAGE_SHIFT)) {
1882 reserved_space = round_up(size - page_start, fs_info->sectorsize);
1883 if (reserved_space < PAGE_SIZE) {
1884 end = page_start + reserved_space - 1;
1885 btrfs_delalloc_release_space(BTRFS_I(inode),
1886 data_reserved, page_start,
1887 PAGE_SIZE - reserved_space, true);
1888 }
1889 }
1890
1891 /*
1892 * page_mkwrite gets called when the page is firstly dirtied after it's
1893 * faulted in, but write(2) could also dirty a page and set delalloc
1894 * bits, thus in this case for space account reason, we still need to
1895 * clear any delalloc bits within this page range since we have to
1896 * reserve data&meta space before lock_page() (see above comments).
1897 */
1898 clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
1899 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
1900 EXTENT_DEFRAG, &cached_state);
1901
1902 ret2 = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, end, 0,
1903 &cached_state);
1904 if (ret2) {
1905 unlock_extent(io_tree, page_start, page_end, &cached_state);
1906 ret = VM_FAULT_SIGBUS;
1907 goto out_unlock;
1908 }
1909
1910 /* Page is wholly or partially inside EOF. */
1911 if (page_start + folio_size(folio) > size)
1912 zero_start = offset_in_folio(folio, size);
1913 else
1914 zero_start = PAGE_SIZE;
1915
1916 if (zero_start != PAGE_SIZE)
1917 folio_zero_range(folio, zero_start, folio_size(folio) - zero_start);
1918
1919 btrfs_folio_clear_checked(fs_info, folio, page_start, PAGE_SIZE);
1920 btrfs_folio_set_dirty(fs_info, folio, page_start, end + 1 - page_start);
1921 btrfs_folio_set_uptodate(fs_info, folio, page_start, end + 1 - page_start);
1922
1923 btrfs_set_inode_last_sub_trans(BTRFS_I(inode));
1924
1925 unlock_extent(io_tree, page_start, page_end, &cached_state);
1926 up_read(&BTRFS_I(inode)->i_mmap_lock);
1927
1928 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
1929 sb_end_pagefault(inode->i_sb);
1930 extent_changeset_free(data_reserved);
1931 return VM_FAULT_LOCKED;
1932
1933out_unlock:
1934 folio_unlock(folio);
1935 up_read(&BTRFS_I(inode)->i_mmap_lock);
1936out:
1937 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
1938 btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start,
1939 reserved_space, (ret != 0));
1940out_noreserve:
1941 sb_end_pagefault(inode->i_sb);
1942 extent_changeset_free(data_reserved);
1943 return ret;
1944}
1945
1946static const struct vm_operations_struct btrfs_file_vm_ops = {
1947 .fault = filemap_fault,
1948 .map_pages = filemap_map_pages,
1949 .page_mkwrite = btrfs_page_mkwrite,
1950};
1951
1952static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1953{
1954 struct address_space *mapping = filp->f_mapping;
1955
1956 if (!mapping->a_ops->read_folio)
1957 return -ENOEXEC;
1958
1959 file_accessed(filp);
1960 vma->vm_ops = &btrfs_file_vm_ops;
1961
1962 return 0;
1963}
1964
1965static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
1966 int slot, u64 start, u64 end)
1967{
1968 struct btrfs_file_extent_item *fi;
1969 struct btrfs_key key;
1970
1971 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1972 return 0;
1973
1974 btrfs_item_key_to_cpu(leaf, &key, slot);
1975 if (key.objectid != btrfs_ino(inode) ||
1976 key.type != BTRFS_EXTENT_DATA_KEY)
1977 return 0;
1978
1979 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1980
1981 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
1982 return 0;
1983
1984 if (btrfs_file_extent_disk_bytenr(leaf, fi))
1985 return 0;
1986
1987 if (key.offset == end)
1988 return 1;
1989 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
1990 return 1;
1991 return 0;
1992}
1993
1994static int fill_holes(struct btrfs_trans_handle *trans,
1995 struct btrfs_inode *inode,
1996 struct btrfs_path *path, u64 offset, u64 end)
1997{
1998 struct btrfs_fs_info *fs_info = trans->fs_info;
1999 struct btrfs_root *root = inode->root;
2000 struct extent_buffer *leaf;
2001 struct btrfs_file_extent_item *fi;
2002 struct extent_map *hole_em;
2003 struct btrfs_key key;
2004 int ret;
2005
2006 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2007 goto out;
2008
2009 key.objectid = btrfs_ino(inode);
2010 key.type = BTRFS_EXTENT_DATA_KEY;
2011 key.offset = offset;
2012
2013 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2014 if (ret <= 0) {
2015 /*
2016 * We should have dropped this offset, so if we find it then
2017 * something has gone horribly wrong.
2018 */
2019 if (ret == 0)
2020 ret = -EINVAL;
2021 return ret;
2022 }
2023
2024 leaf = path->nodes[0];
2025 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2026 u64 num_bytes;
2027
2028 path->slots[0]--;
2029 fi = btrfs_item_ptr(leaf, path->slots[0],
2030 struct btrfs_file_extent_item);
2031 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2032 end - offset;
2033 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2034 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2035 btrfs_set_file_extent_offset(leaf, fi, 0);
2036 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2037 btrfs_mark_buffer_dirty(trans, leaf);
2038 goto out;
2039 }
2040
2041 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2042 u64 num_bytes;
2043
2044 key.offset = offset;
2045 btrfs_set_item_key_safe(trans, path, &key);
2046 fi = btrfs_item_ptr(leaf, path->slots[0],
2047 struct btrfs_file_extent_item);
2048 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2049 offset;
2050 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2051 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2052 btrfs_set_file_extent_offset(leaf, fi, 0);
2053 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
2054 btrfs_mark_buffer_dirty(trans, leaf);
2055 goto out;
2056 }
2057 btrfs_release_path(path);
2058
2059 ret = btrfs_insert_hole_extent(trans, root, btrfs_ino(inode), offset,
2060 end - offset);
2061 if (ret)
2062 return ret;
2063
2064out:
2065 btrfs_release_path(path);
2066
2067 hole_em = alloc_extent_map();
2068 if (!hole_em) {
2069 btrfs_drop_extent_map_range(inode, offset, end - 1, false);
2070 btrfs_set_inode_full_sync(inode);
2071 } else {
2072 hole_em->start = offset;
2073 hole_em->len = end - offset;
2074 hole_em->ram_bytes = hole_em->len;
2075
2076 hole_em->disk_bytenr = EXTENT_MAP_HOLE;
2077 hole_em->disk_num_bytes = 0;
2078 hole_em->generation = trans->transid;
2079
2080 ret = btrfs_replace_extent_map_range(inode, hole_em, true);
2081 free_extent_map(hole_em);
2082 if (ret)
2083 btrfs_set_inode_full_sync(inode);
2084 }
2085
2086 return 0;
2087}
2088
2089/*
2090 * Find a hole extent on given inode and change start/len to the end of hole
2091 * extent.(hole/vacuum extent whose em->start <= start &&
2092 * em->start + em->len > start)
2093 * When a hole extent is found, return 1 and modify start/len.
2094 */
2095static int find_first_non_hole(struct btrfs_inode *inode, u64 *start, u64 *len)
2096{
2097 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2098 struct extent_map *em;
2099 int ret = 0;
2100
2101 em = btrfs_get_extent(inode, NULL,
2102 round_down(*start, fs_info->sectorsize),
2103 round_up(*len, fs_info->sectorsize));
2104 if (IS_ERR(em))
2105 return PTR_ERR(em);
2106
2107 /* Hole or vacuum extent(only exists in no-hole mode) */
2108 if (em->disk_bytenr == EXTENT_MAP_HOLE) {
2109 ret = 1;
2110 *len = em->start + em->len > *start + *len ?
2111 0 : *start + *len - em->start - em->len;
2112 *start = em->start + em->len;
2113 }
2114 free_extent_map(em);
2115 return ret;
2116}
2117
2118static void btrfs_punch_hole_lock_range(struct inode *inode,
2119 const u64 lockstart,
2120 const u64 lockend,
2121 struct extent_state **cached_state)
2122{
2123 /*
2124 * For subpage case, if the range is not at page boundary, we could
2125 * have pages at the leading/tailing part of the range.
2126 * This could lead to dead loop since filemap_range_has_page()
2127 * will always return true.
2128 * So here we need to do extra page alignment for
2129 * filemap_range_has_page().
2130 */
2131 const u64 page_lockstart = round_up(lockstart, PAGE_SIZE);
2132 const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1;
2133
2134 while (1) {
2135 truncate_pagecache_range(inode, lockstart, lockend);
2136
2137 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2138 cached_state);
2139 /*
2140 * We can't have ordered extents in the range, nor dirty/writeback
2141 * pages, because we have locked the inode's VFS lock in exclusive
2142 * mode, we have locked the inode's i_mmap_lock in exclusive mode,
2143 * we have flushed all delalloc in the range and we have waited
2144 * for any ordered extents in the range to complete.
2145 * We can race with anyone reading pages from this range, so after
2146 * locking the range check if we have pages in the range, and if
2147 * we do, unlock the range and retry.
2148 */
2149 if (!filemap_range_has_page(inode->i_mapping, page_lockstart,
2150 page_lockend))
2151 break;
2152
2153 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2154 cached_state);
2155 }
2156
2157 btrfs_assert_inode_range_clean(BTRFS_I(inode), lockstart, lockend);
2158}
2159
2160static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans,
2161 struct btrfs_inode *inode,
2162 struct btrfs_path *path,
2163 struct btrfs_replace_extent_info *extent_info,
2164 const u64 replace_len,
2165 const u64 bytes_to_drop)
2166{
2167 struct btrfs_fs_info *fs_info = trans->fs_info;
2168 struct btrfs_root *root = inode->root;
2169 struct btrfs_file_extent_item *extent;
2170 struct extent_buffer *leaf;
2171 struct btrfs_key key;
2172 int slot;
2173 int ret;
2174
2175 if (replace_len == 0)
2176 return 0;
2177
2178 if (extent_info->disk_offset == 0 &&
2179 btrfs_fs_incompat(fs_info, NO_HOLES)) {
2180 btrfs_update_inode_bytes(inode, 0, bytes_to_drop);
2181 return 0;
2182 }
2183
2184 key.objectid = btrfs_ino(inode);
2185 key.type = BTRFS_EXTENT_DATA_KEY;
2186 key.offset = extent_info->file_offset;
2187 ret = btrfs_insert_empty_item(trans, root, path, &key,
2188 sizeof(struct btrfs_file_extent_item));
2189 if (ret)
2190 return ret;
2191 leaf = path->nodes[0];
2192 slot = path->slots[0];
2193 write_extent_buffer(leaf, extent_info->extent_buf,
2194 btrfs_item_ptr_offset(leaf, slot),
2195 sizeof(struct btrfs_file_extent_item));
2196 extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2197 ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE);
2198 btrfs_set_file_extent_offset(leaf, extent, extent_info->data_offset);
2199 btrfs_set_file_extent_num_bytes(leaf, extent, replace_len);
2200 if (extent_info->is_new_extent)
2201 btrfs_set_file_extent_generation(leaf, extent, trans->transid);
2202 btrfs_mark_buffer_dirty(trans, leaf);
2203 btrfs_release_path(path);
2204
2205 ret = btrfs_inode_set_file_extent_range(inode, extent_info->file_offset,
2206 replace_len);
2207 if (ret)
2208 return ret;
2209
2210 /* If it's a hole, nothing more needs to be done. */
2211 if (extent_info->disk_offset == 0) {
2212 btrfs_update_inode_bytes(inode, 0, bytes_to_drop);
2213 return 0;
2214 }
2215
2216 btrfs_update_inode_bytes(inode, replace_len, bytes_to_drop);
2217
2218 if (extent_info->is_new_extent && extent_info->insertions == 0) {
2219 key.objectid = extent_info->disk_offset;
2220 key.type = BTRFS_EXTENT_ITEM_KEY;
2221 key.offset = extent_info->disk_len;
2222 ret = btrfs_alloc_reserved_file_extent(trans, root,
2223 btrfs_ino(inode),
2224 extent_info->file_offset,
2225 extent_info->qgroup_reserved,
2226 &key);
2227 } else {
2228 struct btrfs_ref ref = {
2229 .action = BTRFS_ADD_DELAYED_REF,
2230 .bytenr = extent_info->disk_offset,
2231 .num_bytes = extent_info->disk_len,
2232 .owning_root = btrfs_root_id(root),
2233 .ref_root = btrfs_root_id(root),
2234 };
2235 u64 ref_offset;
2236
2237 ref_offset = extent_info->file_offset - extent_info->data_offset;
2238 btrfs_init_data_ref(&ref, btrfs_ino(inode), ref_offset, 0, false);
2239 ret = btrfs_inc_extent_ref(trans, &ref);
2240 }
2241
2242 extent_info->insertions++;
2243
2244 return ret;
2245}
2246
2247/*
2248 * The respective range must have been previously locked, as well as the inode.
2249 * The end offset is inclusive (last byte of the range).
2250 * @extent_info is NULL for fallocate's hole punching and non-NULL when replacing
2251 * the file range with an extent.
2252 * When not punching a hole, we don't want to end up in a state where we dropped
2253 * extents without inserting a new one, so we must abort the transaction to avoid
2254 * a corruption.
2255 */
2256int btrfs_replace_file_extents(struct btrfs_inode *inode,
2257 struct btrfs_path *path, const u64 start,
2258 const u64 end,
2259 struct btrfs_replace_extent_info *extent_info,
2260 struct btrfs_trans_handle **trans_out)
2261{
2262 struct btrfs_drop_extents_args drop_args = { 0 };
2263 struct btrfs_root *root = inode->root;
2264 struct btrfs_fs_info *fs_info = root->fs_info;
2265 u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
2266 u64 ino_size = round_up(inode->vfs_inode.i_size, fs_info->sectorsize);
2267 struct btrfs_trans_handle *trans = NULL;
2268 struct btrfs_block_rsv *rsv;
2269 unsigned int rsv_count;
2270 u64 cur_offset;
2271 u64 len = end - start;
2272 int ret = 0;
2273
2274 if (end <= start)
2275 return -EINVAL;
2276
2277 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2278 if (!rsv) {
2279 ret = -ENOMEM;
2280 goto out;
2281 }
2282 rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
2283 rsv->failfast = true;
2284
2285 /*
2286 * 1 - update the inode
2287 * 1 - removing the extents in the range
2288 * 1 - adding the hole extent if no_holes isn't set or if we are
2289 * replacing the range with a new extent
2290 */
2291 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || extent_info)
2292 rsv_count = 3;
2293 else
2294 rsv_count = 2;
2295
2296 trans = btrfs_start_transaction(root, rsv_count);
2297 if (IS_ERR(trans)) {
2298 ret = PTR_ERR(trans);
2299 trans = NULL;
2300 goto out_free;
2301 }
2302
2303 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2304 min_size, false);
2305 if (WARN_ON(ret))
2306 goto out_trans;
2307 trans->block_rsv = rsv;
2308
2309 cur_offset = start;
2310 drop_args.path = path;
2311 drop_args.end = end + 1;
2312 drop_args.drop_cache = true;
2313 while (cur_offset < end) {
2314 drop_args.start = cur_offset;
2315 ret = btrfs_drop_extents(trans, root, inode, &drop_args);
2316 /* If we are punching a hole decrement the inode's byte count */
2317 if (!extent_info)
2318 btrfs_update_inode_bytes(inode, 0,
2319 drop_args.bytes_found);
2320 if (ret != -ENOSPC) {
2321 /*
2322 * The only time we don't want to abort is if we are
2323 * attempting to clone a partial inline extent, in which
2324 * case we'll get EOPNOTSUPP. However if we aren't
2325 * clone we need to abort no matter what, because if we
2326 * got EOPNOTSUPP via prealloc then we messed up and
2327 * need to abort.
2328 */
2329 if (ret &&
2330 (ret != -EOPNOTSUPP ||
2331 (extent_info && extent_info->is_new_extent)))
2332 btrfs_abort_transaction(trans, ret);
2333 break;
2334 }
2335
2336 trans->block_rsv = &fs_info->trans_block_rsv;
2337
2338 if (!extent_info && cur_offset < drop_args.drop_end &&
2339 cur_offset < ino_size) {
2340 ret = fill_holes(trans, inode, path, cur_offset,
2341 drop_args.drop_end);
2342 if (ret) {
2343 /*
2344 * If we failed then we didn't insert our hole
2345 * entries for the area we dropped, so now the
2346 * fs is corrupted, so we must abort the
2347 * transaction.
2348 */
2349 btrfs_abort_transaction(trans, ret);
2350 break;
2351 }
2352 } else if (!extent_info && cur_offset < drop_args.drop_end) {
2353 /*
2354 * We are past the i_size here, but since we didn't
2355 * insert holes we need to clear the mapped area so we
2356 * know to not set disk_i_size in this area until a new
2357 * file extent is inserted here.
2358 */
2359 ret = btrfs_inode_clear_file_extent_range(inode,
2360 cur_offset,
2361 drop_args.drop_end - cur_offset);
2362 if (ret) {
2363 /*
2364 * We couldn't clear our area, so we could
2365 * presumably adjust up and corrupt the fs, so
2366 * we need to abort.
2367 */
2368 btrfs_abort_transaction(trans, ret);
2369 break;
2370 }
2371 }
2372
2373 if (extent_info &&
2374 drop_args.drop_end > extent_info->file_offset) {
2375 u64 replace_len = drop_args.drop_end -
2376 extent_info->file_offset;
2377
2378 ret = btrfs_insert_replace_extent(trans, inode, path,
2379 extent_info, replace_len,
2380 drop_args.bytes_found);
2381 if (ret) {
2382 btrfs_abort_transaction(trans, ret);
2383 break;
2384 }
2385 extent_info->data_len -= replace_len;
2386 extent_info->data_offset += replace_len;
2387 extent_info->file_offset += replace_len;
2388 }
2389
2390 /*
2391 * We are releasing our handle on the transaction, balance the
2392 * dirty pages of the btree inode and flush delayed items, and
2393 * then get a new transaction handle, which may now point to a
2394 * new transaction in case someone else may have committed the
2395 * transaction we used to replace/drop file extent items. So
2396 * bump the inode's iversion and update mtime and ctime except
2397 * if we are called from a dedupe context. This is because a
2398 * power failure/crash may happen after the transaction is
2399 * committed and before we finish replacing/dropping all the
2400 * file extent items we need.
2401 */
2402 inode_inc_iversion(&inode->vfs_inode);
2403
2404 if (!extent_info || extent_info->update_times)
2405 inode_set_mtime_to_ts(&inode->vfs_inode,
2406 inode_set_ctime_current(&inode->vfs_inode));
2407
2408 ret = btrfs_update_inode(trans, inode);
2409 if (ret)
2410 break;
2411
2412 btrfs_end_transaction(trans);
2413 btrfs_btree_balance_dirty(fs_info);
2414
2415 trans = btrfs_start_transaction(root, rsv_count);
2416 if (IS_ERR(trans)) {
2417 ret = PTR_ERR(trans);
2418 trans = NULL;
2419 break;
2420 }
2421
2422 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2423 rsv, min_size, false);
2424 if (WARN_ON(ret))
2425 break;
2426 trans->block_rsv = rsv;
2427
2428 cur_offset = drop_args.drop_end;
2429 len = end - cur_offset;
2430 if (!extent_info && len) {
2431 ret = find_first_non_hole(inode, &cur_offset, &len);
2432 if (unlikely(ret < 0))
2433 break;
2434 if (ret && !len) {
2435 ret = 0;
2436 break;
2437 }
2438 }
2439 }
2440
2441 /*
2442 * If we were cloning, force the next fsync to be a full one since we
2443 * we replaced (or just dropped in the case of cloning holes when
2444 * NO_HOLES is enabled) file extent items and did not setup new extent
2445 * maps for the replacement extents (or holes).
2446 */
2447 if (extent_info && !extent_info->is_new_extent)
2448 btrfs_set_inode_full_sync(inode);
2449
2450 if (ret)
2451 goto out_trans;
2452
2453 trans->block_rsv = &fs_info->trans_block_rsv;
2454 /*
2455 * If we are using the NO_HOLES feature we might have had already an
2456 * hole that overlaps a part of the region [lockstart, lockend] and
2457 * ends at (or beyond) lockend. Since we have no file extent items to
2458 * represent holes, drop_end can be less than lockend and so we must
2459 * make sure we have an extent map representing the existing hole (the
2460 * call to __btrfs_drop_extents() might have dropped the existing extent
2461 * map representing the existing hole), otherwise the fast fsync path
2462 * will not record the existence of the hole region
2463 * [existing_hole_start, lockend].
2464 */
2465 if (drop_args.drop_end <= end)
2466 drop_args.drop_end = end + 1;
2467 /*
2468 * Don't insert file hole extent item if it's for a range beyond eof
2469 * (because it's useless) or if it represents a 0 bytes range (when
2470 * cur_offset == drop_end).
2471 */
2472 if (!extent_info && cur_offset < ino_size &&
2473 cur_offset < drop_args.drop_end) {
2474 ret = fill_holes(trans, inode, path, cur_offset,
2475 drop_args.drop_end);
2476 if (ret) {
2477 /* Same comment as above. */
2478 btrfs_abort_transaction(trans, ret);
2479 goto out_trans;
2480 }
2481 } else if (!extent_info && cur_offset < drop_args.drop_end) {
2482 /* See the comment in the loop above for the reasoning here. */
2483 ret = btrfs_inode_clear_file_extent_range(inode, cur_offset,
2484 drop_args.drop_end - cur_offset);
2485 if (ret) {
2486 btrfs_abort_transaction(trans, ret);
2487 goto out_trans;
2488 }
2489
2490 }
2491 if (extent_info) {
2492 ret = btrfs_insert_replace_extent(trans, inode, path,
2493 extent_info, extent_info->data_len,
2494 drop_args.bytes_found);
2495 if (ret) {
2496 btrfs_abort_transaction(trans, ret);
2497 goto out_trans;
2498 }
2499 }
2500
2501out_trans:
2502 if (!trans)
2503 goto out_free;
2504
2505 trans->block_rsv = &fs_info->trans_block_rsv;
2506 if (ret)
2507 btrfs_end_transaction(trans);
2508 else
2509 *trans_out = trans;
2510out_free:
2511 btrfs_free_block_rsv(fs_info, rsv);
2512out:
2513 return ret;
2514}
2515
2516static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len)
2517{
2518 struct inode *inode = file_inode(file);
2519 struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
2520 struct btrfs_root *root = BTRFS_I(inode)->root;
2521 struct extent_state *cached_state = NULL;
2522 struct btrfs_path *path;
2523 struct btrfs_trans_handle *trans = NULL;
2524 u64 lockstart;
2525 u64 lockend;
2526 u64 tail_start;
2527 u64 tail_len;
2528 u64 orig_start = offset;
2529 int ret = 0;
2530 bool same_block;
2531 u64 ino_size;
2532 bool truncated_block = false;
2533 bool updated_inode = false;
2534
2535 btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
2536
2537 ret = btrfs_wait_ordered_range(BTRFS_I(inode), offset, len);
2538 if (ret)
2539 goto out_only_mutex;
2540
2541 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2542 ret = find_first_non_hole(BTRFS_I(inode), &offset, &len);
2543 if (ret < 0)
2544 goto out_only_mutex;
2545 if (ret && !len) {
2546 /* Already in a large hole */
2547 ret = 0;
2548 goto out_only_mutex;
2549 }
2550
2551 ret = file_modified(file);
2552 if (ret)
2553 goto out_only_mutex;
2554
2555 lockstart = round_up(offset, fs_info->sectorsize);
2556 lockend = round_down(offset + len, fs_info->sectorsize) - 1;
2557 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2558 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2559 /*
2560 * We needn't truncate any block which is beyond the end of the file
2561 * because we are sure there is no data there.
2562 */
2563 /*
2564 * Only do this if we are in the same block and we aren't doing the
2565 * entire block.
2566 */
2567 if (same_block && len < fs_info->sectorsize) {
2568 if (offset < ino_size) {
2569 truncated_block = true;
2570 ret = btrfs_truncate_block(BTRFS_I(inode), offset, len,
2571 0);
2572 } else {
2573 ret = 0;
2574 }
2575 goto out_only_mutex;
2576 }
2577
2578 /* zero back part of the first block */
2579 if (offset < ino_size) {
2580 truncated_block = true;
2581 ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0);
2582 if (ret) {
2583 btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
2584 return ret;
2585 }
2586 }
2587
2588 /* Check the aligned pages after the first unaligned page,
2589 * if offset != orig_start, which means the first unaligned page
2590 * including several following pages are already in holes,
2591 * the extra check can be skipped */
2592 if (offset == orig_start) {
2593 /* after truncate page, check hole again */
2594 len = offset + len - lockstart;
2595 offset = lockstart;
2596 ret = find_first_non_hole(BTRFS_I(inode), &offset, &len);
2597 if (ret < 0)
2598 goto out_only_mutex;
2599 if (ret && !len) {
2600 ret = 0;
2601 goto out_only_mutex;
2602 }
2603 lockstart = offset;
2604 }
2605
2606 /* Check the tail unaligned part is in a hole */
2607 tail_start = lockend + 1;
2608 tail_len = offset + len - tail_start;
2609 if (tail_len) {
2610 ret = find_first_non_hole(BTRFS_I(inode), &tail_start, &tail_len);
2611 if (unlikely(ret < 0))
2612 goto out_only_mutex;
2613 if (!ret) {
2614 /* zero the front end of the last page */
2615 if (tail_start + tail_len < ino_size) {
2616 truncated_block = true;
2617 ret = btrfs_truncate_block(BTRFS_I(inode),
2618 tail_start + tail_len,
2619 0, 1);
2620 if (ret)
2621 goto out_only_mutex;
2622 }
2623 }
2624 }
2625
2626 if (lockend < lockstart) {
2627 ret = 0;
2628 goto out_only_mutex;
2629 }
2630
2631 btrfs_punch_hole_lock_range(inode, lockstart, lockend, &cached_state);
2632
2633 path = btrfs_alloc_path();
2634 if (!path) {
2635 ret = -ENOMEM;
2636 goto out;
2637 }
2638
2639 ret = btrfs_replace_file_extents(BTRFS_I(inode), path, lockstart,
2640 lockend, NULL, &trans);
2641 btrfs_free_path(path);
2642 if (ret)
2643 goto out;
2644
2645 ASSERT(trans != NULL);
2646 inode_inc_iversion(inode);
2647 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
2648 ret = btrfs_update_inode(trans, BTRFS_I(inode));
2649 updated_inode = true;
2650 btrfs_end_transaction(trans);
2651 btrfs_btree_balance_dirty(fs_info);
2652out:
2653 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2654 &cached_state);
2655out_only_mutex:
2656 if (!updated_inode && truncated_block && !ret) {
2657 /*
2658 * If we only end up zeroing part of a page, we still need to
2659 * update the inode item, so that all the time fields are
2660 * updated as well as the necessary btrfs inode in memory fields
2661 * for detecting, at fsync time, if the inode isn't yet in the
2662 * log tree or it's there but not up to date.
2663 */
2664 struct timespec64 now = inode_set_ctime_current(inode);
2665
2666 inode_inc_iversion(inode);
2667 inode_set_mtime_to_ts(inode, now);
2668 trans = btrfs_start_transaction(root, 1);
2669 if (IS_ERR(trans)) {
2670 ret = PTR_ERR(trans);
2671 } else {
2672 int ret2;
2673
2674 ret = btrfs_update_inode(trans, BTRFS_I(inode));
2675 ret2 = btrfs_end_transaction(trans);
2676 if (!ret)
2677 ret = ret2;
2678 }
2679 }
2680 btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
2681 return ret;
2682}
2683
2684/* Helper structure to record which range is already reserved */
2685struct falloc_range {
2686 struct list_head list;
2687 u64 start;
2688 u64 len;
2689};
2690
2691/*
2692 * Helper function to add falloc range
2693 *
2694 * Caller should have locked the larger range of extent containing
2695 * [start, len)
2696 */
2697static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2698{
2699 struct falloc_range *range = NULL;
2700
2701 if (!list_empty(head)) {
2702 /*
2703 * As fallocate iterates by bytenr order, we only need to check
2704 * the last range.
2705 */
2706 range = list_last_entry(head, struct falloc_range, list);
2707 if (range->start + range->len == start) {
2708 range->len += len;
2709 return 0;
2710 }
2711 }
2712
2713 range = kmalloc(sizeof(*range), GFP_KERNEL);
2714 if (!range)
2715 return -ENOMEM;
2716 range->start = start;
2717 range->len = len;
2718 list_add_tail(&range->list, head);
2719 return 0;
2720}
2721
2722static int btrfs_fallocate_update_isize(struct inode *inode,
2723 const u64 end,
2724 const int mode)
2725{
2726 struct btrfs_trans_handle *trans;
2727 struct btrfs_root *root = BTRFS_I(inode)->root;
2728 int ret;
2729 int ret2;
2730
2731 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
2732 return 0;
2733
2734 trans = btrfs_start_transaction(root, 1);
2735 if (IS_ERR(trans))
2736 return PTR_ERR(trans);
2737
2738 inode_set_ctime_current(inode);
2739 i_size_write(inode, end);
2740 btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
2741 ret = btrfs_update_inode(trans, BTRFS_I(inode));
2742 ret2 = btrfs_end_transaction(trans);
2743
2744 return ret ? ret : ret2;
2745}
2746
2747enum {
2748 RANGE_BOUNDARY_WRITTEN_EXTENT,
2749 RANGE_BOUNDARY_PREALLOC_EXTENT,
2750 RANGE_BOUNDARY_HOLE,
2751};
2752
2753static int btrfs_zero_range_check_range_boundary(struct btrfs_inode *inode,
2754 u64 offset)
2755{
2756 const u64 sectorsize = inode->root->fs_info->sectorsize;
2757 struct extent_map *em;
2758 int ret;
2759
2760 offset = round_down(offset, sectorsize);
2761 em = btrfs_get_extent(inode, NULL, offset, sectorsize);
2762 if (IS_ERR(em))
2763 return PTR_ERR(em);
2764
2765 if (em->disk_bytenr == EXTENT_MAP_HOLE)
2766 ret = RANGE_BOUNDARY_HOLE;
2767 else if (em->flags & EXTENT_FLAG_PREALLOC)
2768 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
2769 else
2770 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
2771
2772 free_extent_map(em);
2773 return ret;
2774}
2775
2776static int btrfs_zero_range(struct inode *inode,
2777 loff_t offset,
2778 loff_t len,
2779 const int mode)
2780{
2781 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2782 struct extent_map *em;
2783 struct extent_changeset *data_reserved = NULL;
2784 int ret;
2785 u64 alloc_hint = 0;
2786 const u64 sectorsize = fs_info->sectorsize;
2787 u64 alloc_start = round_down(offset, sectorsize);
2788 u64 alloc_end = round_up(offset + len, sectorsize);
2789 u64 bytes_to_reserve = 0;
2790 bool space_reserved = false;
2791
2792 em = btrfs_get_extent(BTRFS_I(inode), NULL, alloc_start,
2793 alloc_end - alloc_start);
2794 if (IS_ERR(em)) {
2795 ret = PTR_ERR(em);
2796 goto out;
2797 }
2798
2799 /*
2800 * Avoid hole punching and extent allocation for some cases. More cases
2801 * could be considered, but these are unlikely common and we keep things
2802 * as simple as possible for now. Also, intentionally, if the target
2803 * range contains one or more prealloc extents together with regular
2804 * extents and holes, we drop all the existing extents and allocate a
2805 * new prealloc extent, so that we get a larger contiguous disk extent.
2806 */
2807 if (em->start <= alloc_start && (em->flags & EXTENT_FLAG_PREALLOC)) {
2808 const u64 em_end = em->start + em->len;
2809
2810 if (em_end >= offset + len) {
2811 /*
2812 * The whole range is already a prealloc extent,
2813 * do nothing except updating the inode's i_size if
2814 * needed.
2815 */
2816 free_extent_map(em);
2817 ret = btrfs_fallocate_update_isize(inode, offset + len,
2818 mode);
2819 goto out;
2820 }
2821 /*
2822 * Part of the range is already a prealloc extent, so operate
2823 * only on the remaining part of the range.
2824 */
2825 alloc_start = em_end;
2826 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
2827 len = offset + len - alloc_start;
2828 offset = alloc_start;
2829 alloc_hint = extent_map_block_start(em) + em->len;
2830 }
2831 free_extent_map(em);
2832
2833 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
2834 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
2835 em = btrfs_get_extent(BTRFS_I(inode), NULL, alloc_start, sectorsize);
2836 if (IS_ERR(em)) {
2837 ret = PTR_ERR(em);
2838 goto out;
2839 }
2840
2841 if (em->flags & EXTENT_FLAG_PREALLOC) {
2842 free_extent_map(em);
2843 ret = btrfs_fallocate_update_isize(inode, offset + len,
2844 mode);
2845 goto out;
2846 }
2847 if (len < sectorsize && em->disk_bytenr != EXTENT_MAP_HOLE) {
2848 free_extent_map(em);
2849 ret = btrfs_truncate_block(BTRFS_I(inode), offset, len,
2850 0);
2851 if (!ret)
2852 ret = btrfs_fallocate_update_isize(inode,
2853 offset + len,
2854 mode);
2855 return ret;
2856 }
2857 free_extent_map(em);
2858 alloc_start = round_down(offset, sectorsize);
2859 alloc_end = alloc_start + sectorsize;
2860 goto reserve_space;
2861 }
2862
2863 alloc_start = round_up(offset, sectorsize);
2864 alloc_end = round_down(offset + len, sectorsize);
2865
2866 /*
2867 * For unaligned ranges, check the pages at the boundaries, they might
2868 * map to an extent, in which case we need to partially zero them, or
2869 * they might map to a hole, in which case we need our allocation range
2870 * to cover them.
2871 */
2872 if (!IS_ALIGNED(offset, sectorsize)) {
2873 ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode),
2874 offset);
2875 if (ret < 0)
2876 goto out;
2877 if (ret == RANGE_BOUNDARY_HOLE) {
2878 alloc_start = round_down(offset, sectorsize);
2879 ret = 0;
2880 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
2881 ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0);
2882 if (ret)
2883 goto out;
2884 } else {
2885 ret = 0;
2886 }
2887 }
2888
2889 if (!IS_ALIGNED(offset + len, sectorsize)) {
2890 ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode),
2891 offset + len);
2892 if (ret < 0)
2893 goto out;
2894 if (ret == RANGE_BOUNDARY_HOLE) {
2895 alloc_end = round_up(offset + len, sectorsize);
2896 ret = 0;
2897 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
2898 ret = btrfs_truncate_block(BTRFS_I(inode), offset + len,
2899 0, 1);
2900 if (ret)
2901 goto out;
2902 } else {
2903 ret = 0;
2904 }
2905 }
2906
2907reserve_space:
2908 if (alloc_start < alloc_end) {
2909 struct extent_state *cached_state = NULL;
2910 const u64 lockstart = alloc_start;
2911 const u64 lockend = alloc_end - 1;
2912
2913 bytes_to_reserve = alloc_end - alloc_start;
2914 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
2915 bytes_to_reserve);
2916 if (ret < 0)
2917 goto out;
2918 space_reserved = true;
2919 btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2920 &cached_state);
2921 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
2922 alloc_start, bytes_to_reserve);
2923 if (ret) {
2924 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart,
2925 lockend, &cached_state);
2926 goto out;
2927 }
2928 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
2929 alloc_end - alloc_start,
2930 fs_info->sectorsize,
2931 offset + len, &alloc_hint);
2932 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2933 &cached_state);
2934 /* btrfs_prealloc_file_range releases reserved space on error */
2935 if (ret) {
2936 space_reserved = false;
2937 goto out;
2938 }
2939 }
2940 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
2941 out:
2942 if (ret && space_reserved)
2943 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
2944 alloc_start, bytes_to_reserve);
2945 extent_changeset_free(data_reserved);
2946
2947 return ret;
2948}
2949
2950static long btrfs_fallocate(struct file *file, int mode,
2951 loff_t offset, loff_t len)
2952{
2953 struct inode *inode = file_inode(file);
2954 struct extent_state *cached_state = NULL;
2955 struct extent_changeset *data_reserved = NULL;
2956 struct falloc_range *range;
2957 struct falloc_range *tmp;
2958 LIST_HEAD(reserve_list);
2959 u64 cur_offset;
2960 u64 last_byte;
2961 u64 alloc_start;
2962 u64 alloc_end;
2963 u64 alloc_hint = 0;
2964 u64 locked_end;
2965 u64 actual_end = 0;
2966 u64 data_space_needed = 0;
2967 u64 data_space_reserved = 0;
2968 u64 qgroup_reserved = 0;
2969 struct extent_map *em;
2970 int blocksize = BTRFS_I(inode)->root->fs_info->sectorsize;
2971 int ret;
2972
2973 /* Do not allow fallocate in ZONED mode */
2974 if (btrfs_is_zoned(inode_to_fs_info(inode)))
2975 return -EOPNOTSUPP;
2976
2977 alloc_start = round_down(offset, blocksize);
2978 alloc_end = round_up(offset + len, blocksize);
2979 cur_offset = alloc_start;
2980
2981 /* Make sure we aren't being give some crap mode */
2982 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
2983 FALLOC_FL_ZERO_RANGE))
2984 return -EOPNOTSUPP;
2985
2986 if (mode & FALLOC_FL_PUNCH_HOLE)
2987 return btrfs_punch_hole(file, offset, len);
2988
2989 btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
2990
2991 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
2992 ret = inode_newsize_ok(inode, offset + len);
2993 if (ret)
2994 goto out;
2995 }
2996
2997 ret = file_modified(file);
2998 if (ret)
2999 goto out;
3000
3001 /*
3002 * TODO: Move these two operations after we have checked
3003 * accurate reserved space, or fallocate can still fail but
3004 * with page truncated or size expanded.
3005 *
3006 * But that's a minor problem and won't do much harm BTW.
3007 */
3008 if (alloc_start > inode->i_size) {
3009 ret = btrfs_cont_expand(BTRFS_I(inode), i_size_read(inode),
3010 alloc_start);
3011 if (ret)
3012 goto out;
3013 } else if (offset + len > inode->i_size) {
3014 /*
3015 * If we are fallocating from the end of the file onward we
3016 * need to zero out the end of the block if i_size lands in the
3017 * middle of a block.
3018 */
3019 ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, 0, 0);
3020 if (ret)
3021 goto out;
3022 }
3023
3024 /*
3025 * We have locked the inode at the VFS level (in exclusive mode) and we
3026 * have locked the i_mmap_lock lock (in exclusive mode). Now before
3027 * locking the file range, flush all dealloc in the range and wait for
3028 * all ordered extents in the range to complete. After this we can lock
3029 * the file range and, due to the previous locking we did, we know there
3030 * can't be more delalloc or ordered extents in the range.
3031 */
3032 ret = btrfs_wait_ordered_range(BTRFS_I(inode), alloc_start,
3033 alloc_end - alloc_start);
3034 if (ret)
3035 goto out;
3036
3037 if (mode & FALLOC_FL_ZERO_RANGE) {
3038 ret = btrfs_zero_range(inode, offset, len, mode);
3039 btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
3040 return ret;
3041 }
3042
3043 locked_end = alloc_end - 1;
3044 lock_extent(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3045 &cached_state);
3046
3047 btrfs_assert_inode_range_clean(BTRFS_I(inode), alloc_start, locked_end);
3048
3049 /* First, check if we exceed the qgroup limit */
3050 while (cur_offset < alloc_end) {
3051 em = btrfs_get_extent(BTRFS_I(inode), NULL, cur_offset,
3052 alloc_end - cur_offset);
3053 if (IS_ERR(em)) {
3054 ret = PTR_ERR(em);
3055 break;
3056 }
3057 last_byte = min(extent_map_end(em), alloc_end);
3058 actual_end = min_t(u64, extent_map_end(em), offset + len);
3059 last_byte = ALIGN(last_byte, blocksize);
3060 if (em->disk_bytenr == EXTENT_MAP_HOLE ||
3061 (cur_offset >= inode->i_size &&
3062 !(em->flags & EXTENT_FLAG_PREALLOC))) {
3063 const u64 range_len = last_byte - cur_offset;
3064
3065 ret = add_falloc_range(&reserve_list, cur_offset, range_len);
3066 if (ret < 0) {
3067 free_extent_map(em);
3068 break;
3069 }
3070 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode),
3071 &data_reserved, cur_offset, range_len);
3072 if (ret < 0) {
3073 free_extent_map(em);
3074 break;
3075 }
3076 qgroup_reserved += range_len;
3077 data_space_needed += range_len;
3078 }
3079 free_extent_map(em);
3080 cur_offset = last_byte;
3081 }
3082
3083 if (!ret && data_space_needed > 0) {
3084 /*
3085 * We are safe to reserve space here as we can't have delalloc
3086 * in the range, see above.
3087 */
3088 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3089 data_space_needed);
3090 if (!ret)
3091 data_space_reserved = data_space_needed;
3092 }
3093
3094 /*
3095 * If ret is still 0, means we're OK to fallocate.
3096 * Or just cleanup the list and exit.
3097 */
3098 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3099 if (!ret) {
3100 ret = btrfs_prealloc_file_range(inode, mode,
3101 range->start,
3102 range->len, blocksize,
3103 offset + len, &alloc_hint);
3104 /*
3105 * btrfs_prealloc_file_range() releases space even
3106 * if it returns an error.
3107 */
3108 data_space_reserved -= range->len;
3109 qgroup_reserved -= range->len;
3110 } else if (data_space_reserved > 0) {
3111 btrfs_free_reserved_data_space(BTRFS_I(inode),
3112 data_reserved, range->start,
3113 range->len);
3114 data_space_reserved -= range->len;
3115 qgroup_reserved -= range->len;
3116 } else if (qgroup_reserved > 0) {
3117 btrfs_qgroup_free_data(BTRFS_I(inode), data_reserved,
3118 range->start, range->len, NULL);
3119 qgroup_reserved -= range->len;
3120 }
3121 list_del(&range->list);
3122 kfree(range);
3123 }
3124 if (ret < 0)
3125 goto out_unlock;
3126
3127 /*
3128 * We didn't need to allocate any more space, but we still extended the
3129 * size of the file so we need to update i_size and the inode item.
3130 */
3131 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3132out_unlock:
3133 unlock_extent(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3134 &cached_state);
3135out:
3136 btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP);
3137 extent_changeset_free(data_reserved);
3138 return ret;
3139}
3140
3141/*
3142 * Helper for btrfs_find_delalloc_in_range(). Find a subrange in a given range
3143 * that has unflushed and/or flushing delalloc. There might be other adjacent
3144 * subranges after the one it found, so btrfs_find_delalloc_in_range() keeps
3145 * looping while it gets adjacent subranges, and merging them together.
3146 */
3147static bool find_delalloc_subrange(struct btrfs_inode *inode, u64 start, u64 end,
3148 struct extent_state **cached_state,
3149 bool *search_io_tree,
3150 u64 *delalloc_start_ret, u64 *delalloc_end_ret)
3151{
3152 u64 len = end + 1 - start;
3153 u64 delalloc_len = 0;
3154 struct btrfs_ordered_extent *oe;
3155 u64 oe_start;
3156 u64 oe_end;
3157
3158 /*
3159 * Search the io tree first for EXTENT_DELALLOC. If we find any, it
3160 * means we have delalloc (dirty pages) for which writeback has not
3161 * started yet.
3162 */
3163 if (*search_io_tree) {
3164 spin_lock(&inode->lock);
3165 if (inode->delalloc_bytes > 0) {
3166 spin_unlock(&inode->lock);
3167 *delalloc_start_ret = start;
3168 delalloc_len = count_range_bits(&inode->io_tree,
3169 delalloc_start_ret, end,
3170 len, EXTENT_DELALLOC, 1,
3171 cached_state);
3172 } else {
3173 spin_unlock(&inode->lock);
3174 }
3175 }
3176
3177 if (delalloc_len > 0) {
3178 /*
3179 * If delalloc was found then *delalloc_start_ret has a sector size
3180 * aligned value (rounded down).
3181 */
3182 *delalloc_end_ret = *delalloc_start_ret + delalloc_len - 1;
3183
3184 if (*delalloc_start_ret == start) {
3185 /* Delalloc for the whole range, nothing more to do. */
3186 if (*delalloc_end_ret == end)
3187 return true;
3188 /* Else trim our search range for ordered extents. */
3189 start = *delalloc_end_ret + 1;
3190 len = end + 1 - start;
3191 }
3192 } else {
3193 /* No delalloc, future calls don't need to search again. */
3194 *search_io_tree = false;
3195 }
3196
3197 /*
3198 * Now also check if there's any ordered extent in the range.
3199 * We do this because:
3200 *
3201 * 1) When delalloc is flushed, the file range is locked, we clear the
3202 * EXTENT_DELALLOC bit from the io tree and create an extent map and
3203 * an ordered extent for the write. So we might just have been called
3204 * after delalloc is flushed and before the ordered extent completes
3205 * and inserts the new file extent item in the subvolume's btree;
3206 *
3207 * 2) We may have an ordered extent created by flushing delalloc for a
3208 * subrange that starts before the subrange we found marked with
3209 * EXTENT_DELALLOC in the io tree.
3210 *
3211 * We could also use the extent map tree to find such delalloc that is
3212 * being flushed, but using the ordered extents tree is more efficient
3213 * because it's usually much smaller as ordered extents are removed from
3214 * the tree once they complete. With the extent maps, we mau have them
3215 * in the extent map tree for a very long time, and they were either
3216 * created by previous writes or loaded by read operations.
3217 */
3218 oe = btrfs_lookup_first_ordered_range(inode, start, len);
3219 if (!oe)
3220 return (delalloc_len > 0);
3221
3222 /* The ordered extent may span beyond our search range. */
3223 oe_start = max(oe->file_offset, start);
3224 oe_end = min(oe->file_offset + oe->num_bytes - 1, end);
3225
3226 btrfs_put_ordered_extent(oe);
3227
3228 /* Don't have unflushed delalloc, return the ordered extent range. */
3229 if (delalloc_len == 0) {
3230 *delalloc_start_ret = oe_start;
3231 *delalloc_end_ret = oe_end;
3232 return true;
3233 }
3234
3235 /*
3236 * We have both unflushed delalloc (io_tree) and an ordered extent.
3237 * If the ranges are adjacent returned a combined range, otherwise
3238 * return the leftmost range.
3239 */
3240 if (oe_start < *delalloc_start_ret) {
3241 if (oe_end < *delalloc_start_ret)
3242 *delalloc_end_ret = oe_end;
3243 *delalloc_start_ret = oe_start;
3244 } else if (*delalloc_end_ret + 1 == oe_start) {
3245 *delalloc_end_ret = oe_end;
3246 }
3247
3248 return true;
3249}
3250
3251/*
3252 * Check if there's delalloc in a given range.
3253 *
3254 * @inode: The inode.
3255 * @start: The start offset of the range. It does not need to be
3256 * sector size aligned.
3257 * @end: The end offset (inclusive value) of the search range.
3258 * It does not need to be sector size aligned.
3259 * @cached_state: Extent state record used for speeding up delalloc
3260 * searches in the inode's io_tree. Can be NULL.
3261 * @delalloc_start_ret: Output argument, set to the start offset of the
3262 * subrange found with delalloc (may not be sector size
3263 * aligned).
3264 * @delalloc_end_ret: Output argument, set to he end offset (inclusive value)
3265 * of the subrange found with delalloc.
3266 *
3267 * Returns true if a subrange with delalloc is found within the given range, and
3268 * if so it sets @delalloc_start_ret and @delalloc_end_ret with the start and
3269 * end offsets of the subrange.
3270 */
3271bool btrfs_find_delalloc_in_range(struct btrfs_inode *inode, u64 start, u64 end,
3272 struct extent_state **cached_state,
3273 u64 *delalloc_start_ret, u64 *delalloc_end_ret)
3274{
3275 u64 cur_offset = round_down(start, inode->root->fs_info->sectorsize);
3276 u64 prev_delalloc_end = 0;
3277 bool search_io_tree = true;
3278 bool ret = false;
3279
3280 while (cur_offset <= end) {
3281 u64 delalloc_start;
3282 u64 delalloc_end;
3283 bool delalloc;
3284
3285 delalloc = find_delalloc_subrange(inode, cur_offset, end,
3286 cached_state, &search_io_tree,
3287 &delalloc_start,
3288 &delalloc_end);
3289 if (!delalloc)
3290 break;
3291
3292 if (prev_delalloc_end == 0) {
3293 /* First subrange found. */
3294 *delalloc_start_ret = max(delalloc_start, start);
3295 *delalloc_end_ret = delalloc_end;
3296 ret = true;
3297 } else if (delalloc_start == prev_delalloc_end + 1) {
3298 /* Subrange adjacent to the previous one, merge them. */
3299 *delalloc_end_ret = delalloc_end;
3300 } else {
3301 /* Subrange not adjacent to the previous one, exit. */
3302 break;
3303 }
3304
3305 prev_delalloc_end = delalloc_end;
3306 cur_offset = delalloc_end + 1;
3307 cond_resched();
3308 }
3309
3310 return ret;
3311}
3312
3313/*
3314 * Check if there's a hole or delalloc range in a range representing a hole (or
3315 * prealloc extent) found in the inode's subvolume btree.
3316 *
3317 * @inode: The inode.
3318 * @whence: Seek mode (SEEK_DATA or SEEK_HOLE).
3319 * @start: Start offset of the hole region. It does not need to be sector
3320 * size aligned.
3321 * @end: End offset (inclusive value) of the hole region. It does not
3322 * need to be sector size aligned.
3323 * @start_ret: Return parameter, used to set the start of the subrange in the
3324 * hole that matches the search criteria (seek mode), if such
3325 * subrange is found (return value of the function is true).
3326 * The value returned here may not be sector size aligned.
3327 *
3328 * Returns true if a subrange matching the given seek mode is found, and if one
3329 * is found, it updates @start_ret with the start of the subrange.
3330 */
3331static bool find_desired_extent_in_hole(struct btrfs_inode *inode, int whence,
3332 struct extent_state **cached_state,
3333 u64 start, u64 end, u64 *start_ret)
3334{
3335 u64 delalloc_start;
3336 u64 delalloc_end;
3337 bool delalloc;
3338
3339 delalloc = btrfs_find_delalloc_in_range(inode, start, end, cached_state,
3340 &delalloc_start, &delalloc_end);
3341 if (delalloc && whence == SEEK_DATA) {
3342 *start_ret = delalloc_start;
3343 return true;
3344 }
3345
3346 if (delalloc && whence == SEEK_HOLE) {
3347 /*
3348 * We found delalloc but it starts after out start offset. So we
3349 * have a hole between our start offset and the delalloc start.
3350 */
3351 if (start < delalloc_start) {
3352 *start_ret = start;
3353 return true;
3354 }
3355 /*
3356 * Delalloc range starts at our start offset.
3357 * If the delalloc range's length is smaller than our range,
3358 * then it means we have a hole that starts where the delalloc
3359 * subrange ends.
3360 */
3361 if (delalloc_end < end) {
3362 *start_ret = delalloc_end + 1;
3363 return true;
3364 }
3365
3366 /* There's delalloc for the whole range. */
3367 return false;
3368 }
3369
3370 if (!delalloc && whence == SEEK_HOLE) {
3371 *start_ret = start;
3372 return true;
3373 }
3374
3375 /*
3376 * No delalloc in the range and we are seeking for data. The caller has
3377 * to iterate to the next extent item in the subvolume btree.
3378 */
3379 return false;
3380}
3381
3382static loff_t find_desired_extent(struct file *file, loff_t offset, int whence)
3383{
3384 struct btrfs_inode *inode = BTRFS_I(file->f_mapping->host);
3385 struct btrfs_file_private *private;
3386 struct btrfs_fs_info *fs_info = inode->root->fs_info;
3387 struct extent_state *cached_state = NULL;
3388 struct extent_state **delalloc_cached_state;
3389 const loff_t i_size = i_size_read(&inode->vfs_inode);
3390 const u64 ino = btrfs_ino(inode);
3391 struct btrfs_root *root = inode->root;
3392 struct btrfs_path *path;
3393 struct btrfs_key key;
3394 u64 last_extent_end;
3395 u64 lockstart;
3396 u64 lockend;
3397 u64 start;
3398 int ret;
3399 bool found = false;
3400
3401 if (i_size == 0 || offset >= i_size)
3402 return -ENXIO;
3403
3404 /*
3405 * Quick path. If the inode has no prealloc extents and its number of
3406 * bytes used matches its i_size, then it can not have holes.
3407 */
3408 if (whence == SEEK_HOLE &&
3409 !(inode->flags & BTRFS_INODE_PREALLOC) &&
3410 inode_get_bytes(&inode->vfs_inode) == i_size)
3411 return i_size;
3412
3413 spin_lock(&inode->lock);
3414 private = file->private_data;
3415 spin_unlock(&inode->lock);
3416
3417 if (private && private->owner_task != current) {
3418 /*
3419 * Not allocated by us, don't use it as its cached state is used
3420 * by the task that allocated it and we don't want neither to
3421 * mess with it nor get incorrect results because it reflects an
3422 * invalid state for the current task.
3423 */
3424 private = NULL;
3425 } else if (!private) {
3426 private = kzalloc(sizeof(*private), GFP_KERNEL);
3427 /*
3428 * No worries if memory allocation failed.
3429 * The private structure is used only for speeding up multiple
3430 * lseek SEEK_HOLE/DATA calls to a file when there's delalloc,
3431 * so everything will still be correct.
3432 */
3433 if (private) {
3434 bool free = false;
3435
3436 private->owner_task = current;
3437
3438 spin_lock(&inode->lock);
3439 if (file->private_data)
3440 free = true;
3441 else
3442 file->private_data = private;
3443 spin_unlock(&inode->lock);
3444
3445 if (free) {
3446 kfree(private);
3447 private = NULL;
3448 }
3449 }
3450 }
3451
3452 if (private)
3453 delalloc_cached_state = &private->llseek_cached_state;
3454 else
3455 delalloc_cached_state = NULL;
3456
3457 /*
3458 * offset can be negative, in this case we start finding DATA/HOLE from
3459 * the very start of the file.
3460 */
3461 start = max_t(loff_t, 0, offset);
3462
3463 lockstart = round_down(start, fs_info->sectorsize);
3464 lockend = round_up(i_size, fs_info->sectorsize);
3465 if (lockend <= lockstart)
3466 lockend = lockstart + fs_info->sectorsize;
3467 lockend--;
3468
3469 path = btrfs_alloc_path();
3470 if (!path)
3471 return -ENOMEM;
3472 path->reada = READA_FORWARD;
3473
3474 key.objectid = ino;
3475 key.type = BTRFS_EXTENT_DATA_KEY;
3476 key.offset = start;
3477
3478 last_extent_end = lockstart;
3479
3480 lock_extent(&inode->io_tree, lockstart, lockend, &cached_state);
3481
3482 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3483 if (ret < 0) {
3484 goto out;
3485 } else if (ret > 0 && path->slots[0] > 0) {
3486 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
3487 if (key.objectid == ino && key.type == BTRFS_EXTENT_DATA_KEY)
3488 path->slots[0]--;
3489 }
3490
3491 while (start < i_size) {
3492 struct extent_buffer *leaf = path->nodes[0];
3493 struct btrfs_file_extent_item *extent;
3494 u64 extent_end;
3495 u8 type;
3496
3497 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3498 ret = btrfs_next_leaf(root, path);
3499 if (ret < 0)
3500 goto out;
3501 else if (ret > 0)
3502 break;
3503
3504 leaf = path->nodes[0];
3505 }
3506
3507 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3508 if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
3509 break;
3510
3511 extent_end = btrfs_file_extent_end(path);
3512
3513 /*
3514 * In the first iteration we may have a slot that points to an
3515 * extent that ends before our start offset, so skip it.
3516 */
3517 if (extent_end <= start) {
3518 path->slots[0]++;
3519 continue;
3520 }
3521
3522 /* We have an implicit hole, NO_HOLES feature is likely set. */
3523 if (last_extent_end < key.offset) {
3524 u64 search_start = last_extent_end;
3525 u64 found_start;
3526
3527 /*
3528 * First iteration, @start matches @offset and it's
3529 * within the hole.
3530 */
3531 if (start == offset)
3532 search_start = offset;
3533
3534 found = find_desired_extent_in_hole(inode, whence,
3535 delalloc_cached_state,
3536 search_start,
3537 key.offset - 1,
3538 &found_start);
3539 if (found) {
3540 start = found_start;
3541 break;
3542 }
3543 /*
3544 * Didn't find data or a hole (due to delalloc) in the
3545 * implicit hole range, so need to analyze the extent.
3546 */
3547 }
3548
3549 extent = btrfs_item_ptr(leaf, path->slots[0],
3550 struct btrfs_file_extent_item);
3551 type = btrfs_file_extent_type(leaf, extent);
3552
3553 /*
3554 * Can't access the extent's disk_bytenr field if this is an
3555 * inline extent, since at that offset, it's where the extent
3556 * data starts.
3557 */
3558 if (type == BTRFS_FILE_EXTENT_PREALLOC ||
3559 (type == BTRFS_FILE_EXTENT_REG &&
3560 btrfs_file_extent_disk_bytenr(leaf, extent) == 0)) {
3561 /*
3562 * Explicit hole or prealloc extent, search for delalloc.
3563 * A prealloc extent is treated like a hole.
3564 */
3565 u64 search_start = key.offset;
3566 u64 found_start;
3567
3568 /*
3569 * First iteration, @start matches @offset and it's
3570 * within the hole.
3571 */
3572 if (start == offset)
3573 search_start = offset;
3574
3575 found = find_desired_extent_in_hole(inode, whence,
3576 delalloc_cached_state,
3577 search_start,
3578 extent_end - 1,
3579 &found_start);
3580 if (found) {
3581 start = found_start;
3582 break;
3583 }
3584 /*
3585 * Didn't find data or a hole (due to delalloc) in the
3586 * implicit hole range, so need to analyze the next
3587 * extent item.
3588 */
3589 } else {
3590 /*
3591 * Found a regular or inline extent.
3592 * If we are seeking for data, adjust the start offset
3593 * and stop, we're done.
3594 */
3595 if (whence == SEEK_DATA) {
3596 start = max_t(u64, key.offset, offset);
3597 found = true;
3598 break;
3599 }
3600 /*
3601 * Else, we are seeking for a hole, check the next file
3602 * extent item.
3603 */
3604 }
3605
3606 start = extent_end;
3607 last_extent_end = extent_end;
3608 path->slots[0]++;
3609 if (fatal_signal_pending(current)) {
3610 ret = -EINTR;
3611 goto out;
3612 }
3613 cond_resched();
3614 }
3615
3616 /* We have an implicit hole from the last extent found up to i_size. */
3617 if (!found && start < i_size) {
3618 found = find_desired_extent_in_hole(inode, whence,
3619 delalloc_cached_state, start,
3620 i_size - 1, &start);
3621 if (!found)
3622 start = i_size;
3623 }
3624
3625out:
3626 unlock_extent(&inode->io_tree, lockstart, lockend, &cached_state);
3627 btrfs_free_path(path);
3628
3629 if (ret < 0)
3630 return ret;
3631
3632 if (whence == SEEK_DATA && start >= i_size)
3633 return -ENXIO;
3634
3635 return min_t(loff_t, start, i_size);
3636}
3637
3638static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3639{
3640 struct inode *inode = file->f_mapping->host;
3641
3642 switch (whence) {
3643 default:
3644 return generic_file_llseek(file, offset, whence);
3645 case SEEK_DATA:
3646 case SEEK_HOLE:
3647 btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_SHARED);
3648 offset = find_desired_extent(file, offset, whence);
3649 btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_SHARED);
3650 break;
3651 }
3652
3653 if (offset < 0)
3654 return offset;
3655
3656 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3657}
3658
3659static int btrfs_file_open(struct inode *inode, struct file *filp)
3660{
3661 int ret;
3662
3663 filp->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT;
3664
3665 ret = fsverity_file_open(inode, filp);
3666 if (ret)
3667 return ret;
3668 return generic_file_open(inode, filp);
3669}
3670
3671static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
3672{
3673 ssize_t ret = 0;
3674
3675 if (iocb->ki_flags & IOCB_DIRECT) {
3676 ret = btrfs_direct_read(iocb, to);
3677 if (ret < 0 || !iov_iter_count(to) ||
3678 iocb->ki_pos >= i_size_read(file_inode(iocb->ki_filp)))
3679 return ret;
3680 }
3681
3682 return filemap_read(iocb, to, ret);
3683}
3684
3685const struct file_operations btrfs_file_operations = {
3686 .llseek = btrfs_file_llseek,
3687 .read_iter = btrfs_file_read_iter,
3688 .splice_read = filemap_splice_read,
3689 .write_iter = btrfs_file_write_iter,
3690 .splice_write = iter_file_splice_write,
3691 .mmap = btrfs_file_mmap,
3692 .open = btrfs_file_open,
3693 .release = btrfs_release_file,
3694 .get_unmapped_area = thp_get_unmapped_area,
3695 .fsync = btrfs_sync_file,
3696 .fallocate = btrfs_fallocate,
3697 .unlocked_ioctl = btrfs_ioctl,
3698#ifdef CONFIG_COMPAT
3699 .compat_ioctl = btrfs_compat_ioctl,
3700#endif
3701 .remap_file_range = btrfs_remap_file_range,
3702 .uring_cmd = btrfs_uring_cmd,
3703 .fop_flags = FOP_BUFFER_RASYNC | FOP_BUFFER_WASYNC,
3704};
3705
3706int btrfs_fdatawrite_range(struct btrfs_inode *inode, loff_t start, loff_t end)
3707{
3708 struct address_space *mapping = inode->vfs_inode.i_mapping;
3709 int ret;
3710
3711 /*
3712 * So with compression we will find and lock a dirty page and clear the
3713 * first one as dirty, setup an async extent, and immediately return
3714 * with the entire range locked but with nobody actually marked with
3715 * writeback. So we can't just filemap_write_and_wait_range() and
3716 * expect it to work since it will just kick off a thread to do the
3717 * actual work. So we need to call filemap_fdatawrite_range _again_
3718 * since it will wait on the page lock, which won't be unlocked until
3719 * after the pages have been marked as writeback and so we're good to go
3720 * from there. We have to do this otherwise we'll miss the ordered
3721 * extents and that results in badness. Please Josef, do not think you
3722 * know better and pull this out at some point in the future, it is
3723 * right and you are wrong.
3724 */
3725 ret = filemap_fdatawrite_range(mapping, start, end);
3726 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, &inode->runtime_flags))
3727 ret = filemap_fdatawrite_range(mapping, start, end);
3728
3729 return ret;
3730}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/fs.h>
7#include <linux/pagemap.h>
8#include <linux/time.h>
9#include <linux/init.h>
10#include <linux/string.h>
11#include <linux/backing-dev.h>
12#include <linux/falloc.h>
13#include <linux/writeback.h>
14#include <linux/compat.h>
15#include <linux/slab.h>
16#include <linux/btrfs.h>
17#include <linux/uio.h>
18#include <linux/iversion.h>
19#include "ctree.h"
20#include "disk-io.h"
21#include "transaction.h"
22#include "btrfs_inode.h"
23#include "print-tree.h"
24#include "tree-log.h"
25#include "locking.h"
26#include "volumes.h"
27#include "qgroup.h"
28#include "compression.h"
29#include "delalloc-space.h"
30#include "reflink.h"
31#include "subpage.h"
32
33static struct kmem_cache *btrfs_inode_defrag_cachep;
34/*
35 * when auto defrag is enabled we
36 * queue up these defrag structs to remember which
37 * inodes need defragging passes
38 */
39struct inode_defrag {
40 struct rb_node rb_node;
41 /* objectid */
42 u64 ino;
43 /*
44 * transid where the defrag was added, we search for
45 * extents newer than this
46 */
47 u64 transid;
48
49 /* root objectid */
50 u64 root;
51
52 /* last offset we were able to defrag */
53 u64 last_offset;
54
55 /* if we've wrapped around back to zero once already */
56 int cycled;
57};
58
59static int __compare_inode_defrag(struct inode_defrag *defrag1,
60 struct inode_defrag *defrag2)
61{
62 if (defrag1->root > defrag2->root)
63 return 1;
64 else if (defrag1->root < defrag2->root)
65 return -1;
66 else if (defrag1->ino > defrag2->ino)
67 return 1;
68 else if (defrag1->ino < defrag2->ino)
69 return -1;
70 else
71 return 0;
72}
73
74/* pop a record for an inode into the defrag tree. The lock
75 * must be held already
76 *
77 * If you're inserting a record for an older transid than an
78 * existing record, the transid already in the tree is lowered
79 *
80 * If an existing record is found the defrag item you
81 * pass in is freed
82 */
83static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
84 struct inode_defrag *defrag)
85{
86 struct btrfs_fs_info *fs_info = inode->root->fs_info;
87 struct inode_defrag *entry;
88 struct rb_node **p;
89 struct rb_node *parent = NULL;
90 int ret;
91
92 p = &fs_info->defrag_inodes.rb_node;
93 while (*p) {
94 parent = *p;
95 entry = rb_entry(parent, struct inode_defrag, rb_node);
96
97 ret = __compare_inode_defrag(defrag, entry);
98 if (ret < 0)
99 p = &parent->rb_left;
100 else if (ret > 0)
101 p = &parent->rb_right;
102 else {
103 /* if we're reinserting an entry for
104 * an old defrag run, make sure to
105 * lower the transid of our existing record
106 */
107 if (defrag->transid < entry->transid)
108 entry->transid = defrag->transid;
109 if (defrag->last_offset > entry->last_offset)
110 entry->last_offset = defrag->last_offset;
111 return -EEXIST;
112 }
113 }
114 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
115 rb_link_node(&defrag->rb_node, parent, p);
116 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
117 return 0;
118}
119
120static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
121{
122 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
123 return 0;
124
125 if (btrfs_fs_closing(fs_info))
126 return 0;
127
128 return 1;
129}
130
131/*
132 * insert a defrag record for this inode if auto defrag is
133 * enabled
134 */
135int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
136 struct btrfs_inode *inode)
137{
138 struct btrfs_root *root = inode->root;
139 struct btrfs_fs_info *fs_info = root->fs_info;
140 struct inode_defrag *defrag;
141 u64 transid;
142 int ret;
143
144 if (!__need_auto_defrag(fs_info))
145 return 0;
146
147 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
148 return 0;
149
150 if (trans)
151 transid = trans->transid;
152 else
153 transid = inode->root->last_trans;
154
155 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
156 if (!defrag)
157 return -ENOMEM;
158
159 defrag->ino = btrfs_ino(inode);
160 defrag->transid = transid;
161 defrag->root = root->root_key.objectid;
162
163 spin_lock(&fs_info->defrag_inodes_lock);
164 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
165 /*
166 * If we set IN_DEFRAG flag and evict the inode from memory,
167 * and then re-read this inode, this new inode doesn't have
168 * IN_DEFRAG flag. At the case, we may find the existed defrag.
169 */
170 ret = __btrfs_add_inode_defrag(inode, defrag);
171 if (ret)
172 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
173 } else {
174 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
175 }
176 spin_unlock(&fs_info->defrag_inodes_lock);
177 return 0;
178}
179
180/*
181 * Requeue the defrag object. If there is a defrag object that points to
182 * the same inode in the tree, we will merge them together (by
183 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
184 */
185static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
186 struct inode_defrag *defrag)
187{
188 struct btrfs_fs_info *fs_info = inode->root->fs_info;
189 int ret;
190
191 if (!__need_auto_defrag(fs_info))
192 goto out;
193
194 /*
195 * Here we don't check the IN_DEFRAG flag, because we need merge
196 * them together.
197 */
198 spin_lock(&fs_info->defrag_inodes_lock);
199 ret = __btrfs_add_inode_defrag(inode, defrag);
200 spin_unlock(&fs_info->defrag_inodes_lock);
201 if (ret)
202 goto out;
203 return;
204out:
205 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
206}
207
208/*
209 * pick the defragable inode that we want, if it doesn't exist, we will get
210 * the next one.
211 */
212static struct inode_defrag *
213btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
214{
215 struct inode_defrag *entry = NULL;
216 struct inode_defrag tmp;
217 struct rb_node *p;
218 struct rb_node *parent = NULL;
219 int ret;
220
221 tmp.ino = ino;
222 tmp.root = root;
223
224 spin_lock(&fs_info->defrag_inodes_lock);
225 p = fs_info->defrag_inodes.rb_node;
226 while (p) {
227 parent = p;
228 entry = rb_entry(parent, struct inode_defrag, rb_node);
229
230 ret = __compare_inode_defrag(&tmp, entry);
231 if (ret < 0)
232 p = parent->rb_left;
233 else if (ret > 0)
234 p = parent->rb_right;
235 else
236 goto out;
237 }
238
239 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
240 parent = rb_next(parent);
241 if (parent)
242 entry = rb_entry(parent, struct inode_defrag, rb_node);
243 else
244 entry = NULL;
245 }
246out:
247 if (entry)
248 rb_erase(parent, &fs_info->defrag_inodes);
249 spin_unlock(&fs_info->defrag_inodes_lock);
250 return entry;
251}
252
253void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
254{
255 struct inode_defrag *defrag;
256 struct rb_node *node;
257
258 spin_lock(&fs_info->defrag_inodes_lock);
259 node = rb_first(&fs_info->defrag_inodes);
260 while (node) {
261 rb_erase(node, &fs_info->defrag_inodes);
262 defrag = rb_entry(node, struct inode_defrag, rb_node);
263 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
264
265 cond_resched_lock(&fs_info->defrag_inodes_lock);
266
267 node = rb_first(&fs_info->defrag_inodes);
268 }
269 spin_unlock(&fs_info->defrag_inodes_lock);
270}
271
272#define BTRFS_DEFRAG_BATCH 1024
273
274static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
275 struct inode_defrag *defrag)
276{
277 struct btrfs_root *inode_root;
278 struct inode *inode;
279 struct btrfs_ioctl_defrag_range_args range;
280 int num_defrag;
281 int ret;
282
283 /* get the inode */
284 inode_root = btrfs_get_fs_root(fs_info, defrag->root, true);
285 if (IS_ERR(inode_root)) {
286 ret = PTR_ERR(inode_root);
287 goto cleanup;
288 }
289
290 inode = btrfs_iget(fs_info->sb, defrag->ino, inode_root);
291 btrfs_put_root(inode_root);
292 if (IS_ERR(inode)) {
293 ret = PTR_ERR(inode);
294 goto cleanup;
295 }
296
297 /* do a chunk of defrag */
298 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
299 memset(&range, 0, sizeof(range));
300 range.len = (u64)-1;
301 range.start = defrag->last_offset;
302
303 sb_start_write(fs_info->sb);
304 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
305 BTRFS_DEFRAG_BATCH);
306 sb_end_write(fs_info->sb);
307 /*
308 * if we filled the whole defrag batch, there
309 * must be more work to do. Queue this defrag
310 * again
311 */
312 if (num_defrag == BTRFS_DEFRAG_BATCH) {
313 defrag->last_offset = range.start;
314 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
315 } else if (defrag->last_offset && !defrag->cycled) {
316 /*
317 * we didn't fill our defrag batch, but
318 * we didn't start at zero. Make sure we loop
319 * around to the start of the file.
320 */
321 defrag->last_offset = 0;
322 defrag->cycled = 1;
323 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
324 } else {
325 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
326 }
327
328 iput(inode);
329 return 0;
330cleanup:
331 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
332 return ret;
333}
334
335/*
336 * run through the list of inodes in the FS that need
337 * defragging
338 */
339int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
340{
341 struct inode_defrag *defrag;
342 u64 first_ino = 0;
343 u64 root_objectid = 0;
344
345 atomic_inc(&fs_info->defrag_running);
346 while (1) {
347 /* Pause the auto defragger. */
348 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
349 &fs_info->fs_state))
350 break;
351
352 if (!__need_auto_defrag(fs_info))
353 break;
354
355 /* find an inode to defrag */
356 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
357 first_ino);
358 if (!defrag) {
359 if (root_objectid || first_ino) {
360 root_objectid = 0;
361 first_ino = 0;
362 continue;
363 } else {
364 break;
365 }
366 }
367
368 first_ino = defrag->ino + 1;
369 root_objectid = defrag->root;
370
371 __btrfs_run_defrag_inode(fs_info, defrag);
372 }
373 atomic_dec(&fs_info->defrag_running);
374
375 /*
376 * during unmount, we use the transaction_wait queue to
377 * wait for the defragger to stop
378 */
379 wake_up(&fs_info->transaction_wait);
380 return 0;
381}
382
383/* simple helper to fault in pages and copy. This should go away
384 * and be replaced with calls into generic code.
385 */
386static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
387 struct page **prepared_pages,
388 struct iov_iter *i)
389{
390 size_t copied = 0;
391 size_t total_copied = 0;
392 int pg = 0;
393 int offset = offset_in_page(pos);
394
395 while (write_bytes > 0) {
396 size_t count = min_t(size_t,
397 PAGE_SIZE - offset, write_bytes);
398 struct page *page = prepared_pages[pg];
399 /*
400 * Copy data from userspace to the current page
401 */
402 copied = copy_page_from_iter_atomic(page, offset, count, i);
403
404 /* Flush processor's dcache for this page */
405 flush_dcache_page(page);
406
407 /*
408 * if we get a partial write, we can end up with
409 * partially up to date pages. These add
410 * a lot of complexity, so make sure they don't
411 * happen by forcing this copy to be retried.
412 *
413 * The rest of the btrfs_file_write code will fall
414 * back to page at a time copies after we return 0.
415 */
416 if (unlikely(copied < count)) {
417 if (!PageUptodate(page)) {
418 iov_iter_revert(i, copied);
419 copied = 0;
420 }
421 if (!copied)
422 break;
423 }
424
425 write_bytes -= copied;
426 total_copied += copied;
427 offset += copied;
428 if (offset == PAGE_SIZE) {
429 pg++;
430 offset = 0;
431 }
432 }
433 return total_copied;
434}
435
436/*
437 * unlocks pages after btrfs_file_write is done with them
438 */
439static void btrfs_drop_pages(struct page **pages, size_t num_pages)
440{
441 size_t i;
442 for (i = 0; i < num_pages; i++) {
443 /* page checked is some magic around finding pages that
444 * have been modified without going through btrfs_set_page_dirty
445 * clear it here. There should be no need to mark the pages
446 * accessed as prepare_pages should have marked them accessed
447 * in prepare_pages via find_or_create_page()
448 */
449 ClearPageChecked(pages[i]);
450 unlock_page(pages[i]);
451 put_page(pages[i]);
452 }
453}
454
455/*
456 * After btrfs_copy_from_user(), update the following things for delalloc:
457 * - Mark newly dirtied pages as DELALLOC in the io tree.
458 * Used to advise which range is to be written back.
459 * - Mark modified pages as Uptodate/Dirty and not needing COW fixup
460 * - Update inode size for past EOF write
461 */
462int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
463 size_t num_pages, loff_t pos, size_t write_bytes,
464 struct extent_state **cached, bool noreserve)
465{
466 struct btrfs_fs_info *fs_info = inode->root->fs_info;
467 int err = 0;
468 int i;
469 u64 num_bytes;
470 u64 start_pos;
471 u64 end_of_last_block;
472 u64 end_pos = pos + write_bytes;
473 loff_t isize = i_size_read(&inode->vfs_inode);
474 unsigned int extra_bits = 0;
475
476 if (write_bytes == 0)
477 return 0;
478
479 if (noreserve)
480 extra_bits |= EXTENT_NORESERVE;
481
482 start_pos = round_down(pos, fs_info->sectorsize);
483 num_bytes = round_up(write_bytes + pos - start_pos,
484 fs_info->sectorsize);
485 ASSERT(num_bytes <= U32_MAX);
486
487 end_of_last_block = start_pos + num_bytes - 1;
488
489 /*
490 * The pages may have already been dirty, clear out old accounting so
491 * we can set things up properly
492 */
493 clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block,
494 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
495 0, 0, cached);
496
497 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
498 extra_bits, cached);
499 if (err)
500 return err;
501
502 for (i = 0; i < num_pages; i++) {
503 struct page *p = pages[i];
504
505 btrfs_page_clamp_set_uptodate(fs_info, p, start_pos, num_bytes);
506 ClearPageChecked(p);
507 btrfs_page_clamp_set_dirty(fs_info, p, start_pos, num_bytes);
508 }
509
510 /*
511 * we've only changed i_size in ram, and we haven't updated
512 * the disk i_size. There is no need to log the inode
513 * at this time.
514 */
515 if (end_pos > isize)
516 i_size_write(&inode->vfs_inode, end_pos);
517 return 0;
518}
519
520/*
521 * this drops all the extents in the cache that intersect the range
522 * [start, end]. Existing extents are split as required.
523 */
524void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
525 int skip_pinned)
526{
527 struct extent_map *em;
528 struct extent_map *split = NULL;
529 struct extent_map *split2 = NULL;
530 struct extent_map_tree *em_tree = &inode->extent_tree;
531 u64 len = end - start + 1;
532 u64 gen;
533 int ret;
534 int testend = 1;
535 unsigned long flags;
536 int compressed = 0;
537 bool modified;
538
539 WARN_ON(end < start);
540 if (end == (u64)-1) {
541 len = (u64)-1;
542 testend = 0;
543 }
544 while (1) {
545 int no_splits = 0;
546
547 modified = false;
548 if (!split)
549 split = alloc_extent_map();
550 if (!split2)
551 split2 = alloc_extent_map();
552 if (!split || !split2)
553 no_splits = 1;
554
555 write_lock(&em_tree->lock);
556 em = lookup_extent_mapping(em_tree, start, len);
557 if (!em) {
558 write_unlock(&em_tree->lock);
559 break;
560 }
561 flags = em->flags;
562 gen = em->generation;
563 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
564 if (testend && em->start + em->len >= start + len) {
565 free_extent_map(em);
566 write_unlock(&em_tree->lock);
567 break;
568 }
569 start = em->start + em->len;
570 if (testend)
571 len = start + len - (em->start + em->len);
572 free_extent_map(em);
573 write_unlock(&em_tree->lock);
574 continue;
575 }
576 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
577 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
578 clear_bit(EXTENT_FLAG_LOGGING, &flags);
579 modified = !list_empty(&em->list);
580 if (no_splits)
581 goto next;
582
583 if (em->start < start) {
584 split->start = em->start;
585 split->len = start - em->start;
586
587 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
588 split->orig_start = em->orig_start;
589 split->block_start = em->block_start;
590
591 if (compressed)
592 split->block_len = em->block_len;
593 else
594 split->block_len = split->len;
595 split->orig_block_len = max(split->block_len,
596 em->orig_block_len);
597 split->ram_bytes = em->ram_bytes;
598 } else {
599 split->orig_start = split->start;
600 split->block_len = 0;
601 split->block_start = em->block_start;
602 split->orig_block_len = 0;
603 split->ram_bytes = split->len;
604 }
605
606 split->generation = gen;
607 split->flags = flags;
608 split->compress_type = em->compress_type;
609 replace_extent_mapping(em_tree, em, split, modified);
610 free_extent_map(split);
611 split = split2;
612 split2 = NULL;
613 }
614 if (testend && em->start + em->len > start + len) {
615 u64 diff = start + len - em->start;
616
617 split->start = start + len;
618 split->len = em->start + em->len - (start + len);
619 split->flags = flags;
620 split->compress_type = em->compress_type;
621 split->generation = gen;
622
623 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
624 split->orig_block_len = max(em->block_len,
625 em->orig_block_len);
626
627 split->ram_bytes = em->ram_bytes;
628 if (compressed) {
629 split->block_len = em->block_len;
630 split->block_start = em->block_start;
631 split->orig_start = em->orig_start;
632 } else {
633 split->block_len = split->len;
634 split->block_start = em->block_start
635 + diff;
636 split->orig_start = em->orig_start;
637 }
638 } else {
639 split->ram_bytes = split->len;
640 split->orig_start = split->start;
641 split->block_len = 0;
642 split->block_start = em->block_start;
643 split->orig_block_len = 0;
644 }
645
646 if (extent_map_in_tree(em)) {
647 replace_extent_mapping(em_tree, em, split,
648 modified);
649 } else {
650 ret = add_extent_mapping(em_tree, split,
651 modified);
652 ASSERT(ret == 0); /* Logic error */
653 }
654 free_extent_map(split);
655 split = NULL;
656 }
657next:
658 if (extent_map_in_tree(em))
659 remove_extent_mapping(em_tree, em);
660 write_unlock(&em_tree->lock);
661
662 /* once for us */
663 free_extent_map(em);
664 /* once for the tree*/
665 free_extent_map(em);
666 }
667 if (split)
668 free_extent_map(split);
669 if (split2)
670 free_extent_map(split2);
671}
672
673/*
674 * this is very complex, but the basic idea is to drop all extents
675 * in the range start - end. hint_block is filled in with a block number
676 * that would be a good hint to the block allocator for this file.
677 *
678 * If an extent intersects the range but is not entirely inside the range
679 * it is either truncated or split. Anything entirely inside the range
680 * is deleted from the tree.
681 *
682 * Note: the VFS' inode number of bytes is not updated, it's up to the caller
683 * to deal with that. We set the field 'bytes_found' of the arguments structure
684 * with the number of allocated bytes found in the target range, so that the
685 * caller can update the inode's number of bytes in an atomic way when
686 * replacing extents in a range to avoid races with stat(2).
687 */
688int btrfs_drop_extents(struct btrfs_trans_handle *trans,
689 struct btrfs_root *root, struct btrfs_inode *inode,
690 struct btrfs_drop_extents_args *args)
691{
692 struct btrfs_fs_info *fs_info = root->fs_info;
693 struct extent_buffer *leaf;
694 struct btrfs_file_extent_item *fi;
695 struct btrfs_ref ref = { 0 };
696 struct btrfs_key key;
697 struct btrfs_key new_key;
698 u64 ino = btrfs_ino(inode);
699 u64 search_start = args->start;
700 u64 disk_bytenr = 0;
701 u64 num_bytes = 0;
702 u64 extent_offset = 0;
703 u64 extent_end = 0;
704 u64 last_end = args->start;
705 int del_nr = 0;
706 int del_slot = 0;
707 int extent_type;
708 int recow;
709 int ret;
710 int modify_tree = -1;
711 int update_refs;
712 int found = 0;
713 int leafs_visited = 0;
714 struct btrfs_path *path = args->path;
715
716 args->bytes_found = 0;
717 args->extent_inserted = false;
718
719 /* Must always have a path if ->replace_extent is true */
720 ASSERT(!(args->replace_extent && !args->path));
721
722 if (!path) {
723 path = btrfs_alloc_path();
724 if (!path) {
725 ret = -ENOMEM;
726 goto out;
727 }
728 }
729
730 if (args->drop_cache)
731 btrfs_drop_extent_cache(inode, args->start, args->end - 1, 0);
732
733 if (args->start >= inode->disk_i_size && !args->replace_extent)
734 modify_tree = 0;
735
736 update_refs = (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID);
737 while (1) {
738 recow = 0;
739 ret = btrfs_lookup_file_extent(trans, root, path, ino,
740 search_start, modify_tree);
741 if (ret < 0)
742 break;
743 if (ret > 0 && path->slots[0] > 0 && search_start == args->start) {
744 leaf = path->nodes[0];
745 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
746 if (key.objectid == ino &&
747 key.type == BTRFS_EXTENT_DATA_KEY)
748 path->slots[0]--;
749 }
750 ret = 0;
751 leafs_visited++;
752next_slot:
753 leaf = path->nodes[0];
754 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
755 BUG_ON(del_nr > 0);
756 ret = btrfs_next_leaf(root, path);
757 if (ret < 0)
758 break;
759 if (ret > 0) {
760 ret = 0;
761 break;
762 }
763 leafs_visited++;
764 leaf = path->nodes[0];
765 recow = 1;
766 }
767
768 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
769
770 if (key.objectid > ino)
771 break;
772 if (WARN_ON_ONCE(key.objectid < ino) ||
773 key.type < BTRFS_EXTENT_DATA_KEY) {
774 ASSERT(del_nr == 0);
775 path->slots[0]++;
776 goto next_slot;
777 }
778 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= args->end)
779 break;
780
781 fi = btrfs_item_ptr(leaf, path->slots[0],
782 struct btrfs_file_extent_item);
783 extent_type = btrfs_file_extent_type(leaf, fi);
784
785 if (extent_type == BTRFS_FILE_EXTENT_REG ||
786 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
787 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
788 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
789 extent_offset = btrfs_file_extent_offset(leaf, fi);
790 extent_end = key.offset +
791 btrfs_file_extent_num_bytes(leaf, fi);
792 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
793 extent_end = key.offset +
794 btrfs_file_extent_ram_bytes(leaf, fi);
795 } else {
796 /* can't happen */
797 BUG();
798 }
799
800 /*
801 * Don't skip extent items representing 0 byte lengths. They
802 * used to be created (bug) if while punching holes we hit
803 * -ENOSPC condition. So if we find one here, just ensure we
804 * delete it, otherwise we would insert a new file extent item
805 * with the same key (offset) as that 0 bytes length file
806 * extent item in the call to setup_items_for_insert() later
807 * in this function.
808 */
809 if (extent_end == key.offset && extent_end >= search_start) {
810 last_end = extent_end;
811 goto delete_extent_item;
812 }
813
814 if (extent_end <= search_start) {
815 path->slots[0]++;
816 goto next_slot;
817 }
818
819 found = 1;
820 search_start = max(key.offset, args->start);
821 if (recow || !modify_tree) {
822 modify_tree = -1;
823 btrfs_release_path(path);
824 continue;
825 }
826
827 /*
828 * | - range to drop - |
829 * | -------- extent -------- |
830 */
831 if (args->start > key.offset && args->end < extent_end) {
832 BUG_ON(del_nr > 0);
833 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
834 ret = -EOPNOTSUPP;
835 break;
836 }
837
838 memcpy(&new_key, &key, sizeof(new_key));
839 new_key.offset = args->start;
840 ret = btrfs_duplicate_item(trans, root, path,
841 &new_key);
842 if (ret == -EAGAIN) {
843 btrfs_release_path(path);
844 continue;
845 }
846 if (ret < 0)
847 break;
848
849 leaf = path->nodes[0];
850 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
851 struct btrfs_file_extent_item);
852 btrfs_set_file_extent_num_bytes(leaf, fi,
853 args->start - key.offset);
854
855 fi = btrfs_item_ptr(leaf, path->slots[0],
856 struct btrfs_file_extent_item);
857
858 extent_offset += args->start - key.offset;
859 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
860 btrfs_set_file_extent_num_bytes(leaf, fi,
861 extent_end - args->start);
862 btrfs_mark_buffer_dirty(leaf);
863
864 if (update_refs && disk_bytenr > 0) {
865 btrfs_init_generic_ref(&ref,
866 BTRFS_ADD_DELAYED_REF,
867 disk_bytenr, num_bytes, 0);
868 btrfs_init_data_ref(&ref,
869 root->root_key.objectid,
870 new_key.objectid,
871 args->start - extent_offset);
872 ret = btrfs_inc_extent_ref(trans, &ref);
873 BUG_ON(ret); /* -ENOMEM */
874 }
875 key.offset = args->start;
876 }
877 /*
878 * From here on out we will have actually dropped something, so
879 * last_end can be updated.
880 */
881 last_end = extent_end;
882
883 /*
884 * | ---- range to drop ----- |
885 * | -------- extent -------- |
886 */
887 if (args->start <= key.offset && args->end < extent_end) {
888 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
889 ret = -EOPNOTSUPP;
890 break;
891 }
892
893 memcpy(&new_key, &key, sizeof(new_key));
894 new_key.offset = args->end;
895 btrfs_set_item_key_safe(fs_info, path, &new_key);
896
897 extent_offset += args->end - key.offset;
898 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
899 btrfs_set_file_extent_num_bytes(leaf, fi,
900 extent_end - args->end);
901 btrfs_mark_buffer_dirty(leaf);
902 if (update_refs && disk_bytenr > 0)
903 args->bytes_found += args->end - key.offset;
904 break;
905 }
906
907 search_start = extent_end;
908 /*
909 * | ---- range to drop ----- |
910 * | -------- extent -------- |
911 */
912 if (args->start > key.offset && args->end >= extent_end) {
913 BUG_ON(del_nr > 0);
914 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
915 ret = -EOPNOTSUPP;
916 break;
917 }
918
919 btrfs_set_file_extent_num_bytes(leaf, fi,
920 args->start - key.offset);
921 btrfs_mark_buffer_dirty(leaf);
922 if (update_refs && disk_bytenr > 0)
923 args->bytes_found += extent_end - args->start;
924 if (args->end == extent_end)
925 break;
926
927 path->slots[0]++;
928 goto next_slot;
929 }
930
931 /*
932 * | ---- range to drop ----- |
933 * | ------ extent ------ |
934 */
935 if (args->start <= key.offset && args->end >= extent_end) {
936delete_extent_item:
937 if (del_nr == 0) {
938 del_slot = path->slots[0];
939 del_nr = 1;
940 } else {
941 BUG_ON(del_slot + del_nr != path->slots[0]);
942 del_nr++;
943 }
944
945 if (update_refs &&
946 extent_type == BTRFS_FILE_EXTENT_INLINE) {
947 args->bytes_found += extent_end - key.offset;
948 extent_end = ALIGN(extent_end,
949 fs_info->sectorsize);
950 } else if (update_refs && disk_bytenr > 0) {
951 btrfs_init_generic_ref(&ref,
952 BTRFS_DROP_DELAYED_REF,
953 disk_bytenr, num_bytes, 0);
954 btrfs_init_data_ref(&ref,
955 root->root_key.objectid,
956 key.objectid,
957 key.offset - extent_offset);
958 ret = btrfs_free_extent(trans, &ref);
959 BUG_ON(ret); /* -ENOMEM */
960 args->bytes_found += extent_end - key.offset;
961 }
962
963 if (args->end == extent_end)
964 break;
965
966 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
967 path->slots[0]++;
968 goto next_slot;
969 }
970
971 ret = btrfs_del_items(trans, root, path, del_slot,
972 del_nr);
973 if (ret) {
974 btrfs_abort_transaction(trans, ret);
975 break;
976 }
977
978 del_nr = 0;
979 del_slot = 0;
980
981 btrfs_release_path(path);
982 continue;
983 }
984
985 BUG();
986 }
987
988 if (!ret && del_nr > 0) {
989 /*
990 * Set path->slots[0] to first slot, so that after the delete
991 * if items are move off from our leaf to its immediate left or
992 * right neighbor leafs, we end up with a correct and adjusted
993 * path->slots[0] for our insertion (if args->replace_extent).
994 */
995 path->slots[0] = del_slot;
996 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
997 if (ret)
998 btrfs_abort_transaction(trans, ret);
999 }
1000
1001 leaf = path->nodes[0];
1002 /*
1003 * If btrfs_del_items() was called, it might have deleted a leaf, in
1004 * which case it unlocked our path, so check path->locks[0] matches a
1005 * write lock.
1006 */
1007 if (!ret && args->replace_extent && leafs_visited == 1 &&
1008 path->locks[0] == BTRFS_WRITE_LOCK &&
1009 btrfs_leaf_free_space(leaf) >=
1010 sizeof(struct btrfs_item) + args->extent_item_size) {
1011
1012 key.objectid = ino;
1013 key.type = BTRFS_EXTENT_DATA_KEY;
1014 key.offset = args->start;
1015 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1016 struct btrfs_key slot_key;
1017
1018 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1019 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1020 path->slots[0]++;
1021 }
1022 setup_items_for_insert(root, path, &key,
1023 &args->extent_item_size, 1);
1024 args->extent_inserted = true;
1025 }
1026
1027 if (!args->path)
1028 btrfs_free_path(path);
1029 else if (!args->extent_inserted)
1030 btrfs_release_path(path);
1031out:
1032 args->drop_end = found ? min(args->end, last_end) : args->end;
1033
1034 return ret;
1035}
1036
1037static int extent_mergeable(struct extent_buffer *leaf, int slot,
1038 u64 objectid, u64 bytenr, u64 orig_offset,
1039 u64 *start, u64 *end)
1040{
1041 struct btrfs_file_extent_item *fi;
1042 struct btrfs_key key;
1043 u64 extent_end;
1044
1045 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1046 return 0;
1047
1048 btrfs_item_key_to_cpu(leaf, &key, slot);
1049 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1050 return 0;
1051
1052 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1053 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1054 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1055 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1056 btrfs_file_extent_compression(leaf, fi) ||
1057 btrfs_file_extent_encryption(leaf, fi) ||
1058 btrfs_file_extent_other_encoding(leaf, fi))
1059 return 0;
1060
1061 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1062 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1063 return 0;
1064
1065 *start = key.offset;
1066 *end = extent_end;
1067 return 1;
1068}
1069
1070/*
1071 * Mark extent in the range start - end as written.
1072 *
1073 * This changes extent type from 'pre-allocated' to 'regular'. If only
1074 * part of extent is marked as written, the extent will be split into
1075 * two or three.
1076 */
1077int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1078 struct btrfs_inode *inode, u64 start, u64 end)
1079{
1080 struct btrfs_fs_info *fs_info = trans->fs_info;
1081 struct btrfs_root *root = inode->root;
1082 struct extent_buffer *leaf;
1083 struct btrfs_path *path;
1084 struct btrfs_file_extent_item *fi;
1085 struct btrfs_ref ref = { 0 };
1086 struct btrfs_key key;
1087 struct btrfs_key new_key;
1088 u64 bytenr;
1089 u64 num_bytes;
1090 u64 extent_end;
1091 u64 orig_offset;
1092 u64 other_start;
1093 u64 other_end;
1094 u64 split;
1095 int del_nr = 0;
1096 int del_slot = 0;
1097 int recow;
1098 int ret = 0;
1099 u64 ino = btrfs_ino(inode);
1100
1101 path = btrfs_alloc_path();
1102 if (!path)
1103 return -ENOMEM;
1104again:
1105 recow = 0;
1106 split = start;
1107 key.objectid = ino;
1108 key.type = BTRFS_EXTENT_DATA_KEY;
1109 key.offset = split;
1110
1111 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1112 if (ret < 0)
1113 goto out;
1114 if (ret > 0 && path->slots[0] > 0)
1115 path->slots[0]--;
1116
1117 leaf = path->nodes[0];
1118 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1119 if (key.objectid != ino ||
1120 key.type != BTRFS_EXTENT_DATA_KEY) {
1121 ret = -EINVAL;
1122 btrfs_abort_transaction(trans, ret);
1123 goto out;
1124 }
1125 fi = btrfs_item_ptr(leaf, path->slots[0],
1126 struct btrfs_file_extent_item);
1127 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1128 ret = -EINVAL;
1129 btrfs_abort_transaction(trans, ret);
1130 goto out;
1131 }
1132 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1133 if (key.offset > start || extent_end < end) {
1134 ret = -EINVAL;
1135 btrfs_abort_transaction(trans, ret);
1136 goto out;
1137 }
1138
1139 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1140 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1141 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1142 memcpy(&new_key, &key, sizeof(new_key));
1143
1144 if (start == key.offset && end < extent_end) {
1145 other_start = 0;
1146 other_end = start;
1147 if (extent_mergeable(leaf, path->slots[0] - 1,
1148 ino, bytenr, orig_offset,
1149 &other_start, &other_end)) {
1150 new_key.offset = end;
1151 btrfs_set_item_key_safe(fs_info, path, &new_key);
1152 fi = btrfs_item_ptr(leaf, path->slots[0],
1153 struct btrfs_file_extent_item);
1154 btrfs_set_file_extent_generation(leaf, fi,
1155 trans->transid);
1156 btrfs_set_file_extent_num_bytes(leaf, fi,
1157 extent_end - end);
1158 btrfs_set_file_extent_offset(leaf, fi,
1159 end - orig_offset);
1160 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1161 struct btrfs_file_extent_item);
1162 btrfs_set_file_extent_generation(leaf, fi,
1163 trans->transid);
1164 btrfs_set_file_extent_num_bytes(leaf, fi,
1165 end - other_start);
1166 btrfs_mark_buffer_dirty(leaf);
1167 goto out;
1168 }
1169 }
1170
1171 if (start > key.offset && end == extent_end) {
1172 other_start = end;
1173 other_end = 0;
1174 if (extent_mergeable(leaf, path->slots[0] + 1,
1175 ino, bytenr, orig_offset,
1176 &other_start, &other_end)) {
1177 fi = btrfs_item_ptr(leaf, path->slots[0],
1178 struct btrfs_file_extent_item);
1179 btrfs_set_file_extent_num_bytes(leaf, fi,
1180 start - key.offset);
1181 btrfs_set_file_extent_generation(leaf, fi,
1182 trans->transid);
1183 path->slots[0]++;
1184 new_key.offset = start;
1185 btrfs_set_item_key_safe(fs_info, path, &new_key);
1186
1187 fi = btrfs_item_ptr(leaf, path->slots[0],
1188 struct btrfs_file_extent_item);
1189 btrfs_set_file_extent_generation(leaf, fi,
1190 trans->transid);
1191 btrfs_set_file_extent_num_bytes(leaf, fi,
1192 other_end - start);
1193 btrfs_set_file_extent_offset(leaf, fi,
1194 start - orig_offset);
1195 btrfs_mark_buffer_dirty(leaf);
1196 goto out;
1197 }
1198 }
1199
1200 while (start > key.offset || end < extent_end) {
1201 if (key.offset == start)
1202 split = end;
1203
1204 new_key.offset = split;
1205 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1206 if (ret == -EAGAIN) {
1207 btrfs_release_path(path);
1208 goto again;
1209 }
1210 if (ret < 0) {
1211 btrfs_abort_transaction(trans, ret);
1212 goto out;
1213 }
1214
1215 leaf = path->nodes[0];
1216 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1217 struct btrfs_file_extent_item);
1218 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1219 btrfs_set_file_extent_num_bytes(leaf, fi,
1220 split - key.offset);
1221
1222 fi = btrfs_item_ptr(leaf, path->slots[0],
1223 struct btrfs_file_extent_item);
1224
1225 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1226 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1227 btrfs_set_file_extent_num_bytes(leaf, fi,
1228 extent_end - split);
1229 btrfs_mark_buffer_dirty(leaf);
1230
1231 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
1232 num_bytes, 0);
1233 btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
1234 orig_offset);
1235 ret = btrfs_inc_extent_ref(trans, &ref);
1236 if (ret) {
1237 btrfs_abort_transaction(trans, ret);
1238 goto out;
1239 }
1240
1241 if (split == start) {
1242 key.offset = start;
1243 } else {
1244 if (start != key.offset) {
1245 ret = -EINVAL;
1246 btrfs_abort_transaction(trans, ret);
1247 goto out;
1248 }
1249 path->slots[0]--;
1250 extent_end = end;
1251 }
1252 recow = 1;
1253 }
1254
1255 other_start = end;
1256 other_end = 0;
1257 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1258 num_bytes, 0);
1259 btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset);
1260 if (extent_mergeable(leaf, path->slots[0] + 1,
1261 ino, bytenr, orig_offset,
1262 &other_start, &other_end)) {
1263 if (recow) {
1264 btrfs_release_path(path);
1265 goto again;
1266 }
1267 extent_end = other_end;
1268 del_slot = path->slots[0] + 1;
1269 del_nr++;
1270 ret = btrfs_free_extent(trans, &ref);
1271 if (ret) {
1272 btrfs_abort_transaction(trans, ret);
1273 goto out;
1274 }
1275 }
1276 other_start = 0;
1277 other_end = start;
1278 if (extent_mergeable(leaf, path->slots[0] - 1,
1279 ino, bytenr, orig_offset,
1280 &other_start, &other_end)) {
1281 if (recow) {
1282 btrfs_release_path(path);
1283 goto again;
1284 }
1285 key.offset = other_start;
1286 del_slot = path->slots[0];
1287 del_nr++;
1288 ret = btrfs_free_extent(trans, &ref);
1289 if (ret) {
1290 btrfs_abort_transaction(trans, ret);
1291 goto out;
1292 }
1293 }
1294 if (del_nr == 0) {
1295 fi = btrfs_item_ptr(leaf, path->slots[0],
1296 struct btrfs_file_extent_item);
1297 btrfs_set_file_extent_type(leaf, fi,
1298 BTRFS_FILE_EXTENT_REG);
1299 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1300 btrfs_mark_buffer_dirty(leaf);
1301 } else {
1302 fi = btrfs_item_ptr(leaf, del_slot - 1,
1303 struct btrfs_file_extent_item);
1304 btrfs_set_file_extent_type(leaf, fi,
1305 BTRFS_FILE_EXTENT_REG);
1306 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1307 btrfs_set_file_extent_num_bytes(leaf, fi,
1308 extent_end - key.offset);
1309 btrfs_mark_buffer_dirty(leaf);
1310
1311 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1312 if (ret < 0) {
1313 btrfs_abort_transaction(trans, ret);
1314 goto out;
1315 }
1316 }
1317out:
1318 btrfs_free_path(path);
1319 return ret;
1320}
1321
1322/*
1323 * on error we return an unlocked page and the error value
1324 * on success we return a locked page and 0
1325 */
1326static int prepare_uptodate_page(struct inode *inode,
1327 struct page *page, u64 pos,
1328 bool force_uptodate)
1329{
1330 int ret = 0;
1331
1332 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1333 !PageUptodate(page)) {
1334 ret = btrfs_readpage(NULL, page);
1335 if (ret)
1336 return ret;
1337 lock_page(page);
1338 if (!PageUptodate(page)) {
1339 unlock_page(page);
1340 return -EIO;
1341 }
1342 if (page->mapping != inode->i_mapping) {
1343 unlock_page(page);
1344 return -EAGAIN;
1345 }
1346 }
1347 return 0;
1348}
1349
1350/*
1351 * this just gets pages into the page cache and locks them down.
1352 */
1353static noinline int prepare_pages(struct inode *inode, struct page **pages,
1354 size_t num_pages, loff_t pos,
1355 size_t write_bytes, bool force_uptodate)
1356{
1357 int i;
1358 unsigned long index = pos >> PAGE_SHIFT;
1359 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1360 int err = 0;
1361 int faili;
1362
1363 for (i = 0; i < num_pages; i++) {
1364again:
1365 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1366 mask | __GFP_WRITE);
1367 if (!pages[i]) {
1368 faili = i - 1;
1369 err = -ENOMEM;
1370 goto fail;
1371 }
1372
1373 err = set_page_extent_mapped(pages[i]);
1374 if (err < 0) {
1375 faili = i;
1376 goto fail;
1377 }
1378
1379 if (i == 0)
1380 err = prepare_uptodate_page(inode, pages[i], pos,
1381 force_uptodate);
1382 if (!err && i == num_pages - 1)
1383 err = prepare_uptodate_page(inode, pages[i],
1384 pos + write_bytes, false);
1385 if (err) {
1386 put_page(pages[i]);
1387 if (err == -EAGAIN) {
1388 err = 0;
1389 goto again;
1390 }
1391 faili = i - 1;
1392 goto fail;
1393 }
1394 wait_on_page_writeback(pages[i]);
1395 }
1396
1397 return 0;
1398fail:
1399 while (faili >= 0) {
1400 unlock_page(pages[faili]);
1401 put_page(pages[faili]);
1402 faili--;
1403 }
1404 return err;
1405
1406}
1407
1408/*
1409 * This function locks the extent and properly waits for data=ordered extents
1410 * to finish before allowing the pages to be modified if need.
1411 *
1412 * The return value:
1413 * 1 - the extent is locked
1414 * 0 - the extent is not locked, and everything is OK
1415 * -EAGAIN - need re-prepare the pages
1416 * the other < 0 number - Something wrong happens
1417 */
1418static noinline int
1419lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1420 size_t num_pages, loff_t pos,
1421 size_t write_bytes,
1422 u64 *lockstart, u64 *lockend,
1423 struct extent_state **cached_state)
1424{
1425 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1426 u64 start_pos;
1427 u64 last_pos;
1428 int i;
1429 int ret = 0;
1430
1431 start_pos = round_down(pos, fs_info->sectorsize);
1432 last_pos = round_up(pos + write_bytes, fs_info->sectorsize) - 1;
1433
1434 if (start_pos < inode->vfs_inode.i_size) {
1435 struct btrfs_ordered_extent *ordered;
1436
1437 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1438 cached_state);
1439 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1440 last_pos - start_pos + 1);
1441 if (ordered &&
1442 ordered->file_offset + ordered->num_bytes > start_pos &&
1443 ordered->file_offset <= last_pos) {
1444 unlock_extent_cached(&inode->io_tree, start_pos,
1445 last_pos, cached_state);
1446 for (i = 0; i < num_pages; i++) {
1447 unlock_page(pages[i]);
1448 put_page(pages[i]);
1449 }
1450 btrfs_start_ordered_extent(ordered, 1);
1451 btrfs_put_ordered_extent(ordered);
1452 return -EAGAIN;
1453 }
1454 if (ordered)
1455 btrfs_put_ordered_extent(ordered);
1456
1457 *lockstart = start_pos;
1458 *lockend = last_pos;
1459 ret = 1;
1460 }
1461
1462 /*
1463 * We should be called after prepare_pages() which should have locked
1464 * all pages in the range.
1465 */
1466 for (i = 0; i < num_pages; i++)
1467 WARN_ON(!PageLocked(pages[i]));
1468
1469 return ret;
1470}
1471
1472static int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1473 size_t *write_bytes, bool nowait)
1474{
1475 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1476 struct btrfs_root *root = inode->root;
1477 u64 lockstart, lockend;
1478 u64 num_bytes;
1479 int ret;
1480
1481 if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC)))
1482 return 0;
1483
1484 if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock))
1485 return -EAGAIN;
1486
1487 lockstart = round_down(pos, fs_info->sectorsize);
1488 lockend = round_up(pos + *write_bytes,
1489 fs_info->sectorsize) - 1;
1490 num_bytes = lockend - lockstart + 1;
1491
1492 if (nowait) {
1493 struct btrfs_ordered_extent *ordered;
1494
1495 if (!try_lock_extent(&inode->io_tree, lockstart, lockend))
1496 return -EAGAIN;
1497
1498 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1499 num_bytes);
1500 if (ordered) {
1501 btrfs_put_ordered_extent(ordered);
1502 ret = -EAGAIN;
1503 goto out_unlock;
1504 }
1505 } else {
1506 btrfs_lock_and_flush_ordered_range(inode, lockstart,
1507 lockend, NULL);
1508 }
1509
1510 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1511 NULL, NULL, NULL, false);
1512 if (ret <= 0) {
1513 ret = 0;
1514 if (!nowait)
1515 btrfs_drew_write_unlock(&root->snapshot_lock);
1516 } else {
1517 *write_bytes = min_t(size_t, *write_bytes ,
1518 num_bytes - pos + lockstart);
1519 }
1520out_unlock:
1521 unlock_extent(&inode->io_tree, lockstart, lockend);
1522
1523 return ret;
1524}
1525
1526static int check_nocow_nolock(struct btrfs_inode *inode, loff_t pos,
1527 size_t *write_bytes)
1528{
1529 return check_can_nocow(inode, pos, write_bytes, true);
1530}
1531
1532/*
1533 * Check if we can do nocow write into the range [@pos, @pos + @write_bytes)
1534 *
1535 * @pos: File offset
1536 * @write_bytes: The length to write, will be updated to the nocow writeable
1537 * range
1538 *
1539 * This function will flush ordered extents in the range to ensure proper
1540 * nocow checks.
1541 *
1542 * Return:
1543 * >0 and update @write_bytes if we can do nocow write
1544 * 0 if we can't do nocow write
1545 * -EAGAIN if we can't get the needed lock or there are ordered extents
1546 * for * (nowait == true) case
1547 * <0 if other error happened
1548 *
1549 * NOTE: Callers need to release the lock by btrfs_check_nocow_unlock().
1550 */
1551int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos,
1552 size_t *write_bytes)
1553{
1554 return check_can_nocow(inode, pos, write_bytes, false);
1555}
1556
1557void btrfs_check_nocow_unlock(struct btrfs_inode *inode)
1558{
1559 btrfs_drew_write_unlock(&inode->root->snapshot_lock);
1560}
1561
1562static void update_time_for_write(struct inode *inode)
1563{
1564 struct timespec64 now;
1565
1566 if (IS_NOCMTIME(inode))
1567 return;
1568
1569 now = current_time(inode);
1570 if (!timespec64_equal(&inode->i_mtime, &now))
1571 inode->i_mtime = now;
1572
1573 if (!timespec64_equal(&inode->i_ctime, &now))
1574 inode->i_ctime = now;
1575
1576 if (IS_I_VERSION(inode))
1577 inode_inc_iversion(inode);
1578}
1579
1580static int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from,
1581 size_t count)
1582{
1583 struct file *file = iocb->ki_filp;
1584 struct inode *inode = file_inode(file);
1585 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1586 loff_t pos = iocb->ki_pos;
1587 int ret;
1588 loff_t oldsize;
1589 loff_t start_pos;
1590
1591 if (iocb->ki_flags & IOCB_NOWAIT) {
1592 size_t nocow_bytes = count;
1593
1594 /* We will allocate space in case nodatacow is not set, so bail */
1595 if (check_nocow_nolock(BTRFS_I(inode), pos, &nocow_bytes) <= 0)
1596 return -EAGAIN;
1597 /*
1598 * There are holes in the range or parts of the range that must
1599 * be COWed (shared extents, RO block groups, etc), so just bail
1600 * out.
1601 */
1602 if (nocow_bytes < count)
1603 return -EAGAIN;
1604 }
1605
1606 current->backing_dev_info = inode_to_bdi(inode);
1607 ret = file_remove_privs(file);
1608 if (ret)
1609 return ret;
1610
1611 /*
1612 * We reserve space for updating the inode when we reserve space for the
1613 * extent we are going to write, so we will enospc out there. We don't
1614 * need to start yet another transaction to update the inode as we will
1615 * update the inode when we finish writing whatever data we write.
1616 */
1617 update_time_for_write(inode);
1618
1619 start_pos = round_down(pos, fs_info->sectorsize);
1620 oldsize = i_size_read(inode);
1621 if (start_pos > oldsize) {
1622 /* Expand hole size to cover write data, preventing empty gap */
1623 loff_t end_pos = round_up(pos + count, fs_info->sectorsize);
1624
1625 ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos);
1626 if (ret) {
1627 current->backing_dev_info = NULL;
1628 return ret;
1629 }
1630 }
1631
1632 return 0;
1633}
1634
1635static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
1636 struct iov_iter *i)
1637{
1638 struct file *file = iocb->ki_filp;
1639 loff_t pos;
1640 struct inode *inode = file_inode(file);
1641 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1642 struct page **pages = NULL;
1643 struct extent_changeset *data_reserved = NULL;
1644 u64 release_bytes = 0;
1645 u64 lockstart;
1646 u64 lockend;
1647 size_t num_written = 0;
1648 int nrptrs;
1649 ssize_t ret;
1650 bool only_release_metadata = false;
1651 bool force_page_uptodate = false;
1652 loff_t old_isize = i_size_read(inode);
1653 unsigned int ilock_flags = 0;
1654
1655 if (iocb->ki_flags & IOCB_NOWAIT)
1656 ilock_flags |= BTRFS_ILOCK_TRY;
1657
1658 ret = btrfs_inode_lock(inode, ilock_flags);
1659 if (ret < 0)
1660 return ret;
1661
1662 ret = generic_write_checks(iocb, i);
1663 if (ret <= 0)
1664 goto out;
1665
1666 ret = btrfs_write_check(iocb, i, ret);
1667 if (ret < 0)
1668 goto out;
1669
1670 pos = iocb->ki_pos;
1671 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1672 PAGE_SIZE / (sizeof(struct page *)));
1673 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1674 nrptrs = max(nrptrs, 8);
1675 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1676 if (!pages) {
1677 ret = -ENOMEM;
1678 goto out;
1679 }
1680
1681 while (iov_iter_count(i) > 0) {
1682 struct extent_state *cached_state = NULL;
1683 size_t offset = offset_in_page(pos);
1684 size_t sector_offset;
1685 size_t write_bytes = min(iov_iter_count(i),
1686 nrptrs * (size_t)PAGE_SIZE -
1687 offset);
1688 size_t num_pages;
1689 size_t reserve_bytes;
1690 size_t dirty_pages;
1691 size_t copied;
1692 size_t dirty_sectors;
1693 size_t num_sectors;
1694 int extents_locked;
1695
1696 /*
1697 * Fault pages before locking them in prepare_pages
1698 * to avoid recursive lock
1699 */
1700 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1701 ret = -EFAULT;
1702 break;
1703 }
1704
1705 only_release_metadata = false;
1706 sector_offset = pos & (fs_info->sectorsize - 1);
1707
1708 extent_changeset_release(data_reserved);
1709 ret = btrfs_check_data_free_space(BTRFS_I(inode),
1710 &data_reserved, pos,
1711 write_bytes);
1712 if (ret < 0) {
1713 /*
1714 * If we don't have to COW at the offset, reserve
1715 * metadata only. write_bytes may get smaller than
1716 * requested here.
1717 */
1718 if (btrfs_check_nocow_lock(BTRFS_I(inode), pos,
1719 &write_bytes) > 0)
1720 only_release_metadata = true;
1721 else
1722 break;
1723 }
1724
1725 num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE);
1726 WARN_ON(num_pages > nrptrs);
1727 reserve_bytes = round_up(write_bytes + sector_offset,
1728 fs_info->sectorsize);
1729 WARN_ON(reserve_bytes == 0);
1730 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1731 reserve_bytes);
1732 if (ret) {
1733 if (!only_release_metadata)
1734 btrfs_free_reserved_data_space(BTRFS_I(inode),
1735 data_reserved, pos,
1736 write_bytes);
1737 else
1738 btrfs_check_nocow_unlock(BTRFS_I(inode));
1739 break;
1740 }
1741
1742 release_bytes = reserve_bytes;
1743again:
1744 /*
1745 * This is going to setup the pages array with the number of
1746 * pages we want, so we don't really need to worry about the
1747 * contents of pages from loop to loop
1748 */
1749 ret = prepare_pages(inode, pages, num_pages,
1750 pos, write_bytes,
1751 force_page_uptodate);
1752 if (ret) {
1753 btrfs_delalloc_release_extents(BTRFS_I(inode),
1754 reserve_bytes);
1755 break;
1756 }
1757
1758 extents_locked = lock_and_cleanup_extent_if_need(
1759 BTRFS_I(inode), pages,
1760 num_pages, pos, write_bytes, &lockstart,
1761 &lockend, &cached_state);
1762 if (extents_locked < 0) {
1763 if (extents_locked == -EAGAIN)
1764 goto again;
1765 btrfs_delalloc_release_extents(BTRFS_I(inode),
1766 reserve_bytes);
1767 ret = extents_locked;
1768 break;
1769 }
1770
1771 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1772
1773 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1774 dirty_sectors = round_up(copied + sector_offset,
1775 fs_info->sectorsize);
1776 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1777
1778 /*
1779 * if we have trouble faulting in the pages, fall
1780 * back to one page at a time
1781 */
1782 if (copied < write_bytes)
1783 nrptrs = 1;
1784
1785 if (copied == 0) {
1786 force_page_uptodate = true;
1787 dirty_sectors = 0;
1788 dirty_pages = 0;
1789 } else {
1790 force_page_uptodate = false;
1791 dirty_pages = DIV_ROUND_UP(copied + offset,
1792 PAGE_SIZE);
1793 }
1794
1795 if (num_sectors > dirty_sectors) {
1796 /* release everything except the sectors we dirtied */
1797 release_bytes -= dirty_sectors << fs_info->sectorsize_bits;
1798 if (only_release_metadata) {
1799 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1800 release_bytes, true);
1801 } else {
1802 u64 __pos;
1803
1804 __pos = round_down(pos,
1805 fs_info->sectorsize) +
1806 (dirty_pages << PAGE_SHIFT);
1807 btrfs_delalloc_release_space(BTRFS_I(inode),
1808 data_reserved, __pos,
1809 release_bytes, true);
1810 }
1811 }
1812
1813 release_bytes = round_up(copied + sector_offset,
1814 fs_info->sectorsize);
1815
1816 ret = btrfs_dirty_pages(BTRFS_I(inode), pages,
1817 dirty_pages, pos, copied,
1818 &cached_state, only_release_metadata);
1819
1820 /*
1821 * If we have not locked the extent range, because the range's
1822 * start offset is >= i_size, we might still have a non-NULL
1823 * cached extent state, acquired while marking the extent range
1824 * as delalloc through btrfs_dirty_pages(). Therefore free any
1825 * possible cached extent state to avoid a memory leak.
1826 */
1827 if (extents_locked)
1828 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1829 lockstart, lockend, &cached_state);
1830 else
1831 free_extent_state(cached_state);
1832
1833 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1834 if (ret) {
1835 btrfs_drop_pages(pages, num_pages);
1836 break;
1837 }
1838
1839 release_bytes = 0;
1840 if (only_release_metadata)
1841 btrfs_check_nocow_unlock(BTRFS_I(inode));
1842
1843 btrfs_drop_pages(pages, num_pages);
1844
1845 cond_resched();
1846
1847 balance_dirty_pages_ratelimited(inode->i_mapping);
1848
1849 pos += copied;
1850 num_written += copied;
1851 }
1852
1853 kfree(pages);
1854
1855 if (release_bytes) {
1856 if (only_release_metadata) {
1857 btrfs_check_nocow_unlock(BTRFS_I(inode));
1858 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1859 release_bytes, true);
1860 } else {
1861 btrfs_delalloc_release_space(BTRFS_I(inode),
1862 data_reserved,
1863 round_down(pos, fs_info->sectorsize),
1864 release_bytes, true);
1865 }
1866 }
1867
1868 extent_changeset_free(data_reserved);
1869 if (num_written > 0) {
1870 pagecache_isize_extended(inode, old_isize, iocb->ki_pos);
1871 iocb->ki_pos += num_written;
1872 }
1873out:
1874 btrfs_inode_unlock(inode, ilock_flags);
1875 return num_written ? num_written : ret;
1876}
1877
1878static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
1879 const struct iov_iter *iter, loff_t offset)
1880{
1881 const u32 blocksize_mask = fs_info->sectorsize - 1;
1882
1883 if (offset & blocksize_mask)
1884 return -EINVAL;
1885
1886 if (iov_iter_alignment(iter) & blocksize_mask)
1887 return -EINVAL;
1888
1889 return 0;
1890}
1891
1892static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1893{
1894 struct file *file = iocb->ki_filp;
1895 struct inode *inode = file_inode(file);
1896 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1897 loff_t pos;
1898 ssize_t written = 0;
1899 ssize_t written_buffered;
1900 loff_t endbyte;
1901 ssize_t err;
1902 unsigned int ilock_flags = 0;
1903 struct iomap_dio *dio = NULL;
1904
1905 if (iocb->ki_flags & IOCB_NOWAIT)
1906 ilock_flags |= BTRFS_ILOCK_TRY;
1907
1908 /* If the write DIO is within EOF, use a shared lock */
1909 if (iocb->ki_pos + iov_iter_count(from) <= i_size_read(inode))
1910 ilock_flags |= BTRFS_ILOCK_SHARED;
1911
1912relock:
1913 err = btrfs_inode_lock(inode, ilock_flags);
1914 if (err < 0)
1915 return err;
1916
1917 err = generic_write_checks(iocb, from);
1918 if (err <= 0) {
1919 btrfs_inode_unlock(inode, ilock_flags);
1920 return err;
1921 }
1922
1923 err = btrfs_write_check(iocb, from, err);
1924 if (err < 0) {
1925 btrfs_inode_unlock(inode, ilock_flags);
1926 goto out;
1927 }
1928
1929 pos = iocb->ki_pos;
1930 /*
1931 * Re-check since file size may have changed just before taking the
1932 * lock or pos may have changed because of O_APPEND in generic_write_check()
1933 */
1934 if ((ilock_flags & BTRFS_ILOCK_SHARED) &&
1935 pos + iov_iter_count(from) > i_size_read(inode)) {
1936 btrfs_inode_unlock(inode, ilock_flags);
1937 ilock_flags &= ~BTRFS_ILOCK_SHARED;
1938 goto relock;
1939 }
1940
1941 if (check_direct_IO(fs_info, from, pos)) {
1942 btrfs_inode_unlock(inode, ilock_flags);
1943 goto buffered;
1944 }
1945
1946 dio = __iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dio_ops,
1947 0);
1948
1949 btrfs_inode_unlock(inode, ilock_flags);
1950
1951 if (IS_ERR_OR_NULL(dio)) {
1952 err = PTR_ERR_OR_ZERO(dio);
1953 if (err < 0 && err != -ENOTBLK)
1954 goto out;
1955 } else {
1956 written = iomap_dio_complete(dio);
1957 }
1958
1959 if (written < 0 || !iov_iter_count(from)) {
1960 err = written;
1961 goto out;
1962 }
1963
1964buffered:
1965 pos = iocb->ki_pos;
1966 written_buffered = btrfs_buffered_write(iocb, from);
1967 if (written_buffered < 0) {
1968 err = written_buffered;
1969 goto out;
1970 }
1971 /*
1972 * Ensure all data is persisted. We want the next direct IO read to be
1973 * able to read what was just written.
1974 */
1975 endbyte = pos + written_buffered - 1;
1976 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1977 if (err)
1978 goto out;
1979 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1980 if (err)
1981 goto out;
1982 written += written_buffered;
1983 iocb->ki_pos = pos + written_buffered;
1984 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1985 endbyte >> PAGE_SHIFT);
1986out:
1987 return written ? written : err;
1988}
1989
1990static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1991 struct iov_iter *from)
1992{
1993 struct file *file = iocb->ki_filp;
1994 struct btrfs_inode *inode = BTRFS_I(file_inode(file));
1995 ssize_t num_written = 0;
1996 const bool sync = iocb->ki_flags & IOCB_DSYNC;
1997
1998 /*
1999 * If the fs flips readonly due to some impossible error, although we
2000 * have opened a file as writable, we have to stop this write operation
2001 * to ensure consistency.
2002 */
2003 if (test_bit(BTRFS_FS_STATE_ERROR, &inode->root->fs_info->fs_state))
2004 return -EROFS;
2005
2006 if (!(iocb->ki_flags & IOCB_DIRECT) &&
2007 (iocb->ki_flags & IOCB_NOWAIT))
2008 return -EOPNOTSUPP;
2009
2010 if (sync)
2011 atomic_inc(&inode->sync_writers);
2012
2013 if (iocb->ki_flags & IOCB_DIRECT)
2014 num_written = btrfs_direct_write(iocb, from);
2015 else
2016 num_written = btrfs_buffered_write(iocb, from);
2017
2018 btrfs_set_inode_last_sub_trans(inode);
2019
2020 if (num_written > 0)
2021 num_written = generic_write_sync(iocb, num_written);
2022
2023 if (sync)
2024 atomic_dec(&inode->sync_writers);
2025
2026 current->backing_dev_info = NULL;
2027 return num_written;
2028}
2029
2030int btrfs_release_file(struct inode *inode, struct file *filp)
2031{
2032 struct btrfs_file_private *private = filp->private_data;
2033
2034 if (private && private->filldir_buf)
2035 kfree(private->filldir_buf);
2036 kfree(private);
2037 filp->private_data = NULL;
2038
2039 /*
2040 * Set by setattr when we are about to truncate a file from a non-zero
2041 * size to a zero size. This tries to flush down new bytes that may
2042 * have been written if the application were using truncate to replace
2043 * a file in place.
2044 */
2045 if (test_and_clear_bit(BTRFS_INODE_FLUSH_ON_CLOSE,
2046 &BTRFS_I(inode)->runtime_flags))
2047 filemap_flush(inode->i_mapping);
2048 return 0;
2049}
2050
2051static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2052{
2053 int ret;
2054 struct blk_plug plug;
2055
2056 /*
2057 * This is only called in fsync, which would do synchronous writes, so
2058 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2059 * multiple disks using raid profile, a large IO can be split to
2060 * several segments of stripe length (currently 64K).
2061 */
2062 blk_start_plug(&plug);
2063 atomic_inc(&BTRFS_I(inode)->sync_writers);
2064 ret = btrfs_fdatawrite_range(inode, start, end);
2065 atomic_dec(&BTRFS_I(inode)->sync_writers);
2066 blk_finish_plug(&plug);
2067
2068 return ret;
2069}
2070
2071static inline bool skip_inode_logging(const struct btrfs_log_ctx *ctx)
2072{
2073 struct btrfs_inode *inode = BTRFS_I(ctx->inode);
2074 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2075
2076 if (btrfs_inode_in_log(inode, fs_info->generation) &&
2077 list_empty(&ctx->ordered_extents))
2078 return true;
2079
2080 /*
2081 * If we are doing a fast fsync we can not bail out if the inode's
2082 * last_trans is <= then the last committed transaction, because we only
2083 * update the last_trans of the inode during ordered extent completion,
2084 * and for a fast fsync we don't wait for that, we only wait for the
2085 * writeback to complete.
2086 */
2087 if (inode->last_trans <= fs_info->last_trans_committed &&
2088 (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) ||
2089 list_empty(&ctx->ordered_extents)))
2090 return true;
2091
2092 return false;
2093}
2094
2095/*
2096 * fsync call for both files and directories. This logs the inode into
2097 * the tree log instead of forcing full commits whenever possible.
2098 *
2099 * It needs to call filemap_fdatawait so that all ordered extent updates are
2100 * in the metadata btree are up to date for copying to the log.
2101 *
2102 * It drops the inode mutex before doing the tree log commit. This is an
2103 * important optimization for directories because holding the mutex prevents
2104 * new operations on the dir while we write to disk.
2105 */
2106int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2107{
2108 struct dentry *dentry = file_dentry(file);
2109 struct inode *inode = d_inode(dentry);
2110 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2111 struct btrfs_root *root = BTRFS_I(inode)->root;
2112 struct btrfs_trans_handle *trans;
2113 struct btrfs_log_ctx ctx;
2114 int ret = 0, err;
2115 u64 len;
2116 bool full_sync;
2117
2118 trace_btrfs_sync_file(file, datasync);
2119
2120 btrfs_init_log_ctx(&ctx, inode);
2121
2122 /*
2123 * Always set the range to a full range, otherwise we can get into
2124 * several problems, from missing file extent items to represent holes
2125 * when not using the NO_HOLES feature, to log tree corruption due to
2126 * races between hole detection during logging and completion of ordered
2127 * extents outside the range, to missing checksums due to ordered extents
2128 * for which we flushed only a subset of their pages.
2129 */
2130 start = 0;
2131 end = LLONG_MAX;
2132 len = (u64)LLONG_MAX + 1;
2133
2134 /*
2135 * We write the dirty pages in the range and wait until they complete
2136 * out of the ->i_mutex. If so, we can flush the dirty pages by
2137 * multi-task, and make the performance up. See
2138 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2139 */
2140 ret = start_ordered_ops(inode, start, end);
2141 if (ret)
2142 goto out;
2143
2144 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
2145
2146 atomic_inc(&root->log_batch);
2147
2148 /*
2149 * Always check for the full sync flag while holding the inode's lock,
2150 * to avoid races with other tasks. The flag must be either set all the
2151 * time during logging or always off all the time while logging.
2152 */
2153 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2154 &BTRFS_I(inode)->runtime_flags);
2155
2156 /*
2157 * Before we acquired the inode's lock and the mmap lock, someone may
2158 * have dirtied more pages in the target range. We need to make sure
2159 * that writeback for any such pages does not start while we are logging
2160 * the inode, because if it does, any of the following might happen when
2161 * we are not doing a full inode sync:
2162 *
2163 * 1) We log an extent after its writeback finishes but before its
2164 * checksums are added to the csum tree, leading to -EIO errors
2165 * when attempting to read the extent after a log replay.
2166 *
2167 * 2) We can end up logging an extent before its writeback finishes.
2168 * Therefore after the log replay we will have a file extent item
2169 * pointing to an unwritten extent (and no data checksums as well).
2170 *
2171 * So trigger writeback for any eventual new dirty pages and then we
2172 * wait for all ordered extents to complete below.
2173 */
2174 ret = start_ordered_ops(inode, start, end);
2175 if (ret) {
2176 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2177 goto out;
2178 }
2179
2180 /*
2181 * We have to do this here to avoid the priority inversion of waiting on
2182 * IO of a lower priority task while holding a transaction open.
2183 *
2184 * For a full fsync we wait for the ordered extents to complete while
2185 * for a fast fsync we wait just for writeback to complete, and then
2186 * attach the ordered extents to the transaction so that a transaction
2187 * commit waits for their completion, to avoid data loss if we fsync,
2188 * the current transaction commits before the ordered extents complete
2189 * and a power failure happens right after that.
2190 *
2191 * For zoned filesystem, if a write IO uses a ZONE_APPEND command, the
2192 * logical address recorded in the ordered extent may change. We need
2193 * to wait for the IO to stabilize the logical address.
2194 */
2195 if (full_sync || btrfs_is_zoned(fs_info)) {
2196 ret = btrfs_wait_ordered_range(inode, start, len);
2197 } else {
2198 /*
2199 * Get our ordered extents as soon as possible to avoid doing
2200 * checksum lookups in the csum tree, and use instead the
2201 * checksums attached to the ordered extents.
2202 */
2203 btrfs_get_ordered_extents_for_logging(BTRFS_I(inode),
2204 &ctx.ordered_extents);
2205 ret = filemap_fdatawait_range(inode->i_mapping, start, end);
2206 }
2207
2208 if (ret)
2209 goto out_release_extents;
2210
2211 atomic_inc(&root->log_batch);
2212
2213 smp_mb();
2214 if (skip_inode_logging(&ctx)) {
2215 /*
2216 * We've had everything committed since the last time we were
2217 * modified so clear this flag in case it was set for whatever
2218 * reason, it's no longer relevant.
2219 */
2220 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2221 &BTRFS_I(inode)->runtime_flags);
2222 /*
2223 * An ordered extent might have started before and completed
2224 * already with io errors, in which case the inode was not
2225 * updated and we end up here. So check the inode's mapping
2226 * for any errors that might have happened since we last
2227 * checked called fsync.
2228 */
2229 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2230 goto out_release_extents;
2231 }
2232
2233 /*
2234 * We use start here because we will need to wait on the IO to complete
2235 * in btrfs_sync_log, which could require joining a transaction (for
2236 * example checking cross references in the nocow path). If we use join
2237 * here we could get into a situation where we're waiting on IO to
2238 * happen that is blocked on a transaction trying to commit. With start
2239 * we inc the extwriter counter, so we wait for all extwriters to exit
2240 * before we start blocking joiners. This comment is to keep somebody
2241 * from thinking they are super smart and changing this to
2242 * btrfs_join_transaction *cough*Josef*cough*.
2243 */
2244 trans = btrfs_start_transaction(root, 0);
2245 if (IS_ERR(trans)) {
2246 ret = PTR_ERR(trans);
2247 goto out_release_extents;
2248 }
2249 trans->in_fsync = true;
2250
2251 ret = btrfs_log_dentry_safe(trans, dentry, &ctx);
2252 btrfs_release_log_ctx_extents(&ctx);
2253 if (ret < 0) {
2254 /* Fallthrough and commit/free transaction. */
2255 ret = 1;
2256 }
2257
2258 /* we've logged all the items and now have a consistent
2259 * version of the file in the log. It is possible that
2260 * someone will come in and modify the file, but that's
2261 * fine because the log is consistent on disk, and we
2262 * have references to all of the file's extents
2263 *
2264 * It is possible that someone will come in and log the
2265 * file again, but that will end up using the synchronization
2266 * inside btrfs_sync_log to keep things safe.
2267 */
2268 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2269
2270 if (ret != BTRFS_NO_LOG_SYNC) {
2271 if (!ret) {
2272 ret = btrfs_sync_log(trans, root, &ctx);
2273 if (!ret) {
2274 ret = btrfs_end_transaction(trans);
2275 goto out;
2276 }
2277 }
2278 if (!full_sync) {
2279 ret = btrfs_wait_ordered_range(inode, start, len);
2280 if (ret) {
2281 btrfs_end_transaction(trans);
2282 goto out;
2283 }
2284 }
2285 ret = btrfs_commit_transaction(trans);
2286 } else {
2287 ret = btrfs_end_transaction(trans);
2288 }
2289out:
2290 ASSERT(list_empty(&ctx.list));
2291 err = file_check_and_advance_wb_err(file);
2292 if (!ret)
2293 ret = err;
2294 return ret > 0 ? -EIO : ret;
2295
2296out_release_extents:
2297 btrfs_release_log_ctx_extents(&ctx);
2298 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2299 goto out;
2300}
2301
2302static const struct vm_operations_struct btrfs_file_vm_ops = {
2303 .fault = filemap_fault,
2304 .map_pages = filemap_map_pages,
2305 .page_mkwrite = btrfs_page_mkwrite,
2306};
2307
2308static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2309{
2310 struct address_space *mapping = filp->f_mapping;
2311
2312 if (!mapping->a_ops->readpage)
2313 return -ENOEXEC;
2314
2315 file_accessed(filp);
2316 vma->vm_ops = &btrfs_file_vm_ops;
2317
2318 return 0;
2319}
2320
2321static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2322 int slot, u64 start, u64 end)
2323{
2324 struct btrfs_file_extent_item *fi;
2325 struct btrfs_key key;
2326
2327 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2328 return 0;
2329
2330 btrfs_item_key_to_cpu(leaf, &key, slot);
2331 if (key.objectid != btrfs_ino(inode) ||
2332 key.type != BTRFS_EXTENT_DATA_KEY)
2333 return 0;
2334
2335 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2336
2337 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2338 return 0;
2339
2340 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2341 return 0;
2342
2343 if (key.offset == end)
2344 return 1;
2345 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2346 return 1;
2347 return 0;
2348}
2349
2350static int fill_holes(struct btrfs_trans_handle *trans,
2351 struct btrfs_inode *inode,
2352 struct btrfs_path *path, u64 offset, u64 end)
2353{
2354 struct btrfs_fs_info *fs_info = trans->fs_info;
2355 struct btrfs_root *root = inode->root;
2356 struct extent_buffer *leaf;
2357 struct btrfs_file_extent_item *fi;
2358 struct extent_map *hole_em;
2359 struct extent_map_tree *em_tree = &inode->extent_tree;
2360 struct btrfs_key key;
2361 int ret;
2362
2363 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2364 goto out;
2365
2366 key.objectid = btrfs_ino(inode);
2367 key.type = BTRFS_EXTENT_DATA_KEY;
2368 key.offset = offset;
2369
2370 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2371 if (ret <= 0) {
2372 /*
2373 * We should have dropped this offset, so if we find it then
2374 * something has gone horribly wrong.
2375 */
2376 if (ret == 0)
2377 ret = -EINVAL;
2378 return ret;
2379 }
2380
2381 leaf = path->nodes[0];
2382 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2383 u64 num_bytes;
2384
2385 path->slots[0]--;
2386 fi = btrfs_item_ptr(leaf, path->slots[0],
2387 struct btrfs_file_extent_item);
2388 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2389 end - offset;
2390 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2391 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2392 btrfs_set_file_extent_offset(leaf, fi, 0);
2393 btrfs_mark_buffer_dirty(leaf);
2394 goto out;
2395 }
2396
2397 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2398 u64 num_bytes;
2399
2400 key.offset = offset;
2401 btrfs_set_item_key_safe(fs_info, path, &key);
2402 fi = btrfs_item_ptr(leaf, path->slots[0],
2403 struct btrfs_file_extent_item);
2404 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2405 offset;
2406 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2407 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2408 btrfs_set_file_extent_offset(leaf, fi, 0);
2409 btrfs_mark_buffer_dirty(leaf);
2410 goto out;
2411 }
2412 btrfs_release_path(path);
2413
2414 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2415 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2416 if (ret)
2417 return ret;
2418
2419out:
2420 btrfs_release_path(path);
2421
2422 hole_em = alloc_extent_map();
2423 if (!hole_em) {
2424 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2425 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2426 } else {
2427 hole_em->start = offset;
2428 hole_em->len = end - offset;
2429 hole_em->ram_bytes = hole_em->len;
2430 hole_em->orig_start = offset;
2431
2432 hole_em->block_start = EXTENT_MAP_HOLE;
2433 hole_em->block_len = 0;
2434 hole_em->orig_block_len = 0;
2435 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2436 hole_em->generation = trans->transid;
2437
2438 do {
2439 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2440 write_lock(&em_tree->lock);
2441 ret = add_extent_mapping(em_tree, hole_em, 1);
2442 write_unlock(&em_tree->lock);
2443 } while (ret == -EEXIST);
2444 free_extent_map(hole_em);
2445 if (ret)
2446 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2447 &inode->runtime_flags);
2448 }
2449
2450 return 0;
2451}
2452
2453/*
2454 * Find a hole extent on given inode and change start/len to the end of hole
2455 * extent.(hole/vacuum extent whose em->start <= start &&
2456 * em->start + em->len > start)
2457 * When a hole extent is found, return 1 and modify start/len.
2458 */
2459static int find_first_non_hole(struct btrfs_inode *inode, u64 *start, u64 *len)
2460{
2461 struct btrfs_fs_info *fs_info = inode->root->fs_info;
2462 struct extent_map *em;
2463 int ret = 0;
2464
2465 em = btrfs_get_extent(inode, NULL, 0,
2466 round_down(*start, fs_info->sectorsize),
2467 round_up(*len, fs_info->sectorsize));
2468 if (IS_ERR(em))
2469 return PTR_ERR(em);
2470
2471 /* Hole or vacuum extent(only exists in no-hole mode) */
2472 if (em->block_start == EXTENT_MAP_HOLE) {
2473 ret = 1;
2474 *len = em->start + em->len > *start + *len ?
2475 0 : *start + *len - em->start - em->len;
2476 *start = em->start + em->len;
2477 }
2478 free_extent_map(em);
2479 return ret;
2480}
2481
2482static int btrfs_punch_hole_lock_range(struct inode *inode,
2483 const u64 lockstart,
2484 const u64 lockend,
2485 struct extent_state **cached_state)
2486{
2487 /*
2488 * For subpage case, if the range is not at page boundary, we could
2489 * have pages at the leading/tailing part of the range.
2490 * This could lead to dead loop since filemap_range_has_page()
2491 * will always return true.
2492 * So here we need to do extra page alignment for
2493 * filemap_range_has_page().
2494 */
2495 const u64 page_lockstart = round_up(lockstart, PAGE_SIZE);
2496 const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1;
2497
2498 while (1) {
2499 struct btrfs_ordered_extent *ordered;
2500 int ret;
2501
2502 truncate_pagecache_range(inode, lockstart, lockend);
2503
2504 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2505 cached_state);
2506 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode),
2507 lockend);
2508
2509 /*
2510 * We need to make sure we have no ordered extents in this range
2511 * and nobody raced in and read a page in this range, if we did
2512 * we need to try again.
2513 */
2514 if ((!ordered ||
2515 (ordered->file_offset + ordered->num_bytes <= lockstart ||
2516 ordered->file_offset > lockend)) &&
2517 !filemap_range_has_page(inode->i_mapping,
2518 page_lockstart, page_lockend)) {
2519 if (ordered)
2520 btrfs_put_ordered_extent(ordered);
2521 break;
2522 }
2523 if (ordered)
2524 btrfs_put_ordered_extent(ordered);
2525 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2526 lockend, cached_state);
2527 ret = btrfs_wait_ordered_range(inode, lockstart,
2528 lockend - lockstart + 1);
2529 if (ret)
2530 return ret;
2531 }
2532 return 0;
2533}
2534
2535static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans,
2536 struct btrfs_inode *inode,
2537 struct btrfs_path *path,
2538 struct btrfs_replace_extent_info *extent_info,
2539 const u64 replace_len,
2540 const u64 bytes_to_drop)
2541{
2542 struct btrfs_fs_info *fs_info = trans->fs_info;
2543 struct btrfs_root *root = inode->root;
2544 struct btrfs_file_extent_item *extent;
2545 struct extent_buffer *leaf;
2546 struct btrfs_key key;
2547 int slot;
2548 struct btrfs_ref ref = { 0 };
2549 int ret;
2550
2551 if (replace_len == 0)
2552 return 0;
2553
2554 if (extent_info->disk_offset == 0 &&
2555 btrfs_fs_incompat(fs_info, NO_HOLES)) {
2556 btrfs_update_inode_bytes(inode, 0, bytes_to_drop);
2557 return 0;
2558 }
2559
2560 key.objectid = btrfs_ino(inode);
2561 key.type = BTRFS_EXTENT_DATA_KEY;
2562 key.offset = extent_info->file_offset;
2563 ret = btrfs_insert_empty_item(trans, root, path, &key,
2564 sizeof(struct btrfs_file_extent_item));
2565 if (ret)
2566 return ret;
2567 leaf = path->nodes[0];
2568 slot = path->slots[0];
2569 write_extent_buffer(leaf, extent_info->extent_buf,
2570 btrfs_item_ptr_offset(leaf, slot),
2571 sizeof(struct btrfs_file_extent_item));
2572 extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2573 ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE);
2574 btrfs_set_file_extent_offset(leaf, extent, extent_info->data_offset);
2575 btrfs_set_file_extent_num_bytes(leaf, extent, replace_len);
2576 if (extent_info->is_new_extent)
2577 btrfs_set_file_extent_generation(leaf, extent, trans->transid);
2578 btrfs_mark_buffer_dirty(leaf);
2579 btrfs_release_path(path);
2580
2581 ret = btrfs_inode_set_file_extent_range(inode, extent_info->file_offset,
2582 replace_len);
2583 if (ret)
2584 return ret;
2585
2586 /* If it's a hole, nothing more needs to be done. */
2587 if (extent_info->disk_offset == 0) {
2588 btrfs_update_inode_bytes(inode, 0, bytes_to_drop);
2589 return 0;
2590 }
2591
2592 btrfs_update_inode_bytes(inode, replace_len, bytes_to_drop);
2593
2594 if (extent_info->is_new_extent && extent_info->insertions == 0) {
2595 key.objectid = extent_info->disk_offset;
2596 key.type = BTRFS_EXTENT_ITEM_KEY;
2597 key.offset = extent_info->disk_len;
2598 ret = btrfs_alloc_reserved_file_extent(trans, root,
2599 btrfs_ino(inode),
2600 extent_info->file_offset,
2601 extent_info->qgroup_reserved,
2602 &key);
2603 } else {
2604 u64 ref_offset;
2605
2606 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
2607 extent_info->disk_offset,
2608 extent_info->disk_len, 0);
2609 ref_offset = extent_info->file_offset - extent_info->data_offset;
2610 btrfs_init_data_ref(&ref, root->root_key.objectid,
2611 btrfs_ino(inode), ref_offset);
2612 ret = btrfs_inc_extent_ref(trans, &ref);
2613 }
2614
2615 extent_info->insertions++;
2616
2617 return ret;
2618}
2619
2620/*
2621 * The respective range must have been previously locked, as well as the inode.
2622 * The end offset is inclusive (last byte of the range).
2623 * @extent_info is NULL for fallocate's hole punching and non-NULL when replacing
2624 * the file range with an extent.
2625 * When not punching a hole, we don't want to end up in a state where we dropped
2626 * extents without inserting a new one, so we must abort the transaction to avoid
2627 * a corruption.
2628 */
2629int btrfs_replace_file_extents(struct btrfs_inode *inode,
2630 struct btrfs_path *path, const u64 start,
2631 const u64 end,
2632 struct btrfs_replace_extent_info *extent_info,
2633 struct btrfs_trans_handle **trans_out)
2634{
2635 struct btrfs_drop_extents_args drop_args = { 0 };
2636 struct btrfs_root *root = inode->root;
2637 struct btrfs_fs_info *fs_info = root->fs_info;
2638 u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
2639 u64 ino_size = round_up(inode->vfs_inode.i_size, fs_info->sectorsize);
2640 struct btrfs_trans_handle *trans = NULL;
2641 struct btrfs_block_rsv *rsv;
2642 unsigned int rsv_count;
2643 u64 cur_offset;
2644 u64 len = end - start;
2645 int ret = 0;
2646
2647 if (end <= start)
2648 return -EINVAL;
2649
2650 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2651 if (!rsv) {
2652 ret = -ENOMEM;
2653 goto out;
2654 }
2655 rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
2656 rsv->failfast = 1;
2657
2658 /*
2659 * 1 - update the inode
2660 * 1 - removing the extents in the range
2661 * 1 - adding the hole extent if no_holes isn't set or if we are
2662 * replacing the range with a new extent
2663 */
2664 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || extent_info)
2665 rsv_count = 3;
2666 else
2667 rsv_count = 2;
2668
2669 trans = btrfs_start_transaction(root, rsv_count);
2670 if (IS_ERR(trans)) {
2671 ret = PTR_ERR(trans);
2672 trans = NULL;
2673 goto out_free;
2674 }
2675
2676 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2677 min_size, false);
2678 BUG_ON(ret);
2679 trans->block_rsv = rsv;
2680
2681 cur_offset = start;
2682 drop_args.path = path;
2683 drop_args.end = end + 1;
2684 drop_args.drop_cache = true;
2685 while (cur_offset < end) {
2686 drop_args.start = cur_offset;
2687 ret = btrfs_drop_extents(trans, root, inode, &drop_args);
2688 /* If we are punching a hole decrement the inode's byte count */
2689 if (!extent_info)
2690 btrfs_update_inode_bytes(inode, 0,
2691 drop_args.bytes_found);
2692 if (ret != -ENOSPC) {
2693 /*
2694 * The only time we don't want to abort is if we are
2695 * attempting to clone a partial inline extent, in which
2696 * case we'll get EOPNOTSUPP. However if we aren't
2697 * clone we need to abort no matter what, because if we
2698 * got EOPNOTSUPP via prealloc then we messed up and
2699 * need to abort.
2700 */
2701 if (ret &&
2702 (ret != -EOPNOTSUPP ||
2703 (extent_info && extent_info->is_new_extent)))
2704 btrfs_abort_transaction(trans, ret);
2705 break;
2706 }
2707
2708 trans->block_rsv = &fs_info->trans_block_rsv;
2709
2710 if (!extent_info && cur_offset < drop_args.drop_end &&
2711 cur_offset < ino_size) {
2712 ret = fill_holes(trans, inode, path, cur_offset,
2713 drop_args.drop_end);
2714 if (ret) {
2715 /*
2716 * If we failed then we didn't insert our hole
2717 * entries for the area we dropped, so now the
2718 * fs is corrupted, so we must abort the
2719 * transaction.
2720 */
2721 btrfs_abort_transaction(trans, ret);
2722 break;
2723 }
2724 } else if (!extent_info && cur_offset < drop_args.drop_end) {
2725 /*
2726 * We are past the i_size here, but since we didn't
2727 * insert holes we need to clear the mapped area so we
2728 * know to not set disk_i_size in this area until a new
2729 * file extent is inserted here.
2730 */
2731 ret = btrfs_inode_clear_file_extent_range(inode,
2732 cur_offset,
2733 drop_args.drop_end - cur_offset);
2734 if (ret) {
2735 /*
2736 * We couldn't clear our area, so we could
2737 * presumably adjust up and corrupt the fs, so
2738 * we need to abort.
2739 */
2740 btrfs_abort_transaction(trans, ret);
2741 break;
2742 }
2743 }
2744
2745 if (extent_info &&
2746 drop_args.drop_end > extent_info->file_offset) {
2747 u64 replace_len = drop_args.drop_end -
2748 extent_info->file_offset;
2749
2750 ret = btrfs_insert_replace_extent(trans, inode, path,
2751 extent_info, replace_len,
2752 drop_args.bytes_found);
2753 if (ret) {
2754 btrfs_abort_transaction(trans, ret);
2755 break;
2756 }
2757 extent_info->data_len -= replace_len;
2758 extent_info->data_offset += replace_len;
2759 extent_info->file_offset += replace_len;
2760 }
2761
2762 ret = btrfs_update_inode(trans, root, inode);
2763 if (ret)
2764 break;
2765
2766 btrfs_end_transaction(trans);
2767 btrfs_btree_balance_dirty(fs_info);
2768
2769 trans = btrfs_start_transaction(root, rsv_count);
2770 if (IS_ERR(trans)) {
2771 ret = PTR_ERR(trans);
2772 trans = NULL;
2773 break;
2774 }
2775
2776 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2777 rsv, min_size, false);
2778 BUG_ON(ret); /* shouldn't happen */
2779 trans->block_rsv = rsv;
2780
2781 cur_offset = drop_args.drop_end;
2782 len = end - cur_offset;
2783 if (!extent_info && len) {
2784 ret = find_first_non_hole(inode, &cur_offset, &len);
2785 if (unlikely(ret < 0))
2786 break;
2787 if (ret && !len) {
2788 ret = 0;
2789 break;
2790 }
2791 }
2792 }
2793
2794 /*
2795 * If we were cloning, force the next fsync to be a full one since we
2796 * we replaced (or just dropped in the case of cloning holes when
2797 * NO_HOLES is enabled) file extent items and did not setup new extent
2798 * maps for the replacement extents (or holes).
2799 */
2800 if (extent_info && !extent_info->is_new_extent)
2801 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2802
2803 if (ret)
2804 goto out_trans;
2805
2806 trans->block_rsv = &fs_info->trans_block_rsv;
2807 /*
2808 * If we are using the NO_HOLES feature we might have had already an
2809 * hole that overlaps a part of the region [lockstart, lockend] and
2810 * ends at (or beyond) lockend. Since we have no file extent items to
2811 * represent holes, drop_end can be less than lockend and so we must
2812 * make sure we have an extent map representing the existing hole (the
2813 * call to __btrfs_drop_extents() might have dropped the existing extent
2814 * map representing the existing hole), otherwise the fast fsync path
2815 * will not record the existence of the hole region
2816 * [existing_hole_start, lockend].
2817 */
2818 if (drop_args.drop_end <= end)
2819 drop_args.drop_end = end + 1;
2820 /*
2821 * Don't insert file hole extent item if it's for a range beyond eof
2822 * (because it's useless) or if it represents a 0 bytes range (when
2823 * cur_offset == drop_end).
2824 */
2825 if (!extent_info && cur_offset < ino_size &&
2826 cur_offset < drop_args.drop_end) {
2827 ret = fill_holes(trans, inode, path, cur_offset,
2828 drop_args.drop_end);
2829 if (ret) {
2830 /* Same comment as above. */
2831 btrfs_abort_transaction(trans, ret);
2832 goto out_trans;
2833 }
2834 } else if (!extent_info && cur_offset < drop_args.drop_end) {
2835 /* See the comment in the loop above for the reasoning here. */
2836 ret = btrfs_inode_clear_file_extent_range(inode, cur_offset,
2837 drop_args.drop_end - cur_offset);
2838 if (ret) {
2839 btrfs_abort_transaction(trans, ret);
2840 goto out_trans;
2841 }
2842
2843 }
2844 if (extent_info) {
2845 ret = btrfs_insert_replace_extent(trans, inode, path,
2846 extent_info, extent_info->data_len,
2847 drop_args.bytes_found);
2848 if (ret) {
2849 btrfs_abort_transaction(trans, ret);
2850 goto out_trans;
2851 }
2852 }
2853
2854out_trans:
2855 if (!trans)
2856 goto out_free;
2857
2858 trans->block_rsv = &fs_info->trans_block_rsv;
2859 if (ret)
2860 btrfs_end_transaction(trans);
2861 else
2862 *trans_out = trans;
2863out_free:
2864 btrfs_free_block_rsv(fs_info, rsv);
2865out:
2866 return ret;
2867}
2868
2869static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2870{
2871 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2872 struct btrfs_root *root = BTRFS_I(inode)->root;
2873 struct extent_state *cached_state = NULL;
2874 struct btrfs_path *path;
2875 struct btrfs_trans_handle *trans = NULL;
2876 u64 lockstart;
2877 u64 lockend;
2878 u64 tail_start;
2879 u64 tail_len;
2880 u64 orig_start = offset;
2881 int ret = 0;
2882 bool same_block;
2883 u64 ino_size;
2884 bool truncated_block = false;
2885 bool updated_inode = false;
2886
2887 ret = btrfs_wait_ordered_range(inode, offset, len);
2888 if (ret)
2889 return ret;
2890
2891 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
2892 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2893 ret = find_first_non_hole(BTRFS_I(inode), &offset, &len);
2894 if (ret < 0)
2895 goto out_only_mutex;
2896 if (ret && !len) {
2897 /* Already in a large hole */
2898 ret = 0;
2899 goto out_only_mutex;
2900 }
2901
2902 lockstart = round_up(offset, btrfs_inode_sectorsize(BTRFS_I(inode)));
2903 lockend = round_down(offset + len,
2904 btrfs_inode_sectorsize(BTRFS_I(inode))) - 1;
2905 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2906 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2907 /*
2908 * We needn't truncate any block which is beyond the end of the file
2909 * because we are sure there is no data there.
2910 */
2911 /*
2912 * Only do this if we are in the same block and we aren't doing the
2913 * entire block.
2914 */
2915 if (same_block && len < fs_info->sectorsize) {
2916 if (offset < ino_size) {
2917 truncated_block = true;
2918 ret = btrfs_truncate_block(BTRFS_I(inode), offset, len,
2919 0);
2920 } else {
2921 ret = 0;
2922 }
2923 goto out_only_mutex;
2924 }
2925
2926 /* zero back part of the first block */
2927 if (offset < ino_size) {
2928 truncated_block = true;
2929 ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0);
2930 if (ret) {
2931 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
2932 return ret;
2933 }
2934 }
2935
2936 /* Check the aligned pages after the first unaligned page,
2937 * if offset != orig_start, which means the first unaligned page
2938 * including several following pages are already in holes,
2939 * the extra check can be skipped */
2940 if (offset == orig_start) {
2941 /* after truncate page, check hole again */
2942 len = offset + len - lockstart;
2943 offset = lockstart;
2944 ret = find_first_non_hole(BTRFS_I(inode), &offset, &len);
2945 if (ret < 0)
2946 goto out_only_mutex;
2947 if (ret && !len) {
2948 ret = 0;
2949 goto out_only_mutex;
2950 }
2951 lockstart = offset;
2952 }
2953
2954 /* Check the tail unaligned part is in a hole */
2955 tail_start = lockend + 1;
2956 tail_len = offset + len - tail_start;
2957 if (tail_len) {
2958 ret = find_first_non_hole(BTRFS_I(inode), &tail_start, &tail_len);
2959 if (unlikely(ret < 0))
2960 goto out_only_mutex;
2961 if (!ret) {
2962 /* zero the front end of the last page */
2963 if (tail_start + tail_len < ino_size) {
2964 truncated_block = true;
2965 ret = btrfs_truncate_block(BTRFS_I(inode),
2966 tail_start + tail_len,
2967 0, 1);
2968 if (ret)
2969 goto out_only_mutex;
2970 }
2971 }
2972 }
2973
2974 if (lockend < lockstart) {
2975 ret = 0;
2976 goto out_only_mutex;
2977 }
2978
2979 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2980 &cached_state);
2981 if (ret)
2982 goto out_only_mutex;
2983
2984 path = btrfs_alloc_path();
2985 if (!path) {
2986 ret = -ENOMEM;
2987 goto out;
2988 }
2989
2990 ret = btrfs_replace_file_extents(BTRFS_I(inode), path, lockstart,
2991 lockend, NULL, &trans);
2992 btrfs_free_path(path);
2993 if (ret)
2994 goto out;
2995
2996 ASSERT(trans != NULL);
2997 inode_inc_iversion(inode);
2998 inode->i_mtime = inode->i_ctime = current_time(inode);
2999 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
3000 updated_inode = true;
3001 btrfs_end_transaction(trans);
3002 btrfs_btree_balance_dirty(fs_info);
3003out:
3004 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3005 &cached_state);
3006out_only_mutex:
3007 if (!updated_inode && truncated_block && !ret) {
3008 /*
3009 * If we only end up zeroing part of a page, we still need to
3010 * update the inode item, so that all the time fields are
3011 * updated as well as the necessary btrfs inode in memory fields
3012 * for detecting, at fsync time, if the inode isn't yet in the
3013 * log tree or it's there but not up to date.
3014 */
3015 struct timespec64 now = current_time(inode);
3016
3017 inode_inc_iversion(inode);
3018 inode->i_mtime = now;
3019 inode->i_ctime = now;
3020 trans = btrfs_start_transaction(root, 1);
3021 if (IS_ERR(trans)) {
3022 ret = PTR_ERR(trans);
3023 } else {
3024 int ret2;
3025
3026 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
3027 ret2 = btrfs_end_transaction(trans);
3028 if (!ret)
3029 ret = ret2;
3030 }
3031 }
3032 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3033 return ret;
3034}
3035
3036/* Helper structure to record which range is already reserved */
3037struct falloc_range {
3038 struct list_head list;
3039 u64 start;
3040 u64 len;
3041};
3042
3043/*
3044 * Helper function to add falloc range
3045 *
3046 * Caller should have locked the larger range of extent containing
3047 * [start, len)
3048 */
3049static int add_falloc_range(struct list_head *head, u64 start, u64 len)
3050{
3051 struct falloc_range *range = NULL;
3052
3053 if (!list_empty(head)) {
3054 /*
3055 * As fallocate iterates by bytenr order, we only need to check
3056 * the last range.
3057 */
3058 range = list_last_entry(head, struct falloc_range, list);
3059 if (range->start + range->len == start) {
3060 range->len += len;
3061 return 0;
3062 }
3063 }
3064
3065 range = kmalloc(sizeof(*range), GFP_KERNEL);
3066 if (!range)
3067 return -ENOMEM;
3068 range->start = start;
3069 range->len = len;
3070 list_add_tail(&range->list, head);
3071 return 0;
3072}
3073
3074static int btrfs_fallocate_update_isize(struct inode *inode,
3075 const u64 end,
3076 const int mode)
3077{
3078 struct btrfs_trans_handle *trans;
3079 struct btrfs_root *root = BTRFS_I(inode)->root;
3080 int ret;
3081 int ret2;
3082
3083 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
3084 return 0;
3085
3086 trans = btrfs_start_transaction(root, 1);
3087 if (IS_ERR(trans))
3088 return PTR_ERR(trans);
3089
3090 inode->i_ctime = current_time(inode);
3091 i_size_write(inode, end);
3092 btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0);
3093 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
3094 ret2 = btrfs_end_transaction(trans);
3095
3096 return ret ? ret : ret2;
3097}
3098
3099enum {
3100 RANGE_BOUNDARY_WRITTEN_EXTENT,
3101 RANGE_BOUNDARY_PREALLOC_EXTENT,
3102 RANGE_BOUNDARY_HOLE,
3103};
3104
3105static int btrfs_zero_range_check_range_boundary(struct btrfs_inode *inode,
3106 u64 offset)
3107{
3108 const u64 sectorsize = btrfs_inode_sectorsize(inode);
3109 struct extent_map *em;
3110 int ret;
3111
3112 offset = round_down(offset, sectorsize);
3113 em = btrfs_get_extent(inode, NULL, 0, offset, sectorsize);
3114 if (IS_ERR(em))
3115 return PTR_ERR(em);
3116
3117 if (em->block_start == EXTENT_MAP_HOLE)
3118 ret = RANGE_BOUNDARY_HOLE;
3119 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
3120 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
3121 else
3122 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
3123
3124 free_extent_map(em);
3125 return ret;
3126}
3127
3128static int btrfs_zero_range(struct inode *inode,
3129 loff_t offset,
3130 loff_t len,
3131 const int mode)
3132{
3133 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
3134 struct extent_map *em;
3135 struct extent_changeset *data_reserved = NULL;
3136 int ret;
3137 u64 alloc_hint = 0;
3138 const u64 sectorsize = btrfs_inode_sectorsize(BTRFS_I(inode));
3139 u64 alloc_start = round_down(offset, sectorsize);
3140 u64 alloc_end = round_up(offset + len, sectorsize);
3141 u64 bytes_to_reserve = 0;
3142 bool space_reserved = false;
3143
3144 inode_dio_wait(inode);
3145
3146 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start,
3147 alloc_end - alloc_start);
3148 if (IS_ERR(em)) {
3149 ret = PTR_ERR(em);
3150 goto out;
3151 }
3152
3153 /*
3154 * Avoid hole punching and extent allocation for some cases. More cases
3155 * could be considered, but these are unlikely common and we keep things
3156 * as simple as possible for now. Also, intentionally, if the target
3157 * range contains one or more prealloc extents together with regular
3158 * extents and holes, we drop all the existing extents and allocate a
3159 * new prealloc extent, so that we get a larger contiguous disk extent.
3160 */
3161 if (em->start <= alloc_start &&
3162 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3163 const u64 em_end = em->start + em->len;
3164
3165 if (em_end >= offset + len) {
3166 /*
3167 * The whole range is already a prealloc extent,
3168 * do nothing except updating the inode's i_size if
3169 * needed.
3170 */
3171 free_extent_map(em);
3172 ret = btrfs_fallocate_update_isize(inode, offset + len,
3173 mode);
3174 goto out;
3175 }
3176 /*
3177 * Part of the range is already a prealloc extent, so operate
3178 * only on the remaining part of the range.
3179 */
3180 alloc_start = em_end;
3181 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
3182 len = offset + len - alloc_start;
3183 offset = alloc_start;
3184 alloc_hint = em->block_start + em->len;
3185 }
3186 free_extent_map(em);
3187
3188 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
3189 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
3190 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, alloc_start,
3191 sectorsize);
3192 if (IS_ERR(em)) {
3193 ret = PTR_ERR(em);
3194 goto out;
3195 }
3196
3197 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3198 free_extent_map(em);
3199 ret = btrfs_fallocate_update_isize(inode, offset + len,
3200 mode);
3201 goto out;
3202 }
3203 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
3204 free_extent_map(em);
3205 ret = btrfs_truncate_block(BTRFS_I(inode), offset, len,
3206 0);
3207 if (!ret)
3208 ret = btrfs_fallocate_update_isize(inode,
3209 offset + len,
3210 mode);
3211 return ret;
3212 }
3213 free_extent_map(em);
3214 alloc_start = round_down(offset, sectorsize);
3215 alloc_end = alloc_start + sectorsize;
3216 goto reserve_space;
3217 }
3218
3219 alloc_start = round_up(offset, sectorsize);
3220 alloc_end = round_down(offset + len, sectorsize);
3221
3222 /*
3223 * For unaligned ranges, check the pages at the boundaries, they might
3224 * map to an extent, in which case we need to partially zero them, or
3225 * they might map to a hole, in which case we need our allocation range
3226 * to cover them.
3227 */
3228 if (!IS_ALIGNED(offset, sectorsize)) {
3229 ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode),
3230 offset);
3231 if (ret < 0)
3232 goto out;
3233 if (ret == RANGE_BOUNDARY_HOLE) {
3234 alloc_start = round_down(offset, sectorsize);
3235 ret = 0;
3236 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3237 ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0);
3238 if (ret)
3239 goto out;
3240 } else {
3241 ret = 0;
3242 }
3243 }
3244
3245 if (!IS_ALIGNED(offset + len, sectorsize)) {
3246 ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode),
3247 offset + len);
3248 if (ret < 0)
3249 goto out;
3250 if (ret == RANGE_BOUNDARY_HOLE) {
3251 alloc_end = round_up(offset + len, sectorsize);
3252 ret = 0;
3253 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3254 ret = btrfs_truncate_block(BTRFS_I(inode), offset + len,
3255 0, 1);
3256 if (ret)
3257 goto out;
3258 } else {
3259 ret = 0;
3260 }
3261 }
3262
3263reserve_space:
3264 if (alloc_start < alloc_end) {
3265 struct extent_state *cached_state = NULL;
3266 const u64 lockstart = alloc_start;
3267 const u64 lockend = alloc_end - 1;
3268
3269 bytes_to_reserve = alloc_end - alloc_start;
3270 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3271 bytes_to_reserve);
3272 if (ret < 0)
3273 goto out;
3274 space_reserved = true;
3275 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3276 &cached_state);
3277 if (ret)
3278 goto out;
3279 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved,
3280 alloc_start, bytes_to_reserve);
3281 if (ret) {
3282 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3283 lockend, &cached_state);
3284 goto out;
3285 }
3286 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
3287 alloc_end - alloc_start,
3288 i_blocksize(inode),
3289 offset + len, &alloc_hint);
3290 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3291 lockend, &cached_state);
3292 /* btrfs_prealloc_file_range releases reserved space on error */
3293 if (ret) {
3294 space_reserved = false;
3295 goto out;
3296 }
3297 }
3298 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
3299 out:
3300 if (ret && space_reserved)
3301 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
3302 alloc_start, bytes_to_reserve);
3303 extent_changeset_free(data_reserved);
3304
3305 return ret;
3306}
3307
3308static long btrfs_fallocate(struct file *file, int mode,
3309 loff_t offset, loff_t len)
3310{
3311 struct inode *inode = file_inode(file);
3312 struct extent_state *cached_state = NULL;
3313 struct extent_changeset *data_reserved = NULL;
3314 struct falloc_range *range;
3315 struct falloc_range *tmp;
3316 struct list_head reserve_list;
3317 u64 cur_offset;
3318 u64 last_byte;
3319 u64 alloc_start;
3320 u64 alloc_end;
3321 u64 alloc_hint = 0;
3322 u64 locked_end;
3323 u64 actual_end = 0;
3324 struct extent_map *em;
3325 int blocksize = btrfs_inode_sectorsize(BTRFS_I(inode));
3326 int ret;
3327
3328 /* Do not allow fallocate in ZONED mode */
3329 if (btrfs_is_zoned(btrfs_sb(inode->i_sb)))
3330 return -EOPNOTSUPP;
3331
3332 alloc_start = round_down(offset, blocksize);
3333 alloc_end = round_up(offset + len, blocksize);
3334 cur_offset = alloc_start;
3335
3336 /* Make sure we aren't being give some crap mode */
3337 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3338 FALLOC_FL_ZERO_RANGE))
3339 return -EOPNOTSUPP;
3340
3341 if (mode & FALLOC_FL_PUNCH_HOLE)
3342 return btrfs_punch_hole(inode, offset, len);
3343
3344 /*
3345 * Only trigger disk allocation, don't trigger qgroup reserve
3346 *
3347 * For qgroup space, it will be checked later.
3348 */
3349 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3350 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3351 alloc_end - alloc_start);
3352 if (ret < 0)
3353 return ret;
3354 }
3355
3356 btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP);
3357
3358 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3359 ret = inode_newsize_ok(inode, offset + len);
3360 if (ret)
3361 goto out;
3362 }
3363
3364 /*
3365 * TODO: Move these two operations after we have checked
3366 * accurate reserved space, or fallocate can still fail but
3367 * with page truncated or size expanded.
3368 *
3369 * But that's a minor problem and won't do much harm BTW.
3370 */
3371 if (alloc_start > inode->i_size) {
3372 ret = btrfs_cont_expand(BTRFS_I(inode), i_size_read(inode),
3373 alloc_start);
3374 if (ret)
3375 goto out;
3376 } else if (offset + len > inode->i_size) {
3377 /*
3378 * If we are fallocating from the end of the file onward we
3379 * need to zero out the end of the block if i_size lands in the
3380 * middle of a block.
3381 */
3382 ret = btrfs_truncate_block(BTRFS_I(inode), inode->i_size, 0, 0);
3383 if (ret)
3384 goto out;
3385 }
3386
3387 /*
3388 * wait for ordered IO before we have any locks. We'll loop again
3389 * below with the locks held.
3390 */
3391 ret = btrfs_wait_ordered_range(inode, alloc_start,
3392 alloc_end - alloc_start);
3393 if (ret)
3394 goto out;
3395
3396 if (mode & FALLOC_FL_ZERO_RANGE) {
3397 ret = btrfs_zero_range(inode, offset, len, mode);
3398 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3399 return ret;
3400 }
3401
3402 locked_end = alloc_end - 1;
3403 while (1) {
3404 struct btrfs_ordered_extent *ordered;
3405
3406 /* the extent lock is ordered inside the running
3407 * transaction
3408 */
3409 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3410 locked_end, &cached_state);
3411 ordered = btrfs_lookup_first_ordered_extent(BTRFS_I(inode),
3412 locked_end);
3413
3414 if (ordered &&
3415 ordered->file_offset + ordered->num_bytes > alloc_start &&
3416 ordered->file_offset < alloc_end) {
3417 btrfs_put_ordered_extent(ordered);
3418 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3419 alloc_start, locked_end,
3420 &cached_state);
3421 /*
3422 * we can't wait on the range with the transaction
3423 * running or with the extent lock held
3424 */
3425 ret = btrfs_wait_ordered_range(inode, alloc_start,
3426 alloc_end - alloc_start);
3427 if (ret)
3428 goto out;
3429 } else {
3430 if (ordered)
3431 btrfs_put_ordered_extent(ordered);
3432 break;
3433 }
3434 }
3435
3436 /* First, check if we exceed the qgroup limit */
3437 INIT_LIST_HEAD(&reserve_list);
3438 while (cur_offset < alloc_end) {
3439 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3440 alloc_end - cur_offset);
3441 if (IS_ERR(em)) {
3442 ret = PTR_ERR(em);
3443 break;
3444 }
3445 last_byte = min(extent_map_end(em), alloc_end);
3446 actual_end = min_t(u64, extent_map_end(em), offset + len);
3447 last_byte = ALIGN(last_byte, blocksize);
3448 if (em->block_start == EXTENT_MAP_HOLE ||
3449 (cur_offset >= inode->i_size &&
3450 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3451 ret = add_falloc_range(&reserve_list, cur_offset,
3452 last_byte - cur_offset);
3453 if (ret < 0) {
3454 free_extent_map(em);
3455 break;
3456 }
3457 ret = btrfs_qgroup_reserve_data(BTRFS_I(inode),
3458 &data_reserved, cur_offset,
3459 last_byte - cur_offset);
3460 if (ret < 0) {
3461 cur_offset = last_byte;
3462 free_extent_map(em);
3463 break;
3464 }
3465 } else {
3466 /*
3467 * Do not need to reserve unwritten extent for this
3468 * range, free reserved data space first, otherwise
3469 * it'll result in false ENOSPC error.
3470 */
3471 btrfs_free_reserved_data_space(BTRFS_I(inode),
3472 data_reserved, cur_offset,
3473 last_byte - cur_offset);
3474 }
3475 free_extent_map(em);
3476 cur_offset = last_byte;
3477 }
3478
3479 /*
3480 * If ret is still 0, means we're OK to fallocate.
3481 * Or just cleanup the list and exit.
3482 */
3483 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3484 if (!ret)
3485 ret = btrfs_prealloc_file_range(inode, mode,
3486 range->start,
3487 range->len, i_blocksize(inode),
3488 offset + len, &alloc_hint);
3489 else
3490 btrfs_free_reserved_data_space(BTRFS_I(inode),
3491 data_reserved, range->start,
3492 range->len);
3493 list_del(&range->list);
3494 kfree(range);
3495 }
3496 if (ret < 0)
3497 goto out_unlock;
3498
3499 /*
3500 * We didn't need to allocate any more space, but we still extended the
3501 * size of the file so we need to update i_size and the inode item.
3502 */
3503 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3504out_unlock:
3505 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3506 &cached_state);
3507out:
3508 btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP);
3509 /* Let go of our reservation. */
3510 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3511 btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved,
3512 cur_offset, alloc_end - cur_offset);
3513 extent_changeset_free(data_reserved);
3514 return ret;
3515}
3516
3517static loff_t find_desired_extent(struct btrfs_inode *inode, loff_t offset,
3518 int whence)
3519{
3520 struct btrfs_fs_info *fs_info = inode->root->fs_info;
3521 struct extent_map *em = NULL;
3522 struct extent_state *cached_state = NULL;
3523 loff_t i_size = inode->vfs_inode.i_size;
3524 u64 lockstart;
3525 u64 lockend;
3526 u64 start;
3527 u64 len;
3528 int ret = 0;
3529
3530 if (i_size == 0 || offset >= i_size)
3531 return -ENXIO;
3532
3533 /*
3534 * offset can be negative, in this case we start finding DATA/HOLE from
3535 * the very start of the file.
3536 */
3537 start = max_t(loff_t, 0, offset);
3538
3539 lockstart = round_down(start, fs_info->sectorsize);
3540 lockend = round_up(i_size, fs_info->sectorsize);
3541 if (lockend <= lockstart)
3542 lockend = lockstart + fs_info->sectorsize;
3543 lockend--;
3544 len = lockend - lockstart + 1;
3545
3546 lock_extent_bits(&inode->io_tree, lockstart, lockend, &cached_state);
3547
3548 while (start < i_size) {
3549 em = btrfs_get_extent_fiemap(inode, start, len);
3550 if (IS_ERR(em)) {
3551 ret = PTR_ERR(em);
3552 em = NULL;
3553 break;
3554 }
3555
3556 if (whence == SEEK_HOLE &&
3557 (em->block_start == EXTENT_MAP_HOLE ||
3558 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3559 break;
3560 else if (whence == SEEK_DATA &&
3561 (em->block_start != EXTENT_MAP_HOLE &&
3562 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3563 break;
3564
3565 start = em->start + em->len;
3566 free_extent_map(em);
3567 em = NULL;
3568 cond_resched();
3569 }
3570 free_extent_map(em);
3571 unlock_extent_cached(&inode->io_tree, lockstart, lockend,
3572 &cached_state);
3573 if (ret) {
3574 offset = ret;
3575 } else {
3576 if (whence == SEEK_DATA && start >= i_size)
3577 offset = -ENXIO;
3578 else
3579 offset = min_t(loff_t, start, i_size);
3580 }
3581
3582 return offset;
3583}
3584
3585static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3586{
3587 struct inode *inode = file->f_mapping->host;
3588
3589 switch (whence) {
3590 default:
3591 return generic_file_llseek(file, offset, whence);
3592 case SEEK_DATA:
3593 case SEEK_HOLE:
3594 btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
3595 offset = find_desired_extent(BTRFS_I(inode), offset, whence);
3596 btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
3597 break;
3598 }
3599
3600 if (offset < 0)
3601 return offset;
3602
3603 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3604}
3605
3606static int btrfs_file_open(struct inode *inode, struct file *filp)
3607{
3608 filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
3609 return generic_file_open(inode, filp);
3610}
3611
3612static int check_direct_read(struct btrfs_fs_info *fs_info,
3613 const struct iov_iter *iter, loff_t offset)
3614{
3615 int ret;
3616 int i, seg;
3617
3618 ret = check_direct_IO(fs_info, iter, offset);
3619 if (ret < 0)
3620 return ret;
3621
3622 if (!iter_is_iovec(iter))
3623 return 0;
3624
3625 for (seg = 0; seg < iter->nr_segs; seg++)
3626 for (i = seg + 1; i < iter->nr_segs; i++)
3627 if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
3628 return -EINVAL;
3629 return 0;
3630}
3631
3632static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to)
3633{
3634 struct inode *inode = file_inode(iocb->ki_filp);
3635 ssize_t ret;
3636
3637 if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos))
3638 return 0;
3639
3640 btrfs_inode_lock(inode, BTRFS_ILOCK_SHARED);
3641 ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dio_ops, 0);
3642 btrfs_inode_unlock(inode, BTRFS_ILOCK_SHARED);
3643 return ret;
3644}
3645
3646static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
3647{
3648 ssize_t ret = 0;
3649
3650 if (iocb->ki_flags & IOCB_DIRECT) {
3651 ret = btrfs_direct_read(iocb, to);
3652 if (ret < 0 || !iov_iter_count(to) ||
3653 iocb->ki_pos >= i_size_read(file_inode(iocb->ki_filp)))
3654 return ret;
3655 }
3656
3657 return filemap_read(iocb, to, ret);
3658}
3659
3660const struct file_operations btrfs_file_operations = {
3661 .llseek = btrfs_file_llseek,
3662 .read_iter = btrfs_file_read_iter,
3663 .splice_read = generic_file_splice_read,
3664 .write_iter = btrfs_file_write_iter,
3665 .splice_write = iter_file_splice_write,
3666 .mmap = btrfs_file_mmap,
3667 .open = btrfs_file_open,
3668 .release = btrfs_release_file,
3669 .fsync = btrfs_sync_file,
3670 .fallocate = btrfs_fallocate,
3671 .unlocked_ioctl = btrfs_ioctl,
3672#ifdef CONFIG_COMPAT
3673 .compat_ioctl = btrfs_compat_ioctl,
3674#endif
3675 .remap_file_range = btrfs_remap_file_range,
3676};
3677
3678void __cold btrfs_auto_defrag_exit(void)
3679{
3680 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3681}
3682
3683int __init btrfs_auto_defrag_init(void)
3684{
3685 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3686 sizeof(struct inode_defrag), 0,
3687 SLAB_MEM_SPREAD,
3688 NULL);
3689 if (!btrfs_inode_defrag_cachep)
3690 return -ENOMEM;
3691
3692 return 0;
3693}
3694
3695int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3696{
3697 int ret;
3698
3699 /*
3700 * So with compression we will find and lock a dirty page and clear the
3701 * first one as dirty, setup an async extent, and immediately return
3702 * with the entire range locked but with nobody actually marked with
3703 * writeback. So we can't just filemap_write_and_wait_range() and
3704 * expect it to work since it will just kick off a thread to do the
3705 * actual work. So we need to call filemap_fdatawrite_range _again_
3706 * since it will wait on the page lock, which won't be unlocked until
3707 * after the pages have been marked as writeback and so we're good to go
3708 * from there. We have to do this otherwise we'll miss the ordered
3709 * extents and that results in badness. Please Josef, do not think you
3710 * know better and pull this out at some point in the future, it is
3711 * right and you are wrong.
3712 */
3713 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3714 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3715 &BTRFS_I(inode)->runtime_flags))
3716 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3717
3718 return ret;
3719}