1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2008 Oracle. All rights reserved.
4 */
5
6 #include <linux/sched.h>
7 #include <linux/slab.h>
8 #include <linux/blkdev.h>
9 #include <linux/list_sort.h>
10 #include <linux/iversion.h>
11 #include "misc.h"
12 #include "ctree.h"
13 #include "tree-log.h"
14 #include "disk-io.h"
15 #include "locking.h"
16 #include "backref.h"
17 #include "compression.h"
18 #include "qgroup.h"
19 #include "block-group.h"
20 #include "space-info.h"
21 #include "inode-item.h"
22 #include "fs.h"
23 #include "accessors.h"
24 #include "extent-tree.h"
25 #include "root-tree.h"
26 #include "dir-item.h"
27 #include "file-item.h"
28 #include "file.h"
29 #include "orphan.h"
30 #include "tree-checker.h"
31
32 #define MAX_CONFLICT_INODES 10
33
34 /* magic values for the inode_only field in btrfs_log_inode:
35 *
36 * LOG_INODE_ALL means to log everything
37 * LOG_INODE_EXISTS means to log just enough to recreate the inode
38 * during log replay
39 */
40 enum {
41 LOG_INODE_ALL,
42 LOG_INODE_EXISTS,
43 };
44
45 /*
46 * directory trouble cases
47 *
48 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
49 * log, we must force a full commit before doing an fsync of the directory
50 * where the unlink was done.
51 * ---> record transid of last unlink/rename per directory
52 *
53 * mkdir foo/some_dir
54 * normal commit
55 * rename foo/some_dir foo2/some_dir
56 * mkdir foo/some_dir
57 * fsync foo/some_dir/some_file
58 *
59 * The fsync above will unlink the original some_dir without recording
60 * it in its new location (foo2). After a crash, some_dir will be gone
61 * unless the fsync of some_file forces a full commit
62 *
63 * 2) we must log any new names for any file or dir that is in the fsync
64 * log. ---> check inode while renaming/linking.
65 *
66 * 2a) we must log any new names for any file or dir during rename
67 * when the directory they are being removed from was logged.
68 * ---> check inode and old parent dir during rename
69 *
70 * 2a is actually the more important variant. With the extra logging
71 * a crash might unlink the old name without recreating the new one
72 *
73 * 3) after a crash, we must go through any directories with a link count
74 * of zero and redo the rm -rf
75 *
76 * mkdir f1/foo
77 * normal commit
78 * rm -rf f1/foo
79 * fsync(f1)
80 *
81 * The directory f1 was fully removed from the FS, but fsync was never
82 * called on f1, only its parent dir. After a crash the rm -rf must
83 * be replayed. This must be able to recurse down the entire
84 * directory tree. The inode link count fixup code takes care of the
85 * ugly details.
86 */
87
88 /*
89 * stages for the tree walking. The first
90 * stage (0) is to only pin down the blocks we find
91 * the second stage (1) is to make sure that all the inodes
92 * we find in the log are created in the subvolume.
93 *
94 * The last stage is to deal with directories and links and extents
95 * and all the other fun semantics
96 */
97 enum {
98 LOG_WALK_PIN_ONLY,
99 LOG_WALK_REPLAY_INODES,
100 LOG_WALK_REPLAY_DIR_INDEX,
101 LOG_WALK_REPLAY_ALL,
102 };
103
104 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
105 struct btrfs_inode *inode,
106 int inode_only,
107 struct btrfs_log_ctx *ctx);
108 static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
109 struct btrfs_root *root,
110 struct btrfs_path *path, u64 objectid);
111 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
112 struct btrfs_root *root,
113 struct btrfs_root *log,
114 struct btrfs_path *path,
115 u64 dirid, int del_all);
116 static void wait_log_commit(struct btrfs_root *root, int transid);
117
118 /*
119 * tree logging is a special write ahead log used to make sure that
120 * fsyncs and O_SYNCs can happen without doing full tree commits.
121 *
122 * Full tree commits are expensive because they require commonly
123 * modified blocks to be recowed, creating many dirty pages in the
124 * extent tree an 4x-6x higher write load than ext3.
125 *
126 * Instead of doing a tree commit on every fsync, we use the
127 * key ranges and transaction ids to find items for a given file or directory
128 * that have changed in this transaction. Those items are copied into
129 * a special tree (one per subvolume root), that tree is written to disk
130 * and then the fsync is considered complete.
131 *
132 * After a crash, items are copied out of the log-tree back into the
133 * subvolume tree. Any file data extents found are recorded in the extent
134 * allocation tree, and the log-tree freed.
135 *
136 * The log tree is read three times, once to pin down all the extents it is
137 * using in ram and once, once to create all the inodes logged in the tree
138 * and once to do all the other items.
139 */
140
141 static struct inode *btrfs_iget_logging(u64 objectid, struct btrfs_root *root)
142 {
143 unsigned int nofs_flag;
144 struct inode *inode;
145
146 /*
147 * We're holding a transaction handle whether we are logging or
148 * replaying a log tree, so we must make sure NOFS semantics apply
149 * because btrfs_alloc_inode() may be triggered and it uses GFP_KERNEL
150 * to allocate an inode, which can recurse back into the filesystem and
151 * attempt a transaction commit, resulting in a deadlock.
152 */
153 nofs_flag = memalloc_nofs_save();
154 inode = btrfs_iget(objectid, root);
155 memalloc_nofs_restore(nofs_flag);
156
157 return inode;
158 }
159
160 /*
161 * start a sub transaction and setup the log tree
162 * this increments the log tree writer count to make the people
163 * syncing the tree wait for us to finish
164 */
165 static int start_log_trans(struct btrfs_trans_handle *trans,
166 struct btrfs_root *root,
167 struct btrfs_log_ctx *ctx)
168 {
169 struct btrfs_fs_info *fs_info = root->fs_info;
170 struct btrfs_root *tree_root = fs_info->tree_root;
171 const bool zoned = btrfs_is_zoned(fs_info);
172 int ret = 0;
173 bool created = false;
174
175 /*
176 * First check if the log root tree was already created. If not, create
177 * it before locking the root's log_mutex, just to keep lockdep happy.
178 */
179 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) {
180 mutex_lock(&tree_root->log_mutex);
181 if (!fs_info->log_root_tree) {
182 ret = btrfs_init_log_root_tree(trans, fs_info);
183 if (!ret) {
184 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state);
185 created = true;
186 }
187 }
188 mutex_unlock(&tree_root->log_mutex);
189 if (ret)
190 return ret;
191 }
192
193 mutex_lock(&root->log_mutex);
194
195 again:
196 if (root->log_root) {
197 int index = (root->log_transid + 1) % 2;
198
199 if (btrfs_need_log_full_commit(trans)) {
200 ret = BTRFS_LOG_FORCE_COMMIT;
201 goto out;
202 }
203
204 if (zoned && atomic_read(&root->log_commit[index])) {
205 wait_log_commit(root, root->log_transid - 1);
206 goto again;
207 }
208
209 if (!root->log_start_pid) {
210 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
211 root->log_start_pid = current->pid;
212 } else if (root->log_start_pid != current->pid) {
213 set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
214 }
215 } else {
216 /*
217 * This means fs_info->log_root_tree was already created
218 * for some other FS trees. Do the full commit not to mix
219 * nodes from multiple log transactions to do sequential
220 * writing.
221 */
222 if (zoned && !created) {
223 ret = BTRFS_LOG_FORCE_COMMIT;
224 goto out;
225 }
226
227 ret = btrfs_add_log_tree(trans, root);
228 if (ret)
229 goto out;
230
231 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
232 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
233 root->log_start_pid = current->pid;
234 }
235
236 atomic_inc(&root->log_writers);
237 if (!ctx->logging_new_name) {
238 int index = root->log_transid % 2;
239 list_add_tail(&ctx->list, &root->log_ctxs[index]);
240 ctx->log_transid = root->log_transid;
241 }
242
243 out:
244 mutex_unlock(&root->log_mutex);
245 return ret;
246 }
247
248 /*
249 * returns 0 if there was a log transaction running and we were able
250 * to join, or returns -ENOENT if there were not transactions
251 * in progress
252 */
253 static int join_running_log_trans(struct btrfs_root *root)
254 {
255 const bool zoned = btrfs_is_zoned(root->fs_info);
256 int ret = -ENOENT;
257
258 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
259 return ret;
260
261 mutex_lock(&root->log_mutex);
262 again:
263 if (root->log_root) {
264 int index = (root->log_transid + 1) % 2;
265
266 ret = 0;
267 if (zoned && atomic_read(&root->log_commit[index])) {
268 wait_log_commit(root, root->log_transid - 1);
269 goto again;
270 }
271 atomic_inc(&root->log_writers);
272 }
273 mutex_unlock(&root->log_mutex);
274 return ret;
275 }
276
277 /*
278 * This either makes the current running log transaction wait
279 * until you call btrfs_end_log_trans() or it makes any future
280 * log transactions wait until you call btrfs_end_log_trans()
281 */
282 void btrfs_pin_log_trans(struct btrfs_root *root)
283 {
284 atomic_inc(&root->log_writers);
285 }
286
287 /*
288 * indicate we're done making changes to the log tree
289 * and wake up anyone waiting to do a sync
290 */
291 void btrfs_end_log_trans(struct btrfs_root *root)
292 {
293 if (atomic_dec_and_test(&root->log_writers)) {
294 /* atomic_dec_and_test implies a barrier */
295 cond_wake_up_nomb(&root->log_writer_wait);
296 }
297 }
298
299 /*
300 * the walk control struct is used to pass state down the chain when
301 * processing the log tree. The stage field tells us which part
302 * of the log tree processing we are currently doing. The others
303 * are state fields used for that specific part
304 */
305 struct walk_control {
306 /* should we free the extent on disk when done? This is used
307 * at transaction commit time while freeing a log tree
308 */
309 int free;
310
311 /* pin only walk, we record which extents on disk belong to the
312 * log trees
313 */
314 int pin;
315
316 /* what stage of the replay code we're currently in */
317 int stage;
318
319 /*
320 * Ignore any items from the inode currently being processed. Needs
321 * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
322 * the LOG_WALK_REPLAY_INODES stage.
323 */
324 bool ignore_cur_inode;
325
326 /* the root we are currently replaying */
327 struct btrfs_root *replay_dest;
328
329 /* the trans handle for the current replay */
330 struct btrfs_trans_handle *trans;
331
332 /* the function that gets used to process blocks we find in the
333 * tree. Note the extent_buffer might not be up to date when it is
334 * passed in, and it must be checked or read if you need the data
335 * inside it
336 */
337 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
338 struct walk_control *wc, u64 gen, int level);
339 };
340
341 /*
342 * process_func used to pin down extents, write them or wait on them
343 */
344 static int process_one_buffer(struct btrfs_root *log,
345 struct extent_buffer *eb,
346 struct walk_control *wc, u64 gen, int level)
347 {
348 struct btrfs_fs_info *fs_info = log->fs_info;
349 int ret = 0;
350
351 /*
352 * If this fs is mixed then we need to be able to process the leaves to
353 * pin down any logged extents, so we have to read the block.
354 */
355 if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
356 struct btrfs_tree_parent_check check = {
357 .level = level,
358 .transid = gen
359 };
360
361 ret = btrfs_read_extent_buffer(eb, &check);
362 if (ret)
363 return ret;
364 }
365
366 if (wc->pin) {
367 ret = btrfs_pin_extent_for_log_replay(wc->trans, eb);
368 if (ret)
369 return ret;
370
371 if (btrfs_buffer_uptodate(eb, gen, 0) &&
372 btrfs_header_level(eb) == 0)
373 ret = btrfs_exclude_logged_extents(eb);
374 }
375 return ret;
376 }
377
378 /*
379 * Item overwrite used by replay and tree logging. eb, slot and key all refer
380 * to the src data we are copying out.
381 *
382 * root is the tree we are copying into, and path is a scratch
383 * path for use in this function (it should be released on entry and
384 * will be released on exit).
385 *
386 * If the key is already in the destination tree the existing item is
387 * overwritten. If the existing item isn't big enough, it is extended.
388 * If it is too large, it is truncated.
389 *
390 * If the key isn't in the destination yet, a new item is inserted.
391 */
392 static int overwrite_item(struct btrfs_trans_handle *trans,
393 struct btrfs_root *root,
394 struct btrfs_path *path,
395 struct extent_buffer *eb, int slot,
396 struct btrfs_key *key)
397 {
398 int ret;
399 u32 item_size;
400 u64 saved_i_size = 0;
401 int save_old_i_size = 0;
402 unsigned long src_ptr;
403 unsigned long dst_ptr;
404 bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
405
406 /*
407 * This is only used during log replay, so the root is always from a
408 * fs/subvolume tree. In case we ever need to support a log root, then
409 * we'll have to clone the leaf in the path, release the path and use
410 * the leaf before writing into the log tree. See the comments at
411 * copy_items() for more details.
412 */
413 ASSERT(btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID);
414
415 item_size = btrfs_item_size(eb, slot);
416 src_ptr = btrfs_item_ptr_offset(eb, slot);
417
418 /* Look for the key in the destination tree. */
419 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
420 if (ret < 0)
421 return ret;
422
423 if (ret == 0) {
424 char *src_copy;
425 char *dst_copy;
426 u32 dst_size = btrfs_item_size(path->nodes[0],
427 path->slots[0]);
428 if (dst_size != item_size)
429 goto insert;
430
431 if (item_size == 0) {
432 btrfs_release_path(path);
433 return 0;
434 }
435 dst_copy = kmalloc(item_size, GFP_NOFS);
436 src_copy = kmalloc(item_size, GFP_NOFS);
437 if (!dst_copy || !src_copy) {
438 btrfs_release_path(path);
439 kfree(dst_copy);
440 kfree(src_copy);
441 return -ENOMEM;
442 }
443
444 read_extent_buffer(eb, src_copy, src_ptr, item_size);
445
446 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
447 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
448 item_size);
449 ret = memcmp(dst_copy, src_copy, item_size);
450
451 kfree(dst_copy);
452 kfree(src_copy);
453 /*
454 * they have the same contents, just return, this saves
455 * us from cowing blocks in the destination tree and doing
456 * extra writes that may not have been done by a previous
457 * sync
458 */
459 if (ret == 0) {
460 btrfs_release_path(path);
461 return 0;
462 }
463
464 /*
465 * We need to load the old nbytes into the inode so when we
466 * replay the extents we've logged we get the right nbytes.
467 */
468 if (inode_item) {
469 struct btrfs_inode_item *item;
470 u64 nbytes;
471 u32 mode;
472
473 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
474 struct btrfs_inode_item);
475 nbytes = btrfs_inode_nbytes(path->nodes[0], item);
476 item = btrfs_item_ptr(eb, slot,
477 struct btrfs_inode_item);
478 btrfs_set_inode_nbytes(eb, item, nbytes);
479
480 /*
481 * If this is a directory we need to reset the i_size to
482 * 0 so that we can set it up properly when replaying
483 * the rest of the items in this log.
484 */
485 mode = btrfs_inode_mode(eb, item);
486 if (S_ISDIR(mode))
487 btrfs_set_inode_size(eb, item, 0);
488 }
489 } else if (inode_item) {
490 struct btrfs_inode_item *item;
491 u32 mode;
492
493 /*
494 * New inode, set nbytes to 0 so that the nbytes comes out
495 * properly when we replay the extents.
496 */
497 item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
498 btrfs_set_inode_nbytes(eb, item, 0);
499
500 /*
501 * If this is a directory we need to reset the i_size to 0 so
502 * that we can set it up properly when replaying the rest of
503 * the items in this log.
504 */
505 mode = btrfs_inode_mode(eb, item);
506 if (S_ISDIR(mode))
507 btrfs_set_inode_size(eb, item, 0);
508 }
509 insert:
510 btrfs_release_path(path);
511 /* try to insert the key into the destination tree */
512 path->skip_release_on_error = 1;
513 ret = btrfs_insert_empty_item(trans, root, path,
514 key, item_size);
515 path->skip_release_on_error = 0;
516
517 /* make sure any existing item is the correct size */
518 if (ret == -EEXIST || ret == -EOVERFLOW) {
519 u32 found_size;
520 found_size = btrfs_item_size(path->nodes[0],
521 path->slots[0]);
522 if (found_size > item_size)
523 btrfs_truncate_item(trans, path, item_size, 1);
524 else if (found_size < item_size)
525 btrfs_extend_item(trans, path, item_size - found_size);
526 } else if (ret) {
527 return ret;
528 }
529 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
530 path->slots[0]);
531
532 /* don't overwrite an existing inode if the generation number
533 * was logged as zero. This is done when the tree logging code
534 * is just logging an inode to make sure it exists after recovery.
535 *
536 * Also, don't overwrite i_size on directories during replay.
537 * log replay inserts and removes directory items based on the
538 * state of the tree found in the subvolume, and i_size is modified
539 * as it goes
540 */
541 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
542 struct btrfs_inode_item *src_item;
543 struct btrfs_inode_item *dst_item;
544
545 src_item = (struct btrfs_inode_item *)src_ptr;
546 dst_item = (struct btrfs_inode_item *)dst_ptr;
547
548 if (btrfs_inode_generation(eb, src_item) == 0) {
549 struct extent_buffer *dst_eb = path->nodes[0];
550 const u64 ino_size = btrfs_inode_size(eb, src_item);
551
552 /*
553 * For regular files an ino_size == 0 is used only when
554 * logging that an inode exists, as part of a directory
555 * fsync, and the inode wasn't fsynced before. In this
556 * case don't set the size of the inode in the fs/subvol
557 * tree, otherwise we would be throwing valid data away.
558 */
559 if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
560 S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
561 ino_size != 0)
562 btrfs_set_inode_size(dst_eb, dst_item, ino_size);
563 goto no_copy;
564 }
565
566 if (S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
567 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
568 save_old_i_size = 1;
569 saved_i_size = btrfs_inode_size(path->nodes[0],
570 dst_item);
571 }
572 }
573
574 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
575 src_ptr, item_size);
576
577 if (save_old_i_size) {
578 struct btrfs_inode_item *dst_item;
579 dst_item = (struct btrfs_inode_item *)dst_ptr;
580 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
581 }
582
583 /* make sure the generation is filled in */
584 if (key->type == BTRFS_INODE_ITEM_KEY) {
585 struct btrfs_inode_item *dst_item;
586 dst_item = (struct btrfs_inode_item *)dst_ptr;
587 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
588 btrfs_set_inode_generation(path->nodes[0], dst_item,
589 trans->transid);
590 }
591 }
592 no_copy:
593 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
594 btrfs_release_path(path);
595 return 0;
596 }
597
598 static int read_alloc_one_name(struct extent_buffer *eb, void *start, int len,
599 struct fscrypt_str *name)
600 {
601 char *buf;
602
603 buf = kmalloc(len, GFP_NOFS);
604 if (!buf)
605 return -ENOMEM;
606
607 read_extent_buffer(eb, buf, (unsigned long)start, len);
608 name->name = buf;
609 name->len = len;
610 return 0;
611 }
612
613 /*
614 * simple helper to read an inode off the disk from a given root
615 * This can only be called for subvolume roots and not for the log
616 */
617 static noinline struct inode *read_one_inode(struct btrfs_root *root,
618 u64 objectid)
619 {
620 struct inode *inode;
621
622 inode = btrfs_iget_logging(objectid, root);
623 if (IS_ERR(inode))
624 inode = NULL;
625 return inode;
626 }
627
628 /* replays a single extent in 'eb' at 'slot' with 'key' into the
629 * subvolume 'root'. path is released on entry and should be released
630 * on exit.
631 *
632 * extents in the log tree have not been allocated out of the extent
633 * tree yet. So, this completes the allocation, taking a reference
634 * as required if the extent already exists or creating a new extent
635 * if it isn't in the extent allocation tree yet.
636 *
637 * The extent is inserted into the file, dropping any existing extents
638 * from the file that overlap the new one.
639 */
640 static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
641 struct btrfs_root *root,
642 struct btrfs_path *path,
643 struct extent_buffer *eb, int slot,
644 struct btrfs_key *key)
645 {
646 struct btrfs_drop_extents_args drop_args = { 0 };
647 struct btrfs_fs_info *fs_info = root->fs_info;
648 int found_type;
649 u64 extent_end;
650 u64 start = key->offset;
651 u64 nbytes = 0;
652 struct btrfs_file_extent_item *item;
653 struct inode *inode = NULL;
654 unsigned long size;
655 int ret = 0;
656
657 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
658 found_type = btrfs_file_extent_type(eb, item);
659
660 if (found_type == BTRFS_FILE_EXTENT_REG ||
661 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
662 nbytes = btrfs_file_extent_num_bytes(eb, item);
663 extent_end = start + nbytes;
664
665 /*
666 * We don't add to the inodes nbytes if we are prealloc or a
667 * hole.
668 */
669 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
670 nbytes = 0;
671 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
672 size = btrfs_file_extent_ram_bytes(eb, item);
673 nbytes = btrfs_file_extent_ram_bytes(eb, item);
674 extent_end = ALIGN(start + size,
675 fs_info->sectorsize);
676 } else {
677 ret = 0;
678 goto out;
679 }
680
681 inode = read_one_inode(root, key->objectid);
682 if (!inode) {
683 ret = -EIO;
684 goto out;
685 }
686
687 /*
688 * first check to see if we already have this extent in the
689 * file. This must be done before the btrfs_drop_extents run
690 * so we don't try to drop this extent.
691 */
692 ret = btrfs_lookup_file_extent(trans, root, path,
693 btrfs_ino(BTRFS_I(inode)), start, 0);
694
695 if (ret == 0 &&
696 (found_type == BTRFS_FILE_EXTENT_REG ||
697 found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
698 struct btrfs_file_extent_item cmp1;
699 struct btrfs_file_extent_item cmp2;
700 struct btrfs_file_extent_item *existing;
701 struct extent_buffer *leaf;
702
703 leaf = path->nodes[0];
704 existing = btrfs_item_ptr(leaf, path->slots[0],
705 struct btrfs_file_extent_item);
706
707 read_extent_buffer(eb, &cmp1, (unsigned long)item,
708 sizeof(cmp1));
709 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
710 sizeof(cmp2));
711
712 /*
713 * we already have a pointer to this exact extent,
714 * we don't have to do anything
715 */
716 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
717 btrfs_release_path(path);
718 goto out;
719 }
720 }
721 btrfs_release_path(path);
722
723 /* drop any overlapping extents */
724 drop_args.start = start;
725 drop_args.end = extent_end;
726 drop_args.drop_cache = true;
727 ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args);
728 if (ret)
729 goto out;
730
731 if (found_type == BTRFS_FILE_EXTENT_REG ||
732 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
733 u64 offset;
734 unsigned long dest_offset;
735 struct btrfs_key ins;
736
737 if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
738 btrfs_fs_incompat(fs_info, NO_HOLES))
739 goto update_inode;
740
741 ret = btrfs_insert_empty_item(trans, root, path, key,
742 sizeof(*item));
743 if (ret)
744 goto out;
745 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
746 path->slots[0]);
747 copy_extent_buffer(path->nodes[0], eb, dest_offset,
748 (unsigned long)item, sizeof(*item));
749
750 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
751 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
752 ins.type = BTRFS_EXTENT_ITEM_KEY;
753 offset = key->offset - btrfs_file_extent_offset(eb, item);
754
755 /*
756 * Manually record dirty extent, as here we did a shallow
757 * file extent item copy and skip normal backref update,
758 * but modifying extent tree all by ourselves.
759 * So need to manually record dirty extent for qgroup,
760 * as the owner of the file extent changed from log tree
761 * (doesn't affect qgroup) to fs/file tree(affects qgroup)
762 */
763 ret = btrfs_qgroup_trace_extent(trans,
764 btrfs_file_extent_disk_bytenr(eb, item),
765 btrfs_file_extent_disk_num_bytes(eb, item));
766 if (ret < 0)
767 goto out;
768
769 if (ins.objectid > 0) {
770 u64 csum_start;
771 u64 csum_end;
772 LIST_HEAD(ordered_sums);
773
774 /*
775 * is this extent already allocated in the extent
776 * allocation tree? If so, just add a reference
777 */
778 ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
779 ins.offset);
780 if (ret < 0) {
781 goto out;
782 } else if (ret == 0) {
783 struct btrfs_ref ref = {
784 .action = BTRFS_ADD_DELAYED_REF,
785 .bytenr = ins.objectid,
786 .num_bytes = ins.offset,
787 .owning_root = btrfs_root_id(root),
788 .ref_root = btrfs_root_id(root),
789 };
790 btrfs_init_data_ref(&ref, key->objectid, offset,
791 0, false);
792 ret = btrfs_inc_extent_ref(trans, &ref);
793 if (ret)
794 goto out;
795 } else {
796 /*
797 * insert the extent pointer in the extent
798 * allocation tree
799 */
800 ret = btrfs_alloc_logged_file_extent(trans,
801 btrfs_root_id(root),
802 key->objectid, offset, &ins);
803 if (ret)
804 goto out;
805 }
806 btrfs_release_path(path);
807
808 if (btrfs_file_extent_compression(eb, item)) {
809 csum_start = ins.objectid;
810 csum_end = csum_start + ins.offset;
811 } else {
812 csum_start = ins.objectid +
813 btrfs_file_extent_offset(eb, item);
814 csum_end = csum_start +
815 btrfs_file_extent_num_bytes(eb, item);
816 }
817
818 ret = btrfs_lookup_csums_list(root->log_root,
819 csum_start, csum_end - 1,
820 &ordered_sums, false);
821 if (ret < 0)
822 goto out;
823 ret = 0;
824 /*
825 * Now delete all existing cums in the csum root that
826 * cover our range. We do this because we can have an
827 * extent that is completely referenced by one file
828 * extent item and partially referenced by another
829 * file extent item (like after using the clone or
830 * extent_same ioctls). In this case if we end up doing
831 * the replay of the one that partially references the
832 * extent first, and we do not do the csum deletion
833 * below, we can get 2 csum items in the csum tree that
834 * overlap each other. For example, imagine our log has
835 * the two following file extent items:
836 *
837 * key (257 EXTENT_DATA 409600)
838 * extent data disk byte 12845056 nr 102400
839 * extent data offset 20480 nr 20480 ram 102400
840 *
841 * key (257 EXTENT_DATA 819200)
842 * extent data disk byte 12845056 nr 102400
843 * extent data offset 0 nr 102400 ram 102400
844 *
845 * Where the second one fully references the 100K extent
846 * that starts at disk byte 12845056, and the log tree
847 * has a single csum item that covers the entire range
848 * of the extent:
849 *
850 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
851 *
852 * After the first file extent item is replayed, the
853 * csum tree gets the following csum item:
854 *
855 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
856 *
857 * Which covers the 20K sub-range starting at offset 20K
858 * of our extent. Now when we replay the second file
859 * extent item, if we do not delete existing csum items
860 * that cover any of its blocks, we end up getting two
861 * csum items in our csum tree that overlap each other:
862 *
863 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
864 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
865 *
866 * Which is a problem, because after this anyone trying
867 * to lookup up for the checksum of any block of our
868 * extent starting at an offset of 40K or higher, will
869 * end up looking at the second csum item only, which
870 * does not contain the checksum for any block starting
871 * at offset 40K or higher of our extent.
872 */
873 while (!list_empty(&ordered_sums)) {
874 struct btrfs_ordered_sum *sums;
875 struct btrfs_root *csum_root;
876
877 sums = list_entry(ordered_sums.next,
878 struct btrfs_ordered_sum,
879 list);
880 csum_root = btrfs_csum_root(fs_info,
881 sums->logical);
882 if (!ret)
883 ret = btrfs_del_csums(trans, csum_root,
884 sums->logical,
885 sums->len);
886 if (!ret)
887 ret = btrfs_csum_file_blocks(trans,
888 csum_root,
889 sums);
890 list_del(&sums->list);
891 kfree(sums);
892 }
893 if (ret)
894 goto out;
895 } else {
896 btrfs_release_path(path);
897 }
898 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
899 /* inline extents are easy, we just overwrite them */
900 ret = overwrite_item(trans, root, path, eb, slot, key);
901 if (ret)
902 goto out;
903 }
904
905 ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start,
906 extent_end - start);
907 if (ret)
908 goto out;
909
910 update_inode:
911 btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found);
912 ret = btrfs_update_inode(trans, BTRFS_I(inode));
913 out:
914 iput(inode);
915 return ret;
916 }
917
918 static int unlink_inode_for_log_replay(struct btrfs_trans_handle *trans,
919 struct btrfs_inode *dir,
920 struct btrfs_inode *inode,
921 const struct fscrypt_str *name)
922 {
923 int ret;
924
925 ret = btrfs_unlink_inode(trans, dir, inode, name);
926 if (ret)
927 return ret;
928 /*
929 * Whenever we need to check if a name exists or not, we check the
930 * fs/subvolume tree. So after an unlink we must run delayed items, so
931 * that future checks for a name during log replay see that the name
932 * does not exists anymore.
933 */
934 return btrfs_run_delayed_items(trans);
935 }
936
937 /*
938 * when cleaning up conflicts between the directory names in the
939 * subvolume, directory names in the log and directory names in the
940 * inode back references, we may have to unlink inodes from directories.
941 *
942 * This is a helper function to do the unlink of a specific directory
943 * item
944 */
945 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
946 struct btrfs_path *path,
947 struct btrfs_inode *dir,
948 struct btrfs_dir_item *di)
949 {
950 struct btrfs_root *root = dir->root;
951 struct inode *inode;
952 struct fscrypt_str name;
953 struct extent_buffer *leaf;
954 struct btrfs_key location;
955 int ret;
956
957 leaf = path->nodes[0];
958
959 btrfs_dir_item_key_to_cpu(leaf, di, &location);
960 ret = read_alloc_one_name(leaf, di + 1, btrfs_dir_name_len(leaf, di), &name);
961 if (ret)
962 return -ENOMEM;
963
964 btrfs_release_path(path);
965
966 inode = read_one_inode(root, location.objectid);
967 if (!inode) {
968 ret = -EIO;
969 goto out;
970 }
971
972 ret = link_to_fixup_dir(trans, root, path, location.objectid);
973 if (ret)
974 goto out;
975
976 ret = unlink_inode_for_log_replay(trans, dir, BTRFS_I(inode), &name);
977 out:
978 kfree(name.name);
979 iput(inode);
980 return ret;
981 }
982
983 /*
984 * See if a given name and sequence number found in an inode back reference are
985 * already in a directory and correctly point to this inode.
986 *
987 * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it
988 * exists.
989 */
990 static noinline int inode_in_dir(struct btrfs_root *root,
991 struct btrfs_path *path,
992 u64 dirid, u64 objectid, u64 index,
993 struct fscrypt_str *name)
994 {
995 struct btrfs_dir_item *di;
996 struct btrfs_key location;
997 int ret = 0;
998
999 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
1000 index, name, 0);
1001 if (IS_ERR(di)) {
1002 ret = PTR_ERR(di);
1003 goto out;
1004 } else if (di) {
1005 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1006 if (location.objectid != objectid)
1007 goto out;
1008 } else {
1009 goto out;
1010 }
1011
1012 btrfs_release_path(path);
1013 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, 0);
1014 if (IS_ERR(di)) {
1015 ret = PTR_ERR(di);
1016 goto out;
1017 } else if (di) {
1018 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1019 if (location.objectid == objectid)
1020 ret = 1;
1021 }
1022 out:
1023 btrfs_release_path(path);
1024 return ret;
1025 }
1026
1027 /*
1028 * helper function to check a log tree for a named back reference in
1029 * an inode. This is used to decide if a back reference that is
1030 * found in the subvolume conflicts with what we find in the log.
1031 *
1032 * inode backreferences may have multiple refs in a single item,
1033 * during replay we process one reference at a time, and we don't
1034 * want to delete valid links to a file from the subvolume if that
1035 * link is also in the log.
1036 */
1037 static noinline int backref_in_log(struct btrfs_root *log,
1038 struct btrfs_key *key,
1039 u64 ref_objectid,
1040 const struct fscrypt_str *name)
1041 {
1042 struct btrfs_path *path;
1043 int ret;
1044
1045 path = btrfs_alloc_path();
1046 if (!path)
1047 return -ENOMEM;
1048
1049 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
1050 if (ret < 0) {
1051 goto out;
1052 } else if (ret == 1) {
1053 ret = 0;
1054 goto out;
1055 }
1056
1057 if (key->type == BTRFS_INODE_EXTREF_KEY)
1058 ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
1059 path->slots[0],
1060 ref_objectid, name);
1061 else
1062 ret = !!btrfs_find_name_in_backref(path->nodes[0],
1063 path->slots[0], name);
1064 out:
1065 btrfs_free_path(path);
1066 return ret;
1067 }
1068
1069 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1070 struct btrfs_root *root,
1071 struct btrfs_path *path,
1072 struct btrfs_root *log_root,
1073 struct btrfs_inode *dir,
1074 struct btrfs_inode *inode,
1075 u64 inode_objectid, u64 parent_objectid,
1076 u64 ref_index, struct fscrypt_str *name)
1077 {
1078 int ret;
1079 struct extent_buffer *leaf;
1080 struct btrfs_dir_item *di;
1081 struct btrfs_key search_key;
1082 struct btrfs_inode_extref *extref;
1083
1084 again:
1085 /* Search old style refs */
1086 search_key.objectid = inode_objectid;
1087 search_key.type = BTRFS_INODE_REF_KEY;
1088 search_key.offset = parent_objectid;
1089 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
1090 if (ret == 0) {
1091 struct btrfs_inode_ref *victim_ref;
1092 unsigned long ptr;
1093 unsigned long ptr_end;
1094
1095 leaf = path->nodes[0];
1096
1097 /* are we trying to overwrite a back ref for the root directory
1098 * if so, just jump out, we're done
1099 */
1100 if (search_key.objectid == search_key.offset)
1101 return 1;
1102
1103 /* check all the names in this back reference to see
1104 * if they are in the log. if so, we allow them to stay
1105 * otherwise they must be unlinked as a conflict
1106 */
1107 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1108 ptr_end = ptr + btrfs_item_size(leaf, path->slots[0]);
1109 while (ptr < ptr_end) {
1110 struct fscrypt_str victim_name;
1111
1112 victim_ref = (struct btrfs_inode_ref *)ptr;
1113 ret = read_alloc_one_name(leaf, (victim_ref + 1),
1114 btrfs_inode_ref_name_len(leaf, victim_ref),
1115 &victim_name);
1116 if (ret)
1117 return ret;
1118
1119 ret = backref_in_log(log_root, &search_key,
1120 parent_objectid, &victim_name);
1121 if (ret < 0) {
1122 kfree(victim_name.name);
1123 return ret;
1124 } else if (!ret) {
1125 inc_nlink(&inode->vfs_inode);
1126 btrfs_release_path(path);
1127
1128 ret = unlink_inode_for_log_replay(trans, dir, inode,
1129 &victim_name);
1130 kfree(victim_name.name);
1131 if (ret)
1132 return ret;
1133 goto again;
1134 }
1135 kfree(victim_name.name);
1136
1137 ptr = (unsigned long)(victim_ref + 1) + victim_name.len;
1138 }
1139 }
1140 btrfs_release_path(path);
1141
1142 /* Same search but for extended refs */
1143 extref = btrfs_lookup_inode_extref(NULL, root, path, name,
1144 inode_objectid, parent_objectid, 0,
1145 0);
1146 if (IS_ERR(extref)) {
1147 return PTR_ERR(extref);
1148 } else if (extref) {
1149 u32 item_size;
1150 u32 cur_offset = 0;
1151 unsigned long base;
1152 struct inode *victim_parent;
1153
1154 leaf = path->nodes[0];
1155
1156 item_size = btrfs_item_size(leaf, path->slots[0]);
1157 base = btrfs_item_ptr_offset(leaf, path->slots[0]);
1158
1159 while (cur_offset < item_size) {
1160 struct fscrypt_str victim_name;
1161
1162 extref = (struct btrfs_inode_extref *)(base + cur_offset);
1163
1164 if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
1165 goto next;
1166
1167 ret = read_alloc_one_name(leaf, &extref->name,
1168 btrfs_inode_extref_name_len(leaf, extref),
1169 &victim_name);
1170 if (ret)
1171 return ret;
1172
1173 search_key.objectid = inode_objectid;
1174 search_key.type = BTRFS_INODE_EXTREF_KEY;
1175 search_key.offset = btrfs_extref_hash(parent_objectid,
1176 victim_name.name,
1177 victim_name.len);
1178 ret = backref_in_log(log_root, &search_key,
1179 parent_objectid, &victim_name);
1180 if (ret < 0) {
1181 kfree(victim_name.name);
1182 return ret;
1183 } else if (!ret) {
1184 ret = -ENOENT;
1185 victim_parent = read_one_inode(root,
1186 parent_objectid);
1187 if (victim_parent) {
1188 inc_nlink(&inode->vfs_inode);
1189 btrfs_release_path(path);
1190
1191 ret = unlink_inode_for_log_replay(trans,
1192 BTRFS_I(victim_parent),
1193 inode, &victim_name);
1194 }
1195 iput(victim_parent);
1196 kfree(victim_name.name);
1197 if (ret)
1198 return ret;
1199 goto again;
1200 }
1201 kfree(victim_name.name);
1202 next:
1203 cur_offset += victim_name.len + sizeof(*extref);
1204 }
1205 }
1206 btrfs_release_path(path);
1207
1208 /* look for a conflicting sequence number */
1209 di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
1210 ref_index, name, 0);
1211 if (IS_ERR(di)) {
1212 return PTR_ERR(di);
1213 } else if (di) {
1214 ret = drop_one_dir_item(trans, path, dir, di);
1215 if (ret)
1216 return ret;
1217 }
1218 btrfs_release_path(path);
1219
1220 /* look for a conflicting name */
1221 di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir), name, 0);
1222 if (IS_ERR(di)) {
1223 return PTR_ERR(di);
1224 } else if (di) {
1225 ret = drop_one_dir_item(trans, path, dir, di);
1226 if (ret)
1227 return ret;
1228 }
1229 btrfs_release_path(path);
1230
1231 return 0;
1232 }
1233
1234 static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1235 struct fscrypt_str *name, u64 *index,
1236 u64 *parent_objectid)
1237 {
1238 struct btrfs_inode_extref *extref;
1239 int ret;
1240
1241 extref = (struct btrfs_inode_extref *)ref_ptr;
1242
1243 ret = read_alloc_one_name(eb, &extref->name,
1244 btrfs_inode_extref_name_len(eb, extref), name);
1245 if (ret)
1246 return ret;
1247
1248 if (index)
1249 *index = btrfs_inode_extref_index(eb, extref);
1250 if (parent_objectid)
1251 *parent_objectid = btrfs_inode_extref_parent(eb, extref);
1252
1253 return 0;
1254 }
1255
1256 static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1257 struct fscrypt_str *name, u64 *index)
1258 {
1259 struct btrfs_inode_ref *ref;
1260 int ret;
1261
1262 ref = (struct btrfs_inode_ref *)ref_ptr;
1263
1264 ret = read_alloc_one_name(eb, ref + 1, btrfs_inode_ref_name_len(eb, ref),
1265 name);
1266 if (ret)
1267 return ret;
1268
1269 if (index)
1270 *index = btrfs_inode_ref_index(eb, ref);
1271
1272 return 0;
1273 }
1274
1275 /*
1276 * Take an inode reference item from the log tree and iterate all names from the
1277 * inode reference item in the subvolume tree with the same key (if it exists).
1278 * For any name that is not in the inode reference item from the log tree, do a
1279 * proper unlink of that name (that is, remove its entry from the inode
1280 * reference item and both dir index keys).
1281 */
1282 static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
1283 struct btrfs_root *root,
1284 struct btrfs_path *path,
1285 struct btrfs_inode *inode,
1286 struct extent_buffer *log_eb,
1287 int log_slot,
1288 struct btrfs_key *key)
1289 {
1290 int ret;
1291 unsigned long ref_ptr;
1292 unsigned long ref_end;
1293 struct extent_buffer *eb;
1294
1295 again:
1296 btrfs_release_path(path);
1297 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
1298 if (ret > 0) {
1299 ret = 0;
1300 goto out;
1301 }
1302 if (ret < 0)
1303 goto out;
1304
1305 eb = path->nodes[0];
1306 ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
1307 ref_end = ref_ptr + btrfs_item_size(eb, path->slots[0]);
1308 while (ref_ptr < ref_end) {
1309 struct fscrypt_str name;
1310 u64 parent_id;
1311
1312 if (key->type == BTRFS_INODE_EXTREF_KEY) {
1313 ret = extref_get_fields(eb, ref_ptr, &name,
1314 NULL, &parent_id);
1315 } else {
1316 parent_id = key->offset;
1317 ret = ref_get_fields(eb, ref_ptr, &name, NULL);
1318 }
1319 if (ret)
1320 goto out;
1321
1322 if (key->type == BTRFS_INODE_EXTREF_KEY)
1323 ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
1324 parent_id, &name);
1325 else
1326 ret = !!btrfs_find_name_in_backref(log_eb, log_slot, &name);
1327
1328 if (!ret) {
1329 struct inode *dir;
1330
1331 btrfs_release_path(path);
1332 dir = read_one_inode(root, parent_id);
1333 if (!dir) {
1334 ret = -ENOENT;
1335 kfree(name.name);
1336 goto out;
1337 }
1338 ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir),
1339 inode, &name);
1340 kfree(name.name);
1341 iput(dir);
1342 if (ret)
1343 goto out;
1344 goto again;
1345 }
1346
1347 kfree(name.name);
1348 ref_ptr += name.len;
1349 if (key->type == BTRFS_INODE_EXTREF_KEY)
1350 ref_ptr += sizeof(struct btrfs_inode_extref);
1351 else
1352 ref_ptr += sizeof(struct btrfs_inode_ref);
1353 }
1354 ret = 0;
1355 out:
1356 btrfs_release_path(path);
1357 return ret;
1358 }
1359
1360 /*
1361 * replay one inode back reference item found in the log tree.
1362 * eb, slot and key refer to the buffer and key found in the log tree.
1363 * root is the destination we are replaying into, and path is for temp
1364 * use by this function. (it should be released on return).
1365 */
1366 static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
1367 struct btrfs_root *root,
1368 struct btrfs_root *log,
1369 struct btrfs_path *path,
1370 struct extent_buffer *eb, int slot,
1371 struct btrfs_key *key)
1372 {
1373 struct inode *dir = NULL;
1374 struct inode *inode = NULL;
1375 unsigned long ref_ptr;
1376 unsigned long ref_end;
1377 struct fscrypt_str name = { 0 };
1378 int ret;
1379 int log_ref_ver = 0;
1380 u64 parent_objectid;
1381 u64 inode_objectid;
1382 u64 ref_index = 0;
1383 int ref_struct_size;
1384
1385 ref_ptr = btrfs_item_ptr_offset(eb, slot);
1386 ref_end = ref_ptr + btrfs_item_size(eb, slot);
1387
1388 if (key->type == BTRFS_INODE_EXTREF_KEY) {
1389 struct btrfs_inode_extref *r;
1390
1391 ref_struct_size = sizeof(struct btrfs_inode_extref);
1392 log_ref_ver = 1;
1393 r = (struct btrfs_inode_extref *)ref_ptr;
1394 parent_objectid = btrfs_inode_extref_parent(eb, r);
1395 } else {
1396 ref_struct_size = sizeof(struct btrfs_inode_ref);
1397 parent_objectid = key->offset;
1398 }
1399 inode_objectid = key->objectid;
1400
1401 /*
1402 * it is possible that we didn't log all the parent directories
1403 * for a given inode. If we don't find the dir, just don't
1404 * copy the back ref in. The link count fixup code will take
1405 * care of the rest
1406 */
1407 dir = read_one_inode(root, parent_objectid);
1408 if (!dir) {
1409 ret = -ENOENT;
1410 goto out;
1411 }
1412
1413 inode = read_one_inode(root, inode_objectid);
1414 if (!inode) {
1415 ret = -EIO;
1416 goto out;
1417 }
1418
1419 while (ref_ptr < ref_end) {
1420 if (log_ref_ver) {
1421 ret = extref_get_fields(eb, ref_ptr, &name,
1422 &ref_index, &parent_objectid);
1423 /*
1424 * parent object can change from one array
1425 * item to another.
1426 */
1427 if (!dir)
1428 dir = read_one_inode(root, parent_objectid);
1429 if (!dir) {
1430 ret = -ENOENT;
1431 goto out;
1432 }
1433 } else {
1434 ret = ref_get_fields(eb, ref_ptr, &name, &ref_index);
1435 }
1436 if (ret)
1437 goto out;
1438
1439 ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
1440 btrfs_ino(BTRFS_I(inode)), ref_index, &name);
1441 if (ret < 0) {
1442 goto out;
1443 } else if (ret == 0) {
1444 /*
1445 * look for a conflicting back reference in the
1446 * metadata. if we find one we have to unlink that name
1447 * of the file before we add our new link. Later on, we
1448 * overwrite any existing back reference, and we don't
1449 * want to create dangling pointers in the directory.
1450 */
1451 ret = __add_inode_ref(trans, root, path, log,
1452 BTRFS_I(dir), BTRFS_I(inode),
1453 inode_objectid, parent_objectid,
1454 ref_index, &name);
1455 if (ret) {
1456 if (ret == 1)
1457 ret = 0;
1458 goto out;
1459 }
1460
1461 /* insert our name */
1462 ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
1463 &name, 0, ref_index);
1464 if (ret)
1465 goto out;
1466
1467 ret = btrfs_update_inode(trans, BTRFS_I(inode));
1468 if (ret)
1469 goto out;
1470 }
1471 /* Else, ret == 1, we already have a perfect match, we're done. */
1472
1473 ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + name.len;
1474 kfree(name.name);
1475 name.name = NULL;
1476 if (log_ref_ver) {
1477 iput(dir);
1478 dir = NULL;
1479 }
1480 }
1481
1482 /*
1483 * Before we overwrite the inode reference item in the subvolume tree
1484 * with the item from the log tree, we must unlink all names from the
1485 * parent directory that are in the subvolume's tree inode reference
1486 * item, otherwise we end up with an inconsistent subvolume tree where
1487 * dir index entries exist for a name but there is no inode reference
1488 * item with the same name.
1489 */
1490 ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
1491 key);
1492 if (ret)
1493 goto out;
1494
1495 /* finally write the back reference in the inode */
1496 ret = overwrite_item(trans, root, path, eb, slot, key);
1497 out:
1498 btrfs_release_path(path);
1499 kfree(name.name);
1500 iput(dir);
1501 iput(inode);
1502 return ret;
1503 }
1504
1505 static int count_inode_extrefs(struct btrfs_inode *inode, struct btrfs_path *path)
1506 {
1507 int ret = 0;
1508 int name_len;
1509 unsigned int nlink = 0;
1510 u32 item_size;
1511 u32 cur_offset = 0;
1512 u64 inode_objectid = btrfs_ino(inode);
1513 u64 offset = 0;
1514 unsigned long ptr;
1515 struct btrfs_inode_extref *extref;
1516 struct extent_buffer *leaf;
1517
1518 while (1) {
1519 ret = btrfs_find_one_extref(inode->root, inode_objectid, offset,
1520 path, &extref, &offset);
1521 if (ret)
1522 break;
1523
1524 leaf = path->nodes[0];
1525 item_size = btrfs_item_size(leaf, path->slots[0]);
1526 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1527 cur_offset = 0;
1528
1529 while (cur_offset < item_size) {
1530 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
1531 name_len = btrfs_inode_extref_name_len(leaf, extref);
1532
1533 nlink++;
1534
1535 cur_offset += name_len + sizeof(*extref);
1536 }
1537
1538 offset++;
1539 btrfs_release_path(path);
1540 }
1541 btrfs_release_path(path);
1542
1543 if (ret < 0 && ret != -ENOENT)
1544 return ret;
1545 return nlink;
1546 }
1547
1548 static int count_inode_refs(struct btrfs_inode *inode, struct btrfs_path *path)
1549 {
1550 int ret;
1551 struct btrfs_key key;
1552 unsigned int nlink = 0;
1553 unsigned long ptr;
1554 unsigned long ptr_end;
1555 int name_len;
1556 u64 ino = btrfs_ino(inode);
1557
1558 key.objectid = ino;
1559 key.type = BTRFS_INODE_REF_KEY;
1560 key.offset = (u64)-1;
1561
1562 while (1) {
1563 ret = btrfs_search_slot(NULL, inode->root, &key, path, 0, 0);
1564 if (ret < 0)
1565 break;
1566 if (ret > 0) {
1567 if (path->slots[0] == 0)
1568 break;
1569 path->slots[0]--;
1570 }
1571 process_slot:
1572 btrfs_item_key_to_cpu(path->nodes[0], &key,
1573 path->slots[0]);
1574 if (key.objectid != ino ||
1575 key.type != BTRFS_INODE_REF_KEY)
1576 break;
1577 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1578 ptr_end = ptr + btrfs_item_size(path->nodes[0],
1579 path->slots[0]);
1580 while (ptr < ptr_end) {
1581 struct btrfs_inode_ref *ref;
1582
1583 ref = (struct btrfs_inode_ref *)ptr;
1584 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1585 ref);
1586 ptr = (unsigned long)(ref + 1) + name_len;
1587 nlink++;
1588 }
1589
1590 if (key.offset == 0)
1591 break;
1592 if (path->slots[0] > 0) {
1593 path->slots[0]--;
1594 goto process_slot;
1595 }
1596 key.offset--;
1597 btrfs_release_path(path);
1598 }
1599 btrfs_release_path(path);
1600
1601 return nlink;
1602 }
1603
1604 /*
1605 * There are a few corners where the link count of the file can't
1606 * be properly maintained during replay. So, instead of adding
1607 * lots of complexity to the log code, we just scan the backrefs
1608 * for any file that has been through replay.
1609 *
1610 * The scan will update the link count on the inode to reflect the
1611 * number of back refs found. If it goes down to zero, the iput
1612 * will free the inode.
1613 */
1614 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
1615 struct inode *inode)
1616 {
1617 struct btrfs_root *root = BTRFS_I(inode)->root;
1618 struct btrfs_path *path;
1619 int ret;
1620 u64 nlink = 0;
1621 u64 ino = btrfs_ino(BTRFS_I(inode));
1622
1623 path = btrfs_alloc_path();
1624 if (!path)
1625 return -ENOMEM;
1626
1627 ret = count_inode_refs(BTRFS_I(inode), path);
1628 if (ret < 0)
1629 goto out;
1630
1631 nlink = ret;
1632
1633 ret = count_inode_extrefs(BTRFS_I(inode), path);
1634 if (ret < 0)
1635 goto out;
1636
1637 nlink += ret;
1638
1639 ret = 0;
1640
1641 if (nlink != inode->i_nlink) {
1642 set_nlink(inode, nlink);
1643 ret = btrfs_update_inode(trans, BTRFS_I(inode));
1644 if (ret)
1645 goto out;
1646 }
1647 if (S_ISDIR(inode->i_mode))
1648 BTRFS_I(inode)->index_cnt = (u64)-1;
1649
1650 if (inode->i_nlink == 0) {
1651 if (S_ISDIR(inode->i_mode)) {
1652 ret = replay_dir_deletes(trans, root, NULL, path,
1653 ino, 1);
1654 if (ret)
1655 goto out;
1656 }
1657 ret = btrfs_insert_orphan_item(trans, root, ino);
1658 if (ret == -EEXIST)
1659 ret = 0;
1660 }
1661
1662 out:
1663 btrfs_free_path(path);
1664 return ret;
1665 }
1666
1667 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1668 struct btrfs_root *root,
1669 struct btrfs_path *path)
1670 {
1671 int ret;
1672 struct btrfs_key key;
1673 struct inode *inode;
1674
1675 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1676 key.type = BTRFS_ORPHAN_ITEM_KEY;
1677 key.offset = (u64)-1;
1678 while (1) {
1679 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1680 if (ret < 0)
1681 break;
1682
1683 if (ret == 1) {
1684 ret = 0;
1685 if (path->slots[0] == 0)
1686 break;
1687 path->slots[0]--;
1688 }
1689
1690 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1691 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1692 key.type != BTRFS_ORPHAN_ITEM_KEY)
1693 break;
1694
1695 ret = btrfs_del_item(trans, root, path);
1696 if (ret)
1697 break;
1698
1699 btrfs_release_path(path);
1700 inode = read_one_inode(root, key.offset);
1701 if (!inode) {
1702 ret = -EIO;
1703 break;
1704 }
1705
1706 ret = fixup_inode_link_count(trans, inode);
1707 iput(inode);
1708 if (ret)
1709 break;
1710
1711 /*
1712 * fixup on a directory may create new entries,
1713 * make sure we always look for the highset possible
1714 * offset
1715 */
1716 key.offset = (u64)-1;
1717 }
1718 btrfs_release_path(path);
1719 return ret;
1720 }
1721
1722
1723 /*
1724 * record a given inode in the fixup dir so we can check its link
1725 * count when replay is done. The link count is incremented here
1726 * so the inode won't go away until we check it
1727 */
1728 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1729 struct btrfs_root *root,
1730 struct btrfs_path *path,
1731 u64 objectid)
1732 {
1733 struct btrfs_key key;
1734 int ret = 0;
1735 struct inode *inode;
1736
1737 inode = read_one_inode(root, objectid);
1738 if (!inode)
1739 return -EIO;
1740
1741 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1742 key.type = BTRFS_ORPHAN_ITEM_KEY;
1743 key.offset = objectid;
1744
1745 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1746
1747 btrfs_release_path(path);
1748 if (ret == 0) {
1749 if (!inode->i_nlink)
1750 set_nlink(inode, 1);
1751 else
1752 inc_nlink(inode);
1753 ret = btrfs_update_inode(trans, BTRFS_I(inode));
1754 } else if (ret == -EEXIST) {
1755 ret = 0;
1756 }
1757 iput(inode);
1758
1759 return ret;
1760 }
1761
1762 /*
1763 * when replaying the log for a directory, we only insert names
1764 * for inodes that actually exist. This means an fsync on a directory
1765 * does not implicitly fsync all the new files in it
1766 */
1767 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1768 struct btrfs_root *root,
1769 u64 dirid, u64 index,
1770 const struct fscrypt_str *name,
1771 struct btrfs_key *location)
1772 {
1773 struct inode *inode;
1774 struct inode *dir;
1775 int ret;
1776
1777 inode = read_one_inode(root, location->objectid);
1778 if (!inode)
1779 return -ENOENT;
1780
1781 dir = read_one_inode(root, dirid);
1782 if (!dir) {
1783 iput(inode);
1784 return -EIO;
1785 }
1786
1787 ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
1788 1, index);
1789
1790 /* FIXME, put inode into FIXUP list */
1791
1792 iput(inode);
1793 iput(dir);
1794 return ret;
1795 }
1796
1797 static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
1798 struct btrfs_inode *dir,
1799 struct btrfs_path *path,
1800 struct btrfs_dir_item *dst_di,
1801 const struct btrfs_key *log_key,
1802 u8 log_flags,
1803 bool exists)
1804 {
1805 struct btrfs_key found_key;
1806
1807 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1808 /* The existing dentry points to the same inode, don't delete it. */
1809 if (found_key.objectid == log_key->objectid &&
1810 found_key.type == log_key->type &&
1811 found_key.offset == log_key->offset &&
1812 btrfs_dir_flags(path->nodes[0], dst_di) == log_flags)
1813 return 1;
1814
1815 /*
1816 * Don't drop the conflicting directory entry if the inode for the new
1817 * entry doesn't exist.
1818 */
1819 if (!exists)
1820 return 0;
1821
1822 return drop_one_dir_item(trans, path, dir, dst_di);
1823 }
1824
1825 /*
1826 * take a single entry in a log directory item and replay it into
1827 * the subvolume.
1828 *
1829 * if a conflicting item exists in the subdirectory already,
1830 * the inode it points to is unlinked and put into the link count
1831 * fix up tree.
1832 *
1833 * If a name from the log points to a file or directory that does
1834 * not exist in the FS, it is skipped. fsyncs on directories
1835 * do not force down inodes inside that directory, just changes to the
1836 * names or unlinks in a directory.
1837 *
1838 * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
1839 * non-existing inode) and 1 if the name was replayed.
1840 */
1841 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1842 struct btrfs_root *root,
1843 struct btrfs_path *path,
1844 struct extent_buffer *eb,
1845 struct btrfs_dir_item *di,
1846 struct btrfs_key *key)
1847 {
1848 struct fscrypt_str name = { 0 };
1849 struct btrfs_dir_item *dir_dst_di;
1850 struct btrfs_dir_item *index_dst_di;
1851 bool dir_dst_matches = false;
1852 bool index_dst_matches = false;
1853 struct btrfs_key log_key;
1854 struct btrfs_key search_key;
1855 struct inode *dir;
1856 u8 log_flags;
1857 bool exists;
1858 int ret;
1859 bool update_size = true;
1860 bool name_added = false;
1861
1862 dir = read_one_inode(root, key->objectid);
1863 if (!dir)
1864 return -EIO;
1865
1866 ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name);
1867 if (ret)
1868 goto out;
1869
1870 log_flags = btrfs_dir_flags(eb, di);
1871 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1872 ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1873 btrfs_release_path(path);
1874 if (ret < 0)
1875 goto out;
1876 exists = (ret == 0);
1877 ret = 0;
1878
1879 dir_dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1880 &name, 1);
1881 if (IS_ERR(dir_dst_di)) {
1882 ret = PTR_ERR(dir_dst_di);
1883 goto out;
1884 } else if (dir_dst_di) {
1885 ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
1886 dir_dst_di, &log_key,
1887 log_flags, exists);
1888 if (ret < 0)
1889 goto out;
1890 dir_dst_matches = (ret == 1);
1891 }
1892
1893 btrfs_release_path(path);
1894
1895 index_dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1896 key->objectid, key->offset,
1897 &name, 1);
1898 if (IS_ERR(index_dst_di)) {
1899 ret = PTR_ERR(index_dst_di);
1900 goto out;
1901 } else if (index_dst_di) {
1902 ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
1903 index_dst_di, &log_key,
1904 log_flags, exists);
1905 if (ret < 0)
1906 goto out;
1907 index_dst_matches = (ret == 1);
1908 }
1909
1910 btrfs_release_path(path);
1911
1912 if (dir_dst_matches && index_dst_matches) {
1913 ret = 0;
1914 update_size = false;
1915 goto out;
1916 }
1917
1918 /*
1919 * Check if the inode reference exists in the log for the given name,
1920 * inode and parent inode
1921 */
1922 search_key.objectid = log_key.objectid;
1923 search_key.type = BTRFS_INODE_REF_KEY;
1924 search_key.offset = key->objectid;
1925 ret = backref_in_log(root->log_root, &search_key, 0, &name);
1926 if (ret < 0) {
1927 goto out;
1928 } else if (ret) {
1929 /* The dentry will be added later. */
1930 ret = 0;
1931 update_size = false;
1932 goto out;
1933 }
1934
1935 search_key.objectid = log_key.objectid;
1936 search_key.type = BTRFS_INODE_EXTREF_KEY;
1937 search_key.offset = key->objectid;
1938 ret = backref_in_log(root->log_root, &search_key, key->objectid, &name);
1939 if (ret < 0) {
1940 goto out;
1941 } else if (ret) {
1942 /* The dentry will be added later. */
1943 ret = 0;
1944 update_size = false;
1945 goto out;
1946 }
1947 btrfs_release_path(path);
1948 ret = insert_one_name(trans, root, key->objectid, key->offset,
1949 &name, &log_key);
1950 if (ret && ret != -ENOENT && ret != -EEXIST)
1951 goto out;
1952 if (!ret)
1953 name_added = true;
1954 update_size = false;
1955 ret = 0;
1956
1957 out:
1958 if (!ret && update_size) {
1959 btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name.len * 2);
1960 ret = btrfs_update_inode(trans, BTRFS_I(dir));
1961 }
1962 kfree(name.name);
1963 iput(dir);
1964 if (!ret && name_added)
1965 ret = 1;
1966 return ret;
1967 }
1968
1969 /* Replay one dir item from a BTRFS_DIR_INDEX_KEY key. */
1970 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1971 struct btrfs_root *root,
1972 struct btrfs_path *path,
1973 struct extent_buffer *eb, int slot,
1974 struct btrfs_key *key)
1975 {
1976 int ret;
1977 struct btrfs_dir_item *di;
1978
1979 /* We only log dir index keys, which only contain a single dir item. */
1980 ASSERT(key->type == BTRFS_DIR_INDEX_KEY);
1981
1982 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
1983 ret = replay_one_name(trans, root, path, eb, di, key);
1984 if (ret < 0)
1985 return ret;
1986
1987 /*
1988 * If this entry refers to a non-directory (directories can not have a
1989 * link count > 1) and it was added in the transaction that was not
1990 * committed, make sure we fixup the link count of the inode the entry
1991 * points to. Otherwise something like the following would result in a
1992 * directory pointing to an inode with a wrong link that does not account
1993 * for this dir entry:
1994 *
1995 * mkdir testdir
1996 * touch testdir/foo
1997 * touch testdir/bar
1998 * sync
1999 *
2000 * ln testdir/bar testdir/bar_link
2001 * ln testdir/foo testdir/foo_link
2002 * xfs_io -c "fsync" testdir/bar
2003 *
2004 * <power failure>
2005 *
2006 * mount fs, log replay happens
2007 *
2008 * File foo would remain with a link count of 1 when it has two entries
2009 * pointing to it in the directory testdir. This would make it impossible
2010 * to ever delete the parent directory has it would result in stale
2011 * dentries that can never be deleted.
2012 */
2013 if (ret == 1 && btrfs_dir_ftype(eb, di) != BTRFS_FT_DIR) {
2014 struct btrfs_path *fixup_path;
2015 struct btrfs_key di_key;
2016
2017 fixup_path = btrfs_alloc_path();
2018 if (!fixup_path)
2019 return -ENOMEM;
2020
2021 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2022 ret = link_to_fixup_dir(trans, root, fixup_path, di_key.objectid);
2023 btrfs_free_path(fixup_path);
2024 }
2025
2026 return ret;
2027 }
2028
2029 /*
2030 * directory replay has two parts. There are the standard directory
2031 * items in the log copied from the subvolume, and range items
2032 * created in the log while the subvolume was logged.
2033 *
2034 * The range items tell us which parts of the key space the log
2035 * is authoritative for. During replay, if a key in the subvolume
2036 * directory is in a logged range item, but not actually in the log
2037 * that means it was deleted from the directory before the fsync
2038 * and should be removed.
2039 */
2040 static noinline int find_dir_range(struct btrfs_root *root,
2041 struct btrfs_path *path,
2042 u64 dirid,
2043 u64 *start_ret, u64 *end_ret)
2044 {
2045 struct btrfs_key key;
2046 u64 found_end;
2047 struct btrfs_dir_log_item *item;
2048 int ret;
2049 int nritems;
2050
2051 if (*start_ret == (u64)-1)
2052 return 1;
2053
2054 key.objectid = dirid;
2055 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2056 key.offset = *start_ret;
2057
2058 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2059 if (ret < 0)
2060 goto out;
2061 if (ret > 0) {
2062 if (path->slots[0] == 0)
2063 goto out;
2064 path->slots[0]--;
2065 }
2066 if (ret != 0)
2067 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2068
2069 if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
2070 ret = 1;
2071 goto next;
2072 }
2073 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2074 struct btrfs_dir_log_item);
2075 found_end = btrfs_dir_log_end(path->nodes[0], item);
2076
2077 if (*start_ret >= key.offset && *start_ret <= found_end) {
2078 ret = 0;
2079 *start_ret = key.offset;
2080 *end_ret = found_end;
2081 goto out;
2082 }
2083 ret = 1;
2084 next:
2085 /* check the next slot in the tree to see if it is a valid item */
2086 nritems = btrfs_header_nritems(path->nodes[0]);
2087 path->slots[0]++;
2088 if (path->slots[0] >= nritems) {
2089 ret = btrfs_next_leaf(root, path);
2090 if (ret)
2091 goto out;
2092 }
2093
2094 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2095
2096 if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
2097 ret = 1;
2098 goto out;
2099 }
2100 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2101 struct btrfs_dir_log_item);
2102 found_end = btrfs_dir_log_end(path->nodes[0], item);
2103 *start_ret = key.offset;
2104 *end_ret = found_end;
2105 ret = 0;
2106 out:
2107 btrfs_release_path(path);
2108 return ret;
2109 }
2110
2111 /*
2112 * this looks for a given directory item in the log. If the directory
2113 * item is not in the log, the item is removed and the inode it points
2114 * to is unlinked
2115 */
2116 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
2117 struct btrfs_root *log,
2118 struct btrfs_path *path,
2119 struct btrfs_path *log_path,
2120 struct inode *dir,
2121 struct btrfs_key *dir_key)
2122 {
2123 struct btrfs_root *root = BTRFS_I(dir)->root;
2124 int ret;
2125 struct extent_buffer *eb;
2126 int slot;
2127 struct btrfs_dir_item *di;
2128 struct fscrypt_str name = { 0 };
2129 struct inode *inode = NULL;
2130 struct btrfs_key location;
2131
2132 /*
2133 * Currently we only log dir index keys. Even if we replay a log created
2134 * by an older kernel that logged both dir index and dir item keys, all
2135 * we need to do is process the dir index keys, we (and our caller) can
2136 * safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY).
2137 */
2138 ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY);
2139
2140 eb = path->nodes[0];
2141 slot = path->slots[0];
2142 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2143 ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name);
2144 if (ret)
2145 goto out;
2146
2147 if (log) {
2148 struct btrfs_dir_item *log_di;
2149
2150 log_di = btrfs_lookup_dir_index_item(trans, log, log_path,
2151 dir_key->objectid,
2152 dir_key->offset, &name, 0);
2153 if (IS_ERR(log_di)) {
2154 ret = PTR_ERR(log_di);
2155 goto out;
2156 } else if (log_di) {
2157 /* The dentry exists in the log, we have nothing to do. */
2158 ret = 0;
2159 goto out;
2160 }
2161 }
2162
2163 btrfs_dir_item_key_to_cpu(eb, di, &location);
2164 btrfs_release_path(path);
2165 btrfs_release_path(log_path);
2166 inode = read_one_inode(root, location.objectid);
2167 if (!inode) {
2168 ret = -EIO;
2169 goto out;
2170 }
2171
2172 ret = link_to_fixup_dir(trans, root, path, location.objectid);
2173 if (ret)
2174 goto out;
2175
2176 inc_nlink(inode);
2177 ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(inode),
2178 &name);
2179 /*
2180 * Unlike dir item keys, dir index keys can only have one name (entry) in
2181 * them, as there are no key collisions since each key has a unique offset
2182 * (an index number), so we're done.
2183 */
2184 out:
2185 btrfs_release_path(path);
2186 btrfs_release_path(log_path);
2187 kfree(name.name);
2188 iput(inode);
2189 return ret;
2190 }
2191
2192 static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
2193 struct btrfs_root *root,
2194 struct btrfs_root *log,
2195 struct btrfs_path *path,
2196 const u64 ino)
2197 {
2198 struct btrfs_key search_key;
2199 struct btrfs_path *log_path;
2200 int i;
2201 int nritems;
2202 int ret;
2203
2204 log_path = btrfs_alloc_path();
2205 if (!log_path)
2206 return -ENOMEM;
2207
2208 search_key.objectid = ino;
2209 search_key.type = BTRFS_XATTR_ITEM_KEY;
2210 search_key.offset = 0;
2211 again:
2212 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
2213 if (ret < 0)
2214 goto out;
2215 process_leaf:
2216 nritems = btrfs_header_nritems(path->nodes[0]);
2217 for (i = path->slots[0]; i < nritems; i++) {
2218 struct btrfs_key key;
2219 struct btrfs_dir_item *di;
2220 struct btrfs_dir_item *log_di;
2221 u32 total_size;
2222 u32 cur;
2223
2224 btrfs_item_key_to_cpu(path->nodes[0], &key, i);
2225 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
2226 ret = 0;
2227 goto out;
2228 }
2229
2230 di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
2231 total_size = btrfs_item_size(path->nodes[0], i);
2232 cur = 0;
2233 while (cur < total_size) {
2234 u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
2235 u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
2236 u32 this_len = sizeof(*di) + name_len + data_len;
2237 char *name;
2238
2239 name = kmalloc(name_len, GFP_NOFS);
2240 if (!name) {
2241 ret = -ENOMEM;
2242 goto out;
2243 }
2244 read_extent_buffer(path->nodes[0], name,
2245 (unsigned long)(di + 1), name_len);
2246
2247 log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
2248 name, name_len, 0);
2249 btrfs_release_path(log_path);
2250 if (!log_di) {
2251 /* Doesn't exist in log tree, so delete it. */
2252 btrfs_release_path(path);
2253 di = btrfs_lookup_xattr(trans, root, path, ino,
2254 name, name_len, -1);
2255 kfree(name);
2256 if (IS_ERR(di)) {
2257 ret = PTR_ERR(di);
2258 goto out;
2259 }
2260 ASSERT(di);
2261 ret = btrfs_delete_one_dir_name(trans, root,
2262 path, di);
2263 if (ret)
2264 goto out;
2265 btrfs_release_path(path);
2266 search_key = key;
2267 goto again;
2268 }
2269 kfree(name);
2270 if (IS_ERR(log_di)) {
2271 ret = PTR_ERR(log_di);
2272 goto out;
2273 }
2274 cur += this_len;
2275 di = (struct btrfs_dir_item *)((char *)di + this_len);
2276 }
2277 }
2278 ret = btrfs_next_leaf(root, path);
2279 if (ret > 0)
2280 ret = 0;
2281 else if (ret == 0)
2282 goto process_leaf;
2283 out:
2284 btrfs_free_path(log_path);
2285 btrfs_release_path(path);
2286 return ret;
2287 }
2288
2289
2290 /*
2291 * deletion replay happens before we copy any new directory items
2292 * out of the log or out of backreferences from inodes. It
2293 * scans the log to find ranges of keys that log is authoritative for,
2294 * and then scans the directory to find items in those ranges that are
2295 * not present in the log.
2296 *
2297 * Anything we don't find in the log is unlinked and removed from the
2298 * directory.
2299 */
2300 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
2301 struct btrfs_root *root,
2302 struct btrfs_root *log,
2303 struct btrfs_path *path,
2304 u64 dirid, int del_all)
2305 {
2306 u64 range_start;
2307 u64 range_end;
2308 int ret = 0;
2309 struct btrfs_key dir_key;
2310 struct btrfs_key found_key;
2311 struct btrfs_path *log_path;
2312 struct inode *dir;
2313
2314 dir_key.objectid = dirid;
2315 dir_key.type = BTRFS_DIR_INDEX_KEY;
2316 log_path = btrfs_alloc_path();
2317 if (!log_path)
2318 return -ENOMEM;
2319
2320 dir = read_one_inode(root, dirid);
2321 /* it isn't an error if the inode isn't there, that can happen
2322 * because we replay the deletes before we copy in the inode item
2323 * from the log
2324 */
2325 if (!dir) {
2326 btrfs_free_path(log_path);
2327 return 0;
2328 }
2329
2330 range_start = 0;
2331 range_end = 0;
2332 while (1) {
2333 if (del_all)
2334 range_end = (u64)-1;
2335 else {
2336 ret = find_dir_range(log, path, dirid,
2337 &range_start, &range_end);
2338 if (ret < 0)
2339 goto out;
2340 else if (ret > 0)
2341 break;
2342 }
2343
2344 dir_key.offset = range_start;
2345 while (1) {
2346 int nritems;
2347 ret = btrfs_search_slot(NULL, root, &dir_key, path,
2348 0, 0);
2349 if (ret < 0)
2350 goto out;
2351
2352 nritems = btrfs_header_nritems(path->nodes[0]);
2353 if (path->slots[0] >= nritems) {
2354 ret = btrfs_next_leaf(root, path);
2355 if (ret == 1)
2356 break;
2357 else if (ret < 0)
2358 goto out;
2359 }
2360 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2361 path->slots[0]);
2362 if (found_key.objectid != dirid ||
2363 found_key.type != dir_key.type) {
2364 ret = 0;
2365 goto out;
2366 }
2367
2368 if (found_key.offset > range_end)
2369 break;
2370
2371 ret = check_item_in_log(trans, log, path,
2372 log_path, dir,
2373 &found_key);
2374 if (ret)
2375 goto out;
2376 if (found_key.offset == (u64)-1)
2377 break;
2378 dir_key.offset = found_key.offset + 1;
2379 }
2380 btrfs_release_path(path);
2381 if (range_end == (u64)-1)
2382 break;
2383 range_start = range_end + 1;
2384 }
2385 ret = 0;
2386 out:
2387 btrfs_release_path(path);
2388 btrfs_free_path(log_path);
2389 iput(dir);
2390 return ret;
2391 }
2392
2393 /*
2394 * the process_func used to replay items from the log tree. This
2395 * gets called in two different stages. The first stage just looks
2396 * for inodes and makes sure they are all copied into the subvolume.
2397 *
2398 * The second stage copies all the other item types from the log into
2399 * the subvolume. The two stage approach is slower, but gets rid of
2400 * lots of complexity around inodes referencing other inodes that exist
2401 * only in the log (references come from either directory items or inode
2402 * back refs).
2403 */
2404 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
2405 struct walk_control *wc, u64 gen, int level)
2406 {
2407 int nritems;
2408 struct btrfs_tree_parent_check check = {
2409 .transid = gen,
2410 .level = level
2411 };
2412 struct btrfs_path *path;
2413 struct btrfs_root *root = wc->replay_dest;
2414 struct btrfs_key key;
2415 int i;
2416 int ret;
2417
2418 ret = btrfs_read_extent_buffer(eb, &check);
2419 if (ret)
2420 return ret;
2421
2422 level = btrfs_header_level(eb);
2423
2424 if (level != 0)
2425 return 0;
2426
2427 path = btrfs_alloc_path();
2428 if (!path)
2429 return -ENOMEM;
2430
2431 nritems = btrfs_header_nritems(eb);
2432 for (i = 0; i < nritems; i++) {
2433 btrfs_item_key_to_cpu(eb, &key, i);
2434
2435 /* inode keys are done during the first stage */
2436 if (key.type == BTRFS_INODE_ITEM_KEY &&
2437 wc->stage == LOG_WALK_REPLAY_INODES) {
2438 struct btrfs_inode_item *inode_item;
2439 u32 mode;
2440
2441 inode_item = btrfs_item_ptr(eb, i,
2442 struct btrfs_inode_item);
2443 /*
2444 * If we have a tmpfile (O_TMPFILE) that got fsync'ed
2445 * and never got linked before the fsync, skip it, as
2446 * replaying it is pointless since it would be deleted
2447 * later. We skip logging tmpfiles, but it's always
2448 * possible we are replaying a log created with a kernel
2449 * that used to log tmpfiles.
2450 */
2451 if (btrfs_inode_nlink(eb, inode_item) == 0) {
2452 wc->ignore_cur_inode = true;
2453 continue;
2454 } else {
2455 wc->ignore_cur_inode = false;
2456 }
2457 ret = replay_xattr_deletes(wc->trans, root, log,
2458 path, key.objectid);
2459 if (ret)
2460 break;
2461 mode = btrfs_inode_mode(eb, inode_item);
2462 if (S_ISDIR(mode)) {
2463 ret = replay_dir_deletes(wc->trans,
2464 root, log, path, key.objectid, 0);
2465 if (ret)
2466 break;
2467 }
2468 ret = overwrite_item(wc->trans, root, path,
2469 eb, i, &key);
2470 if (ret)
2471 break;
2472
2473 /*
2474 * Before replaying extents, truncate the inode to its
2475 * size. We need to do it now and not after log replay
2476 * because before an fsync we can have prealloc extents
2477 * added beyond the inode's i_size. If we did it after,
2478 * through orphan cleanup for example, we would drop
2479 * those prealloc extents just after replaying them.
2480 */
2481 if (S_ISREG(mode)) {
2482 struct btrfs_drop_extents_args drop_args = { 0 };
2483 struct inode *inode;
2484 u64 from;
2485
2486 inode = read_one_inode(root, key.objectid);
2487 if (!inode) {
2488 ret = -EIO;
2489 break;
2490 }
2491 from = ALIGN(i_size_read(inode),
2492 root->fs_info->sectorsize);
2493 drop_args.start = from;
2494 drop_args.end = (u64)-1;
2495 drop_args.drop_cache = true;
2496 ret = btrfs_drop_extents(wc->trans, root,
2497 BTRFS_I(inode),
2498 &drop_args);
2499 if (!ret) {
2500 inode_sub_bytes(inode,
2501 drop_args.bytes_found);
2502 /* Update the inode's nbytes. */
2503 ret = btrfs_update_inode(wc->trans,
2504 BTRFS_I(inode));
2505 }
2506 iput(inode);
2507 if (ret)
2508 break;
2509 }
2510
2511 ret = link_to_fixup_dir(wc->trans, root,
2512 path, key.objectid);
2513 if (ret)
2514 break;
2515 }
2516
2517 if (wc->ignore_cur_inode)
2518 continue;
2519
2520 if (key.type == BTRFS_DIR_INDEX_KEY &&
2521 wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
2522 ret = replay_one_dir_item(wc->trans, root, path,
2523 eb, i, &key);
2524 if (ret)
2525 break;
2526 }
2527
2528 if (wc->stage < LOG_WALK_REPLAY_ALL)
2529 continue;
2530
2531 /* these keys are simply copied */
2532 if (key.type == BTRFS_XATTR_ITEM_KEY) {
2533 ret = overwrite_item(wc->trans, root, path,
2534 eb, i, &key);
2535 if (ret)
2536 break;
2537 } else if (key.type == BTRFS_INODE_REF_KEY ||
2538 key.type == BTRFS_INODE_EXTREF_KEY) {
2539 ret = add_inode_ref(wc->trans, root, log, path,
2540 eb, i, &key);
2541 if (ret && ret != -ENOENT)
2542 break;
2543 ret = 0;
2544 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
2545 ret = replay_one_extent(wc->trans, root, path,
2546 eb, i, &key);
2547 if (ret)
2548 break;
2549 }
2550 /*
2551 * We don't log BTRFS_DIR_ITEM_KEY keys anymore, only the
2552 * BTRFS_DIR_INDEX_KEY items which we use to derive the
2553 * BTRFS_DIR_ITEM_KEY items. If we are replaying a log from an
2554 * older kernel with such keys, ignore them.
2555 */
2556 }
2557 btrfs_free_path(path);
2558 return ret;
2559 }
2560
2561 /*
2562 * Correctly adjust the reserved bytes occupied by a log tree extent buffer
2563 */
2564 static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
2565 {
2566 struct btrfs_block_group *cache;
2567
2568 cache = btrfs_lookup_block_group(fs_info, start);
2569 if (!cache) {
2570 btrfs_err(fs_info, "unable to find block group for %llu", start);
2571 return;
2572 }
2573
2574 spin_lock(&cache->space_info->lock);
2575 spin_lock(&cache->lock);
2576 cache->reserved -= fs_info->nodesize;
2577 cache->space_info->bytes_reserved -= fs_info->nodesize;
2578 spin_unlock(&cache->lock);
2579 spin_unlock(&cache->space_info->lock);
2580
2581 btrfs_put_block_group(cache);
2582 }
2583
2584 static int clean_log_buffer(struct btrfs_trans_handle *trans,
2585 struct extent_buffer *eb)
2586 {
2587 int ret;
2588
2589 btrfs_tree_lock(eb);
2590 btrfs_clear_buffer_dirty(trans, eb);
2591 wait_on_extent_buffer_writeback(eb);
2592 btrfs_tree_unlock(eb);
2593
2594 if (trans) {
2595 ret = btrfs_pin_reserved_extent(trans, eb);
2596 if (ret)
2597 return ret;
2598 } else {
2599 unaccount_log_buffer(eb->fs_info, eb->start);
2600 }
2601
2602 return 0;
2603 }
2604
2605 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
2606 struct btrfs_root *root,
2607 struct btrfs_path *path, int *level,
2608 struct walk_control *wc)
2609 {
2610 struct btrfs_fs_info *fs_info = root->fs_info;
2611 u64 bytenr;
2612 u64 ptr_gen;
2613 struct extent_buffer *next;
2614 struct extent_buffer *cur;
2615 int ret = 0;
2616
2617 while (*level > 0) {
2618 struct btrfs_tree_parent_check check = { 0 };
2619
2620 cur = path->nodes[*level];
2621
2622 WARN_ON(btrfs_header_level(cur) != *level);
2623
2624 if (path->slots[*level] >=
2625 btrfs_header_nritems(cur))
2626 break;
2627
2628 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2629 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2630 check.transid = ptr_gen;
2631 check.level = *level - 1;
2632 check.has_first_key = true;
2633 btrfs_node_key_to_cpu(cur, &check.first_key, path->slots[*level]);
2634
2635 next = btrfs_find_create_tree_block(fs_info, bytenr,
2636 btrfs_header_owner(cur),
2637 *level - 1);
2638 if (IS_ERR(next))
2639 return PTR_ERR(next);
2640
2641 if (*level == 1) {
2642 ret = wc->process_func(root, next, wc, ptr_gen,
2643 *level - 1);
2644 if (ret) {
2645 free_extent_buffer(next);
2646 return ret;
2647 }
2648
2649 path->slots[*level]++;
2650 if (wc->free) {
2651 ret = btrfs_read_extent_buffer(next, &check);
2652 if (ret) {
2653 free_extent_buffer(next);
2654 return ret;
2655 }
2656
2657 ret = clean_log_buffer(trans, next);
2658 if (ret) {
2659 free_extent_buffer(next);
2660 return ret;
2661 }
2662 }
2663 free_extent_buffer(next);
2664 continue;
2665 }
2666 ret = btrfs_read_extent_buffer(next, &check);
2667 if (ret) {
2668 free_extent_buffer(next);
2669 return ret;
2670 }
2671
2672 if (path->nodes[*level-1])
2673 free_extent_buffer(path->nodes[*level-1]);
2674 path->nodes[*level-1] = next;
2675 *level = btrfs_header_level(next);
2676 path->slots[*level] = 0;
2677 cond_resched();
2678 }
2679 path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
2680
2681 cond_resched();
2682 return 0;
2683 }
2684
2685 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
2686 struct btrfs_root *root,
2687 struct btrfs_path *path, int *level,
2688 struct walk_control *wc)
2689 {
2690 int i;
2691 int slot;
2692 int ret;
2693
2694 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2695 slot = path->slots[i];
2696 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
2697 path->slots[i]++;
2698 *level = i;
2699 WARN_ON(*level == 0);
2700 return 0;
2701 } else {
2702 ret = wc->process_func(root, path->nodes[*level], wc,
2703 btrfs_header_generation(path->nodes[*level]),
2704 *level);
2705 if (ret)
2706 return ret;
2707
2708 if (wc->free) {
2709 ret = clean_log_buffer(trans, path->nodes[*level]);
2710 if (ret)
2711 return ret;
2712 }
2713 free_extent_buffer(path->nodes[*level]);
2714 path->nodes[*level] = NULL;
2715 *level = i + 1;
2716 }
2717 }
2718 return 1;
2719 }
2720
2721 /*
2722 * drop the reference count on the tree rooted at 'snap'. This traverses
2723 * the tree freeing any blocks that have a ref count of zero after being
2724 * decremented.
2725 */
2726 static int walk_log_tree(struct btrfs_trans_handle *trans,
2727 struct btrfs_root *log, struct walk_control *wc)
2728 {
2729 int ret = 0;
2730 int wret;
2731 int level;
2732 struct btrfs_path *path;
2733 int orig_level;
2734
2735 path = btrfs_alloc_path();
2736 if (!path)
2737 return -ENOMEM;
2738
2739 level = btrfs_header_level(log->node);
2740 orig_level = level;
2741 path->nodes[level] = log->node;
2742 atomic_inc(&log->node->refs);
2743 path->slots[level] = 0;
2744
2745 while (1) {
2746 wret = walk_down_log_tree(trans, log, path, &level, wc);
2747 if (wret > 0)
2748 break;
2749 if (wret < 0) {
2750 ret = wret;
2751 goto out;
2752 }
2753
2754 wret = walk_up_log_tree(trans, log, path, &level, wc);
2755 if (wret > 0)
2756 break;
2757 if (wret < 0) {
2758 ret = wret;
2759 goto out;
2760 }
2761 }
2762
2763 /* was the root node processed? if not, catch it here */
2764 if (path->nodes[orig_level]) {
2765 ret = wc->process_func(log, path->nodes[orig_level], wc,
2766 btrfs_header_generation(path->nodes[orig_level]),
2767 orig_level);
2768 if (ret)
2769 goto out;
2770 if (wc->free)
2771 ret = clean_log_buffer(trans, path->nodes[orig_level]);
2772 }
2773
2774 out:
2775 btrfs_free_path(path);
2776 return ret;
2777 }
2778
2779 /*
2780 * helper function to update the item for a given subvolumes log root
2781 * in the tree of log roots
2782 */
2783 static int update_log_root(struct btrfs_trans_handle *trans,
2784 struct btrfs_root *log,
2785 struct btrfs_root_item *root_item)
2786 {
2787 struct btrfs_fs_info *fs_info = log->fs_info;
2788 int ret;
2789
2790 if (log->log_transid == 1) {
2791 /* insert root item on the first sync */
2792 ret = btrfs_insert_root(trans, fs_info->log_root_tree,
2793 &log->root_key, root_item);
2794 } else {
2795 ret = btrfs_update_root(trans, fs_info->log_root_tree,
2796 &log->root_key, root_item);
2797 }
2798 return ret;
2799 }
2800
2801 static void wait_log_commit(struct btrfs_root *root, int transid)
2802 {
2803 DEFINE_WAIT(wait);
2804 int index = transid % 2;
2805
2806 /*
2807 * we only allow two pending log transactions at a time,
2808 * so we know that if ours is more than 2 older than the
2809 * current transaction, we're done
2810 */
2811 for (;;) {
2812 prepare_to_wait(&root->log_commit_wait[index],
2813 &wait, TASK_UNINTERRUPTIBLE);
2814
2815 if (!(root->log_transid_committed < transid &&
2816 atomic_read(&root->log_commit[index])))
2817 break;
2818
2819 mutex_unlock(&root->log_mutex);
2820 schedule();
2821 mutex_lock(&root->log_mutex);
2822 }
2823 finish_wait(&root->log_commit_wait[index], &wait);
2824 }
2825
2826 static void wait_for_writer(struct btrfs_root *root)
2827 {
2828 DEFINE_WAIT(wait);
2829
2830 for (;;) {
2831 prepare_to_wait(&root->log_writer_wait, &wait,
2832 TASK_UNINTERRUPTIBLE);
2833 if (!atomic_read(&root->log_writers))
2834 break;
2835
2836 mutex_unlock(&root->log_mutex);
2837 schedule();
2838 mutex_lock(&root->log_mutex);
2839 }
2840 finish_wait(&root->log_writer_wait, &wait);
2841 }
2842
2843 void btrfs_init_log_ctx(struct btrfs_log_ctx *ctx, struct btrfs_inode *inode)
2844 {
2845 ctx->log_ret = 0;
2846 ctx->log_transid = 0;
2847 ctx->log_new_dentries = false;
2848 ctx->logging_new_name = false;
2849 ctx->logging_new_delayed_dentries = false;
2850 ctx->logged_before = false;
2851 ctx->inode = inode;
2852 INIT_LIST_HEAD(&ctx->list);
2853 INIT_LIST_HEAD(&ctx->ordered_extents);
2854 INIT_LIST_HEAD(&ctx->conflict_inodes);
2855 ctx->num_conflict_inodes = 0;
2856 ctx->logging_conflict_inodes = false;
2857 ctx->scratch_eb = NULL;
2858 }
2859
2860 void btrfs_init_log_ctx_scratch_eb(struct btrfs_log_ctx *ctx)
2861 {
2862 struct btrfs_inode *inode = ctx->inode;
2863
2864 if (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
2865 !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
2866 return;
2867
2868 /*
2869 * Don't care about allocation failure. This is just for optimization,
2870 * if we fail to allocate here, we will try again later if needed.
2871 */
2872 ctx->scratch_eb = alloc_dummy_extent_buffer(inode->root->fs_info, 0);
2873 }
2874
2875 void btrfs_release_log_ctx_extents(struct btrfs_log_ctx *ctx)
2876 {
2877 struct btrfs_ordered_extent *ordered;
2878 struct btrfs_ordered_extent *tmp;
2879
2880 ASSERT(inode_is_locked(&ctx->inode->vfs_inode));
2881
2882 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
2883 list_del_init(&ordered->log_list);
2884 btrfs_put_ordered_extent(ordered);
2885 }
2886 }
2887
2888
2889 static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
2890 struct btrfs_log_ctx *ctx)
2891 {
2892 mutex_lock(&root->log_mutex);
2893 list_del_init(&ctx->list);
2894 mutex_unlock(&root->log_mutex);
2895 }
2896
2897 /*
2898 * Invoked in log mutex context, or be sure there is no other task which
2899 * can access the list.
2900 */
2901 static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
2902 int index, int error)
2903 {
2904 struct btrfs_log_ctx *ctx;
2905 struct btrfs_log_ctx *safe;
2906
2907 list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
2908 list_del_init(&ctx->list);
2909 ctx->log_ret = error;
2910 }
2911 }
2912
2913 /*
2914 * Sends a given tree log down to the disk and updates the super blocks to
2915 * record it. When this call is done, you know that any inodes previously
2916 * logged are safely on disk only if it returns 0.
2917 *
2918 * Any other return value means you need to call btrfs_commit_transaction.
2919 * Some of the edge cases for fsyncing directories that have had unlinks
2920 * or renames done in the past mean that sometimes the only safe
2921 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
2922 * that has happened.
2923 */
2924 int btrfs_sync_log(struct btrfs_trans_handle *trans,
2925 struct btrfs_root *root, struct btrfs_log_ctx *ctx)
2926 {
2927 int index1;
2928 int index2;
2929 int mark;
2930 int ret;
2931 struct btrfs_fs_info *fs_info = root->fs_info;
2932 struct btrfs_root *log = root->log_root;
2933 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
2934 struct btrfs_root_item new_root_item;
2935 int log_transid = 0;
2936 struct btrfs_log_ctx root_log_ctx;
2937 struct blk_plug plug;
2938 u64 log_root_start;
2939 u64 log_root_level;
2940
2941 mutex_lock(&root->log_mutex);
2942 log_transid = ctx->log_transid;
2943 if (root->log_transid_committed >= log_transid) {
2944 mutex_unlock(&root->log_mutex);
2945 return ctx->log_ret;
2946 }
2947
2948 index1 = log_transid % 2;
2949 if (atomic_read(&root->log_commit[index1])) {
2950 wait_log_commit(root, log_transid);
2951 mutex_unlock(&root->log_mutex);
2952 return ctx->log_ret;
2953 }
2954 ASSERT(log_transid == root->log_transid);
2955 atomic_set(&root->log_commit[index1], 1);
2956
2957 /* wait for previous tree log sync to complete */
2958 if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2959 wait_log_commit(root, log_transid - 1);
2960
2961 while (1) {
2962 int batch = atomic_read(&root->log_batch);
2963 /* when we're on an ssd, just kick the log commit out */
2964 if (!btrfs_test_opt(fs_info, SSD) &&
2965 test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
2966 mutex_unlock(&root->log_mutex);
2967 schedule_timeout_uninterruptible(1);
2968 mutex_lock(&root->log_mutex);
2969 }
2970 wait_for_writer(root);
2971 if (batch == atomic_read(&root->log_batch))
2972 break;
2973 }
2974
2975 /* bail out if we need to do a full commit */
2976 if (btrfs_need_log_full_commit(trans)) {
2977 ret = BTRFS_LOG_FORCE_COMMIT;
2978 mutex_unlock(&root->log_mutex);
2979 goto out;
2980 }
2981
2982 if (log_transid % 2 == 0)
2983 mark = EXTENT_DIRTY;
2984 else
2985 mark = EXTENT_NEW;
2986
2987 /* we start IO on all the marked extents here, but we don't actually
2988 * wait for them until later.
2989 */
2990 blk_start_plug(&plug);
2991 ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
2992 /*
2993 * -EAGAIN happens when someone, e.g., a concurrent transaction
2994 * commit, writes a dirty extent in this tree-log commit. This
2995 * concurrent write will create a hole writing out the extents,
2996 * and we cannot proceed on a zoned filesystem, requiring
2997 * sequential writing. While we can bail out to a full commit
2998 * here, but we can continue hoping the concurrent writing fills
2999 * the hole.
3000 */
3001 if (ret == -EAGAIN && btrfs_is_zoned(fs_info))
3002 ret = 0;
3003 if (ret) {
3004 blk_finish_plug(&plug);
3005 btrfs_set_log_full_commit(trans);
3006 mutex_unlock(&root->log_mutex);
3007 goto out;
3008 }
3009
3010 /*
3011 * We _must_ update under the root->log_mutex in order to make sure we
3012 * have a consistent view of the log root we are trying to commit at
3013 * this moment.
3014 *
3015 * We _must_ copy this into a local copy, because we are not holding the
3016 * log_root_tree->log_mutex yet. This is important because when we
3017 * commit the log_root_tree we must have a consistent view of the
3018 * log_root_tree when we update the super block to point at the
3019 * log_root_tree bytenr. If we update the log_root_tree here we'll race
3020 * with the commit and possibly point at the new block which we may not
3021 * have written out.
3022 */
3023 btrfs_set_root_node(&log->root_item, log->node);
3024 memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
3025
3026 btrfs_set_root_log_transid(root, root->log_transid + 1);
3027 log->log_transid = root->log_transid;
3028 root->log_start_pid = 0;
3029 /*
3030 * IO has been started, blocks of the log tree have WRITTEN flag set
3031 * in their headers. new modifications of the log will be written to
3032 * new positions. so it's safe to allow log writers to go in.
3033 */
3034 mutex_unlock(&root->log_mutex);
3035
3036 if (btrfs_is_zoned(fs_info)) {
3037 mutex_lock(&fs_info->tree_root->log_mutex);
3038 if (!log_root_tree->node) {
3039 ret = btrfs_alloc_log_tree_node(trans, log_root_tree);
3040 if (ret) {
3041 mutex_unlock(&fs_info->tree_root->log_mutex);
3042 blk_finish_plug(&plug);
3043 goto out;
3044 }
3045 }
3046 mutex_unlock(&fs_info->tree_root->log_mutex);
3047 }
3048
3049 btrfs_init_log_ctx(&root_log_ctx, NULL);
3050
3051 mutex_lock(&log_root_tree->log_mutex);
3052
3053 index2 = log_root_tree->log_transid % 2;
3054 list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
3055 root_log_ctx.log_transid = log_root_tree->log_transid;
3056
3057 /*
3058 * Now we are safe to update the log_root_tree because we're under the
3059 * log_mutex, and we're a current writer so we're holding the commit
3060 * open until we drop the log_mutex.
3061 */
3062 ret = update_log_root(trans, log, &new_root_item);
3063 if (ret) {
3064 list_del_init(&root_log_ctx.list);
3065 blk_finish_plug(&plug);
3066 btrfs_set_log_full_commit(trans);
3067 if (ret != -ENOSPC)
3068 btrfs_err(fs_info,
3069 "failed to update log for root %llu ret %d",
3070 btrfs_root_id(root), ret);
3071 btrfs_wait_tree_log_extents(log, mark);
3072 mutex_unlock(&log_root_tree->log_mutex);
3073 goto out;
3074 }
3075
3076 if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
3077 blk_finish_plug(&plug);
3078 list_del_init(&root_log_ctx.list);
3079 mutex_unlock(&log_root_tree->log_mutex);
3080 ret = root_log_ctx.log_ret;
3081 goto out;
3082 }
3083
3084 if (atomic_read(&log_root_tree->log_commit[index2])) {
3085 blk_finish_plug(&plug);
3086 ret = btrfs_wait_tree_log_extents(log, mark);
3087 wait_log_commit(log_root_tree,
3088 root_log_ctx.log_transid);
3089 mutex_unlock(&log_root_tree->log_mutex);
3090 if (!ret)
3091 ret = root_log_ctx.log_ret;
3092 goto out;
3093 }
3094 ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
3095 atomic_set(&log_root_tree->log_commit[index2], 1);
3096
3097 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
3098 wait_log_commit(log_root_tree,
3099 root_log_ctx.log_transid - 1);
3100 }
3101
3102 /*
3103 * now that we've moved on to the tree of log tree roots,
3104 * check the full commit flag again
3105 */
3106 if (btrfs_need_log_full_commit(trans)) {
3107 blk_finish_plug(&plug);
3108 btrfs_wait_tree_log_extents(log, mark);
3109 mutex_unlock(&log_root_tree->log_mutex);
3110 ret = BTRFS_LOG_FORCE_COMMIT;
3111 goto out_wake_log_root;
3112 }
3113
3114 ret = btrfs_write_marked_extents(fs_info,
3115 &log_root_tree->dirty_log_pages,
3116 EXTENT_DIRTY | EXTENT_NEW);
3117 blk_finish_plug(&plug);
3118 /*
3119 * As described above, -EAGAIN indicates a hole in the extents. We
3120 * cannot wait for these write outs since the waiting cause a
3121 * deadlock. Bail out to the full commit instead.
3122 */
3123 if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) {
3124 btrfs_set_log_full_commit(trans);
3125 btrfs_wait_tree_log_extents(log, mark);
3126 mutex_unlock(&log_root_tree->log_mutex);
3127 goto out_wake_log_root;
3128 } else if (ret) {
3129 btrfs_set_log_full_commit(trans);
3130 mutex_unlock(&log_root_tree->log_mutex);
3131 goto out_wake_log_root;
3132 }
3133 ret = btrfs_wait_tree_log_extents(log, mark);
3134 if (!ret)
3135 ret = btrfs_wait_tree_log_extents(log_root_tree,
3136 EXTENT_NEW | EXTENT_DIRTY);
3137 if (ret) {
3138 btrfs_set_log_full_commit(trans);
3139 mutex_unlock(&log_root_tree->log_mutex);
3140 goto out_wake_log_root;
3141 }
3142
3143 log_root_start = log_root_tree->node->start;
3144 log_root_level = btrfs_header_level(log_root_tree->node);
3145 log_root_tree->log_transid++;
3146 mutex_unlock(&log_root_tree->log_mutex);
3147
3148 /*
3149 * Here we are guaranteed that nobody is going to write the superblock
3150 * for the current transaction before us and that neither we do write
3151 * our superblock before the previous transaction finishes its commit
3152 * and writes its superblock, because:
3153 *
3154 * 1) We are holding a handle on the current transaction, so no body
3155 * can commit it until we release the handle;
3156 *
3157 * 2) Before writing our superblock we acquire the tree_log_mutex, so
3158 * if the previous transaction is still committing, and hasn't yet
3159 * written its superblock, we wait for it to do it, because a
3160 * transaction commit acquires the tree_log_mutex when the commit
3161 * begins and releases it only after writing its superblock.
3162 */
3163 mutex_lock(&fs_info->tree_log_mutex);
3164
3165 /*
3166 * The previous transaction writeout phase could have failed, and thus
3167 * marked the fs in an error state. We must not commit here, as we
3168 * could have updated our generation in the super_for_commit and
3169 * writing the super here would result in transid mismatches. If there
3170 * is an error here just bail.
3171 */
3172 if (BTRFS_FS_ERROR(fs_info)) {
3173 ret = -EIO;
3174 btrfs_set_log_full_commit(trans);
3175 btrfs_abort_transaction(trans, ret);
3176 mutex_unlock(&fs_info->tree_log_mutex);
3177 goto out_wake_log_root;
3178 }
3179
3180 btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
3181 btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
3182 ret = write_all_supers(fs_info, 1);
3183 mutex_unlock(&fs_info->tree_log_mutex);
3184 if (ret) {
3185 btrfs_set_log_full_commit(trans);
3186 btrfs_abort_transaction(trans, ret);
3187 goto out_wake_log_root;
3188 }
3189
3190 /*
3191 * We know there can only be one task here, since we have not yet set
3192 * root->log_commit[index1] to 0 and any task attempting to sync the
3193 * log must wait for the previous log transaction to commit if it's
3194 * still in progress or wait for the current log transaction commit if
3195 * someone else already started it. We use <= and not < because the
3196 * first log transaction has an ID of 0.
3197 */
3198 ASSERT(btrfs_get_root_last_log_commit(root) <= log_transid);
3199 btrfs_set_root_last_log_commit(root, log_transid);
3200
3201 out_wake_log_root:
3202 mutex_lock(&log_root_tree->log_mutex);
3203 btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
3204
3205 log_root_tree->log_transid_committed++;
3206 atomic_set(&log_root_tree->log_commit[index2], 0);
3207 mutex_unlock(&log_root_tree->log_mutex);
3208
3209 /*
3210 * The barrier before waitqueue_active (in cond_wake_up) is needed so
3211 * all the updates above are seen by the woken threads. It might not be
3212 * necessary, but proving that seems to be hard.
3213 */
3214 cond_wake_up(&log_root_tree->log_commit_wait[index2]);
3215 out:
3216 mutex_lock(&root->log_mutex);
3217 btrfs_remove_all_log_ctxs(root, index1, ret);
3218 root->log_transid_committed++;
3219 atomic_set(&root->log_commit[index1], 0);
3220 mutex_unlock(&root->log_mutex);
3221
3222 /*
3223 * The barrier before waitqueue_active (in cond_wake_up) is needed so
3224 * all the updates above are seen by the woken threads. It might not be
3225 * necessary, but proving that seems to be hard.
3226 */
3227 cond_wake_up(&root->log_commit_wait[index1]);
3228 return ret;
3229 }
3230
3231 static void free_log_tree(struct btrfs_trans_handle *trans,
3232 struct btrfs_root *log)
3233 {
3234 int ret;
3235 struct walk_control wc = {
3236 .free = 1,
3237 .process_func = process_one_buffer
3238 };
3239
3240 if (log->node) {
3241 ret = walk_log_tree(trans, log, &wc);
3242 if (ret) {
3243 /*
3244 * We weren't able to traverse the entire log tree, the
3245 * typical scenario is getting an -EIO when reading an
3246 * extent buffer of the tree, due to a previous writeback
3247 * failure of it.
3248 */
3249 set_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
3250 &log->fs_info->fs_state);
3251
3252 /*
3253 * Some extent buffers of the log tree may still be dirty
3254 * and not yet written back to storage, because we may
3255 * have updates to a log tree without syncing a log tree,
3256 * such as during rename and link operations. So flush
3257 * them out and wait for their writeback to complete, so
3258 * that we properly cleanup their state and pages.
3259 */
3260 btrfs_write_marked_extents(log->fs_info,
3261 &log->dirty_log_pages,
3262 EXTENT_DIRTY | EXTENT_NEW);
3263 btrfs_wait_tree_log_extents(log,
3264 EXTENT_DIRTY | EXTENT_NEW);
3265
3266 if (trans)
3267 btrfs_abort_transaction(trans, ret);
3268 else
3269 btrfs_handle_fs_error(log->fs_info, ret, NULL);
3270 }
3271 }
3272
3273 extent_io_tree_release(&log->dirty_log_pages);
3274 extent_io_tree_release(&log->log_csum_range);
3275
3276 btrfs_put_root(log);
3277 }
3278
3279 /*
3280 * free all the extents used by the tree log. This should be called
3281 * at commit time of the full transaction
3282 */
3283 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
3284 {
3285 if (root->log_root) {
3286 free_log_tree(trans, root->log_root);
3287 root->log_root = NULL;
3288 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
3289 }
3290 return 0;
3291 }
3292
3293 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
3294 struct btrfs_fs_info *fs_info)
3295 {
3296 if (fs_info->log_root_tree) {
3297 free_log_tree(trans, fs_info->log_root_tree);
3298 fs_info->log_root_tree = NULL;
3299 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state);
3300 }
3301 return 0;
3302 }
3303
3304 /*
3305 * Check if an inode was logged in the current transaction. This correctly deals
3306 * with the case where the inode was logged but has a logged_trans of 0, which
3307 * happens if the inode is evicted and loaded again, as logged_trans is an in
3308 * memory only field (not persisted).
3309 *
3310 * Returns 1 if the inode was logged before in the transaction, 0 if it was not,
3311 * and < 0 on error.
3312 */
3313 static int inode_logged(const struct btrfs_trans_handle *trans,
3314 struct btrfs_inode *inode,
3315 struct btrfs_path *path_in)
3316 {
3317 struct btrfs_path *path = path_in;
3318 struct btrfs_key key;
3319 int ret;
3320
3321 if (inode->logged_trans == trans->transid)
3322 return 1;
3323
3324 /*
3325 * If logged_trans is not 0, then we know the inode logged was not logged
3326 * in this transaction, so we can return false right away.
3327 */
3328 if (inode->logged_trans > 0)
3329 return 0;
3330
3331 /*
3332 * If no log tree was created for this root in this transaction, then
3333 * the inode can not have been logged in this transaction. In that case
3334 * set logged_trans to anything greater than 0 and less than the current
3335 * transaction's ID, to avoid the search below in a future call in case
3336 * a log tree gets created after this.
3337 */
3338 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) {
3339 inode->logged_trans = trans->transid - 1;
3340 return 0;
3341 }
3342
3343 /*
3344 * We have a log tree and the inode's logged_trans is 0. We can't tell
3345 * for sure if the inode was logged before in this transaction by looking
3346 * only at logged_trans. We could be pessimistic and assume it was, but
3347 * that can lead to unnecessarily logging an inode during rename and link
3348 * operations, and then further updating the log in followup rename and
3349 * link operations, specially if it's a directory, which adds latency
3350 * visible to applications doing a series of rename or link operations.
3351 *
3352 * A logged_trans of 0 here can mean several things:
3353 *
3354 * 1) The inode was never logged since the filesystem was mounted, and may
3355 * or may have not been evicted and loaded again;
3356 *
3357 * 2) The inode was logged in a previous transaction, then evicted and
3358 * then loaded again;
3359 *
3360 * 3) The inode was logged in the current transaction, then evicted and
3361 * then loaded again.
3362 *
3363 * For cases 1) and 2) we don't want to return true, but we need to detect
3364 * case 3) and return true. So we do a search in the log root for the inode
3365 * item.
3366 */
3367 key.objectid = btrfs_ino(inode);
3368 key.type = BTRFS_INODE_ITEM_KEY;
3369 key.offset = 0;
3370
3371 if (!path) {
3372 path = btrfs_alloc_path();
3373 if (!path)
3374 return -ENOMEM;
3375 }
3376
3377 ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
3378
3379 if (path_in)
3380 btrfs_release_path(path);
3381 else
3382 btrfs_free_path(path);
3383
3384 /*
3385 * Logging an inode always results in logging its inode item. So if we
3386 * did not find the item we know the inode was not logged for sure.
3387 */
3388 if (ret < 0) {
3389 return ret;
3390 } else if (ret > 0) {
3391 /*
3392 * Set logged_trans to a value greater than 0 and less then the
3393 * current transaction to avoid doing the search in future calls.
3394 */
3395 inode->logged_trans = trans->transid - 1;
3396 return 0;
3397 }
3398
3399 /*
3400 * The inode was previously logged and then evicted, set logged_trans to
3401 * the current transacion's ID, to avoid future tree searches as long as
3402 * the inode is not evicted again.
3403 */
3404 inode->logged_trans = trans->transid;
3405
3406 /*
3407 * If it's a directory, then we must set last_dir_index_offset to the
3408 * maximum possible value, so that the next attempt to log the inode does
3409 * not skip checking if dir index keys found in modified subvolume tree
3410 * leaves have been logged before, otherwise it would result in attempts
3411 * to insert duplicate dir index keys in the log tree. This must be done
3412 * because last_dir_index_offset is an in-memory only field, not persisted
3413 * in the inode item or any other on-disk structure, so its value is lost
3414 * once the inode is evicted.
3415 */
3416 if (S_ISDIR(inode->vfs_inode.i_mode))
3417 inode->last_dir_index_offset = (u64)-1;
3418
3419 return 1;
3420 }
3421
3422 /*
3423 * Delete a directory entry from the log if it exists.
3424 *
3425 * Returns < 0 on error
3426 * 1 if the entry does not exists
3427 * 0 if the entry existed and was successfully deleted
3428 */
3429 static int del_logged_dentry(struct btrfs_trans_handle *trans,
3430 struct btrfs_root *log,
3431 struct btrfs_path *path,
3432 u64 dir_ino,
3433 const struct fscrypt_str *name,
3434 u64 index)
3435 {
3436 struct btrfs_dir_item *di;
3437
3438 /*
3439 * We only log dir index items of a directory, so we don't need to look
3440 * for dir item keys.
3441 */
3442 di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
3443 index, name, -1);
3444 if (IS_ERR(di))
3445 return PTR_ERR(di);
3446 else if (!di)
3447 return 1;
3448
3449 /*
3450 * We do not need to update the size field of the directory's
3451 * inode item because on log replay we update the field to reflect
3452 * all existing entries in the directory (see overwrite_item()).
3453 */
3454 return btrfs_delete_one_dir_name(trans, log, path, di);
3455 }
3456
3457 /*
3458 * If both a file and directory are logged, and unlinks or renames are
3459 * mixed in, we have a few interesting corners:
3460 *
3461 * create file X in dir Y
3462 * link file X to X.link in dir Y
3463 * fsync file X
3464 * unlink file X but leave X.link
3465 * fsync dir Y
3466 *
3467 * After a crash we would expect only X.link to exist. But file X
3468 * didn't get fsync'd again so the log has back refs for X and X.link.
3469 *
3470 * We solve this by removing directory entries and inode backrefs from the
3471 * log when a file that was logged in the current transaction is
3472 * unlinked. Any later fsync will include the updated log entries, and
3473 * we'll be able to reconstruct the proper directory items from backrefs.
3474 *
3475 * This optimizations allows us to avoid relogging the entire inode
3476 * or the entire directory.
3477 */
3478 void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
3479 struct btrfs_root *root,
3480 const struct fscrypt_str *name,
3481 struct btrfs_inode *dir, u64 index)
3482 {
3483 struct btrfs_path *path;
3484 int ret;
3485
3486 ret = inode_logged(trans, dir, NULL);
3487 if (ret == 0)
3488 return;
3489 else if (ret < 0) {
3490 btrfs_set_log_full_commit(trans);
3491 return;
3492 }
3493
3494 ret = join_running_log_trans(root);
3495 if (ret)
3496 return;
3497
3498 mutex_lock(&dir->log_mutex);
3499
3500 path = btrfs_alloc_path();
3501 if (!path) {
3502 ret = -ENOMEM;
3503 goto out_unlock;
3504 }
3505
3506 ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
3507 name, index);
3508 btrfs_free_path(path);
3509 out_unlock:
3510 mutex_unlock(&dir->log_mutex);
3511 if (ret < 0)
3512 btrfs_set_log_full_commit(trans);
3513 btrfs_end_log_trans(root);
3514 }
3515
3516 /* see comments for btrfs_del_dir_entries_in_log */
3517 void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
3518 struct btrfs_root *root,
3519 const struct fscrypt_str *name,
3520 struct btrfs_inode *inode, u64 dirid)
3521 {
3522 struct btrfs_root *log;
3523 u64 index;
3524 int ret;
3525
3526 ret = inode_logged(trans, inode, NULL);
3527 if (ret == 0)
3528 return;
3529 else if (ret < 0) {
3530 btrfs_set_log_full_commit(trans);
3531 return;
3532 }
3533
3534 ret = join_running_log_trans(root);
3535 if (ret)
3536 return;
3537 log = root->log_root;
3538 mutex_lock(&inode->log_mutex);
3539
3540 ret = btrfs_del_inode_ref(trans, log, name, btrfs_ino(inode),
3541 dirid, &index);
3542 mutex_unlock(&inode->log_mutex);
3543 if (ret < 0 && ret != -ENOENT)
3544 btrfs_set_log_full_commit(trans);
3545 btrfs_end_log_trans(root);
3546 }
3547
3548 /*
3549 * creates a range item in the log for 'dirid'. first_offset and
3550 * last_offset tell us which parts of the key space the log should
3551 * be considered authoritative for.
3552 */
3553 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
3554 struct btrfs_root *log,
3555 struct btrfs_path *path,
3556 u64 dirid,
3557 u64 first_offset, u64 last_offset)
3558 {
3559 int ret;
3560 struct btrfs_key key;
3561 struct btrfs_dir_log_item *item;
3562
3563 key.objectid = dirid;
3564 key.offset = first_offset;
3565 key.type = BTRFS_DIR_LOG_INDEX_KEY;
3566 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
3567 /*
3568 * -EEXIST is fine and can happen sporadically when we are logging a
3569 * directory and have concurrent insertions in the subvolume's tree for
3570 * items from other inodes and that result in pushing off some dir items
3571 * from one leaf to another in order to accommodate for the new items.
3572 * This results in logging the same dir index range key.
3573 */
3574 if (ret && ret != -EEXIST)
3575 return ret;
3576
3577 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3578 struct btrfs_dir_log_item);
3579 if (ret == -EEXIST) {
3580 const u64 curr_end = btrfs_dir_log_end(path->nodes[0], item);
3581
3582 /*
3583 * btrfs_del_dir_entries_in_log() might have been called during
3584 * an unlink between the initial insertion of this key and the
3585 * current update, or we might be logging a single entry deletion
3586 * during a rename, so set the new last_offset to the max value.
3587 */
3588 last_offset = max(last_offset, curr_end);
3589 }
3590 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
3591 btrfs_mark_buffer_dirty(trans, path->nodes[0]);
3592 btrfs_release_path(path);
3593 return 0;
3594 }
3595
3596 static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
3597 struct btrfs_inode *inode,
3598 struct extent_buffer *src,
3599 struct btrfs_path *dst_path,
3600 int start_slot,
3601 int count)
3602 {
3603 struct btrfs_root *log = inode->root->log_root;
3604 char *ins_data = NULL;
3605 struct btrfs_item_batch batch;
3606 struct extent_buffer *dst;
3607 unsigned long src_offset;
3608 unsigned long dst_offset;
3609 u64 last_index;
3610 struct btrfs_key key;
3611 u32 item_size;
3612 int ret;
3613 int i;
3614
3615 ASSERT(count > 0);
3616 batch.nr = count;
3617
3618 if (count == 1) {
3619 btrfs_item_key_to_cpu(src, &key, start_slot);
3620 item_size = btrfs_item_size(src, start_slot);
3621 batch.keys = &key;
3622 batch.data_sizes = &item_size;
3623 batch.total_data_size = item_size;
3624 } else {
3625 struct btrfs_key *ins_keys;
3626 u32 *ins_sizes;
3627
3628 ins_data = kmalloc(count * sizeof(u32) +
3629 count * sizeof(struct btrfs_key), GFP_NOFS);
3630 if (!ins_data)
3631 return -ENOMEM;
3632
3633 ins_sizes = (u32 *)ins_data;
3634 ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32));
3635 batch.keys = ins_keys;
3636 batch.data_sizes = ins_sizes;
3637 batch.total_data_size = 0;
3638
3639 for (i = 0; i < count; i++) {
3640 const int slot = start_slot + i;
3641
3642 btrfs_item_key_to_cpu(src, &ins_keys[i], slot);
3643 ins_sizes[i] = btrfs_item_size(src, slot);
3644 batch.total_data_size += ins_sizes[i];
3645 }
3646 }
3647
3648 ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
3649 if (ret)
3650 goto out;
3651
3652 dst = dst_path->nodes[0];
3653 /*
3654 * Copy all the items in bulk, in a single copy operation. Item data is
3655 * organized such that it's placed at the end of a leaf and from right
3656 * to left. For example, the data for the second item ends at an offset
3657 * that matches the offset where the data for the first item starts, the
3658 * data for the third item ends at an offset that matches the offset
3659 * where the data of the second items starts, and so on.
3660 * Therefore our source and destination start offsets for copy match the
3661 * offsets of the last items (highest slots).
3662 */
3663 dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1);
3664 src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1);
3665 copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size);
3666 btrfs_release_path(dst_path);
3667
3668 last_index = batch.keys[count - 1].offset;
3669 ASSERT(last_index > inode->last_dir_index_offset);
3670
3671 /*
3672 * If for some unexpected reason the last item's index is not greater
3673 * than the last index we logged, warn and force a transaction commit.
3674 */
3675 if (WARN_ON(last_index <= inode->last_dir_index_offset))
3676 ret = BTRFS_LOG_FORCE_COMMIT;
3677 else
3678 inode->last_dir_index_offset = last_index;
3679
3680 if (btrfs_get_first_dir_index_to_log(inode) == 0)
3681 btrfs_set_first_dir_index_to_log(inode, batch.keys[0].offset);
3682 out:
3683 kfree(ins_data);
3684
3685 return ret;
3686 }
3687
3688 static int clone_leaf(struct btrfs_path *path, struct btrfs_log_ctx *ctx)
3689 {
3690 const int slot = path->slots[0];
3691
3692 if (ctx->scratch_eb) {
3693 copy_extent_buffer_full(ctx->scratch_eb, path->nodes[0]);
3694 } else {
3695 ctx->scratch_eb = btrfs_clone_extent_buffer(path->nodes[0]);
3696 if (!ctx->scratch_eb)
3697 return -ENOMEM;
3698 }
3699
3700 btrfs_release_path(path);
3701 path->nodes[0] = ctx->scratch_eb;
3702 path->slots[0] = slot;
3703 /*
3704 * Add extra ref to scratch eb so that it is not freed when callers
3705 * release the path, so we can reuse it later if needed.
3706 */
3707 atomic_inc(&ctx->scratch_eb->refs);
3708
3709 return 0;
3710 }
3711
3712 static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
3713 struct btrfs_inode *inode,
3714 struct btrfs_path *path,
3715 struct btrfs_path *dst_path,
3716 struct btrfs_log_ctx *ctx,
3717 u64 *last_old_dentry_offset)
3718 {
3719 struct btrfs_root *log = inode->root->log_root;
3720 struct extent_buffer *src;
3721 const int nritems = btrfs_header_nritems(path->nodes[0]);
3722 const u64 ino = btrfs_ino(inode);
3723 bool last_found = false;
3724 int batch_start = 0;
3725 int batch_size = 0;
3726 int ret;
3727
3728 /*
3729 * We need to clone the leaf, release the read lock on it, and use the
3730 * clone before modifying the log tree. See the comment at copy_items()
3731 * about why we need to do this.
3732 */
3733 ret = clone_leaf(path, ctx);
3734 if (ret < 0)
3735 return ret;
3736
3737 src = path->nodes[0];
3738
3739 for (int i = path->slots[0]; i < nritems; i++) {
3740 struct btrfs_dir_item *di;
3741 struct btrfs_key key;
3742 int ret;
3743
3744 btrfs_item_key_to_cpu(src, &key, i);
3745
3746 if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) {
3747 last_found = true;
3748 break;
3749 }
3750
3751 di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
3752
3753 /*
3754 * Skip ranges of items that consist only of dir item keys created
3755 * in past transactions. However if we find a gap, we must log a
3756 * dir index range item for that gap, so that index keys in that
3757 * gap are deleted during log replay.
3758 */
3759 if (btrfs_dir_transid(src, di) < trans->transid) {
3760 if (key.offset > *last_old_dentry_offset + 1) {
3761 ret = insert_dir_log_key(trans, log, dst_path,
3762 ino, *last_old_dentry_offset + 1,
3763 key.offset - 1);
3764 if (ret < 0)
3765 return ret;
3766 }
3767
3768 *last_old_dentry_offset = key.offset;
3769 continue;
3770 }
3771
3772 /* If we logged this dir index item before, we can skip it. */
3773 if (key.offset <= inode->last_dir_index_offset)
3774 continue;
3775
3776 /*
3777 * We must make sure that when we log a directory entry, the
3778 * corresponding inode, after log replay, has a matching link
3779 * count. For example:
3780 *
3781 * touch foo
3782 * mkdir mydir
3783 * sync
3784 * ln foo mydir/bar
3785 * xfs_io -c "fsync" mydir
3786 * <crash>
3787 * <mount fs and log replay>
3788 *
3789 * Would result in a fsync log that when replayed, our file inode
3790 * would have a link count of 1, but we get two directory entries
3791 * pointing to the same inode. After removing one of the names,
3792 * it would not be possible to remove the other name, which
3793 * resulted always in stale file handle errors, and would not be
3794 * possible to rmdir the parent directory, since its i_size could
3795 * never be decremented to the value BTRFS_EMPTY_DIR_SIZE,
3796 * resulting in -ENOTEMPTY errors.
3797 */
3798 if (!ctx->log_new_dentries) {
3799 struct btrfs_key di_key;
3800
3801 btrfs_dir_item_key_to_cpu(src, di, &di_key);
3802 if (di_key.type != BTRFS_ROOT_ITEM_KEY)
3803 ctx->log_new_dentries = true;
3804 }
3805
3806 if (batch_size == 0)
3807 batch_start = i;
3808 batch_size++;
3809 }
3810
3811 if (batch_size > 0) {
3812 int ret;
3813
3814 ret = flush_dir_items_batch(trans, inode, src, dst_path,
3815 batch_start, batch_size);
3816 if (ret < 0)
3817 return ret;
3818 }
3819
3820 return last_found ? 1 : 0;
3821 }
3822
3823 /*
3824 * log all the items included in the current transaction for a given
3825 * directory. This also creates the range items in the log tree required
3826 * to replay anything deleted before the fsync
3827 */
3828 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
3829 struct btrfs_inode *inode,
3830 struct btrfs_path *path,
3831 struct btrfs_path *dst_path,
3832 struct btrfs_log_ctx *ctx,
3833 u64 min_offset, u64 *last_offset_ret)
3834 {
3835 struct btrfs_key min_key;
3836 struct btrfs_root *root = inode->root;
3837 struct btrfs_root *log = root->log_root;
3838 int ret;
3839 u64 last_old_dentry_offset = min_offset - 1;
3840 u64 last_offset = (u64)-1;
3841 u64 ino = btrfs_ino(inode);
3842
3843 min_key.objectid = ino;
3844 min_key.type = BTRFS_DIR_INDEX_KEY;
3845 min_key.offset = min_offset;
3846
3847 ret = btrfs_search_forward(root, &min_key, path, trans->transid);
3848
3849 /*
3850 * we didn't find anything from this transaction, see if there
3851 * is anything at all
3852 */
3853 if (ret != 0 || min_key.objectid != ino ||
3854 min_key.type != BTRFS_DIR_INDEX_KEY) {
3855 min_key.objectid = ino;
3856 min_key.type = BTRFS_DIR_INDEX_KEY;
3857 min_key.offset = (u64)-1;
3858 btrfs_release_path(path);
3859 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3860 if (ret < 0) {
3861 btrfs_release_path(path);
3862 return ret;
3863 }
3864 ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
3865
3866 /* if ret == 0 there are items for this type,
3867 * create a range to tell us the last key of this type.
3868 * otherwise, there are no items in this directory after
3869 * *min_offset, and we create a range to indicate that.
3870 */
3871 if (ret == 0) {
3872 struct btrfs_key tmp;
3873
3874 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
3875 path->slots[0]);
3876 if (tmp.type == BTRFS_DIR_INDEX_KEY)
3877 last_old_dentry_offset = tmp.offset;
3878 } else if (ret > 0) {
3879 ret = 0;
3880 }
3881
3882 goto done;
3883 }
3884
3885 /* go backward to find any previous key */
3886 ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
3887 if (ret == 0) {
3888 struct btrfs_key tmp;
3889
3890 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
3891 /*
3892 * The dir index key before the first one we found that needs to
3893 * be logged might be in a previous leaf, and there might be a
3894 * gap between these keys, meaning that we had deletions that
3895 * happened. So the key range item we log (key type
3896 * BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the
3897 * previous key's offset plus 1, so that those deletes are replayed.
3898 */
3899 if (tmp.type == BTRFS_DIR_INDEX_KEY)
3900 last_old_dentry_offset = tmp.offset;
3901 } else if (ret < 0) {
3902 goto done;
3903 }
3904
3905 btrfs_release_path(path);
3906
3907 /*
3908 * Find the first key from this transaction again or the one we were at
3909 * in the loop below in case we had to reschedule. We may be logging the
3910 * directory without holding its VFS lock, which happen when logging new
3911 * dentries (through log_new_dir_dentries()) or in some cases when we
3912 * need to log the parent directory of an inode. This means a dir index
3913 * key might be deleted from the inode's root, and therefore we may not
3914 * find it anymore. If we can't find it, just move to the next key. We
3915 * can not bail out and ignore, because if we do that we will simply
3916 * not log dir index keys that come after the one that was just deleted
3917 * and we can end up logging a dir index range that ends at (u64)-1
3918 * (@last_offset is initialized to that), resulting in removing dir
3919 * entries we should not remove at log replay time.
3920 */
3921 search:
3922 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3923 if (ret > 0) {
3924 ret = btrfs_next_item(root, path);
3925 if (ret > 0) {
3926 /* There are no more keys in the inode's root. */
3927 ret = 0;
3928 goto done;
3929 }
3930 }
3931 if (ret < 0)
3932 goto done;
3933
3934 /*
3935 * we have a block from this transaction, log every item in it
3936 * from our directory
3937 */
3938 while (1) {
3939 ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx,
3940 &last_old_dentry_offset);
3941 if (ret != 0) {
3942 if (ret > 0)
3943 ret = 0;
3944 goto done;
3945 }
3946 path->slots[0] = btrfs_header_nritems(path->nodes[0]);
3947
3948 /*
3949 * look ahead to the next item and see if it is also
3950 * from this directory and from this transaction
3951 */
3952 ret = btrfs_next_leaf(root, path);
3953 if (ret) {
3954 if (ret == 1) {
3955 last_offset = (u64)-1;
3956 ret = 0;
3957 }
3958 goto done;
3959 }
3960 btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]);
3961 if (min_key.objectid != ino || min_key.type != BTRFS_DIR_INDEX_KEY) {
3962 last_offset = (u64)-1;
3963 goto done;
3964 }
3965 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
3966 /*
3967 * The next leaf was not changed in the current transaction
3968 * and has at least one dir index key.
3969 * We check for the next key because there might have been
3970 * one or more deletions between the last key we logged and
3971 * that next key. So the key range item we log (key type
3972 * BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's
3973 * offset minus 1, so that those deletes are replayed.
3974 */
3975 last_offset = min_key.offset - 1;
3976 goto done;
3977 }
3978 if (need_resched()) {
3979 btrfs_release_path(path);
3980 cond_resched();
3981 goto search;
3982 }
3983 }
3984 done:
3985 btrfs_release_path(path);
3986 btrfs_release_path(dst_path);
3987
3988 if (ret == 0) {
3989 *last_offset_ret = last_offset;
3990 /*
3991 * In case the leaf was changed in the current transaction but
3992 * all its dir items are from a past transaction, the last item
3993 * in the leaf is a dir item and there's no gap between that last
3994 * dir item and the first one on the next leaf (which did not
3995 * change in the current transaction), then we don't need to log
3996 * a range, last_old_dentry_offset is == to last_offset.
3997 */
3998 ASSERT(last_old_dentry_offset <= last_offset);
3999 if (last_old_dentry_offset < last_offset)
4000 ret = insert_dir_log_key(trans, log, path, ino,
4001 last_old_dentry_offset + 1,
4002 last_offset);
4003 }
4004
4005 return ret;
4006 }
4007
4008 /*
4009 * If the inode was logged before and it was evicted, then its
4010 * last_dir_index_offset is (u64)-1, so we don't the value of the last index
4011 * key offset. If that's the case, search for it and update the inode. This
4012 * is to avoid lookups in the log tree every time we try to insert a dir index
4013 * key from a leaf changed in the current transaction, and to allow us to always
4014 * do batch insertions of dir index keys.
4015 */
4016 static int update_last_dir_index_offset(struct btrfs_inode *inode,
4017 struct btrfs_path *path,
4018 const struct btrfs_log_ctx *ctx)
4019 {
4020 const u64 ino = btrfs_ino(inode);
4021 struct btrfs_key key;
4022 int ret;
4023
4024 lockdep_assert_held(&inode->log_mutex);
4025
4026 if (inode->last_dir_index_offset != (u64)-1)
4027 return 0;
4028
4029 if (!ctx->logged_before) {
4030 inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
4031 return 0;
4032 }
4033
4034 key.objectid = ino;
4035 key.type = BTRFS_DIR_INDEX_KEY;
4036 key.offset = (u64)-1;
4037
4038 ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
4039 /*
4040 * An error happened or we actually have an index key with an offset
4041 * value of (u64)-1. Bail out, we're done.
4042 */
4043 if (ret <= 0)
4044 goto out;
4045
4046 ret = 0;
4047 inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
4048
4049 /*
4050 * No dir index items, bail out and leave last_dir_index_offset with
4051 * the value right before the first valid index value.
4052 */
4053 if (path->slots[0] == 0)
4054 goto out;
4055
4056 /*
4057 * btrfs_search_slot() left us at one slot beyond the slot with the last
4058 * index key, or beyond the last key of the directory that is not an
4059 * index key. If we have an index key before, set last_dir_index_offset
4060 * to its offset value, otherwise leave it with a value right before the
4061 * first valid index value, as it means we have an empty directory.
4062 */
4063 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
4064 if (key.objectid == ino && key.type == BTRFS_DIR_INDEX_KEY)
4065 inode->last_dir_index_offset = key.offset;
4066
4067 out:
4068 btrfs_release_path(path);
4069
4070 return ret;
4071 }
4072
4073 /*
4074 * logging directories is very similar to logging inodes, We find all the items
4075 * from the current transaction and write them to the log.
4076 *
4077 * The recovery code scans the directory in the subvolume, and if it finds a
4078 * key in the range logged that is not present in the log tree, then it means
4079 * that dir entry was unlinked during the transaction.
4080 *
4081 * In order for that scan to work, we must include one key smaller than
4082 * the smallest logged by this transaction and one key larger than the largest
4083 * key logged by this transaction.
4084 */
4085 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
4086 struct btrfs_inode *inode,
4087 struct btrfs_path *path,
4088 struct btrfs_path *dst_path,
4089 struct btrfs_log_ctx *ctx)
4090 {
4091 u64 min_key;
4092 u64 max_key;
4093 int ret;
4094
4095 ret = update_last_dir_index_offset(inode, path, ctx);
4096 if (ret)
4097 return ret;
4098
4099 min_key = BTRFS_DIR_START_INDEX;
4100 max_key = 0;
4101
4102 while (1) {
4103 ret = log_dir_items(trans, inode, path, dst_path,
4104 ctx, min_key, &max_key);
4105 if (ret)
4106 return ret;
4107 if (max_key == (u64)-1)
4108 break;
4109 min_key = max_key + 1;
4110 }
4111
4112 return 0;
4113 }
4114
4115 /*
4116 * a helper function to drop items from the log before we relog an
4117 * inode. max_key_type indicates the highest item type to remove.
4118 * This cannot be run for file data extents because it does not
4119 * free the extents they point to.
4120 */
4121 static int drop_inode_items(struct btrfs_trans_handle *trans,
4122 struct btrfs_root *log,
4123 struct btrfs_path *path,
4124 struct btrfs_inode *inode,
4125 int max_key_type)
4126 {
4127 int ret;
4128 struct btrfs_key key;
4129 struct btrfs_key found_key;
4130 int start_slot;
4131
4132 key.objectid = btrfs_ino(inode);
4133 key.type = max_key_type;
4134 key.offset = (u64)-1;
4135
4136 while (1) {
4137 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
4138 if (ret < 0) {
4139 break;
4140 } else if (ret > 0) {
4141 if (path->slots[0] == 0)
4142 break;
4143 path->slots[0]--;
4144 }
4145
4146 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
4147 path->slots[0]);
4148
4149 if (found_key.objectid != key.objectid)
4150 break;
4151
4152 found_key.offset = 0;
4153 found_key.type = 0;
4154 ret = btrfs_bin_search(path->nodes[0], 0, &found_key, &start_slot);
4155 if (ret < 0)
4156 break;
4157
4158 ret = btrfs_del_items(trans, log, path, start_slot,
4159 path->slots[0] - start_slot + 1);
4160 /*
4161 * If start slot isn't 0 then we don't need to re-search, we've
4162 * found the last guy with the objectid in this tree.
4163 */
4164 if (ret || start_slot != 0)
4165 break;
4166 btrfs_release_path(path);
4167 }
4168 btrfs_release_path(path);
4169 if (ret > 0)
4170 ret = 0;
4171 return ret;
4172 }
4173
4174 static int truncate_inode_items(struct btrfs_trans_handle *trans,
4175 struct btrfs_root *log_root,
4176 struct btrfs_inode *inode,
4177 u64 new_size, u32 min_type)
4178 {
4179 struct btrfs_truncate_control control = {
4180 .new_size = new_size,
4181 .ino = btrfs_ino(inode),
4182 .min_type = min_type,
4183 .skip_ref_updates = true,
4184 };
4185
4186 return btrfs_truncate_inode_items(trans, log_root, &control);
4187 }
4188
4189 static void fill_inode_item(struct btrfs_trans_handle *trans,
4190 struct extent_buffer *leaf,
4191 struct btrfs_inode_item *item,
4192 struct inode *inode, int log_inode_only,
4193 u64 logged_isize)
4194 {
4195 struct btrfs_map_token token;
4196 u64 flags;
4197
4198 btrfs_init_map_token(&token, leaf);
4199
4200 if (log_inode_only) {
4201 /* set the generation to zero so the recover code
4202 * can tell the difference between an logging
4203 * just to say 'this inode exists' and a logging
4204 * to say 'update this inode with these values'
4205 */
4206 btrfs_set_token_inode_generation(&token, item, 0);
4207 btrfs_set_token_inode_size(&token, item, logged_isize);
4208 } else {
4209 btrfs_set_token_inode_generation(&token, item,
4210 BTRFS_I(inode)->generation);
4211 btrfs_set_token_inode_size(&token, item, inode->i_size);
4212 }
4213
4214 btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
4215 btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
4216 btrfs_set_token_inode_mode(&token, item, inode->i_mode);
4217 btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
4218
4219 btrfs_set_token_timespec_sec(&token, &item->atime,
4220 inode_get_atime_sec(inode));
4221 btrfs_set_token_timespec_nsec(&token, &item->atime,
4222 inode_get_atime_nsec(inode));
4223
4224 btrfs_set_token_timespec_sec(&token, &item->mtime,
4225 inode_get_mtime_sec(inode));
4226 btrfs_set_token_timespec_nsec(&token, &item->mtime,
4227 inode_get_mtime_nsec(inode));
4228
4229 btrfs_set_token_timespec_sec(&token, &item->ctime,
4230 inode_get_ctime_sec(inode));
4231 btrfs_set_token_timespec_nsec(&token, &item->ctime,
4232 inode_get_ctime_nsec(inode));
4233
4234 /*
4235 * We do not need to set the nbytes field, in fact during a fast fsync
4236 * its value may not even be correct, since a fast fsync does not wait
4237 * for ordered extent completion, which is where we update nbytes, it
4238 * only waits for writeback to complete. During log replay as we find
4239 * file extent items and replay them, we adjust the nbytes field of the
4240 * inode item in subvolume tree as needed (see overwrite_item()).
4241 */
4242
4243 btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
4244 btrfs_set_token_inode_transid(&token, item, trans->transid);
4245 btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
4246 flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
4247 BTRFS_I(inode)->ro_flags);
4248 btrfs_set_token_inode_flags(&token, item, flags);
4249 btrfs_set_token_inode_block_group(&token, item, 0);
4250 }
4251
4252 static int log_inode_item(struct btrfs_trans_handle *trans,
4253 struct btrfs_root *log, struct btrfs_path *path,
4254 struct btrfs_inode *inode, bool inode_item_dropped)
4255 {
4256 struct btrfs_inode_item *inode_item;
4257 struct btrfs_key key;
4258 int ret;
4259
4260 btrfs_get_inode_key(inode, &key);
4261 /*
4262 * If we are doing a fast fsync and the inode was logged before in the
4263 * current transaction, then we know the inode was previously logged and
4264 * it exists in the log tree. For performance reasons, in this case use
4265 * btrfs_search_slot() directly with ins_len set to 0 so that we never
4266 * attempt a write lock on the leaf's parent, which adds unnecessary lock
4267 * contention in case there are concurrent fsyncs for other inodes of the
4268 * same subvolume. Using btrfs_insert_empty_item() when the inode item
4269 * already exists can also result in unnecessarily splitting a leaf.
4270 */
4271 if (!inode_item_dropped && inode->logged_trans == trans->transid) {
4272 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
4273 ASSERT(ret <= 0);
4274 if (ret > 0)
4275 ret = -ENOENT;
4276 } else {
4277 /*
4278 * This means it is the first fsync in the current transaction,
4279 * so the inode item is not in the log and we need to insert it.
4280 * We can never get -EEXIST because we are only called for a fast
4281 * fsync and in case an inode eviction happens after the inode was
4282 * logged before in the current transaction, when we load again
4283 * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
4284 * flags and set ->logged_trans to 0.
4285 */
4286 ret = btrfs_insert_empty_item(trans, log, path, &key,
4287 sizeof(*inode_item));
4288 ASSERT(ret != -EEXIST);
4289 }
4290 if (ret)
4291 return ret;
4292 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4293 struct btrfs_inode_item);
4294 fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
4295 0, 0);
4296 btrfs_release_path(path);
4297 return 0;
4298 }
4299
4300 static int log_csums(struct btrfs_trans_handle *trans,
4301 struct btrfs_inode *inode,
4302 struct btrfs_root *log_root,
4303 struct btrfs_ordered_sum *sums)
4304 {
4305 const u64 lock_end = sums->logical + sums->len - 1;
4306 struct extent_state *cached_state = NULL;
4307 int ret;
4308
4309 /*
4310 * If this inode was not used for reflink operations in the current
4311 * transaction with new extents, then do the fast path, no need to
4312 * worry about logging checksum items with overlapping ranges.
4313 */
4314 if (inode->last_reflink_trans < trans->transid)
4315 return btrfs_csum_file_blocks(trans, log_root, sums);
4316
4317 /*
4318 * Serialize logging for checksums. This is to avoid racing with the
4319 * same checksum being logged by another task that is logging another
4320 * file which happens to refer to the same extent as well. Such races
4321 * can leave checksum items in the log with overlapping ranges.
4322 */
4323 ret = lock_extent(&log_root->log_csum_range, sums->logical, lock_end,
4324 &cached_state);
4325 if (ret)
4326 return ret;
4327 /*
4328 * Due to extent cloning, we might have logged a csum item that covers a
4329 * subrange of a cloned extent, and later we can end up logging a csum
4330 * item for a larger subrange of the same extent or the entire range.
4331 * This would leave csum items in the log tree that cover the same range
4332 * and break the searches for checksums in the log tree, resulting in
4333 * some checksums missing in the fs/subvolume tree. So just delete (or
4334 * trim and adjust) any existing csum items in the log for this range.
4335 */
4336 ret = btrfs_del_csums(trans, log_root, sums->logical, sums->len);
4337 if (!ret)
4338 ret = btrfs_csum_file_blocks(trans, log_root, sums);
4339
4340 unlock_extent(&log_root->log_csum_range, sums->logical, lock_end,
4341 &cached_state);
4342
4343 return ret;
4344 }
4345
4346 static noinline int copy_items(struct btrfs_trans_handle *trans,
4347 struct btrfs_inode *inode,
4348 struct btrfs_path *dst_path,
4349 struct btrfs_path *src_path,
4350 int start_slot, int nr, int inode_only,
4351 u64 logged_isize, struct btrfs_log_ctx *ctx)
4352 {
4353 struct btrfs_root *log = inode->root->log_root;
4354 struct btrfs_file_extent_item *extent;
4355 struct extent_buffer *src;
4356 int ret;
4357 struct btrfs_key *ins_keys;
4358 u32 *ins_sizes;
4359 struct btrfs_item_batch batch;
4360 char *ins_data;
4361 int dst_index;
4362 const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
4363 const u64 i_size = i_size_read(&inode->vfs_inode);
4364
4365 /*
4366 * To keep lockdep happy and avoid deadlocks, clone the source leaf and
4367 * use the clone. This is because otherwise we would be changing the log
4368 * tree, to insert items from the subvolume tree or insert csum items,
4369 * while holding a read lock on a leaf from the subvolume tree, which
4370 * creates a nasty lock dependency when COWing log tree nodes/leaves:
4371 *
4372 * 1) Modifying the log tree triggers an extent buffer allocation while
4373 * holding a write lock on a parent extent buffer from the log tree.
4374 * Allocating the pages for an extent buffer, or the extent buffer
4375 * struct, can trigger inode eviction and finally the inode eviction
4376 * will trigger a release/remove of a delayed node, which requires
4377 * taking the delayed node's mutex;
4378 *
4379 * 2) Allocating a metadata extent for a log tree can trigger the async
4380 * reclaim thread and make us wait for it to release enough space and
4381 * unblock our reservation ticket. The reclaim thread can start
4382 * flushing delayed items, and that in turn results in the need to
4383 * lock delayed node mutexes and in the need to write lock extent
4384 * buffers of a subvolume tree - all this while holding a write lock
4385 * on the parent extent buffer in the log tree.
4386 *
4387 * So one task in scenario 1) running in parallel with another task in
4388 * scenario 2) could lead to a deadlock, one wanting to lock a delayed
4389 * node mutex while having a read lock on a leaf from the subvolume,
4390 * while the other is holding the delayed node's mutex and wants to
4391 * write lock the same subvolume leaf for flushing delayed items.
4392 */
4393 ret = clone_leaf(src_path, ctx);
4394 if (ret < 0)
4395 return ret;
4396
4397 src = src_path->nodes[0];
4398
4399 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
4400 nr * sizeof(u32), GFP_NOFS);
4401 if (!ins_data)
4402 return -ENOMEM;
4403
4404 ins_sizes = (u32 *)ins_data;
4405 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
4406 batch.keys = ins_keys;
4407 batch.data_sizes = ins_sizes;
4408 batch.total_data_size = 0;
4409 batch.nr = 0;
4410
4411 dst_index = 0;
4412 for (int i = 0; i < nr; i++) {
4413 const int src_slot = start_slot + i;
4414 struct btrfs_root *csum_root;
4415 struct btrfs_ordered_sum *sums;
4416 struct btrfs_ordered_sum *sums_next;
4417 LIST_HEAD(ordered_sums);
4418 u64 disk_bytenr;
4419 u64 disk_num_bytes;
4420 u64 extent_offset;
4421 u64 extent_num_bytes;
4422 bool is_old_extent;
4423
4424 btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot);
4425
4426 if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY)
4427 goto add_to_batch;
4428
4429 extent = btrfs_item_ptr(src, src_slot,
4430 struct btrfs_file_extent_item);
4431
4432 is_old_extent = (btrfs_file_extent_generation(src, extent) <
4433 trans->transid);
4434
4435 /*
4436 * Don't copy extents from past generations. That would make us
4437 * log a lot more metadata for common cases like doing only a
4438 * few random writes into a file and then fsync it for the first
4439 * time or after the full sync flag is set on the inode. We can
4440 * get leaves full of extent items, most of which are from past
4441 * generations, so we can skip them - as long as the inode has
4442 * not been the target of a reflink operation in this transaction,
4443 * as in that case it might have had file extent items with old
4444 * generations copied into it. We also must always log prealloc
4445 * extents that start at or beyond eof, otherwise we would lose
4446 * them on log replay.
4447 */
4448 if (is_old_extent &&
4449 ins_keys[dst_index].offset < i_size &&
4450 inode->last_reflink_trans < trans->transid)
4451 continue;
4452
4453 if (skip_csum)
4454 goto add_to_batch;
4455
4456 /* Only regular extents have checksums. */
4457 if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG)
4458 goto add_to_batch;
4459
4460 /*
4461 * If it's an extent created in a past transaction, then its
4462 * checksums are already accessible from the committed csum tree,
4463 * no need to log them.
4464 */
4465 if (is_old_extent)
4466 goto add_to_batch;
4467
4468 disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent);
4469 /* If it's an explicit hole, there are no checksums. */
4470 if (disk_bytenr == 0)
4471 goto add_to_batch;
4472
4473 disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent);
4474
4475 if (btrfs_file_extent_compression(src, extent)) {
4476 extent_offset = 0;
4477 extent_num_bytes = disk_num_bytes;
4478 } else {
4479 extent_offset = btrfs_file_extent_offset(src, extent);
4480 extent_num_bytes = btrfs_file_extent_num_bytes(src, extent);
4481 }
4482
4483 csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr);
4484 disk_bytenr += extent_offset;
4485 ret = btrfs_lookup_csums_list(csum_root, disk_bytenr,
4486 disk_bytenr + extent_num_bytes - 1,
4487 &ordered_sums, false);
4488 if (ret < 0)
4489 goto out;
4490 ret = 0;
4491
4492 list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
4493 if (!ret)
4494 ret = log_csums(trans, inode, log, sums);
4495 list_del(&sums->list);
4496 kfree(sums);
4497 }
4498 if (ret)
4499 goto out;
4500
4501 add_to_batch:
4502 ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
4503 batch.total_data_size += ins_sizes[dst_index];
4504 batch.nr++;
4505 dst_index++;
4506 }
4507
4508 /*
4509 * We have a leaf full of old extent items that don't need to be logged,
4510 * so we don't need to do anything.
4511 */
4512 if (batch.nr == 0)
4513 goto out;
4514
4515 ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
4516 if (ret)
4517 goto out;
4518
4519 dst_index = 0;
4520 for (int i = 0; i < nr; i++) {
4521 const int src_slot = start_slot + i;
4522 const int dst_slot = dst_path->slots[0] + dst_index;
4523 struct btrfs_key key;
4524 unsigned long src_offset;
4525 unsigned long dst_offset;
4526
4527 /*
4528 * We're done, all the remaining items in the source leaf
4529 * correspond to old file extent items.
4530 */
4531 if (dst_index >= batch.nr)
4532 break;
4533
4534 btrfs_item_key_to_cpu(src, &key, src_slot);
4535
4536 if (key.type != BTRFS_EXTENT_DATA_KEY)
4537 goto copy_item;
4538
4539 extent = btrfs_item_ptr(src, src_slot,
4540 struct btrfs_file_extent_item);
4541
4542 /* See the comment in the previous loop, same logic. */
4543 if (btrfs_file_extent_generation(src, extent) < trans->transid &&
4544 key.offset < i_size &&
4545 inode->last_reflink_trans < trans->transid)
4546 continue;
4547
4548 copy_item:
4549 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot);
4550 src_offset = btrfs_item_ptr_offset(src, src_slot);
4551
4552 if (key.type == BTRFS_INODE_ITEM_KEY) {
4553 struct btrfs_inode_item *inode_item;
4554
4555 inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot,
4556 struct btrfs_inode_item);
4557 fill_inode_item(trans, dst_path->nodes[0], inode_item,
4558 &inode->vfs_inode,
4559 inode_only == LOG_INODE_EXISTS,
4560 logged_isize);
4561 } else {
4562 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
4563 src_offset, ins_sizes[dst_index]);
4564 }
4565
4566 dst_index++;
4567 }
4568
4569 btrfs_mark_buffer_dirty(trans, dst_path->nodes[0]);
4570 btrfs_release_path(dst_path);
4571 out:
4572 kfree(ins_data);
4573
4574 return ret;
4575 }
4576
4577 static int extent_cmp(void *priv, const struct list_head *a,
4578 const struct list_head *b)
4579 {
4580 const struct extent_map *em1, *em2;
4581
4582 em1 = list_entry(a, struct extent_map, list);
4583 em2 = list_entry(b, struct extent_map, list);
4584
4585 if (em1->start < em2->start)
4586 return -1;
4587 else if (em1->start > em2->start)
4588 return 1;
4589 return 0;
4590 }
4591
4592 static int log_extent_csums(struct btrfs_trans_handle *trans,
4593 struct btrfs_inode *inode,
4594 struct btrfs_root *log_root,
4595 const struct extent_map *em,
4596 struct btrfs_log_ctx *ctx)
4597 {
4598 struct btrfs_ordered_extent *ordered;
4599 struct btrfs_root *csum_root;
4600 u64 block_start;
4601 u64 csum_offset;
4602 u64 csum_len;
4603 u64 mod_start = em->start;
4604 u64 mod_len = em->len;
4605 LIST_HEAD(ordered_sums);
4606 int ret = 0;
4607
4608 if (inode->flags & BTRFS_INODE_NODATASUM ||
4609 (em->flags & EXTENT_FLAG_PREALLOC) ||
4610 em->disk_bytenr == EXTENT_MAP_HOLE)
4611 return 0;
4612
4613 list_for_each_entry(ordered, &ctx->ordered_extents, log_list) {
4614 const u64 ordered_end = ordered->file_offset + ordered->num_bytes;
4615 const u64 mod_end = mod_start + mod_len;
4616 struct btrfs_ordered_sum *sums;
4617
4618 if (mod_len == 0)
4619 break;
4620
4621 if (ordered_end <= mod_start)
4622 continue;
4623 if (mod_end <= ordered->file_offset)
4624 break;
4625
4626 /*
4627 * We are going to copy all the csums on this ordered extent, so
4628 * go ahead and adjust mod_start and mod_len in case this ordered
4629 * extent has already been logged.
4630 */
4631 if (ordered->file_offset > mod_start) {
4632 if (ordered_end >= mod_end)
4633 mod_len = ordered->file_offset - mod_start;
4634 /*
4635 * If we have this case
4636 *
4637 * |--------- logged extent ---------|
4638 * |----- ordered extent ----|
4639 *
4640 * Just don't mess with mod_start and mod_len, we'll
4641 * just end up logging more csums than we need and it
4642 * will be ok.
4643 */
4644 } else {
4645 if (ordered_end < mod_end) {
4646 mod_len = mod_end - ordered_end;
4647 mod_start = ordered_end;
4648 } else {
4649 mod_len = 0;
4650 }
4651 }
4652
4653 /*
4654 * To keep us from looping for the above case of an ordered
4655 * extent that falls inside of the logged extent.
4656 */
4657 if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags))
4658 continue;
4659
4660 list_for_each_entry(sums, &ordered->list, list) {
4661 ret = log_csums(trans, inode, log_root, sums);
4662 if (ret)
4663 return ret;
4664 }
4665 }
4666
4667 /* We're done, found all csums in the ordered extents. */
4668 if (mod_len == 0)
4669 return 0;
4670
4671 /* If we're compressed we have to save the entire range of csums. */
4672 if (extent_map_is_compressed(em)) {
4673 csum_offset = 0;
4674 csum_len = em->disk_num_bytes;
4675 } else {
4676 csum_offset = mod_start - em->start;
4677 csum_len = mod_len;
4678 }
4679
4680 /* block start is already adjusted for the file extent offset. */
4681 block_start = extent_map_block_start(em);
4682 csum_root = btrfs_csum_root(trans->fs_info, block_start);
4683 ret = btrfs_lookup_csums_list(csum_root, block_start + csum_offset,
4684 block_start + csum_offset + csum_len - 1,
4685 &ordered_sums, false);
4686 if (ret < 0)
4687 return ret;
4688 ret = 0;
4689
4690 while (!list_empty(&ordered_sums)) {
4691 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
4692 struct btrfs_ordered_sum,
4693 list);
4694 if (!ret)
4695 ret = log_csums(trans, inode, log_root, sums);
4696 list_del(&sums->list);
4697 kfree(sums);
4698 }
4699
4700 return ret;
4701 }
4702
4703 static int log_one_extent(struct btrfs_trans_handle *trans,
4704 struct btrfs_inode *inode,
4705 const struct extent_map *em,
4706 struct btrfs_path *path,
4707 struct btrfs_log_ctx *ctx)
4708 {
4709 struct btrfs_drop_extents_args drop_args = { 0 };
4710 struct btrfs_root *log = inode->root->log_root;
4711 struct btrfs_file_extent_item fi = { 0 };
4712 struct extent_buffer *leaf;
4713 struct btrfs_key key;
4714 enum btrfs_compression_type compress_type;
4715 u64 extent_offset = em->offset;
4716 u64 block_start = extent_map_block_start(em);
4717 u64 block_len;
4718 int ret;
4719
4720 btrfs_set_stack_file_extent_generation(&fi, trans->transid);
4721 if (em->flags & EXTENT_FLAG_PREALLOC)
4722 btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC);
4723 else
4724 btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG);
4725
4726 block_len = em->disk_num_bytes;
4727 compress_type = extent_map_compression(em);
4728 if (compress_type != BTRFS_COMPRESS_NONE) {
4729 btrfs_set_stack_file_extent_disk_bytenr(&fi, block_start);
4730 btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
4731 } else if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE) {
4732 btrfs_set_stack_file_extent_disk_bytenr(&fi, block_start - extent_offset);
4733 btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
4734 }
4735
4736 btrfs_set_stack_file_extent_offset(&fi, extent_offset);
4737 btrfs_set_stack_file_extent_num_bytes(&fi, em->len);
4738 btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes);
4739 btrfs_set_stack_file_extent_compression(&fi, compress_type);
4740
4741 ret = log_extent_csums(trans, inode, log, em, ctx);
4742 if (ret)
4743 return ret;
4744
4745 /*
4746 * If this is the first time we are logging the inode in the current
4747 * transaction, we can avoid btrfs_drop_extents(), which is expensive
4748 * because it does a deletion search, which always acquires write locks
4749 * for extent buffers at levels 2, 1 and 0. This not only wastes time
4750 * but also adds significant contention in a log tree, since log trees
4751 * are small, with a root at level 2 or 3 at most, due to their short
4752 * life span.
4753 */
4754 if (ctx->logged_before) {
4755 drop_args.path = path;
4756 drop_args.start = em->start;
4757 drop_args.end = em->start + em->len;
4758 drop_args.replace_extent = true;
4759 drop_args.extent_item_size = sizeof(fi);
4760 ret = btrfs_drop_extents(trans, log, inode, &drop_args);
4761 if (ret)
4762 return ret;
4763 }
4764
4765 if (!drop_args.extent_inserted) {
4766 key.objectid = btrfs_ino(inode);
4767 key.type = BTRFS_EXTENT_DATA_KEY;
4768 key.offset = em->start;
4769
4770 ret = btrfs_insert_empty_item(trans, log, path, &key,
4771 sizeof(fi));
4772 if (ret)
4773 return ret;
4774 }
4775 leaf = path->nodes[0];
4776 write_extent_buffer(leaf, &fi,
4777 btrfs_item_ptr_offset(leaf, path->slots[0]),
4778 sizeof(fi));
4779 btrfs_mark_buffer_dirty(trans, leaf);
4780
4781 btrfs_release_path(path);
4782
4783 return ret;
4784 }
4785
4786 /*
4787 * Log all prealloc extents beyond the inode's i_size to make sure we do not
4788 * lose them after doing a full/fast fsync and replaying the log. We scan the
4789 * subvolume's root instead of iterating the inode's extent map tree because
4790 * otherwise we can log incorrect extent items based on extent map conversion.
4791 * That can happen due to the fact that extent maps are merged when they
4792 * are not in the extent map tree's list of modified extents.
4793 */
4794 static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
4795 struct btrfs_inode *inode,
4796 struct btrfs_path *path,
4797 struct btrfs_log_ctx *ctx)
4798 {
4799 struct btrfs_root *root = inode->root;
4800 struct btrfs_key key;
4801 const u64 i_size = i_size_read(&inode->vfs_inode);
4802 const u64 ino = btrfs_ino(inode);
4803 struct btrfs_path *dst_path = NULL;
4804 bool dropped_extents = false;
4805 u64 truncate_offset = i_size;
4806 struct extent_buffer *leaf;
4807 int slot;
4808 int ins_nr = 0;
4809 int start_slot = 0;
4810 int ret;
4811
4812 if (!(inode->flags & BTRFS_INODE_PREALLOC))
4813 return 0;
4814
4815 key.objectid = ino;
4816 key.type = BTRFS_EXTENT_DATA_KEY;
4817 key.offset = i_size;
4818 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4819 if (ret < 0)
4820 goto out;
4821
4822 /*
4823 * We must check if there is a prealloc extent that starts before the
4824 * i_size and crosses the i_size boundary. This is to ensure later we
4825 * truncate down to the end of that extent and not to the i_size, as
4826 * otherwise we end up losing part of the prealloc extent after a log
4827 * replay and with an implicit hole if there is another prealloc extent
4828 * that starts at an offset beyond i_size.
4829 */
4830 ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
4831 if (ret < 0)
4832 goto out;
4833
4834 if (ret == 0) {
4835 struct btrfs_file_extent_item *ei;
4836
4837 leaf = path->nodes[0];
4838 slot = path->slots[0];
4839 ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4840
4841 if (btrfs_file_extent_type(leaf, ei) ==
4842 BTRFS_FILE_EXTENT_PREALLOC) {
4843 u64 extent_end;
4844
4845 btrfs_item_key_to_cpu(leaf, &key, slot);
4846 extent_end = key.offset +
4847 btrfs_file_extent_num_bytes(leaf, ei);
4848
4849 if (extent_end > i_size)
4850 truncate_offset = extent_end;
4851 }
4852 } else {
4853 ret = 0;
4854 }
4855
4856 while (true) {
4857 leaf = path->nodes[0];
4858 slot = path->slots[0];
4859
4860 if (slot >= btrfs_header_nritems(leaf)) {
4861 if (ins_nr > 0) {
4862 ret = copy_items(trans, inode, dst_path, path,
4863 start_slot, ins_nr, 1, 0, ctx);
4864 if (ret < 0)
4865 goto out;
4866 ins_nr = 0;
4867 }
4868 ret = btrfs_next_leaf(root, path);
4869 if (ret < 0)
4870 goto out;
4871 if (ret > 0) {
4872 ret = 0;
4873 break;
4874 }
4875 continue;
4876 }
4877
4878 btrfs_item_key_to_cpu(leaf, &key, slot);
4879 if (key.objectid > ino)
4880 break;
4881 if (WARN_ON_ONCE(key.objectid < ino) ||
4882 key.type < BTRFS_EXTENT_DATA_KEY ||
4883 key.offset < i_size) {
4884 path->slots[0]++;
4885 continue;
4886 }
4887 /*
4888 * Avoid overlapping items in the log tree. The first time we
4889 * get here, get rid of everything from a past fsync. After
4890 * that, if the current extent starts before the end of the last
4891 * extent we copied, truncate the last one. This can happen if
4892 * an ordered extent completion modifies the subvolume tree
4893 * while btrfs_next_leaf() has the tree unlocked.
4894 */
4895 if (!dropped_extents || key.offset < truncate_offset) {
4896 ret = truncate_inode_items(trans, root->log_root, inode,
4897 min(key.offset, truncate_offset),
4898 BTRFS_EXTENT_DATA_KEY);
4899 if (ret)
4900 goto out;
4901 dropped_extents = true;
4902 }
4903 truncate_offset = btrfs_file_extent_end(path);
4904 if (ins_nr == 0)
4905 start_slot = slot;
4906 ins_nr++;
4907 path->slots[0]++;
4908 if (!dst_path) {
4909 dst_path = btrfs_alloc_path();
4910 if (!dst_path) {
4911 ret = -ENOMEM;
4912 goto out;
4913 }
4914 }
4915 }
4916 if (ins_nr > 0)
4917 ret = copy_items(trans, inode, dst_path, path,
4918 start_slot, ins_nr, 1, 0, ctx);
4919 out:
4920 btrfs_release_path(path);
4921 btrfs_free_path(dst_path);
4922 return ret;
4923 }
4924
4925 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
4926 struct btrfs_inode *inode,
4927 struct btrfs_path *path,
4928 struct btrfs_log_ctx *ctx)
4929 {
4930 struct btrfs_ordered_extent *ordered;
4931 struct btrfs_ordered_extent *tmp;
4932 struct extent_map *em, *n;
4933 LIST_HEAD(extents);
4934 struct extent_map_tree *tree = &inode->extent_tree;
4935 int ret = 0;
4936 int num = 0;
4937
4938 write_lock(&tree->lock);
4939
4940 list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
4941 list_del_init(&em->list);
4942 /*
4943 * Just an arbitrary number, this can be really CPU intensive
4944 * once we start getting a lot of extents, and really once we
4945 * have a bunch of extents we just want to commit since it will
4946 * be faster.
4947 */
4948 if (++num > 32768) {
4949 list_del_init(&tree->modified_extents);
4950 ret = -EFBIG;
4951 goto process;
4952 }
4953
4954 if (em->generation < trans->transid)
4955 continue;
4956
4957 /* We log prealloc extents beyond eof later. */
4958 if ((em->flags & EXTENT_FLAG_PREALLOC) &&
4959 em->start >= i_size_read(&inode->vfs_inode))
4960 continue;
4961
4962 /* Need a ref to keep it from getting evicted from cache */
4963 refcount_inc(&em->refs);
4964 em->flags |= EXTENT_FLAG_LOGGING;
4965 list_add_tail(&em->list, &extents);
4966 num++;
4967 }
4968
4969 list_sort(NULL, &extents, extent_cmp);
4970 process:
4971 while (!list_empty(&extents)) {
4972 em = list_entry(extents.next, struct extent_map, list);
4973
4974 list_del_init(&em->list);
4975
4976 /*
4977 * If we had an error we just need to delete everybody from our
4978 * private list.
4979 */
4980 if (ret) {
4981 clear_em_logging(inode, em);
4982 free_extent_map(em);
4983 continue;
4984 }
4985
4986 write_unlock(&tree->lock);
4987
4988 ret = log_one_extent(trans, inode, em, path, ctx);
4989 write_lock(&tree->lock);
4990 clear_em_logging(inode, em);
4991 free_extent_map(em);
4992 }
4993 WARN_ON(!list_empty(&extents));
4994 write_unlock(&tree->lock);
4995
4996 if (!ret)
4997 ret = btrfs_log_prealloc_extents(trans, inode, path, ctx);
4998 if (ret)
4999 return ret;
5000
5001 /*
5002 * We have logged all extents successfully, now make sure the commit of
5003 * the current transaction waits for the ordered extents to complete
5004 * before it commits and wipes out the log trees, otherwise we would
5005 * lose data if an ordered extents completes after the transaction
5006 * commits and a power failure happens after the transaction commit.
5007 */
5008 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
5009 list_del_init(&ordered->log_list);
5010 set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags);
5011
5012 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
5013 spin_lock_irq(&inode->ordered_tree_lock);
5014 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
5015 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
5016 atomic_inc(&trans->transaction->pending_ordered);
5017 }
5018 spin_unlock_irq(&inode->ordered_tree_lock);
5019 }
5020 btrfs_put_ordered_extent(ordered);
5021 }
5022
5023 return 0;
5024 }
5025
5026 static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
5027 struct btrfs_path *path, u64 *size_ret)
5028 {
5029 struct btrfs_key key;
5030 int ret;
5031
5032 key.objectid = btrfs_ino(inode);
5033 key.type = BTRFS_INODE_ITEM_KEY;
5034 key.offset = 0;
5035
5036 ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
5037 if (ret < 0) {
5038 return ret;
5039 } else if (ret > 0) {
5040 *size_ret = 0;
5041 } else {
5042 struct btrfs_inode_item *item;
5043
5044 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5045 struct btrfs_inode_item);
5046 *size_ret = btrfs_inode_size(path->nodes[0], item);
5047 /*
5048 * If the in-memory inode's i_size is smaller then the inode
5049 * size stored in the btree, return the inode's i_size, so
5050 * that we get a correct inode size after replaying the log
5051 * when before a power failure we had a shrinking truncate
5052 * followed by addition of a new name (rename / new hard link).
5053 * Otherwise return the inode size from the btree, to avoid
5054 * data loss when replaying a log due to previously doing a
5055 * write that expands the inode's size and logging a new name
5056 * immediately after.
5057 */
5058 if (*size_ret > inode->vfs_inode.i_size)
5059 *size_ret = inode->vfs_inode.i_size;
5060 }
5061
5062 btrfs_release_path(path);
5063 return 0;
5064 }
5065
5066 /*
5067 * At the moment we always log all xattrs. This is to figure out at log replay
5068 * time which xattrs must have their deletion replayed. If a xattr is missing
5069 * in the log tree and exists in the fs/subvol tree, we delete it. This is
5070 * because if a xattr is deleted, the inode is fsynced and a power failure
5071 * happens, causing the log to be replayed the next time the fs is mounted,
5072 * we want the xattr to not exist anymore (same behaviour as other filesystems
5073 * with a journal, ext3/4, xfs, f2fs, etc).
5074 */
5075 static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
5076 struct btrfs_inode *inode,
5077 struct btrfs_path *path,
5078 struct btrfs_path *dst_path,
5079 struct btrfs_log_ctx *ctx)
5080 {
5081 struct btrfs_root *root = inode->root;
5082 int ret;
5083 struct btrfs_key key;
5084 const u64 ino = btrfs_ino(inode);
5085 int ins_nr = 0;
5086 int start_slot = 0;
5087 bool found_xattrs = false;
5088
5089 if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags))
5090 return 0;
5091
5092 key.objectid = ino;
5093 key.type = BTRFS_XATTR_ITEM_KEY;
5094 key.offset = 0;
5095
5096 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5097 if (ret < 0)
5098 return ret;
5099
5100 while (true) {
5101 int slot = path->slots[0];
5102 struct extent_buffer *leaf = path->nodes[0];
5103 int nritems = btrfs_header_nritems(leaf);
5104
5105 if (slot >= nritems) {
5106 if (ins_nr > 0) {
5107 ret = copy_items(trans, inode, dst_path, path,
5108 start_slot, ins_nr, 1, 0, ctx);
5109 if (ret < 0)
5110 return ret;
5111 ins_nr = 0;
5112 }
5113 ret = btrfs_next_leaf(root, path);
5114 if (ret < 0)
5115 return ret;
5116 else if (ret > 0)
5117 break;
5118 continue;
5119 }
5120
5121 btrfs_item_key_to_cpu(leaf, &key, slot);
5122 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
5123 break;
5124
5125 if (ins_nr == 0)
5126 start_slot = slot;
5127 ins_nr++;
5128 path->slots[0]++;
5129 found_xattrs = true;
5130 cond_resched();
5131 }
5132 if (ins_nr > 0) {
5133 ret = copy_items(trans, inode, dst_path, path,
5134 start_slot, ins_nr, 1, 0, ctx);
5135 if (ret < 0)
5136 return ret;
5137 }
5138
5139 if (!found_xattrs)
5140 set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags);
5141
5142 return 0;
5143 }
5144
5145 /*
5146 * When using the NO_HOLES feature if we punched a hole that causes the
5147 * deletion of entire leafs or all the extent items of the first leaf (the one
5148 * that contains the inode item and references) we may end up not processing
5149 * any extents, because there are no leafs with a generation matching the
5150 * current transaction that have extent items for our inode. So we need to find
5151 * if any holes exist and then log them. We also need to log holes after any
5152 * truncate operation that changes the inode's size.
5153 */
5154 static int btrfs_log_holes(struct btrfs_trans_handle *trans,
5155 struct btrfs_inode *inode,
5156 struct btrfs_path *path)
5157 {
5158 struct btrfs_root *root = inode->root;
5159 struct btrfs_fs_info *fs_info = root->fs_info;
5160 struct btrfs_key key;
5161 const u64 ino = btrfs_ino(inode);
5162 const u64 i_size = i_size_read(&inode->vfs_inode);
5163 u64 prev_extent_end = 0;
5164 int ret;
5165
5166 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0)
5167 return 0;
5168
5169 key.objectid = ino;
5170 key.type = BTRFS_EXTENT_DATA_KEY;
5171 key.offset = 0;
5172
5173 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5174 if (ret < 0)
5175 return ret;
5176
5177 while (true) {
5178 struct extent_buffer *leaf = path->nodes[0];
5179
5180 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
5181 ret = btrfs_next_leaf(root, path);
5182 if (ret < 0)
5183 return ret;
5184 if (ret > 0) {
5185 ret = 0;
5186 break;
5187 }
5188 leaf = path->nodes[0];
5189 }
5190
5191 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5192 if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
5193 break;
5194
5195 /* We have a hole, log it. */
5196 if (prev_extent_end < key.offset) {
5197 const u64 hole_len = key.offset - prev_extent_end;
5198
5199 /*
5200 * Release the path to avoid deadlocks with other code
5201 * paths that search the root while holding locks on
5202 * leafs from the log root.
5203 */
5204 btrfs_release_path(path);
5205 ret = btrfs_insert_hole_extent(trans, root->log_root,
5206 ino, prev_extent_end,
5207 hole_len);
5208 if (ret < 0)
5209 return ret;
5210
5211 /*
5212 * Search for the same key again in the root. Since it's
5213 * an extent item and we are holding the inode lock, the
5214 * key must still exist. If it doesn't just emit warning
5215 * and return an error to fall back to a transaction
5216 * commit.
5217 */
5218 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5219 if (ret < 0)
5220 return ret;
5221 if (WARN_ON(ret > 0))
5222 return -ENOENT;
5223 leaf = path->nodes[0];
5224 }
5225
5226 prev_extent_end = btrfs_file_extent_end(path);
5227 path->slots[0]++;
5228 cond_resched();
5229 }
5230
5231 if (prev_extent_end < i_size) {
5232 u64 hole_len;
5233
5234 btrfs_release_path(path);
5235 hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize);
5236 ret = btrfs_insert_hole_extent(trans, root->log_root, ino,
5237 prev_extent_end, hole_len);
5238 if (ret < 0)
5239 return ret;
5240 }
5241
5242 return 0;
5243 }
5244
5245 /*
5246 * When we are logging a new inode X, check if it doesn't have a reference that
5247 * matches the reference from some other inode Y created in a past transaction
5248 * and that was renamed in the current transaction. If we don't do this, then at
5249 * log replay time we can lose inode Y (and all its files if it's a directory):
5250 *
5251 * mkdir /mnt/x
5252 * echo "hello world" > /mnt/x/foobar
5253 * sync
5254 * mv /mnt/x /mnt/y
5255 * mkdir /mnt/x # or touch /mnt/x
5256 * xfs_io -c fsync /mnt/x
5257 * <power fail>
5258 * mount fs, trigger log replay
5259 *
5260 * After the log replay procedure, we would lose the first directory and all its
5261 * files (file foobar).
5262 * For the case where inode Y is not a directory we simply end up losing it:
5263 *
5264 * echo "123" > /mnt/foo
5265 * sync
5266 * mv /mnt/foo /mnt/bar
5267 * echo "abc" > /mnt/foo
5268 * xfs_io -c fsync /mnt/foo
5269 * <power fail>
5270 *
5271 * We also need this for cases where a snapshot entry is replaced by some other
5272 * entry (file or directory) otherwise we end up with an unreplayable log due to
5273 * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
5274 * if it were a regular entry:
5275 *
5276 * mkdir /mnt/x
5277 * btrfs subvolume snapshot /mnt /mnt/x/snap
5278 * btrfs subvolume delete /mnt/x/snap
5279 * rmdir /mnt/x
5280 * mkdir /mnt/x
5281 * fsync /mnt/x or fsync some new file inside it
5282 * <power fail>
5283 *
5284 * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
5285 * the same transaction.
5286 */
5287 static int btrfs_check_ref_name_override(struct extent_buffer *eb,
5288 const int slot,
5289 const struct btrfs_key *key,
5290 struct btrfs_inode *inode,
5291 u64 *other_ino, u64 *other_parent)
5292 {
5293 int ret;
5294 struct btrfs_path *search_path;
5295 char *name = NULL;
5296 u32 name_len = 0;
5297 u32 item_size = btrfs_item_size(eb, slot);
5298 u32 cur_offset = 0;
5299 unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
5300
5301 search_path = btrfs_alloc_path();
5302 if (!search_path)
5303 return -ENOMEM;
5304 search_path->search_commit_root = 1;
5305 search_path->skip_locking = 1;
5306
5307 while (cur_offset < item_size) {
5308 u64 parent;
5309 u32 this_name_len;
5310 u32 this_len;
5311 unsigned long name_ptr;
5312 struct btrfs_dir_item *di;
5313 struct fscrypt_str name_str;
5314
5315 if (key->type == BTRFS_INODE_REF_KEY) {
5316 struct btrfs_inode_ref *iref;
5317
5318 iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
5319 parent = key->offset;
5320 this_name_len = btrfs_inode_ref_name_len(eb, iref);
5321 name_ptr = (unsigned long)(iref + 1);
5322 this_len = sizeof(*iref) + this_name_len;
5323 } else {
5324 struct btrfs_inode_extref *extref;
5325
5326 extref = (struct btrfs_inode_extref *)(ptr +
5327 cur_offset);
5328 parent = btrfs_inode_extref_parent(eb, extref);
5329 this_name_len = btrfs_inode_extref_name_len(eb, extref);
5330 name_ptr = (unsigned long)&extref->name;
5331 this_len = sizeof(*extref) + this_name_len;
5332 }
5333
5334 if (this_name_len > name_len) {
5335 char *new_name;
5336
5337 new_name = krealloc(name, this_name_len, GFP_NOFS);
5338 if (!new_name) {
5339 ret = -ENOMEM;
5340 goto out;
5341 }
5342 name_len = this_name_len;
5343 name = new_name;
5344 }
5345
5346 read_extent_buffer(eb, name, name_ptr, this_name_len);
5347
5348 name_str.name = name;
5349 name_str.len = this_name_len;
5350 di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
5351 parent, &name_str, 0);
5352 if (di && !IS_ERR(di)) {
5353 struct btrfs_key di_key;
5354
5355 btrfs_dir_item_key_to_cpu(search_path->nodes[0],
5356 di, &di_key);
5357 if (di_key.type == BTRFS_INODE_ITEM_KEY) {
5358 if (di_key.objectid != key->objectid) {
5359 ret = 1;
5360 *other_ino = di_key.objectid;
5361 *other_parent = parent;
5362 } else {
5363 ret = 0;
5364 }
5365 } else {
5366 ret = -EAGAIN;
5367 }
5368 goto out;
5369 } else if (IS_ERR(di)) {
5370 ret = PTR_ERR(di);
5371 goto out;
5372 }
5373 btrfs_release_path(search_path);
5374
5375 cur_offset += this_len;
5376 }
5377 ret = 0;
5378 out:
5379 btrfs_free_path(search_path);
5380 kfree(name);
5381 return ret;
5382 }
5383
5384 /*
5385 * Check if we need to log an inode. This is used in contexts where while
5386 * logging an inode we need to log another inode (either that it exists or in
5387 * full mode). This is used instead of btrfs_inode_in_log() because the later
5388 * requires the inode to be in the log and have the log transaction committed,
5389 * while here we do not care if the log transaction was already committed - our
5390 * caller will commit the log later - and we want to avoid logging an inode
5391 * multiple times when multiple tasks have joined the same log transaction.
5392 */
5393 static bool need_log_inode(const struct btrfs_trans_handle *trans,
5394 struct btrfs_inode *inode)
5395 {
5396 /*
5397 * If a directory was not modified, no dentries added or removed, we can
5398 * and should avoid logging it.
5399 */
5400 if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid)
5401 return false;
5402
5403 /*
5404 * If this inode does not have new/updated/deleted xattrs since the last
5405 * time it was logged and is flagged as logged in the current transaction,
5406 * we can skip logging it. As for new/deleted names, those are updated in
5407 * the log by link/unlink/rename operations.
5408 * In case the inode was logged and then evicted and reloaded, its
5409 * logged_trans will be 0, in which case we have to fully log it since
5410 * logged_trans is a transient field, not persisted.
5411 */
5412 if (inode_logged(trans, inode, NULL) == 1 &&
5413 !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
5414 return false;
5415
5416 return true;
5417 }
5418
5419 struct btrfs_dir_list {
5420 u64 ino;
5421 struct list_head list;
5422 };
5423
5424 /*
5425 * Log the inodes of the new dentries of a directory.
5426 * See process_dir_items_leaf() for details about why it is needed.
5427 * This is a recursive operation - if an existing dentry corresponds to a
5428 * directory, that directory's new entries are logged too (same behaviour as
5429 * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
5430 * the dentries point to we do not acquire their VFS lock, otherwise lockdep
5431 * complains about the following circular lock dependency / possible deadlock:
5432 *
5433 * CPU0 CPU1
5434 * ---- ----
5435 * lock(&type->i_mutex_dir_key#3/2);
5436 * lock(sb_internal#2);
5437 * lock(&type->i_mutex_dir_key#3/2);
5438 * lock(&sb->s_type->i_mutex_key#14);
5439 *
5440 * Where sb_internal is the lock (a counter that works as a lock) acquired by
5441 * sb_start_intwrite() in btrfs_start_transaction().
5442 * Not acquiring the VFS lock of the inodes is still safe because:
5443 *
5444 * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
5445 * that while logging the inode new references (names) are added or removed
5446 * from the inode, leaving the logged inode item with a link count that does
5447 * not match the number of logged inode reference items. This is fine because
5448 * at log replay time we compute the real number of links and correct the
5449 * link count in the inode item (see replay_one_buffer() and
5450 * link_to_fixup_dir());
5451 *
5452 * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
5453 * while logging the inode's items new index items (key type
5454 * BTRFS_DIR_INDEX_KEY) are added to fs/subvol tree and the logged inode item
5455 * has a size that doesn't match the sum of the lengths of all the logged
5456 * names - this is ok, not a problem, because at log replay time we set the
5457 * directory's i_size to the correct value (see replay_one_name() and
5458 * overwrite_item()).
5459 */
5460 static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
5461 struct btrfs_inode *start_inode,
5462 struct btrfs_log_ctx *ctx)
5463 {
5464 struct btrfs_root *root = start_inode->root;
5465 struct btrfs_path *path;
5466 LIST_HEAD(dir_list);
5467 struct btrfs_dir_list *dir_elem;
5468 u64 ino = btrfs_ino(start_inode);
5469 struct btrfs_inode *curr_inode = start_inode;
5470 int ret = 0;
5471
5472 /*
5473 * If we are logging a new name, as part of a link or rename operation,
5474 * don't bother logging new dentries, as we just want to log the names
5475 * of an inode and that any new parents exist.
5476 */
5477 if (ctx->logging_new_name)
5478 return 0;
5479
5480 path = btrfs_alloc_path();
5481 if (!path)
5482 return -ENOMEM;
5483
5484 /* Pairs with btrfs_add_delayed_iput below. */
5485 ihold(&curr_inode->vfs_inode);
5486
5487 while (true) {
5488 struct inode *vfs_inode;
5489 struct btrfs_key key;
5490 struct btrfs_key found_key;
5491 u64 next_index;
5492 bool continue_curr_inode = true;
5493 int iter_ret;
5494
5495 key.objectid = ino;
5496 key.type = BTRFS_DIR_INDEX_KEY;
5497 key.offset = btrfs_get_first_dir_index_to_log(curr_inode);
5498 next_index = key.offset;
5499 again:
5500 btrfs_for_each_slot(root->log_root, &key, &found_key, path, iter_ret) {
5501 struct extent_buffer *leaf = path->nodes[0];
5502 struct btrfs_dir_item *di;
5503 struct btrfs_key di_key;
5504 struct inode *di_inode;
5505 int log_mode = LOG_INODE_EXISTS;
5506 int type;
5507
5508 if (found_key.objectid != ino ||
5509 found_key.type != BTRFS_DIR_INDEX_KEY) {
5510 continue_curr_inode = false;
5511 break;
5512 }
5513
5514 next_index = found_key.offset + 1;
5515
5516 di = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
5517 type = btrfs_dir_ftype(leaf, di);
5518 if (btrfs_dir_transid(leaf, di) < trans->transid)
5519 continue;
5520 btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
5521 if (di_key.type == BTRFS_ROOT_ITEM_KEY)
5522 continue;
5523
5524 btrfs_release_path(path);
5525 di_inode = btrfs_iget_logging(di_key.objectid, root);
5526 if (IS_ERR(di_inode)) {
5527 ret = PTR_ERR(di_inode);
5528 goto out;
5529 }
5530
5531 if (!need_log_inode(trans, BTRFS_I(di_inode))) {
5532 btrfs_add_delayed_iput(BTRFS_I(di_inode));
5533 break;
5534 }
5535
5536 ctx->log_new_dentries = false;
5537 if (type == BTRFS_FT_DIR)
5538 log_mode = LOG_INODE_ALL;
5539 ret = btrfs_log_inode(trans, BTRFS_I(di_inode),
5540 log_mode, ctx);
5541 btrfs_add_delayed_iput(BTRFS_I(di_inode));
5542 if (ret)
5543 goto out;
5544 if (ctx->log_new_dentries) {
5545 dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
5546 if (!dir_elem) {
5547 ret = -ENOMEM;
5548 goto out;
5549 }
5550 dir_elem->ino = di_key.objectid;
5551 list_add_tail(&dir_elem->list, &dir_list);
5552 }
5553 break;
5554 }
5555
5556 btrfs_release_path(path);
5557
5558 if (iter_ret < 0) {
5559 ret = iter_ret;
5560 goto out;
5561 } else if (iter_ret > 0) {
5562 continue_curr_inode = false;
5563 } else {
5564 key = found_key;
5565 }
5566
5567 if (continue_curr_inode && key.offset < (u64)-1) {
5568 key.offset++;
5569 goto again;
5570 }
5571
5572 btrfs_set_first_dir_index_to_log(curr_inode, next_index);
5573
5574 if (list_empty(&dir_list))
5575 break;
5576
5577 dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, list);
5578 ino = dir_elem->ino;
5579 list_del(&dir_elem->list);
5580 kfree(dir_elem);
5581
5582 btrfs_add_delayed_iput(curr_inode);
5583 curr_inode = NULL;
5584
5585 vfs_inode = btrfs_iget_logging(ino, root);
5586 if (IS_ERR(vfs_inode)) {
5587 ret = PTR_ERR(vfs_inode);
5588 break;
5589 }
5590 curr_inode = BTRFS_I(vfs_inode);
5591 }
5592 out:
5593 btrfs_free_path(path);
5594 if (curr_inode)
5595 btrfs_add_delayed_iput(curr_inode);
5596
5597 if (ret) {
5598 struct btrfs_dir_list *next;
5599
5600 list_for_each_entry_safe(dir_elem, next, &dir_list, list)
5601 kfree(dir_elem);
5602 }
5603
5604 return ret;
5605 }
5606
5607 struct btrfs_ino_list {
5608 u64 ino;
5609 u64 parent;
5610 struct list_head list;
5611 };
5612
5613 static void free_conflicting_inodes(struct btrfs_log_ctx *ctx)
5614 {
5615 struct btrfs_ino_list *curr;
5616 struct btrfs_ino_list *next;
5617
5618 list_for_each_entry_safe(curr, next, &ctx->conflict_inodes, list) {
5619 list_del(&curr->list);
5620 kfree(curr);
5621 }
5622 }
5623
5624 static int conflicting_inode_is_dir(struct btrfs_root *root, u64 ino,
5625 struct btrfs_path *path)
5626 {
5627 struct btrfs_key key;
5628 int ret;
5629
5630 key.objectid = ino;
5631 key.type = BTRFS_INODE_ITEM_KEY;
5632 key.offset = 0;
5633
5634 path->search_commit_root = 1;
5635 path->skip_locking = 1;
5636
5637 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5638 if (WARN_ON_ONCE(ret > 0)) {
5639 /*
5640 * We have previously found the inode through the commit root
5641 * so this should not happen. If it does, just error out and
5642 * fallback to a transaction commit.
5643 */
5644 ret = -ENOENT;
5645 } else if (ret == 0) {
5646 struct btrfs_inode_item *item;
5647
5648 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5649 struct btrfs_inode_item);
5650 if (S_ISDIR(btrfs_inode_mode(path->nodes[0], item)))
5651 ret = 1;
5652 }
5653
5654 btrfs_release_path(path);
5655 path->search_commit_root = 0;
5656 path->skip_locking = 0;
5657
5658 return ret;
5659 }
5660
5661 static int add_conflicting_inode(struct btrfs_trans_handle *trans,
5662 struct btrfs_root *root,
5663 struct btrfs_path *path,
5664 u64 ino, u64 parent,
5665 struct btrfs_log_ctx *ctx)
5666 {
5667 struct btrfs_ino_list *ino_elem;
5668 struct inode *inode;
5669
5670 /*
5671 * It's rare to have a lot of conflicting inodes, in practice it is not
5672 * common to have more than 1 or 2. We don't want to collect too many,
5673 * as we could end up logging too many inodes (even if only in
5674 * LOG_INODE_EXISTS mode) and slow down other fsyncs or transaction
5675 * commits.
5676 */
5677 if (ctx->num_conflict_inodes >= MAX_CONFLICT_INODES)
5678 return BTRFS_LOG_FORCE_COMMIT;
5679
5680 inode = btrfs_iget_logging(ino, root);
5681 /*
5682 * If the other inode that had a conflicting dir entry was deleted in
5683 * the current transaction then we either:
5684 *
5685 * 1) Log the parent directory (later after adding it to the list) if
5686 * the inode is a directory. This is because it may be a deleted
5687 * subvolume/snapshot or it may be a regular directory that had
5688 * deleted subvolumes/snapshots (or subdirectories that had them),
5689 * and at the moment we can't deal with dropping subvolumes/snapshots
5690 * during log replay. So we just log the parent, which will result in
5691 * a fallback to a transaction commit if we are dealing with those
5692 * cases (last_unlink_trans will match the current transaction);
5693 *
5694 * 2) Do nothing if it's not a directory. During log replay we simply
5695 * unlink the conflicting dentry from the parent directory and then
5696 * add the dentry for our inode. Like this we can avoid logging the
5697 * parent directory (and maybe fallback to a transaction commit in
5698 * case it has a last_unlink_trans == trans->transid, due to moving
5699 * some inode from it to some other directory).
5700 */
5701 if (IS_ERR(inode)) {
5702 int ret = PTR_ERR(inode);
5703
5704 if (ret != -ENOENT)
5705 return ret;
5706
5707 ret = conflicting_inode_is_dir(root, ino, path);
5708 /* Not a directory or we got an error. */
5709 if (ret <= 0)
5710 return ret;
5711
5712 /* Conflicting inode is a directory, so we'll log its parent. */
5713 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
5714 if (!ino_elem)
5715 return -ENOMEM;
5716 ino_elem->ino = ino;
5717 ino_elem->parent = parent;
5718 list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
5719 ctx->num_conflict_inodes++;
5720
5721 return 0;
5722 }
5723
5724 /*
5725 * If the inode was already logged skip it - otherwise we can hit an
5726 * infinite loop. Example:
5727 *
5728 * From the commit root (previous transaction) we have the following
5729 * inodes:
5730 *
5731 * inode 257 a directory
5732 * inode 258 with references "zz" and "zz_link" on inode 257
5733 * inode 259 with reference "a" on inode 257
5734 *
5735 * And in the current (uncommitted) transaction we have:
5736 *
5737 * inode 257 a directory, unchanged
5738 * inode 258 with references "a" and "a2" on inode 257
5739 * inode 259 with reference "zz_link" on inode 257
5740 * inode 261 with reference "zz" on inode 257
5741 *
5742 * When logging inode 261 the following infinite loop could
5743 * happen if we don't skip already logged inodes:
5744 *
5745 * - we detect inode 258 as a conflicting inode, with inode 261
5746 * on reference "zz", and log it;
5747 *
5748 * - we detect inode 259 as a conflicting inode, with inode 258
5749 * on reference "a", and log it;
5750 *
5751 * - we detect inode 258 as a conflicting inode, with inode 259
5752 * on reference "zz_link", and log it - again! After this we
5753 * repeat the above steps forever.
5754 *
5755 * Here we can use need_log_inode() because we only need to log the
5756 * inode in LOG_INODE_EXISTS mode and rename operations update the log,
5757 * so that the log ends up with the new name and without the old name.
5758 */
5759 if (!need_log_inode(trans, BTRFS_I(inode))) {
5760 btrfs_add_delayed_iput(BTRFS_I(inode));
5761 return 0;
5762 }
5763
5764 btrfs_add_delayed_iput(BTRFS_I(inode));
5765
5766 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
5767 if (!ino_elem)
5768 return -ENOMEM;
5769 ino_elem->ino = ino;
5770 ino_elem->parent = parent;
5771 list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
5772 ctx->num_conflict_inodes++;
5773
5774 return 0;
5775 }
5776
5777 static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
5778 struct btrfs_root *root,
5779 struct btrfs_log_ctx *ctx)
5780 {
5781 int ret = 0;
5782
5783 /*
5784 * Conflicting inodes are logged by the first call to btrfs_log_inode(),
5785 * otherwise we could have unbounded recursion of btrfs_log_inode()
5786 * calls. This check guarantees we can have only 1 level of recursion.
5787 */
5788 if (ctx->logging_conflict_inodes)
5789 return 0;
5790
5791 ctx->logging_conflict_inodes = true;
5792
5793 /*
5794 * New conflicting inodes may be found and added to the list while we
5795 * are logging a conflicting inode, so keep iterating while the list is
5796 * not empty.
5797 */
5798 while (!list_empty(&ctx->conflict_inodes)) {
5799 struct btrfs_ino_list *curr;
5800 struct inode *inode;
5801 u64 ino;
5802 u64 parent;
5803
5804 curr = list_first_entry(&ctx->conflict_inodes,
5805 struct btrfs_ino_list, list);
5806 ino = curr->ino;
5807 parent = curr->parent;
5808 list_del(&curr->list);
5809 kfree(curr);
5810
5811 inode = btrfs_iget_logging(ino, root);
5812 /*
5813 * If the other inode that had a conflicting dir entry was
5814 * deleted in the current transaction, we need to log its parent
5815 * directory. See the comment at add_conflicting_inode().
5816 */
5817 if (IS_ERR(inode)) {
5818 ret = PTR_ERR(inode);
5819 if (ret != -ENOENT)
5820 break;
5821
5822 inode = btrfs_iget_logging(parent, root);
5823 if (IS_ERR(inode)) {
5824 ret = PTR_ERR(inode);
5825 break;
5826 }
5827
5828 /*
5829 * Always log the directory, we cannot make this
5830 * conditional on need_log_inode() because the directory
5831 * might have been logged in LOG_INODE_EXISTS mode or
5832 * the dir index of the conflicting inode is not in a
5833 * dir index key range logged for the directory. So we
5834 * must make sure the deletion is recorded.
5835 */
5836 ret = btrfs_log_inode(trans, BTRFS_I(inode),
5837 LOG_INODE_ALL, ctx);
5838 btrfs_add_delayed_iput(BTRFS_I(inode));
5839 if (ret)
5840 break;
5841 continue;
5842 }
5843
5844 /*
5845 * Here we can use need_log_inode() because we only need to log
5846 * the inode in LOG_INODE_EXISTS mode and rename operations
5847 * update the log, so that the log ends up with the new name and
5848 * without the old name.
5849 *
5850 * We did this check at add_conflicting_inode(), but here we do
5851 * it again because if some other task logged the inode after
5852 * that, we can avoid doing it again.
5853 */
5854 if (!need_log_inode(trans, BTRFS_I(inode))) {
5855 btrfs_add_delayed_iput(BTRFS_I(inode));
5856 continue;
5857 }
5858
5859 /*
5860 * We are safe logging the other inode without acquiring its
5861 * lock as long as we log with the LOG_INODE_EXISTS mode. We
5862 * are safe against concurrent renames of the other inode as
5863 * well because during a rename we pin the log and update the
5864 * log with the new name before we unpin it.
5865 */
5866 ret = btrfs_log_inode(trans, BTRFS_I(inode), LOG_INODE_EXISTS, ctx);
5867 btrfs_add_delayed_iput(BTRFS_I(inode));
5868 if (ret)
5869 break;
5870 }
5871
5872 ctx->logging_conflict_inodes = false;
5873 if (ret)
5874 free_conflicting_inodes(ctx);
5875
5876 return ret;
5877 }
5878
5879 static int copy_inode_items_to_log(struct btrfs_trans_handle *trans,
5880 struct btrfs_inode *inode,
5881 struct btrfs_key *min_key,
5882 const struct btrfs_key *max_key,
5883 struct btrfs_path *path,
5884 struct btrfs_path *dst_path,
5885 const u64 logged_isize,
5886 const int inode_only,
5887 struct btrfs_log_ctx *ctx,
5888 bool *need_log_inode_item)
5889 {
5890 const u64 i_size = i_size_read(&inode->vfs_inode);
5891 struct btrfs_root *root = inode->root;
5892 int ins_start_slot = 0;
5893 int ins_nr = 0;
5894 int ret;
5895
5896 while (1) {
5897 ret = btrfs_search_forward(root, min_key, path, trans->transid);
5898 if (ret < 0)
5899 return ret;
5900 if (ret > 0) {
5901 ret = 0;
5902 break;
5903 }
5904 again:
5905 /* Note, ins_nr might be > 0 here, cleanup outside the loop */
5906 if (min_key->objectid != max_key->objectid)
5907 break;
5908 if (min_key->type > max_key->type)
5909 break;
5910
5911 if (min_key->type == BTRFS_INODE_ITEM_KEY) {
5912 *need_log_inode_item = false;
5913 } else if (min_key->type == BTRFS_EXTENT_DATA_KEY &&
5914 min_key->offset >= i_size) {
5915 /*
5916 * Extents at and beyond eof are logged with
5917 * btrfs_log_prealloc_extents().
5918 * Only regular files have BTRFS_EXTENT_DATA_KEY keys,
5919 * and no keys greater than that, so bail out.
5920 */
5921 break;
5922 } else if ((min_key->type == BTRFS_INODE_REF_KEY ||
5923 min_key->type == BTRFS_INODE_EXTREF_KEY) &&
5924 (inode->generation == trans->transid ||
5925 ctx->logging_conflict_inodes)) {
5926 u64 other_ino = 0;
5927 u64 other_parent = 0;
5928
5929 ret = btrfs_check_ref_name_override(path->nodes[0],
5930 path->slots[0], min_key, inode,
5931 &other_ino, &other_parent);
5932 if (ret < 0) {
5933 return ret;
5934 } else if (ret > 0 &&
5935 other_ino != btrfs_ino(ctx->inode)) {
5936 if (ins_nr > 0) {
5937 ins_nr++;
5938 } else {
5939 ins_nr = 1;
5940 ins_start_slot = path->slots[0];
5941 }
5942 ret = copy_items(trans, inode, dst_path, path,
5943 ins_start_slot, ins_nr,
5944 inode_only, logged_isize, ctx);
5945 if (ret < 0)
5946 return ret;
5947 ins_nr = 0;
5948
5949 btrfs_release_path(path);
5950 ret = add_conflicting_inode(trans, root, path,
5951 other_ino,
5952 other_parent, ctx);
5953 if (ret)
5954 return ret;
5955 goto next_key;
5956 }
5957 } else if (min_key->type == BTRFS_XATTR_ITEM_KEY) {
5958 /* Skip xattrs, logged later with btrfs_log_all_xattrs() */
5959 if (ins_nr == 0)
5960 goto next_slot;
5961 ret = copy_items(trans, inode, dst_path, path,
5962 ins_start_slot,
5963 ins_nr, inode_only, logged_isize, ctx);
5964 if (ret < 0)
5965 return ret;
5966 ins_nr = 0;
5967 goto next_slot;
5968 }
5969
5970 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
5971 ins_nr++;
5972 goto next_slot;
5973 } else if (!ins_nr) {
5974 ins_start_slot = path->slots[0];
5975 ins_nr = 1;
5976 goto next_slot;
5977 }
5978
5979 ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
5980 ins_nr, inode_only, logged_isize, ctx);
5981 if (ret < 0)
5982 return ret;
5983 ins_nr = 1;
5984 ins_start_slot = path->slots[0];
5985 next_slot:
5986 path->slots[0]++;
5987 if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
5988 btrfs_item_key_to_cpu(path->nodes[0], min_key,
5989 path->slots[0]);
5990 goto again;
5991 }
5992 if (ins_nr) {
5993 ret = copy_items(trans, inode, dst_path, path,
5994 ins_start_slot, ins_nr, inode_only,
5995 logged_isize, ctx);
5996 if (ret < 0)
5997 return ret;
5998 ins_nr = 0;
5999 }
6000 btrfs_release_path(path);
6001 next_key:
6002 if (min_key->offset < (u64)-1) {
6003 min_key->offset++;
6004 } else if (min_key->type < max_key->type) {
6005 min_key->type++;
6006 min_key->offset = 0;
6007 } else {
6008 break;
6009 }
6010
6011 /*
6012 * We may process many leaves full of items for our inode, so
6013 * avoid monopolizing a cpu for too long by rescheduling while
6014 * not holding locks on any tree.
6015 */
6016 cond_resched();
6017 }
6018 if (ins_nr) {
6019 ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
6020 ins_nr, inode_only, logged_isize, ctx);
6021 if (ret)
6022 return ret;
6023 }
6024
6025 if (inode_only == LOG_INODE_ALL && S_ISREG(inode->vfs_inode.i_mode)) {
6026 /*
6027 * Release the path because otherwise we might attempt to double
6028 * lock the same leaf with btrfs_log_prealloc_extents() below.
6029 */
6030 btrfs_release_path(path);
6031 ret = btrfs_log_prealloc_extents(trans, inode, dst_path, ctx);
6032 }
6033
6034 return ret;
6035 }
6036
6037 static int insert_delayed_items_batch(struct btrfs_trans_handle *trans,
6038 struct btrfs_root *log,
6039 struct btrfs_path *path,
6040 const struct btrfs_item_batch *batch,
6041 const struct btrfs_delayed_item *first_item)
6042 {
6043 const struct btrfs_delayed_item *curr = first_item;
6044 int ret;
6045
6046 ret = btrfs_insert_empty_items(trans, log, path, batch);
6047 if (ret)
6048 return ret;
6049
6050 for (int i = 0; i < batch->nr; i++) {
6051 char *data_ptr;
6052
6053 data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
6054 write_extent_buffer(path->nodes[0], &curr->data,
6055 (unsigned long)data_ptr, curr->data_len);
6056 curr = list_next_entry(curr, log_list);
6057 path->slots[0]++;
6058 }
6059
6060 btrfs_release_path(path);
6061
6062 return 0;
6063 }
6064
6065 static int log_delayed_insertion_items(struct btrfs_trans_handle *trans,
6066 struct btrfs_inode *inode,
6067 struct btrfs_path *path,
6068 const struct list_head *delayed_ins_list,
6069 struct btrfs_log_ctx *ctx)
6070 {
6071 /* 195 (4095 bytes of keys and sizes) fits in a single 4K page. */
6072 const int max_batch_size = 195;
6073 const int leaf_data_size = BTRFS_LEAF_DATA_SIZE(trans->fs_info);
6074 const u64 ino = btrfs_ino(inode);
6075 struct btrfs_root *log = inode->root->log_root;
6076 struct btrfs_item_batch batch = {
6077 .nr = 0,
6078 .total_data_size = 0,
6079 };
6080 const struct btrfs_delayed_item *first = NULL;
6081 const struct btrfs_delayed_item *curr;
6082 char *ins_data;
6083 struct btrfs_key *ins_keys;
6084 u32 *ins_sizes;
6085 u64 curr_batch_size = 0;
6086 int batch_idx = 0;
6087 int ret;
6088
6089 /* We are adding dir index items to the log tree. */
6090 lockdep_assert_held(&inode->log_mutex);
6091
6092 /*
6093 * We collect delayed items before copying index keys from the subvolume
6094 * to the log tree. However just after we collected them, they may have
6095 * been flushed (all of them or just some of them), and therefore we
6096 * could have copied them from the subvolume tree to the log tree.
6097 * So find the first delayed item that was not yet logged (they are
6098 * sorted by index number).
6099 */
6100 list_for_each_entry(curr, delayed_ins_list, log_list) {
6101 if (curr->index > inode->last_dir_index_offset) {
6102 first = curr;
6103 break;
6104 }
6105 }
6106
6107 /* Empty list or all delayed items were already logged. */
6108 if (!first)
6109 return 0;
6110
6111 ins_data = kmalloc(max_batch_size * sizeof(u32) +
6112 max_batch_size * sizeof(struct btrfs_key), GFP_NOFS);
6113 if (!ins_data)
6114 return -ENOMEM;
6115 ins_sizes = (u32 *)ins_data;
6116 batch.data_sizes = ins_sizes;
6117 ins_keys = (struct btrfs_key *)(ins_data + max_batch_size * sizeof(u32));
6118 batch.keys = ins_keys;
6119
6120 curr = first;
6121 while (!list_entry_is_head(curr, delayed_ins_list, log_list)) {
6122 const u32 curr_size = curr->data_len + sizeof(struct btrfs_item);
6123
6124 if (curr_batch_size + curr_size > leaf_data_size ||
6125 batch.nr == max_batch_size) {
6126 ret = insert_delayed_items_batch(trans, log, path,
6127 &batch, first);
6128 if (ret)
6129 goto out;
6130 batch_idx = 0;
6131 batch.nr = 0;
6132 batch.total_data_size = 0;
6133 curr_batch_size = 0;
6134 first = curr;
6135 }
6136
6137 ins_sizes[batch_idx] = curr->data_len;
6138 ins_keys[batch_idx].objectid = ino;
6139 ins_keys[batch_idx].type = BTRFS_DIR_INDEX_KEY;
6140 ins_keys[batch_idx].offset = curr->index;
6141 curr_batch_size += curr_size;
6142 batch.total_data_size += curr->data_len;
6143 batch.nr++;
6144 batch_idx++;
6145 curr = list_next_entry(curr, log_list);
6146 }
6147
6148 ASSERT(batch.nr >= 1);
6149 ret = insert_delayed_items_batch(trans, log, path, &batch, first);
6150
6151 curr = list_last_entry(delayed_ins_list, struct btrfs_delayed_item,
6152 log_list);
6153 inode->last_dir_index_offset = curr->index;
6154 out:
6155 kfree(ins_data);
6156
6157 return ret;
6158 }
6159
6160 static int log_delayed_deletions_full(struct btrfs_trans_handle *trans,
6161 struct btrfs_inode *inode,
6162 struct btrfs_path *path,
6163 const struct list_head *delayed_del_list,
6164 struct btrfs_log_ctx *ctx)
6165 {
6166 const u64 ino = btrfs_ino(inode);
6167 const struct btrfs_delayed_item *curr;
6168
6169 curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
6170 log_list);
6171
6172 while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
6173 u64 first_dir_index = curr->index;
6174 u64 last_dir_index;
6175 const struct btrfs_delayed_item *next;
6176 int ret;
6177
6178 /*
6179 * Find a range of consecutive dir index items to delete. Like
6180 * this we log a single dir range item spanning several contiguous
6181 * dir items instead of logging one range item per dir index item.
6182 */
6183 next = list_next_entry(curr, log_list);
6184 while (!list_entry_is_head(next, delayed_del_list, log_list)) {
6185 if (next->index != curr->index + 1)
6186 break;
6187 curr = next;
6188 next = list_next_entry(next, log_list);
6189 }
6190
6191 last_dir_index = curr->index;
6192 ASSERT(last_dir_index >= first_dir_index);
6193
6194 ret = insert_dir_log_key(trans, inode->root->log_root, path,
6195 ino, first_dir_index, last_dir_index);
6196 if (ret)
6197 return ret;
6198 curr = list_next_entry(curr, log_list);
6199 }
6200
6201 return 0;
6202 }
6203
6204 static int batch_delete_dir_index_items(struct btrfs_trans_handle *trans,
6205 struct btrfs_inode *inode,
6206 struct btrfs_path *path,
6207 struct btrfs_log_ctx *ctx,
6208 const struct list_head *delayed_del_list,
6209 const struct btrfs_delayed_item *first,
6210 const struct btrfs_delayed_item **last_ret)
6211 {
6212 const struct btrfs_delayed_item *next;
6213 struct extent_buffer *leaf = path->nodes[0];
6214 const int last_slot = btrfs_header_nritems(leaf) - 1;
6215 int slot = path->slots[0] + 1;
6216 const u64 ino = btrfs_ino(inode);
6217
6218 next = list_next_entry(first, log_list);
6219
6220 while (slot < last_slot &&
6221 !list_entry_is_head(next, delayed_del_list, log_list)) {
6222 struct btrfs_key key;
6223
6224 btrfs_item_key_to_cpu(leaf, &key, slot);
6225 if (key.objectid != ino ||
6226 key.type != BTRFS_DIR_INDEX_KEY ||
6227 key.offset != next->index)
6228 break;
6229
6230 slot++;
6231 *last_ret = next;
6232 next = list_next_entry(next, log_list);
6233 }
6234
6235 return btrfs_del_items(trans, inode->root->log_root, path,
6236 path->slots[0], slot - path->slots[0]);
6237 }
6238
6239 static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans,
6240 struct btrfs_inode *inode,
6241 struct btrfs_path *path,
6242 const struct list_head *delayed_del_list,
6243 struct btrfs_log_ctx *ctx)
6244 {
6245 struct btrfs_root *log = inode->root->log_root;
6246 const struct btrfs_delayed_item *curr;
6247 u64 last_range_start = 0;
6248 u64 last_range_end = 0;
6249 struct btrfs_key key;
6250
6251 key.objectid = btrfs_ino(inode);
6252 key.type = BTRFS_DIR_INDEX_KEY;
6253 curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
6254 log_list);
6255
6256 while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
6257 const struct btrfs_delayed_item *last = curr;
6258 u64 first_dir_index = curr->index;
6259 u64 last_dir_index;
6260 bool deleted_items = false;
6261 int ret;
6262
6263 key.offset = curr->index;
6264 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
6265 if (ret < 0) {
6266 return ret;
6267 } else if (ret == 0) {
6268 ret = batch_delete_dir_index_items(trans, inode, path, ctx,
6269 delayed_del_list, curr,
6270 &last);
6271 if (ret)
6272 return ret;
6273 deleted_items = true;
6274 }
6275
6276 btrfs_release_path(path);
6277
6278 /*
6279 * If we deleted items from the leaf, it means we have a range
6280 * item logging their range, so no need to add one or update an
6281 * existing one. Otherwise we have to log a dir range item.
6282 */
6283 if (deleted_items)
6284 goto next_batch;
6285
6286 last_dir_index = last->index;
6287 ASSERT(last_dir_index >= first_dir_index);
6288 /*
6289 * If this range starts right after where the previous one ends,
6290 * then we want to reuse the previous range item and change its
6291 * end offset to the end of this range. This is just to minimize
6292 * leaf space usage, by avoiding adding a new range item.
6293 */
6294 if (last_range_end != 0 && first_dir_index == last_range_end + 1)
6295 first_dir_index = last_range_start;
6296
6297 ret = insert_dir_log_key(trans, log, path, key.objectid,
6298 first_dir_index, last_dir_index);
6299 if (ret)
6300 return ret;
6301
6302 last_range_start = first_dir_index;
6303 last_range_end = last_dir_index;
6304 next_batch:
6305 curr = list_next_entry(last, log_list);
6306 }
6307
6308 return 0;
6309 }
6310
6311 static int log_delayed_deletion_items(struct btrfs_trans_handle *trans,
6312 struct btrfs_inode *inode,
6313 struct btrfs_path *path,
6314 const struct list_head *delayed_del_list,
6315 struct btrfs_log_ctx *ctx)
6316 {
6317 /*
6318 * We are deleting dir index items from the log tree or adding range
6319 * items to it.
6320 */
6321 lockdep_assert_held(&inode->log_mutex);
6322
6323 if (list_empty(delayed_del_list))
6324 return 0;
6325
6326 if (ctx->logged_before)
6327 return log_delayed_deletions_incremental(trans, inode, path,
6328 delayed_del_list, ctx);
6329
6330 return log_delayed_deletions_full(trans, inode, path, delayed_del_list,
6331 ctx);
6332 }
6333
6334 /*
6335 * Similar logic as for log_new_dir_dentries(), but it iterates over the delayed
6336 * items instead of the subvolume tree.
6337 */
6338 static int log_new_delayed_dentries(struct btrfs_trans_handle *trans,
6339 struct btrfs_inode *inode,
6340 const struct list_head *delayed_ins_list,
6341 struct btrfs_log_ctx *ctx)
6342 {
6343 const bool orig_log_new_dentries = ctx->log_new_dentries;
6344 struct btrfs_delayed_item *item;
6345 int ret = 0;
6346
6347 /*
6348 * No need for the log mutex, plus to avoid potential deadlocks or
6349 * lockdep annotations due to nesting of delayed inode mutexes and log
6350 * mutexes.
6351 */
6352 lockdep_assert_not_held(&inode->log_mutex);
6353
6354 ASSERT(!ctx->logging_new_delayed_dentries);
6355 ctx->logging_new_delayed_dentries = true;
6356
6357 list_for_each_entry(item, delayed_ins_list, log_list) {
6358 struct btrfs_dir_item *dir_item;
6359 struct inode *di_inode;
6360 struct btrfs_key key;
6361 int log_mode = LOG_INODE_EXISTS;
6362
6363 dir_item = (struct btrfs_dir_item *)item->data;
6364 btrfs_disk_key_to_cpu(&key, &dir_item->location);
6365
6366 if (key.type == BTRFS_ROOT_ITEM_KEY)
6367 continue;
6368
6369 di_inode = btrfs_iget_logging(key.objectid, inode->root);
6370 if (IS_ERR(di_inode)) {
6371 ret = PTR_ERR(di_inode);
6372 break;
6373 }
6374
6375 if (!need_log_inode(trans, BTRFS_I(di_inode))) {
6376 btrfs_add_delayed_iput(BTRFS_I(di_inode));
6377 continue;
6378 }
6379
6380 if (btrfs_stack_dir_ftype(dir_item) == BTRFS_FT_DIR)
6381 log_mode = LOG_INODE_ALL;
6382
6383 ctx->log_new_dentries = false;
6384 ret = btrfs_log_inode(trans, BTRFS_I(di_inode), log_mode, ctx);
6385
6386 if (!ret && ctx->log_new_dentries)
6387 ret = log_new_dir_dentries(trans, BTRFS_I(di_inode), ctx);
6388
6389 btrfs_add_delayed_iput(BTRFS_I(di_inode));
6390
6391 if (ret)
6392 break;
6393 }
6394
6395 ctx->log_new_dentries = orig_log_new_dentries;
6396 ctx->logging_new_delayed_dentries = false;
6397
6398 return ret;
6399 }
6400
6401 /* log a single inode in the tree log.
6402 * At least one parent directory for this inode must exist in the tree
6403 * or be logged already.
6404 *
6405 * Any items from this inode changed by the current transaction are copied
6406 * to the log tree. An extra reference is taken on any extents in this
6407 * file, allowing us to avoid a whole pile of corner cases around logging
6408 * blocks that have been removed from the tree.
6409 *
6410 * See LOG_INODE_ALL and related defines for a description of what inode_only
6411 * does.
6412 *
6413 * This handles both files and directories.
6414 */
6415 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
6416 struct btrfs_inode *inode,
6417 int inode_only,
6418 struct btrfs_log_ctx *ctx)
6419 {
6420 struct btrfs_path *path;
6421 struct btrfs_path *dst_path;
6422 struct btrfs_key min_key;
6423 struct btrfs_key max_key;
6424 struct btrfs_root *log = inode->root->log_root;
6425 int ret;
6426 bool fast_search = false;
6427 u64 ino = btrfs_ino(inode);
6428 struct extent_map_tree *em_tree = &inode->extent_tree;
6429 u64 logged_isize = 0;
6430 bool need_log_inode_item = true;
6431 bool xattrs_logged = false;
6432 bool inode_item_dropped = true;
6433 bool full_dir_logging = false;
6434 LIST_HEAD(delayed_ins_list);
6435 LIST_HEAD(delayed_del_list);
6436
6437 path = btrfs_alloc_path();
6438 if (!path)
6439 return -ENOMEM;
6440 dst_path = btrfs_alloc_path();
6441 if (!dst_path) {
6442 btrfs_free_path(path);
6443 return -ENOMEM;
6444 }
6445
6446 min_key.objectid = ino;
6447 min_key.type = BTRFS_INODE_ITEM_KEY;
6448 min_key.offset = 0;
6449
6450 max_key.objectid = ino;
6451
6452
6453 /* today the code can only do partial logging of directories */
6454 if (S_ISDIR(inode->vfs_inode.i_mode) ||
6455 (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
6456 &inode->runtime_flags) &&
6457 inode_only >= LOG_INODE_EXISTS))
6458 max_key.type = BTRFS_XATTR_ITEM_KEY;
6459 else
6460 max_key.type = (u8)-1;
6461 max_key.offset = (u64)-1;
6462
6463 if (S_ISDIR(inode->vfs_inode.i_mode) && inode_only == LOG_INODE_ALL)
6464 full_dir_logging = true;
6465
6466 /*
6467 * If we are logging a directory while we are logging dentries of the
6468 * delayed items of some other inode, then we need to flush the delayed
6469 * items of this directory and not log the delayed items directly. This
6470 * is to prevent more than one level of recursion into btrfs_log_inode()
6471 * by having something like this:
6472 *
6473 * $ mkdir -p a/b/c/d/e/f/g/h/...
6474 * $ xfs_io -c "fsync" a
6475 *
6476 * Where all directories in the path did not exist before and are
6477 * created in the current transaction.
6478 * So in such a case we directly log the delayed items of the main
6479 * directory ("a") without flushing them first, while for each of its
6480 * subdirectories we flush their delayed items before logging them.
6481 * This prevents a potential unbounded recursion like this:
6482 *
6483 * btrfs_log_inode()
6484 * log_new_delayed_dentries()
6485 * btrfs_log_inode()
6486 * log_new_delayed_dentries()
6487 * btrfs_log_inode()
6488 * log_new_delayed_dentries()
6489 * (...)
6490 *
6491 * We have thresholds for the maximum number of delayed items to have in
6492 * memory, and once they are hit, the items are flushed asynchronously.
6493 * However the limit is quite high, so lets prevent deep levels of
6494 * recursion to happen by limiting the maximum depth to be 1.
6495 */
6496 if (full_dir_logging && ctx->logging_new_delayed_dentries) {
6497 ret = btrfs_commit_inode_delayed_items(trans, inode);
6498 if (ret)
6499 goto out;
6500 }
6501
6502 mutex_lock(&inode->log_mutex);
6503
6504 /*
6505 * For symlinks, we must always log their content, which is stored in an
6506 * inline extent, otherwise we could end up with an empty symlink after
6507 * log replay, which is invalid on linux (symlink(2) returns -ENOENT if
6508 * one attempts to create an empty symlink).
6509 * We don't need to worry about flushing delalloc, because when we create
6510 * the inline extent when the symlink is created (we never have delalloc
6511 * for symlinks).
6512 */
6513 if (S_ISLNK(inode->vfs_inode.i_mode))
6514 inode_only = LOG_INODE_ALL;
6515
6516 /*
6517 * Before logging the inode item, cache the value returned by
6518 * inode_logged(), because after that we have the need to figure out if
6519 * the inode was previously logged in this transaction.
6520 */
6521 ret = inode_logged(trans, inode, path);
6522 if (ret < 0)
6523 goto out_unlock;
6524 ctx->logged_before = (ret == 1);
6525 ret = 0;
6526
6527 /*
6528 * This is for cases where logging a directory could result in losing a
6529 * a file after replaying the log. For example, if we move a file from a
6530 * directory A to a directory B, then fsync directory A, we have no way
6531 * to known the file was moved from A to B, so logging just A would
6532 * result in losing the file after a log replay.
6533 */
6534 if (full_dir_logging && inode->last_unlink_trans >= trans->transid) {
6535 ret = BTRFS_LOG_FORCE_COMMIT;
6536 goto out_unlock;
6537 }
6538
6539 /*
6540 * a brute force approach to making sure we get the most uptodate
6541 * copies of everything.
6542 */
6543 if (S_ISDIR(inode->vfs_inode.i_mode)) {
6544 clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
6545 if (ctx->logged_before)
6546 ret = drop_inode_items(trans, log, path, inode,
6547 BTRFS_XATTR_ITEM_KEY);
6548 } else {
6549 if (inode_only == LOG_INODE_EXISTS && ctx->logged_before) {
6550 /*
6551 * Make sure the new inode item we write to the log has
6552 * the same isize as the current one (if it exists).
6553 * This is necessary to prevent data loss after log
6554 * replay, and also to prevent doing a wrong expanding
6555 * truncate - for e.g. create file, write 4K into offset
6556 * 0, fsync, write 4K into offset 4096, add hard link,
6557 * fsync some other file (to sync log), power fail - if
6558 * we use the inode's current i_size, after log replay
6559 * we get a 8Kb file, with the last 4Kb extent as a hole
6560 * (zeroes), as if an expanding truncate happened,
6561 * instead of getting a file of 4Kb only.
6562 */
6563 ret = logged_inode_size(log, inode, path, &logged_isize);
6564 if (ret)
6565 goto out_unlock;
6566 }
6567 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
6568 &inode->runtime_flags)) {
6569 if (inode_only == LOG_INODE_EXISTS) {
6570 max_key.type = BTRFS_XATTR_ITEM_KEY;
6571 if (ctx->logged_before)
6572 ret = drop_inode_items(trans, log, path,
6573 inode, max_key.type);
6574 } else {
6575 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
6576 &inode->runtime_flags);
6577 clear_bit(BTRFS_INODE_COPY_EVERYTHING,
6578 &inode->runtime_flags);
6579 if (ctx->logged_before)
6580 ret = truncate_inode_items(trans, log,
6581 inode, 0, 0);
6582 }
6583 } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
6584 &inode->runtime_flags) ||
6585 inode_only == LOG_INODE_EXISTS) {
6586 if (inode_only == LOG_INODE_ALL)
6587 fast_search = true;
6588 max_key.type = BTRFS_XATTR_ITEM_KEY;
6589 if (ctx->logged_before)
6590 ret = drop_inode_items(trans, log, path, inode,
6591 max_key.type);
6592 } else {
6593 if (inode_only == LOG_INODE_ALL)
6594 fast_search = true;
6595 inode_item_dropped = false;
6596 goto log_extents;
6597 }
6598
6599 }
6600 if (ret)
6601 goto out_unlock;
6602
6603 /*
6604 * If we are logging a directory in full mode, collect the delayed items
6605 * before iterating the subvolume tree, so that we don't miss any new
6606 * dir index items in case they get flushed while or right after we are
6607 * iterating the subvolume tree.
6608 */
6609 if (full_dir_logging && !ctx->logging_new_delayed_dentries)
6610 btrfs_log_get_delayed_items(inode, &delayed_ins_list,
6611 &delayed_del_list);
6612
6613 ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
6614 path, dst_path, logged_isize,
6615 inode_only, ctx,
6616 &need_log_inode_item);
6617 if (ret)
6618 goto out_unlock;
6619
6620 btrfs_release_path(path);
6621 btrfs_release_path(dst_path);
6622 ret = btrfs_log_all_xattrs(trans, inode, path, dst_path, ctx);
6623 if (ret)
6624 goto out_unlock;
6625 xattrs_logged = true;
6626 if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
6627 btrfs_release_path(path);
6628 btrfs_release_path(dst_path);
6629 ret = btrfs_log_holes(trans, inode, path);
6630 if (ret)
6631 goto out_unlock;
6632 }
6633 log_extents:
6634 btrfs_release_path(path);
6635 btrfs_release_path(dst_path);
6636 if (need_log_inode_item) {
6637 ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
6638 if (ret)
6639 goto out_unlock;
6640 /*
6641 * If we are doing a fast fsync and the inode was logged before
6642 * in this transaction, we don't need to log the xattrs because
6643 * they were logged before. If xattrs were added, changed or
6644 * deleted since the last time we logged the inode, then we have
6645 * already logged them because the inode had the runtime flag
6646 * BTRFS_INODE_COPY_EVERYTHING set.
6647 */
6648 if (!xattrs_logged && inode->logged_trans < trans->transid) {
6649 ret = btrfs_log_all_xattrs(trans, inode, path, dst_path, ctx);
6650 if (ret)
6651 goto out_unlock;
6652 btrfs_release_path(path);
6653 }
6654 }
6655 if (fast_search) {
6656 ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx);
6657 if (ret)
6658 goto out_unlock;
6659 } else if (inode_only == LOG_INODE_ALL) {
6660 struct extent_map *em, *n;
6661
6662 write_lock(&em_tree->lock);
6663 list_for_each_entry_safe(em, n, &em_tree->modified_extents, list)
6664 list_del_init(&em->list);
6665 write_unlock(&em_tree->lock);
6666 }
6667
6668 if (full_dir_logging) {
6669 ret = log_directory_changes(trans, inode, path, dst_path, ctx);
6670 if (ret)
6671 goto out_unlock;
6672 ret = log_delayed_insertion_items(trans, inode, path,
6673 &delayed_ins_list, ctx);
6674 if (ret)
6675 goto out_unlock;
6676 ret = log_delayed_deletion_items(trans, inode, path,
6677 &delayed_del_list, ctx);
6678 if (ret)
6679 goto out_unlock;
6680 }
6681
6682 spin_lock(&inode->lock);
6683 inode->logged_trans = trans->transid;
6684 /*
6685 * Don't update last_log_commit if we logged that an inode exists.
6686 * We do this for three reasons:
6687 *
6688 * 1) We might have had buffered writes to this inode that were
6689 * flushed and had their ordered extents completed in this
6690 * transaction, but we did not previously log the inode with
6691 * LOG_INODE_ALL. Later the inode was evicted and after that
6692 * it was loaded again and this LOG_INODE_EXISTS log operation
6693 * happened. We must make sure that if an explicit fsync against
6694 * the inode is performed later, it logs the new extents, an
6695 * updated inode item, etc, and syncs the log. The same logic
6696 * applies to direct IO writes instead of buffered writes.
6697 *
6698 * 2) When we log the inode with LOG_INODE_EXISTS, its inode item
6699 * is logged with an i_size of 0 or whatever value was logged
6700 * before. If later the i_size of the inode is increased by a
6701 * truncate operation, the log is synced through an fsync of
6702 * some other inode and then finally an explicit fsync against
6703 * this inode is made, we must make sure this fsync logs the
6704 * inode with the new i_size, the hole between old i_size and
6705 * the new i_size, and syncs the log.
6706 *
6707 * 3) If we are logging that an ancestor inode exists as part of
6708 * logging a new name from a link or rename operation, don't update
6709 * its last_log_commit - otherwise if an explicit fsync is made
6710 * against an ancestor, the fsync considers the inode in the log
6711 * and doesn't sync the log, resulting in the ancestor missing after
6712 * a power failure unless the log was synced as part of an fsync
6713 * against any other unrelated inode.
6714 */
6715 if (inode_only != LOG_INODE_EXISTS)
6716 inode->last_log_commit = inode->last_sub_trans;
6717 spin_unlock(&inode->lock);
6718
6719 /*
6720 * Reset the last_reflink_trans so that the next fsync does not need to
6721 * go through the slower path when logging extents and their checksums.
6722 */
6723 if (inode_only == LOG_INODE_ALL)
6724 inode->last_reflink_trans = 0;
6725
6726 out_unlock:
6727 mutex_unlock(&inode->log_mutex);
6728 out:
6729 btrfs_free_path(path);
6730 btrfs_free_path(dst_path);
6731
6732 if (ret)
6733 free_conflicting_inodes(ctx);
6734 else
6735 ret = log_conflicting_inodes(trans, inode->root, ctx);
6736
6737 if (full_dir_logging && !ctx->logging_new_delayed_dentries) {
6738 if (!ret)
6739 ret = log_new_delayed_dentries(trans, inode,
6740 &delayed_ins_list, ctx);
6741
6742 btrfs_log_put_delayed_items(inode, &delayed_ins_list,
6743 &delayed_del_list);
6744 }
6745
6746 return ret;
6747 }
6748
6749 static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
6750 struct btrfs_inode *inode,
6751 struct btrfs_log_ctx *ctx)
6752 {
6753 int ret;
6754 struct btrfs_path *path;
6755 struct btrfs_key key;
6756 struct btrfs_root *root = inode->root;
6757 const u64 ino = btrfs_ino(inode);
6758
6759 path = btrfs_alloc_path();
6760 if (!path)
6761 return -ENOMEM;
6762 path->skip_locking = 1;
6763 path->search_commit_root = 1;
6764
6765 key.objectid = ino;
6766 key.type = BTRFS_INODE_REF_KEY;
6767 key.offset = 0;
6768 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6769 if (ret < 0)
6770 goto out;
6771
6772 while (true) {
6773 struct extent_buffer *leaf = path->nodes[0];
6774 int slot = path->slots[0];
6775 u32 cur_offset = 0;
6776 u32 item_size;
6777 unsigned long ptr;
6778
6779 if (slot >= btrfs_header_nritems(leaf)) {
6780 ret = btrfs_next_leaf(root, path);
6781 if (ret < 0)
6782 goto out;
6783 else if (ret > 0)
6784 break;
6785 continue;
6786 }
6787
6788 btrfs_item_key_to_cpu(leaf, &key, slot);
6789 /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
6790 if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
6791 break;
6792
6793 item_size = btrfs_item_size(leaf, slot);
6794 ptr = btrfs_item_ptr_offset(leaf, slot);
6795 while (cur_offset < item_size) {
6796 struct btrfs_key inode_key;
6797 struct inode *dir_inode;
6798
6799 inode_key.type = BTRFS_INODE_ITEM_KEY;
6800 inode_key.offset = 0;
6801
6802 if (key.type == BTRFS_INODE_EXTREF_KEY) {
6803 struct btrfs_inode_extref *extref;
6804
6805 extref = (struct btrfs_inode_extref *)
6806 (ptr + cur_offset);
6807 inode_key.objectid = btrfs_inode_extref_parent(
6808 leaf, extref);
6809 cur_offset += sizeof(*extref);
6810 cur_offset += btrfs_inode_extref_name_len(leaf,
6811 extref);
6812 } else {
6813 inode_key.objectid = key.offset;
6814 cur_offset = item_size;
6815 }
6816
6817 dir_inode = btrfs_iget_logging(inode_key.objectid, root);
6818 /*
6819 * If the parent inode was deleted, return an error to
6820 * fallback to a transaction commit. This is to prevent
6821 * getting an inode that was moved from one parent A to
6822 * a parent B, got its former parent A deleted and then
6823 * it got fsync'ed, from existing at both parents after
6824 * a log replay (and the old parent still existing).
6825 * Example:
6826 *
6827 * mkdir /mnt/A
6828 * mkdir /mnt/B
6829 * touch /mnt/B/bar
6830 * sync
6831 * mv /mnt/B/bar /mnt/A/bar
6832 * mv -T /mnt/A /mnt/B
6833 * fsync /mnt/B/bar
6834 * <power fail>
6835 *
6836 * If we ignore the old parent B which got deleted,
6837 * after a log replay we would have file bar linked
6838 * at both parents and the old parent B would still
6839 * exist.
6840 */
6841 if (IS_ERR(dir_inode)) {
6842 ret = PTR_ERR(dir_inode);
6843 goto out;
6844 }
6845
6846 if (!need_log_inode(trans, BTRFS_I(dir_inode))) {
6847 btrfs_add_delayed_iput(BTRFS_I(dir_inode));
6848 continue;
6849 }
6850
6851 ctx->log_new_dentries = false;
6852 ret = btrfs_log_inode(trans, BTRFS_I(dir_inode),
6853 LOG_INODE_ALL, ctx);
6854 if (!ret && ctx->log_new_dentries)
6855 ret = log_new_dir_dentries(trans,
6856 BTRFS_I(dir_inode), ctx);
6857 btrfs_add_delayed_iput(BTRFS_I(dir_inode));
6858 if (ret)
6859 goto out;
6860 }
6861 path->slots[0]++;
6862 }
6863 ret = 0;
6864 out:
6865 btrfs_free_path(path);
6866 return ret;
6867 }
6868
6869 static int log_new_ancestors(struct btrfs_trans_handle *trans,
6870 struct btrfs_root *root,
6871 struct btrfs_path *path,
6872 struct btrfs_log_ctx *ctx)
6873 {
6874 struct btrfs_key found_key;
6875
6876 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
6877
6878 while (true) {
6879 struct extent_buffer *leaf;
6880 int slot;
6881 struct btrfs_key search_key;
6882 struct inode *inode;
6883 u64 ino;
6884 int ret = 0;
6885
6886 btrfs_release_path(path);
6887
6888 ino = found_key.offset;
6889
6890 search_key.objectid = found_key.offset;
6891 search_key.type = BTRFS_INODE_ITEM_KEY;
6892 search_key.offset = 0;
6893 inode = btrfs_iget_logging(ino, root);
6894 if (IS_ERR(inode))
6895 return PTR_ERR(inode);
6896
6897 if (BTRFS_I(inode)->generation >= trans->transid &&
6898 need_log_inode(trans, BTRFS_I(inode)))
6899 ret = btrfs_log_inode(trans, BTRFS_I(inode),
6900 LOG_INODE_EXISTS, ctx);
6901 btrfs_add_delayed_iput(BTRFS_I(inode));
6902 if (ret)
6903 return ret;
6904
6905 if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
6906 break;
6907
6908 search_key.type = BTRFS_INODE_REF_KEY;
6909 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
6910 if (ret < 0)
6911 return ret;
6912
6913 leaf = path->nodes[0];
6914 slot = path->slots[0];
6915 if (slot >= btrfs_header_nritems(leaf)) {
6916 ret = btrfs_next_leaf(root, path);
6917 if (ret < 0)
6918 return ret;
6919 else if (ret > 0)
6920 return -ENOENT;
6921 leaf = path->nodes[0];
6922 slot = path->slots[0];
6923 }
6924
6925 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6926 if (found_key.objectid != search_key.objectid ||
6927 found_key.type != BTRFS_INODE_REF_KEY)
6928 return -ENOENT;
6929 }
6930 return 0;
6931 }
6932
6933 static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
6934 struct btrfs_inode *inode,
6935 struct dentry *parent,
6936 struct btrfs_log_ctx *ctx)
6937 {
6938 struct btrfs_root *root = inode->root;
6939 struct dentry *old_parent = NULL;
6940 struct super_block *sb = inode->vfs_inode.i_sb;
6941 int ret = 0;
6942
6943 while (true) {
6944 if (!parent || d_really_is_negative(parent) ||
6945 sb != parent->d_sb)
6946 break;
6947
6948 inode = BTRFS_I(d_inode(parent));
6949 if (root != inode->root)
6950 break;
6951
6952 if (inode->generation >= trans->transid &&
6953 need_log_inode(trans, inode)) {
6954 ret = btrfs_log_inode(trans, inode,
6955 LOG_INODE_EXISTS, ctx);
6956 if (ret)
6957 break;
6958 }
6959 if (IS_ROOT(parent))
6960 break;
6961
6962 parent = dget_parent(parent);
6963 dput(old_parent);
6964 old_parent = parent;
6965 }
6966 dput(old_parent);
6967
6968 return ret;
6969 }
6970
6971 static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
6972 struct btrfs_inode *inode,
6973 struct dentry *parent,
6974 struct btrfs_log_ctx *ctx)
6975 {
6976 struct btrfs_root *root = inode->root;
6977 const u64 ino = btrfs_ino(inode);
6978 struct btrfs_path *path;
6979 struct btrfs_key search_key;
6980 int ret;
6981
6982 /*
6983 * For a single hard link case, go through a fast path that does not
6984 * need to iterate the fs/subvolume tree.
6985 */
6986 if (inode->vfs_inode.i_nlink < 2)
6987 return log_new_ancestors_fast(trans, inode, parent, ctx);
6988
6989 path = btrfs_alloc_path();
6990 if (!path)
6991 return -ENOMEM;
6992
6993 search_key.objectid = ino;
6994 search_key.type = BTRFS_INODE_REF_KEY;
6995 search_key.offset = 0;
6996 again:
6997 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
6998 if (ret < 0)
6999 goto out;
7000 if (ret == 0)
7001 path->slots[0]++;
7002
7003 while (true) {
7004 struct extent_buffer *leaf = path->nodes[0];
7005 int slot = path->slots[0];
7006 struct btrfs_key found_key;
7007
7008 if (slot >= btrfs_header_nritems(leaf)) {
7009 ret = btrfs_next_leaf(root, path);
7010 if (ret < 0)
7011 goto out;
7012 else if (ret > 0)
7013 break;
7014 continue;
7015 }
7016
7017 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7018 if (found_key.objectid != ino ||
7019 found_key.type > BTRFS_INODE_EXTREF_KEY)
7020 break;
7021
7022 /*
7023 * Don't deal with extended references because they are rare
7024 * cases and too complex to deal with (we would need to keep
7025 * track of which subitem we are processing for each item in
7026 * this loop, etc). So just return some error to fallback to
7027 * a transaction commit.
7028 */
7029 if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
7030 ret = -EMLINK;
7031 goto out;
7032 }
7033
7034 /*
7035 * Logging ancestors needs to do more searches on the fs/subvol
7036 * tree, so it releases the path as needed to avoid deadlocks.
7037 * Keep track of the last inode ref key and resume from that key
7038 * after logging all new ancestors for the current hard link.
7039 */
7040 memcpy(&search_key, &found_key, sizeof(search_key));
7041
7042 ret = log_new_ancestors(trans, root, path, ctx);
7043 if (ret)
7044 goto out;
7045 btrfs_release_path(path);
7046 goto again;
7047 }
7048 ret = 0;
7049 out:
7050 btrfs_free_path(path);
7051 return ret;
7052 }
7053
7054 /*
7055 * helper function around btrfs_log_inode to make sure newly created
7056 * parent directories also end up in the log. A minimal inode and backref
7057 * only logging is done of any parent directories that are older than
7058 * the last committed transaction
7059 */
7060 static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
7061 struct btrfs_inode *inode,
7062 struct dentry *parent,
7063 int inode_only,
7064 struct btrfs_log_ctx *ctx)
7065 {
7066 struct btrfs_root *root = inode->root;
7067 struct btrfs_fs_info *fs_info = root->fs_info;
7068 int ret = 0;
7069 bool log_dentries = false;
7070
7071 if (btrfs_test_opt(fs_info, NOTREELOG)) {
7072 ret = BTRFS_LOG_FORCE_COMMIT;
7073 goto end_no_trans;
7074 }
7075
7076 if (btrfs_root_refs(&root->root_item) == 0) {
7077 ret = BTRFS_LOG_FORCE_COMMIT;
7078 goto end_no_trans;
7079 }
7080
7081 /*
7082 * If we're logging an inode from a subvolume created in the current
7083 * transaction we must force a commit since the root is not persisted.
7084 */
7085 if (btrfs_root_generation(&root->root_item) == trans->transid) {
7086 ret = BTRFS_LOG_FORCE_COMMIT;
7087 goto end_no_trans;
7088 }
7089
7090 /*
7091 * Skip already logged inodes or inodes corresponding to tmpfiles
7092 * (since logging them is pointless, a link count of 0 means they
7093 * will never be accessible).
7094 */
7095 if ((btrfs_inode_in_log(inode, trans->transid) &&
7096 list_empty(&ctx->ordered_extents)) ||
7097 inode->vfs_inode.i_nlink == 0) {
7098 ret = BTRFS_NO_LOG_SYNC;
7099 goto end_no_trans;
7100 }
7101
7102 ret = start_log_trans(trans, root, ctx);
7103 if (ret)
7104 goto end_no_trans;
7105
7106 ret = btrfs_log_inode(trans, inode, inode_only, ctx);
7107 if (ret)
7108 goto end_trans;
7109
7110 /*
7111 * for regular files, if its inode is already on disk, we don't
7112 * have to worry about the parents at all. This is because
7113 * we can use the last_unlink_trans field to record renames
7114 * and other fun in this file.
7115 */
7116 if (S_ISREG(inode->vfs_inode.i_mode) &&
7117 inode->generation < trans->transid &&
7118 inode->last_unlink_trans < trans->transid) {
7119 ret = 0;
7120 goto end_trans;
7121 }
7122
7123 if (S_ISDIR(inode->vfs_inode.i_mode) && ctx->log_new_dentries)
7124 log_dentries = true;
7125
7126 /*
7127 * On unlink we must make sure all our current and old parent directory
7128 * inodes are fully logged. This is to prevent leaving dangling
7129 * directory index entries in directories that were our parents but are
7130 * not anymore. Not doing this results in old parent directory being
7131 * impossible to delete after log replay (rmdir will always fail with
7132 * error -ENOTEMPTY).
7133 *
7134 * Example 1:
7135 *
7136 * mkdir testdir
7137 * touch testdir/foo
7138 * ln testdir/foo testdir/bar
7139 * sync
7140 * unlink testdir/bar
7141 * xfs_io -c fsync testdir/foo
7142 * <power failure>
7143 * mount fs, triggers log replay
7144 *
7145 * If we don't log the parent directory (testdir), after log replay the
7146 * directory still has an entry pointing to the file inode using the bar
7147 * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
7148 * the file inode has a link count of 1.
7149 *
7150 * Example 2:
7151 *
7152 * mkdir testdir
7153 * touch foo
7154 * ln foo testdir/foo2
7155 * ln foo testdir/foo3
7156 * sync
7157 * unlink testdir/foo3
7158 * xfs_io -c fsync foo
7159 * <power failure>
7160 * mount fs, triggers log replay
7161 *
7162 * Similar as the first example, after log replay the parent directory
7163 * testdir still has an entry pointing to the inode file with name foo3
7164 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
7165 * and has a link count of 2.
7166 */
7167 if (inode->last_unlink_trans >= trans->transid) {
7168 ret = btrfs_log_all_parents(trans, inode, ctx);
7169 if (ret)
7170 goto end_trans;
7171 }
7172
7173 ret = log_all_new_ancestors(trans, inode, parent, ctx);
7174 if (ret)
7175 goto end_trans;
7176
7177 if (log_dentries)
7178 ret = log_new_dir_dentries(trans, inode, ctx);
7179 else
7180 ret = 0;
7181 end_trans:
7182 if (ret < 0) {
7183 btrfs_set_log_full_commit(trans);
7184 ret = BTRFS_LOG_FORCE_COMMIT;
7185 }
7186
7187 if (ret)
7188 btrfs_remove_log_ctx(root, ctx);
7189 btrfs_end_log_trans(root);
7190 end_no_trans:
7191 return ret;
7192 }
7193
7194 /*
7195 * it is not safe to log dentry if the chunk root has added new
7196 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
7197 * If this returns 1, you must commit the transaction to safely get your
7198 * data on disk.
7199 */
7200 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
7201 struct dentry *dentry,
7202 struct btrfs_log_ctx *ctx)
7203 {
7204 struct dentry *parent = dget_parent(dentry);
7205 int ret;
7206
7207 ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
7208 LOG_INODE_ALL, ctx);
7209 dput(parent);
7210
7211 return ret;
7212 }
7213
7214 /*
7215 * should be called during mount to recover any replay any log trees
7216 * from the FS
7217 */
7218 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
7219 {
7220 int ret;
7221 struct btrfs_path *path;
7222 struct btrfs_trans_handle *trans;
7223 struct btrfs_key key;
7224 struct btrfs_key found_key;
7225 struct btrfs_root *log;
7226 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
7227 struct walk_control wc = {
7228 .process_func = process_one_buffer,
7229 .stage = LOG_WALK_PIN_ONLY,
7230 };
7231
7232 path = btrfs_alloc_path();
7233 if (!path)
7234 return -ENOMEM;
7235
7236 set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
7237
7238 trans = btrfs_start_transaction(fs_info->tree_root, 0);
7239 if (IS_ERR(trans)) {
7240 ret = PTR_ERR(trans);
7241 goto error;
7242 }
7243
7244 wc.trans = trans;
7245 wc.pin = 1;
7246
7247 ret = walk_log_tree(trans, log_root_tree, &wc);
7248 if (ret) {
7249 btrfs_abort_transaction(trans, ret);
7250 goto error;
7251 }
7252
7253 again:
7254 key.objectid = BTRFS_TREE_LOG_OBJECTID;
7255 key.offset = (u64)-1;
7256 key.type = BTRFS_ROOT_ITEM_KEY;
7257
7258 while (1) {
7259 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
7260
7261 if (ret < 0) {
7262 btrfs_abort_transaction(trans, ret);
7263 goto error;
7264 }
7265 if (ret > 0) {
7266 if (path->slots[0] == 0)
7267 break;
7268 path->slots[0]--;
7269 }
7270 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
7271 path->slots[0]);
7272 btrfs_release_path(path);
7273 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
7274 break;
7275
7276 log = btrfs_read_tree_root(log_root_tree, &found_key);
7277 if (IS_ERR(log)) {
7278 ret = PTR_ERR(log);
7279 btrfs_abort_transaction(trans, ret);
7280 goto error;
7281 }
7282
7283 wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset,
7284 true);
7285 if (IS_ERR(wc.replay_dest)) {
7286 ret = PTR_ERR(wc.replay_dest);
7287
7288 /*
7289 * We didn't find the subvol, likely because it was
7290 * deleted. This is ok, simply skip this log and go to
7291 * the next one.
7292 *
7293 * We need to exclude the root because we can't have
7294 * other log replays overwriting this log as we'll read
7295 * it back in a few more times. This will keep our
7296 * block from being modified, and we'll just bail for
7297 * each subsequent pass.
7298 */
7299 if (ret == -ENOENT)
7300 ret = btrfs_pin_extent_for_log_replay(trans, log->node);
7301 btrfs_put_root(log);
7302
7303 if (!ret)
7304 goto next;
7305 btrfs_abort_transaction(trans, ret);
7306 goto error;
7307 }
7308
7309 wc.replay_dest->log_root = log;
7310 ret = btrfs_record_root_in_trans(trans, wc.replay_dest);
7311 if (ret)
7312 /* The loop needs to continue due to the root refs */
7313 btrfs_abort_transaction(trans, ret);
7314 else
7315 ret = walk_log_tree(trans, log, &wc);
7316
7317 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
7318 ret = fixup_inode_link_counts(trans, wc.replay_dest,
7319 path);
7320 if (ret)
7321 btrfs_abort_transaction(trans, ret);
7322 }
7323
7324 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
7325 struct btrfs_root *root = wc.replay_dest;
7326
7327 btrfs_release_path(path);
7328
7329 /*
7330 * We have just replayed everything, and the highest
7331 * objectid of fs roots probably has changed in case
7332 * some inode_item's got replayed.
7333 *
7334 * root->objectid_mutex is not acquired as log replay
7335 * could only happen during mount.
7336 */
7337 ret = btrfs_init_root_free_objectid(root);
7338 if (ret)
7339 btrfs_abort_transaction(trans, ret);
7340 }
7341
7342 wc.replay_dest->log_root = NULL;
7343 btrfs_put_root(wc.replay_dest);
7344 btrfs_put_root(log);
7345
7346 if (ret)
7347 goto error;
7348 next:
7349 if (found_key.offset == 0)
7350 break;
7351 key.offset = found_key.offset - 1;
7352 }
7353 btrfs_release_path(path);
7354
7355 /* step one is to pin it all, step two is to replay just inodes */
7356 if (wc.pin) {
7357 wc.pin = 0;
7358 wc.process_func = replay_one_buffer;
7359 wc.stage = LOG_WALK_REPLAY_INODES;
7360 goto again;
7361 }
7362 /* step three is to replay everything */
7363 if (wc.stage < LOG_WALK_REPLAY_ALL) {
7364 wc.stage++;
7365 goto again;
7366 }
7367
7368 btrfs_free_path(path);
7369
7370 /* step 4: commit the transaction, which also unpins the blocks */
7371 ret = btrfs_commit_transaction(trans);
7372 if (ret)
7373 return ret;
7374
7375 log_root_tree->log_root = NULL;
7376 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
7377 btrfs_put_root(log_root_tree);
7378
7379 return 0;
7380 error:
7381 if (wc.trans)
7382 btrfs_end_transaction(wc.trans);
7383 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
7384 btrfs_free_path(path);
7385 return ret;
7386 }
7387
7388 /*
7389 * there are some corner cases where we want to force a full
7390 * commit instead of allowing a directory to be logged.
7391 *
7392 * They revolve around files there were unlinked from the directory, and
7393 * this function updates the parent directory so that a full commit is
7394 * properly done if it is fsync'd later after the unlinks are done.
7395 *
7396 * Must be called before the unlink operations (updates to the subvolume tree,
7397 * inodes, etc) are done.
7398 */
7399 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
7400 struct btrfs_inode *dir, struct btrfs_inode *inode,
7401 bool for_rename)
7402 {
7403 /*
7404 * when we're logging a file, if it hasn't been renamed
7405 * or unlinked, and its inode is fully committed on disk,
7406 * we don't have to worry about walking up the directory chain
7407 * to log its parents.
7408 *
7409 * So, we use the last_unlink_trans field to put this transid
7410 * into the file. When the file is logged we check it and
7411 * don't log the parents if the file is fully on disk.
7412 */
7413 mutex_lock(&inode->log_mutex);
7414 inode->last_unlink_trans = trans->transid;
7415 mutex_unlock(&inode->log_mutex);
7416
7417 if (!for_rename)
7418 return;
7419
7420 /*
7421 * If this directory was already logged, any new names will be logged
7422 * with btrfs_log_new_name() and old names will be deleted from the log
7423 * tree with btrfs_del_dir_entries_in_log() or with
7424 * btrfs_del_inode_ref_in_log().
7425 */
7426 if (inode_logged(trans, dir, NULL) == 1)
7427 return;
7428
7429 /*
7430 * If the inode we're about to unlink was logged before, the log will be
7431 * properly updated with the new name with btrfs_log_new_name() and the
7432 * old name removed with btrfs_del_dir_entries_in_log() or with
7433 * btrfs_del_inode_ref_in_log().
7434 */
7435 if (inode_logged(trans, inode, NULL) == 1)
7436 return;
7437
7438 /*
7439 * when renaming files across directories, if the directory
7440 * there we're unlinking from gets fsync'd later on, there's
7441 * no way to find the destination directory later and fsync it
7442 * properly. So, we have to be conservative and force commits
7443 * so the new name gets discovered.
7444 */
7445 mutex_lock(&dir->log_mutex);
7446 dir->last_unlink_trans = trans->transid;
7447 mutex_unlock(&dir->log_mutex);
7448 }
7449
7450 /*
7451 * Make sure that if someone attempts to fsync the parent directory of a deleted
7452 * snapshot, it ends up triggering a transaction commit. This is to guarantee
7453 * that after replaying the log tree of the parent directory's root we will not
7454 * see the snapshot anymore and at log replay time we will not see any log tree
7455 * corresponding to the deleted snapshot's root, which could lead to replaying
7456 * it after replaying the log tree of the parent directory (which would replay
7457 * the snapshot delete operation).
7458 *
7459 * Must be called before the actual snapshot destroy operation (updates to the
7460 * parent root and tree of tree roots trees, etc) are done.
7461 */
7462 void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
7463 struct btrfs_inode *dir)
7464 {
7465 mutex_lock(&dir->log_mutex);
7466 dir->last_unlink_trans = trans->transid;
7467 mutex_unlock(&dir->log_mutex);
7468 }
7469
7470 /*
7471 * Call this when creating a subvolume in a directory.
7472 * Because we don't commit a transaction when creating a subvolume, we can't
7473 * allow the directory pointing to the subvolume to be logged with an entry that
7474 * points to an unpersisted root if we are still in the transaction used to
7475 * create the subvolume, so make any attempt to log the directory to result in a
7476 * full log sync.
7477 * Also we don't need to worry with renames, since btrfs_rename() marks the log
7478 * for full commit when renaming a subvolume.
7479 */
7480 void btrfs_record_new_subvolume(const struct btrfs_trans_handle *trans,
7481 struct btrfs_inode *dir)
7482 {
7483 mutex_lock(&dir->log_mutex);
7484 dir->last_unlink_trans = trans->transid;
7485 mutex_unlock(&dir->log_mutex);
7486 }
7487
7488 /*
7489 * Update the log after adding a new name for an inode.
7490 *
7491 * @trans: Transaction handle.
7492 * @old_dentry: The dentry associated with the old name and the old
7493 * parent directory.
7494 * @old_dir: The inode of the previous parent directory for the case
7495 * of a rename. For a link operation, it must be NULL.
7496 * @old_dir_index: The index number associated with the old name, meaningful
7497 * only for rename operations (when @old_dir is not NULL).
7498 * Ignored for link operations.
7499 * @parent: The dentry associated with the directory under which the
7500 * new name is located.
7501 *
7502 * Call this after adding a new name for an inode, as a result of a link or
7503 * rename operation, and it will properly update the log to reflect the new name.
7504 */
7505 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
7506 struct dentry *old_dentry, struct btrfs_inode *old_dir,
7507 u64 old_dir_index, struct dentry *parent)
7508 {
7509 struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
7510 struct btrfs_root *root = inode->root;
7511 struct btrfs_log_ctx ctx;
7512 bool log_pinned = false;
7513 int ret;
7514
7515 /*
7516 * this will force the logging code to walk the dentry chain
7517 * up for the file
7518 */
7519 if (!S_ISDIR(inode->vfs_inode.i_mode))
7520 inode->last_unlink_trans = trans->transid;
7521
7522 /*
7523 * if this inode hasn't been logged and directory we're renaming it
7524 * from hasn't been logged, we don't need to log it
7525 */
7526 ret = inode_logged(trans, inode, NULL);
7527 if (ret < 0) {
7528 goto out;
7529 } else if (ret == 0) {
7530 if (!old_dir)
7531 return;
7532 /*
7533 * If the inode was not logged and we are doing a rename (old_dir is not
7534 * NULL), check if old_dir was logged - if it was not we can return and
7535 * do nothing.
7536 */
7537 ret = inode_logged(trans, old_dir, NULL);
7538 if (ret < 0)
7539 goto out;
7540 else if (ret == 0)
7541 return;
7542 }
7543 ret = 0;
7544
7545 /*
7546 * If we are doing a rename (old_dir is not NULL) from a directory that
7547 * was previously logged, make sure that on log replay we get the old
7548 * dir entry deleted. This is needed because we will also log the new
7549 * name of the renamed inode, so we need to make sure that after log
7550 * replay we don't end up with both the new and old dir entries existing.
7551 */
7552 if (old_dir && old_dir->logged_trans == trans->transid) {
7553 struct btrfs_root *log = old_dir->root->log_root;
7554 struct btrfs_path *path;
7555 struct fscrypt_name fname;
7556
7557 ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX);
7558
7559 ret = fscrypt_setup_filename(&old_dir->vfs_inode,
7560 &old_dentry->d_name, 0, &fname);
7561 if (ret)
7562 goto out;
7563 /*
7564 * We have two inodes to update in the log, the old directory and
7565 * the inode that got renamed, so we must pin the log to prevent
7566 * anyone from syncing the log until we have updated both inodes
7567 * in the log.
7568 */
7569 ret = join_running_log_trans(root);
7570 /*
7571 * At least one of the inodes was logged before, so this should
7572 * not fail, but if it does, it's not serious, just bail out and
7573 * mark the log for a full commit.
7574 */
7575 if (WARN_ON_ONCE(ret < 0)) {
7576 fscrypt_free_filename(&fname);
7577 goto out;
7578 }
7579
7580 log_pinned = true;
7581
7582 path = btrfs_alloc_path();
7583 if (!path) {
7584 ret = -ENOMEM;
7585 fscrypt_free_filename(&fname);
7586 goto out;
7587 }
7588
7589 /*
7590 * Other concurrent task might be logging the old directory,
7591 * as it can be triggered when logging other inode that had or
7592 * still has a dentry in the old directory. We lock the old
7593 * directory's log_mutex to ensure the deletion of the old
7594 * name is persisted, because during directory logging we
7595 * delete all BTRFS_DIR_LOG_INDEX_KEY keys and the deletion of
7596 * the old name's dir index item is in the delayed items, so
7597 * it could be missed by an in progress directory logging.
7598 */
7599 mutex_lock(&old_dir->log_mutex);
7600 ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir),
7601 &fname.disk_name, old_dir_index);
7602 if (ret > 0) {
7603 /*
7604 * The dentry does not exist in the log, so record its
7605 * deletion.
7606 */
7607 btrfs_release_path(path);
7608 ret = insert_dir_log_key(trans, log, path,
7609 btrfs_ino(old_dir),
7610 old_dir_index, old_dir_index);
7611 }
7612 mutex_unlock(&old_dir->log_mutex);
7613
7614 btrfs_free_path(path);
7615 fscrypt_free_filename(&fname);
7616 if (ret < 0)
7617 goto out;
7618 }
7619
7620 btrfs_init_log_ctx(&ctx, inode);
7621 ctx.logging_new_name = true;
7622 btrfs_init_log_ctx_scratch_eb(&ctx);
7623 /*
7624 * We don't care about the return value. If we fail to log the new name
7625 * then we know the next attempt to sync the log will fallback to a full
7626 * transaction commit (due to a call to btrfs_set_log_full_commit()), so
7627 * we don't need to worry about getting a log committed that has an
7628 * inconsistent state after a rename operation.
7629 */
7630 btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
7631 free_extent_buffer(ctx.scratch_eb);
7632 ASSERT(list_empty(&ctx.conflict_inodes));
7633 out:
7634 /*
7635 * If an error happened mark the log for a full commit because it's not
7636 * consistent and up to date or we couldn't find out if one of the
7637 * inodes was logged before in this transaction. Do it before unpinning
7638 * the log, to avoid any races with someone else trying to commit it.
7639 */
7640 if (ret < 0)
7641 btrfs_set_log_full_commit(trans);
7642 if (log_pinned)
7643 btrfs_end_log_trans(root);
7644 }
7645
7646
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