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, bool 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
btrfs_iget_logging(u64 objectid,struct btrfs_root * root)141 static struct btrfs_inode *btrfs_iget_logging(u64 objectid, struct btrfs_root *root)
142 {
143 unsigned int nofs_flag;
144 struct btrfs_inode *inode;
145
146 /* Only meant to be called for subvolume roots and not for log roots. */
147 ASSERT(btrfs_is_fstree(btrfs_root_id(root)));
148
149 /*
150 * We're holding a transaction handle whether we are logging or
151 * replaying a log tree, so we must make sure NOFS semantics apply
152 * because btrfs_alloc_inode() may be triggered and it uses GFP_KERNEL
153 * to allocate an inode, which can recurse back into the filesystem and
154 * attempt a transaction commit, resulting in a deadlock.
155 */
156 nofs_flag = memalloc_nofs_save();
157 inode = btrfs_iget(objectid, root);
158 memalloc_nofs_restore(nofs_flag);
159
160 return inode;
161 }
162
163 /*
164 * start a sub transaction and setup the log tree
165 * this increments the log tree writer count to make the people
166 * syncing the tree wait for us to finish
167 */
start_log_trans(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_log_ctx * ctx)168 static int start_log_trans(struct btrfs_trans_handle *trans,
169 struct btrfs_root *root,
170 struct btrfs_log_ctx *ctx)
171 {
172 struct btrfs_fs_info *fs_info = root->fs_info;
173 struct btrfs_root *tree_root = fs_info->tree_root;
174 const bool zoned = btrfs_is_zoned(fs_info);
175 int ret = 0;
176 bool created = false;
177
178 /*
179 * First check if the log root tree was already created. If not, create
180 * it before locking the root's log_mutex, just to keep lockdep happy.
181 */
182 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) {
183 mutex_lock(&tree_root->log_mutex);
184 if (!fs_info->log_root_tree) {
185 ret = btrfs_init_log_root_tree(trans, fs_info);
186 if (!ret) {
187 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state);
188 created = true;
189 }
190 }
191 mutex_unlock(&tree_root->log_mutex);
192 if (ret)
193 return ret;
194 }
195
196 mutex_lock(&root->log_mutex);
197
198 again:
199 if (root->log_root) {
200 int index = (root->log_transid + 1) % 2;
201
202 if (btrfs_need_log_full_commit(trans)) {
203 ret = BTRFS_LOG_FORCE_COMMIT;
204 goto out;
205 }
206
207 if (zoned && atomic_read(&root->log_commit[index])) {
208 wait_log_commit(root, root->log_transid - 1);
209 goto again;
210 }
211
212 if (!root->log_start_pid) {
213 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
214 root->log_start_pid = current->pid;
215 } else if (root->log_start_pid != current->pid) {
216 set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
217 }
218 } else {
219 /*
220 * This means fs_info->log_root_tree was already created
221 * for some other FS trees. Do the full commit not to mix
222 * nodes from multiple log transactions to do sequential
223 * writing.
224 */
225 if (zoned && !created) {
226 ret = BTRFS_LOG_FORCE_COMMIT;
227 goto out;
228 }
229
230 ret = btrfs_add_log_tree(trans, root);
231 if (ret)
232 goto out;
233
234 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
235 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
236 root->log_start_pid = current->pid;
237 }
238
239 atomic_inc(&root->log_writers);
240 if (!ctx->logging_new_name) {
241 int index = root->log_transid % 2;
242 list_add_tail(&ctx->list, &root->log_ctxs[index]);
243 ctx->log_transid = root->log_transid;
244 }
245
246 out:
247 mutex_unlock(&root->log_mutex);
248 return ret;
249 }
250
251 /*
252 * returns 0 if there was a log transaction running and we were able
253 * to join, or returns -ENOENT if there were not transactions
254 * in progress
255 */
join_running_log_trans(struct btrfs_root * root)256 static int join_running_log_trans(struct btrfs_root *root)
257 {
258 const bool zoned = btrfs_is_zoned(root->fs_info);
259 int ret = -ENOENT;
260
261 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
262 return ret;
263
264 mutex_lock(&root->log_mutex);
265 again:
266 if (root->log_root) {
267 int index = (root->log_transid + 1) % 2;
268
269 ret = 0;
270 if (zoned && atomic_read(&root->log_commit[index])) {
271 wait_log_commit(root, root->log_transid - 1);
272 goto again;
273 }
274 atomic_inc(&root->log_writers);
275 }
276 mutex_unlock(&root->log_mutex);
277 return ret;
278 }
279
280 /*
281 * This either makes the current running log transaction wait
282 * until you call btrfs_end_log_trans() or it makes any future
283 * log transactions wait until you call btrfs_end_log_trans()
284 */
btrfs_pin_log_trans(struct btrfs_root * root)285 void btrfs_pin_log_trans(struct btrfs_root *root)
286 {
287 atomic_inc(&root->log_writers);
288 }
289
290 /*
291 * indicate we're done making changes to the log tree
292 * and wake up anyone waiting to do a sync
293 */
btrfs_end_log_trans(struct btrfs_root * root)294 void btrfs_end_log_trans(struct btrfs_root *root)
295 {
296 if (atomic_dec_and_test(&root->log_writers)) {
297 /* atomic_dec_and_test implies a barrier */
298 cond_wake_up_nomb(&root->log_writer_wait);
299 }
300 }
301
302 /*
303 * the walk control struct is used to pass state down the chain when
304 * processing the log tree. The stage field tells us which part
305 * of the log tree processing we are currently doing. The others
306 * are state fields used for that specific part
307 */
308 struct walk_control {
309 /* should we free the extent on disk when done? This is used
310 * at transaction commit time while freeing a log tree
311 */
312 int free;
313
314 /* pin only walk, we record which extents on disk belong to the
315 * log trees
316 */
317 int pin;
318
319 /* what stage of the replay code we're currently in */
320 int stage;
321
322 /*
323 * Ignore any items from the inode currently being processed. Needs
324 * to be set every time we find a BTRFS_INODE_ITEM_KEY.
325 */
326 bool ignore_cur_inode;
327
328 /* the root we are currently replaying */
329 struct btrfs_root *replay_dest;
330
331 /* the trans handle for the current replay */
332 struct btrfs_trans_handle *trans;
333
334 /* the function that gets used to process blocks we find in the
335 * tree. Note the extent_buffer might not be up to date when it is
336 * passed in, and it must be checked or read if you need the data
337 * inside it
338 */
339 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
340 struct walk_control *wc, u64 gen, int level);
341 };
342
343 /*
344 * process_func used to pin down extents, write them or wait on them
345 */
process_one_buffer(struct btrfs_root * log,struct extent_buffer * eb,struct walk_control * wc,u64 gen,int level)346 static int process_one_buffer(struct btrfs_root *log,
347 struct extent_buffer *eb,
348 struct walk_control *wc, u64 gen, int level)
349 {
350 struct btrfs_fs_info *fs_info = log->fs_info;
351 int ret = 0;
352
353 /*
354 * If this fs is mixed then we need to be able to process the leaves to
355 * pin down any logged extents, so we have to read the block.
356 */
357 if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
358 struct btrfs_tree_parent_check check = {
359 .level = level,
360 .transid = gen
361 };
362
363 ret = btrfs_read_extent_buffer(eb, &check);
364 if (ret)
365 return ret;
366 }
367
368 if (wc->pin) {
369 ret = btrfs_pin_extent_for_log_replay(wc->trans, eb);
370 if (ret)
371 return ret;
372
373 if (btrfs_buffer_uptodate(eb, gen, 0) &&
374 btrfs_header_level(eb) == 0)
375 ret = btrfs_exclude_logged_extents(eb);
376 }
377 return ret;
378 }
379
380 /*
381 * Item overwrite used by log replay. The given eb, slot and key all refer to
382 * the source data we are copying out.
383 *
384 * The given root is for the tree we are copying into, and path is a scratch
385 * path for use in this function (it should be released on entry and will be
386 * released on exit).
387 *
388 * If the key is already in the destination tree the existing item is
389 * overwritten. If the existing item isn't big enough, it is extended.
390 * If it is too large, it is truncated.
391 *
392 * If the key isn't in the destination yet, a new item is inserted.
393 */
overwrite_item(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct extent_buffer * eb,int slot,struct btrfs_key * key)394 static int overwrite_item(struct btrfs_trans_handle *trans,
395 struct btrfs_root *root,
396 struct btrfs_path *path,
397 struct extent_buffer *eb, int slot,
398 struct btrfs_key *key)
399 {
400 int ret;
401 u32 item_size;
402 u64 saved_i_size = 0;
403 int save_old_i_size = 0;
404 unsigned long src_ptr;
405 unsigned long dst_ptr;
406 struct extent_buffer *dst_eb;
407 int dst_slot;
408 bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
409
410 /*
411 * This is only used during log replay, so the root is always from a
412 * fs/subvolume tree. In case we ever need to support a log root, then
413 * we'll have to clone the leaf in the path, release the path and use
414 * the leaf before writing into the log tree. See the comments at
415 * copy_items() for more details.
416 */
417 ASSERT(btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID);
418
419 item_size = btrfs_item_size(eb, slot);
420 src_ptr = btrfs_item_ptr_offset(eb, slot);
421
422 /* Look for the key in the destination tree. */
423 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
424 if (ret < 0)
425 return ret;
426
427 dst_eb = path->nodes[0];
428 dst_slot = path->slots[0];
429
430 if (ret == 0) {
431 char *src_copy;
432 const u32 dst_size = btrfs_item_size(dst_eb, dst_slot);
433
434 if (dst_size != item_size)
435 goto insert;
436
437 if (item_size == 0) {
438 btrfs_release_path(path);
439 return 0;
440 }
441 src_copy = kmalloc(item_size, GFP_NOFS);
442 if (!src_copy) {
443 btrfs_release_path(path);
444 return -ENOMEM;
445 }
446
447 read_extent_buffer(eb, src_copy, src_ptr, item_size);
448 dst_ptr = btrfs_item_ptr_offset(dst_eb, dst_slot);
449 ret = memcmp_extent_buffer(dst_eb, src_copy, dst_ptr, item_size);
450
451 kfree(src_copy);
452 /*
453 * they have the same contents, just return, this saves
454 * us from cowing blocks in the destination tree and doing
455 * extra writes that may not have been done by a previous
456 * sync
457 */
458 if (ret == 0) {
459 btrfs_release_path(path);
460 return 0;
461 }
462
463 /*
464 * We need to load the old nbytes into the inode so when we
465 * replay the extents we've logged we get the right nbytes.
466 */
467 if (inode_item) {
468 struct btrfs_inode_item *item;
469 u64 nbytes;
470 u32 mode;
471
472 item = btrfs_item_ptr(dst_eb, dst_slot,
473 struct btrfs_inode_item);
474 nbytes = btrfs_inode_nbytes(dst_eb, item);
475 item = btrfs_item_ptr(eb, slot,
476 struct btrfs_inode_item);
477 btrfs_set_inode_nbytes(eb, item, nbytes);
478
479 /*
480 * If this is a directory we need to reset the i_size to
481 * 0 so that we can set it up properly when replaying
482 * the rest of the items in this log.
483 */
484 mode = btrfs_inode_mode(eb, item);
485 if (S_ISDIR(mode))
486 btrfs_set_inode_size(eb, item, 0);
487 }
488 } else if (inode_item) {
489 struct btrfs_inode_item *item;
490 u32 mode;
491
492 /*
493 * New inode, set nbytes to 0 so that the nbytes comes out
494 * properly when we replay the extents.
495 */
496 item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
497 btrfs_set_inode_nbytes(eb, item, 0);
498
499 /*
500 * If this is a directory we need to reset the i_size to 0 so
501 * that we can set it up properly when replaying the rest of
502 * the items in this log.
503 */
504 mode = btrfs_inode_mode(eb, item);
505 if (S_ISDIR(mode))
506 btrfs_set_inode_size(eb, item, 0);
507 }
508 insert:
509 btrfs_release_path(path);
510 /* try to insert the key into the destination tree */
511 path->skip_release_on_error = 1;
512 ret = btrfs_insert_empty_item(trans, root, path,
513 key, item_size);
514 path->skip_release_on_error = 0;
515
516 dst_eb = path->nodes[0];
517 dst_slot = path->slots[0];
518
519 /* make sure any existing item is the correct size */
520 if (ret == -EEXIST || ret == -EOVERFLOW) {
521 const u32 found_size = btrfs_item_size(dst_eb, dst_slot);
522
523 if (found_size > item_size)
524 btrfs_truncate_item(trans, path, item_size, 1);
525 else if (found_size < item_size)
526 btrfs_extend_item(trans, path, item_size - found_size);
527 } else if (ret) {
528 return ret;
529 }
530 dst_ptr = btrfs_item_ptr_offset(dst_eb, dst_slot);
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 const u64 ino_size = btrfs_inode_size(eb, src_item);
550
551 /*
552 * For regular files an ino_size == 0 is used only when
553 * logging that an inode exists, as part of a directory
554 * fsync, and the inode wasn't fsynced before. In this
555 * case don't set the size of the inode in the fs/subvol
556 * tree, otherwise we would be throwing valid data away.
557 */
558 if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
559 S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
560 ino_size != 0)
561 btrfs_set_inode_size(dst_eb, dst_item, ino_size);
562 goto no_copy;
563 }
564
565 if (S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
566 S_ISDIR(btrfs_inode_mode(dst_eb, dst_item))) {
567 save_old_i_size = 1;
568 saved_i_size = btrfs_inode_size(dst_eb, dst_item);
569 }
570 }
571
572 copy_extent_buffer(dst_eb, eb, dst_ptr, src_ptr, item_size);
573
574 if (save_old_i_size) {
575 struct btrfs_inode_item *dst_item;
576
577 dst_item = (struct btrfs_inode_item *)dst_ptr;
578 btrfs_set_inode_size(dst_eb, dst_item, saved_i_size);
579 }
580
581 /* make sure the generation is filled in */
582 if (key->type == BTRFS_INODE_ITEM_KEY) {
583 struct btrfs_inode_item *dst_item;
584
585 dst_item = (struct btrfs_inode_item *)dst_ptr;
586 if (btrfs_inode_generation(dst_eb, dst_item) == 0)
587 btrfs_set_inode_generation(dst_eb, dst_item, trans->transid);
588 }
589 no_copy:
590 btrfs_release_path(path);
591 return 0;
592 }
593
read_alloc_one_name(struct extent_buffer * eb,void * start,int len,struct fscrypt_str * name)594 static int read_alloc_one_name(struct extent_buffer *eb, void *start, int len,
595 struct fscrypt_str *name)
596 {
597 char *buf;
598
599 buf = kmalloc(len, GFP_NOFS);
600 if (!buf)
601 return -ENOMEM;
602
603 read_extent_buffer(eb, buf, (unsigned long)start, len);
604 name->name = buf;
605 name->len = len;
606 return 0;
607 }
608
609 /* replays a single extent in 'eb' at 'slot' with 'key' into the
610 * subvolume 'root'. path is released on entry and should be released
611 * on exit.
612 *
613 * extents in the log tree have not been allocated out of the extent
614 * tree yet. So, this completes the allocation, taking a reference
615 * as required if the extent already exists or creating a new extent
616 * if it isn't in the extent allocation tree yet.
617 *
618 * The extent is inserted into the file, dropping any existing extents
619 * from the file that overlap the new one.
620 */
replay_one_extent(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct extent_buffer * eb,int slot,struct btrfs_key * key)621 static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
622 struct btrfs_root *root,
623 struct btrfs_path *path,
624 struct extent_buffer *eb, int slot,
625 struct btrfs_key *key)
626 {
627 struct btrfs_drop_extents_args drop_args = { 0 };
628 struct btrfs_fs_info *fs_info = root->fs_info;
629 int found_type;
630 u64 extent_end;
631 u64 start = key->offset;
632 u64 nbytes = 0;
633 struct btrfs_file_extent_item *item;
634 struct btrfs_inode *inode = NULL;
635 unsigned long size;
636 int ret = 0;
637
638 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
639 found_type = btrfs_file_extent_type(eb, item);
640
641 if (found_type == BTRFS_FILE_EXTENT_REG ||
642 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
643 nbytes = btrfs_file_extent_num_bytes(eb, item);
644 extent_end = start + nbytes;
645
646 /*
647 * We don't add to the inodes nbytes if we are prealloc or a
648 * hole.
649 */
650 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
651 nbytes = 0;
652 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
653 size = btrfs_file_extent_ram_bytes(eb, item);
654 nbytes = btrfs_file_extent_ram_bytes(eb, item);
655 extent_end = ALIGN(start + size,
656 fs_info->sectorsize);
657 } else {
658 btrfs_err(fs_info,
659 "unexpected extent type=%d root=%llu inode=%llu offset=%llu",
660 found_type, btrfs_root_id(root), key->objectid, key->offset);
661 return -EUCLEAN;
662 }
663
664 inode = btrfs_iget_logging(key->objectid, root);
665 if (IS_ERR(inode))
666 return PTR_ERR(inode);
667
668 /*
669 * first check to see if we already have this extent in the
670 * file. This must be done before the btrfs_drop_extents run
671 * so we don't try to drop this extent.
672 */
673 ret = btrfs_lookup_file_extent(trans, root, path, btrfs_ino(inode), start, 0);
674
675 if (ret == 0 &&
676 (found_type == BTRFS_FILE_EXTENT_REG ||
677 found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
678 struct btrfs_file_extent_item existing;
679 unsigned long ptr;
680
681 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
682 read_extent_buffer(path->nodes[0], &existing, ptr, sizeof(existing));
683
684 /*
685 * we already have a pointer to this exact extent,
686 * we don't have to do anything
687 */
688 if (memcmp_extent_buffer(eb, &existing, (unsigned long)item,
689 sizeof(existing)) == 0) {
690 btrfs_release_path(path);
691 goto out;
692 }
693 }
694 btrfs_release_path(path);
695
696 /* drop any overlapping extents */
697 drop_args.start = start;
698 drop_args.end = extent_end;
699 drop_args.drop_cache = true;
700 ret = btrfs_drop_extents(trans, root, inode, &drop_args);
701 if (ret)
702 goto out;
703
704 if (found_type == BTRFS_FILE_EXTENT_REG ||
705 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
706 u64 offset;
707 unsigned long dest_offset;
708 struct btrfs_key ins;
709
710 if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
711 btrfs_fs_incompat(fs_info, NO_HOLES))
712 goto update_inode;
713
714 ret = btrfs_insert_empty_item(trans, root, path, key,
715 sizeof(*item));
716 if (ret)
717 goto out;
718 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
719 path->slots[0]);
720 copy_extent_buffer(path->nodes[0], eb, dest_offset,
721 (unsigned long)item, sizeof(*item));
722
723 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
724 ins.type = BTRFS_EXTENT_ITEM_KEY;
725 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
726 offset = key->offset - btrfs_file_extent_offset(eb, item);
727
728 /*
729 * Manually record dirty extent, as here we did a shallow
730 * file extent item copy and skip normal backref update,
731 * but modifying extent tree all by ourselves.
732 * So need to manually record dirty extent for qgroup,
733 * as the owner of the file extent changed from log tree
734 * (doesn't affect qgroup) to fs/file tree(affects qgroup)
735 */
736 ret = btrfs_qgroup_trace_extent(trans,
737 btrfs_file_extent_disk_bytenr(eb, item),
738 btrfs_file_extent_disk_num_bytes(eb, item));
739 if (ret < 0)
740 goto out;
741
742 if (ins.objectid > 0) {
743 u64 csum_start;
744 u64 csum_end;
745 LIST_HEAD(ordered_sums);
746
747 /*
748 * is this extent already allocated in the extent
749 * allocation tree? If so, just add a reference
750 */
751 ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
752 ins.offset);
753 if (ret < 0) {
754 goto out;
755 } else if (ret == 0) {
756 struct btrfs_ref ref = {
757 .action = BTRFS_ADD_DELAYED_REF,
758 .bytenr = ins.objectid,
759 .num_bytes = ins.offset,
760 .owning_root = btrfs_root_id(root),
761 .ref_root = btrfs_root_id(root),
762 };
763 btrfs_init_data_ref(&ref, key->objectid, offset,
764 0, false);
765 ret = btrfs_inc_extent_ref(trans, &ref);
766 if (ret)
767 goto out;
768 } else {
769 /*
770 * insert the extent pointer in the extent
771 * allocation tree
772 */
773 ret = btrfs_alloc_logged_file_extent(trans,
774 btrfs_root_id(root),
775 key->objectid, offset, &ins);
776 if (ret)
777 goto out;
778 }
779 btrfs_release_path(path);
780
781 if (btrfs_file_extent_compression(eb, item)) {
782 csum_start = ins.objectid;
783 csum_end = csum_start + ins.offset;
784 } else {
785 csum_start = ins.objectid +
786 btrfs_file_extent_offset(eb, item);
787 csum_end = csum_start +
788 btrfs_file_extent_num_bytes(eb, item);
789 }
790
791 ret = btrfs_lookup_csums_list(root->log_root,
792 csum_start, csum_end - 1,
793 &ordered_sums, false);
794 if (ret < 0)
795 goto out;
796 ret = 0;
797 /*
798 * Now delete all existing cums in the csum root that
799 * cover our range. We do this because we can have an
800 * extent that is completely referenced by one file
801 * extent item and partially referenced by another
802 * file extent item (like after using the clone or
803 * extent_same ioctls). In this case if we end up doing
804 * the replay of the one that partially references the
805 * extent first, and we do not do the csum deletion
806 * below, we can get 2 csum items in the csum tree that
807 * overlap each other. For example, imagine our log has
808 * the two following file extent items:
809 *
810 * key (257 EXTENT_DATA 409600)
811 * extent data disk byte 12845056 nr 102400
812 * extent data offset 20480 nr 20480 ram 102400
813 *
814 * key (257 EXTENT_DATA 819200)
815 * extent data disk byte 12845056 nr 102400
816 * extent data offset 0 nr 102400 ram 102400
817 *
818 * Where the second one fully references the 100K extent
819 * that starts at disk byte 12845056, and the log tree
820 * has a single csum item that covers the entire range
821 * of the extent:
822 *
823 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
824 *
825 * After the first file extent item is replayed, the
826 * csum tree gets the following csum item:
827 *
828 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
829 *
830 * Which covers the 20K sub-range starting at offset 20K
831 * of our extent. Now when we replay the second file
832 * extent item, if we do not delete existing csum items
833 * that cover any of its blocks, we end up getting two
834 * csum items in our csum tree that overlap each other:
835 *
836 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
837 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
838 *
839 * Which is a problem, because after this anyone trying
840 * to lookup up for the checksum of any block of our
841 * extent starting at an offset of 40K or higher, will
842 * end up looking at the second csum item only, which
843 * does not contain the checksum for any block starting
844 * at offset 40K or higher of our extent.
845 */
846 while (!list_empty(&ordered_sums)) {
847 struct btrfs_ordered_sum *sums;
848 struct btrfs_root *csum_root;
849
850 sums = list_first_entry(&ordered_sums,
851 struct btrfs_ordered_sum,
852 list);
853 csum_root = btrfs_csum_root(fs_info,
854 sums->logical);
855 if (!ret)
856 ret = btrfs_del_csums(trans, csum_root,
857 sums->logical,
858 sums->len);
859 if (!ret)
860 ret = btrfs_csum_file_blocks(trans,
861 csum_root,
862 sums);
863 list_del(&sums->list);
864 kfree(sums);
865 }
866 if (ret)
867 goto out;
868 } else {
869 btrfs_release_path(path);
870 }
871 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
872 /* inline extents are easy, we just overwrite them */
873 ret = overwrite_item(trans, root, path, eb, slot, key);
874 if (ret)
875 goto out;
876 }
877
878 ret = btrfs_inode_set_file_extent_range(inode, start, extent_end - start);
879 if (ret)
880 goto out;
881
882 update_inode:
883 btrfs_update_inode_bytes(inode, nbytes, drop_args.bytes_found);
884 ret = btrfs_update_inode(trans, inode);
885 out:
886 iput(&inode->vfs_inode);
887 return ret;
888 }
889
unlink_inode_for_log_replay(struct btrfs_trans_handle * trans,struct btrfs_inode * dir,struct btrfs_inode * inode,const struct fscrypt_str * name)890 static int unlink_inode_for_log_replay(struct btrfs_trans_handle *trans,
891 struct btrfs_inode *dir,
892 struct btrfs_inode *inode,
893 const struct fscrypt_str *name)
894 {
895 int ret;
896
897 ret = btrfs_unlink_inode(trans, dir, inode, name);
898 if (ret)
899 return ret;
900 /*
901 * Whenever we need to check if a name exists or not, we check the
902 * fs/subvolume tree. So after an unlink we must run delayed items, so
903 * that future checks for a name during log replay see that the name
904 * does not exists anymore.
905 */
906 return btrfs_run_delayed_items(trans);
907 }
908
909 /*
910 * when cleaning up conflicts between the directory names in the
911 * subvolume, directory names in the log and directory names in the
912 * inode back references, we may have to unlink inodes from directories.
913 *
914 * This is a helper function to do the unlink of a specific directory
915 * item
916 */
drop_one_dir_item(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_inode * dir,struct btrfs_dir_item * di)917 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
918 struct btrfs_path *path,
919 struct btrfs_inode *dir,
920 struct btrfs_dir_item *di)
921 {
922 struct btrfs_root *root = dir->root;
923 struct btrfs_inode *inode;
924 struct fscrypt_str name;
925 struct extent_buffer *leaf;
926 struct btrfs_key location;
927 int ret;
928
929 leaf = path->nodes[0];
930
931 btrfs_dir_item_key_to_cpu(leaf, di, &location);
932 ret = read_alloc_one_name(leaf, di + 1, btrfs_dir_name_len(leaf, di), &name);
933 if (ret)
934 return -ENOMEM;
935
936 btrfs_release_path(path);
937
938 inode = btrfs_iget_logging(location.objectid, root);
939 if (IS_ERR(inode)) {
940 ret = PTR_ERR(inode);
941 inode = NULL;
942 goto out;
943 }
944
945 ret = link_to_fixup_dir(trans, root, path, location.objectid);
946 if (ret)
947 goto out;
948
949 ret = unlink_inode_for_log_replay(trans, dir, inode, &name);
950 out:
951 kfree(name.name);
952 if (inode)
953 iput(&inode->vfs_inode);
954 return ret;
955 }
956
957 /*
958 * See if a given name and sequence number found in an inode back reference are
959 * already in a directory and correctly point to this inode.
960 *
961 * Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it
962 * exists.
963 */
inode_in_dir(struct btrfs_root * root,struct btrfs_path * path,u64 dirid,u64 objectid,u64 index,struct fscrypt_str * name)964 static noinline int inode_in_dir(struct btrfs_root *root,
965 struct btrfs_path *path,
966 u64 dirid, u64 objectid, u64 index,
967 struct fscrypt_str *name)
968 {
969 struct btrfs_dir_item *di;
970 struct btrfs_key location;
971 int ret = 0;
972
973 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
974 index, name, 0);
975 if (IS_ERR(di)) {
976 ret = PTR_ERR(di);
977 goto out;
978 } else if (di) {
979 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
980 if (location.objectid != objectid)
981 goto out;
982 } else {
983 goto out;
984 }
985
986 btrfs_release_path(path);
987 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, 0);
988 if (IS_ERR(di)) {
989 ret = PTR_ERR(di);
990 goto out;
991 } else if (di) {
992 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
993 if (location.objectid == objectid)
994 ret = 1;
995 }
996 out:
997 btrfs_release_path(path);
998 return ret;
999 }
1000
1001 /*
1002 * helper function to check a log tree for a named back reference in
1003 * an inode. This is used to decide if a back reference that is
1004 * found in the subvolume conflicts with what we find in the log.
1005 *
1006 * inode backreferences may have multiple refs in a single item,
1007 * during replay we process one reference at a time, and we don't
1008 * want to delete valid links to a file from the subvolume if that
1009 * link is also in the log.
1010 */
backref_in_log(struct btrfs_root * log,struct btrfs_key * key,u64 ref_objectid,const struct fscrypt_str * name)1011 static noinline int backref_in_log(struct btrfs_root *log,
1012 struct btrfs_key *key,
1013 u64 ref_objectid,
1014 const struct fscrypt_str *name)
1015 {
1016 struct btrfs_path *path;
1017 int ret;
1018
1019 path = btrfs_alloc_path();
1020 if (!path)
1021 return -ENOMEM;
1022
1023 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
1024 if (ret < 0) {
1025 goto out;
1026 } else if (ret == 1) {
1027 ret = 0;
1028 goto out;
1029 }
1030
1031 if (key->type == BTRFS_INODE_EXTREF_KEY)
1032 ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
1033 path->slots[0],
1034 ref_objectid, name);
1035 else
1036 ret = !!btrfs_find_name_in_backref(path->nodes[0],
1037 path->slots[0], name);
1038 out:
1039 btrfs_free_path(path);
1040 return ret;
1041 }
1042
unlink_refs_not_in_log(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_root * log_root,struct btrfs_key * search_key,struct btrfs_inode * dir,struct btrfs_inode * inode,u64 parent_objectid)1043 static int unlink_refs_not_in_log(struct btrfs_trans_handle *trans,
1044 struct btrfs_path *path,
1045 struct btrfs_root *log_root,
1046 struct btrfs_key *search_key,
1047 struct btrfs_inode *dir,
1048 struct btrfs_inode *inode,
1049 u64 parent_objectid)
1050 {
1051 struct extent_buffer *leaf = path->nodes[0];
1052 unsigned long ptr;
1053 unsigned long ptr_end;
1054
1055 /*
1056 * Check all the names in this back reference to see if they are in the
1057 * log. If so, we allow them to stay otherwise they must be unlinked as
1058 * a conflict.
1059 */
1060 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1061 ptr_end = ptr + btrfs_item_size(leaf, path->slots[0]);
1062 while (ptr < ptr_end) {
1063 struct fscrypt_str victim_name;
1064 struct btrfs_inode_ref *victim_ref;
1065 int ret;
1066
1067 victim_ref = (struct btrfs_inode_ref *)ptr;
1068 ret = read_alloc_one_name(leaf, (victim_ref + 1),
1069 btrfs_inode_ref_name_len(leaf, victim_ref),
1070 &victim_name);
1071 if (ret)
1072 return ret;
1073
1074 ret = backref_in_log(log_root, search_key, parent_objectid, &victim_name);
1075 if (ret) {
1076 kfree(victim_name.name);
1077 if (ret < 0)
1078 return ret;
1079 ptr = (unsigned long)(victim_ref + 1) + victim_name.len;
1080 continue;
1081 }
1082
1083 inc_nlink(&inode->vfs_inode);
1084 btrfs_release_path(path);
1085
1086 ret = unlink_inode_for_log_replay(trans, dir, inode, &victim_name);
1087 kfree(victim_name.name);
1088 if (ret)
1089 return ret;
1090 return -EAGAIN;
1091 }
1092
1093 return 0;
1094 }
1095
unlink_extrefs_not_in_log(struct btrfs_trans_handle * trans,struct btrfs_path * path,struct btrfs_root * root,struct btrfs_root * log_root,struct btrfs_key * search_key,struct btrfs_inode * inode,u64 inode_objectid,u64 parent_objectid)1096 static int unlink_extrefs_not_in_log(struct btrfs_trans_handle *trans,
1097 struct btrfs_path *path,
1098 struct btrfs_root *root,
1099 struct btrfs_root *log_root,
1100 struct btrfs_key *search_key,
1101 struct btrfs_inode *inode,
1102 u64 inode_objectid,
1103 u64 parent_objectid)
1104 {
1105 struct extent_buffer *leaf = path->nodes[0];
1106 const unsigned long base = btrfs_item_ptr_offset(leaf, path->slots[0]);
1107 const u32 item_size = btrfs_item_size(leaf, path->slots[0]);
1108 u32 cur_offset = 0;
1109
1110 while (cur_offset < item_size) {
1111 struct btrfs_inode_extref *extref;
1112 struct btrfs_inode *victim_parent;
1113 struct fscrypt_str victim_name;
1114 int ret;
1115
1116 extref = (struct btrfs_inode_extref *)(base + cur_offset);
1117 victim_name.len = btrfs_inode_extref_name_len(leaf, extref);
1118
1119 if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
1120 goto next;
1121
1122 ret = read_alloc_one_name(leaf, &extref->name, victim_name.len,
1123 &victim_name);
1124 if (ret)
1125 return ret;
1126
1127 search_key->objectid = inode_objectid;
1128 search_key->type = BTRFS_INODE_EXTREF_KEY;
1129 search_key->offset = btrfs_extref_hash(parent_objectid,
1130 victim_name.name,
1131 victim_name.len);
1132 ret = backref_in_log(log_root, search_key, parent_objectid, &victim_name);
1133 if (ret) {
1134 kfree(victim_name.name);
1135 if (ret < 0)
1136 return ret;
1137 next:
1138 cur_offset += victim_name.len + sizeof(*extref);
1139 continue;
1140 }
1141
1142 victim_parent = btrfs_iget_logging(parent_objectid, root);
1143 if (IS_ERR(victim_parent)) {
1144 kfree(victim_name.name);
1145 return PTR_ERR(victim_parent);
1146 }
1147
1148 inc_nlink(&inode->vfs_inode);
1149 btrfs_release_path(path);
1150
1151 ret = unlink_inode_for_log_replay(trans, victim_parent, inode,
1152 &victim_name);
1153 iput(&victim_parent->vfs_inode);
1154 kfree(victim_name.name);
1155 if (ret)
1156 return ret;
1157 return -EAGAIN;
1158 }
1159
1160 return 0;
1161 }
1162
__add_inode_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct btrfs_root * log_root,struct btrfs_inode * dir,struct btrfs_inode * inode,u64 inode_objectid,u64 parent_objectid,u64 ref_index,struct fscrypt_str * name)1163 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
1164 struct btrfs_root *root,
1165 struct btrfs_path *path,
1166 struct btrfs_root *log_root,
1167 struct btrfs_inode *dir,
1168 struct btrfs_inode *inode,
1169 u64 inode_objectid, u64 parent_objectid,
1170 u64 ref_index, struct fscrypt_str *name)
1171 {
1172 int ret;
1173 struct btrfs_dir_item *di;
1174 struct btrfs_key search_key;
1175 struct btrfs_inode_extref *extref;
1176
1177 again:
1178 /* Search old style refs */
1179 search_key.objectid = inode_objectid;
1180 search_key.type = BTRFS_INODE_REF_KEY;
1181 search_key.offset = parent_objectid;
1182 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
1183 if (ret < 0) {
1184 return ret;
1185 } else if (ret == 0) {
1186 /*
1187 * Are we trying to overwrite a back ref for the root directory?
1188 * If so, we're done.
1189 */
1190 if (search_key.objectid == search_key.offset)
1191 return 1;
1192
1193 ret = unlink_refs_not_in_log(trans, path, log_root, &search_key,
1194 dir, inode, parent_objectid);
1195 if (ret == -EAGAIN)
1196 goto again;
1197 else if (ret)
1198 return ret;
1199 }
1200 btrfs_release_path(path);
1201
1202 /* Same search but for extended refs */
1203 extref = btrfs_lookup_inode_extref(root, path, name, inode_objectid, parent_objectid);
1204 if (IS_ERR(extref)) {
1205 return PTR_ERR(extref);
1206 } else if (extref) {
1207 ret = unlink_extrefs_not_in_log(trans, path, root, log_root,
1208 &search_key, inode,
1209 inode_objectid, parent_objectid);
1210 if (ret == -EAGAIN)
1211 goto again;
1212 else if (ret)
1213 return ret;
1214 }
1215 btrfs_release_path(path);
1216
1217 /* look for a conflicting sequence number */
1218 di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
1219 ref_index, name, 0);
1220 if (IS_ERR(di)) {
1221 return PTR_ERR(di);
1222 } else if (di) {
1223 ret = drop_one_dir_item(trans, path, dir, di);
1224 if (ret)
1225 return ret;
1226 }
1227 btrfs_release_path(path);
1228
1229 /* look for a conflicting name */
1230 di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir), name, 0);
1231 if (IS_ERR(di)) {
1232 return PTR_ERR(di);
1233 } else if (di) {
1234 ret = drop_one_dir_item(trans, path, dir, di);
1235 if (ret)
1236 return ret;
1237 }
1238 btrfs_release_path(path);
1239
1240 return 0;
1241 }
1242
extref_get_fields(struct extent_buffer * eb,unsigned long ref_ptr,struct fscrypt_str * name,u64 * index,u64 * parent_objectid)1243 static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1244 struct fscrypt_str *name, u64 *index,
1245 u64 *parent_objectid)
1246 {
1247 struct btrfs_inode_extref *extref;
1248 int ret;
1249
1250 extref = (struct btrfs_inode_extref *)ref_ptr;
1251
1252 ret = read_alloc_one_name(eb, &extref->name,
1253 btrfs_inode_extref_name_len(eb, extref), name);
1254 if (ret)
1255 return ret;
1256
1257 if (index)
1258 *index = btrfs_inode_extref_index(eb, extref);
1259 if (parent_objectid)
1260 *parent_objectid = btrfs_inode_extref_parent(eb, extref);
1261
1262 return 0;
1263 }
1264
ref_get_fields(struct extent_buffer * eb,unsigned long ref_ptr,struct fscrypt_str * name,u64 * index)1265 static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1266 struct fscrypt_str *name, u64 *index)
1267 {
1268 struct btrfs_inode_ref *ref;
1269 int ret;
1270
1271 ref = (struct btrfs_inode_ref *)ref_ptr;
1272
1273 ret = read_alloc_one_name(eb, ref + 1, btrfs_inode_ref_name_len(eb, ref),
1274 name);
1275 if (ret)
1276 return ret;
1277
1278 if (index)
1279 *index = btrfs_inode_ref_index(eb, ref);
1280
1281 return 0;
1282 }
1283
1284 /*
1285 * Take an inode reference item from the log tree and iterate all names from the
1286 * inode reference item in the subvolume tree with the same key (if it exists).
1287 * For any name that is not in the inode reference item from the log tree, do a
1288 * proper unlink of that name (that is, remove its entry from the inode
1289 * reference item and both dir index keys).
1290 */
unlink_old_inode_refs(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct btrfs_inode * inode,struct extent_buffer * log_eb,int log_slot,struct btrfs_key * key)1291 static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
1292 struct btrfs_root *root,
1293 struct btrfs_path *path,
1294 struct btrfs_inode *inode,
1295 struct extent_buffer *log_eb,
1296 int log_slot,
1297 struct btrfs_key *key)
1298 {
1299 int ret;
1300 unsigned long ref_ptr;
1301 unsigned long ref_end;
1302 struct extent_buffer *eb;
1303
1304 again:
1305 btrfs_release_path(path);
1306 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
1307 if (ret > 0) {
1308 ret = 0;
1309 goto out;
1310 }
1311 if (ret < 0)
1312 goto out;
1313
1314 eb = path->nodes[0];
1315 ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
1316 ref_end = ref_ptr + btrfs_item_size(eb, path->slots[0]);
1317 while (ref_ptr < ref_end) {
1318 struct fscrypt_str name;
1319 u64 parent_id;
1320
1321 if (key->type == BTRFS_INODE_EXTREF_KEY) {
1322 ret = extref_get_fields(eb, ref_ptr, &name,
1323 NULL, &parent_id);
1324 } else {
1325 parent_id = key->offset;
1326 ret = ref_get_fields(eb, ref_ptr, &name, NULL);
1327 }
1328 if (ret)
1329 goto out;
1330
1331 if (key->type == BTRFS_INODE_EXTREF_KEY)
1332 ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
1333 parent_id, &name);
1334 else
1335 ret = !!btrfs_find_name_in_backref(log_eb, log_slot, &name);
1336
1337 if (!ret) {
1338 struct btrfs_inode *dir;
1339
1340 btrfs_release_path(path);
1341 dir = btrfs_iget_logging(parent_id, root);
1342 if (IS_ERR(dir)) {
1343 ret = PTR_ERR(dir);
1344 kfree(name.name);
1345 goto out;
1346 }
1347 ret = unlink_inode_for_log_replay(trans, dir, inode, &name);
1348 kfree(name.name);
1349 iput(&dir->vfs_inode);
1350 if (ret)
1351 goto out;
1352 goto again;
1353 }
1354
1355 kfree(name.name);
1356 ref_ptr += name.len;
1357 if (key->type == BTRFS_INODE_EXTREF_KEY)
1358 ref_ptr += sizeof(struct btrfs_inode_extref);
1359 else
1360 ref_ptr += sizeof(struct btrfs_inode_ref);
1361 }
1362 ret = 0;
1363 out:
1364 btrfs_release_path(path);
1365 return ret;
1366 }
1367
1368 /*
1369 * replay one inode back reference item found in the log tree.
1370 * eb, slot and key refer to the buffer and key found in the log tree.
1371 * root is the destination we are replaying into, and path is for temp
1372 * use by this function. (it should be released on return).
1373 */
add_inode_ref(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_root * log,struct btrfs_path * path,struct extent_buffer * eb,int slot,struct btrfs_key * key)1374 static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
1375 struct btrfs_root *root,
1376 struct btrfs_root *log,
1377 struct btrfs_path *path,
1378 struct extent_buffer *eb, int slot,
1379 struct btrfs_key *key)
1380 {
1381 struct btrfs_inode *dir = NULL;
1382 struct btrfs_inode *inode = NULL;
1383 unsigned long ref_ptr;
1384 unsigned long ref_end;
1385 struct fscrypt_str name = { 0 };
1386 int ret;
1387 const bool is_extref_item = (key->type == BTRFS_INODE_EXTREF_KEY);
1388 u64 parent_objectid;
1389 u64 inode_objectid;
1390 u64 ref_index = 0;
1391 int ref_struct_size;
1392
1393 ref_ptr = btrfs_item_ptr_offset(eb, slot);
1394 ref_end = ref_ptr + btrfs_item_size(eb, slot);
1395
1396 if (is_extref_item) {
1397 struct btrfs_inode_extref *r;
1398
1399 ref_struct_size = sizeof(struct btrfs_inode_extref);
1400 r = (struct btrfs_inode_extref *)ref_ptr;
1401 parent_objectid = btrfs_inode_extref_parent(eb, r);
1402 } else {
1403 ref_struct_size = sizeof(struct btrfs_inode_ref);
1404 parent_objectid = key->offset;
1405 }
1406 inode_objectid = key->objectid;
1407
1408 /*
1409 * it is possible that we didn't log all the parent directories
1410 * for a given inode. If we don't find the dir, just don't
1411 * copy the back ref in. The link count fixup code will take
1412 * care of the rest
1413 */
1414 dir = btrfs_iget_logging(parent_objectid, root);
1415 if (IS_ERR(dir)) {
1416 ret = PTR_ERR(dir);
1417 if (ret == -ENOENT)
1418 ret = 0;
1419 dir = NULL;
1420 goto out;
1421 }
1422
1423 inode = btrfs_iget_logging(inode_objectid, root);
1424 if (IS_ERR(inode)) {
1425 ret = PTR_ERR(inode);
1426 inode = NULL;
1427 goto out;
1428 }
1429
1430 while (ref_ptr < ref_end) {
1431 if (is_extref_item) {
1432 ret = extref_get_fields(eb, ref_ptr, &name,
1433 &ref_index, &parent_objectid);
1434 if (ret)
1435 goto out;
1436 /*
1437 * parent object can change from one array
1438 * item to another.
1439 */
1440 if (!dir) {
1441 dir = btrfs_iget_logging(parent_objectid, root);
1442 if (IS_ERR(dir)) {
1443 ret = PTR_ERR(dir);
1444 dir = NULL;
1445 /*
1446 * A new parent dir may have not been
1447 * logged and not exist in the subvolume
1448 * tree, see the comment above before
1449 * the loop when getting the first
1450 * parent dir.
1451 */
1452 if (ret == -ENOENT) {
1453 /*
1454 * The next extref may refer to
1455 * another parent dir that
1456 * exists, so continue.
1457 */
1458 ret = 0;
1459 goto next;
1460 }
1461 goto out;
1462 }
1463 }
1464 } else {
1465 ret = ref_get_fields(eb, ref_ptr, &name, &ref_index);
1466 if (ret)
1467 goto out;
1468 }
1469
1470 ret = inode_in_dir(root, path, btrfs_ino(dir), btrfs_ino(inode),
1471 ref_index, &name);
1472 if (ret < 0) {
1473 goto out;
1474 } else if (ret == 0) {
1475 /*
1476 * look for a conflicting back reference in the
1477 * metadata. if we find one we have to unlink that name
1478 * of the file before we add our new link. Later on, we
1479 * overwrite any existing back reference, and we don't
1480 * want to create dangling pointers in the directory.
1481 */
1482 ret = __add_inode_ref(trans, root, path, log, dir, inode,
1483 inode_objectid, parent_objectid,
1484 ref_index, &name);
1485 if (ret) {
1486 if (ret == 1)
1487 ret = 0;
1488 goto out;
1489 }
1490
1491 /* insert our name */
1492 ret = btrfs_add_link(trans, dir, inode, &name, 0, ref_index);
1493 if (ret)
1494 goto out;
1495
1496 ret = btrfs_update_inode(trans, inode);
1497 if (ret)
1498 goto out;
1499 }
1500 /* Else, ret == 1, we already have a perfect match, we're done. */
1501
1502 next:
1503 ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + name.len;
1504 kfree(name.name);
1505 name.name = NULL;
1506 if (is_extref_item && dir) {
1507 iput(&dir->vfs_inode);
1508 dir = NULL;
1509 }
1510 }
1511
1512 /*
1513 * Before we overwrite the inode reference item in the subvolume tree
1514 * with the item from the log tree, we must unlink all names from the
1515 * parent directory that are in the subvolume's tree inode reference
1516 * item, otherwise we end up with an inconsistent subvolume tree where
1517 * dir index entries exist for a name but there is no inode reference
1518 * item with the same name.
1519 */
1520 ret = unlink_old_inode_refs(trans, root, path, inode, eb, slot, key);
1521 if (ret)
1522 goto out;
1523
1524 /* finally write the back reference in the inode */
1525 ret = overwrite_item(trans, root, path, eb, slot, key);
1526 out:
1527 btrfs_release_path(path);
1528 kfree(name.name);
1529 if (dir)
1530 iput(&dir->vfs_inode);
1531 if (inode)
1532 iput(&inode->vfs_inode);
1533 return ret;
1534 }
1535
count_inode_extrefs(struct btrfs_inode * inode,struct btrfs_path * path)1536 static int count_inode_extrefs(struct btrfs_inode *inode, struct btrfs_path *path)
1537 {
1538 int ret = 0;
1539 int name_len;
1540 unsigned int nlink = 0;
1541 u32 item_size;
1542 u32 cur_offset = 0;
1543 u64 inode_objectid = btrfs_ino(inode);
1544 u64 offset = 0;
1545 unsigned long ptr;
1546 struct btrfs_inode_extref *extref;
1547 struct extent_buffer *leaf;
1548
1549 while (1) {
1550 ret = btrfs_find_one_extref(inode->root, inode_objectid, offset,
1551 path, &extref, &offset);
1552 if (ret)
1553 break;
1554
1555 leaf = path->nodes[0];
1556 item_size = btrfs_item_size(leaf, path->slots[0]);
1557 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1558 cur_offset = 0;
1559
1560 while (cur_offset < item_size) {
1561 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
1562 name_len = btrfs_inode_extref_name_len(leaf, extref);
1563
1564 nlink++;
1565
1566 cur_offset += name_len + sizeof(*extref);
1567 }
1568
1569 offset++;
1570 btrfs_release_path(path);
1571 }
1572 btrfs_release_path(path);
1573
1574 if (ret < 0 && ret != -ENOENT)
1575 return ret;
1576 return nlink;
1577 }
1578
count_inode_refs(struct btrfs_inode * inode,struct btrfs_path * path)1579 static int count_inode_refs(struct btrfs_inode *inode, struct btrfs_path *path)
1580 {
1581 int ret;
1582 struct btrfs_key key;
1583 unsigned int nlink = 0;
1584 unsigned long ptr;
1585 unsigned long ptr_end;
1586 int name_len;
1587 u64 ino = btrfs_ino(inode);
1588
1589 key.objectid = ino;
1590 key.type = BTRFS_INODE_REF_KEY;
1591 key.offset = (u64)-1;
1592
1593 while (1) {
1594 ret = btrfs_search_slot(NULL, inode->root, &key, path, 0, 0);
1595 if (ret < 0)
1596 break;
1597 if (ret > 0) {
1598 if (path->slots[0] == 0)
1599 break;
1600 path->slots[0]--;
1601 }
1602 process_slot:
1603 btrfs_item_key_to_cpu(path->nodes[0], &key,
1604 path->slots[0]);
1605 if (key.objectid != ino ||
1606 key.type != BTRFS_INODE_REF_KEY)
1607 break;
1608 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1609 ptr_end = ptr + btrfs_item_size(path->nodes[0],
1610 path->slots[0]);
1611 while (ptr < ptr_end) {
1612 struct btrfs_inode_ref *ref;
1613
1614 ref = (struct btrfs_inode_ref *)ptr;
1615 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1616 ref);
1617 ptr = (unsigned long)(ref + 1) + name_len;
1618 nlink++;
1619 }
1620
1621 if (key.offset == 0)
1622 break;
1623 if (path->slots[0] > 0) {
1624 path->slots[0]--;
1625 goto process_slot;
1626 }
1627 key.offset--;
1628 btrfs_release_path(path);
1629 }
1630 btrfs_release_path(path);
1631
1632 return nlink;
1633 }
1634
1635 /*
1636 * There are a few corners where the link count of the file can't
1637 * be properly maintained during replay. So, instead of adding
1638 * lots of complexity to the log code, we just scan the backrefs
1639 * for any file that has been through replay.
1640 *
1641 * The scan will update the link count on the inode to reflect the
1642 * number of back refs found. If it goes down to zero, the iput
1643 * will free the inode.
1644 */
fixup_inode_link_count(struct btrfs_trans_handle * trans,struct btrfs_inode * inode)1645 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
1646 struct btrfs_inode *inode)
1647 {
1648 struct btrfs_root *root = inode->root;
1649 struct btrfs_path *path;
1650 int ret;
1651 u64 nlink = 0;
1652 const u64 ino = btrfs_ino(inode);
1653
1654 path = btrfs_alloc_path();
1655 if (!path)
1656 return -ENOMEM;
1657
1658 ret = count_inode_refs(inode, path);
1659 if (ret < 0)
1660 goto out;
1661
1662 nlink = ret;
1663
1664 ret = count_inode_extrefs(inode, path);
1665 if (ret < 0)
1666 goto out;
1667
1668 nlink += ret;
1669
1670 ret = 0;
1671
1672 if (nlink != inode->vfs_inode.i_nlink) {
1673 set_nlink(&inode->vfs_inode, nlink);
1674 ret = btrfs_update_inode(trans, inode);
1675 if (ret)
1676 goto out;
1677 }
1678 if (S_ISDIR(inode->vfs_inode.i_mode))
1679 inode->index_cnt = (u64)-1;
1680
1681 if (inode->vfs_inode.i_nlink == 0) {
1682 if (S_ISDIR(inode->vfs_inode.i_mode)) {
1683 ret = replay_dir_deletes(trans, root, NULL, path, ino, true);
1684 if (ret)
1685 goto out;
1686 }
1687 ret = btrfs_insert_orphan_item(trans, root, ino);
1688 if (ret == -EEXIST)
1689 ret = 0;
1690 }
1691
1692 out:
1693 btrfs_free_path(path);
1694 return ret;
1695 }
1696
fixup_inode_link_counts(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path)1697 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1698 struct btrfs_root *root,
1699 struct btrfs_path *path)
1700 {
1701 int ret;
1702 struct btrfs_key key;
1703
1704 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1705 key.type = BTRFS_ORPHAN_ITEM_KEY;
1706 key.offset = (u64)-1;
1707 while (1) {
1708 struct btrfs_inode *inode;
1709
1710 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1711 if (ret < 0)
1712 break;
1713
1714 if (ret == 1) {
1715 ret = 0;
1716 if (path->slots[0] == 0)
1717 break;
1718 path->slots[0]--;
1719 }
1720
1721 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1722 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1723 key.type != BTRFS_ORPHAN_ITEM_KEY)
1724 break;
1725
1726 ret = btrfs_del_item(trans, root, path);
1727 if (ret)
1728 break;
1729
1730 btrfs_release_path(path);
1731 inode = btrfs_iget_logging(key.offset, root);
1732 if (IS_ERR(inode)) {
1733 ret = PTR_ERR(inode);
1734 break;
1735 }
1736
1737 ret = fixup_inode_link_count(trans, inode);
1738 iput(&inode->vfs_inode);
1739 if (ret)
1740 break;
1741
1742 /*
1743 * fixup on a directory may create new entries,
1744 * make sure we always look for the highset possible
1745 * offset
1746 */
1747 key.offset = (u64)-1;
1748 }
1749 btrfs_release_path(path);
1750 return ret;
1751 }
1752
1753
1754 /*
1755 * record a given inode in the fixup dir so we can check its link
1756 * count when replay is done. The link count is incremented here
1757 * so the inode won't go away until we check it
1758 */
link_to_fixup_dir(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,u64 objectid)1759 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1760 struct btrfs_root *root,
1761 struct btrfs_path *path,
1762 u64 objectid)
1763 {
1764 struct btrfs_key key;
1765 int ret = 0;
1766 struct btrfs_inode *inode;
1767 struct inode *vfs_inode;
1768
1769 inode = btrfs_iget_logging(objectid, root);
1770 if (IS_ERR(inode))
1771 return PTR_ERR(inode);
1772
1773 vfs_inode = &inode->vfs_inode;
1774 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1775 key.type = BTRFS_ORPHAN_ITEM_KEY;
1776 key.offset = objectid;
1777
1778 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1779
1780 btrfs_release_path(path);
1781 if (ret == 0) {
1782 if (!vfs_inode->i_nlink)
1783 set_nlink(vfs_inode, 1);
1784 else
1785 inc_nlink(vfs_inode);
1786 ret = btrfs_update_inode(trans, inode);
1787 } else if (ret == -EEXIST) {
1788 ret = 0;
1789 }
1790 iput(vfs_inode);
1791
1792 return ret;
1793 }
1794
1795 /*
1796 * when replaying the log for a directory, we only insert names
1797 * for inodes that actually exist. This means an fsync on a directory
1798 * does not implicitly fsync all the new files in it
1799 */
insert_one_name(struct btrfs_trans_handle * trans,struct btrfs_root * root,u64 dirid,u64 index,const struct fscrypt_str * name,struct btrfs_key * location)1800 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1801 struct btrfs_root *root,
1802 u64 dirid, u64 index,
1803 const struct fscrypt_str *name,
1804 struct btrfs_key *location)
1805 {
1806 struct btrfs_inode *inode;
1807 struct btrfs_inode *dir;
1808 int ret;
1809
1810 inode = btrfs_iget_logging(location->objectid, root);
1811 if (IS_ERR(inode))
1812 return PTR_ERR(inode);
1813
1814 dir = btrfs_iget_logging(dirid, root);
1815 if (IS_ERR(dir)) {
1816 iput(&inode->vfs_inode);
1817 return PTR_ERR(dir);
1818 }
1819
1820 ret = btrfs_add_link(trans, dir, inode, name, 1, index);
1821
1822 /* FIXME, put inode into FIXUP list */
1823
1824 iput(&inode->vfs_inode);
1825 iput(&dir->vfs_inode);
1826 return ret;
1827 }
1828
delete_conflicting_dir_entry(struct btrfs_trans_handle * trans,struct btrfs_inode * dir,struct btrfs_path * path,struct btrfs_dir_item * dst_di,const struct btrfs_key * log_key,u8 log_flags,bool exists)1829 static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
1830 struct btrfs_inode *dir,
1831 struct btrfs_path *path,
1832 struct btrfs_dir_item *dst_di,
1833 const struct btrfs_key *log_key,
1834 u8 log_flags,
1835 bool exists)
1836 {
1837 struct btrfs_key found_key;
1838
1839 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1840 /* The existing dentry points to the same inode, don't delete it. */
1841 if (found_key.objectid == log_key->objectid &&
1842 found_key.type == log_key->type &&
1843 found_key.offset == log_key->offset &&
1844 btrfs_dir_flags(path->nodes[0], dst_di) == log_flags)
1845 return 1;
1846
1847 /*
1848 * Don't drop the conflicting directory entry if the inode for the new
1849 * entry doesn't exist.
1850 */
1851 if (!exists)
1852 return 0;
1853
1854 return drop_one_dir_item(trans, path, dir, dst_di);
1855 }
1856
1857 /*
1858 * take a single entry in a log directory item and replay it into
1859 * the subvolume.
1860 *
1861 * if a conflicting item exists in the subdirectory already,
1862 * the inode it points to is unlinked and put into the link count
1863 * fix up tree.
1864 *
1865 * If a name from the log points to a file or directory that does
1866 * not exist in the FS, it is skipped. fsyncs on directories
1867 * do not force down inodes inside that directory, just changes to the
1868 * names or unlinks in a directory.
1869 *
1870 * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
1871 * non-existing inode) and 1 if the name was replayed.
1872 */
replay_one_name(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct extent_buffer * eb,struct btrfs_dir_item * di,struct btrfs_key * key)1873 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1874 struct btrfs_root *root,
1875 struct btrfs_path *path,
1876 struct extent_buffer *eb,
1877 struct btrfs_dir_item *di,
1878 struct btrfs_key *key)
1879 {
1880 struct fscrypt_str name = { 0 };
1881 struct btrfs_dir_item *dir_dst_di;
1882 struct btrfs_dir_item *index_dst_di;
1883 bool dir_dst_matches = false;
1884 bool index_dst_matches = false;
1885 struct btrfs_key log_key;
1886 struct btrfs_key search_key;
1887 struct btrfs_inode *dir;
1888 u8 log_flags;
1889 bool exists;
1890 int ret;
1891 bool update_size = true;
1892 bool name_added = false;
1893
1894 dir = btrfs_iget_logging(key->objectid, root);
1895 if (IS_ERR(dir))
1896 return PTR_ERR(dir);
1897
1898 ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name);
1899 if (ret)
1900 goto out;
1901
1902 log_flags = btrfs_dir_flags(eb, di);
1903 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1904 ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1905 btrfs_release_path(path);
1906 if (ret < 0)
1907 goto out;
1908 exists = (ret == 0);
1909 ret = 0;
1910
1911 dir_dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1912 &name, 1);
1913 if (IS_ERR(dir_dst_di)) {
1914 ret = PTR_ERR(dir_dst_di);
1915 goto out;
1916 } else if (dir_dst_di) {
1917 ret = delete_conflicting_dir_entry(trans, dir, path, dir_dst_di,
1918 &log_key, log_flags, exists);
1919 if (ret < 0)
1920 goto out;
1921 dir_dst_matches = (ret == 1);
1922 }
1923
1924 btrfs_release_path(path);
1925
1926 index_dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1927 key->objectid, key->offset,
1928 &name, 1);
1929 if (IS_ERR(index_dst_di)) {
1930 ret = PTR_ERR(index_dst_di);
1931 goto out;
1932 } else if (index_dst_di) {
1933 ret = delete_conflicting_dir_entry(trans, dir, path, index_dst_di,
1934 &log_key, log_flags, exists);
1935 if (ret < 0)
1936 goto out;
1937 index_dst_matches = (ret == 1);
1938 }
1939
1940 btrfs_release_path(path);
1941
1942 if (dir_dst_matches && index_dst_matches) {
1943 ret = 0;
1944 update_size = false;
1945 goto out;
1946 }
1947
1948 /*
1949 * Check if the inode reference exists in the log for the given name,
1950 * inode and parent inode
1951 */
1952 search_key.objectid = log_key.objectid;
1953 search_key.type = BTRFS_INODE_REF_KEY;
1954 search_key.offset = key->objectid;
1955 ret = backref_in_log(root->log_root, &search_key, 0, &name);
1956 if (ret < 0) {
1957 goto out;
1958 } else if (ret) {
1959 /* The dentry will be added later. */
1960 ret = 0;
1961 update_size = false;
1962 goto out;
1963 }
1964
1965 search_key.objectid = log_key.objectid;
1966 search_key.type = BTRFS_INODE_EXTREF_KEY;
1967 search_key.offset = key->objectid;
1968 ret = backref_in_log(root->log_root, &search_key, key->objectid, &name);
1969 if (ret < 0) {
1970 goto out;
1971 } else if (ret) {
1972 /* The dentry will be added later. */
1973 ret = 0;
1974 update_size = false;
1975 goto out;
1976 }
1977 btrfs_release_path(path);
1978 ret = insert_one_name(trans, root, key->objectid, key->offset,
1979 &name, &log_key);
1980 if (ret && ret != -ENOENT && ret != -EEXIST)
1981 goto out;
1982 if (!ret)
1983 name_added = true;
1984 update_size = false;
1985 ret = 0;
1986
1987 out:
1988 if (!ret && update_size) {
1989 btrfs_i_size_write(dir, dir->vfs_inode.i_size + name.len * 2);
1990 ret = btrfs_update_inode(trans, dir);
1991 }
1992 kfree(name.name);
1993 iput(&dir->vfs_inode);
1994 if (!ret && name_added)
1995 ret = 1;
1996 return ret;
1997 }
1998
1999 /* Replay one dir item from a BTRFS_DIR_INDEX_KEY key. */
replay_one_dir_item(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct extent_buffer * eb,int slot,struct btrfs_key * key)2000 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
2001 struct btrfs_root *root,
2002 struct btrfs_path *path,
2003 struct extent_buffer *eb, int slot,
2004 struct btrfs_key *key)
2005 {
2006 int ret;
2007 struct btrfs_dir_item *di;
2008
2009 /* We only log dir index keys, which only contain a single dir item. */
2010 ASSERT(key->type == BTRFS_DIR_INDEX_KEY);
2011
2012 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2013 ret = replay_one_name(trans, root, path, eb, di, key);
2014 if (ret < 0)
2015 return ret;
2016
2017 /*
2018 * If this entry refers to a non-directory (directories can not have a
2019 * link count > 1) and it was added in the transaction that was not
2020 * committed, make sure we fixup the link count of the inode the entry
2021 * points to. Otherwise something like the following would result in a
2022 * directory pointing to an inode with a wrong link that does not account
2023 * for this dir entry:
2024 *
2025 * mkdir testdir
2026 * touch testdir/foo
2027 * touch testdir/bar
2028 * sync
2029 *
2030 * ln testdir/bar testdir/bar_link
2031 * ln testdir/foo testdir/foo_link
2032 * xfs_io -c "fsync" testdir/bar
2033 *
2034 * <power failure>
2035 *
2036 * mount fs, log replay happens
2037 *
2038 * File foo would remain with a link count of 1 when it has two entries
2039 * pointing to it in the directory testdir. This would make it impossible
2040 * to ever delete the parent directory has it would result in stale
2041 * dentries that can never be deleted.
2042 */
2043 if (ret == 1 && btrfs_dir_ftype(eb, di) != BTRFS_FT_DIR) {
2044 struct btrfs_path *fixup_path;
2045 struct btrfs_key di_key;
2046
2047 fixup_path = btrfs_alloc_path();
2048 if (!fixup_path)
2049 return -ENOMEM;
2050
2051 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2052 ret = link_to_fixup_dir(trans, root, fixup_path, di_key.objectid);
2053 btrfs_free_path(fixup_path);
2054 }
2055
2056 return ret;
2057 }
2058
2059 /*
2060 * directory replay has two parts. There are the standard directory
2061 * items in the log copied from the subvolume, and range items
2062 * created in the log while the subvolume was logged.
2063 *
2064 * The range items tell us which parts of the key space the log
2065 * is authoritative for. During replay, if a key in the subvolume
2066 * directory is in a logged range item, but not actually in the log
2067 * that means it was deleted from the directory before the fsync
2068 * and should be removed.
2069 */
find_dir_range(struct btrfs_root * root,struct btrfs_path * path,u64 dirid,u64 * start_ret,u64 * end_ret)2070 static noinline int find_dir_range(struct btrfs_root *root,
2071 struct btrfs_path *path,
2072 u64 dirid,
2073 u64 *start_ret, u64 *end_ret)
2074 {
2075 struct btrfs_key key;
2076 u64 found_end;
2077 struct btrfs_dir_log_item *item;
2078 int ret;
2079 int nritems;
2080
2081 if (*start_ret == (u64)-1)
2082 return 1;
2083
2084 key.objectid = dirid;
2085 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2086 key.offset = *start_ret;
2087
2088 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2089 if (ret < 0)
2090 goto out;
2091 if (ret > 0) {
2092 if (path->slots[0] == 0)
2093 goto out;
2094 path->slots[0]--;
2095 }
2096 if (ret != 0)
2097 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2098
2099 if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
2100 ret = 1;
2101 goto next;
2102 }
2103 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2104 struct btrfs_dir_log_item);
2105 found_end = btrfs_dir_log_end(path->nodes[0], item);
2106
2107 if (*start_ret >= key.offset && *start_ret <= found_end) {
2108 ret = 0;
2109 *start_ret = key.offset;
2110 *end_ret = found_end;
2111 goto out;
2112 }
2113 ret = 1;
2114 next:
2115 /* check the next slot in the tree to see if it is a valid item */
2116 nritems = btrfs_header_nritems(path->nodes[0]);
2117 path->slots[0]++;
2118 if (path->slots[0] >= nritems) {
2119 ret = btrfs_next_leaf(root, path);
2120 if (ret)
2121 goto out;
2122 }
2123
2124 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2125
2126 if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
2127 ret = 1;
2128 goto out;
2129 }
2130 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2131 struct btrfs_dir_log_item);
2132 found_end = btrfs_dir_log_end(path->nodes[0], item);
2133 *start_ret = key.offset;
2134 *end_ret = found_end;
2135 ret = 0;
2136 out:
2137 btrfs_release_path(path);
2138 return ret;
2139 }
2140
2141 /*
2142 * this looks for a given directory item in the log. If the directory
2143 * item is not in the log, the item is removed and the inode it points
2144 * to is unlinked
2145 */
check_item_in_log(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_path * path,struct btrfs_path * log_path,struct btrfs_inode * dir,struct btrfs_key * dir_key)2146 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
2147 struct btrfs_root *log,
2148 struct btrfs_path *path,
2149 struct btrfs_path *log_path,
2150 struct btrfs_inode *dir,
2151 struct btrfs_key *dir_key)
2152 {
2153 struct btrfs_root *root = dir->root;
2154 int ret;
2155 struct extent_buffer *eb;
2156 int slot;
2157 struct btrfs_dir_item *di;
2158 struct fscrypt_str name = { 0 };
2159 struct btrfs_inode *inode = NULL;
2160 struct btrfs_key location;
2161
2162 /*
2163 * Currently we only log dir index keys. Even if we replay a log created
2164 * by an older kernel that logged both dir index and dir item keys, all
2165 * we need to do is process the dir index keys, we (and our caller) can
2166 * safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY).
2167 */
2168 ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY);
2169
2170 eb = path->nodes[0];
2171 slot = path->slots[0];
2172 di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
2173 ret = read_alloc_one_name(eb, di + 1, btrfs_dir_name_len(eb, di), &name);
2174 if (ret)
2175 goto out;
2176
2177 if (log) {
2178 struct btrfs_dir_item *log_di;
2179
2180 log_di = btrfs_lookup_dir_index_item(trans, log, log_path,
2181 dir_key->objectid,
2182 dir_key->offset, &name, 0);
2183 if (IS_ERR(log_di)) {
2184 ret = PTR_ERR(log_di);
2185 goto out;
2186 } else if (log_di) {
2187 /* The dentry exists in the log, we have nothing to do. */
2188 ret = 0;
2189 goto out;
2190 }
2191 }
2192
2193 btrfs_dir_item_key_to_cpu(eb, di, &location);
2194 btrfs_release_path(path);
2195 btrfs_release_path(log_path);
2196 inode = btrfs_iget_logging(location.objectid, root);
2197 if (IS_ERR(inode)) {
2198 ret = PTR_ERR(inode);
2199 inode = NULL;
2200 goto out;
2201 }
2202
2203 ret = link_to_fixup_dir(trans, root, path, location.objectid);
2204 if (ret)
2205 goto out;
2206
2207 inc_nlink(&inode->vfs_inode);
2208 ret = unlink_inode_for_log_replay(trans, dir, inode, &name);
2209 /*
2210 * Unlike dir item keys, dir index keys can only have one name (entry) in
2211 * them, as there are no key collisions since each key has a unique offset
2212 * (an index number), so we're done.
2213 */
2214 out:
2215 btrfs_release_path(path);
2216 btrfs_release_path(log_path);
2217 kfree(name.name);
2218 if (inode)
2219 iput(&inode->vfs_inode);
2220 return ret;
2221 }
2222
replay_xattr_deletes(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_root * log,struct btrfs_path * path,const u64 ino)2223 static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
2224 struct btrfs_root *root,
2225 struct btrfs_root *log,
2226 struct btrfs_path *path,
2227 const u64 ino)
2228 {
2229 struct btrfs_key search_key;
2230 struct btrfs_path *log_path;
2231 int i;
2232 int nritems;
2233 int ret;
2234
2235 log_path = btrfs_alloc_path();
2236 if (!log_path)
2237 return -ENOMEM;
2238
2239 search_key.objectid = ino;
2240 search_key.type = BTRFS_XATTR_ITEM_KEY;
2241 search_key.offset = 0;
2242 again:
2243 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
2244 if (ret < 0)
2245 goto out;
2246 process_leaf:
2247 nritems = btrfs_header_nritems(path->nodes[0]);
2248 for (i = path->slots[0]; i < nritems; i++) {
2249 struct btrfs_key key;
2250 struct btrfs_dir_item *di;
2251 struct btrfs_dir_item *log_di;
2252 u32 total_size;
2253 u32 cur;
2254
2255 btrfs_item_key_to_cpu(path->nodes[0], &key, i);
2256 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
2257 ret = 0;
2258 goto out;
2259 }
2260
2261 di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
2262 total_size = btrfs_item_size(path->nodes[0], i);
2263 cur = 0;
2264 while (cur < total_size) {
2265 u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
2266 u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
2267 u32 this_len = sizeof(*di) + name_len + data_len;
2268 char *name;
2269
2270 name = kmalloc(name_len, GFP_NOFS);
2271 if (!name) {
2272 ret = -ENOMEM;
2273 goto out;
2274 }
2275 read_extent_buffer(path->nodes[0], name,
2276 (unsigned long)(di + 1), name_len);
2277
2278 log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
2279 name, name_len, 0);
2280 btrfs_release_path(log_path);
2281 if (!log_di) {
2282 /* Doesn't exist in log tree, so delete it. */
2283 btrfs_release_path(path);
2284 di = btrfs_lookup_xattr(trans, root, path, ino,
2285 name, name_len, -1);
2286 kfree(name);
2287 if (IS_ERR(di)) {
2288 ret = PTR_ERR(di);
2289 goto out;
2290 }
2291 ASSERT(di);
2292 ret = btrfs_delete_one_dir_name(trans, root,
2293 path, di);
2294 if (ret)
2295 goto out;
2296 btrfs_release_path(path);
2297 search_key = key;
2298 goto again;
2299 }
2300 kfree(name);
2301 if (IS_ERR(log_di)) {
2302 ret = PTR_ERR(log_di);
2303 goto out;
2304 }
2305 cur += this_len;
2306 di = (struct btrfs_dir_item *)((char *)di + this_len);
2307 }
2308 }
2309 ret = btrfs_next_leaf(root, path);
2310 if (ret > 0)
2311 ret = 0;
2312 else if (ret == 0)
2313 goto process_leaf;
2314 out:
2315 btrfs_free_path(log_path);
2316 btrfs_release_path(path);
2317 return ret;
2318 }
2319
2320
2321 /*
2322 * deletion replay happens before we copy any new directory items
2323 * out of the log or out of backreferences from inodes. It
2324 * scans the log to find ranges of keys that log is authoritative for,
2325 * and then scans the directory to find items in those ranges that are
2326 * not present in the log.
2327 *
2328 * Anything we don't find in the log is unlinked and removed from the
2329 * directory.
2330 */
replay_dir_deletes(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_root * log,struct btrfs_path * path,u64 dirid,bool del_all)2331 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
2332 struct btrfs_root *root,
2333 struct btrfs_root *log,
2334 struct btrfs_path *path,
2335 u64 dirid, bool del_all)
2336 {
2337 u64 range_start;
2338 u64 range_end;
2339 int ret = 0;
2340 struct btrfs_key dir_key;
2341 struct btrfs_key found_key;
2342 struct btrfs_path *log_path;
2343 struct btrfs_inode *dir;
2344
2345 dir_key.objectid = dirid;
2346 dir_key.type = BTRFS_DIR_INDEX_KEY;
2347 log_path = btrfs_alloc_path();
2348 if (!log_path)
2349 return -ENOMEM;
2350
2351 dir = btrfs_iget_logging(dirid, root);
2352 /*
2353 * It isn't an error if the inode isn't there, that can happen because
2354 * we replay the deletes before we copy in the inode item from the log.
2355 */
2356 if (IS_ERR(dir)) {
2357 btrfs_free_path(log_path);
2358 ret = PTR_ERR(dir);
2359 if (ret == -ENOENT)
2360 ret = 0;
2361 return ret;
2362 }
2363
2364 range_start = 0;
2365 range_end = 0;
2366 while (1) {
2367 if (del_all)
2368 range_end = (u64)-1;
2369 else {
2370 ret = find_dir_range(log, path, dirid,
2371 &range_start, &range_end);
2372 if (ret < 0)
2373 goto out;
2374 else if (ret > 0)
2375 break;
2376 }
2377
2378 dir_key.offset = range_start;
2379 while (1) {
2380 int nritems;
2381 ret = btrfs_search_slot(NULL, root, &dir_key, path,
2382 0, 0);
2383 if (ret < 0)
2384 goto out;
2385
2386 nritems = btrfs_header_nritems(path->nodes[0]);
2387 if (path->slots[0] >= nritems) {
2388 ret = btrfs_next_leaf(root, path);
2389 if (ret == 1)
2390 break;
2391 else if (ret < 0)
2392 goto out;
2393 }
2394 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2395 path->slots[0]);
2396 if (found_key.objectid != dirid ||
2397 found_key.type != dir_key.type) {
2398 ret = 0;
2399 goto out;
2400 }
2401
2402 if (found_key.offset > range_end)
2403 break;
2404
2405 ret = check_item_in_log(trans, log, path,
2406 log_path, dir,
2407 &found_key);
2408 if (ret)
2409 goto out;
2410 if (found_key.offset == (u64)-1)
2411 break;
2412 dir_key.offset = found_key.offset + 1;
2413 }
2414 btrfs_release_path(path);
2415 if (range_end == (u64)-1)
2416 break;
2417 range_start = range_end + 1;
2418 }
2419 ret = 0;
2420 out:
2421 btrfs_release_path(path);
2422 btrfs_free_path(log_path);
2423 iput(&dir->vfs_inode);
2424 return ret;
2425 }
2426
2427 /*
2428 * the process_func used to replay items from the log tree. This
2429 * gets called in two different stages. The first stage just looks
2430 * for inodes and makes sure they are all copied into the subvolume.
2431 *
2432 * The second stage copies all the other item types from the log into
2433 * the subvolume. The two stage approach is slower, but gets rid of
2434 * lots of complexity around inodes referencing other inodes that exist
2435 * only in the log (references come from either directory items or inode
2436 * back refs).
2437 */
replay_one_buffer(struct btrfs_root * log,struct extent_buffer * eb,struct walk_control * wc,u64 gen,int level)2438 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
2439 struct walk_control *wc, u64 gen, int level)
2440 {
2441 int nritems;
2442 struct btrfs_tree_parent_check check = {
2443 .transid = gen,
2444 .level = level
2445 };
2446 struct btrfs_path *path;
2447 struct btrfs_root *root = wc->replay_dest;
2448 struct btrfs_key key;
2449 int i;
2450 int ret;
2451
2452 ret = btrfs_read_extent_buffer(eb, &check);
2453 if (ret)
2454 return ret;
2455
2456 level = btrfs_header_level(eb);
2457
2458 if (level != 0)
2459 return 0;
2460
2461 path = btrfs_alloc_path();
2462 if (!path)
2463 return -ENOMEM;
2464
2465 nritems = btrfs_header_nritems(eb);
2466 for (i = 0; i < nritems; i++) {
2467 struct btrfs_inode_item *inode_item;
2468
2469 btrfs_item_key_to_cpu(eb, &key, i);
2470
2471 if (key.type == BTRFS_INODE_ITEM_KEY) {
2472 inode_item = btrfs_item_ptr(eb, i, struct btrfs_inode_item);
2473 /*
2474 * An inode with no links is either:
2475 *
2476 * 1) A tmpfile (O_TMPFILE) that got fsync'ed and never
2477 * got linked before the fsync, skip it, as replaying
2478 * it is pointless since it would be deleted later.
2479 * We skip logging tmpfiles, but it's always possible
2480 * we are replaying a log created with a kernel that
2481 * used to log tmpfiles;
2482 *
2483 * 2) A non-tmpfile which got its last link deleted
2484 * while holding an open fd on it and later got
2485 * fsynced through that fd. We always log the
2486 * parent inodes when inode->last_unlink_trans is
2487 * set to the current transaction, so ignore all the
2488 * inode items for this inode. We will delete the
2489 * inode when processing the parent directory with
2490 * replay_dir_deletes().
2491 */
2492 if (btrfs_inode_nlink(eb, inode_item) == 0) {
2493 wc->ignore_cur_inode = true;
2494 continue;
2495 } else {
2496 wc->ignore_cur_inode = false;
2497 }
2498 }
2499
2500 /* Inode keys are done during the first stage. */
2501 if (key.type == BTRFS_INODE_ITEM_KEY &&
2502 wc->stage == LOG_WALK_REPLAY_INODES) {
2503 u32 mode;
2504
2505 ret = replay_xattr_deletes(wc->trans, root, log, path, key.objectid);
2506 if (ret)
2507 break;
2508 mode = btrfs_inode_mode(eb, inode_item);
2509 if (S_ISDIR(mode)) {
2510 ret = replay_dir_deletes(wc->trans, root, log, path,
2511 key.objectid, false);
2512 if (ret)
2513 break;
2514 }
2515 ret = overwrite_item(wc->trans, root, path,
2516 eb, i, &key);
2517 if (ret)
2518 break;
2519
2520 /*
2521 * Before replaying extents, truncate the inode to its
2522 * size. We need to do it now and not after log replay
2523 * because before an fsync we can have prealloc extents
2524 * added beyond the inode's i_size. If we did it after,
2525 * through orphan cleanup for example, we would drop
2526 * those prealloc extents just after replaying them.
2527 */
2528 if (S_ISREG(mode)) {
2529 struct btrfs_drop_extents_args drop_args = { 0 };
2530 struct btrfs_inode *inode;
2531 u64 from;
2532
2533 inode = btrfs_iget_logging(key.objectid, root);
2534 if (IS_ERR(inode)) {
2535 ret = PTR_ERR(inode);
2536 break;
2537 }
2538 from = ALIGN(i_size_read(&inode->vfs_inode),
2539 root->fs_info->sectorsize);
2540 drop_args.start = from;
2541 drop_args.end = (u64)-1;
2542 drop_args.drop_cache = true;
2543 ret = btrfs_drop_extents(wc->trans, root, inode,
2544 &drop_args);
2545 if (!ret) {
2546 inode_sub_bytes(&inode->vfs_inode,
2547 drop_args.bytes_found);
2548 /* Update the inode's nbytes. */
2549 ret = btrfs_update_inode(wc->trans, inode);
2550 }
2551 iput(&inode->vfs_inode);
2552 if (ret)
2553 break;
2554 }
2555
2556 ret = link_to_fixup_dir(wc->trans, root,
2557 path, key.objectid);
2558 if (ret)
2559 break;
2560 }
2561
2562 if (wc->ignore_cur_inode)
2563 continue;
2564
2565 if (key.type == BTRFS_DIR_INDEX_KEY &&
2566 wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
2567 ret = replay_one_dir_item(wc->trans, root, path,
2568 eb, i, &key);
2569 if (ret)
2570 break;
2571 }
2572
2573 if (wc->stage < LOG_WALK_REPLAY_ALL)
2574 continue;
2575
2576 /* these keys are simply copied */
2577 if (key.type == BTRFS_XATTR_ITEM_KEY) {
2578 ret = overwrite_item(wc->trans, root, path,
2579 eb, i, &key);
2580 if (ret)
2581 break;
2582 } else if (key.type == BTRFS_INODE_REF_KEY ||
2583 key.type == BTRFS_INODE_EXTREF_KEY) {
2584 ret = add_inode_ref(wc->trans, root, log, path,
2585 eb, i, &key);
2586 if (ret)
2587 break;
2588 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
2589 ret = replay_one_extent(wc->trans, root, path,
2590 eb, i, &key);
2591 if (ret)
2592 break;
2593 }
2594 /*
2595 * We don't log BTRFS_DIR_ITEM_KEY keys anymore, only the
2596 * BTRFS_DIR_INDEX_KEY items which we use to derive the
2597 * BTRFS_DIR_ITEM_KEY items. If we are replaying a log from an
2598 * older kernel with such keys, ignore them.
2599 */
2600 }
2601 btrfs_free_path(path);
2602 return ret;
2603 }
2604
2605 /*
2606 * Correctly adjust the reserved bytes occupied by a log tree extent buffer
2607 */
unaccount_log_buffer(struct btrfs_fs_info * fs_info,u64 start)2608 static int unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
2609 {
2610 struct btrfs_block_group *cache;
2611
2612 cache = btrfs_lookup_block_group(fs_info, start);
2613 if (!cache) {
2614 btrfs_err(fs_info, "unable to find block group for %llu", start);
2615 return -ENOENT;
2616 }
2617
2618 spin_lock(&cache->space_info->lock);
2619 spin_lock(&cache->lock);
2620 cache->reserved -= fs_info->nodesize;
2621 cache->space_info->bytes_reserved -= fs_info->nodesize;
2622 spin_unlock(&cache->lock);
2623 spin_unlock(&cache->space_info->lock);
2624
2625 btrfs_put_block_group(cache);
2626
2627 return 0;
2628 }
2629
clean_log_buffer(struct btrfs_trans_handle * trans,struct extent_buffer * eb)2630 static int clean_log_buffer(struct btrfs_trans_handle *trans,
2631 struct extent_buffer *eb)
2632 {
2633 btrfs_tree_lock(eb);
2634 btrfs_clear_buffer_dirty(trans, eb);
2635 wait_on_extent_buffer_writeback(eb);
2636 btrfs_tree_unlock(eb);
2637
2638 if (trans)
2639 return btrfs_pin_reserved_extent(trans, eb);
2640
2641 return unaccount_log_buffer(eb->fs_info, eb->start);
2642 }
2643
walk_down_log_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,int * level,struct walk_control * wc)2644 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
2645 struct btrfs_root *root,
2646 struct btrfs_path *path, int *level,
2647 struct walk_control *wc)
2648 {
2649 struct btrfs_fs_info *fs_info = root->fs_info;
2650 u64 bytenr;
2651 u64 ptr_gen;
2652 struct extent_buffer *next;
2653 struct extent_buffer *cur;
2654 int ret = 0;
2655
2656 while (*level > 0) {
2657 struct btrfs_tree_parent_check check = { 0 };
2658
2659 cur = path->nodes[*level];
2660
2661 WARN_ON(btrfs_header_level(cur) != *level);
2662
2663 if (path->slots[*level] >=
2664 btrfs_header_nritems(cur))
2665 break;
2666
2667 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2668 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2669 check.transid = ptr_gen;
2670 check.level = *level - 1;
2671 check.has_first_key = true;
2672 btrfs_node_key_to_cpu(cur, &check.first_key, path->slots[*level]);
2673
2674 next = btrfs_find_create_tree_block(fs_info, bytenr,
2675 btrfs_header_owner(cur),
2676 *level - 1);
2677 if (IS_ERR(next))
2678 return PTR_ERR(next);
2679
2680 if (*level == 1) {
2681 ret = wc->process_func(root, next, wc, ptr_gen,
2682 *level - 1);
2683 if (ret) {
2684 free_extent_buffer(next);
2685 return ret;
2686 }
2687
2688 path->slots[*level]++;
2689 if (wc->free) {
2690 ret = btrfs_read_extent_buffer(next, &check);
2691 if (ret) {
2692 free_extent_buffer(next);
2693 return ret;
2694 }
2695
2696 ret = clean_log_buffer(trans, next);
2697 if (ret) {
2698 free_extent_buffer(next);
2699 return ret;
2700 }
2701 }
2702 free_extent_buffer(next);
2703 continue;
2704 }
2705 ret = btrfs_read_extent_buffer(next, &check);
2706 if (ret) {
2707 free_extent_buffer(next);
2708 return ret;
2709 }
2710
2711 if (path->nodes[*level-1])
2712 free_extent_buffer(path->nodes[*level-1]);
2713 path->nodes[*level-1] = next;
2714 *level = btrfs_header_level(next);
2715 path->slots[*level] = 0;
2716 cond_resched();
2717 }
2718 path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
2719
2720 cond_resched();
2721 return 0;
2722 }
2723
walk_up_log_tree(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,int * level,struct walk_control * wc)2724 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
2725 struct btrfs_root *root,
2726 struct btrfs_path *path, int *level,
2727 struct walk_control *wc)
2728 {
2729 int i;
2730 int slot;
2731 int ret;
2732
2733 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2734 slot = path->slots[i];
2735 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
2736 path->slots[i]++;
2737 *level = i;
2738 WARN_ON(*level == 0);
2739 return 0;
2740 } else {
2741 ret = wc->process_func(root, path->nodes[*level], wc,
2742 btrfs_header_generation(path->nodes[*level]),
2743 *level);
2744 if (ret)
2745 return ret;
2746
2747 if (wc->free) {
2748 ret = clean_log_buffer(trans, path->nodes[*level]);
2749 if (ret)
2750 return ret;
2751 }
2752 free_extent_buffer(path->nodes[*level]);
2753 path->nodes[*level] = NULL;
2754 *level = i + 1;
2755 }
2756 }
2757 return 1;
2758 }
2759
2760 /*
2761 * drop the reference count on the tree rooted at 'snap'. This traverses
2762 * the tree freeing any blocks that have a ref count of zero after being
2763 * decremented.
2764 */
walk_log_tree(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct walk_control * wc)2765 static int walk_log_tree(struct btrfs_trans_handle *trans,
2766 struct btrfs_root *log, struct walk_control *wc)
2767 {
2768 int ret = 0;
2769 int wret;
2770 int level;
2771 struct btrfs_path *path;
2772 int orig_level;
2773
2774 path = btrfs_alloc_path();
2775 if (!path)
2776 return -ENOMEM;
2777
2778 level = btrfs_header_level(log->node);
2779 orig_level = level;
2780 path->nodes[level] = log->node;
2781 refcount_inc(&log->node->refs);
2782 path->slots[level] = 0;
2783
2784 while (1) {
2785 wret = walk_down_log_tree(trans, log, path, &level, wc);
2786 if (wret > 0)
2787 break;
2788 if (wret < 0) {
2789 ret = wret;
2790 goto out;
2791 }
2792
2793 wret = walk_up_log_tree(trans, log, path, &level, wc);
2794 if (wret > 0)
2795 break;
2796 if (wret < 0) {
2797 ret = wret;
2798 goto out;
2799 }
2800 }
2801
2802 /* was the root node processed? if not, catch it here */
2803 if (path->nodes[orig_level]) {
2804 ret = wc->process_func(log, path->nodes[orig_level], wc,
2805 btrfs_header_generation(path->nodes[orig_level]),
2806 orig_level);
2807 if (ret)
2808 goto out;
2809 if (wc->free)
2810 ret = clean_log_buffer(trans, path->nodes[orig_level]);
2811 }
2812
2813 out:
2814 btrfs_free_path(path);
2815 return ret;
2816 }
2817
2818 /*
2819 * helper function to update the item for a given subvolumes log root
2820 * in the tree of log roots
2821 */
update_log_root(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_root_item * root_item)2822 static int update_log_root(struct btrfs_trans_handle *trans,
2823 struct btrfs_root *log,
2824 struct btrfs_root_item *root_item)
2825 {
2826 struct btrfs_fs_info *fs_info = log->fs_info;
2827 int ret;
2828
2829 if (log->log_transid == 1) {
2830 /* insert root item on the first sync */
2831 ret = btrfs_insert_root(trans, fs_info->log_root_tree,
2832 &log->root_key, root_item);
2833 } else {
2834 ret = btrfs_update_root(trans, fs_info->log_root_tree,
2835 &log->root_key, root_item);
2836 }
2837 return ret;
2838 }
2839
wait_log_commit(struct btrfs_root * root,int transid)2840 static void wait_log_commit(struct btrfs_root *root, int transid)
2841 {
2842 DEFINE_WAIT(wait);
2843 int index = transid % 2;
2844
2845 /*
2846 * we only allow two pending log transactions at a time,
2847 * so we know that if ours is more than 2 older than the
2848 * current transaction, we're done
2849 */
2850 for (;;) {
2851 prepare_to_wait(&root->log_commit_wait[index],
2852 &wait, TASK_UNINTERRUPTIBLE);
2853
2854 if (!(root->log_transid_committed < transid &&
2855 atomic_read(&root->log_commit[index])))
2856 break;
2857
2858 mutex_unlock(&root->log_mutex);
2859 schedule();
2860 mutex_lock(&root->log_mutex);
2861 }
2862 finish_wait(&root->log_commit_wait[index], &wait);
2863 }
2864
wait_for_writer(struct btrfs_root * root)2865 static void wait_for_writer(struct btrfs_root *root)
2866 {
2867 DEFINE_WAIT(wait);
2868
2869 for (;;) {
2870 prepare_to_wait(&root->log_writer_wait, &wait,
2871 TASK_UNINTERRUPTIBLE);
2872 if (!atomic_read(&root->log_writers))
2873 break;
2874
2875 mutex_unlock(&root->log_mutex);
2876 schedule();
2877 mutex_lock(&root->log_mutex);
2878 }
2879 finish_wait(&root->log_writer_wait, &wait);
2880 }
2881
btrfs_init_log_ctx(struct btrfs_log_ctx * ctx,struct btrfs_inode * inode)2882 void btrfs_init_log_ctx(struct btrfs_log_ctx *ctx, struct btrfs_inode *inode)
2883 {
2884 ctx->log_ret = 0;
2885 ctx->log_transid = 0;
2886 ctx->log_new_dentries = false;
2887 ctx->logging_new_name = false;
2888 ctx->logging_new_delayed_dentries = false;
2889 ctx->logged_before = false;
2890 ctx->inode = inode;
2891 INIT_LIST_HEAD(&ctx->list);
2892 INIT_LIST_HEAD(&ctx->ordered_extents);
2893 INIT_LIST_HEAD(&ctx->conflict_inodes);
2894 ctx->num_conflict_inodes = 0;
2895 ctx->logging_conflict_inodes = false;
2896 ctx->scratch_eb = NULL;
2897 }
2898
btrfs_init_log_ctx_scratch_eb(struct btrfs_log_ctx * ctx)2899 void btrfs_init_log_ctx_scratch_eb(struct btrfs_log_ctx *ctx)
2900 {
2901 struct btrfs_inode *inode = ctx->inode;
2902
2903 if (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
2904 !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
2905 return;
2906
2907 /*
2908 * Don't care about allocation failure. This is just for optimization,
2909 * if we fail to allocate here, we will try again later if needed.
2910 */
2911 ctx->scratch_eb = alloc_dummy_extent_buffer(inode->root->fs_info, 0);
2912 }
2913
btrfs_release_log_ctx_extents(struct btrfs_log_ctx * ctx)2914 void btrfs_release_log_ctx_extents(struct btrfs_log_ctx *ctx)
2915 {
2916 struct btrfs_ordered_extent *ordered;
2917 struct btrfs_ordered_extent *tmp;
2918
2919 btrfs_assert_inode_locked(ctx->inode);
2920
2921 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
2922 list_del_init(&ordered->log_list);
2923 btrfs_put_ordered_extent(ordered);
2924 }
2925 }
2926
2927
btrfs_remove_log_ctx(struct btrfs_root * root,struct btrfs_log_ctx * ctx)2928 static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
2929 struct btrfs_log_ctx *ctx)
2930 {
2931 mutex_lock(&root->log_mutex);
2932 list_del_init(&ctx->list);
2933 mutex_unlock(&root->log_mutex);
2934 }
2935
2936 /*
2937 * Invoked in log mutex context, or be sure there is no other task which
2938 * can access the list.
2939 */
btrfs_remove_all_log_ctxs(struct btrfs_root * root,int index,int error)2940 static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
2941 int index, int error)
2942 {
2943 struct btrfs_log_ctx *ctx;
2944 struct btrfs_log_ctx *safe;
2945
2946 list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
2947 list_del_init(&ctx->list);
2948 ctx->log_ret = error;
2949 }
2950 }
2951
2952 /*
2953 * Sends a given tree log down to the disk and updates the super blocks to
2954 * record it. When this call is done, you know that any inodes previously
2955 * logged are safely on disk only if it returns 0.
2956 *
2957 * Any other return value means you need to call btrfs_commit_transaction.
2958 * Some of the edge cases for fsyncing directories that have had unlinks
2959 * or renames done in the past mean that sometimes the only safe
2960 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
2961 * that has happened.
2962 */
btrfs_sync_log(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_log_ctx * ctx)2963 int btrfs_sync_log(struct btrfs_trans_handle *trans,
2964 struct btrfs_root *root, struct btrfs_log_ctx *ctx)
2965 {
2966 int index1;
2967 int index2;
2968 int mark;
2969 int ret;
2970 struct btrfs_fs_info *fs_info = root->fs_info;
2971 struct btrfs_root *log = root->log_root;
2972 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
2973 struct btrfs_root_item new_root_item;
2974 int log_transid = 0;
2975 struct btrfs_log_ctx root_log_ctx;
2976 struct blk_plug plug;
2977 u64 log_root_start;
2978 u64 log_root_level;
2979
2980 mutex_lock(&root->log_mutex);
2981 log_transid = ctx->log_transid;
2982 if (root->log_transid_committed >= log_transid) {
2983 mutex_unlock(&root->log_mutex);
2984 return ctx->log_ret;
2985 }
2986
2987 index1 = log_transid % 2;
2988 if (atomic_read(&root->log_commit[index1])) {
2989 wait_log_commit(root, log_transid);
2990 mutex_unlock(&root->log_mutex);
2991 return ctx->log_ret;
2992 }
2993 ASSERT(log_transid == root->log_transid);
2994 atomic_set(&root->log_commit[index1], 1);
2995
2996 /* wait for previous tree log sync to complete */
2997 if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
2998 wait_log_commit(root, log_transid - 1);
2999
3000 while (1) {
3001 int batch = atomic_read(&root->log_batch);
3002 /* when we're on an ssd, just kick the log commit out */
3003 if (!btrfs_test_opt(fs_info, SSD) &&
3004 test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
3005 mutex_unlock(&root->log_mutex);
3006 schedule_timeout_uninterruptible(1);
3007 mutex_lock(&root->log_mutex);
3008 }
3009 wait_for_writer(root);
3010 if (batch == atomic_read(&root->log_batch))
3011 break;
3012 }
3013
3014 /* bail out if we need to do a full commit */
3015 if (btrfs_need_log_full_commit(trans)) {
3016 ret = BTRFS_LOG_FORCE_COMMIT;
3017 mutex_unlock(&root->log_mutex);
3018 goto out;
3019 }
3020
3021 if (log_transid % 2 == 0)
3022 mark = EXTENT_DIRTY_LOG1;
3023 else
3024 mark = EXTENT_DIRTY_LOG2;
3025
3026 /* we start IO on all the marked extents here, but we don't actually
3027 * wait for them until later.
3028 */
3029 blk_start_plug(&plug);
3030 ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
3031 /*
3032 * -EAGAIN happens when someone, e.g., a concurrent transaction
3033 * commit, writes a dirty extent in this tree-log commit. This
3034 * concurrent write will create a hole writing out the extents,
3035 * and we cannot proceed on a zoned filesystem, requiring
3036 * sequential writing. While we can bail out to a full commit
3037 * here, but we can continue hoping the concurrent writing fills
3038 * the hole.
3039 */
3040 if (ret == -EAGAIN && btrfs_is_zoned(fs_info))
3041 ret = 0;
3042 if (ret) {
3043 blk_finish_plug(&plug);
3044 btrfs_set_log_full_commit(trans);
3045 mutex_unlock(&root->log_mutex);
3046 goto out;
3047 }
3048
3049 /*
3050 * We _must_ update under the root->log_mutex in order to make sure we
3051 * have a consistent view of the log root we are trying to commit at
3052 * this moment.
3053 *
3054 * We _must_ copy this into a local copy, because we are not holding the
3055 * log_root_tree->log_mutex yet. This is important because when we
3056 * commit the log_root_tree we must have a consistent view of the
3057 * log_root_tree when we update the super block to point at the
3058 * log_root_tree bytenr. If we update the log_root_tree here we'll race
3059 * with the commit and possibly point at the new block which we may not
3060 * have written out.
3061 */
3062 btrfs_set_root_node(&log->root_item, log->node);
3063 memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
3064
3065 btrfs_set_root_log_transid(root, root->log_transid + 1);
3066 log->log_transid = root->log_transid;
3067 root->log_start_pid = 0;
3068 /*
3069 * IO has been started, blocks of the log tree have WRITTEN flag set
3070 * in their headers. new modifications of the log will be written to
3071 * new positions. so it's safe to allow log writers to go in.
3072 */
3073 mutex_unlock(&root->log_mutex);
3074
3075 if (btrfs_is_zoned(fs_info)) {
3076 mutex_lock(&fs_info->tree_root->log_mutex);
3077 if (!log_root_tree->node) {
3078 ret = btrfs_alloc_log_tree_node(trans, log_root_tree);
3079 if (ret) {
3080 mutex_unlock(&fs_info->tree_root->log_mutex);
3081 blk_finish_plug(&plug);
3082 goto out;
3083 }
3084 }
3085 mutex_unlock(&fs_info->tree_root->log_mutex);
3086 }
3087
3088 btrfs_init_log_ctx(&root_log_ctx, NULL);
3089
3090 mutex_lock(&log_root_tree->log_mutex);
3091
3092 index2 = log_root_tree->log_transid % 2;
3093 list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
3094 root_log_ctx.log_transid = log_root_tree->log_transid;
3095
3096 /*
3097 * Now we are safe to update the log_root_tree because we're under the
3098 * log_mutex, and we're a current writer so we're holding the commit
3099 * open until we drop the log_mutex.
3100 */
3101 ret = update_log_root(trans, log, &new_root_item);
3102 if (ret) {
3103 list_del_init(&root_log_ctx.list);
3104 blk_finish_plug(&plug);
3105 btrfs_set_log_full_commit(trans);
3106 if (ret != -ENOSPC)
3107 btrfs_err(fs_info,
3108 "failed to update log for root %llu ret %d",
3109 btrfs_root_id(root), ret);
3110 btrfs_wait_tree_log_extents(log, mark);
3111 mutex_unlock(&log_root_tree->log_mutex);
3112 goto out;
3113 }
3114
3115 if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
3116 blk_finish_plug(&plug);
3117 list_del_init(&root_log_ctx.list);
3118 mutex_unlock(&log_root_tree->log_mutex);
3119 ret = root_log_ctx.log_ret;
3120 goto out;
3121 }
3122
3123 if (atomic_read(&log_root_tree->log_commit[index2])) {
3124 blk_finish_plug(&plug);
3125 ret = btrfs_wait_tree_log_extents(log, mark);
3126 wait_log_commit(log_root_tree,
3127 root_log_ctx.log_transid);
3128 mutex_unlock(&log_root_tree->log_mutex);
3129 if (!ret)
3130 ret = root_log_ctx.log_ret;
3131 goto out;
3132 }
3133 ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
3134 atomic_set(&log_root_tree->log_commit[index2], 1);
3135
3136 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
3137 wait_log_commit(log_root_tree,
3138 root_log_ctx.log_transid - 1);
3139 }
3140
3141 /*
3142 * now that we've moved on to the tree of log tree roots,
3143 * check the full commit flag again
3144 */
3145 if (btrfs_need_log_full_commit(trans)) {
3146 blk_finish_plug(&plug);
3147 btrfs_wait_tree_log_extents(log, mark);
3148 mutex_unlock(&log_root_tree->log_mutex);
3149 ret = BTRFS_LOG_FORCE_COMMIT;
3150 goto out_wake_log_root;
3151 }
3152
3153 ret = btrfs_write_marked_extents(fs_info,
3154 &log_root_tree->dirty_log_pages,
3155 EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2);
3156 blk_finish_plug(&plug);
3157 /*
3158 * As described above, -EAGAIN indicates a hole in the extents. We
3159 * cannot wait for these write outs since the waiting cause a
3160 * deadlock. Bail out to the full commit instead.
3161 */
3162 if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) {
3163 btrfs_set_log_full_commit(trans);
3164 btrfs_wait_tree_log_extents(log, mark);
3165 mutex_unlock(&log_root_tree->log_mutex);
3166 goto out_wake_log_root;
3167 } else if (ret) {
3168 btrfs_set_log_full_commit(trans);
3169 mutex_unlock(&log_root_tree->log_mutex);
3170 goto out_wake_log_root;
3171 }
3172 ret = btrfs_wait_tree_log_extents(log, mark);
3173 if (!ret)
3174 ret = btrfs_wait_tree_log_extents(log_root_tree,
3175 EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2);
3176 if (ret) {
3177 btrfs_set_log_full_commit(trans);
3178 mutex_unlock(&log_root_tree->log_mutex);
3179 goto out_wake_log_root;
3180 }
3181
3182 log_root_start = log_root_tree->node->start;
3183 log_root_level = btrfs_header_level(log_root_tree->node);
3184 log_root_tree->log_transid++;
3185 mutex_unlock(&log_root_tree->log_mutex);
3186
3187 /*
3188 * Here we are guaranteed that nobody is going to write the superblock
3189 * for the current transaction before us and that neither we do write
3190 * our superblock before the previous transaction finishes its commit
3191 * and writes its superblock, because:
3192 *
3193 * 1) We are holding a handle on the current transaction, so no body
3194 * can commit it until we release the handle;
3195 *
3196 * 2) Before writing our superblock we acquire the tree_log_mutex, so
3197 * if the previous transaction is still committing, and hasn't yet
3198 * written its superblock, we wait for it to do it, because a
3199 * transaction commit acquires the tree_log_mutex when the commit
3200 * begins and releases it only after writing its superblock.
3201 */
3202 mutex_lock(&fs_info->tree_log_mutex);
3203
3204 /*
3205 * The previous transaction writeout phase could have failed, and thus
3206 * marked the fs in an error state. We must not commit here, as we
3207 * could have updated our generation in the super_for_commit and
3208 * writing the super here would result in transid mismatches. If there
3209 * is an error here just bail.
3210 */
3211 if (BTRFS_FS_ERROR(fs_info)) {
3212 ret = -EIO;
3213 btrfs_set_log_full_commit(trans);
3214 btrfs_abort_transaction(trans, ret);
3215 mutex_unlock(&fs_info->tree_log_mutex);
3216 goto out_wake_log_root;
3217 }
3218
3219 btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
3220 btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
3221 ret = write_all_supers(fs_info, 1);
3222 mutex_unlock(&fs_info->tree_log_mutex);
3223 if (ret) {
3224 btrfs_set_log_full_commit(trans);
3225 btrfs_abort_transaction(trans, ret);
3226 goto out_wake_log_root;
3227 }
3228
3229 /*
3230 * We know there can only be one task here, since we have not yet set
3231 * root->log_commit[index1] to 0 and any task attempting to sync the
3232 * log must wait for the previous log transaction to commit if it's
3233 * still in progress or wait for the current log transaction commit if
3234 * someone else already started it. We use <= and not < because the
3235 * first log transaction has an ID of 0.
3236 */
3237 ASSERT(btrfs_get_root_last_log_commit(root) <= log_transid);
3238 btrfs_set_root_last_log_commit(root, log_transid);
3239
3240 out_wake_log_root:
3241 mutex_lock(&log_root_tree->log_mutex);
3242 btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
3243
3244 log_root_tree->log_transid_committed++;
3245 atomic_set(&log_root_tree->log_commit[index2], 0);
3246 mutex_unlock(&log_root_tree->log_mutex);
3247
3248 /*
3249 * The barrier before waitqueue_active (in cond_wake_up) is needed so
3250 * all the updates above are seen by the woken threads. It might not be
3251 * necessary, but proving that seems to be hard.
3252 */
3253 cond_wake_up(&log_root_tree->log_commit_wait[index2]);
3254 out:
3255 mutex_lock(&root->log_mutex);
3256 btrfs_remove_all_log_ctxs(root, index1, ret);
3257 root->log_transid_committed++;
3258 atomic_set(&root->log_commit[index1], 0);
3259 mutex_unlock(&root->log_mutex);
3260
3261 /*
3262 * The barrier before waitqueue_active (in cond_wake_up) is needed so
3263 * all the updates above are seen by the woken threads. It might not be
3264 * necessary, but proving that seems to be hard.
3265 */
3266 cond_wake_up(&root->log_commit_wait[index1]);
3267 return ret;
3268 }
3269
free_log_tree(struct btrfs_trans_handle * trans,struct btrfs_root * log)3270 static void free_log_tree(struct btrfs_trans_handle *trans,
3271 struct btrfs_root *log)
3272 {
3273 int ret;
3274 struct walk_control wc = {
3275 .free = 1,
3276 .process_func = process_one_buffer
3277 };
3278
3279 if (log->node) {
3280 ret = walk_log_tree(trans, log, &wc);
3281 if (ret) {
3282 /*
3283 * We weren't able to traverse the entire log tree, the
3284 * typical scenario is getting an -EIO when reading an
3285 * extent buffer of the tree, due to a previous writeback
3286 * failure of it.
3287 */
3288 set_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
3289 &log->fs_info->fs_state);
3290
3291 /*
3292 * Some extent buffers of the log tree may still be dirty
3293 * and not yet written back to storage, because we may
3294 * have updates to a log tree without syncing a log tree,
3295 * such as during rename and link operations. So flush
3296 * them out and wait for their writeback to complete, so
3297 * that we properly cleanup their state and pages.
3298 */
3299 btrfs_write_marked_extents(log->fs_info,
3300 &log->dirty_log_pages,
3301 EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2);
3302 btrfs_wait_tree_log_extents(log,
3303 EXTENT_DIRTY_LOG1 | EXTENT_DIRTY_LOG2);
3304
3305 if (trans)
3306 btrfs_abort_transaction(trans, ret);
3307 else
3308 btrfs_handle_fs_error(log->fs_info, ret, NULL);
3309 }
3310 }
3311
3312 btrfs_extent_io_tree_release(&log->dirty_log_pages);
3313 btrfs_extent_io_tree_release(&log->log_csum_range);
3314
3315 btrfs_put_root(log);
3316 }
3317
3318 /*
3319 * free all the extents used by the tree log. This should be called
3320 * at commit time of the full transaction
3321 */
btrfs_free_log(struct btrfs_trans_handle * trans,struct btrfs_root * root)3322 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
3323 {
3324 if (root->log_root) {
3325 free_log_tree(trans, root->log_root);
3326 root->log_root = NULL;
3327 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
3328 }
3329 return 0;
3330 }
3331
btrfs_free_log_root_tree(struct btrfs_trans_handle * trans,struct btrfs_fs_info * fs_info)3332 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
3333 struct btrfs_fs_info *fs_info)
3334 {
3335 if (fs_info->log_root_tree) {
3336 free_log_tree(trans, fs_info->log_root_tree);
3337 fs_info->log_root_tree = NULL;
3338 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state);
3339 }
3340 return 0;
3341 }
3342
mark_inode_as_not_logged(const struct btrfs_trans_handle * trans,struct btrfs_inode * inode)3343 static bool mark_inode_as_not_logged(const struct btrfs_trans_handle *trans,
3344 struct btrfs_inode *inode)
3345 {
3346 bool ret = false;
3347
3348 /*
3349 * Do this only if ->logged_trans is still 0 to prevent races with
3350 * concurrent logging as we may see the inode not logged when
3351 * inode_logged() is called but it gets logged after inode_logged() did
3352 * not find it in the log tree and we end up setting ->logged_trans to a
3353 * value less than trans->transid after the concurrent logging task has
3354 * set it to trans->transid. As a consequence, subsequent rename, unlink
3355 * and link operations may end up not logging new names and removing old
3356 * names from the log.
3357 */
3358 spin_lock(&inode->lock);
3359 if (inode->logged_trans == 0)
3360 inode->logged_trans = trans->transid - 1;
3361 else if (inode->logged_trans == trans->transid)
3362 ret = true;
3363 spin_unlock(&inode->lock);
3364
3365 return ret;
3366 }
3367
3368 /*
3369 * Check if an inode was logged in the current transaction. This correctly deals
3370 * with the case where the inode was logged but has a logged_trans of 0, which
3371 * happens if the inode is evicted and loaded again, as logged_trans is an in
3372 * memory only field (not persisted).
3373 *
3374 * Returns 1 if the inode was logged before in the transaction, 0 if it was not,
3375 * and < 0 on error.
3376 */
inode_logged(const struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path_in)3377 static int inode_logged(const struct btrfs_trans_handle *trans,
3378 struct btrfs_inode *inode,
3379 struct btrfs_path *path_in)
3380 {
3381 struct btrfs_path *path = path_in;
3382 struct btrfs_key key;
3383 int ret;
3384
3385 /*
3386 * Quick lockless call, since once ->logged_trans is set to the current
3387 * transaction, we never set it to a lower value anywhere else.
3388 */
3389 if (data_race(inode->logged_trans) == trans->transid)
3390 return 1;
3391
3392 /*
3393 * If logged_trans is not 0 and not trans->transid, then we know the
3394 * inode was not logged in this transaction, so we can return false
3395 * right away. We take the lock to avoid a race caused by load/store
3396 * tearing with a concurrent btrfs_log_inode() call or a concurrent task
3397 * in this function further below - an update to trans->transid can be
3398 * teared into two 32 bits updates for example, in which case we could
3399 * see a positive value that is not trans->transid and assume the inode
3400 * was not logged when it was.
3401 */
3402 spin_lock(&inode->lock);
3403 if (inode->logged_trans == trans->transid) {
3404 spin_unlock(&inode->lock);
3405 return 1;
3406 } else if (inode->logged_trans > 0) {
3407 spin_unlock(&inode->lock);
3408 return 0;
3409 }
3410 spin_unlock(&inode->lock);
3411
3412 /*
3413 * If no log tree was created for this root in this transaction, then
3414 * the inode can not have been logged in this transaction. In that case
3415 * set logged_trans to anything greater than 0 and less than the current
3416 * transaction's ID, to avoid the search below in a future call in case
3417 * a log tree gets created after this.
3418 */
3419 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state))
3420 return mark_inode_as_not_logged(trans, inode);
3421
3422 /*
3423 * We have a log tree and the inode's logged_trans is 0. We can't tell
3424 * for sure if the inode was logged before in this transaction by looking
3425 * only at logged_trans. We could be pessimistic and assume it was, but
3426 * that can lead to unnecessarily logging an inode during rename and link
3427 * operations, and then further updating the log in followup rename and
3428 * link operations, specially if it's a directory, which adds latency
3429 * visible to applications doing a series of rename or link operations.
3430 *
3431 * A logged_trans of 0 here can mean several things:
3432 *
3433 * 1) The inode was never logged since the filesystem was mounted, and may
3434 * or may have not been evicted and loaded again;
3435 *
3436 * 2) The inode was logged in a previous transaction, then evicted and
3437 * then loaded again;
3438 *
3439 * 3) The inode was logged in the current transaction, then evicted and
3440 * then loaded again.
3441 *
3442 * For cases 1) and 2) we don't want to return true, but we need to detect
3443 * case 3) and return true. So we do a search in the log root for the inode
3444 * item.
3445 */
3446 key.objectid = btrfs_ino(inode);
3447 key.type = BTRFS_INODE_ITEM_KEY;
3448 key.offset = 0;
3449
3450 if (!path) {
3451 path = btrfs_alloc_path();
3452 if (!path)
3453 return -ENOMEM;
3454 }
3455
3456 ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
3457
3458 if (path_in)
3459 btrfs_release_path(path);
3460 else
3461 btrfs_free_path(path);
3462
3463 /*
3464 * Logging an inode always results in logging its inode item. So if we
3465 * did not find the item we know the inode was not logged for sure.
3466 */
3467 if (ret < 0) {
3468 return ret;
3469 } else if (ret > 0) {
3470 /*
3471 * Set logged_trans to a value greater than 0 and less then the
3472 * current transaction to avoid doing the search in future calls.
3473 */
3474 return mark_inode_as_not_logged(trans, inode);
3475 }
3476
3477 /*
3478 * The inode was previously logged and then evicted, set logged_trans to
3479 * the current transacion's ID, to avoid future tree searches as long as
3480 * the inode is not evicted again.
3481 */
3482 spin_lock(&inode->lock);
3483 inode->logged_trans = trans->transid;
3484 spin_unlock(&inode->lock);
3485
3486 return 1;
3487 }
3488
3489 /*
3490 * Delete a directory entry from the log if it exists.
3491 *
3492 * Returns < 0 on error
3493 * 1 if the entry does not exists
3494 * 0 if the entry existed and was successfully deleted
3495 */
del_logged_dentry(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_path * path,u64 dir_ino,const struct fscrypt_str * name,u64 index)3496 static int del_logged_dentry(struct btrfs_trans_handle *trans,
3497 struct btrfs_root *log,
3498 struct btrfs_path *path,
3499 u64 dir_ino,
3500 const struct fscrypt_str *name,
3501 u64 index)
3502 {
3503 struct btrfs_dir_item *di;
3504
3505 /*
3506 * We only log dir index items of a directory, so we don't need to look
3507 * for dir item keys.
3508 */
3509 di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
3510 index, name, -1);
3511 if (IS_ERR(di))
3512 return PTR_ERR(di);
3513 else if (!di)
3514 return 1;
3515
3516 /*
3517 * We do not need to update the size field of the directory's
3518 * inode item because on log replay we update the field to reflect
3519 * all existing entries in the directory (see overwrite_item()).
3520 */
3521 return btrfs_del_item(trans, log, path);
3522 }
3523
3524 /*
3525 * If both a file and directory are logged, and unlinks or renames are
3526 * mixed in, we have a few interesting corners:
3527 *
3528 * create file X in dir Y
3529 * link file X to X.link in dir Y
3530 * fsync file X
3531 * unlink file X but leave X.link
3532 * fsync dir Y
3533 *
3534 * After a crash we would expect only X.link to exist. But file X
3535 * didn't get fsync'd again so the log has back refs for X and X.link.
3536 *
3537 * We solve this by removing directory entries and inode backrefs from the
3538 * log when a file that was logged in the current transaction is
3539 * unlinked. Any later fsync will include the updated log entries, and
3540 * we'll be able to reconstruct the proper directory items from backrefs.
3541 *
3542 * This optimizations allows us to avoid relogging the entire inode
3543 * or the entire directory.
3544 */
btrfs_del_dir_entries_in_log(struct btrfs_trans_handle * trans,struct btrfs_root * root,const struct fscrypt_str * name,struct btrfs_inode * dir,u64 index)3545 void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
3546 struct btrfs_root *root,
3547 const struct fscrypt_str *name,
3548 struct btrfs_inode *dir, u64 index)
3549 {
3550 struct btrfs_path *path;
3551 int ret;
3552
3553 ret = inode_logged(trans, dir, NULL);
3554 if (ret == 0)
3555 return;
3556 else if (ret < 0) {
3557 btrfs_set_log_full_commit(trans);
3558 return;
3559 }
3560
3561 path = btrfs_alloc_path();
3562 if (!path) {
3563 btrfs_set_log_full_commit(trans);
3564 return;
3565 }
3566
3567 ret = join_running_log_trans(root);
3568 ASSERT(ret == 0, "join_running_log_trans() ret=%d", ret);
3569 if (WARN_ON(ret))
3570 goto out;
3571
3572 mutex_lock(&dir->log_mutex);
3573
3574 ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
3575 name, index);
3576 mutex_unlock(&dir->log_mutex);
3577 if (ret < 0)
3578 btrfs_set_log_full_commit(trans);
3579 btrfs_end_log_trans(root);
3580 out:
3581 btrfs_free_path(path);
3582 }
3583
3584 /* see comments for btrfs_del_dir_entries_in_log */
btrfs_del_inode_ref_in_log(struct btrfs_trans_handle * trans,struct btrfs_root * root,const struct fscrypt_str * name,struct btrfs_inode * inode,u64 dirid)3585 void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
3586 struct btrfs_root *root,
3587 const struct fscrypt_str *name,
3588 struct btrfs_inode *inode, u64 dirid)
3589 {
3590 struct btrfs_root *log;
3591 int ret;
3592
3593 ret = inode_logged(trans, inode, NULL);
3594 if (ret == 0)
3595 return;
3596 else if (ret < 0) {
3597 btrfs_set_log_full_commit(trans);
3598 return;
3599 }
3600
3601 ret = join_running_log_trans(root);
3602 ASSERT(ret == 0, "join_running_log_trans() ret=%d", ret);
3603 if (WARN_ON(ret))
3604 return;
3605 log = root->log_root;
3606 mutex_lock(&inode->log_mutex);
3607
3608 ret = btrfs_del_inode_ref(trans, log, name, btrfs_ino(inode), dirid, NULL);
3609 mutex_unlock(&inode->log_mutex);
3610 if (ret < 0 && ret != -ENOENT)
3611 btrfs_set_log_full_commit(trans);
3612 btrfs_end_log_trans(root);
3613 }
3614
3615 /*
3616 * creates a range item in the log for 'dirid'. first_offset and
3617 * last_offset tell us which parts of the key space the log should
3618 * be considered authoritative for.
3619 */
insert_dir_log_key(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_path * path,u64 dirid,u64 first_offset,u64 last_offset)3620 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
3621 struct btrfs_root *log,
3622 struct btrfs_path *path,
3623 u64 dirid,
3624 u64 first_offset, u64 last_offset)
3625 {
3626 int ret;
3627 struct btrfs_key key;
3628 struct btrfs_dir_log_item *item;
3629
3630 key.objectid = dirid;
3631 key.type = BTRFS_DIR_LOG_INDEX_KEY;
3632 key.offset = first_offset;
3633 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
3634 /*
3635 * -EEXIST is fine and can happen sporadically when we are logging a
3636 * directory and have concurrent insertions in the subvolume's tree for
3637 * items from other inodes and that result in pushing off some dir items
3638 * from one leaf to another in order to accommodate for the new items.
3639 * This results in logging the same dir index range key.
3640 */
3641 if (ret && ret != -EEXIST)
3642 return ret;
3643
3644 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3645 struct btrfs_dir_log_item);
3646 if (ret == -EEXIST) {
3647 const u64 curr_end = btrfs_dir_log_end(path->nodes[0], item);
3648
3649 /*
3650 * btrfs_del_dir_entries_in_log() might have been called during
3651 * an unlink between the initial insertion of this key and the
3652 * current update, or we might be logging a single entry deletion
3653 * during a rename, so set the new last_offset to the max value.
3654 */
3655 last_offset = max(last_offset, curr_end);
3656 }
3657 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
3658 btrfs_release_path(path);
3659 return 0;
3660 }
3661
flush_dir_items_batch(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct extent_buffer * src,struct btrfs_path * dst_path,int start_slot,int count)3662 static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
3663 struct btrfs_inode *inode,
3664 struct extent_buffer *src,
3665 struct btrfs_path *dst_path,
3666 int start_slot,
3667 int count)
3668 {
3669 struct btrfs_root *log = inode->root->log_root;
3670 char *ins_data = NULL;
3671 struct btrfs_item_batch batch;
3672 struct extent_buffer *dst;
3673 unsigned long src_offset;
3674 unsigned long dst_offset;
3675 u64 last_index;
3676 struct btrfs_key key;
3677 u32 item_size;
3678 int ret;
3679 int i;
3680
3681 ASSERT(count > 0);
3682 batch.nr = count;
3683
3684 if (count == 1) {
3685 btrfs_item_key_to_cpu(src, &key, start_slot);
3686 item_size = btrfs_item_size(src, start_slot);
3687 batch.keys = &key;
3688 batch.data_sizes = &item_size;
3689 batch.total_data_size = item_size;
3690 } else {
3691 struct btrfs_key *ins_keys;
3692 u32 *ins_sizes;
3693
3694 ins_data = kmalloc(count * sizeof(u32) +
3695 count * sizeof(struct btrfs_key), GFP_NOFS);
3696 if (!ins_data)
3697 return -ENOMEM;
3698
3699 ins_sizes = (u32 *)ins_data;
3700 ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32));
3701 batch.keys = ins_keys;
3702 batch.data_sizes = ins_sizes;
3703 batch.total_data_size = 0;
3704
3705 for (i = 0; i < count; i++) {
3706 const int slot = start_slot + i;
3707
3708 btrfs_item_key_to_cpu(src, &ins_keys[i], slot);
3709 ins_sizes[i] = btrfs_item_size(src, slot);
3710 batch.total_data_size += ins_sizes[i];
3711 }
3712 }
3713
3714 ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
3715 if (ret)
3716 goto out;
3717
3718 dst = dst_path->nodes[0];
3719 /*
3720 * Copy all the items in bulk, in a single copy operation. Item data is
3721 * organized such that it's placed at the end of a leaf and from right
3722 * to left. For example, the data for the second item ends at an offset
3723 * that matches the offset where the data for the first item starts, the
3724 * data for the third item ends at an offset that matches the offset
3725 * where the data of the second items starts, and so on.
3726 * Therefore our source and destination start offsets for copy match the
3727 * offsets of the last items (highest slots).
3728 */
3729 dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1);
3730 src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1);
3731 copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size);
3732 btrfs_release_path(dst_path);
3733
3734 last_index = batch.keys[count - 1].offset;
3735 ASSERT(last_index > inode->last_dir_index_offset);
3736
3737 /*
3738 * If for some unexpected reason the last item's index is not greater
3739 * than the last index we logged, warn and force a transaction commit.
3740 */
3741 if (WARN_ON(last_index <= inode->last_dir_index_offset))
3742 ret = BTRFS_LOG_FORCE_COMMIT;
3743 else
3744 inode->last_dir_index_offset = last_index;
3745
3746 if (btrfs_get_first_dir_index_to_log(inode) == 0)
3747 btrfs_set_first_dir_index_to_log(inode, batch.keys[0].offset);
3748 out:
3749 kfree(ins_data);
3750
3751 return ret;
3752 }
3753
clone_leaf(struct btrfs_path * path,struct btrfs_log_ctx * ctx)3754 static int clone_leaf(struct btrfs_path *path, struct btrfs_log_ctx *ctx)
3755 {
3756 const int slot = path->slots[0];
3757
3758 if (ctx->scratch_eb) {
3759 copy_extent_buffer_full(ctx->scratch_eb, path->nodes[0]);
3760 } else {
3761 ctx->scratch_eb = btrfs_clone_extent_buffer(path->nodes[0]);
3762 if (!ctx->scratch_eb)
3763 return -ENOMEM;
3764 }
3765
3766 btrfs_release_path(path);
3767 path->nodes[0] = ctx->scratch_eb;
3768 path->slots[0] = slot;
3769 /*
3770 * Add extra ref to scratch eb so that it is not freed when callers
3771 * release the path, so we can reuse it later if needed.
3772 */
3773 refcount_inc(&ctx->scratch_eb->refs);
3774
3775 return 0;
3776 }
3777
process_dir_items_leaf(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_path * dst_path,struct btrfs_log_ctx * ctx,u64 * last_old_dentry_offset)3778 static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
3779 struct btrfs_inode *inode,
3780 struct btrfs_path *path,
3781 struct btrfs_path *dst_path,
3782 struct btrfs_log_ctx *ctx,
3783 u64 *last_old_dentry_offset)
3784 {
3785 struct btrfs_root *log = inode->root->log_root;
3786 struct extent_buffer *src;
3787 const int nritems = btrfs_header_nritems(path->nodes[0]);
3788 const u64 ino = btrfs_ino(inode);
3789 bool last_found = false;
3790 int batch_start = 0;
3791 int batch_size = 0;
3792 int ret;
3793
3794 /*
3795 * We need to clone the leaf, release the read lock on it, and use the
3796 * clone before modifying the log tree. See the comment at copy_items()
3797 * about why we need to do this.
3798 */
3799 ret = clone_leaf(path, ctx);
3800 if (ret < 0)
3801 return ret;
3802
3803 src = path->nodes[0];
3804
3805 for (int i = path->slots[0]; i < nritems; i++) {
3806 struct btrfs_dir_item *di;
3807 struct btrfs_key key;
3808 int ret;
3809
3810 btrfs_item_key_to_cpu(src, &key, i);
3811
3812 if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) {
3813 last_found = true;
3814 break;
3815 }
3816
3817 di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
3818
3819 /*
3820 * Skip ranges of items that consist only of dir item keys created
3821 * in past transactions. However if we find a gap, we must log a
3822 * dir index range item for that gap, so that index keys in that
3823 * gap are deleted during log replay.
3824 */
3825 if (btrfs_dir_transid(src, di) < trans->transid) {
3826 if (key.offset > *last_old_dentry_offset + 1) {
3827 ret = insert_dir_log_key(trans, log, dst_path,
3828 ino, *last_old_dentry_offset + 1,
3829 key.offset - 1);
3830 if (ret < 0)
3831 return ret;
3832 }
3833
3834 *last_old_dentry_offset = key.offset;
3835 continue;
3836 }
3837
3838 /* If we logged this dir index item before, we can skip it. */
3839 if (key.offset <= inode->last_dir_index_offset)
3840 continue;
3841
3842 /*
3843 * We must make sure that when we log a directory entry, the
3844 * corresponding inode, after log replay, has a matching link
3845 * count. For example:
3846 *
3847 * touch foo
3848 * mkdir mydir
3849 * sync
3850 * ln foo mydir/bar
3851 * xfs_io -c "fsync" mydir
3852 * <crash>
3853 * <mount fs and log replay>
3854 *
3855 * Would result in a fsync log that when replayed, our file inode
3856 * would have a link count of 1, but we get two directory entries
3857 * pointing to the same inode. After removing one of the names,
3858 * it would not be possible to remove the other name, which
3859 * resulted always in stale file handle errors, and would not be
3860 * possible to rmdir the parent directory, since its i_size could
3861 * never be decremented to the value BTRFS_EMPTY_DIR_SIZE,
3862 * resulting in -ENOTEMPTY errors.
3863 */
3864 if (!ctx->log_new_dentries) {
3865 struct btrfs_key di_key;
3866
3867 btrfs_dir_item_key_to_cpu(src, di, &di_key);
3868 if (di_key.type != BTRFS_ROOT_ITEM_KEY)
3869 ctx->log_new_dentries = true;
3870 }
3871
3872 if (batch_size == 0)
3873 batch_start = i;
3874 batch_size++;
3875 }
3876
3877 if (batch_size > 0) {
3878 int ret;
3879
3880 ret = flush_dir_items_batch(trans, inode, src, dst_path,
3881 batch_start, batch_size);
3882 if (ret < 0)
3883 return ret;
3884 }
3885
3886 return last_found ? 1 : 0;
3887 }
3888
3889 /*
3890 * log all the items included in the current transaction for a given
3891 * directory. This also creates the range items in the log tree required
3892 * to replay anything deleted before the fsync
3893 */
log_dir_items(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_path * dst_path,struct btrfs_log_ctx * ctx,u64 min_offset,u64 * last_offset_ret)3894 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
3895 struct btrfs_inode *inode,
3896 struct btrfs_path *path,
3897 struct btrfs_path *dst_path,
3898 struct btrfs_log_ctx *ctx,
3899 u64 min_offset, u64 *last_offset_ret)
3900 {
3901 struct btrfs_key min_key;
3902 struct btrfs_root *root = inode->root;
3903 struct btrfs_root *log = root->log_root;
3904 int ret;
3905 u64 last_old_dentry_offset = min_offset - 1;
3906 u64 last_offset = (u64)-1;
3907 u64 ino = btrfs_ino(inode);
3908
3909 min_key.objectid = ino;
3910 min_key.type = BTRFS_DIR_INDEX_KEY;
3911 min_key.offset = min_offset;
3912
3913 ret = btrfs_search_forward(root, &min_key, path, trans->transid);
3914
3915 /*
3916 * we didn't find anything from this transaction, see if there
3917 * is anything at all
3918 */
3919 if (ret != 0 || min_key.objectid != ino ||
3920 min_key.type != BTRFS_DIR_INDEX_KEY) {
3921 min_key.objectid = ino;
3922 min_key.type = BTRFS_DIR_INDEX_KEY;
3923 min_key.offset = (u64)-1;
3924 btrfs_release_path(path);
3925 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3926 if (ret < 0) {
3927 btrfs_release_path(path);
3928 return ret;
3929 }
3930 ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
3931
3932 /* if ret == 0 there are items for this type,
3933 * create a range to tell us the last key of this type.
3934 * otherwise, there are no items in this directory after
3935 * *min_offset, and we create a range to indicate that.
3936 */
3937 if (ret == 0) {
3938 struct btrfs_key tmp;
3939
3940 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
3941 path->slots[0]);
3942 if (tmp.type == BTRFS_DIR_INDEX_KEY)
3943 last_old_dentry_offset = tmp.offset;
3944 } else if (ret > 0) {
3945 ret = 0;
3946 }
3947
3948 goto done;
3949 }
3950
3951 /* go backward to find any previous key */
3952 ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
3953 if (ret == 0) {
3954 struct btrfs_key tmp;
3955
3956 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
3957 /*
3958 * The dir index key before the first one we found that needs to
3959 * be logged might be in a previous leaf, and there might be a
3960 * gap between these keys, meaning that we had deletions that
3961 * happened. So the key range item we log (key type
3962 * BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the
3963 * previous key's offset plus 1, so that those deletes are replayed.
3964 */
3965 if (tmp.type == BTRFS_DIR_INDEX_KEY)
3966 last_old_dentry_offset = tmp.offset;
3967 } else if (ret < 0) {
3968 goto done;
3969 }
3970
3971 btrfs_release_path(path);
3972
3973 /*
3974 * Find the first key from this transaction again or the one we were at
3975 * in the loop below in case we had to reschedule. We may be logging the
3976 * directory without holding its VFS lock, which happen when logging new
3977 * dentries (through log_new_dir_dentries()) or in some cases when we
3978 * need to log the parent directory of an inode. This means a dir index
3979 * key might be deleted from the inode's root, and therefore we may not
3980 * find it anymore. If we can't find it, just move to the next key. We
3981 * can not bail out and ignore, because if we do that we will simply
3982 * not log dir index keys that come after the one that was just deleted
3983 * and we can end up logging a dir index range that ends at (u64)-1
3984 * (@last_offset is initialized to that), resulting in removing dir
3985 * entries we should not remove at log replay time.
3986 */
3987 search:
3988 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3989 if (ret > 0) {
3990 ret = btrfs_next_item(root, path);
3991 if (ret > 0) {
3992 /* There are no more keys in the inode's root. */
3993 ret = 0;
3994 goto done;
3995 }
3996 }
3997 if (ret < 0)
3998 goto done;
3999
4000 /*
4001 * we have a block from this transaction, log every item in it
4002 * from our directory
4003 */
4004 while (1) {
4005 ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx,
4006 &last_old_dentry_offset);
4007 if (ret != 0) {
4008 if (ret > 0)
4009 ret = 0;
4010 goto done;
4011 }
4012 path->slots[0] = btrfs_header_nritems(path->nodes[0]);
4013
4014 /*
4015 * look ahead to the next item and see if it is also
4016 * from this directory and from this transaction
4017 */
4018 ret = btrfs_next_leaf(root, path);
4019 if (ret) {
4020 if (ret == 1) {
4021 last_offset = (u64)-1;
4022 ret = 0;
4023 }
4024 goto done;
4025 }
4026 btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]);
4027 if (min_key.objectid != ino || min_key.type != BTRFS_DIR_INDEX_KEY) {
4028 last_offset = (u64)-1;
4029 goto done;
4030 }
4031 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
4032 /*
4033 * The next leaf was not changed in the current transaction
4034 * and has at least one dir index key.
4035 * We check for the next key because there might have been
4036 * one or more deletions between the last key we logged and
4037 * that next key. So the key range item we log (key type
4038 * BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's
4039 * offset minus 1, so that those deletes are replayed.
4040 */
4041 last_offset = min_key.offset - 1;
4042 goto done;
4043 }
4044 if (need_resched()) {
4045 btrfs_release_path(path);
4046 cond_resched();
4047 goto search;
4048 }
4049 }
4050 done:
4051 btrfs_release_path(path);
4052 btrfs_release_path(dst_path);
4053
4054 if (ret == 0) {
4055 *last_offset_ret = last_offset;
4056 /*
4057 * In case the leaf was changed in the current transaction but
4058 * all its dir items are from a past transaction, the last item
4059 * in the leaf is a dir item and there's no gap between that last
4060 * dir item and the first one on the next leaf (which did not
4061 * change in the current transaction), then we don't need to log
4062 * a range, last_old_dentry_offset is == to last_offset.
4063 */
4064 ASSERT(last_old_dentry_offset <= last_offset);
4065 if (last_old_dentry_offset < last_offset)
4066 ret = insert_dir_log_key(trans, log, path, ino,
4067 last_old_dentry_offset + 1,
4068 last_offset);
4069 }
4070
4071 return ret;
4072 }
4073
4074 /*
4075 * If the inode was logged before and it was evicted, then its
4076 * last_dir_index_offset is 0, so we don't know the value of the last index
4077 * key offset. If that's the case, search for it and update the inode. This
4078 * is to avoid lookups in the log tree every time we try to insert a dir index
4079 * key from a leaf changed in the current transaction, and to allow us to always
4080 * do batch insertions of dir index keys.
4081 */
update_last_dir_index_offset(struct btrfs_inode * inode,struct btrfs_path * path,const struct btrfs_log_ctx * ctx)4082 static int update_last_dir_index_offset(struct btrfs_inode *inode,
4083 struct btrfs_path *path,
4084 const struct btrfs_log_ctx *ctx)
4085 {
4086 const u64 ino = btrfs_ino(inode);
4087 struct btrfs_key key;
4088 int ret;
4089
4090 lockdep_assert_held(&inode->log_mutex);
4091
4092 if (inode->last_dir_index_offset != 0)
4093 return 0;
4094
4095 if (!ctx->logged_before) {
4096 inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
4097 return 0;
4098 }
4099
4100 key.objectid = ino;
4101 key.type = BTRFS_DIR_INDEX_KEY;
4102 key.offset = (u64)-1;
4103
4104 ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
4105 /*
4106 * An error happened or we actually have an index key with an offset
4107 * value of (u64)-1. Bail out, we're done.
4108 */
4109 if (ret <= 0)
4110 goto out;
4111
4112 ret = 0;
4113 inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
4114
4115 /*
4116 * No dir index items, bail out and leave last_dir_index_offset with
4117 * the value right before the first valid index value.
4118 */
4119 if (path->slots[0] == 0)
4120 goto out;
4121
4122 /*
4123 * btrfs_search_slot() left us at one slot beyond the slot with the last
4124 * index key, or beyond the last key of the directory that is not an
4125 * index key. If we have an index key before, set last_dir_index_offset
4126 * to its offset value, otherwise leave it with a value right before the
4127 * first valid index value, as it means we have an empty directory.
4128 */
4129 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
4130 if (key.objectid == ino && key.type == BTRFS_DIR_INDEX_KEY)
4131 inode->last_dir_index_offset = key.offset;
4132
4133 out:
4134 btrfs_release_path(path);
4135
4136 return ret;
4137 }
4138
4139 /*
4140 * logging directories is very similar to logging inodes, We find all the items
4141 * from the current transaction and write them to the log.
4142 *
4143 * The recovery code scans the directory in the subvolume, and if it finds a
4144 * key in the range logged that is not present in the log tree, then it means
4145 * that dir entry was unlinked during the transaction.
4146 *
4147 * In order for that scan to work, we must include one key smaller than
4148 * the smallest logged by this transaction and one key larger than the largest
4149 * key logged by this transaction.
4150 */
log_directory_changes(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_path * dst_path,struct btrfs_log_ctx * ctx)4151 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
4152 struct btrfs_inode *inode,
4153 struct btrfs_path *path,
4154 struct btrfs_path *dst_path,
4155 struct btrfs_log_ctx *ctx)
4156 {
4157 u64 min_key;
4158 u64 max_key;
4159 int ret;
4160
4161 ret = update_last_dir_index_offset(inode, path, ctx);
4162 if (ret)
4163 return ret;
4164
4165 min_key = BTRFS_DIR_START_INDEX;
4166 max_key = 0;
4167
4168 while (1) {
4169 ret = log_dir_items(trans, inode, path, dst_path,
4170 ctx, min_key, &max_key);
4171 if (ret)
4172 return ret;
4173 if (max_key == (u64)-1)
4174 break;
4175 min_key = max_key + 1;
4176 }
4177
4178 return 0;
4179 }
4180
4181 /*
4182 * a helper function to drop items from the log before we relog an
4183 * inode. max_key_type indicates the highest item type to remove.
4184 * This cannot be run for file data extents because it does not
4185 * free the extents they point to.
4186 */
drop_inode_items(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_path * path,struct btrfs_inode * inode,int max_key_type)4187 static int drop_inode_items(struct btrfs_trans_handle *trans,
4188 struct btrfs_root *log,
4189 struct btrfs_path *path,
4190 struct btrfs_inode *inode,
4191 int max_key_type)
4192 {
4193 int ret;
4194 struct btrfs_key key;
4195 struct btrfs_key found_key;
4196 int start_slot;
4197
4198 key.objectid = btrfs_ino(inode);
4199 key.type = max_key_type;
4200 key.offset = (u64)-1;
4201
4202 while (1) {
4203 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
4204 if (ret < 0) {
4205 break;
4206 } else if (ret > 0) {
4207 if (path->slots[0] == 0)
4208 break;
4209 path->slots[0]--;
4210 }
4211
4212 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
4213 path->slots[0]);
4214
4215 if (found_key.objectid != key.objectid)
4216 break;
4217
4218 found_key.offset = 0;
4219 found_key.type = 0;
4220 ret = btrfs_bin_search(path->nodes[0], 0, &found_key, &start_slot);
4221 if (ret < 0)
4222 break;
4223
4224 ret = btrfs_del_items(trans, log, path, start_slot,
4225 path->slots[0] - start_slot + 1);
4226 /*
4227 * If start slot isn't 0 then we don't need to re-search, we've
4228 * found the last guy with the objectid in this tree.
4229 */
4230 if (ret || start_slot != 0)
4231 break;
4232 btrfs_release_path(path);
4233 }
4234 btrfs_release_path(path);
4235 if (ret > 0)
4236 ret = 0;
4237 return ret;
4238 }
4239
truncate_inode_items(struct btrfs_trans_handle * trans,struct btrfs_root * log_root,struct btrfs_inode * inode,u64 new_size,u32 min_type)4240 static int truncate_inode_items(struct btrfs_trans_handle *trans,
4241 struct btrfs_root *log_root,
4242 struct btrfs_inode *inode,
4243 u64 new_size, u32 min_type)
4244 {
4245 struct btrfs_truncate_control control = {
4246 .new_size = new_size,
4247 .ino = btrfs_ino(inode),
4248 .min_type = min_type,
4249 .skip_ref_updates = true,
4250 };
4251
4252 return btrfs_truncate_inode_items(trans, log_root, &control);
4253 }
4254
fill_inode_item(struct btrfs_trans_handle * trans,struct extent_buffer * leaf,struct btrfs_inode_item * item,struct inode * inode,int log_inode_only,u64 logged_isize)4255 static void fill_inode_item(struct btrfs_trans_handle *trans,
4256 struct extent_buffer *leaf,
4257 struct btrfs_inode_item *item,
4258 struct inode *inode, int log_inode_only,
4259 u64 logged_isize)
4260 {
4261 u64 flags;
4262
4263 if (log_inode_only) {
4264 /* set the generation to zero so the recover code
4265 * can tell the difference between an logging
4266 * just to say 'this inode exists' and a logging
4267 * to say 'update this inode with these values'
4268 */
4269 btrfs_set_inode_generation(leaf, item, 0);
4270 btrfs_set_inode_size(leaf, item, logged_isize);
4271 } else {
4272 btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
4273 btrfs_set_inode_size(leaf, item, inode->i_size);
4274 }
4275
4276 btrfs_set_inode_uid(leaf, item, i_uid_read(inode));
4277 btrfs_set_inode_gid(leaf, item, i_gid_read(inode));
4278 btrfs_set_inode_mode(leaf, item, inode->i_mode);
4279 btrfs_set_inode_nlink(leaf, item, inode->i_nlink);
4280
4281 btrfs_set_timespec_sec(leaf, &item->atime, inode_get_atime_sec(inode));
4282 btrfs_set_timespec_nsec(leaf, &item->atime, inode_get_atime_nsec(inode));
4283
4284 btrfs_set_timespec_sec(leaf, &item->mtime, inode_get_mtime_sec(inode));
4285 btrfs_set_timespec_nsec(leaf, &item->mtime, inode_get_mtime_nsec(inode));
4286
4287 btrfs_set_timespec_sec(leaf, &item->ctime, inode_get_ctime_sec(inode));
4288 btrfs_set_timespec_nsec(leaf, &item->ctime, inode_get_ctime_nsec(inode));
4289
4290 btrfs_set_timespec_sec(leaf, &item->otime, BTRFS_I(inode)->i_otime_sec);
4291 btrfs_set_timespec_nsec(leaf, &item->otime, BTRFS_I(inode)->i_otime_nsec);
4292
4293 /*
4294 * We do not need to set the nbytes field, in fact during a fast fsync
4295 * its value may not even be correct, since a fast fsync does not wait
4296 * for ordered extent completion, which is where we update nbytes, it
4297 * only waits for writeback to complete. During log replay as we find
4298 * file extent items and replay them, we adjust the nbytes field of the
4299 * inode item in subvolume tree as needed (see overwrite_item()).
4300 */
4301
4302 btrfs_set_inode_sequence(leaf, item, inode_peek_iversion(inode));
4303 btrfs_set_inode_transid(leaf, item, trans->transid);
4304 btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
4305 flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
4306 BTRFS_I(inode)->ro_flags);
4307 btrfs_set_inode_flags(leaf, item, flags);
4308 btrfs_set_inode_block_group(leaf, item, 0);
4309 }
4310
log_inode_item(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_path * path,struct btrfs_inode * inode,bool inode_item_dropped)4311 static int log_inode_item(struct btrfs_trans_handle *trans,
4312 struct btrfs_root *log, struct btrfs_path *path,
4313 struct btrfs_inode *inode, bool inode_item_dropped)
4314 {
4315 struct btrfs_inode_item *inode_item;
4316 struct btrfs_key key;
4317 int ret;
4318
4319 btrfs_get_inode_key(inode, &key);
4320 /*
4321 * If we are doing a fast fsync and the inode was logged before in the
4322 * current transaction, then we know the inode was previously logged and
4323 * it exists in the log tree. For performance reasons, in this case use
4324 * btrfs_search_slot() directly with ins_len set to 0 so that we never
4325 * attempt a write lock on the leaf's parent, which adds unnecessary lock
4326 * contention in case there are concurrent fsyncs for other inodes of the
4327 * same subvolume. Using btrfs_insert_empty_item() when the inode item
4328 * already exists can also result in unnecessarily splitting a leaf.
4329 */
4330 if (!inode_item_dropped && inode->logged_trans == trans->transid) {
4331 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
4332 ASSERT(ret <= 0);
4333 if (ret > 0)
4334 ret = -ENOENT;
4335 } else {
4336 /*
4337 * This means it is the first fsync in the current transaction,
4338 * so the inode item is not in the log and we need to insert it.
4339 * We can never get -EEXIST because we are only called for a fast
4340 * fsync and in case an inode eviction happens after the inode was
4341 * logged before in the current transaction, when we load again
4342 * the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
4343 * flags and set ->logged_trans to 0.
4344 */
4345 ret = btrfs_insert_empty_item(trans, log, path, &key,
4346 sizeof(*inode_item));
4347 ASSERT(ret != -EEXIST);
4348 }
4349 if (ret)
4350 return ret;
4351 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4352 struct btrfs_inode_item);
4353 fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
4354 0, 0);
4355 btrfs_release_path(path);
4356 return 0;
4357 }
4358
log_csums(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_root * log_root,struct btrfs_ordered_sum * sums)4359 static int log_csums(struct btrfs_trans_handle *trans,
4360 struct btrfs_inode *inode,
4361 struct btrfs_root *log_root,
4362 struct btrfs_ordered_sum *sums)
4363 {
4364 const u64 lock_end = sums->logical + sums->len - 1;
4365 struct extent_state *cached_state = NULL;
4366 int ret;
4367
4368 /*
4369 * If this inode was not used for reflink operations in the current
4370 * transaction with new extents, then do the fast path, no need to
4371 * worry about logging checksum items with overlapping ranges.
4372 */
4373 if (inode->last_reflink_trans < trans->transid)
4374 return btrfs_csum_file_blocks(trans, log_root, sums);
4375
4376 /*
4377 * Serialize logging for checksums. This is to avoid racing with the
4378 * same checksum being logged by another task that is logging another
4379 * file which happens to refer to the same extent as well. Such races
4380 * can leave checksum items in the log with overlapping ranges.
4381 */
4382 ret = btrfs_lock_extent(&log_root->log_csum_range, sums->logical, lock_end,
4383 &cached_state);
4384 if (ret)
4385 return ret;
4386 /*
4387 * Due to extent cloning, we might have logged a csum item that covers a
4388 * subrange of a cloned extent, and later we can end up logging a csum
4389 * item for a larger subrange of the same extent or the entire range.
4390 * This would leave csum items in the log tree that cover the same range
4391 * and break the searches for checksums in the log tree, resulting in
4392 * some checksums missing in the fs/subvolume tree. So just delete (or
4393 * trim and adjust) any existing csum items in the log for this range.
4394 */
4395 ret = btrfs_del_csums(trans, log_root, sums->logical, sums->len);
4396 if (!ret)
4397 ret = btrfs_csum_file_blocks(trans, log_root, sums);
4398
4399 btrfs_unlock_extent(&log_root->log_csum_range, sums->logical, lock_end,
4400 &cached_state);
4401
4402 return ret;
4403 }
4404
copy_items(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * dst_path,struct btrfs_path * src_path,int start_slot,int nr,int inode_only,u64 logged_isize,struct btrfs_log_ctx * ctx)4405 static noinline int copy_items(struct btrfs_trans_handle *trans,
4406 struct btrfs_inode *inode,
4407 struct btrfs_path *dst_path,
4408 struct btrfs_path *src_path,
4409 int start_slot, int nr, int inode_only,
4410 u64 logged_isize, struct btrfs_log_ctx *ctx)
4411 {
4412 struct btrfs_root *log = inode->root->log_root;
4413 struct btrfs_file_extent_item *extent;
4414 struct extent_buffer *src;
4415 int ret;
4416 struct btrfs_key *ins_keys;
4417 u32 *ins_sizes;
4418 struct btrfs_item_batch batch;
4419 char *ins_data;
4420 int dst_index;
4421 const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
4422 const u64 i_size = i_size_read(&inode->vfs_inode);
4423
4424 /*
4425 * To keep lockdep happy and avoid deadlocks, clone the source leaf and
4426 * use the clone. This is because otherwise we would be changing the log
4427 * tree, to insert items from the subvolume tree or insert csum items,
4428 * while holding a read lock on a leaf from the subvolume tree, which
4429 * creates a nasty lock dependency when COWing log tree nodes/leaves:
4430 *
4431 * 1) Modifying the log tree triggers an extent buffer allocation while
4432 * holding a write lock on a parent extent buffer from the log tree.
4433 * Allocating the pages for an extent buffer, or the extent buffer
4434 * struct, can trigger inode eviction and finally the inode eviction
4435 * will trigger a release/remove of a delayed node, which requires
4436 * taking the delayed node's mutex;
4437 *
4438 * 2) Allocating a metadata extent for a log tree can trigger the async
4439 * reclaim thread and make us wait for it to release enough space and
4440 * unblock our reservation ticket. The reclaim thread can start
4441 * flushing delayed items, and that in turn results in the need to
4442 * lock delayed node mutexes and in the need to write lock extent
4443 * buffers of a subvolume tree - all this while holding a write lock
4444 * on the parent extent buffer in the log tree.
4445 *
4446 * So one task in scenario 1) running in parallel with another task in
4447 * scenario 2) could lead to a deadlock, one wanting to lock a delayed
4448 * node mutex while having a read lock on a leaf from the subvolume,
4449 * while the other is holding the delayed node's mutex and wants to
4450 * write lock the same subvolume leaf for flushing delayed items.
4451 */
4452 ret = clone_leaf(src_path, ctx);
4453 if (ret < 0)
4454 return ret;
4455
4456 src = src_path->nodes[0];
4457
4458 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
4459 nr * sizeof(u32), GFP_NOFS);
4460 if (!ins_data)
4461 return -ENOMEM;
4462
4463 ins_sizes = (u32 *)ins_data;
4464 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
4465 batch.keys = ins_keys;
4466 batch.data_sizes = ins_sizes;
4467 batch.total_data_size = 0;
4468 batch.nr = 0;
4469
4470 dst_index = 0;
4471 for (int i = 0; i < nr; i++) {
4472 const int src_slot = start_slot + i;
4473 struct btrfs_root *csum_root;
4474 struct btrfs_ordered_sum *sums;
4475 struct btrfs_ordered_sum *sums_next;
4476 LIST_HEAD(ordered_sums);
4477 u64 disk_bytenr;
4478 u64 disk_num_bytes;
4479 u64 extent_offset;
4480 u64 extent_num_bytes;
4481 bool is_old_extent;
4482
4483 btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot);
4484
4485 if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY)
4486 goto add_to_batch;
4487
4488 extent = btrfs_item_ptr(src, src_slot,
4489 struct btrfs_file_extent_item);
4490
4491 is_old_extent = (btrfs_file_extent_generation(src, extent) <
4492 trans->transid);
4493
4494 /*
4495 * Don't copy extents from past generations. That would make us
4496 * log a lot more metadata for common cases like doing only a
4497 * few random writes into a file and then fsync it for the first
4498 * time or after the full sync flag is set on the inode. We can
4499 * get leaves full of extent items, most of which are from past
4500 * generations, so we can skip them - as long as the inode has
4501 * not been the target of a reflink operation in this transaction,
4502 * as in that case it might have had file extent items with old
4503 * generations copied into it. We also must always log prealloc
4504 * extents that start at or beyond eof, otherwise we would lose
4505 * them on log replay.
4506 */
4507 if (is_old_extent &&
4508 ins_keys[dst_index].offset < i_size &&
4509 inode->last_reflink_trans < trans->transid)
4510 continue;
4511
4512 if (skip_csum)
4513 goto add_to_batch;
4514
4515 /* Only regular extents have checksums. */
4516 if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG)
4517 goto add_to_batch;
4518
4519 /*
4520 * If it's an extent created in a past transaction, then its
4521 * checksums are already accessible from the committed csum tree,
4522 * no need to log them.
4523 */
4524 if (is_old_extent)
4525 goto add_to_batch;
4526
4527 disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent);
4528 /* If it's an explicit hole, there are no checksums. */
4529 if (disk_bytenr == 0)
4530 goto add_to_batch;
4531
4532 disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent);
4533
4534 if (btrfs_file_extent_compression(src, extent)) {
4535 extent_offset = 0;
4536 extent_num_bytes = disk_num_bytes;
4537 } else {
4538 extent_offset = btrfs_file_extent_offset(src, extent);
4539 extent_num_bytes = btrfs_file_extent_num_bytes(src, extent);
4540 }
4541
4542 csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr);
4543 disk_bytenr += extent_offset;
4544 ret = btrfs_lookup_csums_list(csum_root, disk_bytenr,
4545 disk_bytenr + extent_num_bytes - 1,
4546 &ordered_sums, false);
4547 if (ret < 0)
4548 goto out;
4549 ret = 0;
4550
4551 list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
4552 if (!ret)
4553 ret = log_csums(trans, inode, log, sums);
4554 list_del(&sums->list);
4555 kfree(sums);
4556 }
4557 if (ret)
4558 goto out;
4559
4560 add_to_batch:
4561 ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
4562 batch.total_data_size += ins_sizes[dst_index];
4563 batch.nr++;
4564 dst_index++;
4565 }
4566
4567 /*
4568 * We have a leaf full of old extent items that don't need to be logged,
4569 * so we don't need to do anything.
4570 */
4571 if (batch.nr == 0)
4572 goto out;
4573
4574 ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
4575 if (ret)
4576 goto out;
4577
4578 dst_index = 0;
4579 for (int i = 0; i < nr; i++) {
4580 const int src_slot = start_slot + i;
4581 const int dst_slot = dst_path->slots[0] + dst_index;
4582 struct btrfs_key key;
4583 unsigned long src_offset;
4584 unsigned long dst_offset;
4585
4586 /*
4587 * We're done, all the remaining items in the source leaf
4588 * correspond to old file extent items.
4589 */
4590 if (dst_index >= batch.nr)
4591 break;
4592
4593 btrfs_item_key_to_cpu(src, &key, src_slot);
4594
4595 if (key.type != BTRFS_EXTENT_DATA_KEY)
4596 goto copy_item;
4597
4598 extent = btrfs_item_ptr(src, src_slot,
4599 struct btrfs_file_extent_item);
4600
4601 /* See the comment in the previous loop, same logic. */
4602 if (btrfs_file_extent_generation(src, extent) < trans->transid &&
4603 key.offset < i_size &&
4604 inode->last_reflink_trans < trans->transid)
4605 continue;
4606
4607 copy_item:
4608 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot);
4609 src_offset = btrfs_item_ptr_offset(src, src_slot);
4610
4611 if (key.type == BTRFS_INODE_ITEM_KEY) {
4612 struct btrfs_inode_item *inode_item;
4613
4614 inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot,
4615 struct btrfs_inode_item);
4616 fill_inode_item(trans, dst_path->nodes[0], inode_item,
4617 &inode->vfs_inode,
4618 inode_only == LOG_INODE_EXISTS,
4619 logged_isize);
4620 } else {
4621 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
4622 src_offset, ins_sizes[dst_index]);
4623 }
4624
4625 dst_index++;
4626 }
4627
4628 btrfs_release_path(dst_path);
4629 out:
4630 kfree(ins_data);
4631
4632 return ret;
4633 }
4634
extent_cmp(void * priv,const struct list_head * a,const struct list_head * b)4635 static int extent_cmp(void *priv, const struct list_head *a,
4636 const struct list_head *b)
4637 {
4638 const struct extent_map *em1, *em2;
4639
4640 em1 = list_entry(a, struct extent_map, list);
4641 em2 = list_entry(b, struct extent_map, list);
4642
4643 if (em1->start < em2->start)
4644 return -1;
4645 else if (em1->start > em2->start)
4646 return 1;
4647 return 0;
4648 }
4649
log_extent_csums(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_root * log_root,const struct extent_map * em,struct btrfs_log_ctx * ctx)4650 static int log_extent_csums(struct btrfs_trans_handle *trans,
4651 struct btrfs_inode *inode,
4652 struct btrfs_root *log_root,
4653 const struct extent_map *em,
4654 struct btrfs_log_ctx *ctx)
4655 {
4656 struct btrfs_ordered_extent *ordered;
4657 struct btrfs_root *csum_root;
4658 u64 block_start;
4659 u64 csum_offset;
4660 u64 csum_len;
4661 u64 mod_start = em->start;
4662 u64 mod_len = em->len;
4663 LIST_HEAD(ordered_sums);
4664 int ret = 0;
4665
4666 if (inode->flags & BTRFS_INODE_NODATASUM ||
4667 (em->flags & EXTENT_FLAG_PREALLOC) ||
4668 em->disk_bytenr == EXTENT_MAP_HOLE)
4669 return 0;
4670
4671 list_for_each_entry(ordered, &ctx->ordered_extents, log_list) {
4672 const u64 ordered_end = ordered->file_offset + ordered->num_bytes;
4673 const u64 mod_end = mod_start + mod_len;
4674 struct btrfs_ordered_sum *sums;
4675
4676 if (mod_len == 0)
4677 break;
4678
4679 if (ordered_end <= mod_start)
4680 continue;
4681 if (mod_end <= ordered->file_offset)
4682 break;
4683
4684 /*
4685 * We are going to copy all the csums on this ordered extent, so
4686 * go ahead and adjust mod_start and mod_len in case this ordered
4687 * extent has already been logged.
4688 */
4689 if (ordered->file_offset > mod_start) {
4690 if (ordered_end >= mod_end)
4691 mod_len = ordered->file_offset - mod_start;
4692 /*
4693 * If we have this case
4694 *
4695 * |--------- logged extent ---------|
4696 * |----- ordered extent ----|
4697 *
4698 * Just don't mess with mod_start and mod_len, we'll
4699 * just end up logging more csums than we need and it
4700 * will be ok.
4701 */
4702 } else {
4703 if (ordered_end < mod_end) {
4704 mod_len = mod_end - ordered_end;
4705 mod_start = ordered_end;
4706 } else {
4707 mod_len = 0;
4708 }
4709 }
4710
4711 /*
4712 * To keep us from looping for the above case of an ordered
4713 * extent that falls inside of the logged extent.
4714 */
4715 if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags))
4716 continue;
4717
4718 list_for_each_entry(sums, &ordered->list, list) {
4719 ret = log_csums(trans, inode, log_root, sums);
4720 if (ret)
4721 return ret;
4722 }
4723 }
4724
4725 /* We're done, found all csums in the ordered extents. */
4726 if (mod_len == 0)
4727 return 0;
4728
4729 /* If we're compressed we have to save the entire range of csums. */
4730 if (btrfs_extent_map_is_compressed(em)) {
4731 csum_offset = 0;
4732 csum_len = em->disk_num_bytes;
4733 } else {
4734 csum_offset = mod_start - em->start;
4735 csum_len = mod_len;
4736 }
4737
4738 /* block start is already adjusted for the file extent offset. */
4739 block_start = btrfs_extent_map_block_start(em);
4740 csum_root = btrfs_csum_root(trans->fs_info, block_start);
4741 ret = btrfs_lookup_csums_list(csum_root, block_start + csum_offset,
4742 block_start + csum_offset + csum_len - 1,
4743 &ordered_sums, false);
4744 if (ret < 0)
4745 return ret;
4746 ret = 0;
4747
4748 while (!list_empty(&ordered_sums)) {
4749 struct btrfs_ordered_sum *sums = list_first_entry(&ordered_sums,
4750 struct btrfs_ordered_sum,
4751 list);
4752 if (!ret)
4753 ret = log_csums(trans, inode, log_root, sums);
4754 list_del(&sums->list);
4755 kfree(sums);
4756 }
4757
4758 return ret;
4759 }
4760
log_one_extent(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,const struct extent_map * em,struct btrfs_path * path,struct btrfs_log_ctx * ctx)4761 static int log_one_extent(struct btrfs_trans_handle *trans,
4762 struct btrfs_inode *inode,
4763 const struct extent_map *em,
4764 struct btrfs_path *path,
4765 struct btrfs_log_ctx *ctx)
4766 {
4767 struct btrfs_drop_extents_args drop_args = { 0 };
4768 struct btrfs_root *log = inode->root->log_root;
4769 struct btrfs_file_extent_item fi = { 0 };
4770 struct extent_buffer *leaf;
4771 struct btrfs_key key;
4772 enum btrfs_compression_type compress_type;
4773 u64 extent_offset = em->offset;
4774 u64 block_start = btrfs_extent_map_block_start(em);
4775 u64 block_len;
4776 int ret;
4777
4778 btrfs_set_stack_file_extent_generation(&fi, trans->transid);
4779 if (em->flags & EXTENT_FLAG_PREALLOC)
4780 btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC);
4781 else
4782 btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG);
4783
4784 block_len = em->disk_num_bytes;
4785 compress_type = btrfs_extent_map_compression(em);
4786 if (compress_type != BTRFS_COMPRESS_NONE) {
4787 btrfs_set_stack_file_extent_disk_bytenr(&fi, block_start);
4788 btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
4789 } else if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE) {
4790 btrfs_set_stack_file_extent_disk_bytenr(&fi, block_start - extent_offset);
4791 btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
4792 }
4793
4794 btrfs_set_stack_file_extent_offset(&fi, extent_offset);
4795 btrfs_set_stack_file_extent_num_bytes(&fi, em->len);
4796 btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes);
4797 btrfs_set_stack_file_extent_compression(&fi, compress_type);
4798
4799 ret = log_extent_csums(trans, inode, log, em, ctx);
4800 if (ret)
4801 return ret;
4802
4803 /*
4804 * If this is the first time we are logging the inode in the current
4805 * transaction, we can avoid btrfs_drop_extents(), which is expensive
4806 * because it does a deletion search, which always acquires write locks
4807 * for extent buffers at levels 2, 1 and 0. This not only wastes time
4808 * but also adds significant contention in a log tree, since log trees
4809 * are small, with a root at level 2 or 3 at most, due to their short
4810 * life span.
4811 */
4812 if (ctx->logged_before) {
4813 drop_args.path = path;
4814 drop_args.start = em->start;
4815 drop_args.end = em->start + em->len;
4816 drop_args.replace_extent = true;
4817 drop_args.extent_item_size = sizeof(fi);
4818 ret = btrfs_drop_extents(trans, log, inode, &drop_args);
4819 if (ret)
4820 return ret;
4821 }
4822
4823 if (!drop_args.extent_inserted) {
4824 key.objectid = btrfs_ino(inode);
4825 key.type = BTRFS_EXTENT_DATA_KEY;
4826 key.offset = em->start;
4827
4828 ret = btrfs_insert_empty_item(trans, log, path, &key,
4829 sizeof(fi));
4830 if (ret)
4831 return ret;
4832 }
4833 leaf = path->nodes[0];
4834 write_extent_buffer(leaf, &fi,
4835 btrfs_item_ptr_offset(leaf, path->slots[0]),
4836 sizeof(fi));
4837
4838 btrfs_release_path(path);
4839
4840 return ret;
4841 }
4842
4843 /*
4844 * Log all prealloc extents beyond the inode's i_size to make sure we do not
4845 * lose them after doing a full/fast fsync and replaying the log. We scan the
4846 * subvolume's root instead of iterating the inode's extent map tree because
4847 * otherwise we can log incorrect extent items based on extent map conversion.
4848 * That can happen due to the fact that extent maps are merged when they
4849 * are not in the extent map tree's list of modified extents.
4850 */
btrfs_log_prealloc_extents(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_log_ctx * ctx)4851 static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
4852 struct btrfs_inode *inode,
4853 struct btrfs_path *path,
4854 struct btrfs_log_ctx *ctx)
4855 {
4856 struct btrfs_root *root = inode->root;
4857 struct btrfs_key key;
4858 const u64 i_size = i_size_read(&inode->vfs_inode);
4859 const u64 ino = btrfs_ino(inode);
4860 struct btrfs_path *dst_path = NULL;
4861 bool dropped_extents = false;
4862 u64 truncate_offset = i_size;
4863 struct extent_buffer *leaf;
4864 int slot;
4865 int ins_nr = 0;
4866 int start_slot = 0;
4867 int ret;
4868
4869 if (!(inode->flags & BTRFS_INODE_PREALLOC))
4870 return 0;
4871
4872 key.objectid = ino;
4873 key.type = BTRFS_EXTENT_DATA_KEY;
4874 key.offset = i_size;
4875 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4876 if (ret < 0)
4877 goto out;
4878
4879 /*
4880 * We must check if there is a prealloc extent that starts before the
4881 * i_size and crosses the i_size boundary. This is to ensure later we
4882 * truncate down to the end of that extent and not to the i_size, as
4883 * otherwise we end up losing part of the prealloc extent after a log
4884 * replay and with an implicit hole if there is another prealloc extent
4885 * that starts at an offset beyond i_size.
4886 */
4887 ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
4888 if (ret < 0)
4889 goto out;
4890
4891 if (ret == 0) {
4892 struct btrfs_file_extent_item *ei;
4893
4894 leaf = path->nodes[0];
4895 slot = path->slots[0];
4896 ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4897
4898 if (btrfs_file_extent_type(leaf, ei) ==
4899 BTRFS_FILE_EXTENT_PREALLOC) {
4900 u64 extent_end;
4901
4902 btrfs_item_key_to_cpu(leaf, &key, slot);
4903 extent_end = key.offset +
4904 btrfs_file_extent_num_bytes(leaf, ei);
4905
4906 if (extent_end > i_size)
4907 truncate_offset = extent_end;
4908 }
4909 } else {
4910 ret = 0;
4911 }
4912
4913 while (true) {
4914 leaf = path->nodes[0];
4915 slot = path->slots[0];
4916
4917 if (slot >= btrfs_header_nritems(leaf)) {
4918 if (ins_nr > 0) {
4919 ret = copy_items(trans, inode, dst_path, path,
4920 start_slot, ins_nr, 1, 0, ctx);
4921 if (ret < 0)
4922 goto out;
4923 ins_nr = 0;
4924 }
4925 ret = btrfs_next_leaf(root, path);
4926 if (ret < 0)
4927 goto out;
4928 if (ret > 0) {
4929 ret = 0;
4930 break;
4931 }
4932 continue;
4933 }
4934
4935 btrfs_item_key_to_cpu(leaf, &key, slot);
4936 if (key.objectid > ino)
4937 break;
4938 if (WARN_ON_ONCE(key.objectid < ino) ||
4939 key.type < BTRFS_EXTENT_DATA_KEY ||
4940 key.offset < i_size) {
4941 path->slots[0]++;
4942 continue;
4943 }
4944 /*
4945 * Avoid overlapping items in the log tree. The first time we
4946 * get here, get rid of everything from a past fsync. After
4947 * that, if the current extent starts before the end of the last
4948 * extent we copied, truncate the last one. This can happen if
4949 * an ordered extent completion modifies the subvolume tree
4950 * while btrfs_next_leaf() has the tree unlocked.
4951 */
4952 if (!dropped_extents || key.offset < truncate_offset) {
4953 ret = truncate_inode_items(trans, root->log_root, inode,
4954 min(key.offset, truncate_offset),
4955 BTRFS_EXTENT_DATA_KEY);
4956 if (ret)
4957 goto out;
4958 dropped_extents = true;
4959 }
4960 truncate_offset = btrfs_file_extent_end(path);
4961 if (ins_nr == 0)
4962 start_slot = slot;
4963 ins_nr++;
4964 path->slots[0]++;
4965 if (!dst_path) {
4966 dst_path = btrfs_alloc_path();
4967 if (!dst_path) {
4968 ret = -ENOMEM;
4969 goto out;
4970 }
4971 }
4972 }
4973 if (ins_nr > 0)
4974 ret = copy_items(trans, inode, dst_path, path,
4975 start_slot, ins_nr, 1, 0, ctx);
4976 out:
4977 btrfs_release_path(path);
4978 btrfs_free_path(dst_path);
4979 return ret;
4980 }
4981
btrfs_log_changed_extents(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_log_ctx * ctx)4982 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
4983 struct btrfs_inode *inode,
4984 struct btrfs_path *path,
4985 struct btrfs_log_ctx *ctx)
4986 {
4987 struct btrfs_ordered_extent *ordered;
4988 struct btrfs_ordered_extent *tmp;
4989 struct extent_map *em, *n;
4990 LIST_HEAD(extents);
4991 struct extent_map_tree *tree = &inode->extent_tree;
4992 int ret = 0;
4993 int num = 0;
4994
4995 write_lock(&tree->lock);
4996
4997 list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
4998 list_del_init(&em->list);
4999 /*
5000 * Just an arbitrary number, this can be really CPU intensive
5001 * once we start getting a lot of extents, and really once we
5002 * have a bunch of extents we just want to commit since it will
5003 * be faster.
5004 */
5005 if (++num > 32768) {
5006 list_del_init(&tree->modified_extents);
5007 ret = -EFBIG;
5008 goto process;
5009 }
5010
5011 if (em->generation < trans->transid)
5012 continue;
5013
5014 /* We log prealloc extents beyond eof later. */
5015 if ((em->flags & EXTENT_FLAG_PREALLOC) &&
5016 em->start >= i_size_read(&inode->vfs_inode))
5017 continue;
5018
5019 /* Need a ref to keep it from getting evicted from cache */
5020 refcount_inc(&em->refs);
5021 em->flags |= EXTENT_FLAG_LOGGING;
5022 list_add_tail(&em->list, &extents);
5023 num++;
5024 }
5025
5026 list_sort(NULL, &extents, extent_cmp);
5027 process:
5028 while (!list_empty(&extents)) {
5029 em = list_first_entry(&extents, struct extent_map, list);
5030
5031 list_del_init(&em->list);
5032
5033 /*
5034 * If we had an error we just need to delete everybody from our
5035 * private list.
5036 */
5037 if (ret) {
5038 btrfs_clear_em_logging(inode, em);
5039 btrfs_free_extent_map(em);
5040 continue;
5041 }
5042
5043 write_unlock(&tree->lock);
5044
5045 ret = log_one_extent(trans, inode, em, path, ctx);
5046 write_lock(&tree->lock);
5047 btrfs_clear_em_logging(inode, em);
5048 btrfs_free_extent_map(em);
5049 }
5050 WARN_ON(!list_empty(&extents));
5051 write_unlock(&tree->lock);
5052
5053 if (!ret)
5054 ret = btrfs_log_prealloc_extents(trans, inode, path, ctx);
5055 if (ret)
5056 return ret;
5057
5058 /*
5059 * We have logged all extents successfully, now make sure the commit of
5060 * the current transaction waits for the ordered extents to complete
5061 * before it commits and wipes out the log trees, otherwise we would
5062 * lose data if an ordered extents completes after the transaction
5063 * commits and a power failure happens after the transaction commit.
5064 */
5065 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
5066 list_del_init(&ordered->log_list);
5067 set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags);
5068
5069 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
5070 spin_lock_irq(&inode->ordered_tree_lock);
5071 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
5072 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
5073 atomic_inc(&trans->transaction->pending_ordered);
5074 }
5075 spin_unlock_irq(&inode->ordered_tree_lock);
5076 }
5077 btrfs_put_ordered_extent(ordered);
5078 }
5079
5080 return 0;
5081 }
5082
logged_inode_size(struct btrfs_root * log,struct btrfs_inode * inode,struct btrfs_path * path,u64 * size_ret)5083 static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
5084 struct btrfs_path *path, u64 *size_ret)
5085 {
5086 struct btrfs_key key;
5087 int ret;
5088
5089 key.objectid = btrfs_ino(inode);
5090 key.type = BTRFS_INODE_ITEM_KEY;
5091 key.offset = 0;
5092
5093 ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
5094 if (ret < 0) {
5095 return ret;
5096 } else if (ret > 0) {
5097 *size_ret = 0;
5098 } else {
5099 struct btrfs_inode_item *item;
5100
5101 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5102 struct btrfs_inode_item);
5103 *size_ret = btrfs_inode_size(path->nodes[0], item);
5104 /*
5105 * If the in-memory inode's i_size is smaller then the inode
5106 * size stored in the btree, return the inode's i_size, so
5107 * that we get a correct inode size after replaying the log
5108 * when before a power failure we had a shrinking truncate
5109 * followed by addition of a new name (rename / new hard link).
5110 * Otherwise return the inode size from the btree, to avoid
5111 * data loss when replaying a log due to previously doing a
5112 * write that expands the inode's size and logging a new name
5113 * immediately after.
5114 */
5115 if (*size_ret > inode->vfs_inode.i_size)
5116 *size_ret = inode->vfs_inode.i_size;
5117 }
5118
5119 btrfs_release_path(path);
5120 return 0;
5121 }
5122
5123 /*
5124 * At the moment we always log all xattrs. This is to figure out at log replay
5125 * time which xattrs must have their deletion replayed. If a xattr is missing
5126 * in the log tree and exists in the fs/subvol tree, we delete it. This is
5127 * because if a xattr is deleted, the inode is fsynced and a power failure
5128 * happens, causing the log to be replayed the next time the fs is mounted,
5129 * we want the xattr to not exist anymore (same behaviour as other filesystems
5130 * with a journal, ext3/4, xfs, f2fs, etc).
5131 */
btrfs_log_all_xattrs(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,struct btrfs_path * dst_path,struct btrfs_log_ctx * ctx)5132 static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
5133 struct btrfs_inode *inode,
5134 struct btrfs_path *path,
5135 struct btrfs_path *dst_path,
5136 struct btrfs_log_ctx *ctx)
5137 {
5138 struct btrfs_root *root = inode->root;
5139 int ret;
5140 struct btrfs_key key;
5141 const u64 ino = btrfs_ino(inode);
5142 int ins_nr = 0;
5143 int start_slot = 0;
5144 bool found_xattrs = false;
5145
5146 if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags))
5147 return 0;
5148
5149 key.objectid = ino;
5150 key.type = BTRFS_XATTR_ITEM_KEY;
5151 key.offset = 0;
5152
5153 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5154 if (ret < 0)
5155 return ret;
5156
5157 while (true) {
5158 int slot = path->slots[0];
5159 struct extent_buffer *leaf = path->nodes[0];
5160 int nritems = btrfs_header_nritems(leaf);
5161
5162 if (slot >= nritems) {
5163 if (ins_nr > 0) {
5164 ret = copy_items(trans, inode, dst_path, path,
5165 start_slot, ins_nr, 1, 0, ctx);
5166 if (ret < 0)
5167 return ret;
5168 ins_nr = 0;
5169 }
5170 ret = btrfs_next_leaf(root, path);
5171 if (ret < 0)
5172 return ret;
5173 else if (ret > 0)
5174 break;
5175 continue;
5176 }
5177
5178 btrfs_item_key_to_cpu(leaf, &key, slot);
5179 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
5180 break;
5181
5182 if (ins_nr == 0)
5183 start_slot = slot;
5184 ins_nr++;
5185 path->slots[0]++;
5186 found_xattrs = true;
5187 cond_resched();
5188 }
5189 if (ins_nr > 0) {
5190 ret = copy_items(trans, inode, dst_path, path,
5191 start_slot, ins_nr, 1, 0, ctx);
5192 if (ret < 0)
5193 return ret;
5194 }
5195
5196 if (!found_xattrs)
5197 set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags);
5198
5199 return 0;
5200 }
5201
5202 /*
5203 * When using the NO_HOLES feature if we punched a hole that causes the
5204 * deletion of entire leafs or all the extent items of the first leaf (the one
5205 * that contains the inode item and references) we may end up not processing
5206 * any extents, because there are no leafs with a generation matching the
5207 * current transaction that have extent items for our inode. So we need to find
5208 * if any holes exist and then log them. We also need to log holes after any
5209 * truncate operation that changes the inode's size.
5210 */
btrfs_log_holes(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path)5211 static int btrfs_log_holes(struct btrfs_trans_handle *trans,
5212 struct btrfs_inode *inode,
5213 struct btrfs_path *path)
5214 {
5215 struct btrfs_root *root = inode->root;
5216 struct btrfs_fs_info *fs_info = root->fs_info;
5217 struct btrfs_key key;
5218 const u64 ino = btrfs_ino(inode);
5219 const u64 i_size = i_size_read(&inode->vfs_inode);
5220 u64 prev_extent_end = 0;
5221 int ret;
5222
5223 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0)
5224 return 0;
5225
5226 key.objectid = ino;
5227 key.type = BTRFS_EXTENT_DATA_KEY;
5228 key.offset = 0;
5229
5230 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5231 if (ret < 0)
5232 return ret;
5233
5234 while (true) {
5235 struct extent_buffer *leaf = path->nodes[0];
5236
5237 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
5238 ret = btrfs_next_leaf(root, path);
5239 if (ret < 0)
5240 return ret;
5241 if (ret > 0) {
5242 ret = 0;
5243 break;
5244 }
5245 leaf = path->nodes[0];
5246 }
5247
5248 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
5249 if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
5250 break;
5251
5252 /* We have a hole, log it. */
5253 if (prev_extent_end < key.offset) {
5254 const u64 hole_len = key.offset - prev_extent_end;
5255
5256 /*
5257 * Release the path to avoid deadlocks with other code
5258 * paths that search the root while holding locks on
5259 * leafs from the log root.
5260 */
5261 btrfs_release_path(path);
5262 ret = btrfs_insert_hole_extent(trans, root->log_root,
5263 ino, prev_extent_end,
5264 hole_len);
5265 if (ret < 0)
5266 return ret;
5267
5268 /*
5269 * Search for the same key again in the root. Since it's
5270 * an extent item and we are holding the inode lock, the
5271 * key must still exist. If it doesn't just emit warning
5272 * and return an error to fall back to a transaction
5273 * commit.
5274 */
5275 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5276 if (ret < 0)
5277 return ret;
5278 if (WARN_ON(ret > 0))
5279 return -ENOENT;
5280 leaf = path->nodes[0];
5281 }
5282
5283 prev_extent_end = btrfs_file_extent_end(path);
5284 path->slots[0]++;
5285 cond_resched();
5286 }
5287
5288 if (prev_extent_end < i_size) {
5289 u64 hole_len;
5290
5291 btrfs_release_path(path);
5292 hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize);
5293 ret = btrfs_insert_hole_extent(trans, root->log_root, ino,
5294 prev_extent_end, hole_len);
5295 if (ret < 0)
5296 return ret;
5297 }
5298
5299 return 0;
5300 }
5301
5302 /*
5303 * When we are logging a new inode X, check if it doesn't have a reference that
5304 * matches the reference from some other inode Y created in a past transaction
5305 * and that was renamed in the current transaction. If we don't do this, then at
5306 * log replay time we can lose inode Y (and all its files if it's a directory):
5307 *
5308 * mkdir /mnt/x
5309 * echo "hello world" > /mnt/x/foobar
5310 * sync
5311 * mv /mnt/x /mnt/y
5312 * mkdir /mnt/x # or touch /mnt/x
5313 * xfs_io -c fsync /mnt/x
5314 * <power fail>
5315 * mount fs, trigger log replay
5316 *
5317 * After the log replay procedure, we would lose the first directory and all its
5318 * files (file foobar).
5319 * For the case where inode Y is not a directory we simply end up losing it:
5320 *
5321 * echo "123" > /mnt/foo
5322 * sync
5323 * mv /mnt/foo /mnt/bar
5324 * echo "abc" > /mnt/foo
5325 * xfs_io -c fsync /mnt/foo
5326 * <power fail>
5327 *
5328 * We also need this for cases where a snapshot entry is replaced by some other
5329 * entry (file or directory) otherwise we end up with an unreplayable log due to
5330 * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
5331 * if it were a regular entry:
5332 *
5333 * mkdir /mnt/x
5334 * btrfs subvolume snapshot /mnt /mnt/x/snap
5335 * btrfs subvolume delete /mnt/x/snap
5336 * rmdir /mnt/x
5337 * mkdir /mnt/x
5338 * fsync /mnt/x or fsync some new file inside it
5339 * <power fail>
5340 *
5341 * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
5342 * the same transaction.
5343 */
btrfs_check_ref_name_override(struct extent_buffer * eb,const int slot,const struct btrfs_key * key,struct btrfs_inode * inode,u64 * other_ino,u64 * other_parent)5344 static int btrfs_check_ref_name_override(struct extent_buffer *eb,
5345 const int slot,
5346 const struct btrfs_key *key,
5347 struct btrfs_inode *inode,
5348 u64 *other_ino, u64 *other_parent)
5349 {
5350 int ret;
5351 struct btrfs_path *search_path;
5352 char *name = NULL;
5353 u32 name_len = 0;
5354 u32 item_size = btrfs_item_size(eb, slot);
5355 u32 cur_offset = 0;
5356 unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
5357
5358 search_path = btrfs_alloc_path();
5359 if (!search_path)
5360 return -ENOMEM;
5361 search_path->search_commit_root = 1;
5362 search_path->skip_locking = 1;
5363
5364 while (cur_offset < item_size) {
5365 u64 parent;
5366 u32 this_name_len;
5367 u32 this_len;
5368 unsigned long name_ptr;
5369 struct btrfs_dir_item *di;
5370 struct fscrypt_str name_str;
5371
5372 if (key->type == BTRFS_INODE_REF_KEY) {
5373 struct btrfs_inode_ref *iref;
5374
5375 iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
5376 parent = key->offset;
5377 this_name_len = btrfs_inode_ref_name_len(eb, iref);
5378 name_ptr = (unsigned long)(iref + 1);
5379 this_len = sizeof(*iref) + this_name_len;
5380 } else {
5381 struct btrfs_inode_extref *extref;
5382
5383 extref = (struct btrfs_inode_extref *)(ptr +
5384 cur_offset);
5385 parent = btrfs_inode_extref_parent(eb, extref);
5386 this_name_len = btrfs_inode_extref_name_len(eb, extref);
5387 name_ptr = (unsigned long)&extref->name;
5388 this_len = sizeof(*extref) + this_name_len;
5389 }
5390
5391 if (this_name_len > name_len) {
5392 char *new_name;
5393
5394 new_name = krealloc(name, this_name_len, GFP_NOFS);
5395 if (!new_name) {
5396 ret = -ENOMEM;
5397 goto out;
5398 }
5399 name_len = this_name_len;
5400 name = new_name;
5401 }
5402
5403 read_extent_buffer(eb, name, name_ptr, this_name_len);
5404
5405 name_str.name = name;
5406 name_str.len = this_name_len;
5407 di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
5408 parent, &name_str, 0);
5409 if (di && !IS_ERR(di)) {
5410 struct btrfs_key di_key;
5411
5412 btrfs_dir_item_key_to_cpu(search_path->nodes[0],
5413 di, &di_key);
5414 if (di_key.type == BTRFS_INODE_ITEM_KEY) {
5415 if (di_key.objectid != key->objectid) {
5416 ret = 1;
5417 *other_ino = di_key.objectid;
5418 *other_parent = parent;
5419 } else {
5420 ret = 0;
5421 }
5422 } else {
5423 ret = -EAGAIN;
5424 }
5425 goto out;
5426 } else if (IS_ERR(di)) {
5427 ret = PTR_ERR(di);
5428 goto out;
5429 }
5430 btrfs_release_path(search_path);
5431
5432 cur_offset += this_len;
5433 }
5434 ret = 0;
5435 out:
5436 btrfs_free_path(search_path);
5437 kfree(name);
5438 return ret;
5439 }
5440
5441 /*
5442 * Check if we need to log an inode. This is used in contexts where while
5443 * logging an inode we need to log another inode (either that it exists or in
5444 * full mode). This is used instead of btrfs_inode_in_log() because the later
5445 * requires the inode to be in the log and have the log transaction committed,
5446 * while here we do not care if the log transaction was already committed - our
5447 * caller will commit the log later - and we want to avoid logging an inode
5448 * multiple times when multiple tasks have joined the same log transaction.
5449 */
need_log_inode(const struct btrfs_trans_handle * trans,struct btrfs_inode * inode)5450 static bool need_log_inode(const struct btrfs_trans_handle *trans,
5451 struct btrfs_inode *inode)
5452 {
5453 /*
5454 * If a directory was not modified, no dentries added or removed, we can
5455 * and should avoid logging it.
5456 */
5457 if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid)
5458 return false;
5459
5460 /*
5461 * If this inode does not have new/updated/deleted xattrs since the last
5462 * time it was logged and is flagged as logged in the current transaction,
5463 * we can skip logging it. As for new/deleted names, those are updated in
5464 * the log by link/unlink/rename operations.
5465 * In case the inode was logged and then evicted and reloaded, its
5466 * logged_trans will be 0, in which case we have to fully log it since
5467 * logged_trans is a transient field, not persisted.
5468 */
5469 if (inode_logged(trans, inode, NULL) == 1 &&
5470 !test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
5471 return false;
5472
5473 return true;
5474 }
5475
5476 struct btrfs_dir_list {
5477 u64 ino;
5478 struct list_head list;
5479 };
5480
5481 /*
5482 * Log the inodes of the new dentries of a directory.
5483 * See process_dir_items_leaf() for details about why it is needed.
5484 * This is a recursive operation - if an existing dentry corresponds to a
5485 * directory, that directory's new entries are logged too (same behaviour as
5486 * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
5487 * the dentries point to we do not acquire their VFS lock, otherwise lockdep
5488 * complains about the following circular lock dependency / possible deadlock:
5489 *
5490 * CPU0 CPU1
5491 * ---- ----
5492 * lock(&type->i_mutex_dir_key#3/2);
5493 * lock(sb_internal#2);
5494 * lock(&type->i_mutex_dir_key#3/2);
5495 * lock(&sb->s_type->i_mutex_key#14);
5496 *
5497 * Where sb_internal is the lock (a counter that works as a lock) acquired by
5498 * sb_start_intwrite() in btrfs_start_transaction().
5499 * Not acquiring the VFS lock of the inodes is still safe because:
5500 *
5501 * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
5502 * that while logging the inode new references (names) are added or removed
5503 * from the inode, leaving the logged inode item with a link count that does
5504 * not match the number of logged inode reference items. This is fine because
5505 * at log replay time we compute the real number of links and correct the
5506 * link count in the inode item (see replay_one_buffer() and
5507 * link_to_fixup_dir());
5508 *
5509 * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
5510 * while logging the inode's items new index items (key type
5511 * BTRFS_DIR_INDEX_KEY) are added to fs/subvol tree and the logged inode item
5512 * has a size that doesn't match the sum of the lengths of all the logged
5513 * names - this is ok, not a problem, because at log replay time we set the
5514 * directory's i_size to the correct value (see replay_one_name() and
5515 * overwrite_item()).
5516 */
log_new_dir_dentries(struct btrfs_trans_handle * trans,struct btrfs_inode * start_inode,struct btrfs_log_ctx * ctx)5517 static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
5518 struct btrfs_inode *start_inode,
5519 struct btrfs_log_ctx *ctx)
5520 {
5521 struct btrfs_root *root = start_inode->root;
5522 struct btrfs_path *path;
5523 LIST_HEAD(dir_list);
5524 struct btrfs_dir_list *dir_elem;
5525 u64 ino = btrfs_ino(start_inode);
5526 struct btrfs_inode *curr_inode = start_inode;
5527 int ret = 0;
5528
5529 /*
5530 * If we are logging a new name, as part of a link or rename operation,
5531 * don't bother logging new dentries, as we just want to log the names
5532 * of an inode and that any new parents exist.
5533 */
5534 if (ctx->logging_new_name)
5535 return 0;
5536
5537 path = btrfs_alloc_path();
5538 if (!path)
5539 return -ENOMEM;
5540
5541 /* Pairs with btrfs_add_delayed_iput below. */
5542 ihold(&curr_inode->vfs_inode);
5543
5544 while (true) {
5545 struct btrfs_key key;
5546 struct btrfs_key found_key;
5547 u64 next_index;
5548 bool continue_curr_inode = true;
5549 int iter_ret;
5550
5551 key.objectid = ino;
5552 key.type = BTRFS_DIR_INDEX_KEY;
5553 key.offset = btrfs_get_first_dir_index_to_log(curr_inode);
5554 next_index = key.offset;
5555 again:
5556 btrfs_for_each_slot(root->log_root, &key, &found_key, path, iter_ret) {
5557 struct extent_buffer *leaf = path->nodes[0];
5558 struct btrfs_dir_item *di;
5559 struct btrfs_key di_key;
5560 struct btrfs_inode *di_inode;
5561 int log_mode = LOG_INODE_EXISTS;
5562 int type;
5563
5564 if (found_key.objectid != ino ||
5565 found_key.type != BTRFS_DIR_INDEX_KEY) {
5566 continue_curr_inode = false;
5567 break;
5568 }
5569
5570 next_index = found_key.offset + 1;
5571
5572 di = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_dir_item);
5573 type = btrfs_dir_ftype(leaf, di);
5574 if (btrfs_dir_transid(leaf, di) < trans->transid)
5575 continue;
5576 btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
5577 if (di_key.type == BTRFS_ROOT_ITEM_KEY)
5578 continue;
5579
5580 btrfs_release_path(path);
5581 di_inode = btrfs_iget_logging(di_key.objectid, root);
5582 if (IS_ERR(di_inode)) {
5583 ret = PTR_ERR(di_inode);
5584 goto out;
5585 }
5586
5587 if (!need_log_inode(trans, di_inode)) {
5588 btrfs_add_delayed_iput(di_inode);
5589 break;
5590 }
5591
5592 ctx->log_new_dentries = false;
5593 if (type == BTRFS_FT_DIR)
5594 log_mode = LOG_INODE_ALL;
5595 ret = btrfs_log_inode(trans, di_inode, log_mode, ctx);
5596 btrfs_add_delayed_iput(di_inode);
5597 if (ret)
5598 goto out;
5599 if (ctx->log_new_dentries) {
5600 dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
5601 if (!dir_elem) {
5602 ret = -ENOMEM;
5603 goto out;
5604 }
5605 dir_elem->ino = di_key.objectid;
5606 list_add_tail(&dir_elem->list, &dir_list);
5607 }
5608 break;
5609 }
5610
5611 btrfs_release_path(path);
5612
5613 if (iter_ret < 0) {
5614 ret = iter_ret;
5615 goto out;
5616 } else if (iter_ret > 0) {
5617 continue_curr_inode = false;
5618 } else {
5619 key = found_key;
5620 }
5621
5622 if (continue_curr_inode && key.offset < (u64)-1) {
5623 key.offset++;
5624 goto again;
5625 }
5626
5627 btrfs_set_first_dir_index_to_log(curr_inode, next_index);
5628
5629 if (list_empty(&dir_list))
5630 break;
5631
5632 dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, list);
5633 ino = dir_elem->ino;
5634 list_del(&dir_elem->list);
5635 kfree(dir_elem);
5636
5637 btrfs_add_delayed_iput(curr_inode);
5638
5639 curr_inode = btrfs_iget_logging(ino, root);
5640 if (IS_ERR(curr_inode)) {
5641 ret = PTR_ERR(curr_inode);
5642 curr_inode = NULL;
5643 break;
5644 }
5645 }
5646 out:
5647 btrfs_free_path(path);
5648 if (curr_inode)
5649 btrfs_add_delayed_iput(curr_inode);
5650
5651 if (ret) {
5652 struct btrfs_dir_list *next;
5653
5654 list_for_each_entry_safe(dir_elem, next, &dir_list, list)
5655 kfree(dir_elem);
5656 }
5657
5658 return ret;
5659 }
5660
5661 struct btrfs_ino_list {
5662 u64 ino;
5663 u64 parent;
5664 struct list_head list;
5665 };
5666
free_conflicting_inodes(struct btrfs_log_ctx * ctx)5667 static void free_conflicting_inodes(struct btrfs_log_ctx *ctx)
5668 {
5669 struct btrfs_ino_list *curr;
5670 struct btrfs_ino_list *next;
5671
5672 list_for_each_entry_safe(curr, next, &ctx->conflict_inodes, list) {
5673 list_del(&curr->list);
5674 kfree(curr);
5675 }
5676 }
5677
conflicting_inode_is_dir(struct btrfs_root * root,u64 ino,struct btrfs_path * path)5678 static int conflicting_inode_is_dir(struct btrfs_root *root, u64 ino,
5679 struct btrfs_path *path)
5680 {
5681 struct btrfs_key key;
5682 int ret;
5683
5684 key.objectid = ino;
5685 key.type = BTRFS_INODE_ITEM_KEY;
5686 key.offset = 0;
5687
5688 path->search_commit_root = 1;
5689 path->skip_locking = 1;
5690
5691 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5692 if (WARN_ON_ONCE(ret > 0)) {
5693 /*
5694 * We have previously found the inode through the commit root
5695 * so this should not happen. If it does, just error out and
5696 * fallback to a transaction commit.
5697 */
5698 ret = -ENOENT;
5699 } else if (ret == 0) {
5700 struct btrfs_inode_item *item;
5701
5702 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
5703 struct btrfs_inode_item);
5704 if (S_ISDIR(btrfs_inode_mode(path->nodes[0], item)))
5705 ret = 1;
5706 }
5707
5708 btrfs_release_path(path);
5709 path->search_commit_root = 0;
5710 path->skip_locking = 0;
5711
5712 return ret;
5713 }
5714
add_conflicting_inode(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,u64 ino,u64 parent,struct btrfs_log_ctx * ctx)5715 static int add_conflicting_inode(struct btrfs_trans_handle *trans,
5716 struct btrfs_root *root,
5717 struct btrfs_path *path,
5718 u64 ino, u64 parent,
5719 struct btrfs_log_ctx *ctx)
5720 {
5721 struct btrfs_ino_list *ino_elem;
5722 struct btrfs_inode *inode;
5723
5724 /*
5725 * It's rare to have a lot of conflicting inodes, in practice it is not
5726 * common to have more than 1 or 2. We don't want to collect too many,
5727 * as we could end up logging too many inodes (even if only in
5728 * LOG_INODE_EXISTS mode) and slow down other fsyncs or transaction
5729 * commits.
5730 */
5731 if (ctx->num_conflict_inodes >= MAX_CONFLICT_INODES)
5732 return BTRFS_LOG_FORCE_COMMIT;
5733
5734 inode = btrfs_iget_logging(ino, root);
5735 /*
5736 * If the other inode that had a conflicting dir entry was deleted in
5737 * the current transaction then we either:
5738 *
5739 * 1) Log the parent directory (later after adding it to the list) if
5740 * the inode is a directory. This is because it may be a deleted
5741 * subvolume/snapshot or it may be a regular directory that had
5742 * deleted subvolumes/snapshots (or subdirectories that had them),
5743 * and at the moment we can't deal with dropping subvolumes/snapshots
5744 * during log replay. So we just log the parent, which will result in
5745 * a fallback to a transaction commit if we are dealing with those
5746 * cases (last_unlink_trans will match the current transaction);
5747 *
5748 * 2) Do nothing if it's not a directory. During log replay we simply
5749 * unlink the conflicting dentry from the parent directory and then
5750 * add the dentry for our inode. Like this we can avoid logging the
5751 * parent directory (and maybe fallback to a transaction commit in
5752 * case it has a last_unlink_trans == trans->transid, due to moving
5753 * some inode from it to some other directory).
5754 */
5755 if (IS_ERR(inode)) {
5756 int ret = PTR_ERR(inode);
5757
5758 if (ret != -ENOENT)
5759 return ret;
5760
5761 ret = conflicting_inode_is_dir(root, ino, path);
5762 /* Not a directory or we got an error. */
5763 if (ret <= 0)
5764 return ret;
5765
5766 /* Conflicting inode is a directory, so we'll log its parent. */
5767 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
5768 if (!ino_elem)
5769 return -ENOMEM;
5770 ino_elem->ino = ino;
5771 ino_elem->parent = parent;
5772 list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
5773 ctx->num_conflict_inodes++;
5774
5775 return 0;
5776 }
5777
5778 /*
5779 * If the inode was already logged skip it - otherwise we can hit an
5780 * infinite loop. Example:
5781 *
5782 * From the commit root (previous transaction) we have the following
5783 * inodes:
5784 *
5785 * inode 257 a directory
5786 * inode 258 with references "zz" and "zz_link" on inode 257
5787 * inode 259 with reference "a" on inode 257
5788 *
5789 * And in the current (uncommitted) transaction we have:
5790 *
5791 * inode 257 a directory, unchanged
5792 * inode 258 with references "a" and "a2" on inode 257
5793 * inode 259 with reference "zz_link" on inode 257
5794 * inode 261 with reference "zz" on inode 257
5795 *
5796 * When logging inode 261 the following infinite loop could
5797 * happen if we don't skip already logged inodes:
5798 *
5799 * - we detect inode 258 as a conflicting inode, with inode 261
5800 * on reference "zz", and log it;
5801 *
5802 * - we detect inode 259 as a conflicting inode, with inode 258
5803 * on reference "a", and log it;
5804 *
5805 * - we detect inode 258 as a conflicting inode, with inode 259
5806 * on reference "zz_link", and log it - again! After this we
5807 * repeat the above steps forever.
5808 *
5809 * Here we can use need_log_inode() because we only need to log the
5810 * inode in LOG_INODE_EXISTS mode and rename operations update the log,
5811 * so that the log ends up with the new name and without the old name.
5812 */
5813 if (!need_log_inode(trans, inode)) {
5814 btrfs_add_delayed_iput(inode);
5815 return 0;
5816 }
5817
5818 btrfs_add_delayed_iput(inode);
5819
5820 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
5821 if (!ino_elem)
5822 return -ENOMEM;
5823 ino_elem->ino = ino;
5824 ino_elem->parent = parent;
5825 list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
5826 ctx->num_conflict_inodes++;
5827
5828 return 0;
5829 }
5830
log_conflicting_inodes(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_log_ctx * ctx)5831 static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
5832 struct btrfs_root *root,
5833 struct btrfs_log_ctx *ctx)
5834 {
5835 int ret = 0;
5836
5837 /*
5838 * Conflicting inodes are logged by the first call to btrfs_log_inode(),
5839 * otherwise we could have unbounded recursion of btrfs_log_inode()
5840 * calls. This check guarantees we can have only 1 level of recursion.
5841 */
5842 if (ctx->logging_conflict_inodes)
5843 return 0;
5844
5845 ctx->logging_conflict_inodes = true;
5846
5847 /*
5848 * New conflicting inodes may be found and added to the list while we
5849 * are logging a conflicting inode, so keep iterating while the list is
5850 * not empty.
5851 */
5852 while (!list_empty(&ctx->conflict_inodes)) {
5853 struct btrfs_ino_list *curr;
5854 struct btrfs_inode *inode;
5855 u64 ino;
5856 u64 parent;
5857
5858 curr = list_first_entry(&ctx->conflict_inodes,
5859 struct btrfs_ino_list, list);
5860 ino = curr->ino;
5861 parent = curr->parent;
5862 list_del(&curr->list);
5863 kfree(curr);
5864
5865 inode = btrfs_iget_logging(ino, root);
5866 /*
5867 * If the other inode that had a conflicting dir entry was
5868 * deleted in the current transaction, we need to log its parent
5869 * directory. See the comment at add_conflicting_inode().
5870 */
5871 if (IS_ERR(inode)) {
5872 ret = PTR_ERR(inode);
5873 if (ret != -ENOENT)
5874 break;
5875
5876 inode = btrfs_iget_logging(parent, root);
5877 if (IS_ERR(inode)) {
5878 ret = PTR_ERR(inode);
5879 break;
5880 }
5881
5882 /*
5883 * Always log the directory, we cannot make this
5884 * conditional on need_log_inode() because the directory
5885 * might have been logged in LOG_INODE_EXISTS mode or
5886 * the dir index of the conflicting inode is not in a
5887 * dir index key range logged for the directory. So we
5888 * must make sure the deletion is recorded.
5889 */
5890 ret = btrfs_log_inode(trans, inode, LOG_INODE_ALL, ctx);
5891 btrfs_add_delayed_iput(inode);
5892 if (ret)
5893 break;
5894 continue;
5895 }
5896
5897 /*
5898 * Here we can use need_log_inode() because we only need to log
5899 * the inode in LOG_INODE_EXISTS mode and rename operations
5900 * update the log, so that the log ends up with the new name and
5901 * without the old name.
5902 *
5903 * We did this check at add_conflicting_inode(), but here we do
5904 * it again because if some other task logged the inode after
5905 * that, we can avoid doing it again.
5906 */
5907 if (!need_log_inode(trans, inode)) {
5908 btrfs_add_delayed_iput(inode);
5909 continue;
5910 }
5911
5912 /*
5913 * We are safe logging the other inode without acquiring its
5914 * lock as long as we log with the LOG_INODE_EXISTS mode. We
5915 * are safe against concurrent renames of the other inode as
5916 * well because during a rename we pin the log and update the
5917 * log with the new name before we unpin it.
5918 */
5919 ret = btrfs_log_inode(trans, inode, LOG_INODE_EXISTS, ctx);
5920 btrfs_add_delayed_iput(inode);
5921 if (ret)
5922 break;
5923 }
5924
5925 ctx->logging_conflict_inodes = false;
5926 if (ret)
5927 free_conflicting_inodes(ctx);
5928
5929 return ret;
5930 }
5931
copy_inode_items_to_log(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_key * min_key,const struct btrfs_key * max_key,struct btrfs_path * path,struct btrfs_path * dst_path,const u64 logged_isize,const int inode_only,struct btrfs_log_ctx * ctx,bool * need_log_inode_item)5932 static int copy_inode_items_to_log(struct btrfs_trans_handle *trans,
5933 struct btrfs_inode *inode,
5934 struct btrfs_key *min_key,
5935 const struct btrfs_key *max_key,
5936 struct btrfs_path *path,
5937 struct btrfs_path *dst_path,
5938 const u64 logged_isize,
5939 const int inode_only,
5940 struct btrfs_log_ctx *ctx,
5941 bool *need_log_inode_item)
5942 {
5943 const u64 i_size = i_size_read(&inode->vfs_inode);
5944 struct btrfs_root *root = inode->root;
5945 int ins_start_slot = 0;
5946 int ins_nr = 0;
5947 int ret;
5948
5949 while (1) {
5950 ret = btrfs_search_forward(root, min_key, path, trans->transid);
5951 if (ret < 0)
5952 return ret;
5953 if (ret > 0) {
5954 ret = 0;
5955 break;
5956 }
5957 again:
5958 /* Note, ins_nr might be > 0 here, cleanup outside the loop */
5959 if (min_key->objectid != max_key->objectid)
5960 break;
5961 if (min_key->type > max_key->type)
5962 break;
5963
5964 if (min_key->type == BTRFS_INODE_ITEM_KEY) {
5965 *need_log_inode_item = false;
5966 } else if (min_key->type == BTRFS_EXTENT_DATA_KEY &&
5967 min_key->offset >= i_size) {
5968 /*
5969 * Extents at and beyond eof are logged with
5970 * btrfs_log_prealloc_extents().
5971 * Only regular files have BTRFS_EXTENT_DATA_KEY keys,
5972 * and no keys greater than that, so bail out.
5973 */
5974 break;
5975 } else if ((min_key->type == BTRFS_INODE_REF_KEY ||
5976 min_key->type == BTRFS_INODE_EXTREF_KEY) &&
5977 (inode->generation == trans->transid ||
5978 ctx->logging_conflict_inodes)) {
5979 u64 other_ino = 0;
5980 u64 other_parent = 0;
5981
5982 ret = btrfs_check_ref_name_override(path->nodes[0],
5983 path->slots[0], min_key, inode,
5984 &other_ino, &other_parent);
5985 if (ret < 0) {
5986 return ret;
5987 } else if (ret > 0 &&
5988 other_ino != btrfs_ino(ctx->inode)) {
5989 if (ins_nr > 0) {
5990 ins_nr++;
5991 } else {
5992 ins_nr = 1;
5993 ins_start_slot = path->slots[0];
5994 }
5995 ret = copy_items(trans, inode, dst_path, path,
5996 ins_start_slot, ins_nr,
5997 inode_only, logged_isize, ctx);
5998 if (ret < 0)
5999 return ret;
6000 ins_nr = 0;
6001
6002 btrfs_release_path(path);
6003 ret = add_conflicting_inode(trans, root, path,
6004 other_ino,
6005 other_parent, ctx);
6006 if (ret)
6007 return ret;
6008 goto next_key;
6009 }
6010 } else if (min_key->type == BTRFS_XATTR_ITEM_KEY) {
6011 /* Skip xattrs, logged later with btrfs_log_all_xattrs() */
6012 if (ins_nr == 0)
6013 goto next_slot;
6014 ret = copy_items(trans, inode, dst_path, path,
6015 ins_start_slot,
6016 ins_nr, inode_only, logged_isize, ctx);
6017 if (ret < 0)
6018 return ret;
6019 ins_nr = 0;
6020 goto next_slot;
6021 }
6022
6023 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
6024 ins_nr++;
6025 goto next_slot;
6026 } else if (!ins_nr) {
6027 ins_start_slot = path->slots[0];
6028 ins_nr = 1;
6029 goto next_slot;
6030 }
6031
6032 ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
6033 ins_nr, inode_only, logged_isize, ctx);
6034 if (ret < 0)
6035 return ret;
6036 ins_nr = 1;
6037 ins_start_slot = path->slots[0];
6038 next_slot:
6039 path->slots[0]++;
6040 if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
6041 btrfs_item_key_to_cpu(path->nodes[0], min_key,
6042 path->slots[0]);
6043 goto again;
6044 }
6045 if (ins_nr) {
6046 ret = copy_items(trans, inode, dst_path, path,
6047 ins_start_slot, ins_nr, inode_only,
6048 logged_isize, ctx);
6049 if (ret < 0)
6050 return ret;
6051 ins_nr = 0;
6052 }
6053 btrfs_release_path(path);
6054 next_key:
6055 if (min_key->offset < (u64)-1) {
6056 min_key->offset++;
6057 } else if (min_key->type < max_key->type) {
6058 min_key->type++;
6059 min_key->offset = 0;
6060 } else {
6061 break;
6062 }
6063
6064 /*
6065 * We may process many leaves full of items for our inode, so
6066 * avoid monopolizing a cpu for too long by rescheduling while
6067 * not holding locks on any tree.
6068 */
6069 cond_resched();
6070 }
6071 if (ins_nr) {
6072 ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
6073 ins_nr, inode_only, logged_isize, ctx);
6074 if (ret)
6075 return ret;
6076 }
6077
6078 if (inode_only == LOG_INODE_ALL && S_ISREG(inode->vfs_inode.i_mode)) {
6079 /*
6080 * Release the path because otherwise we might attempt to double
6081 * lock the same leaf with btrfs_log_prealloc_extents() below.
6082 */
6083 btrfs_release_path(path);
6084 ret = btrfs_log_prealloc_extents(trans, inode, dst_path, ctx);
6085 }
6086
6087 return ret;
6088 }
6089
insert_delayed_items_batch(struct btrfs_trans_handle * trans,struct btrfs_root * log,struct btrfs_path * path,const struct btrfs_item_batch * batch,const struct btrfs_delayed_item * first_item)6090 static int insert_delayed_items_batch(struct btrfs_trans_handle *trans,
6091 struct btrfs_root *log,
6092 struct btrfs_path *path,
6093 const struct btrfs_item_batch *batch,
6094 const struct btrfs_delayed_item *first_item)
6095 {
6096 const struct btrfs_delayed_item *curr = first_item;
6097 int ret;
6098
6099 ret = btrfs_insert_empty_items(trans, log, path, batch);
6100 if (ret)
6101 return ret;
6102
6103 for (int i = 0; i < batch->nr; i++) {
6104 char *data_ptr;
6105
6106 data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
6107 write_extent_buffer(path->nodes[0], &curr->data,
6108 (unsigned long)data_ptr, curr->data_len);
6109 curr = list_next_entry(curr, log_list);
6110 path->slots[0]++;
6111 }
6112
6113 btrfs_release_path(path);
6114
6115 return 0;
6116 }
6117
log_delayed_insertion_items(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,const struct list_head * delayed_ins_list,struct btrfs_log_ctx * ctx)6118 static int log_delayed_insertion_items(struct btrfs_trans_handle *trans,
6119 struct btrfs_inode *inode,
6120 struct btrfs_path *path,
6121 const struct list_head *delayed_ins_list,
6122 struct btrfs_log_ctx *ctx)
6123 {
6124 /* 195 (4095 bytes of keys and sizes) fits in a single 4K page. */
6125 const int max_batch_size = 195;
6126 const int leaf_data_size = BTRFS_LEAF_DATA_SIZE(trans->fs_info);
6127 const u64 ino = btrfs_ino(inode);
6128 struct btrfs_root *log = inode->root->log_root;
6129 struct btrfs_item_batch batch = {
6130 .nr = 0,
6131 .total_data_size = 0,
6132 };
6133 const struct btrfs_delayed_item *first = NULL;
6134 const struct btrfs_delayed_item *curr;
6135 char *ins_data;
6136 struct btrfs_key *ins_keys;
6137 u32 *ins_sizes;
6138 u64 curr_batch_size = 0;
6139 int batch_idx = 0;
6140 int ret;
6141
6142 /* We are adding dir index items to the log tree. */
6143 lockdep_assert_held(&inode->log_mutex);
6144
6145 /*
6146 * We collect delayed items before copying index keys from the subvolume
6147 * to the log tree. However just after we collected them, they may have
6148 * been flushed (all of them or just some of them), and therefore we
6149 * could have copied them from the subvolume tree to the log tree.
6150 * So find the first delayed item that was not yet logged (they are
6151 * sorted by index number).
6152 */
6153 list_for_each_entry(curr, delayed_ins_list, log_list) {
6154 if (curr->index > inode->last_dir_index_offset) {
6155 first = curr;
6156 break;
6157 }
6158 }
6159
6160 /* Empty list or all delayed items were already logged. */
6161 if (!first)
6162 return 0;
6163
6164 ins_data = kmalloc(max_batch_size * sizeof(u32) +
6165 max_batch_size * sizeof(struct btrfs_key), GFP_NOFS);
6166 if (!ins_data)
6167 return -ENOMEM;
6168 ins_sizes = (u32 *)ins_data;
6169 batch.data_sizes = ins_sizes;
6170 ins_keys = (struct btrfs_key *)(ins_data + max_batch_size * sizeof(u32));
6171 batch.keys = ins_keys;
6172
6173 curr = first;
6174 while (!list_entry_is_head(curr, delayed_ins_list, log_list)) {
6175 const u32 curr_size = curr->data_len + sizeof(struct btrfs_item);
6176
6177 if (curr_batch_size + curr_size > leaf_data_size ||
6178 batch.nr == max_batch_size) {
6179 ret = insert_delayed_items_batch(trans, log, path,
6180 &batch, first);
6181 if (ret)
6182 goto out;
6183 batch_idx = 0;
6184 batch.nr = 0;
6185 batch.total_data_size = 0;
6186 curr_batch_size = 0;
6187 first = curr;
6188 }
6189
6190 ins_sizes[batch_idx] = curr->data_len;
6191 ins_keys[batch_idx].objectid = ino;
6192 ins_keys[batch_idx].type = BTRFS_DIR_INDEX_KEY;
6193 ins_keys[batch_idx].offset = curr->index;
6194 curr_batch_size += curr_size;
6195 batch.total_data_size += curr->data_len;
6196 batch.nr++;
6197 batch_idx++;
6198 curr = list_next_entry(curr, log_list);
6199 }
6200
6201 ASSERT(batch.nr >= 1);
6202 ret = insert_delayed_items_batch(trans, log, path, &batch, first);
6203
6204 curr = list_last_entry(delayed_ins_list, struct btrfs_delayed_item,
6205 log_list);
6206 inode->last_dir_index_offset = curr->index;
6207 out:
6208 kfree(ins_data);
6209
6210 return ret;
6211 }
6212
log_delayed_deletions_full(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,const struct list_head * delayed_del_list,struct btrfs_log_ctx * ctx)6213 static int log_delayed_deletions_full(struct btrfs_trans_handle *trans,
6214 struct btrfs_inode *inode,
6215 struct btrfs_path *path,
6216 const struct list_head *delayed_del_list,
6217 struct btrfs_log_ctx *ctx)
6218 {
6219 const u64 ino = btrfs_ino(inode);
6220 const struct btrfs_delayed_item *curr;
6221
6222 curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
6223 log_list);
6224
6225 while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
6226 u64 first_dir_index = curr->index;
6227 u64 last_dir_index;
6228 const struct btrfs_delayed_item *next;
6229 int ret;
6230
6231 /*
6232 * Find a range of consecutive dir index items to delete. Like
6233 * this we log a single dir range item spanning several contiguous
6234 * dir items instead of logging one range item per dir index item.
6235 */
6236 next = list_next_entry(curr, log_list);
6237 while (!list_entry_is_head(next, delayed_del_list, log_list)) {
6238 if (next->index != curr->index + 1)
6239 break;
6240 curr = next;
6241 next = list_next_entry(next, log_list);
6242 }
6243
6244 last_dir_index = curr->index;
6245 ASSERT(last_dir_index >= first_dir_index);
6246
6247 ret = insert_dir_log_key(trans, inode->root->log_root, path,
6248 ino, first_dir_index, last_dir_index);
6249 if (ret)
6250 return ret;
6251 curr = list_next_entry(curr, log_list);
6252 }
6253
6254 return 0;
6255 }
6256
batch_delete_dir_index_items(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,const struct list_head * delayed_del_list,const struct btrfs_delayed_item * first,const struct btrfs_delayed_item ** last_ret)6257 static int batch_delete_dir_index_items(struct btrfs_trans_handle *trans,
6258 struct btrfs_inode *inode,
6259 struct btrfs_path *path,
6260 const struct list_head *delayed_del_list,
6261 const struct btrfs_delayed_item *first,
6262 const struct btrfs_delayed_item **last_ret)
6263 {
6264 const struct btrfs_delayed_item *next;
6265 struct extent_buffer *leaf = path->nodes[0];
6266 const int last_slot = btrfs_header_nritems(leaf) - 1;
6267 int slot = path->slots[0] + 1;
6268 const u64 ino = btrfs_ino(inode);
6269
6270 next = list_next_entry(first, log_list);
6271
6272 while (slot < last_slot &&
6273 !list_entry_is_head(next, delayed_del_list, log_list)) {
6274 struct btrfs_key key;
6275
6276 btrfs_item_key_to_cpu(leaf, &key, slot);
6277 if (key.objectid != ino ||
6278 key.type != BTRFS_DIR_INDEX_KEY ||
6279 key.offset != next->index)
6280 break;
6281
6282 slot++;
6283 *last_ret = next;
6284 next = list_next_entry(next, log_list);
6285 }
6286
6287 return btrfs_del_items(trans, inode->root->log_root, path,
6288 path->slots[0], slot - path->slots[0]);
6289 }
6290
log_delayed_deletions_incremental(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,const struct list_head * delayed_del_list,struct btrfs_log_ctx * ctx)6291 static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans,
6292 struct btrfs_inode *inode,
6293 struct btrfs_path *path,
6294 const struct list_head *delayed_del_list,
6295 struct btrfs_log_ctx *ctx)
6296 {
6297 struct btrfs_root *log = inode->root->log_root;
6298 const struct btrfs_delayed_item *curr;
6299 u64 last_range_start = 0;
6300 u64 last_range_end = 0;
6301 struct btrfs_key key;
6302
6303 key.objectid = btrfs_ino(inode);
6304 key.type = BTRFS_DIR_INDEX_KEY;
6305 curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
6306 log_list);
6307
6308 while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
6309 const struct btrfs_delayed_item *last = curr;
6310 u64 first_dir_index = curr->index;
6311 u64 last_dir_index;
6312 bool deleted_items = false;
6313 int ret;
6314
6315 key.offset = curr->index;
6316 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
6317 if (ret < 0) {
6318 return ret;
6319 } else if (ret == 0) {
6320 ret = batch_delete_dir_index_items(trans, inode, path,
6321 delayed_del_list, curr,
6322 &last);
6323 if (ret)
6324 return ret;
6325 deleted_items = true;
6326 }
6327
6328 btrfs_release_path(path);
6329
6330 /*
6331 * If we deleted items from the leaf, it means we have a range
6332 * item logging their range, so no need to add one or update an
6333 * existing one. Otherwise we have to log a dir range item.
6334 */
6335 if (deleted_items)
6336 goto next_batch;
6337
6338 last_dir_index = last->index;
6339 ASSERT(last_dir_index >= first_dir_index);
6340 /*
6341 * If this range starts right after where the previous one ends,
6342 * then we want to reuse the previous range item and change its
6343 * end offset to the end of this range. This is just to minimize
6344 * leaf space usage, by avoiding adding a new range item.
6345 */
6346 if (last_range_end != 0 && first_dir_index == last_range_end + 1)
6347 first_dir_index = last_range_start;
6348
6349 ret = insert_dir_log_key(trans, log, path, key.objectid,
6350 first_dir_index, last_dir_index);
6351 if (ret)
6352 return ret;
6353
6354 last_range_start = first_dir_index;
6355 last_range_end = last_dir_index;
6356 next_batch:
6357 curr = list_next_entry(last, log_list);
6358 }
6359
6360 return 0;
6361 }
6362
log_delayed_deletion_items(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_path * path,const struct list_head * delayed_del_list,struct btrfs_log_ctx * ctx)6363 static int log_delayed_deletion_items(struct btrfs_trans_handle *trans,
6364 struct btrfs_inode *inode,
6365 struct btrfs_path *path,
6366 const struct list_head *delayed_del_list,
6367 struct btrfs_log_ctx *ctx)
6368 {
6369 /*
6370 * We are deleting dir index items from the log tree or adding range
6371 * items to it.
6372 */
6373 lockdep_assert_held(&inode->log_mutex);
6374
6375 if (list_empty(delayed_del_list))
6376 return 0;
6377
6378 if (ctx->logged_before)
6379 return log_delayed_deletions_incremental(trans, inode, path,
6380 delayed_del_list, ctx);
6381
6382 return log_delayed_deletions_full(trans, inode, path, delayed_del_list,
6383 ctx);
6384 }
6385
6386 /*
6387 * Similar logic as for log_new_dir_dentries(), but it iterates over the delayed
6388 * items instead of the subvolume tree.
6389 */
log_new_delayed_dentries(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,const struct list_head * delayed_ins_list,struct btrfs_log_ctx * ctx)6390 static int log_new_delayed_dentries(struct btrfs_trans_handle *trans,
6391 struct btrfs_inode *inode,
6392 const struct list_head *delayed_ins_list,
6393 struct btrfs_log_ctx *ctx)
6394 {
6395 const bool orig_log_new_dentries = ctx->log_new_dentries;
6396 struct btrfs_delayed_item *item;
6397 int ret = 0;
6398
6399 /*
6400 * No need for the log mutex, plus to avoid potential deadlocks or
6401 * lockdep annotations due to nesting of delayed inode mutexes and log
6402 * mutexes.
6403 */
6404 lockdep_assert_not_held(&inode->log_mutex);
6405
6406 ASSERT(!ctx->logging_new_delayed_dentries);
6407 ctx->logging_new_delayed_dentries = true;
6408
6409 list_for_each_entry(item, delayed_ins_list, log_list) {
6410 struct btrfs_dir_item *dir_item;
6411 struct btrfs_inode *di_inode;
6412 struct btrfs_key key;
6413 int log_mode = LOG_INODE_EXISTS;
6414
6415 dir_item = (struct btrfs_dir_item *)item->data;
6416 btrfs_disk_key_to_cpu(&key, &dir_item->location);
6417
6418 if (key.type == BTRFS_ROOT_ITEM_KEY)
6419 continue;
6420
6421 di_inode = btrfs_iget_logging(key.objectid, inode->root);
6422 if (IS_ERR(di_inode)) {
6423 ret = PTR_ERR(di_inode);
6424 break;
6425 }
6426
6427 if (!need_log_inode(trans, di_inode)) {
6428 btrfs_add_delayed_iput(di_inode);
6429 continue;
6430 }
6431
6432 if (btrfs_stack_dir_ftype(dir_item) == BTRFS_FT_DIR)
6433 log_mode = LOG_INODE_ALL;
6434
6435 ctx->log_new_dentries = false;
6436 ret = btrfs_log_inode(trans, di_inode, log_mode, ctx);
6437
6438 if (!ret && ctx->log_new_dentries)
6439 ret = log_new_dir_dentries(trans, di_inode, ctx);
6440
6441 btrfs_add_delayed_iput(di_inode);
6442
6443 if (ret)
6444 break;
6445 }
6446
6447 ctx->log_new_dentries = orig_log_new_dentries;
6448 ctx->logging_new_delayed_dentries = false;
6449
6450 return ret;
6451 }
6452
6453 /* log a single inode in the tree log.
6454 * At least one parent directory for this inode must exist in the tree
6455 * or be logged already.
6456 *
6457 * Any items from this inode changed by the current transaction are copied
6458 * to the log tree. An extra reference is taken on any extents in this
6459 * file, allowing us to avoid a whole pile of corner cases around logging
6460 * blocks that have been removed from the tree.
6461 *
6462 * See LOG_INODE_ALL and related defines for a description of what inode_only
6463 * does.
6464 *
6465 * This handles both files and directories.
6466 */
btrfs_log_inode(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,int inode_only,struct btrfs_log_ctx * ctx)6467 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
6468 struct btrfs_inode *inode,
6469 int inode_only,
6470 struct btrfs_log_ctx *ctx)
6471 {
6472 struct btrfs_path *path;
6473 struct btrfs_path *dst_path;
6474 struct btrfs_key min_key;
6475 struct btrfs_key max_key;
6476 struct btrfs_root *log = inode->root->log_root;
6477 int ret;
6478 bool fast_search = false;
6479 u64 ino = btrfs_ino(inode);
6480 struct extent_map_tree *em_tree = &inode->extent_tree;
6481 u64 logged_isize = 0;
6482 bool need_log_inode_item = true;
6483 bool xattrs_logged = false;
6484 bool inode_item_dropped = true;
6485 bool full_dir_logging = false;
6486 LIST_HEAD(delayed_ins_list);
6487 LIST_HEAD(delayed_del_list);
6488
6489 path = btrfs_alloc_path();
6490 if (!path)
6491 return -ENOMEM;
6492 dst_path = btrfs_alloc_path();
6493 if (!dst_path) {
6494 btrfs_free_path(path);
6495 return -ENOMEM;
6496 }
6497
6498 min_key.objectid = ino;
6499 min_key.type = BTRFS_INODE_ITEM_KEY;
6500 min_key.offset = 0;
6501
6502 max_key.objectid = ino;
6503
6504
6505 /* today the code can only do partial logging of directories */
6506 if (S_ISDIR(inode->vfs_inode.i_mode) ||
6507 (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
6508 &inode->runtime_flags) &&
6509 inode_only >= LOG_INODE_EXISTS))
6510 max_key.type = BTRFS_XATTR_ITEM_KEY;
6511 else
6512 max_key.type = (u8)-1;
6513 max_key.offset = (u64)-1;
6514
6515 if (S_ISDIR(inode->vfs_inode.i_mode) && inode_only == LOG_INODE_ALL)
6516 full_dir_logging = true;
6517
6518 /*
6519 * If we are logging a directory while we are logging dentries of the
6520 * delayed items of some other inode, then we need to flush the delayed
6521 * items of this directory and not log the delayed items directly. This
6522 * is to prevent more than one level of recursion into btrfs_log_inode()
6523 * by having something like this:
6524 *
6525 * $ mkdir -p a/b/c/d/e/f/g/h/...
6526 * $ xfs_io -c "fsync" a
6527 *
6528 * Where all directories in the path did not exist before and are
6529 * created in the current transaction.
6530 * So in such a case we directly log the delayed items of the main
6531 * directory ("a") without flushing them first, while for each of its
6532 * subdirectories we flush their delayed items before logging them.
6533 * This prevents a potential unbounded recursion like this:
6534 *
6535 * btrfs_log_inode()
6536 * log_new_delayed_dentries()
6537 * btrfs_log_inode()
6538 * log_new_delayed_dentries()
6539 * btrfs_log_inode()
6540 * log_new_delayed_dentries()
6541 * (...)
6542 *
6543 * We have thresholds for the maximum number of delayed items to have in
6544 * memory, and once they are hit, the items are flushed asynchronously.
6545 * However the limit is quite high, so lets prevent deep levels of
6546 * recursion to happen by limiting the maximum depth to be 1.
6547 */
6548 if (full_dir_logging && ctx->logging_new_delayed_dentries) {
6549 ret = btrfs_commit_inode_delayed_items(trans, inode);
6550 if (ret)
6551 goto out;
6552 }
6553
6554 mutex_lock(&inode->log_mutex);
6555
6556 /*
6557 * For symlinks, we must always log their content, which is stored in an
6558 * inline extent, otherwise we could end up with an empty symlink after
6559 * log replay, which is invalid on linux (symlink(2) returns -ENOENT if
6560 * one attempts to create an empty symlink).
6561 * We don't need to worry about flushing delalloc, because when we create
6562 * the inline extent when the symlink is created (we never have delalloc
6563 * for symlinks).
6564 */
6565 if (S_ISLNK(inode->vfs_inode.i_mode))
6566 inode_only = LOG_INODE_ALL;
6567
6568 /*
6569 * Before logging the inode item, cache the value returned by
6570 * inode_logged(), because after that we have the need to figure out if
6571 * the inode was previously logged in this transaction.
6572 */
6573 ret = inode_logged(trans, inode, path);
6574 if (ret < 0)
6575 goto out_unlock;
6576 ctx->logged_before = (ret == 1);
6577 ret = 0;
6578
6579 /*
6580 * This is for cases where logging a directory could result in losing a
6581 * a file after replaying the log. For example, if we move a file from a
6582 * directory A to a directory B, then fsync directory A, we have no way
6583 * to known the file was moved from A to B, so logging just A would
6584 * result in losing the file after a log replay.
6585 */
6586 if (full_dir_logging && inode->last_unlink_trans >= trans->transid) {
6587 ret = BTRFS_LOG_FORCE_COMMIT;
6588 goto out_unlock;
6589 }
6590
6591 /*
6592 * a brute force approach to making sure we get the most uptodate
6593 * copies of everything.
6594 */
6595 if (S_ISDIR(inode->vfs_inode.i_mode)) {
6596 clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
6597 if (ctx->logged_before)
6598 ret = drop_inode_items(trans, log, path, inode,
6599 BTRFS_XATTR_ITEM_KEY);
6600 } else {
6601 if (inode_only == LOG_INODE_EXISTS && ctx->logged_before) {
6602 /*
6603 * Make sure the new inode item we write to the log has
6604 * the same isize as the current one (if it exists).
6605 * This is necessary to prevent data loss after log
6606 * replay, and also to prevent doing a wrong expanding
6607 * truncate - for e.g. create file, write 4K into offset
6608 * 0, fsync, write 4K into offset 4096, add hard link,
6609 * fsync some other file (to sync log), power fail - if
6610 * we use the inode's current i_size, after log replay
6611 * we get a 8Kb file, with the last 4Kb extent as a hole
6612 * (zeroes), as if an expanding truncate happened,
6613 * instead of getting a file of 4Kb only.
6614 */
6615 ret = logged_inode_size(log, inode, path, &logged_isize);
6616 if (ret)
6617 goto out_unlock;
6618 }
6619 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
6620 &inode->runtime_flags)) {
6621 if (inode_only == LOG_INODE_EXISTS) {
6622 max_key.type = BTRFS_XATTR_ITEM_KEY;
6623 if (ctx->logged_before)
6624 ret = drop_inode_items(trans, log, path,
6625 inode, max_key.type);
6626 } else {
6627 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
6628 &inode->runtime_flags);
6629 clear_bit(BTRFS_INODE_COPY_EVERYTHING,
6630 &inode->runtime_flags);
6631 if (ctx->logged_before)
6632 ret = truncate_inode_items(trans, log,
6633 inode, 0, 0);
6634 }
6635 } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
6636 &inode->runtime_flags) ||
6637 inode_only == LOG_INODE_EXISTS) {
6638 if (inode_only == LOG_INODE_ALL)
6639 fast_search = true;
6640 max_key.type = BTRFS_XATTR_ITEM_KEY;
6641 if (ctx->logged_before)
6642 ret = drop_inode_items(trans, log, path, inode,
6643 max_key.type);
6644 } else {
6645 if (inode_only == LOG_INODE_ALL)
6646 fast_search = true;
6647 inode_item_dropped = false;
6648 goto log_extents;
6649 }
6650
6651 }
6652 if (ret)
6653 goto out_unlock;
6654
6655 /*
6656 * If we are logging a directory in full mode, collect the delayed items
6657 * before iterating the subvolume tree, so that we don't miss any new
6658 * dir index items in case they get flushed while or right after we are
6659 * iterating the subvolume tree.
6660 */
6661 if (full_dir_logging && !ctx->logging_new_delayed_dentries)
6662 btrfs_log_get_delayed_items(inode, &delayed_ins_list,
6663 &delayed_del_list);
6664
6665 /*
6666 * If we are fsyncing a file with 0 hard links, then commit the delayed
6667 * inode because the last inode ref (or extref) item may still be in the
6668 * subvolume tree and if we log it the file will still exist after a log
6669 * replay. So commit the delayed inode to delete that last ref and we
6670 * skip logging it.
6671 */
6672 if (inode->vfs_inode.i_nlink == 0) {
6673 ret = btrfs_commit_inode_delayed_inode(inode);
6674 if (ret)
6675 goto out_unlock;
6676 }
6677
6678 ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
6679 path, dst_path, logged_isize,
6680 inode_only, ctx,
6681 &need_log_inode_item);
6682 if (ret)
6683 goto out_unlock;
6684
6685 btrfs_release_path(path);
6686 btrfs_release_path(dst_path);
6687 ret = btrfs_log_all_xattrs(trans, inode, path, dst_path, ctx);
6688 if (ret)
6689 goto out_unlock;
6690 xattrs_logged = true;
6691 if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
6692 btrfs_release_path(path);
6693 btrfs_release_path(dst_path);
6694 ret = btrfs_log_holes(trans, inode, path);
6695 if (ret)
6696 goto out_unlock;
6697 }
6698 log_extents:
6699 btrfs_release_path(path);
6700 btrfs_release_path(dst_path);
6701 if (need_log_inode_item) {
6702 ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
6703 if (ret)
6704 goto out_unlock;
6705 /*
6706 * If we are doing a fast fsync and the inode was logged before
6707 * in this transaction, we don't need to log the xattrs because
6708 * they were logged before. If xattrs were added, changed or
6709 * deleted since the last time we logged the inode, then we have
6710 * already logged them because the inode had the runtime flag
6711 * BTRFS_INODE_COPY_EVERYTHING set.
6712 */
6713 if (!xattrs_logged && inode->logged_trans < trans->transid) {
6714 ret = btrfs_log_all_xattrs(trans, inode, path, dst_path, ctx);
6715 if (ret)
6716 goto out_unlock;
6717 btrfs_release_path(path);
6718 }
6719 }
6720 if (fast_search) {
6721 ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx);
6722 if (ret)
6723 goto out_unlock;
6724 } else if (inode_only == LOG_INODE_ALL) {
6725 struct extent_map *em, *n;
6726
6727 write_lock(&em_tree->lock);
6728 list_for_each_entry_safe(em, n, &em_tree->modified_extents, list)
6729 list_del_init(&em->list);
6730 write_unlock(&em_tree->lock);
6731 }
6732
6733 if (full_dir_logging) {
6734 ret = log_directory_changes(trans, inode, path, dst_path, ctx);
6735 if (ret)
6736 goto out_unlock;
6737 ret = log_delayed_insertion_items(trans, inode, path,
6738 &delayed_ins_list, ctx);
6739 if (ret)
6740 goto out_unlock;
6741 ret = log_delayed_deletion_items(trans, inode, path,
6742 &delayed_del_list, ctx);
6743 if (ret)
6744 goto out_unlock;
6745 }
6746
6747 spin_lock(&inode->lock);
6748 inode->logged_trans = trans->transid;
6749 /*
6750 * Don't update last_log_commit if we logged that an inode exists.
6751 * We do this for three reasons:
6752 *
6753 * 1) We might have had buffered writes to this inode that were
6754 * flushed and had their ordered extents completed in this
6755 * transaction, but we did not previously log the inode with
6756 * LOG_INODE_ALL. Later the inode was evicted and after that
6757 * it was loaded again and this LOG_INODE_EXISTS log operation
6758 * happened. We must make sure that if an explicit fsync against
6759 * the inode is performed later, it logs the new extents, an
6760 * updated inode item, etc, and syncs the log. The same logic
6761 * applies to direct IO writes instead of buffered writes.
6762 *
6763 * 2) When we log the inode with LOG_INODE_EXISTS, its inode item
6764 * is logged with an i_size of 0 or whatever value was logged
6765 * before. If later the i_size of the inode is increased by a
6766 * truncate operation, the log is synced through an fsync of
6767 * some other inode and then finally an explicit fsync against
6768 * this inode is made, we must make sure this fsync logs the
6769 * inode with the new i_size, the hole between old i_size and
6770 * the new i_size, and syncs the log.
6771 *
6772 * 3) If we are logging that an ancestor inode exists as part of
6773 * logging a new name from a link or rename operation, don't update
6774 * its last_log_commit - otherwise if an explicit fsync is made
6775 * against an ancestor, the fsync considers the inode in the log
6776 * and doesn't sync the log, resulting in the ancestor missing after
6777 * a power failure unless the log was synced as part of an fsync
6778 * against any other unrelated inode.
6779 */
6780 if (inode_only != LOG_INODE_EXISTS)
6781 inode->last_log_commit = inode->last_sub_trans;
6782 spin_unlock(&inode->lock);
6783
6784 /*
6785 * Reset the last_reflink_trans so that the next fsync does not need to
6786 * go through the slower path when logging extents and their checksums.
6787 */
6788 if (inode_only == LOG_INODE_ALL)
6789 inode->last_reflink_trans = 0;
6790
6791 out_unlock:
6792 mutex_unlock(&inode->log_mutex);
6793 out:
6794 btrfs_free_path(path);
6795 btrfs_free_path(dst_path);
6796
6797 if (ret)
6798 free_conflicting_inodes(ctx);
6799 else
6800 ret = log_conflicting_inodes(trans, inode->root, ctx);
6801
6802 if (full_dir_logging && !ctx->logging_new_delayed_dentries) {
6803 if (!ret)
6804 ret = log_new_delayed_dentries(trans, inode,
6805 &delayed_ins_list, ctx);
6806
6807 btrfs_log_put_delayed_items(inode, &delayed_ins_list,
6808 &delayed_del_list);
6809 }
6810
6811 return ret;
6812 }
6813
btrfs_log_all_parents(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct btrfs_log_ctx * ctx)6814 static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
6815 struct btrfs_inode *inode,
6816 struct btrfs_log_ctx *ctx)
6817 {
6818 int ret;
6819 struct btrfs_path *path;
6820 struct btrfs_key key;
6821 struct btrfs_root *root = inode->root;
6822 const u64 ino = btrfs_ino(inode);
6823
6824 path = btrfs_alloc_path();
6825 if (!path)
6826 return -ENOMEM;
6827 path->skip_locking = 1;
6828 path->search_commit_root = 1;
6829
6830 key.objectid = ino;
6831 key.type = BTRFS_INODE_REF_KEY;
6832 key.offset = 0;
6833 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
6834 if (ret < 0)
6835 goto out;
6836
6837 while (true) {
6838 struct extent_buffer *leaf = path->nodes[0];
6839 int slot = path->slots[0];
6840 u32 cur_offset = 0;
6841 u32 item_size;
6842 unsigned long ptr;
6843
6844 if (slot >= btrfs_header_nritems(leaf)) {
6845 ret = btrfs_next_leaf(root, path);
6846 if (ret < 0)
6847 goto out;
6848 else if (ret > 0)
6849 break;
6850 continue;
6851 }
6852
6853 btrfs_item_key_to_cpu(leaf, &key, slot);
6854 /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
6855 if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
6856 break;
6857
6858 item_size = btrfs_item_size(leaf, slot);
6859 ptr = btrfs_item_ptr_offset(leaf, slot);
6860 while (cur_offset < item_size) {
6861 struct btrfs_key inode_key;
6862 struct btrfs_inode *dir_inode;
6863
6864 inode_key.type = BTRFS_INODE_ITEM_KEY;
6865 inode_key.offset = 0;
6866
6867 if (key.type == BTRFS_INODE_EXTREF_KEY) {
6868 struct btrfs_inode_extref *extref;
6869
6870 extref = (struct btrfs_inode_extref *)
6871 (ptr + cur_offset);
6872 inode_key.objectid = btrfs_inode_extref_parent(
6873 leaf, extref);
6874 cur_offset += sizeof(*extref);
6875 cur_offset += btrfs_inode_extref_name_len(leaf,
6876 extref);
6877 } else {
6878 inode_key.objectid = key.offset;
6879 cur_offset = item_size;
6880 }
6881
6882 dir_inode = btrfs_iget_logging(inode_key.objectid, root);
6883 /*
6884 * If the parent inode was deleted, return an error to
6885 * fallback to a transaction commit. This is to prevent
6886 * getting an inode that was moved from one parent A to
6887 * a parent B, got its former parent A deleted and then
6888 * it got fsync'ed, from existing at both parents after
6889 * a log replay (and the old parent still existing).
6890 * Example:
6891 *
6892 * mkdir /mnt/A
6893 * mkdir /mnt/B
6894 * touch /mnt/B/bar
6895 * sync
6896 * mv /mnt/B/bar /mnt/A/bar
6897 * mv -T /mnt/A /mnt/B
6898 * fsync /mnt/B/bar
6899 * <power fail>
6900 *
6901 * If we ignore the old parent B which got deleted,
6902 * after a log replay we would have file bar linked
6903 * at both parents and the old parent B would still
6904 * exist.
6905 */
6906 if (IS_ERR(dir_inode)) {
6907 ret = PTR_ERR(dir_inode);
6908 goto out;
6909 }
6910
6911 if (!need_log_inode(trans, dir_inode)) {
6912 btrfs_add_delayed_iput(dir_inode);
6913 continue;
6914 }
6915
6916 ctx->log_new_dentries = false;
6917 ret = btrfs_log_inode(trans, dir_inode, LOG_INODE_ALL, ctx);
6918 if (!ret && ctx->log_new_dentries)
6919 ret = log_new_dir_dentries(trans, dir_inode, ctx);
6920 btrfs_add_delayed_iput(dir_inode);
6921 if (ret)
6922 goto out;
6923 }
6924 path->slots[0]++;
6925 }
6926 ret = 0;
6927 out:
6928 btrfs_free_path(path);
6929 return ret;
6930 }
6931
log_new_ancestors(struct btrfs_trans_handle * trans,struct btrfs_root * root,struct btrfs_path * path,struct btrfs_log_ctx * ctx)6932 static int log_new_ancestors(struct btrfs_trans_handle *trans,
6933 struct btrfs_root *root,
6934 struct btrfs_path *path,
6935 struct btrfs_log_ctx *ctx)
6936 {
6937 struct btrfs_key found_key;
6938
6939 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
6940
6941 while (true) {
6942 struct extent_buffer *leaf;
6943 int slot;
6944 struct btrfs_key search_key;
6945 struct btrfs_inode *inode;
6946 u64 ino;
6947 int ret = 0;
6948
6949 btrfs_release_path(path);
6950
6951 ino = found_key.offset;
6952
6953 search_key.objectid = found_key.offset;
6954 search_key.type = BTRFS_INODE_ITEM_KEY;
6955 search_key.offset = 0;
6956 inode = btrfs_iget_logging(ino, root);
6957 if (IS_ERR(inode))
6958 return PTR_ERR(inode);
6959
6960 if (inode->generation >= trans->transid &&
6961 need_log_inode(trans, inode))
6962 ret = btrfs_log_inode(trans, inode, LOG_INODE_EXISTS, ctx);
6963 btrfs_add_delayed_iput(inode);
6964 if (ret)
6965 return ret;
6966
6967 if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
6968 break;
6969
6970 search_key.type = BTRFS_INODE_REF_KEY;
6971 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
6972 if (ret < 0)
6973 return ret;
6974
6975 leaf = path->nodes[0];
6976 slot = path->slots[0];
6977 if (slot >= btrfs_header_nritems(leaf)) {
6978 ret = btrfs_next_leaf(root, path);
6979 if (ret < 0)
6980 return ret;
6981 else if (ret > 0)
6982 return -ENOENT;
6983 leaf = path->nodes[0];
6984 slot = path->slots[0];
6985 }
6986
6987 btrfs_item_key_to_cpu(leaf, &found_key, slot);
6988 if (found_key.objectid != search_key.objectid ||
6989 found_key.type != BTRFS_INODE_REF_KEY)
6990 return -ENOENT;
6991 }
6992 return 0;
6993 }
6994
log_new_ancestors_fast(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct dentry * parent,struct btrfs_log_ctx * ctx)6995 static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
6996 struct btrfs_inode *inode,
6997 struct dentry *parent,
6998 struct btrfs_log_ctx *ctx)
6999 {
7000 struct btrfs_root *root = inode->root;
7001 struct dentry *old_parent = NULL;
7002 struct super_block *sb = inode->vfs_inode.i_sb;
7003 int ret = 0;
7004
7005 while (true) {
7006 if (!parent || d_really_is_negative(parent) ||
7007 sb != parent->d_sb)
7008 break;
7009
7010 inode = BTRFS_I(d_inode(parent));
7011 if (root != inode->root)
7012 break;
7013
7014 if (inode->generation >= trans->transid &&
7015 need_log_inode(trans, inode)) {
7016 ret = btrfs_log_inode(trans, inode,
7017 LOG_INODE_EXISTS, ctx);
7018 if (ret)
7019 break;
7020 }
7021 if (IS_ROOT(parent))
7022 break;
7023
7024 parent = dget_parent(parent);
7025 dput(old_parent);
7026 old_parent = parent;
7027 }
7028 dput(old_parent);
7029
7030 return ret;
7031 }
7032
log_all_new_ancestors(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct dentry * parent,struct btrfs_log_ctx * ctx)7033 static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
7034 struct btrfs_inode *inode,
7035 struct dentry *parent,
7036 struct btrfs_log_ctx *ctx)
7037 {
7038 struct btrfs_root *root = inode->root;
7039 const u64 ino = btrfs_ino(inode);
7040 struct btrfs_path *path;
7041 struct btrfs_key search_key;
7042 int ret;
7043
7044 /*
7045 * For a single hard link case, go through a fast path that does not
7046 * need to iterate the fs/subvolume tree.
7047 */
7048 if (inode->vfs_inode.i_nlink < 2)
7049 return log_new_ancestors_fast(trans, inode, parent, ctx);
7050
7051 path = btrfs_alloc_path();
7052 if (!path)
7053 return -ENOMEM;
7054
7055 search_key.objectid = ino;
7056 search_key.type = BTRFS_INODE_REF_KEY;
7057 search_key.offset = 0;
7058 again:
7059 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
7060 if (ret < 0)
7061 goto out;
7062 if (ret == 0)
7063 path->slots[0]++;
7064
7065 while (true) {
7066 struct extent_buffer *leaf = path->nodes[0];
7067 int slot = path->slots[0];
7068 struct btrfs_key found_key;
7069
7070 if (slot >= btrfs_header_nritems(leaf)) {
7071 ret = btrfs_next_leaf(root, path);
7072 if (ret < 0)
7073 goto out;
7074 else if (ret > 0)
7075 break;
7076 continue;
7077 }
7078
7079 btrfs_item_key_to_cpu(leaf, &found_key, slot);
7080 if (found_key.objectid != ino ||
7081 found_key.type > BTRFS_INODE_EXTREF_KEY)
7082 break;
7083
7084 /*
7085 * Don't deal with extended references because they are rare
7086 * cases and too complex to deal with (we would need to keep
7087 * track of which subitem we are processing for each item in
7088 * this loop, etc). So just return some error to fallback to
7089 * a transaction commit.
7090 */
7091 if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
7092 ret = -EMLINK;
7093 goto out;
7094 }
7095
7096 /*
7097 * Logging ancestors needs to do more searches on the fs/subvol
7098 * tree, so it releases the path as needed to avoid deadlocks.
7099 * Keep track of the last inode ref key and resume from that key
7100 * after logging all new ancestors for the current hard link.
7101 */
7102 memcpy(&search_key, &found_key, sizeof(search_key));
7103
7104 ret = log_new_ancestors(trans, root, path, ctx);
7105 if (ret)
7106 goto out;
7107 btrfs_release_path(path);
7108 goto again;
7109 }
7110 ret = 0;
7111 out:
7112 btrfs_free_path(path);
7113 return ret;
7114 }
7115
7116 /*
7117 * helper function around btrfs_log_inode to make sure newly created
7118 * parent directories also end up in the log. A minimal inode and backref
7119 * only logging is done of any parent directories that are older than
7120 * the last committed transaction
7121 */
btrfs_log_inode_parent(struct btrfs_trans_handle * trans,struct btrfs_inode * inode,struct dentry * parent,int inode_only,struct btrfs_log_ctx * ctx)7122 static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
7123 struct btrfs_inode *inode,
7124 struct dentry *parent,
7125 int inode_only,
7126 struct btrfs_log_ctx *ctx)
7127 {
7128 struct btrfs_root *root = inode->root;
7129 struct btrfs_fs_info *fs_info = root->fs_info;
7130 int ret = 0;
7131 bool log_dentries;
7132
7133 if (btrfs_test_opt(fs_info, NOTREELOG))
7134 return BTRFS_LOG_FORCE_COMMIT;
7135
7136 if (btrfs_root_refs(&root->root_item) == 0)
7137 return BTRFS_LOG_FORCE_COMMIT;
7138
7139 /*
7140 * If we're logging an inode from a subvolume created in the current
7141 * transaction we must force a commit since the root is not persisted.
7142 */
7143 if (btrfs_root_generation(&root->root_item) == trans->transid)
7144 return BTRFS_LOG_FORCE_COMMIT;
7145
7146 /* Skip already logged inodes and without new extents. */
7147 if (btrfs_inode_in_log(inode, trans->transid) &&
7148 list_empty(&ctx->ordered_extents))
7149 return BTRFS_NO_LOG_SYNC;
7150
7151 ret = start_log_trans(trans, root, ctx);
7152 if (ret)
7153 return ret;
7154
7155 ret = btrfs_log_inode(trans, inode, inode_only, ctx);
7156 if (ret)
7157 goto end_trans;
7158
7159 /*
7160 * for regular files, if its inode is already on disk, we don't
7161 * have to worry about the parents at all. This is because
7162 * we can use the last_unlink_trans field to record renames
7163 * and other fun in this file.
7164 */
7165 if (S_ISREG(inode->vfs_inode.i_mode) &&
7166 inode->generation < trans->transid &&
7167 inode->last_unlink_trans < trans->transid) {
7168 ret = 0;
7169 goto end_trans;
7170 }
7171
7172 /*
7173 * Track if we need to log dentries because ctx->log_new_dentries can
7174 * be modified in the call chains below.
7175 */
7176 log_dentries = ctx->log_new_dentries;
7177
7178 /*
7179 * On unlink we must make sure all our current and old parent directory
7180 * inodes are fully logged. This is to prevent leaving dangling
7181 * directory index entries in directories that were our parents but are
7182 * not anymore. Not doing this results in old parent directory being
7183 * impossible to delete after log replay (rmdir will always fail with
7184 * error -ENOTEMPTY).
7185 *
7186 * Example 1:
7187 *
7188 * mkdir testdir
7189 * touch testdir/foo
7190 * ln testdir/foo testdir/bar
7191 * sync
7192 * unlink testdir/bar
7193 * xfs_io -c fsync testdir/foo
7194 * <power failure>
7195 * mount fs, triggers log replay
7196 *
7197 * If we don't log the parent directory (testdir), after log replay the
7198 * directory still has an entry pointing to the file inode using the bar
7199 * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
7200 * the file inode has a link count of 1.
7201 *
7202 * Example 2:
7203 *
7204 * mkdir testdir
7205 * touch foo
7206 * ln foo testdir/foo2
7207 * ln foo testdir/foo3
7208 * sync
7209 * unlink testdir/foo3
7210 * xfs_io -c fsync foo
7211 * <power failure>
7212 * mount fs, triggers log replay
7213 *
7214 * Similar as the first example, after log replay the parent directory
7215 * testdir still has an entry pointing to the inode file with name foo3
7216 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
7217 * and has a link count of 2.
7218 */
7219 if (inode->last_unlink_trans >= trans->transid) {
7220 ret = btrfs_log_all_parents(trans, inode, ctx);
7221 if (ret)
7222 goto end_trans;
7223 }
7224
7225 ret = log_all_new_ancestors(trans, inode, parent, ctx);
7226 if (ret)
7227 goto end_trans;
7228
7229 if (log_dentries)
7230 ret = log_new_dir_dentries(trans, inode, ctx);
7231 end_trans:
7232 if (ret < 0) {
7233 btrfs_set_log_full_commit(trans);
7234 ret = BTRFS_LOG_FORCE_COMMIT;
7235 }
7236
7237 if (ret)
7238 btrfs_remove_log_ctx(root, ctx);
7239 btrfs_end_log_trans(root);
7240
7241 return ret;
7242 }
7243
7244 /*
7245 * it is not safe to log dentry if the chunk root has added new
7246 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
7247 * If this returns 1, you must commit the transaction to safely get your
7248 * data on disk.
7249 */
btrfs_log_dentry_safe(struct btrfs_trans_handle * trans,struct dentry * dentry,struct btrfs_log_ctx * ctx)7250 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
7251 struct dentry *dentry,
7252 struct btrfs_log_ctx *ctx)
7253 {
7254 struct dentry *parent = dget_parent(dentry);
7255 int ret;
7256
7257 ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
7258 LOG_INODE_ALL, ctx);
7259 dput(parent);
7260
7261 return ret;
7262 }
7263
7264 /*
7265 * should be called during mount to recover any replay any log trees
7266 * from the FS
7267 */
btrfs_recover_log_trees(struct btrfs_root * log_root_tree)7268 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
7269 {
7270 int ret;
7271 struct btrfs_path *path;
7272 struct btrfs_trans_handle *trans;
7273 struct btrfs_key key;
7274 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
7275 struct walk_control wc = {
7276 .process_func = process_one_buffer,
7277 .stage = LOG_WALK_PIN_ONLY,
7278 };
7279
7280 path = btrfs_alloc_path();
7281 if (!path)
7282 return -ENOMEM;
7283
7284 set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
7285
7286 trans = btrfs_start_transaction(fs_info->tree_root, 0);
7287 if (IS_ERR(trans)) {
7288 ret = PTR_ERR(trans);
7289 goto error;
7290 }
7291
7292 wc.trans = trans;
7293 wc.pin = 1;
7294
7295 ret = walk_log_tree(trans, log_root_tree, &wc);
7296 if (ret) {
7297 btrfs_abort_transaction(trans, ret);
7298 goto error;
7299 }
7300
7301 again:
7302 key.objectid = BTRFS_TREE_LOG_OBJECTID;
7303 key.type = BTRFS_ROOT_ITEM_KEY;
7304 key.offset = (u64)-1;
7305
7306 while (1) {
7307 struct btrfs_root *log;
7308 struct btrfs_key found_key;
7309
7310 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
7311
7312 if (ret < 0) {
7313 btrfs_abort_transaction(trans, ret);
7314 goto error;
7315 }
7316 if (ret > 0) {
7317 if (path->slots[0] == 0)
7318 break;
7319 path->slots[0]--;
7320 }
7321 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
7322 path->slots[0]);
7323 btrfs_release_path(path);
7324 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
7325 break;
7326
7327 log = btrfs_read_tree_root(log_root_tree, &found_key);
7328 if (IS_ERR(log)) {
7329 ret = PTR_ERR(log);
7330 btrfs_abort_transaction(trans, ret);
7331 goto error;
7332 }
7333
7334 wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset,
7335 true);
7336 if (IS_ERR(wc.replay_dest)) {
7337 ret = PTR_ERR(wc.replay_dest);
7338 wc.replay_dest = NULL;
7339 if (ret != -ENOENT) {
7340 btrfs_put_root(log);
7341 btrfs_abort_transaction(trans, ret);
7342 goto error;
7343 }
7344
7345 /*
7346 * We didn't find the subvol, likely because it was
7347 * deleted. This is ok, simply skip this log and go to
7348 * the next one.
7349 *
7350 * We need to exclude the root because we can't have
7351 * other log replays overwriting this log as we'll read
7352 * it back in a few more times. This will keep our
7353 * block from being modified, and we'll just bail for
7354 * each subsequent pass.
7355 */
7356 ret = btrfs_pin_extent_for_log_replay(trans, log->node);
7357 if (ret) {
7358 btrfs_put_root(log);
7359 btrfs_abort_transaction(trans, ret);
7360 goto error;
7361 }
7362 goto next;
7363 }
7364
7365 wc.replay_dest->log_root = log;
7366 ret = btrfs_record_root_in_trans(trans, wc.replay_dest);
7367 if (ret) {
7368 btrfs_abort_transaction(trans, ret);
7369 goto next;
7370 }
7371
7372 ret = walk_log_tree(trans, log, &wc);
7373 if (ret) {
7374 btrfs_abort_transaction(trans, ret);
7375 goto next;
7376 }
7377
7378 if (wc.stage == LOG_WALK_REPLAY_ALL) {
7379 struct btrfs_root *root = wc.replay_dest;
7380
7381 ret = fixup_inode_link_counts(trans, wc.replay_dest, path);
7382 if (ret) {
7383 btrfs_abort_transaction(trans, ret);
7384 goto next;
7385 }
7386 /*
7387 * We have just replayed everything, and the highest
7388 * objectid of fs roots probably has changed in case
7389 * some inode_item's got replayed.
7390 *
7391 * root->objectid_mutex is not acquired as log replay
7392 * could only happen during mount.
7393 */
7394 ret = btrfs_init_root_free_objectid(root);
7395 if (ret) {
7396 btrfs_abort_transaction(trans, ret);
7397 goto next;
7398 }
7399 }
7400 next:
7401 if (wc.replay_dest) {
7402 wc.replay_dest->log_root = NULL;
7403 btrfs_put_root(wc.replay_dest);
7404 }
7405 btrfs_put_root(log);
7406
7407 if (ret)
7408 goto error;
7409 if (found_key.offset == 0)
7410 break;
7411 key.offset = found_key.offset - 1;
7412 }
7413 btrfs_release_path(path);
7414
7415 /* step one is to pin it all, step two is to replay just inodes */
7416 if (wc.pin) {
7417 wc.pin = 0;
7418 wc.process_func = replay_one_buffer;
7419 wc.stage = LOG_WALK_REPLAY_INODES;
7420 goto again;
7421 }
7422 /* step three is to replay everything */
7423 if (wc.stage < LOG_WALK_REPLAY_ALL) {
7424 wc.stage++;
7425 goto again;
7426 }
7427
7428 btrfs_free_path(path);
7429
7430 /* step 4: commit the transaction, which also unpins the blocks */
7431 ret = btrfs_commit_transaction(trans);
7432 if (ret)
7433 return ret;
7434
7435 log_root_tree->log_root = NULL;
7436 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
7437 btrfs_put_root(log_root_tree);
7438
7439 return 0;
7440 error:
7441 if (wc.trans)
7442 btrfs_end_transaction(wc.trans);
7443 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
7444 btrfs_free_path(path);
7445 return ret;
7446 }
7447
7448 /*
7449 * there are some corner cases where we want to force a full
7450 * commit instead of allowing a directory to be logged.
7451 *
7452 * They revolve around files there were unlinked from the directory, and
7453 * this function updates the parent directory so that a full commit is
7454 * properly done if it is fsync'd later after the unlinks are done.
7455 *
7456 * Must be called before the unlink operations (updates to the subvolume tree,
7457 * inodes, etc) are done.
7458 */
btrfs_record_unlink_dir(struct btrfs_trans_handle * trans,struct btrfs_inode * dir,struct btrfs_inode * inode,bool for_rename)7459 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
7460 struct btrfs_inode *dir, struct btrfs_inode *inode,
7461 bool for_rename)
7462 {
7463 /*
7464 * when we're logging a file, if it hasn't been renamed
7465 * or unlinked, and its inode is fully committed on disk,
7466 * we don't have to worry about walking up the directory chain
7467 * to log its parents.
7468 *
7469 * So, we use the last_unlink_trans field to put this transid
7470 * into the file. When the file is logged we check it and
7471 * don't log the parents if the file is fully on disk.
7472 */
7473 mutex_lock(&inode->log_mutex);
7474 inode->last_unlink_trans = trans->transid;
7475 mutex_unlock(&inode->log_mutex);
7476
7477 if (!for_rename)
7478 return;
7479
7480 /*
7481 * If this directory was already logged, any new names will be logged
7482 * with btrfs_log_new_name() and old names will be deleted from the log
7483 * tree with btrfs_del_dir_entries_in_log() or with
7484 * btrfs_del_inode_ref_in_log().
7485 */
7486 if (inode_logged(trans, dir, NULL) == 1)
7487 return;
7488
7489 /*
7490 * If the inode we're about to unlink was logged before, the log will be
7491 * properly updated with the new name with btrfs_log_new_name() and the
7492 * old name removed with btrfs_del_dir_entries_in_log() or with
7493 * btrfs_del_inode_ref_in_log().
7494 */
7495 if (inode_logged(trans, inode, NULL) == 1)
7496 return;
7497
7498 /*
7499 * when renaming files across directories, if the directory
7500 * there we're unlinking from gets fsync'd later on, there's
7501 * no way to find the destination directory later and fsync it
7502 * properly. So, we have to be conservative and force commits
7503 * so the new name gets discovered.
7504 */
7505 mutex_lock(&dir->log_mutex);
7506 dir->last_unlink_trans = trans->transid;
7507 mutex_unlock(&dir->log_mutex);
7508 }
7509
7510 /*
7511 * Make sure that if someone attempts to fsync the parent directory of a deleted
7512 * snapshot, it ends up triggering a transaction commit. This is to guarantee
7513 * that after replaying the log tree of the parent directory's root we will not
7514 * see the snapshot anymore and at log replay time we will not see any log tree
7515 * corresponding to the deleted snapshot's root, which could lead to replaying
7516 * it after replaying the log tree of the parent directory (which would replay
7517 * the snapshot delete operation).
7518 *
7519 * Must be called before the actual snapshot destroy operation (updates to the
7520 * parent root and tree of tree roots trees, etc) are done.
7521 */
btrfs_record_snapshot_destroy(struct btrfs_trans_handle * trans,struct btrfs_inode * dir)7522 void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
7523 struct btrfs_inode *dir)
7524 {
7525 mutex_lock(&dir->log_mutex);
7526 dir->last_unlink_trans = trans->transid;
7527 mutex_unlock(&dir->log_mutex);
7528 }
7529
7530 /*
7531 * Call this when creating a subvolume in a directory.
7532 * Because we don't commit a transaction when creating a subvolume, we can't
7533 * allow the directory pointing to the subvolume to be logged with an entry that
7534 * points to an unpersisted root if we are still in the transaction used to
7535 * create the subvolume, so make any attempt to log the directory to result in a
7536 * full log sync.
7537 * Also we don't need to worry with renames, since btrfs_rename() marks the log
7538 * for full commit when renaming a subvolume.
7539 *
7540 * Must be called before creating the subvolume entry in its parent directory.
7541 */
btrfs_record_new_subvolume(const struct btrfs_trans_handle * trans,struct btrfs_inode * dir)7542 void btrfs_record_new_subvolume(const struct btrfs_trans_handle *trans,
7543 struct btrfs_inode *dir)
7544 {
7545 mutex_lock(&dir->log_mutex);
7546 dir->last_unlink_trans = trans->transid;
7547 mutex_unlock(&dir->log_mutex);
7548 }
7549
7550 /*
7551 * Update the log after adding a new name for an inode.
7552 *
7553 * @trans: Transaction handle.
7554 * @old_dentry: The dentry associated with the old name and the old
7555 * parent directory.
7556 * @old_dir: The inode of the previous parent directory for the case
7557 * of a rename. For a link operation, it must be NULL.
7558 * @old_dir_index: The index number associated with the old name, meaningful
7559 * only for rename operations (when @old_dir is not NULL).
7560 * Ignored for link operations.
7561 * @parent: The dentry associated with the directory under which the
7562 * new name is located.
7563 *
7564 * Call this after adding a new name for an inode, as a result of a link or
7565 * rename operation, and it will properly update the log to reflect the new name.
7566 */
btrfs_log_new_name(struct btrfs_trans_handle * trans,struct dentry * old_dentry,struct btrfs_inode * old_dir,u64 old_dir_index,struct dentry * parent)7567 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
7568 struct dentry *old_dentry, struct btrfs_inode *old_dir,
7569 u64 old_dir_index, struct dentry *parent)
7570 {
7571 struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
7572 struct btrfs_root *root = inode->root;
7573 struct btrfs_log_ctx ctx;
7574 bool log_pinned = false;
7575 int ret;
7576
7577 btrfs_init_log_ctx(&ctx, inode);
7578 ctx.logging_new_name = true;
7579
7580 /*
7581 * this will force the logging code to walk the dentry chain
7582 * up for the file
7583 */
7584 if (!S_ISDIR(inode->vfs_inode.i_mode))
7585 inode->last_unlink_trans = trans->transid;
7586
7587 /*
7588 * if this inode hasn't been logged and directory we're renaming it
7589 * from hasn't been logged, we don't need to log it
7590 */
7591 ret = inode_logged(trans, inode, NULL);
7592 if (ret < 0) {
7593 goto out;
7594 } else if (ret == 0) {
7595 if (!old_dir)
7596 return;
7597 /*
7598 * If the inode was not logged and we are doing a rename (old_dir is not
7599 * NULL), check if old_dir was logged - if it was not we can return and
7600 * do nothing.
7601 */
7602 ret = inode_logged(trans, old_dir, NULL);
7603 if (ret < 0)
7604 goto out;
7605 else if (ret == 0)
7606 return;
7607 }
7608 ret = 0;
7609
7610 /*
7611 * Now that we know we need to update the log, allocate the scratch eb
7612 * for the context before joining a log transaction below, as this can
7613 * take time and therefore we could delay log commits from other tasks.
7614 */
7615 btrfs_init_log_ctx_scratch_eb(&ctx);
7616
7617 /*
7618 * If we are doing a rename (old_dir is not NULL) from a directory that
7619 * was previously logged, make sure that on log replay we get the old
7620 * dir entry deleted. This is needed because we will also log the new
7621 * name of the renamed inode, so we need to make sure that after log
7622 * replay we don't end up with both the new and old dir entries existing.
7623 */
7624 if (old_dir && old_dir->logged_trans == trans->transid) {
7625 struct btrfs_root *log = old_dir->root->log_root;
7626 struct btrfs_path *path;
7627 struct fscrypt_name fname;
7628
7629 ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX);
7630
7631 ret = fscrypt_setup_filename(&old_dir->vfs_inode,
7632 &old_dentry->d_name, 0, &fname);
7633 if (ret)
7634 goto out;
7635
7636 path = btrfs_alloc_path();
7637 if (!path) {
7638 ret = -ENOMEM;
7639 fscrypt_free_filename(&fname);
7640 goto out;
7641 }
7642
7643 /*
7644 * We have two inodes to update in the log, the old directory and
7645 * the inode that got renamed, so we must pin the log to prevent
7646 * anyone from syncing the log until we have updated both inodes
7647 * in the log.
7648 */
7649 ret = join_running_log_trans(root);
7650 /*
7651 * At least one of the inodes was logged before, so this should
7652 * not fail, but if it does, it's not serious, just bail out and
7653 * mark the log for a full commit.
7654 */
7655 if (WARN_ON_ONCE(ret < 0)) {
7656 btrfs_free_path(path);
7657 fscrypt_free_filename(&fname);
7658 goto out;
7659 }
7660
7661 log_pinned = true;
7662
7663 /*
7664 * Other concurrent task might be logging the old directory,
7665 * as it can be triggered when logging other inode that had or
7666 * still has a dentry in the old directory. We lock the old
7667 * directory's log_mutex to ensure the deletion of the old
7668 * name is persisted, because during directory logging we
7669 * delete all BTRFS_DIR_LOG_INDEX_KEY keys and the deletion of
7670 * the old name's dir index item is in the delayed items, so
7671 * it could be missed by an in progress directory logging.
7672 */
7673 mutex_lock(&old_dir->log_mutex);
7674 ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir),
7675 &fname.disk_name, old_dir_index);
7676 if (ret > 0) {
7677 /*
7678 * The dentry does not exist in the log, so record its
7679 * deletion.
7680 */
7681 btrfs_release_path(path);
7682 ret = insert_dir_log_key(trans, log, path,
7683 btrfs_ino(old_dir),
7684 old_dir_index, old_dir_index);
7685 }
7686 mutex_unlock(&old_dir->log_mutex);
7687
7688 btrfs_free_path(path);
7689 fscrypt_free_filename(&fname);
7690 if (ret < 0)
7691 goto out;
7692 }
7693
7694 /*
7695 * We don't care about the return value. If we fail to log the new name
7696 * then we know the next attempt to sync the log will fallback to a full
7697 * transaction commit (due to a call to btrfs_set_log_full_commit()), so
7698 * we don't need to worry about getting a log committed that has an
7699 * inconsistent state after a rename operation.
7700 */
7701 btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
7702 ASSERT(list_empty(&ctx.conflict_inodes));
7703 out:
7704 /*
7705 * If an error happened mark the log for a full commit because it's not
7706 * consistent and up to date or we couldn't find out if one of the
7707 * inodes was logged before in this transaction. Do it before unpinning
7708 * the log, to avoid any races with someone else trying to commit it.
7709 */
7710 if (ret < 0)
7711 btrfs_set_log_full_commit(trans);
7712 if (log_pinned)
7713 btrfs_end_log_trans(root);
7714 free_extent_buffer(ctx.scratch_eb);
7715 }
7716
7717