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