aboutsummaryrefslogtreecommitdiffstats
path: root/fs/btrfs/tree-log.c
diff options
context:
space:
mode:
authorChris Mason <chris.mason@oracle.com>2008-09-05 16:13:11 -0400
committerChris Mason <chris.mason@oracle.com>2008-09-25 11:04:07 -0400
commite02119d5a7b4396c5a872582fddc8bd6d305a70a (patch)
tree825efe2a79dbca8d61256183f3526a5b5dc40dc6 /fs/btrfs/tree-log.c
parenta1b32a5932cfac7c38b442582285f3da2a09dfd8 (diff)
Btrfs: Add a write ahead tree log to optimize synchronous operations
File syncs and directory syncs are optimized by copying their items into a special (copy-on-write) log tree. There is one log tree per subvolume and the btrfs super block points to a tree of log tree roots. After a crash, items are copied out of the log tree and back into the subvolume. See tree-log.c for all the details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/tree-log.c')
-rw-r--r--fs/btrfs/tree-log.c2804
1 files changed, 2804 insertions, 0 deletions
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
new file mode 100644
index 000000000000..d1ce8314b948
--- /dev/null
+++ b/fs/btrfs/tree-log.c
@@ -0,0 +1,2804 @@
1/*
2 * Copyright (C) 2008 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/sched.h>
20#include "ctree.h"
21#include "transaction.h"
22#include "disk-io.h"
23#include "locking.h"
24#include "print-tree.h"
25#include "compat.h"
26
27/* magic values for the inode_only field in btrfs_log_inode:
28 *
29 * LOG_INODE_ALL means to log everything
30 * LOG_INODE_EXISTS means to log just enough to recreate the inode
31 * during log replay
32 */
33#define LOG_INODE_ALL 0
34#define LOG_INODE_EXISTS 1
35
36/*
37 * stages for the tree walking. The first
38 * stage (0) is to only pin down the blocks we find
39 * the second stage (1) is to make sure that all the inodes
40 * we find in the log are created in the subvolume.
41 *
42 * The last stage is to deal with directories and links and extents
43 * and all the other fun semantics
44 */
45#define LOG_WALK_PIN_ONLY 0
46#define LOG_WALK_REPLAY_INODES 1
47#define LOG_WALK_REPLAY_ALL 2
48
49static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
50 struct btrfs_root *root, struct inode *inode,
51 int inode_only);
52
53/*
54 * tree logging is a special write ahead log used to make sure that
55 * fsyncs and O_SYNCs can happen without doing full tree commits.
56 *
57 * Full tree commits are expensive because they require commonly
58 * modified blocks to be recowed, creating many dirty pages in the
59 * extent tree an 4x-6x higher write load than ext3.
60 *
61 * Instead of doing a tree commit on every fsync, we use the
62 * key ranges and transaction ids to find items for a given file or directory
63 * that have changed in this transaction. Those items are copied into
64 * a special tree (one per subvolume root), that tree is written to disk
65 * and then the fsync is considered complete.
66 *
67 * After a crash, items are copied out of the log-tree back into the
68 * subvolume tree. Any file data extents found are recorded in the extent
69 * allocation tree, and the log-tree freed.
70 *
71 * The log tree is read three times, once to pin down all the extents it is
72 * using in ram and once, once to create all the inodes logged in the tree
73 * and once to do all the other items.
74 */
75
76/*
77 * btrfs_add_log_tree adds a new per-subvolume log tree into the
78 * tree of log tree roots. This must be called with a tree log transaction
79 * running (see start_log_trans).
80 */
81int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root)
83{
84 struct btrfs_key key;
85 struct btrfs_root_item root_item;
86 struct btrfs_inode_item *inode_item;
87 struct extent_buffer *leaf;
88 struct btrfs_root *new_root = root;
89 int ret;
90 u64 objectid = root->root_key.objectid;
91
92 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
93 BTRFS_TREE_LOG_OBJECTID,
94 0, 0, 0, 0, 0);
95 if (IS_ERR(leaf)) {
96 ret = PTR_ERR(leaf);
97 return ret;
98 }
99
100 btrfs_set_header_nritems(leaf, 0);
101 btrfs_set_header_level(leaf, 0);
102 btrfs_set_header_bytenr(leaf, leaf->start);
103 btrfs_set_header_generation(leaf, trans->transid);
104 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
105
106 write_extent_buffer(leaf, root->fs_info->fsid,
107 (unsigned long)btrfs_header_fsid(leaf),
108 BTRFS_FSID_SIZE);
109 btrfs_mark_buffer_dirty(leaf);
110
111 inode_item = &root_item.inode;
112 memset(inode_item, 0, sizeof(*inode_item));
113 inode_item->generation = cpu_to_le64(1);
114 inode_item->size = cpu_to_le64(3);
115 inode_item->nlink = cpu_to_le32(1);
116 inode_item->nblocks = cpu_to_le64(1);
117 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
118
119 btrfs_set_root_bytenr(&root_item, leaf->start);
120 btrfs_set_root_level(&root_item, 0);
121 btrfs_set_root_refs(&root_item, 0);
122 btrfs_set_root_used(&root_item, 0);
123
124 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
125 root_item.drop_level = 0;
126
127 btrfs_tree_unlock(leaf);
128 free_extent_buffer(leaf);
129 leaf = NULL;
130
131 btrfs_set_root_dirid(&root_item, 0);
132
133 key.objectid = BTRFS_TREE_LOG_OBJECTID;
134 key.offset = objectid;
135 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
136 ret = btrfs_insert_root(trans, root->fs_info->log_root_tree, &key,
137 &root_item);
138 if (ret)
139 goto fail;
140
141 new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree,
142 &key);
143 BUG_ON(!new_root);
144
145 WARN_ON(root->log_root);
146 root->log_root = new_root;
147
148 /*
149 * log trees do not get reference counted because they go away
150 * before a real commit is actually done. They do store pointers
151 * to file data extents, and those reference counts still get
152 * updated (along with back refs to the log tree).
153 */
154 new_root->ref_cows = 0;
155 new_root->last_trans = trans->transid;
156fail:
157 return ret;
158}
159
160/*
161 * start a sub transaction and setup the log tree
162 * this increments the log tree writer count to make the people
163 * syncing the tree wait for us to finish
164 */
165static int start_log_trans(struct btrfs_trans_handle *trans,
166 struct btrfs_root *root)
167{
168 int ret;
169 mutex_lock(&root->fs_info->tree_log_mutex);
170 if (!root->fs_info->log_root_tree) {
171 ret = btrfs_init_log_root_tree(trans, root->fs_info);
172 BUG_ON(ret);
173 }
174 if (!root->log_root) {
175 ret = btrfs_add_log_tree(trans, root);
176 BUG_ON(ret);
177 }
178 atomic_inc(&root->fs_info->tree_log_writers);
179 root->fs_info->tree_log_batch++;
180 mutex_unlock(&root->fs_info->tree_log_mutex);
181 return 0;
182}
183
184/*
185 * returns 0 if there was a log transaction running and we were able
186 * to join, or returns -ENOENT if there were not transactions
187 * in progress
188 */
189static int join_running_log_trans(struct btrfs_root *root)
190{
191 int ret = -ENOENT;
192
193 smp_mb();
194 if (!root->log_root)
195 return -ENOENT;
196
197 mutex_lock(&root->fs_info->tree_log_mutex);
198 if (root->log_root) {
199 ret = 0;
200 atomic_inc(&root->fs_info->tree_log_writers);
201 root->fs_info->tree_log_batch++;
202 }
203 mutex_unlock(&root->fs_info->tree_log_mutex);
204 return ret;
205}
206
207/*
208 * indicate we're done making changes to the log tree
209 * and wake up anyone waiting to do a sync
210 */
211static int end_log_trans(struct btrfs_root *root)
212{
213 atomic_dec(&root->fs_info->tree_log_writers);
214 smp_mb();
215 if (waitqueue_active(&root->fs_info->tree_log_wait))
216 wake_up(&root->fs_info->tree_log_wait);
217 return 0;
218}
219
220
221/*
222 * the walk control struct is used to pass state down the chain when
223 * processing the log tree. The stage field tells us which part
224 * of the log tree processing we are currently doing. The others
225 * are state fields used for that specific part
226 */
227struct walk_control {
228 /* should we free the extent on disk when done? This is used
229 * at transaction commit time while freeing a log tree
230 */
231 int free;
232
233 /* should we write out the extent buffer? This is used
234 * while flushing the log tree to disk during a sync
235 */
236 int write;
237
238 /* should we wait for the extent buffer io to finish? Also used
239 * while flushing the log tree to disk for a sync
240 */
241 int wait;
242
243 /* pin only walk, we record which extents on disk belong to the
244 * log trees
245 */
246 int pin;
247
248 /* what stage of the replay code we're currently in */
249 int stage;
250
251 /* the root we are currently replaying */
252 struct btrfs_root *replay_dest;
253
254 /* the trans handle for the current replay */
255 struct btrfs_trans_handle *trans;
256
257 /* the function that gets used to process blocks we find in the
258 * tree. Note the extent_buffer might not be up to date when it is
259 * passed in, and it must be checked or read if you need the data
260 * inside it
261 */
262 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
263 struct walk_control *wc, u64 gen);
264};
265
266/*
267 * process_func used to pin down extents, write them or wait on them
268 */
269static int process_one_buffer(struct btrfs_root *log,
270 struct extent_buffer *eb,
271 struct walk_control *wc, u64 gen)
272{
273 if (wc->pin) {
274 mutex_lock(&log->fs_info->alloc_mutex);
275 btrfs_update_pinned_extents(log->fs_info->extent_root,
276 eb->start, eb->len, 1);
277 mutex_unlock(&log->fs_info->alloc_mutex);
278 }
279
280 if (btrfs_buffer_uptodate(eb, gen)) {
281 if (wc->write)
282 btrfs_write_tree_block(eb);
283 if (wc->wait)
284 btrfs_wait_tree_block_writeback(eb);
285 }
286 return 0;
287}
288
289/*
290 * Item overwrite used by replay and tree logging. eb, slot and key all refer
291 * to the src data we are copying out.
292 *
293 * root is the tree we are copying into, and path is a scratch
294 * path for use in this function (it should be released on entry and
295 * will be released on exit).
296 *
297 * If the key is already in the destination tree the existing item is
298 * overwritten. If the existing item isn't big enough, it is extended.
299 * If it is too large, it is truncated.
300 *
301 * If the key isn't in the destination yet, a new item is inserted.
302 */
303static noinline int overwrite_item(struct btrfs_trans_handle *trans,
304 struct btrfs_root *root,
305 struct btrfs_path *path,
306 struct extent_buffer *eb, int slot,
307 struct btrfs_key *key)
308{
309 int ret;
310 u32 item_size;
311 u64 saved_i_size = 0;
312 int save_old_i_size = 0;
313 unsigned long src_ptr;
314 unsigned long dst_ptr;
315 int overwrite_root = 0;
316
317 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
318 overwrite_root = 1;
319
320 item_size = btrfs_item_size_nr(eb, slot);
321 src_ptr = btrfs_item_ptr_offset(eb, slot);
322
323 /* look for the key in the destination tree */
324 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
325 if (ret == 0) {
326 char *src_copy;
327 char *dst_copy;
328 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
329 path->slots[0]);
330 if (dst_size != item_size)
331 goto insert;
332
333 if (item_size == 0) {
334 btrfs_release_path(root, path);
335 return 0;
336 }
337 dst_copy = kmalloc(item_size, GFP_NOFS);
338 src_copy = kmalloc(item_size, GFP_NOFS);
339
340 read_extent_buffer(eb, src_copy, src_ptr, item_size);
341
342 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
343 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
344 item_size);
345 ret = memcmp(dst_copy, src_copy, item_size);
346
347 kfree(dst_copy);
348 kfree(src_copy);
349 /*
350 * they have the same contents, just return, this saves
351 * us from cowing blocks in the destination tree and doing
352 * extra writes that may not have been done by a previous
353 * sync
354 */
355 if (ret == 0) {
356 btrfs_release_path(root, path);
357 return 0;
358 }
359
360 }
361insert:
362 btrfs_release_path(root, path);
363 /* try to insert the key into the destination tree */
364 ret = btrfs_insert_empty_item(trans, root, path,
365 key, item_size);
366
367 /* make sure any existing item is the correct size */
368 if (ret == -EEXIST) {
369 u32 found_size;
370 found_size = btrfs_item_size_nr(path->nodes[0],
371 path->slots[0]);
372 if (found_size > item_size) {
373 btrfs_truncate_item(trans, root, path, item_size, 1);
374 } else if (found_size < item_size) {
375 ret = btrfs_del_item(trans, root,
376 path);
377 BUG_ON(ret);
378
379 btrfs_release_path(root, path);
380 ret = btrfs_insert_empty_item(trans,
381 root, path, key, item_size);
382 BUG_ON(ret);
383 }
384 } else if (ret) {
385 BUG();
386 }
387 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
388 path->slots[0]);
389
390 /* don't overwrite an existing inode if the generation number
391 * was logged as zero. This is done when the tree logging code
392 * is just logging an inode to make sure it exists after recovery.
393 *
394 * Also, don't overwrite i_size on directories during replay.
395 * log replay inserts and removes directory items based on the
396 * state of the tree found in the subvolume, and i_size is modified
397 * as it goes
398 */
399 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
400 struct btrfs_inode_item *src_item;
401 struct btrfs_inode_item *dst_item;
402
403 src_item = (struct btrfs_inode_item *)src_ptr;
404 dst_item = (struct btrfs_inode_item *)dst_ptr;
405
406 if (btrfs_inode_generation(eb, src_item) == 0)
407 goto no_copy;
408
409 if (overwrite_root &&
410 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
411 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
412 save_old_i_size = 1;
413 saved_i_size = btrfs_inode_size(path->nodes[0],
414 dst_item);
415 }
416 }
417
418 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
419 src_ptr, item_size);
420
421 if (save_old_i_size) {
422 struct btrfs_inode_item *dst_item;
423 dst_item = (struct btrfs_inode_item *)dst_ptr;
424 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
425 }
426
427 /* make sure the generation is filled in */
428 if (key->type == BTRFS_INODE_ITEM_KEY) {
429 struct btrfs_inode_item *dst_item;
430 dst_item = (struct btrfs_inode_item *)dst_ptr;
431 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
432 btrfs_set_inode_generation(path->nodes[0], dst_item,
433 trans->transid);
434 }
435 }
436no_copy:
437 btrfs_mark_buffer_dirty(path->nodes[0]);
438 btrfs_release_path(root, path);
439 return 0;
440}
441
442/*
443 * simple helper to read an inode off the disk from a given root
444 * This can only be called for subvolume roots and not for the log
445 */
446static noinline struct inode *read_one_inode(struct btrfs_root *root,
447 u64 objectid)
448{
449 struct inode *inode;
450 inode = btrfs_iget_locked(root->fs_info->sb, objectid, root);
451 if (inode->i_state & I_NEW) {
452 BTRFS_I(inode)->root = root;
453 BTRFS_I(inode)->location.objectid = objectid;
454 BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY;
455 BTRFS_I(inode)->location.offset = 0;
456 btrfs_read_locked_inode(inode);
457 unlock_new_inode(inode);
458
459 }
460 if (is_bad_inode(inode)) {
461 iput(inode);
462 inode = NULL;
463 }
464 return inode;
465}
466
467/* replays a single extent in 'eb' at 'slot' with 'key' into the
468 * subvolume 'root'. path is released on entry and should be released
469 * on exit.
470 *
471 * extents in the log tree have not been allocated out of the extent
472 * tree yet. So, this completes the allocation, taking a reference
473 * as required if the extent already exists or creating a new extent
474 * if it isn't in the extent allocation tree yet.
475 *
476 * The extent is inserted into the file, dropping any existing extents
477 * from the file that overlap the new one.
478 */
479static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
480 struct btrfs_root *root,
481 struct btrfs_path *path,
482 struct extent_buffer *eb, int slot,
483 struct btrfs_key *key)
484{
485 int found_type;
486 u64 mask = root->sectorsize - 1;
487 u64 extent_end;
488 u64 alloc_hint;
489 u64 start = key->offset;
490 struct btrfs_file_extent_item *item;
491 struct inode *inode = NULL;
492 unsigned long size;
493 int ret = 0;
494
495 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
496 found_type = btrfs_file_extent_type(eb, item);
497
498 if (found_type == BTRFS_FILE_EXTENT_REG)
499 extent_end = start + btrfs_file_extent_num_bytes(eb, item);
500 else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
501 size = btrfs_file_extent_inline_len(eb,
502 btrfs_item_nr(eb, slot));
503 extent_end = (start + size + mask) & ~mask;
504 } else {
505 ret = 0;
506 goto out;
507 }
508
509 inode = read_one_inode(root, key->objectid);
510 if (!inode) {
511 ret = -EIO;
512 goto out;
513 }
514
515 /*
516 * first check to see if we already have this extent in the
517 * file. This must be done before the btrfs_drop_extents run
518 * so we don't try to drop this extent.
519 */
520 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
521 start, 0);
522
523 if (ret == 0 && found_type == BTRFS_FILE_EXTENT_REG) {
524 struct btrfs_file_extent_item cmp1;
525 struct btrfs_file_extent_item cmp2;
526 struct btrfs_file_extent_item *existing;
527 struct extent_buffer *leaf;
528
529 leaf = path->nodes[0];
530 existing = btrfs_item_ptr(leaf, path->slots[0],
531 struct btrfs_file_extent_item);
532
533 read_extent_buffer(eb, &cmp1, (unsigned long)item,
534 sizeof(cmp1));
535 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
536 sizeof(cmp2));
537
538 /*
539 * we already have a pointer to this exact extent,
540 * we don't have to do anything
541 */
542 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
543 btrfs_release_path(root, path);
544 goto out;
545 }
546 }
547 btrfs_release_path(root, path);
548
549 /* drop any overlapping extents */
550 ret = btrfs_drop_extents(trans, root, inode,
551 start, extent_end, start, &alloc_hint);
552 BUG_ON(ret);
553
554 BUG_ON(ret);
555 if (found_type == BTRFS_FILE_EXTENT_REG) {
556 struct btrfs_key ins;
557
558 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
559 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
560 ins.type = BTRFS_EXTENT_ITEM_KEY;
561
562 /* insert the extent pointer in the file */
563 ret = overwrite_item(trans, root, path, eb, slot, key);
564 BUG_ON(ret);
565
566 /*
567 * is this extent already allocated in the extent
568 * allocation tree? If so, just add a reference
569 */
570 ret = btrfs_lookup_extent(root, path, ins.objectid, ins.offset);
571 btrfs_release_path(root, path);
572 if (ret == 0) {
573 ret = btrfs_inc_extent_ref(trans, root,
574 ins.objectid, ins.offset,
575 root->root_key.objectid,
576 trans->transid, key->objectid, start);
577 } else {
578 /*
579 * insert the extent pointer in the extent
580 * allocation tree
581 */
582 ret = btrfs_alloc_logged_extent(trans, root,
583 root->root_key.objectid,
584 trans->transid, key->objectid,
585 start, &ins);
586 BUG_ON(ret);
587 }
588 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
589 /* inline extents are easy, we just overwrite them */
590 ret = overwrite_item(trans, root, path, eb, slot, key);
591 BUG_ON(ret);
592 }
593 /* btrfs_drop_extents changes i_blocks, update it here */
594 inode->i_blocks += (extent_end - start) >> 9;
595 btrfs_update_inode(trans, root, inode);
596out:
597 if (inode)
598 iput(inode);
599 return ret;
600}
601
602/*
603 * when cleaning up conflicts between the directory names in the
604 * subvolume, directory names in the log and directory names in the
605 * inode back references, we may have to unlink inodes from directories.
606 *
607 * This is a helper function to do the unlink of a specific directory
608 * item
609 */
610static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
611 struct btrfs_root *root,
612 struct btrfs_path *path,
613 struct inode *dir,
614 struct btrfs_dir_item *di)
615{
616 struct inode *inode;
617 char *name;
618 int name_len;
619 struct extent_buffer *leaf;
620 struct btrfs_key location;
621 int ret;
622
623 leaf = path->nodes[0];
624
625 btrfs_dir_item_key_to_cpu(leaf, di, &location);
626 name_len = btrfs_dir_name_len(leaf, di);
627 name = kmalloc(name_len, GFP_NOFS);
628 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
629 btrfs_release_path(root, path);
630
631 inode = read_one_inode(root, location.objectid);
632 BUG_ON(!inode);
633
634 btrfs_inc_nlink(inode);
635 ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
636 kfree(name);
637
638 iput(inode);
639 return ret;
640}
641
642/*
643 * helper function to see if a given name and sequence number found
644 * in an inode back reference are already in a directory and correctly
645 * point to this inode
646 */
647static noinline int inode_in_dir(struct btrfs_root *root,
648 struct btrfs_path *path,
649 u64 dirid, u64 objectid, u64 index,
650 const char *name, int name_len)
651{
652 struct btrfs_dir_item *di;
653 struct btrfs_key location;
654 int match = 0;
655
656 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
657 index, name, name_len, 0);
658 if (di && !IS_ERR(di)) {
659 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
660 if (location.objectid != objectid)
661 goto out;
662 } else
663 goto out;
664 btrfs_release_path(root, path);
665
666 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
667 if (di && !IS_ERR(di)) {
668 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
669 if (location.objectid != objectid)
670 goto out;
671 } else
672 goto out;
673 match = 1;
674out:
675 btrfs_release_path(root, path);
676 return match;
677}
678
679/*
680 * helper function to check a log tree for a named back reference in
681 * an inode. This is used to decide if a back reference that is
682 * found in the subvolume conflicts with what we find in the log.
683 *
684 * inode backreferences may have multiple refs in a single item,
685 * during replay we process one reference at a time, and we don't
686 * want to delete valid links to a file from the subvolume if that
687 * link is also in the log.
688 */
689static noinline int backref_in_log(struct btrfs_root *log,
690 struct btrfs_key *key,
691 char *name, int namelen)
692{
693 struct btrfs_path *path;
694 struct btrfs_inode_ref *ref;
695 unsigned long ptr;
696 unsigned long ptr_end;
697 unsigned long name_ptr;
698 int found_name_len;
699 int item_size;
700 int ret;
701 int match = 0;
702
703 path = btrfs_alloc_path();
704 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
705 if (ret != 0)
706 goto out;
707
708 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
709 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
710 ptr_end = ptr + item_size;
711 while (ptr < ptr_end) {
712 ref = (struct btrfs_inode_ref *)ptr;
713 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
714 if (found_name_len == namelen) {
715 name_ptr = (unsigned long)(ref + 1);
716 ret = memcmp_extent_buffer(path->nodes[0], name,
717 name_ptr, namelen);
718 if (ret == 0) {
719 match = 1;
720 goto out;
721 }
722 }
723 ptr = (unsigned long)(ref + 1) + found_name_len;
724 }
725out:
726 btrfs_free_path(path);
727 return match;
728}
729
730
731/*
732 * replay one inode back reference item found in the log tree.
733 * eb, slot and key refer to the buffer and key found in the log tree.
734 * root is the destination we are replaying into, and path is for temp
735 * use by this function. (it should be released on return).
736 */
737static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
738 struct btrfs_root *root,
739 struct btrfs_root *log,
740 struct btrfs_path *path,
741 struct extent_buffer *eb, int slot,
742 struct btrfs_key *key)
743{
744 struct inode *dir;
745 int ret;
746 struct btrfs_key location;
747 struct btrfs_inode_ref *ref;
748 struct btrfs_dir_item *di;
749 struct inode *inode;
750 char *name;
751 int namelen;
752 unsigned long ref_ptr;
753 unsigned long ref_end;
754
755 location.objectid = key->objectid;
756 location.type = BTRFS_INODE_ITEM_KEY;
757 location.offset = 0;
758
759 /*
760 * it is possible that we didn't log all the parent directories
761 * for a given inode. If we don't find the dir, just don't
762 * copy the back ref in. The link count fixup code will take
763 * care of the rest
764 */
765 dir = read_one_inode(root, key->offset);
766 if (!dir)
767 return -ENOENT;
768
769 inode = read_one_inode(root, key->objectid);
770 BUG_ON(!dir);
771
772 ref_ptr = btrfs_item_ptr_offset(eb, slot);
773 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
774
775again:
776 ref = (struct btrfs_inode_ref *)ref_ptr;
777
778 namelen = btrfs_inode_ref_name_len(eb, ref);
779 name = kmalloc(namelen, GFP_NOFS);
780 BUG_ON(!name);
781
782 read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
783
784 /* if we already have a perfect match, we're done */
785 if (inode_in_dir(root, path, dir->i_ino, inode->i_ino,
786 btrfs_inode_ref_index(eb, ref),
787 name, namelen)) {
788 goto out;
789 }
790
791 /*
792 * look for a conflicting back reference in the metadata.
793 * if we find one we have to unlink that name of the file
794 * before we add our new link. Later on, we overwrite any
795 * existing back reference, and we don't want to create
796 * dangling pointers in the directory.
797 */
798conflict_again:
799 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
800 if (ret == 0) {
801 char *victim_name;
802 int victim_name_len;
803 struct btrfs_inode_ref *victim_ref;
804 unsigned long ptr;
805 unsigned long ptr_end;
806 struct extent_buffer *leaf = path->nodes[0];
807
808 /* are we trying to overwrite a back ref for the root directory
809 * if so, just jump out, we're done
810 */
811 if (key->objectid == key->offset)
812 goto out_nowrite;
813
814 /* check all the names in this back reference to see
815 * if they are in the log. if so, we allow them to stay
816 * otherwise they must be unlinked as a conflict
817 */
818 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
819 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
820 while(ptr < ptr_end) {
821 victim_ref = (struct btrfs_inode_ref *)ptr;
822 victim_name_len = btrfs_inode_ref_name_len(leaf,
823 victim_ref);
824 victim_name = kmalloc(victim_name_len, GFP_NOFS);
825 BUG_ON(!victim_name);
826
827 read_extent_buffer(leaf, victim_name,
828 (unsigned long)(victim_ref + 1),
829 victim_name_len);
830
831 if (!backref_in_log(log, key, victim_name,
832 victim_name_len)) {
833 btrfs_inc_nlink(inode);
834 btrfs_release_path(root, path);
835 ret = btrfs_unlink_inode(trans, root, dir,
836 inode, victim_name,
837 victim_name_len);
838 kfree(victim_name);
839 btrfs_release_path(root, path);
840 goto conflict_again;
841 }
842 kfree(victim_name);
843 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
844 }
845 BUG_ON(ret);
846 }
847 btrfs_release_path(root, path);
848
849 /* look for a conflicting sequence number */
850 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
851 btrfs_inode_ref_index(eb, ref),
852 name, namelen, 0);
853 if (di && !IS_ERR(di)) {
854 ret = drop_one_dir_item(trans, root, path, dir, di);
855 BUG_ON(ret);
856 }
857 btrfs_release_path(root, path);
858
859
860 /* look for a conflicting name */
861 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
862 name, namelen, 0);
863 if (di && !IS_ERR(di)) {
864 ret = drop_one_dir_item(trans, root, path, dir, di);
865 BUG_ON(ret);
866 }
867 btrfs_release_path(root, path);
868
869 /* insert our name */
870 ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
871 btrfs_inode_ref_index(eb, ref));
872 BUG_ON(ret);
873
874 btrfs_update_inode(trans, root, inode);
875
876out:
877 ref_ptr = (unsigned long)(ref + 1) + namelen;
878 kfree(name);
879 if (ref_ptr < ref_end)
880 goto again;
881
882 /* finally write the back reference in the inode */
883 ret = overwrite_item(trans, root, path, eb, slot, key);
884 BUG_ON(ret);
885
886out_nowrite:
887 btrfs_release_path(root, path);
888 iput(dir);
889 iput(inode);
890 return 0;
891}
892
893/*
894 * replay one csum item from the log tree into the subvolume 'root'
895 * eb, slot and key all refer to the log tree
896 * path is for temp use by this function and should be released on return
897 *
898 * This copies the checksums out of the log tree and inserts them into
899 * the subvolume. Any existing checksums for this range in the file
900 * are overwritten, and new items are added where required.
901 *
902 * We keep this simple by reusing the btrfs_ordered_sum code from
903 * the data=ordered mode. This basically means making a copy
904 * of all the checksums in ram, which we have to do anyway for kmap
905 * rules.
906 *
907 * The copy is then sent down to btrfs_csum_file_blocks, which
908 * does all the hard work of finding existing items in the file
909 * or adding new ones.
910 */
911static noinline int replay_one_csum(struct btrfs_trans_handle *trans,
912 struct btrfs_root *root,
913 struct btrfs_path *path,
914 struct extent_buffer *eb, int slot,
915 struct btrfs_key *key)
916{
917 int ret;
918 u32 item_size = btrfs_item_size_nr(eb, slot);
919 u64 cur_offset;
920 unsigned long file_bytes;
921 struct btrfs_ordered_sum *sums;
922 struct btrfs_sector_sum *sector_sum;
923 struct inode *inode;
924 unsigned long ptr;
925
926 file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize;
927 inode = read_one_inode(root, key->objectid);
928 if (!inode) {
929 return -EIO;
930 }
931
932 sums = kzalloc(btrfs_ordered_sum_size(root, file_bytes), GFP_NOFS);
933 if (!sums) {
934 iput(inode);
935 return -ENOMEM;
936 }
937
938 INIT_LIST_HEAD(&sums->list);
939 sums->len = file_bytes;
940 sums->file_offset = key->offset;
941
942 /*
943 * copy all the sums into the ordered sum struct
944 */
945 sector_sum = sums->sums;
946 cur_offset = key->offset;
947 ptr = btrfs_item_ptr_offset(eb, slot);
948 while(item_size > 0) {
949 sector_sum->offset = cur_offset;
950 read_extent_buffer(eb, &sector_sum->sum, ptr, BTRFS_CRC32_SIZE);
951 sector_sum++;
952 item_size -= BTRFS_CRC32_SIZE;
953 ptr += BTRFS_CRC32_SIZE;
954 cur_offset += root->sectorsize;
955 }
956
957 /* let btrfs_csum_file_blocks add them into the file */
958 ret = btrfs_csum_file_blocks(trans, root, inode, sums);
959 BUG_ON(ret);
960 kfree(sums);
961 iput(inode);
962
963 return 0;
964}
965/*
966 * There are a few corners where the link count of the file can't
967 * be properly maintained during replay. So, instead of adding
968 * lots of complexity to the log code, we just scan the backrefs
969 * for any file that has been through replay.
970 *
971 * The scan will update the link count on the inode to reflect the
972 * number of back refs found. If it goes down to zero, the iput
973 * will free the inode.
974 */
975static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
976 struct btrfs_root *root,
977 struct inode *inode)
978{
979 struct btrfs_path *path;
980 int ret;
981 struct btrfs_key key;
982 u64 nlink = 0;
983 unsigned long ptr;
984 unsigned long ptr_end;
985 int name_len;
986
987 key.objectid = inode->i_ino;
988 key.type = BTRFS_INODE_REF_KEY;
989 key.offset = (u64)-1;
990
991 path = btrfs_alloc_path();
992
993 while(1) {
994 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
995 if (ret < 0)
996 break;
997 if (ret > 0) {
998 if (path->slots[0] == 0)
999 break;
1000 path->slots[0]--;
1001 }
1002 btrfs_item_key_to_cpu(path->nodes[0], &key,
1003 path->slots[0]);
1004 if (key.objectid != inode->i_ino ||
1005 key.type != BTRFS_INODE_REF_KEY)
1006 break;
1007 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1008 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1009 path->slots[0]);
1010 while(ptr < ptr_end) {
1011 struct btrfs_inode_ref *ref;
1012
1013 ref = (struct btrfs_inode_ref *)ptr;
1014 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1015 ref);
1016 ptr = (unsigned long)(ref + 1) + name_len;
1017 nlink++;
1018 }
1019
1020 if (key.offset == 0)
1021 break;
1022 key.offset--;
1023 btrfs_release_path(root, path);
1024 }
1025 btrfs_free_path(path);
1026 if (nlink != inode->i_nlink) {
1027 inode->i_nlink = nlink;
1028 btrfs_update_inode(trans, root, inode);
1029 }
1030
1031 return 0;
1032}
1033
1034static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1035 struct btrfs_root *root,
1036 struct btrfs_path *path)
1037{
1038 int ret;
1039 struct btrfs_key key;
1040 struct inode *inode;
1041
1042 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1043 key.type = BTRFS_ORPHAN_ITEM_KEY;
1044 key.offset = (u64)-1;
1045 while(1) {
1046 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1047 if (ret < 0)
1048 break;
1049
1050 if (ret == 1) {
1051 if (path->slots[0] == 0)
1052 break;
1053 path->slots[0]--;
1054 }
1055
1056 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1057 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1058 key.type != BTRFS_ORPHAN_ITEM_KEY)
1059 break;
1060
1061 ret = btrfs_del_item(trans, root, path);
1062 BUG_ON(ret);
1063
1064 btrfs_release_path(root, path);
1065 inode = read_one_inode(root, key.offset);
1066 BUG_ON(!inode);
1067
1068 ret = fixup_inode_link_count(trans, root, inode);
1069 BUG_ON(ret);
1070
1071 iput(inode);
1072
1073 if (key.offset == 0)
1074 break;
1075 key.offset--;
1076 }
1077 btrfs_release_path(root, path);
1078 return 0;
1079}
1080
1081
1082/*
1083 * record a given inode in the fixup dir so we can check its link
1084 * count when replay is done. The link count is incremented here
1085 * so the inode won't go away until we check it
1086 */
1087static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1088 struct btrfs_root *root,
1089 struct btrfs_path *path,
1090 u64 objectid)
1091{
1092 struct btrfs_key key;
1093 int ret = 0;
1094 struct inode *inode;
1095
1096 inode = read_one_inode(root, objectid);
1097 BUG_ON(!inode);
1098
1099 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1100 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1101 key.offset = objectid;
1102
1103 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1104
1105 btrfs_release_path(root, path);
1106 if (ret == 0) {
1107 btrfs_inc_nlink(inode);
1108 btrfs_update_inode(trans, root, inode);
1109 } else if (ret == -EEXIST) {
1110 ret = 0;
1111 } else {
1112 BUG();
1113 }
1114 iput(inode);
1115
1116 return ret;
1117}
1118
1119/*
1120 * when replaying the log for a directory, we only insert names
1121 * for inodes that actually exist. This means an fsync on a directory
1122 * does not implicitly fsync all the new files in it
1123 */
1124static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1125 struct btrfs_root *root,
1126 struct btrfs_path *path,
1127 u64 dirid, u64 index,
1128 char *name, int name_len, u8 type,
1129 struct btrfs_key *location)
1130{
1131 struct inode *inode;
1132 struct inode *dir;
1133 int ret;
1134
1135 inode = read_one_inode(root, location->objectid);
1136 if (!inode)
1137 return -ENOENT;
1138
1139 dir = read_one_inode(root, dirid);
1140 if (!dir) {
1141 iput(inode);
1142 return -EIO;
1143 }
1144 ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1145
1146 /* FIXME, put inode into FIXUP list */
1147
1148 iput(inode);
1149 iput(dir);
1150 return ret;
1151}
1152
1153/*
1154 * take a single entry in a log directory item and replay it into
1155 * the subvolume.
1156 *
1157 * if a conflicting item exists in the subdirectory already,
1158 * the inode it points to is unlinked and put into the link count
1159 * fix up tree.
1160 *
1161 * If a name from the log points to a file or directory that does
1162 * not exist in the FS, it is skipped. fsyncs on directories
1163 * do not force down inodes inside that directory, just changes to the
1164 * names or unlinks in a directory.
1165 */
1166static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1167 struct btrfs_root *root,
1168 struct btrfs_path *path,
1169 struct extent_buffer *eb,
1170 struct btrfs_dir_item *di,
1171 struct btrfs_key *key)
1172{
1173 char *name;
1174 int name_len;
1175 struct btrfs_dir_item *dst_di;
1176 struct btrfs_key found_key;
1177 struct btrfs_key log_key;
1178 struct inode *dir;
1179 struct inode *inode;
1180 u8 log_type;
1181 int ret;
1182
1183 dir = read_one_inode(root, key->objectid);
1184 BUG_ON(!dir);
1185
1186 name_len = btrfs_dir_name_len(eb, di);
1187 name = kmalloc(name_len, GFP_NOFS);
1188 log_type = btrfs_dir_type(eb, di);
1189 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1190 name_len);
1191
1192 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1193 if (key->type == BTRFS_DIR_ITEM_KEY) {
1194 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1195 name, name_len, 1);
1196 }
1197 else if (key->type == BTRFS_DIR_INDEX_KEY) {
1198 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1199 key->objectid,
1200 key->offset, name,
1201 name_len, 1);
1202 } else {
1203 BUG();
1204 }
1205 if (!dst_di || IS_ERR(dst_di)) {
1206 /* we need a sequence number to insert, so we only
1207 * do inserts for the BTRFS_DIR_INDEX_KEY types
1208 */
1209 if (key->type != BTRFS_DIR_INDEX_KEY)
1210 goto out;
1211 goto insert;
1212 }
1213
1214 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1215 /* the existing item matches the logged item */
1216 if (found_key.objectid == log_key.objectid &&
1217 found_key.type == log_key.type &&
1218 found_key.offset == log_key.offset &&
1219 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1220 goto out;
1221 }
1222
1223 /*
1224 * don't drop the conflicting directory entry if the inode
1225 * for the new entry doesn't exist
1226 */
1227 inode = read_one_inode(root, log_key.objectid);
1228 if (!inode)
1229 goto out;
1230
1231 iput(inode);
1232 ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1233 BUG_ON(ret);
1234
1235 if (key->type == BTRFS_DIR_INDEX_KEY)
1236 goto insert;
1237out:
1238 btrfs_release_path(root, path);
1239 kfree(name);
1240 iput(dir);
1241 return 0;
1242
1243insert:
1244 btrfs_release_path(root, path);
1245 ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1246 name, name_len, log_type, &log_key);
1247
1248 if (ret && ret != -ENOENT)
1249 BUG();
1250 goto out;
1251}
1252
1253/*
1254 * find all the names in a directory item and reconcile them into
1255 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
1256 * one name in a directory item, but the same code gets used for
1257 * both directory index types
1258 */
1259static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1260 struct btrfs_root *root,
1261 struct btrfs_path *path,
1262 struct extent_buffer *eb, int slot,
1263 struct btrfs_key *key)
1264{
1265 int ret;
1266 u32 item_size = btrfs_item_size_nr(eb, slot);
1267 struct btrfs_dir_item *di;
1268 int name_len;
1269 unsigned long ptr;
1270 unsigned long ptr_end;
1271
1272 ptr = btrfs_item_ptr_offset(eb, slot);
1273 ptr_end = ptr + item_size;
1274 while(ptr < ptr_end) {
1275 di = (struct btrfs_dir_item *)ptr;
1276 name_len = btrfs_dir_name_len(eb, di);
1277 ret = replay_one_name(trans, root, path, eb, di, key);
1278 BUG_ON(ret);
1279 ptr = (unsigned long)(di + 1);
1280 ptr += name_len;
1281 }
1282 return 0;
1283}
1284
1285/*
1286 * directory replay has two parts. There are the standard directory
1287 * items in the log copied from the subvolume, and range items
1288 * created in the log while the subvolume was logged.
1289 *
1290 * The range items tell us which parts of the key space the log
1291 * is authoritative for. During replay, if a key in the subvolume
1292 * directory is in a logged range item, but not actually in the log
1293 * that means it was deleted from the directory before the fsync
1294 * and should be removed.
1295 */
1296static noinline int find_dir_range(struct btrfs_root *root,
1297 struct btrfs_path *path,
1298 u64 dirid, int key_type,
1299 u64 *start_ret, u64 *end_ret)
1300{
1301 struct btrfs_key key;
1302 u64 found_end;
1303 struct btrfs_dir_log_item *item;
1304 int ret;
1305 int nritems;
1306
1307 if (*start_ret == (u64)-1)
1308 return 1;
1309
1310 key.objectid = dirid;
1311 key.type = key_type;
1312 key.offset = *start_ret;
1313
1314 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1315 if (ret < 0)
1316 goto out;
1317 if (ret > 0) {
1318 if (path->slots[0] == 0)
1319 goto out;
1320 path->slots[0]--;
1321 }
1322 if (ret != 0)
1323 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1324
1325 if (key.type != key_type || key.objectid != dirid) {
1326 ret = 1;
1327 goto next;
1328 }
1329 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1330 struct btrfs_dir_log_item);
1331 found_end = btrfs_dir_log_end(path->nodes[0], item);
1332
1333 if (*start_ret >= key.offset && *start_ret <= found_end) {
1334 ret = 0;
1335 *start_ret = key.offset;
1336 *end_ret = found_end;
1337 goto out;
1338 }
1339 ret = 1;
1340next:
1341 /* check the next slot in the tree to see if it is a valid item */
1342 nritems = btrfs_header_nritems(path->nodes[0]);
1343 if (path->slots[0] >= nritems) {
1344 ret = btrfs_next_leaf(root, path);
1345 if (ret)
1346 goto out;
1347 } else {
1348 path->slots[0]++;
1349 }
1350
1351 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1352
1353 if (key.type != key_type || key.objectid != dirid) {
1354 ret = 1;
1355 goto out;
1356 }
1357 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1358 struct btrfs_dir_log_item);
1359 found_end = btrfs_dir_log_end(path->nodes[0], item);
1360 *start_ret = key.offset;
1361 *end_ret = found_end;
1362 ret = 0;
1363out:
1364 btrfs_release_path(root, path);
1365 return ret;
1366}
1367
1368/*
1369 * this looks for a given directory item in the log. If the directory
1370 * item is not in the log, the item is removed and the inode it points
1371 * to is unlinked
1372 */
1373static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1374 struct btrfs_root *root,
1375 struct btrfs_root *log,
1376 struct btrfs_path *path,
1377 struct btrfs_path *log_path,
1378 struct inode *dir,
1379 struct btrfs_key *dir_key)
1380{
1381 int ret;
1382 struct extent_buffer *eb;
1383 int slot;
1384 u32 item_size;
1385 struct btrfs_dir_item *di;
1386 struct btrfs_dir_item *log_di;
1387 int name_len;
1388 unsigned long ptr;
1389 unsigned long ptr_end;
1390 char *name;
1391 struct inode *inode;
1392 struct btrfs_key location;
1393
1394again:
1395 eb = path->nodes[0];
1396 slot = path->slots[0];
1397 item_size = btrfs_item_size_nr(eb, slot);
1398 ptr = btrfs_item_ptr_offset(eb, slot);
1399 ptr_end = ptr + item_size;
1400 while(ptr < ptr_end) {
1401 di = (struct btrfs_dir_item *)ptr;
1402 name_len = btrfs_dir_name_len(eb, di);
1403 name = kmalloc(name_len, GFP_NOFS);
1404 if (!name) {
1405 ret = -ENOMEM;
1406 goto out;
1407 }
1408 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1409 name_len);
1410 log_di = NULL;
1411 if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
1412 log_di = btrfs_lookup_dir_item(trans, log, log_path,
1413 dir_key->objectid,
1414 name, name_len, 0);
1415 } else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
1416 log_di = btrfs_lookup_dir_index_item(trans, log,
1417 log_path,
1418 dir_key->objectid,
1419 dir_key->offset,
1420 name, name_len, 0);
1421 }
1422 if (!log_di || IS_ERR(log_di)) {
1423 btrfs_dir_item_key_to_cpu(eb, di, &location);
1424 btrfs_release_path(root, path);
1425 btrfs_release_path(log, log_path);
1426 inode = read_one_inode(root, location.objectid);
1427 BUG_ON(!inode);
1428
1429 ret = link_to_fixup_dir(trans, root,
1430 path, location.objectid);
1431 BUG_ON(ret);
1432 btrfs_inc_nlink(inode);
1433 ret = btrfs_unlink_inode(trans, root, dir, inode,
1434 name, name_len);
1435 BUG_ON(ret);
1436 kfree(name);
1437 iput(inode);
1438
1439 /* there might still be more names under this key
1440 * check and repeat if required
1441 */
1442 ret = btrfs_search_slot(NULL, root, dir_key, path,
1443 0, 0);
1444 if (ret == 0)
1445 goto again;
1446 ret = 0;
1447 goto out;
1448 }
1449 btrfs_release_path(log, log_path);
1450 kfree(name);
1451
1452 ptr = (unsigned long)(di + 1);
1453 ptr += name_len;
1454 }
1455 ret = 0;
1456out:
1457 btrfs_release_path(root, path);
1458 btrfs_release_path(log, log_path);
1459 return ret;
1460}
1461
1462/*
1463 * deletion replay happens before we copy any new directory items
1464 * out of the log or out of backreferences from inodes. It
1465 * scans the log to find ranges of keys that log is authoritative for,
1466 * and then scans the directory to find items in those ranges that are
1467 * not present in the log.
1468 *
1469 * Anything we don't find in the log is unlinked and removed from the
1470 * directory.
1471 */
1472static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1473 struct btrfs_root *root,
1474 struct btrfs_root *log,
1475 struct btrfs_path *path,
1476 u64 dirid)
1477{
1478 u64 range_start;
1479 u64 range_end;
1480 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1481 int ret = 0;
1482 struct btrfs_key dir_key;
1483 struct btrfs_key found_key;
1484 struct btrfs_path *log_path;
1485 struct inode *dir;
1486
1487 dir_key.objectid = dirid;
1488 dir_key.type = BTRFS_DIR_ITEM_KEY;
1489 log_path = btrfs_alloc_path();
1490 if (!log_path)
1491 return -ENOMEM;
1492
1493 dir = read_one_inode(root, dirid);
1494 /* it isn't an error if the inode isn't there, that can happen
1495 * because we replay the deletes before we copy in the inode item
1496 * from the log
1497 */
1498 if (!dir) {
1499 btrfs_free_path(log_path);
1500 return 0;
1501 }
1502again:
1503 range_start = 0;
1504 range_end = 0;
1505 while(1) {
1506 ret = find_dir_range(log, path, dirid, key_type,
1507 &range_start, &range_end);
1508 if (ret != 0)
1509 break;
1510
1511 dir_key.offset = range_start;
1512 while(1) {
1513 int nritems;
1514 ret = btrfs_search_slot(NULL, root, &dir_key, path,
1515 0, 0);
1516 if (ret < 0)
1517 goto out;
1518
1519 nritems = btrfs_header_nritems(path->nodes[0]);
1520 if (path->slots[0] >= nritems) {
1521 ret = btrfs_next_leaf(root, path);
1522 if (ret)
1523 break;
1524 }
1525 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1526 path->slots[0]);
1527 if (found_key.objectid != dirid ||
1528 found_key.type != dir_key.type)
1529 goto next_type;
1530
1531 if (found_key.offset > range_end)
1532 break;
1533
1534 ret = check_item_in_log(trans, root, log, path,
1535 log_path, dir, &found_key);
1536 BUG_ON(ret);
1537 if (found_key.offset == (u64)-1)
1538 break;
1539 dir_key.offset = found_key.offset + 1;
1540 }
1541 btrfs_release_path(root, path);
1542 if (range_end == (u64)-1)
1543 break;
1544 range_start = range_end + 1;
1545 }
1546
1547next_type:
1548 ret = 0;
1549 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1550 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1551 dir_key.type = BTRFS_DIR_INDEX_KEY;
1552 btrfs_release_path(root, path);
1553 goto again;
1554 }
1555out:
1556 btrfs_release_path(root, path);
1557 btrfs_free_path(log_path);
1558 iput(dir);
1559 return ret;
1560}
1561
1562/*
1563 * the process_func used to replay items from the log tree. This
1564 * gets called in two different stages. The first stage just looks
1565 * for inodes and makes sure they are all copied into the subvolume.
1566 *
1567 * The second stage copies all the other item types from the log into
1568 * the subvolume. The two stage approach is slower, but gets rid of
1569 * lots of complexity around inodes referencing other inodes that exist
1570 * only in the log (references come from either directory items or inode
1571 * back refs).
1572 */
1573static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1574 struct walk_control *wc, u64 gen)
1575{
1576 int nritems;
1577 struct btrfs_path *path;
1578 struct btrfs_root *root = wc->replay_dest;
1579 struct btrfs_key key;
1580 u32 item_size;
1581 int level;
1582 int i;
1583 int ret;
1584
1585 btrfs_read_buffer(eb, gen);
1586
1587 level = btrfs_header_level(eb);
1588
1589 if (level != 0)
1590 return 0;
1591
1592 path = btrfs_alloc_path();
1593 BUG_ON(!path);
1594
1595 nritems = btrfs_header_nritems(eb);
1596 for (i = 0; i < nritems; i++) {
1597 btrfs_item_key_to_cpu(eb, &key, i);
1598 item_size = btrfs_item_size_nr(eb, i);
1599
1600 /* inode keys are done during the first stage */
1601 if (key.type == BTRFS_INODE_ITEM_KEY &&
1602 wc->stage == LOG_WALK_REPLAY_INODES) {
1603 struct inode *inode;
1604 struct btrfs_inode_item *inode_item;
1605 u32 mode;
1606
1607 inode_item = btrfs_item_ptr(eb, i,
1608 struct btrfs_inode_item);
1609 mode = btrfs_inode_mode(eb, inode_item);
1610 if (S_ISDIR(mode)) {
1611 ret = replay_dir_deletes(wc->trans,
1612 root, log, path, key.objectid);
1613 BUG_ON(ret);
1614 }
1615 ret = overwrite_item(wc->trans, root, path,
1616 eb, i, &key);
1617 BUG_ON(ret);
1618
1619 /* for regular files, truncate away
1620 * extents past the new EOF
1621 */
1622 if (S_ISREG(mode)) {
1623 inode = read_one_inode(root,
1624 key.objectid);
1625 BUG_ON(!inode);
1626
1627 ret = btrfs_truncate_inode_items(wc->trans,
1628 root, inode, inode->i_size,
1629 BTRFS_EXTENT_DATA_KEY);
1630 BUG_ON(ret);
1631 iput(inode);
1632 }
1633 ret = link_to_fixup_dir(wc->trans, root,
1634 path, key.objectid);
1635 BUG_ON(ret);
1636 }
1637 if (wc->stage < LOG_WALK_REPLAY_ALL)
1638 continue;
1639
1640 /* these keys are simply copied */
1641 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1642 ret = overwrite_item(wc->trans, root, path,
1643 eb, i, &key);
1644 BUG_ON(ret);
1645 } else if (key.type == BTRFS_INODE_REF_KEY) {
1646 ret = add_inode_ref(wc->trans, root, log, path,
1647 eb, i, &key);
1648 BUG_ON(ret && ret != -ENOENT);
1649 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1650 ret = replay_one_extent(wc->trans, root, path,
1651 eb, i, &key);
1652 BUG_ON(ret);
1653 } else if (key.type == BTRFS_CSUM_ITEM_KEY) {
1654 ret = replay_one_csum(wc->trans, root, path,
1655 eb, i, &key);
1656 BUG_ON(ret);
1657 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1658 key.type == BTRFS_DIR_INDEX_KEY) {
1659 ret = replay_one_dir_item(wc->trans, root, path,
1660 eb, i, &key);
1661 BUG_ON(ret);
1662 }
1663 }
1664 btrfs_free_path(path);
1665 return 0;
1666}
1667
1668static int noinline walk_down_log_tree(struct btrfs_trans_handle *trans,
1669 struct btrfs_root *root,
1670 struct btrfs_path *path, int *level,
1671 struct walk_control *wc)
1672{
1673 u64 root_owner;
1674 u64 root_gen;
1675 u64 bytenr;
1676 u64 ptr_gen;
1677 struct extent_buffer *next;
1678 struct extent_buffer *cur;
1679 struct extent_buffer *parent;
1680 u32 blocksize;
1681 int ret = 0;
1682
1683 WARN_ON(*level < 0);
1684 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1685
1686 while(*level > 0) {
1687 WARN_ON(*level < 0);
1688 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1689 cur = path->nodes[*level];
1690
1691 if (btrfs_header_level(cur) != *level)
1692 WARN_ON(1);
1693
1694 if (path->slots[*level] >=
1695 btrfs_header_nritems(cur))
1696 break;
1697
1698 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1699 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1700 blocksize = btrfs_level_size(root, *level - 1);
1701
1702 parent = path->nodes[*level];
1703 root_owner = btrfs_header_owner(parent);
1704 root_gen = btrfs_header_generation(parent);
1705
1706 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1707
1708 wc->process_func(root, next, wc, ptr_gen);
1709
1710 if (*level == 1) {
1711 path->slots[*level]++;
1712 if (wc->free) {
1713 btrfs_read_buffer(next, ptr_gen);
1714
1715 btrfs_tree_lock(next);
1716 clean_tree_block(trans, root, next);
1717 btrfs_wait_tree_block_writeback(next);
1718 btrfs_tree_unlock(next);
1719
1720 ret = btrfs_drop_leaf_ref(trans, root, next);
1721 BUG_ON(ret);
1722
1723 WARN_ON(root_owner !=
1724 BTRFS_TREE_LOG_OBJECTID);
1725 ret = btrfs_free_extent(trans, root, bytenr,
1726 blocksize, root_owner,
1727 root_gen, 0, 0, 1);
1728 BUG_ON(ret);
1729 }
1730 free_extent_buffer(next);
1731 continue;
1732 }
1733 btrfs_read_buffer(next, ptr_gen);
1734
1735 WARN_ON(*level <= 0);
1736 if (path->nodes[*level-1])
1737 free_extent_buffer(path->nodes[*level-1]);
1738 path->nodes[*level-1] = next;
1739 *level = btrfs_header_level(next);
1740 path->slots[*level] = 0;
1741 cond_resched();
1742 }
1743 WARN_ON(*level < 0);
1744 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1745
1746 if (path->nodes[*level] == root->node) {
1747 parent = path->nodes[*level];
1748 } else {
1749 parent = path->nodes[*level + 1];
1750 }
1751 bytenr = path->nodes[*level]->start;
1752
1753 blocksize = btrfs_level_size(root, *level);
1754 root_owner = btrfs_header_owner(parent);
1755 root_gen = btrfs_header_generation(parent);
1756
1757 wc->process_func(root, path->nodes[*level], wc,
1758 btrfs_header_generation(path->nodes[*level]));
1759
1760 if (wc->free) {
1761 next = path->nodes[*level];
1762 btrfs_tree_lock(next);
1763 clean_tree_block(trans, root, next);
1764 btrfs_wait_tree_block_writeback(next);
1765 btrfs_tree_unlock(next);
1766
1767 if (*level == 0) {
1768 ret = btrfs_drop_leaf_ref(trans, root, next);
1769 BUG_ON(ret);
1770 }
1771 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1772 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
1773 root_owner, root_gen, 0, 0, 1);
1774 BUG_ON(ret);
1775 }
1776 free_extent_buffer(path->nodes[*level]);
1777 path->nodes[*level] = NULL;
1778 *level += 1;
1779
1780 cond_resched();
1781 return 0;
1782}
1783
1784static int noinline walk_up_log_tree(struct btrfs_trans_handle *trans,
1785 struct btrfs_root *root,
1786 struct btrfs_path *path, int *level,
1787 struct walk_control *wc)
1788{
1789 u64 root_owner;
1790 u64 root_gen;
1791 int i;
1792 int slot;
1793 int ret;
1794
1795 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1796 slot = path->slots[i];
1797 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1798 struct extent_buffer *node;
1799 node = path->nodes[i];
1800 path->slots[i]++;
1801 *level = i;
1802 WARN_ON(*level == 0);
1803 return 0;
1804 } else {
1805 if (path->nodes[*level] == root->node) {
1806 root_owner = root->root_key.objectid;
1807 root_gen =
1808 btrfs_header_generation(path->nodes[*level]);
1809 } else {
1810 struct extent_buffer *node;
1811 node = path->nodes[*level + 1];
1812 root_owner = btrfs_header_owner(node);
1813 root_gen = btrfs_header_generation(node);
1814 }
1815 wc->process_func(root, path->nodes[*level], wc,
1816 btrfs_header_generation(path->nodes[*level]));
1817 if (wc->free) {
1818 struct extent_buffer *next;
1819
1820 next = path->nodes[*level];
1821
1822 btrfs_tree_lock(next);
1823 clean_tree_block(trans, root, next);
1824 btrfs_wait_tree_block_writeback(next);
1825 btrfs_tree_unlock(next);
1826
1827 if (*level == 0) {
1828 ret = btrfs_drop_leaf_ref(trans, root,
1829 next);
1830 BUG_ON(ret);
1831 }
1832
1833 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1834 ret = btrfs_free_extent(trans, root,
1835 path->nodes[*level]->start,
1836 path->nodes[*level]->len,
1837 root_owner, root_gen, 0, 0, 1);
1838 BUG_ON(ret);
1839 }
1840 free_extent_buffer(path->nodes[*level]);
1841 path->nodes[*level] = NULL;
1842 *level = i + 1;
1843 }
1844 }
1845 return 1;
1846}
1847
1848/*
1849 * drop the reference count on the tree rooted at 'snap'. This traverses
1850 * the tree freeing any blocks that have a ref count of zero after being
1851 * decremented.
1852 */
1853static int walk_log_tree(struct btrfs_trans_handle *trans,
1854 struct btrfs_root *log, struct walk_control *wc)
1855{
1856 int ret = 0;
1857 int wret;
1858 int level;
1859 struct btrfs_path *path;
1860 int i;
1861 int orig_level;
1862
1863 path = btrfs_alloc_path();
1864 BUG_ON(!path);
1865
1866 level = btrfs_header_level(log->node);
1867 orig_level = level;
1868 path->nodes[level] = log->node;
1869 extent_buffer_get(log->node);
1870 path->slots[level] = 0;
1871
1872 while(1) {
1873 wret = walk_down_log_tree(trans, log, path, &level, wc);
1874 if (wret > 0)
1875 break;
1876 if (wret < 0)
1877 ret = wret;
1878
1879 wret = walk_up_log_tree(trans, log, path, &level, wc);
1880 if (wret > 0)
1881 break;
1882 if (wret < 0)
1883 ret = wret;
1884 }
1885
1886 /* was the root node processed? if not, catch it here */
1887 if (path->nodes[orig_level]) {
1888 wc->process_func(log, path->nodes[orig_level], wc,
1889 btrfs_header_generation(path->nodes[orig_level]));
1890 if (wc->free) {
1891 struct extent_buffer *next;
1892
1893 next = path->nodes[orig_level];
1894
1895 btrfs_tree_lock(next);
1896 clean_tree_block(trans, log, next);
1897 btrfs_wait_tree_block_writeback(next);
1898 btrfs_tree_unlock(next);
1899
1900 if (orig_level == 0) {
1901 ret = btrfs_drop_leaf_ref(trans, log,
1902 next);
1903 BUG_ON(ret);
1904 }
1905 WARN_ON(log->root_key.objectid !=
1906 BTRFS_TREE_LOG_OBJECTID);
1907 ret = btrfs_free_extent(trans, log,
1908 next->start, next->len,
1909 log->root_key.objectid,
1910 btrfs_header_generation(next),
1911 0, 0, 1);
1912 BUG_ON(ret);
1913 }
1914 }
1915
1916 for (i = 0; i <= orig_level; i++) {
1917 if (path->nodes[i]) {
1918 free_extent_buffer(path->nodes[i]);
1919 path->nodes[i] = NULL;
1920 }
1921 }
1922 btrfs_free_path(path);
1923 if (wc->free)
1924 free_extent_buffer(log->node);
1925 return ret;
1926}
1927
1928int wait_log_commit(struct btrfs_root *log)
1929{
1930 DEFINE_WAIT(wait);
1931 u64 transid = log->fs_info->tree_log_transid;
1932
1933 do {
1934 prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
1935 TASK_UNINTERRUPTIBLE);
1936 mutex_unlock(&log->fs_info->tree_log_mutex);
1937 if (atomic_read(&log->fs_info->tree_log_commit))
1938 schedule();
1939 finish_wait(&log->fs_info->tree_log_wait, &wait);
1940 mutex_lock(&log->fs_info->tree_log_mutex);
1941 } while(transid == log->fs_info->tree_log_transid &&
1942 atomic_read(&log->fs_info->tree_log_commit));
1943 return 0;
1944}
1945
1946/*
1947 * btrfs_sync_log does sends a given tree log down to the disk and
1948 * updates the super blocks to record it. When this call is done,
1949 * you know that any inodes previously logged are safely on disk
1950 */
1951int btrfs_sync_log(struct btrfs_trans_handle *trans,
1952 struct btrfs_root *root)
1953{
1954 int ret;
1955 unsigned long batch;
1956 struct btrfs_root *log = root->log_root;
1957 struct walk_control wc = {
1958 .write = 1,
1959 .process_func = process_one_buffer
1960 };
1961
1962 mutex_lock(&log->fs_info->tree_log_mutex);
1963 if (atomic_read(&log->fs_info->tree_log_commit)) {
1964 wait_log_commit(log);
1965 goto out;
1966 }
1967 atomic_set(&log->fs_info->tree_log_commit, 1);
1968
1969 while(1) {
1970 mutex_unlock(&log->fs_info->tree_log_mutex);
1971 schedule_timeout_uninterruptible(1);
1972 mutex_lock(&log->fs_info->tree_log_mutex);
1973 batch = log->fs_info->tree_log_batch;
1974
1975 while(atomic_read(&log->fs_info->tree_log_writers)) {
1976 DEFINE_WAIT(wait);
1977 prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
1978 TASK_UNINTERRUPTIBLE);
1979 batch = log->fs_info->tree_log_batch;
1980 mutex_unlock(&log->fs_info->tree_log_mutex);
1981 if (atomic_read(&log->fs_info->tree_log_writers))
1982 schedule();
1983 mutex_lock(&log->fs_info->tree_log_mutex);
1984 finish_wait(&log->fs_info->tree_log_wait, &wait);
1985 }
1986 if (batch == log->fs_info->tree_log_batch)
1987 break;
1988 }
1989 ret = walk_log_tree(trans, log, &wc);
1990 BUG_ON(ret);
1991
1992 ret = walk_log_tree(trans, log->fs_info->log_root_tree, &wc);
1993 BUG_ON(ret);
1994
1995 wc.wait = 1;
1996
1997 ret = walk_log_tree(trans, log, &wc);
1998 BUG_ON(ret);
1999
2000 ret = walk_log_tree(trans, log->fs_info->log_root_tree, &wc);
2001 BUG_ON(ret);
2002
2003 btrfs_set_super_log_root(&root->fs_info->super_for_commit,
2004 log->fs_info->log_root_tree->node->start);
2005 btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
2006 btrfs_header_level(log->fs_info->log_root_tree->node));
2007
2008 write_ctree_super(trans, log->fs_info->tree_root);
2009 log->fs_info->tree_log_transid++;
2010 log->fs_info->tree_log_batch = 0;
2011 atomic_set(&log->fs_info->tree_log_commit, 0);
2012 smp_mb();
2013 if (waitqueue_active(&log->fs_info->tree_log_wait))
2014 wake_up(&log->fs_info->tree_log_wait);
2015out:
2016 mutex_unlock(&log->fs_info->tree_log_mutex);
2017 return 0;
2018
2019}
2020
2021/*
2022 * free all the extents used by the tree log. This should be called
2023 * at commit time of the full transaction
2024 */
2025int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2026{
2027 int ret;
2028 struct btrfs_root *log;
2029 struct key;
2030 struct walk_control wc = {
2031 .free = 1,
2032 .process_func = process_one_buffer
2033 };
2034
2035 if (!root->log_root)
2036 return 0;
2037
2038 log = root->log_root;
2039 ret = walk_log_tree(trans, log, &wc);
2040 BUG_ON(ret);
2041
2042 log = root->log_root;
2043 ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
2044 &log->root_key);
2045 BUG_ON(ret);
2046 root->log_root = NULL;
2047 kfree(root->log_root);
2048 return 0;
2049}
2050
2051/*
2052 * helper function to update the item for a given subvolumes log root
2053 * in the tree of log roots
2054 */
2055static int update_log_root(struct btrfs_trans_handle *trans,
2056 struct btrfs_root *log)
2057{
2058 u64 bytenr = btrfs_root_bytenr(&log->root_item);
2059 int ret;
2060
2061 if (log->node->start == bytenr)
2062 return 0;
2063
2064 btrfs_set_root_bytenr(&log->root_item, log->node->start);
2065 btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
2066 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
2067 &log->root_key, &log->root_item);
2068 BUG_ON(ret);
2069 return ret;
2070}
2071
2072/*
2073 * If both a file and directory are logged, and unlinks or renames are
2074 * mixed in, we have a few interesting corners:
2075 *
2076 * create file X in dir Y
2077 * link file X to X.link in dir Y
2078 * fsync file X
2079 * unlink file X but leave X.link
2080 * fsync dir Y
2081 *
2082 * After a crash we would expect only X.link to exist. But file X
2083 * didn't get fsync'd again so the log has back refs for X and X.link.
2084 *
2085 * We solve this by removing directory entries and inode backrefs from the
2086 * log when a file that was logged in the current transaction is
2087 * unlinked. Any later fsync will include the updated log entries, and
2088 * we'll be able to reconstruct the proper directory items from backrefs.
2089 *
2090 * This optimizations allows us to avoid relogging the entire inode
2091 * or the entire directory.
2092 */
2093int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2094 struct btrfs_root *root,
2095 const char *name, int name_len,
2096 struct inode *dir, u64 index)
2097{
2098 struct btrfs_root *log;
2099 struct btrfs_dir_item *di;
2100 struct btrfs_path *path;
2101 int ret;
2102 int bytes_del = 0;
2103
2104 ret = join_running_log_trans(root);
2105 if (ret)
2106 return 0;
2107
2108 mutex_lock(&BTRFS_I(dir)->log_mutex);
2109
2110 log = root->log_root;
2111 path = btrfs_alloc_path();
2112 di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
2113 name, name_len, -1);
2114 if (di && !IS_ERR(di)) {
2115 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2116 bytes_del += name_len;
2117 BUG_ON(ret);
2118 }
2119 btrfs_release_path(log, path);
2120 di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
2121 index, name, name_len, -1);
2122 if (di && !IS_ERR(di)) {
2123 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2124 bytes_del += name_len;
2125 BUG_ON(ret);
2126 }
2127
2128 /* update the directory size in the log to reflect the names
2129 * we have removed
2130 */
2131 if (bytes_del) {
2132 struct btrfs_key key;
2133
2134 key.objectid = dir->i_ino;
2135 key.offset = 0;
2136 key.type = BTRFS_INODE_ITEM_KEY;
2137 btrfs_release_path(log, path);
2138
2139 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2140 if (ret == 0) {
2141 struct btrfs_inode_item *item;
2142 u64 i_size;
2143
2144 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2145 struct btrfs_inode_item);
2146 i_size = btrfs_inode_size(path->nodes[0], item);
2147 if (i_size > bytes_del)
2148 i_size -= bytes_del;
2149 else
2150 i_size = 0;
2151 btrfs_set_inode_size(path->nodes[0], item, i_size);
2152 btrfs_mark_buffer_dirty(path->nodes[0]);
2153 } else
2154 ret = 0;
2155 btrfs_release_path(log, path);
2156 }
2157
2158 btrfs_free_path(path);
2159 mutex_unlock(&BTRFS_I(dir)->log_mutex);
2160 end_log_trans(root);
2161
2162 return 0;
2163}
2164
2165/* see comments for btrfs_del_dir_entries_in_log */
2166int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2167 struct btrfs_root *root,
2168 const char *name, int name_len,
2169 struct inode *inode, u64 dirid)
2170{
2171 struct btrfs_root *log;
2172 u64 index;
2173 int ret;
2174
2175 ret = join_running_log_trans(root);
2176 if (ret)
2177 return 0;
2178 log = root->log_root;
2179 mutex_lock(&BTRFS_I(inode)->log_mutex);
2180
2181 ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
2182 dirid, &index);
2183 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2184 end_log_trans(root);
2185
2186 if (ret == 0 || ret == -ENOENT)
2187 return 0;
2188 return ret;
2189}
2190
2191/*
2192 * creates a range item in the log for 'dirid'. first_offset and
2193 * last_offset tell us which parts of the key space the log should
2194 * be considered authoritative for.
2195 */
2196static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2197 struct btrfs_root *log,
2198 struct btrfs_path *path,
2199 int key_type, u64 dirid,
2200 u64 first_offset, u64 last_offset)
2201{
2202 int ret;
2203 struct btrfs_key key;
2204 struct btrfs_dir_log_item *item;
2205
2206 key.objectid = dirid;
2207 key.offset = first_offset;
2208 if (key_type == BTRFS_DIR_ITEM_KEY)
2209 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2210 else
2211 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2212 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2213 BUG_ON(ret);
2214
2215 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2216 struct btrfs_dir_log_item);
2217 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2218 btrfs_mark_buffer_dirty(path->nodes[0]);
2219 btrfs_release_path(log, path);
2220 return 0;
2221}
2222
2223/*
2224 * log all the items included in the current transaction for a given
2225 * directory. This also creates the range items in the log tree required
2226 * to replay anything deleted before the fsync
2227 */
2228static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2229 struct btrfs_root *root, struct inode *inode,
2230 struct btrfs_path *path,
2231 struct btrfs_path *dst_path, int key_type,
2232 u64 min_offset, u64 *last_offset_ret)
2233{
2234 struct btrfs_key min_key;
2235 struct btrfs_key max_key;
2236 struct btrfs_root *log = root->log_root;
2237 struct extent_buffer *src;
2238 int ret;
2239 int i;
2240 int nritems;
2241 u64 first_offset = min_offset;
2242 u64 last_offset = (u64)-1;
2243
2244 log = root->log_root;
2245 max_key.objectid = inode->i_ino;
2246 max_key.offset = (u64)-1;
2247 max_key.type = key_type;
2248
2249 min_key.objectid = inode->i_ino;
2250 min_key.type = key_type;
2251 min_key.offset = min_offset;
2252
2253 path->keep_locks = 1;
2254
2255 ret = btrfs_search_forward(root, &min_key, &max_key,
2256 path, 0, trans->transid);
2257
2258 /*
2259 * we didn't find anything from this transaction, see if there
2260 * is anything at all
2261 */
2262 if (ret != 0 || min_key.objectid != inode->i_ino ||
2263 min_key.type != key_type) {
2264 min_key.objectid = inode->i_ino;
2265 min_key.type = key_type;
2266 min_key.offset = (u64)-1;
2267 btrfs_release_path(root, path);
2268 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2269 if (ret < 0) {
2270 btrfs_release_path(root, path);
2271 return ret;
2272 }
2273 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2274
2275 /* if ret == 0 there are items for this type,
2276 * create a range to tell us the last key of this type.
2277 * otherwise, there are no items in this directory after
2278 * *min_offset, and we create a range to indicate that.
2279 */
2280 if (ret == 0) {
2281 struct btrfs_key tmp;
2282 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2283 path->slots[0]);
2284 if (key_type == tmp.type) {
2285 first_offset = max(min_offset, tmp.offset) + 1;
2286 }
2287 }
2288 goto done;
2289 }
2290
2291 /* go backward to find any previous key */
2292 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2293 if (ret == 0) {
2294 struct btrfs_key tmp;
2295 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2296 if (key_type == tmp.type) {
2297 first_offset = tmp.offset;
2298 ret = overwrite_item(trans, log, dst_path,
2299 path->nodes[0], path->slots[0],
2300 &tmp);
2301 }
2302 }
2303 btrfs_release_path(root, path);
2304
2305 /* find the first key from this transaction again */
2306 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2307 if (ret != 0) {
2308 WARN_ON(1);
2309 goto done;
2310 }
2311
2312 /*
2313 * we have a block from this transaction, log every item in it
2314 * from our directory
2315 */
2316 while(1) {
2317 struct btrfs_key tmp;
2318 src = path->nodes[0];
2319 nritems = btrfs_header_nritems(src);
2320 for (i = path->slots[0]; i < nritems; i++) {
2321 btrfs_item_key_to_cpu(src, &min_key, i);
2322
2323 if (min_key.objectid != inode->i_ino ||
2324 min_key.type != key_type)
2325 goto done;
2326 ret = overwrite_item(trans, log, dst_path, src, i,
2327 &min_key);
2328 BUG_ON(ret);
2329 }
2330 path->slots[0] = nritems;
2331
2332 /*
2333 * look ahead to the next item and see if it is also
2334 * from this directory and from this transaction
2335 */
2336 ret = btrfs_next_leaf(root, path);
2337 if (ret == 1) {
2338 last_offset = (u64)-1;
2339 goto done;
2340 }
2341 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2342 if (tmp.objectid != inode->i_ino || tmp.type != key_type) {
2343 last_offset = (u64)-1;
2344 goto done;
2345 }
2346 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2347 ret = overwrite_item(trans, log, dst_path,
2348 path->nodes[0], path->slots[0],
2349 &tmp);
2350
2351 BUG_ON(ret);
2352 last_offset = tmp.offset;
2353 goto done;
2354 }
2355 }
2356done:
2357 *last_offset_ret = last_offset;
2358 btrfs_release_path(root, path);
2359 btrfs_release_path(log, dst_path);
2360
2361 /* insert the log range keys to indicate where the log is valid */
2362 ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
2363 first_offset, last_offset);
2364 BUG_ON(ret);
2365 return 0;
2366}
2367
2368/*
2369 * logging directories is very similar to logging inodes, We find all the items
2370 * from the current transaction and write them to the log.
2371 *
2372 * The recovery code scans the directory in the subvolume, and if it finds a
2373 * key in the range logged that is not present in the log tree, then it means
2374 * that dir entry was unlinked during the transaction.
2375 *
2376 * In order for that scan to work, we must include one key smaller than
2377 * the smallest logged by this transaction and one key larger than the largest
2378 * key logged by this transaction.
2379 */
2380static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2381 struct btrfs_root *root, struct inode *inode,
2382 struct btrfs_path *path,
2383 struct btrfs_path *dst_path)
2384{
2385 u64 min_key;
2386 u64 max_key;
2387 int ret;
2388 int key_type = BTRFS_DIR_ITEM_KEY;
2389
2390again:
2391 min_key = 0;
2392 max_key = 0;
2393 while(1) {
2394 ret = log_dir_items(trans, root, inode, path,
2395 dst_path, key_type, min_key,
2396 &max_key);
2397 BUG_ON(ret);
2398 if (max_key == (u64)-1)
2399 break;
2400 min_key = max_key + 1;
2401 }
2402
2403 if (key_type == BTRFS_DIR_ITEM_KEY) {
2404 key_type = BTRFS_DIR_INDEX_KEY;
2405 goto again;
2406 }
2407 return 0;
2408}
2409
2410/*
2411 * a helper function to drop items from the log before we relog an
2412 * inode. max_key_type indicates the highest item type to remove.
2413 * This cannot be run for file data extents because it does not
2414 * free the extents they point to.
2415 */
2416static int drop_objectid_items(struct btrfs_trans_handle *trans,
2417 struct btrfs_root *log,
2418 struct btrfs_path *path,
2419 u64 objectid, int max_key_type)
2420{
2421 int ret;
2422 struct btrfs_key key;
2423 struct btrfs_key found_key;
2424
2425 key.objectid = objectid;
2426 key.type = max_key_type;
2427 key.offset = (u64)-1;
2428
2429 while(1) {
2430 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2431
2432 if (ret != 1)
2433 break;
2434
2435 if (path->slots[0] == 0)
2436 break;
2437
2438 path->slots[0]--;
2439 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2440 path->slots[0]);
2441
2442 if (found_key.objectid != objectid)
2443 break;
2444
2445 ret = btrfs_del_item(trans, log, path);
2446 BUG_ON(ret);
2447 btrfs_release_path(log, path);
2448 }
2449 btrfs_release_path(log, path);
2450 return 0;
2451}
2452
2453/* log a single inode in the tree log.
2454 * At least one parent directory for this inode must exist in the tree
2455 * or be logged already.
2456 *
2457 * Any items from this inode changed by the current transaction are copied
2458 * to the log tree. An extra reference is taken on any extents in this
2459 * file, allowing us to avoid a whole pile of corner cases around logging
2460 * blocks that have been removed from the tree.
2461 *
2462 * See LOG_INODE_ALL and related defines for a description of what inode_only
2463 * does.
2464 *
2465 * This handles both files and directories.
2466 */
2467static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
2468 struct btrfs_root *root, struct inode *inode,
2469 int inode_only)
2470{
2471 struct btrfs_path *path;
2472 struct btrfs_path *dst_path;
2473 struct btrfs_key min_key;
2474 struct btrfs_key max_key;
2475 struct btrfs_root *log = root->log_root;
2476 unsigned long src_offset;
2477 unsigned long dst_offset;
2478 struct extent_buffer *src;
2479 struct btrfs_file_extent_item *extent;
2480 struct btrfs_inode_item *inode_item;
2481 u32 size;
2482 int ret;
2483
2484 log = root->log_root;
2485
2486 path = btrfs_alloc_path();
2487 dst_path = btrfs_alloc_path();
2488
2489 min_key.objectid = inode->i_ino;
2490 min_key.type = BTRFS_INODE_ITEM_KEY;
2491 min_key.offset = 0;
2492
2493 max_key.objectid = inode->i_ino;
2494 if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
2495 max_key.type = BTRFS_XATTR_ITEM_KEY;
2496 else
2497 max_key.type = (u8)-1;
2498 max_key.offset = (u64)-1;
2499
2500 /*
2501 * if this inode has already been logged and we're in inode_only
2502 * mode, we don't want to delete the things that have already
2503 * been written to the log.
2504 *
2505 * But, if the inode has been through an inode_only log,
2506 * the logged_trans field is not set. This allows us to catch
2507 * any new names for this inode in the backrefs by logging it
2508 * again
2509 */
2510 if (inode_only == LOG_INODE_EXISTS &&
2511 BTRFS_I(inode)->logged_trans == trans->transid) {
2512 btrfs_free_path(path);
2513 btrfs_free_path(dst_path);
2514 goto out;
2515 }
2516 mutex_lock(&BTRFS_I(inode)->log_mutex);
2517
2518 /*
2519 * a brute force approach to making sure we get the most uptodate
2520 * copies of everything.
2521 */
2522 if (S_ISDIR(inode->i_mode)) {
2523 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
2524
2525 if (inode_only == LOG_INODE_EXISTS)
2526 max_key_type = BTRFS_XATTR_ITEM_KEY;
2527 ret = drop_objectid_items(trans, log, path,
2528 inode->i_ino, max_key_type);
2529 } else {
2530 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
2531 }
2532 BUG_ON(ret);
2533 path->keep_locks = 1;
2534
2535 while(1) {
2536 ret = btrfs_search_forward(root, &min_key, &max_key,
2537 path, 0, trans->transid);
2538 if (ret != 0)
2539 break;
2540
2541 if (min_key.objectid != inode->i_ino)
2542 break;
2543 if (min_key.type > max_key.type)
2544 break;
2545
2546 src = path->nodes[0];
2547 size = btrfs_item_size_nr(src, path->slots[0]);
2548 ret = btrfs_insert_empty_item(trans, log, dst_path, &min_key,
2549 size);
2550 if (ret)
2551 BUG();
2552
2553 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
2554 dst_path->slots[0]);
2555
2556 src_offset = btrfs_item_ptr_offset(src, path->slots[0]);
2557
2558 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
2559 src_offset, size);
2560
2561 if (inode_only == LOG_INODE_EXISTS &&
2562 min_key.type == BTRFS_INODE_ITEM_KEY) {
2563 inode_item = btrfs_item_ptr(dst_path->nodes[0],
2564 dst_path->slots[0],
2565 struct btrfs_inode_item);
2566 btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
2567
2568 /* set the generation to zero so the recover code
2569 * can tell the difference between an logging
2570 * just to say 'this inode exists' and a logging
2571 * to say 'update this inode with these values'
2572 */
2573 btrfs_set_inode_generation(dst_path->nodes[0],
2574 inode_item, 0);
2575 }
2576 /* take a reference on file data extents so that truncates
2577 * or deletes of this inode don't have to relog the inode
2578 * again
2579 */
2580 if (btrfs_key_type(&min_key) == BTRFS_EXTENT_DATA_KEY) {
2581 int found_type;
2582 extent = btrfs_item_ptr(src, path->slots[0],
2583 struct btrfs_file_extent_item);
2584
2585 found_type = btrfs_file_extent_type(src, extent);
2586 if (found_type == BTRFS_FILE_EXTENT_REG) {
2587 u64 ds = btrfs_file_extent_disk_bytenr(src,
2588 extent);
2589 u64 dl = btrfs_file_extent_disk_num_bytes(src,
2590 extent);
2591 /* ds == 0 is a hole */
2592 if (ds != 0) {
2593 ret = btrfs_inc_extent_ref(trans, log,
2594 ds, dl,
2595 log->root_key.objectid,
2596 0,
2597 inode->i_ino,
2598 min_key.offset);
2599 BUG_ON(ret);
2600 }
2601 }
2602 }
2603
2604 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2605 btrfs_release_path(root, path);
2606 btrfs_release_path(log, dst_path);
2607
2608 if (min_key.offset < (u64)-1)
2609 min_key.offset++;
2610 else if (min_key.type < (u8)-1)
2611 min_key.type++;
2612 else if (min_key.objectid < (u64)-1)
2613 min_key.objectid++;
2614 else
2615 break;
2616 }
2617 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2618 btrfs_release_path(root, path);
2619 btrfs_release_path(log, dst_path);
2620 ret = log_directory_changes(trans, root, inode, path, dst_path);
2621 BUG_ON(ret);
2622 }
2623 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2624
2625 btrfs_free_path(path);
2626 btrfs_free_path(dst_path);
2627
2628 mutex_lock(&root->fs_info->tree_log_mutex);
2629 ret = update_log_root(trans, log);
2630 BUG_ON(ret);
2631 mutex_unlock(&root->fs_info->tree_log_mutex);
2632out:
2633 return 0;
2634}
2635
2636int btrfs_log_inode(struct btrfs_trans_handle *trans,
2637 struct btrfs_root *root, struct inode *inode,
2638 int inode_only)
2639{
2640 int ret;
2641
2642 start_log_trans(trans, root);
2643 ret = __btrfs_log_inode(trans, root, inode, inode_only);
2644 end_log_trans(root);
2645 return ret;
2646}
2647
2648/*
2649 * helper function around btrfs_log_inode to make sure newly created
2650 * parent directories also end up in the log. A minimal inode and backref
2651 * only logging is done of any parent directories that are older than
2652 * the last committed transaction
2653 */
2654int btrfs_log_dentry(struct btrfs_trans_handle *trans,
2655 struct btrfs_root *root, struct dentry *dentry)
2656{
2657 int inode_only = LOG_INODE_ALL;
2658 struct super_block *sb;
2659 int ret;
2660
2661 start_log_trans(trans, root);
2662 sb = dentry->d_inode->i_sb;
2663 while(1) {
2664 ret = __btrfs_log_inode(trans, root, dentry->d_inode,
2665 inode_only);
2666 BUG_ON(ret);
2667 inode_only = LOG_INODE_EXISTS;
2668
2669 dentry = dentry->d_parent;
2670 if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
2671 break;
2672
2673 if (BTRFS_I(dentry->d_inode)->generation <=
2674 root->fs_info->last_trans_committed)
2675 break;
2676 }
2677 end_log_trans(root);
2678 return 0;
2679}
2680
2681/*
2682 * it is not safe to log dentry if the chunk root has added new
2683 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
2684 * If this returns 1, you must commit the transaction to safely get your
2685 * data on disk.
2686 */
2687int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
2688 struct btrfs_root *root, struct dentry *dentry)
2689{
2690 u64 gen;
2691 gen = root->fs_info->last_trans_new_blockgroup;
2692 if (gen > root->fs_info->last_trans_committed)
2693 return 1;
2694 else
2695 return btrfs_log_dentry(trans, root, dentry);
2696}
2697
2698/*
2699 * should be called during mount to recover any replay any log trees
2700 * from the FS
2701 */
2702int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
2703{
2704 int ret;
2705 struct btrfs_path *path;
2706 struct btrfs_trans_handle *trans;
2707 struct btrfs_key key;
2708 struct btrfs_key found_key;
2709 struct btrfs_key tmp_key;
2710 struct btrfs_root *log;
2711 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
2712 struct walk_control wc = {
2713 .process_func = process_one_buffer,
2714 .stage = 0,
2715 };
2716
2717 fs_info->log_root_recovering = 1;
2718 path = btrfs_alloc_path();
2719 BUG_ON(!path);
2720
2721 trans = btrfs_start_transaction(fs_info->tree_root, 1);
2722
2723 wc.trans = trans;
2724 wc.pin = 1;
2725
2726 walk_log_tree(trans, log_root_tree, &wc);
2727
2728again:
2729 key.objectid = BTRFS_TREE_LOG_OBJECTID;
2730 key.offset = (u64)-1;
2731 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2732
2733 while(1) {
2734 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
2735 if (ret < 0)
2736 break;
2737 if (ret > 0) {
2738 if (path->slots[0] == 0)
2739 break;
2740 path->slots[0]--;
2741 }
2742 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2743 path->slots[0]);
2744 btrfs_release_path(log_root_tree, path);
2745 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
2746 break;
2747
2748 log = btrfs_read_fs_root_no_radix(log_root_tree,
2749 &found_key);
2750 BUG_ON(!log);
2751
2752
2753 tmp_key.objectid = found_key.offset;
2754 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
2755 tmp_key.offset = (u64)-1;
2756
2757 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
2758
2759 BUG_ON(!wc.replay_dest);
2760
2761 btrfs_record_root_in_trans(wc.replay_dest);
2762 ret = walk_log_tree(trans, log, &wc);
2763 BUG_ON(ret);
2764
2765 if (wc.stage == LOG_WALK_REPLAY_ALL) {
2766 ret = fixup_inode_link_counts(trans, wc.replay_dest,
2767 path);
2768 BUG_ON(ret);
2769 }
2770
2771 key.offset = found_key.offset - 1;
2772 free_extent_buffer(log->node);
2773 kfree(log);
2774
2775 if (found_key.offset == 0)
2776 break;
2777 }
2778 btrfs_release_path(log_root_tree, path);
2779
2780 /* step one is to pin it all, step two is to replay just inodes */
2781 if (wc.pin) {
2782 wc.pin = 0;
2783 wc.process_func = replay_one_buffer;
2784 wc.stage = LOG_WALK_REPLAY_INODES;
2785 goto again;
2786 }
2787 /* step three is to replay everything */
2788 if (wc.stage < LOG_WALK_REPLAY_ALL) {
2789 wc.stage++;
2790 goto again;
2791 }
2792
2793 btrfs_free_path(path);
2794
2795 free_extent_buffer(log_root_tree->node);
2796 log_root_tree->log_root = NULL;
2797 fs_info->log_root_recovering = 0;
2798
2799 /* step 4: commit the transaction, which also unpins the blocks */
2800 btrfs_commit_transaction(trans, fs_info->tree_root);
2801
2802 kfree(log_root_tree);
2803 return 0;
2804}
generated by cgit v1.2.2 (git 2.25.0) at 2024-09-23 12:24:29 -0400