2 * Copyright (C) 2008 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/sched.h>
21 #include "transaction.h"
24 #include "print-tree.h"
27 /* magic values for the inode_only field in btrfs_log_inode:
29 * LOG_INODE_ALL means to log everything
30 * LOG_INODE_EXISTS means to log just enough to recreate the inode
33 #define LOG_INODE_ALL 0
34 #define LOG_INODE_EXISTS 1
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.
42 * The last stage is to deal with directories and links and extents
43 * and all the other fun semantics
45 #define LOG_WALK_PIN_ONLY 0
46 #define LOG_WALK_REPLAY_INODES 1
47 #define LOG_WALK_REPLAY_ALL 2
49 static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
50 struct btrfs_root *root, struct inode *inode,
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.
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.
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.
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.
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.
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).
81 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
82 struct btrfs_root *root)
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;
90 u64 objectid = root->root_key.objectid;
92 leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
93 BTRFS_TREE_LOG_OBJECTID,
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);
106 write_extent_buffer(leaf, root->fs_info->fsid,
107 (unsigned long)btrfs_header_fsid(leaf),
109 btrfs_mark_buffer_dirty(leaf);
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);
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);
124 memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
125 root_item.drop_level = 0;
127 btrfs_tree_unlock(leaf);
128 free_extent_buffer(leaf);
131 btrfs_set_root_dirid(&root_item, 0);
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,
141 new_root = btrfs_read_fs_root_no_radix(root->fs_info->log_root_tree,
145 WARN_ON(root->log_root);
146 root->log_root = new_root;
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).
154 new_root->ref_cows = 0;
155 new_root->last_trans = trans->transid;
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
165 static int start_log_trans(struct btrfs_trans_handle *trans,
166 struct btrfs_root *root)
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);
174 if (!root->log_root) {
175 ret = btrfs_add_log_tree(trans, root);
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);
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
189 static int join_running_log_trans(struct btrfs_root *root)
197 mutex_lock(&root->fs_info->tree_log_mutex);
198 if (root->log_root) {
200 atomic_inc(&root->fs_info->tree_log_writers);
201 root->fs_info->tree_log_batch++;
203 mutex_unlock(&root->fs_info->tree_log_mutex);
208 * indicate we're done making changes to the log tree
209 * and wake up anyone waiting to do a sync
211 static int end_log_trans(struct btrfs_root *root)
213 atomic_dec(&root->fs_info->tree_log_writers);
215 if (waitqueue_active(&root->fs_info->tree_log_wait))
216 wake_up(&root->fs_info->tree_log_wait);
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
227 struct 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
233 /* should we write out the extent buffer? This is used
234 * while flushing the log tree to disk during a sync
238 /* should we wait for the extent buffer io to finish? Also used
239 * while flushing the log tree to disk for a sync
243 /* pin only walk, we record which extents on disk belong to the
248 /* what stage of the replay code we're currently in */
251 /* the root we are currently replaying */
252 struct btrfs_root *replay_dest;
254 /* the trans handle for the current replay */
255 struct btrfs_trans_handle *trans;
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
262 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
263 struct walk_control *wc, u64 gen);
267 * process_func used to pin down extents, write them or wait on them
269 static int process_one_buffer(struct btrfs_root *log,
270 struct extent_buffer *eb,
271 struct walk_control *wc, u64 gen)
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);
280 if (btrfs_buffer_uptodate(eb, gen)) {
282 btrfs_write_tree_block(eb);
284 btrfs_wait_tree_block_writeback(eb);
290 * Item overwrite used by replay and tree logging. eb, slot and key all refer
291 * to the src data we are copying out.
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).
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.
301 * If the key isn't in the destination yet, a new item is inserted.
303 static 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)
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;
317 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
320 item_size = btrfs_item_size_nr(eb, slot);
321 src_ptr = btrfs_item_ptr_offset(eb, slot);
323 /* look for the key in the destination tree */
324 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
328 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
330 if (dst_size != item_size)
333 if (item_size == 0) {
334 btrfs_release_path(root, path);
337 dst_copy = kmalloc(item_size, GFP_NOFS);
338 src_copy = kmalloc(item_size, GFP_NOFS);
340 read_extent_buffer(eb, src_copy, src_ptr, item_size);
342 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
343 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
345 ret = memcmp(dst_copy, src_copy, item_size);
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
356 btrfs_release_path(root, path);
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,
367 /* make sure any existing item is the correct size */
368 if (ret == -EEXIST) {
370 found_size = btrfs_item_size_nr(path->nodes[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,
379 btrfs_release_path(root, path);
380 ret = btrfs_insert_empty_item(trans,
381 root, path, key, item_size);
387 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
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.
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
399 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
400 struct btrfs_inode_item *src_item;
401 struct btrfs_inode_item *dst_item;
403 src_item = (struct btrfs_inode_item *)src_ptr;
404 dst_item = (struct btrfs_inode_item *)dst_ptr;
406 if (btrfs_inode_generation(eb, src_item) == 0)
409 if (overwrite_root &&
410 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
411 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
413 saved_i_size = btrfs_inode_size(path->nodes[0],
418 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
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);
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,
437 btrfs_mark_buffer_dirty(path->nodes[0]);
438 btrfs_release_path(root, path);
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
446 static noinline struct inode *read_one_inode(struct btrfs_root *root,
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);
460 if (is_bad_inode(inode)) {
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
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.
476 * The extent is inserted into the file, dropping any existing extents
477 * from the file that overlap the new one.
479 static 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)
486 u64 mask = root->sectorsize - 1;
489 u64 start = key->offset;
490 struct btrfs_file_extent_item *item;
491 struct inode *inode = NULL;
495 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
496 found_type = btrfs_file_extent_type(eb, item);
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;
509 inode = read_one_inode(root, key->objectid);
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.
520 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
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;
529 leaf = path->nodes[0];
530 existing = btrfs_item_ptr(leaf, path->slots[0],
531 struct btrfs_file_extent_item);
533 read_extent_buffer(eb, &cmp1, (unsigned long)item,
535 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
539 * we already have a pointer to this exact extent,
540 * we don't have to do anything
542 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
543 btrfs_release_path(root, path);
547 btrfs_release_path(root, path);
549 /* drop any overlapping extents */
550 ret = btrfs_drop_extents(trans, root, inode,
551 start, extent_end, start, &alloc_hint);
555 if (found_type == BTRFS_FILE_EXTENT_REG) {
556 struct btrfs_key ins;
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;
562 /* insert the extent pointer in the file */
563 ret = overwrite_item(trans, root, path, eb, slot, key);
567 * is this extent already allocated in the extent
568 * allocation tree? If so, just add a reference
570 ret = btrfs_lookup_extent(root, path, ins.objectid, ins.offset);
571 btrfs_release_path(root, path);
573 ret = btrfs_inc_extent_ref(trans, root,
574 ins.objectid, ins.offset,
575 root->root_key.objectid,
576 trans->transid, key->objectid, start);
579 * insert the extent pointer in the extent
582 ret = btrfs_alloc_logged_extent(trans, root,
583 root->root_key.objectid,
584 trans->transid, key->objectid,
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);
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);
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.
607 * This is a helper function to do the unlink of a specific directory
610 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
611 struct btrfs_root *root,
612 struct btrfs_path *path,
614 struct btrfs_dir_item *di)
619 struct extent_buffer *leaf;
620 struct btrfs_key location;
623 leaf = path->nodes[0];
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);
631 inode = read_one_inode(root, location.objectid);
634 btrfs_inc_nlink(inode);
635 ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
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
647 static 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)
652 struct btrfs_dir_item *di;
653 struct btrfs_key location;
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)
664 btrfs_release_path(root, path);
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)
675 btrfs_release_path(root, path);
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.
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.
689 static noinline int backref_in_log(struct btrfs_root *log,
690 struct btrfs_key *key,
691 char *name, int namelen)
693 struct btrfs_path *path;
694 struct btrfs_inode_ref *ref;
696 unsigned long ptr_end;
697 unsigned long name_ptr;
703 path = btrfs_alloc_path();
704 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
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,
723 ptr = (unsigned long)(ref + 1) + found_name_len;
726 btrfs_free_path(path);
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).
737 static 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)
746 struct btrfs_key location;
747 struct btrfs_inode_ref *ref;
748 struct btrfs_dir_item *di;
752 unsigned long ref_ptr;
753 unsigned long ref_end;
755 location.objectid = key->objectid;
756 location.type = BTRFS_INODE_ITEM_KEY;
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
765 dir = read_one_inode(root, key->offset);
769 inode = read_one_inode(root, key->objectid);
772 ref_ptr = btrfs_item_ptr_offset(eb, slot);
773 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
776 ref = (struct btrfs_inode_ref *)ref_ptr;
778 namelen = btrfs_inode_ref_name_len(eb, ref);
779 name = kmalloc(namelen, GFP_NOFS);
782 read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
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),
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.
799 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
803 struct btrfs_inode_ref *victim_ref;
805 unsigned long ptr_end;
806 struct extent_buffer *leaf = path->nodes[0];
808 /* are we trying to overwrite a back ref for the root directory
809 * if so, just jump out, we're done
811 if (key->objectid == key->offset)
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
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,
824 victim_name = kmalloc(victim_name_len, GFP_NOFS);
825 BUG_ON(!victim_name);
827 read_extent_buffer(leaf, victim_name,
828 (unsigned long)(victim_ref + 1),
831 if (!backref_in_log(log, key, victim_name,
833 btrfs_inc_nlink(inode);
834 btrfs_release_path(root, path);
835 ret = btrfs_unlink_inode(trans, root, dir,
839 btrfs_release_path(root, path);
843 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
847 btrfs_release_path(root, path);
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),
853 if (di && !IS_ERR(di)) {
854 ret = drop_one_dir_item(trans, root, path, dir, di);
857 btrfs_release_path(root, path);
860 /* look for a conflicting name */
861 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
863 if (di && !IS_ERR(di)) {
864 ret = drop_one_dir_item(trans, root, path, dir, di);
867 btrfs_release_path(root, path);
869 /* insert our name */
870 ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
871 btrfs_inode_ref_index(eb, ref));
874 btrfs_update_inode(trans, root, inode);
877 ref_ptr = (unsigned long)(ref + 1) + namelen;
879 if (ref_ptr < ref_end)
882 /* finally write the back reference in the inode */
883 ret = overwrite_item(trans, root, path, eb, slot, key);
887 btrfs_release_path(root, path);
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
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.
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
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.
911 static 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)
918 u32 item_size = btrfs_item_size_nr(eb, slot);
920 unsigned long file_bytes;
921 struct btrfs_ordered_sum *sums;
922 struct btrfs_sector_sum *sector_sum;
926 file_bytes = (item_size / BTRFS_CRC32_SIZE) * root->sectorsize;
927 inode = read_one_inode(root, key->objectid);
932 sums = kzalloc(btrfs_ordered_sum_size(root, file_bytes), GFP_NOFS);
938 INIT_LIST_HEAD(&sums->list);
939 sums->len = file_bytes;
940 sums->file_offset = key->offset;
943 * copy all the sums into the ordered sum struct
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, §or_sum->sum, ptr, BTRFS_CRC32_SIZE);
952 item_size -= BTRFS_CRC32_SIZE;
953 ptr += BTRFS_CRC32_SIZE;
954 cur_offset += root->sectorsize;
957 /* let btrfs_csum_file_blocks add them into the file */
958 ret = btrfs_csum_file_blocks(trans, root, inode, sums);
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.
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.
975 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
976 struct btrfs_root *root,
979 struct btrfs_path *path;
981 struct btrfs_key key;
984 unsigned long ptr_end;
987 key.objectid = inode->i_ino;
988 key.type = BTRFS_INODE_REF_KEY;
989 key.offset = (u64)-1;
991 path = btrfs_alloc_path();
994 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
998 if (path->slots[0] == 0)
1002 btrfs_item_key_to_cpu(path->nodes[0], &key,
1004 if (key.objectid != inode->i_ino ||
1005 key.type != BTRFS_INODE_REF_KEY)
1007 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1008 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1010 while(ptr < ptr_end) {
1011 struct btrfs_inode_ref *ref;
1013 ref = (struct btrfs_inode_ref *)ptr;
1014 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1016 ptr = (unsigned long)(ref + 1) + name_len;
1020 if (key.offset == 0)
1023 btrfs_release_path(root, path);
1025 btrfs_free_path(path);
1026 if (nlink != inode->i_nlink) {
1027 inode->i_nlink = nlink;
1028 btrfs_update_inode(trans, root, inode);
1034 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1035 struct btrfs_root *root,
1036 struct btrfs_path *path)
1039 struct btrfs_key key;
1040 struct inode *inode;
1042 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1043 key.type = BTRFS_ORPHAN_ITEM_KEY;
1044 key.offset = (u64)-1;
1046 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1051 if (path->slots[0] == 0)
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)
1061 ret = btrfs_del_item(trans, root, path);
1064 btrfs_release_path(root, path);
1065 inode = read_one_inode(root, key.offset);
1068 ret = fixup_inode_link_count(trans, root, inode);
1073 if (key.offset == 0)
1077 btrfs_release_path(root, path);
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
1087 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1088 struct btrfs_root *root,
1089 struct btrfs_path *path,
1092 struct btrfs_key key;
1094 struct inode *inode;
1096 inode = read_one_inode(root, objectid);
1099 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1100 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1101 key.offset = objectid;
1103 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1105 btrfs_release_path(root, path);
1107 btrfs_inc_nlink(inode);
1108 btrfs_update_inode(trans, root, inode);
1109 } else if (ret == -EEXIST) {
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
1124 static 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)
1131 struct inode *inode;
1135 inode = read_one_inode(root, location->objectid);
1139 dir = read_one_inode(root, dirid);
1144 ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1146 /* FIXME, put inode into FIXUP list */
1154 * take a single entry in a log directory item and replay it into
1157 * if a conflicting item exists in the subdirectory already,
1158 * the inode it points to is unlinked and put into the link count
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.
1166 static 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)
1175 struct btrfs_dir_item *dst_di;
1176 struct btrfs_key found_key;
1177 struct btrfs_key log_key;
1183 dir = read_one_inode(root, key->objectid);
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),
1192 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1193 exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1198 btrfs_release_path(root, path);
1200 if (key->type == BTRFS_DIR_ITEM_KEY) {
1201 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1204 else if (key->type == BTRFS_DIR_INDEX_KEY) {
1205 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1212 if (!dst_di || IS_ERR(dst_di)) {
1213 /* we need a sequence number to insert, so we only
1214 * do inserts for the BTRFS_DIR_INDEX_KEY types
1216 if (key->type != BTRFS_DIR_INDEX_KEY)
1221 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1222 /* the existing item matches the logged item */
1223 if (found_key.objectid == log_key.objectid &&
1224 found_key.type == log_key.type &&
1225 found_key.offset == log_key.offset &&
1226 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1231 * don't drop the conflicting directory entry if the inode
1232 * for the new entry doesn't exist
1237 ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1240 if (key->type == BTRFS_DIR_INDEX_KEY)
1243 btrfs_release_path(root, path);
1249 btrfs_release_path(root, path);
1250 ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1251 name, name_len, log_type, &log_key);
1253 if (ret && ret != -ENOENT)
1259 * find all the names in a directory item and reconcile them into
1260 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
1261 * one name in a directory item, but the same code gets used for
1262 * both directory index types
1264 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1265 struct btrfs_root *root,
1266 struct btrfs_path *path,
1267 struct extent_buffer *eb, int slot,
1268 struct btrfs_key *key)
1271 u32 item_size = btrfs_item_size_nr(eb, slot);
1272 struct btrfs_dir_item *di;
1275 unsigned long ptr_end;
1277 ptr = btrfs_item_ptr_offset(eb, slot);
1278 ptr_end = ptr + item_size;
1279 while(ptr < ptr_end) {
1280 di = (struct btrfs_dir_item *)ptr;
1281 name_len = btrfs_dir_name_len(eb, di);
1282 ret = replay_one_name(trans, root, path, eb, di, key);
1284 ptr = (unsigned long)(di + 1);
1291 * directory replay has two parts. There are the standard directory
1292 * items in the log copied from the subvolume, and range items
1293 * created in the log while the subvolume was logged.
1295 * The range items tell us which parts of the key space the log
1296 * is authoritative for. During replay, if a key in the subvolume
1297 * directory is in a logged range item, but not actually in the log
1298 * that means it was deleted from the directory before the fsync
1299 * and should be removed.
1301 static noinline int find_dir_range(struct btrfs_root *root,
1302 struct btrfs_path *path,
1303 u64 dirid, int key_type,
1304 u64 *start_ret, u64 *end_ret)
1306 struct btrfs_key key;
1308 struct btrfs_dir_log_item *item;
1312 if (*start_ret == (u64)-1)
1315 key.objectid = dirid;
1316 key.type = key_type;
1317 key.offset = *start_ret;
1319 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1323 if (path->slots[0] == 0)
1328 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1330 if (key.type != key_type || key.objectid != dirid) {
1334 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1335 struct btrfs_dir_log_item);
1336 found_end = btrfs_dir_log_end(path->nodes[0], item);
1338 if (*start_ret >= key.offset && *start_ret <= found_end) {
1340 *start_ret = key.offset;
1341 *end_ret = found_end;
1346 /* check the next slot in the tree to see if it is a valid item */
1347 nritems = btrfs_header_nritems(path->nodes[0]);
1348 if (path->slots[0] >= nritems) {
1349 ret = btrfs_next_leaf(root, path);
1356 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1358 if (key.type != key_type || key.objectid != dirid) {
1362 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1363 struct btrfs_dir_log_item);
1364 found_end = btrfs_dir_log_end(path->nodes[0], item);
1365 *start_ret = key.offset;
1366 *end_ret = found_end;
1369 btrfs_release_path(root, path);
1374 * this looks for a given directory item in the log. If the directory
1375 * item is not in the log, the item is removed and the inode it points
1378 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1379 struct btrfs_root *root,
1380 struct btrfs_root *log,
1381 struct btrfs_path *path,
1382 struct btrfs_path *log_path,
1384 struct btrfs_key *dir_key)
1387 struct extent_buffer *eb;
1390 struct btrfs_dir_item *di;
1391 struct btrfs_dir_item *log_di;
1394 unsigned long ptr_end;
1396 struct inode *inode;
1397 struct btrfs_key location;
1400 eb = path->nodes[0];
1401 slot = path->slots[0];
1402 item_size = btrfs_item_size_nr(eb, slot);
1403 ptr = btrfs_item_ptr_offset(eb, slot);
1404 ptr_end = ptr + item_size;
1405 while(ptr < ptr_end) {
1406 di = (struct btrfs_dir_item *)ptr;
1407 name_len = btrfs_dir_name_len(eb, di);
1408 name = kmalloc(name_len, GFP_NOFS);
1413 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1416 if (dir_key->type == BTRFS_DIR_ITEM_KEY) {
1417 log_di = btrfs_lookup_dir_item(trans, log, log_path,
1420 } else if (dir_key->type == BTRFS_DIR_INDEX_KEY) {
1421 log_di = btrfs_lookup_dir_index_item(trans, log,
1427 if (!log_di || IS_ERR(log_di)) {
1428 btrfs_dir_item_key_to_cpu(eb, di, &location);
1429 btrfs_release_path(root, path);
1430 btrfs_release_path(log, log_path);
1431 inode = read_one_inode(root, location.objectid);
1434 ret = link_to_fixup_dir(trans, root,
1435 path, location.objectid);
1437 btrfs_inc_nlink(inode);
1438 ret = btrfs_unlink_inode(trans, root, dir, inode,
1444 /* there might still be more names under this key
1445 * check and repeat if required
1447 ret = btrfs_search_slot(NULL, root, dir_key, path,
1454 btrfs_release_path(log, log_path);
1457 ptr = (unsigned long)(di + 1);
1462 btrfs_release_path(root, path);
1463 btrfs_release_path(log, log_path);
1468 * deletion replay happens before we copy any new directory items
1469 * out of the log or out of backreferences from inodes. It
1470 * scans the log to find ranges of keys that log is authoritative for,
1471 * and then scans the directory to find items in those ranges that are
1472 * not present in the log.
1474 * Anything we don't find in the log is unlinked and removed from the
1477 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1478 struct btrfs_root *root,
1479 struct btrfs_root *log,
1480 struct btrfs_path *path,
1485 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1487 struct btrfs_key dir_key;
1488 struct btrfs_key found_key;
1489 struct btrfs_path *log_path;
1492 dir_key.objectid = dirid;
1493 dir_key.type = BTRFS_DIR_ITEM_KEY;
1494 log_path = btrfs_alloc_path();
1498 dir = read_one_inode(root, dirid);
1499 /* it isn't an error if the inode isn't there, that can happen
1500 * because we replay the deletes before we copy in the inode item
1504 btrfs_free_path(log_path);
1511 ret = find_dir_range(log, path, dirid, key_type,
1512 &range_start, &range_end);
1516 dir_key.offset = range_start;
1519 ret = btrfs_search_slot(NULL, root, &dir_key, path,
1524 nritems = btrfs_header_nritems(path->nodes[0]);
1525 if (path->slots[0] >= nritems) {
1526 ret = btrfs_next_leaf(root, path);
1530 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1532 if (found_key.objectid != dirid ||
1533 found_key.type != dir_key.type)
1536 if (found_key.offset > range_end)
1539 ret = check_item_in_log(trans, root, log, path,
1540 log_path, dir, &found_key);
1542 if (found_key.offset == (u64)-1)
1544 dir_key.offset = found_key.offset + 1;
1546 btrfs_release_path(root, path);
1547 if (range_end == (u64)-1)
1549 range_start = range_end + 1;
1554 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1555 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1556 dir_key.type = BTRFS_DIR_INDEX_KEY;
1557 btrfs_release_path(root, path);
1561 btrfs_release_path(root, path);
1562 btrfs_free_path(log_path);
1568 * the process_func used to replay items from the log tree. This
1569 * gets called in two different stages. The first stage just looks
1570 * for inodes and makes sure they are all copied into the subvolume.
1572 * The second stage copies all the other item types from the log into
1573 * the subvolume. The two stage approach is slower, but gets rid of
1574 * lots of complexity around inodes referencing other inodes that exist
1575 * only in the log (references come from either directory items or inode
1578 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1579 struct walk_control *wc, u64 gen)
1582 struct btrfs_path *path;
1583 struct btrfs_root *root = wc->replay_dest;
1584 struct btrfs_key key;
1590 btrfs_read_buffer(eb, gen);
1592 level = btrfs_header_level(eb);
1597 path = btrfs_alloc_path();
1600 nritems = btrfs_header_nritems(eb);
1601 for (i = 0; i < nritems; i++) {
1602 btrfs_item_key_to_cpu(eb, &key, i);
1603 item_size = btrfs_item_size_nr(eb, i);
1605 /* inode keys are done during the first stage */
1606 if (key.type == BTRFS_INODE_ITEM_KEY &&
1607 wc->stage == LOG_WALK_REPLAY_INODES) {
1608 struct inode *inode;
1609 struct btrfs_inode_item *inode_item;
1612 inode_item = btrfs_item_ptr(eb, i,
1613 struct btrfs_inode_item);
1614 mode = btrfs_inode_mode(eb, inode_item);
1615 if (S_ISDIR(mode)) {
1616 ret = replay_dir_deletes(wc->trans,
1617 root, log, path, key.objectid);
1620 ret = overwrite_item(wc->trans, root, path,
1624 /* for regular files, truncate away
1625 * extents past the new EOF
1627 if (S_ISREG(mode)) {
1628 inode = read_one_inode(root,
1632 ret = btrfs_truncate_inode_items(wc->trans,
1633 root, inode, inode->i_size,
1634 BTRFS_EXTENT_DATA_KEY);
1638 ret = link_to_fixup_dir(wc->trans, root,
1639 path, key.objectid);
1642 if (wc->stage < LOG_WALK_REPLAY_ALL)
1645 /* these keys are simply copied */
1646 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1647 ret = overwrite_item(wc->trans, root, path,
1650 } else if (key.type == BTRFS_INODE_REF_KEY) {
1651 ret = add_inode_ref(wc->trans, root, log, path,
1653 BUG_ON(ret && ret != -ENOENT);
1654 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1655 ret = replay_one_extent(wc->trans, root, path,
1658 } else if (key.type == BTRFS_CSUM_ITEM_KEY) {
1659 ret = replay_one_csum(wc->trans, root, path,
1662 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1663 key.type == BTRFS_DIR_INDEX_KEY) {
1664 ret = replay_one_dir_item(wc->trans, root, path,
1669 btrfs_free_path(path);
1673 static int noinline walk_down_log_tree(struct btrfs_trans_handle *trans,
1674 struct btrfs_root *root,
1675 struct btrfs_path *path, int *level,
1676 struct walk_control *wc)
1682 struct extent_buffer *next;
1683 struct extent_buffer *cur;
1684 struct extent_buffer *parent;
1688 WARN_ON(*level < 0);
1689 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1692 WARN_ON(*level < 0);
1693 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1694 cur = path->nodes[*level];
1696 if (btrfs_header_level(cur) != *level)
1699 if (path->slots[*level] >=
1700 btrfs_header_nritems(cur))
1703 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1704 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1705 blocksize = btrfs_level_size(root, *level - 1);
1707 parent = path->nodes[*level];
1708 root_owner = btrfs_header_owner(parent);
1709 root_gen = btrfs_header_generation(parent);
1711 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1713 wc->process_func(root, next, wc, ptr_gen);
1716 path->slots[*level]++;
1718 btrfs_read_buffer(next, ptr_gen);
1720 btrfs_tree_lock(next);
1721 clean_tree_block(trans, root, next);
1722 btrfs_wait_tree_block_writeback(next);
1723 btrfs_tree_unlock(next);
1725 ret = btrfs_drop_leaf_ref(trans, root, next);
1728 WARN_ON(root_owner !=
1729 BTRFS_TREE_LOG_OBJECTID);
1730 ret = btrfs_free_extent(trans, root, bytenr,
1731 blocksize, root_owner,
1735 free_extent_buffer(next);
1738 btrfs_read_buffer(next, ptr_gen);
1740 WARN_ON(*level <= 0);
1741 if (path->nodes[*level-1])
1742 free_extent_buffer(path->nodes[*level-1]);
1743 path->nodes[*level-1] = next;
1744 *level = btrfs_header_level(next);
1745 path->slots[*level] = 0;
1748 WARN_ON(*level < 0);
1749 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1751 if (path->nodes[*level] == root->node) {
1752 parent = path->nodes[*level];
1754 parent = path->nodes[*level + 1];
1756 bytenr = path->nodes[*level]->start;
1758 blocksize = btrfs_level_size(root, *level);
1759 root_owner = btrfs_header_owner(parent);
1760 root_gen = btrfs_header_generation(parent);
1762 wc->process_func(root, path->nodes[*level], wc,
1763 btrfs_header_generation(path->nodes[*level]));
1766 next = path->nodes[*level];
1767 btrfs_tree_lock(next);
1768 clean_tree_block(trans, root, next);
1769 btrfs_wait_tree_block_writeback(next);
1770 btrfs_tree_unlock(next);
1773 ret = btrfs_drop_leaf_ref(trans, root, next);
1776 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1777 ret = btrfs_free_extent(trans, root, bytenr, blocksize,
1778 root_owner, root_gen, 0, 0, 1);
1781 free_extent_buffer(path->nodes[*level]);
1782 path->nodes[*level] = NULL;
1789 static int noinline walk_up_log_tree(struct btrfs_trans_handle *trans,
1790 struct btrfs_root *root,
1791 struct btrfs_path *path, int *level,
1792 struct walk_control *wc)
1800 for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1801 slot = path->slots[i];
1802 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1803 struct extent_buffer *node;
1804 node = path->nodes[i];
1807 WARN_ON(*level == 0);
1810 if (path->nodes[*level] == root->node) {
1811 root_owner = root->root_key.objectid;
1813 btrfs_header_generation(path->nodes[*level]);
1815 struct extent_buffer *node;
1816 node = path->nodes[*level + 1];
1817 root_owner = btrfs_header_owner(node);
1818 root_gen = btrfs_header_generation(node);
1820 wc->process_func(root, path->nodes[*level], wc,
1821 btrfs_header_generation(path->nodes[*level]));
1823 struct extent_buffer *next;
1825 next = path->nodes[*level];
1827 btrfs_tree_lock(next);
1828 clean_tree_block(trans, root, next);
1829 btrfs_wait_tree_block_writeback(next);
1830 btrfs_tree_unlock(next);
1833 ret = btrfs_drop_leaf_ref(trans, root,
1838 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1839 ret = btrfs_free_extent(trans, root,
1840 path->nodes[*level]->start,
1841 path->nodes[*level]->len,
1842 root_owner, root_gen, 0, 0, 1);
1845 free_extent_buffer(path->nodes[*level]);
1846 path->nodes[*level] = NULL;
1854 * drop the reference count on the tree rooted at 'snap'. This traverses
1855 * the tree freeing any blocks that have a ref count of zero after being
1858 static int walk_log_tree(struct btrfs_trans_handle *trans,
1859 struct btrfs_root *log, struct walk_control *wc)
1864 struct btrfs_path *path;
1868 path = btrfs_alloc_path();
1871 level = btrfs_header_level(log->node);
1873 path->nodes[level] = log->node;
1874 extent_buffer_get(log->node);
1875 path->slots[level] = 0;
1878 wret = walk_down_log_tree(trans, log, path, &level, wc);
1884 wret = walk_up_log_tree(trans, log, path, &level, wc);
1891 /* was the root node processed? if not, catch it here */
1892 if (path->nodes[orig_level]) {
1893 wc->process_func(log, path->nodes[orig_level], wc,
1894 btrfs_header_generation(path->nodes[orig_level]));
1896 struct extent_buffer *next;
1898 next = path->nodes[orig_level];
1900 btrfs_tree_lock(next);
1901 clean_tree_block(trans, log, next);
1902 btrfs_wait_tree_block_writeback(next);
1903 btrfs_tree_unlock(next);
1905 if (orig_level == 0) {
1906 ret = btrfs_drop_leaf_ref(trans, log,
1910 WARN_ON(log->root_key.objectid !=
1911 BTRFS_TREE_LOG_OBJECTID);
1912 ret = btrfs_free_extent(trans, log,
1913 next->start, next->len,
1914 log->root_key.objectid,
1915 btrfs_header_generation(next),
1921 for (i = 0; i <= orig_level; i++) {
1922 if (path->nodes[i]) {
1923 free_extent_buffer(path->nodes[i]);
1924 path->nodes[i] = NULL;
1927 btrfs_free_path(path);
1929 free_extent_buffer(log->node);
1933 int wait_log_commit(struct btrfs_root *log)
1936 u64 transid = log->fs_info->tree_log_transid;
1939 prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
1940 TASK_UNINTERRUPTIBLE);
1941 mutex_unlock(&log->fs_info->tree_log_mutex);
1942 if (atomic_read(&log->fs_info->tree_log_commit))
1944 finish_wait(&log->fs_info->tree_log_wait, &wait);
1945 mutex_lock(&log->fs_info->tree_log_mutex);
1946 } while(transid == log->fs_info->tree_log_transid &&
1947 atomic_read(&log->fs_info->tree_log_commit));
1952 * btrfs_sync_log does sends a given tree log down to the disk and
1953 * updates the super blocks to record it. When this call is done,
1954 * you know that any inodes previously logged are safely on disk
1956 int btrfs_sync_log(struct btrfs_trans_handle *trans,
1957 struct btrfs_root *root)
1960 unsigned long batch;
1961 struct btrfs_root *log = root->log_root;
1962 struct walk_control wc = {
1964 .process_func = process_one_buffer
1967 mutex_lock(&log->fs_info->tree_log_mutex);
1968 if (atomic_read(&log->fs_info->tree_log_commit)) {
1969 wait_log_commit(log);
1972 atomic_set(&log->fs_info->tree_log_commit, 1);
1975 mutex_unlock(&log->fs_info->tree_log_mutex);
1976 schedule_timeout_uninterruptible(1);
1977 mutex_lock(&log->fs_info->tree_log_mutex);
1978 batch = log->fs_info->tree_log_batch;
1980 while(atomic_read(&log->fs_info->tree_log_writers)) {
1982 prepare_to_wait(&log->fs_info->tree_log_wait, &wait,
1983 TASK_UNINTERRUPTIBLE);
1984 batch = log->fs_info->tree_log_batch;
1985 mutex_unlock(&log->fs_info->tree_log_mutex);
1986 if (atomic_read(&log->fs_info->tree_log_writers))
1988 mutex_lock(&log->fs_info->tree_log_mutex);
1989 finish_wait(&log->fs_info->tree_log_wait, &wait);
1991 if (batch == log->fs_info->tree_log_batch)
1994 ret = walk_log_tree(trans, log, &wc);
1997 ret = walk_log_tree(trans, log->fs_info->log_root_tree, &wc);
2002 ret = walk_log_tree(trans, log, &wc);
2005 ret = walk_log_tree(trans, log->fs_info->log_root_tree, &wc);
2008 btrfs_set_super_log_root(&root->fs_info->super_for_commit,
2009 log->fs_info->log_root_tree->node->start);
2010 btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
2011 btrfs_header_level(log->fs_info->log_root_tree->node));
2013 write_ctree_super(trans, log->fs_info->tree_root);
2014 log->fs_info->tree_log_transid++;
2015 log->fs_info->tree_log_batch = 0;
2016 atomic_set(&log->fs_info->tree_log_commit, 0);
2018 if (waitqueue_active(&log->fs_info->tree_log_wait))
2019 wake_up(&log->fs_info->tree_log_wait);
2021 mutex_unlock(&log->fs_info->tree_log_mutex);
2027 * free all the extents used by the tree log. This should be called
2028 * at commit time of the full transaction
2030 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2033 struct btrfs_root *log;
2035 struct walk_control wc = {
2037 .process_func = process_one_buffer
2040 if (!root->log_root)
2043 log = root->log_root;
2044 ret = walk_log_tree(trans, log, &wc);
2047 log = root->log_root;
2048 ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
2051 root->log_root = NULL;
2052 kfree(root->log_root);
2057 * helper function to update the item for a given subvolumes log root
2058 * in the tree of log roots
2060 static int update_log_root(struct btrfs_trans_handle *trans,
2061 struct btrfs_root *log)
2063 u64 bytenr = btrfs_root_bytenr(&log->root_item);
2066 if (log->node->start == bytenr)
2069 btrfs_set_root_bytenr(&log->root_item, log->node->start);
2070 btrfs_set_root_level(&log->root_item, btrfs_header_level(log->node));
2071 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
2072 &log->root_key, &log->root_item);
2078 * If both a file and directory are logged, and unlinks or renames are
2079 * mixed in, we have a few interesting corners:
2081 * create file X in dir Y
2082 * link file X to X.link in dir Y
2084 * unlink file X but leave X.link
2087 * After a crash we would expect only X.link to exist. But file X
2088 * didn't get fsync'd again so the log has back refs for X and X.link.
2090 * We solve this by removing directory entries and inode backrefs from the
2091 * log when a file that was logged in the current transaction is
2092 * unlinked. Any later fsync will include the updated log entries, and
2093 * we'll be able to reconstruct the proper directory items from backrefs.
2095 * This optimizations allows us to avoid relogging the entire inode
2096 * or the entire directory.
2098 int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2099 struct btrfs_root *root,
2100 const char *name, int name_len,
2101 struct inode *dir, u64 index)
2103 struct btrfs_root *log;
2104 struct btrfs_dir_item *di;
2105 struct btrfs_path *path;
2109 ret = join_running_log_trans(root);
2113 mutex_lock(&BTRFS_I(dir)->log_mutex);
2115 log = root->log_root;
2116 path = btrfs_alloc_path();
2117 di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
2118 name, name_len, -1);
2119 if (di && !IS_ERR(di)) {
2120 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2121 bytes_del += name_len;
2124 btrfs_release_path(log, path);
2125 di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
2126 index, name, name_len, -1);
2127 if (di && !IS_ERR(di)) {
2128 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2129 bytes_del += name_len;
2133 /* update the directory size in the log to reflect the names
2137 struct btrfs_key key;
2139 key.objectid = dir->i_ino;
2141 key.type = BTRFS_INODE_ITEM_KEY;
2142 btrfs_release_path(log, path);
2144 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2146 struct btrfs_inode_item *item;
2149 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2150 struct btrfs_inode_item);
2151 i_size = btrfs_inode_size(path->nodes[0], item);
2152 if (i_size > bytes_del)
2153 i_size -= bytes_del;
2156 btrfs_set_inode_size(path->nodes[0], item, i_size);
2157 btrfs_mark_buffer_dirty(path->nodes[0]);
2160 btrfs_release_path(log, path);
2163 btrfs_free_path(path);
2164 mutex_unlock(&BTRFS_I(dir)->log_mutex);
2165 end_log_trans(root);
2170 /* see comments for btrfs_del_dir_entries_in_log */
2171 int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2172 struct btrfs_root *root,
2173 const char *name, int name_len,
2174 struct inode *inode, u64 dirid)
2176 struct btrfs_root *log;
2180 ret = join_running_log_trans(root);
2183 log = root->log_root;
2184 mutex_lock(&BTRFS_I(inode)->log_mutex);
2186 ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
2188 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2189 end_log_trans(root);
2191 if (ret == 0 || ret == -ENOENT)
2197 * creates a range item in the log for 'dirid'. first_offset and
2198 * last_offset tell us which parts of the key space the log should
2199 * be considered authoritative for.
2201 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2202 struct btrfs_root *log,
2203 struct btrfs_path *path,
2204 int key_type, u64 dirid,
2205 u64 first_offset, u64 last_offset)
2208 struct btrfs_key key;
2209 struct btrfs_dir_log_item *item;
2211 key.objectid = dirid;
2212 key.offset = first_offset;
2213 if (key_type == BTRFS_DIR_ITEM_KEY)
2214 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2216 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2217 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2220 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2221 struct btrfs_dir_log_item);
2222 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2223 btrfs_mark_buffer_dirty(path->nodes[0]);
2224 btrfs_release_path(log, path);
2229 * log all the items included in the current transaction for a given
2230 * directory. This also creates the range items in the log tree required
2231 * to replay anything deleted before the fsync
2233 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2234 struct btrfs_root *root, struct inode *inode,
2235 struct btrfs_path *path,
2236 struct btrfs_path *dst_path, int key_type,
2237 u64 min_offset, u64 *last_offset_ret)
2239 struct btrfs_key min_key;
2240 struct btrfs_key max_key;
2241 struct btrfs_root *log = root->log_root;
2242 struct extent_buffer *src;
2246 u64 first_offset = min_offset;
2247 u64 last_offset = (u64)-1;
2249 log = root->log_root;
2250 max_key.objectid = inode->i_ino;
2251 max_key.offset = (u64)-1;
2252 max_key.type = key_type;
2254 min_key.objectid = inode->i_ino;
2255 min_key.type = key_type;
2256 min_key.offset = min_offset;
2258 path->keep_locks = 1;
2260 ret = btrfs_search_forward(root, &min_key, &max_key,
2261 path, 0, trans->transid);
2264 * we didn't find anything from this transaction, see if there
2265 * is anything at all
2267 if (ret != 0 || min_key.objectid != inode->i_ino ||
2268 min_key.type != key_type) {
2269 min_key.objectid = inode->i_ino;
2270 min_key.type = key_type;
2271 min_key.offset = (u64)-1;
2272 btrfs_release_path(root, path);
2273 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2275 btrfs_release_path(root, path);
2278 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2280 /* if ret == 0 there are items for this type,
2281 * create a range to tell us the last key of this type.
2282 * otherwise, there are no items in this directory after
2283 * *min_offset, and we create a range to indicate that.
2286 struct btrfs_key tmp;
2287 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2289 if (key_type == tmp.type) {
2290 first_offset = max(min_offset, tmp.offset) + 1;
2296 /* go backward to find any previous key */
2297 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2299 struct btrfs_key tmp;
2300 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2301 if (key_type == tmp.type) {
2302 first_offset = tmp.offset;
2303 ret = overwrite_item(trans, log, dst_path,
2304 path->nodes[0], path->slots[0],
2308 btrfs_release_path(root, path);
2310 /* find the first key from this transaction again */
2311 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2318 * we have a block from this transaction, log every item in it
2319 * from our directory
2322 struct btrfs_key tmp;
2323 src = path->nodes[0];
2324 nritems = btrfs_header_nritems(src);
2325 for (i = path->slots[0]; i < nritems; i++) {
2326 btrfs_item_key_to_cpu(src, &min_key, i);
2328 if (min_key.objectid != inode->i_ino ||
2329 min_key.type != key_type)
2331 ret = overwrite_item(trans, log, dst_path, src, i,
2335 path->slots[0] = nritems;
2338 * look ahead to the next item and see if it is also
2339 * from this directory and from this transaction
2341 ret = btrfs_next_leaf(root, path);
2343 last_offset = (u64)-1;
2346 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2347 if (tmp.objectid != inode->i_ino || tmp.type != key_type) {
2348 last_offset = (u64)-1;
2351 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2352 ret = overwrite_item(trans, log, dst_path,
2353 path->nodes[0], path->slots[0],
2357 last_offset = tmp.offset;
2362 *last_offset_ret = last_offset;
2363 btrfs_release_path(root, path);
2364 btrfs_release_path(log, dst_path);
2366 /* insert the log range keys to indicate where the log is valid */
2367 ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
2368 first_offset, last_offset);
2374 * logging directories is very similar to logging inodes, We find all the items
2375 * from the current transaction and write them to the log.
2377 * The recovery code scans the directory in the subvolume, and if it finds a
2378 * key in the range logged that is not present in the log tree, then it means
2379 * that dir entry was unlinked during the transaction.
2381 * In order for that scan to work, we must include one key smaller than
2382 * the smallest logged by this transaction and one key larger than the largest
2383 * key logged by this transaction.
2385 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2386 struct btrfs_root *root, struct inode *inode,
2387 struct btrfs_path *path,
2388 struct btrfs_path *dst_path)
2393 int key_type = BTRFS_DIR_ITEM_KEY;
2399 ret = log_dir_items(trans, root, inode, path,
2400 dst_path, key_type, min_key,
2403 if (max_key == (u64)-1)
2405 min_key = max_key + 1;
2408 if (key_type == BTRFS_DIR_ITEM_KEY) {
2409 key_type = BTRFS_DIR_INDEX_KEY;
2416 * a helper function to drop items from the log before we relog an
2417 * inode. max_key_type indicates the highest item type to remove.
2418 * This cannot be run for file data extents because it does not
2419 * free the extents they point to.
2421 static int drop_objectid_items(struct btrfs_trans_handle *trans,
2422 struct btrfs_root *log,
2423 struct btrfs_path *path,
2424 u64 objectid, int max_key_type)
2427 struct btrfs_key key;
2428 struct btrfs_key found_key;
2430 key.objectid = objectid;
2431 key.type = max_key_type;
2432 key.offset = (u64)-1;
2435 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2440 if (path->slots[0] == 0)
2444 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2447 if (found_key.objectid != objectid)
2450 ret = btrfs_del_item(trans, log, path);
2452 btrfs_release_path(log, path);
2454 btrfs_release_path(log, path);
2458 /* log a single inode in the tree log.
2459 * At least one parent directory for this inode must exist in the tree
2460 * or be logged already.
2462 * Any items from this inode changed by the current transaction are copied
2463 * to the log tree. An extra reference is taken on any extents in this
2464 * file, allowing us to avoid a whole pile of corner cases around logging
2465 * blocks that have been removed from the tree.
2467 * See LOG_INODE_ALL and related defines for a description of what inode_only
2470 * This handles both files and directories.
2472 static int __btrfs_log_inode(struct btrfs_trans_handle *trans,
2473 struct btrfs_root *root, struct inode *inode,
2476 struct btrfs_path *path;
2477 struct btrfs_path *dst_path;
2478 struct btrfs_key min_key;
2479 struct btrfs_key max_key;
2480 struct btrfs_root *log = root->log_root;
2481 unsigned long src_offset;
2482 unsigned long dst_offset;
2483 struct extent_buffer *src;
2484 struct btrfs_file_extent_item *extent;
2485 struct btrfs_inode_item *inode_item;
2489 log = root->log_root;
2491 path = btrfs_alloc_path();
2492 dst_path = btrfs_alloc_path();
2494 min_key.objectid = inode->i_ino;
2495 min_key.type = BTRFS_INODE_ITEM_KEY;
2498 max_key.objectid = inode->i_ino;
2499 if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
2500 max_key.type = BTRFS_XATTR_ITEM_KEY;
2502 max_key.type = (u8)-1;
2503 max_key.offset = (u64)-1;
2506 * if this inode has already been logged and we're in inode_only
2507 * mode, we don't want to delete the things that have already
2508 * been written to the log.
2510 * But, if the inode has been through an inode_only log,
2511 * the logged_trans field is not set. This allows us to catch
2512 * any new names for this inode in the backrefs by logging it
2515 if (inode_only == LOG_INODE_EXISTS &&
2516 BTRFS_I(inode)->logged_trans == trans->transid) {
2517 btrfs_free_path(path);
2518 btrfs_free_path(dst_path);
2521 mutex_lock(&BTRFS_I(inode)->log_mutex);
2524 * a brute force approach to making sure we get the most uptodate
2525 * copies of everything.
2527 if (S_ISDIR(inode->i_mode)) {
2528 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
2530 if (inode_only == LOG_INODE_EXISTS)
2531 max_key_type = BTRFS_XATTR_ITEM_KEY;
2532 ret = drop_objectid_items(trans, log, path,
2533 inode->i_ino, max_key_type);
2535 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
2538 path->keep_locks = 1;
2541 ret = btrfs_search_forward(root, &min_key, &max_key,
2542 path, 0, trans->transid);
2546 if (min_key.objectid != inode->i_ino)
2548 if (min_key.type > max_key.type)
2551 src = path->nodes[0];
2552 size = btrfs_item_size_nr(src, path->slots[0]);
2553 ret = btrfs_insert_empty_item(trans, log, dst_path, &min_key,
2558 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
2559 dst_path->slots[0]);
2561 src_offset = btrfs_item_ptr_offset(src, path->slots[0]);
2563 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
2566 if (inode_only == LOG_INODE_EXISTS &&
2567 min_key.type == BTRFS_INODE_ITEM_KEY) {
2568 inode_item = btrfs_item_ptr(dst_path->nodes[0],
2570 struct btrfs_inode_item);
2571 btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
2573 /* set the generation to zero so the recover code
2574 * can tell the difference between an logging
2575 * just to say 'this inode exists' and a logging
2576 * to say 'update this inode with these values'
2578 btrfs_set_inode_generation(dst_path->nodes[0],
2581 /* take a reference on file data extents so that truncates
2582 * or deletes of this inode don't have to relog the inode
2585 if (btrfs_key_type(&min_key) == BTRFS_EXTENT_DATA_KEY) {
2587 extent = btrfs_item_ptr(src, path->slots[0],
2588 struct btrfs_file_extent_item);
2590 found_type = btrfs_file_extent_type(src, extent);
2591 if (found_type == BTRFS_FILE_EXTENT_REG) {
2592 u64 ds = btrfs_file_extent_disk_bytenr(src,
2594 u64 dl = btrfs_file_extent_disk_num_bytes(src,
2596 /* ds == 0 is a hole */
2598 ret = btrfs_inc_extent_ref(trans, log,
2600 log->root_key.objectid,
2609 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2610 btrfs_release_path(root, path);
2611 btrfs_release_path(log, dst_path);
2613 if (min_key.offset < (u64)-1)
2615 else if (min_key.type < (u8)-1)
2617 else if (min_key.objectid < (u64)-1)
2622 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2623 btrfs_release_path(root, path);
2624 btrfs_release_path(log, dst_path);
2625 ret = log_directory_changes(trans, root, inode, path, dst_path);
2628 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2630 btrfs_free_path(path);
2631 btrfs_free_path(dst_path);
2633 mutex_lock(&root->fs_info->tree_log_mutex);
2634 ret = update_log_root(trans, log);
2636 mutex_unlock(&root->fs_info->tree_log_mutex);
2641 int btrfs_log_inode(struct btrfs_trans_handle *trans,
2642 struct btrfs_root *root, struct inode *inode,
2647 start_log_trans(trans, root);
2648 ret = __btrfs_log_inode(trans, root, inode, inode_only);
2649 end_log_trans(root);
2654 * helper function around btrfs_log_inode to make sure newly created
2655 * parent directories also end up in the log. A minimal inode and backref
2656 * only logging is done of any parent directories that are older than
2657 * the last committed transaction
2659 int btrfs_log_dentry(struct btrfs_trans_handle *trans,
2660 struct btrfs_root *root, struct dentry *dentry)
2662 int inode_only = LOG_INODE_ALL;
2663 struct super_block *sb;
2666 start_log_trans(trans, root);
2667 sb = dentry->d_inode->i_sb;
2669 ret = __btrfs_log_inode(trans, root, dentry->d_inode,
2672 inode_only = LOG_INODE_EXISTS;
2674 dentry = dentry->d_parent;
2675 if (!dentry || !dentry->d_inode || sb != dentry->d_inode->i_sb)
2678 if (BTRFS_I(dentry->d_inode)->generation <=
2679 root->fs_info->last_trans_committed)
2682 end_log_trans(root);
2687 * it is not safe to log dentry if the chunk root has added new
2688 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
2689 * If this returns 1, you must commit the transaction to safely get your
2692 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
2693 struct btrfs_root *root, struct dentry *dentry)
2696 gen = root->fs_info->last_trans_new_blockgroup;
2697 if (gen > root->fs_info->last_trans_committed)
2700 return btrfs_log_dentry(trans, root, dentry);
2704 * should be called during mount to recover any replay any log trees
2707 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
2710 struct btrfs_path *path;
2711 struct btrfs_trans_handle *trans;
2712 struct btrfs_key key;
2713 struct btrfs_key found_key;
2714 struct btrfs_key tmp_key;
2715 struct btrfs_root *log;
2716 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
2717 struct walk_control wc = {
2718 .process_func = process_one_buffer,
2722 fs_info->log_root_recovering = 1;
2723 path = btrfs_alloc_path();
2726 trans = btrfs_start_transaction(fs_info->tree_root, 1);
2731 walk_log_tree(trans, log_root_tree, &wc);
2734 key.objectid = BTRFS_TREE_LOG_OBJECTID;
2735 key.offset = (u64)-1;
2736 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
2739 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
2743 if (path->slots[0] == 0)
2747 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2749 btrfs_release_path(log_root_tree, path);
2750 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
2753 log = btrfs_read_fs_root_no_radix(log_root_tree,
2758 tmp_key.objectid = found_key.offset;
2759 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
2760 tmp_key.offset = (u64)-1;
2762 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
2764 BUG_ON(!wc.replay_dest);
2766 btrfs_record_root_in_trans(wc.replay_dest);
2767 ret = walk_log_tree(trans, log, &wc);
2770 if (wc.stage == LOG_WALK_REPLAY_ALL) {
2771 ret = fixup_inode_link_counts(trans, wc.replay_dest,
2776 key.offset = found_key.offset - 1;
2777 free_extent_buffer(log->node);
2780 if (found_key.offset == 0)
2783 btrfs_release_path(log_root_tree, path);
2785 /* step one is to pin it all, step two is to replay just inodes */
2788 wc.process_func = replay_one_buffer;
2789 wc.stage = LOG_WALK_REPLAY_INODES;
2792 /* step three is to replay everything */
2793 if (wc.stage < LOG_WALK_REPLAY_ALL) {
2798 btrfs_free_path(path);
2800 free_extent_buffer(log_root_tree->node);
2801 log_root_tree->log_root = NULL;
2802 fs_info->log_root_recovering = 0;
2804 /* step 4: commit the transaction, which also unpins the blocks */
2805 btrfs_commit_transaction(trans, fs_info->tree_root);
2807 kfree(log_root_tree);