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>
20 #include <linux/slab.h>
22 #include "transaction.h"
25 #include "print-tree.h"
29 /* magic values for the inode_only field in btrfs_log_inode:
31 * LOG_INODE_ALL means to log everything
32 * LOG_INODE_EXISTS means to log just enough to recreate the inode
35 #define LOG_INODE_ALL 0
36 #define LOG_INODE_EXISTS 1
39 * directory trouble cases
41 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
42 * log, we must force a full commit before doing an fsync of the directory
43 * where the unlink was done.
44 * ---> record transid of last unlink/rename per directory
48 * rename foo/some_dir foo2/some_dir
50 * fsync foo/some_dir/some_file
52 * The fsync above will unlink the original some_dir without recording
53 * it in its new location (foo2). After a crash, some_dir will be gone
54 * unless the fsync of some_file forces a full commit
56 * 2) we must log any new names for any file or dir that is in the fsync
57 * log. ---> check inode while renaming/linking.
59 * 2a) we must log any new names for any file or dir during rename
60 * when the directory they are being removed from was logged.
61 * ---> check inode and old parent dir during rename
63 * 2a is actually the more important variant. With the extra logging
64 * a crash might unlink the old name without recreating the new one
66 * 3) after a crash, we must go through any directories with a link count
67 * of zero and redo the rm -rf
74 * The directory f1 was fully removed from the FS, but fsync was never
75 * called on f1, only its parent dir. After a crash the rm -rf must
76 * be replayed. This must be able to recurse down the entire
77 * directory tree. The inode link count fixup code takes care of the
82 * stages for the tree walking. The first
83 * stage (0) is to only pin down the blocks we find
84 * the second stage (1) is to make sure that all the inodes
85 * we find in the log are created in the subvolume.
87 * The last stage is to deal with directories and links and extents
88 * and all the other fun semantics
90 #define LOG_WALK_PIN_ONLY 0
91 #define LOG_WALK_REPLAY_INODES 1
92 #define LOG_WALK_REPLAY_ALL 2
94 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
95 struct btrfs_root *root, struct inode *inode,
97 static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
98 struct btrfs_root *root,
99 struct btrfs_path *path, u64 objectid);
100 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
101 struct btrfs_root *root,
102 struct btrfs_root *log,
103 struct btrfs_path *path,
104 u64 dirid, int del_all);
107 * tree logging is a special write ahead log used to make sure that
108 * fsyncs and O_SYNCs can happen without doing full tree commits.
110 * Full tree commits are expensive because they require commonly
111 * modified blocks to be recowed, creating many dirty pages in the
112 * extent tree an 4x-6x higher write load than ext3.
114 * Instead of doing a tree commit on every fsync, we use the
115 * key ranges and transaction ids to find items for a given file or directory
116 * that have changed in this transaction. Those items are copied into
117 * a special tree (one per subvolume root), that tree is written to disk
118 * and then the fsync is considered complete.
120 * After a crash, items are copied out of the log-tree back into the
121 * subvolume tree. Any file data extents found are recorded in the extent
122 * allocation tree, and the log-tree freed.
124 * The log tree is read three times, once to pin down all the extents it is
125 * using in ram and once, once to create all the inodes logged in the tree
126 * and once to do all the other items.
130 * start a sub transaction and setup the log tree
131 * this increments the log tree writer count to make the people
132 * syncing the tree wait for us to finish
134 static int start_log_trans(struct btrfs_trans_handle *trans,
135 struct btrfs_root *root)
139 mutex_lock(&root->log_mutex);
140 if (root->log_root) {
141 if (!root->log_start_pid) {
142 root->log_start_pid = current->pid;
143 root->log_multiple_pids = false;
144 } else if (root->log_start_pid != current->pid) {
145 root->log_multiple_pids = true;
149 atomic_inc(&root->log_writers);
150 mutex_unlock(&root->log_mutex);
153 root->log_multiple_pids = false;
154 root->log_start_pid = current->pid;
155 mutex_lock(&root->fs_info->tree_log_mutex);
156 if (!root->fs_info->log_root_tree) {
157 ret = btrfs_init_log_root_tree(trans, root->fs_info);
160 if (!root->log_root) {
161 ret = btrfs_add_log_tree(trans, root);
164 mutex_unlock(&root->fs_info->tree_log_mutex);
166 atomic_inc(&root->log_writers);
167 mutex_unlock(&root->log_mutex);
172 * returns 0 if there was a log transaction running and we were able
173 * to join, or returns -ENOENT if there were not transactions
176 static int join_running_log_trans(struct btrfs_root *root)
184 mutex_lock(&root->log_mutex);
185 if (root->log_root) {
187 atomic_inc(&root->log_writers);
189 mutex_unlock(&root->log_mutex);
194 * This either makes the current running log transaction wait
195 * until you call btrfs_end_log_trans() or it makes any future
196 * log transactions wait until you call btrfs_end_log_trans()
198 int btrfs_pin_log_trans(struct btrfs_root *root)
202 mutex_lock(&root->log_mutex);
203 atomic_inc(&root->log_writers);
204 mutex_unlock(&root->log_mutex);
209 * indicate we're done making changes to the log tree
210 * and wake up anyone waiting to do a sync
212 int btrfs_end_log_trans(struct btrfs_root *root)
214 if (atomic_dec_and_test(&root->log_writers)) {
216 if (waitqueue_active(&root->log_writer_wait))
217 wake_up(&root->log_writer_wait);
224 * the walk control struct is used to pass state down the chain when
225 * processing the log tree. The stage field tells us which part
226 * of the log tree processing we are currently doing. The others
227 * are state fields used for that specific part
229 struct walk_control {
230 /* should we free the extent on disk when done? This is used
231 * at transaction commit time while freeing a log tree
235 /* should we write out the extent buffer? This is used
236 * while flushing the log tree to disk during a sync
240 /* should we wait for the extent buffer io to finish? Also used
241 * while flushing the log tree to disk for a sync
245 /* pin only walk, we record which extents on disk belong to the
250 /* what stage of the replay code we're currently in */
253 /* the root we are currently replaying */
254 struct btrfs_root *replay_dest;
256 /* the trans handle for the current replay */
257 struct btrfs_trans_handle *trans;
259 /* the function that gets used to process blocks we find in the
260 * tree. Note the extent_buffer might not be up to date when it is
261 * passed in, and it must be checked or read if you need the data
264 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
265 struct walk_control *wc, u64 gen);
269 * process_func used to pin down extents, write them or wait on them
271 static int process_one_buffer(struct btrfs_root *log,
272 struct extent_buffer *eb,
273 struct walk_control *wc, u64 gen)
276 btrfs_pin_extent(log->fs_info->extent_root,
277 eb->start, eb->len, 0);
279 if (btrfs_buffer_uptodate(eb, gen)) {
281 btrfs_write_tree_block(eb);
283 btrfs_wait_tree_block_writeback(eb);
289 * Item overwrite used by replay and tree logging. eb, slot and key all refer
290 * to the src data we are copying out.
292 * root is the tree we are copying into, and path is a scratch
293 * path for use in this function (it should be released on entry and
294 * will be released on exit).
296 * If the key is already in the destination tree the existing item is
297 * overwritten. If the existing item isn't big enough, it is extended.
298 * If it is too large, it is truncated.
300 * If the key isn't in the destination yet, a new item is inserted.
302 static noinline int overwrite_item(struct btrfs_trans_handle *trans,
303 struct btrfs_root *root,
304 struct btrfs_path *path,
305 struct extent_buffer *eb, int slot,
306 struct btrfs_key *key)
310 u64 saved_i_size = 0;
311 int save_old_i_size = 0;
312 unsigned long src_ptr;
313 unsigned long dst_ptr;
314 int overwrite_root = 0;
316 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
319 item_size = btrfs_item_size_nr(eb, slot);
320 src_ptr = btrfs_item_ptr_offset(eb, slot);
322 /* look for the key in the destination tree */
323 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
327 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
329 if (dst_size != item_size)
332 if (item_size == 0) {
333 btrfs_release_path(root, path);
336 dst_copy = kmalloc(item_size, GFP_NOFS);
337 src_copy = kmalloc(item_size, GFP_NOFS);
339 read_extent_buffer(eb, src_copy, src_ptr, item_size);
341 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
342 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
344 ret = memcmp(dst_copy, src_copy, item_size);
349 * they have the same contents, just return, this saves
350 * us from cowing blocks in the destination tree and doing
351 * extra writes that may not have been done by a previous
355 btrfs_release_path(root, path);
361 btrfs_release_path(root, path);
362 /* try to insert the key into the destination tree */
363 ret = btrfs_insert_empty_item(trans, root, path,
366 /* make sure any existing item is the correct size */
367 if (ret == -EEXIST) {
369 found_size = btrfs_item_size_nr(path->nodes[0],
371 if (found_size > item_size) {
372 btrfs_truncate_item(trans, root, path, item_size, 1);
373 } else if (found_size < item_size) {
374 ret = btrfs_extend_item(trans, root, path,
375 item_size - found_size);
381 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
384 /* don't overwrite an existing inode if the generation number
385 * was logged as zero. This is done when the tree logging code
386 * is just logging an inode to make sure it exists after recovery.
388 * Also, don't overwrite i_size on directories during replay.
389 * log replay inserts and removes directory items based on the
390 * state of the tree found in the subvolume, and i_size is modified
393 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
394 struct btrfs_inode_item *src_item;
395 struct btrfs_inode_item *dst_item;
397 src_item = (struct btrfs_inode_item *)src_ptr;
398 dst_item = (struct btrfs_inode_item *)dst_ptr;
400 if (btrfs_inode_generation(eb, src_item) == 0)
403 if (overwrite_root &&
404 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
405 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
407 saved_i_size = btrfs_inode_size(path->nodes[0],
412 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
415 if (save_old_i_size) {
416 struct btrfs_inode_item *dst_item;
417 dst_item = (struct btrfs_inode_item *)dst_ptr;
418 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
421 /* make sure the generation is filled in */
422 if (key->type == BTRFS_INODE_ITEM_KEY) {
423 struct btrfs_inode_item *dst_item;
424 dst_item = (struct btrfs_inode_item *)dst_ptr;
425 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
426 btrfs_set_inode_generation(path->nodes[0], dst_item,
431 btrfs_mark_buffer_dirty(path->nodes[0]);
432 btrfs_release_path(root, path);
437 * simple helper to read an inode off the disk from a given root
438 * This can only be called for subvolume roots and not for the log
440 static noinline struct inode *read_one_inode(struct btrfs_root *root,
443 struct btrfs_key key;
446 key.objectid = objectid;
447 key.type = BTRFS_INODE_ITEM_KEY;
449 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
452 } else if (is_bad_inode(inode)) {
459 /* replays a single extent in 'eb' at 'slot' with 'key' into the
460 * subvolume 'root'. path is released on entry and should be released
463 * extents in the log tree have not been allocated out of the extent
464 * tree yet. So, this completes the allocation, taking a reference
465 * as required if the extent already exists or creating a new extent
466 * if it isn't in the extent allocation tree yet.
468 * The extent is inserted into the file, dropping any existing extents
469 * from the file that overlap the new one.
471 static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
472 struct btrfs_root *root,
473 struct btrfs_path *path,
474 struct extent_buffer *eb, int slot,
475 struct btrfs_key *key)
478 u64 mask = root->sectorsize - 1;
481 u64 start = key->offset;
483 struct btrfs_file_extent_item *item;
484 struct inode *inode = NULL;
488 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
489 found_type = btrfs_file_extent_type(eb, item);
491 if (found_type == BTRFS_FILE_EXTENT_REG ||
492 found_type == BTRFS_FILE_EXTENT_PREALLOC)
493 extent_end = start + btrfs_file_extent_num_bytes(eb, item);
494 else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
495 size = btrfs_file_extent_inline_len(eb, item);
496 extent_end = (start + size + mask) & ~mask;
502 inode = read_one_inode(root, key->objectid);
509 * first check to see if we already have this extent in the
510 * file. This must be done before the btrfs_drop_extents run
511 * so we don't try to drop this extent.
513 ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
517 (found_type == BTRFS_FILE_EXTENT_REG ||
518 found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
519 struct btrfs_file_extent_item cmp1;
520 struct btrfs_file_extent_item cmp2;
521 struct btrfs_file_extent_item *existing;
522 struct extent_buffer *leaf;
524 leaf = path->nodes[0];
525 existing = btrfs_item_ptr(leaf, path->slots[0],
526 struct btrfs_file_extent_item);
528 read_extent_buffer(eb, &cmp1, (unsigned long)item,
530 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
534 * we already have a pointer to this exact extent,
535 * we don't have to do anything
537 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
538 btrfs_release_path(root, path);
542 btrfs_release_path(root, path);
544 saved_nbytes = inode_get_bytes(inode);
545 /* drop any overlapping extents */
546 ret = btrfs_drop_extents(trans, inode, start, extent_end,
550 if (found_type == BTRFS_FILE_EXTENT_REG ||
551 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
553 unsigned long dest_offset;
554 struct btrfs_key ins;
556 ret = btrfs_insert_empty_item(trans, root, path, key,
559 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
561 copy_extent_buffer(path->nodes[0], eb, dest_offset,
562 (unsigned long)item, sizeof(*item));
564 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
565 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
566 ins.type = BTRFS_EXTENT_ITEM_KEY;
567 offset = key->offset - btrfs_file_extent_offset(eb, item);
569 if (ins.objectid > 0) {
572 LIST_HEAD(ordered_sums);
574 * is this extent already allocated in the extent
575 * allocation tree? If so, just add a reference
577 ret = btrfs_lookup_extent(root, ins.objectid,
580 ret = btrfs_inc_extent_ref(trans, root,
581 ins.objectid, ins.offset,
582 0, root->root_key.objectid,
583 key->objectid, offset);
586 * insert the extent pointer in the extent
589 ret = btrfs_alloc_logged_file_extent(trans,
590 root, root->root_key.objectid,
591 key->objectid, offset, &ins);
594 btrfs_release_path(root, path);
596 if (btrfs_file_extent_compression(eb, item)) {
597 csum_start = ins.objectid;
598 csum_end = csum_start + ins.offset;
600 csum_start = ins.objectid +
601 btrfs_file_extent_offset(eb, item);
602 csum_end = csum_start +
603 btrfs_file_extent_num_bytes(eb, item);
606 ret = btrfs_lookup_csums_range(root->log_root,
607 csum_start, csum_end - 1,
610 while (!list_empty(&ordered_sums)) {
611 struct btrfs_ordered_sum *sums;
612 sums = list_entry(ordered_sums.next,
613 struct btrfs_ordered_sum,
615 ret = btrfs_csum_file_blocks(trans,
616 root->fs_info->csum_root,
619 list_del(&sums->list);
623 btrfs_release_path(root, path);
625 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
626 /* inline extents are easy, we just overwrite them */
627 ret = overwrite_item(trans, root, path, eb, slot, key);
631 inode_set_bytes(inode, saved_nbytes);
632 btrfs_update_inode(trans, root, inode);
640 * when cleaning up conflicts between the directory names in the
641 * subvolume, directory names in the log and directory names in the
642 * inode back references, we may have to unlink inodes from directories.
644 * This is a helper function to do the unlink of a specific directory
647 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
648 struct btrfs_root *root,
649 struct btrfs_path *path,
651 struct btrfs_dir_item *di)
656 struct extent_buffer *leaf;
657 struct btrfs_key location;
660 leaf = path->nodes[0];
662 btrfs_dir_item_key_to_cpu(leaf, di, &location);
663 name_len = btrfs_dir_name_len(leaf, di);
664 name = kmalloc(name_len, GFP_NOFS);
665 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
666 btrfs_release_path(root, path);
668 inode = read_one_inode(root, location.objectid);
671 ret = link_to_fixup_dir(trans, root, path, location.objectid);
674 ret = btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
683 * helper function to see if a given name and sequence number found
684 * in an inode back reference are already in a directory and correctly
685 * point to this inode
687 static noinline int inode_in_dir(struct btrfs_root *root,
688 struct btrfs_path *path,
689 u64 dirid, u64 objectid, u64 index,
690 const char *name, int name_len)
692 struct btrfs_dir_item *di;
693 struct btrfs_key location;
696 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
697 index, name, name_len, 0);
698 if (di && !IS_ERR(di)) {
699 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
700 if (location.objectid != objectid)
704 btrfs_release_path(root, path);
706 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
707 if (di && !IS_ERR(di)) {
708 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
709 if (location.objectid != objectid)
715 btrfs_release_path(root, path);
720 * helper function to check a log tree for a named back reference in
721 * an inode. This is used to decide if a back reference that is
722 * found in the subvolume conflicts with what we find in the log.
724 * inode backreferences may have multiple refs in a single item,
725 * during replay we process one reference at a time, and we don't
726 * want to delete valid links to a file from the subvolume if that
727 * link is also in the log.
729 static noinline int backref_in_log(struct btrfs_root *log,
730 struct btrfs_key *key,
731 char *name, int namelen)
733 struct btrfs_path *path;
734 struct btrfs_inode_ref *ref;
736 unsigned long ptr_end;
737 unsigned long name_ptr;
743 path = btrfs_alloc_path();
744 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
748 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
749 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
750 ptr_end = ptr + item_size;
751 while (ptr < ptr_end) {
752 ref = (struct btrfs_inode_ref *)ptr;
753 found_name_len = btrfs_inode_ref_name_len(path->nodes[0], ref);
754 if (found_name_len == namelen) {
755 name_ptr = (unsigned long)(ref + 1);
756 ret = memcmp_extent_buffer(path->nodes[0], name,
763 ptr = (unsigned long)(ref + 1) + found_name_len;
766 btrfs_free_path(path);
772 * replay one inode back reference item found in the log tree.
773 * eb, slot and key refer to the buffer and key found in the log tree.
774 * root is the destination we are replaying into, and path is for temp
775 * use by this function. (it should be released on return).
777 static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
778 struct btrfs_root *root,
779 struct btrfs_root *log,
780 struct btrfs_path *path,
781 struct extent_buffer *eb, int slot,
782 struct btrfs_key *key)
786 struct btrfs_key location;
787 struct btrfs_inode_ref *ref;
788 struct btrfs_dir_item *di;
792 unsigned long ref_ptr;
793 unsigned long ref_end;
795 location.objectid = key->objectid;
796 location.type = BTRFS_INODE_ITEM_KEY;
800 * it is possible that we didn't log all the parent directories
801 * for a given inode. If we don't find the dir, just don't
802 * copy the back ref in. The link count fixup code will take
805 dir = read_one_inode(root, key->offset);
809 inode = read_one_inode(root, key->objectid);
812 ref_ptr = btrfs_item_ptr_offset(eb, slot);
813 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
816 ref = (struct btrfs_inode_ref *)ref_ptr;
818 namelen = btrfs_inode_ref_name_len(eb, ref);
819 name = kmalloc(namelen, GFP_NOFS);
822 read_extent_buffer(eb, name, (unsigned long)(ref + 1), namelen);
824 /* if we already have a perfect match, we're done */
825 if (inode_in_dir(root, path, dir->i_ino, inode->i_ino,
826 btrfs_inode_ref_index(eb, ref),
832 * look for a conflicting back reference in the metadata.
833 * if we find one we have to unlink that name of the file
834 * before we add our new link. Later on, we overwrite any
835 * existing back reference, and we don't want to create
836 * dangling pointers in the directory.
839 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
843 struct btrfs_inode_ref *victim_ref;
845 unsigned long ptr_end;
846 struct extent_buffer *leaf = path->nodes[0];
848 /* are we trying to overwrite a back ref for the root directory
849 * if so, just jump out, we're done
851 if (key->objectid == key->offset)
854 /* check all the names in this back reference to see
855 * if they are in the log. if so, we allow them to stay
856 * otherwise they must be unlinked as a conflict
858 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
859 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
860 while (ptr < ptr_end) {
861 victim_ref = (struct btrfs_inode_ref *)ptr;
862 victim_name_len = btrfs_inode_ref_name_len(leaf,
864 victim_name = kmalloc(victim_name_len, GFP_NOFS);
865 BUG_ON(!victim_name);
867 read_extent_buffer(leaf, victim_name,
868 (unsigned long)(victim_ref + 1),
871 if (!backref_in_log(log, key, victim_name,
873 btrfs_inc_nlink(inode);
874 btrfs_release_path(root, path);
876 ret = btrfs_unlink_inode(trans, root, dir,
880 btrfs_release_path(root, path);
884 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
888 btrfs_release_path(root, path);
890 /* look for a conflicting sequence number */
891 di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
892 btrfs_inode_ref_index(eb, ref),
894 if (di && !IS_ERR(di)) {
895 ret = drop_one_dir_item(trans, root, path, dir, di);
898 btrfs_release_path(root, path);
901 /* look for a conflicting name */
902 di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
904 if (di && !IS_ERR(di)) {
905 ret = drop_one_dir_item(trans, root, path, dir, di);
908 btrfs_release_path(root, path);
910 /* insert our name */
911 ret = btrfs_add_link(trans, dir, inode, name, namelen, 0,
912 btrfs_inode_ref_index(eb, ref));
915 btrfs_update_inode(trans, root, inode);
918 ref_ptr = (unsigned long)(ref + 1) + namelen;
920 if (ref_ptr < ref_end)
923 /* finally write the back reference in the inode */
924 ret = overwrite_item(trans, root, path, eb, slot, key);
928 btrfs_release_path(root, path);
934 static int insert_orphan_item(struct btrfs_trans_handle *trans,
935 struct btrfs_root *root, u64 offset)
938 ret = btrfs_find_orphan_item(root, offset);
940 ret = btrfs_insert_orphan_item(trans, root, offset);
946 * There are a few corners where the link count of the file can't
947 * be properly maintained during replay. So, instead of adding
948 * lots of complexity to the log code, we just scan the backrefs
949 * for any file that has been through replay.
951 * The scan will update the link count on the inode to reflect the
952 * number of back refs found. If it goes down to zero, the iput
953 * will free the inode.
955 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
956 struct btrfs_root *root,
959 struct btrfs_path *path;
961 struct btrfs_key key;
964 unsigned long ptr_end;
967 key.objectid = inode->i_ino;
968 key.type = BTRFS_INODE_REF_KEY;
969 key.offset = (u64)-1;
971 path = btrfs_alloc_path();
974 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
978 if (path->slots[0] == 0)
982 btrfs_item_key_to_cpu(path->nodes[0], &key,
984 if (key.objectid != inode->i_ino ||
985 key.type != BTRFS_INODE_REF_KEY)
987 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
988 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
990 while (ptr < ptr_end) {
991 struct btrfs_inode_ref *ref;
993 ref = (struct btrfs_inode_ref *)ptr;
994 name_len = btrfs_inode_ref_name_len(path->nodes[0],
996 ptr = (unsigned long)(ref + 1) + name_len;
1000 if (key.offset == 0)
1003 btrfs_release_path(root, path);
1005 btrfs_release_path(root, path);
1006 if (nlink != inode->i_nlink) {
1007 inode->i_nlink = nlink;
1008 btrfs_update_inode(trans, root, inode);
1010 BTRFS_I(inode)->index_cnt = (u64)-1;
1012 if (inode->i_nlink == 0) {
1013 if (S_ISDIR(inode->i_mode)) {
1014 ret = replay_dir_deletes(trans, root, NULL, path,
1018 ret = insert_orphan_item(trans, root, inode->i_ino);
1021 btrfs_free_path(path);
1026 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1027 struct btrfs_root *root,
1028 struct btrfs_path *path)
1031 struct btrfs_key key;
1032 struct inode *inode;
1034 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1035 key.type = BTRFS_ORPHAN_ITEM_KEY;
1036 key.offset = (u64)-1;
1038 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1043 if (path->slots[0] == 0)
1048 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1049 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1050 key.type != BTRFS_ORPHAN_ITEM_KEY)
1053 ret = btrfs_del_item(trans, root, path);
1056 btrfs_release_path(root, path);
1057 inode = read_one_inode(root, key.offset);
1060 ret = fixup_inode_link_count(trans, root, inode);
1066 * fixup on a directory may create new entries,
1067 * make sure we always look for the highset possible
1070 key.offset = (u64)-1;
1072 btrfs_release_path(root, path);
1078 * record a given inode in the fixup dir so we can check its link
1079 * count when replay is done. The link count is incremented here
1080 * so the inode won't go away until we check it
1082 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1083 struct btrfs_root *root,
1084 struct btrfs_path *path,
1087 struct btrfs_key key;
1089 struct inode *inode;
1091 inode = read_one_inode(root, objectid);
1094 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1095 btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
1096 key.offset = objectid;
1098 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1100 btrfs_release_path(root, path);
1102 btrfs_inc_nlink(inode);
1103 btrfs_update_inode(trans, root, inode);
1104 } else if (ret == -EEXIST) {
1115 * when replaying the log for a directory, we only insert names
1116 * for inodes that actually exist. This means an fsync on a directory
1117 * does not implicitly fsync all the new files in it
1119 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1120 struct btrfs_root *root,
1121 struct btrfs_path *path,
1122 u64 dirid, u64 index,
1123 char *name, int name_len, u8 type,
1124 struct btrfs_key *location)
1126 struct inode *inode;
1130 inode = read_one_inode(root, location->objectid);
1134 dir = read_one_inode(root, dirid);
1139 ret = btrfs_add_link(trans, dir, inode, name, name_len, 1, index);
1141 /* FIXME, put inode into FIXUP list */
1149 * take a single entry in a log directory item and replay it into
1152 * if a conflicting item exists in the subdirectory already,
1153 * the inode it points to is unlinked and put into the link count
1156 * If a name from the log points to a file or directory that does
1157 * not exist in the FS, it is skipped. fsyncs on directories
1158 * do not force down inodes inside that directory, just changes to the
1159 * names or unlinks in a directory.
1161 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1162 struct btrfs_root *root,
1163 struct btrfs_path *path,
1164 struct extent_buffer *eb,
1165 struct btrfs_dir_item *di,
1166 struct btrfs_key *key)
1170 struct btrfs_dir_item *dst_di;
1171 struct btrfs_key found_key;
1172 struct btrfs_key log_key;
1178 dir = read_one_inode(root, key->objectid);
1181 name_len = btrfs_dir_name_len(eb, di);
1182 name = kmalloc(name_len, GFP_NOFS);
1183 log_type = btrfs_dir_type(eb, di);
1184 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1187 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1188 exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1193 btrfs_release_path(root, path);
1195 if (key->type == BTRFS_DIR_ITEM_KEY) {
1196 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1198 } else if (key->type == BTRFS_DIR_INDEX_KEY) {
1199 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1206 if (!dst_di || IS_ERR(dst_di)) {
1207 /* we need a sequence number to insert, so we only
1208 * do inserts for the BTRFS_DIR_INDEX_KEY types
1210 if (key->type != BTRFS_DIR_INDEX_KEY)
1215 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1216 /* the existing item matches the logged item */
1217 if (found_key.objectid == log_key.objectid &&
1218 found_key.type == log_key.type &&
1219 found_key.offset == log_key.offset &&
1220 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1225 * don't drop the conflicting directory entry if the inode
1226 * for the new entry doesn't exist
1231 ret = drop_one_dir_item(trans, root, path, dir, dst_di);
1234 if (key->type == BTRFS_DIR_INDEX_KEY)
1237 btrfs_release_path(root, path);
1243 btrfs_release_path(root, path);
1244 ret = insert_one_name(trans, root, path, key->objectid, key->offset,
1245 name, name_len, log_type, &log_key);
1247 BUG_ON(ret && ret != -ENOENT);
1252 * find all the names in a directory item and reconcile them into
1253 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
1254 * one name in a directory item, but the same code gets used for
1255 * both directory index types
1257 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
1258 struct btrfs_root *root,
1259 struct btrfs_path *path,
1260 struct extent_buffer *eb, int slot,
1261 struct btrfs_key *key)
1264 u32 item_size = btrfs_item_size_nr(eb, slot);
1265 struct btrfs_dir_item *di;
1268 unsigned long ptr_end;
1270 ptr = btrfs_item_ptr_offset(eb, slot);
1271 ptr_end = ptr + item_size;
1272 while (ptr < ptr_end) {
1273 di = (struct btrfs_dir_item *)ptr;
1274 name_len = btrfs_dir_name_len(eb, di);
1275 ret = replay_one_name(trans, root, path, eb, di, key);
1277 ptr = (unsigned long)(di + 1);
1284 * directory replay has two parts. There are the standard directory
1285 * items in the log copied from the subvolume, and range items
1286 * created in the log while the subvolume was logged.
1288 * The range items tell us which parts of the key space the log
1289 * is authoritative for. During replay, if a key in the subvolume
1290 * directory is in a logged range item, but not actually in the log
1291 * that means it was deleted from the directory before the fsync
1292 * and should be removed.
1294 static noinline int find_dir_range(struct btrfs_root *root,
1295 struct btrfs_path *path,
1296 u64 dirid, int key_type,
1297 u64 *start_ret, u64 *end_ret)
1299 struct btrfs_key key;
1301 struct btrfs_dir_log_item *item;
1305 if (*start_ret == (u64)-1)
1308 key.objectid = dirid;
1309 key.type = key_type;
1310 key.offset = *start_ret;
1312 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1316 if (path->slots[0] == 0)
1321 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1323 if (key.type != key_type || key.objectid != dirid) {
1327 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1328 struct btrfs_dir_log_item);
1329 found_end = btrfs_dir_log_end(path->nodes[0], item);
1331 if (*start_ret >= key.offset && *start_ret <= found_end) {
1333 *start_ret = key.offset;
1334 *end_ret = found_end;
1339 /* check the next slot in the tree to see if it is a valid item */
1340 nritems = btrfs_header_nritems(path->nodes[0]);
1341 if (path->slots[0] >= nritems) {
1342 ret = btrfs_next_leaf(root, path);
1349 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1351 if (key.type != key_type || key.objectid != dirid) {
1355 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
1356 struct btrfs_dir_log_item);
1357 found_end = btrfs_dir_log_end(path->nodes[0], item);
1358 *start_ret = key.offset;
1359 *end_ret = found_end;
1362 btrfs_release_path(root, path);
1367 * this looks for a given directory item in the log. If the directory
1368 * item is not in the log, the item is removed and the inode it points
1371 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
1372 struct btrfs_root *root,
1373 struct btrfs_root *log,
1374 struct btrfs_path *path,
1375 struct btrfs_path *log_path,
1377 struct btrfs_key *dir_key)
1380 struct extent_buffer *eb;
1383 struct btrfs_dir_item *di;
1384 struct btrfs_dir_item *log_di;
1387 unsigned long ptr_end;
1389 struct inode *inode;
1390 struct btrfs_key location;
1393 eb = path->nodes[0];
1394 slot = path->slots[0];
1395 item_size = btrfs_item_size_nr(eb, slot);
1396 ptr = btrfs_item_ptr_offset(eb, slot);
1397 ptr_end = ptr + item_size;
1398 while (ptr < ptr_end) {
1399 di = (struct btrfs_dir_item *)ptr;
1400 name_len = btrfs_dir_name_len(eb, di);
1401 name = kmalloc(name_len, GFP_NOFS);
1406 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1409 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
1410 log_di = btrfs_lookup_dir_item(trans, log, log_path,
1413 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
1414 log_di = btrfs_lookup_dir_index_item(trans, log,
1420 if (!log_di || IS_ERR(log_di)) {
1421 btrfs_dir_item_key_to_cpu(eb, di, &location);
1422 btrfs_release_path(root, path);
1423 btrfs_release_path(log, log_path);
1424 inode = read_one_inode(root, location.objectid);
1427 ret = link_to_fixup_dir(trans, root,
1428 path, location.objectid);
1430 btrfs_inc_nlink(inode);
1431 ret = btrfs_unlink_inode(trans, root, dir, inode,
1437 /* there might still be more names under this key
1438 * check and repeat if required
1440 ret = btrfs_search_slot(NULL, root, dir_key, path,
1447 btrfs_release_path(log, log_path);
1450 ptr = (unsigned long)(di + 1);
1455 btrfs_release_path(root, path);
1456 btrfs_release_path(log, log_path);
1461 * deletion replay happens before we copy any new directory items
1462 * out of the log or out of backreferences from inodes. It
1463 * scans the log to find ranges of keys that log is authoritative for,
1464 * and then scans the directory to find items in those ranges that are
1465 * not present in the log.
1467 * Anything we don't find in the log is unlinked and removed from the
1470 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
1471 struct btrfs_root *root,
1472 struct btrfs_root *log,
1473 struct btrfs_path *path,
1474 u64 dirid, int del_all)
1478 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
1480 struct btrfs_key dir_key;
1481 struct btrfs_key found_key;
1482 struct btrfs_path *log_path;
1485 dir_key.objectid = dirid;
1486 dir_key.type = BTRFS_DIR_ITEM_KEY;
1487 log_path = btrfs_alloc_path();
1491 dir = read_one_inode(root, dirid);
1492 /* it isn't an error if the inode isn't there, that can happen
1493 * because we replay the deletes before we copy in the inode item
1497 btrfs_free_path(log_path);
1505 range_end = (u64)-1;
1507 ret = find_dir_range(log, path, dirid, key_type,
1508 &range_start, &range_end);
1513 dir_key.offset = range_start;
1516 ret = btrfs_search_slot(NULL, root, &dir_key, path,
1521 nritems = btrfs_header_nritems(path->nodes[0]);
1522 if (path->slots[0] >= nritems) {
1523 ret = btrfs_next_leaf(root, path);
1527 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
1529 if (found_key.objectid != dirid ||
1530 found_key.type != dir_key.type)
1533 if (found_key.offset > range_end)
1536 ret = check_item_in_log(trans, root, log, path,
1540 if (found_key.offset == (u64)-1)
1542 dir_key.offset = found_key.offset + 1;
1544 btrfs_release_path(root, path);
1545 if (range_end == (u64)-1)
1547 range_start = range_end + 1;
1552 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
1553 key_type = BTRFS_DIR_LOG_INDEX_KEY;
1554 dir_key.type = BTRFS_DIR_INDEX_KEY;
1555 btrfs_release_path(root, path);
1559 btrfs_release_path(root, path);
1560 btrfs_free_path(log_path);
1566 * the process_func used to replay items from the log tree. This
1567 * gets called in two different stages. The first stage just looks
1568 * for inodes and makes sure they are all copied into the subvolume.
1570 * The second stage copies all the other item types from the log into
1571 * the subvolume. The two stage approach is slower, but gets rid of
1572 * lots of complexity around inodes referencing other inodes that exist
1573 * only in the log (references come from either directory items or inode
1576 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
1577 struct walk_control *wc, u64 gen)
1580 struct btrfs_path *path;
1581 struct btrfs_root *root = wc->replay_dest;
1582 struct btrfs_key key;
1588 btrfs_read_buffer(eb, gen);
1590 level = btrfs_header_level(eb);
1595 path = btrfs_alloc_path();
1598 nritems = btrfs_header_nritems(eb);
1599 for (i = 0; i < nritems; i++) {
1600 btrfs_item_key_to_cpu(eb, &key, i);
1601 item_size = btrfs_item_size_nr(eb, i);
1603 /* inode keys are done during the first stage */
1604 if (key.type == BTRFS_INODE_ITEM_KEY &&
1605 wc->stage == LOG_WALK_REPLAY_INODES) {
1606 struct btrfs_inode_item *inode_item;
1609 inode_item = btrfs_item_ptr(eb, i,
1610 struct btrfs_inode_item);
1611 mode = btrfs_inode_mode(eb, inode_item);
1612 if (S_ISDIR(mode)) {
1613 ret = replay_dir_deletes(wc->trans,
1614 root, log, path, key.objectid, 0);
1617 ret = overwrite_item(wc->trans, root, path,
1621 /* for regular files, make sure corresponding
1622 * orhpan item exist. extents past the new EOF
1623 * will be truncated later by orphan cleanup.
1625 if (S_ISREG(mode)) {
1626 ret = insert_orphan_item(wc->trans, root,
1631 ret = link_to_fixup_dir(wc->trans, root,
1632 path, key.objectid);
1635 if (wc->stage < LOG_WALK_REPLAY_ALL)
1638 /* these keys are simply copied */
1639 if (key.type == BTRFS_XATTR_ITEM_KEY) {
1640 ret = overwrite_item(wc->trans, root, path,
1643 } else if (key.type == BTRFS_INODE_REF_KEY) {
1644 ret = add_inode_ref(wc->trans, root, log, path,
1646 BUG_ON(ret && ret != -ENOENT);
1647 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
1648 ret = replay_one_extent(wc->trans, root, path,
1651 } else if (key.type == BTRFS_DIR_ITEM_KEY ||
1652 key.type == BTRFS_DIR_INDEX_KEY) {
1653 ret = replay_one_dir_item(wc->trans, root, path,
1658 btrfs_free_path(path);
1662 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
1663 struct btrfs_root *root,
1664 struct btrfs_path *path, int *level,
1665 struct walk_control *wc)
1671 struct extent_buffer *next;
1672 struct extent_buffer *cur;
1673 struct extent_buffer *parent;
1677 WARN_ON(*level < 0);
1678 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1680 while (*level > 0) {
1681 WARN_ON(*level < 0);
1682 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1683 cur = path->nodes[*level];
1685 if (btrfs_header_level(cur) != *level)
1688 if (path->slots[*level] >=
1689 btrfs_header_nritems(cur))
1692 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
1693 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
1694 blocksize = btrfs_level_size(root, *level - 1);
1696 parent = path->nodes[*level];
1697 root_owner = btrfs_header_owner(parent);
1698 root_gen = btrfs_header_generation(parent);
1700 next = btrfs_find_create_tree_block(root, bytenr, blocksize);
1702 wc->process_func(root, next, wc, ptr_gen);
1705 path->slots[*level]++;
1707 btrfs_read_buffer(next, ptr_gen);
1709 btrfs_tree_lock(next);
1710 clean_tree_block(trans, root, next);
1711 btrfs_set_lock_blocking(next);
1712 btrfs_wait_tree_block_writeback(next);
1713 btrfs_tree_unlock(next);
1715 WARN_ON(root_owner !=
1716 BTRFS_TREE_LOG_OBJECTID);
1717 ret = btrfs_free_reserved_extent(root,
1721 free_extent_buffer(next);
1724 btrfs_read_buffer(next, ptr_gen);
1726 WARN_ON(*level <= 0);
1727 if (path->nodes[*level-1])
1728 free_extent_buffer(path->nodes[*level-1]);
1729 path->nodes[*level-1] = next;
1730 *level = btrfs_header_level(next);
1731 path->slots[*level] = 0;
1734 WARN_ON(*level < 0);
1735 WARN_ON(*level >= BTRFS_MAX_LEVEL);
1737 if (path->nodes[*level] == root->node)
1738 parent = path->nodes[*level];
1740 parent = path->nodes[*level + 1];
1742 bytenr = path->nodes[*level]->start;
1744 blocksize = btrfs_level_size(root, *level);
1745 root_owner = btrfs_header_owner(parent);
1746 root_gen = btrfs_header_generation(parent);
1748 wc->process_func(root, path->nodes[*level], wc,
1749 btrfs_header_generation(path->nodes[*level]));
1752 next = path->nodes[*level];
1753 btrfs_tree_lock(next);
1754 clean_tree_block(trans, root, next);
1755 btrfs_set_lock_blocking(next);
1756 btrfs_wait_tree_block_writeback(next);
1757 btrfs_tree_unlock(next);
1759 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1760 ret = btrfs_free_reserved_extent(root, bytenr, blocksize);
1763 free_extent_buffer(path->nodes[*level]);
1764 path->nodes[*level] = NULL;
1771 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
1772 struct btrfs_root *root,
1773 struct btrfs_path *path, int *level,
1774 struct walk_control *wc)
1782 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
1783 slot = path->slots[i];
1784 if (slot < btrfs_header_nritems(path->nodes[i]) - 1) {
1785 struct extent_buffer *node;
1786 node = path->nodes[i];
1789 WARN_ON(*level == 0);
1792 struct extent_buffer *parent;
1793 if (path->nodes[*level] == root->node)
1794 parent = path->nodes[*level];
1796 parent = path->nodes[*level + 1];
1798 root_owner = btrfs_header_owner(parent);
1799 root_gen = btrfs_header_generation(parent);
1800 wc->process_func(root, path->nodes[*level], wc,
1801 btrfs_header_generation(path->nodes[*level]));
1803 struct extent_buffer *next;
1805 next = path->nodes[*level];
1807 btrfs_tree_lock(next);
1808 clean_tree_block(trans, root, next);
1809 btrfs_set_lock_blocking(next);
1810 btrfs_wait_tree_block_writeback(next);
1811 btrfs_tree_unlock(next);
1813 WARN_ON(root_owner != BTRFS_TREE_LOG_OBJECTID);
1814 ret = btrfs_free_reserved_extent(root,
1815 path->nodes[*level]->start,
1816 path->nodes[*level]->len);
1819 free_extent_buffer(path->nodes[*level]);
1820 path->nodes[*level] = NULL;
1828 * drop the reference count on the tree rooted at 'snap'. This traverses
1829 * the tree freeing any blocks that have a ref count of zero after being
1832 static int walk_log_tree(struct btrfs_trans_handle *trans,
1833 struct btrfs_root *log, struct walk_control *wc)
1838 struct btrfs_path *path;
1842 path = btrfs_alloc_path();
1845 level = btrfs_header_level(log->node);
1847 path->nodes[level] = log->node;
1848 extent_buffer_get(log->node);
1849 path->slots[level] = 0;
1852 wret = walk_down_log_tree(trans, log, path, &level, wc);
1858 wret = walk_up_log_tree(trans, log, path, &level, wc);
1865 /* was the root node processed? if not, catch it here */
1866 if (path->nodes[orig_level]) {
1867 wc->process_func(log, path->nodes[orig_level], wc,
1868 btrfs_header_generation(path->nodes[orig_level]));
1870 struct extent_buffer *next;
1872 next = path->nodes[orig_level];
1874 btrfs_tree_lock(next);
1875 clean_tree_block(trans, log, next);
1876 btrfs_set_lock_blocking(next);
1877 btrfs_wait_tree_block_writeback(next);
1878 btrfs_tree_unlock(next);
1880 WARN_ON(log->root_key.objectid !=
1881 BTRFS_TREE_LOG_OBJECTID);
1882 ret = btrfs_free_reserved_extent(log, next->start,
1888 for (i = 0; i <= orig_level; i++) {
1889 if (path->nodes[i]) {
1890 free_extent_buffer(path->nodes[i]);
1891 path->nodes[i] = NULL;
1894 btrfs_free_path(path);
1899 * helper function to update the item for a given subvolumes log root
1900 * in the tree of log roots
1902 static int update_log_root(struct btrfs_trans_handle *trans,
1903 struct btrfs_root *log)
1907 if (log->log_transid == 1) {
1908 /* insert root item on the first sync */
1909 ret = btrfs_insert_root(trans, log->fs_info->log_root_tree,
1910 &log->root_key, &log->root_item);
1912 ret = btrfs_update_root(trans, log->fs_info->log_root_tree,
1913 &log->root_key, &log->root_item);
1918 static int wait_log_commit(struct btrfs_trans_handle *trans,
1919 struct btrfs_root *root, unsigned long transid)
1922 int index = transid % 2;
1925 * we only allow two pending log transactions at a time,
1926 * so we know that if ours is more than 2 older than the
1927 * current transaction, we're done
1930 prepare_to_wait(&root->log_commit_wait[index],
1931 &wait, TASK_UNINTERRUPTIBLE);
1932 mutex_unlock(&root->log_mutex);
1934 if (root->fs_info->last_trans_log_full_commit !=
1935 trans->transid && root->log_transid < transid + 2 &&
1936 atomic_read(&root->log_commit[index]))
1939 finish_wait(&root->log_commit_wait[index], &wait);
1940 mutex_lock(&root->log_mutex);
1941 } while (root->log_transid < transid + 2 &&
1942 atomic_read(&root->log_commit[index]));
1946 static int wait_for_writer(struct btrfs_trans_handle *trans,
1947 struct btrfs_root *root)
1950 while (atomic_read(&root->log_writers)) {
1951 prepare_to_wait(&root->log_writer_wait,
1952 &wait, TASK_UNINTERRUPTIBLE);
1953 mutex_unlock(&root->log_mutex);
1954 if (root->fs_info->last_trans_log_full_commit !=
1955 trans->transid && atomic_read(&root->log_writers))
1957 mutex_lock(&root->log_mutex);
1958 finish_wait(&root->log_writer_wait, &wait);
1964 * btrfs_sync_log does sends a given tree log down to the disk and
1965 * updates the super blocks to record it. When this call is done,
1966 * you know that any inodes previously logged are safely on disk only
1969 * Any other return value means you need to call btrfs_commit_transaction.
1970 * Some of the edge cases for fsyncing directories that have had unlinks
1971 * or renames done in the past mean that sometimes the only safe
1972 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
1973 * that has happened.
1975 int btrfs_sync_log(struct btrfs_trans_handle *trans,
1976 struct btrfs_root *root)
1982 struct btrfs_root *log = root->log_root;
1983 struct btrfs_root *log_root_tree = root->fs_info->log_root_tree;
1984 unsigned long log_transid = 0;
1986 mutex_lock(&root->log_mutex);
1987 index1 = root->log_transid % 2;
1988 if (atomic_read(&root->log_commit[index1])) {
1989 wait_log_commit(trans, root, root->log_transid);
1990 mutex_unlock(&root->log_mutex);
1993 atomic_set(&root->log_commit[index1], 1);
1995 /* wait for previous tree log sync to complete */
1996 if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
1997 wait_log_commit(trans, root, root->log_transid - 1);
2000 unsigned long batch = root->log_batch;
2001 if (root->log_multiple_pids) {
2002 mutex_unlock(&root->log_mutex);
2003 schedule_timeout_uninterruptible(1);
2004 mutex_lock(&root->log_mutex);
2006 wait_for_writer(trans, root);
2007 if (batch == root->log_batch)
2011 /* bail out if we need to do a full commit */
2012 if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2014 mutex_unlock(&root->log_mutex);
2018 log_transid = root->log_transid;
2019 if (log_transid % 2 == 0)
2020 mark = EXTENT_DIRTY;
2024 /* we start IO on all the marked extents here, but we don't actually
2025 * wait for them until later.
2027 ret = btrfs_write_marked_extents(log, &log->dirty_log_pages, mark);
2030 btrfs_set_root_node(&log->root_item, log->node);
2032 root->log_batch = 0;
2033 root->log_transid++;
2034 log->log_transid = root->log_transid;
2035 root->log_start_pid = 0;
2038 * IO has been started, blocks of the log tree have WRITTEN flag set
2039 * in their headers. new modifications of the log will be written to
2040 * new positions. so it's safe to allow log writers to go in.
2042 mutex_unlock(&root->log_mutex);
2044 mutex_lock(&log_root_tree->log_mutex);
2045 log_root_tree->log_batch++;
2046 atomic_inc(&log_root_tree->log_writers);
2047 mutex_unlock(&log_root_tree->log_mutex);
2049 ret = update_log_root(trans, log);
2052 mutex_lock(&log_root_tree->log_mutex);
2053 if (atomic_dec_and_test(&log_root_tree->log_writers)) {
2055 if (waitqueue_active(&log_root_tree->log_writer_wait))
2056 wake_up(&log_root_tree->log_writer_wait);
2059 index2 = log_root_tree->log_transid % 2;
2060 if (atomic_read(&log_root_tree->log_commit[index2])) {
2061 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2062 wait_log_commit(trans, log_root_tree,
2063 log_root_tree->log_transid);
2064 mutex_unlock(&log_root_tree->log_mutex);
2067 atomic_set(&log_root_tree->log_commit[index2], 1);
2069 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
2070 wait_log_commit(trans, log_root_tree,
2071 log_root_tree->log_transid - 1);
2074 wait_for_writer(trans, log_root_tree);
2077 * now that we've moved on to the tree of log tree roots,
2078 * check the full commit flag again
2080 if (root->fs_info->last_trans_log_full_commit == trans->transid) {
2081 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2082 mutex_unlock(&log_root_tree->log_mutex);
2084 goto out_wake_log_root;
2087 ret = btrfs_write_and_wait_marked_extents(log_root_tree,
2088 &log_root_tree->dirty_log_pages,
2089 EXTENT_DIRTY | EXTENT_NEW);
2091 btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
2093 btrfs_set_super_log_root(&root->fs_info->super_for_commit,
2094 log_root_tree->node->start);
2095 btrfs_set_super_log_root_level(&root->fs_info->super_for_commit,
2096 btrfs_header_level(log_root_tree->node));
2098 log_root_tree->log_batch = 0;
2099 log_root_tree->log_transid++;
2102 mutex_unlock(&log_root_tree->log_mutex);
2105 * nobody else is going to jump in and write the the ctree
2106 * super here because the log_commit atomic below is protecting
2107 * us. We must be called with a transaction handle pinning
2108 * the running transaction open, so a full commit can't hop
2109 * in and cause problems either.
2111 write_ctree_super(trans, root->fs_info->tree_root, 1);
2114 mutex_lock(&root->log_mutex);
2115 if (root->last_log_commit < log_transid)
2116 root->last_log_commit = log_transid;
2117 mutex_unlock(&root->log_mutex);
2120 atomic_set(&log_root_tree->log_commit[index2], 0);
2122 if (waitqueue_active(&log_root_tree->log_commit_wait[index2]))
2123 wake_up(&log_root_tree->log_commit_wait[index2]);
2125 atomic_set(&root->log_commit[index1], 0);
2127 if (waitqueue_active(&root->log_commit_wait[index1]))
2128 wake_up(&root->log_commit_wait[index1]);
2133 * free all the extents used by the tree log. This should be called
2134 * at commit time of the full transaction
2136 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
2139 struct btrfs_root *log;
2143 struct walk_control wc = {
2145 .process_func = process_one_buffer
2148 if (!root->log_root || root->fs_info->log_root_recovering)
2151 log = root->log_root;
2152 ret = walk_log_tree(trans, log, &wc);
2156 ret = find_first_extent_bit(&log->dirty_log_pages,
2157 0, &start, &end, EXTENT_DIRTY | EXTENT_NEW);
2161 clear_extent_bits(&log->dirty_log_pages, start, end,
2162 EXTENT_DIRTY | EXTENT_NEW, GFP_NOFS);
2165 if (log->log_transid > 0) {
2166 ret = btrfs_del_root(trans, root->fs_info->log_root_tree,
2170 root->log_root = NULL;
2171 free_extent_buffer(log->node);
2177 * If both a file and directory are logged, and unlinks or renames are
2178 * mixed in, we have a few interesting corners:
2180 * create file X in dir Y
2181 * link file X to X.link in dir Y
2183 * unlink file X but leave X.link
2186 * After a crash we would expect only X.link to exist. But file X
2187 * didn't get fsync'd again so the log has back refs for X and X.link.
2189 * We solve this by removing directory entries and inode backrefs from the
2190 * log when a file that was logged in the current transaction is
2191 * unlinked. Any later fsync will include the updated log entries, and
2192 * we'll be able to reconstruct the proper directory items from backrefs.
2194 * This optimizations allows us to avoid relogging the entire inode
2195 * or the entire directory.
2197 int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
2198 struct btrfs_root *root,
2199 const char *name, int name_len,
2200 struct inode *dir, u64 index)
2202 struct btrfs_root *log;
2203 struct btrfs_dir_item *di;
2204 struct btrfs_path *path;
2208 if (BTRFS_I(dir)->logged_trans < trans->transid)
2211 ret = join_running_log_trans(root);
2215 mutex_lock(&BTRFS_I(dir)->log_mutex);
2217 log = root->log_root;
2218 path = btrfs_alloc_path();
2219 di = btrfs_lookup_dir_item(trans, log, path, dir->i_ino,
2220 name, name_len, -1);
2221 if (di && !IS_ERR(di)) {
2222 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2223 bytes_del += name_len;
2226 btrfs_release_path(log, path);
2227 di = btrfs_lookup_dir_index_item(trans, log, path, dir->i_ino,
2228 index, name, name_len, -1);
2229 if (di && !IS_ERR(di)) {
2230 ret = btrfs_delete_one_dir_name(trans, log, path, di);
2231 bytes_del += name_len;
2235 /* update the directory size in the log to reflect the names
2239 struct btrfs_key key;
2241 key.objectid = dir->i_ino;
2243 key.type = BTRFS_INODE_ITEM_KEY;
2244 btrfs_release_path(log, path);
2246 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
2248 struct btrfs_inode_item *item;
2251 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2252 struct btrfs_inode_item);
2253 i_size = btrfs_inode_size(path->nodes[0], item);
2254 if (i_size > bytes_del)
2255 i_size -= bytes_del;
2258 btrfs_set_inode_size(path->nodes[0], item, i_size);
2259 btrfs_mark_buffer_dirty(path->nodes[0]);
2262 btrfs_release_path(log, path);
2265 btrfs_free_path(path);
2266 mutex_unlock(&BTRFS_I(dir)->log_mutex);
2267 btrfs_end_log_trans(root);
2272 /* see comments for btrfs_del_dir_entries_in_log */
2273 int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
2274 struct btrfs_root *root,
2275 const char *name, int name_len,
2276 struct inode *inode, u64 dirid)
2278 struct btrfs_root *log;
2282 if (BTRFS_I(inode)->logged_trans < trans->transid)
2285 ret = join_running_log_trans(root);
2288 log = root->log_root;
2289 mutex_lock(&BTRFS_I(inode)->log_mutex);
2291 ret = btrfs_del_inode_ref(trans, log, name, name_len, inode->i_ino,
2293 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2294 btrfs_end_log_trans(root);
2300 * creates a range item in the log for 'dirid'. first_offset and
2301 * last_offset tell us which parts of the key space the log should
2302 * be considered authoritative for.
2304 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
2305 struct btrfs_root *log,
2306 struct btrfs_path *path,
2307 int key_type, u64 dirid,
2308 u64 first_offset, u64 last_offset)
2311 struct btrfs_key key;
2312 struct btrfs_dir_log_item *item;
2314 key.objectid = dirid;
2315 key.offset = first_offset;
2316 if (key_type == BTRFS_DIR_ITEM_KEY)
2317 key.type = BTRFS_DIR_LOG_ITEM_KEY;
2319 key.type = BTRFS_DIR_LOG_INDEX_KEY;
2320 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
2323 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2324 struct btrfs_dir_log_item);
2325 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
2326 btrfs_mark_buffer_dirty(path->nodes[0]);
2327 btrfs_release_path(log, path);
2332 * log all the items included in the current transaction for a given
2333 * directory. This also creates the range items in the log tree required
2334 * to replay anything deleted before the fsync
2336 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
2337 struct btrfs_root *root, struct inode *inode,
2338 struct btrfs_path *path,
2339 struct btrfs_path *dst_path, int key_type,
2340 u64 min_offset, u64 *last_offset_ret)
2342 struct btrfs_key min_key;
2343 struct btrfs_key max_key;
2344 struct btrfs_root *log = root->log_root;
2345 struct extent_buffer *src;
2349 u64 first_offset = min_offset;
2350 u64 last_offset = (u64)-1;
2352 log = root->log_root;
2353 max_key.objectid = inode->i_ino;
2354 max_key.offset = (u64)-1;
2355 max_key.type = key_type;
2357 min_key.objectid = inode->i_ino;
2358 min_key.type = key_type;
2359 min_key.offset = min_offset;
2361 path->keep_locks = 1;
2363 ret = btrfs_search_forward(root, &min_key, &max_key,
2364 path, 0, trans->transid);
2367 * we didn't find anything from this transaction, see if there
2368 * is anything at all
2370 if (ret != 0 || min_key.objectid != inode->i_ino ||
2371 min_key.type != key_type) {
2372 min_key.objectid = inode->i_ino;
2373 min_key.type = key_type;
2374 min_key.offset = (u64)-1;
2375 btrfs_release_path(root, path);
2376 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2378 btrfs_release_path(root, path);
2381 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2383 /* if ret == 0 there are items for this type,
2384 * create a range to tell us the last key of this type.
2385 * otherwise, there are no items in this directory after
2386 * *min_offset, and we create a range to indicate that.
2389 struct btrfs_key tmp;
2390 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
2392 if (key_type == tmp.type)
2393 first_offset = max(min_offset, tmp.offset) + 1;
2398 /* go backward to find any previous key */
2399 ret = btrfs_previous_item(root, path, inode->i_ino, key_type);
2401 struct btrfs_key tmp;
2402 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2403 if (key_type == tmp.type) {
2404 first_offset = tmp.offset;
2405 ret = overwrite_item(trans, log, dst_path,
2406 path->nodes[0], path->slots[0],
2410 btrfs_release_path(root, path);
2412 /* find the first key from this transaction again */
2413 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
2420 * we have a block from this transaction, log every item in it
2421 * from our directory
2424 struct btrfs_key tmp;
2425 src = path->nodes[0];
2426 nritems = btrfs_header_nritems(src);
2427 for (i = path->slots[0]; i < nritems; i++) {
2428 btrfs_item_key_to_cpu(src, &min_key, i);
2430 if (min_key.objectid != inode->i_ino ||
2431 min_key.type != key_type)
2433 ret = overwrite_item(trans, log, dst_path, src, i,
2437 path->slots[0] = nritems;
2440 * look ahead to the next item and see if it is also
2441 * from this directory and from this transaction
2443 ret = btrfs_next_leaf(root, path);
2445 last_offset = (u64)-1;
2448 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
2449 if (tmp.objectid != inode->i_ino || tmp.type != key_type) {
2450 last_offset = (u64)-1;
2453 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
2454 ret = overwrite_item(trans, log, dst_path,
2455 path->nodes[0], path->slots[0],
2459 last_offset = tmp.offset;
2464 *last_offset_ret = last_offset;
2465 btrfs_release_path(root, path);
2466 btrfs_release_path(log, dst_path);
2468 /* insert the log range keys to indicate where the log is valid */
2469 ret = insert_dir_log_key(trans, log, path, key_type, inode->i_ino,
2470 first_offset, last_offset);
2476 * logging directories is very similar to logging inodes, We find all the items
2477 * from the current transaction and write them to the log.
2479 * The recovery code scans the directory in the subvolume, and if it finds a
2480 * key in the range logged that is not present in the log tree, then it means
2481 * that dir entry was unlinked during the transaction.
2483 * In order for that scan to work, we must include one key smaller than
2484 * the smallest logged by this transaction and one key larger than the largest
2485 * key logged by this transaction.
2487 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
2488 struct btrfs_root *root, struct inode *inode,
2489 struct btrfs_path *path,
2490 struct btrfs_path *dst_path)
2495 int key_type = BTRFS_DIR_ITEM_KEY;
2501 ret = log_dir_items(trans, root, inode, path,
2502 dst_path, key_type, min_key,
2505 if (max_key == (u64)-1)
2507 min_key = max_key + 1;
2510 if (key_type == BTRFS_DIR_ITEM_KEY) {
2511 key_type = BTRFS_DIR_INDEX_KEY;
2518 * a helper function to drop items from the log before we relog an
2519 * inode. max_key_type indicates the highest item type to remove.
2520 * This cannot be run for file data extents because it does not
2521 * free the extents they point to.
2523 static int drop_objectid_items(struct btrfs_trans_handle *trans,
2524 struct btrfs_root *log,
2525 struct btrfs_path *path,
2526 u64 objectid, int max_key_type)
2529 struct btrfs_key key;
2530 struct btrfs_key found_key;
2532 key.objectid = objectid;
2533 key.type = max_key_type;
2534 key.offset = (u64)-1;
2537 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
2542 if (path->slots[0] == 0)
2546 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2549 if (found_key.objectid != objectid)
2552 ret = btrfs_del_item(trans, log, path);
2554 btrfs_release_path(log, path);
2556 btrfs_release_path(log, path);
2560 static noinline int copy_items(struct btrfs_trans_handle *trans,
2561 struct btrfs_root *log,
2562 struct btrfs_path *dst_path,
2563 struct extent_buffer *src,
2564 int start_slot, int nr, int inode_only)
2566 unsigned long src_offset;
2567 unsigned long dst_offset;
2568 struct btrfs_file_extent_item *extent;
2569 struct btrfs_inode_item *inode_item;
2571 struct btrfs_key *ins_keys;
2575 struct list_head ordered_sums;
2577 INIT_LIST_HEAD(&ordered_sums);
2579 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
2580 nr * sizeof(u32), GFP_NOFS);
2581 ins_sizes = (u32 *)ins_data;
2582 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
2584 for (i = 0; i < nr; i++) {
2585 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
2586 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
2588 ret = btrfs_insert_empty_items(trans, log, dst_path,
2589 ins_keys, ins_sizes, nr);
2592 for (i = 0; i < nr; i++, dst_path->slots[0]++) {
2593 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
2594 dst_path->slots[0]);
2596 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
2598 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
2599 src_offset, ins_sizes[i]);
2601 if (inode_only == LOG_INODE_EXISTS &&
2602 ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
2603 inode_item = btrfs_item_ptr(dst_path->nodes[0],
2605 struct btrfs_inode_item);
2606 btrfs_set_inode_size(dst_path->nodes[0], inode_item, 0);
2608 /* set the generation to zero so the recover code
2609 * can tell the difference between an logging
2610 * just to say 'this inode exists' and a logging
2611 * to say 'update this inode with these values'
2613 btrfs_set_inode_generation(dst_path->nodes[0],
2616 /* take a reference on file data extents so that truncates
2617 * or deletes of this inode don't have to relog the inode
2620 if (btrfs_key_type(ins_keys + i) == BTRFS_EXTENT_DATA_KEY) {
2622 extent = btrfs_item_ptr(src, start_slot + i,
2623 struct btrfs_file_extent_item);
2625 found_type = btrfs_file_extent_type(src, extent);
2626 if (found_type == BTRFS_FILE_EXTENT_REG ||
2627 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
2629 ds = btrfs_file_extent_disk_bytenr(src,
2631 /* ds == 0 is a hole */
2635 dl = btrfs_file_extent_disk_num_bytes(src,
2637 cs = btrfs_file_extent_offset(src, extent);
2638 cl = btrfs_file_extent_num_bytes(src,
2640 if (btrfs_file_extent_compression(src,
2646 ret = btrfs_lookup_csums_range(
2647 log->fs_info->csum_root,
2648 ds + cs, ds + cs + cl - 1,
2655 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
2656 btrfs_release_path(log, dst_path);
2660 * we have to do this after the loop above to avoid changing the
2661 * log tree while trying to change the log tree.
2663 while (!list_empty(&ordered_sums)) {
2664 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
2665 struct btrfs_ordered_sum,
2667 ret = btrfs_csum_file_blocks(trans, log, sums);
2669 list_del(&sums->list);
2675 /* log a single inode in the tree log.
2676 * At least one parent directory for this inode must exist in the tree
2677 * or be logged already.
2679 * Any items from this inode changed by the current transaction are copied
2680 * to the log tree. An extra reference is taken on any extents in this
2681 * file, allowing us to avoid a whole pile of corner cases around logging
2682 * blocks that have been removed from the tree.
2684 * See LOG_INODE_ALL and related defines for a description of what inode_only
2687 * This handles both files and directories.
2689 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
2690 struct btrfs_root *root, struct inode *inode,
2693 struct btrfs_path *path;
2694 struct btrfs_path *dst_path;
2695 struct btrfs_key min_key;
2696 struct btrfs_key max_key;
2697 struct btrfs_root *log = root->log_root;
2698 struct extent_buffer *src = NULL;
2702 int ins_start_slot = 0;
2705 log = root->log_root;
2707 path = btrfs_alloc_path();
2708 dst_path = btrfs_alloc_path();
2710 min_key.objectid = inode->i_ino;
2711 min_key.type = BTRFS_INODE_ITEM_KEY;
2714 max_key.objectid = inode->i_ino;
2716 /* today the code can only do partial logging of directories */
2717 if (!S_ISDIR(inode->i_mode))
2718 inode_only = LOG_INODE_ALL;
2720 if (inode_only == LOG_INODE_EXISTS || S_ISDIR(inode->i_mode))
2721 max_key.type = BTRFS_XATTR_ITEM_KEY;
2723 max_key.type = (u8)-1;
2724 max_key.offset = (u64)-1;
2726 mutex_lock(&BTRFS_I(inode)->log_mutex);
2729 * a brute force approach to making sure we get the most uptodate
2730 * copies of everything.
2732 if (S_ISDIR(inode->i_mode)) {
2733 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
2735 if (inode_only == LOG_INODE_EXISTS)
2736 max_key_type = BTRFS_XATTR_ITEM_KEY;
2737 ret = drop_objectid_items(trans, log, path,
2738 inode->i_ino, max_key_type);
2740 ret = btrfs_truncate_inode_items(trans, log, inode, 0, 0);
2743 path->keep_locks = 1;
2747 ret = btrfs_search_forward(root, &min_key, &max_key,
2748 path, 0, trans->transid);
2752 /* note, ins_nr might be > 0 here, cleanup outside the loop */
2753 if (min_key.objectid != inode->i_ino)
2755 if (min_key.type > max_key.type)
2758 src = path->nodes[0];
2759 size = btrfs_item_size_nr(src, path->slots[0]);
2760 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
2763 } else if (!ins_nr) {
2764 ins_start_slot = path->slots[0];
2769 ret = copy_items(trans, log, dst_path, src, ins_start_slot,
2770 ins_nr, inode_only);
2773 ins_start_slot = path->slots[0];
2776 nritems = btrfs_header_nritems(path->nodes[0]);
2778 if (path->slots[0] < nritems) {
2779 btrfs_item_key_to_cpu(path->nodes[0], &min_key,
2784 ret = copy_items(trans, log, dst_path, src,
2786 ins_nr, inode_only);
2790 btrfs_release_path(root, path);
2792 if (min_key.offset < (u64)-1)
2794 else if (min_key.type < (u8)-1)
2796 else if (min_key.objectid < (u64)-1)
2802 ret = copy_items(trans, log, dst_path, src,
2804 ins_nr, inode_only);
2809 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->i_mode)) {
2810 btrfs_release_path(root, path);
2811 btrfs_release_path(log, dst_path);
2812 ret = log_directory_changes(trans, root, inode, path, dst_path);
2815 BTRFS_I(inode)->logged_trans = trans->transid;
2816 mutex_unlock(&BTRFS_I(inode)->log_mutex);
2818 btrfs_free_path(path);
2819 btrfs_free_path(dst_path);
2824 * follow the dentry parent pointers up the chain and see if any
2825 * of the directories in it require a full commit before they can
2826 * be logged. Returns zero if nothing special needs to be done or 1 if
2827 * a full commit is required.
2829 static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
2830 struct inode *inode,
2831 struct dentry *parent,
2832 struct super_block *sb,
2836 struct btrfs_root *root;
2839 * for regular files, if its inode is already on disk, we don't
2840 * have to worry about the parents at all. This is because
2841 * we can use the last_unlink_trans field to record renames
2842 * and other fun in this file.
2844 if (S_ISREG(inode->i_mode) &&
2845 BTRFS_I(inode)->generation <= last_committed &&
2846 BTRFS_I(inode)->last_unlink_trans <= last_committed)
2849 if (!S_ISDIR(inode->i_mode)) {
2850 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
2852 inode = parent->d_inode;
2856 BTRFS_I(inode)->logged_trans = trans->transid;
2859 if (BTRFS_I(inode)->last_unlink_trans > last_committed) {
2860 root = BTRFS_I(inode)->root;
2863 * make sure any commits to the log are forced
2864 * to be full commits
2866 root->fs_info->last_trans_log_full_commit =
2872 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
2875 if (IS_ROOT(parent))
2878 parent = parent->d_parent;
2879 inode = parent->d_inode;
2886 static int inode_in_log(struct btrfs_trans_handle *trans,
2887 struct inode *inode)
2889 struct btrfs_root *root = BTRFS_I(inode)->root;
2892 mutex_lock(&root->log_mutex);
2893 if (BTRFS_I(inode)->logged_trans == trans->transid &&
2894 BTRFS_I(inode)->last_sub_trans <= root->last_log_commit)
2896 mutex_unlock(&root->log_mutex);
2902 * helper function around btrfs_log_inode to make sure newly created
2903 * parent directories also end up in the log. A minimal inode and backref
2904 * only logging is done of any parent directories that are older than
2905 * the last committed transaction
2907 int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
2908 struct btrfs_root *root, struct inode *inode,
2909 struct dentry *parent, int exists_only)
2911 int inode_only = exists_only ? LOG_INODE_EXISTS : LOG_INODE_ALL;
2912 struct super_block *sb;
2914 u64 last_committed = root->fs_info->last_trans_committed;
2918 if (btrfs_test_opt(root, NOTREELOG)) {
2923 if (root->fs_info->last_trans_log_full_commit >
2924 root->fs_info->last_trans_committed) {
2929 if (root != BTRFS_I(inode)->root ||
2930 btrfs_root_refs(&root->root_item) == 0) {
2935 ret = check_parent_dirs_for_sync(trans, inode, parent,
2936 sb, last_committed);
2940 if (inode_in_log(trans, inode)) {
2941 ret = BTRFS_NO_LOG_SYNC;
2945 start_log_trans(trans, root);
2947 ret = btrfs_log_inode(trans, root, inode, inode_only);
2951 * for regular files, if its inode is already on disk, we don't
2952 * have to worry about the parents at all. This is because
2953 * we can use the last_unlink_trans field to record renames
2954 * and other fun in this file.
2956 if (S_ISREG(inode->i_mode) &&
2957 BTRFS_I(inode)->generation <= last_committed &&
2958 BTRFS_I(inode)->last_unlink_trans <= last_committed)
2961 inode_only = LOG_INODE_EXISTS;
2963 if (!parent || !parent->d_inode || sb != parent->d_inode->i_sb)
2966 inode = parent->d_inode;
2967 if (root != BTRFS_I(inode)->root)
2970 if (BTRFS_I(inode)->generation >
2971 root->fs_info->last_trans_committed) {
2972 ret = btrfs_log_inode(trans, root, inode, inode_only);
2975 if (IS_ROOT(parent))
2978 parent = parent->d_parent;
2982 btrfs_end_log_trans(root);
2988 * it is not safe to log dentry if the chunk root has added new
2989 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
2990 * If this returns 1, you must commit the transaction to safely get your
2993 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
2994 struct btrfs_root *root, struct dentry *dentry)
2996 return btrfs_log_inode_parent(trans, root, dentry->d_inode,
2997 dentry->d_parent, 0);
3001 * should be called during mount to recover any replay any log trees
3004 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
3007 struct btrfs_path *path;
3008 struct btrfs_trans_handle *trans;
3009 struct btrfs_key key;
3010 struct btrfs_key found_key;
3011 struct btrfs_key tmp_key;
3012 struct btrfs_root *log;
3013 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
3014 struct walk_control wc = {
3015 .process_func = process_one_buffer,
3019 fs_info->log_root_recovering = 1;
3020 path = btrfs_alloc_path();
3023 trans = btrfs_start_transaction(fs_info->tree_root, 1);
3028 walk_log_tree(trans, log_root_tree, &wc);
3031 key.objectid = BTRFS_TREE_LOG_OBJECTID;
3032 key.offset = (u64)-1;
3033 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
3036 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
3040 if (path->slots[0] == 0)
3044 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
3046 btrfs_release_path(log_root_tree, path);
3047 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
3050 log = btrfs_read_fs_root_no_radix(log_root_tree,
3055 tmp_key.objectid = found_key.offset;
3056 tmp_key.type = BTRFS_ROOT_ITEM_KEY;
3057 tmp_key.offset = (u64)-1;
3059 wc.replay_dest = btrfs_read_fs_root_no_name(fs_info, &tmp_key);
3060 BUG_ON(!wc.replay_dest);
3062 wc.replay_dest->log_root = log;
3063 btrfs_record_root_in_trans(trans, wc.replay_dest);
3064 ret = walk_log_tree(trans, log, &wc);
3067 if (wc.stage == LOG_WALK_REPLAY_ALL) {
3068 ret = fixup_inode_link_counts(trans, wc.replay_dest,
3073 key.offset = found_key.offset - 1;
3074 wc.replay_dest->log_root = NULL;
3075 free_extent_buffer(log->node);
3076 free_extent_buffer(log->commit_root);
3079 if (found_key.offset == 0)
3082 btrfs_release_path(log_root_tree, path);
3084 /* step one is to pin it all, step two is to replay just inodes */
3087 wc.process_func = replay_one_buffer;
3088 wc.stage = LOG_WALK_REPLAY_INODES;
3091 /* step three is to replay everything */
3092 if (wc.stage < LOG_WALK_REPLAY_ALL) {
3097 btrfs_free_path(path);
3099 free_extent_buffer(log_root_tree->node);
3100 log_root_tree->log_root = NULL;
3101 fs_info->log_root_recovering = 0;
3103 /* step 4: commit the transaction, which also unpins the blocks */
3104 btrfs_commit_transaction(trans, fs_info->tree_root);
3106 kfree(log_root_tree);
3111 * there are some corner cases where we want to force a full
3112 * commit instead of allowing a directory to be logged.
3114 * They revolve around files there were unlinked from the directory, and
3115 * this function updates the parent directory so that a full commit is
3116 * properly done if it is fsync'd later after the unlinks are done.
3118 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
3119 struct inode *dir, struct inode *inode,
3123 * when we're logging a file, if it hasn't been renamed
3124 * or unlinked, and its inode is fully committed on disk,
3125 * we don't have to worry about walking up the directory chain
3126 * to log its parents.
3128 * So, we use the last_unlink_trans field to put this transid
3129 * into the file. When the file is logged we check it and
3130 * don't log the parents if the file is fully on disk.
3132 if (S_ISREG(inode->i_mode))
3133 BTRFS_I(inode)->last_unlink_trans = trans->transid;
3136 * if this directory was already logged any new
3137 * names for this file/dir will get recorded
3140 if (BTRFS_I(dir)->logged_trans == trans->transid)
3144 * if the inode we're about to unlink was logged,
3145 * the log will be properly updated for any new names
3147 if (BTRFS_I(inode)->logged_trans == trans->transid)
3151 * when renaming files across directories, if the directory
3152 * there we're unlinking from gets fsync'd later on, there's
3153 * no way to find the destination directory later and fsync it
3154 * properly. So, we have to be conservative and force commits
3155 * so the new name gets discovered.
3160 /* we can safely do the unlink without any special recording */
3164 BTRFS_I(dir)->last_unlink_trans = trans->transid;
3168 * Call this after adding a new name for a file and it will properly
3169 * update the log to reflect the new name.
3171 * It will return zero if all goes well, and it will return 1 if a
3172 * full transaction commit is required.
3174 int btrfs_log_new_name(struct btrfs_trans_handle *trans,
3175 struct inode *inode, struct inode *old_dir,
3176 struct dentry *parent)
3178 struct btrfs_root * root = BTRFS_I(inode)->root;
3181 * this will force the logging code to walk the dentry chain
3184 if (S_ISREG(inode->i_mode))
3185 BTRFS_I(inode)->last_unlink_trans = trans->transid;
3188 * if this inode hasn't been logged and directory we're renaming it
3189 * from hasn't been logged, we don't need to log it
3191 if (BTRFS_I(inode)->logged_trans <=
3192 root->fs_info->last_trans_committed &&
3193 (!old_dir || BTRFS_I(old_dir)->logged_trans <=
3194 root->fs_info->last_trans_committed))
3197 return btrfs_log_inode_parent(trans, root, inode, parent, 1);