1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2008 Oracle. All rights reserved.
6 #include <linux/sched.h>
7 #include <linux/slab.h>
8 #include <linux/blkdev.h>
9 #include <linux/list_sort.h>
10 #include <linux/iversion.h>
16 #include "print-tree.h"
18 #include "compression.h"
20 #include "block-group.h"
21 #include "space-info.h"
23 /* magic values for the inode_only field in btrfs_log_inode:
25 * LOG_INODE_ALL means to log everything
26 * LOG_INODE_EXISTS means to log just enough to recreate the inode
37 * directory trouble cases
39 * 1) on rename or unlink, if the inode being unlinked isn't in the fsync
40 * log, we must force a full commit before doing an fsync of the directory
41 * where the unlink was done.
42 * ---> record transid of last unlink/rename per directory
46 * rename foo/some_dir foo2/some_dir
48 * fsync foo/some_dir/some_file
50 * The fsync above will unlink the original some_dir without recording
51 * it in its new location (foo2). After a crash, some_dir will be gone
52 * unless the fsync of some_file forces a full commit
54 * 2) we must log any new names for any file or dir that is in the fsync
55 * log. ---> check inode while renaming/linking.
57 * 2a) we must log any new names for any file or dir during rename
58 * when the directory they are being removed from was logged.
59 * ---> check inode and old parent dir during rename
61 * 2a is actually the more important variant. With the extra logging
62 * a crash might unlink the old name without recreating the new one
64 * 3) after a crash, we must go through any directories with a link count
65 * of zero and redo the rm -rf
72 * The directory f1 was fully removed from the FS, but fsync was never
73 * called on f1, only its parent dir. After a crash the rm -rf must
74 * be replayed. This must be able to recurse down the entire
75 * directory tree. The inode link count fixup code takes care of the
80 * stages for the tree walking. The first
81 * stage (0) is to only pin down the blocks we find
82 * the second stage (1) is to make sure that all the inodes
83 * we find in the log are created in the subvolume.
85 * The last stage is to deal with directories and links and extents
86 * and all the other fun semantics
90 LOG_WALK_REPLAY_INODES,
91 LOG_WALK_REPLAY_DIR_INDEX,
95 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
96 struct btrfs_root *root, struct btrfs_inode *inode,
98 struct btrfs_log_ctx *ctx);
99 static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
100 struct btrfs_root *root,
101 struct btrfs_path *path, u64 objectid);
102 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
103 struct btrfs_root *root,
104 struct btrfs_root *log,
105 struct btrfs_path *path,
106 u64 dirid, int del_all);
109 * tree logging is a special write ahead log used to make sure that
110 * fsyncs and O_SYNCs can happen without doing full tree commits.
112 * Full tree commits are expensive because they require commonly
113 * modified blocks to be recowed, creating many dirty pages in the
114 * extent tree an 4x-6x higher write load than ext3.
116 * Instead of doing a tree commit on every fsync, we use the
117 * key ranges and transaction ids to find items for a given file or directory
118 * that have changed in this transaction. Those items are copied into
119 * a special tree (one per subvolume root), that tree is written to disk
120 * and then the fsync is considered complete.
122 * After a crash, items are copied out of the log-tree back into the
123 * subvolume tree. Any file data extents found are recorded in the extent
124 * allocation tree, and the log-tree freed.
126 * The log tree is read three times, once to pin down all the extents it is
127 * using in ram and once, once to create all the inodes logged in the tree
128 * and once to do all the other items.
132 * start a sub transaction and setup the log tree
133 * this increments the log tree writer count to make the people
134 * syncing the tree wait for us to finish
136 static int start_log_trans(struct btrfs_trans_handle *trans,
137 struct btrfs_root *root,
138 struct btrfs_log_ctx *ctx)
140 struct btrfs_fs_info *fs_info = root->fs_info;
141 struct btrfs_root *tree_root = fs_info->tree_root;
145 * First check if the log root tree was already created. If not, create
146 * it before locking the root's log_mutex, just to keep lockdep happy.
148 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) {
149 mutex_lock(&tree_root->log_mutex);
150 if (!fs_info->log_root_tree) {
151 ret = btrfs_init_log_root_tree(trans, fs_info);
153 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state);
155 mutex_unlock(&tree_root->log_mutex);
160 mutex_lock(&root->log_mutex);
162 if (root->log_root) {
163 if (btrfs_need_log_full_commit(trans)) {
168 if (!root->log_start_pid) {
169 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
170 root->log_start_pid = current->pid;
171 } else if (root->log_start_pid != current->pid) {
172 set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
175 ret = btrfs_add_log_tree(trans, root);
179 set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
180 clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
181 root->log_start_pid = current->pid;
184 atomic_inc(&root->log_writers);
185 if (ctx && !ctx->logging_new_name) {
186 int index = root->log_transid % 2;
187 list_add_tail(&ctx->list, &root->log_ctxs[index]);
188 ctx->log_transid = root->log_transid;
192 mutex_unlock(&root->log_mutex);
197 * returns 0 if there was a log transaction running and we were able
198 * to join, or returns -ENOENT if there were not transactions
201 static int join_running_log_trans(struct btrfs_root *root)
205 if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
208 mutex_lock(&root->log_mutex);
209 if (root->log_root) {
211 atomic_inc(&root->log_writers);
213 mutex_unlock(&root->log_mutex);
218 * This either makes the current running log transaction wait
219 * until you call btrfs_end_log_trans() or it makes any future
220 * log transactions wait until you call btrfs_end_log_trans()
222 void btrfs_pin_log_trans(struct btrfs_root *root)
224 atomic_inc(&root->log_writers);
228 * indicate we're done making changes to the log tree
229 * and wake up anyone waiting to do a sync
231 void btrfs_end_log_trans(struct btrfs_root *root)
233 if (atomic_dec_and_test(&root->log_writers)) {
234 /* atomic_dec_and_test implies a barrier */
235 cond_wake_up_nomb(&root->log_writer_wait);
239 static int btrfs_write_tree_block(struct extent_buffer *buf)
241 return filemap_fdatawrite_range(buf->pages[0]->mapping, buf->start,
242 buf->start + buf->len - 1);
245 static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
247 filemap_fdatawait_range(buf->pages[0]->mapping,
248 buf->start, buf->start + buf->len - 1);
252 * the walk control struct is used to pass state down the chain when
253 * processing the log tree. The stage field tells us which part
254 * of the log tree processing we are currently doing. The others
255 * are state fields used for that specific part
257 struct walk_control {
258 /* should we free the extent on disk when done? This is used
259 * at transaction commit time while freeing a log tree
263 /* should we write out the extent buffer? This is used
264 * while flushing the log tree to disk during a sync
268 /* should we wait for the extent buffer io to finish? Also used
269 * while flushing the log tree to disk for a sync
273 /* pin only walk, we record which extents on disk belong to the
278 /* what stage of the replay code we're currently in */
282 * Ignore any items from the inode currently being processed. Needs
283 * to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
284 * the LOG_WALK_REPLAY_INODES stage.
286 bool ignore_cur_inode;
288 /* the root we are currently replaying */
289 struct btrfs_root *replay_dest;
291 /* the trans handle for the current replay */
292 struct btrfs_trans_handle *trans;
294 /* the function that gets used to process blocks we find in the
295 * tree. Note the extent_buffer might not be up to date when it is
296 * passed in, and it must be checked or read if you need the data
299 int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
300 struct walk_control *wc, u64 gen, int level);
304 * process_func used to pin down extents, write them or wait on them
306 static int process_one_buffer(struct btrfs_root *log,
307 struct extent_buffer *eb,
308 struct walk_control *wc, u64 gen, int level)
310 struct btrfs_fs_info *fs_info = log->fs_info;
314 * If this fs is mixed then we need to be able to process the leaves to
315 * pin down any logged extents, so we have to read the block.
317 if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
318 ret = btrfs_read_buffer(eb, gen, level, NULL);
324 ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start,
327 if (!ret && btrfs_buffer_uptodate(eb, gen, 0)) {
328 if (wc->pin && btrfs_header_level(eb) == 0)
329 ret = btrfs_exclude_logged_extents(eb);
331 btrfs_write_tree_block(eb);
333 btrfs_wait_tree_block_writeback(eb);
339 * Item overwrite used by replay and tree logging. eb, slot and key all refer
340 * to the src data we are copying out.
342 * root is the tree we are copying into, and path is a scratch
343 * path for use in this function (it should be released on entry and
344 * will be released on exit).
346 * If the key is already in the destination tree the existing item is
347 * overwritten. If the existing item isn't big enough, it is extended.
348 * If it is too large, it is truncated.
350 * If the key isn't in the destination yet, a new item is inserted.
352 static noinline int overwrite_item(struct btrfs_trans_handle *trans,
353 struct btrfs_root *root,
354 struct btrfs_path *path,
355 struct extent_buffer *eb, int slot,
356 struct btrfs_key *key)
360 u64 saved_i_size = 0;
361 int save_old_i_size = 0;
362 unsigned long src_ptr;
363 unsigned long dst_ptr;
364 int overwrite_root = 0;
365 bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
367 if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
370 item_size = btrfs_item_size_nr(eb, slot);
371 src_ptr = btrfs_item_ptr_offset(eb, slot);
373 /* look for the key in the destination tree */
374 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
381 u32 dst_size = btrfs_item_size_nr(path->nodes[0],
383 if (dst_size != item_size)
386 if (item_size == 0) {
387 btrfs_release_path(path);
390 dst_copy = kmalloc(item_size, GFP_NOFS);
391 src_copy = kmalloc(item_size, GFP_NOFS);
392 if (!dst_copy || !src_copy) {
393 btrfs_release_path(path);
399 read_extent_buffer(eb, src_copy, src_ptr, item_size);
401 dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
402 read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
404 ret = memcmp(dst_copy, src_copy, item_size);
409 * they have the same contents, just return, this saves
410 * us from cowing blocks in the destination tree and doing
411 * extra writes that may not have been done by a previous
415 btrfs_release_path(path);
420 * We need to load the old nbytes into the inode so when we
421 * replay the extents we've logged we get the right nbytes.
424 struct btrfs_inode_item *item;
428 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
429 struct btrfs_inode_item);
430 nbytes = btrfs_inode_nbytes(path->nodes[0], item);
431 item = btrfs_item_ptr(eb, slot,
432 struct btrfs_inode_item);
433 btrfs_set_inode_nbytes(eb, item, nbytes);
436 * If this is a directory we need to reset the i_size to
437 * 0 so that we can set it up properly when replaying
438 * the rest of the items in this log.
440 mode = btrfs_inode_mode(eb, item);
442 btrfs_set_inode_size(eb, item, 0);
444 } else if (inode_item) {
445 struct btrfs_inode_item *item;
449 * New inode, set nbytes to 0 so that the nbytes comes out
450 * properly when we replay the extents.
452 item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
453 btrfs_set_inode_nbytes(eb, item, 0);
456 * If this is a directory we need to reset the i_size to 0 so
457 * that we can set it up properly when replaying the rest of
458 * the items in this log.
460 mode = btrfs_inode_mode(eb, item);
462 btrfs_set_inode_size(eb, item, 0);
465 btrfs_release_path(path);
466 /* try to insert the key into the destination tree */
467 path->skip_release_on_error = 1;
468 ret = btrfs_insert_empty_item(trans, root, path,
470 path->skip_release_on_error = 0;
472 /* make sure any existing item is the correct size */
473 if (ret == -EEXIST || ret == -EOVERFLOW) {
475 found_size = btrfs_item_size_nr(path->nodes[0],
477 if (found_size > item_size)
478 btrfs_truncate_item(path, item_size, 1);
479 else if (found_size < item_size)
480 btrfs_extend_item(path, item_size - found_size);
484 dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
487 /* don't overwrite an existing inode if the generation number
488 * was logged as zero. This is done when the tree logging code
489 * is just logging an inode to make sure it exists after recovery.
491 * Also, don't overwrite i_size on directories during replay.
492 * log replay inserts and removes directory items based on the
493 * state of the tree found in the subvolume, and i_size is modified
496 if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
497 struct btrfs_inode_item *src_item;
498 struct btrfs_inode_item *dst_item;
500 src_item = (struct btrfs_inode_item *)src_ptr;
501 dst_item = (struct btrfs_inode_item *)dst_ptr;
503 if (btrfs_inode_generation(eb, src_item) == 0) {
504 struct extent_buffer *dst_eb = path->nodes[0];
505 const u64 ino_size = btrfs_inode_size(eb, src_item);
508 * For regular files an ino_size == 0 is used only when
509 * logging that an inode exists, as part of a directory
510 * fsync, and the inode wasn't fsynced before. In this
511 * case don't set the size of the inode in the fs/subvol
512 * tree, otherwise we would be throwing valid data away.
514 if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
515 S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
517 btrfs_set_inode_size(dst_eb, dst_item, ino_size);
521 if (overwrite_root &&
522 S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
523 S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
525 saved_i_size = btrfs_inode_size(path->nodes[0],
530 copy_extent_buffer(path->nodes[0], eb, dst_ptr,
533 if (save_old_i_size) {
534 struct btrfs_inode_item *dst_item;
535 dst_item = (struct btrfs_inode_item *)dst_ptr;
536 btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
539 /* make sure the generation is filled in */
540 if (key->type == BTRFS_INODE_ITEM_KEY) {
541 struct btrfs_inode_item *dst_item;
542 dst_item = (struct btrfs_inode_item *)dst_ptr;
543 if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
544 btrfs_set_inode_generation(path->nodes[0], dst_item,
549 btrfs_mark_buffer_dirty(path->nodes[0]);
550 btrfs_release_path(path);
555 * simple helper to read an inode off the disk from a given root
556 * This can only be called for subvolume roots and not for the log
558 static noinline struct inode *read_one_inode(struct btrfs_root *root,
563 inode = btrfs_iget(root->fs_info->sb, objectid, root);
569 /* replays a single extent in 'eb' at 'slot' with 'key' into the
570 * subvolume 'root'. path is released on entry and should be released
573 * extents in the log tree have not been allocated out of the extent
574 * tree yet. So, this completes the allocation, taking a reference
575 * as required if the extent already exists or creating a new extent
576 * if it isn't in the extent allocation tree yet.
578 * The extent is inserted into the file, dropping any existing extents
579 * from the file that overlap the new one.
581 static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
582 struct btrfs_root *root,
583 struct btrfs_path *path,
584 struct extent_buffer *eb, int slot,
585 struct btrfs_key *key)
587 struct btrfs_drop_extents_args drop_args = { 0 };
588 struct btrfs_fs_info *fs_info = root->fs_info;
591 u64 start = key->offset;
593 struct btrfs_file_extent_item *item;
594 struct inode *inode = NULL;
598 item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
599 found_type = btrfs_file_extent_type(eb, item);
601 if (found_type == BTRFS_FILE_EXTENT_REG ||
602 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
603 nbytes = btrfs_file_extent_num_bytes(eb, item);
604 extent_end = start + nbytes;
607 * We don't add to the inodes nbytes if we are prealloc or a
610 if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
612 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
613 size = btrfs_file_extent_ram_bytes(eb, item);
614 nbytes = btrfs_file_extent_ram_bytes(eb, item);
615 extent_end = ALIGN(start + size,
616 fs_info->sectorsize);
622 inode = read_one_inode(root, key->objectid);
629 * first check to see if we already have this extent in the
630 * file. This must be done before the btrfs_drop_extents run
631 * so we don't try to drop this extent.
633 ret = btrfs_lookup_file_extent(trans, root, path,
634 btrfs_ino(BTRFS_I(inode)), start, 0);
637 (found_type == BTRFS_FILE_EXTENT_REG ||
638 found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
639 struct btrfs_file_extent_item cmp1;
640 struct btrfs_file_extent_item cmp2;
641 struct btrfs_file_extent_item *existing;
642 struct extent_buffer *leaf;
644 leaf = path->nodes[0];
645 existing = btrfs_item_ptr(leaf, path->slots[0],
646 struct btrfs_file_extent_item);
648 read_extent_buffer(eb, &cmp1, (unsigned long)item,
650 read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
654 * we already have a pointer to this exact extent,
655 * we don't have to do anything
657 if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
658 btrfs_release_path(path);
662 btrfs_release_path(path);
664 /* drop any overlapping extents */
665 drop_args.start = start;
666 drop_args.end = extent_end;
667 drop_args.drop_cache = true;
668 ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args);
672 if (found_type == BTRFS_FILE_EXTENT_REG ||
673 found_type == BTRFS_FILE_EXTENT_PREALLOC) {
675 unsigned long dest_offset;
676 struct btrfs_key ins;
678 if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
679 btrfs_fs_incompat(fs_info, NO_HOLES))
682 ret = btrfs_insert_empty_item(trans, root, path, key,
686 dest_offset = btrfs_item_ptr_offset(path->nodes[0],
688 copy_extent_buffer(path->nodes[0], eb, dest_offset,
689 (unsigned long)item, sizeof(*item));
691 ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
692 ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
693 ins.type = BTRFS_EXTENT_ITEM_KEY;
694 offset = key->offset - btrfs_file_extent_offset(eb, item);
697 * Manually record dirty extent, as here we did a shallow
698 * file extent item copy and skip normal backref update,
699 * but modifying extent tree all by ourselves.
700 * So need to manually record dirty extent for qgroup,
701 * as the owner of the file extent changed from log tree
702 * (doesn't affect qgroup) to fs/file tree(affects qgroup)
704 ret = btrfs_qgroup_trace_extent(trans,
705 btrfs_file_extent_disk_bytenr(eb, item),
706 btrfs_file_extent_disk_num_bytes(eb, item),
711 if (ins.objectid > 0) {
712 struct btrfs_ref ref = { 0 };
715 LIST_HEAD(ordered_sums);
718 * is this extent already allocated in the extent
719 * allocation tree? If so, just add a reference
721 ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
724 btrfs_init_generic_ref(&ref,
725 BTRFS_ADD_DELAYED_REF,
726 ins.objectid, ins.offset, 0);
727 btrfs_init_data_ref(&ref,
728 root->root_key.objectid,
729 key->objectid, offset);
730 ret = btrfs_inc_extent_ref(trans, &ref);
735 * insert the extent pointer in the extent
738 ret = btrfs_alloc_logged_file_extent(trans,
739 root->root_key.objectid,
740 key->objectid, offset, &ins);
744 btrfs_release_path(path);
746 if (btrfs_file_extent_compression(eb, item)) {
747 csum_start = ins.objectid;
748 csum_end = csum_start + ins.offset;
750 csum_start = ins.objectid +
751 btrfs_file_extent_offset(eb, item);
752 csum_end = csum_start +
753 btrfs_file_extent_num_bytes(eb, item);
756 ret = btrfs_lookup_csums_range(root->log_root,
757 csum_start, csum_end - 1,
762 * Now delete all existing cums in the csum root that
763 * cover our range. We do this because we can have an
764 * extent that is completely referenced by one file
765 * extent item and partially referenced by another
766 * file extent item (like after using the clone or
767 * extent_same ioctls). In this case if we end up doing
768 * the replay of the one that partially references the
769 * extent first, and we do not do the csum deletion
770 * below, we can get 2 csum items in the csum tree that
771 * overlap each other. For example, imagine our log has
772 * the two following file extent items:
774 * key (257 EXTENT_DATA 409600)
775 * extent data disk byte 12845056 nr 102400
776 * extent data offset 20480 nr 20480 ram 102400
778 * key (257 EXTENT_DATA 819200)
779 * extent data disk byte 12845056 nr 102400
780 * extent data offset 0 nr 102400 ram 102400
782 * Where the second one fully references the 100K extent
783 * that starts at disk byte 12845056, and the log tree
784 * has a single csum item that covers the entire range
787 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
789 * After the first file extent item is replayed, the
790 * csum tree gets the following csum item:
792 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
794 * Which covers the 20K sub-range starting at offset 20K
795 * of our extent. Now when we replay the second file
796 * extent item, if we do not delete existing csum items
797 * that cover any of its blocks, we end up getting two
798 * csum items in our csum tree that overlap each other:
800 * key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
801 * key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
803 * Which is a problem, because after this anyone trying
804 * to lookup up for the checksum of any block of our
805 * extent starting at an offset of 40K or higher, will
806 * end up looking at the second csum item only, which
807 * does not contain the checksum for any block starting
808 * at offset 40K or higher of our extent.
810 while (!list_empty(&ordered_sums)) {
811 struct btrfs_ordered_sum *sums;
812 sums = list_entry(ordered_sums.next,
813 struct btrfs_ordered_sum,
816 ret = btrfs_del_csums(trans,
821 ret = btrfs_csum_file_blocks(trans,
822 fs_info->csum_root, sums);
823 list_del(&sums->list);
829 btrfs_release_path(path);
831 } else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
832 /* inline extents are easy, we just overwrite them */
833 ret = overwrite_item(trans, root, path, eb, slot, key);
838 ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start,
844 btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found);
845 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
853 * when cleaning up conflicts between the directory names in the
854 * subvolume, directory names in the log and directory names in the
855 * inode back references, we may have to unlink inodes from directories.
857 * This is a helper function to do the unlink of a specific directory
860 static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
861 struct btrfs_root *root,
862 struct btrfs_path *path,
863 struct btrfs_inode *dir,
864 struct btrfs_dir_item *di)
869 struct extent_buffer *leaf;
870 struct btrfs_key location;
873 leaf = path->nodes[0];
875 btrfs_dir_item_key_to_cpu(leaf, di, &location);
876 name_len = btrfs_dir_name_len(leaf, di);
877 name = kmalloc(name_len, GFP_NOFS);
881 read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
882 btrfs_release_path(path);
884 inode = read_one_inode(root, location.objectid);
890 ret = link_to_fixup_dir(trans, root, path, location.objectid);
894 ret = btrfs_unlink_inode(trans, root, dir, BTRFS_I(inode), name,
899 ret = btrfs_run_delayed_items(trans);
907 * helper function to see if a given name and sequence number found
908 * in an inode back reference are already in a directory and correctly
909 * point to this inode
911 static noinline int inode_in_dir(struct btrfs_root *root,
912 struct btrfs_path *path,
913 u64 dirid, u64 objectid, u64 index,
914 const char *name, int name_len)
916 struct btrfs_dir_item *di;
917 struct btrfs_key location;
920 di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
921 index, name, name_len, 0);
922 if (di && !IS_ERR(di)) {
923 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
924 if (location.objectid != objectid)
928 btrfs_release_path(path);
930 di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
931 if (di && !IS_ERR(di)) {
932 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
933 if (location.objectid != objectid)
939 btrfs_release_path(path);
944 * helper function to check a log tree for a named back reference in
945 * an inode. This is used to decide if a back reference that is
946 * found in the subvolume conflicts with what we find in the log.
948 * inode backreferences may have multiple refs in a single item,
949 * during replay we process one reference at a time, and we don't
950 * want to delete valid links to a file from the subvolume if that
951 * link is also in the log.
953 static noinline int backref_in_log(struct btrfs_root *log,
954 struct btrfs_key *key,
956 const char *name, int namelen)
958 struct btrfs_path *path;
961 path = btrfs_alloc_path();
965 ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
968 } else if (ret == 1) {
973 if (key->type == BTRFS_INODE_EXTREF_KEY)
974 ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
979 ret = !!btrfs_find_name_in_backref(path->nodes[0],
983 btrfs_free_path(path);
987 static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
988 struct btrfs_root *root,
989 struct btrfs_path *path,
990 struct btrfs_root *log_root,
991 struct btrfs_inode *dir,
992 struct btrfs_inode *inode,
993 u64 inode_objectid, u64 parent_objectid,
994 u64 ref_index, char *name, int namelen,
1000 struct extent_buffer *leaf;
1001 struct btrfs_dir_item *di;
1002 struct btrfs_key search_key;
1003 struct btrfs_inode_extref *extref;
1006 /* Search old style refs */
1007 search_key.objectid = inode_objectid;
1008 search_key.type = BTRFS_INODE_REF_KEY;
1009 search_key.offset = parent_objectid;
1010 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
1012 struct btrfs_inode_ref *victim_ref;
1014 unsigned long ptr_end;
1016 leaf = path->nodes[0];
1018 /* are we trying to overwrite a back ref for the root directory
1019 * if so, just jump out, we're done
1021 if (search_key.objectid == search_key.offset)
1024 /* check all the names in this back reference to see
1025 * if they are in the log. if so, we allow them to stay
1026 * otherwise they must be unlinked as a conflict
1028 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1029 ptr_end = ptr + btrfs_item_size_nr(leaf, path->slots[0]);
1030 while (ptr < ptr_end) {
1031 victim_ref = (struct btrfs_inode_ref *)ptr;
1032 victim_name_len = btrfs_inode_ref_name_len(leaf,
1034 victim_name = kmalloc(victim_name_len, GFP_NOFS);
1038 read_extent_buffer(leaf, victim_name,
1039 (unsigned long)(victim_ref + 1),
1042 ret = backref_in_log(log_root, &search_key,
1043 parent_objectid, victim_name,
1049 inc_nlink(&inode->vfs_inode);
1050 btrfs_release_path(path);
1052 ret = btrfs_unlink_inode(trans, root, dir, inode,
1053 victim_name, victim_name_len);
1057 ret = btrfs_run_delayed_items(trans);
1065 ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
1069 * NOTE: we have searched root tree and checked the
1070 * corresponding ref, it does not need to check again.
1074 btrfs_release_path(path);
1076 /* Same search but for extended refs */
1077 extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
1078 inode_objectid, parent_objectid, 0,
1080 if (!IS_ERR_OR_NULL(extref)) {
1084 struct inode *victim_parent;
1086 leaf = path->nodes[0];
1088 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1089 base = btrfs_item_ptr_offset(leaf, path->slots[0]);
1091 while (cur_offset < item_size) {
1092 extref = (struct btrfs_inode_extref *)(base + cur_offset);
1094 victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
1096 if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
1099 victim_name = kmalloc(victim_name_len, GFP_NOFS);
1102 read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
1105 search_key.objectid = inode_objectid;
1106 search_key.type = BTRFS_INODE_EXTREF_KEY;
1107 search_key.offset = btrfs_extref_hash(parent_objectid,
1110 ret = backref_in_log(log_root, &search_key,
1111 parent_objectid, victim_name,
1117 victim_parent = read_one_inode(root,
1119 if (victim_parent) {
1120 inc_nlink(&inode->vfs_inode);
1121 btrfs_release_path(path);
1123 ret = btrfs_unlink_inode(trans, root,
1124 BTRFS_I(victim_parent),
1129 ret = btrfs_run_delayed_items(
1132 iput(victim_parent);
1141 cur_offset += victim_name_len + sizeof(*extref);
1145 btrfs_release_path(path);
1147 /* look for a conflicting sequence number */
1148 di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
1149 ref_index, name, namelen, 0);
1150 if (di && !IS_ERR(di)) {
1151 ret = drop_one_dir_item(trans, root, path, dir, di);
1155 btrfs_release_path(path);
1157 /* look for a conflicting name */
1158 di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
1160 if (di && !IS_ERR(di)) {
1161 ret = drop_one_dir_item(trans, root, path, dir, di);
1165 btrfs_release_path(path);
1170 static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1171 u32 *namelen, char **name, u64 *index,
1172 u64 *parent_objectid)
1174 struct btrfs_inode_extref *extref;
1176 extref = (struct btrfs_inode_extref *)ref_ptr;
1178 *namelen = btrfs_inode_extref_name_len(eb, extref);
1179 *name = kmalloc(*namelen, GFP_NOFS);
1183 read_extent_buffer(eb, *name, (unsigned long)&extref->name,
1187 *index = btrfs_inode_extref_index(eb, extref);
1188 if (parent_objectid)
1189 *parent_objectid = btrfs_inode_extref_parent(eb, extref);
1194 static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
1195 u32 *namelen, char **name, u64 *index)
1197 struct btrfs_inode_ref *ref;
1199 ref = (struct btrfs_inode_ref *)ref_ptr;
1201 *namelen = btrfs_inode_ref_name_len(eb, ref);
1202 *name = kmalloc(*namelen, GFP_NOFS);
1206 read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
1209 *index = btrfs_inode_ref_index(eb, ref);
1215 * Take an inode reference item from the log tree and iterate all names from the
1216 * inode reference item in the subvolume tree with the same key (if it exists).
1217 * For any name that is not in the inode reference item from the log tree, do a
1218 * proper unlink of that name (that is, remove its entry from the inode
1219 * reference item and both dir index keys).
1221 static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
1222 struct btrfs_root *root,
1223 struct btrfs_path *path,
1224 struct btrfs_inode *inode,
1225 struct extent_buffer *log_eb,
1227 struct btrfs_key *key)
1230 unsigned long ref_ptr;
1231 unsigned long ref_end;
1232 struct extent_buffer *eb;
1235 btrfs_release_path(path);
1236 ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
1244 eb = path->nodes[0];
1245 ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
1246 ref_end = ref_ptr + btrfs_item_size_nr(eb, path->slots[0]);
1247 while (ref_ptr < ref_end) {
1252 if (key->type == BTRFS_INODE_EXTREF_KEY) {
1253 ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
1256 parent_id = key->offset;
1257 ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
1263 if (key->type == BTRFS_INODE_EXTREF_KEY)
1264 ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
1268 ret = !!btrfs_find_name_in_backref(log_eb, log_slot,
1274 btrfs_release_path(path);
1275 dir = read_one_inode(root, parent_id);
1281 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
1282 inode, name, namelen);
1292 if (key->type == BTRFS_INODE_EXTREF_KEY)
1293 ref_ptr += sizeof(struct btrfs_inode_extref);
1295 ref_ptr += sizeof(struct btrfs_inode_ref);
1299 btrfs_release_path(path);
1303 static int btrfs_inode_ref_exists(struct inode *inode, struct inode *dir,
1304 const u8 ref_type, const char *name,
1307 struct btrfs_key key;
1308 struct btrfs_path *path;
1309 const u64 parent_id = btrfs_ino(BTRFS_I(dir));
1312 path = btrfs_alloc_path();
1316 key.objectid = btrfs_ino(BTRFS_I(inode));
1317 key.type = ref_type;
1318 if (key.type == BTRFS_INODE_REF_KEY)
1319 key.offset = parent_id;
1321 key.offset = btrfs_extref_hash(parent_id, name, namelen);
1323 ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0);
1330 if (key.type == BTRFS_INODE_EXTREF_KEY)
1331 ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
1332 path->slots[0], parent_id, name, namelen);
1334 ret = !!btrfs_find_name_in_backref(path->nodes[0], path->slots[0],
1338 btrfs_free_path(path);
1342 static int add_link(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1343 struct inode *dir, struct inode *inode, const char *name,
1344 int namelen, u64 ref_index)
1346 struct btrfs_dir_item *dir_item;
1347 struct btrfs_key key;
1348 struct btrfs_path *path;
1349 struct inode *other_inode = NULL;
1352 path = btrfs_alloc_path();
1356 dir_item = btrfs_lookup_dir_item(NULL, root, path,
1357 btrfs_ino(BTRFS_I(dir)),
1360 btrfs_release_path(path);
1362 } else if (IS_ERR(dir_item)) {
1363 ret = PTR_ERR(dir_item);
1368 * Our inode's dentry collides with the dentry of another inode which is
1369 * in the log but not yet processed since it has a higher inode number.
1370 * So delete that other dentry.
1372 btrfs_dir_item_key_to_cpu(path->nodes[0], dir_item, &key);
1373 btrfs_release_path(path);
1374 other_inode = read_one_inode(root, key.objectid);
1379 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir), BTRFS_I(other_inode),
1384 * If we dropped the link count to 0, bump it so that later the iput()
1385 * on the inode will not free it. We will fixup the link count later.
1387 if (other_inode->i_nlink == 0)
1388 inc_nlink(other_inode);
1390 ret = btrfs_run_delayed_items(trans);
1394 ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
1395 name, namelen, 0, ref_index);
1398 btrfs_free_path(path);
1404 * replay one inode back reference item found in the log tree.
1405 * eb, slot and key refer to the buffer and key found in the log tree.
1406 * root is the destination we are replaying into, and path is for temp
1407 * use by this function. (it should be released on return).
1409 static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
1410 struct btrfs_root *root,
1411 struct btrfs_root *log,
1412 struct btrfs_path *path,
1413 struct extent_buffer *eb, int slot,
1414 struct btrfs_key *key)
1416 struct inode *dir = NULL;
1417 struct inode *inode = NULL;
1418 unsigned long ref_ptr;
1419 unsigned long ref_end;
1423 int search_done = 0;
1424 int log_ref_ver = 0;
1425 u64 parent_objectid;
1428 int ref_struct_size;
1430 ref_ptr = btrfs_item_ptr_offset(eb, slot);
1431 ref_end = ref_ptr + btrfs_item_size_nr(eb, slot);
1433 if (key->type == BTRFS_INODE_EXTREF_KEY) {
1434 struct btrfs_inode_extref *r;
1436 ref_struct_size = sizeof(struct btrfs_inode_extref);
1438 r = (struct btrfs_inode_extref *)ref_ptr;
1439 parent_objectid = btrfs_inode_extref_parent(eb, r);
1441 ref_struct_size = sizeof(struct btrfs_inode_ref);
1442 parent_objectid = key->offset;
1444 inode_objectid = key->objectid;
1447 * it is possible that we didn't log all the parent directories
1448 * for a given inode. If we don't find the dir, just don't
1449 * copy the back ref in. The link count fixup code will take
1452 dir = read_one_inode(root, parent_objectid);
1458 inode = read_one_inode(root, inode_objectid);
1464 while (ref_ptr < ref_end) {
1466 ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
1467 &ref_index, &parent_objectid);
1469 * parent object can change from one array
1473 dir = read_one_inode(root, parent_objectid);
1479 ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
1485 /* if we already have a perfect match, we're done */
1486 if (!inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
1487 btrfs_ino(BTRFS_I(inode)), ref_index,
1490 * look for a conflicting back reference in the
1491 * metadata. if we find one we have to unlink that name
1492 * of the file before we add our new link. Later on, we
1493 * overwrite any existing back reference, and we don't
1494 * want to create dangling pointers in the directory.
1498 ret = __add_inode_ref(trans, root, path, log,
1503 ref_index, name, namelen,
1513 * If a reference item already exists for this inode
1514 * with the same parent and name, but different index,
1515 * drop it and the corresponding directory index entries
1516 * from the parent before adding the new reference item
1517 * and dir index entries, otherwise we would fail with
1518 * -EEXIST returned from btrfs_add_link() below.
1520 ret = btrfs_inode_ref_exists(inode, dir, key->type,
1523 ret = btrfs_unlink_inode(trans, root,
1528 * If we dropped the link count to 0, bump it so
1529 * that later the iput() on the inode will not
1530 * free it. We will fixup the link count later.
1532 if (!ret && inode->i_nlink == 0)
1538 /* insert our name */
1539 ret = add_link(trans, root, dir, inode, name, namelen,
1544 btrfs_update_inode(trans, root, BTRFS_I(inode));
1547 ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
1557 * Before we overwrite the inode reference item in the subvolume tree
1558 * with the item from the log tree, we must unlink all names from the
1559 * parent directory that are in the subvolume's tree inode reference
1560 * item, otherwise we end up with an inconsistent subvolume tree where
1561 * dir index entries exist for a name but there is no inode reference
1562 * item with the same name.
1564 ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
1569 /* finally write the back reference in the inode */
1570 ret = overwrite_item(trans, root, path, eb, slot, key);
1572 btrfs_release_path(path);
1579 static int count_inode_extrefs(struct btrfs_root *root,
1580 struct btrfs_inode *inode, struct btrfs_path *path)
1584 unsigned int nlink = 0;
1587 u64 inode_objectid = btrfs_ino(inode);
1590 struct btrfs_inode_extref *extref;
1591 struct extent_buffer *leaf;
1594 ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
1599 leaf = path->nodes[0];
1600 item_size = btrfs_item_size_nr(leaf, path->slots[0]);
1601 ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
1604 while (cur_offset < item_size) {
1605 extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
1606 name_len = btrfs_inode_extref_name_len(leaf, extref);
1610 cur_offset += name_len + sizeof(*extref);
1614 btrfs_release_path(path);
1616 btrfs_release_path(path);
1618 if (ret < 0 && ret != -ENOENT)
1623 static int count_inode_refs(struct btrfs_root *root,
1624 struct btrfs_inode *inode, struct btrfs_path *path)
1627 struct btrfs_key key;
1628 unsigned int nlink = 0;
1630 unsigned long ptr_end;
1632 u64 ino = btrfs_ino(inode);
1635 key.type = BTRFS_INODE_REF_KEY;
1636 key.offset = (u64)-1;
1639 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
1643 if (path->slots[0] == 0)
1648 btrfs_item_key_to_cpu(path->nodes[0], &key,
1650 if (key.objectid != ino ||
1651 key.type != BTRFS_INODE_REF_KEY)
1653 ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
1654 ptr_end = ptr + btrfs_item_size_nr(path->nodes[0],
1656 while (ptr < ptr_end) {
1657 struct btrfs_inode_ref *ref;
1659 ref = (struct btrfs_inode_ref *)ptr;
1660 name_len = btrfs_inode_ref_name_len(path->nodes[0],
1662 ptr = (unsigned long)(ref + 1) + name_len;
1666 if (key.offset == 0)
1668 if (path->slots[0] > 0) {
1673 btrfs_release_path(path);
1675 btrfs_release_path(path);
1681 * There are a few corners where the link count of the file can't
1682 * be properly maintained during replay. So, instead of adding
1683 * lots of complexity to the log code, we just scan the backrefs
1684 * for any file that has been through replay.
1686 * The scan will update the link count on the inode to reflect the
1687 * number of back refs found. If it goes down to zero, the iput
1688 * will free the inode.
1690 static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
1691 struct btrfs_root *root,
1692 struct inode *inode)
1694 struct btrfs_path *path;
1697 u64 ino = btrfs_ino(BTRFS_I(inode));
1699 path = btrfs_alloc_path();
1703 ret = count_inode_refs(root, BTRFS_I(inode), path);
1709 ret = count_inode_extrefs(root, BTRFS_I(inode), path);
1717 if (nlink != inode->i_nlink) {
1718 set_nlink(inode, nlink);
1719 btrfs_update_inode(trans, root, BTRFS_I(inode));
1721 BTRFS_I(inode)->index_cnt = (u64)-1;
1723 if (inode->i_nlink == 0) {
1724 if (S_ISDIR(inode->i_mode)) {
1725 ret = replay_dir_deletes(trans, root, NULL, path,
1730 ret = btrfs_insert_orphan_item(trans, root, ino);
1736 btrfs_free_path(path);
1740 static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
1741 struct btrfs_root *root,
1742 struct btrfs_path *path)
1745 struct btrfs_key key;
1746 struct inode *inode;
1748 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1749 key.type = BTRFS_ORPHAN_ITEM_KEY;
1750 key.offset = (u64)-1;
1752 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1757 if (path->slots[0] == 0)
1762 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
1763 if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
1764 key.type != BTRFS_ORPHAN_ITEM_KEY)
1767 ret = btrfs_del_item(trans, root, path);
1771 btrfs_release_path(path);
1772 inode = read_one_inode(root, key.offset);
1776 ret = fixup_inode_link_count(trans, root, inode);
1782 * fixup on a directory may create new entries,
1783 * make sure we always look for the highset possible
1786 key.offset = (u64)-1;
1790 btrfs_release_path(path);
1796 * record a given inode in the fixup dir so we can check its link
1797 * count when replay is done. The link count is incremented here
1798 * so the inode won't go away until we check it
1800 static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
1801 struct btrfs_root *root,
1802 struct btrfs_path *path,
1805 struct btrfs_key key;
1807 struct inode *inode;
1809 inode = read_one_inode(root, objectid);
1813 key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
1814 key.type = BTRFS_ORPHAN_ITEM_KEY;
1815 key.offset = objectid;
1817 ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
1819 btrfs_release_path(path);
1821 if (!inode->i_nlink)
1822 set_nlink(inode, 1);
1825 ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
1826 } else if (ret == -EEXIST) {
1829 BUG(); /* Logic Error */
1837 * when replaying the log for a directory, we only insert names
1838 * for inodes that actually exist. This means an fsync on a directory
1839 * does not implicitly fsync all the new files in it
1841 static noinline int insert_one_name(struct btrfs_trans_handle *trans,
1842 struct btrfs_root *root,
1843 u64 dirid, u64 index,
1844 char *name, int name_len,
1845 struct btrfs_key *location)
1847 struct inode *inode;
1851 inode = read_one_inode(root, location->objectid);
1855 dir = read_one_inode(root, dirid);
1861 ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
1862 name_len, 1, index);
1864 /* FIXME, put inode into FIXUP list */
1872 * take a single entry in a log directory item and replay it into
1875 * if a conflicting item exists in the subdirectory already,
1876 * the inode it points to is unlinked and put into the link count
1879 * If a name from the log points to a file or directory that does
1880 * not exist in the FS, it is skipped. fsyncs on directories
1881 * do not force down inodes inside that directory, just changes to the
1882 * names or unlinks in a directory.
1884 * Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
1885 * non-existing inode) and 1 if the name was replayed.
1887 static noinline int replay_one_name(struct btrfs_trans_handle *trans,
1888 struct btrfs_root *root,
1889 struct btrfs_path *path,
1890 struct extent_buffer *eb,
1891 struct btrfs_dir_item *di,
1892 struct btrfs_key *key)
1896 struct btrfs_dir_item *dst_di;
1897 struct btrfs_key found_key;
1898 struct btrfs_key log_key;
1903 bool update_size = (key->type == BTRFS_DIR_INDEX_KEY);
1904 bool name_added = false;
1906 dir = read_one_inode(root, key->objectid);
1910 name_len = btrfs_dir_name_len(eb, di);
1911 name = kmalloc(name_len, GFP_NOFS);
1917 log_type = btrfs_dir_type(eb, di);
1918 read_extent_buffer(eb, name, (unsigned long)(di + 1),
1921 btrfs_dir_item_key_to_cpu(eb, di, &log_key);
1922 exists = btrfs_lookup_inode(trans, root, path, &log_key, 0);
1927 btrfs_release_path(path);
1929 if (key->type == BTRFS_DIR_ITEM_KEY) {
1930 dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
1932 } else if (key->type == BTRFS_DIR_INDEX_KEY) {
1933 dst_di = btrfs_lookup_dir_index_item(trans, root, path,
1942 if (IS_ERR_OR_NULL(dst_di)) {
1943 /* we need a sequence number to insert, so we only
1944 * do inserts for the BTRFS_DIR_INDEX_KEY types
1946 if (key->type != BTRFS_DIR_INDEX_KEY)
1951 btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
1952 /* the existing item matches the logged item */
1953 if (found_key.objectid == log_key.objectid &&
1954 found_key.type == log_key.type &&
1955 found_key.offset == log_key.offset &&
1956 btrfs_dir_type(path->nodes[0], dst_di) == log_type) {
1957 update_size = false;
1962 * don't drop the conflicting directory entry if the inode
1963 * for the new entry doesn't exist
1968 ret = drop_one_dir_item(trans, root, path, BTRFS_I(dir), dst_di);
1972 if (key->type == BTRFS_DIR_INDEX_KEY)
1975 btrfs_release_path(path);
1976 if (!ret && update_size) {
1977 btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2);
1978 ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
1982 if (!ret && name_added)
1988 * Check if the inode reference exists in the log for the given name,
1989 * inode and parent inode
1991 found_key.objectid = log_key.objectid;
1992 found_key.type = BTRFS_INODE_REF_KEY;
1993 found_key.offset = key->objectid;
1994 ret = backref_in_log(root->log_root, &found_key, 0, name, name_len);
1998 /* The dentry will be added later. */
2000 update_size = false;
2004 found_key.objectid = log_key.objectid;
2005 found_key.type = BTRFS_INODE_EXTREF_KEY;
2006 found_key.offset = key->objectid;
2007 ret = backref_in_log(root->log_root, &found_key, key->objectid, name,
2012 /* The dentry will be added later. */
2014 update_size = false;
2017 btrfs_release_path(path);
2018 ret = insert_one_name(trans, root, key->objectid, key->offset,
2019 name, name_len, &log_key);
2020 if (ret && ret != -ENOENT && ret != -EEXIST)
2024 update_size = false;
2030 * find all the names in a directory item and reconcile them into
2031 * the subvolume. Only BTRFS_DIR_ITEM_KEY types will have more than
2032 * one name in a directory item, but the same code gets used for
2033 * both directory index types
2035 static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
2036 struct btrfs_root *root,
2037 struct btrfs_path *path,
2038 struct extent_buffer *eb, int slot,
2039 struct btrfs_key *key)
2042 u32 item_size = btrfs_item_size_nr(eb, slot);
2043 struct btrfs_dir_item *di;
2046 unsigned long ptr_end;
2047 struct btrfs_path *fixup_path = NULL;
2049 ptr = btrfs_item_ptr_offset(eb, slot);
2050 ptr_end = ptr + item_size;
2051 while (ptr < ptr_end) {
2052 di = (struct btrfs_dir_item *)ptr;
2053 name_len = btrfs_dir_name_len(eb, di);
2054 ret = replay_one_name(trans, root, path, eb, di, key);
2057 ptr = (unsigned long)(di + 1);
2061 * If this entry refers to a non-directory (directories can not
2062 * have a link count > 1) and it was added in the transaction
2063 * that was not committed, make sure we fixup the link count of
2064 * the inode it the entry points to. Otherwise something like
2065 * the following would result in a directory pointing to an
2066 * inode with a wrong link that does not account for this dir
2074 * ln testdir/bar testdir/bar_link
2075 * ln testdir/foo testdir/foo_link
2076 * xfs_io -c "fsync" testdir/bar
2080 * mount fs, log replay happens
2082 * File foo would remain with a link count of 1 when it has two
2083 * entries pointing to it in the directory testdir. This would
2084 * make it impossible to ever delete the parent directory has
2085 * it would result in stale dentries that can never be deleted.
2087 if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
2088 struct btrfs_key di_key;
2091 fixup_path = btrfs_alloc_path();
2098 btrfs_dir_item_key_to_cpu(eb, di, &di_key);
2099 ret = link_to_fixup_dir(trans, root, fixup_path,
2106 btrfs_free_path(fixup_path);
2111 * directory replay has two parts. There are the standard directory
2112 * items in the log copied from the subvolume, and range items
2113 * created in the log while the subvolume was logged.
2115 * The range items tell us which parts of the key space the log
2116 * is authoritative for. During replay, if a key in the subvolume
2117 * directory is in a logged range item, but not actually in the log
2118 * that means it was deleted from the directory before the fsync
2119 * and should be removed.
2121 static noinline int find_dir_range(struct btrfs_root *root,
2122 struct btrfs_path *path,
2123 u64 dirid, int key_type,
2124 u64 *start_ret, u64 *end_ret)
2126 struct btrfs_key key;
2128 struct btrfs_dir_log_item *item;
2132 if (*start_ret == (u64)-1)
2135 key.objectid = dirid;
2136 key.type = key_type;
2137 key.offset = *start_ret;
2139 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2143 if (path->slots[0] == 0)
2148 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2150 if (key.type != key_type || key.objectid != dirid) {
2154 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2155 struct btrfs_dir_log_item);
2156 found_end = btrfs_dir_log_end(path->nodes[0], item);
2158 if (*start_ret >= key.offset && *start_ret <= found_end) {
2160 *start_ret = key.offset;
2161 *end_ret = found_end;
2166 /* check the next slot in the tree to see if it is a valid item */
2167 nritems = btrfs_header_nritems(path->nodes[0]);
2169 if (path->slots[0] >= nritems) {
2170 ret = btrfs_next_leaf(root, path);
2175 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
2177 if (key.type != key_type || key.objectid != dirid) {
2181 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
2182 struct btrfs_dir_log_item);
2183 found_end = btrfs_dir_log_end(path->nodes[0], item);
2184 *start_ret = key.offset;
2185 *end_ret = found_end;
2188 btrfs_release_path(path);
2193 * this looks for a given directory item in the log. If the directory
2194 * item is not in the log, the item is removed and the inode it points
2197 static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
2198 struct btrfs_root *root,
2199 struct btrfs_root *log,
2200 struct btrfs_path *path,
2201 struct btrfs_path *log_path,
2203 struct btrfs_key *dir_key)
2206 struct extent_buffer *eb;
2209 struct btrfs_dir_item *di;
2210 struct btrfs_dir_item *log_di;
2213 unsigned long ptr_end;
2215 struct inode *inode;
2216 struct btrfs_key location;
2219 eb = path->nodes[0];
2220 slot = path->slots[0];
2221 item_size = btrfs_item_size_nr(eb, slot);
2222 ptr = btrfs_item_ptr_offset(eb, slot);
2223 ptr_end = ptr + item_size;
2224 while (ptr < ptr_end) {
2225 di = (struct btrfs_dir_item *)ptr;
2226 name_len = btrfs_dir_name_len(eb, di);
2227 name = kmalloc(name_len, GFP_NOFS);
2232 read_extent_buffer(eb, name, (unsigned long)(di + 1),
2235 if (log && dir_key->type == BTRFS_DIR_ITEM_KEY) {
2236 log_di = btrfs_lookup_dir_item(trans, log, log_path,
2239 } else if (log && dir_key->type == BTRFS_DIR_INDEX_KEY) {
2240 log_di = btrfs_lookup_dir_index_item(trans, log,
2246 if (!log_di || log_di == ERR_PTR(-ENOENT)) {
2247 btrfs_dir_item_key_to_cpu(eb, di, &location);
2248 btrfs_release_path(path);
2249 btrfs_release_path(log_path);
2250 inode = read_one_inode(root, location.objectid);
2256 ret = link_to_fixup_dir(trans, root,
2257 path, location.objectid);
2265 ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
2266 BTRFS_I(inode), name, name_len);
2268 ret = btrfs_run_delayed_items(trans);
2274 /* there might still be more names under this key
2275 * check and repeat if required
2277 ret = btrfs_search_slot(NULL, root, dir_key, path,
2283 } else if (IS_ERR(log_di)) {
2285 return PTR_ERR(log_di);
2287 btrfs_release_path(log_path);
2290 ptr = (unsigned long)(di + 1);
2295 btrfs_release_path(path);
2296 btrfs_release_path(log_path);
2300 static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
2301 struct btrfs_root *root,
2302 struct btrfs_root *log,
2303 struct btrfs_path *path,
2306 struct btrfs_key search_key;
2307 struct btrfs_path *log_path;
2312 log_path = btrfs_alloc_path();
2316 search_key.objectid = ino;
2317 search_key.type = BTRFS_XATTR_ITEM_KEY;
2318 search_key.offset = 0;
2320 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
2324 nritems = btrfs_header_nritems(path->nodes[0]);
2325 for (i = path->slots[0]; i < nritems; i++) {
2326 struct btrfs_key key;
2327 struct btrfs_dir_item *di;
2328 struct btrfs_dir_item *log_di;
2332 btrfs_item_key_to_cpu(path->nodes[0], &key, i);
2333 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
2338 di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
2339 total_size = btrfs_item_size_nr(path->nodes[0], i);
2341 while (cur < total_size) {
2342 u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
2343 u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
2344 u32 this_len = sizeof(*di) + name_len + data_len;
2347 name = kmalloc(name_len, GFP_NOFS);
2352 read_extent_buffer(path->nodes[0], name,
2353 (unsigned long)(di + 1), name_len);
2355 log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
2357 btrfs_release_path(log_path);
2359 /* Doesn't exist in log tree, so delete it. */
2360 btrfs_release_path(path);
2361 di = btrfs_lookup_xattr(trans, root, path, ino,
2362 name, name_len, -1);
2369 ret = btrfs_delete_one_dir_name(trans, root,
2373 btrfs_release_path(path);
2378 if (IS_ERR(log_di)) {
2379 ret = PTR_ERR(log_di);
2383 di = (struct btrfs_dir_item *)((char *)di + this_len);
2386 ret = btrfs_next_leaf(root, path);
2392 btrfs_free_path(log_path);
2393 btrfs_release_path(path);
2399 * deletion replay happens before we copy any new directory items
2400 * out of the log or out of backreferences from inodes. It
2401 * scans the log to find ranges of keys that log is authoritative for,
2402 * and then scans the directory to find items in those ranges that are
2403 * not present in the log.
2405 * Anything we don't find in the log is unlinked and removed from the
2408 static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
2409 struct btrfs_root *root,
2410 struct btrfs_root *log,
2411 struct btrfs_path *path,
2412 u64 dirid, int del_all)
2416 int key_type = BTRFS_DIR_LOG_ITEM_KEY;
2418 struct btrfs_key dir_key;
2419 struct btrfs_key found_key;
2420 struct btrfs_path *log_path;
2423 dir_key.objectid = dirid;
2424 dir_key.type = BTRFS_DIR_ITEM_KEY;
2425 log_path = btrfs_alloc_path();
2429 dir = read_one_inode(root, dirid);
2430 /* it isn't an error if the inode isn't there, that can happen
2431 * because we replay the deletes before we copy in the inode item
2435 btrfs_free_path(log_path);
2443 range_end = (u64)-1;
2445 ret = find_dir_range(log, path, dirid, key_type,
2446 &range_start, &range_end);
2451 dir_key.offset = range_start;
2454 ret = btrfs_search_slot(NULL, root, &dir_key, path,
2459 nritems = btrfs_header_nritems(path->nodes[0]);
2460 if (path->slots[0] >= nritems) {
2461 ret = btrfs_next_leaf(root, path);
2467 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
2469 if (found_key.objectid != dirid ||
2470 found_key.type != dir_key.type)
2473 if (found_key.offset > range_end)
2476 ret = check_item_in_log(trans, root, log, path,
2481 if (found_key.offset == (u64)-1)
2483 dir_key.offset = found_key.offset + 1;
2485 btrfs_release_path(path);
2486 if (range_end == (u64)-1)
2488 range_start = range_end + 1;
2493 if (key_type == BTRFS_DIR_LOG_ITEM_KEY) {
2494 key_type = BTRFS_DIR_LOG_INDEX_KEY;
2495 dir_key.type = BTRFS_DIR_INDEX_KEY;
2496 btrfs_release_path(path);
2500 btrfs_release_path(path);
2501 btrfs_free_path(log_path);
2507 * the process_func used to replay items from the log tree. This
2508 * gets called in two different stages. The first stage just looks
2509 * for inodes and makes sure they are all copied into the subvolume.
2511 * The second stage copies all the other item types from the log into
2512 * the subvolume. The two stage approach is slower, but gets rid of
2513 * lots of complexity around inodes referencing other inodes that exist
2514 * only in the log (references come from either directory items or inode
2517 static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
2518 struct walk_control *wc, u64 gen, int level)
2521 struct btrfs_path *path;
2522 struct btrfs_root *root = wc->replay_dest;
2523 struct btrfs_key key;
2527 ret = btrfs_read_buffer(eb, gen, level, NULL);
2531 level = btrfs_header_level(eb);
2536 path = btrfs_alloc_path();
2540 nritems = btrfs_header_nritems(eb);
2541 for (i = 0; i < nritems; i++) {
2542 btrfs_item_key_to_cpu(eb, &key, i);
2544 /* inode keys are done during the first stage */
2545 if (key.type == BTRFS_INODE_ITEM_KEY &&
2546 wc->stage == LOG_WALK_REPLAY_INODES) {
2547 struct btrfs_inode_item *inode_item;
2550 inode_item = btrfs_item_ptr(eb, i,
2551 struct btrfs_inode_item);
2553 * If we have a tmpfile (O_TMPFILE) that got fsync'ed
2554 * and never got linked before the fsync, skip it, as
2555 * replaying it is pointless since it would be deleted
2556 * later. We skip logging tmpfiles, but it's always
2557 * possible we are replaying a log created with a kernel
2558 * that used to log tmpfiles.
2560 if (btrfs_inode_nlink(eb, inode_item) == 0) {
2561 wc->ignore_cur_inode = true;
2564 wc->ignore_cur_inode = false;
2566 ret = replay_xattr_deletes(wc->trans, root, log,
2567 path, key.objectid);
2570 mode = btrfs_inode_mode(eb, inode_item);
2571 if (S_ISDIR(mode)) {
2572 ret = replay_dir_deletes(wc->trans,
2573 root, log, path, key.objectid, 0);
2577 ret = overwrite_item(wc->trans, root, path,
2583 * Before replaying extents, truncate the inode to its
2584 * size. We need to do it now and not after log replay
2585 * because before an fsync we can have prealloc extents
2586 * added beyond the inode's i_size. If we did it after,
2587 * through orphan cleanup for example, we would drop
2588 * those prealloc extents just after replaying them.
2590 if (S_ISREG(mode)) {
2591 struct btrfs_drop_extents_args drop_args = { 0 };
2592 struct inode *inode;
2595 inode = read_one_inode(root, key.objectid);
2600 from = ALIGN(i_size_read(inode),
2601 root->fs_info->sectorsize);
2602 drop_args.start = from;
2603 drop_args.end = (u64)-1;
2604 drop_args.drop_cache = true;
2605 ret = btrfs_drop_extents(wc->trans, root,
2609 inode_sub_bytes(inode,
2610 drop_args.bytes_found);
2611 /* Update the inode's nbytes. */
2612 ret = btrfs_update_inode(wc->trans,
2613 root, BTRFS_I(inode));
2620 ret = link_to_fixup_dir(wc->trans, root,
2621 path, key.objectid);
2626 if (wc->ignore_cur_inode)
2629 if (key.type == BTRFS_DIR_INDEX_KEY &&
2630 wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
2631 ret = replay_one_dir_item(wc->trans, root, path,
2637 if (wc->stage < LOG_WALK_REPLAY_ALL)
2640 /* these keys are simply copied */
2641 if (key.type == BTRFS_XATTR_ITEM_KEY) {
2642 ret = overwrite_item(wc->trans, root, path,
2646 } else if (key.type == BTRFS_INODE_REF_KEY ||
2647 key.type == BTRFS_INODE_EXTREF_KEY) {
2648 ret = add_inode_ref(wc->trans, root, log, path,
2650 if (ret && ret != -ENOENT)
2653 } else if (key.type == BTRFS_EXTENT_DATA_KEY) {
2654 ret = replay_one_extent(wc->trans, root, path,
2658 } else if (key.type == BTRFS_DIR_ITEM_KEY) {
2659 ret = replay_one_dir_item(wc->trans, root, path,
2665 btrfs_free_path(path);
2670 * Correctly adjust the reserved bytes occupied by a log tree extent buffer
2672 static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
2674 struct btrfs_block_group *cache;
2676 cache = btrfs_lookup_block_group(fs_info, start);
2678 btrfs_err(fs_info, "unable to find block group for %llu", start);
2682 spin_lock(&cache->space_info->lock);
2683 spin_lock(&cache->lock);
2684 cache->reserved -= fs_info->nodesize;
2685 cache->space_info->bytes_reserved -= fs_info->nodesize;
2686 spin_unlock(&cache->lock);
2687 spin_unlock(&cache->space_info->lock);
2689 btrfs_put_block_group(cache);
2692 static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
2693 struct btrfs_root *root,
2694 struct btrfs_path *path, int *level,
2695 struct walk_control *wc)
2697 struct btrfs_fs_info *fs_info = root->fs_info;
2700 struct extent_buffer *next;
2701 struct extent_buffer *cur;
2705 while (*level > 0) {
2706 struct btrfs_key first_key;
2708 cur = path->nodes[*level];
2710 WARN_ON(btrfs_header_level(cur) != *level);
2712 if (path->slots[*level] >=
2713 btrfs_header_nritems(cur))
2716 bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
2717 ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
2718 btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
2719 blocksize = fs_info->nodesize;
2721 next = btrfs_find_create_tree_block(fs_info, bytenr,
2722 btrfs_header_owner(cur),
2725 return PTR_ERR(next);
2728 ret = wc->process_func(root, next, wc, ptr_gen,
2731 free_extent_buffer(next);
2735 path->slots[*level]++;
2737 ret = btrfs_read_buffer(next, ptr_gen,
2738 *level - 1, &first_key);
2740 free_extent_buffer(next);
2745 btrfs_tree_lock(next);
2746 btrfs_clean_tree_block(next);
2747 btrfs_wait_tree_block_writeback(next);
2748 btrfs_tree_unlock(next);
2749 ret = btrfs_pin_reserved_extent(trans,
2752 free_extent_buffer(next);
2756 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
2757 clear_extent_buffer_dirty(next);
2758 unaccount_log_buffer(fs_info, bytenr);
2761 free_extent_buffer(next);
2764 ret = btrfs_read_buffer(next, ptr_gen, *level - 1, &first_key);
2766 free_extent_buffer(next);
2770 if (path->nodes[*level-1])
2771 free_extent_buffer(path->nodes[*level-1]);
2772 path->nodes[*level-1] = next;
2773 *level = btrfs_header_level(next);
2774 path->slots[*level] = 0;
2777 path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
2783 static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
2784 struct btrfs_root *root,
2785 struct btrfs_path *path, int *level,
2786 struct walk_control *wc)
2788 struct btrfs_fs_info *fs_info = root->fs_info;
2793 for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
2794 slot = path->slots[i];
2795 if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
2798 WARN_ON(*level == 0);
2801 ret = wc->process_func(root, path->nodes[*level], wc,
2802 btrfs_header_generation(path->nodes[*level]),
2808 struct extent_buffer *next;
2810 next = path->nodes[*level];
2813 btrfs_tree_lock(next);
2814 btrfs_clean_tree_block(next);
2815 btrfs_wait_tree_block_writeback(next);
2816 btrfs_tree_unlock(next);
2817 ret = btrfs_pin_reserved_extent(trans,
2818 path->nodes[*level]->start,
2819 path->nodes[*level]->len);
2823 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
2824 clear_extent_buffer_dirty(next);
2826 unaccount_log_buffer(fs_info,
2827 path->nodes[*level]->start);
2830 free_extent_buffer(path->nodes[*level]);
2831 path->nodes[*level] = NULL;
2839 * drop the reference count on the tree rooted at 'snap'. This traverses
2840 * the tree freeing any blocks that have a ref count of zero after being
2843 static int walk_log_tree(struct btrfs_trans_handle *trans,
2844 struct btrfs_root *log, struct walk_control *wc)
2846 struct btrfs_fs_info *fs_info = log->fs_info;
2850 struct btrfs_path *path;
2853 path = btrfs_alloc_path();
2857 level = btrfs_header_level(log->node);
2859 path->nodes[level] = log->node;
2860 atomic_inc(&log->node->refs);
2861 path->slots[level] = 0;
2864 wret = walk_down_log_tree(trans, log, path, &level, wc);
2872 wret = walk_up_log_tree(trans, log, path, &level, wc);
2881 /* was the root node processed? if not, catch it here */
2882 if (path->nodes[orig_level]) {
2883 ret = wc->process_func(log, path->nodes[orig_level], wc,
2884 btrfs_header_generation(path->nodes[orig_level]),
2889 struct extent_buffer *next;
2891 next = path->nodes[orig_level];
2894 btrfs_tree_lock(next);
2895 btrfs_clean_tree_block(next);
2896 btrfs_wait_tree_block_writeback(next);
2897 btrfs_tree_unlock(next);
2898 ret = btrfs_pin_reserved_extent(trans,
2899 next->start, next->len);
2903 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
2904 clear_extent_buffer_dirty(next);
2905 unaccount_log_buffer(fs_info, next->start);
2911 btrfs_free_path(path);
2916 * helper function to update the item for a given subvolumes log root
2917 * in the tree of log roots
2919 static int update_log_root(struct btrfs_trans_handle *trans,
2920 struct btrfs_root *log,
2921 struct btrfs_root_item *root_item)
2923 struct btrfs_fs_info *fs_info = log->fs_info;
2926 if (log->log_transid == 1) {
2927 /* insert root item on the first sync */
2928 ret = btrfs_insert_root(trans, fs_info->log_root_tree,
2929 &log->root_key, root_item);
2931 ret = btrfs_update_root(trans, fs_info->log_root_tree,
2932 &log->root_key, root_item);
2937 static void wait_log_commit(struct btrfs_root *root, int transid)
2940 int index = transid % 2;
2943 * we only allow two pending log transactions at a time,
2944 * so we know that if ours is more than 2 older than the
2945 * current transaction, we're done
2948 prepare_to_wait(&root->log_commit_wait[index],
2949 &wait, TASK_UNINTERRUPTIBLE);
2951 if (!(root->log_transid_committed < transid &&
2952 atomic_read(&root->log_commit[index])))
2955 mutex_unlock(&root->log_mutex);
2957 mutex_lock(&root->log_mutex);
2959 finish_wait(&root->log_commit_wait[index], &wait);
2962 static void wait_for_writer(struct btrfs_root *root)
2967 prepare_to_wait(&root->log_writer_wait, &wait,
2968 TASK_UNINTERRUPTIBLE);
2969 if (!atomic_read(&root->log_writers))
2972 mutex_unlock(&root->log_mutex);
2974 mutex_lock(&root->log_mutex);
2976 finish_wait(&root->log_writer_wait, &wait);
2979 static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
2980 struct btrfs_log_ctx *ctx)
2985 mutex_lock(&root->log_mutex);
2986 list_del_init(&ctx->list);
2987 mutex_unlock(&root->log_mutex);
2991 * Invoked in log mutex context, or be sure there is no other task which
2992 * can access the list.
2994 static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
2995 int index, int error)
2997 struct btrfs_log_ctx *ctx;
2998 struct btrfs_log_ctx *safe;
3000 list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
3001 list_del_init(&ctx->list);
3002 ctx->log_ret = error;
3005 INIT_LIST_HEAD(&root->log_ctxs[index]);
3009 * btrfs_sync_log does sends a given tree log down to the disk and
3010 * updates the super blocks to record it. When this call is done,
3011 * you know that any inodes previously logged are safely on disk only
3014 * Any other return value means you need to call btrfs_commit_transaction.
3015 * Some of the edge cases for fsyncing directories that have had unlinks
3016 * or renames done in the past mean that sometimes the only safe
3017 * fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
3018 * that has happened.
3020 int btrfs_sync_log(struct btrfs_trans_handle *trans,
3021 struct btrfs_root *root, struct btrfs_log_ctx *ctx)
3027 struct btrfs_fs_info *fs_info = root->fs_info;
3028 struct btrfs_root *log = root->log_root;
3029 struct btrfs_root *log_root_tree = fs_info->log_root_tree;
3030 struct btrfs_root_item new_root_item;
3031 int log_transid = 0;
3032 struct btrfs_log_ctx root_log_ctx;
3033 struct blk_plug plug;
3037 mutex_lock(&root->log_mutex);
3038 log_transid = ctx->log_transid;
3039 if (root->log_transid_committed >= log_transid) {
3040 mutex_unlock(&root->log_mutex);
3041 return ctx->log_ret;
3044 index1 = log_transid % 2;
3045 if (atomic_read(&root->log_commit[index1])) {
3046 wait_log_commit(root, log_transid);
3047 mutex_unlock(&root->log_mutex);
3048 return ctx->log_ret;
3050 ASSERT(log_transid == root->log_transid);
3051 atomic_set(&root->log_commit[index1], 1);
3053 /* wait for previous tree log sync to complete */
3054 if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
3055 wait_log_commit(root, log_transid - 1);
3058 int batch = atomic_read(&root->log_batch);
3059 /* when we're on an ssd, just kick the log commit out */
3060 if (!btrfs_test_opt(fs_info, SSD) &&
3061 test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
3062 mutex_unlock(&root->log_mutex);
3063 schedule_timeout_uninterruptible(1);
3064 mutex_lock(&root->log_mutex);
3066 wait_for_writer(root);
3067 if (batch == atomic_read(&root->log_batch))
3071 /* bail out if we need to do a full commit */
3072 if (btrfs_need_log_full_commit(trans)) {
3074 mutex_unlock(&root->log_mutex);
3078 if (log_transid % 2 == 0)
3079 mark = EXTENT_DIRTY;
3083 /* we start IO on all the marked extents here, but we don't actually
3084 * wait for them until later.
3086 blk_start_plug(&plug);
3087 ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
3089 blk_finish_plug(&plug);
3090 btrfs_abort_transaction(trans, ret);
3091 btrfs_set_log_full_commit(trans);
3092 mutex_unlock(&root->log_mutex);
3097 * We _must_ update under the root->log_mutex in order to make sure we
3098 * have a consistent view of the log root we are trying to commit at
3101 * We _must_ copy this into a local copy, because we are not holding the
3102 * log_root_tree->log_mutex yet. This is important because when we
3103 * commit the log_root_tree we must have a consistent view of the
3104 * log_root_tree when we update the super block to point at the
3105 * log_root_tree bytenr. If we update the log_root_tree here we'll race
3106 * with the commit and possibly point at the new block which we may not
3109 btrfs_set_root_node(&log->root_item, log->node);
3110 memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
3112 root->log_transid++;
3113 log->log_transid = root->log_transid;
3114 root->log_start_pid = 0;
3116 * IO has been started, blocks of the log tree have WRITTEN flag set
3117 * in their headers. new modifications of the log will be written to
3118 * new positions. so it's safe to allow log writers to go in.
3120 mutex_unlock(&root->log_mutex);
3122 btrfs_init_log_ctx(&root_log_ctx, NULL);
3124 mutex_lock(&log_root_tree->log_mutex);
3126 index2 = log_root_tree->log_transid % 2;
3127 list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
3128 root_log_ctx.log_transid = log_root_tree->log_transid;
3131 * Now we are safe to update the log_root_tree because we're under the
3132 * log_mutex, and we're a current writer so we're holding the commit
3133 * open until we drop the log_mutex.
3135 ret = update_log_root(trans, log, &new_root_item);
3137 if (!list_empty(&root_log_ctx.list))
3138 list_del_init(&root_log_ctx.list);
3140 blk_finish_plug(&plug);
3141 btrfs_set_log_full_commit(trans);
3143 if (ret != -ENOSPC) {
3144 btrfs_abort_transaction(trans, ret);
3145 mutex_unlock(&log_root_tree->log_mutex);
3148 btrfs_wait_tree_log_extents(log, mark);
3149 mutex_unlock(&log_root_tree->log_mutex);
3154 if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
3155 blk_finish_plug(&plug);
3156 list_del_init(&root_log_ctx.list);
3157 mutex_unlock(&log_root_tree->log_mutex);
3158 ret = root_log_ctx.log_ret;
3162 index2 = root_log_ctx.log_transid % 2;
3163 if (atomic_read(&log_root_tree->log_commit[index2])) {
3164 blk_finish_plug(&plug);
3165 ret = btrfs_wait_tree_log_extents(log, mark);
3166 wait_log_commit(log_root_tree,
3167 root_log_ctx.log_transid);
3168 mutex_unlock(&log_root_tree->log_mutex);
3170 ret = root_log_ctx.log_ret;
3173 ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
3174 atomic_set(&log_root_tree->log_commit[index2], 1);
3176 if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
3177 wait_log_commit(log_root_tree,
3178 root_log_ctx.log_transid - 1);
3182 * now that we've moved on to the tree of log tree roots,
3183 * check the full commit flag again
3185 if (btrfs_need_log_full_commit(trans)) {
3186 blk_finish_plug(&plug);
3187 btrfs_wait_tree_log_extents(log, mark);
3188 mutex_unlock(&log_root_tree->log_mutex);
3190 goto out_wake_log_root;
3193 ret = btrfs_write_marked_extents(fs_info,
3194 &log_root_tree->dirty_log_pages,
3195 EXTENT_DIRTY | EXTENT_NEW);
3196 blk_finish_plug(&plug);
3198 btrfs_set_log_full_commit(trans);
3199 btrfs_abort_transaction(trans, ret);
3200 mutex_unlock(&log_root_tree->log_mutex);
3201 goto out_wake_log_root;
3203 ret = btrfs_wait_tree_log_extents(log, mark);
3205 ret = btrfs_wait_tree_log_extents(log_root_tree,
3206 EXTENT_NEW | EXTENT_DIRTY);
3208 btrfs_set_log_full_commit(trans);
3209 mutex_unlock(&log_root_tree->log_mutex);
3210 goto out_wake_log_root;
3213 log_root_start = log_root_tree->node->start;
3214 log_root_level = btrfs_header_level(log_root_tree->node);
3215 log_root_tree->log_transid++;
3216 mutex_unlock(&log_root_tree->log_mutex);
3219 * Here we are guaranteed that nobody is going to write the superblock
3220 * for the current transaction before us and that neither we do write
3221 * our superblock before the previous transaction finishes its commit
3222 * and writes its superblock, because:
3224 * 1) We are holding a handle on the current transaction, so no body
3225 * can commit it until we release the handle;
3227 * 2) Before writing our superblock we acquire the tree_log_mutex, so
3228 * if the previous transaction is still committing, and hasn't yet
3229 * written its superblock, we wait for it to do it, because a
3230 * transaction commit acquires the tree_log_mutex when the commit
3231 * begins and releases it only after writing its superblock.
3233 mutex_lock(&fs_info->tree_log_mutex);
3234 btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
3235 btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
3236 ret = write_all_supers(fs_info, 1);
3237 mutex_unlock(&fs_info->tree_log_mutex);
3239 btrfs_set_log_full_commit(trans);
3240 btrfs_abort_transaction(trans, ret);
3241 goto out_wake_log_root;
3244 mutex_lock(&root->log_mutex);
3245 if (root->last_log_commit < log_transid)
3246 root->last_log_commit = log_transid;
3247 mutex_unlock(&root->log_mutex);
3250 mutex_lock(&log_root_tree->log_mutex);
3251 btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
3253 log_root_tree->log_transid_committed++;
3254 atomic_set(&log_root_tree->log_commit[index2], 0);
3255 mutex_unlock(&log_root_tree->log_mutex);
3258 * The barrier before waitqueue_active (in cond_wake_up) is needed so
3259 * all the updates above are seen by the woken threads. It might not be
3260 * necessary, but proving that seems to be hard.
3262 cond_wake_up(&log_root_tree->log_commit_wait[index2]);
3264 mutex_lock(&root->log_mutex);
3265 btrfs_remove_all_log_ctxs(root, index1, ret);
3266 root->log_transid_committed++;
3267 atomic_set(&root->log_commit[index1], 0);
3268 mutex_unlock(&root->log_mutex);
3271 * The barrier before waitqueue_active (in cond_wake_up) is needed so
3272 * all the updates above are seen by the woken threads. It might not be
3273 * necessary, but proving that seems to be hard.
3275 cond_wake_up(&root->log_commit_wait[index1]);
3279 static void free_log_tree(struct btrfs_trans_handle *trans,
3280 struct btrfs_root *log)
3283 struct walk_control wc = {
3285 .process_func = process_one_buffer
3288 ret = walk_log_tree(trans, log, &wc);
3291 btrfs_abort_transaction(trans, ret);
3293 btrfs_handle_fs_error(log->fs_info, ret, NULL);
3296 clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
3297 EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
3298 extent_io_tree_release(&log->log_csum_range);
3299 btrfs_put_root(log);
3303 * free all the extents used by the tree log. This should be called
3304 * at commit time of the full transaction
3306 int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
3308 if (root->log_root) {
3309 free_log_tree(trans, root->log_root);
3310 root->log_root = NULL;
3311 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
3316 int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
3317 struct btrfs_fs_info *fs_info)
3319 if (fs_info->log_root_tree) {
3320 free_log_tree(trans, fs_info->log_root_tree);
3321 fs_info->log_root_tree = NULL;
3322 clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state);
3328 * Check if an inode was logged in the current transaction. We can't always rely
3329 * on an inode's logged_trans value, because it's an in-memory only field and
3330 * therefore not persisted. This means that its value is lost if the inode gets
3331 * evicted and loaded again from disk (in which case it has a value of 0, and
3332 * certainly it is smaller then any possible transaction ID), when that happens
3333 * the full_sync flag is set in the inode's runtime flags, so on that case we
3334 * assume eviction happened and ignore the logged_trans value, assuming the
3335 * worst case, that the inode was logged before in the current transaction.
3337 static bool inode_logged(struct btrfs_trans_handle *trans,
3338 struct btrfs_inode *inode)
3340 if (inode->logged_trans == trans->transid)
3343 if (inode->last_trans == trans->transid &&
3344 test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) &&
3345 !test_bit(BTRFS_FS_LOG_RECOVERING, &trans->fs_info->flags))
3352 * If both a file and directory are logged, and unlinks or renames are
3353 * mixed in, we have a few interesting corners:
3355 * create file X in dir Y
3356 * link file X to X.link in dir Y
3358 * unlink file X but leave X.link
3361 * After a crash we would expect only X.link to exist. But file X
3362 * didn't get fsync'd again so the log has back refs for X and X.link.
3364 * We solve this by removing directory entries and inode backrefs from the
3365 * log when a file that was logged in the current transaction is
3366 * unlinked. Any later fsync will include the updated log entries, and
3367 * we'll be able to reconstruct the proper directory items from backrefs.
3369 * This optimizations allows us to avoid relogging the entire inode
3370 * or the entire directory.
3372 int btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
3373 struct btrfs_root *root,
3374 const char *name, int name_len,
3375 struct btrfs_inode *dir, u64 index)
3377 struct btrfs_root *log;
3378 struct btrfs_dir_item *di;
3379 struct btrfs_path *path;
3383 u64 dir_ino = btrfs_ino(dir);
3385 if (!inode_logged(trans, dir))
3388 ret = join_running_log_trans(root);
3392 mutex_lock(&dir->log_mutex);
3394 log = root->log_root;
3395 path = btrfs_alloc_path();
3401 di = btrfs_lookup_dir_item(trans, log, path, dir_ino,
3402 name, name_len, -1);
3408 ret = btrfs_delete_one_dir_name(trans, log, path, di);
3409 bytes_del += name_len;
3415 btrfs_release_path(path);
3416 di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
3417 index, name, name_len, -1);
3423 ret = btrfs_delete_one_dir_name(trans, log, path, di);
3424 bytes_del += name_len;
3431 /* update the directory size in the log to reflect the names
3435 struct btrfs_key key;
3437 key.objectid = dir_ino;
3439 key.type = BTRFS_INODE_ITEM_KEY;
3440 btrfs_release_path(path);
3442 ret = btrfs_search_slot(trans, log, &key, path, 0, 1);
3448 struct btrfs_inode_item *item;
3451 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3452 struct btrfs_inode_item);
3453 i_size = btrfs_inode_size(path->nodes[0], item);
3454 if (i_size > bytes_del)
3455 i_size -= bytes_del;
3458 btrfs_set_inode_size(path->nodes[0], item, i_size);
3459 btrfs_mark_buffer_dirty(path->nodes[0]);
3462 btrfs_release_path(path);
3465 btrfs_free_path(path);
3467 mutex_unlock(&dir->log_mutex);
3468 if (err == -ENOSPC) {
3469 btrfs_set_log_full_commit(trans);
3471 } else if (err < 0 && err != -ENOENT) {
3472 /* ENOENT can be returned if the entry hasn't been fsynced yet */
3473 btrfs_abort_transaction(trans, err);
3476 btrfs_end_log_trans(root);
3481 /* see comments for btrfs_del_dir_entries_in_log */
3482 int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
3483 struct btrfs_root *root,
3484 const char *name, int name_len,
3485 struct btrfs_inode *inode, u64 dirid)
3487 struct btrfs_root *log;
3491 if (!inode_logged(trans, inode))
3494 ret = join_running_log_trans(root);
3497 log = root->log_root;
3498 mutex_lock(&inode->log_mutex);
3500 ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
3502 mutex_unlock(&inode->log_mutex);
3503 if (ret == -ENOSPC) {
3504 btrfs_set_log_full_commit(trans);
3506 } else if (ret < 0 && ret != -ENOENT)
3507 btrfs_abort_transaction(trans, ret);
3508 btrfs_end_log_trans(root);
3514 * creates a range item in the log for 'dirid'. first_offset and
3515 * last_offset tell us which parts of the key space the log should
3516 * be considered authoritative for.
3518 static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
3519 struct btrfs_root *log,
3520 struct btrfs_path *path,
3521 int key_type, u64 dirid,
3522 u64 first_offset, u64 last_offset)
3525 struct btrfs_key key;
3526 struct btrfs_dir_log_item *item;
3528 key.objectid = dirid;
3529 key.offset = first_offset;
3530 if (key_type == BTRFS_DIR_ITEM_KEY)
3531 key.type = BTRFS_DIR_LOG_ITEM_KEY;
3533 key.type = BTRFS_DIR_LOG_INDEX_KEY;
3534 ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
3538 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3539 struct btrfs_dir_log_item);
3540 btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
3541 btrfs_mark_buffer_dirty(path->nodes[0]);
3542 btrfs_release_path(path);
3547 * log all the items included in the current transaction for a given
3548 * directory. This also creates the range items in the log tree required
3549 * to replay anything deleted before the fsync
3551 static noinline int log_dir_items(struct btrfs_trans_handle *trans,
3552 struct btrfs_root *root, struct btrfs_inode *inode,
3553 struct btrfs_path *path,
3554 struct btrfs_path *dst_path, int key_type,
3555 struct btrfs_log_ctx *ctx,
3556 u64 min_offset, u64 *last_offset_ret)
3558 struct btrfs_key min_key;
3559 struct btrfs_root *log = root->log_root;
3560 struct extent_buffer *src;
3565 u64 first_offset = min_offset;
3566 u64 last_offset = (u64)-1;
3567 u64 ino = btrfs_ino(inode);
3569 log = root->log_root;
3571 min_key.objectid = ino;
3572 min_key.type = key_type;
3573 min_key.offset = min_offset;
3575 ret = btrfs_search_forward(root, &min_key, path, trans->transid);
3578 * we didn't find anything from this transaction, see if there
3579 * is anything at all
3581 if (ret != 0 || min_key.objectid != ino || min_key.type != key_type) {
3582 min_key.objectid = ino;
3583 min_key.type = key_type;
3584 min_key.offset = (u64)-1;
3585 btrfs_release_path(path);
3586 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3588 btrfs_release_path(path);
3591 ret = btrfs_previous_item(root, path, ino, key_type);
3593 /* if ret == 0 there are items for this type,
3594 * create a range to tell us the last key of this type.
3595 * otherwise, there are no items in this directory after
3596 * *min_offset, and we create a range to indicate that.
3599 struct btrfs_key tmp;
3600 btrfs_item_key_to_cpu(path->nodes[0], &tmp,
3602 if (key_type == tmp.type)
3603 first_offset = max(min_offset, tmp.offset) + 1;
3608 /* go backward to find any previous key */
3609 ret = btrfs_previous_item(root, path, ino, key_type);
3611 struct btrfs_key tmp;
3612 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
3613 if (key_type == tmp.type) {
3614 first_offset = tmp.offset;
3615 ret = overwrite_item(trans, log, dst_path,
3616 path->nodes[0], path->slots[0],
3624 btrfs_release_path(path);
3627 * Find the first key from this transaction again. See the note for
3628 * log_new_dir_dentries, if we're logging a directory recursively we
3629 * won't be holding its i_mutex, which means we can modify the directory
3630 * while we're logging it. If we remove an entry between our first
3631 * search and this search we'll not find the key again and can just
3635 ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
3640 * we have a block from this transaction, log every item in it
3641 * from our directory
3644 struct btrfs_key tmp;
3645 src = path->nodes[0];
3646 nritems = btrfs_header_nritems(src);
3647 for (i = path->slots[0]; i < nritems; i++) {
3648 struct btrfs_dir_item *di;
3650 btrfs_item_key_to_cpu(src, &min_key, i);
3652 if (min_key.objectid != ino || min_key.type != key_type)
3655 if (need_resched()) {
3656 btrfs_release_path(path);
3661 ret = overwrite_item(trans, log, dst_path, src, i,
3669 * We must make sure that when we log a directory entry,
3670 * the corresponding inode, after log replay, has a
3671 * matching link count. For example:
3677 * xfs_io -c "fsync" mydir
3679 * <mount fs and log replay>
3681 * Would result in a fsync log that when replayed, our
3682 * file inode would have a link count of 1, but we get
3683 * two directory entries pointing to the same inode.
3684 * After removing one of the names, it would not be
3685 * possible to remove the other name, which resulted
3686 * always in stale file handle errors, and would not
3687 * be possible to rmdir the parent directory, since
3688 * its i_size could never decrement to the value
3689 * BTRFS_EMPTY_DIR_SIZE, resulting in -ENOTEMPTY errors.
3691 di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
3692 btrfs_dir_item_key_to_cpu(src, di, &tmp);
3694 (btrfs_dir_transid(src, di) == trans->transid ||
3695 btrfs_dir_type(src, di) == BTRFS_FT_DIR) &&
3696 tmp.type != BTRFS_ROOT_ITEM_KEY)
3697 ctx->log_new_dentries = true;
3699 path->slots[0] = nritems;
3702 * look ahead to the next item and see if it is also
3703 * from this directory and from this transaction
3705 ret = btrfs_next_leaf(root, path);
3708 last_offset = (u64)-1;
3713 btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
3714 if (tmp.objectid != ino || tmp.type != key_type) {
3715 last_offset = (u64)-1;
3718 if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
3719 ret = overwrite_item(trans, log, dst_path,
3720 path->nodes[0], path->slots[0],
3725 last_offset = tmp.offset;
3730 btrfs_release_path(path);
3731 btrfs_release_path(dst_path);
3734 *last_offset_ret = last_offset;
3736 * insert the log range keys to indicate where the log
3739 ret = insert_dir_log_key(trans, log, path, key_type,
3740 ino, first_offset, last_offset);
3748 * logging directories is very similar to logging inodes, We find all the items
3749 * from the current transaction and write them to the log.
3751 * The recovery code scans the directory in the subvolume, and if it finds a
3752 * key in the range logged that is not present in the log tree, then it means
3753 * that dir entry was unlinked during the transaction.
3755 * In order for that scan to work, we must include one key smaller than
3756 * the smallest logged by this transaction and one key larger than the largest
3757 * key logged by this transaction.
3759 static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
3760 struct btrfs_root *root, struct btrfs_inode *inode,
3761 struct btrfs_path *path,
3762 struct btrfs_path *dst_path,
3763 struct btrfs_log_ctx *ctx)
3768 int key_type = BTRFS_DIR_ITEM_KEY;
3774 ret = log_dir_items(trans, root, inode, path, dst_path, key_type,
3775 ctx, min_key, &max_key);
3778 if (max_key == (u64)-1)
3780 min_key = max_key + 1;
3783 if (key_type == BTRFS_DIR_ITEM_KEY) {
3784 key_type = BTRFS_DIR_INDEX_KEY;
3791 * a helper function to drop items from the log before we relog an
3792 * inode. max_key_type indicates the highest item type to remove.
3793 * This cannot be run for file data extents because it does not
3794 * free the extents they point to.
3796 static int drop_objectid_items(struct btrfs_trans_handle *trans,
3797 struct btrfs_root *log,
3798 struct btrfs_path *path,
3799 u64 objectid, int max_key_type)
3802 struct btrfs_key key;
3803 struct btrfs_key found_key;
3806 key.objectid = objectid;
3807 key.type = max_key_type;
3808 key.offset = (u64)-1;
3811 ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
3812 BUG_ON(ret == 0); /* Logic error */
3816 if (path->slots[0] == 0)
3820 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
3823 if (found_key.objectid != objectid)
3826 found_key.offset = 0;
3828 ret = btrfs_bin_search(path->nodes[0], &found_key, &start_slot);
3832 ret = btrfs_del_items(trans, log, path, start_slot,
3833 path->slots[0] - start_slot + 1);
3835 * If start slot isn't 0 then we don't need to re-search, we've
3836 * found the last guy with the objectid in this tree.
3838 if (ret || start_slot != 0)
3840 btrfs_release_path(path);
3842 btrfs_release_path(path);
3848 static void fill_inode_item(struct btrfs_trans_handle *trans,
3849 struct extent_buffer *leaf,
3850 struct btrfs_inode_item *item,
3851 struct inode *inode, int log_inode_only,
3854 struct btrfs_map_token token;
3856 btrfs_init_map_token(&token, leaf);
3858 if (log_inode_only) {
3859 /* set the generation to zero so the recover code
3860 * can tell the difference between an logging
3861 * just to say 'this inode exists' and a logging
3862 * to say 'update this inode with these values'
3864 btrfs_set_token_inode_generation(&token, item, 0);
3865 btrfs_set_token_inode_size(&token, item, logged_isize);
3867 btrfs_set_token_inode_generation(&token, item,
3868 BTRFS_I(inode)->generation);
3869 btrfs_set_token_inode_size(&token, item, inode->i_size);
3872 btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
3873 btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
3874 btrfs_set_token_inode_mode(&token, item, inode->i_mode);
3875 btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
3877 btrfs_set_token_timespec_sec(&token, &item->atime,
3878 inode->i_atime.tv_sec);
3879 btrfs_set_token_timespec_nsec(&token, &item->atime,
3880 inode->i_atime.tv_nsec);
3882 btrfs_set_token_timespec_sec(&token, &item->mtime,
3883 inode->i_mtime.tv_sec);
3884 btrfs_set_token_timespec_nsec(&token, &item->mtime,
3885 inode->i_mtime.tv_nsec);
3887 btrfs_set_token_timespec_sec(&token, &item->ctime,
3888 inode->i_ctime.tv_sec);
3889 btrfs_set_token_timespec_nsec(&token, &item->ctime,
3890 inode->i_ctime.tv_nsec);
3892 btrfs_set_token_inode_nbytes(&token, item, inode_get_bytes(inode));
3894 btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
3895 btrfs_set_token_inode_transid(&token, item, trans->transid);
3896 btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
3897 btrfs_set_token_inode_flags(&token, item, BTRFS_I(inode)->flags);
3898 btrfs_set_token_inode_block_group(&token, item, 0);
3901 static int log_inode_item(struct btrfs_trans_handle *trans,
3902 struct btrfs_root *log, struct btrfs_path *path,
3903 struct btrfs_inode *inode)
3905 struct btrfs_inode_item *inode_item;
3908 ret = btrfs_insert_empty_item(trans, log, path,
3909 &inode->location, sizeof(*inode_item));
3910 if (ret && ret != -EEXIST)
3912 inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
3913 struct btrfs_inode_item);
3914 fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
3916 btrfs_release_path(path);
3920 static int log_csums(struct btrfs_trans_handle *trans,
3921 struct btrfs_inode *inode,
3922 struct btrfs_root *log_root,
3923 struct btrfs_ordered_sum *sums)
3925 const u64 lock_end = sums->bytenr + sums->len - 1;
3926 struct extent_state *cached_state = NULL;
3930 * If this inode was not used for reflink operations in the current
3931 * transaction with new extents, then do the fast path, no need to
3932 * worry about logging checksum items with overlapping ranges.
3934 if (inode->last_reflink_trans < trans->transid)
3935 return btrfs_csum_file_blocks(trans, log_root, sums);
3938 * Serialize logging for checksums. This is to avoid racing with the
3939 * same checksum being logged by another task that is logging another
3940 * file which happens to refer to the same extent as well. Such races
3941 * can leave checksum items in the log with overlapping ranges.
3943 ret = lock_extent_bits(&log_root->log_csum_range, sums->bytenr,
3944 lock_end, &cached_state);
3948 * Due to extent cloning, we might have logged a csum item that covers a
3949 * subrange of a cloned extent, and later we can end up logging a csum
3950 * item for a larger subrange of the same extent or the entire range.
3951 * This would leave csum items in the log tree that cover the same range
3952 * and break the searches for checksums in the log tree, resulting in
3953 * some checksums missing in the fs/subvolume tree. So just delete (or
3954 * trim and adjust) any existing csum items in the log for this range.
3956 ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len);
3958 ret = btrfs_csum_file_blocks(trans, log_root, sums);
3960 unlock_extent_cached(&log_root->log_csum_range, sums->bytenr, lock_end,
3966 static noinline int copy_items(struct btrfs_trans_handle *trans,
3967 struct btrfs_inode *inode,
3968 struct btrfs_path *dst_path,
3969 struct btrfs_path *src_path,
3970 int start_slot, int nr, int inode_only,
3973 struct btrfs_fs_info *fs_info = trans->fs_info;
3974 unsigned long src_offset;
3975 unsigned long dst_offset;
3976 struct btrfs_root *log = inode->root->log_root;
3977 struct btrfs_file_extent_item *extent;
3978 struct btrfs_inode_item *inode_item;
3979 struct extent_buffer *src = src_path->nodes[0];
3981 struct btrfs_key *ins_keys;
3985 struct list_head ordered_sums;
3986 int skip_csum = inode->flags & BTRFS_INODE_NODATASUM;
3988 INIT_LIST_HEAD(&ordered_sums);
3990 ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
3991 nr * sizeof(u32), GFP_NOFS);
3995 ins_sizes = (u32 *)ins_data;
3996 ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
3998 for (i = 0; i < nr; i++) {
3999 ins_sizes[i] = btrfs_item_size_nr(src, i + start_slot);
4000 btrfs_item_key_to_cpu(src, ins_keys + i, i + start_slot);
4002 ret = btrfs_insert_empty_items(trans, log, dst_path,
4003 ins_keys, ins_sizes, nr);
4009 for (i = 0; i < nr; i++, dst_path->slots[0]++) {
4010 dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0],
4011 dst_path->slots[0]);
4013 src_offset = btrfs_item_ptr_offset(src, start_slot + i);
4015 if (ins_keys[i].type == BTRFS_INODE_ITEM_KEY) {
4016 inode_item = btrfs_item_ptr(dst_path->nodes[0],
4018 struct btrfs_inode_item);
4019 fill_inode_item(trans, dst_path->nodes[0], inode_item,
4021 inode_only == LOG_INODE_EXISTS,
4024 copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
4025 src_offset, ins_sizes[i]);
4028 /* take a reference on file data extents so that truncates
4029 * or deletes of this inode don't have to relog the inode
4032 if (ins_keys[i].type == BTRFS_EXTENT_DATA_KEY &&
4035 extent = btrfs_item_ptr(src, start_slot + i,
4036 struct btrfs_file_extent_item);
4038 if (btrfs_file_extent_generation(src, extent) < trans->transid)
4041 found_type = btrfs_file_extent_type(src, extent);
4042 if (found_type == BTRFS_FILE_EXTENT_REG) {
4044 ds = btrfs_file_extent_disk_bytenr(src,
4046 /* ds == 0 is a hole */
4050 dl = btrfs_file_extent_disk_num_bytes(src,
4052 cs = btrfs_file_extent_offset(src, extent);
4053 cl = btrfs_file_extent_num_bytes(src,
4055 if (btrfs_file_extent_compression(src,
4061 ret = btrfs_lookup_csums_range(
4063 ds + cs, ds + cs + cl - 1,
4071 btrfs_mark_buffer_dirty(dst_path->nodes[0]);
4072 btrfs_release_path(dst_path);
4076 * we have to do this after the loop above to avoid changing the
4077 * log tree while trying to change the log tree.
4079 while (!list_empty(&ordered_sums)) {
4080 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
4081 struct btrfs_ordered_sum,
4084 ret = log_csums(trans, inode, log, sums);
4085 list_del(&sums->list);
4092 static int extent_cmp(void *priv, struct list_head *a, struct list_head *b)
4094 struct extent_map *em1, *em2;
4096 em1 = list_entry(a, struct extent_map, list);
4097 em2 = list_entry(b, struct extent_map, list);
4099 if (em1->start < em2->start)
4101 else if (em1->start > em2->start)
4106 static int log_extent_csums(struct btrfs_trans_handle *trans,
4107 struct btrfs_inode *inode,
4108 struct btrfs_root *log_root,
4109 const struct extent_map *em,
4110 struct btrfs_log_ctx *ctx)
4112 struct btrfs_ordered_extent *ordered;
4115 u64 mod_start = em->mod_start;
4116 u64 mod_len = em->mod_len;
4117 LIST_HEAD(ordered_sums);
4120 if (inode->flags & BTRFS_INODE_NODATASUM ||
4121 test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
4122 em->block_start == EXTENT_MAP_HOLE)
4125 list_for_each_entry(ordered, &ctx->ordered_extents, log_list) {
4126 const u64 ordered_end = ordered->file_offset + ordered->num_bytes;
4127 const u64 mod_end = mod_start + mod_len;
4128 struct btrfs_ordered_sum *sums;
4133 if (ordered_end <= mod_start)
4135 if (mod_end <= ordered->file_offset)
4139 * We are going to copy all the csums on this ordered extent, so
4140 * go ahead and adjust mod_start and mod_len in case this ordered
4141 * extent has already been logged.
4143 if (ordered->file_offset > mod_start) {
4144 if (ordered_end >= mod_end)
4145 mod_len = ordered->file_offset - mod_start;
4147 * If we have this case
4149 * |--------- logged extent ---------|
4150 * |----- ordered extent ----|
4152 * Just don't mess with mod_start and mod_len, we'll
4153 * just end up logging more csums than we need and it
4157 if (ordered_end < mod_end) {
4158 mod_len = mod_end - ordered_end;
4159 mod_start = ordered_end;
4166 * To keep us from looping for the above case of an ordered
4167 * extent that falls inside of the logged extent.
4169 if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags))
4172 list_for_each_entry(sums, &ordered->list, list) {
4173 ret = log_csums(trans, inode, log_root, sums);
4179 /* We're done, found all csums in the ordered extents. */
4183 /* If we're compressed we have to save the entire range of csums. */
4184 if (em->compress_type) {
4186 csum_len = max(em->block_len, em->orig_block_len);
4188 csum_offset = mod_start - em->start;
4192 /* block start is already adjusted for the file extent offset. */
4193 ret = btrfs_lookup_csums_range(trans->fs_info->csum_root,
4194 em->block_start + csum_offset,
4195 em->block_start + csum_offset +
4196 csum_len - 1, &ordered_sums, 0);
4200 while (!list_empty(&ordered_sums)) {
4201 struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
4202 struct btrfs_ordered_sum,
4205 ret = log_csums(trans, inode, log_root, sums);
4206 list_del(&sums->list);
4213 static int log_one_extent(struct btrfs_trans_handle *trans,
4214 struct btrfs_inode *inode, struct btrfs_root *root,
4215 const struct extent_map *em,
4216 struct btrfs_path *path,
4217 struct btrfs_log_ctx *ctx)
4219 struct btrfs_drop_extents_args drop_args = { 0 };
4220 struct btrfs_root *log = root->log_root;
4221 struct btrfs_file_extent_item *fi;
4222 struct extent_buffer *leaf;
4223 struct btrfs_map_token token;
4224 struct btrfs_key key;
4225 u64 extent_offset = em->start - em->orig_start;
4229 ret = log_extent_csums(trans, inode, log, em, ctx);
4233 drop_args.path = path;
4234 drop_args.start = em->start;
4235 drop_args.end = em->start + em->len;
4236 drop_args.replace_extent = true;
4237 drop_args.extent_item_size = sizeof(*fi);
4238 ret = btrfs_drop_extents(trans, log, inode, &drop_args);
4242 if (!drop_args.extent_inserted) {
4243 key.objectid = btrfs_ino(inode);
4244 key.type = BTRFS_EXTENT_DATA_KEY;
4245 key.offset = em->start;
4247 ret = btrfs_insert_empty_item(trans, log, path, &key,
4252 leaf = path->nodes[0];
4253 btrfs_init_map_token(&token, leaf);
4254 fi = btrfs_item_ptr(leaf, path->slots[0],
4255 struct btrfs_file_extent_item);
4257 btrfs_set_token_file_extent_generation(&token, fi, trans->transid);
4258 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
4259 btrfs_set_token_file_extent_type(&token, fi,
4260 BTRFS_FILE_EXTENT_PREALLOC);
4262 btrfs_set_token_file_extent_type(&token, fi,
4263 BTRFS_FILE_EXTENT_REG);
4265 block_len = max(em->block_len, em->orig_block_len);
4266 if (em->compress_type != BTRFS_COMPRESS_NONE) {
4267 btrfs_set_token_file_extent_disk_bytenr(&token, fi,
4269 btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len);
4270 } else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
4271 btrfs_set_token_file_extent_disk_bytenr(&token, fi,
4274 btrfs_set_token_file_extent_disk_num_bytes(&token, fi, block_len);
4276 btrfs_set_token_file_extent_disk_bytenr(&token, fi, 0);
4277 btrfs_set_token_file_extent_disk_num_bytes(&token, fi, 0);
4280 btrfs_set_token_file_extent_offset(&token, fi, extent_offset);
4281 btrfs_set_token_file_extent_num_bytes(&token, fi, em->len);
4282 btrfs_set_token_file_extent_ram_bytes(&token, fi, em->ram_bytes);
4283 btrfs_set_token_file_extent_compression(&token, fi, em->compress_type);
4284 btrfs_set_token_file_extent_encryption(&token, fi, 0);
4285 btrfs_set_token_file_extent_other_encoding(&token, fi, 0);
4286 btrfs_mark_buffer_dirty(leaf);
4288 btrfs_release_path(path);
4294 * Log all prealloc extents beyond the inode's i_size to make sure we do not
4295 * lose them after doing a fast fsync and replaying the log. We scan the
4296 * subvolume's root instead of iterating the inode's extent map tree because
4297 * otherwise we can log incorrect extent items based on extent map conversion.
4298 * That can happen due to the fact that extent maps are merged when they
4299 * are not in the extent map tree's list of modified extents.
4301 static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
4302 struct btrfs_inode *inode,
4303 struct btrfs_path *path)
4305 struct btrfs_root *root = inode->root;
4306 struct btrfs_key key;
4307 const u64 i_size = i_size_read(&inode->vfs_inode);
4308 const u64 ino = btrfs_ino(inode);
4309 struct btrfs_path *dst_path = NULL;
4310 bool dropped_extents = false;
4311 u64 truncate_offset = i_size;
4312 struct extent_buffer *leaf;
4318 if (!(inode->flags & BTRFS_INODE_PREALLOC))
4322 key.type = BTRFS_EXTENT_DATA_KEY;
4323 key.offset = i_size;
4324 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4329 * We must check if there is a prealloc extent that starts before the
4330 * i_size and crosses the i_size boundary. This is to ensure later we
4331 * truncate down to the end of that extent and not to the i_size, as
4332 * otherwise we end up losing part of the prealloc extent after a log
4333 * replay and with an implicit hole if there is another prealloc extent
4334 * that starts at an offset beyond i_size.
4336 ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
4341 struct btrfs_file_extent_item *ei;
4343 leaf = path->nodes[0];
4344 slot = path->slots[0];
4345 ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
4347 if (btrfs_file_extent_type(leaf, ei) ==
4348 BTRFS_FILE_EXTENT_PREALLOC) {
4351 btrfs_item_key_to_cpu(leaf, &key, slot);
4352 extent_end = key.offset +
4353 btrfs_file_extent_num_bytes(leaf, ei);
4355 if (extent_end > i_size)
4356 truncate_offset = extent_end;
4363 leaf = path->nodes[0];
4364 slot = path->slots[0];
4366 if (slot >= btrfs_header_nritems(leaf)) {
4368 ret = copy_items(trans, inode, dst_path, path,
4369 start_slot, ins_nr, 1, 0);
4374 ret = btrfs_next_leaf(root, path);
4384 btrfs_item_key_to_cpu(leaf, &key, slot);
4385 if (key.objectid > ino)
4387 if (WARN_ON_ONCE(key.objectid < ino) ||
4388 key.type < BTRFS_EXTENT_DATA_KEY ||
4389 key.offset < i_size) {
4393 if (!dropped_extents) {
4395 * Avoid logging extent items logged in past fsync calls
4396 * and leading to duplicate keys in the log tree.
4399 ret = btrfs_truncate_inode_items(trans,
4401 inode, truncate_offset,
4402 BTRFS_EXTENT_DATA_KEY);
4403 } while (ret == -EAGAIN);
4406 dropped_extents = true;
4413 dst_path = btrfs_alloc_path();
4421 ret = copy_items(trans, inode, dst_path, path,
4422 start_slot, ins_nr, 1, 0);
4424 btrfs_release_path(path);
4425 btrfs_free_path(dst_path);
4429 static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
4430 struct btrfs_root *root,
4431 struct btrfs_inode *inode,
4432 struct btrfs_path *path,
4433 struct btrfs_log_ctx *ctx)
4435 struct btrfs_ordered_extent *ordered;
4436 struct btrfs_ordered_extent *tmp;
4437 struct extent_map *em, *n;
4438 struct list_head extents;
4439 struct extent_map_tree *tree = &inode->extent_tree;
4443 INIT_LIST_HEAD(&extents);
4445 write_lock(&tree->lock);
4447 list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
4448 list_del_init(&em->list);
4450 * Just an arbitrary number, this can be really CPU intensive
4451 * once we start getting a lot of extents, and really once we
4452 * have a bunch of extents we just want to commit since it will
4455 if (++num > 32768) {
4456 list_del_init(&tree->modified_extents);
4461 if (em->generation < trans->transid)
4464 /* We log prealloc extents beyond eof later. */
4465 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) &&
4466 em->start >= i_size_read(&inode->vfs_inode))
4469 /* Need a ref to keep it from getting evicted from cache */
4470 refcount_inc(&em->refs);
4471 set_bit(EXTENT_FLAG_LOGGING, &em->flags);
4472 list_add_tail(&em->list, &extents);
4476 list_sort(NULL, &extents, extent_cmp);
4478 while (!list_empty(&extents)) {
4479 em = list_entry(extents.next, struct extent_map, list);
4481 list_del_init(&em->list);
4484 * If we had an error we just need to delete everybody from our
4488 clear_em_logging(tree, em);
4489 free_extent_map(em);
4493 write_unlock(&tree->lock);
4495 ret = log_one_extent(trans, inode, root, em, path, ctx);
4496 write_lock(&tree->lock);
4497 clear_em_logging(tree, em);
4498 free_extent_map(em);
4500 WARN_ON(!list_empty(&extents));
4501 write_unlock(&tree->lock);
4503 btrfs_release_path(path);
4505 ret = btrfs_log_prealloc_extents(trans, inode, path);
4510 * We have logged all extents successfully, now make sure the commit of
4511 * the current transaction waits for the ordered extents to complete
4512 * before it commits and wipes out the log trees, otherwise we would
4513 * lose data if an ordered extents completes after the transaction
4514 * commits and a power failure happens after the transaction commit.
4516 list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
4517 list_del_init(&ordered->log_list);
4518 set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags);
4520 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
4521 spin_lock_irq(&inode->ordered_tree.lock);
4522 if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
4523 set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
4524 atomic_inc(&trans->transaction->pending_ordered);
4526 spin_unlock_irq(&inode->ordered_tree.lock);
4528 btrfs_put_ordered_extent(ordered);
4534 static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
4535 struct btrfs_path *path, u64 *size_ret)
4537 struct btrfs_key key;
4540 key.objectid = btrfs_ino(inode);
4541 key.type = BTRFS_INODE_ITEM_KEY;
4544 ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
4547 } else if (ret > 0) {
4550 struct btrfs_inode_item *item;
4552 item = btrfs_item_ptr(path->nodes[0], path->slots[0],
4553 struct btrfs_inode_item);
4554 *size_ret = btrfs_inode_size(path->nodes[0], item);
4556 * If the in-memory inode's i_size is smaller then the inode
4557 * size stored in the btree, return the inode's i_size, so
4558 * that we get a correct inode size after replaying the log
4559 * when before a power failure we had a shrinking truncate
4560 * followed by addition of a new name (rename / new hard link).
4561 * Otherwise return the inode size from the btree, to avoid
4562 * data loss when replaying a log due to previously doing a
4563 * write that expands the inode's size and logging a new name
4564 * immediately after.
4566 if (*size_ret > inode->vfs_inode.i_size)
4567 *size_ret = inode->vfs_inode.i_size;
4570 btrfs_release_path(path);
4575 * At the moment we always log all xattrs. This is to figure out at log replay
4576 * time which xattrs must have their deletion replayed. If a xattr is missing
4577 * in the log tree and exists in the fs/subvol tree, we delete it. This is
4578 * because if a xattr is deleted, the inode is fsynced and a power failure
4579 * happens, causing the log to be replayed the next time the fs is mounted,
4580 * we want the xattr to not exist anymore (same behaviour as other filesystems
4581 * with a journal, ext3/4, xfs, f2fs, etc).
4583 static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
4584 struct btrfs_root *root,
4585 struct btrfs_inode *inode,
4586 struct btrfs_path *path,
4587 struct btrfs_path *dst_path)
4590 struct btrfs_key key;
4591 const u64 ino = btrfs_ino(inode);
4594 bool found_xattrs = false;
4596 if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags))
4600 key.type = BTRFS_XATTR_ITEM_KEY;
4603 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4608 int slot = path->slots[0];
4609 struct extent_buffer *leaf = path->nodes[0];
4610 int nritems = btrfs_header_nritems(leaf);
4612 if (slot >= nritems) {
4614 ret = copy_items(trans, inode, dst_path, path,
4615 start_slot, ins_nr, 1, 0);
4620 ret = btrfs_next_leaf(root, path);
4628 btrfs_item_key_to_cpu(leaf, &key, slot);
4629 if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
4636 found_xattrs = true;
4640 ret = copy_items(trans, inode, dst_path, path,
4641 start_slot, ins_nr, 1, 0);
4647 set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags);
4653 * When using the NO_HOLES feature if we punched a hole that causes the
4654 * deletion of entire leafs or all the extent items of the first leaf (the one
4655 * that contains the inode item and references) we may end up not processing
4656 * any extents, because there are no leafs with a generation matching the
4657 * current transaction that have extent items for our inode. So we need to find
4658 * if any holes exist and then log them. We also need to log holes after any
4659 * truncate operation that changes the inode's size.
4661 static int btrfs_log_holes(struct btrfs_trans_handle *trans,
4662 struct btrfs_root *root,
4663 struct btrfs_inode *inode,
4664 struct btrfs_path *path)
4666 struct btrfs_fs_info *fs_info = root->fs_info;
4667 struct btrfs_key key;
4668 const u64 ino = btrfs_ino(inode);
4669 const u64 i_size = i_size_read(&inode->vfs_inode);
4670 u64 prev_extent_end = 0;
4673 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0)
4677 key.type = BTRFS_EXTENT_DATA_KEY;
4680 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4685 struct extent_buffer *leaf = path->nodes[0];
4687 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
4688 ret = btrfs_next_leaf(root, path);
4695 leaf = path->nodes[0];
4698 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4699 if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
4702 /* We have a hole, log it. */
4703 if (prev_extent_end < key.offset) {
4704 const u64 hole_len = key.offset - prev_extent_end;
4707 * Release the path to avoid deadlocks with other code
4708 * paths that search the root while holding locks on
4709 * leafs from the log root.
4711 btrfs_release_path(path);
4712 ret = btrfs_insert_file_extent(trans, root->log_root,
4713 ino, prev_extent_end, 0,
4714 0, hole_len, 0, hole_len,
4720 * Search for the same key again in the root. Since it's
4721 * an extent item and we are holding the inode lock, the
4722 * key must still exist. If it doesn't just emit warning
4723 * and return an error to fall back to a transaction
4726 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
4729 if (WARN_ON(ret > 0))
4731 leaf = path->nodes[0];
4734 prev_extent_end = btrfs_file_extent_end(path);
4739 if (prev_extent_end < i_size) {
4742 btrfs_release_path(path);
4743 hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize);
4744 ret = btrfs_insert_file_extent(trans, root->log_root,
4745 ino, prev_extent_end, 0, 0,
4746 hole_len, 0, hole_len,
4756 * When we are logging a new inode X, check if it doesn't have a reference that
4757 * matches the reference from some other inode Y created in a past transaction
4758 * and that was renamed in the current transaction. If we don't do this, then at
4759 * log replay time we can lose inode Y (and all its files if it's a directory):
4762 * echo "hello world" > /mnt/x/foobar
4765 * mkdir /mnt/x # or touch /mnt/x
4766 * xfs_io -c fsync /mnt/x
4768 * mount fs, trigger log replay
4770 * After the log replay procedure, we would lose the first directory and all its
4771 * files (file foobar).
4772 * For the case where inode Y is not a directory we simply end up losing it:
4774 * echo "123" > /mnt/foo
4776 * mv /mnt/foo /mnt/bar
4777 * echo "abc" > /mnt/foo
4778 * xfs_io -c fsync /mnt/foo
4781 * We also need this for cases where a snapshot entry is replaced by some other
4782 * entry (file or directory) otherwise we end up with an unreplayable log due to
4783 * attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
4784 * if it were a regular entry:
4787 * btrfs subvolume snapshot /mnt /mnt/x/snap
4788 * btrfs subvolume delete /mnt/x/snap
4791 * fsync /mnt/x or fsync some new file inside it
4794 * The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
4795 * the same transaction.
4797 static int btrfs_check_ref_name_override(struct extent_buffer *eb,
4799 const struct btrfs_key *key,
4800 struct btrfs_inode *inode,
4801 u64 *other_ino, u64 *other_parent)
4804 struct btrfs_path *search_path;
4807 u32 item_size = btrfs_item_size_nr(eb, slot);
4809 unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
4811 search_path = btrfs_alloc_path();
4814 search_path->search_commit_root = 1;
4815 search_path->skip_locking = 1;
4817 while (cur_offset < item_size) {
4821 unsigned long name_ptr;
4822 struct btrfs_dir_item *di;
4824 if (key->type == BTRFS_INODE_REF_KEY) {
4825 struct btrfs_inode_ref *iref;
4827 iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
4828 parent = key->offset;
4829 this_name_len = btrfs_inode_ref_name_len(eb, iref);
4830 name_ptr = (unsigned long)(iref + 1);
4831 this_len = sizeof(*iref) + this_name_len;
4833 struct btrfs_inode_extref *extref;
4835 extref = (struct btrfs_inode_extref *)(ptr +
4837 parent = btrfs_inode_extref_parent(eb, extref);
4838 this_name_len = btrfs_inode_extref_name_len(eb, extref);
4839 name_ptr = (unsigned long)&extref->name;
4840 this_len = sizeof(*extref) + this_name_len;
4843 if (this_name_len > name_len) {
4846 new_name = krealloc(name, this_name_len, GFP_NOFS);
4851 name_len = this_name_len;
4855 read_extent_buffer(eb, name, name_ptr, this_name_len);
4856 di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
4857 parent, name, this_name_len, 0);
4858 if (di && !IS_ERR(di)) {
4859 struct btrfs_key di_key;
4861 btrfs_dir_item_key_to_cpu(search_path->nodes[0],
4863 if (di_key.type == BTRFS_INODE_ITEM_KEY) {
4864 if (di_key.objectid != key->objectid) {
4866 *other_ino = di_key.objectid;
4867 *other_parent = parent;
4875 } else if (IS_ERR(di)) {
4879 btrfs_release_path(search_path);
4881 cur_offset += this_len;
4885 btrfs_free_path(search_path);
4890 struct btrfs_ino_list {
4893 struct list_head list;
4896 static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
4897 struct btrfs_root *root,
4898 struct btrfs_path *path,
4899 struct btrfs_log_ctx *ctx,
4900 u64 ino, u64 parent)
4902 struct btrfs_ino_list *ino_elem;
4903 LIST_HEAD(inode_list);
4906 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
4909 ino_elem->ino = ino;
4910 ino_elem->parent = parent;
4911 list_add_tail(&ino_elem->list, &inode_list);
4913 while (!list_empty(&inode_list)) {
4914 struct btrfs_fs_info *fs_info = root->fs_info;
4915 struct btrfs_key key;
4916 struct inode *inode;
4918 ino_elem = list_first_entry(&inode_list, struct btrfs_ino_list,
4920 ino = ino_elem->ino;
4921 parent = ino_elem->parent;
4922 list_del(&ino_elem->list);
4927 btrfs_release_path(path);
4929 inode = btrfs_iget(fs_info->sb, ino, root);
4931 * If the other inode that had a conflicting dir entry was
4932 * deleted in the current transaction, we need to log its parent
4935 if (IS_ERR(inode)) {
4936 ret = PTR_ERR(inode);
4937 if (ret == -ENOENT) {
4938 inode = btrfs_iget(fs_info->sb, parent, root);
4939 if (IS_ERR(inode)) {
4940 ret = PTR_ERR(inode);
4942 ret = btrfs_log_inode(trans, root,
4944 LOG_OTHER_INODE_ALL,
4946 btrfs_add_delayed_iput(inode);
4952 * If the inode was already logged skip it - otherwise we can
4953 * hit an infinite loop. Example:
4955 * From the commit root (previous transaction) we have the
4958 * inode 257 a directory
4959 * inode 258 with references "zz" and "zz_link" on inode 257
4960 * inode 259 with reference "a" on inode 257
4962 * And in the current (uncommitted) transaction we have:
4964 * inode 257 a directory, unchanged
4965 * inode 258 with references "a" and "a2" on inode 257
4966 * inode 259 with reference "zz_link" on inode 257
4967 * inode 261 with reference "zz" on inode 257
4969 * When logging inode 261 the following infinite loop could
4970 * happen if we don't skip already logged inodes:
4972 * - we detect inode 258 as a conflicting inode, with inode 261
4973 * on reference "zz", and log it;
4975 * - we detect inode 259 as a conflicting inode, with inode 258
4976 * on reference "a", and log it;
4978 * - we detect inode 258 as a conflicting inode, with inode 259
4979 * on reference "zz_link", and log it - again! After this we
4980 * repeat the above steps forever.
4982 spin_lock(&BTRFS_I(inode)->lock);
4984 * Check the inode's logged_trans only instead of
4985 * btrfs_inode_in_log(). This is because the last_log_commit of
4986 * the inode is not updated when we only log that it exists and
4987 * it has the full sync bit set (see btrfs_log_inode()).
4989 if (BTRFS_I(inode)->logged_trans == trans->transid) {
4990 spin_unlock(&BTRFS_I(inode)->lock);
4991 btrfs_add_delayed_iput(inode);
4994 spin_unlock(&BTRFS_I(inode)->lock);
4996 * We are safe logging the other inode without acquiring its
4997 * lock as long as we log with the LOG_INODE_EXISTS mode. We
4998 * are safe against concurrent renames of the other inode as
4999 * well because during a rename we pin the log and update the
5000 * log with the new name before we unpin it.
5002 ret = btrfs_log_inode(trans, root, BTRFS_I(inode),
5003 LOG_OTHER_INODE, ctx);
5005 btrfs_add_delayed_iput(inode);
5010 key.type = BTRFS_INODE_REF_KEY;
5012 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5014 btrfs_add_delayed_iput(inode);
5019 struct extent_buffer *leaf = path->nodes[0];
5020 int slot = path->slots[0];
5022 u64 other_parent = 0;
5024 if (slot >= btrfs_header_nritems(leaf)) {
5025 ret = btrfs_next_leaf(root, path);
5028 } else if (ret > 0) {
5035 btrfs_item_key_to_cpu(leaf, &key, slot);
5036 if (key.objectid != ino ||
5037 (key.type != BTRFS_INODE_REF_KEY &&
5038 key.type != BTRFS_INODE_EXTREF_KEY)) {
5043 ret = btrfs_check_ref_name_override(leaf, slot, &key,
5044 BTRFS_I(inode), &other_ino,
5049 ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
5054 ino_elem->ino = other_ino;
5055 ino_elem->parent = other_parent;
5056 list_add_tail(&ino_elem->list, &inode_list);
5061 btrfs_add_delayed_iput(inode);
5067 static int copy_inode_items_to_log(struct btrfs_trans_handle *trans,
5068 struct btrfs_inode *inode,
5069 struct btrfs_key *min_key,
5070 const struct btrfs_key *max_key,
5071 struct btrfs_path *path,
5072 struct btrfs_path *dst_path,
5073 const u64 logged_isize,
5074 const bool recursive_logging,
5075 const int inode_only,
5076 struct btrfs_log_ctx *ctx,
5077 bool *need_log_inode_item)
5079 struct btrfs_root *root = inode->root;
5080 int ins_start_slot = 0;
5085 ret = btrfs_search_forward(root, min_key, path, trans->transid);
5093 /* Note, ins_nr might be > 0 here, cleanup outside the loop */
5094 if (min_key->objectid != max_key->objectid)
5096 if (min_key->type > max_key->type)
5099 if (min_key->type == BTRFS_INODE_ITEM_KEY)
5100 *need_log_inode_item = false;
5102 if ((min_key->type == BTRFS_INODE_REF_KEY ||
5103 min_key->type == BTRFS_INODE_EXTREF_KEY) &&
5104 inode->generation == trans->transid &&
5105 !recursive_logging) {
5107 u64 other_parent = 0;
5109 ret = btrfs_check_ref_name_override(path->nodes[0],
5110 path->slots[0], min_key, inode,
5111 &other_ino, &other_parent);
5114 } else if (ret > 0 && ctx &&
5115 other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
5120 ins_start_slot = path->slots[0];
5122 ret = copy_items(trans, inode, dst_path, path,
5123 ins_start_slot, ins_nr,
5124 inode_only, logged_isize);
5129 ret = log_conflicting_inodes(trans, root, path,
5130 ctx, other_ino, other_parent);
5133 btrfs_release_path(path);
5138 /* Skip xattrs, we log them later with btrfs_log_all_xattrs() */
5139 if (min_key->type == BTRFS_XATTR_ITEM_KEY) {
5142 ret = copy_items(trans, inode, dst_path, path,
5144 ins_nr, inode_only, logged_isize);
5151 if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
5154 } else if (!ins_nr) {
5155 ins_start_slot = path->slots[0];
5160 ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
5161 ins_nr, inode_only, logged_isize);
5165 ins_start_slot = path->slots[0];
5168 if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
5169 btrfs_item_key_to_cpu(path->nodes[0], min_key,
5174 ret = copy_items(trans, inode, dst_path, path,
5175 ins_start_slot, ins_nr, inode_only,
5181 btrfs_release_path(path);
5183 if (min_key->offset < (u64)-1) {
5185 } else if (min_key->type < max_key->type) {
5187 min_key->offset = 0;
5193 ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
5194 ins_nr, inode_only, logged_isize);
5199 /* log a single inode in the tree log.
5200 * At least one parent directory for this inode must exist in the tree
5201 * or be logged already.
5203 * Any items from this inode changed by the current transaction are copied
5204 * to the log tree. An extra reference is taken on any extents in this
5205 * file, allowing us to avoid a whole pile of corner cases around logging
5206 * blocks that have been removed from the tree.
5208 * See LOG_INODE_ALL and related defines for a description of what inode_only
5211 * This handles both files and directories.
5213 static int btrfs_log_inode(struct btrfs_trans_handle *trans,
5214 struct btrfs_root *root, struct btrfs_inode *inode,
5216 struct btrfs_log_ctx *ctx)
5218 struct btrfs_path *path;
5219 struct btrfs_path *dst_path;
5220 struct btrfs_key min_key;
5221 struct btrfs_key max_key;
5222 struct btrfs_root *log = root->log_root;
5225 bool fast_search = false;
5226 u64 ino = btrfs_ino(inode);
5227 struct extent_map_tree *em_tree = &inode->extent_tree;
5228 u64 logged_isize = 0;
5229 bool need_log_inode_item = true;
5230 bool xattrs_logged = false;
5231 bool recursive_logging = false;
5233 path = btrfs_alloc_path();
5236 dst_path = btrfs_alloc_path();
5238 btrfs_free_path(path);
5242 min_key.objectid = ino;
5243 min_key.type = BTRFS_INODE_ITEM_KEY;
5246 max_key.objectid = ino;
5249 /* today the code can only do partial logging of directories */
5250 if (S_ISDIR(inode->vfs_inode.i_mode) ||
5251 (!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
5252 &inode->runtime_flags) &&
5253 inode_only >= LOG_INODE_EXISTS))
5254 max_key.type = BTRFS_XATTR_ITEM_KEY;
5256 max_key.type = (u8)-1;
5257 max_key.offset = (u64)-1;
5260 * Only run delayed items if we are a directory. We want to make sure
5261 * all directory indexes hit the fs/subvolume tree so we can find them
5262 * and figure out which index ranges have to be logged.
5264 * Otherwise commit the delayed inode only if the full sync flag is set,
5265 * as we want to make sure an up to date version is in the subvolume
5266 * tree so copy_inode_items_to_log() / copy_items() can find it and copy
5267 * it to the log tree. For a non full sync, we always log the inode item
5268 * based on the in-memory struct btrfs_inode which is always up to date.
5270 if (S_ISDIR(inode->vfs_inode.i_mode))
5271 ret = btrfs_commit_inode_delayed_items(trans, inode);
5272 else if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags))
5273 ret = btrfs_commit_inode_delayed_inode(inode);
5276 btrfs_free_path(path);
5277 btrfs_free_path(dst_path);
5281 if (inode_only == LOG_OTHER_INODE || inode_only == LOG_OTHER_INODE_ALL) {
5282 recursive_logging = true;
5283 if (inode_only == LOG_OTHER_INODE)
5284 inode_only = LOG_INODE_EXISTS;
5286 inode_only = LOG_INODE_ALL;
5287 mutex_lock_nested(&inode->log_mutex, SINGLE_DEPTH_NESTING);
5289 mutex_lock(&inode->log_mutex);
5293 * a brute force approach to making sure we get the most uptodate
5294 * copies of everything.
5296 if (S_ISDIR(inode->vfs_inode.i_mode)) {
5297 int max_key_type = BTRFS_DIR_LOG_INDEX_KEY;
5299 if (inode_only == LOG_INODE_EXISTS)
5300 max_key_type = BTRFS_XATTR_ITEM_KEY;
5301 ret = drop_objectid_items(trans, log, path, ino, max_key_type);
5303 if (inode_only == LOG_INODE_EXISTS) {
5305 * Make sure the new inode item we write to the log has
5306 * the same isize as the current one (if it exists).
5307 * This is necessary to prevent data loss after log
5308 * replay, and also to prevent doing a wrong expanding
5309 * truncate - for e.g. create file, write 4K into offset
5310 * 0, fsync, write 4K into offset 4096, add hard link,
5311 * fsync some other file (to sync log), power fail - if
5312 * we use the inode's current i_size, after log replay
5313 * we get a 8Kb file, with the last 4Kb extent as a hole
5314 * (zeroes), as if an expanding truncate happened,
5315 * instead of getting a file of 4Kb only.
5317 err = logged_inode_size(log, inode, path, &logged_isize);
5321 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
5322 &inode->runtime_flags)) {
5323 if (inode_only == LOG_INODE_EXISTS) {
5324 max_key.type = BTRFS_XATTR_ITEM_KEY;
5325 ret = drop_objectid_items(trans, log, path, ino,
5328 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
5329 &inode->runtime_flags);
5330 clear_bit(BTRFS_INODE_COPY_EVERYTHING,
5331 &inode->runtime_flags);
5333 ret = btrfs_truncate_inode_items(trans,
5339 } else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
5340 &inode->runtime_flags) ||
5341 inode_only == LOG_INODE_EXISTS) {
5342 if (inode_only == LOG_INODE_ALL)
5344 max_key.type = BTRFS_XATTR_ITEM_KEY;
5345 ret = drop_objectid_items(trans, log, path, ino,
5348 if (inode_only == LOG_INODE_ALL)
5359 err = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
5360 path, dst_path, logged_isize,
5361 recursive_logging, inode_only, ctx,
5362 &need_log_inode_item);
5366 btrfs_release_path(path);
5367 btrfs_release_path(dst_path);
5368 err = btrfs_log_all_xattrs(trans, root, inode, path, dst_path);
5371 xattrs_logged = true;
5372 if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
5373 btrfs_release_path(path);
5374 btrfs_release_path(dst_path);
5375 err = btrfs_log_holes(trans, root, inode, path);
5380 btrfs_release_path(path);
5381 btrfs_release_path(dst_path);
5382 if (need_log_inode_item) {
5383 err = log_inode_item(trans, log, dst_path, inode);
5384 if (!err && !xattrs_logged) {
5385 err = btrfs_log_all_xattrs(trans, root, inode, path,
5387 btrfs_release_path(path);
5393 ret = btrfs_log_changed_extents(trans, root, inode, dst_path,
5399 } else if (inode_only == LOG_INODE_ALL) {
5400 struct extent_map *em, *n;
5402 write_lock(&em_tree->lock);
5403 list_for_each_entry_safe(em, n, &em_tree->modified_extents, list)
5404 list_del_init(&em->list);
5405 write_unlock(&em_tree->lock);
5408 if (inode_only == LOG_INODE_ALL && S_ISDIR(inode->vfs_inode.i_mode)) {
5409 ret = log_directory_changes(trans, root, inode, path, dst_path,
5418 * If we are logging that an ancestor inode exists as part of logging a
5419 * new name from a link or rename operation, don't mark the inode as
5420 * logged - otherwise if an explicit fsync is made against an ancestor,
5421 * the fsync considers the inode in the log and doesn't sync the log,
5422 * resulting in the ancestor missing after a power failure unless the
5423 * log was synced as part of an fsync against any other unrelated inode.
5424 * So keep it simple for this case and just don't flag the ancestors as
5428 !(S_ISDIR(inode->vfs_inode.i_mode) && ctx->logging_new_name &&
5429 &inode->vfs_inode != ctx->inode)) {
5430 spin_lock(&inode->lock);
5431 inode->logged_trans = trans->transid;
5433 * Don't update last_log_commit if we logged that an inode exists
5434 * after it was loaded to memory (full_sync bit set).
5435 * This is to prevent data loss when we do a write to the inode,
5436 * then the inode gets evicted after all delalloc was flushed,
5437 * then we log it exists (due to a rename for example) and then
5438 * fsync it. This last fsync would do nothing (not logging the
5439 * extents previously written).
5441 if (inode_only != LOG_INODE_EXISTS ||
5442 !test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags))
5443 inode->last_log_commit = inode->last_sub_trans;
5444 spin_unlock(&inode->lock);
5447 mutex_unlock(&inode->log_mutex);
5449 btrfs_free_path(path);
5450 btrfs_free_path(dst_path);
5455 * Check if we must fallback to a transaction commit when logging an inode.
5456 * This must be called after logging the inode and is used only in the context
5457 * when fsyncing an inode requires the need to log some other inode - in which
5458 * case we can't lock the i_mutex of each other inode we need to log as that
5459 * can lead to deadlocks with concurrent fsync against other inodes (as we can
5460 * log inodes up or down in the hierarchy) or rename operations for example. So
5461 * we take the log_mutex of the inode after we have logged it and then check for
5462 * its last_unlink_trans value - this is safe because any task setting
5463 * last_unlink_trans must take the log_mutex and it must do this before it does
5464 * the actual unlink operation, so if we do this check before a concurrent task
5465 * sets last_unlink_trans it means we've logged a consistent version/state of
5466 * all the inode items, otherwise we are not sure and must do a transaction
5467 * commit (the concurrent task might have only updated last_unlink_trans before
5468 * we logged the inode or it might have also done the unlink).
5470 static bool btrfs_must_commit_transaction(struct btrfs_trans_handle *trans,
5471 struct btrfs_inode *inode)
5475 mutex_lock(&inode->log_mutex);
5476 if (inode->last_unlink_trans >= trans->transid) {
5478 * Make sure any commits to the log are forced to be full
5481 btrfs_set_log_full_commit(trans);
5484 mutex_unlock(&inode->log_mutex);
5490 * follow the dentry parent pointers up the chain and see if any
5491 * of the directories in it require a full commit before they can
5492 * be logged. Returns zero if nothing special needs to be done or 1 if
5493 * a full commit is required.
5495 static noinline int check_parent_dirs_for_sync(struct btrfs_trans_handle *trans,
5496 struct btrfs_inode *inode,
5497 struct dentry *parent,
5498 struct super_block *sb)
5501 struct dentry *old_parent = NULL;
5504 * for regular files, if its inode is already on disk, we don't
5505 * have to worry about the parents at all. This is because
5506 * we can use the last_unlink_trans field to record renames
5507 * and other fun in this file.
5509 if (S_ISREG(inode->vfs_inode.i_mode) &&
5510 inode->generation < trans->transid &&
5511 inode->last_unlink_trans < trans->transid)
5514 if (!S_ISDIR(inode->vfs_inode.i_mode)) {
5515 if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
5517 inode = BTRFS_I(d_inode(parent));
5521 if (btrfs_must_commit_transaction(trans, inode)) {
5526 if (!parent || d_really_is_negative(parent) || sb != parent->d_sb)
5529 if (IS_ROOT(parent)) {
5530 inode = BTRFS_I(d_inode(parent));
5531 if (btrfs_must_commit_transaction(trans, inode))
5536 parent = dget_parent(parent);
5538 old_parent = parent;
5539 inode = BTRFS_I(d_inode(parent));
5547 struct btrfs_dir_list {
5549 struct list_head list;
5553 * Log the inodes of the new dentries of a directory. See log_dir_items() for
5554 * details about the why it is needed.
5555 * This is a recursive operation - if an existing dentry corresponds to a
5556 * directory, that directory's new entries are logged too (same behaviour as
5557 * ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
5558 * the dentries point to we do not lock their i_mutex, otherwise lockdep
5559 * complains about the following circular lock dependency / possible deadlock:
5563 * lock(&type->i_mutex_dir_key#3/2);
5564 * lock(sb_internal#2);
5565 * lock(&type->i_mutex_dir_key#3/2);
5566 * lock(&sb->s_type->i_mutex_key#14);
5568 * Where sb_internal is the lock (a counter that works as a lock) acquired by
5569 * sb_start_intwrite() in btrfs_start_transaction().
5570 * Not locking i_mutex of the inodes is still safe because:
5572 * 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
5573 * that while logging the inode new references (names) are added or removed
5574 * from the inode, leaving the logged inode item with a link count that does
5575 * not match the number of logged inode reference items. This is fine because
5576 * at log replay time we compute the real number of links and correct the
5577 * link count in the inode item (see replay_one_buffer() and
5578 * link_to_fixup_dir());
5580 * 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
5581 * while logging the inode's items new items with keys BTRFS_DIR_ITEM_KEY and
5582 * BTRFS_DIR_INDEX_KEY are added to fs/subvol tree and the logged inode item
5583 * has a size that doesn't match the sum of the lengths of all the logged
5584 * names. This does not result in a problem because if a dir_item key is
5585 * logged but its matching dir_index key is not logged, at log replay time we
5586 * don't use it to replay the respective name (see replay_one_name()). On the
5587 * other hand if only the dir_index key ends up being logged, the respective
5588 * name is added to the fs/subvol tree with both the dir_item and dir_index
5589 * keys created (see replay_one_name()).
5590 * The directory's inode item with a wrong i_size is not a problem as well,
5591 * since we don't use it at log replay time to set the i_size in the inode
5592 * item of the fs/subvol tree (see overwrite_item()).
5594 static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
5595 struct btrfs_root *root,
5596 struct btrfs_inode *start_inode,
5597 struct btrfs_log_ctx *ctx)
5599 struct btrfs_fs_info *fs_info = root->fs_info;
5600 struct btrfs_root *log = root->log_root;
5601 struct btrfs_path *path;
5602 LIST_HEAD(dir_list);
5603 struct btrfs_dir_list *dir_elem;
5606 path = btrfs_alloc_path();
5610 dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
5612 btrfs_free_path(path);
5615 dir_elem->ino = btrfs_ino(start_inode);
5616 list_add_tail(&dir_elem->list, &dir_list);
5618 while (!list_empty(&dir_list)) {
5619 struct extent_buffer *leaf;
5620 struct btrfs_key min_key;
5624 dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list,
5627 goto next_dir_inode;
5629 min_key.objectid = dir_elem->ino;
5630 min_key.type = BTRFS_DIR_ITEM_KEY;
5633 btrfs_release_path(path);
5634 ret = btrfs_search_forward(log, &min_key, path, trans->transid);
5636 goto next_dir_inode;
5637 } else if (ret > 0) {
5639 goto next_dir_inode;
5643 leaf = path->nodes[0];
5644 nritems = btrfs_header_nritems(leaf);
5645 for (i = path->slots[0]; i < nritems; i++) {
5646 struct btrfs_dir_item *di;
5647 struct btrfs_key di_key;
5648 struct inode *di_inode;
5649 struct btrfs_dir_list *new_dir_elem;
5650 int log_mode = LOG_INODE_EXISTS;
5653 btrfs_item_key_to_cpu(leaf, &min_key, i);
5654 if (min_key.objectid != dir_elem->ino ||
5655 min_key.type != BTRFS_DIR_ITEM_KEY)
5656 goto next_dir_inode;
5658 di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
5659 type = btrfs_dir_type(leaf, di);
5660 if (btrfs_dir_transid(leaf, di) < trans->transid &&
5661 type != BTRFS_FT_DIR)
5663 btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
5664 if (di_key.type == BTRFS_ROOT_ITEM_KEY)
5667 btrfs_release_path(path);
5668 di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root);
5669 if (IS_ERR(di_inode)) {
5670 ret = PTR_ERR(di_inode);
5671 goto next_dir_inode;
5674 if (btrfs_inode_in_log(BTRFS_I(di_inode), trans->transid)) {
5675 btrfs_add_delayed_iput(di_inode);
5679 ctx->log_new_dentries = false;
5680 if (type == BTRFS_FT_DIR || type == BTRFS_FT_SYMLINK)
5681 log_mode = LOG_INODE_ALL;
5682 ret = btrfs_log_inode(trans, root, BTRFS_I(di_inode),
5685 btrfs_must_commit_transaction(trans, BTRFS_I(di_inode)))
5687 btrfs_add_delayed_iput(di_inode);
5689 goto next_dir_inode;
5690 if (ctx->log_new_dentries) {
5691 new_dir_elem = kmalloc(sizeof(*new_dir_elem),
5693 if (!new_dir_elem) {
5695 goto next_dir_inode;
5697 new_dir_elem->ino = di_key.objectid;
5698 list_add_tail(&new_dir_elem->list, &dir_list);
5703 ret = btrfs_next_leaf(log, path);
5705 goto next_dir_inode;
5706 } else if (ret > 0) {
5708 goto next_dir_inode;
5712 if (min_key.offset < (u64)-1) {
5717 list_del(&dir_elem->list);
5721 btrfs_free_path(path);
5725 static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
5726 struct btrfs_inode *inode,
5727 struct btrfs_log_ctx *ctx)
5729 struct btrfs_fs_info *fs_info = trans->fs_info;
5731 struct btrfs_path *path;
5732 struct btrfs_key key;
5733 struct btrfs_root *root = inode->root;
5734 const u64 ino = btrfs_ino(inode);
5736 path = btrfs_alloc_path();
5739 path->skip_locking = 1;
5740 path->search_commit_root = 1;
5743 key.type = BTRFS_INODE_REF_KEY;
5745 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
5750 struct extent_buffer *leaf = path->nodes[0];
5751 int slot = path->slots[0];
5756 if (slot >= btrfs_header_nritems(leaf)) {
5757 ret = btrfs_next_leaf(root, path);
5765 btrfs_item_key_to_cpu(leaf, &key, slot);
5766 /* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
5767 if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
5770 item_size = btrfs_item_size_nr(leaf, slot);
5771 ptr = btrfs_item_ptr_offset(leaf, slot);
5772 while (cur_offset < item_size) {
5773 struct btrfs_key inode_key;
5774 struct inode *dir_inode;
5776 inode_key.type = BTRFS_INODE_ITEM_KEY;
5777 inode_key.offset = 0;
5779 if (key.type == BTRFS_INODE_EXTREF_KEY) {
5780 struct btrfs_inode_extref *extref;
5782 extref = (struct btrfs_inode_extref *)
5784 inode_key.objectid = btrfs_inode_extref_parent(
5786 cur_offset += sizeof(*extref);
5787 cur_offset += btrfs_inode_extref_name_len(leaf,
5790 inode_key.objectid = key.offset;
5791 cur_offset = item_size;
5794 dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid,
5797 * If the parent inode was deleted, return an error to
5798 * fallback to a transaction commit. This is to prevent
5799 * getting an inode that was moved from one parent A to
5800 * a parent B, got its former parent A deleted and then
5801 * it got fsync'ed, from existing at both parents after
5802 * a log replay (and the old parent still existing).
5809 * mv /mnt/B/bar /mnt/A/bar
5810 * mv -T /mnt/A /mnt/B
5814 * If we ignore the old parent B which got deleted,
5815 * after a log replay we would have file bar linked
5816 * at both parents and the old parent B would still
5819 if (IS_ERR(dir_inode)) {
5820 ret = PTR_ERR(dir_inode);
5825 ctx->log_new_dentries = false;
5826 ret = btrfs_log_inode(trans, root, BTRFS_I(dir_inode),
5827 LOG_INODE_ALL, ctx);
5829 btrfs_must_commit_transaction(trans, BTRFS_I(dir_inode)))
5831 if (!ret && ctx && ctx->log_new_dentries)
5832 ret = log_new_dir_dentries(trans, root,
5833 BTRFS_I(dir_inode), ctx);
5834 btrfs_add_delayed_iput(dir_inode);
5842 btrfs_free_path(path);
5846 static int log_new_ancestors(struct btrfs_trans_handle *trans,
5847 struct btrfs_root *root,
5848 struct btrfs_path *path,
5849 struct btrfs_log_ctx *ctx)
5851 struct btrfs_key found_key;
5853 btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
5856 struct btrfs_fs_info *fs_info = root->fs_info;
5857 struct extent_buffer *leaf = path->nodes[0];
5858 int slot = path->slots[0];
5859 struct btrfs_key search_key;
5860 struct inode *inode;
5864 btrfs_release_path(path);
5866 ino = found_key.offset;
5868 search_key.objectid = found_key.offset;
5869 search_key.type = BTRFS_INODE_ITEM_KEY;
5870 search_key.offset = 0;
5871 inode = btrfs_iget(fs_info->sb, ino, root);
5873 return PTR_ERR(inode);
5875 if (BTRFS_I(inode)->generation >= trans->transid)
5876 ret = btrfs_log_inode(trans, root, BTRFS_I(inode),
5877 LOG_INODE_EXISTS, ctx);
5878 btrfs_add_delayed_iput(inode);
5882 if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
5885 search_key.type = BTRFS_INODE_REF_KEY;
5886 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
5890 leaf = path->nodes[0];
5891 slot = path->slots[0];
5892 if (slot >= btrfs_header_nritems(leaf)) {
5893 ret = btrfs_next_leaf(root, path);
5898 leaf = path->nodes[0];
5899 slot = path->slots[0];
5902 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5903 if (found_key.objectid != search_key.objectid ||
5904 found_key.type != BTRFS_INODE_REF_KEY)
5910 static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
5911 struct btrfs_inode *inode,
5912 struct dentry *parent,
5913 struct btrfs_log_ctx *ctx)
5915 struct btrfs_root *root = inode->root;
5916 struct dentry *old_parent = NULL;
5917 struct super_block *sb = inode->vfs_inode.i_sb;
5921 if (!parent || d_really_is_negative(parent) ||
5925 inode = BTRFS_I(d_inode(parent));
5926 if (root != inode->root)
5929 if (inode->generation >= trans->transid) {
5930 ret = btrfs_log_inode(trans, root, inode,
5931 LOG_INODE_EXISTS, ctx);
5935 if (IS_ROOT(parent))
5938 parent = dget_parent(parent);
5940 old_parent = parent;
5947 static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
5948 struct btrfs_inode *inode,
5949 struct dentry *parent,
5950 struct btrfs_log_ctx *ctx)
5952 struct btrfs_root *root = inode->root;
5953 const u64 ino = btrfs_ino(inode);
5954 struct btrfs_path *path;
5955 struct btrfs_key search_key;
5959 * For a single hard link case, go through a fast path that does not
5960 * need to iterate the fs/subvolume tree.
5962 if (inode->vfs_inode.i_nlink < 2)
5963 return log_new_ancestors_fast(trans, inode, parent, ctx);
5965 path = btrfs_alloc_path();
5969 search_key.objectid = ino;
5970 search_key.type = BTRFS_INODE_REF_KEY;
5971 search_key.offset = 0;
5973 ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
5980 struct extent_buffer *leaf = path->nodes[0];
5981 int slot = path->slots[0];
5982 struct btrfs_key found_key;
5984 if (slot >= btrfs_header_nritems(leaf)) {
5985 ret = btrfs_next_leaf(root, path);
5993 btrfs_item_key_to_cpu(leaf, &found_key, slot);
5994 if (found_key.objectid != ino ||
5995 found_key.type > BTRFS_INODE_EXTREF_KEY)
5999 * Don't deal with extended references because they are rare
6000 * cases and too complex to deal with (we would need to keep
6001 * track of which subitem we are processing for each item in
6002 * this loop, etc). So just return some error to fallback to
6003 * a transaction commit.
6005 if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
6011 * Logging ancestors needs to do more searches on the fs/subvol
6012 * tree, so it releases the path as needed to avoid deadlocks.
6013 * Keep track of the last inode ref key and resume from that key
6014 * after logging all new ancestors for the current hard link.
6016 memcpy(&search_key, &found_key, sizeof(search_key));
6018 ret = log_new_ancestors(trans, root, path, ctx);
6021 btrfs_release_path(path);
6026 btrfs_free_path(path);
6031 * helper function around btrfs_log_inode to make sure newly created
6032 * parent directories also end up in the log. A minimal inode and backref
6033 * only logging is done of any parent directories that are older than
6034 * the last committed transaction
6036 static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
6037 struct btrfs_inode *inode,
6038 struct dentry *parent,
6040 struct btrfs_log_ctx *ctx)
6042 struct btrfs_root *root = inode->root;
6043 struct btrfs_fs_info *fs_info = root->fs_info;
6044 struct super_block *sb;
6046 bool log_dentries = false;
6048 sb = inode->vfs_inode.i_sb;
6050 if (btrfs_test_opt(fs_info, NOTREELOG)) {
6055 if (btrfs_root_refs(&root->root_item) == 0) {
6060 ret = check_parent_dirs_for_sync(trans, inode, parent, sb);
6065 * Skip already logged inodes or inodes corresponding to tmpfiles
6066 * (since logging them is pointless, a link count of 0 means they
6067 * will never be accessible).
6069 if (btrfs_inode_in_log(inode, trans->transid) ||
6070 inode->vfs_inode.i_nlink == 0) {
6071 ret = BTRFS_NO_LOG_SYNC;
6075 ret = start_log_trans(trans, root, ctx);
6079 ret = btrfs_log_inode(trans, root, inode, inode_only, ctx);
6084 * for regular files, if its inode is already on disk, we don't
6085 * have to worry about the parents at all. This is because
6086 * we can use the last_unlink_trans field to record renames
6087 * and other fun in this file.
6089 if (S_ISREG(inode->vfs_inode.i_mode) &&
6090 inode->generation < trans->transid &&
6091 inode->last_unlink_trans < trans->transid) {
6096 if (S_ISDIR(inode->vfs_inode.i_mode) && ctx && ctx->log_new_dentries)
6097 log_dentries = true;
6100 * On unlink we must make sure all our current and old parent directory
6101 * inodes are fully logged. This is to prevent leaving dangling
6102 * directory index entries in directories that were our parents but are
6103 * not anymore. Not doing this results in old parent directory being
6104 * impossible to delete after log replay (rmdir will always fail with
6105 * error -ENOTEMPTY).
6111 * ln testdir/foo testdir/bar
6113 * unlink testdir/bar
6114 * xfs_io -c fsync testdir/foo
6116 * mount fs, triggers log replay
6118 * If we don't log the parent directory (testdir), after log replay the
6119 * directory still has an entry pointing to the file inode using the bar
6120 * name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
6121 * the file inode has a link count of 1.
6127 * ln foo testdir/foo2
6128 * ln foo testdir/foo3
6130 * unlink testdir/foo3
6131 * xfs_io -c fsync foo
6133 * mount fs, triggers log replay
6135 * Similar as the first example, after log replay the parent directory
6136 * testdir still has an entry pointing to the inode file with name foo3
6137 * but the file inode does not have a matching BTRFS_INODE_REF_KEY item
6138 * and has a link count of 2.
6140 if (inode->last_unlink_trans >= trans->transid) {
6141 ret = btrfs_log_all_parents(trans, inode, ctx);
6146 ret = log_all_new_ancestors(trans, inode, parent, ctx);
6151 ret = log_new_dir_dentries(trans, root, inode, ctx);
6156 btrfs_set_log_full_commit(trans);
6161 btrfs_remove_log_ctx(root, ctx);
6162 btrfs_end_log_trans(root);
6168 * it is not safe to log dentry if the chunk root has added new
6169 * chunks. This returns 0 if the dentry was logged, and 1 otherwise.
6170 * If this returns 1, you must commit the transaction to safely get your
6173 int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
6174 struct dentry *dentry,
6175 struct btrfs_log_ctx *ctx)
6177 struct dentry *parent = dget_parent(dentry);
6180 ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
6181 LOG_INODE_ALL, ctx);
6188 * should be called during mount to recover any replay any log trees
6191 int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
6194 struct btrfs_path *path;
6195 struct btrfs_trans_handle *trans;
6196 struct btrfs_key key;
6197 struct btrfs_key found_key;
6198 struct btrfs_root *log;
6199 struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
6200 struct walk_control wc = {
6201 .process_func = process_one_buffer,
6202 .stage = LOG_WALK_PIN_ONLY,
6205 path = btrfs_alloc_path();
6209 set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
6211 trans = btrfs_start_transaction(fs_info->tree_root, 0);
6212 if (IS_ERR(trans)) {
6213 ret = PTR_ERR(trans);
6220 ret = walk_log_tree(trans, log_root_tree, &wc);
6222 btrfs_handle_fs_error(fs_info, ret,
6223 "Failed to pin buffers while recovering log root tree.");
6228 key.objectid = BTRFS_TREE_LOG_OBJECTID;
6229 key.offset = (u64)-1;
6230 key.type = BTRFS_ROOT_ITEM_KEY;
6233 ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
6236 btrfs_handle_fs_error(fs_info, ret,
6237 "Couldn't find tree log root.");
6241 if (path->slots[0] == 0)
6245 btrfs_item_key_to_cpu(path->nodes[0], &found_key,
6247 btrfs_release_path(path);
6248 if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
6251 log = btrfs_read_tree_root(log_root_tree, &found_key);
6254 btrfs_handle_fs_error(fs_info, ret,
6255 "Couldn't read tree log root.");
6259 wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset,
6261 if (IS_ERR(wc.replay_dest)) {
6262 ret = PTR_ERR(wc.replay_dest);
6265 * We didn't find the subvol, likely because it was
6266 * deleted. This is ok, simply skip this log and go to
6269 * We need to exclude the root because we can't have
6270 * other log replays overwriting this log as we'll read
6271 * it back in a few more times. This will keep our
6272 * block from being modified, and we'll just bail for
6273 * each subsequent pass.
6276 ret = btrfs_pin_extent_for_log_replay(trans,
6279 btrfs_put_root(log);
6283 btrfs_handle_fs_error(fs_info, ret,
6284 "Couldn't read target root for tree log recovery.");
6288 wc.replay_dest->log_root = log;
6289 btrfs_record_root_in_trans(trans, wc.replay_dest);
6290 ret = walk_log_tree(trans, log, &wc);
6292 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
6293 ret = fixup_inode_link_counts(trans, wc.replay_dest,
6297 if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
6298 struct btrfs_root *root = wc.replay_dest;
6300 btrfs_release_path(path);
6303 * We have just replayed everything, and the highest
6304 * objectid of fs roots probably has changed in case
6305 * some inode_item's got replayed.
6307 * root->objectid_mutex is not acquired as log replay
6308 * could only happen during mount.
6310 ret = btrfs_find_highest_objectid(root,
6311 &root->highest_objectid);
6314 wc.replay_dest->log_root = NULL;
6315 btrfs_put_root(wc.replay_dest);
6316 btrfs_put_root(log);
6321 if (found_key.offset == 0)
6323 key.offset = found_key.offset - 1;
6325 btrfs_release_path(path);
6327 /* step one is to pin it all, step two is to replay just inodes */
6330 wc.process_func = replay_one_buffer;
6331 wc.stage = LOG_WALK_REPLAY_INODES;
6334 /* step three is to replay everything */
6335 if (wc.stage < LOG_WALK_REPLAY_ALL) {
6340 btrfs_free_path(path);
6342 /* step 4: commit the transaction, which also unpins the blocks */
6343 ret = btrfs_commit_transaction(trans);
6347 log_root_tree->log_root = NULL;
6348 clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
6349 btrfs_put_root(log_root_tree);
6354 btrfs_end_transaction(wc.trans);
6355 btrfs_free_path(path);
6360 * there are some corner cases where we want to force a full
6361 * commit instead of allowing a directory to be logged.
6363 * They revolve around files there were unlinked from the directory, and
6364 * this function updates the parent directory so that a full commit is
6365 * properly done if it is fsync'd later after the unlinks are done.
6367 * Must be called before the unlink operations (updates to the subvolume tree,
6368 * inodes, etc) are done.
6370 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
6371 struct btrfs_inode *dir, struct btrfs_inode *inode,
6375 * when we're logging a file, if it hasn't been renamed
6376 * or unlinked, and its inode is fully committed on disk,
6377 * we don't have to worry about walking up the directory chain
6378 * to log its parents.
6380 * So, we use the last_unlink_trans field to put this transid
6381 * into the file. When the file is logged we check it and
6382 * don't log the parents if the file is fully on disk.
6384 mutex_lock(&inode->log_mutex);
6385 inode->last_unlink_trans = trans->transid;
6386 mutex_unlock(&inode->log_mutex);
6389 * if this directory was already logged any new
6390 * names for this file/dir will get recorded
6392 if (dir->logged_trans == trans->transid)
6396 * if the inode we're about to unlink was logged,
6397 * the log will be properly updated for any new names
6399 if (inode->logged_trans == trans->transid)
6403 * when renaming files across directories, if the directory
6404 * there we're unlinking from gets fsync'd later on, there's
6405 * no way to find the destination directory later and fsync it
6406 * properly. So, we have to be conservative and force commits
6407 * so the new name gets discovered.
6412 /* we can safely do the unlink without any special recording */
6416 mutex_lock(&dir->log_mutex);
6417 dir->last_unlink_trans = trans->transid;
6418 mutex_unlock(&dir->log_mutex);
6422 * Make sure that if someone attempts to fsync the parent directory of a deleted
6423 * snapshot, it ends up triggering a transaction commit. This is to guarantee
6424 * that after replaying the log tree of the parent directory's root we will not
6425 * see the snapshot anymore and at log replay time we will not see any log tree
6426 * corresponding to the deleted snapshot's root, which could lead to replaying
6427 * it after replaying the log tree of the parent directory (which would replay
6428 * the snapshot delete operation).
6430 * Must be called before the actual snapshot destroy operation (updates to the
6431 * parent root and tree of tree roots trees, etc) are done.
6433 void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
6434 struct btrfs_inode *dir)
6436 mutex_lock(&dir->log_mutex);
6437 dir->last_unlink_trans = trans->transid;
6438 mutex_unlock(&dir->log_mutex);
6442 * Call this after adding a new name for a file and it will properly
6443 * update the log to reflect the new name.
6445 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
6446 struct btrfs_inode *inode, struct btrfs_inode *old_dir,
6447 struct dentry *parent)
6449 struct btrfs_log_ctx ctx;
6452 * this will force the logging code to walk the dentry chain
6455 if (!S_ISDIR(inode->vfs_inode.i_mode))
6456 inode->last_unlink_trans = trans->transid;
6459 * if this inode hasn't been logged and directory we're renaming it
6460 * from hasn't been logged, we don't need to log it
6462 if (inode->logged_trans < trans->transid &&
6463 (!old_dir || old_dir->logged_trans < trans->transid))
6466 btrfs_init_log_ctx(&ctx, &inode->vfs_inode);
6467 ctx.logging_new_name = true;
6469 * We don't care about the return value. If we fail to log the new name
6470 * then we know the next attempt to sync the log will fallback to a full
6471 * transaction commit (due to a call to btrfs_set_log_full_commit()), so
6472 * we don't need to worry about getting a log committed that has an
6473 * inconsistent state after a rename operation.
6475 btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);