Btrfs: send, fix more issues related to directory renames
This is a continuation of the previous changes titled: Btrfs: fix incremental send's decision to delay a dir move/rename Btrfs: part 2, fix incremental send's decision to delay a dir move/rename There's a few more cases where a directory rename/move must be delayed which was previously overlooked. If our immediate ancestor has a lower inode number than ours and it doesn't have a delayed rename/move operation associated to it, it doesn't mean there isn't any non-direct ancestor of our current inode that needs to be renamed/moved before our current inode (i.e. with a higher inode number than ours). So we can't stop the search if our immediate ancestor has a lower inode number than ours, we need to navigate the directory hierarchy upwards until we hit the root or: 1) find an ancestor with an higher inode number that was renamed/moved in the send root too (or already has a pending rename/move registered); 2) find an ancestor that is a new directory (higher inode number than ours and exists only in the send root). Reproducer for case 1) $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir -p /mnt/a/b $ mkdir -p /mnt/a/c/d $ mkdir /mnt/a/b/e $ mkdir /mnt/a/c/d/f $ mv /mnt/a/b /mnt/a/c/d/2b $ mkdir /mnt/a/x $ mkdir /mnt/a/y $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mv /mnt/a/x /mnt/a/y $ mv /mnt/a/c/d/2b/e /mnt/a/c/d/2b/2e $ mv /mnt/a/c/d /mnt/a/h/2d $ mv /mnt/a/c /mnt/a/h/2d/2b/2c $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send Simple reproducer for case 2) $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/a/c $ mv /mnt/a/b /mnt/a/c/b2 $ mkdir /mnt/a/e $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mv /mnt/a/c/b2 /mnt/a/e/b3 $ mkdir /mnt/a/e/b3/f $ mkdir /mnt/a/h $ mv /mnt/a/c /mnt/a/e/b3/f/c2 $ mv /mnt/a/e /mnt/a/h/e2 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send Another simple reproducer for case 2) $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir -p /mnt/a/b $ mkdir /mnt/a/c $ mkdir /mnt/a/b/d $ mkdir /mnt/a/c/e $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mkdir /mnt/a/b/d/f $ mkdir /mnt/a/b/g $ mv /mnt/a/c/e /mnt/a/b/g/e2 $ mv /mnt/a/c /mnt/a/b/d/f/c2 $ mv /mnt/a/b/d/f /mnt/a/b/g/e2/f2 $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send More complex reproducer for case 2) $ mkfs.btrfs -f /dev/sdd $ mount /dev/sdd /mnt $ mkdir -p /mnt/a/b $ mkdir -p /mnt/a/c/d $ mkdir /mnt/a/b/e $ mkdir /mnt/a/c/d/f $ mv /mnt/a/b /mnt/a/c/d/2b $ mkdir /mnt/a/x $ mkdir /mnt/a/y $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ btrfs send /mnt/snap1 -f /tmp/base.send $ mv /mnt/a/x /mnt/a/y $ mv /mnt/a/c/d/2b/e /mnt/a/c/d/2b/2e $ mv /mnt/a/c/d /mnt/a/h/2d $ mv /mnt/a/c /mnt/a/h/2d/2b/2c $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/incremental.send For both cases the incremental send would enter an infinite loop when building path strings. While solving these cases, this change also re-implements the code to detect when directory moves/renames should be delayed. Instead of dealing with several specific cases separately, it's now more generic handling all cases with a simple detection algorithm and if when applying a delayed move/rename there's a path loop detected, it further delays the move/rename registering a new ancestor inode as the dependency inode (so our rename happens after that ancestor is renamed). Tests for these cases is being added to xfstests too. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
parent
a10c40766c
commit
f959492fc1
190
fs/btrfs/send.c
190
fs/btrfs/send.c
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@ -2940,7 +2940,9 @@ static void free_waiting_dir_move(struct send_ctx *sctx,
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static int add_pending_dir_move(struct send_ctx *sctx,
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u64 ino,
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u64 ino_gen,
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u64 parent_ino)
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u64 parent_ino,
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struct list_head *new_refs,
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struct list_head *deleted_refs)
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{
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struct rb_node **p = &sctx->pending_dir_moves.rb_node;
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struct rb_node *parent = NULL;
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@ -2972,12 +2974,12 @@ static int add_pending_dir_move(struct send_ctx *sctx,
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}
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}
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list_for_each_entry(cur, &sctx->deleted_refs, list) {
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list_for_each_entry(cur, deleted_refs, list) {
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ret = dup_ref(cur, &pm->update_refs);
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if (ret < 0)
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goto out;
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}
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list_for_each_entry(cur, &sctx->new_refs, list) {
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list_for_each_entry(cur, new_refs, list) {
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ret = dup_ref(cur, &pm->update_refs);
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if (ret < 0)
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goto out;
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@ -3020,6 +3022,48 @@ static struct pending_dir_move *get_pending_dir_moves(struct send_ctx *sctx,
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return NULL;
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}
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static int path_loop(struct send_ctx *sctx, struct fs_path *name,
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u64 ino, u64 gen, u64 *ancestor_ino)
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{
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int ret = 0;
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u64 parent_inode = 0;
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u64 parent_gen = 0;
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u64 start_ino = ino;
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*ancestor_ino = 0;
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while (ino != BTRFS_FIRST_FREE_OBJECTID) {
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fs_path_reset(name);
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if (is_waiting_for_rm(sctx, ino))
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break;
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if (is_waiting_for_move(sctx, ino)) {
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if (*ancestor_ino == 0)
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*ancestor_ino = ino;
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ret = get_first_ref(sctx->parent_root, ino,
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&parent_inode, &parent_gen, name);
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} else {
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ret = __get_cur_name_and_parent(sctx, ino, gen,
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&parent_inode,
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&parent_gen, name);
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if (ret > 0) {
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ret = 0;
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break;
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}
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}
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if (ret < 0)
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break;
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if (parent_inode == start_ino) {
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ret = 1;
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if (*ancestor_ino == 0)
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*ancestor_ino = ino;
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break;
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}
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ino = parent_inode;
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gen = parent_gen;
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}
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return ret;
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}
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static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
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{
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struct fs_path *from_path = NULL;
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@ -3031,6 +3075,7 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
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struct waiting_dir_move *dm = NULL;
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u64 rmdir_ino = 0;
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int ret;
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u64 ancestor = 0;
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name = fs_path_alloc();
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from_path = fs_path_alloc();
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@ -3057,11 +3102,25 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
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if (ret < 0)
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goto out;
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sctx->send_progress = sctx->cur_ino + 1;
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ret = path_loop(sctx, name, pm->ino, pm->gen, &ancestor);
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if (ret) {
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LIST_HEAD(deleted_refs);
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ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);
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ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor,
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&pm->update_refs, &deleted_refs);
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if (ret < 0)
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goto out;
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if (rmdir_ino) {
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dm = get_waiting_dir_move(sctx, pm->ino);
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ASSERT(dm);
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dm->rmdir_ino = rmdir_ino;
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}
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goto out;
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}
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fs_path_reset(name);
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to_path = name;
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name = NULL;
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sctx->send_progress = sctx->cur_ino + 1;
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ret = get_cur_path(sctx, pm->ino, pm->gen, to_path);
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if (ret < 0)
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goto out;
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@ -3185,127 +3244,74 @@ out:
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static int wait_for_parent_move(struct send_ctx *sctx,
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struct recorded_ref *parent_ref)
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{
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int ret;
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int ret = 0;
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u64 ino = parent_ref->dir;
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u64 parent_ino_before, parent_ino_after;
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u64 old_gen;
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struct fs_path *path_before = NULL;
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struct fs_path *path_after = NULL;
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int len1, len2;
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int register_upper_dirs;
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u64 gen;
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if (is_waiting_for_move(sctx, ino))
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return 1;
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if (parent_ref->dir <= sctx->cur_ino)
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return 0;
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ret = get_inode_info(sctx->parent_root, ino, NULL, &old_gen,
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NULL, NULL, NULL, NULL);
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if (ret == -ENOENT)
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return 0;
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else if (ret < 0)
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return ret;
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if (parent_ref->dir_gen != old_gen)
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return 0;
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path_before = fs_path_alloc();
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if (!path_before)
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return -ENOMEM;
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ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
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NULL, path_before);
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if (ret == -ENOENT) {
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ret = 0;
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goto out;
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} else if (ret < 0) {
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goto out;
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}
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path_after = fs_path_alloc();
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if (!path_after) {
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path_before = fs_path_alloc();
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if (!path_after || !path_before) {
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ret = -ENOMEM;
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goto out;
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}
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ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
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&gen, path_after);
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if (ret == -ENOENT) {
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ret = 0;
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goto out;
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} else if (ret < 0) {
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goto out;
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}
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len1 = fs_path_len(path_before);
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len2 = fs_path_len(path_after);
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if (parent_ino_before != parent_ino_after || len1 != len2 ||
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memcmp(path_before->start, path_after->start, len1)) {
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ret = 1;
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goto out;
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}
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ret = 0;
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/*
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* Ok, our new most direct ancestor has a higher inode number but
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* wasn't moved/renamed. So maybe some of the new ancestors higher in
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* the hierarchy have an higher inode number too *and* were renamed
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* or moved - in this case we need to wait for the ancestor's rename
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* or move operation before we can do the move/rename for the current
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* inode.
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* Our current directory inode may not yet be renamed/moved because some
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* ancestor (immediate or not) has to be renamed/moved first. So find if
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* such ancestor exists and make sure our own rename/move happens after
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* that ancestor is processed.
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*/
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register_upper_dirs = 0;
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ino = parent_ino_after;
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again:
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while ((ret == 0 || register_upper_dirs) && ino > sctx->cur_ino) {
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u64 parent_gen;
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while (ino > BTRFS_FIRST_FREE_OBJECTID) {
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if (is_waiting_for_move(sctx, ino)) {
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ret = 1;
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break;
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}
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fs_path_reset(path_before);
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fs_path_reset(path_after);
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ret = get_first_ref(sctx->send_root, ino, &parent_ino_after,
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&parent_gen, path_after);
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NULL, path_after);
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if (ret < 0)
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goto out;
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ret = get_first_ref(sctx->parent_root, ino, &parent_ino_before,
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NULL, path_before);
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if (ret == -ENOENT) {
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ret = 0;
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break;
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} else if (ret < 0) {
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if (ret < 0 && ret != -ENOENT) {
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goto out;
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} else if (ret == -ENOENT) {
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ret = 1;
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break;
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}
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len1 = fs_path_len(path_before);
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len2 = fs_path_len(path_after);
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if (parent_ino_before != parent_ino_after || len1 != len2 ||
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memcmp(path_before->start, path_after->start, len1)) {
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if (ino > sctx->cur_ino &&
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(parent_ino_before != parent_ino_after || len1 != len2 ||
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memcmp(path_before->start, path_after->start, len1))) {
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ret = 1;
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if (register_upper_dirs) {
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break;
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} else {
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register_upper_dirs = 1;
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ino = parent_ref->dir;
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gen = parent_ref->dir_gen;
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goto again;
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}
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} else if (register_upper_dirs) {
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ret = add_pending_dir_move(sctx, ino, gen,
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parent_ino_after);
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if (ret < 0 && ret != -EEXIST)
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goto out;
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break;
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}
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ino = parent_ino_after;
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gen = parent_gen;
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}
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out:
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fs_path_free(path_before);
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fs_path_free(path_after);
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if (ret == 1) {
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ret = add_pending_dir_move(sctx,
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sctx->cur_ino,
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sctx->cur_inode_gen,
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ino,
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&sctx->new_refs,
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&sctx->deleted_refs);
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if (!ret)
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ret = 1;
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}
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return ret;
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}
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@ -3466,10 +3472,6 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
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if (ret < 0)
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goto out;
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if (ret) {
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ret = add_pending_dir_move(sctx,
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sctx->cur_ino,
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sctx->cur_inode_gen,
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cur->dir);
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*pending_move = 1;
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} else {
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ret = send_rename(sctx, valid_path,
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Reference in a new issue