@@ -230,6 +230,7 @@ struct pending_dir_move {
u64 parent_ino;
u64 ino;
u64 gen;
+ bool is_orphan;
struct list_head update_refs;
};
@@ -2984,7 +2985,8 @@ static int add_pending_dir_move(struct send_ctx *sctx,
u64 ino_gen,
u64 parent_ino,
struct list_head *new_refs,
- struct list_head *deleted_refs)
+ struct list_head *deleted_refs,
+ const bool is_orphan)
{
struct rb_node **p = &sctx->pending_dir_moves.rb_node;
struct rb_node *parent = NULL;
@@ -2999,6 +3001,7 @@ static int add_pending_dir_move(struct send_ctx *sctx,
pm->parent_ino = parent_ino;
pm->ino = ino;
pm->gen = ino_gen;
+ pm->is_orphan = is_orphan;
INIT_LIST_HEAD(&pm->list);
INIT_LIST_HEAD(&pm->update_refs);
RB_CLEAR_NODE(&pm->node);
@@ -3131,16 +3134,20 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
rmdir_ino = dm->rmdir_ino;
free_waiting_dir_move(sctx, dm);
- ret = get_first_ref(sctx->parent_root, pm->ino,
- &parent_ino, &parent_gen, name);
- if (ret < 0)
- goto out;
-
- ret = get_cur_path(sctx, parent_ino, parent_gen,
- from_path);
- if (ret < 0)
- goto out;
- ret = fs_path_add_path(from_path, name);
+ if (pm->is_orphan) {
+ ret = gen_unique_name(sctx, pm->ino,
+ pm->gen, from_path);
+ } else {
+ ret = get_first_ref(sctx->parent_root, pm->ino,
+ &parent_ino, &parent_gen, name);
+ if (ret < 0)
+ goto out;
+ ret = get_cur_path(sctx, parent_ino, parent_gen,
+ from_path);
+ if (ret < 0)
+ goto out;
+ ret = fs_path_add_path(from_path, name);
+ }
if (ret < 0)
goto out;
@@ -3150,7 +3157,8 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
LIST_HEAD(deleted_refs);
ASSERT(ancestor > BTRFS_FIRST_FREE_OBJECTID);
ret = add_pending_dir_move(sctx, pm->ino, pm->gen, ancestor,
- &pm->update_refs, &deleted_refs);
+ &pm->update_refs, &deleted_refs,
+ pm->is_orphan);
if (ret < 0)
goto out;
if (rmdir_ino) {
@@ -3283,6 +3291,127 @@ out:
return ret;
}
+/*
+ * We might need to delay a directory rename even when no ancestor directory
+ * (in the send root) with a higher inode number than ours (sctx->cur_ino) was
+ * renamed. This happens when we rename a directory to the old name (the name
+ * in the parent root) of some other unrelated directory that got its rename
+ * delayed due to some ancestor with higher number that got renamed.
+ *
+ * Example:
+ *
+ * Parent snapshot:
+ * . (ino 256)
+ * |---- a/ (ino 257)
+ * | |---- file (ino 260)
+ * |
+ * |---- b/ (ino 258)
+ * |---- c/ (ino 259)
+ *
+ * Send snapshot:
+ * . (ino 256)
+ * |---- a/ (ino 258)
+ * |---- x/ (ino 259)
+ * |---- y/ (ino 257)
+ * |----- file (ino 260)
+ *
+ * Here we can not rename 258 from 'b' to 'a' without the rename of inode 257
+ * from 'a' to 'x/y' happening first, which in turn depends on the rename of
+ * inode 259 from 'c' to 'x'. So the order of rename commands the send stream
+ * must issue is:
+ *
+ * 1 - rename 259 from 'c' to 'x'
+ * 2 - rename 257 from 'a' to 'x/y'
+ * 3 - rename 258 from 'b' to 'a'
+ *
+ * Returns 1 if the rename of sctx->cur_ino needs to be delayed, 0 if it can
+ * be done right away and < 0 on error.
+ */
+static int wait_for_dest_dir_move(struct send_ctx *sctx,
+ struct recorded_ref *parent_ref,
+ const bool is_orphan)
+{
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_key di_key;
+ struct btrfs_dir_item *di;
+ u64 left_gen;
+ u64 right_gen;
+ int ret = 0;
+
+ if (RB_EMPTY_ROOT(&sctx->waiting_dir_moves))
+ return 0;
+
+ path = alloc_path_for_send();
+ if (!path)
+ return -ENOMEM;
+
+ key.objectid = parent_ref->dir;
+ key.type = BTRFS_DIR_ITEM_KEY;
+ key.offset = btrfs_name_hash(parent_ref->name, parent_ref->name_len);
+
+ ret = btrfs_search_slot(NULL, sctx->parent_root, &key, path, 0, 0);
+ if (ret < 0) {
+ goto out;
+ } else if (ret > 0) {
+ ret = 0;
+ goto out;
+ }
+
+ di = btrfs_match_dir_item_name(sctx->parent_root, path,
+ parent_ref->name, parent_ref->name_len);
+ if (!di) {
+ ret = 0;
+ goto out;
+ }
+ /*
+ * di_key.objectid has the number of the inode that has a dentry in the
+ * parent directory with the same name that sctx->cur_ino is being
+ * renamed to. We need to check if that inode is in the send root as
+ * well and if it is currently marked as an inode with a pending rename,
+ * if it is, we need to delay the rename of sctx->cur_ino as well, so
+ * that it happens after that other inode is renamed.
+ */
+ btrfs_dir_item_key_to_cpu(path->nodes[0], di, &di_key);
+ if (di_key.type != BTRFS_INODE_ITEM_KEY) {
+ ret = 0;
+ goto out;
+ }
+
+ ret = get_inode_info(sctx->parent_root, di_key.objectid, NULL,
+ &left_gen, NULL, NULL, NULL, NULL);
+ if (ret < 0)
+ goto out;
+ ret = get_inode_info(sctx->send_root, di_key.objectid, NULL,
+ &right_gen, NULL, NULL, NULL, NULL);
+ if (ret < 0) {
+ if (ret == -ENOENT)
+ ret = 0;
+ goto out;
+ }
+
+ /* Different inode, no need to delay the rename of sctx->cur_ino */
+ if (right_gen != left_gen) {
+ ret = 0;
+ goto out;
+ }
+
+ if (is_waiting_for_move(sctx, di_key.objectid)) {
+ ret = add_pending_dir_move(sctx,
+ sctx->cur_ino,
+ sctx->cur_inode_gen,
+ di_key.objectid,
+ &sctx->new_refs,
+ &sctx->deleted_refs,
+ is_orphan);
+ if (!ret)
+ ret = 1;
+ }
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
static int wait_for_parent_move(struct send_ctx *sctx,
struct recorded_ref *parent_ref)
{
@@ -3349,7 +3478,8 @@ out:
sctx->cur_inode_gen,
ino,
&sctx->new_refs,
- &sctx->deleted_refs);
+ &sctx->deleted_refs,
+ false);
if (!ret)
ret = 1;
}
@@ -3372,6 +3502,7 @@ static int process_recorded_refs(struct send_ctx *sctx, int *pending_move)
int did_overwrite = 0;
int is_orphan = 0;
u64 last_dir_ino_rm = 0;
+ bool can_rename = true;
verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
@@ -3490,12 +3621,22 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
}
}
+ if (S_ISDIR(sctx->cur_inode_mode) && sctx->parent_root) {
+ ret = wait_for_dest_dir_move(sctx, cur, is_orphan);
+ if (ret < 0)
+ goto out;
+ if (ret == 1) {
+ can_rename = false;
+ *pending_move = 1;
+ }
+ }
+
/*
* link/move the ref to the new place. If we have an orphan
* inode, move it and update valid_path. If not, link or move
* it depending on the inode mode.
*/
- if (is_orphan) {
+ if (is_orphan && can_rename) {
ret = send_rename(sctx, valid_path, cur->full_path);
if (ret < 0)
goto out;
@@ -3503,7 +3644,7 @@ verbose_printk("btrfs: process_recorded_refs %llu\n", sctx->cur_ino);
ret = fs_path_copy(valid_path, cur->full_path);
if (ret < 0)
goto out;
- } else {
+ } else if (can_rename) {
if (S_ISDIR(sctx->cur_inode_mode)) {
/*
* Dirs can't be linked, so move it. For moved
There's one more case where we can't issue a rename operation for a directory as soon as we process it. We used to delay directory renames only if they have some ancestor directory with a higher inode number that got renamed too, but there's another case where we need to delay the rename too - when a directory A is renamed to the old name of a directory B but that directory B has its rename delayed because it has now (in the send root) an ancestor with a higher inode number that was renamed. If we don't delay the directory rename in this case, the receiving end of the send stream will attempt to rename A to the old name of B before B got renamed to its new name, which results in a "directory not empty" error. So fix this by delaying directory renames for this case too. Steps to reproduce: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/a $ mkdir /mnt/b $ mkdir /mnt/c $ touch /mnt/a/file $ btrfs subvolume snapshot -r /mnt /mnt/snap1 $ mv /mnt/c /mnt/x $ mv /mnt/a /mnt/x/y $ mv /mnt/b /mnt/a $ btrfs subvolume snapshot -r /mnt /mnt/snap2 $ btrfs send /mnt/snap1 -f /tmp/1.send $ btrfs send -p /mnt/snap1 /mnt/snap2 -f /tmp/2.send $ mkfs.btrfs -f /dev/sdc $ mount /dev/sdc /mnt2 $ btrfs receive /mnt2 -f /tmp/1.send $ btrfs receive /mnt2 -f /tmp/2.send ERROR: rename b -> a failed. Directory not empty A test case for xfstests follows soon. Reported-by: Ames Cornish <ames@cornishes.net> Signed-off-by: Filipe Manana <fdmanana@suse.com> --- V2: Skip btree searches if rbtree of waiting dir moves is empty. fs/btrfs/send.c | 171 +++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 156 insertions(+), 15 deletions(-)