diff options
author | Chris Mason <chris.mason@oracle.com> | 2008-11-18 02:14:24 (GMT) |
---|---|---|
committer | Chris Mason <chris.mason@oracle.com> | 2008-11-18 02:14:24 (GMT) |
commit | ea9e8b11bd1252dcbc23afefcf1a52ec6aa3c113 (patch) | |
tree | 3573c8d79e1936e8c921a3be77abda35124e0d78 /fs/btrfs/root-tree.c | |
parent | 0660b5af3f7ac0fac69de975914e1f4a3a586fb3 (diff) | |
download | linux-fsl-qoriq-ea9e8b11bd1252dcbc23afefcf1a52ec6aa3c113.tar.xz |
Btrfs: prevent loops in the directory tree when creating snapshots
For a directory tree:
/mnt/subvolA/subvolB
btrfsctl -s /mnt/subvolA/subvolB /mnt
Will create a directory loop with subvolA under subvolB. This
commit uses the forward refs for each subvol and snapshot to error out
before creating the loop.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/root-tree.c')
-rw-r--r-- | fs/btrfs/root-tree.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index e9be3ab..dbe20d4 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -300,6 +300,22 @@ int btrfs_del_root_ref(struct btrfs_trans_handle *trans, return ret; } +int btrfs_find_root_ref(struct btrfs_root *tree_root, + struct btrfs_path *path, + u64 root_id, u64 ref_id) +{ + struct btrfs_key key; + int ret; + + key.objectid = root_id; + key.type = BTRFS_ROOT_REF_KEY; + key.offset = ref_id; + + ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); + return ret; +} + + /* * add a btrfs_root_ref item. type is either BTRFS_ROOT_REF_KEY * or BTRFS_ROOT_BACKREF_KEY. |