Btrfs: btrfs_ioctl_default_subvol: Revert back to toplevel subvolume when arg is 0

This patch makes it possible to set BTRFS_FS_TREE_OBJECTID as the default
subvolume by passing a subvolume id of 0.

Signed-off-by: chandan <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index fd6557e7118a..fba259ab9994 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3310,7 +3310,7 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
         }
 
         if (!objectid)
-                objectid = root->root_key.objectid;
+                objectid = BTRFS_FS_TREE_OBJECTID;
 
         location.objectid = objectid;
         location.type = BTRFS_ROOT_ITEM_KEY;