tree 3079d0eccddbdb689879eb6d71ded878806da08c
parent d86e56cf7d3669dd292012ac82b986bd1573b6cc
author Miao Xie <miaox@cn.fujitsu.com> 1350905993 +0000
committer Josef Bacik <josef@toxicpanda.com> 1358189552 -0500

Btrfs: do not delete a subvolume which is in a R/O subvolume

Step to reproduce:
 # mkfs.btrfs <disk>
 # mount <disk> <mnt>
 # btrfs sub create <mnt>/subv0
 # btrfs sub snap <mnt> <mnt>/subv0/snap0
 # change <mnt>/subv0 from R/W to R/O
 # btrfs sub del <mnt>/subv0/snap0

We deleted the snapshot successfully. I think we should not be able to delete
the snapshot since the parent subvolume is R/O.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>