tree 5e8b6c5e0b0b35c65ed509029cda85bd54a8aab8
parent 75eaa0e22c055e38982df267d0f84cc510ba38bf
author Li Zefan <lizf@cn.fujitsu.com> 1291686686 +0000
committer Chris Mason <chris.mason@oracle.com> 1292016550 -0500

Btrfs: Fix a crash when mounting a subvolume

We should drop dentry before deactivating the superblock, otherwise
we can hit this bug:

BUG: Dentry f349a690{i=100,n=/} still in use (1) [unmount of btrfs loop1]
...

Steps to reproduce the bug:

  # mount /dev/loop1 /mnt
  # mkdir save
  # btrfs subvolume snapshot /mnt save/snap1
  # umount /mnt
  # mount -o subvol=save/snap1 /dev/loop1 /mnt
  (crash)

Reported-by: Michael Niederle <mniederle@gmx.at>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>