]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
btrfs: fix crash when trying to resume balance without the resume flag
authorAnand Jain <anand.jain@oracle.com>
Thu, 17 May 2018 07:16:51 +0000 (15:16 +0800)
committerDavid Sterba <dsterba@suse.com>
Thu, 17 May 2018 12:38:24 +0000 (14:38 +0200)
commit02ee654d3a04563c67bfe658a05384548b9bb105
tree28fd96d01ae0bca8ef64a8b588234ad1593ae36e
parentfe816d0f1d4c31c4c31d42ca78a87660565fc800
btrfs: fix crash when trying to resume balance without the resume flag

We set the BTRFS_BALANCE_RESUME flag in the btrfs_recover_balance()
only, which isn't called during the remount. So when resuming from
the paused balance we hit the bug:

 kernel: kernel BUG at fs/btrfs/volumes.c:3890!
 ::
 kernel:  balance_kthread+0x51/0x60 [btrfs]
 kernel:  kthread+0x111/0x130
 ::
 kernel: RIP: btrfs_balance+0x12e1/0x1570 [btrfs] RSP: ffffba7d0090bde8

Reproducer:
  On a mounted filesystem:

  btrfs balance start --full-balance /btrfs
  btrfs balance pause /btrfs
  mount -o remount,ro /dev/sdb /btrfs
  mount -o remount,rw /dev/sdb /btrfs

To fix this set the BTRFS_BALANCE_RESUME flag in
btrfs_resume_balance_async().

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
fs/btrfs/volumes.c