Re: [PATCH] btrfs: unlock i_mutex after attempting to delete subvolume during send

[David Sterba <dsterba@suse.cz>]

On Sat, Mar 28, 2015 at 11:37:43AM +0000, Filipe David Manana wrote:
> On Sat, Mar 28, 2015 at 11:02 AM, Omar Sandoval <osandov@osandov.com> wrote:
> > Whenever the check for a send in progress introduced in commit
> > 521e0546c970 (btrfs: protect snapshots from deleting during send) is
> > hit, we return without unlocking inode->i_mutex. This is easy to see
> > with lockdep enabled:
> >
> > [  +0.000059] ================================================
> > [  +0.000028] [ BUG: lock held when returning to user space! ]
> > [  +0.000029] 4.0.0-rc5-00096-g3c435c1 #93 Not tainted
> > [  +0.000026] ------------------------------------------------
> > [  +0.000029] btrfs/211 is leaving the kernel with locks still held!
> > [  +0.000029] 1 lock held by btrfs/211:
> > [  +0.000023]  #0:  (&type->i_mutex_dir_key){+.+.+.}, at: [<ffffffff8135b8df>] btrfs_ioctl_snap_destroy+0x2df/0x7a0
> >
> > Make sure we unlock it in the error path.
> >
> > Signed-off-by: Omar Sandoval <osandov@osandov.com>
> Reviewed-by: Filipe Manana <fdmanana@suse.com>
> 
> Thanks, should go to stable in my opinion.

Agreed.