[xfs-masters] Re: xfs_io "BUG: lock held when returning to user space!" on suspend

[David Chinner <dgc@xxxxxxx>]

On Wed, Apr 02, 2008 at 11:58:54AM -0700, Jeremy Fitzhardinge wrote:
> I'm getting this:
> 
> ================================================
> [ BUG: lock held when returning to user space! ]
> ------------------------------------------------
> xfs_io/18796 is leaving the kernel with locks still held!
> 1 lock held by xfs_io/18796:
> #0:  (&type->s_umount_key#19){----}, at: [<c048c9ac>] get_super+0x42/0x87
> 
> when I suspend, possibly during an xfs-freeze.  There don't seem to be any 
> ill-effects.

Yup, both the sb->s_umount and bdev->bd_mount_sem seaphores are held
across freeze_bdev()/thaw_bdev(), and they are issued via separate
ioctls generally from separate processes. Not great design, but not
a bug....

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group