Re: [PATCH] xfs: lock the rt summary inode when unmapping realtime extents

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

On Thu, Jun 30, 2016 at 08:21:42AM +1000, Dave Chinner wrote:
> On Wed, Jun 29, 2016 at 01:02:34PM -0700, Darrick J. Wong wrote:
> > When we're deleting realtime extents, lock the summary inode
> > in case we need to update the summary info.  This prevents an
> > assert on the rsumip inode lock on a debug kernel.
> > 
> > (Same idea as "xfs: lock rt summary inode on allocation".)
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> > ---
> >  fs/xfs/libxfs/xfs_bmap.c |    2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> > index 97820c1..9c7227b 100644
> > --- a/fs/xfs/libxfs/xfs_bmap.c
> > +++ b/fs/xfs/libxfs/xfs_bmap.c
> > @@ -5524,6 +5524,8 @@ __xfs_bunmapi(
> >              */
> >             xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL);
> >             xfs_trans_ijoin(tp, mp->m_rbmip, XFS_ILOCK_EXCL);
> > +           xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL);
> > +           xfs_trans_ijoin(tp, mp->m_rsumip, XFS_ILOCK_EXCL);
> 
> These need a lockdep annotations, right? i.e.
> 
>       xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
>       xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
> 
> Because they are nested inside the inode ilock?

Yes, they do, as does the other _ilock(rbmip) in xfs_bmap_util.c.
Will send updated patch.

--D

> 
> Cheers,
> 
> Dave.
> -- 
> Dave Chinner
> david@xxxxxxxxxxxxx