Re: [PATCH 01/12] xfs: bmap debugging should never panic the system

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

On Thu, May 10, 2018 at 09:53:19AM -0400, Brian Foster wrote:
> On Thu, May 03, 2018 at 11:05:59AM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Don't panic() the system if the bmap records are garbage, just call
> > ASSERT which gives us the same backtrace but enables developers to
> > control if the system goes down or not.  This makes debugging with
> > generic/388 much easier because it won't reboot the machine midway
> > through a run just because btree_read_bufl returns EIO when the fs has
> > already shut down.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> >  fs/xfs/libxfs/xfs_bmap.c |    8 ++++++--
> >  1 file changed, 6 insertions(+), 2 deletions(-)
> > 
> > 
> > diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
> > index 6a7c2f03ea11..393b4e2c63ad 100644
> > --- a/fs/xfs/libxfs/xfs_bmap.c
> > +++ b/fs/xfs/libxfs/xfs_bmap.c
> > @@ -312,8 +312,10 @@ xfs_check_block(
> >  				xfs_warn(mp, "%s: thispa(%d) == pp(%d) %Ld",
> >  					__func__, j, i,
> >  					(unsigned long long)be64_to_cpu(*thispa));
> > -				panic("%s: ptrs are equal in node\n",
> > +				xfs_err(mp, "%s: ptrs are equal in node\n",
> >  					__func__);
> > +				ASSERT(XFS_FORCED_SHUTDOWN(mp));
> > +				xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
> 
> Why the assert if we're just going to shutdown? At minimum, it looks a
> bit funny to assert that the fs is shutdown just prior to issuing a
> shutdown. Can we just shutdown and let the error level dictate whether
> we want a backtrace?

Ok.

--D

> Brian
> 
> >  			}
> >  		}
> >  	}
> > @@ -483,7 +485,9 @@ xfs_bmap_check_leaf_extents(
> >  error_norelse:
> >  	xfs_warn(mp, "%s: BAD after btree leaves for %d extents",
> >  		__func__, i);
> > -	panic("%s: CORRUPTED BTREE OR SOMETHING", __func__);
> > +	xfs_err(mp, "%s: CORRUPTED BTREE OR SOMETHING", __func__);
> > +	ASSERT(XFS_FORCED_SHUTDOWN(mp));
> > +	xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
> >  	return;
> >  }
> >  
> > 
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html