Re: [PATCH 1/8] xfs: never try to scrub more than 64 inodes per inobt record

[Chandan Rajendra <chandan@linux.ibm.com>]

On Wednesday, January 2, 2019 6:09:29 PM IST Carlos Maiolino wrote:
> On Mon, Dec 31, 2018 at 06:08:33PM -0800, Darrick J. Wong wrote:
> > From: Darrick J. Wong <darrick.wong@oracle.com>
> > 
> > Make sure we never check more than XFS_INODES_PER_CHUNK inodes for any
> > given inobt record since there can be more than one inobt record mapped
> > to an inode cluster.
> > 
> > Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> > ---
> >  fs/xfs/scrub/ialloc.c |    3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > 
> > diff --git a/fs/xfs/scrub/ialloc.c b/fs/xfs/scrub/ialloc.c
> > index 882dc56c5c21..fd431682db0b 100644
> > --- a/fs/xfs/scrub/ialloc.c
> > +++ b/fs/xfs/scrub/ialloc.c
> > @@ -203,7 +203,8 @@ xchk_iallocbt_check_freemask(
> >  	int				error = 0;
> >  
> >  	/* Make sure the freemask matches the inode records. */
> > -	nr_inodes = mp->m_inodes_per_cluster;
> > +	nr_inodes = min_t(unsigned int, XFS_INODES_PER_CHUNK,
> > +			mp->m_inodes_per_cluster);
> 
> Pardon me if this doesn't make sense, but, this looks like a good time to catch
> a possible corruption?! If mp->m_inodes_per_cluster is > XFS_INODES_PER_CHUNK
> something is terribly wrong and we could report it here instead of max it out to
> XFS_INODES_PER_CHUNK, but I haven't studied the scrub code that deep yet to see
> if my suggestion makes sense or not :)

With 64k block size, we would have 128 inodes per cluster i.e. more than one
chunk can be accommodated within a cluster.

-- 
chandan