Re: [PATCH 31/32] repair: support RT data checksums

["Darrick J. Wong" <djwong@kernel.org>]

On Sat, Sep 26, 2026 at 08:23:13AM +0200, Christoph Hellwig wrote:
> On Fri, Sep 25, 2026 at 04:54:35PM -0700, Darrick J. Wong wrote:
> > > +		}
> > > +		ip = rtg->rtg_inodes[XFS_RTGI_CSUM];
> > > +		error = -xfs_rtcsum_alloc_blocks(rtg);
> > 
> > Does this need the usual -libxfsification macros?
> 
> Probably.  Or I should go for another attempt to kill them everywhere...
> 
> > > +		xfs_csum_seed(mp, &csum);
> > > +		xfs_csum_gen(mp, data_buf + XFS_FSB_TO_B(mp, i),
> > > +				 mp->m_sb.sb_blocksize, &csum);
> > > +		if (i == 0)
> > > +			printf("calculated checksum 0x%x\n", csum.crc32c);
> > 
> > Debug code?
> 
> Yes.
> 
> > > +
> > > +		nr_blocks = min(DATA_BLOCKS_PER_BUF, rtg_blocks(rtg) - rgbno);
> > > +		error = read_data(mp->m_rtdev_targp,
> > > +				xfs_gbno_to_daddr(rtg_group(rtg), rgbno),
> > > +				XFS_FSB_TO_BB(mp, nr_blocks),
> > > +				data_buf);
> > > +		if (error) {
> > > +			do_warn(
> > > +_("Reading data at RG %u/%u failed, error %d"),
> > > +				rtg_rgno(rtg), rgbno, error);
> > > +			continue;
> > 
> > Er... so a read failure means we just leave broken checksums?
> 
> A zero-initialized one to be exact, yes.  I don't think there is
> much more we can do here?

I can't see anything that we can do about it either, but xfs_repair
ought to warn the user that they're going to get read errors.

--D