On Wed, Oct 04, 2017 at 05:28:40PM +1100, Dave Chinner wrote:
> On Tue, Oct 03, 2017 at 09:21:40PM -0700, Darrick J. Wong wrote:
> > On Wed, Oct 04, 2017 at 12:31:48PM +1100, Dave Chinner wrote:
> > > On Tue, Oct 03, 2017 at 01:41:52PM -0700, Darrick J. Wong wrote:
> > > > +/*
> > > > + * Load as many of the AG headers and btree cursors as we can for an
> > > > + * examination and cross-reference of an AG header.
> > > > + */
> > > > +int
> > > > +xfs_scrub_load_ag_headers(
> > > > + struct xfs_scrub_context *sc,
> > > > + xfs_agnumber_t agno,
> > > > + unsigned int type)
> > > > +{
> > > > + struct xfs_mount *mp = sc->mp;
> > > > + int error;
> > > > +
> > > > + ASSERT(type == XFS_SCRUB_TYPE_AGF || type == XFS_SCRUB_TYPE_AGFL);
> > > > + memset(&sc->sa, 0, sizeof(sc->sa));
> > > > + sc->sa.agno = agno;
> > > > +
> > > > + error = xfs_scrub_load_ag_header(sc, XFS_AGI_DADDR(mp),
> > > > + &sc->sa.agi_bp, &xfs_agi_buf_ops, false);
> > > > + if (error)
> > > > + return error;
> > > > +
> > > > + error = xfs_scrub_load_ag_header(sc, XFS_AGF_DADDR(mp),
> > > > + &sc->sa.agf_bp, &xfs_agf_buf_ops,
> > > > + type == XFS_SCRUB_TYPE_AGF);
> > > > + if (error)
> > > > + return error;
> > > > +
> > > > + error = xfs_scrub_load_ag_header(sc, XFS_AGFL_DADDR(mp),
> > > > + &sc->sa.agfl_bp, &xfs_agfl_buf_ops,
> > > > + type == XFS_SCRUB_TYPE_AGFL);
> > > > + if (error)
> > > > + return error;
> > > > +
> > > > + return 0;
> > > > +}
> > >
> > > This should probably be combined with xfs_scrub_ag_read_headers().
> > > They essentially do the same thing, the only difference is the
> > > "target" error reporting.
> >
> > It's quite different -- this function ignores verifier errors for
> > the two headers that don't match 'type' In other words, if we're
> > checking the AGF (for example) we'll try to grab the AGI and the AGFL.
> > Verifier errors on the AGI/AGFL don't matter, but we /do/ want to hear
> > the results if the AGF verifier fails.
>
> What they do is quite different. The implementation is /almost/
> identical. type is just an error masking variable and ....
>
> > xfs_scrub_ag_read_headers on the other hand will fail if /any/ of the
> > three verifiers fail.
>
> .... if no type is set, then we don't mask any errors at all and
> we bail if any of the three verifiers fail. i.e.:
>
> error = xfs_ialloc_read_agi(mp, sc->tp, agno, agi);
> if (error && (!type || type == XFS_SCRUB_TYPE_AGI)
> return error;
>
> error = xfs_alloc_read_agf(mp, sc->tp, agno, 0, agf);
> if (error && (!type || type == XFS_SCRUB_TYPE_AGF)
> return error;
>
> error = xfs_alloc_read_agfl(mp, sc->tp, agno, agfl);
> if (error && (!type || type == XFS_SCRUB_TYPE_AGFL)
> return error;
>
> It's also much simpler to understand because we are using the proper
> functions for reading these headers....
Ok, sounds good to me.
> > The two functions /could/ be combined, though the 'type' test becomes
> > trickier. Maybe it'd be better just to enhance the comments for the two
> > header loader functions to spell out how they differ in usage.
>
> Again, I'd much prefer similar functionality is combined into
> common helpers if it's simple enough to do...
<nod>
--D
> Cheers,
>
> Dave.
> --
> Dave Chinner
> david@xxxxxxxxxxxxx
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