From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:64362 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752519AbdJPXTc (ORCPT ); Mon, 16 Oct 2017 19:19:32 -0400 Date: Tue, 17 Oct 2017 10:14:13 +1100 From: Dave Chinner Subject: Re: [PATCH 25/30] xfs: scrub directory freespace Message-ID: <20171016231413.GM15067@dastard> References: <150777244315.1724.6916081372861799350.stgit@magnolia> <150777260602.1724.16339769636569418352.stgit@magnolia> <20171016044921.GB3666@dastard> <20171016223708.GR4703@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171016223708.GR4703@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org On Mon, Oct 16, 2017 at 03:37:08PM -0700, Darrick J. Wong wrote: > On Mon, Oct 16, 2017 at 03:49:21PM +1100, Dave Chinner wrote: > > On Wed, Oct 11, 2017 at 06:43:26PM -0700, Darrick J. Wong wrote: > > > From: Darrick J. Wong > > > > > > Check the free space information in a directory. > > > > .... > > > > > +/* Check free space info in a directory leaf1 block. */ > > > +STATIC int > > > +xfs_scrub_directory_leaf1_bestfree( > > > + struct xfs_scrub_context *sc, > > > + struct xfs_da_args *args, > > > + xfs_dablk_t lblk) > > > +{ > > > + struct xfs_dir2_leaf_tail *ltp; > > > + struct xfs_buf *dbp; > > > + struct xfs_buf *bp; > > > + struct xfs_mount *mp = sc->mp; > > > + __be16 *bestp; > > > + __u16 best; > > > + int i; > > > + int error; > > > + > > > + /* > > > + * Read the free space block. The verifier will check for hash > > > + * value ordering problems and check the stale entry count. > > > + */ > > > + error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, -1, &bp); > > > + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error)) > > > + goto out; > > > + > > > + /* Check all the entries. */ > > > + ltp = xfs_dir2_leaf_tail_p(mp->m_dir_geo, bp->b_addr); > > > + bestp = xfs_dir2_leaf_bests_p(ltp); > > > + for (i = 0; i < be32_to_cpu(ltp->bestcount); i++, bestp++) { > > > + best = be16_to_cpu(*bestp); > > > + if (best == NULLDATAOFF) > > > + continue; > > > > Count stale entries, check if matches hdr->stale ? > > This should already be done by xfs_dir3_leaf_read -> > xfs_dir3_leaf1_read_verify -> __read_verify -> xfs_dir3_leaf_verify -> > xfs_dir3_leaf_check_int, right? True. However, it's simple to do and we're already iterating over all the structures necessary and detecting the case necessary to check it, so it doesn't hurt and might catch in-core corruptions before they hit the write verifier? And it makes it do the same checks as the free_bestfree checks below.... > > > + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, > > > + &error)) > > > + continue; > > > + xfs_scrub_directory_check_freesp(sc, lblk, dbp, best); > > > + xfs_trans_brelse(sc->tp, dbp); > > > + } > > > +out: > > > + return error; > > > +} > > > + > > > +/* Check free space info in a directory freespace block. */ > > > +STATIC int > > > +xfs_scrub_directory_free_bestfree( > > > + struct xfs_scrub_context *sc, > > > + struct xfs_da_args *args, > > > + xfs_dablk_t lblk) > > > +{ > > > + struct xfs_dir3_icfree_hdr freehdr; > > > + struct xfs_buf *dbp; > > > + struct xfs_buf *bp; > > > + __be16 *bestp; > > > + __be16 best; > > > + int i; > > > + int error; > > > + > > > + /* Read the free space block */ > > > + error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp); > > > + if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error)) > > > + goto out; > > > + > > > + /* Check all the entries. */ > > > + sc->ip->d_ops->free_hdr_from_disk(&freehdr, bp->b_addr); > > > + bestp = sc->ip->d_ops->free_bests_p(bp->b_addr); > > > + for (i = 0; i < freehdr.nvalid; i++, bestp++) { > > > + best = be16_to_cpu(*bestp); > > > + if (best == NULLDATAOFF) > > > + continue; > > > > Count stale entries, check freehdr.nvalid + stale = freehdr.nused? > > Aha, yes, that needs to be checked. > > Also that for loop needs to be terminated on i < freehdr.nused. Good catch - I missed that, too :P Cheers, Dave. -- Dave Chinner david@fromorbit.com