From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail03.adl6.internode.on.net ([150.101.137.143]:13990 "EHLO ipmail03.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750731AbdJPEtY (ORCPT ); Mon, 16 Oct 2017 00:49:24 -0400 Date: Mon, 16 Oct 2017 15:49:21 +1100 From: Dave Chinner Subject: Re: [PATCH 25/30] xfs: scrub directory freespace Message-ID: <20171016044921.GB3666@dastard> References: <150777244315.1724.6916081372861799350.stgit@magnolia> <150777260602.1724.16339769636569418352.stgit@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <150777260602.1724.16339769636569418352.stgit@magnolia> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: "Darrick J. Wong" Cc: linux-xfs@vger.kernel.org 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. .... > diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c > index e2a8f90..a41310f 100644 > --- a/fs/xfs/scrub/dir.c > +++ b/fs/xfs/scrub/dir.c > @@ -250,6 +250,426 @@ xfs_scrub_dir_rec( > return error; > } > > +/* > + * Is this unused entry either in the bestfree or smaller than all of them? > + * We assume the bestfrees are sorted longest to shortest, and that there > + * aren't any bogus entries. s/We assume/We've already checked/ > + */ > +static inline void > +xfs_scrub_directory_check_free_entry( > + struct xfs_scrub_context *sc, > + xfs_dablk_t lblk, > + struct xfs_dir2_data_free *bf, > + struct xfs_dir2_data_unused *dup) .... > + while (ptr < endptr) { > + dup = (struct xfs_dir2_data_unused *)ptr; > + /* Skip real entries */ > + if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) { > + struct xfs_dir2_data_entry *dep; > + > + dep = (struct xfs_dir2_data_entry *)ptr; > + newlen = d_ops->data_entsize(dep->namelen); > + if (newlen <= 0) { > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, > + lblk); > + goto out_buf; > + } > + ptr += newlen; > + if (endptr < ptr) > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, > + lblk); > + continue; > + } > + > + /* Spot check this free entry */ > + tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup)); > + if (tag != ((char *)dup - (char *)bp->b_addr)) > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk); > + > + /* > + * Either this entry is a bestfree or it's smaller than > + * any of the bestfrees. > + */ > + xfs_scrub_directory_check_free_entry(sc, lblk, bf, dup); > + > + /* Move on. */ > + newlen = be16_to_cpu(dup->length); > + if (newlen <= 0) { > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk); > + goto out_buf; > + } > + ptr += newlen; > + if (endptr < ptr) > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk); I'd prefer this matches the loop logic order. ie. if (ptr >= endptr) > + else > + nr_frees++; > + } > + > + /* Did we see at least as many free slots as there are bestfrees? */ > + if (nr_frees < nr_bestfrees) > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk); > +out_buf: > + xfs_trans_brelse(sc->tp, bp); > +out: > + return error; > +} > + > +/* > + * Does the free space length in the free space index block ($len) match > + * the longest length in the directory data block's bestfree array? > + * Assume that we've already checked that the data block's bestfree > + * array is in order. > + */ > +static inline void > +xfs_scrub_directory_check_freesp( No need for inline here, the compiler will do that automatically if appropriate. > + struct xfs_scrub_context *sc, > + xfs_dablk_t lblk, > + struct xfs_buf *dbp, > + unsigned int len) > +{ > + struct xfs_dir2_data_free *bf; > + struct xfs_dir2_data_free *dfp; > + int offset; > + > + if (len == 0) > + return; > + > + bf = sc->ip->d_ops->data_bestfree_p(dbp->b_addr); > + for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) { > + offset = be16_to_cpu(dfp->offset); > + if (offset == 0) > + break; > + if (len == be16_to_cpu(dfp->length)) > + return; > + /* Didn't find the best length in the bestfree data */ > + break; > + } > + > + xfs_scrub_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk); > +} > + > +/* 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 ? > + error = xfs_dir3_data_read(sc->tp, sc->ip, > + i * args->geo->fsbcount, -1, &dbp); > + 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? Cheers, Dave. -- Dave Chinner david@fromorbit.com