From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from aserp1040.oracle.com ([141.146.126.69]:40797 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752209AbdJPWhN (ORCPT ); Mon, 16 Oct 2017 18:37:13 -0400 Date: Mon, 16 Oct 2017 15:37:08 -0700 From: "Darrick J. Wong" Subject: Re: [PATCH 25/30] xfs: scrub directory freespace Message-ID: <20171016223708.GR4703@magnolia> References: <150777244315.1724.6916081372861799350.stgit@magnolia> <150777260602.1724.16339769636569418352.stgit@magnolia> <20171016044921.GB3666@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171016044921.GB3666@dastard> Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Dave Chinner Cc: linux-xfs@vger.kernel.org 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. > > .... > > > 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/ Ok. > > + */ > > +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) > Ok. That check can be lifted out of the loop anyway. > > + 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. Ok. I'll make it STATIC like everything else here. > > + 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 ? 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? > > > + 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? Aha, yes, that needs to be checked. Also that for loop needs to be terminated on i < freehdr.nused. --D > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html