From d625c0c5ad6396e39f79a5d41aab60cabd4a70d6 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Thu, 14 Jul 2022 11:05:51 -0700 Subject: xfs: check for reverse mapping records that could be merged Enhance the rmap scrubber to flag adjacent records that could be merged. Signed-off-by: Darrick J. Wong --- fs/xfs/scrub/rmap.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c index efb13a21afbc..76ac2279e37d 100644 --- a/fs/xfs/scrub/rmap.c +++ b/fs/xfs/scrub/rmap.c @@ -39,6 +39,12 @@ struct xchk_rmap { * allocations that cannot be shared. */ struct xfs_rmap_irec overlap_rec; + + /* + * The previous rmapbt record, so that we can check for two records + * that could be one. + */ + struct xfs_rmap_irec prev_rec; }; /* Cross-reference a rmap against the refcount btree. */ @@ -146,6 +152,51 @@ set_prev: memcpy(&cr->overlap_rec, irec, sizeof(struct xfs_rmap_irec)); } +/* Decide if two reverse-mapping records can be merged. */ +static inline bool +xchk_rmap_mergeable( + struct xchk_rmap *cr, + const struct xfs_rmap_irec *r2) +{ + const struct xfs_rmap_irec *r1 = &cr->prev_rec; + + /* Ignore if prev_rec is not yet initialized. */ + if (cr->prev_rec.rm_blockcount == 0) + return false; + + if (r1->rm_owner != r2->rm_owner) + return false; + if (r1->rm_startblock + r1->rm_blockcount != r2->rm_startblock) + return false; + if ((unsigned long long)r1->rm_blockcount + r2->rm_blockcount > + XFS_RMAP_LEN_MAX) + return false; + if (XFS_RMAP_NON_INODE_OWNER(r2->rm_owner)) + return true; + /* must be an inode owner below here */ + if (r1->rm_flags != r2->rm_flags) + return false; + if (r1->rm_flags & XFS_RMAP_BMBT_BLOCK) + return true; + return r1->rm_offset + r1->rm_blockcount == r2->rm_offset; +} + +/* Flag failures for records that could be merged. */ +STATIC void +xchk_rmapbt_check_mergeable( + struct xchk_btree *bs, + struct xchk_rmap *cr, + const struct xfs_rmap_irec *irec) +{ + if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT) + return; + + if (xchk_rmap_mergeable(cr, irec)) + xchk_btree_set_corrupt(bs->sc, bs->cur, 0); + + memcpy(&cr->prev_rec, irec, sizeof(struct xfs_rmap_irec)); +} + /* Scrub an rmapbt record. */ STATIC int xchk_rmapbt_rec( @@ -218,6 +269,7 @@ xchk_rmapbt_rec( xchk_btree_set_corrupt(bs->sc, bs->cur, 0); } + xchk_rmapbt_check_mergeable(bs, cr, &irec); xchk_rmapbt_check_overlapping(bs, cr, &irec); xchk_rmapbt_xref(bs->sc, &irec); out: -- cgit v1.2.3