xfs: don't coalesce file mappings that cross rtgroup boundaries in scrub

The bmbt scrubber will combine file mappings if they are mergeable to
reduce the number of cross-referencing checks.  However, we shouldn't
combine mappings that cross rt group boundaries because that will cause
verifiers to trip incorrectly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
index 008630b..7e00312 100644 (file)
--- a/fs/xfs/scrub/bmap.c
+++ b/fs/xfs/scrub/bmap.c
@@ -834,9 +834,12 @@ xchk_bmap_iext_mapping(
 /* Are these two mappings contiguous with each other? */
 static inline bool
 xchk_are_bmaps_contiguous(
+       const struct xchk_bmap_info     *info,
        const struct xfs_bmbt_irec      *b1,
        const struct xfs_bmbt_irec      *b2)
 {
+       struct xfs_mount                *mp = info->sc->mp;
+
        /* Don't try to combine unallocated mappings. */
        if (!xfs_bmap_is_real_extent(b1))
                return false;
@@ -850,6 +853,17 @@ xchk_are_bmaps_contiguous(
                return false;
        if (b1->br_state != b2->br_state)
                return false;
+
+       /*
+        * Don't combine bmaps that would cross rtgroup boundaries.  This is a
+        * valid state, but if combined they will fail rtb extent checks.
+        */
+       if (info->is_rt && xfs_has_rtgroups(mp)) {
+               if (xfs_rtb_to_rgno(mp, b1->br_startblock) !=
+                   xfs_rtb_to_rgno(mp, b2->br_startblock))
+                       return false;
+       }
+
        return true;
 }
 
@@ -887,7 +901,7 @@ xchk_bmap_iext_iter(
         * that we just read, if possible.
         */
        while (xfs_iext_peek_next_extent(ifp, &info->icur, &got)) {
-               if (!xchk_are_bmaps_contiguous(irec, &got))
+               if (!xchk_are_bmaps_contiguous(info, irec, &got))
                        break;
 
                if (!xchk_bmap_iext_mapping(info, &got)) {