From e8b01aaafffe6b852325debdf1ef4b13ccea1cd7 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 1 Sep 2026 22:49:47 -0700 Subject: [PATCH] xfs: fix backwards mergeability logic in refcount scrubber When we start the refcount or rtrefcount btree scanners, prev_rec is initialized to all zeroes. This is done so that the record mergeability checks skip the first record because you must have two records to compare. Unfortunately, I got the logic backwards, so scrub has never complained about mergeable refcountbt records. Fix this bug that LOLLM noticed. Cc: stable@vger.kernel.org # v6.4 Fixes: db0502b39c21d1 ("xfs: flag refcount btree records that could be merged") Signed-off-by: Darrick J. Wong Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino --- fs/xfs/scrub/refcount.c | 2 +- fs/xfs/scrub/rtrefcount.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/xfs/scrub/refcount.c b/fs/xfs/scrub/refcount.c index 4e1bf23e5b89..f2addaf13c58 100644 --- a/fs/xfs/scrub/refcount.c +++ b/fs/xfs/scrub/refcount.c @@ -410,7 +410,7 @@ xchk_refcount_mergeable( const struct xfs_refcount_irec *r1 = &rrc->prev_rec; /* Ignore if prev_rec is not yet initialized. */ - if (r1->rc_blockcount > 0) + if (r1->rc_blockcount == 0) return false; if (r1->rc_domain != r2->rc_domain) diff --git a/fs/xfs/scrub/rtrefcount.c b/fs/xfs/scrub/rtrefcount.c index 4e7c540c8d23..de100178f41c 100644 --- a/fs/xfs/scrub/rtrefcount.c +++ b/fs/xfs/scrub/rtrefcount.c @@ -375,7 +375,7 @@ xchk_rtrefcount_mergeable( const struct xfs_refcount_irec *r1 = &rrc->prev_rec; /* Ignore if prev_rec is not yet initialized. */ - if (r1->rc_blockcount > 0) + if (r1->rc_blockcount == 0) return false; if (r1->rc_startblock + r1->rc_blockcount != r2->rc_startblock)