[PATCH 6.1 05/19] xfs: fix units conversion error in xfs_bmap_del_extent_delay

From: "Darrick J. Wong" <[email protected]>

[ Upstream commit ddd98076d5c075c8a6c49d9e6e8ee12844137f23 ]

The unit conversions in this function do not make sense.  First we
convert a block count to bytes, then divide that bytes value by
rextsize, which is in blocks, to get an rt extent count.  You can't
divide bytes by blocks to get a (possibly multiblock) extent value.

Fortunately nobody uses delalloc on the rt volume so this hasn't
mattered.

Fixes: fa5c836ca8eb5 ("xfs: refactor xfs_bunmapi_cow")
Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Leah Rumancik <[email protected]>
---
 fs/xfs/libxfs/xfs_bmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index d45a2e681f93..27d3121e6da9 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4805,11 +4805,11 @@ xfs_bmap_del_extent_delay(
 	ASSERT(del->br_blockcount > 0);
 	ASSERT(got->br_startoff <= del->br_startoff);
 	ASSERT(got_endoff >= del_endoff);
 
 	if (isrt) {
-		uint64_t rtexts = XFS_FSB_TO_B(mp, del->br_blockcount);
+		uint64_t	rtexts = del->br_blockcount;
 
 		do_div(rtexts, mp->m_sb.sb_rextsize);
 		xfs_mod_frextents(mp, rtexts);
 	}
 
-- 
2.48.1.362.g079036d154-goog