xfs: improve the xg_active_ref check in xfs_group_free

Source kernel commit: 59655147ec34fb72cc090ca4ee688ece05ffac56

Split up the XFS_IS_CORRUPT statement so that it immediately shows
if the reference counter overflowed or underflowed.

I ran into this quite a bit when developing the zoned allocator, and had
to reapply the patch for some work recently.  We might as well just apply
it upstream given that freeing group is far removed from performance
critical code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>

diff --git a/libxfs/xfs_group.c b/libxfs/xfs_group.c
index b7ac9dbd8e79d6504ec35912f5427ce88815cc90..03c508242d52f61f9b8d81af6abe9a21a4d370fb 100644 (file)
--- a/libxfs/xfs_group.c
+++ b/libxfs/xfs_group.c
@@ -170,7 +170,8 @@ xfs_group_free(
 
        /* drop the mount's active reference */
        xfs_group_rele(xg);
-       XFS_IS_CORRUPT(mp, atomic_read(&xg->xg_active_ref) != 0);
+       XFS_IS_CORRUPT(mp, atomic_read(&xg->xg_active_ref) > 0);
+       XFS_IS_CORRUPT(mp, atomic_read(&xg->xg_active_ref) < 0);
        kfree_rcu_mightsleep(xg);
 }