[Cluster-devel] [PATCH] gfs2: Avoid alignment hole in struct lm_lockname

[Andreas Gruenbacher <agruenba@redhat.com>]

Commit 88ffbf3e03 switches to using rhashtables for glocks, hashing over
the entire struct lm_lockname instead of its individual fields.  On some
architectures, struct lm_lockname contains a hole of uninitialized
memory due to alignment rules, which now leads to incorrect hash values.
Get rid of that hole.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
CC: <stable@vger.kernel.org> #v4.3+
---
 fs/gfs2/incore.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index c45084a..511e1ed 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -207,7 +207,7 @@ struct lm_lockname {
 	struct gfs2_sbd *ln_sbd;
 	u64 ln_number;
 	unsigned int ln_type;
-};
+} __packed __aligned(sizeof(int));
 
 #define lm_name_equal(name1, name2) \
         (((name1)->ln_number == (name2)->ln_number) &&	\
-- 
2.7.4