[PATCH 4.10 24/27] gfs2: Avoid alignment hole in struct lm_lockname

Greg Kroah-Hartman
2017-03-24T18:24:16Z

From: Andreas Gruenbacher <agruenba@redhat.com>

commit 28ea06c46fbcab63fd9a55531387b7928a18a590 upstream.

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>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/gfs2/incore.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- 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) && \