From: Andreas Gruenbacher <agruenba@redhat.com>
Date: Mon, 6 Mar 2017 17:58:42 +0000 (-0500)
Subject: gfs2: Avoid alignment hole in struct lm_lockname
X-Git-Tag: v4.4.57~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e08f608ab4288f4192a504e6c94dd7c9c931dad8;p=thirdparty%2Fkernel%2Fstable.git

gfs2: Avoid alignment hole in struct lm_lockname

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>
---

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index de7b4f97ac755..be519416c1123 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) &&	\