Linux: make sure backing_dev_info is zeroed

The afs backing_dev_info structure is allocated dynamically
without zeroing out the contents.  In particular there's no
guarantee that congested_fn is NULL, causing spurious oopses
when bdi_congested in the kernel tries to call it.

(adapted from commit 8e97cf6f215d5575c63d86eaec59031399f4beda)

Change-Id: I83755b6bb5ec2fada7e077c00d3d8edf8af1cae4
Reviewed-on: http://gerrit.openafs.org/6104
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit 032736bc052d3fb1a1d4f033a47e844d7f4ea05a)

diff --git a/src/afs/LINUX/osi_vfsops.c b/src/afs/LINUX/osi_vfsops.c
index d32720f5ccf2944c3874d33476ee3f8614e4cdeb..0d41bc7f3b983fb2f565a37d2077a81e5351896a 100644 (file)
--- a/src/afs/LINUX/osi_vfsops.c
+++ b/src/afs/LINUX/osi_vfsops.c
@@ -114,6 +114,7 @@ afs_fill_super(struct super_block *sb, void *data, int silent)
 
     /* used for inodes backing_dev_info field, also */
     afs_backing_dev_info = osi_Alloc(sizeof(struct backing_dev_info));
+    memset(afs_backing_dev_info, 0, sizeof(struct backing_dev_info));
 #if defined(HAVE_LINUX_BDI_INIT)
     bdi_init(afs_backing_dev_info);
 #endif