vfs: simple_set_mnt() should return void

simple_set_mnt() is defined as returning 'int' but always returns 0.
Callers assume simple_set_mnt() never fails and don't properly cleanup if
it were to _ever_ fail.  For instance, get_sb_single() and get_sb_nodev()
should:

        up_write(sb->s_unmount);
        deactivate_super(sb);

if simple_set_mnt() fails.

Since simple_set_mnt() never fails, would be cleaner if it did not
return anything.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 1 deletions

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b01100ebd074..c500ca7239b2 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1071,7 +1071,8 @@ static int cgroup_get_sb(struct file_system_type *fs_type,
                 mutex_unlock(&cgroup_mutex);
         }
 
-        return simple_set_mnt(mnt, sb);
+        simple_set_mnt(mnt, sb);
+        return 0;
 
  free_cg_links:
         free_cg_links(&tmp_cg_links);