1 files changed, 2 insertions, 0 deletions

diff --git a/fs/super.c b/fs/super.c
index e8486490826..8a06881b192 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -71,6 +71,7 @@ static struct super_block *alloc_super(struct file_system_type *type)
 #else
                 INIT_LIST_HEAD(&s->s_files);
 #endif
+                s->s_bdi = &default_backing_dev_info;
                 INIT_LIST_HEAD(&s->s_instances);
                 INIT_HLIST_BL_HEAD(&s->s_anon);
                 INIT_LIST_HEAD(&s->s_inodes);
@@ -936,6 +937,7 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
         sb = root->d_sb;
         BUG_ON(!sb);
         WARN_ON(!sb->s_bdi);
+        WARN_ON(sb->s_bdi == &default_backing_dev_info);
         sb->s_flags |= MS_BORN;
 
         error = security_sb_kern_mount(sb, flags, secdata);