From: Arjan van de Ven The s_umount rwsem needs to be classified as per-superblock since it's perfectly legit to keep multiple of those recursively in the VFS locking rules. Has no effect on non-lockdep kernels. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Andrew Morton --- fs/super.c | 1 + include/linux/fs.h | 1 + 2 files changed, 2 insertions(+) diff -puN fs/super.c~lockdep-annotate-sb-s_umount fs/super.c --- a/fs/super.c~lockdep-annotate-sb-s_umount +++ a/fs/super.c @@ -73,6 +73,7 @@ static struct super_block *alloc_super(s INIT_LIST_HEAD(&s->s_inodes); init_rwsem(&s->s_umount); mutex_init(&s->s_lock); + lockdep_set_class(&s->s_umount, &type->s_umount_key); /* * The locking rules for s_lock are up to the * filesystem. For example ext3fs has different diff -puN include/linux/fs.h~lockdep-annotate-sb-s_umount include/linux/fs.h --- a/include/linux/fs.h~lockdep-annotate-sb-s_umount +++ a/include/linux/fs.h @@ -1354,6 +1354,7 @@ struct file_system_type { struct file_system_type * next; struct list_head fs_supers; struct lock_class_key s_lock_key; + struct lock_class_key s_umount_key; }; extern int get_sb_bdev(struct file_system_type *fs_type, _