From: Ingo Molnar Teach special (per-filesystem) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton --- fs/super.c | 13 +++++++++---- include/linux/fs.h | 1 + 2 files changed, 10 insertions(+), 4 deletions(-) diff -puN fs/super.c~lock-validator-special-locking-s_lock fs/super.c --- devel/fs/super.c~lock-validator-special-locking-s_lock 2006-06-02 19:00:31.000000000 -0700 +++ devel-akpm/fs/super.c 2006-06-02 19:00:31.000000000 -0700 @@ -54,7 +54,7 @@ DEFINE_SPINLOCK(sb_lock); * Allocates and initializes a new &struct super_block. alloc_super() * returns a pointer new superblock or %NULL if allocation had failed. */ -static struct super_block *alloc_super(void) +static struct super_block *alloc_super(struct file_system_type *type) { struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER); static struct super_operations default_op; @@ -72,7 +72,12 @@ static struct super_block *alloc_super(v INIT_HLIST_HEAD(&s->s_anon); INIT_LIST_HEAD(&s->s_inodes); init_rwsem(&s->s_umount); - mutex_init(&s->s_lock); + /* + * The locking rules for s_lock are up to the + * filesystem. For example ext3fs has different + * lock ordering than usbfs: + */ + mutex_init_key(&s->s_lock, type->name, &type->s_lock_key); down_write(&s->s_umount); s->s_count = S_BIAS; atomic_set(&s->s_active, 1); @@ -296,7 +301,7 @@ retry: } if (!s) { spin_unlock(&sb_lock); - s = alloc_super(); + s = alloc_super(type); if (!s) return ERR_PTR(-ENOMEM); goto retry; @@ -695,7 +700,7 @@ struct super_block *get_sb_bdev(struct f */ mutex_lock(&bdev->bd_mount_mutex); s = sget(fs_type, test_bdev_super, set_bdev_super, bdev); - mutex_unlock(&bdev->bd_mount_mutex); + mutex_unlock_non_nested(&bdev->bd_mount_mutex); if (IS_ERR(s)) goto out; diff -puN include/linux/fs.h~lock-validator-special-locking-s_lock include/linux/fs.h --- devel/include/linux/fs.h~lock-validator-special-locking-s_lock 2006-06-02 19:00:31.000000000 -0700 +++ devel-akpm/include/linux/fs.h 2006-06-02 19:00:31.000000000 -0700 @@ -1361,6 +1361,7 @@ struct file_system_type { struct module *owner; struct file_system_type * next; struct list_head fs_supers; + struct lockdep_type_key s_lock_key; }; struct super_block *get_sb_bdev(struct file_system_type *fs_type, _