lockd: fix nlmsvc_notify_blocked locking

nlmsvc_notify_blocked walks the nlm_blocked list,
which requires nlm_blocked_lock.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

fs/lockd/svclock.c

@@ -700,14 +700,16 @@ nlmsvc_notify_blocked(struct file_lock *fl)
 	struct nlm_block	*block;
 
 	dprintk("lockd: VFS unblock notification for block %p\n", fl);
+	spin_lock(&nlm_blocked_lock);
 	list_for_each_entry(block, &nlm_blocked, b_list) {
 		if (nlm_compare_locks(&block->b_call->a_args.lock.fl, fl)) {
-			nlmsvc_insert_block(block, 0);
+			nlmsvc_insert_block_locked(block, 0);
+			spin_unlock(&nlm_blocked_lock);
 			svc_wake_up(block->b_daemon);
 			return;
 		}
 	}
-
+	spin_unlock(&nlm_blocked_lock);
 	printk(KERN_WARNING "lockd: notification for unknown block!\n");
 }