AFS: implement file locking

Implement file locking for AFS.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index bacf518..b824394 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -125,6 +125,9 @@
 		spin_unlock(&server->cb_lock);
 
 		queue_work(afs_callback_update_worker, &vnode->cb_broken_work);
+		if (list_empty(&vnode->granted_locks) &&
+		    !list_empty(&vnode->pending_locks))
+			afs_lock_may_be_available(vnode);
 		spin_unlock(&vnode->lock);
 	}
 }