fuse: account as waiting before queuing for background

Move accounting of fc->num_waiting to the point where the request actually
starts waiting.  This is earlier than the current queue_request() for
background requests, since they might be waiting on the fc->bg_queue before
being queued on fc->pending.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: Ashish Samant <ashish.samant@oracle.com>

fs/fuse/dev.c

@@ -327,10 +327,6 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
 		len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
 	list_add_tail(&req->list, &fc->pending);
 	req->state = FUSE_REQ_PENDING;
-	if (!req->waiting) {
-		req->waiting = 1;
-		atomic_inc(&fc->num_waiting);
-	}
 	wake_up(&fc->waitq);
 	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 }
@@ -519,6 +515,10 @@ static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 {
 	req->isreply = 1;
+	if (!req->waiting) {
+		req->waiting = 1;
+		atomic_inc(&fc->num_waiting);
+	}
 	__fuse_request_send(fc, req);
 }
 EXPORT_SYMBOL_GPL(fuse_request_send);
@@ -592,6 +592,10 @@ static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
 					    struct fuse_req *req)
 {
 	BUG_ON(!req->background);
+	if (!req->waiting) {
+		req->waiting = 1;
+		atomic_inc(&fc->num_waiting);
+	}
 	fc->num_background++;
 	if (fc->num_background == fc->max_background)
 		fc->blocked = 1;