Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754415AbcDZXSf (ORCPT ); Tue, 26 Apr 2016 19:18:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40636 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753944AbcDZXSd (ORCPT ); Tue, 26 Apr 2016 19:18:33 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Markus Pargmann" , "Dan Streetman" Date: Wed, 27 Apr 2016 01:02:21 +0200 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 015/217] nbd: ratelimit error msgs after socket close In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8426:ae4:c500:9cba:69ae:962d:6167 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1503 Lines: 41 3.16.35-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Dan Streetman commit da6ccaaa79caca4f38b540b651238f87215217a2 upstream. Make the "Attempted send on closed socket" error messages generated in nbd_request_handler() ratelimited. When the nbd socket is shutdown, the nbd_request_handler() function emits an error message for every request remaining in its queue. If the queue is large, this will spam a large amount of messages to the log. There's no need for a separate error message for each request, so this patch ratelimits it. In the specific case this was found, the system was virtual and the error messages were logged to the serial port, which overwhelmed it. Fixes: 4d48a542b427 ("nbd: fix I/O hang on disconnected nbds") Signed-off-by: Dan Streetman Signed-off-by: Markus Pargmann Signed-off-by: Ben Hutchings --- drivers/block/nbd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -578,8 +578,8 @@ static void do_nbd_request(struct reques BUG_ON(nbd->magic != NBD_MAGIC); if (unlikely(!nbd->sock)) { - dev_err(disk_to_dev(nbd->disk), - "Attempted send on closed socket\n"); + dev_err_ratelimited(disk_to_dev(nbd->disk), + "Attempted send on closed socket\n"); req->errors++; nbd_end_request(req); spin_lock_irq(q->queue_lock);