Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932951AbXHXTJ0 (ORCPT ); Fri, 24 Aug 2007 15:09:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1762030AbXHXTJS (ORCPT ); Fri, 24 Aug 2007 15:09:18 -0400 Received: from hancock.steeleye.com ([71.30.118.248]:33917 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1758382AbXHXTJS (ORCPT ); Fri, 24 Aug 2007 15:09:18 -0400 Message-ID: <46CF2CDD.5000802@steeleye.com> Date: Fri, 24 Aug 2007 15:09:17 -0400 From: Paul Clements User-Agent: Thunderbird 1.5.0.10 (X11/20070306) MIME-Version: 1.0 To: Mike Snitzer CC: Andrew Morton , linux-kernel@vger.kernel.org, david@dgreaves.com, Wouter Verhelst , Corey Minyard , nbd-general@lists.sourceforge.net Subject: Re: [PATCH 2/2] NBD: allow hung network I/O to be cancelled References: <46CF101F.4050603@steeleye.com> <46CF1826.9050101@steeleye.com> <170fa0d20708241113y31d2ba95xf30c83c7c4c98cd2@mail.gmail.com> In-Reply-To: <170fa0d20708241113y31d2ba95xf30c83c7c4c98cd2@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1393 Lines: 31 Mike Snitzer wrote: > On 8/24/07, Paul Clements wrote: >> This patch allows NBD I/O to be cancelled when a network outage occurs. >> Previously, I/O would just hang, and if enough I/O was hung in nbd, the >> system (at least user-level) would completely hang until a TCP timeout >> (default, 15 minutes) occurred. >> >> The patch introduces a new ioctl NBD_SET_TIMEOUT that allows a transmit >> timeout value (in seconds) to be specified. Any network send that >> exceeds the timeout will be cancelled and the nbd connection will be >> shut down. I've tested with various timeout values and 6 seconds seems >> to be a good choice for the timeout. If the NBD_SET_TIMEOUT ioctl is not >> called, you get the old (I/O hang) behavior. > > Hi Paul, > > Thanks for implementing this! Do you happen to have an associated > nbd-client patch for userspace? If not I'd be happy to coordinate > with you and Wouter on a patch. No, I don't. I just basically hardcoded my nbd-client to do a 6 second timeout by default, but Wouter will probably want to do something a little less hackish for the official nbd-client. -- Paul - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/