From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: ide: Requeue request after DMA timeout Date: Thu, 01 Apr 2010 15:25:50 +0900 Message-ID: <4BB43C6E.3050900@kernel.org> References: <20100331061731.GA11480@gondor.apana.org.au> <4BB40D4C.7010204@kernel.org> <20100401043201.GA20470@gondor.apana.org.au> <4BB42795.5070008@kernel.org> <20100401055455.GA20865@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:55885 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753337Ab0DAG0R (ORCPT ); Thu, 1 Apr 2010 02:26:17 -0400 In-Reply-To: <20100401055455.GA20865@gondor.apana.org.au> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Herbert Xu Cc: "David S. Miller" , linux-ide@vger.kernel.org Hello, On 04/01/2010 02:54 PM, Herbert Xu wrote: > On Thu, Apr 01, 2010 at 01:56:53PM +0900, Tejun Heo wrote: >> >> OIC. It's also cleared in ide_timer_expiry() too. Asymmetry among >> different failure paths worries me. e.g. looking at the code, I can't >> find how ide_error() would requeue the request either. It looks like >> each hwif->rq = NULL in failure path should be investigated and the >> affected ones should be replaced with a function which requeues and >> clears hwif->rq. Hmmm.... am I misunderstanding something? > > I had a look at the rest of them and they seemed to be fine. In ide_timer_expiry() if drive->waiting_for_dma is false, ide_error() is called, which in turn calls __ide_error() for fs requests. ide_ata_error() will be called if the device is a disk. If the request hasn't reached the retry limit and reset is not necessary, ide_ata_error() will return ide_stopped without requeueing the request. ide_timer_expiry() will clear hwif->rq without requeueing the request and the request will be lost. No? > So are you OK for this patch to go in? Yeah yeah, I think those patches are okay by themselves and am just trying to find out whether anything similar is missing, in which case the requeue might fit better somewhere higher in the call chain. Thanks. -- tejun