From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [SCSI][REGRESSION][BISECTED] Disk errors loop forever in 2.6.29 Date: Thu, 19 Feb 2009 21:48:54 +0000 Message-ID: <1235080134.12500.45.camel@localhost.localdomain> References: <56979.43325.qm@web110612.mail.gq1.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([76.243.235.52]:33494 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757453AbZBSVs7 (ORCPT ); Thu, 19 Feb 2009 16:48:59 -0500 In-Reply-To: <56979.43325.qm@web110612.mail.gq1.yahoo.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Sitsofe Wheeler Cc: Alan Stern , linux-kernel@vger.kernel.org, rjw@sisk.pl, Ingo Molnar , linux-scsi@vger.kernel.org On Thu, 2009-02-19 at 13:11 -0800, Sitsofe Wheeler wrote: > > From: James Bottomley > > > > Can you try this patch ... it was something I meant to get into 2.6.29 > > but forgot about. The key problem that you seem to be hitting is that > > the requeue evades the timeout check. Moving the timeout check to block > > should fix that. > > Even by itself this patch works although the behaviour is now different > to that of 2.6.28. Whereas in 2.6.28 it would timeout very quickly > (after about 1 or 2 seconds) it now times out after 30 seconds > (initially I hadn't realised that it would be so much longer). The > other difference is that the failure becomes cached - trying to reread > the same area using dd instantly fails from now on without any more disk > IO/kernel error messages until echo 1 > /proc/sys/vm/drop_caches is > issued. Before it would always go straight to the disk for the unread > section and the kernel spew would be repeated before the failure. Well, the block patch is more of a catch all: without it apparently the scsi_io_completion() rewrite has several cases where it will apparently loop forever. Your specific behaviour change seems to be a bug in the way the rewrite is handling ABORTED_COMMAND. Could you try the patch below (with or without the block patch, it shouldn't matter) and see if it gets you back to 2.6.28 behaviour? Thanks, James --- diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index c034841..4b13e36 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -850,12 +850,11 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) action = ACTION_FAIL; break; case ABORTED_COMMAND: + action = ACTION_FAIL; if (sshdr.asc == 0x10) { /* DIF */ description = "Target Data Integrity Failure"; - action = ACTION_FAIL; error = -EILSEQ; - } else - action = ACTION_RETRY; + } break; case NOT_READY: /* If the device is in the process of becoming