From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: ata_eh_link_autopsy: Bug? Date: Tue, 01 May 2012 19:48:37 -0400 Message-ID: <4FA07655.6090506@teksavvy.com> References: <4FA043BE.2010009@teksavvy.com> <4FA04714.7050602@teksavvy.com> <20120501215854.GA21677@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from ironport-out.teksavvy.com ([206.248.143.162]:31703 "EHLO ironport-out.teksavvy.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753481Ab2EAXsi (ORCPT ); Tue, 1 May 2012 19:48:38 -0400 In-Reply-To: <20120501215854.GA21677@google.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Tejun Heo Cc: IDE/ATA development list On 12-05-01 05:58 PM, Tejun Heo wrote: > On Tue, May 01, 2012 at 04:27:00PM -0400, Mark Lord wrote: >> MMmm.. even that isn't good enough, because the first ATA_QCFLAG_IO test >> bypasses the rest of that logic and triggers unconditional retries. Ugh. > > Hmmm... the unconditional retry on ATA_QCFLAG_IO is intenttional so > that known good requests from FS are guaranteed to be retried no > matter how whacky the underlying device is. I'm not sure whether that > was a good decision tho. Maybe we should trust the hardware a bit > more. So, I'm not necessarily against changing it. With multi-terabyte drives being commonplace now, bad sectors seem to be a more frequent occurrence than I can remember from the past. And when libata stumbles across a bad sector, it literally hangs the machine for _minutes_ doing retries. I have never seen a retry make any difference whatsoever on a bad sector read. New, old, or ancient hardware. Cheers