From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757222AbXEQQsv (ORCPT ); Thu, 17 May 2007 12:48:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755809AbXEQQso (ORCPT ); Thu, 17 May 2007 12:48:44 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:41772 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755263AbXEQQsn (ORCPT ); Thu, 17 May 2007 12:48:43 -0400 Date: Thu, 17 May 2007 09:47:30 -0700 From: Andrew Morton To: Johann Lombardi Cc: linux-kernel@vger.kernel.org Subject: Re: Clear PG_error before reading a page Message-Id: <20070517094730.5cdfaa64.akpm@linux-foundation.org> In-Reply-To: <20070517114250.GA2141@chiva> References: <20070515143726.GC2160@chiva> <20070515101144.f7072476.akpm@linux-foundation.org> <20070515210124.GA23698@chiva> <20070515142339.4d9098f3.akpm@linux-foundation.org> <20070516153919.GC2630@chiva> <20070516091217.b9bb5797.akpm@linux-foundation.org> <20070517114250.GA2141@chiva> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 17 May 2007 13:42:50 +0200 Johann Lombardi wrote: > > What is the actual real-world operational scenario here? Would it be a > > hotplugged disk? A transient network failure in a SAN? IOW, is it > > something from which the kernel should automatically recover, or it is a > > situation in which manual intervention would be better? > > The real-world operational scenario is a storage system reporting medium > errors which can be corrected by a manual intervention. So running ioctl(BLKFLSBUF) against the device will fix things up? Perhaps not, and we should invalidate all the file data as well. The only ways we have of doing that are umount+mount or /proc/sys/vm/drop_caches. I'm not sure what is the best thing to do here - there are advantages to caching the fact that the device (or some of it) is unreadable.