From: tmhikaru@gmail.com Subject: Re: Weird I/O errors with USB hard drive not remounting filesystem readonly Date: Tue, 24 Nov 2009 16:50:44 -0500 Message-ID: <20091124215044.GA20245@roll> References: <20091124195607.GC16662@quack.suse.cz> <20091124203944.GD16662@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Alan Stern , Boaz Harrosh , tmhikaru@gmail.com, Kernel development list , USB list , Jens Axboe , SCSI development list , linux-ext4@vger.kernel.org To: Jan Kara Return-path: Content-Disposition: inline In-Reply-To: <20091124203944.GD16662@quack.suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Tue, Nov 24, 2009 at 09:39:44PM +0100, Jan Kara wrote: > On Tue 24-11-09 15:13:01, Alan Stern wrote: > > On Tue, 24 Nov 2009, Jan Kara wrote: > > > > > After digging in block layer code, it's as we suspected: > > > In case of host error DID_ERROR (which is our case), scsi request is > > > retried iff it is not a FAILFAST request which is set if bio is doing > > > readahead... So this is explained and everything behaves as it should. > > > Thanks everybody involved :). > > > > Okay, very good. There remains the question of the disturbing error > > messages in the system log. Should they be supressed for FAILFAST > > requests? > I think it's useful they are there because ultimately, something really > went wrong and you should better investigate. BTW, "end_request: I/O error" > messages are in the log even for requests where we retried and succeeded... > > Honza While I agree it is useful information, I think that if the error messages are going to be printed, you should *also* print that this is a NON FATAL error and that it's going to be retried. It'd help diagnosing the path it's following through the failure code IMHO as well as not making users completely freak out like I did in my case. It is *not* particularly obvious given the message printed to syslog what is going wrong or why. Just my opinion, Tim McGrath