From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750761AbVJWWJw (ORCPT ); Sun, 23 Oct 2005 18:09:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750790AbVJWWJw (ORCPT ); Sun, 23 Oct 2005 18:09:52 -0400 Received: from embla.aitel.hist.no ([158.38.50.22]:41370 "HELO embla.aitel.hist.no") by vger.kernel.org with SMTP id S1750781AbVJWWJv (ORCPT ); Sun, 23 Oct 2005 18:09:51 -0400 Date: Mon, 24 Oct 2005 00:12:04 +0200 To: Alan Cox Cc: Alan Stern , Jens Axboe , Kernel development list Subject: Re: BUG in the block layer (partial reads not reported) Message-ID: <20051023221204.GA20162@aitel.hist.no> References: <1129915917.3542.7.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1129915917.3542.7.camel@localhost.localdomain> User-Agent: Mutt/1.5.9i From: Helge Hafting Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 21, 2005 at 06:31:57PM +0100, Alan Cox wrote: > > The essential problem however is that if you say a disc is a given size > and it turns out not to be (as happens with CD-R especially or with > buggy readers) then Linux block layer can't cope. Its well known and > causes endless problems for CD-R users with some IDE drives on Linux. > Its a big generator of 2.6 vendor bug reports. > Seems to me that the best fix for devices that may re�port the wrong size is to always use a foolproof way of determining the size. I.e. when a CD-R cannot be trusted, determine the size by trying to read the last sectors instead of using the reported number. Helge Hafting