From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755551Ab1D2IPy (ORCPT ); Fri, 29 Apr 2011 04:15:54 -0400 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:45388 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752114Ab1D2IPw (ORCPT ); Fri, 29 Apr 2011 04:15:52 -0400 Message-ID: <4DBA73B6.6040603@kernel.dk> Date: Fri, 29 Apr 2011 10:15:50 +0200 From: Jens Axboe MIME-Version: 1.0 To: Amit Shah CC: Tejun Heo , David Zeuthen , Martin Pitt , Kay Sievers , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] cdrom: always check_disk_change() on open References: <20110406121920.GC4142@mtj.dyndns.org> <20110429060200.GA5107@amit-x200.redhat.com> In-Reply-To: <20110429060200.GA5107@amit-x200.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2011-04-29 08:57, Amit Shah wrote: > On (Wed) 06 Apr 2011 [05:20:09], Tejun Heo wrote: >> cdrom_open() called check_disk_change() after the rest of open path >> succeeded which leads to the following bizarre behavior. >> >> * After media change, if the device opened without O_NONBLOCK, >> open_for_data() naturally fails with -ENOMEDIA and >> check_disk_change() is never called. The media is known to be gone >> and the open failure makes it obvious to the userland but device >> invalidation never happens. >> >> * But if the device is opened with O_NONBLOCK, all the checks are >> bypassed and cdrom_open() doesn't notice that the media is not there >> and check_disk_change() is called and invalidation happens. >> >> There's nothing to be gained by avoiding calling check_disk_change() >> on open failure. Common cases end up calling check_disk_change() >> anyway. All we get is inconsistent behavior. >> >> Fix it by moving check_disk_change() invocation to the top of >> cdrom_open() so that it always gets called regardless of how the rest >> of open proceeds. >> >> Signed-off-by: Tejun Heo >> Reported-by: Amit Shah >> Tested-by: Amit Shah > > Ping? > > Also, please mark this for stable-2.6.38. Done, added for 2.6.39 and marked stable for 2.6.38. -- Jens Axboe