Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755395Ab1D2G5d (ORCPT ); Fri, 29 Apr 2011 02:57:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:15602 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753878Ab1D2G5c (ORCPT ); Fri, 29 Apr 2011 02:57:32 -0400 Date: Fri, 29 Apr 2011 12:27:18 +0530 From: Amit Shah To: Tejun Heo Cc: Jens Axboe , David Zeuthen , Martin Pitt , Kay Sievers , linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] cdrom: always check_disk_change() on open Message-ID: <20110429060200.GA5107@amit-x200.redhat.com> References: <20110406121920.GC4142@mtj.dyndns.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110406121920.GC4142@mtj.dyndns.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1484 Lines: 38 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. Thanks, Amit -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/