From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.fusionio.com ([64.244.102.30]:55887 "EHLO mx1.fusionio.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750881Ab0HEJQ0 (ORCPT ); Thu, 5 Aug 2010 05:16:26 -0400 Message-ID: <4C5A7E33.3060101@fusionio.com> Date: Thu, 5 Aug 2010 11:02:43 +0200 From: Jens Axboe MIME-Version: 1.0 To: Tejun Heo CC: "Rafael J. Wysocki" , Linux Kernel Mailing List , Maciej Rutecki , Andrew Morton , Kernel Testers List , Network Development , Linux ACPI , Linux PM List , Linux SCSI List , Linux Wireless List , DRI , Linus Torvalds , "stable@kernel.org" Subject: Re: [PATCH RESEND block#for-2.6.36] block_dev: always serialize exclusive open attempts References: <2dWFdr9kTFM.A.P0D.spXVMB@chimera> <4C56F30D.3020304@kernel.org> <4C598E6B.7050405@gmail.com> In-Reply-To: <4C598E6B.7050405@gmail.com> Content-Type: text/plain; charset="ISO-8859-1" Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2010-08-04 17:59, Tejun Heo wrote: > bd_prepare_to_claim() incorrectly allowed multiple attempts for > exclusive open to progress in parallel if the attempting holders are > identical. This triggered BUG_ON() as reported in the following bug. > > https://bugzilla.kernel.org/show_bug.cgi?id=16393 > > __bd_abort_claiming() is used to finish claiming blocks and doesn't > work if multiple openers are inside a claiming block. Allowing > multiple parallel open attempts to continue doesn't gain anything as > those are serialized down in the call chain anyway. Fix it by always > allowing only single open attempt in a claiming block. > > This problem can easily be reproduced by adding a delay after > bd_prepare_to_claim() and attempting to mount two partitions of a > disk. > > stable: only applicable to v2.6.35 > > Signed-off-by: Tejun Heo > Reported-by: Markus Trippelsdorf > Cc: stable@kernel.org Thanks Tejun, applied. -- Jens Axboe Confidentiality Notice: This e-mail message, its contents and any attachments to it are confidential to the intended recipient, and may contain information that is privileged and/or exempt from disclosure under applicable law. If you are not the intended recipient, please immediately notify the sender and destroy the original e-mail message and any attachments (and any copies that may have been made) from your system or otherwise. Any unauthorized use, copying, disclosure or distribution of this information is strictly prohibited.