From: Surbhi Palande Subject: Re: [RFC][PATCH] Re: [BUG] ext4: cannot unfreeze a filesystem due to a deadlock Date: Mon, 02 May 2011 16:27:39 +0300 Message-ID: <4DBEB14B.70208@ubuntu.com> References: <20110406054005.GD31057@dastard> <20110406061856.GC23285@quack.suse.cz> <20110406112135.GE31057@dastard> <4DBE746F.3090707@ubuntu.com> <20110502105629.GA4556@quack.suse.cz> <4DBE9537.4050708@ubuntu.com> <20110502122055.GB5855@quack.suse.cz> <4DBEA3DF.1060306@ubuntu.com> <20110502131619.GC5855@quack.suse.cz> <4DBEB025.90704@ubuntu.com> <20110502132449.GB7708@infradead.org> Reply-To: surbhi.palande@ubuntu.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Jan Kara , Dave Chinner , Toshiyuki Okajima , Ted Ts'o , Masayoshi MIZUMA , Andreas Dilger , linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org To: Christoph Hellwig Return-path: Received: from adelie.canonical.com ([91.189.90.139]:48376 "EHLO adelie.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757606Ab1EBN1t (ORCPT ); Mon, 2 May 2011 09:27:49 -0400 In-Reply-To: <20110502132449.GB7708@infradead.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 05/02/2011 04:24 PM, Christoph Hellwig wrote: > On Mon, May 02, 2011 at 04:22:45PM +0300, Surbhi Palande wrote: >> This has another advantage, that it rightfully does not let you >> update the access time when the F.S is frozen (touch_atime called >> from a read path when the F.S is frozen) Otherwise we also need to >> fix this path. > In most filesystens atime updates aren't transactional. They just > get written into inode->i_atime, and at some later point when the > VFS tries to clean the inode it gets writtent back, either through > a transaction or not. > Yes, agreed. But then when a F.S is frozen the inode should not be dirtied? Right? So this has to be fixed? Also, in ext4, I think that updating atime starts a transaction. Warm Regards, Surbhi