From: OGAWA Hirofumi Subject: Re: [PATCHSET v3.1 0/7] data integrity: Stabilize pages during writeback for various fses Date: Wed, 11 May 2011 05:50:07 +0900 Message-ID: <87liyep9fk.fsf@devron.myhome.or.jp> References: <20110509230318.19566.66202.stgit@elm3c44.beaverton.ibm.com> <87tyd31fkc.fsf@devron.myhome.or.jp> <20110510133603.GA5823@infradead.org> <874o524q9h.fsf@devron.myhome.or.jp> <20110510144939.GI4402@quack.suse.cz> <87aaeur31x.fsf@devron.myhome.or.jp> <20110510170339.GA27538@infradead.org> Mime-Version: 1.0 Content-Type: text/plain Cc: Jan Kara , "Darrick J. Wong" , Theodore Tso , Alexander Viro , Jens Axboe , "Martin K. Petersen" , Jeff Layton , Dave Chinner , linux-kernel , Dave Hansen , linux-mm@kvack.org, Chris Mason , Joel Becker , linux-scsi , linux-fsdevel , linux-ext4@vger.kernel.org, Mingming Cao To: Christoph Hellwig Return-path: Received: from mail.parknet.co.jp ([210.171.160.6]:45228 "EHLO mail.parknet.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750707Ab1EJUuR (ORCPT ); Tue, 10 May 2011 16:50:17 -0400 In-Reply-To: <20110510170339.GA27538@infradead.org> (Christoph Hellwig's message of "Tue, 10 May 2011 13:03:39 -0400") Sender: linux-ext4-owner@vger.kernel.org List-ID: Christoph Hellwig writes: > On Wed, May 11, 2011 at 12:24:58AM +0900, OGAWA Hirofumi wrote: >> > under writeback and when it's freed no writeback is started. >> >> Sure for data -> data reallocated case. metadata -> data/metadata is >> still there. > > That's usually handled differently. For XFS take a look at the > xfs_alloc_busy_* function. For 2.6.40 they've been mostly rewritten > to rarely wait for the reuse but instead avoid busy blocks. But that's > a real data integrity issue even without stable pages for I/O. Sounds good. So... Are you suggesting this series should use better approach than just blocking? Thanks. -- OGAWA Hirofumi