From mboxrd@z Thu Jan 1 00:00:00 1970 From: OGAWA Hirofumi Subject: Re: Regression in suspend to ram in 2.6.31-rc kernels Date: Wed, 09 Sep 2009 22:52:26 +0900 Message-ID: <87hbvc5ip1.fsf@devron.myhome.or.jp> References: <200908312119.12121.rjw@sisk.pl> <20090903232317.GA6760@lst.de> <87ljkvmt71.fsf@devron.myhome.or.jp> <20090908190614.GA18545@lst.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.parknet.ad.jp ([210.171.162.6]:40129 "EHLO mail.officemail.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752484AbZIINw0 (ORCPT ); Wed, 9 Sep 2009 09:52:26 -0400 In-Reply-To: <20090908190614.GA18545@lst.de> (Christoph Hellwig's message of "Tue, 8 Sep 2009 21:06:14 +0200") Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Christoph Hellwig Cc: Zdenek Kabelac , "Rafael J. Wysocki" , Linux Kernel Mailing List , linux-mmc@vger.kernel.org, viro@zeniv.linux.org.uk Christoph Hellwig writes: > On Fri, Sep 04, 2009 at 09:47:46AM +0900, OGAWA Hirofumi wrote: >> Well, that commit seems a bit strange. It calls fat_clusters_flush() >> unconditionally without checking sb->s_dirt. However, if my guess is >> right, "sync after removed event" itself sounds like the issue in >> suspend process. > > The idea of ->sync_fs is that we always perform the sync activity, > and not just the usual background superblock writeback trigerred by > s_dirt. If FAT doesn't need that and never has races around s_dirt > you can add the check back, but I would recommend against it. I'm not sure the detail of your idea of ->sync_fs. "always perform" is not the goal of it, right? Anyway, we should consider about unnecessary write reduces the lifetime of flash base device. And what races of s_dirt? ("always perform" fixed those? and why we gave up to fix the real problems or root-casue?) Maybe, I already noticed one of those, but I may not be noticing all of those. If you can explain the detail of those known problems, I appreciate and would be useful. And write_super() of FAT doesn't affect to fs consistency, it's one of reasons why I moved it to write_super(). Thanks. -- OGAWA Hirofumi