From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752837Ab0G0Uof (ORCPT ); Tue, 27 Jul 2010 16:44:35 -0400 Received: from cantor2.suse.de ([195.135.220.15]:37103 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752699Ab0G0Uod (ORCPT ); Tue, 27 Jul 2010 16:44:33 -0400 Date: Tue, 27 Jul 2010 22:44:07 +0200 From: Jan Kara To: Christoph Hellwig Cc: Jan Kara , LKML , Andrew Morton Subject: Re: [PATCH 1/3] bdi: Use parent filesystem BDI for inodes not capable of writeback Message-ID: <20100727204407.GH6820@quack.suse.cz> References: <1280250301-17603-1-git-send-email-jack@suse.cz> <1280250301-17603-2-git-send-email-jack@suse.cz> <20100727170903.GA9034@infradead.org> <20100727172437.GE6820@quack.suse.cz> <20100727172731.GA25727@infradead.org> <20100727180131.GG6820@quack.suse.cz> <20100727201207.GA16335@infradead.org> <20100727202129.GA28641@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100727202129.GA28641@infradead.org> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 27-07-10 16:21:29, Christoph Hellwig wrote: > On Tue, Jul 27, 2010 at 04:12:07PM -0400, Christoph Hellwig wrote: > > On Tue, Jul 27, 2010 at 08:01:31PM +0200, Jan Kara wrote: > > > > It shouldn't. Block device nodes are on the bdev filesystems, and > > > Ok, so inode->i_sb->s_bdi will actually point to noop_backing_dev_info > > > as set by set_anon_super(). Or am I completely out? > > > > I think you're right. This seems rather bad if it's indeed true. I'll > > quickly verify it using Dave's new tracing once I've built a block > > tree kernel. > > Indeed it does. So using ->s_bdi actually is wrong for the block > device node, given that it does set up the bdevfs inode's > backing_dev_info to the proper one, but can't actually do it for > the per-sb one. Yes. So what I do in inode_to_bdi() is necessary (although I agree it looks a bit ugly). Honza -- Jan Kara SUSE Labs, CR