From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 2/4] Assign bdi in super_block Date: Fri, 11 Sep 2009 20:12:27 +0200 Message-ID: <20090911181227.GM14984@kernel.dk> References: <1252669832-13553-1-git-send-email-jens.axboe@oracle.com> <1252669832-13553-3-git-send-email-jens.axboe@oracle.com> <20090911180106.GB19598@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, chris.mason@oracle.com, tytso@mit.edu, akpm@linux-foundation.org, jack@suse.cz, trond.myklebust@fys.uio.no To: Christoph Hellwig Return-path: Received: from brick.kernel.dk ([93.163.65.50]:33008 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753940AbZIKSMY (ORCPT ); Fri, 11 Sep 2009 14:12:24 -0400 Content-Disposition: inline In-Reply-To: <20090911180106.GB19598@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Sep 11 2009, Christoph Hellwig wrote: > On Fri, Sep 11, 2009 at 01:50:30PM +0200, Jens Axboe wrote: > > We do this automatically in get_sb_bdev() from the set_bdev_super() > > callback. Filesystems that have their own private backing_dev_info > > must assign that in ->fill_super(). > > > > Note that ->s_bdi assignment is required for proper writeback! > > Looks good to me. Can we get rid of BDI_CAP_NO_WRITEBACK with this by > simply not assigning a bdi? Good question, I was indeed looking for an sb equivalent of that bdi flag. And now ->s_bdi being set or not is indeed that. Some of our generated writeback originates at the bdi level though, so we may or may not have the sb. From a quick look at fs-writeback.c, it looks feasible though. I'll try. Can I take that as an acked-by? -- Jens Axboe