From: Tejun Heo Subject: Re: [PATCH 1/3] block: Create sysfs knobs to override FLUSH/FUA support flags Date: Wed, 26 Jan 2011 10:30:51 +0100 Message-ID: <20110126093051.GA12520@htj.dyndns.org> References: <20110126071200.GE32261@tux1.beaverton.ibm.com> <20110126071626.GI27190@tux1.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Vivek Goyal , axboe@kernel.dk, tytso@mit.edu, shli@kernel.org, neilb@suse.de, adilger.kernel@dilger.ca, jack@suse.cz, snitzer@redhat.com, linux-kernel@vger.kernel.org, kmannth@us.ibm.com, cmm@us.ibm.com, linux-ext4@vger.kernel.org, rwheeler@redhat.com, hch@lst.de, josef@redhat.com To: "Darrick J. Wong" Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:50759 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751039Ab1AZJa5 (ORCPT ); Wed, 26 Jan 2011 04:30:57 -0500 Content-Disposition: inline In-Reply-To: <20110126071626.GI27190@tux1.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jan 25, 2011 at 11:16:26PM -0800, Darrick J. Wong wrote: > This patch is the first in a series to refactor the barrier= mount options out > of the filesystem code. This patch adds sysfs knobs to disable flush and FUA; > of course, the automatic default is the safe choice, i.e. to leave them > enabled. Obviously, only a seasoned administrator should ever be overriding > the defaults. Hmmm... wouldn't it be better to just export flush and fua instead of ignore_*? So that the admin can turn things on and off as [s]he seems fit? Also, it might be better to export them in a single attribute, say cache_control or something. Only subset of the combinations make sense anyway - none, flush, flush_fua. Thanks. -- tejun