From: Tejun Heo Subject: Re: [PATCH 3/3] ext4: Deprecate barrier= and nobarrier mount options Date: Wed, 26 Jan 2011 10:36:32 +0100 Message-ID: <20110126093632.GB12520@htj.dyndns.org> References: <20110126071200.GE32261@tux1.beaverton.ibm.com> <20110126072329.GK27190@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: Content-Disposition: inline In-Reply-To: <20110126072329.GK27190@tux1.beaverton.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Hello, On Tue, Jan 25, 2011 at 11:23:29PM -0800, Darrick J. Wong wrote: > As part of migrating the FLUSH/FUA knob to the block layer, remove the support > code for the barrier-related mount options and remove the conditionals around > flushes in favor of always issuing the flush. The block layer will handle > gracefully the situation where a FLUSH or FUA request is issued to a device > that doesn't support it. Modify the option parsing code to print a warning if > someone tries to use the old mount option. > > Note: The nobarrier bit in the default mount flags is now useless. The option is something which users are already quite familiar with. I think we'll just have to carry this around. What we can do, tho, is moving the actual control mechanism to block layer - ie. blkdev_skip_flush() or something like that which ignores flush requests for the current exclusive opener. Thanks. -- tejun