From mboxrd@z Thu Jan 1 00:00:00 1970 From: tytso@mit.edu Subject: Re: Updated ext4 quota design document Date: Tue, 22 Jun 2010 17:52:00 -0400 Message-ID: <20100622215200.GE6843@thunk.org> References: <20100622142047.GF3338@quack.suse.cz> <20100622200853.GD6843@thunk.org> <20100622202927.GA9413@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org To: Jan Kara Return-path: Received: from thunk.org ([69.25.196.29]:55223 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750938Ab0FVVwE (ORCPT ); Tue, 22 Jun 2010 17:52:04 -0400 Content-Disposition: inline In-Reply-To: <20100622202927.GA9413@quack.suse.cz> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Tue, Jun 22, 2010 at 10:29:27PM +0200, Jan Kara wrote: > With metadata which get journaled it should be quite easy. JBD already > must know before you go and modify buffer contents - that's why > journal_get_write_access and friends exist. It also makes sure that your > data cannot be modified from the moment the buffer enters commit upto the > moment the commit is finished. So you can use buffer commit hook to compute > and store block checksum safely. True, but we're also interested in making sure this feature can be used in the non-journal case as well.... - Ted