From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q0D4YFJ3069721 for ; Thu, 12 Jan 2012 22:34:16 -0600 Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net [150.101.137.129]) by cuda.sgi.com with ESMTP id XInSLlfHSctchxPs for ; Thu, 12 Jan 2012 20:34:14 -0800 (PST) Date: Fri, 13 Jan 2012 15:34:11 +1100 From: Dave Chinner Subject: Re: working on extent locks for i_mutex Message-ID: <20120113043411.GH2806@dastard> References: <4F0F9E97.1090403@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4F0F9E97.1090403@linux.vnet.ibm.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Allison Henderson Cc: Lukas Czerner , Ext4 Developers List , xfs@oss.sgi.com On Thu, Jan 12, 2012 at 08:01:43PM -0700, Allison Henderson wrote: > Hi All, > > I know this is an old topic, but I am poking it again because I've > had some work items wrap up, and Im planning on picking up on this > one again. I am thinking about implementing extent locks to replace > i_mutex. So I just wanted to touch base with folks and see what > people are working on because I know there were some folks out there > that were thing about doing similar solutions. What locking API are you looking at? If you are looking at an something like: read_range_{try}lock(lock, off, len) read_range_unlock(lock, off, len) write_range_{try}lock(lock, off, len) write_range_unlock(lock, off, len) and implementing with an rbtree or a btree for tracking, then I definitely have a use for it in XFS - replacing the current rwsem that is used for the iolock. Range locks like this are the only thing we need to allow concurrent buffered writes to the same file to maintain the per-write exclusion that posix requires. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs