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 q0DKox3F160083 for ; Fri, 13 Jan 2012 14:51:00 -0600 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by cuda.sgi.com with ESMTP id fhB6SKirgHcHB876 for ; Fri, 13 Jan 2012 12:50:58 -0800 (PST) Received: from /spool/local by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 13 Jan 2012 13:50:58 -0700 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay03.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q0DKosoN158196 for ; Fri, 13 Jan 2012 13:50:54 -0700 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q0DKosBW019530 for ; Fri, 13 Jan 2012 13:50:54 -0700 Message-ID: <4F10992C.3070303@linux.vnet.ibm.com> Date: Fri, 13 Jan 2012 13:50:52 -0700 From: Allison Henderson MIME-Version: 1.0 Subject: Re: working on extent locks for i_mutex References: <4F0F9E97.1090403@linux.vnet.ibm.com> <20120113043411.GH2806@dastard> In-Reply-To: <20120113043411.GH2806@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: Lukas Czerner , Ext4 Developers List , xfs@oss.sgi.com On 01/12/2012 09:34 PM, Dave Chinner wrote: > 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. Yes that is generally the idea I was thinking about doing, but at the time, I was not thinking outside the scope of ext4. You are thinking maybe it should be in vfs layer so that it's something that all the filesystems will use? That seems to be the impression I'm getting from folks. Thx! Allison Henderson _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs