From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Wed, 27 Aug 2008 17:18:50 -0700 (PDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m7S0IlFi030182 for ; Wed, 27 Aug 2008 17:18:48 -0700 Received: from ipmail01.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 856DDFD1021 for ; Wed, 27 Aug 2008 17:20:10 -0700 (PDT) Received: from ipmail01.adl6.internode.on.net (ipmail01.adl6.internode.on.net [203.16.214.146]) by cuda.sgi.com with ESMTP id qEwHBiyCHw0DwnpZ for ; Wed, 27 Aug 2008 17:20:10 -0700 (PDT) Date: Thu, 28 Aug 2008 10:20:05 +1000 From: Dave Chinner Subject: Re: XFS issue under 2.6.25.13 kernel Message-ID: <20080828002005.GA30189@disturbed> References: <50ed5c760808220303p37e03e8dge5b868a572374e0b@mail.gmail.com> <20080823010524.GM5706@disturbed> <50ed5c760808250408o44aeaf07me262eab8da8340ba@mail.gmail.com> <20080826014133.GS5706@disturbed> <50ed5c760808260553i7def5e93qb0bcb4d2206a4a38@mail.gmail.com> <20080827005243.GB5706@disturbed> <50ed5c760808271109u4dee0311ha7cf2c1e7cae31dd@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <50ed5c760808271109u4dee0311ha7cf2c1e7cae31dd@mail.gmail.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: =?utf-8?B?U8WCYXdvbWly?= Nowakowski Cc: xfs@oss.sgi.com On Wed, Aug 27, 2008 at 08:09:18PM +0200, Sławomir Nowakowski wrote: > Dear Dave, > > We really apreciate your help.. > > In the realtion to previous correspondations about differences between > implementation of kernels 2.6.17.13 and 2.6.25.13 we'd like to ask > some questions. > > We was based on git repository: > > git://git.kernel.org > > We have reverted some changes for XFS in 2.6.25.13 kernel. We have > usedf 3 commits: > > - 94E1E99F11... (SGI-PV: 964468) > - 4BE536DEBE... (SGI-PV: 955674) > - 4CA488EB4... (SGI-PV: 971186) > > With these changes we have created patch for 2.6.25.13 kernel. This > patch should eliminate additional reservation of disk space in XFS > file system. Our intention was to get similarity space of disk between > 2.6.17.13 and 2.6.25.13 kernels. After removing the reservation with xfs_io (the big difference), I don't see why you need to hack the kernel as well. Have you got such little margin in your filesystem provisioning that you can't spare 4 blocks per AG? > Does patch that is attached to this mail do everything properly? Don't know. You've taken away a bunch of reserved blocks other code relies on existing for correct operation at ENOSPC. Given that you are doing this because you are running so close to ENOSPC there's a good chance that you've broken something. I don't have the time (or the desire) to analyse the impact of the changes being made, but I bet that the XFSQA tests that exercise behaviour at ENOSPC will start to deadlock again... > Is it > 100% compatibe with XFS API? You've changed statfs. You'll have to make sure it reports the correct thing in all cases (there's an XFSQA test for this). Cheers, Dave. -- Dave Chinner david@fromorbit.com