Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:59390 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1750708Ab0HRDSl (ORCPT ); Tue, 17 Aug 2010 23:18:41 -0400 Message-ID: <4C6B50B3.4090403@cn.fujitsu.com> Date: Wed, 18 Aug 2010 11:17:07 +0800 From: Bian Naimeng To: Trond Myklebust CC: linux-nfs@vger.kernel.org Subject: Re: [PATCH 2/2] We should clear NFS_DELEGATED_STATE after return delegation References: <4C592F85.8070308@cn.fujitsu.com> <4C59306A.9090302@cn.fujitsu.com> <1280925913.3011.23.camel@heimdal.trondhjem.org> <4C5A213F.9000506@cn.fujitsu.com> <1281013423.2948.1.camel@heimdal.trondhjem.org> <4C5B8B48.4050008@cn.fujitsu.com> <1281101448.3586.11.camel@heimdal.trondhjem.org> <4C68EDAE.5000201@cn.fujitsu.com> <1282087012.18385.30.camel@heimdal.trondhjem.org> In-Reply-To: <1282087012.18385.30.camel@heimdal.trondhjem.org> Content-Type: text/plain; charset=Shift_JIS Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 >>> I still don't see why this should be necessary. In the case of a server >>> reboot or network partition, the state recovery thread ought to be >>> taking care of this for us. >>> >> A open state can be found at nfsi->open_states and owner->so_states always, but >> it not be found at nfsi->open_files until we call nfs4_intent_set_file. >> >> At _nfs4_do_open, we will invoke nfs4_return_incompatible_delegation to return a >> delegation, a open stateid which set NFS_DELEGATED_STATE bit may not be found at >> nfsi->open_files, but it still at nfsi->open_states, so we do not clear >> NFS_DELEGATED_STATE bit for it. >> >> Then _nfs4_do_open will find it by nfs4_get_open_state, and we still use it >> as a delegation, some error will occur. >> > > OK. I see agree that is a race, but AFAICS, your fix means that we end > up with an nfs_state structure that has cleared NFS_DELEGATED_STATE, but > that did not recover its open stateid. > Hi trond, i am not sure my opinion is right. If the state not at nfsi->open_states, i think maybe that means it's not a open stateid, it just a old state we want reuse it. After we update it, it become a open stateid. -- Regards Bian Naimeng