Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:52280 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754598Ab0IIB3x (ORCPT ); Wed, 8 Sep 2010 21:29:53 -0400 Message-ID: <4C883883.7070803@cn.fujitsu.com> Date: Thu, 09 Sep 2010 09:29:39 +0800 From: Bian Naimeng To: Trond Myklebust CC: linux-nfs@vger.kernel.org, "J. Bruce Fields" 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> <4C7DF56B.3040206@cn.fujitsu.com> <1283897068.9097.15.camel@heimdal.trondhjem.org> <4C86E7FA.7020701@cn.fujitsu.com> <1283911036.16070.1.camel@heimdal.trondhjem.org> <4C86FECF.2050103@cn.fujitsu.com> <1283978245.2905.23.camel@heimdal.trondhjem.org> In-Reply-To: <1283978245.2905.23.camel@heimdal.trondhjem.org> Content-Type: text/plain; charset=Shift_JIS Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 >> index 089da5b..f7e45b4 100644 >> --- a/fs/nfs/nfs4proc.c >> +++ b/fs/nfs/nfs4proc.c >> @@ -919,8 +919,18 @@ static int update_open_stateid(struct nfs4_state *state, nfs4_stateid *open_stat >> >> rcu_read_lock(); >> deleg_cur = rcu_dereference(nfsi->delegation); >> - if (deleg_cur == NULL) >> + if (deleg_cur == NULL) { >> + if (delegation == NULL && open_stateid != NULL) { > > Well... What I really meant was that we should make sure that we don't > get into this situation. > Thanks very much for your explainning. > I think the clear_bit() should be unconditional if delegation == NULL, en..., i have a question. If the (deleg_cur == NULL && delegation == NULL) occured, that means there are not any delegation at this nfs_inode, i think this state do not need a NFS_DELEGATED_STATE bit anymore, is it right? > but if the (delegation == NULL && open_stateid == NULL) _can_ occur, > then we should probably mark the nfs4_state for recovery using > nfs4_state_mark_reclaim_nograce(), and then fire of a recovery thread. > It looks like that (delegation == NULL && open_stateid == NULL) can not occur at our kernel. And..., would you tell me why we must start recovery with using nfs4_state_mark_reclaim_nograce, are there any hint tell us that this state has expired ? -- Regards Bian Naimeng >> + /* >> + * FIXME: If the state has NFS_DELEGATED_STATE bit >> + * we catch a race. Maybe should recover its open >> + * stateid, now we just clear the NFS_DELEGATED_STATE >> + * bit. >> + */ >> + clear_bit(NFS_DELEGATED_STATE, &state->flags); >> + } >> goto no_delegation; >> + } >> >> spin_lock(&deleg_cur->lock); >> if (nfsi->delegation != deleg_cur || >> -- >> 1.7.0 -- Regards Bian Naimeng