From patchwork Tue Oct 11 22:14:20 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 9371831 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BAA876048F for ; Tue, 11 Oct 2016 22:33:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9649E29106 for ; Tue, 11 Oct 2016 22:33:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8AB1D29108; Tue, 11 Oct 2016 22:33:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_TVD_MIME_EPI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7BCB729103 for ; Tue, 11 Oct 2016 22:33:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754592AbcJKWdq (ORCPT ); Tue, 11 Oct 2016 18:33:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:60530 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754589AbcJKWdp (ORCPT ); Tue, 11 Oct 2016 18:33:45 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 145E7AC74; Tue, 11 Oct 2016 22:14:27 +0000 (UTC) From: NeilBrown To: Trond Myklebust Date: Wed, 12 Oct 2016 09:14:20 +1100 Cc: Schumaker Anna , List Linux NFS Mailing Subject: Re: [PATCH] NFS: Don't disconnect open-owner on NFS4ERR_BAD_SEQID In-Reply-To: References: <87y46monel.fsf@notabene.neil.brown.name> <87bmyx3q3u.fsf@notabene.neil.brown.name> User-Agent: Notmuch/0.22.1 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-suse-linux-gnu) Message-ID: <8737k2354z.fsf@notabene.neil.brown.name> MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Sat, Oct 08 2016, Trond Myklebust wrote: >> + set_bit(NFS_OWNER_STALE, &sp->so_flags); >> + /* Delegation recall might insist on using this open_owner >> + * so reset it to force a new 'confirm' stage to be initiated. >> + */ >> + sp->so_seqid.create_time = ktime_get(); > > Hmm…. If you’re going to do this, then why mark the state_owner as stale at all? Why not just reset sp->so_seqid.flags and call nfs4_clear_open_state() to let the state recovery try to do what it can. Good point ... I was too focused on how I got there and what I had tested... I cannot test this properly as I don't have a server that returned BAD_SEQID, and I doubt I can convince the customer to test some new as they have something that works, but I think this is correct. Thanks, NeilBrown From: NeilBrown Date: Fri, 3 Jun 2016 14:58:02 +1000 Subject: [PATCH] NFS: Don't disconnect open-owner on NFS4ERR_BAD_SEQID When an NFS4ERR_BAD_SEQID is received the open-owner is removed from the ->state_owners rbtree so that it will no longer be used. If any stateids attached to this open-owner are still in use, and if a request using one gets an NFS4ERR_BAD_STATEID reply, this can for bad. The state is marked as needing recovery and the nfs4_state_manager() is scheduled to clean up. nfs4_state_manager() finds states to be recovered by walking the state_owners rbtree. As the open-owner is not in the rbtree, the bad state is not found so nfs4_state_manager() completes having done nothing. The request is then retried, with a predicatable result (indefinite retries). If the stateid is for a delegation, this open_owner will be used to open files when the delegation is returned. For that to work, a new open-owner needs to be presented to the server. This patch changes NFS4ERR_BAD_SEQID handling to leave the open-owner in the rbtree but updates the 'create_time' so it looks like a new open-owner. With this the indefinite retries no longer happen. Signed-off-by: NeilBrown --- fs/nfs/nfs4state.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 74cc32490c7a..c4d721ed493d 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -496,19 +496,10 @@ nfs4_alloc_state_owner(struct nfs_server *server, static void nfs4_drop_state_owner(struct nfs4_state_owner *sp) { - struct rb_node *rb_node = &sp->so_server_node; - - if (!RB_EMPTY_NODE(rb_node)) { - struct nfs_server *server = sp->so_server; - struct nfs_client *clp = server->nfs_client; - - spin_lock(&clp->cl_lock); - if (!RB_EMPTY_NODE(rb_node)) { - rb_erase(rb_node, &server->state_owners); - RB_CLEAR_NODE(rb_node); - } - spin_unlock(&clp->cl_lock); - } + /* Delegation recall might insist on using this open_owner + * so reset it to force a new 'confirm' stage to be initiated. + */ + sp->so_seqid.create_time = ktime_get(); } static void nfs4_free_state_owner(struct nfs4_state_owner *sp)