From patchwork Mon Dec 19 00:48:23 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 9479507 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 1EB1B60832 for ; Mon, 19 Dec 2016 00:48:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 04574283A6 for ; Mon, 19 Dec 2016 00:48:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DA7E8283E5; Mon, 19 Dec 2016 00:48:37 +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 4AB4E283A6 for ; Mon, 19 Dec 2016 00:48:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752833AbcLSAsg (ORCPT ); Sun, 18 Dec 2016 19:48:36 -0500 Received: from mx2.suse.de ([195.135.220.15]:51778 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750914AbcLSAsf (ORCPT ); Sun, 18 Dec 2016 19:48:35 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id A04CCABB0; Mon, 19 Dec 2016 00:48:33 +0000 (UTC) From: NeilBrown To: Trond Myklebust Date: Mon, 19 Dec 2016 11:48:23 +1100 Cc: Schumaker Anna , List Linux NFS Mailing Subject: [PATCH resend] NFS: Don't disconnect open-owner on NFS4ERR_BAD_SEQID In-Reply-To: <8737k2354z.fsf@notabene.neil.brown.name> References: <87y46monel.fsf@notabene.neil.brown.name> <87bmyx3q3u.fsf@notabene.neil.brown.name> <8737k2354z.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: <87zijsu4ko.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 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 --- Hi Trond, It appears this one got lost too. I've added a comment as I thought an explanation was needed, and renamed the function from "drop" to "reset". Thanks, NeilBrown fs/nfs/nfs4state.c | 29 +++++++++++++---------------- 1 file changed, 13 insertions(+), 16 deletions(-) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index cf869802ff23..1d152f4470cd 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -494,21 +494,18 @@ 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); - } +nfs4_reset_state_owner(struct nfs4_state_owner *sp) +{ + /* This state_owner is no longer usable, but must + * remain in place so that state recovery can find it + * and the opens associated with it. + * It may also be used for new 'open' request to + * return a delegation to the server. + * So update the 'create_time' so that it looks like + * a new state_owner. This will cause the server to + * request an OPEN_CONFIRM to start a new sequence. + */ + sp->so_seqid.create_time = ktime_get(); } static void nfs4_free_state_owner(struct nfs4_state_owner *sp) @@ -1113,7 +1110,7 @@ void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid) sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid); if (status == -NFS4ERR_BAD_SEQID) - nfs4_drop_state_owner(sp); + nfs4_reset_state_owner(sp); if (!nfs4_has_session(sp->so_server->nfs_client)) nfs_increment_seqid(status, seqid); }