From patchwork Tue Jan 11 16:21:23 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bruce Fields X-Patchwork-Id: 471951 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter1.kernel.org (8.14.4/8.14.3) with ESMTP id p0BGM6gl030575 for ; Tue, 11 Jan 2011 16:22:08 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932366Ab1AKQVo (ORCPT ); Tue, 11 Jan 2011 11:21:44 -0500 Received: from fieldses.org ([174.143.236.118]:56180 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932357Ab1AKQVm (ORCPT ); Tue, 11 Jan 2011 11:21:42 -0500 Received: from bfields by fieldses.org with local (Exim 4.72) (envelope-from ) id 1Pcgyb-0005dk-S4; Tue, 11 Jan 2011 11:21:41 -0500 From: "J. Bruce Fields" To: linux-nfs@vger.kernel.org Cc: "J. Bruce Fields" Subject: [PATCH 03/14] nfsd4: allow backchannel recovery Date: Tue, 11 Jan 2011 11:21:23 -0500 Message-Id: <1294762894-21371-4-git-send-email-bfields@redhat.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1294762894-21371-1-git-send-email-bfields@redhat.com> References: <1294762894-21371-1-git-send-email-bfields@redhat.com> Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Tue, 11 Jan 2011 16:22:08 +0000 (UTC) diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index dd183af..18b740b 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -473,8 +473,7 @@ static int max_cb_time(void) /* Reference counting, callback cleanup, etc., all look racy as heck. * And why is cl_cb_set an atomic? */ -static int setup_callback_client(struct nfs4_client *clp, - struct nfs4_cb_conn *conn) +static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses) { struct rpc_timeout timeparms = { .to_initval = max_cb_time(), @@ -501,6 +500,10 @@ static int setup_callback_client(struct nfs4_client *clp, args.protocol = XPRT_TRANSPORT_TCP; clp->cl_cb_ident = conn->cb_ident; } else { + if (!conn->cb_xprt) + return -EINVAL; + clp->cl_cb_conn.cb_xprt = conn->cb_xprt; + clp->cl_cb_session = ses; args.bc_xprt = conn->cb_xprt; args.prognumber = clp->cl_cb_session->se_cb_prog; args.protocol = XPRT_TRANSPORT_BC_TCP; @@ -756,10 +759,27 @@ static void nfsd4_release_cb(struct nfsd4_callback *cb) cb->cb_ops->rpc_release(cb); } +/* requires cl_lock: */ +static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp) +{ + struct nfsd4_session *s; + struct nfsd4_conn *c; + + list_for_each_entry(s, &clp->cl_sessions, se_perclnt) { + list_for_each_entry(c, &s->se_conns, cn_persession) { + if (c->cn_flags & NFS4_CDFC4_BACK) + return c; + } + } + return NULL; +} + static void nfsd4_process_cb_update(struct nfsd4_callback *cb) { struct nfs4_cb_conn conn; struct nfs4_client *clp = cb->cb_clp; + struct nfsd4_session *ses = NULL; + struct nfsd4_conn *c; int err; /* @@ -770,6 +790,10 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) rpc_shutdown_client(clp->cl_cb_client); clp->cl_cb_client = NULL; } + if (clp->cl_cb_conn.cb_xprt) { + svc_xprt_put(clp->cl_cb_conn.cb_xprt); + clp->cl_cb_conn.cb_xprt = NULL; + } if (test_bit(NFSD4_CLIENT_KILL, &clp->cl_cb_flags)) return; spin_lock(&clp->cl_lock); @@ -780,9 +804,15 @@ static void nfsd4_process_cb_update(struct nfsd4_callback *cb) BUG_ON(!clp->cl_cb_flags); clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_cb_flags); memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn)); + c = __nfsd4_find_backchannel(clp); + if (c) { + svc_xprt_get(c->cn_xprt); + conn.cb_xprt = c->cn_xprt; + ses = c->cn_session; + } spin_unlock(&clp->cl_lock); - err = setup_callback_client(clp, &conn); + err = setup_callback_client(clp, &conn, ses); if (err) warn_no_callback_path(clp, err); } diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index 956174f..290370b 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -642,6 +642,7 @@ static void nfsd4_conn_lost(struct svc_xpt_user *u) free_conn(c); } spin_unlock(&clp->cl_lock); + /* XXX: mark callback for update, probe callback */ } static struct nfsd4_conn *alloc_conn(struct svc_rqst *rqstp, u32 flags) @@ -790,16 +791,19 @@ static struct nfsd4_session *alloc_init_session(struct svc_rqst *rqstp, struct n free_session(&new->se_ref); return NULL; } - if (!clp->cl_cb_session && (cses->flags & SESSION4_BACK_CHAN)) { + if (cses->flags & SESSION4_BACK_CHAN) { struct sockaddr *sa = svc_addr(rqstp); - - clp->cl_cb_session = new; - clp->cl_cb_conn.cb_xprt = rqstp->rq_xprt; - svc_xprt_get(rqstp->rq_xprt); + /* + * This is a little silly; with sessions there's no real + * use for the callback address. Use the peer address + * as a reasonable default for now, but consider fixing + * the rpc client not to require an address in the + * future: + */ rpc_copy_addr((struct sockaddr *)&clp->cl_cb_conn.cb_addr, sa); clp->cl_cb_conn.cb_addrlen = svc_addr_len(sa); - nfsd4_probe_callback(clp); } + nfsd4_probe_callback(clp); return new; }