From patchwork Tue Jan 11 16:21:25 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bruce Fields X-Patchwork-Id: 471971 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 p0BGM6gn030575 for ; Tue, 11 Jan 2011 16:22:08 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932328Ab1AKQVp (ORCPT ); Tue, 11 Jan 2011 11:21:45 -0500 Received: from fieldses.org ([174.143.236.118]:56184 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932359Ab1AKQVn (ORCPT ); Tue, 11 Jan 2011 11:21:43 -0500 Received: from bfields by fieldses.org with local (Exim 4.72) (envelope-from ) id 1Pcgyc-0005du-LO; Tue, 11 Jan 2011 11:21:43 -0500 From: "J. Bruce Fields" To: linux-nfs@vger.kernel.org Cc: "J. Bruce Fields" Subject: [PATCH 05/14] rpc: keep backchannel xprt as long as server connection Date: Tue, 11 Jan 2011 11:21:25 -0500 Message-Id: <1294762894-21371-6-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/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 173f3b9..ab86b79 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -13,6 +13,7 @@ #include #include #include +#include #define RPCDBG_FACILITY RPCDBG_SVCXPRT @@ -128,6 +129,9 @@ static void svc_xprt_free(struct kref *kref) if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) svcauth_unix_info_release(xprt); put_net(xprt->xpt_net); + /* See comment on corresponding get in xs_setup_bc_tcp(): */ + if (xprt->xpt_bc_xprt) + xprt_put(xprt->xpt_bc_xprt); xprt->xpt_ops->xpo_free(xprt); module_put(owner); } diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 4c8f18a..749ad15 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -965,6 +965,7 @@ struct rpc_xprt *xprt_alloc(struct net *net, int size, int max_req) xprt = kzalloc(size, GFP_KERNEL); if (xprt == NULL) goto out; + kref_init(&xprt->kref); xprt->max_reqs = max_req; xprt->slot = kcalloc(max_req, sizeof(struct rpc_rqst), GFP_KERNEL); @@ -1102,7 +1103,6 @@ found: return xprt; } - kref_init(&xprt->kref); spin_lock_init(&xprt->transport_lock); spin_lock_init(&xprt->reserve_lock); diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 18dc42e..0ef4dd4 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2375,16 +2375,6 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args) xprt->reestablish_timeout = 0; xprt->idle_timeout = 0; - /* - * The backchannel uses the same socket connection as the - * forechannel - */ - args->bc_xprt->xpt_bc_xprt = xprt; - xprt->bc_xprt = args->bc_xprt; - bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt); - transport->sock = bc_sock->sk_sock; - transport->inet = bc_sock->sk_sk; - xprt->ops = &bc_tcp_ops; switch (addr->sa_family) { @@ -2407,6 +2397,29 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args) xprt->address_strings[RPC_DISPLAY_PROTO]); /* + * The backchannel uses the same socket connection as the + * forechannel + */ + if (args->bc_xprt->xpt_bc_xprt) { + /* XXX: actually, want to catch this case... */ + ret = ERR_PTR(-EINVAL); + goto out_err; + } + /* + * Once we've associated a backchannel xprt with a connection, + * we want to keep it around as long as long as the connection + * lasts, in case we need to start using it for a backchannel + * again; this reference won't be dropped until bc_xprt is + * destroyed. + */ + xprt_get(xprt); + args->bc_xprt->xpt_bc_xprt = xprt; + xprt->bc_xprt = args->bc_xprt; + bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt); + transport->sock = bc_sock->sk_sock; + transport->inet = bc_sock->sk_sk; + + /* * Since we don't want connections for the backchannel, we set * the xprt status to connected */ @@ -2415,6 +2428,7 @@ static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args) if (try_module_get(THIS_MODULE)) return xprt; + xprt_put(xprt); ret = ERR_PTR(-EINVAL); out_err: xprt_free(xprt);