From patchwork Mon Mar 12 12:59:41 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Kinsbursky X-Patchwork-Id: 146097 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id B046FB6EE8 for ; Mon, 12 Mar 2012 23:59:58 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755214Ab2CLM75 (ORCPT ); Mon, 12 Mar 2012 08:59:57 -0400 Received: from mailhub.sw.ru ([195.214.232.25]:23283 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753793Ab2CLM74 (ORCPT ); Mon, 12 Mar 2012 08:59:56 -0400 Received: from localhost6.localdomain6 ([10.30.20.35]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id q2CCxgJE002890; Mon, 12 Mar 2012 16:59:43 +0400 (MSK) Subject: [PATCH v3] tun: don't hold network namespace by tun sockets To: davem@davemloft.net From: Stanislav Kinsbursky Cc: xemul@parallels.com, ebiederm@aristanetworks.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, shemminger@vyatta.com, devel@openvz.org Date: Mon, 12 Mar 2012 16:59:41 +0400 Message-ID: <20120312125833.24166.72610.stgit@localhost6.localdomain6> User-Agent: StGit/0.15 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org v3: added previously removed sock_put() to the tun_release() callback, because sk_release_kernel() doesn't drop the socket reference. v2: sk_release_kernel() used for socket release. Dummy tun_release() is required for sk_release_kernel() ---> sock_release() ---> sock->ops->release() call. TUN was designed to destroy it's socket on network namesapce shutdown. But this will never happen for persistent device, because it's socket holds network namespace. This patch removes of holding network namespace by TUN socket and replaces it by creating socket in init_net and then changing it's net it to desired one. On shutdown socket is moved back to init_net prior to final put. Signed-off-by: Stanislav Kinsbursky --- drivers/net/tun.c | 15 ++++++++++++--- 1 files changed, 12 insertions(+), 3 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 2c5d349..74d7f76 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -359,7 +359,7 @@ static void tun_free_netdev(struct net_device *dev) { struct tun_struct *tun = netdev_priv(dev); - sock_put(tun->socket.sk); + sk_release_kernel(tun->socket.sk); } /* Net device open. */ @@ -980,10 +980,18 @@ static int tun_recvmsg(struct kiocb *iocb, struct socket *sock, return ret; } +static int tun_release(struct socket *sock) +{ + if (sock->sk) + sock_put(sock->sk); + return 0; +} + /* Ops structure to mimic raw sockets with tun */ static const struct proto_ops tun_socket_ops = { .sendmsg = tun_sendmsg, .recvmsg = tun_recvmsg, + .release = tun_release, }; static struct proto tun_proto = { @@ -1110,10 +1118,11 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) tun->vnet_hdr_sz = sizeof(struct virtio_net_hdr); err = -ENOMEM; - sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto); + sk = sk_alloc(&init_net, AF_UNSPEC, GFP_KERNEL, &tun_proto); if (!sk) goto err_free_dev; + sk_change_net(sk, net); tun->socket.wq = &tun->wq; init_waitqueue_head(&tun->wq.wait); tun->socket.ops = &tun_socket_ops; @@ -1174,7 +1183,7 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) return 0; err_free_sk: - sock_put(sk); + tun_free_netdev(dev); err_free_dev: free_netdev(dev); failed: