From patchwork Wed Mar 7 16:25:17 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Kinsbursky X-Patchwork-Id: 145317 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 DC255B70B2 for ; Thu, 8 Mar 2012 03:26:17 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932396Ab2CGQ0Q (ORCPT ); Wed, 7 Mar 2012 11:26:16 -0500 Received: from mailhub.sw.ru ([195.214.232.25]:8632 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754569Ab2CGQ0O (ORCPT ); Wed, 7 Mar 2012 11:26:14 -0500 Received: from localhost6.localdomain6 ([10.30.20.35]) by relay.sw.ru (8.13.4/8.13.4) with ESMTP id q27GPeDx010413; Wed, 7 Mar 2012 20:25:41 +0400 (MSK) Subject: [PATCH v2] SUNRPC: set desired file system root before connecting local transports To: Trond.Myklebust@netapp.com From: Stanislav Kinsbursky Cc: bfields@fieldses.org, linux-nfs@vger.kernel.org, xemul@parallels.com, neilb@suse.de, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jbottomley@parallels.com, hch@infradead.org, viro@zeniv.linux.org.uk, davem@davemloft.net, devel@openvz.org Date: Wed, 07 Mar 2012 20:25:17 +0400 Message-ID: <20120307162359.6359.76479.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 v2: added Alexander Viro and Christoph Hellwig to recipience. Today, there is a problem in connecting of local SUNRPC thansports. These transports uses UNIX sockets and connection itself is done by rpciod workqueue. But UNIX sockets lookup is done in context of process file system root. I.e. all local thunsports are connecting in rpciod context. This works nice until we will try to mount NFS from process with other root - for example in container. This container can have it's own (nested) root and rcpbind process, listening on it's own unix sockets. But NFS mount attempt in this container will register new service (Lockd for example) in global rpcbind - not containers's one. This patch solves the problem by switching rpciod kernel thread's file system root to right one (stored on transport) while connecting of local transports. Signed-off-by: Stanislav Kinsbursky --- fs/fs_struct.c | 1 + net/sunrpc/xprtsock.c | 32 ++++++++++++++++++++++++++++++-- 2 files changed, 31 insertions(+), 2 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/fs/fs_struct.c b/fs/fs_struct.c index 78b519c..0f984c3 100644 --- a/fs/fs_struct.c +++ b/fs/fs_struct.c @@ -36,6 +36,7 @@ void set_fs_root(struct fs_struct *fs, struct path *path) if (old_root.dentry) path_put_longterm(&old_root); } +EXPORT_SYMBOL_GPL(set_fs_root); /* * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values. diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 4c8281d..c94c181 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -37,6 +37,7 @@ #include #include #include +#include #ifdef CONFIG_SUNRPC_BACKCHANNEL #include #endif @@ -255,6 +256,11 @@ struct sock_xprt { void (*old_state_change)(struct sock *); void (*old_write_space)(struct sock *); void (*old_error_report)(struct sock *); + + /* + * Saved transport creator root. Required for local transports only. + */ + struct path root; }; /* @@ -1891,6 +1897,7 @@ static void xs_local_setup_socket(struct work_struct *work) struct rpc_xprt *xprt = &transport->xprt; struct socket *sock; int status = -EIO; + struct path root; if (xprt->shutdown) goto out; @@ -1908,7 +1915,14 @@ static void xs_local_setup_socket(struct work_struct *work) dprintk("RPC: worker connecting xprt %p via AF_LOCAL to %s\n", xprt, xprt->address_strings[RPC_DISPLAY_ADDR]); + get_fs_root(current->fs, &root); + set_fs_root(current->fs, &transport->root); + status = xs_local_finish_connecting(xprt, sock); + + set_fs_root(current->fs, &root); + path_put(&root); + switch (status) { case 0: dprintk("RPC: xprt %p connected to %s\n", @@ -2213,6 +2227,18 @@ static void xs_connect(struct rpc_task *task) } } +static void xs_local_destroy(struct rpc_xprt *xprt) +{ + struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); + struct path root = transport->root; + + dprintk("RPC: xs_local_destroy xprt %p\n", xprt); + + xs_destroy(xprt); + + path_put(&root); +} + /** * xs_local_print_stats - display AF_LOCAL socket-specifc stats * @xprt: rpc_xprt struct containing statistics @@ -2431,7 +2457,7 @@ static struct rpc_xprt_ops xs_local_ops = { .send_request = xs_local_send_request, .set_retrans_timeout = xprt_set_retrans_timeout_def, .close = xs_close, - .destroy = xs_destroy, + .destroy = xs_local_destroy, .print_stats = xs_local_print_stats, }; @@ -2606,8 +2632,10 @@ static struct rpc_xprt *xs_setup_local(struct xprt_create *args) dprintk("RPC: set up xprt to %s via AF_LOCAL\n", xprt->address_strings[RPC_DISPLAY_ADDR]); - if (try_module_get(THIS_MODULE)) + if (try_module_get(THIS_MODULE)) { + get_fs_root(current->fs, &transport->root); return xprt; + } ret = ERR_PTR(-EINVAL); out_err: xprt_free(xprt);