From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrei Vagin Subject: [PATCH net-next] net: allow to kill a task which waits net_mutex in copy_new_ns Date: Thu, 20 Oct 2016 19:45:43 -0700 Message-ID: <1477017943-18786-1-git-send-email-avagin@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, "Eric W . Biederman" , Andrey Vagin , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "David S. Miller" Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: netdev.vger.kernel.org From: Andrey Vagin net_mutex can be locked for a long time. It may be because many namespaces are being destroyed or many processes decide to create a network namespace. Both these operations are heavy, so it is better to have an ability to kill a process which is waiting net_mutex. Cc: "David S. Miller" Cc: Eric W. Biederman Signed-off-by: Andrei Vagin --- net/core/net_namespace.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 989434f..b9243b1 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -379,7 +379,14 @@ struct net *copy_net_ns(unsigned long flags, get_user_ns(user_ns); - mutex_lock(&net_mutex); + rv = mutex_lock_killable(&net_mutex); + if (rv < 0) { + net_free(net); + dec_net_namespaces(ucounts); + put_user_ns(user_ns); + return ERR_PTR(rv); + } + net->ucounts = ucounts; rv = setup_net(net, user_ns); if (rv == 0) { -- 2.7.4