From: Andrey Vagin <ava...@openvz.org>
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" <da...@davemloft.net>
Cc: Eric W. Biederman <ebied...@xmission.com>
Signed-off-by: Andrei Vagin <ava...@openvz.org>
---
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
