net: add uevent socket member

This commit adds struct uevent_sock to struct net. Since struct uevent_sock
records the position of the uevent socket in the uevent socket list we can
trivially remove it from the uevent socket list during cleanup. This speeds
up the old removal codepath.
Note, list_del() will hit __list_del_entry_valid() in its call chain which
will validate that the element is a member of the list. If it isn't it will
take care that the list is not modified.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 71abc8d791782f90513000d13dc6a7b098847e3c..09e30bdc78767cbf37472a5494839c44069bbb1e 100644 (file)
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -40,7 +40,7 @@ struct net_device;
 struct sock;
 struct ctl_table_header;
 struct net_generic;
-struct sock;
+struct uevent_sock;
 struct netns_ipvs;
 
 
@@ -83,6 +83,8 @@ struct net {
        struct sock             *rtnl;                  /* rtnetlink socket */
        struct sock             *genl_sock;
 
+       struct uevent_sock      *uevent_sock;           /* uevent socket */
+
        struct list_head        dev_base_head;
        struct hlist_head       *dev_name_head;
        struct hlist_head       *dev_index_head;

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 9539d7ab3ea85e86d3f5d4bc13f5191a37dc0c4e..54cfbaeb3a4ebdc3bc304441a934435453ef4b1e 100644 (file)
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -32,11 +32,13 @@ u64 uevent_seqnum;
 #ifdef CONFIG_UEVENT_HELPER
 char uevent_helper[UEVENT_HELPER_PATH_LEN] = CONFIG_UEVENT_HELPER_PATH;
 #endif
-#ifdef CONFIG_NET
+
 struct uevent_sock {
        struct list_head list;
        struct sock *sk;
 };
+
+#ifdef CONFIG_NET
 static LIST_HEAD(uevent_sock_list);
 #endif
 
@@ -621,6 +623,9 @@ static int uevent_net_init(struct net *net)
                kfree(ue_sk);
                return -ENODEV;
        }
+
+       net->uevent_sock = ue_sk;
+
        mutex_lock(&uevent_sock_mutex);
        list_add_tail(&ue_sk->list, &uevent_sock_list);
        mutex_unlock(&uevent_sock_mutex);
@@ -629,17 +634,9 @@ static int uevent_net_init(struct net *net)
 
 static void uevent_net_exit(struct net *net)
 {
-       struct uevent_sock *ue_sk;
+       struct uevent_sock *ue_sk = net->uevent_sock;
 
        mutex_lock(&uevent_sock_mutex);
-       list_for_each_entry(ue_sk, &uevent_sock_list, list) {
-               if (sock_net(ue_sk->sk) == net)
-                       goto found;
-       }
-       mutex_unlock(&uevent_sock_mutex);
-       return;
-
-found:
        list_del(&ue_sk->list);
        mutex_unlock(&uevent_sock_mutex);