[net-next,2/2] netlink: convert netlink tap spinlock to mutex

Message ID 20171206230320.22191-3-xiyou.wangcong@gmail.com
State Accepted
Delegated to: David Miller
Headers show
Series
  • netlink: improve netlink tap code
Related show

Commit Message

Cong Wang Dec. 6, 2017, 11:03 p.m.
Both netlink_add_tap() and netlink_remove_tap() are
called in process context, no need to bother spinlock.

Note, in fact, currently we always hold RTNL when calling
these two functions, so we don't need any other lock at
all, but keeping this lock doesn't harm anything.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 net/netlink/af_netlink.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Patch

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index de5324cc98d4..f6e6d2278fa9 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -176,7 +176,7 @@  static unsigned int netlink_tap_net_id;
 
 struct netlink_tap_net {
 	struct list_head netlink_tap_all;
-	spinlock_t netlink_tap_lock;
+	struct mutex netlink_tap_lock;
 };
 
 int netlink_add_tap(struct netlink_tap *nt)
@@ -187,9 +187,9 @@  int netlink_add_tap(struct netlink_tap *nt)
 	if (unlikely(nt->dev->type != ARPHRD_NETLINK))
 		return -EINVAL;
 
-	spin_lock(&nn->netlink_tap_lock);
+	mutex_lock(&nn->netlink_tap_lock);
 	list_add_rcu(&nt->list, &nn->netlink_tap_all);
-	spin_unlock(&nn->netlink_tap_lock);
+	mutex_unlock(&nn->netlink_tap_lock);
 
 	__module_get(nt->module);
 
@@ -204,7 +204,7 @@  static int __netlink_remove_tap(struct netlink_tap *nt)
 	bool found = false;
 	struct netlink_tap *tmp;
 
-	spin_lock(&nn->netlink_tap_lock);
+	mutex_lock(&nn->netlink_tap_lock);
 
 	list_for_each_entry(tmp, &nn->netlink_tap_all, list) {
 		if (nt == tmp) {
@@ -216,7 +216,7 @@  static int __netlink_remove_tap(struct netlink_tap *nt)
 
 	pr_warn("__netlink_remove_tap: %p not found\n", nt);
 out:
-	spin_unlock(&nn->netlink_tap_lock);
+	mutex_unlock(&nn->netlink_tap_lock);
 
 	if (found)
 		module_put(nt->module);
@@ -240,7 +240,7 @@  static __net_init int netlink_tap_init_net(struct net *net)
 	struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
 
 	INIT_LIST_HEAD(&nn->netlink_tap_all);
-	spin_lock_init(&nn->netlink_tap_lock);
+	mutex_init(&nn->netlink_tap_lock);
 	return 0;
 }