diff mbox

batman-adv: Don't remove interface with spinlock held

Message ID 1290369268-9525-1-git-send-email-sven.eckelmann@gmx.de (mailing list archive)
State Accepted, archived
Headers

Commit Message

Sven Eckelmann Nov. 21, 2010, 7:54 p.m. UTC 
  We call a lot of the netdevice code when holding if_list_lock which will
spin the whole time. This is not necessary because we only want to
protect the access to the list to be serialized. An extra queue can be
used which hold all interfaces which should be removed and then use that
queue without any locks for netdevice cleanup.

Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
 batman-adv/hard-interface.c |   19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

Comments

Marek Lindner Nov. 21, 2010, 11:14 p.m. UTC | #1 
On Sunday 21 November 2010 20:54:28 Sven Eckelmann wrote:
> We call a lot of the netdevice code when holding if_list_lock which will
> spin the whole time. This is not necessary because we only want to
> protect the access to the list to be serialized. An extra queue can be
> used which hold all interfaces which should be removed and then use that
> queue without any locks for netdevice cleanup.

Applied in revision 1867.

Thanks,
Marek
diff mbox

Patch

diff --git a/batman-adv/hard-interface.c b/batman-adv/hard-interface.c
index e22f0dd..bf98b90 100644
--- a/batman-adv/hard-interface.c
+++ b/batman-adv/hard-interface.c
@@ -469,9 +469,6 @@  static void hardif_remove_interface(struct batman_if *batman_if)
 		return;
 
 	batman_if->if_status = IF_TO_BE_REMOVED;
-
-	/* caller must take if_list_lock */
-	list_del_rcu(&batman_if->list);
 	sysfs_del_hardif(&batman_if->hardif_obj);
 	call_rcu(&batman_if->rcu, hardif_free_rcu);
 }
@@ -479,13 +476,21 @@  static void hardif_remove_interface(struct batman_if *batman_if)
 void hardif_remove_interfaces(void)
 {
 	struct batman_if *batman_if, *batman_if_tmp;
+	struct list_head if_list_queue;
+
+	INIT_LIST_HEAD(&if_list_queue);
 
-	rtnl_lock();
 	spin_lock(&if_list_lock);
 	list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list, list) {
-		hardif_remove_interface(batman_if);
+		list_del_rcu(&batman_if->list);
+		list_add_tail(&batman_if->list, &if_list_queue);
 	}
 	spin_unlock(&if_list_lock);
+
+	rtnl_lock();
+	list_for_each_entry_safe(batman_if, batman_if_tmp, &if_list_queue, list) {
+		hardif_remove_interface(batman_if);
+	}
 	rtnl_unlock();
 }
 
@@ -512,8 +517,10 @@  static int hard_if_event(struct notifier_block *this,
 		break;
 	case NETDEV_UNREGISTER:
 		spin_lock(&if_list_lock);
-		hardif_remove_interface(batman_if);
+		list_del_rcu(&batman_if->list);
 		spin_unlock(&if_list_lock);
+
+		hardif_remove_interface(batman_if);
 		break;
 	case NETDEV_CHANGEMTU:
 		if (batman_if->soft_iface)