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authorSven Eckelmann <sven.eckelmann@gmx.de>2010-11-22 12:34:50 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2010-11-29 10:53:14 -0800
commit9ee898739b7e4d292abed911008b3f91b442118a (patch)
treebcc05c7f9cf249b2391989a222e5e5f268886b4d /drivers
parent6df78338e7af7960b67fa00aa2a5c63986a23d3c (diff)
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Staging: batman-adv: Don't remove interface with spinlock held
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. We create a "scheduling while atomic" Oops when calling different netdevice related functions inside a spinlock protected area on a preemtible kernel. Reported-by: Rafal Lesniak <lesniak@eresi-project.org> Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/batman-adv/hard-interface.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/drivers/staging/batman-adv/hard-interface.c b/drivers/staging/batman-adv/hard-interface.c
index b68a7e5173b..d85de82f941 100644
--- a/drivers/staging/batman-adv/hard-interface.c
+++ b/drivers/staging/batman-adv/hard-interface.c
@@ -463,9 +463,6 @@ 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);
synchronize_rcu();
sysfs_del_hardif(&batman_if->hardif_obj);
hardif_put(batman_if);
@@ -474,13 +471,21 @@ 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_queue;
+
+ INIT_LIST_HEAD(&if_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_queue);
}
spin_unlock(&if_list_lock);
+
+ rtnl_lock();
+ list_for_each_entry_safe(batman_if, batman_if_tmp, &if_queue, list) {
+ hardif_remove_interface(batman_if);
+ }
rtnl_unlock();
}
@@ -507,8 +512,10 @@ 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)