[B.A.T.M.A.N.] [PATCH] batman-adv: Don't call sysfs_del_hardif() in atomic context

["Linus Lüssing" <linus.luessing@web.de>]

sysfs_del_hardif invokes kobject_put, which might sleep. However, we
are not allowed to sleep during a call_rcu. There is also no need to
do the removal with an atomic call_rcu, as kobject_put only frees the
kobject when there is no more reference to it anyway.

This commit basically revokes 7f32f2e8d97150ba5b80410dda86b01b0879fe8d,
despite not reintroducing the synchronize_rcu, our rcu_barrier should
handle this.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
---
 hard-interface.c |   14 +++-----------
 1 files changed, 3 insertions(+), 11 deletions(-)

diff --git a/hard-interface.c b/hard-interface.c
index 37f0f8b..5c6ce3f 100644
--- a/hard-interface.c
+++ b/hard-interface.c
@@ -36,16 +36,6 @@
 /* protect update critical side of if_list - but not the content */
 static DEFINE_SPINLOCK(if_list_lock);
 
-static void hardif_free_rcu(struct rcu_head *rcu)
-{
-	struct batman_if *batman_if;
-
-	batman_if = container_of(rcu, struct batman_if, rcu);
-	sysfs_del_hardif(&batman_if->hardif_obj);
-	dev_put(batman_if->net_dev);
-	kref_put(&batman_if->refcount, hardif_free_ref);
-}
-
 struct batman_if *get_batman_if_by_netdev(struct net_device *net_dev)
 {
 	struct batman_if *batman_if;
@@ -470,7 +460,9 @@ static void hardif_remove_interface(struct batman_if *batman_if)
 
 	/* caller must take if_list_lock */
 	list_del_rcu(&batman_if->list);
-	call_rcu(&batman_if->rcu, hardif_free_rcu);
+	sysfs_del_hardif(&batman_if->hardif_obj);
+	dev_put(batman_if->net_dev);
+	kref_put(&batman_if->refcount, hardif_free_ref);
 }
 
 void hardif_remove_interfaces(void)
-- 
1.7.1