wireguard: allowedips: use kfree_rcu() and don't wait on rcu_barrier()HEADstable

Since SLOB was removed, it is not necessary to use call_rcu() when the
callback only performs kmem_cache_free(), so we can use kfree_rcu()
directly. kfree_rcu() happens in batches and doesn't need to wait on
rcu_barrier() to complete, so also remove the barrier.

Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 2 insertions, 8 deletions

diff --git a/drivers/net/wireguard/allowedips.c b/drivers/net/wireguard/allowedips.c
index 0ba714c..c95f693 100644
--- a/drivers/net/wireguard/allowedips.c
+++ b/drivers/net/wireguard/allowedips.c
@@ -48,11 +48,6 @@ static void push_rcu(struct allowedips_node **stack,
 	}
 }
 
-static void node_free_rcu(struct rcu_head *rcu)
-{
-	kmem_cache_free(node_cache, container_of(rcu, struct allowedips_node, rcu));
-}
-
 static void root_free_rcu(struct rcu_head *rcu)
 {
 	struct allowedips_node *node, *stack[MAX_ALLOWEDIPS_DEPTH] = {
@@ -330,13 +325,13 @@ void wg_allowedips_remove_by_peer(struct allowedips *table,
 			child = rcu_dereference_protected(
 					parent->bit[!(node->parent_bit_packed & 1)],
 					lockdep_is_held(lock));
-		call_rcu(&node->rcu, node_free_rcu);
+		kfree_rcu(node, rcu);
 		if (!free_parent)
 			continue;
 		if (child)
 			child->parent_bit_packed = parent->parent_bit_packed;
 		*(struct allowedips_node **)(parent->parent_bit_packed & ~3UL) = child;
-		call_rcu(&parent->rcu, node_free_rcu);
+		kfree_rcu(parent, rcu);
 	}
 }
 
@@ -382,7 +377,6 @@ int __init wg_allowedips_slab_init(void)
 
 void wg_allowedips_slab_uninit(void)
 {
-	rcu_barrier();
 	kmem_cache_destroy(node_cache);
 }