tuntap: dont use a private kmem_cache

Commit 96442e42429 (tuntap: choose the txq based on rxq)
added a per tun_struct kmem_cache.

As soon as several tun_struct are used, we get an error
because two caches cannot have same name.

Use the default kmalloc()/kfree_rcu(), as it reduce code
size and doesn't have performance impact here.

Reported-by: Paul Moore <pmoore@redhat.com>
Tested-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 21 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 504f7f1cad94..fbd106edbe59 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -180,7 +180,6 @@ struct tun_struct {
         int debug;
 #endif
         spinlock_t lock;
-        struct kmem_cache *flow_cache;
         struct hlist_head flows[TUN_NUM_FLOW_ENTRIES];
         struct timer_list flow_gc_timer;
         unsigned long ageing_time;
@@ -209,8 +208,8 @@ static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
                                               struct hlist_head *head,
                                               u32 rxhash, u16 queue_index)
 {
-        struct tun_flow_entry *e = kmem_cache_alloc(tun->flow_cache,
-                                                    GFP_ATOMIC);
+        struct tun_flow_entry *e = kmalloc(sizeof(*e), GFP_ATOMIC);
+
         if (e) {
                 tun_debug(KERN_INFO, tun, "create flow: hash %u index %u\n",
                           rxhash, queue_index);
@@ -223,19 +222,12 @@ static struct tun_flow_entry *tun_flow_create(struct tun_struct *tun,
         return e;
 }
 
-static void tun_flow_free(struct rcu_head *head)
-{
-        struct tun_flow_entry *e
-                = container_of(head, struct tun_flow_entry, rcu);
-        kmem_cache_free(e->tun->flow_cache, e);
-}
-
 static void tun_flow_delete(struct tun_struct *tun, struct tun_flow_entry *e)
 {
         tun_debug(KERN_INFO, tun, "delete flow: hash %u index %u\n",
                   e->rxhash, e->queue_index);
         hlist_del_rcu(&e->hash_link);
-        call_rcu(&e->rcu, tun_flow_free);
+        kfree_rcu(e, rcu);
 }
 
 static void tun_flow_flush(struct tun_struct *tun)
@@ -833,12 +825,6 @@ static int tun_flow_init(struct tun_struct *tun)
 {
         int i;
 
-        tun->flow_cache = kmem_cache_create("tun_flow_cache",
-                                            sizeof(struct tun_flow_entry), 0, 0,
-                                            NULL);
-        if (!tun->flow_cache)
-                return -ENOMEM;
-
         for (i = 0; i < TUN_NUM_FLOW_ENTRIES; i++)
                 INIT_HLIST_HEAD(&tun->flows[i]);
 
@@ -854,10 +840,6 @@ static void tun_flow_uninit(struct tun_struct *tun)
 {
         del_timer_sync(&tun->flow_gc_timer);
         tun_flow_flush(tun);
-
-        /* Wait for completion of call_rcu()'s */
-        rcu_barrier();
-        kmem_cache_destroy(tun->flow_cache);
 }
 
 /* Initialize net device. */