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>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 504f7f1..fbd106e 100644 (file)
--- 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. */