[NETFILTER]: nfnetlink_queue: avoid unnecessary atomic operation

The sequence counter doesn't need to be an atomic_t, just move the increment
inside the locked section.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 5 deletions

diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index d9ce3942af2..bd18de72e3c 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -56,7 +56,7 @@ struct nfqnl_instance {
         unsigned int queue_dropped;
         unsigned int queue_user_dropped;
 
-        atomic_t id_sequence;                   /* 'sequence' of pkt ids */
+        unsigned int id_sequence;               /* 'sequence' of pkt ids */
 
         u_int16_t queue_num;                    /* number of this queue */
         u_int8_t copy_mode;
@@ -139,7 +139,6 @@ instance_create(u_int16_t queue_num, int pid)
         inst->queue_maxlen = NFQNL_QMAX_DEFAULT;
         inst->copy_range = 0xfffff;
         inst->copy_mode = NFQNL_COPY_NONE;
-        atomic_set(&inst->id_sequence, 0);
         /* needs to be two, since we _put() after creation */
         atomic_set(&inst->use, 2);
         spin_lock_init(&inst->lock);
@@ -340,6 +339,8 @@ nfqnl_build_packet_message(struct nfqnl_instance *queue,
                 return NULL;
         }
 
+        entry->id = queue->id_sequence++;
+
         spin_unlock_bh(&queue->lock);
 
         skb = alloc_skb(size, GFP_ATOMIC);
@@ -496,8 +497,6 @@ nfqnl_enqueue_packet(struct nf_queue_entry *entry, unsigned int queuenum)
                 goto err_out_put;
         }
 
-        entry->id = atomic_inc_return(&queue->id_sequence);
-
         nskb = nfqnl_build_packet_message(queue, entry, &status);
         if (nskb == NULL)
                 goto err_out_put;
@@ -948,7 +947,7 @@ static int seq_show(struct seq_file *s, void *v)
                           inst->peer_pid, inst->queue_total,
                           inst->copy_mode, inst->copy_range,
                           inst->queue_dropped, inst->queue_user_dropped,
-                          atomic_read(&inst->id_sequence),
+                          inst->id_sequence,
                           atomic_read(&inst->use));
 }