[NET] CORE: Introducing new memory accounting interface.

This patch introduces new memory accounting functions for each network
protocol. Most of them are renamed from memory accounting functions
for stream protocols. At the same time, some stream memory accounting
functions are removed since other functions do same thing.

Renaming:
	sk_stream_free_skb()		->	sk_wmem_free_skb()
	__sk_stream_mem_reclaim()	->	__sk_mem_reclaim()
	sk_stream_mem_reclaim()		->	sk_mem_reclaim()
	sk_stream_mem_schedule 		->    	__sk_mem_schedule()
	sk_stream_pages()      		->	sk_mem_pages()
	sk_stream_rmem_schedule()	->	sk_rmem_schedule()
	sk_stream_wmem_schedule()	->	sk_wmem_schedule()
	sk_charge_skb()			->	sk_mem_charge()

Removeing
	sk_stream_rfree():	consolidates into sock_rfree()
	sk_stream_set_owner_r(): consolidates into skb_set_owner_r()
	sk_stream_mem_schedule()

The following functions are added.
    	sk_has_account(): check if the protocol supports accounting
	sk_mem_uncharge(): do the opposite of sk_mem_charge()

In addition, to achieve consolidation, updating sk_wmem_queued is
removed from sk_mem_charge().

Next, to consolidate memory accounting functions, this patch adds
memory accounting calls to network core functions. Moreover, present
memory accounting call is renamed to new accounting call.

Finally we replace present memory accounting calls with new interface
in TCP and SCTP.

Signed-off-by: Takahiro Yasui <tyasui@redhat.com>
Signed-off-by: Hideo Aoki <haoki@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/protocol.c

@@ -1109,7 +1109,7 @@ SCTP_STATIC __init int sctp_init(void)
 	sysctl_sctp_rmem[1] = (1500 *(sizeof(struct sk_buff) + 1));
 	sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
 
-	sysctl_sctp_wmem[0] = SK_STREAM_MEM_QUANTUM;
+	sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
 	sysctl_sctp_wmem[1] = 16*1024;
 	sysctl_sctp_wmem[2] = max(64*1024, max_share);
 

net/sctp/sm_statefuns.c

@@ -5844,7 +5844,7 @@ static int sctp_eat_data(const struct sctp_association *asoc,
 	/*
 	 * Also try to renege to limit our memory usage in the event that
 	 * we are under memory pressure
-	 * If we can't renege, don't worry about it, the sk_stream_rmem_schedule
+	 * If we can't renege, don't worry about it, the sk_rmem_schedule
 	 * in sctp_ulpevent_make_rcvmsg will drop the frame if we grow our
 	 * memory usage too much
 	 */

net/sctp/socket.c

@@ -174,7 +174,8 @@ static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
 				sizeof(struct sctp_chunk);
 
 	atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
-	sk_charge_skb(sk, chunk->skb);
+	sk->sk_wmem_queued += chunk->skb->truesize;
+	sk_mem_charge(sk, chunk->skb->truesize);
 }
 
 /* Verify that this is a valid address. */
@@ -6035,10 +6036,10 @@ static void sctp_wfree(struct sk_buff *skb)
 	atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
 
 	/*
-	 * This undoes what is done via sk_charge_skb
+	 * This undoes what is done via sctp_set_owner_w and sk_mem_charge
 	 */
 	sk->sk_wmem_queued   -= skb->truesize;
-	sk->sk_forward_alloc += skb->truesize;
+	sk_mem_uncharge(sk, skb->truesize);
 
 	sock_wfree(skb);
 	__sctp_write_space(asoc);
@@ -6059,9 +6060,9 @@ void sctp_sock_rfree(struct sk_buff *skb)
 	atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);
 
 	/*
-	 * Mimic the behavior of sk_stream_rfree
+	 * Mimic the behavior of sock_rfree
 	 */
-	sk->sk_forward_alloc += event->rmem_len;
+	sk_mem_uncharge(sk, event->rmem_len);
 }
 
 

net/sctp/ulpevent.c

@@ -700,7 +700,7 @@ struct sctp_ulpevent *sctp_ulpevent_make_rcvmsg(struct sctp_association *asoc,
 	if (rx_count >= asoc->base.sk->sk_rcvbuf) {
 
 		if ((asoc->base.sk->sk_userlocks & SOCK_RCVBUF_LOCK) ||
-		   (!sk_stream_rmem_schedule(asoc->base.sk, chunk->skb)))
+		    (!sk_rmem_schedule(asoc->base.sk, chunk->skb->truesize)))
 			goto fail;
 	}
 

net/sctp/ulpqueue.c

@@ -1046,7 +1046,7 @@ void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk,
 		sctp_ulpq_partial_delivery(ulpq, chunk, gfp);
 	}
 
-	sk_stream_mem_reclaim(asoc->base.sk);
+	sk_mem_reclaim(asoc->base.sk);
 	return;
 }