linux-stable/net/rxrpc/skbuff.c
David Howells a1767077b0 rxrpc: Make Tx loss-injection go through normal return and adjust tracing
In rxrpc_send_data_packet() make the loss-injection path return through the
same code as the transmission path so that the RTT determination is
initiated and any future timer shuffling will be done, despite the packet
having been binned.

Whilst we're at it:

 (1) Add to the tx_data tracepoint an indication of whether or not we're
     retransmitting a data packet.

 (2) When we're deciding whether or not to request an ACK, rather than
     checking if we're in fast-retransmit mode check instead if we're
     retransmitting.

 (3) Don't invoke the lose_skb tracepoint when losing a Tx packet as we're
     not altering the sk_buff refcount nor are we just seeing it after
     getting it off the Tx list.

 (4) The rxrpc_skb_tx_lost note is then no longer used so remove it.

 (5) rxrpc_lose_skb() no longer needs to deal with rxrpc_skb_tx_lost.

Signed-off-by: David Howells <dhowells@redhat.com>
2016-09-29 22:37:15 +01:00

99 lines
2.7 KiB
C

/* ar-skbuff.c: socket buffer destruction handling
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/net.h>
#include <linux/skbuff.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
#define select_skb_count(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs)
/*
* Note the allocation or reception of a socket buffer.
*/
void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
{
const void *here = __builtin_return_address(0);
int n = atomic_inc_return(select_skb_count(op));
trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
}
/*
* Note the re-emergence of a socket buffer from a queue or buffer.
*/
void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
{
const void *here = __builtin_return_address(0);
if (skb) {
int n = atomic_read(select_skb_count(op));
trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
}
}
/*
* Note the addition of a ref on a socket buffer.
*/
void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
{
const void *here = __builtin_return_address(0);
int n = atomic_inc_return(select_skb_count(op));
trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
skb_get(skb);
}
/*
* Note the destruction of a socket buffer.
*/
void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
{
const void *here = __builtin_return_address(0);
if (skb) {
int n;
CHECK_SLAB_OKAY(&skb->users);
n = atomic_dec_return(select_skb_count(op));
trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
kfree_skb(skb);
}
}
/*
* Note the injected loss of a socket buffer.
*/
void rxrpc_lose_skb(struct sk_buff *skb, enum rxrpc_skb_trace op)
{
const void *here = __builtin_return_address(0);
if (skb) {
int n;
CHECK_SLAB_OKAY(&skb->users);
n = atomic_dec_return(select_skb_count(op));
trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here);
kfree_skb(skb);
}
}
/*
* Clear a queue of socket buffers.
*/
void rxrpc_purge_queue(struct sk_buff_head *list)
{
const void *here = __builtin_return_address(0);
struct sk_buff *skb;
while ((skb = skb_dequeue((list))) != NULL) {
int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged));
trace_rxrpc_skb(skb, rxrpc_skb_rx_purged,
atomic_read(&skb->users), n, here);
kfree_skb(skb);
}
}