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tipc: extract bundled buffers by cloning instead of copying

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When we currently extract a bundled buffer from a message bundle in
the function tipc_msg_extract(), we allocate a new buffer and explicitly
copy the linear data area.

This is unnecessary, since we can just clone the buffer and do
skb_pull() on the clone to move the data pointer to the correct
position.

This is what we do in this commit.

Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jon Paul Maloy
2015-03-13 16:08:08 -04:00
committed by David S. Miller
parent 1149557d64
commit c1336ee472
2 changed files with 29 additions and 48 deletions
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45
net/tipc/link.c
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@@ -1,7 +1,7 @@
/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, 2012-2014, Ericsson AB
* Copyright (c) 1996-2007, 2012-2015, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, Wind River Systems
* All rights reserved.
*
@@ -1117,7 +1117,7 @@ void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
ackd = msg_ack(msg);
/* Release acked messages */
if (n_ptr->bclink.recv_permitted)
if (likely(n_ptr->bclink.recv_permitted))
tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
released = 0;
@@ -1712,45 +1712,24 @@ void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
}
}
/**
* buf_extract - extracts embedded TIPC message from another message
* @skb: encapsulating message buffer
* @from_pos: offset to extract from
*
* Returns a new message buffer containing an embedded message. The
* encapsulating buffer is left unchanged.
*/
static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
{
struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
u32 size = msg_size(msg);
struct sk_buff *eb;
eb = tipc_buf_acquire(size);
if (eb)
skb_copy_to_linear_data(eb, msg, size);
return eb;
}
/* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
* Owner node is locked.
*/
static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
struct sk_buff *t_buf)
static void tipc_link_dup_rcv(struct tipc_link *link,
struct sk_buff *skb)
{
struct sk_buff *buf;
struct sk_buff *iskb;
int pos = 0;
if (!tipc_link_is_up(l_ptr))
if (!tipc_link_is_up(link))
return;
buf = buf_extract(t_buf, INT_H_SIZE);
if (buf == NULL) {
if (!tipc_msg_extract(skb, &iskb, &pos)) {
pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
return;
}
/* Add buffer to deferred queue, if applicable: */
link_handle_out_of_seq_msg(l_ptr, buf);
/* Append buffer to deferred queue, if applicable: */
link_handle_out_of_seq_msg(link, iskb);
}
/* tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
@@ -1762,6 +1741,7 @@ static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
struct tipc_msg *t_msg = buf_msg(t_buf);
struct sk_buff *buf = NULL;
struct tipc_msg *msg;
int pos = 0;
if (tipc_link_is_up(l_ptr))
tipc_link_reset(l_ptr);
@@ -1773,8 +1753,7 @@ static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
/* Should there be an inner packet? */
if (l_ptr->exp_msg_count) {
l_ptr->exp_msg_count--;
buf = buf_extract(t_buf, INT_H_SIZE);
if (buf == NULL) {
if (!tipc_msg_extract(t_buf, &buf, &pos)) {
pr_warn("%sno inner failover pkt\n", link_co_err);
goto exit;
}