tcp: move stats merge to the end of tcp_try_coalesce
This change cleans up the last bits of tcp_try_coalesce so that we only
need one goto which jumps to the end of the function. The idea is to make
the code more readable by putting things in a linear order so that we start
execution at the top of the function, and end it at the bottom.
I also made a slight tweak to the code for handling frags when we are a
clone. Instead of making it an if (clone) loop else nr_frags = 0 I changed
the logic so that if (!clone) we just set the number of frags to 0 which
disables the for loop anyway.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 41fa5df..84e69e0 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4548,15 +4548,13 @@
int i, delta, len = from->len;
*fragstolen = false;
+
if (tcp_hdr(from)->fin || skb_cloned(to))
return false;
+
if (len <= skb_tailroom(to)) {
BUG_ON(skb_copy_bits(from, 0, skb_put(to, len), len));
-merge:
- NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRCVCOALESCE);
- TCP_SKB_CB(to)->end_seq = TCP_SKB_CB(from)->end_seq;
- TCP_SKB_CB(to)->ack_seq = TCP_SKB_CB(from)->ack_seq;
- return true;
+ goto merge;
}
if (skb_has_frag_list(to) || skb_has_frag_list(from))
@@ -4581,7 +4579,6 @@
skb_fill_page_desc(to, skb_shinfo(to)->nr_frags,
page, offset, skb_headlen(from));
*fragstolen = true;
- goto copyfrags;
} else {
if (skb_shinfo(to)->nr_frags +
skb_shinfo(from)->nr_frags > MAX_SKB_FRAGS)
@@ -4589,27 +4586,33 @@
delta = from->truesize -
SKB_TRUESIZE(skb_end_pointer(from) - from->head);
-copyfrags:
- WARN_ON_ONCE(delta < len);
- memcpy(skb_shinfo(to)->frags + skb_shinfo(to)->nr_frags,
- skb_shinfo(from)->frags,
- skb_shinfo(from)->nr_frags * sizeof(skb_frag_t));
- skb_shinfo(to)->nr_frags += skb_shinfo(from)->nr_frags;
-
- if (skb_cloned(from))
- for (i = 0; i < skb_shinfo(from)->nr_frags; i++)
- skb_frag_ref(from, i);
- else
- skb_shinfo(from)->nr_frags = 0;
-
- to->truesize += delta;
- atomic_add(delta, &sk->sk_rmem_alloc);
- sk_mem_charge(sk, delta);
- to->len += len;
- to->data_len += len;
- goto merge;
}
- return false;
+
+ WARN_ON_ONCE(delta < len);
+
+ memcpy(skb_shinfo(to)->frags + skb_shinfo(to)->nr_frags,
+ skb_shinfo(from)->frags,
+ skb_shinfo(from)->nr_frags * sizeof(skb_frag_t));
+ skb_shinfo(to)->nr_frags += skb_shinfo(from)->nr_frags;
+
+ if (!skb_cloned(from))
+ skb_shinfo(from)->nr_frags = 0;
+
+ /* if the skb is cloned this does nothing since we set nr_frags to 0 */
+ for (i = 0; i < skb_shinfo(from)->nr_frags; i++)
+ skb_frag_ref(from, i);
+
+ to->truesize += delta;
+ atomic_add(delta, &sk->sk_rmem_alloc);
+ sk_mem_charge(sk, delta);
+ to->len += len;
+ to->data_len += len;
+
+merge:
+ NET_INC_STATS_BH(sock_net(sk), LINUX_MIB_TCPRCVCOALESCE);
+ TCP_SKB_CB(to)->end_seq = TCP_SKB_CB(from)->end_seq;
+ TCP_SKB_CB(to)->ack_seq = TCP_SKB_CB(from)->ack_seq;
+ return true;
}
static void kfree_skb_partial(struct sk_buff *skb, bool head_stolen)
