tcp: factor out tcp_build_frag()

[linux-2.6-microblaze.git] / net / ipv4 / tcp.c

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b2bc3d7..a40981e 100644 (file)
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -954,7 +954,7 @@ int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
  * importantly be able to generate EPOLLOUT for Edge Trigger epoll()
  * users.
  */
-static void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb)
+void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb)
 {
        if (skb && !skb->len) {
                tcp_unlink_write_queue(skb, sk);
@@ -964,6 +964,68 @@ static void tcp_remove_empty_skb(struct sock *sk, struct sk_buff *skb)
        }
 }
 
+struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
+                              struct page *page, int offset, size_t *size)
+{
+       struct sk_buff *skb = tcp_write_queue_tail(sk);
+       struct tcp_sock *tp = tcp_sk(sk);
+       bool can_coalesce;
+       int copy, i;
+
+       if (!skb || (copy = size_goal - skb->len) <= 0 ||
+           !tcp_skb_can_collapse_to(skb)) {
+new_segment:
+               if (!sk_stream_memory_free(sk))
+                       return NULL;
+
+               skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
+                                         tcp_rtx_and_write_queues_empty(sk));
+               if (!skb)
+                       return NULL;
+
+#ifdef CONFIG_TLS_DEVICE
+               skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
+#endif
+               skb_entail(sk, skb);
+               copy = size_goal;
+       }
+
+       if (copy > *size)
+               copy = *size;
+
+       i = skb_shinfo(skb)->nr_frags;
+       can_coalesce = skb_can_coalesce(skb, i, page, offset);
+       if (!can_coalesce && i >= sysctl_max_skb_frags) {
+               tcp_mark_push(tp, skb);
+               goto new_segment;
+       }
+       if (!sk_wmem_schedule(sk, copy))
+               return NULL;
+
+       if (can_coalesce) {
+               skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
+       } else {
+               get_page(page);
+               skb_fill_page_desc(skb, i, page, offset, copy);
+       }
+
+       if (!(flags & MSG_NO_SHARED_FRAGS))
+               skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+
+       skb->len += copy;
+       skb->data_len += copy;
+       skb->truesize += copy;
+       sk_wmem_queued_add(sk, copy);
+       sk_mem_charge(sk, copy);
+       skb->ip_summed = CHECKSUM_PARTIAL;
+       WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
+       TCP_SKB_CB(skb)->end_seq += copy;
+       tcp_skb_pcount_set(skb, 0);
+
+       *size = copy;
+       return skb;
+}
+
 ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
                         size_t size, int flags)
 {
@@ -999,60 +1061,13 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
                goto out_err;
 
        while (size > 0) {
-               struct sk_buff *skb = tcp_write_queue_tail(sk);
-               int copy, i;
-               bool can_coalesce;
-
-               if (!skb || (copy = size_goal - skb->len) <= 0 ||
-                   !tcp_skb_can_collapse_to(skb)) {
-new_segment:
-                       if (!sk_stream_memory_free(sk))
-                               goto wait_for_space;
-
-                       skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
-                                       tcp_rtx_and_write_queues_empty(sk));
-                       if (!skb)
-                               goto wait_for_space;
-
-#ifdef CONFIG_TLS_DEVICE
-                       skb->decrypted = !!(flags & MSG_SENDPAGE_DECRYPTED);
-#endif
-                       skb_entail(sk, skb);
-                       copy = size_goal;
-               }
+               struct sk_buff *skb;
+               size_t copy = size;
 
-               if (copy > size)
-                       copy = size;
-
-               i = skb_shinfo(skb)->nr_frags;
-               can_coalesce = skb_can_coalesce(skb, i, page, offset);
-               if (!can_coalesce && i >= sysctl_max_skb_frags) {
-                       tcp_mark_push(tp, skb);
-                       goto new_segment;
-               }
-               if (!sk_wmem_schedule(sk, copy))
+               skb = tcp_build_frag(sk, size_goal, flags, page, offset, &copy);
+               if (!skb)
                        goto wait_for_space;
 
-               if (can_coalesce) {
-                       skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
-               } else {
-                       get_page(page);
-                       skb_fill_page_desc(skb, i, page, offset, copy);
-               }
-
-               if (!(flags & MSG_NO_SHARED_FRAGS))
-                       skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
-
-               skb->len += copy;
-               skb->data_len += copy;
-               skb->truesize += copy;
-               sk_wmem_queued_add(sk, copy);
-               sk_mem_charge(sk, copy);
-               skb->ip_summed = CHECKSUM_PARTIAL;
-               WRITE_ONCE(tp->write_seq, tp->write_seq + copy);
-               TCP_SKB_CB(skb)->end_seq += copy;
-               tcp_skb_pcount_set(skb, 0);
-
                if (!copied)
                        TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;