@@ -65,10 +65,11 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
struct socket *ssock;
struct sock *ssk;
struct mptcp_ext *mpext = NULL;
- struct page *page = NULL;
+ struct page_frag *pfrag;
struct sk_buff *skb;
size_t psize;
int poffset;
+ long timeo;
lock_sock(sk);
ssock = __mptcp_fallback_get_ref(msk);
@@ -97,32 +98,32 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
goto put_out;
}
- /* Initial experiment: new page per send. Real code will
- * maintain list of active pages and DSS mappings, append to the
- * end and honor zerocopy
+ lock_sock(ssk);
+ timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
+
+ /* use the mptcp page cache so that we can easily move the data
+ * from one substream to another, but do per subflow memory accounting
*/
- page = alloc_page(GFP_KERNEL);
- if (!page) {
- ret = -ENOMEM;
- goto put_out;
+ pfrag = sk_page_frag(sk);
+ while (!sk_page_frag_refill(ssk, pfrag)) {
+ ret = sk_stream_wait_memory(ssk, &timeo);
+ if (ret)
+ goto put_out;
}
/* Copy to page */
- poffset = 0;
+ poffset = pfrag->offset;
pr_debug("left=%zu", msg_data_left(msg));
- psize = copy_page_from_iter(page, poffset,
+ psize = copy_page_from_iter(pfrag->page, poffset,
min_t(size_t, msg_data_left(msg),
- PAGE_SIZE),
+ pfrag->size - poffset),
&msg->msg_iter);
pr_debug("left=%zu", msg_data_left(msg));
-
if (!psize) {
ret = -EINVAL;
goto put_out;
}
- lock_sock(ssk);
-
/* Mark the end of the previous write so the beginning of the
* next write (with its own mptcp skb extension data) is not
* collapsed.
@@ -132,8 +133,8 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
TCP_SKB_CB(skb)->eor = 1;
mss_now = tcp_send_mss(ssk, &size_goal, msg->msg_flags);
-
- ret = do_tcp_sendpages(ssk, page, poffset, min_t(int, size_goal, psize),
+ psize = min_t(int, size_goal, psize);
+ ret = do_tcp_sendpages(ssk, pfrag->page, poffset, psize,
msg->msg_flags | MSG_SENDPAGE_NOTLAST);
if (ret <= 0)
goto put_out;
@@ -159,14 +160,13 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
mpext->checksum, mpext->dsn64);
} /* TODO: else fallback */
+ pfrag->offset += ret;
msk->write_seq += ret;
mptcp_subflow_ctx(ssk)->rel_write_seq += ret;
tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle, size_goal);
put_out:
- if (page)
- put_page(page);
release_sock(sk);
sock_put(ssk);
return ret;