mptcp: fill skb page frag cache outside of mptcp_sendmsg_frag

The mptcp_sendmsg_frag helper contains a loop that will wait on the
subflow sk.

It seems preferrable to only wait in mptcp_sendmsg() when blocking io is
requested.  mptcp_sendmsg already has such a wait loop that is used when
no subflow socket is available for transmission.

This is another preparation patch that makes sure we call
mptcp_sendmsg_frag only if the page frag cache has been refilled.

Followup patch will remove the wait loop from mptcp_sendmsg_frag().

The retransmit worker doesn't need to do this refill as it won't
transmit new mptcp-level data.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Westphal 2020-05-16 10:46:21 +02:00 committed by David S. Miller
parent 149f7c71e2
commit 17091708d1

View File

@ -713,6 +713,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
int mss_now = 0, size_goal = 0, ret = 0;
struct mptcp_sock *msk = mptcp_sk(sk);
struct page_frag *pfrag;
struct socket *ssock;
size_t copied = 0;
struct sock *ssk;
@ -741,13 +742,16 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
return ret >= 0 ? ret + copied : (copied ? copied : ret);
}
pfrag = sk_page_frag(sk);
restart:
mptcp_clean_una(sk);
wait_for_sndbuf:
__mptcp_flush_join_list(msk);
ssk = mptcp_subflow_get_send(msk);
while (!sk_stream_memory_free(sk) || !ssk) {
while (!sk_stream_memory_free(sk) ||
!ssk ||
!mptcp_page_frag_refill(ssk, pfrag)) {
if (ssk) {
/* make sure retransmit timer is
* running before we wait for memory.
@ -808,6 +812,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
break;
if (!sk_stream_memory_free(ssk) ||
!mptcp_page_frag_refill(ssk, pfrag) ||
!mptcp_ext_cache_refill(msk)) {
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
tcp_push(ssk, msg->msg_flags, mss_now,