mptcp: fill skb page frag cache outside of mptcp_sendmsg_frag (17091708) · Commits · 戴 / test

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>

net/mptcp/protocol.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -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 @@ fallback:
		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 @@ wait_for_sndbuf:
		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,

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