mptcp: fill skb extension 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 a preparation patch that makes sure we call
mptcp_sendmsg_frag only if a skb extension has been allocated.

Moreover, such allocation currently uses GFP_ATOMIC while it
could use sleeping allocation instead.

Followup patches will remove the wait loop from mptcp_sendmsg_frag()
and will allow to do a sleeping allocation for the extension.

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 10:46:20 +02:00 committed by David S. Miller
parent 72511aab95
commit 149f7c71e2

View file

@ -669,6 +669,9 @@ static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
sock_owned_by_me((const struct sock *)msk);
if (!mptcp_ext_cache_refill(msk))
return NULL;
mptcp_for_each_subflow(msk, subflow) {
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
@ -804,7 +807,8 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
if (!tx_ok)
break;
if (!sk_stream_memory_free(ssk)) {
if (!sk_stream_memory_free(ssk) ||
!mptcp_ext_cache_refill(msk)) {
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
tcp_push(ssk, msg->msg_flags, mss_now,
tcp_sk(ssk)->nonagle, size_goal);
@ -1158,7 +1162,7 @@ static void mptcp_worker(struct work_struct *work)
{
struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work);
struct sock *ssk, *sk = &msk->sk.icsk_inet.sk;
int orig_len, orig_offset, ret, mss_now = 0, size_goal = 0;
int orig_len, orig_offset, mss_now = 0, size_goal = 0;
struct mptcp_data_frag *dfrag;
u64 orig_write_seq;
size_t copied = 0;
@ -1180,6 +1184,9 @@ static void mptcp_worker(struct work_struct *work)
if (!dfrag)
goto unlock;
if (!mptcp_ext_cache_refill(msk))
goto reset_unlock;
ssk = mptcp_subflow_get_retrans(msk);
if (!ssk)
goto reset_unlock;
@ -1191,8 +1198,8 @@ static void mptcp_worker(struct work_struct *work)
orig_offset = dfrag->offset;
orig_write_seq = dfrag->data_seq;
while (dfrag->data_len > 0) {
ret = mptcp_sendmsg_frag(sk, ssk, &msg, dfrag, &timeo, &mss_now,
&size_goal);
int ret = mptcp_sendmsg_frag(sk, ssk, &msg, dfrag, &timeo,
&mss_now, &size_goal);
if (ret < 0)
break;
@ -1200,6 +1207,9 @@ static void mptcp_worker(struct work_struct *work)
copied += ret;
dfrag->data_len -= ret;
dfrag->offset += ret;
if (!mptcp_ext_cache_refill(msk))
break;
}
if (copied)
tcp_push(ssk, msg.msg_flags, mss_now, tcp_sk(ssk)->nonagle,