mptcp: sched: check both directions for backup

BugLink: https://bugs.launchpad.net/bugs/2083488

commit b6a66e521a2032f7fcba2af5a9bcbaeaa19b7ca3 upstream.

The 'mptcp_subflow_context' structure has two items related to the
backup flags:

 - 'backup': the subflow has been marked as backup by the other peer

 - 'request_bkup': the backup flag has been set by the host

Before this patch, the scheduler was only looking at the 'backup' flag.
That can make sense in some cases, but it looks like that's not what we
wanted for the general use, because either the path-manager was setting
both of them when sending an MP_PRIO, or the receiver was duplicating
the 'backup' flag in the subflow request.

Note that the use of these two flags in the path-manager are going to be
fixed in the next commits, but this change here is needed not to modify
the behaviour.

Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
This commit is contained in:
Matthieu Baerts (NGI0)
2024-07-27 12:01:23 +02:00
committed by Mehmet Basaran
parent 511f1a5690
commit 7f50ecab40
2 changed files with 7 additions and 5 deletions
+1 -1
View File
@@ -34,7 +34,7 @@ TRACE_EVENT(mptcp_subflow_get_send,
struct sock *ssk;
__entry->active = mptcp_subflow_active(subflow);
__entry->backup = subflow->backup;
__entry->backup = subflow->backup || subflow->request_bkup;
if (subflow->tcp_sock && sk_fullsock(subflow->tcp_sock))
__entry->free = sk_stream_memory_free(subflow->tcp_sock);
+6 -4
View File
@@ -1415,13 +1415,15 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
}
mptcp_for_each_subflow(msk, subflow) {
bool backup = subflow->backup || subflow->request_bkup;
trace_mptcp_subflow_get_send(subflow);
ssk = mptcp_subflow_tcp_sock(subflow);
if (!mptcp_subflow_active(subflow))
continue;
tout = max(tout, mptcp_timeout_from_subflow(subflow));
nr_active += !subflow->backup;
nr_active += !backup;
pace = subflow->avg_pacing_rate;
if (unlikely(!pace)) {
/* init pacing rate from socket */
@@ -1432,9 +1434,9 @@ struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
}
linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace);
if (linger_time < send_info[subflow->backup].linger_time) {
send_info[subflow->backup].ssk = ssk;
send_info[subflow->backup].linger_time = linger_time;
if (linger_time < send_info[backup].linger_time) {
send_info[backup].ssk = ssk;
send_info[backup].linger_time = linger_time;
}
}
__mptcp_set_timeout(sk, tout);