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
Looking only at the 'backup' flag can make sense in some cases, but it is not the behaviour of the default packet scheduler when selecting paths.
As explained in the commit b6a66e521a20 ("mptcp: sched: check both directions for backup"), the packet scheduler should look at both flags, because that was the behaviour from the beginning: the 'backup' flag was set by accident instead of the 'request_bkup' one. Now that the latter has been fixed, get_retrans() needs to be adapted as well.
Fixes: b6a66e521a20 ("mptcp: sched: check both directions for backup") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau martineau@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- net/mptcp/protocol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 151e82e2ff2e..34fec753b9c1 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -2326,7 +2326,7 @@ struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk) continue; }
- if (subflow->backup) { + if (subflow->backup || subflow->request_bkup) { if (!backup) backup = ssk; continue;