mptcp: fix missing wakeup

__mptcp_clean_una() can free write memory and should wake-up
user-space processes when needed.

When such function is invoked by the MPTCP receive path, the wakeup
is not needed, as the TCP stack will later trigger subflow_write_space
which will do the wakeup as needed.

Other __mptcp_clean_una() call sites need an additional wakeup check
Let's bundle the relevant code in a new helper and use it.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/165
Fixes: 6e628cd3a8f7 ("mptcp: use mptcp release_cb for delayed tasks")
Fixes: 64b9cea7a0af ("mptcp: fix spurious retransmissions")
Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index d2a2169e6d9e7ad2c88acc8941c4893747c70a17..76958570ae7f258a0276e423bb7ddbbd0a200224 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1061,6 +1061,12 @@ out:
        }
 }
 
+static void __mptcp_clean_una_wakeup(struct sock *sk)
+{
+       __mptcp_clean_una(sk);
+       mptcp_write_space(sk);
+}
+
 static void mptcp_enter_memory_pressure(struct sock *sk)
 {
        struct mptcp_subflow_context *subflow;
@@ -2270,7 +2276,7 @@ static void __mptcp_retrans(struct sock *sk)
        struct sock *ssk;
        int ret;
 
-       __mptcp_clean_una(sk);
+       __mptcp_clean_una_wakeup(sk);
        dfrag = mptcp_rtx_head(sk);
        if (!dfrag)
                return;
@@ -2983,7 +2989,7 @@ static void mptcp_release_cb(struct sock *sk)
        }
 
        if (test_and_clear_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->flags))
-               __mptcp_clean_una(sk);
+               __mptcp_clean_una_wakeup(sk);
        if (test_and_clear_bit(MPTCP_ERROR_REPORT, &mptcp_sk(sk)->flags))
                __mptcp_error_report(sk);