__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") Signed-off-by: Paolo Abeni <pabeni(a)redhat.com&gt; --- v1 -> v2: - drop self-tests changes, slipped here due to PEBKAC net/mptcp/protocol.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2859ad2c6990c..87f62fe66317d 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1061,6 +1061,12 @@ static void __mptcp_clean_una(struct sock *sk) } } +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; @@ -2263,7 +2269,7 @@ 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); -- 2.26.2