From: Florian Westphal fw@strlen.de
[ Upstream commit 1cec170d458b1d18f6f1654ca84c0804a701c5ef ]
After subflow lock is dropped, more wmem might have been made available.
This fixes a deadlock in mptcp_connect.sh 'mmap' mode: wmem is exhausted. But as the mptcp socket holds on to already-acked data (for retransmit) no wakeup will occur.
Using 'goto restart' calls mptcp_clean_una(sk) which will free pages that have been acked completely in the mean time.
Fixes: fb529e62d3f3 ("mptcp: break and restart in case mptcp sndbuf is full") Signed-off-by: Florian Westphal fw@strlen.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/mptcp/protocol.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -772,7 +772,6 @@ fallback: restart: mptcp_clean_una(sk);
-wait_for_sndbuf: __mptcp_flush_join_list(msk); ssk = mptcp_subflow_get_send(msk); while (!sk_stream_memory_free(sk) || @@ -873,7 +872,7 @@ wait_for_sndbuf: */ mptcp_set_timeout(sk, ssk); release_sock(ssk); - goto wait_for_sndbuf; + goto restart; } } }