| Message ID | 20200825233105.15172-1-fw@strlen.de |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] mptcp: free acked data before waiting for more memory | expand |
From: Florian Westphal <fw@strlen.de> Date: Wed, 26 Aug 2020 01:31:05 +0200 > 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> Applied and queued up for -stable, thanks.
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 1aad411a0e46..8ccd4a151dcb 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -892,7 +892,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) goto out; } -wait_for_sndbuf: __mptcp_flush_join_list(msk); ssk = mptcp_subflow_get_send(msk); while (!sk_stream_memory_free(sk) || @@ -982,7 +981,7 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) */ mptcp_set_timeout(sk, ssk); release_sock(ssk); - goto wait_for_sndbuf; + goto restart; } } }
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> --- net/mptcp/protocol.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)