mptcp: track and update contiguous data status

commit 0530020a7c8f2204e784f0dbdc882bbd961fdbde upstream.

This patch adds a new member allow_infinite_fallback in mptcp_sock,
which is initialized to 'true' when the connection begins and is set
to 'false' on any retransmit or successful MP_JOIN. Only do infinite
mapping fallback if there is a single subflow AND there have been no
retransmissions AND there have never been any MP_JOINs.

Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Geliang Tang <geliang.tang@suse.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: e32d262c89e2 ("mptcp: handle consistently DSS corruption")
[ Conflicts in protocol.c, because commit 3e5014909b56 ("mptcp: cleanup
  MPJ subflow list handling") is not in this version. This commit is
  linked to a new feature, changing the context around. The new line
  can still be added at the same place.
  Conflicts in protocol.h, because commit 4f6e14bd19d6 ("mptcp: support
  TCP_CORK and TCP_NODELAY") is not in this version. This commit is
  linked to a new feature, changing the context around. The new line can
  still be added at the same place.
  Conflicts in subflow.c, because commit 0348c690ed37 ("mptcp: add the
  fallback check") is not in this version. This commit is linked to a
  new feature, changing the context around. The new line can still be
  added at the same place.
  Extra conflicts in v5.10, because the context has been changed. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 590e2c9bb67e2f6f23d4a1d766de0ad1ad262c41..24a21ff0cb8a8aa25ee59ea9a24029e43a507c18 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1810,9 +1810,11 @@ static void mptcp_worker(struct work_struct *work)
                if (!mptcp_ext_cache_refill(msk))
                        break;
        }
-       if (copied)
+       if (copied) {
                tcp_push(ssk, msg.msg_flags, mss_now, tcp_sk(ssk)->nonagle,
                         size_goal);
+               WRITE_ONCE(msk->allow_infinite_fallback, false);
+       }
 
        dfrag->data_seq = orig_write_seq;
        dfrag->offset = orig_offset;
@@ -1845,6 +1847,7 @@ static int __mptcp_init_sock(struct sock *sk)
 
        msk->first = NULL;
        inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;
+       WRITE_ONCE(msk->allow_infinite_fallback, true);
 
        mptcp_pm_data_init(msk);
 
@@ -2543,6 +2546,7 @@ bool mptcp_finish_join(struct sock *sk)
        if (parent_sock && !sk->sk_socket)
                mptcp_sock_graft(sk, parent_sock);
        subflow->map_seq = READ_ONCE(msk->ack_seq);
+       WRITE_ONCE(msk->allow_infinite_fallback, false);
        return true;
 }
 

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 44944e8f73c50a48f3aa49f238fe090649bbee72..2330140d6b1ccb4f1a8362b4948e2782b4f62b22 100644 (file)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -213,6 +213,7 @@ struct mptcp_sock {
        bool            rcv_data_fin;
        bool            snd_data_fin_enable;
        bool            use_64bit_ack; /* Set when we received a 64-bit DSN */
+       bool            allow_infinite_fallback;
        spinlock_t      join_list_lock;
        struct work_struct work;
        struct sk_buff  *ooo_last_skb;

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 843c61ebd42115947a0f8b929f33f8cfbc3ee38d..0c020ca463f43f664f97de6d5469e9aa45cdec0d 100644 (file)
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1179,6 +1179,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,
        list_add_tail(&subflow->node, &msk->join_list);
        spin_unlock_bh(&msk->join_list_lock);
 
+       WRITE_ONCE(msk->allow_infinite_fallback, false);
        return err;
 
 failed: