mptcp: remove tx_pending_data

The update on recovery is not correct.

msk->tx_pending_data += msk->snd_nxt - rtx_head->data_seq;

will update tx_pending_data multiple times when a subflow is declared
stale while earlier recovery is still in progress.
This means that tx_pending_data will still be positive even after
all data as has been transmitted.

Rather than fix it, remove this field: there are no consumers.
The outstanding data byte count can be computed either via

 "msk->write_seq - rtx_head->data_seq" or
 "msk->write_seq - msk->snd_una".

The latter is more recent/accurate estimate as rtx_head adjustment
is deferred until mptcp lock can be acquired.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
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 87ee409d68ab0d586b74a24979e9fa9298e88e48..5b0ed64c5cd2abfa4bc20c5f067c2f31c593b84c 100644 (file)
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1531,7 +1531,6 @@ static void mptcp_update_post_push(struct mptcp_sock *msk,
        dfrag->already_sent += sent;
 
        msk->snd_burst -= sent;
-       msk->tx_pending_data -= sent;
 
        snd_nxt_new += dfrag->already_sent;
 
@@ -1761,7 +1760,6 @@ static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
                frag_truesize += psize;
                pfrag->offset += frag_truesize;
                WRITE_ONCE(msk->write_seq, msk->write_seq + psize);
-               msk->tx_pending_data += psize;
 
                /* charge data on mptcp pending queue to the msk socket
                 * Note: we charge such data both to sk and ssk
@@ -2254,7 +2252,6 @@ bool __mptcp_retransmit_pending_data(struct sock *sk)
        mptcp_data_unlock(sk);
 
        msk->first_pending = rtx_head;
-       msk->tx_pending_data += msk->snd_nxt - rtx_head->data_seq;
        msk->snd_burst = 0;
 
        /* be sure to clear the "sent status" on all re-injected fragments */
@@ -2525,7 +2522,6 @@ static int __mptcp_init_sock(struct sock *sk)
        msk->first_pending = NULL;
        msk->wmem_reserved = 0;
        WRITE_ONCE(msk->rmem_released, 0);
-       msk->tx_pending_data = 0;
        msk->timer_ival = TCP_RTO_MIN;
 
        msk->first = NULL;

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index d3e6fd1615f1f728b4ad51e861afee7037d23b7d..d516fb6578cc8e457e307fb23a8d09fbc03c3bdf 100644 (file)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -254,7 +254,6 @@ struct mptcp_sock {
        struct sk_buff  *ooo_last_skb;
        struct rb_root  out_of_order_queue;
        struct sk_buff_head receive_queue;
-       int             tx_pending_data;
        struct list_head conn_list;
        struct list_head rtx_queue;
        struct mptcp_data_frag *first_pending;