diff options
Diffstat (limited to 'net/rxrpc/call_event.c')
-rw-r--r-- | net/rxrpc/call_event.c | 117 |
1 files changed, 97 insertions, 20 deletions
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index dbfaf8170929..1e21a708390e 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -132,48 +132,127 @@ static void rxrpc_congestion_timeout(struct rxrpc_call *call) */ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j) { + struct rxrpc_ackpacket *ack = NULL; struct rxrpc_txbuf *txb; + struct sk_buff *ack_skb = NULL; unsigned long resend_at; rxrpc_seq_t transmitted = READ_ONCE(call->tx_transmitted); ktime_t now, max_age, oldest, ack_ts; bool unacked = false; + unsigned int i; LIST_HEAD(retrans_queue); _enter("{%d,%d}", call->acks_hard_ack, call->tx_top); now = ktime_get_real(); max_age = ktime_sub_us(now, jiffies_to_usecs(call->peer->rto_j)); + oldest = now; + + /* See if there's an ACK saved with a soft-ACK table in it. */ + if (call->acks_soft_tbl) { + spin_lock_bh(&call->acks_ack_lock); + ack_skb = call->acks_soft_tbl; + if (ack_skb) { + rxrpc_get_skb(ack_skb, rxrpc_skb_ack); + ack = (void *)ack_skb->data + sizeof(struct rxrpc_wire_header); + } + spin_unlock_bh(&call->acks_ack_lock); + } + + if (list_empty(&call->tx_buffer)) + goto no_resend; spin_lock(&call->tx_lock); - /* Scan the packet list without dropping the lock and decide which of - * the packets in the Tx buffer we're going to resend and what the new - * resend timeout will be. - */ + if (list_empty(&call->tx_buffer)) + goto no_further_resend; + trace_rxrpc_resend(call); - oldest = now; - list_for_each_entry(txb, &call->tx_buffer, call_link) { - if (test_bit(RXRPC_TXBUF_ACKED, &txb->flags)) - continue; - if (after(txb->seq, transmitted)) - break; + txb = list_first_entry(&call->tx_buffer, struct rxrpc_txbuf, call_link); - rxrpc_see_txbuf(txb, rxrpc_txbuf_see_unacked); + /* Scan the soft ACK table without dropping the lock and resend any + * explicitly NAK'd packets. + */ + if (ack) { + for (i = 0; i < ack->nAcks; i++) { + rxrpc_seq_t seq; - if (test_bit(RXRPC_TXBUF_RESENT, &txb->flags)) { - if (ktime_after(txb->last_sent, max_age)) { - if (ktime_before(txb->last_sent, oldest)) - oldest = txb->last_sent; + if (ack->acks[i] & 1) continue; + seq = ntohl(ack->firstPacket) + i; + if (after(txb->seq, transmitted)) + break; + if (after(txb->seq, seq)) + continue; /* A new hard ACK probably came in */ + list_for_each_entry_from(txb, &call->tx_buffer, call_link) { + if (txb->seq == seq) + goto found_txb; + } + goto no_further_resend; + + found_txb: + if (after(ntohl(txb->wire.serial), call->acks_highest_serial)) + continue; /* Ack point not yet reached */ + + rxrpc_see_txbuf(txb, rxrpc_txbuf_see_unacked); + + if (list_empty(&txb->tx_link)) { + rxrpc_get_txbuf(txb, rxrpc_txbuf_get_retrans); + rxrpc_get_call(call, rxrpc_call_got_tx); + list_add_tail(&txb->tx_link, &retrans_queue); + set_bit(RXRPC_TXBUF_RESENT, &txb->flags); } - unacked = true; + + trace_rxrpc_retransmit(call, txb->seq, + ktime_to_ns(ktime_sub(txb->last_sent, + max_age))); + + if (list_is_last(&txb->call_link, &call->tx_buffer)) + goto no_further_resend; + txb = list_next_entry(txb, call_link); } + } - rxrpc_get_txbuf(txb, rxrpc_txbuf_get_retrans); - list_move_tail(&txb->tx_link, &retrans_queue); + /* Fast-forward through the Tx queue to the point the peer says it has + * seen. Anything between the soft-ACK table and that point will get + * ACK'd or NACK'd in due course, so don't worry about it here; here we + * need to consider retransmitting anything beyond that point. + * + * Note that ACK for a packet can beat the update of tx_transmitted. + */ + if (after_eq(READ_ONCE(call->acks_prev_seq), READ_ONCE(call->tx_transmitted))) + goto no_further_resend; + + list_for_each_entry_from(txb, &call->tx_buffer, call_link) { + if (before_eq(txb->seq, READ_ONCE(call->acks_prev_seq))) + continue; + if (after(txb->seq, READ_ONCE(call->tx_transmitted))) + break; /* Not transmitted yet */ + + if (ack && ack->reason == RXRPC_ACK_PING_RESPONSE && + before(ntohl(txb->wire.serial), ntohl(ack->serial))) + goto do_resend; /* Wasn't accounted for by a more recent ping. */ + + if (ktime_after(txb->last_sent, max_age)) { + if (ktime_before(txb->last_sent, oldest)) + oldest = txb->last_sent; + continue; + } + + do_resend: + unacked = true; + if (list_empty(&txb->tx_link)) { + rxrpc_get_txbuf(txb, rxrpc_txbuf_get_retrans); + list_add_tail(&txb->tx_link, &retrans_queue); + set_bit(RXRPC_TXBUF_RESENT, &txb->flags); + rxrpc_inc_stat(call->rxnet, stat_tx_data_retrans); + } } +no_further_resend: spin_unlock(&call->tx_lock); +no_resend: + rxrpc_free_skb(ack_skb, rxrpc_skb_freed); resend_at = nsecs_to_jiffies(ktime_to_ns(ktime_sub(now, oldest))); resend_at += jiffies + rxrpc_get_rto_backoff(call->peer, @@ -201,8 +280,6 @@ static void rxrpc_resend(struct rxrpc_call *call, unsigned long now_j) while ((txb = list_first_entry_or_null(&retrans_queue, struct rxrpc_txbuf, tx_link))) { list_del_init(&txb->tx_link); - set_bit(RXRPC_TXBUF_RESENT, &txb->flags); - rxrpc_inc_stat(call->rxnet, stat_tx_data_retrans); rxrpc_send_data_packet(call, txb); rxrpc_put_txbuf(txb, rxrpc_txbuf_put_trans); |