From dfa7d9204054b091949d87270e55e0fd5800c3ae Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 17 Sep 2016 10:49:12 +0100 Subject: [PATCH] rxrpc: Fix retransmission algorithm Make the retransmission algorithm use for-loops instead of do-loops and move the counter increments into the for-statement increment slots. Though the do-loops are slighly more efficient since there will be at least one pass through the each loop, the counter increments are harder to get right as the continue-statements skip them. Without this, if there are any positive acks within the loop, the do-loop will cycle forever because the counter increment is never done. Signed-off-by: David Howells --- net/rxrpc/call_event.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c index 9367c3be31eb..f0cabc48a1b7 100644 --- a/net/rxrpc/call_event.c +++ b/net/rxrpc/call_event.c @@ -163,8 +163,7 @@ static void rxrpc_resend(struct rxrpc_call *call) */ now = jiffies; resend_at = now + rxrpc_resend_timeout; - seq = cursor + 1; - do { + for (seq = cursor + 1; before_eq(seq, top); seq++) { ix = seq & RXRPC_RXTX_BUFF_MASK; annotation = call->rxtx_annotations[ix]; if (annotation == RXRPC_TX_ANNO_ACK) @@ -184,8 +183,7 @@ static void rxrpc_resend(struct rxrpc_call *call) /* Okay, we need to retransmit a packet. */ call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS; - seq++; - } while (before_eq(seq, top)); + } call->resend_at = resend_at; @@ -194,8 +192,7 @@ static void rxrpc_resend(struct rxrpc_call *call) * lock is dropped, it may clear some of the retransmission markers for * packets that it soft-ACKs. */ - seq = cursor + 1; - do { + for (seq = cursor + 1; before_eq(seq, top); seq++) { ix = seq & RXRPC_RXTX_BUFF_MASK; annotation = call->rxtx_annotations[ix]; if (annotation != RXRPC_TX_ANNO_RETRANS) @@ -237,8 +234,7 @@ static void rxrpc_resend(struct rxrpc_call *call) if (after(call->tx_hard_ack, seq)) seq = call->tx_hard_ack; - seq++; - } while (before_eq(seq, top)); + } out_unlock: spin_unlock_bh(&call->lock); -- 2.30.2