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 <dhowells@redhat.com>
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 9367c3b..f0cabc4 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -163,8 +163,7 @@
*/
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 @@
/* 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 @@
* 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 @@
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);