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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>
hifive-unleashed-5.1
David Howells 2016-09-17 10:49:12 +01:00
parent d01dc4c3c1
commit dfa7d92040
1 changed files with 4 additions and 8 deletions
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12
net/rxrpc/call_event.c
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@ -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);