[PATCH AUTOSEL 5.4 12/32] rxrpc: Abstract out the calculation of whether there's Tx space

Sasha Levin
2020-04-07T00:06:46Z

From: David Howells <dhowells@redhat.com>

[ Upstream commit 158fe6665389964a1de212818b4a5c52b7f7aff4 ]

Abstract out the calculation of there being sufficient Tx buffer space.
This is reproduced several times in the rxrpc sendmsg code.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/rxrpc/sendmsg.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 813fd68881429..a13051d380973 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -17,6 +17,21 @@
#include <net/af_rxrpc.h>
#include "ar-internal.h"

+/*
+ * Return true if there's sufficient Tx queue space.
+ */
+static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
+{
+ unsigned int win_size =
+ min_t(unsigned int, call->tx_winsize,
+ call->cong_cwnd + call->cong_extra);
+ rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
+
+ if (_tx_win)
+ *_tx_win = tx_win;
+ return call->tx_top - tx_win < win_size;
+}
+
/*
* Wait for space to appear in the Tx queue or a signal to occur.
*/
@@ -26,9 +41,7 @@ static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
{
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
- if (call->tx_top - call->tx_hard_ack <
- min_t(unsigned int, call->tx_winsize,
- call->cong_cwnd + call->cong_extra))
+ if (rxrpc_check_tx_space(call, NULL))
return 0;

if (call->state >= RXRPC_CALL_COMPLETE)
@@ -68,9 +81,7 @@ static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
set_current_state(TASK_UNINTERRUPTIBLE);

tx_win = READ_ONCE(call->tx_hard_ack);
- if (call->tx_top - tx_win <
- min_t(unsigned int, call->tx_winsize,
- call->cong_cwnd + call->cong_extra))
+ if (rxrpc_check_tx_space(call, &tx_win))
return 0;

if (call->state >= RXRPC_CALL_COMPLETE)
@@ -302,9 +313,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,

_debug("alloc");

- if (call->tx_top - call->tx_hard_ack >=
- min_t(unsigned int, call->tx_winsize,
- call->cong_cwnd + call->cong_extra)) {
+ if (!rxrpc_check_tx_space(call, NULL)) {
ret = -EAGAIN;
if (msg->msg_flags & MSG_DONTWAIT)
goto maybe_error;
--
2.20.1