[PATCH net-next 13/32] rxrpc: Don't lock call->tx_lock to access call->tx_buffer

From: David Howells
Date: Tue Dec 06 2022 - 11:02:00 EST


call->tx_buffer is now only accessed within the I/O thread (->tx_sendmsg is
the way sendmsg passes packets to the I/O thread) so there's no need to
lock around it.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
---

net/rxrpc/txbuf.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/net/rxrpc/txbuf.c b/net/rxrpc/txbuf.c
index d2cf2aac3adb..d43be8512386 100644
--- a/net/rxrpc/txbuf.c
+++ b/net/rxrpc/txbuf.c
@@ -110,12 +110,8 @@ void rxrpc_shrink_call_tx_buffer(struct rxrpc_call *call)

_enter("%x/%x/%x", call->tx_bottom, call->acks_hard_ack, call->tx_top);

- for (;;) {
- spin_lock(&call->tx_lock);
- txb = list_first_entry_or_null(&call->tx_buffer,
- struct rxrpc_txbuf, call_link);
- if (!txb)
- break;
+ while ((txb = list_first_entry_or_null(&call->tx_buffer,
+ struct rxrpc_txbuf, call_link))) {
hard_ack = smp_load_acquire(&call->acks_hard_ack);
if (before(hard_ack, txb->seq))
break;
@@ -128,15 +124,11 @@ void rxrpc_shrink_call_tx_buffer(struct rxrpc_call *call)

trace_rxrpc_txqueue(call, rxrpc_txqueue_dequeue);

- spin_unlock(&call->tx_lock);
-
rxrpc_put_txbuf(txb, rxrpc_txbuf_put_rotated);
if (after(call->acks_hard_ack, call->tx_bottom + 128))
wake = true;
}

- spin_unlock(&call->tx_lock);
-
if (wake)
wake_up(&call->waitq);
}