rxrpc: Implement a mechanism to send an event notification to a call

Provide a means by which an event notification can be sent to a call such
that the I/O thread can process it rather than it being done in a separate
workqueue.  This will allow a lot of locking to be removed.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org

1 files changed, 24 insertions, 0 deletions

diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index f6d1b3a6f8c6..997641e3d1c8 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -45,6 +45,29 @@ static struct semaphore rxrpc_call_limiter =
 static struct semaphore rxrpc_kernel_call_limiter =
 	__SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000);
 
+void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what)
+{
+	struct rxrpc_local *local;
+	struct rxrpc_peer *peer = call->peer;
+	bool busy;
+
+	if (WARN_ON_ONCE(!peer))
+		return;
+	local = peer->local;
+
+	if (call->state < RXRPC_CALL_COMPLETE) {
+		spin_lock_bh(&local->lock);
+		busy = !list_empty(&call->attend_link);
+		trace_rxrpc_poke_call(call, busy, what);
+		if (!busy) {
+			rxrpc_get_call(call, rxrpc_call_get_poke);
+			list_add_tail(&call->attend_link, &local->call_attend_q);
+		}
+		spin_unlock_bh(&local->lock);
+		rxrpc_wake_up_io_thread(local);
+	}
+}
+
 static void rxrpc_call_timer_expired(struct timer_list *t)
 {
 	struct rxrpc_call *call = from_timer(call, t, timer);
@@ -137,6 +160,7 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 	INIT_LIST_HEAD(&call->accept_link);
 	INIT_LIST_HEAD(&call->recvmsg_link);
 	INIT_LIST_HEAD(&call->sock_link);
+	INIT_LIST_HEAD(&call->attend_link);
 	INIT_LIST_HEAD(&call->tx_buffer);
 	skb_queue_head_init(&call->recvmsg_queue);
 	skb_queue_head_init(&call->rx_oos_queue);