[PATCH net-next 27/32] rxrpc: Make the local endpoint hold a ref on a connected call

[David Howells]

Make the local endpoint and it's I/O thread hold a reference on a connected
call until that call is disconnected.  Without this, we're reliant on
either the AF_RXRPC socket to hold a ref (which is dropped when the call is
released) or a queued work item to hold a ref (the work item is being
replaced with the I/O thread).

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

 include/trace/events/rxrpc.h |    2 ++
 net/rxrpc/conn_client.c      |    4 ++++
 2 files changed, 6 insertions(+)

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 4d5eb08025c0..81182efca327 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -257,6 +257,7 @@
 	E_(rxrpc_client_to_idle,		"->Idle")
 
 #define rxrpc_call_traces \
+	EM(rxrpc_call_get_io_thread,		"GET iothread") \
 	EM(rxrpc_call_get_input,		"GET input   ") \
 	EM(rxrpc_call_get_kernel_service,	"GET krnl-srv") \
 	EM(rxrpc_call_get_notify_socket,	"GET notify  ") \
@@ -269,6 +270,7 @@
 	EM(rxrpc_call_new_prealloc_service,	"NEW prealloc") \
 	EM(rxrpc_call_put_discard_prealloc,	"PUT disc-pre") \
 	EM(rxrpc_call_put_discard_error,	"PUT disc-err") \
+	EM(rxrpc_call_put_io_thread,		"PUT iothread") \
 	EM(rxrpc_call_put_input,		"PUT input   ") \
 	EM(rxrpc_call_put_kernel,		"PUT kernel  ") \
 	EM(rxrpc_call_put_poke,			"PUT poke    ") \
diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index 8e3e0ffa4417..26b0ad38f91b 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -718,8 +718,11 @@ int rxrpc_connect_call(struct rxrpc_call *call, gfp_t gfp)
 
 	rxrpc_discard_expired_client_conns(&rxnet->client_conn_reaper);
 
+	rxrpc_get_call(call, rxrpc_call_get_io_thread);
+
 	bundle = rxrpc_prep_call(call, gfp);
 	if (IS_ERR(bundle)) {
+		rxrpc_put_call(call, rxrpc_call_get_io_thread);
 		ret = PTR_ERR(bundle);
 		goto out;
 	}
@@ -902,6 +905,7 @@ void rxrpc_disconnect_client_call(struct rxrpc_bundle *bundle, struct rxrpc_call
 
 out:
 	spin_unlock(&bundle->channel_lock);
+	rxrpc_put_call(call, rxrpc_call_put_io_thread);
 	_leave("");
 	return;
 }