rxrpc: Wrap accesses to get call state to put the barrier in one place

Wrap accesses to get the state of a call from outside of the I/O thread in
a single place so that the barrier needed to order wrt the error code and
abort code is in just that place.

Also use a barrier when setting the call state and again when reading the
call state such that the auxiliary completion info (error code, abort code)
can be read without taking a read lock on the call state lock.

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

1 files changed, 16 insertions, 0 deletions

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 203e0354d86b..9e992487649c 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -903,6 +903,22 @@ bool __rxrpc_abort_call(struct rxrpc_call *call, rxrpc_seq_t seq,
 bool rxrpc_abort_call(struct rxrpc_call *call, rxrpc_seq_t seq,
 		      u32 abort_code, int error, enum rxrpc_abort_reason why);
 
+static inline enum rxrpc_call_state rxrpc_call_state(const struct rxrpc_call *call)
+{
+	/* Order read ->state before read ->error. */
+	return smp_load_acquire(&call->state);
+}
+
+static inline bool rxrpc_call_is_complete(const struct rxrpc_call *call)
+{
+	return rxrpc_call_state(call) == RXRPC_CALL_COMPLETE;
+}
+
+static inline bool rxrpc_call_has_failed(const struct rxrpc_call *call)
+{
+	return rxrpc_call_is_complete(call) && call->completion != RXRPC_CALL_SUCCEEDED;
+}
+
 /*
  * conn_client.c
  */