Commit d41b3f5b authored by David Howells's avatar David Howells
Browse files

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: default avatarDavid Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
parent 0b9bb322

net/rxrpc/af_rxrpc.c

+1 −1
Original line number Diff line number Diff line
@@ -379,7 +379,7 @@ EXPORT_SYMBOL(rxrpc_kernel_end_call); 
bool rxrpc_kernel_check_life(const struct socket *sock,

			     const struct rxrpc_call *call)

{

	return call->state != RXRPC_CALL_COMPLETE;

	return !rxrpc_call_is_complete(call);

}

EXPORT_SYMBOL(rxrpc_kernel_check_life);

net/rxrpc/ar-internal.h

+16 −0
Original line number Diff line number Diff line
@@ -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

 */

net/rxrpc/call_state.c

+2 −1
Original line number Diff line number Diff line
@@ -19,7 +19,8 @@ bool __rxrpc_set_call_completion(struct rxrpc_call *call, 
		call->abort_code = abort_code;

		call->error = error;

		call->completion = compl;

		call->state = RXRPC_CALL_COMPLETE;

		/* Allow reader of completion state to operate locklessly */

		smp_store_release(&call->state, RXRPC_CALL_COMPLETE);

		trace_rxrpc_call_complete(call);

		wake_up(&call->waitq);

		rxrpc_notify_socket(call);

net/rxrpc/recvmsg.c

+6 −6
Original line number Diff line number Diff line
@@ -89,7 +89,7 @@ static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg) 
		ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp);

		break;

	default:

		pr_err("Invalid terminal call state %u\n", call->state);

		pr_err("Invalid terminal call state %u\n", call->completion);

		BUG();

		break;

	}
@@ -111,7 +111,7 @@ static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) 


	trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh);



	if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY)

	if (rxrpc_call_state(call) == RXRPC_CALL_CLIENT_RECV_REPLY)

		rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack);



	write_lock(&call->state_lock);
@@ -210,7 +210,7 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, 
	rx_pkt_offset = call->rx_pkt_offset;

	rx_pkt_len = call->rx_pkt_len;



	if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) {

	if (rxrpc_call_state(call) >= RXRPC_CALL_SERVER_ACK_REQUEST) {

		seq = lower_32_bits(atomic64_read(&call->ackr_window)) - 1;

		ret = 1;

		goto done;
@@ -416,7 +416,7 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 
		msg->msg_namelen = len;

	}



	switch (READ_ONCE(call->state)) {

	switch (rxrpc_call_state(call)) {

	case RXRPC_CALL_CLIENT_RECV_REPLY:

	case RXRPC_CALL_SERVER_RECV_REQUEST:

	case RXRPC_CALL_SERVER_ACK_REQUEST:
@@ -436,7 +436,7 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 
	if (ret < 0)

		goto error_unlock_call;



	if (call->state == RXRPC_CALL_COMPLETE) {

	if (rxrpc_call_is_complete(call)) {

		ret = rxrpc_recvmsg_term(call, msg);

		if (ret < 0)

			goto error_unlock_call;
@@ -516,7 +516,7 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call, 


	mutex_lock(&call->user_mutex);



	switch (READ_ONCE(call->state)) {

	switch (rxrpc_call_state(call)) {

	case RXRPC_CALL_CLIENT_RECV_REPLY:

	case RXRPC_CALL_SERVER_RECV_REQUEST:

	case RXRPC_CALL_SERVER_ACK_REQUEST:

net/rxrpc/sendmsg.c

+13 −16
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error, 
{

	_enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);



	if (!call->send_abort && call->state < RXRPC_CALL_COMPLETE) {

	if (!call->send_abort && !rxrpc_call_is_complete(call)) {

		call->send_abort_why = why;

		call->send_abort_err = error;

		call->send_abort_seq = 0;
@@ -60,7 +60,7 @@ static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx, 
		if (rxrpc_check_tx_space(call, NULL))

			return 0;



		if (call->state >= RXRPC_CALL_COMPLETE)

		if (rxrpc_call_is_complete(call))

			return call->error;



		if (signal_pending(current))
@@ -95,7 +95,7 @@ static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx, 
		if (rxrpc_check_tx_space(call, &tx_win))

			return 0;



		if (call->state >= RXRPC_CALL_COMPLETE)

		if (rxrpc_call_is_complete(call))

			return call->error;



		if (timeout == 0 &&
@@ -124,7 +124,7 @@ static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx, 
		if (rxrpc_check_tx_space(call, NULL))

			return 0;



		if (call->state >= RXRPC_CALL_COMPLETE)

		if (rxrpc_call_is_complete(call))

			return call->error;



		trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
@@ -273,7 +273,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx, 
	ret = -EPIPE;

	if (sk->sk_shutdown & SEND_SHUTDOWN)

		goto maybe_error;

	state = READ_ONCE(call->state);

	state = rxrpc_call_state(call);

	ret = -ESHUTDOWN;

	if (state >= RXRPC_CALL_COMPLETE)

		goto maybe_error;
@@ -350,7 +350,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx, 


		/* check for the far side aborting the call or a network error

		 * occurring */

		if (call->state == RXRPC_CALL_COMPLETE)

		if (rxrpc_call_is_complete(call))

			goto call_terminated;



		/* add the packet to the send queue if it's now full */
@@ -375,12 +375,9 @@ static int rxrpc_send_data(struct rxrpc_sock *rx, 


success:

	ret = copied;

	if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {

		read_lock(&call->state_lock);

		if (call->error < 0)

	if (rxrpc_call_is_complete(call) &&

	    call->error < 0)

		ret = call->error;

		read_unlock(&call->state_lock);

	}

out:

	call->tx_pending = txb;

	_leave(" = %d", ret);
@@ -618,10 +615,10 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len) 
			return PTR_ERR(call);

		/* ... and we have the call lock. */

		ret = 0;

		if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)

		if (rxrpc_call_is_complete(call))

			goto out_put_unlock;

	} else {

		switch (READ_ONCE(call->state)) {

		switch (rxrpc_call_state(call)) {

		case RXRPC_CALL_UNINITIALISED:

		case RXRPC_CALL_CLIENT_AWAIT_CONN:

		case RXRPC_CALL_SERVER_PREALLOC:
@@ -675,7 +672,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len) 
		break;

	}



	state = READ_ONCE(call->state);

	state = rxrpc_call_state(call);

	_debug("CALL %d USR %lx ST %d on CONN %p",

	       call->debug_id, call->user_call_ID, state, call->conn);
@@ -735,7 +732,7 @@ int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call, 
	_debug("CALL %d USR %lx ST %d on CONN %p",

	       call->debug_id, call->user_call_ID, call->state, call->conn);



	switch (READ_ONCE(call->state)) {

	switch (rxrpc_call_state(call)) {

	case RXRPC_CALL_CLIENT_SEND_REQUEST:

	case RXRPC_CALL_SERVER_ACK_REQUEST:

	case RXRPC_CALL_SERVER_SEND_REPLY: