rxrpc: Use refcount_t rather than atomic_t

Move to using refcount_t rather than atomic_t for refcounts in rxrpc.

Signed-off-by: David Howells <[email protected]>
cc: Marc Dionne <[email protected]>
cc: [email protected]
Signed-off-by: David S. Miller <[email protected]>

Author: dhowells

include/trace/events/rxrpc.h

@@ -583,7 +583,7 @@ TRACE_EVENT(rxrpc_client,
 	    TP_fast_assign(
 		    __entry->conn = conn ? conn->debug_id : 0;
 		    __entry->channel = channel;
-		    __entry->usage = conn ? atomic_read(&conn->usage) : -2;
+		    __entry->usage = conn ? refcount_read(&conn->ref) : -2;
 		    __entry->op = op;
 		    __entry->cid = conn ? conn->proto.cid : 0;
 			   ),

net/rxrpc/af_rxrpc.c

@@ -351,7 +351,7 @@ static void rxrpc_dummy_notify_rx(struct sock *sk, struct rxrpc_call *rxcall,
  */
 void rxrpc_kernel_end_call(struct socket *sock, struct rxrpc_call *call)
 {
-	_enter("%d{%d}", call->debug_id, atomic_read(&call->usage));
+	_enter("%d{%d}", call->debug_id, refcount_read(&call->ref));
 
 	mutex_lock(&call->user_mutex);
 	rxrpc_release_call(rxrpc_sk(sock->sk), call);

net/rxrpc/ar-internal.h

@@ -15,14 +15,6 @@
 #include <keys/rxrpc-type.h>
 #include "protocol.h"
 
-#if 0
-#define CHECK_SLAB_OKAY(X)				     \
-	BUG_ON(atomic_read((X)) >> (sizeof(atomic_t) - 2) == \
-	       (POISON_FREE << 8 | POISON_FREE))
-#else
-#define CHECK_SLAB_OKAY(X) do {} while (0)
-#endif
-
 #define FCRYPT_BSIZE 8
 struct rxrpc_crypt {
 	union {
@@ -279,7 +271,7 @@ struct rxrpc_security {
 struct rxrpc_local {
 	struct rcu_head		rcu;
 	atomic_t		active_users;	/* Number of users of the local endpoint */
-	atomic_t		usage;		/* Number of references to the structure */
+	refcount_t		ref;		/* Number of references to the structure */
 	struct rxrpc_net	*rxnet;		/* The network ns in which this resides */
 	struct hlist_node	link;
 	struct socket		*socket;	/* my UDP socket */
@@ -304,7 +296,7 @@ struct rxrpc_local {
  */
 struct rxrpc_peer {
 	struct rcu_head		rcu;		/* This must be first */
-	atomic_t		usage;
+	refcount_t		ref;
 	unsigned long		hash_key;
 	struct hlist_node	hash_link;
 	struct rxrpc_local	*local;
@@ -406,7 +398,7 @@ enum rxrpc_conn_proto_state {
  */
 struct rxrpc_bundle {
 	struct rxrpc_conn_parameters params;
-	atomic_t		usage;
+	refcount_t		ref;
 	unsigned int		debug_id;
 	bool			try_upgrade;	/* True if the bundle is attempting upgrade */
 	bool			alloc_conn;	/* True if someone's getting a conn */
@@ -427,7 +419,7 @@ struct rxrpc_connection {
 	struct rxrpc_conn_proto	proto;
 	struct rxrpc_conn_parameters params;
 
-	atomic_t		usage;
+	refcount_t		ref;
 	struct rcu_head		rcu;
 	struct list_head	cache_link;
 
@@ -609,7 +601,7 @@ struct rxrpc_call {
 	int			error;		/* Local error incurred */
 	enum rxrpc_call_state	state;		/* current state of call */
 	enum rxrpc_call_completion completion;	/* Call completion condition */
-	atomic_t		usage;
+	refcount_t		ref;
 	u16			service_id;	/* service ID */
 	u8			security_ix;	/* Security type */
 	enum rxrpc_interruptibility interruptibility; /* At what point call may be interrupted */

net/rxrpc/call_accept.c

@@ -91,7 +91,7 @@ static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
 				  (head + 1) & (size - 1));
 
 		trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service,
-				 atomic_read(&conn->usage), here);
+				 refcount_read(&conn->ref), here);
 	}
 
 	/* Now it gets complicated, because calls get registered with the
@@ -104,7 +104,7 @@ static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
 	call->state = RXRPC_CALL_SERVER_PREALLOC;
 
 	trace_rxrpc_call(call->debug_id, rxrpc_call_new_service,
-			 atomic_read(&call->usage),
+			 refcount_read(&call->ref),
 			 here, (const void *)user_call_ID);
 
 	write_lock(&rx->call_lock);

net/rxrpc/call_object.c

@@ -112,7 +112,7 @@ struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
 found_extant_call:
 	rxrpc_get_call(call, rxrpc_call_got);
 	read_unlock(&rx->call_lock);
-	_leave(" = %p [%d]", call, atomic_read(&call->usage));
+	_leave(" = %p [%d]", call, refcount_read(&call->ref));
 	return call;
 }
 
@@ -160,7 +160,7 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp,
 	spin_lock_init(&call->notify_lock);
 	spin_lock_init(&call->input_lock);
 	rwlock_init(&call->state_lock);
-	atomic_set(&call->usage, 1);
+	refcount_set(&call->ref, 1);
 	call->debug_id = debug_id;
 	call->tx_total_len = -1;
 	call->next_rx_timo = 20 * HZ;
@@ -299,7 +299,7 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 	call->interruptibility = p->interruptibility;
 	call->tx_total_len = p->tx_total_len;
 	trace_rxrpc_call(call->debug_id, rxrpc_call_new_client,
-			 atomic_read(&call->usage),
+			 refcount_read(&call->ref),
 			 here, (const void *)p->user_call_ID);
 	if (p->kernel)
 		__set_bit(RXRPC_CALL_KERNEL, &call->flags);
@@ -352,7 +352,7 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 		goto error_attached_to_socket;
 
 	trace_rxrpc_call(call->debug_id, rxrpc_call_connected,
-			 atomic_read(&call->usage), here, NULL);
+			 refcount_read(&call->ref), here, NULL);
 
 	rxrpc_start_call_timer(call);
 
@@ -372,7 +372,7 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 				    RX_CALL_DEAD, -EEXIST);
 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
-			 atomic_read(&call->usage), here, ERR_PTR(-EEXIST));
+			 refcount_read(&call->ref), here, ERR_PTR(-EEXIST));
 	rxrpc_release_call(rx, call);
 	mutex_unlock(&call->user_mutex);
 	rxrpc_put_call(call, rxrpc_call_put);
@@ -386,7 +386,7 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 	 */
 error_attached_to_socket:
 	trace_rxrpc_call(call->debug_id, rxrpc_call_error,
-			 atomic_read(&call->usage), here, ERR_PTR(ret));
+			 refcount_read(&call->ref), here, ERR_PTR(ret));
 	set_bit(RXRPC_CALL_DISCONNECTED, &call->flags);
 	__rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 				    RX_CALL_DEAD, ret);
@@ -442,8 +442,9 @@ void rxrpc_incoming_call(struct rxrpc_sock *rx,
 bool rxrpc_queue_call(struct rxrpc_call *call)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_fetch_add_unless(&call->usage, 1, 0);
-	if (n == 0)
+	int n;
+
+	if (!__refcount_inc_not_zero(&call->ref, &n))
 		return false;
 	if (rxrpc_queue_work(&call->processor))
 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued, n + 1,
@@ -459,7 +460,7 @@ bool rxrpc_queue_call(struct rxrpc_call *call)
 bool __rxrpc_queue_call(struct rxrpc_call *call)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_read(&call->usage);
+	int n = refcount_read(&call->ref);
 	ASSERTCMP(n, >=, 1);
 	if (rxrpc_queue_work(&call->processor))
 		trace_rxrpc_call(call->debug_id, rxrpc_call_queued_ref, n,
@@ -476,7 +477,7 @@ void rxrpc_see_call(struct rxrpc_call *call)
 {
 	const void *here = __builtin_return_address(0);
 	if (call) {
-		int n = atomic_read(&call->usage);
+		int n = refcount_read(&call->ref);
 
 		trace_rxrpc_call(call->debug_id, rxrpc_call_seen, n,
 				 here, NULL);
@@ -486,11 +487,11 @@ void rxrpc_see_call(struct rxrpc_call *call)
 bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_fetch_add_unless(&call->usage, 1, 0);
+	int n;
 
-	if (n == 0)
+	if (!__refcount_inc_not_zero(&call->ref, &n))
 		return false;
-	trace_rxrpc_call(call->debug_id, op, n, here, NULL);
+	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
 	return true;
 }
 
@@ -500,9 +501,10 @@ bool rxrpc_try_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 {
 	const void *here = __builtin_return_address(0);
-	int n = atomic_inc_return(&call->usage);
+	int n;
 
-	trace_rxrpc_call(call->debug_id, op, n, here, NULL);
+	__refcount_inc(&call->ref, &n);
+	trace_rxrpc_call(call->debug_id, op, n + 1, here, NULL);
 }
 
 /*
@@ -527,10 +529,10 @@ void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 	struct rxrpc_connection *conn = call->conn;
 	bool put = false;
 
-	_enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
+	_enter("{%d,%d}", call->debug_id, refcount_read(&call->ref));
 
 	trace_rxrpc_call(call->debug_id, rxrpc_call_release,
-			 atomic_read(&call->usage),
+			 refcount_read(&call->ref),
 			 here, (const void *)call->flags);
 
 	ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
@@ -619,14 +621,14 @@ void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 	struct rxrpc_net *rxnet = call->rxnet;
 	const void *here = __builtin_return_address(0);
 	unsigned int debug_id = call->debug_id;
+	bool dead;
 	int n;
 
 	ASSERT(call != NULL);
 
-	n = atomic_dec_return(&call->usage);
+	dead = __refcount_dec_and_test(&call->ref, &n);
 	trace_rxrpc_call(debug_id, op, n, here, NULL);
-	ASSERTCMP(n, >=, 0);
-	if (n == 0) {
+	if (dead) {
 		_debug("call %d dead", call->debug_id);
 		ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 
@@ -716,7 +718,7 @@ void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 			list_del_init(&call->link);
 
 			pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
-			       call, atomic_read(&call->usage),
+			       call, refcount_read(&call->ref),
 			       rxrpc_call_states[call->state],
 			       call->flags, call->events);
 

net/rxrpc/conn_client.c

@@ -102,7 +102,7 @@ void rxrpc_destroy_client_conn_ids(void)
 	if (!idr_is_empty(&rxrpc_client_conn_ids)) {
 		idr_for_each_entry(&rxrpc_client_conn_ids, conn, id) {
 			pr_err("AF_RXRPC: Leaked client conn %p {%d}\n",
-			       conn, atomic_read(&conn->usage));
+			       conn, refcount_read(&conn->ref));
 		}
 		BUG();
 	}
@@ -122,7 +122,7 @@ static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_conn_parameters *cp,
 	if (bundle) {
 		bundle->params = *cp;
 		rxrpc_get_peer(bundle->params.peer);
-		atomic_set(&bundle->usage, 1);
+		refcount_set(&bundle->ref, 1);
 		spin_lock_init(&bundle->channel_lock);
 		INIT_LIST_HEAD(&bundle->waiting_calls);
 	}
@@ -131,7 +131,7 @@ static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_conn_parameters *cp,
 
 struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *bundle)
 {
-	atomic_inc(&bundle->usage);
+	refcount_inc(&bundle->ref);
 	return bundle;
 }
 
@@ -144,10 +144,13 @@ static void rxrpc_free_bundle(struct rxrpc_bundle *bundle)
 void rxrpc_put_bundle(struct rxrpc_bundle *bundle)
 {
 	unsigned int d = bundle->debug_id;
-	unsigned int u = atomic_dec_return(&bundle->usage);
+	bool dead;
+	int r;
 
-	_debug("PUT B=%x %u", d, u);
-	if (u == 0)
+	dead = __refcount_dec_and_test(&bundle->ref, &r);
+
+	_debug("PUT B=%x %d", d, r);
+	if (dead)
 		rxrpc_free_bundle(bundle);
 }
 
@@ -169,7 +172,7 @@ rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle, gfp_t gfp)
 		return ERR_PTR(-ENOMEM);
 	}
 
-	atomic_set(&conn->usage, 1);
+	refcount_set(&conn->ref, 1);
 	conn->bundle		= bundle;
 	conn->params		= bundle->params;
 	conn->out_clientflag	= RXRPC_CLIENT_INITIATED;
@@ -195,7 +198,7 @@ rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle, gfp_t gfp)
 	key_get(conn->params.key);
 
 	trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_client,
-			 atomic_read(&conn->usage),
+			 refcount_read(&conn->ref),
 			 __builtin_return_address(0));
 
 	atomic_inc(&rxnet->nr_client_conns);
@@ -966,14 +969,13 @@ void rxrpc_put_client_conn(struct rxrpc_connection *conn)
 {
 	const void *here = __builtin_return_address(0);
 	unsigned int debug_id = conn->debug_id;
-	int n;
+	bool dead;
+	int r;
 
-	n = atomic_dec_return(&conn->usage);
-	trace_rxrpc_conn(debug_id, rxrpc_conn_put_client, n, here);
-	if (n <= 0) {
-		ASSERTCMP(n, >=, 0);
+	dead = __refcount_dec_and_test(&conn->ref, &r);
+	trace_rxrpc_conn(debug_id, rxrpc_conn_put_client, r - 1, here);
+	if (dead)
 		rxrpc_kill_client_conn(conn);
-	}
 }
 
 /*