dlm: use per-attribute show and store methods

To simplify the configfs interface and remove boilerplate code that also
causes binary bloat.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Teigland <teigland@redhat.com
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
diff --git a/fs/dlm/config.c b/fs/dlm/config.c
index d521bdd..8e294fb 100644
--- a/fs/dlm/config.c
+++ b/fs/dlm/config.c
@@ -61,35 +61,8 @@
 static void drop_node(struct config_group *, struct config_item *);
 static void release_node(struct config_item *);
 
-static ssize_t show_cluster(struct config_item *i, struct configfs_attribute *a,
-			    char *buf);
-static ssize_t store_cluster(struct config_item *i,
-			     struct configfs_attribute *a,
-			     const char *buf, size_t len);
-static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
-			 char *buf);
-static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
-			  const char *buf, size_t len);
-static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
-			 char *buf);
-static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
-			  const char *buf, size_t len);
-
-static ssize_t comm_nodeid_read(struct dlm_comm *cm, char *buf);
-static ssize_t comm_nodeid_write(struct dlm_comm *cm, const char *buf,
-				size_t len);
-static ssize_t comm_local_read(struct dlm_comm *cm, char *buf);
-static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
-				size_t len);
-static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf,
-				size_t len);
-static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf);
-static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf);
-static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
-				size_t len);
-static ssize_t node_weight_read(struct dlm_node *nd, char *buf);
-static ssize_t node_weight_write(struct dlm_node *nd, const char *buf,
-				size_t len);
+static struct configfs_attribute *comm_attrs[];
+static struct configfs_attribute *node_attrs[];
 
 struct dlm_cluster {
 	struct config_group group;
@@ -108,6 +81,12 @@
 	char cl_cluster_name[DLM_LOCKSPACE_LEN];
 };
 
+static struct dlm_cluster *config_item_to_cluster(struct config_item *i)
+{
+	return i ? container_of(to_config_group(i), struct dlm_cluster, group) :
+		   NULL;
+}
+
 enum {
 	CLUSTER_ATTR_TCP_PORT = 0,
 	CLUSTER_ATTR_BUFFER_SIZE,
@@ -124,33 +103,24 @@
 	CLUSTER_ATTR_CLUSTER_NAME,
 };
 
-struct cluster_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct dlm_cluster *, char *);
-	ssize_t (*store)(struct dlm_cluster *, const char *, size_t);
-};
-
-static ssize_t cluster_cluster_name_read(struct dlm_cluster *cl, char *buf)
+static ssize_t cluster_cluster_name_show(struct config_item *item, char *buf)
 {
+	struct dlm_cluster *cl = config_item_to_cluster(item);
 	return sprintf(buf, "%s\n", cl->cl_cluster_name);
 }
 
-static ssize_t cluster_cluster_name_write(struct dlm_cluster *cl,
+static ssize_t cluster_cluster_name_store(struct config_item *item,
 					  const char *buf, size_t len)
 {
+	struct dlm_cluster *cl = config_item_to_cluster(item);
+
 	strlcpy(dlm_config.ci_cluster_name, buf,
 				sizeof(dlm_config.ci_cluster_name));
 	strlcpy(cl->cl_cluster_name, buf, sizeof(cl->cl_cluster_name));
 	return len;
 }
 
-static struct cluster_attribute cluster_attr_cluster_name = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "cluster_name",
-                    .ca_mode = S_IRUGO | S_IWUSR },
-	.show   = cluster_cluster_name_read,
-	.store  = cluster_cluster_name_write,
-};
+CONFIGFS_ATTR(cluster_, cluster_name);
 
 static ssize_t cluster_set(struct dlm_cluster *cl, unsigned int *cl_field,
 			   int *info_field, int check_zero,
@@ -175,17 +145,19 @@
 }
 
 #define CLUSTER_ATTR(name, check_zero)                                        \
-static ssize_t name##_write(struct dlm_cluster *cl, const char *buf, size_t len) \
+static ssize_t cluster_##name##_store(struct config_item *item, \
+		const char *buf, size_t len) \
 {                                                                             \
+	struct dlm_cluster *cl = config_item_to_cluster(item);		      \
 	return cluster_set(cl, &cl->cl_##name, &dlm_config.ci_##name,         \
 			   check_zero, buf, len);                             \
 }                                                                             \
-static ssize_t name##_read(struct dlm_cluster *cl, char *buf)                 \
+static ssize_t cluster_##name##_show(struct config_item *item, char *buf)     \
 {                                                                             \
+	struct dlm_cluster *cl = config_item_to_cluster(item);		      \
 	return snprintf(buf, PAGE_SIZE, "%u\n", cl->cl_##name);               \
 }                                                                             \
-static struct cluster_attribute cluster_attr_##name =                         \
-__CONFIGFS_ATTR(name, 0644, name##_read, name##_write)
+CONFIGFS_ATTR(cluster_, name);
 
 CLUSTER_ATTR(tcp_port, 1);
 CLUSTER_ATTR(buffer_size, 1);
@@ -201,19 +173,19 @@
 CLUSTER_ATTR(recover_callbacks, 0);
 
 static struct configfs_attribute *cluster_attrs[] = {
-	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
-	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size.attr,
-	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size.attr,
-	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer.attr,
-	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs.attr,
-	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs.attr,
-	[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug.attr,
-	[CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol.attr,
-	[CLUSTER_ATTR_TIMEWARN_CS] = &cluster_attr_timewarn_cs.attr,
-	[CLUSTER_ATTR_WAITWARN_US] = &cluster_attr_waitwarn_us.attr,
-	[CLUSTER_ATTR_NEW_RSB_COUNT] = &cluster_attr_new_rsb_count.attr,
-	[CLUSTER_ATTR_RECOVER_CALLBACKS] = &cluster_attr_recover_callbacks.attr,
-	[CLUSTER_ATTR_CLUSTER_NAME] = &cluster_attr_cluster_name.attr,
+	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port,
+	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size,
+	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size,
+	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer,
+	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs,
+	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs,
+	[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug,
+	[CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol,
+	[CLUSTER_ATTR_TIMEWARN_CS] = &cluster_attr_timewarn_cs,
+	[CLUSTER_ATTR_WAITWARN_US] = &cluster_attr_waitwarn_us,
+	[CLUSTER_ATTR_NEW_RSB_COUNT] = &cluster_attr_new_rsb_count,
+	[CLUSTER_ATTR_RECOVER_CALLBACKS] = &cluster_attr_recover_callbacks,
+	[CLUSTER_ATTR_CLUSTER_NAME] = &cluster_attr_cluster_name,
 	NULL,
 };
 
@@ -224,83 +196,11 @@
 	COMM_ATTR_ADDR_LIST,
 };
 
-struct comm_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct dlm_comm *, char *);
-	ssize_t (*store)(struct dlm_comm *, const char *, size_t);
-};
-
-static struct comm_attribute comm_attr_nodeid = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "nodeid",
-                    .ca_mode = S_IRUGO | S_IWUSR },
-	.show   = comm_nodeid_read,
-	.store  = comm_nodeid_write,
-};
-
-static struct comm_attribute comm_attr_local = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "local",
-                    .ca_mode = S_IRUGO | S_IWUSR },
-	.show   = comm_local_read,
-	.store  = comm_local_write,
-};
-
-static struct comm_attribute comm_attr_addr = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "addr",
-                    .ca_mode = S_IWUSR },
-	.store  = comm_addr_write,
-};
-
-static struct comm_attribute comm_attr_addr_list = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "addr_list",
-                    .ca_mode = S_IRUGO },
-	.show   = comm_addr_list_read,
-};
-
-static struct configfs_attribute *comm_attrs[] = {
-	[COMM_ATTR_NODEID] = &comm_attr_nodeid.attr,
-	[COMM_ATTR_LOCAL] = &comm_attr_local.attr,
-	[COMM_ATTR_ADDR] = &comm_attr_addr.attr,
-	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list.attr,
-	NULL,
-};
-
 enum {
 	NODE_ATTR_NODEID = 0,
 	NODE_ATTR_WEIGHT,
 };
 
-struct node_attribute {
-	struct configfs_attribute attr;
-	ssize_t (*show)(struct dlm_node *, char *);
-	ssize_t (*store)(struct dlm_node *, const char *, size_t);
-};
-
-static struct node_attribute node_attr_nodeid = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "nodeid",
-                    .ca_mode = S_IRUGO | S_IWUSR },
-	.show   = node_nodeid_read,
-	.store  = node_nodeid_write,
-};
-
-static struct node_attribute node_attr_weight = {
-	.attr   = { .ca_owner = THIS_MODULE,
-                    .ca_name = "weight",
-                    .ca_mode = S_IRUGO | S_IWUSR },
-	.show   = node_weight_read,
-	.store  = node_weight_write,
-};
-
-static struct configfs_attribute *node_attrs[] = {
-	[NODE_ATTR_NODEID] = &node_attr_nodeid.attr,
-	[NODE_ATTR_WEIGHT] = &node_attr_weight.attr,
-	NULL,
-};
-
 struct dlm_clusters {
 	struct configfs_subsystem subsys;
 };
@@ -349,8 +249,6 @@
 
 static struct configfs_item_operations cluster_ops = {
 	.release = release_cluster,
-	.show_attribute = show_cluster,
-	.store_attribute = store_cluster,
 };
 
 static struct configfs_group_operations spaces_ops = {
@@ -369,8 +267,6 @@
 
 static struct configfs_item_operations comm_ops = {
 	.release = release_comm,
-	.show_attribute = show_comm,
-	.store_attribute = store_comm,
 };
 
 static struct configfs_group_operations nodes_ops = {
@@ -380,8 +276,6 @@
 
 static struct configfs_item_operations node_ops = {
 	.release = release_node,
-	.show_attribute = show_node,
-	.store_attribute = store_node,
 };
 
 static struct config_item_type clusters_type = {
@@ -427,12 +321,6 @@
 	.ct_owner = THIS_MODULE,
 };
 
-static struct dlm_cluster *config_item_to_cluster(struct config_item *i)
-{
-	return i ? container_of(to_config_group(i), struct dlm_cluster, group) :
-		   NULL;
-}
-
 static struct dlm_space *config_item_to_space(struct config_item *i)
 {
 	return i ? container_of(to_config_group(i), struct dlm_space, group) :
@@ -687,66 +575,30 @@
  * Functions for user space to read/write attributes
  */
 
-static ssize_t show_cluster(struct config_item *i, struct configfs_attribute *a,
-			    char *buf)
+static ssize_t comm_nodeid_show(struct config_item *item, char *buf)
 {
-	struct dlm_cluster *cl = config_item_to_cluster(i);
-	struct cluster_attribute *cla =
-			container_of(a, struct cluster_attribute, attr);
-	return cla->show ? cla->show(cl, buf) : 0;
+	return sprintf(buf, "%d\n", config_item_to_comm(item)->nodeid);
 }
 
-static ssize_t store_cluster(struct config_item *i,
-			     struct configfs_attribute *a,
-			     const char *buf, size_t len)
-{
-	struct dlm_cluster *cl = config_item_to_cluster(i);
-	struct cluster_attribute *cla =
-		container_of(a, struct cluster_attribute, attr);
-	return cla->store ? cla->store(cl, buf, len) : -EINVAL;
-}
-
-static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
-			 char *buf)
-{
-	struct dlm_comm *cm = config_item_to_comm(i);
-	struct comm_attribute *cma =
-			container_of(a, struct comm_attribute, attr);
-	return cma->show ? cma->show(cm, buf) : 0;
-}
-
-static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
-			  const char *buf, size_t len)
-{
-	struct dlm_comm *cm = config_item_to_comm(i);
-	struct comm_attribute *cma =
-		container_of(a, struct comm_attribute, attr);
-	return cma->store ? cma->store(cm, buf, len) : -EINVAL;
-}
-
-static ssize_t comm_nodeid_read(struct dlm_comm *cm, char *buf)
-{
-	return sprintf(buf, "%d\n", cm->nodeid);
-}
-
-static ssize_t comm_nodeid_write(struct dlm_comm *cm, const char *buf,
+static ssize_t comm_nodeid_store(struct config_item *item, const char *buf,
 				 size_t len)
 {
-	int rc = kstrtoint(buf, 0, &cm->nodeid);
+	int rc = kstrtoint(buf, 0, &config_item_to_comm(item)->nodeid);
 
 	if (rc)
 		return rc;
 	return len;
 }
 
-static ssize_t comm_local_read(struct dlm_comm *cm, char *buf)
+static ssize_t comm_local_show(struct config_item *item, char *buf)
 {
-	return sprintf(buf, "%d\n", cm->local);
+	return sprintf(buf, "%d\n", config_item_to_comm(item)->local);
 }
 
-static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
+static ssize_t comm_local_store(struct config_item *item, const char *buf,
 				size_t len)
 {
+	struct dlm_comm *cm = config_item_to_comm(item);
 	int rc = kstrtoint(buf, 0, &cm->local);
 
 	if (rc)
@@ -756,8 +608,10 @@
 	return len;
 }
 
-static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf, size_t len)
+static ssize_t comm_addr_store(struct config_item *item, const char *buf,
+		size_t len)
 {
+	struct dlm_comm *cm = config_item_to_comm(item);
 	struct sockaddr_storage *addr;
 	int rv;
 
@@ -783,8 +637,9 @@
 	return len;
 }
 
-static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf)
+static ssize_t comm_addr_list_show(struct config_item *item, char *buf)
 {
+	struct dlm_comm *cm = config_item_to_comm(item);
 	ssize_t s;
 	ssize_t allowance;
 	int i;
@@ -827,32 +682,28 @@
 	return 4096 - allowance;
 }
 
-static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
-			 char *buf)
+CONFIGFS_ATTR(comm_, nodeid);
+CONFIGFS_ATTR(comm_, local);
+CONFIGFS_ATTR_WO(comm_, addr);
+CONFIGFS_ATTR_RO(comm_, addr_list);
+
+static struct configfs_attribute *comm_attrs[] = {
+	[COMM_ATTR_NODEID] = &comm_attr_nodeid,
+	[COMM_ATTR_LOCAL] = &comm_attr_local,
+	[COMM_ATTR_ADDR] = &comm_attr_addr,
+	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list,
+	NULL,
+};
+
+static ssize_t node_nodeid_show(struct config_item *item, char *buf)
 {
-	struct dlm_node *nd = config_item_to_node(i);
-	struct node_attribute *nda =
-			container_of(a, struct node_attribute, attr);
-	return nda->show ? nda->show(nd, buf) : 0;
+	return sprintf(buf, "%d\n", config_item_to_node(item)->nodeid);
 }
 
-static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
-			  const char *buf, size_t len)
-{
-	struct dlm_node *nd = config_item_to_node(i);
-	struct node_attribute *nda =
-		container_of(a, struct node_attribute, attr);
-	return nda->store ? nda->store(nd, buf, len) : -EINVAL;
-}
-
-static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf)
-{
-	return sprintf(buf, "%d\n", nd->nodeid);
-}
-
-static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
+static ssize_t node_nodeid_store(struct config_item *item, const char *buf,
 				 size_t len)
 {
+	struct dlm_node *nd = config_item_to_node(item);
 	uint32_t seq = 0;
 	int rc = kstrtoint(buf, 0, &nd->nodeid);
 
@@ -863,21 +714,30 @@
 	return len;
 }
 
-static ssize_t node_weight_read(struct dlm_node *nd, char *buf)
+static ssize_t node_weight_show(struct config_item *item, char *buf)
 {
-	return sprintf(buf, "%d\n", nd->weight);
+	return sprintf(buf, "%d\n", config_item_to_node(item)->weight);
 }
 
-static ssize_t node_weight_write(struct dlm_node *nd, const char *buf,
+static ssize_t node_weight_store(struct config_item *item, const char *buf,
 				 size_t len)
 {
-	int rc = kstrtoint(buf, 0, &nd->weight);
+	int rc = kstrtoint(buf, 0, &config_item_to_node(item)->weight);
 
 	if (rc)
 		return rc;
 	return len;
 }
 
+CONFIGFS_ATTR(node_, nodeid);
+CONFIGFS_ATTR(node_, weight);
+
+static struct configfs_attribute *node_attrs[] = {
+	[NODE_ATTR_NODEID] = &node_attr_nodeid,
+	[NODE_ATTR_WEIGHT] = &node_attr_weight,
+	NULL,
+};
+
 /*
  * Functions for the dlm to get the info that's been configured
  */