Merge branch 'configfs-fixup-ptr-error' of git://oss.oracle.com/git/jlbec/linux-2.6

* 'configfs-fixup-ptr-error' of git://oss.oracle.com/git/jlbec/linux-2.6:
  configfs: Allow ->make_item() and ->make_group() to return detailed errors.
  Revert "configfs: Allow ->make_item() and ->make_group() to return detailed errors."

Documentation/filesystems/configfs/configfs.txt

@@ -233,12 +233,10 @@ accomplished via the group operations specified on the group's
 config_item_type.
 
 	struct configfs_group_operations {
-		int (*make_item)(struct config_group *group,
-				 const char *name,
-				 struct config_item **new_item);
-		int (*make_group)(struct config_group *group,
-				  const char *name,
-				  struct config_group **new_group);
+		struct config_item *(*make_item)(struct config_group *group,
+						 const char *name);
+		struct config_group *(*make_group)(struct config_group *group,
+						   const char *name);
 		int (*commit_item)(struct config_item *item);
 		void (*disconnect_notify)(struct config_group *group,
 					  struct config_item *item);

Documentation/filesystems/configfs/configfs_example.c

@@ -273,13 +273,13 @@ static inline struct simple_children *to_simple_children(struct config_item *ite
 	return item ? container_of(to_config_group(item), struct simple_children, group) : NULL;
 }
 
-static int simple_children_make_item(struct config_group *group, const char *name, struct config_item **new_item)
+static struct config_item *simple_children_make_item(struct config_group *group, const char *name)
 {
 	struct simple_child *simple_child;
 
 	simple_child = kzalloc(sizeof(struct simple_child), GFP_KERNEL);
 	if (!simple_child)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 
 	config_item_init_type_name(&simple_child->item, name,
@@ -287,8 +287,7 @@ static int simple_children_make_item(struct config_group *group, const char *nam
 
 	simple_child->storeme = 0;
 
-	*new_item = &simple_child->item;
-	return 0;
+	return &simple_child->item;
 }
 
 static struct configfs_attribute simple_children_attr_description = {
@@ -360,21 +359,20 @@ static struct configfs_subsystem simple_children_subsys = {
  * children of its own.
  */
 
-static int group_children_make_group(struct config_group *group, const char *name, struct config_group **new_group)
+static struct config_group *group_children_make_group(struct config_group *group, const char *name)
 {
 	struct simple_children *simple_children;
 
 	simple_children = kzalloc(sizeof(struct simple_children),
 				  GFP_KERNEL);
 	if (!simple_children)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 
 	config_group_init_type_name(&simple_children->group, name,
 				    &simple_children_type);
 
-	*new_group = &simple_children->group;
-	return 0;
+	return &simple_children->group;
 }
 
 static struct configfs_attribute group_children_attr_description = {

drivers/net/netconsole.c

@@ -585,9 +585,8 @@ static struct config_item_type netconsole_target_type = {
  * Group operations and type for netconsole_subsys.
  */
 
-static int make_netconsole_target(struct config_group *group,
-				  const char *name,
-				  struct config_item **new_item)
+static struct config_item *make_netconsole_target(struct config_group *group,
+						  const char *name)
 {
 	unsigned long flags;
 	struct netconsole_target *nt;
@@ -599,7 +598,7 @@ static int make_netconsole_target(struct config_group *group,
 	nt = kzalloc(sizeof(*nt), GFP_KERNEL);
 	if (!nt) {
 		printk(KERN_ERR "netconsole: failed to allocate memory\n");
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	nt->np.name = "netconsole";
@@ -616,8 +615,7 @@ static int make_netconsole_target(struct config_group *group,
 	list_add(&nt->list, &target_list);
 	spin_unlock_irqrestore(&target_list_lock, flags);
 
-	*new_item = &nt->item;
-	return 0;
+	return &nt->item;
 }
 
 static void drop_netconsole_target(struct config_group *group,

fs/configfs/dir.c

@@ -1027,9 +1027,10 @@ EXPORT_SYMBOL(configfs_undepend_item);
 
 static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 {
-	int ret, module_got = 0;
-	struct config_group *group;
-	struct config_item *item;
+	int ret = 0;
+	int module_got = 0;
+	struct config_group *group = NULL;
+	struct config_item *item = NULL;
 	struct config_item *parent_item;
 	struct configfs_subsystem *subsys;
 	struct configfs_dirent *sd;
@@ -1070,25 +1071,30 @@ static int configfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
 
 	mutex_lock(&subsys->su_mutex);
-	group = NULL;
-	item = NULL;
 	if (type->ct_group_ops->make_group) {
-		ret = type->ct_group_ops->make_group(to_config_group(parent_item), name, &group);
-		if (!ret) {
+		group = type->ct_group_ops->make_group(to_config_group(parent_item), name);
+		if (!group)
+			group = ERR_PTR(-ENOMEM);
+		if (!IS_ERR(group)) {
 			link_group(to_config_group(parent_item), group);
 			item = &group->cg_item;
-		}
+		} else
+			ret = PTR_ERR(group);
 	} else {
-		ret = type->ct_group_ops->make_item(to_config_group(parent_item), name, &item);
-		if (!ret)
+		item = type->ct_group_ops->make_item(to_config_group(parent_item), name);
+		if (!item)
+			item = ERR_PTR(-ENOMEM);
+		if (!IS_ERR(item))
 			link_obj(parent_item, item);
+		else
+			ret = PTR_ERR(item);
 	}
 	mutex_unlock(&subsys->su_mutex);
 
 	kfree(name);
 	if (ret) {
 		/*
-		 * If ret != 0, then link_obj() was never called.
+		 * If item == NULL, then link_obj() was never called.
 		 * There are no extra references to clean up.
 		 */
 		goto out_put;

fs/dlm/config.c

@@ -41,20 +41,16 @@ struct comm;
 struct nodes;
 struct node;
 
-static int make_cluster(struct config_group *, const char *,
-			struct config_group **);
+static struct config_group *make_cluster(struct config_group *, const char *);
 static void drop_cluster(struct config_group *, struct config_item *);
 static void release_cluster(struct config_item *);
-static int make_space(struct config_group *, const char *,
-		      struct config_group **);
+static struct config_group *make_space(struct config_group *, const char *);
 static void drop_space(struct config_group *, struct config_item *);
 static void release_space(struct config_item *);
-static int make_comm(struct config_group *, const char *,
-		     struct config_item **);
+static struct config_item *make_comm(struct config_group *, const char *);
 static void drop_comm(struct config_group *, struct config_item *);
 static void release_comm(struct config_item *);
-static int make_node(struct config_group *, const char *,
-		     struct config_item **);
+static struct config_item *make_node(struct config_group *, const char *);
 static void drop_node(struct config_group *, struct config_item *);
 static void release_node(struct config_item *);
 
@@ -396,8 +392,8 @@ static struct node *to_node(struct config_item *i)
 	return i ? container_of(i, struct node, item) : NULL;
 }
 
-static int make_cluster(struct config_group *g, const char *name,
-			struct config_group **new_g)
+static struct config_group *make_cluster(struct config_group *g,
+					 const char *name)
 {
 	struct cluster *cl = NULL;
 	struct spaces *sps = NULL;
@@ -435,15 +431,14 @@ static int make_cluster(struct config_group *g, const char *name,
 
 	space_list = &sps->ss_group;
 	comm_list = &cms->cs_group;
-	*new_g = &cl->group;
-	return 0;
+	return &cl->group;
 
  fail:
 	kfree(cl);
 	kfree(gps);
 	kfree(sps);
 	kfree(cms);
-	return -ENOMEM;
+	return ERR_PTR(-ENOMEM);
 }
 
 static void drop_cluster(struct config_group *g, struct config_item *i)
@@ -471,8 +466,7 @@ static void release_cluster(struct config_item *i)
 	kfree(cl);
 }
 
-static int make_space(struct config_group *g, const char *name,
-		      struct config_group **new_g)
+static struct config_group *make_space(struct config_group *g, const char *name)
 {
 	struct space *sp = NULL;
 	struct nodes *nds = NULL;
@@ -495,14 +489,13 @@ static int make_space(struct config_group *g, const char *name,
 	INIT_LIST_HEAD(&sp->members);
 	mutex_init(&sp->members_lock);
 	sp->members_count = 0;
-	*new_g = &sp->group;
-	return 0;
+	return &sp->group;
 
  fail:
 	kfree(sp);
 	kfree(gps);
 	kfree(nds);
-	return -ENOMEM;
+	return ERR_PTR(-ENOMEM);
 }
 
 static void drop_space(struct config_group *g, struct config_item *i)
@@ -529,21 +522,19 @@ static void release_space(struct config_item *i)
 	kfree(sp);
 }
 
-static int make_comm(struct config_group *g, const char *name,
-		     struct config_item **new_i)
+static struct config_item *make_comm(struct config_group *g, const char *name)
 {
 	struct comm *cm;
 
 	cm = kzalloc(sizeof(struct comm), GFP_KERNEL);
 	if (!cm)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	config_item_init_type_name(&cm->item, name, &comm_type);
 	cm->nodeid = -1;
 	cm->local = 0;
 	cm->addr_count = 0;
-	*new_i = &cm->item;
-	return 0;
+	return &cm->item;
 }
 
 static void drop_comm(struct config_group *g, struct config_item *i)
@@ -563,15 +554,14 @@ static void release_comm(struct config_item *i)
 	kfree(cm);
 }
 
-static int make_node(struct config_group *g, const char *name,
-		     struct config_item **new_i)
+static struct config_item *make_node(struct config_group *g, const char *name)
 {
 	struct space *sp = to_space(g->cg_item.ci_parent);
 	struct node *nd;
 
 	nd = kzalloc(sizeof(struct node), GFP_KERNEL);
 	if (!nd)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	config_item_init_type_name(&nd->item, name, &node_type);
 	nd->nodeid = -1;
@@ -583,8 +573,7 @@ static int make_node(struct config_group *g, const char *name,
 	sp->members_count++;
 	mutex_unlock(&sp->members_lock);
 
-	*new_i = &nd->item;
-	return 0;
+	return &nd->item;
 }
 
 static void drop_node(struct config_group *g, struct config_item *i)

fs/ocfs2/cluster/heartbeat.c

@@ -1489,31 +1489,22 @@ static struct o2hb_heartbeat_group *to_o2hb_heartbeat_group(struct config_group
 		: NULL;
 }
 
-static int o2hb_heartbeat_group_make_item(struct config_group *group,
-					  const char *name,
-					  struct config_item **new_item)
+static struct config_item *o2hb_heartbeat_group_make_item(struct config_group *group,
+							  const char *name)
 {
 	struct o2hb_region *reg = NULL;
-	int ret = 0;
 
 	reg = kzalloc(sizeof(struct o2hb_region), GFP_KERNEL);
-	if (reg == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (reg == NULL)
+		return ERR_PTR(-ENOMEM);
 
 	config_item_init_type_name(&reg->hr_item, name, &o2hb_region_type);
 
-	*new_item = &reg->hr_item;
-
 	spin_lock(&o2hb_live_lock);
 	list_add_tail(&reg->hr_all_item, &o2hb_all_regions);
 	spin_unlock(&o2hb_live_lock);
-out:
-	if (ret)
-		kfree(reg);
 
-	return ret;
+	return &reg->hr_item;
 }
 
 static void o2hb_heartbeat_group_drop_item(struct config_group *group,

fs/ocfs2/cluster/nodemanager.c

@@ -644,35 +644,23 @@ out:
 	return ret;
 }
 
-static int o2nm_node_group_make_item(struct config_group *group,
-				     const char *name,
-				     struct config_item **new_item)
+static struct config_item *o2nm_node_group_make_item(struct config_group *group,
+						     const char *name)
 {
 	struct o2nm_node *node = NULL;
-	int ret = 0;
 
-	if (strlen(name) > O2NM_MAX_NAME_LEN) {
-		ret = -ENAMETOOLONG;
-		goto out;
-	}
+	if (strlen(name) > O2NM_MAX_NAME_LEN)
+		return ERR_PTR(-ENAMETOOLONG);
 
 	node = kzalloc(sizeof(struct o2nm_node), GFP_KERNEL);
-	if (node == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (node == NULL)
+		return ERR_PTR(-ENOMEM);
 
 	strcpy(node->nd_name, name); /* use item.ci_namebuf instead? */
 	config_item_init_type_name(&node->nd_item, name, &o2nm_node_type);
 	spin_lock_init(&node->nd_lock);
 
-	*new_item = &node->nd_item;
-
-out:
-	if (ret)
-		kfree(node);
-
-	return ret;
+	return &node->nd_item;
 }
 
 static void o2nm_node_group_drop_item(struct config_group *group,
@@ -756,31 +744,25 @@ static struct o2nm_cluster_group *to_o2nm_cluster_group(struct config_group *gro
 }
 #endif
 
-static int o2nm_cluster_group_make_group(struct config_group *group,
-					 const char *name,
-					 struct config_group **new_group)
+static struct config_group *o2nm_cluster_group_make_group(struct config_group *group,
+							  const char *name)
 {
 	struct o2nm_cluster *cluster = NULL;
 	struct o2nm_node_group *ns = NULL;
-	struct config_group *o2hb_group = NULL;
+	struct config_group *o2hb_group = NULL, *ret = NULL;
 	void *defs = NULL;
-	int ret = 0;
 
 	/* this runs under the parent dir's i_mutex; there can be only
 	 * one caller in here at a time */
-	if (o2nm_single_cluster) {
-		ret = -ENOSPC;
-		goto out;
-	}
+	if (o2nm_single_cluster)
+		return ERR_PTR(-ENOSPC);
 
 	cluster = kzalloc(sizeof(struct o2nm_cluster), GFP_KERNEL);
 	ns = kzalloc(sizeof(struct o2nm_node_group), GFP_KERNEL);
 	defs = kcalloc(3, sizeof(struct config_group *), GFP_KERNEL);
 	o2hb_group = o2hb_alloc_hb_set();
-	if (cluster == NULL || ns == NULL || o2hb_group == NULL || defs == NULL) {
-		ret = -ENOMEM;
+	if (cluster == NULL || ns == NULL || o2hb_group == NULL || defs == NULL)
 		goto out;
-	}
 
 	config_group_init_type_name(&cluster->cl_group, name,
 				    &o2nm_cluster_type);
@@ -797,15 +779,16 @@ static int o2nm_cluster_group_make_group(struct config_group *group,
 	cluster->cl_idle_timeout_ms    = O2NET_IDLE_TIMEOUT_MS_DEFAULT;
 	cluster->cl_keepalive_delay_ms = O2NET_KEEPALIVE_DELAY_MS_DEFAULT;
 
-	*new_group = &cluster->cl_group;
+	ret = &cluster->cl_group;
 	o2nm_single_cluster = cluster;
 
 out:
-	if (ret) {
+	if (ret == NULL) {
 		kfree(cluster);
 		kfree(ns);
 		o2hb_free_hb_set(o2hb_group);
 		kfree(defs);
+		ret = ERR_PTR(-ENOMEM);
 	}
 
 	return ret;

include/linux/configfs.h

@@ -148,7 +148,8 @@ struct configfs_attribute {
  * items.  If the item is a group, it may support mkdir(2).
  * Groups supply one of make_group() and make_item().  If the
  * group supports make_group(), one can create group children.  If it
- * supports make_item(), one can create config_item children.  If it has
+ * supports make_item(), one can create config_item children.  make_group()
+ * and make_item() return ERR_PTR() on errors.  If it has
  * default_groups on group->default_groups, it has automatically created
  * group children.  default_groups may coexist alongsize make_group() or
  * make_item(), but if the group wishes to have only default_groups
@@ -165,8 +166,8 @@ struct configfs_item_operations {
 };
 
 struct configfs_group_operations {
-	int (*make_item)(struct config_group *group, const char *name, struct config_item **new_item);
-	int (*make_group)(struct config_group *group, const char *name, struct config_group **new_group);
+	struct config_item *(*make_item)(struct config_group *group, const char *name);
+	struct config_group *(*make_group)(struct config_group *group, const char *name);
 	int (*commit_item)(struct config_item *item);
 	void (*disconnect_notify)(struct config_group *group, struct config_item *item);
 	void (*drop_item)(struct config_group *group, struct config_item *item);