C++ config_item_put函数代码示例

static void target_fabric_drop_lun(
	struct config_group *group,
	struct config_item *item)
{
	struct se_lun *lun = container_of(to_config_group(item),
				struct se_lun, lun_group);
	struct config_item *df_item;
	struct config_group *lun_cg, *port_stat_grp;
	int i;

	port_stat_grp = &lun->port_stat_grps.stat_group;
	for (i = 0; port_stat_grp->default_groups[i]; i++) {
		df_item = &port_stat_grp->default_groups[i]->cg_item;
		port_stat_grp->default_groups[i] = NULL;
		config_item_put(df_item);
	}
	kfree(port_stat_grp->default_groups);

	lun_cg = &lun->lun_group;
	for (i = 0; lun_cg->default_groups[i]; i++) {
		df_item = &lun_cg->default_groups[i]->cg_item;
		lun_cg->default_groups[i] = NULL;
		config_item_put(df_item);
	}
	kfree(lun_cg->default_groups);

	config_item_put(item);
}

static void target_fabric_drop_mappedlun(
	struct config_group *group,
	struct config_item *item)
{
	struct se_lun_acl *lacl = container_of(to_config_group(item),
			struct se_lun_acl, se_lun_group);
	struct config_item *df_item;
	struct config_group *lacl_cg = NULL, *ml_stat_grp = NULL;
	int i;

	ml_stat_grp = &lacl->ml_stat_grps.stat_group;
	for (i = 0; ml_stat_grp->default_groups[i]; i++) {
		df_item = &ml_stat_grp->default_groups[i]->cg_item;
		ml_stat_grp->default_groups[i] = NULL;
		config_item_put(df_item);
	}
	kfree(ml_stat_grp->default_groups);

	lacl_cg = &lacl->se_lun_group;
	for (i = 0; lacl_cg->default_groups[i]; i++) {
		df_item = &lacl_cg->default_groups[i]->cg_item;
		lacl_cg->default_groups[i] = NULL;
		config_item_put(df_item);
	}
	kfree(lacl_cg->default_groups);

	config_item_put(item);
}

int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
	int ret;
	struct path path;
	struct configfs_dirent *sd;
	struct config_item *parent_item;
	struct config_item *target_item = NULL;
	struct config_item_type *type;

	ret = -EPERM;  /* What lack-of-symlink returns */
	if (dentry->d_parent == configfs_sb->s_root)
		goto out;

	sd = dentry->d_parent->d_fsdata;
	/*
	 * Fake invisibility if dir belongs to a group/default groups hierarchy
	 * being attached
	 */
	ret = -ENOENT;
	if (!configfs_dirent_is_ready(sd))
		goto out;

	parent_item = configfs_get_config_item(dentry->d_parent);
	type = parent_item->ci_type;

	ret = -EPERM;
	if (!type || !type->ct_item_ops ||
	    !type->ct_item_ops->allow_link)
		goto out_put;

	ret = get_target(symname, &path, &target_item);
	if (ret)
		goto out_put;

	ret = type->ct_item_ops->allow_link(parent_item, target_item);
	if (!ret) {
		mutex_lock(&configfs_symlink_mutex);
		ret = create_link(parent_item, target_item, dentry);
		mutex_unlock(&configfs_symlink_mutex);
		if (ret && type->ct_item_ops->drop_link)
			type->ct_item_ops->drop_link(parent_item,
						     target_item);
	}

	config_item_put(target_item);
	path_put(&path);

out_put:
	config_item_put(parent_item);

out:
	return ret;
}

int configfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct configfs_dirent *sd = dentry->d_fsdata;
	struct configfs_symlink *sl;
	struct config_item *parent_item;
	struct config_item_type *type;
	int ret;

	ret = -EPERM;  /* What lack-of-symlink returns */
	if (!(sd->s_type & CONFIGFS_ITEM_LINK))
		goto out;

	BUG_ON(dentry->d_parent == configfs_sb->s_root);

	sl = sd->s_element;

	parent_item = configfs_get_config_item(dentry->d_parent);
	type = parent_item->ci_type;

	spin_lock(&configfs_dirent_lock);
	list_del_init(&sd->s_sibling);
	spin_unlock(&configfs_dirent_lock);
	configfs_drop_dentry(sd, dentry->d_parent);
	dput(dentry);
	configfs_put(sd);

	/*
	 * drop_link() must be called before
	 * list_del_init(&sl->sl_list), so that the order of
	 * drop_link(this, target) and drop_item(target) is preserved.
	 */
	if (type && type->ct_item_ops &&
	    type->ct_item_ops->drop_link)
		type->ct_item_ops->drop_link(parent_item,
					       sl->sl_target);

	spin_lock(&configfs_dirent_lock);
	list_del_init(&sl->sl_list);
	spin_unlock(&configfs_dirent_lock);

	/* Put reference from create_link() */
	config_item_put(sl->sl_target);
	kfree(sl);

	config_item_put(parent_item);

	ret = 0;

out:
	return ret;
}

int configfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct configfs_dirent *sd = dentry->d_fsdata;
	struct configfs_symlink *sl;
	struct config_item *parent_item;
	struct config_item_type *type;
	int ret;

	ret = -EPERM;  /*                              */
	if (!(sd->s_type & CONFIGFS_ITEM_LINK))
		goto out;

	sl = sd->s_element;

	parent_item = configfs_get_config_item(dentry->d_parent);
	type = parent_item->ci_type;

	spin_lock(&configfs_dirent_lock);
	list_del_init(&sd->s_sibling);
	spin_unlock(&configfs_dirent_lock);
	configfs_drop_dentry(sd, dentry->d_parent);
	dput(dentry);
	configfs_put(sd);

	/*
                                     
                                                     
                                                               
  */
	if (type && type->ct_item_ops &&
	    type->ct_item_ops->drop_link)
		type->ct_item_ops->drop_link(parent_item,
					       sl->sl_target);

	spin_lock(&configfs_dirent_lock);
	list_del_init(&sl->sl_list);
	spin_unlock(&configfs_dirent_lock);

	/*                                  */
	config_item_put(sl->sl_target);
	kfree(sl);

	config_item_put(parent_item);

	ret = 0;

out:
	return ret;
}

int configfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
	int ret;
	struct path path;
	struct configfs_dirent *sd;
	struct config_item *parent_item;
	struct config_item *target_item = NULL;
	struct config_item_type *type;

	sd = dentry->d_parent->d_fsdata;
	/*
                                                                        
                  
  */
	ret = -ENOENT;
	if (!configfs_dirent_is_ready(sd))
		goto out;

	parent_item = configfs_get_config_item(dentry->d_parent);
	type = parent_item->ci_type;

	ret = -EPERM;
	if (!type || !type->ct_item_ops ||
	    !type->ct_item_ops->allow_link)
		goto out_put;

	ret = get_target(symname, &path, &target_item, dentry->d_sb);
	if (ret)
		goto out_put;

	ret = type->ct_item_ops->allow_link(parent_item, target_item);
	if (!ret) {
		mutex_lock(&configfs_symlink_mutex);
		ret = create_link(parent_item, target_item, dentry);
		mutex_unlock(&configfs_symlink_mutex);
		if (ret && type->ct_item_ops->drop_link)
			type->ct_item_ops->drop_link(parent_item,
						     target_item);
	}

	config_item_put(target_item);
	path_put(&path);

out_put:
	config_item_put(parent_item);

out:
	return ret;
}

static void device_drop_group(struct config_group *group,
			       struct config_item *item)
{
 	iio_dummy_remove(item->ci_name);
	printk(KERN_ALERT "device drop group called\n");
	config_item_put(item);	
}

static int create_link(struct config_item *parent_item,
               struct config_item *item,
               struct dentry *dentry)
{
    struct configfs_dirent *target_sd = item->ci_dentry->d_fsdata;
    struct configfs_symlink *sl;
    int ret;

    ret = -ENOMEM;
    sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL);
    if (sl) {
        sl->sl_target = config_item_get(item);
        /* FIXME: needs a lock, I'd bet */
        list_add(&sl->sl_list, &target_sd->s_links);
        ret = configfs_create_link(sl, parent_item->ci_dentry,
                       dentry);
        if (ret) {
            list_del_init(&sl->sl_list);
            config_item_put(item);
            kfree(sl);
        }
    }

    return ret;
}

/**
 * dtbocfg_overlay_group_drop_item() - Drop Device Tree Overlay Group Item
 * @group: Pointer to Configuration Group
 * @item : Pointer to Device Tree Overlay Group Item
 */
static void dtbocfg_overlay_group_drop_item(struct config_group *group, struct config_item *item)
{
    struct dtbocfg_overlay_item *overlay = container_of_dtbocfg_overlay_item(item);

    pr_debug("%s\n", __func__);

    config_item_put(&overlay->item);
}

static void device_drop_group(struct config_group *group,
			      struct config_item *item)
{
	struct iio_sw_device *d = to_iio_sw_device(item);

	iio_sw_device_destroy(d);
	config_item_put(item);
}

static void target_fabric_drop_tpg(
	struct config_group *group,
	struct config_item *item)
{
	struct se_portal_group *se_tpg = container_of(to_config_group(item),
				struct se_portal_group, tpg_group);
	struct config_group *tpg_cg = &se_tpg->tpg_group;
	struct config_item *df_item;
	int i;
	for (i = 0; tpg_cg->default_groups[i]; i++) {
		df_item = &tpg_cg->default_groups[i]->cg_item;
		tpg_cg->default_groups[i] = NULL;
		config_item_put(df_item);
	}

	config_item_put(item);
}

static void target_fabric_drop_wwn(
	struct config_group *group,
	struct config_item *item)
{
	struct se_wwn *wwn = container_of(to_config_group(item),
				struct se_wwn, wwn_group);
	struct config_item *df_item;
	struct config_group *cg = &wwn->wwn_group;
	int i;

	for (i = 0; cg->default_groups[i]; i++) {
		df_item = &cg->default_groups[i]->cg_item;
		cg->default_groups[i] = NULL;
		config_item_put(df_item);
	}

	config_item_put(item);
}

static void target_fabric_drop_np(
	struct config_group *group,
	struct config_item *item)
{
	/*
	 * struct se_tpg_np is released via target_fabric_np_base_release()
	 */
	config_item_put(item);
}

static void trigger_drop_group(struct config_group *group,
			       struct config_item *item)
{
	struct iio_sw_trigger *t = to_iio_sw_trigger(item);

	printk(KERN_ALERT "Called drop_group");
	iio_sw_trigger_destroy(t);
	config_item_put(item);
}

static void target_fabric_drop_nodeacl(
	struct config_group *group,
	struct config_item *item)
{
	struct se_node_acl *se_nacl = container_of(to_config_group(item),
			struct se_node_acl, acl_group);
	struct config_item *df_item;
	struct config_group *nacl_cg;
	int i;

	nacl_cg = &se_nacl->acl_group;
	for (i = 0; nacl_cg->default_groups[i]; i++) {
		df_item = &nacl_cg->default_groups[i]->cg_item;
		nacl_cg->default_groups[i] = NULL;
		config_item_put(df_item);
	}
	config_item_put(item);
}