/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * item.c - library routines for handling generic config items * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. * * Based on kobject: * kobject is Copyright (c) 2002-2003 Patrick Mochel * * configfs Copyright (C) 2005 Oracle. All rights reserved. * * Please see the file Documentation/filesystems/configfs.txt for * critical information about using the config_item interface. */ #include <linux/string.h> #include <linux/module.h> #include <linux/stat.h> #include <linux/slab.h> #include <linux/configfs.h> static inline struct config_item * to_item(struct list_head * entry) { return container_of(entry,struct config_item,ci_entry); } /* Evil kernel */ static void config_item_release(struct kref *kref); /** * config_item_init - initialize item. * @item: item in question. */ void config_item_init(struct config_item * item) { kref_init(&item->ci_kref); INIT_LIST_HEAD(&item->ci_entry); } /** * config_item_set_name - Set the name of an item * @item: item. * @name: name. * * If strlen(name) >= CONFIGFS_ITEM_NAME_LEN, then use a * dynamically allocated string that @item->ci_name points to. * Otherwise, use the static @item->ci_namebuf array. */ int config_item_set_name(struct config_item * item, const char * fmt, ...) { int error = 0; int limit = CONFIGFS_ITEM_NAME_LEN; int need; va_list args; char * name; /* * First, try the static array */ va_start(args,fmt); need = vsnprintf(item->ci_namebuf,limit,fmt,args); va_end(args); if (need < limit) name = item->ci_namebuf; else { /* * Need more space? Allocate it and try again */ limit = need + 1; name = kmalloc(limit,GFP_KERNEL); if (!name) { error = -ENOMEM; goto Done; } va_start(args,fmt); need = vsnprintf(name,limit,fmt,args); va_end(args); /* Still? Give up. */ if (need >= limit) { kfree(name); error = -EFAULT; goto Done; } } /* Free the old name, if necessary. */ if (item->ci_name && item->ci_name != item->ci_namebuf) kfree(item->ci_name); /* Now, set the new name */ item->ci_name = name; Done: return error; } EXPORT_SYMBOL(config_item_set_name); void config_item_init_type_name(struct config_item *item, const char *name, struct config_item_type *type) { config_item_set_name(item, name); item->ci_type = type; config_item_init(item); } EXPORT_SYMBOL(config_item_init_type_name); void config_group_init_type_name(struct config_group *group, const char *name, struct config_item_type *type) { config_item_set_name(&group->cg_item, name); group->cg_item.ci_type = type; config_group_init(group); } EXPORT_SYMBOL(config_group_init_type_name); struct config_item * config_item_get(struct config_item * item) { if (item) kref_get(&item->ci_kref); return item; } /** * config_item_cleanup - free config_item resources. * @item: item. */ void config_item_cleanup(struct config_item * item) { struct config_item_type * t = item->ci_type; struct config_group * s = item->ci_group; struct config_item * parent = item->ci_parent; pr_debug("config_item %s: cleaning up\n",config_item_name(item)); if (item->ci_name != item->ci_namebuf) kfree(item->ci_name); item->ci_name = NULL; if (t && t->ct_item_ops && t->ct_item_ops->release) t->ct_item_ops->release(item); if (s) config_group_put(s); if (parent) config_item_put(parent); } static void config_item_release(struct kref *kref) { config_item_cleanup(container_of(kref, struct config_item, ci_kref)); } /** * config_item_put - decrement refcount for item. * @item: item. * * Decrement the refcount, and if 0, call config_item_cleanup(). */ void config_item_put(struct config_item * item) { if (item) kref_put(&item->ci_kref, config_item_release); } /** * config_group_init - initialize a group for use * @k: group */ void config_group_init(struct config_group *group) { config_item_init(&group->cg_item); INIT_LIST_HEAD(&group->cg_children); } /** * config_group_find_obj - search for item in group. * @group: group we're looking in. * @name: item's name. * * Lock group via @group->cg_subsys, and iterate over @group->cg_list, * looking for a matching config_item. If matching item is found * take a reference and return the item. */ struct config_item * config_group_find_obj(struct config_group * group, const char * name) { struct list_head * entry; struct config_item * ret = NULL; /* XXX LOCKING! */ list_for_each(entry,&group->cg_children) { struct config_item * item = to_item(entry); if (config_item_name(item) && !strcmp(config_item_name(item), name)) { ret = config_item_get(item); break; } } return ret; } EXPORT_SYMBOL(config_item_init); EXPORT_SYMBOL(config_group_init); EXPORT_SYMBOL(config_item_get); EXPORT_SYMBOL(config_item_put); EXPORT_SYMBOL(config_group_find_obj);