linux/fs/configfs/item.c
Thomas Gleixner 328970de0e treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 145
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 84 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190524100844.756442981@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:25:18 -07:00

193 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* item.c - library routines for handling generic config items
*
* 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/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.
*/
static 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.
* @fmt: The vsnprintf()'s format string.
*
* 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 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 {
va_start(args, fmt);
name = kvasprintf(GFP_KERNEL, fmt, args);
va_end(args);
if (!name)
return -EFAULT;
}
/* 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;
return 0;
}
EXPORT_SYMBOL(config_item_set_name);
void config_item_init_type_name(struct config_item *item,
const char *name,
const struct config_item_type *type)
{
config_item_set_name(item, "%s", 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,
const struct config_item_type *type)
{
config_item_set_name(&group->cg_item, "%s", 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;
}
EXPORT_SYMBOL(config_item_get);
struct config_item *config_item_get_unless_zero(struct config_item *item)
{
if (item && kref_get_unless_zero(&item->ci_kref))
return item;
return NULL;
}
EXPORT_SYMBOL(config_item_get_unless_zero);
static void config_item_cleanup(struct config_item *item)
{
const 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);
}
EXPORT_SYMBOL(config_item_put);
/**
* config_group_init - initialize a group for use
* @group: config_group
*/
void config_group_init(struct config_group *group)
{
config_item_init(&group->cg_item);
INIT_LIST_HEAD(&group->cg_children);
INIT_LIST_HEAD(&group->default_groups);
}
EXPORT_SYMBOL(config_group_init);
/**
* config_group_find_item - search for item in group.
* @group: group we're looking in.
* @name: item's name.
*
* Iterate over @group->cg_list, looking for a matching config_item.
* If matching item is found take a reference and return the item.
* Caller must have locked group via @group->cg_subsys->su_mtx.
*/
struct config_item *config_group_find_item(struct config_group *group,
const char *name)
{
struct list_head *entry;
struct config_item *ret = NULL;
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_group_find_item);