dm-sysfs.c
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/*
* Copyright (C) 2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include <linux/sysfs.h>
#include <linux/dm-ioctl.h>
#include "dm.h"
struct dm_sysfs_attr {
struct attribute attr;
ssize_t (*show)(struct mapped_device *, char *);
ssize_t (*store)(struct mapped_device *, char *);
};
#define DM_ATTR_RO(_name) \
struct dm_sysfs_attr dm_attr_##_name = \
__ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL)
static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,
char *page)
{
struct dm_sysfs_attr *dm_attr;
struct mapped_device *md;
ssize_t ret;
dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
if (!dm_attr->show)
return -EIO;
md = dm_get_from_kobject(kobj);
if (!md)
return -EINVAL;
ret = dm_attr->show(md, page);
dm_put(md);
return ret;
}
static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf)
{
if (dm_copy_name_and_uuid(md, buf, NULL))
return -EIO;
strcat(buf, "\n");
return strlen(buf);
}
static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
{
if (dm_copy_name_and_uuid(md, NULL, buf))
return -EIO;
strcat(buf, "\n");
return strlen(buf);
}
static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
{
sprintf(buf, "%d\n", dm_suspended_md(md));
return strlen(buf);
}
static DM_ATTR_RO(name);
static DM_ATTR_RO(uuid);
static DM_ATTR_RO(suspended);
static struct attribute *dm_attrs[] = {
&dm_attr_name.attr,
&dm_attr_uuid.attr,
&dm_attr_suspended.attr,
NULL,
};
static const struct sysfs_ops dm_sysfs_ops = {
.show = dm_attr_show,
};
/*
* dm kobject is embedded in mapped_device structure
* no need to define release function here
*/
static struct kobj_type dm_ktype = {
.sysfs_ops = &dm_sysfs_ops,
.default_attrs = dm_attrs,
.release = dm_kobject_release,
};
/*
* Initialize kobj
* because nobody using md yet, no need to call explicit dm_get/put
*/
int dm_sysfs_init(struct mapped_device *md)
{
return kobject_init_and_add(dm_kobject(md), &dm_ktype,
&disk_to_dev(dm_disk(md))->kobj,
"%s", "dm");
}
/*
* Remove kobj, called after all references removed
*/
void dm_sysfs_exit(struct mapped_device *md)
{
struct kobject *kobj = dm_kobject(md);
kobject_put(kobj);
wait_for_completion(dm_get_completion_from_kobject(kobj));
}