linux/drivers/md/dm-sysfs.c
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   1/*
   2 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
   3 *
   4 * This file is released under the GPL.
   5 */
   6
   7#include <linux/sysfs.h>
   8#include <linux/dm-ioctl.h>
   9#include "dm.h"
  10
  11struct dm_sysfs_attr {
  12        struct attribute attr;
  13        ssize_t (*show)(struct mapped_device *, char *);
  14        ssize_t (*store)(struct mapped_device *, char *);
  15};
  16
  17#define DM_ATTR_RO(_name) \
  18struct dm_sysfs_attr dm_attr_##_name = \
  19        __ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL)
  20
  21static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,
  22                            char *page)
  23{
  24        struct dm_sysfs_attr *dm_attr;
  25        struct mapped_device *md;
  26        ssize_t ret;
  27
  28        dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
  29        if (!dm_attr->show)
  30                return -EIO;
  31
  32        md = dm_get_from_kobject(kobj);
  33        if (!md)
  34                return -EINVAL;
  35
  36        ret = dm_attr->show(md, page);
  37        dm_put(md);
  38
  39        return ret;
  40}
  41
  42static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf)
  43{
  44        if (dm_copy_name_and_uuid(md, buf, NULL))
  45                return -EIO;
  46
  47        strcat(buf, "\n");
  48        return strlen(buf);
  49}
  50
  51static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
  52{
  53        if (dm_copy_name_and_uuid(md, NULL, buf))
  54                return -EIO;
  55
  56        strcat(buf, "\n");
  57        return strlen(buf);
  58}
  59
  60static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
  61{
  62        sprintf(buf, "%d\n", dm_suspended_md(md));
  63
  64        return strlen(buf);
  65}
  66
  67static DM_ATTR_RO(name);
  68static DM_ATTR_RO(uuid);
  69static DM_ATTR_RO(suspended);
  70
  71static struct attribute *dm_attrs[] = {
  72        &dm_attr_name.attr,
  73        &dm_attr_uuid.attr,
  74        &dm_attr_suspended.attr,
  75        NULL,
  76};
  77
  78static const struct sysfs_ops dm_sysfs_ops = {
  79        .show   = dm_attr_show,
  80};
  81
  82/*
  83 * dm kobject is embedded in mapped_device structure
  84 * no need to define release function here
  85 */
  86static struct kobj_type dm_ktype = {
  87        .sysfs_ops      = &dm_sysfs_ops,
  88        .default_attrs  = dm_attrs,
  89};
  90
  91/*
  92 * Initialize kobj
  93 * because nobody using md yet, no need to call explicit dm_get/put
  94 */
  95int dm_sysfs_init(struct mapped_device *md)
  96{
  97        return kobject_init_and_add(dm_kobject(md), &dm_ktype,
  98                                    &disk_to_dev(dm_disk(md))->kobj,
  99                                    "%s", "dm");
 100}
 101
 102/*
 103 * Remove kobj, called after all references removed
 104 */
 105void dm_sysfs_exit(struct mapped_device *md)
 106{
 107        kobject_put(dm_kobject(md));
 108}
 109
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