tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 DM_ATTR_RO(name);
61static DM_ATTR_RO(uuid);
62
63static struct attribute *dm_attrs[] = {
64 &dm_attr_name.attr,
65 &dm_attr_uuid.attr,
66 NULL,
67};
68
69static struct sysfs_ops dm_sysfs_ops = {
70 .show = dm_attr_show,
71};
72
73/*
74 * dm kobject is embedded in mapped_device structure
75 * no need to define release function here
76 */
77static struct kobj_type dm_ktype = {
78 .sysfs_ops = &dm_sysfs_ops,
79 .default_attrs = dm_attrs,
80};
81
82/*
83 * Initialize kobj
84 * because nobody using md yet, no need to call explicit dm_get/put
85 */
86int dm_sysfs_init(struct mapped_device *md)
87{
88 return kobject_init_and_add(dm_kobject(md), &dm_ktype,
89 &disk_to_dev(dm_disk(md))->kobj,
90 "%s", "dm");
91}
92
93/*
94 * Remove kobj, called after all references removed
95 */
96void dm_sysfs_exit(struct mapped_device *md)
97{
98 kobject_put(dm_kobject(md));
99}