1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8#include <linux/sysfs.h>
9#include <linux/dm-ioctl.h>
10#include "dm-core.h"
11#include "dm-rq.h"
12
13struct dm_sysfs_attr {
14 struct attribute attr;
15 ssize_t (*show)(struct mapped_device *md, char *p);
16 ssize_t (*store)(struct mapped_device *md, const char *p, size_t count);
17};
18
19#define DM_ATTR_RO(_name) \
20struct dm_sysfs_attr dm_attr_##_name = \
21 __ATTR(_name, 0444, dm_attr_##_name##_show, NULL)
22
23static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,
24 char *page)
25{
26 struct dm_sysfs_attr *dm_attr;
27 struct mapped_device *md;
28 ssize_t ret;
29
30 dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
31 if (!dm_attr->show)
32 return -EIO;
33
34 md = dm_get_from_kobject(kobj);
35 if (!md)
36 return -EINVAL;
37
38 ret = dm_attr->show(md, page);
39 dm_put(md);
40
41 return ret;
42}
43
44#define DM_ATTR_RW(_name) \
45struct dm_sysfs_attr dm_attr_##_name = \
46 __ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store)
47
48static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr,
49 const char *page, size_t count)
50{
51 struct dm_sysfs_attr *dm_attr;
52 struct mapped_device *md;
53 ssize_t ret;
54
55 dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
56 if (!dm_attr->store)
57 return -EIO;
58
59 md = dm_get_from_kobject(kobj);
60 if (!md)
61 return -EINVAL;
62
63 ret = dm_attr->store(md, page, count);
64 dm_put(md);
65
66 return ret;
67}
68
69static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf)
70{
71 if (dm_copy_name_and_uuid(md, name: buf, NULL))
72 return -EIO;
73
74 strcat(buf, "\n");
75 return strlen(buf);
76}
77
78static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
79{
80 if (dm_copy_name_and_uuid(md, NULL, uuid: buf))
81 return -EIO;
82
83 strcat(buf, "\n");
84 return strlen(buf);
85}
86
87static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
88{
89 sprintf(buf, fmt: "%d\n", dm_suspended_md(md));
90
91 return strlen(buf);
92}
93
94static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
95{
96 /* Purely for userspace compatibility */
97 sprintf(buf, fmt: "%d\n", true);
98
99 return strlen(buf);
100}
101
102static DM_ATTR_RO(name);
103static DM_ATTR_RO(uuid);
104static DM_ATTR_RO(suspended);
105static DM_ATTR_RO(use_blk_mq);
106static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
107
108static struct attribute *dm_attrs[] = {
109 &dm_attr_name.attr,
110 &dm_attr_uuid.attr,
111 &dm_attr_suspended.attr,
112 &dm_attr_use_blk_mq.attr,
113 &dm_attr_rq_based_seq_io_merge_deadline.attr,
114 NULL,
115};
116ATTRIBUTE_GROUPS(dm);
117
118static const struct sysfs_ops dm_sysfs_ops = {
119 .show = dm_attr_show,
120 .store = dm_attr_store,
121};
122
123static const struct kobj_type dm_ktype = {
124 .sysfs_ops = &dm_sysfs_ops,
125 .default_groups = dm_groups,
126 .release = dm_kobject_release,
127};
128
129/*
130 * Initialize kobj
131 * because nobody using md yet, no need to call explicit dm_get/put
132 */
133int dm_sysfs_init(struct mapped_device *md)
134{
135 return kobject_init_and_add(kobj: dm_kobject(md), ktype: &dm_ktype,
136 parent: &disk_to_dev(dm_disk(md))->kobj,
137 fmt: "%s", "dm");
138}
139
140/*
141 * Remove kobj, called after all references removed
142 */
143void dm_sysfs_exit(struct mapped_device *md)
144{
145 struct kobject *kobj = dm_kobject(md);
146
147 kobject_put(kobj);
148 wait_for_completion(dm_get_completion_from_kobject(kobj));
149}
150