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