Merge tag 'arc-4.10-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupt...
[linux-2.6-microblaze.git] / drivers / md / dm-sysfs.c
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
12 struct 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) \
19 struct dm_sysfs_attr dm_attr_##_name = \
20         __ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL)
21
22 static 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) \
44 struct dm_sysfs_attr dm_attr_##_name = \
45         __ATTR(_name, S_IRUGO | S_IWUSR, dm_attr_##_name##_show, dm_attr_##_name##_store)
46
47 static 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
68 static 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
77 static 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
86 static 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
93 static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
94 {
95         sprintf(buf, "%d\n", dm_use_blk_mq(md));
96
97         return strlen(buf);
98 }
99
100 static DM_ATTR_RO(name);
101 static DM_ATTR_RO(uuid);
102 static DM_ATTR_RO(suspended);
103 static DM_ATTR_RO(use_blk_mq);
104 static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
105
106 static struct attribute *dm_attrs[] = {
107         &dm_attr_name.attr,
108         &dm_attr_uuid.attr,
109         &dm_attr_suspended.attr,
110         &dm_attr_use_blk_mq.attr,
111         &dm_attr_rq_based_seq_io_merge_deadline.attr,
112         NULL,
113 };
114
115 static const struct sysfs_ops dm_sysfs_ops = {
116         .show   = dm_attr_show,
117         .store  = dm_attr_store,
118 };
119
120 static struct kobj_type dm_ktype = {
121         .sysfs_ops      = &dm_sysfs_ops,
122         .default_attrs  = dm_attrs,
123         .release        = dm_kobject_release,
124 };
125
126 /*
127  * Initialize kobj
128  * because nobody using md yet, no need to call explicit dm_get/put
129  */
130 int dm_sysfs_init(struct mapped_device *md)
131 {
132         return kobject_init_and_add(dm_kobject(md), &dm_ktype,
133                                     &disk_to_dev(dm_disk(md))->kobj,
134                                     "%s", "dm");
135 }
136
137 /*
138  * Remove kobj, called after all references removed
139  */
140 void dm_sysfs_exit(struct mapped_device *md)
141 {
142         struct kobject *kobj = dm_kobject(md);
143         kobject_put(kobj);
144         wait_for_completion(dm_get_completion_from_kobject(kobj));
145 }