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
11 struct 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) \
18 struct dm_sysfs_attr dm_attr_##_name = \
19 __ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL)
20
dm_attr_show(struct kobject * kobj,struct attribute * attr,char * page)21 static 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
dm_attr_name_show(struct mapped_device * md,char * buf)42 static 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
dm_attr_uuid_show(struct mapped_device * md,char * buf)51 static 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
dm_attr_suspended_show(struct mapped_device * md,char * buf)60 static 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
67 static DM_ATTR_RO(name);
68 static DM_ATTR_RO(uuid);
69 static DM_ATTR_RO(suspended);
70
71 static struct attribute *dm_attrs[] = {
72 &dm_attr_name.attr,
73 &dm_attr_uuid.attr,
74 &dm_attr_suspended.attr,
75 NULL,
76 };
77
78 static 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 */
86 static struct kobj_type dm_ktype = {
87 .sysfs_ops = &dm_sysfs_ops,
88 .default_attrs = dm_attrs,
89 .release = dm_kobject_release,
90 };
91
92 /*
93 * Initialize kobj
94 * because nobody using md yet, no need to call explicit dm_get/put
95 */
dm_sysfs_init(struct mapped_device * md)96 int dm_sysfs_init(struct mapped_device *md)
97 {
98 return kobject_init_and_add(dm_kobject(md), &dm_ktype,
99 &disk_to_dev(dm_disk(md))->kobj,
100 "%s", "dm");
101 }
102
103 /*
104 * Remove kobj, called after all references removed
105 */
dm_sysfs_exit(struct mapped_device * md)106 void dm_sysfs_exit(struct mapped_device *md)
107 {
108 struct kobject *kobj = dm_kobject(md);
109 kobject_put(kobj);
110 wait_for_completion(dm_get_completion_from_kobject(kobj));
111 }
112