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
dm_attr_show(struct kobject * kobj,struct attribute * attr,char * page)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
dm_attr_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t count)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
dm_attr_name_show(struct mapped_device * md,char * buf)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
dm_attr_uuid_show(struct mapped_device * md,char * buf)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
dm_attr_suspended_show(struct mapped_device * md,char * buf)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
dm_attr_use_blk_mq_show(struct mapped_device * md,char * buf)93 static 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
101 static DM_ATTR_RO(name);
102 static DM_ATTR_RO(uuid);
103 static DM_ATTR_RO(suspended);
104 static DM_ATTR_RO(use_blk_mq);
105 static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
106
107 static 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
116 static const struct sysfs_ops dm_sysfs_ops = {
117 .show = dm_attr_show,
118 .store = dm_attr_store,
119 };
120
121 static 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 */
dm_sysfs_init(struct mapped_device * md)131 int 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 */
dm_sysfs_exit(struct mapped_device * md)141 void 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
