1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.
5 * This file is released under the GPL.
8 #include <linux/sysfs.h>
9 #include <linux/dm-ioctl.h>
13 struct 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);
19 #define DM_ATTR_RO(_name) \
20 struct dm_sysfs_attr dm_attr_##_name = \
21 __ATTR(_name, 0444, dm_attr_##_name##_show, NULL)
23 static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,
26 struct dm_sysfs_attr *dm_attr;
27 struct mapped_device *md;
30 dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
34 md = dm_get_from_kobject(kobj);
38 ret = dm_attr->show(md, page);
44 #define DM_ATTR_RW(_name) \
45 struct dm_sysfs_attr dm_attr_##_name = \
46 __ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store)
48 static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr,
49 const char *page, size_t count)
51 struct dm_sysfs_attr *dm_attr;
52 struct mapped_device *md;
55 dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
59 md = dm_get_from_kobject(kobj);
63 ret = dm_attr->store(md, page, count);
69 static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf)
71 if (dm_copy_name_and_uuid(md, buf, NULL))
78 static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf)
80 if (dm_copy_name_and_uuid(md, NULL, buf))
87 static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
89 sprintf(buf, "%d\n", dm_suspended_md(md));
94 static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
96 /* Purely for userspace compatibility */
97 sprintf(buf, "%d\n", true);
102 static DM_ATTR_RO(name);
103 static DM_ATTR_RO(uuid);
104 static DM_ATTR_RO(suspended);
105 static DM_ATTR_RO(use_blk_mq);
106 static DM_ATTR_RW(rq_based_seq_io_merge_deadline);
108 static struct attribute *dm_attrs[] = {
111 &dm_attr_suspended.attr,
112 &dm_attr_use_blk_mq.attr,
113 &dm_attr_rq_based_seq_io_merge_deadline.attr,
116 ATTRIBUTE_GROUPS(dm);
118 static const struct sysfs_ops dm_sysfs_ops = {
119 .show = dm_attr_show,
120 .store = dm_attr_store,
123 static const struct kobj_type dm_ktype = {
124 .sysfs_ops = &dm_sysfs_ops,
125 .default_groups = dm_groups,
126 .release = dm_kobject_release,
131 * because nobody using md yet, no need to call explicit dm_get/put
133 int dm_sysfs_init(struct mapped_device *md)
135 return kobject_init_and_add(dm_kobject(md), &dm_ktype,
136 &disk_to_dev(dm_disk(md))->kobj,
141 * Remove kobj, called after all references removed
143 void dm_sysfs_exit(struct mapped_device *md)
145 struct kobject *kobj = dm_kobject(md);
148 wait_for_completion(dm_get_completion_from_kobject(kobj));