1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (C) 2008 Red Hat, Inc. All rights reserved. 4 * 5 * This file is released under the GPL. 6 */ 7 8#include <linux/sysfs.h> 9#include <linux/dm-ioctl.h> 10#include "dm-core.h" 11#include "dm-rq.h" 12 13struct 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); 17}; 18 19#define DM_ATTR_RO(_name) \ 20struct dm_sysfs_attr dm_attr_##_name = \ 21 __ATTR(_name, 0444, dm_attr_##_name##_show, NULL) 22 23static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr, 24 char *page) 25{ 26 struct dm_sysfs_attr *dm_attr; 27 struct mapped_device *md; 28 ssize_t ret; 29 30 dm_attr = container_of(attr, struct dm_sysfs_attr, attr); 31 if (!dm_attr->show) 32 return -EIO; 33 34 md = dm_get_from_kobject(kobj); 35 if (!md) 36 return -EINVAL; 37 38 ret = dm_attr->show(md, page); 39 dm_put(md); 40 41 return ret; 42} 43 44#define DM_ATTR_RW(_name) \ 45struct dm_sysfs_attr dm_attr_##_name = \ 46 __ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store) 47 48static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr, 49 const char *page, size_t count) 50{ 51 struct dm_sysfs_attr *dm_attr; 52 struct mapped_device *md; 53 ssize_t ret; 54 55 dm_attr = container_of(attr, struct dm_sysfs_attr, attr); 56 if (!dm_attr->store) 57 return -EIO; 58 59 md = dm_get_from_kobject(kobj); 60 if (!md) 61 return -EINVAL; 62 63 ret = dm_attr->store(md, page, count); 64 dm_put(md); 65 66 return ret; 67} 68 69static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf) 70{ 71 if (dm_copy_name_and_uuid(md, buf, NULL)) 72 return -EIO; 73 74 strcat(buf, "\n"); 75 return strlen(buf); 76} 77 78static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf) 79{ 80 if (dm_copy_name_and_uuid(md, NULL, buf)) 81 return -EIO; 82 83 strcat(buf, "\n"); 84 return strlen(buf); 85} 86 87static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf) 88{ 89 sprintf(buf, "%d\n", dm_suspended_md(md)); 90 91 return strlen(buf); 92} 93 94static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf) 95{ 96 /* Purely for userspace compatibility */ 97 sprintf(buf, "%d\n", true); 98 99 return strlen(buf); 100} 101 102static DM_ATTR_RO(name); 103static DM_ATTR_RO(uuid); 104static DM_ATTR_RO(suspended); 105static DM_ATTR_RO(use_blk_mq); 106static DM_ATTR_RW(rq_based_seq_io_merge_deadline); 107 108static struct attribute *dm_attrs[] = { 109 &dm_attr_name.attr, 110 &dm_attr_uuid.attr, 111 &dm_attr_suspended.attr, 112 &dm_attr_use_blk_mq.attr, 113 &dm_attr_rq_based_seq_io_merge_deadline.attr, 114 NULL, 115}; 116ATTRIBUTE_GROUPS(dm); 117 118static const struct sysfs_ops dm_sysfs_ops = { 119 .show = dm_attr_show, 120 .store = dm_attr_store, 121}; 122 123static const struct kobj_type dm_ktype = { 124 .sysfs_ops = &dm_sysfs_ops, 125 .default_groups = dm_groups, 126 .release = dm_kobject_release, 127}; 128 129/* 130 * Initialize kobj 131 * because nobody using md yet, no need to call explicit dm_get/put 132 */ 133int dm_sysfs_init(struct mapped_device *md) 134{ 135 return kobject_init_and_add(dm_kobject(md), &dm_ktype, 136 &disk_to_dev(dm_disk(md))->kobj, 137 "%s", "dm"); 138} 139 140/* 141 * Remove kobj, called after all references removed 142 */ 143void dm_sysfs_exit(struct mapped_device *md) 144{ 145 struct kobject *kobj = dm_kobject(md); 146 147 kobject_put(kobj); 148 wait_for_completion(dm_get_completion_from_kobject(kobj)); 149} 150