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 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); 17 }; 18 19 #define DM_ATTR_RO(_name) \ 20 struct dm_sysfs_attr dm_attr_##_name = \ 21 __ATTR(_name, 0444, dm_attr_##_name##_show, NULL) 22 23 static 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) \ 45 struct dm_sysfs_attr dm_attr_##_name = \ 46 __ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store) 47 48 static 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 69 static 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 78 static 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 87 static 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 94 static 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 } 101 102 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); 107 108 static 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 }; 116 ATTRIBUTE_GROUPS(dm); 117 118 static const struct sysfs_ops dm_sysfs_ops = { 119 .show = dm_attr_show, 120 .store = dm_attr_store, 121 }; 122 123 static 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 */ 133 int 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 */ 143 void 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