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 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 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 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 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 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 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 */ 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 */ 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