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.h" 10 11 struct dm_sysfs_attr { 12 struct attribute attr; 13 ssize_t (*show)(struct mapped_device *, char *); 14 ssize_t (*store)(struct mapped_device *, const char *, size_t count); 15 }; 16 17 #define DM_ATTR_RO(_name) \ 18 struct dm_sysfs_attr dm_attr_##_name = \ 19 __ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL) 20 21 static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr, 22 char *page) 23 { 24 struct dm_sysfs_attr *dm_attr; 25 struct mapped_device *md; 26 ssize_t ret; 27 28 dm_attr = container_of(attr, struct dm_sysfs_attr, attr); 29 if (!dm_attr->show) 30 return -EIO; 31 32 md = dm_get_from_kobject(kobj); 33 if (!md) 34 return -EINVAL; 35 36 ret = dm_attr->show(md, page); 37 dm_put(md); 38 39 return ret; 40 } 41 42 #define DM_ATTR_RW(_name) \ 43 struct dm_sysfs_attr dm_attr_##_name = \ 44 __ATTR(_name, S_IRUGO | S_IWUSR, dm_attr_##_name##_show, dm_attr_##_name##_store) 45 46 static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr, 47 const char *page, size_t count) 48 { 49 struct dm_sysfs_attr *dm_attr; 50 struct mapped_device *md; 51 ssize_t ret; 52 53 dm_attr = container_of(attr, struct dm_sysfs_attr, attr); 54 if (!dm_attr->store) 55 return -EIO; 56 57 md = dm_get_from_kobject(kobj); 58 if (!md) 59 return -EINVAL; 60 61 ret = dm_attr->store(md, page, count); 62 dm_put(md); 63 64 return ret; 65 } 66 67 static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf) 68 { 69 if (dm_copy_name_and_uuid(md, buf, NULL)) 70 return -EIO; 71 72 strcat(buf, "\n"); 73 return strlen(buf); 74 } 75 76 static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf) 77 { 78 if (dm_copy_name_and_uuid(md, NULL, buf)) 79 return -EIO; 80 81 strcat(buf, "\n"); 82 return strlen(buf); 83 } 84 85 static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf) 86 { 87 sprintf(buf, "%d\n", dm_suspended_md(md)); 88 89 return strlen(buf); 90 } 91 92 static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf) 93 { 94 sprintf(buf, "%d\n", dm_use_blk_mq(md)); 95 96 return strlen(buf); 97 } 98 99 static DM_ATTR_RO(name); 100 static DM_ATTR_RO(uuid); 101 static DM_ATTR_RO(suspended); 102 static DM_ATTR_RO(use_blk_mq); 103 static DM_ATTR_RW(rq_based_seq_io_merge_deadline); 104 105 static struct attribute *dm_attrs[] = { 106 &dm_attr_name.attr, 107 &dm_attr_uuid.attr, 108 &dm_attr_suspended.attr, 109 &dm_attr_use_blk_mq.attr, 110 &dm_attr_rq_based_seq_io_merge_deadline.attr, 111 NULL, 112 }; 113 114 static const struct sysfs_ops dm_sysfs_ops = { 115 .show = dm_attr_show, 116 .store = dm_attr_store, 117 }; 118 119 static struct kobj_type dm_ktype = { 120 .sysfs_ops = &dm_sysfs_ops, 121 .default_attrs = dm_attrs, 122 .release = dm_kobject_release, 123 }; 124 125 /* 126 * Initialize kobj 127 * because nobody using md yet, no need to call explicit dm_get/put 128 */ 129 int dm_sysfs_init(struct mapped_device *md) 130 { 131 return kobject_init_and_add(dm_kobject(md), &dm_ktype, 132 &disk_to_dev(dm_disk(md))->kobj, 133 "%s", "dm"); 134 } 135 136 /* 137 * Remove kobj, called after all references removed 138 */ 139 void dm_sysfs_exit(struct mapped_device *md) 140 { 141 struct kobject *kobj = dm_kobject(md); 142 kobject_put(kobj); 143 wait_for_completion(dm_get_completion_from_kobject(kobj)); 144 } 145