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 *, char *); 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 static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf) 43 { 44 if (dm_copy_name_and_uuid(md, buf, NULL)) 45 return -EIO; 46 47 strcat(buf, "\n"); 48 return strlen(buf); 49 } 50 51 static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf) 52 { 53 if (dm_copy_name_and_uuid(md, NULL, buf)) 54 return -EIO; 55 56 strcat(buf, "\n"); 57 return strlen(buf); 58 } 59 60 static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf) 61 { 62 sprintf(buf, "%d\n", dm_suspended_md(md)); 63 64 return strlen(buf); 65 } 66 67 static DM_ATTR_RO(name); 68 static DM_ATTR_RO(uuid); 69 static DM_ATTR_RO(suspended); 70 71 static struct attribute *dm_attrs[] = { 72 &dm_attr_name.attr, 73 &dm_attr_uuid.attr, 74 &dm_attr_suspended.attr, 75 NULL, 76 }; 77 78 static const struct sysfs_ops dm_sysfs_ops = { 79 .show = dm_attr_show, 80 }; 81 82 static void dm_kobject_release(struct kobject *kobj) 83 { 84 complete(dm_get_completion_from_kobject(kobj)); 85 } 86 87 /* 88 * dm kobject is embedded in mapped_device structure 89 * no need to define release function here 90 */ 91 static struct kobj_type dm_ktype = { 92 .sysfs_ops = &dm_sysfs_ops, 93 .default_attrs = dm_attrs, 94 .release = dm_kobject_release, 95 }; 96 97 /* 98 * Initialize kobj 99 * because nobody using md yet, no need to call explicit dm_get/put 100 */ 101 int dm_sysfs_init(struct mapped_device *md) 102 { 103 return kobject_init_and_add(dm_kobject(md), &dm_ktype, 104 &disk_to_dev(dm_disk(md))->kobj, 105 "%s", "dm"); 106 } 107 108 /* 109 * Remove kobj, called after all references removed 110 */ 111 void dm_sysfs_exit(struct mapped_device *md) 112 { 113 struct kobject *kobj = dm_kobject(md); 114 kobject_put(kobj); 115 wait_for_completion(dm_get_completion_from_kobject(kobj)); 116 } 117