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 12struct 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) \ 19struct dm_sysfs_attr dm_attr_##_name = \ 20 __ATTR(_name, S_IRUGO, dm_attr_##_name##_show, NULL) 21 22static 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) \ 44struct dm_sysfs_attr dm_attr_##_name = \ 45 __ATTR(_name, S_IRUGO | S_IWUSR, dm_attr_##_name##_show, dm_attr_##_name##_store) 46 47static 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 68static 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 77static 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 86static 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 93static 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 101static DM_ATTR_RO(name); 102static DM_ATTR_RO(uuid); 103static DM_ATTR_RO(suspended); 104static DM_ATTR_RO(use_blk_mq); 105static DM_ATTR_RW(rq_based_seq_io_merge_deadline); 106 107static 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 116static const struct sysfs_ops dm_sysfs_ops = { 117 .show = dm_attr_show, 118 .store = dm_attr_store, 119}; 120 121static 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 */ 131int 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 */ 141void 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