150 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*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 13struct 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) \20struct dm_sysfs_attr dm_attr_##_name = \21 __ATTR(_name, 0444, dm_attr_##_name##_show, NULL)22 23static 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) \45struct dm_sysfs_attr dm_attr_##_name = \46 __ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store)47 48static 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 69static 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 78static 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 87static 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 94static 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 102static DM_ATTR_RO(name);103static DM_ATTR_RO(uuid);104static DM_ATTR_RO(suspended);105static DM_ATTR_RO(use_blk_mq);106static DM_ATTR_RW(rq_based_seq_io_merge_deadline);107 108static 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};116ATTRIBUTE_GROUPS(dm);117 118static const struct sysfs_ops dm_sysfs_ops = {119 .show = dm_attr_show,120 .store = dm_attr_store,121};122 123static 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 kobj131 * because nobody using md yet, no need to call explicit dm_get/put132 */133int 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 removed142 */143void 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