// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (C) 2008 Red Hat, Inc. All rights reserved. * * This file is released under the GPL. */ #include <linux/sysfs.h>#include <linux/dm-ioctl.h>#include "dm-core.h"#include "dm-rq.h" struct dm_sysfs_attr {	struct attribute attr;	ssize_t (*show)(struct mapped_device *md, char *p);	ssize_t (*store)(struct mapped_device *md, const char *p, size_t count);}; #define DM_ATTR_RO(_name) \struct dm_sysfs_attr dm_attr_##_name = \	__ATTR(_name, 0444, dm_attr_##_name##_show, NULL) static ssize_t dm_attr_show(struct kobject *kobj, struct attribute *attr,			    char *page){	struct dm_sysfs_attr *dm_attr;	struct mapped_device *md;	ssize_t ret; 	dm_attr = container_of(attr, struct dm_sysfs_attr, attr);	if (!dm_attr->show)		return -EIO; 	md = dm_get_from_kobject(kobj);	if (!md)		return -EINVAL; 	ret = dm_attr->show(md, page);	dm_put(md); 	return ret;} #define DM_ATTR_RW(_name) \struct dm_sysfs_attr dm_attr_##_name = \	__ATTR(_name, 0644, dm_attr_##_name##_show, dm_attr_##_name##_store) static ssize_t dm_attr_store(struct kobject *kobj, struct attribute *attr,			     const char *page, size_t count){	struct dm_sysfs_attr *dm_attr;	struct mapped_device *md;	ssize_t ret; 	dm_attr = container_of(attr, struct dm_sysfs_attr, attr);	if (!dm_attr->store)		return -EIO; 	md = dm_get_from_kobject(kobj);	if (!md)		return -EINVAL; 	ret = dm_attr->store(md, page, count);	dm_put(md); 	return ret;} static ssize_t dm_attr_name_show(struct mapped_device *md, char *buf){	if (dm_copy_name_and_uuid(md, buf, NULL))		return -EIO; 	strcat(buf, "\n");	return strlen(buf);} static ssize_t dm_attr_uuid_show(struct mapped_device *md, char *buf){	if (dm_copy_name_and_uuid(md, NULL, buf))		return -EIO; 	strcat(buf, "\n");	return strlen(buf);} static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf){	return sysfs_emit(buf, "%d\n", dm_suspended_md(md));} static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf){	/* Purely for userspace compatibility */	return sysfs_emit(buf, "%d\n", true);} static DM_ATTR_RO(name);static DM_ATTR_RO(uuid);static DM_ATTR_RO(suspended);static DM_ATTR_RO(use_blk_mq);static DM_ATTR_RW(rq_based_seq_io_merge_deadline); static struct attribute *dm_attrs[] = {	&dm_attr_name.attr,	&dm_attr_uuid.attr,	&dm_attr_suspended.attr,	&dm_attr_use_blk_mq.attr,	&dm_attr_rq_based_seq_io_merge_deadline.attr,	NULL,};ATTRIBUTE_GROUPS(dm); static const struct sysfs_ops dm_sysfs_ops = {	.show	= dm_attr_show,	.store	= dm_attr_store,}; static const struct kobj_type dm_ktype = {	.sysfs_ops	= &dm_sysfs_ops,	.default_groups	= dm_groups,	.release	= dm_kobject_release,}; /* * Initialize kobj * because nobody using md yet, no need to call explicit dm_get/put */int dm_sysfs_init(struct mapped_device *md){	return kobject_init_and_add(dm_kobject(md), &dm_ktype,				    &disk_to_dev(dm_disk(md))->kobj,				    "%s", "dm");} /* * Remove kobj, called after all references removed */void dm_sysfs_exit(struct mapped_device *md){	struct kobject *kobj = dm_kobject(md); 	kobject_put(kobj);	wait_for_completion(dm_get_completion_from_kobject(kobj));}