/*
   * 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 *, char *);

  	ssize_t (*store)(struct mapped_device *, const char *, size_t count);

  };
  
  #define DM_ATTR_RO(_name) \
  struct dm_sysfs_attr dm_attr_##_name = \
  	__ATTR(_name, S_IRUGO, 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, S_IRUGO | S_IWUSR, 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, "
  ");
  	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, "
  ");
  	return strlen(buf);
  }

  static ssize_t dm_attr_suspended_show(struct mapped_device *md, char *buf)
  {

  	sprintf(buf, "%d
  ", dm_suspended_md(md));

  
  	return strlen(buf);
  }

  static ssize_t dm_attr_use_blk_mq_show(struct mapped_device *md, char *buf)
  {

  	/* Purely for userspace compatibility */
  	sprintf(buf, "%d
  ", true);

  
  	return strlen(buf);
  }

  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,
  };

  static const struct sysfs_ops dm_sysfs_ops = {

  	.show	= dm_attr_show,

  	.store	= dm_attr_store,

  };

  static struct kobj_type dm_ktype = {
  	.sysfs_ops	= &dm_sysfs_ops,
  	.default_attrs	= dm_attrs,

  	.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));

  }