text: /*
   * Internal header file for device mapper
   *
   * Copyright (C) 2001, 2002 Sistina Software
   * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
   *
   * This file is released under the LGPL.
   */
  
  #ifndef DM_INTERNAL_H
  #define DM_INTERNAL_H
  
  #include <linux/fs.h>
  #include <linux/device-mapper.h>
  #include <linux/list.h>
  #include <linux/blkdev.h>
  #include <linux/hdreg.h>
  
  /*
   * Suspend feature flags
   */
  #define DM_SUSPEND_LOCKFS_FLAG		(1 << 0)
  #define DM_SUSPEND_NOFLUSH_FLAG		(1 << 1)
  
  /*
   * Type of table and mapped_device's mempool
   */
  #define DM_TYPE_NONE		0
  #define DM_TYPE_BIO_BASED	1
  #define DM_TYPE_REQUEST_BASED	2
  
  /*
   * List of devices that a metadevice uses and should open/close.
   */
  struct dm_dev_internal {
  	struct list_head list;
  	atomic_t count;
  	struct dm_dev dm_dev;
  };
  
  struct dm_table;
  struct dm_md_mempools;
  
  /*-----------------------------------------------------------------
   * Internal table functions.
   *---------------------------------------------------------------*/
  void dm_table_destroy(struct dm_table *t);
  void dm_table_event_callback(struct dm_table *t,
  			     void (*fn)(void *), void *context);
  struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
  struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
  int dm_calculate_queue_limits(struct dm_table *table,
  			      struct queue_limits *limits);
  void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
  			       struct queue_limits *limits);
  struct list_head *dm_table_get_devices(struct dm_table *t);
  void dm_table_presuspend_targets(struct dm_table *t);
  void dm_table_postsuspend_targets(struct dm_table *t);
  int dm_table_resume_targets(struct dm_table *t);
  int dm_table_any_congested(struct dm_table *t, int bdi_bits);
  int dm_table_any_busy_target(struct dm_table *t);
  unsigned dm_table_get_type(struct dm_table *t);
  struct target_type *dm_table_get_immutable_target_type(struct dm_table *t);
  bool dm_table_request_based(struct dm_table *t);
  bool dm_table_supports_discards(struct dm_table *t);
  int dm_table_alloc_md_mempools(struct dm_table *t);
  void dm_table_free_md_mempools(struct dm_table *t);
  struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
  
  int dm_queue_merge_is_compulsory(struct request_queue *q);
  
  void dm_lock_md_type(struct mapped_device *md);
  void dm_unlock_md_type(struct mapped_device *md);
  void dm_set_md_type(struct mapped_device *md, unsigned type);
  unsigned dm_get_md_type(struct mapped_device *md);
  struct target_type *dm_get_immutable_target_type(struct mapped_device *md);
  
  int dm_setup_md_queue(struct mapped_device *md);
  
  /*
   * To check the return value from dm_table_find_target().
   */
  #define dm_target_is_valid(t) ((t)->table)
  
  /*
   * To check whether the target type is request-based or not (bio-based).
   */
  #define dm_target_request_based(t) ((t)->type->map_rq != NULL)
  
  /*-----------------------------------------------------------------
   * A registry of target types.
   *---------------------------------------------------------------*/
  int dm_target_init(void);
  void dm_target_exit(void);
  struct target_type *dm_get_target_type(const char *name);
  void dm_put_target_type(struct target_type *tt);
  int dm_target_iterate(void (*iter_func)(struct target_type *tt,
  					void *param), void *param);
  
  int dm_split_args(int *argc, char ***argvp, char *input);
  
  /*
   * Is this mapped_device being deleted?
   */
  int dm_deleting_md(struct mapped_device *md);
  
  /*
   * Is this mapped_device suspended?
   */
  int dm_suspended_md(struct mapped_device *md);
  
  /*
   * The device-mapper can be driven through one of two interfaces;
   * ioctl or filesystem, depending which patch you have applied.
   */
  int dm_interface_init(void);
  void dm_interface_exit(void);
  
  /*
   * sysfs interface
   */
  int dm_sysfs_init(struct mapped_device *md);
  void dm_sysfs_exit(struct mapped_device *md);
  struct kobject *dm_kobject(struct mapped_device *md);
  struct mapped_device *dm_get_from_kobject(struct kobject *kobj);
  
  /*
   * Targets for linear and striped mappings
   */
  int dm_linear_init(void);
  void dm_linear_exit(void);
  
  int dm_stripe_init(void);
  void dm_stripe_exit(void);
  
  /*
   * mapped_device operations
   */
  void dm_destroy(struct mapped_device *md);
  void dm_destroy_immediate(struct mapped_device *md);
  int dm_open_count(struct mapped_device *md);
  int dm_lock_for_deletion(struct mapped_device *md);
  
  int dm_kobject_uevent(struct mapped_device *md, enum kobject_action action,
  		      unsigned cookie);
  
  int dm_io_init(void);
  void dm_io_exit(void);
  
  int dm_kcopyd_init(void);
  void dm_kcopyd_exit(void);
  
  /*
   * Mempool operations
   */
  struct dm_md_mempools *dm_alloc_md_mempools(unsigned type, unsigned integrity);
  void dm_free_md_mempools(struct dm_md_mempools *pools);
  
  #endif
  