/* SPDX-License-Identifier: GPL-2.0-or-later */

  /*
   * runlist.h - Defines for runlist handling in NTFS Linux kernel driver.
   *	       Part of the Linux-NTFS project.
   *

   * Copyright (c) 2001-2005 Anton Altaparmakov

   * Copyright (c) 2002 Richard Russon

   */
  
  #ifndef _LINUX_NTFS_RUNLIST_H
  #define _LINUX_NTFS_RUNLIST_H
  
  #include "types.h"
  #include "layout.h"
  #include "volume.h"
  
  /**
   * runlist_element - in memory vcn to lcn mapping array element
   * @vcn:	starting vcn of the current array element
   * @lcn:	starting lcn of the current array element
   * @length:	length in clusters of the current array element
   *
   * The last vcn (in fact the last vcn + 1) is reached when length == 0.
   *
   * When lcn == -1 this means that the count vcns starting at vcn are not
   * physically allocated (i.e. this is a hole / data is sparse).
   */
  typedef struct {	/* In memory vcn to lcn mapping structure element. */
  	VCN vcn;	/* vcn = Starting virtual cluster number. */
  	LCN lcn;	/* lcn = Starting logical cluster number. */
  	s64 length;	/* Run length in clusters. */
  } runlist_element;
  
  /**
   * runlist - in memory vcn to lcn mapping array including a read/write lock
   * @rl:		pointer to an array of runlist elements
   * @lock:	read/write spinlock for serializing access to @rl
   *
   */
  typedef struct {
  	runlist_element *rl;
  	struct rw_semaphore lock;
  } runlist;
  
  static inline void ntfs_init_runlist(runlist *rl)
  {
  	rl->rl = NULL;
  	init_rwsem(&rl->lock);
  }
  
  typedef enum {
  	LCN_HOLE		= -1,	/* Keep this as highest value or die! */
  	LCN_RL_NOT_MAPPED	= -2,
  	LCN_ENOENT		= -3,

  	LCN_ENOMEM		= -4,
  	LCN_EIO			= -5,

  } LCN_SPECIAL_VALUES;
  
  extern runlist_element *ntfs_runlists_merge(runlist_element *drl,
  		runlist_element *srl);
  
  extern runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol,
  		const ATTR_RECORD *attr, runlist_element *old_rl);
  
  extern LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn);

  #ifdef NTFS_RW
  
  extern runlist_element *ntfs_rl_find_vcn_nolock(runlist_element *rl,
  		const VCN vcn);

  extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,

  		const runlist_element *rl, const VCN first_vcn,
  		const VCN last_vcn);

  
  extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
  		const int dst_len, const runlist_element *rl,

  		const VCN first_vcn, const VCN last_vcn, VCN *const stop_vcn);

  
  extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol,
  		runlist *const runlist, const s64 new_length);

  int ntfs_rl_punch_nolock(const ntfs_volume *vol, runlist *const runlist,
  		const VCN start, const s64 length);

  #endif /* NTFS_RW */

  #endif /* _LINUX_NTFS_RUNLIST_H */