/*
* runlist.h - Defines for runlist handling in NTFS Linux kernel driver.
* Part of the Linux-NTFS project.
*
* Copyright (c) 2001-2004 Anton Altaparmakov
* Copyright (c) 2002 Richard Russon
*
* This program/include file is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as published
* by the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program/include file is distributed in the hope that it will be
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program (in the main directory of the Linux-NTFS
* distribution in the file COPYING); if not, write to the Free Software
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#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_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);
extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
const runlist_element *rl, const VCN start_vcn);
extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
const int dst_len, const runlist_element *rl,
const VCN start_vcn, VCN *const stop_vcn);
extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol,
runlist *const runlist, const s64 new_length);
#endif /* _LINUX_NTFS_RUNLIST_H */
