Root/fs/ntfs/runlist.h

1/*
2 * runlist.h - Defines for runlist handling in NTFS Linux kernel driver.
3 * Part of the Linux-NTFS project.
4 *
5 * Copyright (c) 2001-2005 Anton Altaparmakov
6 * Copyright (c) 2002 Richard Russon
7 *
8 * This program/include file is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as published
10 * by the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program/include file is distributed in the hope that it will be
14 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program (in the main directory of the Linux-NTFS
20 * distribution in the file COPYING); if not, write to the Free Software
21 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23
24#ifndef _LINUX_NTFS_RUNLIST_H
25#define _LINUX_NTFS_RUNLIST_H
26
27#include "types.h"
28#include "layout.h"
29#include "volume.h"
30
31/**
32 * runlist_element - in memory vcn to lcn mapping array element
33 * @vcn: starting vcn of the current array element
34 * @lcn: starting lcn of the current array element
35 * @length: length in clusters of the current array element
36 *
37 * The last vcn (in fact the last vcn + 1) is reached when length == 0.
38 *
39 * When lcn == -1 this means that the count vcns starting at vcn are not
40 * physically allocated (i.e. this is a hole / data is sparse).
41 */
42typedef struct { /* In memory vcn to lcn mapping structure element. */
43    VCN vcn; /* vcn = Starting virtual cluster number. */
44    LCN lcn; /* lcn = Starting logical cluster number. */
45    s64 length; /* Run length in clusters. */
46} runlist_element;
47
48/**
49 * runlist - in memory vcn to lcn mapping array including a read/write lock
50 * @rl: pointer to an array of runlist elements
51 * @lock: read/write spinlock for serializing access to @rl
52 *
53 */
54typedef struct {
55    runlist_element *rl;
56    struct rw_semaphore lock;
57} runlist;
58
59static inline void ntfs_init_runlist(runlist *rl)
60{
61    rl->rl = NULL;
62    init_rwsem(&rl->lock);
63}
64
65typedef enum {
66    LCN_HOLE = -1, /* Keep this as highest value or die! */
67    LCN_RL_NOT_MAPPED = -2,
68    LCN_ENOENT = -3,
69    LCN_ENOMEM = -4,
70    LCN_EIO = -5,
71} LCN_SPECIAL_VALUES;
72
73extern runlist_element *ntfs_runlists_merge(runlist_element *drl,
74        runlist_element *srl);
75
76extern runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol,
77        const ATTR_RECORD *attr, runlist_element *old_rl);
78
79extern LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn);
80
81#ifdef NTFS_RW
82
83extern runlist_element *ntfs_rl_find_vcn_nolock(runlist_element *rl,
84        const VCN vcn);
85
86extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
87        const runlist_element *rl, const VCN first_vcn,
88        const VCN last_vcn);
89
90extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
91        const int dst_len, const runlist_element *rl,
92        const VCN first_vcn, const VCN last_vcn, VCN *const stop_vcn);
93
94extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol,
95        runlist *const runlist, const s64 new_length);
96
97int ntfs_rl_punch_nolock(const ntfs_volume *vol, runlist *const runlist,
98        const VCN start, const s64 length);
99
100#endif /* NTFS_RW */
101
102#endif /* _LINUX_NTFS_RUNLIST_H */
103

Archive Download this file



interactive