1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * runlist.h - Defines for runlist handling in NTFS Linux kernel driver.
4 * Part of the Linux-NTFS project.
5 *
6 * Copyright (c) 2001-2005 Anton Altaparmakov
7 * Copyright (c) 2002 Richard Russon
8 */
9
10 #ifndef _LINUX_NTFS_RUNLIST_H
11 #define _LINUX_NTFS_RUNLIST_H
12
13 #include "types.h"
14 #include "layout.h"
15 #include "volume.h"
16
17 /**
18 * runlist_element - in memory vcn to lcn mapping array element
19 * @vcn: starting vcn of the current array element
20 * @lcn: starting lcn of the current array element
21 * @length: length in clusters of the current array element
22 *
23 * The last vcn (in fact the last vcn + 1) is reached when length == 0.
24 *
25 * When lcn == -1 this means that the count vcns starting at vcn are not
26 * physically allocated (i.e. this is a hole / data is sparse).
27 */
28 typedef struct { /* In memory vcn to lcn mapping structure element. */
29 VCN vcn; /* vcn = Starting virtual cluster number. */
30 LCN lcn; /* lcn = Starting logical cluster number. */
31 s64 length; /* Run length in clusters. */
32 } runlist_element;
33
34 /**
35 * runlist - in memory vcn to lcn mapping array including a read/write lock
36 * @rl: pointer to an array of runlist elements
37 * @lock: read/write spinlock for serializing access to @rl
38 *
39 */
40 typedef struct {
41 runlist_element *rl;
42 struct rw_semaphore lock;
43 } runlist;
44
ntfs_init_runlist(runlist * rl)45 static inline void ntfs_init_runlist(runlist *rl)
46 {
47 rl->rl = NULL;
48 init_rwsem(&rl->lock);
49 }
50
51 typedef enum {
52 LCN_HOLE = -1, /* Keep this as highest value or die! */
53 LCN_RL_NOT_MAPPED = -2,
54 LCN_ENOENT = -3,
55 LCN_ENOMEM = -4,
56 LCN_EIO = -5,
57 } LCN_SPECIAL_VALUES;
58
59 extern runlist_element *ntfs_runlists_merge(runlist_element *drl,
60 runlist_element *srl);
61
62 extern runlist_element *ntfs_mapping_pairs_decompress(const ntfs_volume *vol,
63 const ATTR_RECORD *attr, runlist_element *old_rl);
64
65 extern LCN ntfs_rl_vcn_to_lcn(const runlist_element *rl, const VCN vcn);
66
67 #ifdef NTFS_RW
68
69 extern runlist_element *ntfs_rl_find_vcn_nolock(runlist_element *rl,
70 const VCN vcn);
71
72 extern int ntfs_get_size_for_mapping_pairs(const ntfs_volume *vol,
73 const runlist_element *rl, const VCN first_vcn,
74 const VCN last_vcn);
75
76 extern int ntfs_mapping_pairs_build(const ntfs_volume *vol, s8 *dst,
77 const int dst_len, const runlist_element *rl,
78 const VCN first_vcn, const VCN last_vcn, VCN *const stop_vcn);
79
80 extern int ntfs_rl_truncate_nolock(const ntfs_volume *vol,
81 runlist *const runlist, const s64 new_length);
82
83 int ntfs_rl_punch_nolock(const ntfs_volume *vol, runlist *const runlist,
84 const VCN start, const s64 length);
85
86 #endif /* NTFS_RW */
87
88 #endif /* _LINUX_NTFS_RUNLIST_H */
89