1 /*
2 * mft.h - Exports for MFT record handling. Originated from the Linux-NTFS project.
3 *
4 * Copyright (c) 2000-2002 Anton Altaparmakov
5 * Copyright (c) 2004-2005 Richard Russon
6 * Copyright (c) 2006-2008 Szabolcs Szakacsits
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 NTFS-3G
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 _NTFS_MFT_H
25 #define _NTFS_MFT_H
26
27 #include "volume.h"
28 #include "inode.h"
29 #include "layout.h"
30 #include "logging.h"
31
32 extern int ntfs_mft_records_read(const ntfs_volume *vol, const MFT_REF mref,
33 const s64 count, MFT_RECORD *b);
34
35 /**
36 * ntfs_mft_record_read - read a record from the mft
37 * @vol: volume to read from
38 * @mref: mft record number to read
39 * @b: output data buffer
40 *
41 * Read the mft record specified by @mref from volume @vol into buffer @b.
42 * Return 0 on success or -1 on error, with errno set to the error code.
43 *
44 * The read mft record is mst deprotected and is hence ready to use. The caller
45 * should check the record with is_baad_record() in case mst deprotection
46 * failed.
47 *
48 * NOTE: @b has to be at least of size vol->mft_record_size.
49 */
ntfs_mft_record_read(const ntfs_volume * vol,const MFT_REF mref,MFT_RECORD * b)50 static __inline__ int ntfs_mft_record_read(const ntfs_volume *vol,
51 const MFT_REF mref, MFT_RECORD *b)
52 {
53 int ret;
54
55 ntfs_log_enter("Entering for inode %lld\n", (long long)MREF(mref));
56 ret = ntfs_mft_records_read(vol, mref, 1, b);
57 ntfs_log_leave("\n");
58 return ret;
59 }
60
61 extern int ntfs_mft_record_check(const ntfs_volume *vol, const MFT_REF mref,
62 MFT_RECORD *m);
63
64 extern int ntfs_file_record_read(const ntfs_volume *vol, const MFT_REF mref,
65 MFT_RECORD **mrec, ATTR_RECORD **attr);
66
67 extern int ntfs_mft_records_write(const ntfs_volume *vol, const MFT_REF mref,
68 const s64 count, MFT_RECORD *b);
69
70 /**
71 * ntfs_mft_record_write - write an mft record to disk
72 * @vol: volume to write to
73 * @mref: mft record number to write
74 * @b: data buffer containing the mft record to write
75 *
76 * Write the mft record specified by @mref from buffer @b to volume @vol.
77 * Return 0 on success or -1 on error, with errno set to the error code.
78 *
79 * Before the mft record is written, it is mst protected. After the write, it
80 * is deprotected again, thus resulting in an increase in the update sequence
81 * number inside the buffer @b.
82 *
83 * NOTE: @b has to be at least of size vol->mft_record_size.
84 */
ntfs_mft_record_write(const ntfs_volume * vol,const MFT_REF mref,MFT_RECORD * b)85 static __inline__ int ntfs_mft_record_write(const ntfs_volume *vol,
86 const MFT_REF mref, MFT_RECORD *b)
87 {
88 int ret;
89
90 ntfs_log_enter("Entering for inode %lld\n", (long long)MREF(mref));
91 ret = ntfs_mft_records_write(vol, mref, 1, b);
92 ntfs_log_leave("\n");
93 return ret;
94 }
95
96 /**
97 * ntfs_mft_record_get_data_size - return number of bytes used in mft record @b
98 * @m: mft record to get the data size of
99 *
100 * Takes the mft record @m and returns the number of bytes used in the record
101 * or 0 on error (i.e. @m is not a valid mft record). Zero is not a valid size
102 * for an mft record as it at least has to have the MFT_RECORD itself and a
103 * zero length attribute of type AT_END, thus making the minimum size 56 bytes.
104 *
105 * Aside: The size is independent of NTFS versions 1.x/3.x because the 8-byte
106 * alignment of the first attribute mask the difference in MFT_RECORD size
107 * between NTFS 1.x and 3.x. Also, you would expect every mft record to
108 * contain an update sequence array as well but that could in theory be
109 * non-existent (don't know if Windows' NTFS driver/chkdsk wouldn't view this
110 * as corruption in itself though).
111 */
ntfs_mft_record_get_data_size(const MFT_RECORD * m)112 static __inline__ u32 ntfs_mft_record_get_data_size(const MFT_RECORD *m)
113 {
114 if (!m || !ntfs_is_mft_record(m->magic))
115 return 0;
116 /* Get the number of used bytes and return it. */
117 return le32_to_cpu(m->bytes_in_use);
118 }
119
120 extern int ntfs_mft_record_layout(const ntfs_volume *vol, const MFT_REF mref,
121 MFT_RECORD *mrec);
122
123 extern int ntfs_mft_record_format(const ntfs_volume *vol, const MFT_REF mref);
124
125 extern ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, ntfs_inode *base_ni);
126
127 extern ntfs_inode *ntfs_mft_rec_alloc(ntfs_volume *vol, BOOL mft_data);
128
129 extern int ntfs_mft_record_free(ntfs_volume *vol, ntfs_inode *ni);
130
131 extern int ntfs_mft_usn_dec(MFT_RECORD *mrec);
132
133 #endif /* defined _NTFS_MFT_H */
134
135