1 /*
2 * mft.h - Exports for MFT record handling. Part of the Linux-NTFS project.
3 *
4 * Copyright (c) 2000-2002 Anton Altaparmakov
5 * Copyright (c) 2004-2005 Richard Russon
6 *
7 * This program/include file is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as published
9 * by the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program/include file is distributed in the hope that it will be
13 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program (in the main directory of the Linux-NTFS
19 * distribution in the file COPYING); if not, write to the Free Software
20 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #ifndef _NTFS_MFT_H
24 #define _NTFS_MFT_H
25
26 #include "volume.h"
27 #include "inode.h"
28 #include "layout.h"
29
30 extern int ntfs_mft_records_read(const ntfs_volume *vol, const MFT_REF mref,
31 const s64 count, MFT_RECORD *b);
32
33 /**
34 * ntfs_mft_record_read - read a record from the mft
35 * @vol: volume to read from
36 * @mref: mft record number to read
37 * @b: output data buffer
38 *
39 * Read the mft record specified by @mref from volume @vol into buffer @b.
40 * Return 0 on success or -1 on error, with errno set to the error code.
41 *
42 * The read mft record is mst deprotected and is hence ready to use. The caller
43 * should check the record with is_baad_record() in case mst deprotection
44 * failed.
45 *
46 * NOTE: @b has to be at least of size vol->mft_record_size.
47 */
48 static __inline__ int ntfs_mft_record_read(const ntfs_volume *vol,
49 const MFT_REF mref, MFT_RECORD *b)
50 {
51 return ntfs_mft_records_read(vol, mref, 1, b);
52 }
53
54 extern int ntfs_file_record_read(const ntfs_volume *vol, const MFT_REF mref,
55 MFT_RECORD **mrec, ATTR_RECORD **attr);
56
57 extern int ntfs_mft_records_write(const ntfs_volume *vol, const MFT_REF mref,
58 const s64 count, MFT_RECORD *b);
59
60 /**
61 * ntfs_mft_record_write - write an mft record to disk
62 * @vol: volume to write to
63 * @mref: mft record number to write
64 * @b: data buffer containing the mft record to write
65 *
66 * Write the mft record specified by @mref from buffer @b to volume @vol.
67 * Return 0 on success or -1 on error, with errno set to the error code.
68 *
69 * Before the mft record is written, it is mst protected. After the write, it
70 * is deprotected again, thus resulting in an increase in the update sequence
71 * number inside the buffer @b.
72 *
73 * NOTE: @b has to be at least of size vol->mft_record_size.
74 */
75 static __inline__ int ntfs_mft_record_write(const ntfs_volume *vol,
76 const MFT_REF mref, MFT_RECORD *b)
77 {
78 return ntfs_mft_records_write(vol, mref, 1, b);
79 }
80
81 /**
82 * ntfs_mft_record_get_data_size - return number of bytes used in mft record @b
83 * @m: mft record to get the data size of
84 *
85 * Takes the mft record @m and returns the number of bytes used in the record
86 * or 0 on error (i.e. @m is not a valid mft record). Zero is not a valid size
87 * for an mft record as it at least has to have the MFT_RECORD itself and a
88 * zero length attribute of type AT_END, thus making the minimum size 56 bytes.
89 *
90 * Aside: The size is independent of NTFS versions 1.x/3.x because the 8-byte
91 * alignment of the first attribute mask the difference in MFT_RECORD size
92 * between NTFS 1.x and 3.x. Also, you would expect every mft record to
93 * contain an update sequence array as well but that could in theory be
94 * non-existent (don't know if Windows' NTFS driver/chkdsk wouldn't view this
95 * as corruption in itself though).
96 */
97 static __inline__ u32 ntfs_mft_record_get_data_size(const MFT_RECORD *m)
98 {
99 if (!m || !ntfs_is_mft_record(m->magic))
100 return 0;
101 /* Get the number of used bytes and return it. */
102 return le32_to_cpu(m->bytes_in_use);
103 }
104
105 extern int ntfs_mft_record_layout(const ntfs_volume *vol, const MFT_REF mref,
106 MFT_RECORD *mrec);
107
108 extern int ntfs_mft_record_format(const ntfs_volume *vol, const MFT_REF mref);
109
110 extern ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, ntfs_inode *base_ni);
111
112 extern int ntfs_mft_record_free(ntfs_volume *vol, ntfs_inode *ni);
113
114 extern int ntfs_mft_usn_dec(MFT_RECORD *mrec);
115
116 #endif /* defined _NTFS_MFT_H */