xref: /onnv-gate/usr/src/lib/libntfs/common/include/ntfs/mft.h (revision 9663:ace9a2ac3683)
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  */
ntfs_mft_record_read(const ntfs_volume * vol,const MFT_REF mref,MFT_RECORD * b)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  */
ntfs_mft_record_write(const ntfs_volume * vol,const MFT_REF mref,MFT_RECORD * b)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  */
ntfs_mft_record_get_data_size(const MFT_RECORD * m)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 */
117