2 * mft.h - Exports for MFT record handling. Part of the Linux-NTFS project.
4 * Copyright (c) 2000-2002 Anton Altaparmakov
6 * This program/include file is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as published
8 * by the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program/include file is distributed in the hope that it will be
12 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program (in the main directory of the Linux-NTFS
18 * distribution in the file COPYING); if not, write to the Free Software
19 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 extern int ntfs_mft_records_read(const ntfs_volume *vol, const MFT_REF mref,
30 const s64 count, MFT_RECORD *b);
33 * ntfs_mft_record_read - read a record from the mft
34 * @vol: volume to read from
35 * @mref: mft record number to read
36 * @b: output data buffer
38 * Read the mft record specified by @mref from volume @vol into buffer @b.
39 * Return 0 on success or -1 on error, with errno set to the error code.
41 * The read mft record is mst deprotected and is hence ready to use. The caller
42 * should check the record with is_baad_record() in case mst deprotection
45 * NOTE: @b has to be at least of size vol->mft_record_size.
47 static __inline__ int ntfs_mft_record_read(const ntfs_volume *vol,
48 const MFT_REF mref, MFT_RECORD *b)
50 return ntfs_mft_records_read(vol, mref, 1, b);
53 extern int ntfs_file_record_read(const ntfs_volume *vol, const MFT_REF mref,
54 MFT_RECORD **mrec, ATTR_RECORD **attr);
56 extern int ntfs_mft_records_write(const ntfs_volume *vol, const MFT_REF mref,
57 const s64 count, MFT_RECORD *b);
60 * ntfs_mft_record_write - write an mft record to disk
61 * @vol: volume to write to
62 * @mref: mft record number to write
63 * @b: data buffer containing the mft record to write
65 * Write the mft record specified by @mref from buffer @b to volume @vol.
66 * Return 0 on success or -1 on error, with errno set to the error code.
68 * Before the mft record is written, it is mst protected. After the write, it
69 * is deprotected again, thus resulting in an increase in the update sequence
70 * number inside the buffer @b.
72 * NOTE: @b has to be at least of size vol->mft_record_size.
74 static __inline__ int ntfs_mft_record_write(const ntfs_volume *vol,
75 const MFT_REF mref, MFT_RECORD *b)
77 return ntfs_mft_records_write(vol, mref, 1, b);
81 * ntfs_mft_record_get_data_size - return number of bytes used in mft record @b
82 * @m: mft record to get the data size of
84 * Takes the mft record @m and returns the number of bytes used in the record
85 * or 0 on error (i.e. @m is not a valid mft record). Zero is not a valid size
86 * for an mft record as it at least has to have the MFT_RECORD, thus making the
88 * (sizeof(MFT_RECORD) + 7) & ~7 + sizeof(ATTR_TYPES) = 52 bytes
89 * Aside: The 8-byte alignment and the 4 bytes for the attribute type are needed
90 * as each mft record has to have a list of attributes even if it only contains
91 * the attribute $END which doesn't contain anything else apart from its type.
92 * Also, you would expect every mft record to contain an update sequence array
93 * as well but that could in theory be non-existent (don't know if Windows'
94 * NTFS driver/chkdsk wouldn't view this as corruption in itself though).
96 static __inline__ u32 ntfs_mft_record_get_data_size(const MFT_RECORD *m)
98 if (!m || !ntfs_is_mft_record(m->magic))
100 /* Get the number of used bytes and return it. */
101 return le32_to_cpu(m->bytes_in_use);
104 extern ntfs_inode *ntfs_mft_record_alloc(ntfs_volume *vol, u64 start);
106 extern int ntfs_mft_record_free(ntfs_volume *vol, ntfs_inode *ni);
108 #endif /* defined _NTFS_MFT_H */