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