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 */ 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 */ 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 */ 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