/* * logfile.h - Exports for $LogFile handling. Part of the Linux-NTFS project. * * Copyright (c) 2000-2002 Anton Altaparmakov * * This program/include file is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program/include file is distributed in the hope that it will be * useful, but WITHOUT ANY WARRANTY; without even the implied warranty * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program (in the main directory of the Linux-NTFS * distribution in the file COPYING); if not, write to the Free Software * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #ifndef _NTFS_LOGFILE_H #define _NTFS_LOGFILE_H #include "types.h" typedef enum { magic_RSTR = const_cpu_to_le32(0x52545352), /* "RSTR", restart area */ magic_RCRD = const_cpu_to_le32(0x44524352), /* "RCRD", log record */ } LOG_FILE_RECORD_TYPES; /* * Specialised magic comparison macros. */ #define ntfs_is_rstr_record(x) ( ntfs_is_magic (x, RSTR) ) #define ntfs_is_rstr_recordp(p) ( ntfs_is_magicp(p, RSTR) ) #define ntfs_is_rcrd_record(x) ( ntfs_is_magic (x, RCRD) ) #define ntfs_is_rcrd_recordp(p) ( ntfs_is_magicp(p, RCRD) ) /* * Log file organization: * Two restart areas present in the first two pages (restart pages). When * the volume is unmounted they should be identical. * These are followed by log records organized in pages headed by a record * header going up to log file size. Not all pages contain log records when a * volume is first formatted, but as the volume ages, all records will be used. * When the log file fills up, the records at the beginning are purged (by * modifying the oldest_lsn to a higher value presumably) and writing begins * at the beginning of the file. Effectively, the log file is viewed as a * circular entity. */ /* * Log file restart page header (begins the restart area). */ typedef struct { NTFS_RECORD; /* The magic is "RSTR". */ u64 chkdsk_lsn; /* The check disk log file sequence number for this restart page. Only used when the magic is changed to "CHKD". = 0 */ u32 system_page_size; /* Byte size of system pages, has to be >= 512 and a power of 2. Use this to calculate the required size of the usa and add this to the ntfs.usa_offset value. Then verify that the result is less than the value of the restart_offset. = 0x1000 */ u32 log_page_size; /* Byte size of log file records, has to be >= 512 and a power of 2. = 0x1000 */ u16 restart_offset; /* Byte offset from the start of the record to the restart record. Value has to be aligned to 8-byte boundary. = 0x30 */ s16 minor_ver; /* Log file minor version. Only check if major version is 1. (=1 but >=1 is treated the same and <=0 is also ok) */ u16 major_ver; /* Log file major version (=1 but =0 is ok) */ } __attribute__ ((__packed__)) RESTART_PAGE_HEADER; /* * Log file restart area record. The offset of this record is found by adding * the offset of the RESTART_PAGE_HEADER to the restart_offset value found in * it. */ typedef struct { u64 current_lsn; /* Log file record. = 0x700000, 0x700808 */ u16 log_clients; /* Number of log client records following the restart_area. = 1 */ s16 client_free_list; /* How many clients are free(?). If != 0xffff, check that log_clients > client_free_list. = 0xffff */ s16 client_in_use_list;/* How many clients are in use(?). If != 0xffff check that log_clients > client_in_use_list. = 0 */ u16 flags; /* ??? = 0 */ u32 seq_number_bits; /* ??? = 0x2c or 0x2d */ u16 restart_area_length;/* Length of the restart area. Following checks required if version matches. Otherwise, skip them. restart_offset + restart_area_length has to be <= system_page_size. Also, restart_area_length has to be >= client_array_offset + (log_clients * 0xa0). = 0xd0 */ u16 client_array_offset;/* Offset from the start of this record to the first client record if versions are matched. The offset is otherwise assumed to be (sizeof(RESTART_AREA) + 7) & ~7, i.e. rounded up to first 8-byte boundary. Either way, the offset to the client array has to be aligned to an 8-byte boundary. Also, restart_offset + offset to the client array have to be <= 510. Also, the offset to the client array + (log_clients * 0xa0) have to be <= SystemPageSize. = 0x30 */ u64 file_size; /* Byte size of the log file. If the restart_offset + the offset of the file_size are > 510 then corruption has occured. This is the very first check when starting with the restart_area as if it fails it means that some of the above values will be corrupted by the multi sector transfer protection! If the structure is deprotected then these checks are futile of course. Calculate the file_size bits and check that seq_number_bits == 0x43 - file_size bits. = 0x400000 */ u32 last_lsn_data_length;/* ??? = 0, 0x40 */ u16 record_length; /* Byte size of this record. If the version matches then check that the value of record_length is a multiple of 8, i.e. (record_length + 7) & ~7 == record_length. = 0x30 */ u16 log_page_data_offset;/* ??? = 0x40 */ /* * There are eight bytes here at offset 0x58, which contain a value, * which we don't know what it means. It looks like it could be a * 64-bit number or a 32-bit plus something else (the second 32-bits * are zero so can't tell). Have to try to zero it and see if Windows * copes with this. */ } __attribute__ ((__packed__)) RESTART_AREA; /* * Log file restart client. The offset of this record is found by adding * the offset of the RESTART_AREA to the client_array_offset value found in it. */ typedef struct { u64 oldest_lsn; /* Oldest log file sequence number for this client record. */ u64 client_restart_lsn; /* Log file sequence number at which to restart the volume, i.e. the current position within the logfile. */ s16 prev_client; /* ??? = 0xffff */ s16 next_client; /* ??? = 0xffff */ u64 seq_number; /* ??? = 1, size uncertain, Regis calls this "volume clear flag" and gives a size of one byte. */ u32 client_name_length; /* ??? length of client name in bytes. = 8, size uncertain, offset uncertain */ uchar_t client_name[0]; /* ??? Name of the client in unicode. = NTFS */ /* * Or it could be the client name is fixed size like in attr def struct * and the 8 means something else. Favouring this is that the * RESTART_CLIENT struct is assumed to be fixed size of 0xa0 bytes, * just like the attr def struct! There might be parallels to be drawn * between the two. */ } __attribute__ ((__packed__)) RESTART_CLIENT; /* * Log page record page header. Each log page begins with this header and is * followed by several LOG_RECORD structures, starting at offset 0x40 (the * size of this structure and the following update sequence array and then * aligned to 8 byte boundary, but is this specified anywhere?). */ typedef struct { NTFS_RECORD; /* The magic is "RCRD". */ union { u64 last_lsn; u32 file_offset; } __attribute__ ((__packed__)) copy; u32 flags; u16 page_count; u16 page_position; union { struct { u64 next_record_offset; u64 last_end_lsn; } __attribute__ ((__packed__)) packed; } __attribute__ ((__packed__)) header; } __attribute__ ((__packed__)) RECORD_PAGE_HEADER; /* * Possible flags for log records. */ typedef enum { LOG_RECORD_MULTI_PAGE = const_cpu_to_le16(0x0001), /* ??? */ LOG_RECORD_SIZE_PLACE_HOLDER = 0xffff, /* This has nothing to do with the log record. It is only so gcc knows to make the flags 16-bit. */ } __attribute__ ((__packed__)) LOG_RECORD_FLAGS; /* * Log record header. Each log record seems to have a constant size of 0x70 * bytes. */ typedef struct { u64 this_lsn; u64 client_previous_lsn; u64 client_undo_next_lsn; u32 client_data_length; struct { u16 seq_number; u16 client_index; } __attribute__ ((__packed__)) client_id; u32 record_type; u32 transaction_id; LOG_RECORD_FLAGS flags; u16 reserved_or_alignment[3]; /* Now are at ofs 0x30 into struct. */ u16 redo_operation; u16 undo_operation; u16 redo_offset; u16 redo_length; u16 undo_offset; u16 undo_length; u16 target_attribute; u16 lcns_to_follow; /* Number of lcn_list entries following this entry. */ /* Now at ofs 0x40. */ u16 record_offset; u16 attribute_offset; u32 alignment_or_reserved; s64 target_vcn; /* Now at ofs 0x50. */ struct { /* Only present if lcns_to_follow is not 0. */ s64 lcn; } __attribute__((__packed__)) lcn_list[0]; } __attribute__ ((__packed__)) LOG_RECORD; #endif /* defined _NTFS_LOGFILE_H */