310 lines
14 KiB
C
310 lines
14 KiB
C
/*
|
|
* logfile.h - Defines for NTFS kernel journal ($LogFile) handling. Part of
|
|
* the Linux-NTFS project.
|
|
*
|
|
* Copyright (c) 2000-2005 Anton Altaparmakov
|
|
*
|
|
* This program/include file is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as published
|
|
* by the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program/include file is distributed in the hope that it will be
|
|
* useful, but WITHOUT ANY WARRANTY; without even the implied warranty
|
|
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program (in the main directory of the Linux-NTFS
|
|
* distribution in the file COPYING); if not, write to the Free Software
|
|
* Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#ifndef _LINUX_NTFS_LOGFILE_H
|
|
#define _LINUX_NTFS_LOGFILE_H
|
|
|
|
#ifdef NTFS_RW
|
|
|
|
#include <linux/fs.h>
|
|
|
|
#include "types.h"
|
|
#include "endian.h"
|
|
#include "layout.h"
|
|
|
|
/*
|
|
* Journal ($LogFile) organization:
|
|
*
|
|
* Two restart areas present in the first two pages (restart pages, one restart
|
|
* area in each page). When the volume is dismounted they should be identical,
|
|
* except for the update sequence array which usually has a different update
|
|
* sequence number.
|
|
*
|
|
* These are followed by log records organized in pages headed by a log 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.
|
|
*
|
|
* NOTE: Windows NT, 2000, and XP all use log file version 1.1 but they accept
|
|
* versions <= 1.x, including 0.-1. (Yes, that is a minus one in there!) We
|
|
* probably only want to support 1.1 as this seems to be the current version
|
|
* and we don't know how that differs from the older versions. The only
|
|
* exception is if the journal is clean as marked by the two restart pages
|
|
* then it doesn't matter whether we are on an earlier version. We can just
|
|
* reinitialize the logfile and start again with version 1.1.
|
|
*/
|
|
|
|
/* Some $LogFile related constants. */
|
|
#define MaxLogFileSize 0x100000000ULL
|
|
#define DefaultLogPageSize 4096
|
|
#define MinLogRecordPages 48
|
|
|
|
/*
|
|
* Log file restart page header (begins the restart area).
|
|
*/
|
|
typedef struct {
|
|
/*Ofs*/
|
|
/* 0 NTFS_RECORD; -- Unfolded here as gcc doesn't like unnamed structs. */
|
|
/* 0*/ NTFS_RECORD_TYPE magic; /* The magic is "RSTR". */
|
|
/* 4*/ le16 usa_ofs; /* See NTFS_RECORD definition in layout.h.
|
|
When creating, set this to be immediately
|
|
after this header structure (without any
|
|
alignment). */
|
|
/* 6*/ le16 usa_count; /* See NTFS_RECORD definition in layout.h. */
|
|
|
|
/* 8*/ leLSN chkdsk_lsn; /* The last log file sequence number found by
|
|
chkdsk. Only used when the magic is changed
|
|
to "CHKD". Otherwise this is zero. */
|
|
/* 16*/ le32 system_page_size; /* Byte size of system pages when the log file
|
|
was created, has to be >= 512 and a power of
|
|
2. Use this to calculate the required size
|
|
of the usa (usa_count) and add it to usa_ofs.
|
|
Then verify that the result is less than the
|
|
value of the restart_area_offset. */
|
|
/* 20*/ le32 log_page_size; /* Byte size of log file pages, has to be >=
|
|
512 and a power of 2. The default is 4096
|
|
and is used when the system page size is
|
|
between 4096 and 8192. Otherwise this is
|
|
set to the system page size instead. */
|
|
/* 24*/ le16 restart_area_offset;/* Byte offset from the start of this header to
|
|
the RESTART_AREA. Value has to be aligned
|
|
to 8-byte boundary. When creating, set this
|
|
to be after the usa. */
|
|
/* 26*/ sle16 minor_ver; /* Log file minor version. Only check if major
|
|
version is 1. */
|
|
/* 28*/ sle16 major_ver; /* Log file major version. We only support
|
|
version 1.1. */
|
|
/* sizeof() = 30 (0x1e) bytes */
|
|
} __attribute__ ((__packed__)) RESTART_PAGE_HEADER;
|
|
|
|
/*
|
|
* Constant for the log client indices meaning that there are no client records
|
|
* in this particular client array. Also inside the client records themselves,
|
|
* this means that there are no client records preceding or following this one.
|
|
*/
|
|
#define LOGFILE_NO_CLIENT const_cpu_to_le16(0xffff)
|
|
#define LOGFILE_NO_CLIENT_CPU 0xffff
|
|
|
|
/*
|
|
* These are the so far known RESTART_AREA_* flags (16-bit) which contain
|
|
* information about the log file in which they are present.
|
|
*/
|
|
enum {
|
|
RESTART_VOLUME_IS_CLEAN = const_cpu_to_le16(0x0002),
|
|
RESTART_SPACE_FILLER = const_cpu_to_le16(0xffff), /* gcc: Force enum bit width to 16. */
|
|
} __attribute__ ((__packed__));
|
|
|
|
typedef le16 RESTART_AREA_FLAGS;
|
|
|
|
/*
|
|
* Log file restart area record. The offset of this record is found by adding
|
|
* the offset of the RESTART_PAGE_HEADER to the restart_area_offset value found
|
|
* in it. See notes at restart_area_offset above.
|
|
*/
|
|
typedef struct {
|
|
/*Ofs*/
|
|
/* 0*/ leLSN current_lsn; /* The current, i.e. last LSN inside the log
|
|
when the restart area was last written.
|
|
This happens often but what is the interval?
|
|
Is it just fixed time or is it every time a
|
|
check point is written or somethine else?
|
|
On create set to 0. */
|
|
/* 8*/ le16 log_clients; /* Number of log client records in the array of
|
|
log client records which follows this
|
|
restart area. Must be 1. */
|
|
/* 10*/ le16 client_free_list; /* The index of the first free log client record
|
|
in the array of log client records.
|
|
LOGFILE_NO_CLIENT means that there are no
|
|
free log client records in the array.
|
|
If != LOGFILE_NO_CLIENT, check that
|
|
log_clients > client_free_list. On Win2k
|
|
and presumably earlier, on a clean volume
|
|
this is != LOGFILE_NO_CLIENT, and it should
|
|
be 0, i.e. the first (and only) client
|
|
record is free and thus the logfile is
|
|
closed and hence clean. A dirty volume
|
|
would have left the logfile open and hence
|
|
this would be LOGFILE_NO_CLIENT. On WinXP
|
|
and presumably later, the logfile is always
|
|
open, even on clean shutdown so this should
|
|
always be LOGFILE_NO_CLIENT. */
|
|
/* 12*/ le16 client_in_use_list;/* The index of the first in-use log client
|
|
record in the array of log client records.
|
|
LOGFILE_NO_CLIENT means that there are no
|
|
in-use log client records in the array. If
|
|
!= LOGFILE_NO_CLIENT check that log_clients
|
|
> client_in_use_list. On Win2k and
|
|
presumably earlier, on a clean volume this
|
|
is LOGFILE_NO_CLIENT, i.e. there are no
|
|
client records in use and thus the logfile
|
|
is closed and hence clean. A dirty volume
|
|
would have left the logfile open and hence
|
|
this would be != LOGFILE_NO_CLIENT, and it
|
|
should be 0, i.e. the first (and only)
|
|
client record is in use. On WinXP and
|
|
presumably later, the logfile is always
|
|
open, even on clean shutdown so this should
|
|
always be 0. */
|
|
/* 14*/ RESTART_AREA_FLAGS flags;/* Flags modifying LFS behaviour. On Win2k
|
|
and presumably earlier this is always 0. On
|
|
WinXP and presumably later, if the logfile
|
|
was shutdown cleanly, the second bit,
|
|
RESTART_VOLUME_IS_CLEAN, is set. This bit
|
|
is cleared when the volume is mounted by
|
|
WinXP and set when the volume is dismounted,
|
|
thus if the logfile is dirty, this bit is
|
|
clear. Thus we don't need to check the
|
|
Windows version to determine if the logfile
|
|
is clean. Instead if the logfile is closed,
|
|
we know it must be clean. If it is open and
|
|
this bit is set, we also know it must be
|
|
clean. If on the other hand the logfile is
|
|
open and this bit is clear, we can be almost
|
|
certain that the logfile is dirty. */
|
|
/* 16*/ le32 seq_number_bits; /* How many bits to use for the sequence
|
|
number. This is calculated as 67 - the
|
|
number of bits required to store the logfile
|
|
size in bytes and this can be used in with
|
|
the specified file_size as a consistency
|
|
check. */
|
|
/* 20*/ le16 restart_area_length;/* Length of the restart area including the
|
|
client array. Following checks required if
|
|
version matches. Otherwise, skip them.
|
|
restart_area_offset + restart_area_length
|
|
has to be <= system_page_size. Also,
|
|
restart_area_length has to be >=
|
|
client_array_offset + (log_clients *
|
|
sizeof(log client record)). */
|
|
/* 22*/ le16 client_array_offset;/* Offset from the start of this record to
|
|
the first log client record if versions are
|
|
matched. When creating, set this to be
|
|
after this restart area structure, aligned
|
|
to 8-bytes boundary. If the versions do not
|
|
match, this is ignored and the offset is
|
|
assumed to be (sizeof(RESTART_AREA) + 7) &
|
|
~7, i.e. rounded up to first 8-byte
|
|
boundary. Either way, client_array_offset
|
|
has to be aligned to an 8-byte boundary.
|
|
Also, restart_area_offset +
|
|
client_array_offset has to be <= 510.
|
|
Finally, client_array_offset + (log_clients
|
|
* sizeof(log client record)) has to be <=
|
|
system_page_size. On Win2k and presumably
|
|
earlier, this is 0x30, i.e. immediately
|
|
following this record. On WinXP and
|
|
presumably later, this is 0x40, i.e. there
|
|
are 16 extra bytes between this record and
|
|
the client array. This probably means that
|
|
the RESTART_AREA record is actually bigger
|
|
in WinXP and later. */
|
|
/* 24*/ sle64 file_size; /* Usable byte size of the log file. If the
|
|
restart_area_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. The file_size has to
|
|
be rounded down to be a multiple of the
|
|
log_page_size in the RESTART_PAGE_HEADER and
|
|
then it has to be at least big enough to
|
|
store the two restart pages and 48 (0x30)
|
|
log record pages. */
|
|
/* 32*/ le32 last_lsn_data_length;/* Length of data of last LSN, not including
|
|
the log record header. On create set to
|
|
0. */
|
|
/* 36*/ le16 log_record_header_length;/* Byte size of the log record header.
|
|
If the version matches then check that the
|
|
value of log_record_header_length is a
|
|
multiple of 8, i.e.
|
|
(log_record_header_length + 7) & ~7 ==
|
|
log_record_header_length. When creating set
|
|
it to sizeof(LOG_RECORD_HEADER), aligned to
|
|
8 bytes. */
|
|
/* 38*/ le16 log_page_data_offset;/* Offset to the start of data in a log record
|
|
page. Must be a multiple of 8. On create
|
|
set it to immediately after the update
|
|
sequence array of the log record page. */
|
|
/* 40*/ le32 restart_log_open_count;/* A counter that gets incremented every
|
|
time the logfile is restarted which happens
|
|
at mount time when the logfile is opened.
|
|
When creating set to a random value. Win2k
|
|
sets it to the low 32 bits of the current
|
|
system time in NTFS format (see time.h). */
|
|
/* 44*/ le32 reserved; /* Reserved/alignment to 8-byte boundary. */
|
|
/* sizeof() = 48 (0x30) bytes */
|
|
} __attribute__ ((__packed__)) RESTART_AREA;
|
|
|
|
/*
|
|
* Log client record. 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 {
|
|
/*Ofs*/
|
|
/* 0*/ leLSN oldest_lsn; /* Oldest LSN needed by this client. On create
|
|
set to 0. */
|
|
/* 8*/ leLSN client_restart_lsn;/* LSN at which this client needs to restart
|
|
the volume, i.e. the current position within
|
|
the log file. At present, if clean this
|
|
should = current_lsn in restart area but it
|
|
probably also = current_lsn when dirty most
|
|
of the time. At create set to 0. */
|
|
/* 16*/ le16 prev_client; /* The offset to the previous log client record
|
|
in the array of log client records.
|
|
LOGFILE_NO_CLIENT means there is no previous
|
|
client record, i.e. this is the first one.
|
|
This is always LOGFILE_NO_CLIENT. */
|
|
/* 18*/ le16 next_client; /* The offset to the next log client record in
|
|
the array of log client records.
|
|
LOGFILE_NO_CLIENT means there are no next
|
|
client records, i.e. this is the last one.
|
|
This is always LOGFILE_NO_CLIENT. */
|
|
/* 20*/ le16 seq_number; /* On Win2k and presumably earlier, this is set
|
|
to zero every time the logfile is restarted
|
|
and it is incremented when the logfile is
|
|
closed at dismount time. Thus it is 0 when
|
|
dirty and 1 when clean. On WinXP and
|
|
presumably later, this is always 0. */
|
|
/* 22*/ u8 reserved[6]; /* Reserved/alignment. */
|
|
/* 28*/ le32 client_name_length;/* Length of client name in bytes. Should
|
|
always be 8. */
|
|
/* 32*/ ntfschar client_name[64];/* Name of the client in Unicode. Should
|
|
always be "NTFS" with the remaining bytes
|
|
set to 0. */
|
|
/* sizeof() = 160 (0xa0) bytes */
|
|
} __attribute__ ((__packed__)) LOG_CLIENT_RECORD;
|
|
|
|
extern BOOL ntfs_check_logfile(struct inode *log_vi,
|
|
RESTART_PAGE_HEADER **rp);
|
|
|
|
extern BOOL ntfs_is_logfile_clean(struct inode *log_vi,
|
|
const RESTART_PAGE_HEADER *rp);
|
|
|
|
extern BOOL ntfs_empty_logfile(struct inode *log_vi);
|
|
|
|
#endif /* NTFS_RW */
|
|
|
|
#endif /* _LINUX_NTFS_LOGFILE_H */
|