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/* vi: set sw=4 ts=4: */
/*
* linux/include/linux/jbd.h
*
* Written by Stephen C. Tweedie <sct@redhat.com>
*
* Copyright 1998-2000 Red Hat, Inc --- All Rights Reserved
*
* This file is part of the Linux kernel and is made available under
* the terms of the GNU General Public License, version 2, or at your
* option, any later version, incorporated herein by reference.
*
* Definitions for transaction data structures for the buffer cache
* filesystem journaling support.
*/
#ifndef LINUX_JBD_H
#define LINUX_JBD_H 1
#include <sys/types.h>
#include <linux/types.h>
#include "ext2fs.h"
/*
* Standard header for all descriptor blocks:
*/
typedef struct journal_header_s
{
__u32 h_magic;
__u32 h_blocktype;
__u32 h_sequence;
} journal_header_t;
/*
* This is the global e2fsck structure.
*/
typedef struct e2fsck_struct *e2fsck_t;
struct inode {
e2fsck_t i_ctx;
ext2_ino_t i_ino;
struct ext2_inode i_ext2;
};
/*
* The journal superblock. All fields are in big-endian byte order.
*/
typedef struct journal_superblock_s
{
/* 0x0000 */
journal_header_t s_header;
/* 0x000C */
/* Static information describing the journal */
__u32 s_blocksize; /* journal device blocksize */
__u32 s_maxlen; /* total blocks in journal file */
__u32 s_first; /* first block of log information */
/* 0x0018 */
/* Dynamic information describing the current state of the log */
__u32 s_sequence; /* first commit ID expected in log */
__u32 s_start; /* blocknr of start of log */
/* 0x0020 */
/* Error value, as set by journal_abort(). */
__s32 s_errno;
/* 0x0024 */
/* Remaining fields are only valid in a version-2 superblock */
__u32 s_feature_compat; /* compatible feature set */
__u32 s_feature_incompat; /* incompatible feature set */
__u32 s_feature_ro_compat; /* readonly-compatible feature set */
/* 0x0030 */
__u8 s_uuid[16]; /* 128-bit uuid for journal */
/* 0x0040 */
__u32 s_nr_users; /* Nr of filesystems sharing log */
__u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
/* 0x0048 */
__u32 s_max_transaction; /* Limit of journal blocks per trans.*/
__u32 s_max_trans_data; /* Limit of data blocks per trans. */
/* 0x0050 */
__u32 s_padding[44];
/* 0x0100 */
__u8 s_users[16*48]; /* ids of all fs'es sharing the log */
/* 0x0400 */
} journal_superblock_t;
extern int journal_blocks_per_page(struct inode *inode);
extern int jbd_blocks_per_page(struct inode *inode);
#define JFS_MIN_JOURNAL_BLOCKS 1024
/*
* Internal structures used by the logging mechanism:
*/
#define JFS_MAGIC_NUMBER 0xc03b3998U /* The first 4 bytes of /dev/random! */
/*
* Descriptor block types:
*/
#define JFS_DESCRIPTOR_BLOCK 1
#define JFS_COMMIT_BLOCK 2
#define JFS_SUPERBLOCK_V1 3
#define JFS_SUPERBLOCK_V2 4
#define JFS_REVOKE_BLOCK 5
/*
* The block tag: used to describe a single buffer in the journal
*/
typedef struct journal_block_tag_s
{
__u32 t_blocknr; /* The on-disk block number */
__u32 t_flags; /* See below */
} journal_block_tag_t;
/*
* The revoke descriptor: used on disk to describe a series of blocks to
* be revoked from the log
*/
typedef struct journal_revoke_header_s
{
journal_header_t r_header;
int r_count; /* Count of bytes used in the block */
} journal_revoke_header_t;
/* Definitions for the journal tag flags word: */
#define JFS_FLAG_ESCAPE 1 /* on-disk block is escaped */
#define JFS_FLAG_SAME_UUID 2 /* block has same uuid as previous */
#define JFS_FLAG_DELETED 4 /* block deleted by this transaction */
#define JFS_FLAG_LAST_TAG 8 /* last tag in this descriptor block */
#define JFS_HAS_COMPAT_FEATURE(j,mask) \
((j)->j_format_version >= 2 && \
((j)->j_superblock->s_feature_compat & cpu_to_be32((mask))))
#define JFS_HAS_RO_COMPAT_FEATURE(j,mask) \
((j)->j_format_version >= 2 && \
((j)->j_superblock->s_feature_ro_compat & cpu_to_be32((mask))))
#define JFS_HAS_INCOMPAT_FEATURE(j,mask) \
((j)->j_format_version >= 2 && \
((j)->j_superblock->s_feature_incompat & cpu_to_be32((mask))))
#define JFS_FEATURE_INCOMPAT_REVOKE 0x00000001
/* Features known to this kernel version: */
#define JFS_KNOWN_COMPAT_FEATURES 0
#define JFS_KNOWN_ROCOMPAT_FEATURES 0
#define JFS_KNOWN_INCOMPAT_FEATURES JFS_FEATURE_INCOMPAT_REVOKE
/* Comparison functions for transaction IDs: perform comparisons using
* modulo arithmetic so that they work over sequence number wraps. */
/*
* Definitions which augment the buffer_head layer
*/
/* journaling buffer types */
#define BJ_None 0 /* Not journaled */
#define BJ_SyncData 1 /* Normal data: flush before commit */
#define BJ_AsyncData 2 /* writepage data: wait on it before commit */
#define BJ_Metadata 3 /* Normal journaled metadata */
#define BJ_Forget 4 /* Buffer superceded by this transaction */
#define BJ_IO 5 /* Buffer is for temporary IO use */
#define BJ_Shadow 6 /* Buffer contents being shadowed to the log */
#define BJ_LogCtl 7 /* Buffer contains log descriptors */
#define BJ_Reserved 8 /* Buffer is reserved for access by journal */
#define BJ_Types 9
struct kdev_s {
e2fsck_t k_ctx;
int k_dev;
};
typedef struct kdev_s *kdev_t;
typedef unsigned int tid_t;
struct journal_s
{
unsigned long j_flags;
int j_errno;
struct buffer_head * j_sb_buffer;
struct journal_superblock_s *j_superblock;
int j_format_version;
unsigned long j_head;
unsigned long j_tail;
unsigned long j_free;
unsigned long j_first, j_last;
kdev_t j_dev;
kdev_t j_fs_dev;
int j_blocksize;
unsigned int j_blk_offset;
unsigned int j_maxlen;
struct inode * j_inode;
tid_t j_tail_sequence;
tid_t j_transaction_sequence;
__u8 j_uuid[16];
struct jbd_revoke_table_s *j_revoke;
};
typedef struct journal_s journal_t;
extern int journal_recover (journal_t *journal);
extern int journal_skip_recovery (journal_t *);
/* Primary revoke support */
extern int journal_init_revoke(journal_t *, int);
extern void journal_destroy_revoke_caches(void);
extern int journal_init_revoke_caches(void);
/* Recovery revoke support */
extern int journal_set_revoke(journal_t *, unsigned long, tid_t);
extern int journal_test_revoke(journal_t *, unsigned long, tid_t);
extern void journal_clear_revoke(journal_t *);
extern void journal_brelse_array(struct buffer_head *b[], int n);
extern void journal_destroy_revoke(journal_t *);
#endif
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