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/*
* 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
#if defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE) || !defined(__KERNEL__)
/* Allow this file to be included directly into e2fsprogs */
#include "jfs_compat.h"
#define JFS_DEBUG
#define jfs_debug jbd_debug
extern int journal_oom_retry;
#ifdef CONFIG_JBD_DEBUG
/*
* Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
* consistency checks. By default we don't do this unless
* CONFIG_JBD_DEBUG is on.
*/
#define JBD_EXPENSIVE_CHECKING
extern int journal_enable_debug;
extern int journal_no_write[2];
#define jbd_debug(n, f, a...) \
do { \
if ((n) <= journal_enable_debug) { \
printk (KERN_DEBUG "(%s, %d): %s: ", \
__FILE__, __LINE__, __FUNCTION__); \
printk (f, ## a); \
} \
} while (0)
#else
#define jbd_debug(f, a...) /**/
#endif
extern void * __jbd_kmalloc (char *where, size_t size, int flags, int retry);
#define jbd_kmalloc(size, flags) \
__jbd_kmalloc(__FUNCTION__, (size), (flags), journal_oom_retry)
#define jbd_rep_kmalloc(size, flags) \
__jbd_kmalloc(__FUNCTION__, (size), (flags), 1)
#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! */
/*
* On-disk structures
*/
/*
* 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
/*
* Standard header for all descriptor blocks:
*/
typedef struct journal_header_s
{
__u32 h_magic;
__u32 h_blocktype;
__u32 h_sequence;
} journal_header_t;
/*
* 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 */
/*
* 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;
#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
*/
/* JBD additions */
/* 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
extern int jbd_blocks_per_page(struct inode *inode);
#endif /* CONFIG_JBD || CONFIG_JBD_MODULE || !__KERNEL__ */
/*
* Compatibility no-ops which allow the kernel to compile without CONFIG_JBD
* go here.
*/
#if defined(__KERNEL__) && !(defined(CONFIG_JBD) || defined(CONFIG_JBD_MODULE))
#define J_ASSERT(expr) do {} while (0)
#define J_ASSERT_BH(bh, expr) do {} while (0)
#define buffer_jbd(bh) 0
#define buffer_jlist_eq(bh, val) 0
#define journal_buffer_journal_lru(bh) 0
#endif /* defined(__KERNEL__) && !defined(CONFIG_JBD) */
#endif /* _LINUX_JBD_H */