/* 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#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	9struct 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	/* _LINUX_JBD_H */