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