/* * linux/include/linux/jbd.h * * Written by Stephen C. Tweedie * * 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 #include #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 /* _LINUX_JBD_H */