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authorMike Frysinger2005-05-09 22:10:42 +0000
committerMike Frysinger2005-05-09 22:10:42 +0000
commit1fd98e039d146dcff02a5350f509cabca65fd29c (patch)
tree1564707d41a6271bb44cf3fa5b88b9cc70fedd35 /e2fsprogs/ext2fs/kernel-jbd.h
parentb32011943a0764872ca1ea17f13b53176ace8e69 (diff)
downloadbusybox-1fd98e039d146dcff02a5350f509cabca65fd29c.zip
busybox-1fd98e039d146dcff02a5350f509cabca65fd29c.tar.gz
import ext2fs lib to prep for new e2fsprogs
Diffstat (limited to 'e2fsprogs/ext2fs/kernel-jbd.h')
-rw-r--r--e2fsprogs/ext2fs/kernel-jbd.h910
1 files changed, 910 insertions, 0 deletions
diff --git a/e2fsprogs/ext2fs/kernel-jbd.h b/e2fsprogs/ext2fs/kernel-jbd.h
new file mode 100644
index 0000000..d0efdb3
--- /dev/null
+++ b/e2fsprogs/ext2fs/kernel-jbd.h
@@ -0,0 +1,910 @@
+/*
+ * 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 */
+#ifndef __KERNEL__
+#include "jfs_compat.h"
+#define JFS_DEBUG
+#define jfs_debug jbd_debug
+#else
+
+#include <linux/journal-head.h>
+#include <linux/stddef.h>
+#include <asm/semaphore.h>
+#endif
+
+#ifndef __GNUC__
+#define __FUNCTION__ ""
+#endif
+
+#define journal_oom_retry 1
+
+#ifdef __STDC__
+#ifdef __CONFIG_JBD_DEBUG__E2FS
+/*
+ * Define JBD_EXPENSIVE_CHECKING to enable more expensive internal
+ * consistency checks. By default we don't do this unless
+ * __CONFIG_JBD_DEBUG__E2FS is on.
+ */
+#define JBD_EXPENSIVE_CHECKING
+extern int journal_enable_debug;
+
+#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
+#ifdef __GNUC__
+#define jbd_debug(f, a...) /**/
+#else
+#define jbd_debug(f, ...) /**/
+#endif
+#endif
+#else
+#define jbd_debug(x) /* AIX doesn't do STDC */
+#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
+
+#ifdef __KERNEL__
+typedef struct handle_s handle_t; /* Atomic operation type */
+typedef struct journal_s journal_t; /* Journal control structure */
+#endif
+
+/*
+ * 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_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
+
+#ifdef __KERNEL__
+
+#include <linux/fs.h>
+#include <linux/sched.h>
+
+#define JBD_ASSERTIONS
+#ifdef JBD_ASSERTIONS
+#define J_ASSERT(assert) \
+do { \
+ if (!(assert)) { \
+ printk (KERN_EMERG \
+ "Assertion failure in %s() at %s:%d: \"%s\"\n", \
+ __FUNCTION__, __FILE__, __LINE__, # assert); \
+ BUG(); \
+ } \
+} while (0)
+
+#if defined(CONFIG_BUFFER_DEBUG)
+void buffer_assertion_failure(struct buffer_head *bh);
+#define J_ASSERT_BH(bh, expr) \
+ do { \
+ if (!(expr)) \
+ buffer_assertion_failure(bh); \
+ J_ASSERT(expr); \
+ } while (0)
+#define J_ASSERT_JH(jh, expr) J_ASSERT_BH(jh2bh(jh), expr)
+#else
+#define J_ASSERT_BH(bh, expr) J_ASSERT(expr)
+#define J_ASSERT_JH(jh, expr) J_ASSERT(expr)
+#endif
+
+#else
+#define J_ASSERT(assert)
+#endif /* JBD_ASSERTIONS */
+
+enum jbd_state_bits {
+ BH_JWrite
+ = BH_PrivateStart, /* 1 if being written to log (@@@ DEBUGGING) */
+ BH_Freed, /* 1 if buffer has been freed (truncated) */
+ BH_Revoked, /* 1 if buffer has been revoked from the log */
+ BH_RevokeValid, /* 1 if buffer revoked flag is valid */
+ BH_JBDDirty, /* 1 if buffer is dirty but journaled */
+};
+
+/* Return true if the buffer is one which JBD is managing */
+static inline int buffer_jbd(struct buffer_head *bh)
+{
+ return __buffer_state(bh, JBD);
+}
+
+static inline struct buffer_head *jh2bh(struct journal_head *jh)
+{
+ return jh->b_bh;
+}
+
+static inline struct journal_head *bh2jh(struct buffer_head *bh)
+{
+ return bh->b_private;
+}
+
+struct jbd_revoke_table_s;
+
+/* The handle_t type represents a single atomic update being performed
+ * by some process. All filesystem modifications made by the process go
+ * through this handle. Recursive operations (such as quota operations)
+ * are gathered into a single update.
+ *
+ * The buffer credits field is used to account for journaled buffers
+ * being modified by the running process. To ensure that there is
+ * enough log space for all outstanding operations, we need to limit the
+ * number of outstanding buffers possible at any time. When the
+ * operation completes, any buffer credits not used are credited back to
+ * the transaction, so that at all times we know how many buffers the
+ * outstanding updates on a transaction might possibly touch. */
+
+struct handle_s
+{
+ /* Which compound transaction is this update a part of? */
+ transaction_t * h_transaction;
+
+ /* Number of remaining buffers we are allowed to dirty: */
+ int h_buffer_credits;
+
+ /* Reference count on this handle */
+ int h_ref;
+
+ /* Field for caller's use to track errors through large fs
+ operations */
+ int h_err;
+
+ /* Flags */
+ unsigned int h_sync: 1; /* sync-on-close */
+ unsigned int h_jdata: 1; /* force data journaling */
+ unsigned int h_aborted: 1; /* fatal error on handle */
+};
+
+
+/* The transaction_t type is the guts of the journaling mechanism. It
+ * tracks a compound transaction through its various states:
+ *
+ * RUNNING: accepting new updates
+ * LOCKED: Updates still running but we don't accept new ones
+ * RUNDOWN: Updates are tidying up but have finished requesting
+ * new buffers to modify (state not used for now)
+ * FLUSH: All updates complete, but we are still writing to disk
+ * COMMIT: All data on disk, writing commit record
+ * FINISHED: We still have to keep the transaction for checkpointing.
+ *
+ * The transaction keeps track of all of the buffers modified by a
+ * running transaction, and all of the buffers committed but not yet
+ * flushed to home for finished transactions.
+ */
+
+struct transaction_s
+{
+ /* Pointer to the journal for this transaction. */
+ journal_t * t_journal;
+
+ /* Sequence number for this transaction */
+ tid_t t_tid;
+
+ /* Transaction's current state */
+ enum {
+ T_RUNNING,
+ T_LOCKED,
+ T_RUNDOWN,
+ T_FLUSH,
+ T_COMMIT,
+ T_FINISHED
+ } t_state;
+
+ /* Where in the log does this transaction's commit start? */
+ unsigned long t_log_start;
+
+ /* Doubly-linked circular list of all inodes owned by this
+ transaction */ /* AKPM: unused */
+ struct inode * t_ilist;
+
+ /* Number of buffers on the t_buffers list */
+ int t_nr_buffers;
+
+ /* Doubly-linked circular list of all buffers reserved but not
+ yet modified by this transaction */
+ struct journal_head * t_reserved_list;
+
+ /* Doubly-linked circular list of all metadata buffers owned by this
+ transaction */
+ struct journal_head * t_buffers;
+
+ /*
+ * Doubly-linked circular list of all data buffers still to be
+ * flushed before this transaction can be committed.
+ * Protected by journal_datalist_lock.
+ */
+ struct journal_head * t_sync_datalist;
+
+ /*
+ * Doubly-linked circular list of all writepage data buffers
+ * still to be written before this transaction can be committed.
+ * Protected by journal_datalist_lock.
+ */
+ struct journal_head * t_async_datalist;
+
+ /* Doubly-linked circular list of all forget buffers (superceded
+ buffers which we can un-checkpoint once this transaction
+ commits) */
+ struct journal_head * t_forget;
+
+ /*
+ * Doubly-linked circular list of all buffers still to be
+ * flushed before this transaction can be checkpointed.
+ */
+ /* Protected by journal_datalist_lock */
+ struct journal_head * t_checkpoint_list;
+
+ /* Doubly-linked circular list of temporary buffers currently
+ undergoing IO in the log */
+ struct journal_head * t_iobuf_list;
+
+ /* Doubly-linked circular list of metadata buffers being
+ shadowed by log IO. The IO buffers on the iobuf list and the
+ shadow buffers on this list match each other one for one at
+ all times. */
+ struct journal_head * t_shadow_list;
+
+ /* Doubly-linked circular list of control buffers being written
+ to the log. */
+ struct journal_head * t_log_list;
+
+ /* Number of outstanding updates running on this transaction */
+ int t_updates;
+
+ /* Number of buffers reserved for use by all handles in this
+ * transaction handle but not yet modified. */
+ int t_outstanding_credits;
+
+ /*
+ * Forward and backward links for the circular list of all
+ * transactions awaiting checkpoint.
+ */
+ /* Protected by journal_datalist_lock */
+ transaction_t *t_cpnext, *t_cpprev;
+
+ /* When will the transaction expire (become due for commit), in
+ * jiffies ? */
+ unsigned long t_expires;
+
+ /* How many handles used this transaction? */
+ int t_handle_count;
+};
+
+
+/* The journal_t maintains all of the journaling state information for a
+ * single filesystem. It is linked to from the fs superblock structure.
+ *
+ * We use the journal_t to keep track of all outstanding transaction
+ * activity on the filesystem, and to manage the state of the log
+ * writing process. */
+
+struct journal_s
+{
+ /* General journaling state flags */
+ unsigned long j_flags;
+
+ /* Is there an outstanding uncleared error on the journal (from
+ * a prior abort)? */
+ int j_errno;
+
+ /* The superblock buffer */
+ struct buffer_head * j_sb_buffer;
+ journal_superblock_t * j_superblock;
+
+ /* Version of the superblock format */
+ int j_format_version;
+
+ /* Number of processes waiting to create a barrier lock */
+ int j_barrier_count;
+
+ /* The barrier lock itself */
+ struct semaphore j_barrier;
+
+ /* Transactions: The current running transaction... */
+ transaction_t * j_running_transaction;
+
+ /* ... the transaction we are pushing to disk ... */
+ transaction_t * j_committing_transaction;
+
+ /* ... and a linked circular list of all transactions waiting
+ * for checkpointing. */
+ /* Protected by journal_datalist_lock */
+ transaction_t * j_checkpoint_transactions;
+
+ /* Wait queue for waiting for a locked transaction to start
+ committing, or for a barrier lock to be released */
+ wait_queue_head_t j_wait_transaction_locked;
+
+ /* Wait queue for waiting for checkpointing to complete */
+ wait_queue_head_t j_wait_logspace;
+
+ /* Wait queue for waiting for commit to complete */
+ wait_queue_head_t j_wait_done_commit;
+
+ /* Wait queue to trigger checkpointing */
+ wait_queue_head_t j_wait_checkpoint;
+
+ /* Wait queue to trigger commit */
+ wait_queue_head_t j_wait_commit;
+
+ /* Wait queue to wait for updates to complete */
+ wait_queue_head_t j_wait_updates;
+
+ /* Semaphore for locking against concurrent checkpoints */
+ struct semaphore j_checkpoint_sem;
+
+ /* The main journal lock, used by lock_journal() */
+ struct semaphore j_sem;
+
+ /* Journal head: identifies the first unused block in the journal. */
+ unsigned long j_head;
+
+ /* Journal tail: identifies the oldest still-used block in the
+ * journal. */
+ unsigned long j_tail;
+
+ /* Journal free: how many free blocks are there in the journal? */
+ unsigned long j_free;
+
+ /* Journal start and end: the block numbers of the first usable
+ * block and one beyond the last usable block in the journal. */
+ unsigned long j_first, j_last;
+
+ /* Device, blocksize and starting block offset for the location
+ * where we store the journal. */
+ kdev_t j_dev;
+ int j_blocksize;
+ unsigned int j_blk_offset;
+
+ /* Device which holds the client fs. For internal journal this
+ * will be equal to j_dev. */
+ kdev_t j_fs_dev;
+
+ /* Total maximum capacity of the journal region on disk. */
+ unsigned int j_maxlen;
+
+ /* Optional inode where we store the journal. If present, all
+ * journal block numbers are mapped into this inode via
+ * bmap(). */
+ struct inode * j_inode;
+
+ /* Sequence number of the oldest transaction in the log */
+ tid_t j_tail_sequence;
+ /* Sequence number of the next transaction to grant */
+ tid_t j_transaction_sequence;
+ /* Sequence number of the most recently committed transaction */
+ tid_t j_commit_sequence;
+ /* Sequence number of the most recent transaction wanting commit */
+ tid_t j_commit_request;
+
+ /* Journal uuid: identifies the object (filesystem, LVM volume
+ * etc) backed by this journal. This will eventually be
+ * replaced by an array of uuids, allowing us to index multiple
+ * devices within a single journal and to perform atomic updates
+ * across them. */
+
+ __u8 j_uuid[16];
+
+ /* Pointer to the current commit thread for this journal */
+ struct task_struct * j_task;
+
+ /* Maximum number of metadata buffers to allow in a single
+ * compound commit transaction */
+ int j_max_transaction_buffers;
+
+ /* What is the maximum transaction lifetime before we begin a
+ * commit? */
+ unsigned long j_commit_interval;
+
+ /* The timer used to wakeup the commit thread: */
+ struct timer_list * j_commit_timer;
+ int j_commit_timer_active;
+
+ /* Link all journals together - system-wide */
+ struct list_head j_all_journals;
+
+ /* The revoke table: maintains the list of revoked blocks in the
+ current transaction. */
+ struct jbd_revoke_table_s *j_revoke;
+};
+
+/*
+ * Journal flag definitions
+ */
+#define JFS_UNMOUNT 0x001 /* Journal thread is being destroyed */
+#define JFS_ABORT 0x002 /* Journaling has been aborted for errors. */
+#define JFS_ACK_ERR 0x004 /* The errno in the sb has been acked */
+#define JFS_FLUSHED 0x008 /* The journal superblock has been flushed */
+#define JFS_LOADED 0x010 /* The journal superblock has been loaded */
+
+/*
+ * Function declarations for the journaling transaction and buffer
+ * management
+ */
+
+/* Filing buffers */
+extern void __journal_unfile_buffer(struct journal_head *);
+extern void journal_unfile_buffer(struct journal_head *);
+extern void __journal_refile_buffer(struct journal_head *);
+extern void journal_refile_buffer(struct journal_head *);
+extern void __journal_file_buffer(struct journal_head *, transaction_t *, int);
+extern void __journal_free_buffer(struct journal_head *bh);
+extern void journal_file_buffer(struct journal_head *, transaction_t *, int);
+extern void __journal_clean_data_list(transaction_t *transaction);
+
+/* Log buffer allocation */
+extern struct journal_head * journal_get_descriptor_buffer(journal_t *);
+extern unsigned long journal_next_log_block(journal_t *);
+
+/* Commit management */
+extern void journal_commit_transaction(journal_t *);
+
+/* Checkpoint list management */
+int __journal_clean_checkpoint_list(journal_t *journal);
+extern void journal_remove_checkpoint(struct journal_head *);
+extern void __journal_remove_checkpoint(struct journal_head *);
+extern void journal_insert_checkpoint(struct journal_head *, transaction_t *);
+extern void __journal_insert_checkpoint(struct journal_head *,transaction_t *);
+
+/* Buffer IO */
+extern int
+journal_write_metadata_buffer(transaction_t *transaction,
+ struct journal_head *jh_in,
+ struct journal_head **jh_out,
+ int blocknr);
+
+/* Transaction locking */
+extern void __wait_on_journal (journal_t *);
+
+/*
+ * Journal locking.
+ *
+ * We need to lock the journal during transaction state changes so that
+ * nobody ever tries to take a handle on the running transaction while
+ * we are in the middle of moving it to the commit phase.
+ *
+ * Note that the locking is completely interrupt unsafe. We never touch
+ * journal structures from interrupts.
+ *
+ * In 2.2, the BKL was required for lock_journal. This is no longer
+ * the case.
+ */
+
+static inline void lock_journal(journal_t *journal)
+{
+ down(&journal->j_sem);
+}
+
+/* This returns zero if we acquired the semaphore */
+static inline int try_lock_journal(journal_t * journal)
+{
+ return down_trylock(&journal->j_sem);
+}
+
+static inline void unlock_journal(journal_t * journal)
+{
+ up(&journal->j_sem);
+}
+
+
+static inline handle_t *journal_current_handle(void)
+{
+ return current->journal_info;
+}
+
+/* The journaling code user interface:
+ *
+ * Create and destroy handles
+ * Register buffer modifications against the current transaction.
+ */
+
+extern handle_t *journal_start(journal_t *, int nblocks);
+extern handle_t *journal_try_start(journal_t *, int nblocks);
+extern int journal_restart (handle_t *, int nblocks);
+extern int journal_extend (handle_t *, int nblocks);
+extern int journal_get_write_access (handle_t *, struct buffer_head *);
+extern int journal_get_create_access (handle_t *, struct buffer_head *);
+extern int journal_get_undo_access (handle_t *, struct buffer_head *);
+extern int journal_dirty_data (handle_t *,
+ struct buffer_head *, int async);
+extern int journal_dirty_metadata (handle_t *, struct buffer_head *);
+extern void journal_release_buffer (handle_t *, struct buffer_head *);
+extern void journal_forget (handle_t *, struct buffer_head *);
+extern void journal_sync_buffer (struct buffer_head *);
+extern int journal_flushpage(journal_t *, struct page *, unsigned long);
+extern int journal_try_to_free_buffers(journal_t *, struct page *, int);
+extern int journal_stop(handle_t *);
+extern int journal_flush (journal_t *);
+
+extern void journal_lock_updates (journal_t *);
+extern void journal_unlock_updates (journal_t *);
+
+extern journal_t * journal_init_dev(kdev_t dev, kdev_t fs_dev,
+ int start, int len, int bsize);
+extern journal_t * journal_init_inode (struct inode *);
+extern int journal_update_format (journal_t *);
+extern int journal_check_used_features
+ (journal_t *, unsigned long, unsigned long, unsigned long);
+extern int journal_check_available_features
+ (journal_t *, unsigned long, unsigned long, unsigned long);
+extern int journal_set_features
+ (journal_t *, unsigned long, unsigned long, unsigned long);
+extern int journal_create (journal_t *);
+extern int journal_load (journal_t *journal);
+extern void journal_destroy (journal_t *);
+extern int journal_recover (journal_t *journal);
+extern int journal_wipe (journal_t *, int);
+extern int journal_skip_recovery (journal_t *);
+extern void journal_update_superblock (journal_t *, int);
+extern void __journal_abort (journal_t *);
+extern void journal_abort (journal_t *, int);
+extern int journal_errno (journal_t *);
+extern void journal_ack_err (journal_t *);
+extern int journal_clear_err (journal_t *);
+extern unsigned long journal_bmap(journal_t *journal, unsigned long blocknr);
+extern int journal_force_commit(journal_t *journal);
+
+/*
+ * journal_head management
+ */
+extern struct journal_head
+ *journal_add_journal_head(struct buffer_head *bh);
+extern void journal_remove_journal_head(struct buffer_head *bh);
+extern void __journal_remove_journal_head(struct buffer_head *bh);
+extern void journal_unlock_journal_head(struct journal_head *jh);
+
+/* Primary revoke support */
+#define JOURNAL_REVOKE_DEFAULT_HASH 256
+extern int journal_init_revoke(journal_t *, int);
+extern void journal_destroy_revoke_caches(void);
+extern int journal_init_revoke_caches(void);
+
+extern void journal_destroy_revoke(journal_t *);
+extern int journal_revoke (handle_t *,
+ unsigned long, struct buffer_head *);
+extern int journal_cancel_revoke(handle_t *, struct journal_head *);
+extern void journal_write_revoke_records(journal_t *, transaction_t *);
+
+/* 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);
+
+/* The log thread user interface:
+ *
+ * Request space in the current transaction, and force transaction commit
+ * transitions on demand.
+ */
+
+extern int log_space_left (journal_t *); /* Called with journal locked */
+extern tid_t log_start_commit (journal_t *, transaction_t *);
+extern void log_wait_commit (journal_t *, tid_t);
+extern int log_do_checkpoint (journal_t *, int);
+
+extern void log_wait_for_space(journal_t *, int nblocks);
+extern void __journal_drop_transaction(journal_t *, transaction_t *);
+extern int cleanup_journal_tail(journal_t *);
+
+/* Reduce journal memory usage by flushing */
+extern void shrink_journal_memory(void);
+
+/* Debugging code only: */
+
+#define jbd_ENOSYS() \
+do { \
+ printk (KERN_ERR "JBD unimplemented function " __FUNCTION__); \
+ current->state = TASK_UNINTERRUPTIBLE; \
+ schedule(); \
+} while (1)
+
+/*
+ * is_journal_abort
+ *
+ * Simple test wrapper function to test the JFS_ABORT state flag. This
+ * bit, when set, indicates that we have had a fatal error somewhere,
+ * either inside the journaling layer or indicated to us by the client
+ * (eg. ext3), and that we and should not commit any further
+ * transactions.
+ */
+
+static inline int is_journal_aborted(journal_t *journal)
+{
+ return journal->j_flags & JFS_ABORT;
+}
+
+static inline int is_handle_aborted(handle_t *handle)
+{
+ if (handle->h_aborted)
+ return 1;
+ return is_journal_aborted(handle->h_transaction->t_journal);
+}
+
+static inline void journal_abort_handle(handle_t *handle)
+{
+ handle->h_aborted = 1;
+}
+
+/* Not all architectures define BUG() */
+#ifndef BUG
+#define BUG() do { \
+ printk("kernel BUG at %s:%d!\n", __FILE__, __LINE__); \
+ * ((char *) 0) = 0; \
+ } while (0)
+#endif /* BUG */
+
+#else
+
+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 /* __KERNEL__ */
+
+/* Comparison functions for transaction IDs: perform comparisons using
+ * modulo arithmetic so that they work over sequence number wraps. */
+
+static inline int tid_gt(tid_t x, tid_t y)
+{
+ int difference = (x - y);
+ return (difference > 0);
+}
+
+static inline int tid_geq(tid_t x, tid_t y)
+{
+ int difference = (x - y);
+ return (difference >= 0);
+}
+
+extern int journal_blocks_per_page(struct inode *inode);
+
+/*
+ * 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
+
+extern int jbd_blocks_per_page(struct inode *inode);
+
+#ifdef __KERNEL__
+
+extern spinlock_t jh_splice_lock;
+/*
+ * Once `expr1' has been found true, take jh_splice_lock
+ * and then reevaluate everything.
+ */
+#define SPLICE_LOCK(expr1, expr2) \
+ ({ \
+ int ret = (expr1); \
+ if (ret) { \
+ spin_lock(&jh_splice_lock); \
+ ret = (expr1) && (expr2); \
+ spin_unlock(&jh_splice_lock); \
+ } \
+ ret; \
+ })
+
+/*
+ * A number of buffer state predicates. They test for
+ * buffer_jbd() because they are used in core kernel code.
+ *
+ * These will be racy on SMP unless we're *sure* that the
+ * buffer won't be detached from the journalling system
+ * in parallel.
+ */
+
+/* Return true if the buffer is on journal list `list' */
+static inline int buffer_jlist_eq(struct buffer_head *bh, int list)
+{
+ return SPLICE_LOCK(buffer_jbd(bh), bh2jh(bh)->b_jlist == list);
+}
+
+/* Return true if this bufer is dirty wrt the journal */
+static inline int buffer_jdirty(struct buffer_head *bh)
+{
+ return buffer_jbd(bh) && __buffer_state(bh, JBDDirty);
+}
+
+/* Return true if it's a data buffer which journalling is managing */
+static inline int buffer_jbd_data(struct buffer_head *bh)
+{
+ return SPLICE_LOCK(buffer_jbd(bh),
+ bh2jh(bh)->b_jlist == BJ_SyncData ||
+ bh2jh(bh)->b_jlist == BJ_AsyncData);
+}
+
+#ifdef CONFIG_SMP
+#define assert_spin_locked(lock) J_ASSERT(spin_is_locked(lock))
+#else
+#define assert_spin_locked(lock) do {} while(0)
+#endif
+
+#define buffer_trace_init(bh) do {} while (0)
+#define print_buffer_fields(bh) do {} while (0)
+#define print_buffer_trace(bh) do {} while (0)
+#define BUFFER_TRACE(bh, info) do {} while (0)
+#define BUFFER_TRACE2(bh, bh2, info) do {} while (0)
+#define JBUFFER_TRACE(jh, info) do {} while (0)
+
+#endif /* __KERNEL__ */
+
+#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 */