busybox/e2fsprogs/ext2fs/kernel-jbd.h

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/*
* linux/include/linux/jbd.h
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*
* 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__); \
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printk (f, ## a); \
} \
} while (0)
#else
#ifdef __GNUC__
#define jbd_debug(f, a...) /**/
#else
#define jbd_debug(f, ...) /**/
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#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
*/
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/*
* 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;
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/*
* 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;
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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
*/
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 */
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/* 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 */
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__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 */
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__u32 s_dynsuper; /* Blocknr of dynamic superblock copy*/
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/* 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. */
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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.
*/
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struct transaction_s
{
/* Pointer to the journal for this transaction. */
journal_t * t_journal;
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/* Sequence number for this transaction */
tid_t t_tid;
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/* Transaction's current state */
enum {
T_RUNNING,
T_LOCKED,
T_RUNDOWN,
T_FLUSH,
T_COMMIT,
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T_FINISHED
} t_state;
/* Where in the log does this transaction's commit start? */
unsigned long t_log_start;
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/* Doubly-linked circular list of all inodes owned by this
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transaction */ /* AKPM: unused */
struct inode * t_ilist;
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/* Number of buffers on the t_buffers list */
int t_nr_buffers;
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/* Doubly-linked circular list of all buffers reserved but not
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yet modified by this transaction */
struct journal_head * t_reserved_list;
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/* Doubly-linked circular list of all metadata buffers owned by this
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transaction */
struct journal_head * t_buffers;
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/*
* 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;
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/*
* 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;
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/* Doubly-linked circular list of all forget buffers (superceded
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buffers which we can un-checkpoint once this transaction
commits) */
struct journal_head * t_forget;
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/*
* 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;
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/* Doubly-linked circular list of temporary buffers currently
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undergoing IO in the log */
struct journal_head * t_iobuf_list;
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/* Doubly-linked circular list of metadata buffers being
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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;
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/* Doubly-linked circular list of control buffers being written
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to the log. */
struct journal_head * t_log_list;
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/* 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;
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/*
* 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.
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*
* 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;
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/* 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;
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/* The barrier lock itself */
struct semaphore j_barrier;
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/* Transactions: The current running transaction... */
transaction_t * j_running_transaction;
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/* ... the transaction we are pushing to disk ... */
transaction_t * j_committing_transaction;
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/* ... 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
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committing, or for a barrier lock to be released */
wait_queue_head_t j_wait_transaction_locked;
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/* Wait queue for waiting for checkpointing to complete */
wait_queue_head_t j_wait_logspace;
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/* Wait queue for waiting for commit to complete */
wait_queue_head_t j_wait_done_commit;
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/* Wait queue to trigger checkpointing */
wait_queue_head_t j_wait_checkpoint;
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/* Wait queue to trigger commit */
wait_queue_head_t j_wait_commit;
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/* Wait queue to wait for updates to complete */
wait_queue_head_t j_wait_updates;
/* Semaphore for locking against concurrent checkpoints */
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struct semaphore j_checkpoint_sem;
/* The main journal lock, used by lock_journal() */
struct semaphore j_sem;
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/* Journal head: identifies the first unused block in the journal. */
unsigned long j_head;
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/* 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
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current transaction. */
struct jbd_revoke_table_s *j_revoke;
};
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/*
* 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 */
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/*
* 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 */
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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
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* 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
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* 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 *);
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extern int journal_check_used_features
(journal_t *, unsigned long, unsigned long, unsigned long);
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extern int journal_check_available_features
(journal_t *, unsigned long, unsigned long, unsigned long);
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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
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* 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 { \
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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
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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 */