+++ /dev/null
-/*
- * linux/include/linux/jfs.h
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- 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_JFS_H
-#define _LINUX_JFS_H
-
-#ifndef __KERNEL__
-#include "jfs_compat.h"
-#endif
-
-/*
- * Debug code
- */
-
-/* #define JFS_DEBUG */
-
-#ifdef JFS_DEBUG
-extern int journal_enable_debug;
-
-#define jfs_debug(n, f, a...) \
- do { \
- if ((n) <= journal_enable_debug) { \
- printk (KERN_DEBUG "JFS DEBUG: (%s, %d): %s: ", \
- __FILE__, __LINE__, __FUNCTION__); \
- printk (f, ## a); \
- } \
- } while (0)
-#else
-#define jfs_debug(f, a...) /**/
-#endif
-
-#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! */
-
-
-/*
- * 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
-
-/*
- * 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;
-
-/* 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
-
-#ifdef __KERNEL__
-
-#include <linux/fs.h>
-
-
-#define J_ASSERT(assert) \
- do { if (!(assert)) { \
- printk (KERN_CRIT \
- "Assertion failure in %s() at %s line %d: " \
- "\"%s\"\n", \
- __FUNCTION__, __FILE__, __LINE__, # assert); \
- * ((char *) 0) = 0; \
- } } while (0)
-
-
-
-/* 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;
-
- /* Flags */
- unsigned int h_sync : 1; /* sync-on-close */
- unsigned int h_jdata : 1; /* force data journaling */
-};
-
-
-/* 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 */
- 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 buffer_head * t_reserved_list;
-
- /* Doubly-linked circular list of all metadata buffers owned by this
- transaction */
- struct buffer_head * t_buffers;
-
- /* Doubly-linked circular list of all data buffers still to be
- flushed before this transaction can be committed */
- struct buffer_head * t_datalist;
-
- /* Doubly-linked circular list of all forget buffers (superceded
- buffers which we can un-checkpoint once this transaction
- commits) */
- struct buffer_head * t_forget;
-
- /* Doubly-linked circular list of all buffers still to be
- flushed before this transaction can be checkpointed */
- struct buffer_head * t_checkpoint_list;
-
- /* Doubly-linked circular list of temporary buffers currently
- undergoing IO in the log */
- struct buffer_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 buffer_head * t_shadow_list;
-
- /* Doubly-linked circular list of control buffers being written
- to the log. */
- struct buffer_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;
-
- /* Wait queue to wait for updates to complete */
- struct wait_queue * t_wait;
-
- /* Forward and backward links for the circular list of all
- * transactions awaiting checkpoint */
- transaction_t *t_cpnext, *t_cpprev;
-
- /* When will the transaction expire (become due for commit), in
- * jiffies ? */
- unsigned long t_expires;
-};
-
-
-/* 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;
-
- /* 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. */
- transaction_t * j_checkpoint_transactions;
-
- /* Wait queue for locking of the journal structure. */
- struct wait_queue * j_wait_lock;
-
- /* Wait queue for waiting for a locked transaction to start
- committing */
- struct wait_queue * j_wait_transaction_locked;
-
- /* Wait queue for waiting for checkpointing to complete */
- struct wait_queue * j_wait_logspace;
-
- /* Wait queue for waiting for commit to complete */
- struct wait_queue * j_wait_done_commit;
-
- /* Wait queue to trigger checkpointing */
- struct wait_queue * j_wait_checkpoint;
-
- /* Wait queue to trigger commit */
- struct wait_queue * j_wait_commit;
-
- /* Semaphore for locking against concurrent checkpoints */
- struct semaphore j_checkpoint_sem;
-
- /* Journal running state: */
- /* The lock flag is *NEVER* touched from interrupts. */
- unsigned int j_locked : 1;
-
- /* 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;
-
- /* 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;
-};
-
-/*
- * Journal flag definitions
- */
-#define JFS_UNMOUNT 1 /* Journal thread is being destroyed */
-#define JFS_SYNC 2 /* Perform synchronous transaction commits */
-#define JFS_ABORT 4 /* Journaling has been aborted for errors. */
-#define JFS_ACK_ERR 8 /* The errno in the sb has been acked */
-
-/*
- * Journaling internal variables/parameters
- */
-
-extern int journal_flush_nr_buffers;
-
-
-/*
- * Function declarations for the journaling transaction and buffer
- * management
- */
-
-/* Filing buffers */
-extern void journal_unfile_buffer(struct buffer_head *);
-extern void journal_refile_buffer(struct buffer_head *);
-extern void journal_file_buffer(struct buffer_head *, transaction_t *, int);
-extern void journal_clean_data_list(transaction_t *transaction);
-
-/* Log buffer allocation */
-extern struct buffer_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 */
-extern void journal_remove_checkpoint(struct buffer_head *);
-extern void journal_insert_checkpoint(struct buffer_head *, transaction_t *);
-
-/* Buffer IO */
-extern int
-journal_write_metadata_buffer(transaction_t *transaction,
- struct buffer_head *bh_in,
- struct buffer_head **bh_out,
- int blocknr);
-
-/* Create and destroy transactions */
-extern transaction_t * get_transaction (journal_t *);
-extern void put_transaction (transaction_t *);
-
-/* Notify state transitions (called by the log writer thread): */
-extern int set_transaction_state (transaction_t *, int);
-
-
-/* Transaction locking */
-extern void __wait_on_journal (journal_t *);
-
-/* Journal locking. In 2.2, we assume that the kernel lock is already
- * held. */
-static inline void lock_journal (journal_t * journal)
-{
-#ifdef __SMP__
- J_ASSERT(current->lock_depth >= 0);
-#endif
- if (journal->j_locked)
- __wait_on_journal(journal);
- journal->j_locked = 1;
-}
-
-static inline int try_lock_journal (journal_t * journal)
-{
- if (journal->j_locked)
- return 1;
- journal->j_locked = 1;
- return 0;
-}
-
-static inline void unlock_journal (journal_t * journal)
-{
- J_ASSERT (journal->j_locked);
- journal->j_locked = 0;
- wake_up(&journal->j_wait_lock);
-}
-
-/* This function is gross, but unfortunately we need it as long as
- * existing filesystems want to guard against races by testing
- * bh->b_count. @@@ Remove this? We no longer abuse b_count so badly!
- */
-
-static inline int journal_is_buffer_shared(struct buffer_head *bh)
-{
- int count = bh->b_count;
- J_ASSERT (count >= 1);
- return (count > 1);
-}
-
-/* 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 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 *);
-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_stop (handle_t *);
-extern int journal_flush (journal_t *);
-extern int journal_revoke (handle_t *, int);
-
-extern journal_t * journal_init_dev (kdev_t, 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_features (journal_t *, unsigned long, unsigned long, unsigned long);
-extern int journal_create (journal_t *);
-extern int journal_load (journal_t *);
-extern void journal_release (journal_t *);
-extern int journal_recover (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 *);
-
-
-/* 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 void 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 *);
-
-
-/* Debugging code only: */
-
-#define jfs_ENOSYS() \
-do { \
- printk (KERN_ERR "JFS unimplemented function " __FUNCTION__); \
- current->state = TASK_UNINTERRUPTIBLE; \
- schedule(); \
-} while (1)
-
-#endif /* __KERNEL__ */
-#endif /* _LINUX_JFS_H */
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