text: /*
   * Write ahead logging implementation copyright Chris Mason 2000
   *
   * The background commits make this code very interrelated, and
   * overly complex.  I need to rethink things a bit....The major players:
   *
   * journal_begin -- call with the number of blocks you expect to log.
   *                  If the current transaction is too
   *		    old, it will block until the current transaction is
   *		    finished, and then start a new one.
   *		    Usually, your transaction will get joined in with
   *                  previous ones for speed.
   *
   * journal_join  -- same as journal_begin, but won't block on the current
   *                  transaction regardless of age.  Don't ever call
   *                  this.  Ever.  There are only two places it should be
   *                  called from, and they are both inside this file.
   *
   * journal_mark_dirty -- adds blocks into this transaction.  clears any flags
   *                       that might make them get sent to disk
   *                       and then marks them BH_JDirty.  Puts the buffer head
   *                       into the current transaction hash.
   *
   * journal_end -- if the current transaction is batchable, it does nothing
   *                   otherwise, it could do an async/synchronous commit, or
   *                   a full flush of all log and real blocks in the
   *                   transaction.
   *
   * flush_old_commits -- if the current transaction is too old, it is ended and
   *                      commit blocks are sent to disk.  Forces commit blocks
   *                      to disk for all backgrounded commits that have been
   *                      around too long.
   *		     -- Note, if you call this as an immediate flush from
   *		        from within kupdate, it will ignore the immediate flag
   */
  
  #include <linux/time.h>
  #include <linux/semaphore.h>
  #include <linux/vmalloc.h>
  #include "reiserfs.h"
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/fcntl.h>
  #include <linux/stat.h>
  #include <linux/string.h>
  #include <linux/buffer_head.h>
  #include <linux/workqueue.h>
  #include <linux/writeback.h>
  #include <linux/blkdev.h>
  #include <linux/backing-dev.h>
  #include <linux/uaccess.h>
  #include <linux/slab.h>
  
  
  /* gets a struct reiserfs_journal_list * from a list head */
  #define JOURNAL_LIST_ENTRY(h) (list_entry((h), struct reiserfs_journal_list, \
                                 j_list))
  #define JOURNAL_WORK_ENTRY(h) (list_entry((h), struct reiserfs_journal_list, \
                                 j_working_list))
  
  /* must be correct to keep the desc and commit structs at 4k */
  #define JOURNAL_TRANS_HALF 1018
  #define BUFNR 64		/*read ahead */
  
  /* cnode stat bits.  Move these into reiserfs_fs.h */
  
  /* this block was freed, and can't be written.  */
  #define BLOCK_FREED 2
  /* this block was freed during this transaction, and can't be written */
  #define BLOCK_FREED_HOLDER 3
  
  /* used in flush_journal_list */
  #define BLOCK_NEEDS_FLUSH 4
  #define BLOCK_DIRTIED 5
  
  /* journal list state bits */
  #define LIST_TOUCHED 1
  #define LIST_DIRTY   2
  #define LIST_COMMIT_PENDING  4	/* someone will commit this list */
  
  /* flags for do_journal_end */
  #define FLUSH_ALL   1		/* flush commit and real blocks */
  #define COMMIT_NOW  2		/* end and commit this transaction */
  #define WAIT        4		/* wait for the log blocks to hit the disk */
  
  static int do_journal_end(struct reiserfs_transaction_handle *, int flags);
  static int flush_journal_list(struct super_block *s,
  			      struct reiserfs_journal_list *jl, int flushall);
  static int flush_commit_list(struct super_block *s,
  			     struct reiserfs_journal_list *jl, int flushall);
  static int can_dirty(struct reiserfs_journal_cnode *cn);
  static int journal_join(struct reiserfs_transaction_handle *th,
  			struct super_block *sb);
  static void release_journal_dev(struct super_block *super,
  			       struct reiserfs_journal *journal);
  static int dirty_one_transaction(struct super_block *s,
  				 struct reiserfs_journal_list *jl);
  static void flush_async_commits(struct work_struct *work);
  static void queue_log_writer(struct super_block *s);
  
  /* values for join in do_journal_begin_r */
  enum {
  	JBEGIN_REG = 0,		/* regular journal begin */
  	/* join the running transaction if at all possible */
  	JBEGIN_JOIN = 1,
  	/* called from cleanup code, ignores aborted flag */
  	JBEGIN_ABORT = 2,
  };
  
  static int do_journal_begin_r(struct reiserfs_transaction_handle *th,
  			      struct super_block *sb,
  			      unsigned long nblocks, int join);
  
  static void init_journal_hash(struct super_block *sb)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	memset(journal->j_hash_table, 0,
  	       JOURNAL_HASH_SIZE * sizeof(struct reiserfs_journal_cnode *));
  }
  
  /*
   * clears BH_Dirty and sticks the buffer on the clean list.  Called because
   * I can't allow refile_buffer to make schedule happen after I've freed a
   * block.  Look at remove_from_transaction and journal_mark_freed for
   * more details.
   */
  static int reiserfs_clean_and_file_buffer(struct buffer_head *bh)
  {
  	if (bh) {
  		clear_buffer_dirty(bh);
  		clear_buffer_journal_test(bh);
  	}
  	return 0;
  }
  
  static struct reiserfs_bitmap_node *allocate_bitmap_node(struct super_block
  							 *sb)
  {
  	struct reiserfs_bitmap_node *bn;
  	static int id;
  
  	bn = kmalloc(sizeof(struct reiserfs_bitmap_node), GFP_NOFS);
  	if (!bn) {
  		return NULL;
  	}
  	bn->data = kzalloc(sb->s_blocksize, GFP_NOFS);
  	if (!bn->data) {
  		kfree(bn);
  		return NULL;
  	}
  	bn->id = id++;
  	INIT_LIST_HEAD(&bn->list);
  	return bn;
  }
  
  static struct reiserfs_bitmap_node *get_bitmap_node(struct super_block *sb)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_bitmap_node *bn = NULL;
  	struct list_head *entry = journal->j_bitmap_nodes.next;
  
  	journal->j_used_bitmap_nodes++;
  repeat:
  
  	if (entry != &journal->j_bitmap_nodes) {
  		bn = list_entry(entry, struct reiserfs_bitmap_node, list);
  		list_del(entry);
  		memset(bn->data, 0, sb->s_blocksize);
  		journal->j_free_bitmap_nodes--;
  		return bn;
  	}
  	bn = allocate_bitmap_node(sb);
  	if (!bn) {
  		yield();
  		goto repeat;
  	}
  	return bn;
  }
  static inline void free_bitmap_node(struct super_block *sb,
  				    struct reiserfs_bitmap_node *bn)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	journal->j_used_bitmap_nodes--;
  	if (journal->j_free_bitmap_nodes > REISERFS_MAX_BITMAP_NODES) {
  		kfree(bn->data);
  		kfree(bn);
  	} else {
  		list_add(&bn->list, &journal->j_bitmap_nodes);
  		journal->j_free_bitmap_nodes++;
  	}
  }
  
  static void allocate_bitmap_nodes(struct super_block *sb)
  {
  	int i;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_bitmap_node *bn = NULL;
  	for (i = 0; i < REISERFS_MIN_BITMAP_NODES; i++) {
  		bn = allocate_bitmap_node(sb);
  		if (bn) {
  			list_add(&bn->list, &journal->j_bitmap_nodes);
  			journal->j_free_bitmap_nodes++;
  		} else {
  			/* this is ok, we'll try again when more are needed */
  			break;
  		}
  	}
  }
  
  static int set_bit_in_list_bitmap(struct super_block *sb,
  				  b_blocknr_t block,
  				  struct reiserfs_list_bitmap *jb)
  {
  	unsigned int bmap_nr = block / (sb->s_blocksize << 3);
  	unsigned int bit_nr = block % (sb->s_blocksize << 3);
  
  	if (!jb->bitmaps[bmap_nr]) {
  		jb->bitmaps[bmap_nr] = get_bitmap_node(sb);
  	}
  	set_bit(bit_nr, (unsigned long *)jb->bitmaps[bmap_nr]->data);
  	return 0;
  }
  
  static void cleanup_bitmap_list(struct super_block *sb,
  				struct reiserfs_list_bitmap *jb)
  {
  	int i;
  	if (jb->bitmaps == NULL)
  		return;
  
  	for (i = 0; i < reiserfs_bmap_count(sb); i++) {
  		if (jb->bitmaps[i]) {
  			free_bitmap_node(sb, jb->bitmaps[i]);
  			jb->bitmaps[i] = NULL;
  		}
  	}
  }
  
  /*
   * only call this on FS unmount.
   */
  static int free_list_bitmaps(struct super_block *sb,
  			     struct reiserfs_list_bitmap *jb_array)
  {
  	int i;
  	struct reiserfs_list_bitmap *jb;
  	for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
  		jb = jb_array + i;
  		jb->journal_list = NULL;
  		cleanup_bitmap_list(sb, jb);
  		vfree(jb->bitmaps);
  		jb->bitmaps = NULL;
  	}
  	return 0;
  }
  
  static int free_bitmap_nodes(struct super_block *sb)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct list_head *next = journal->j_bitmap_nodes.next;
  	struct reiserfs_bitmap_node *bn;
  
  	while (next != &journal->j_bitmap_nodes) {
  		bn = list_entry(next, struct reiserfs_bitmap_node, list);
  		list_del(next);
  		kfree(bn->data);
  		kfree(bn);
  		next = journal->j_bitmap_nodes.next;
  		journal->j_free_bitmap_nodes--;
  	}
  
  	return 0;
  }
  
  /*
   * get memory for JOURNAL_NUM_BITMAPS worth of bitmaps.
   * jb_array is the array to be filled in.
   */
  int reiserfs_allocate_list_bitmaps(struct super_block *sb,
  				   struct reiserfs_list_bitmap *jb_array,
  				   unsigned int bmap_nr)
  {
  	int i;
  	int failed = 0;
  	struct reiserfs_list_bitmap *jb;
  	int mem = bmap_nr * sizeof(struct reiserfs_bitmap_node *);
  
  	for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
  		jb = jb_array + i;
  		jb->journal_list = NULL;
  		jb->bitmaps = vzalloc(mem);
  		if (!jb->bitmaps) {
  			reiserfs_warning(sb, "clm-2000", "unable to "
  					 "allocate bitmaps for journal lists");
  			failed = 1;
  			break;
  		}
  	}
  	if (failed) {
  		free_list_bitmaps(sb, jb_array);
  		return -1;
  	}
  	return 0;
  }
  
  /*
   * find an available list bitmap.  If you can't find one, flush a commit list
   * and try again
   */
  static struct reiserfs_list_bitmap *get_list_bitmap(struct super_block *sb,
  						    struct reiserfs_journal_list
  						    *jl)
  {
  	int i, j;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_list_bitmap *jb = NULL;
  
  	for (j = 0; j < (JOURNAL_NUM_BITMAPS * 3); j++) {
  		i = journal->j_list_bitmap_index;
  		journal->j_list_bitmap_index = (i + 1) % JOURNAL_NUM_BITMAPS;
  		jb = journal->j_list_bitmap + i;
  		if (journal->j_list_bitmap[i].journal_list) {
  			flush_commit_list(sb,
  					  journal->j_list_bitmap[i].
  					  journal_list, 1);
  			if (!journal->j_list_bitmap[i].journal_list) {
  				break;
  			}
  		} else {
  			break;
  		}
  	}
  	/* double check to make sure if flushed correctly */
  	if (jb->journal_list)
  		return NULL;
  	jb->journal_list = jl;
  	return jb;
  }
  
  /*
   * allocates a new chunk of X nodes, and links them all together as a list.
   * Uses the cnode->next and cnode->prev pointers
   * returns NULL on failure
   */
  static struct reiserfs_journal_cnode *allocate_cnodes(int num_cnodes)
  {
  	struct reiserfs_journal_cnode *head;
  	int i;
  	if (num_cnodes <= 0) {
  		return NULL;
  	}
  	head = vzalloc(num_cnodes * sizeof(struct reiserfs_journal_cnode));
  	if (!head) {
  		return NULL;
  	}
  	head[0].prev = NULL;
  	head[0].next = head + 1;
  	for (i = 1; i < num_cnodes; i++) {
  		head[i].prev = head + (i - 1);
  		head[i].next = head + (i + 1);	/* if last one, overwrite it after the if */
  	}
  	head[num_cnodes - 1].next = NULL;
  	return head;
  }
  
  /* pulls a cnode off the free list, or returns NULL on failure */
  static struct reiserfs_journal_cnode *get_cnode(struct super_block *sb)
  {
  	struct reiserfs_journal_cnode *cn;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  
  	reiserfs_check_lock_depth(sb, "get_cnode");
  
  	if (journal->j_cnode_free <= 0) {
  		return NULL;
  	}
  	journal->j_cnode_used++;
  	journal->j_cnode_free--;
  	cn = journal->j_cnode_free_list;
  	if (!cn) {
  		return cn;
  	}
  	if (cn->next) {
  		cn->next->prev = NULL;
  	}
  	journal->j_cnode_free_list = cn->next;
  	memset(cn, 0, sizeof(struct reiserfs_journal_cnode));
  	return cn;
  }
  
  /*
   * returns a cnode to the free list
   */
  static void free_cnode(struct super_block *sb,
  		       struct reiserfs_journal_cnode *cn)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  
  	reiserfs_check_lock_depth(sb, "free_cnode");
  
  	journal->j_cnode_used--;
  	journal->j_cnode_free++;
  	/* memset(cn, 0, sizeof(struct reiserfs_journal_cnode)) ; */
  	cn->next = journal->j_cnode_free_list;
  	if (journal->j_cnode_free_list) {
  		journal->j_cnode_free_list->prev = cn;
  	}
  	cn->prev = NULL;	/* not needed with the memset, but I might kill the memset, and forget to do this */
  	journal->j_cnode_free_list = cn;
  }
  
  static void clear_prepared_bits(struct buffer_head *bh)
  {
  	clear_buffer_journal_prepared(bh);
  	clear_buffer_journal_restore_dirty(bh);
  }
  
  /*
   * return a cnode with same dev, block number and size in table,
   * or null if not found
   */
  static inline struct reiserfs_journal_cnode *get_journal_hash_dev(struct
  								  super_block
  								  *sb,
  								  struct
  								  reiserfs_journal_cnode
  								  **table,
  								  long bl)
  {
  	struct reiserfs_journal_cnode *cn;
  	cn = journal_hash(table, sb, bl);
  	while (cn) {
  		if (cn->blocknr == bl && cn->sb == sb)
  			return cn;
  		cn = cn->hnext;
  	}
  	return (struct reiserfs_journal_cnode *)0;
  }
  
  /*
   * this actually means 'can this block be reallocated yet?'.  If you set
   * search_all, a block can only be allocated if it is not in the current
   * transaction, was not freed by the current transaction, and has no chance
   * of ever being overwritten by a replay after crashing.
   *
   * If you don't set search_all, a block can only be allocated if it is not
   * in the current transaction.  Since deleting a block removes it from the
   * current transaction, this case should never happen.  If you don't set
   * search_all, make sure you never write the block without logging it.
   *
   * next_zero_bit is a suggestion about the next block to try for find_forward.
   * when bl is rejected because it is set in a journal list bitmap, we search
   * for the next zero bit in the bitmap that rejected bl.  Then, we return
   * that through next_zero_bit for find_forward to try.
   *
   * Just because we return something in next_zero_bit does not mean we won't
   * reject it on the next call to reiserfs_in_journal
   */
  int reiserfs_in_journal(struct super_block *sb,
  			unsigned int bmap_nr, int bit_nr, int search_all,
  			b_blocknr_t * next_zero_bit)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_cnode *cn;
  	struct reiserfs_list_bitmap *jb;
  	int i;
  	unsigned long bl;
  
  	*next_zero_bit = 0;	/* always start this at zero. */
  
  	PROC_INFO_INC(sb, journal.in_journal);
  	/*
  	 * If we aren't doing a search_all, this is a metablock, and it
  	 * will be logged before use.  if we crash before the transaction
  	 * that freed it commits,  this transaction won't have committed
  	 * either, and the block will never be written
  	 */
  	if (search_all) {
  		for (i = 0; i < JOURNAL_NUM_BITMAPS; i++) {
  			PROC_INFO_INC(sb, journal.in_journal_bitmap);
  			jb = journal->j_list_bitmap + i;
  			if (jb->journal_list && jb->bitmaps[bmap_nr] &&
  			    test_bit(bit_nr,
  				     (unsigned long *)jb->bitmaps[bmap_nr]->
  				     data)) {
  				*next_zero_bit =
  				    find_next_zero_bit((unsigned long *)
  						       (jb->bitmaps[bmap_nr]->
  							data),
  						       sb->s_blocksize << 3,
  						       bit_nr + 1);
  				return 1;
  			}
  		}
  	}
  
  	bl = bmap_nr * (sb->s_blocksize << 3) + bit_nr;
  	/* is it in any old transactions? */
  	if (search_all
  	    && (cn =
  		get_journal_hash_dev(sb, journal->j_list_hash_table, bl))) {
  		return 1;
  	}
  
  	/* is it in the current transaction.  This should never happen */
  	if ((cn = get_journal_hash_dev(sb, journal->j_hash_table, bl))) {
  		BUG();
  		return 1;
  	}
  
  	PROC_INFO_INC(sb, journal.in_journal_reusable);
  	/* safe for reuse */
  	return 0;
  }
  
  /* insert cn into table */
  static inline void insert_journal_hash(struct reiserfs_journal_cnode **table,
  				       struct reiserfs_journal_cnode *cn)
  {
  	struct reiserfs_journal_cnode *cn_orig;
  
  	cn_orig = journal_hash(table, cn->sb, cn->blocknr);
  	cn->hnext = cn_orig;
  	cn->hprev = NULL;
  	if (cn_orig) {
  		cn_orig->hprev = cn;
  	}
  	journal_hash(table, cn->sb, cn->blocknr) = cn;
  }
  
  /* lock the current transaction */
  static inline void lock_journal(struct super_block *sb)
  {
  	PROC_INFO_INC(sb, journal.lock_journal);
  
  	reiserfs_mutex_lock_safe(&SB_JOURNAL(sb)->j_mutex, sb);
  }
  
  /* unlock the current transaction */
  static inline void unlock_journal(struct super_block *sb)
  {
  	mutex_unlock(&SB_JOURNAL(sb)->j_mutex);
  }
  
  static inline void get_journal_list(struct reiserfs_journal_list *jl)
  {
  	jl->j_refcount++;
  }
  
  static inline void put_journal_list(struct super_block *s,
  				    struct reiserfs_journal_list *jl)
  {
  	if (jl->j_refcount < 1) {
  		reiserfs_panic(s, "journal-2", "trans id %u, refcount at %d",
  			       jl->j_trans_id, jl->j_refcount);
  	}
  	if (--jl->j_refcount == 0)
  		kfree(jl);
  }
  
  /*
   * this used to be much more involved, and I'm keeping it just in case
   * things get ugly again.  it gets called by flush_commit_list, and
   * cleans up any data stored about blocks freed during a transaction.
   */
  static void cleanup_freed_for_journal_list(struct super_block *sb,
  					   struct reiserfs_journal_list *jl)
  {
  
  	struct reiserfs_list_bitmap *jb = jl->j_list_bitmap;
  	if (jb) {
  		cleanup_bitmap_list(sb, jb);
  	}
  	jl->j_list_bitmap->journal_list = NULL;
  	jl->j_list_bitmap = NULL;
  }
  
  static int journal_list_still_alive(struct super_block *s,
  				    unsigned int trans_id)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	struct list_head *entry = &journal->j_journal_list;
  	struct reiserfs_journal_list *jl;
  
  	if (!list_empty(entry)) {
  		jl = JOURNAL_LIST_ENTRY(entry->next);
  		if (jl->j_trans_id <= trans_id) {
  			return 1;
  		}
  	}
  	return 0;
  }
  
  /*
   * If page->mapping was null, we failed to truncate this page for
   * some reason.  Most likely because it was truncated after being
   * logged via data=journal.
   *
   * This does a check to see if the buffer belongs to one of these
   * lost pages before doing the final put_bh.  If page->mapping was
   * null, it tries to free buffers on the page, which should make the
   * final page_cache_release drop the page from the lru.
   */
  static void release_buffer_page(struct buffer_head *bh)
  {
  	struct page *page = bh->b_page;
  	if (!page->mapping && trylock_page(page)) {
  		page_cache_get(page);
  		put_bh(bh);
  		if (!page->mapping)
  			try_to_free_buffers(page);
  		unlock_page(page);
  		page_cache_release(page);
  	} else {
  		put_bh(bh);
  	}
  }
  
  static void reiserfs_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
  {
  	if (buffer_journaled(bh)) {
  		reiserfs_warning(NULL, "clm-2084",
  				 "pinned buffer %lu:%pg sent to disk",
  				 bh->b_blocknr, bh->b_bdev);
  	}
  	if (uptodate)
  		set_buffer_uptodate(bh);
  	else
  		clear_buffer_uptodate(bh);
  
  	unlock_buffer(bh);
  	release_buffer_page(bh);
  }
  
  static void reiserfs_end_ordered_io(struct buffer_head *bh, int uptodate)
  {
  	if (uptodate)
  		set_buffer_uptodate(bh);
  	else
  		clear_buffer_uptodate(bh);
  	unlock_buffer(bh);
  	put_bh(bh);
  }
  
  static void submit_logged_buffer(struct buffer_head *bh)
  {
  	get_bh(bh);
  	bh->b_end_io = reiserfs_end_buffer_io_sync;
  	clear_buffer_journal_new(bh);
  	clear_buffer_dirty(bh);
  	if (!test_clear_buffer_journal_test(bh))
  		BUG();
  	if (!buffer_uptodate(bh))
  		BUG();
  	submit_bh(WRITE, bh);
  }
  
  static void submit_ordered_buffer(struct buffer_head *bh)
  {
  	get_bh(bh);
  	bh->b_end_io = reiserfs_end_ordered_io;
  	clear_buffer_dirty(bh);
  	if (!buffer_uptodate(bh))
  		BUG();
  	submit_bh(WRITE, bh);
  }
  
  #define CHUNK_SIZE 32
  struct buffer_chunk {
  	struct buffer_head *bh[CHUNK_SIZE];
  	int nr;
  };
  
  static void write_chunk(struct buffer_chunk *chunk)
  {
  	int i;
  	for (i = 0; i < chunk->nr; i++) {
  		submit_logged_buffer(chunk->bh[i]);
  	}
  	chunk->nr = 0;
  }
  
  static void write_ordered_chunk(struct buffer_chunk *chunk)
  {
  	int i;
  	for (i = 0; i < chunk->nr; i++) {
  		submit_ordered_buffer(chunk->bh[i]);
  	}
  	chunk->nr = 0;
  }
  
  static int add_to_chunk(struct buffer_chunk *chunk, struct buffer_head *bh,
  			spinlock_t * lock, void (fn) (struct buffer_chunk *))
  {
  	int ret = 0;
  	BUG_ON(chunk->nr >= CHUNK_SIZE);
  	chunk->bh[chunk->nr++] = bh;
  	if (chunk->nr >= CHUNK_SIZE) {
  		ret = 1;
  		if (lock) {
  			spin_unlock(lock);
  			fn(chunk);
  			spin_lock(lock);
  		} else {
  			fn(chunk);
  		}
  	}
  	return ret;
  }
  
  static atomic_t nr_reiserfs_jh = ATOMIC_INIT(0);
  static struct reiserfs_jh *alloc_jh(void)
  {
  	struct reiserfs_jh *jh;
  	while (1) {
  		jh = kmalloc(sizeof(*jh), GFP_NOFS);
  		if (jh) {
  			atomic_inc(&nr_reiserfs_jh);
  			return jh;
  		}
  		yield();
  	}
  }
  
  /*
   * we want to free the jh when the buffer has been written
   * and waited on
   */
  void reiserfs_free_jh(struct buffer_head *bh)
  {
  	struct reiserfs_jh *jh;
  
  	jh = bh->b_private;
  	if (jh) {
  		bh->b_private = NULL;
  		jh->bh = NULL;
  		list_del_init(&jh->list);
  		kfree(jh);
  		if (atomic_read(&nr_reiserfs_jh) <= 0)
  			BUG();
  		atomic_dec(&nr_reiserfs_jh);
  		put_bh(bh);
  	}
  }
  
  static inline int __add_jh(struct reiserfs_journal *j, struct buffer_head *bh,
  			   int tail)
  {
  	struct reiserfs_jh *jh;
  
  	if (bh->b_private) {
  		spin_lock(&j->j_dirty_buffers_lock);
  		if (!bh->b_private) {
  			spin_unlock(&j->j_dirty_buffers_lock);
  			goto no_jh;
  		}
  		jh = bh->b_private;
  		list_del_init(&jh->list);
  	} else {
  no_jh:
  		get_bh(bh);
  		jh = alloc_jh();
  		spin_lock(&j->j_dirty_buffers_lock);
  		/*
  		 * buffer must be locked for __add_jh, should be able to have
  		 * two adds at the same time
  		 */
  		BUG_ON(bh->b_private);
  		jh->bh = bh;
  		bh->b_private = jh;
  	}
  	jh->jl = j->j_current_jl;
  	if (tail)
  		list_add_tail(&jh->list, &jh->jl->j_tail_bh_list);
  	else {
  		list_add_tail(&jh->list, &jh->jl->j_bh_list);
  	}
  	spin_unlock(&j->j_dirty_buffers_lock);
  	return 0;
  }
  
  int reiserfs_add_tail_list(struct inode *inode, struct buffer_head *bh)
  {
  	return __add_jh(SB_JOURNAL(inode->i_sb), bh, 1);
  }
  int reiserfs_add_ordered_list(struct inode *inode, struct buffer_head *bh)
  {
  	return __add_jh(SB_JOURNAL(inode->i_sb), bh, 0);
  }
  
  #define JH_ENTRY(l) list_entry((l), struct reiserfs_jh, list)
  static int write_ordered_buffers(spinlock_t * lock,
  				 struct reiserfs_journal *j,
  				 struct reiserfs_journal_list *jl,
  				 struct list_head *list)
  {
  	struct buffer_head *bh;
  	struct reiserfs_jh *jh;
  	int ret = j->j_errno;
  	struct buffer_chunk chunk;
  	struct list_head tmp;
  	INIT_LIST_HEAD(&tmp);
  
  	chunk.nr = 0;
  	spin_lock(lock);
  	while (!list_empty(list)) {
  		jh = JH_ENTRY(list->next);
  		bh = jh->bh;
  		get_bh(bh);
  		if (!trylock_buffer(bh)) {
  			if (!buffer_dirty(bh)) {
  				list_move(&jh->list, &tmp);
  				goto loop_next;
  			}
  			spin_unlock(lock);
  			if (chunk.nr)
  				write_ordered_chunk(&chunk);
  			wait_on_buffer(bh);
  			cond_resched();
  			spin_lock(lock);
  			goto loop_next;
  		}
  		/*
  		 * in theory, dirty non-uptodate buffers should never get here,
  		 * but the upper layer io error paths still have a few quirks.
  		 * Handle them here as gracefully as we can
  		 */
  		if (!buffer_uptodate(bh) && buffer_dirty(bh)) {
  			clear_buffer_dirty(bh);
  			ret = -EIO;
  		}
  		if (buffer_dirty(bh)) {
  			list_move(&jh->list, &tmp);
  			add_to_chunk(&chunk, bh, lock, write_ordered_chunk);
  		} else {
  			reiserfs_free_jh(bh);
  			unlock_buffer(bh);
  		}
  loop_next:
  		put_bh(bh);
  		cond_resched_lock(lock);
  	}
  	if (chunk.nr) {
  		spin_unlock(lock);
  		write_ordered_chunk(&chunk);
  		spin_lock(lock);
  	}
  	while (!list_empty(&tmp)) {
  		jh = JH_ENTRY(tmp.prev);
  		bh = jh->bh;
  		get_bh(bh);
  		reiserfs_free_jh(bh);
  
  		if (buffer_locked(bh)) {
  			spin_unlock(lock);
  			wait_on_buffer(bh);
  			spin_lock(lock);
  		}
  		if (!buffer_uptodate(bh)) {
  			ret = -EIO;
  		}
  		/*
  		 * ugly interaction with invalidatepage here.
  		 * reiserfs_invalidate_page will pin any buffer that has a
  		 * valid journal head from an older transaction.  If someone
  		 * else sets our buffer dirty after we write it in the first
  		 * loop, and then someone truncates the page away, nobody
  		 * will ever write the buffer. We're safe if we write the
  		 * page one last time after freeing the journal header.
  		 */
  		if (buffer_dirty(bh) && unlikely(bh->b_page->mapping == NULL)) {
  			spin_unlock(lock);
  			ll_rw_block(WRITE, 1, &bh);
  			spin_lock(lock);
  		}
  		put_bh(bh);
  		cond_resched_lock(lock);
  	}
  	spin_unlock(lock);
  	return ret;
  }
  
  static int flush_older_commits(struct super_block *s,
  			       struct reiserfs_journal_list *jl)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	struct reiserfs_journal_list *other_jl;
  	struct reiserfs_journal_list *first_jl;
  	struct list_head *entry;
  	unsigned int trans_id = jl->j_trans_id;
  	unsigned int other_trans_id;
  	unsigned int first_trans_id;
  
  find_first:
  	/*
  	 * first we walk backwards to find the oldest uncommitted transation
  	 */
  	first_jl = jl;
  	entry = jl->j_list.prev;
  	while (1) {
  		other_jl = JOURNAL_LIST_ENTRY(entry);
  		if (entry == &journal->j_journal_list ||
  		    atomic_read(&other_jl->j_older_commits_done))
  			break;
  
  		first_jl = other_jl;
  		entry = other_jl->j_list.prev;
  	}
  
  	/* if we didn't find any older uncommitted transactions, return now */
  	if (first_jl == jl) {
  		return 0;
  	}
  
  	first_trans_id = first_jl->j_trans_id;
  
  	entry = &first_jl->j_list;
  	while (1) {
  		other_jl = JOURNAL_LIST_ENTRY(entry);
  		other_trans_id = other_jl->j_trans_id;
  
  		if (other_trans_id < trans_id) {
  			if (atomic_read(&other_jl->j_commit_left) != 0) {
  				flush_commit_list(s, other_jl, 0);
  
  				/* list we were called with is gone, return */
  				if (!journal_list_still_alive(s, trans_id))
  					return 1;
  
  				/*
  				 * the one we just flushed is gone, this means
  				 * all older lists are also gone, so first_jl
  				 * is no longer valid either.  Go back to the
  				 * beginning.
  				 */
  				if (!journal_list_still_alive
  				    (s, other_trans_id)) {
  					goto find_first;
  				}
  			}
  			entry = entry->next;
  			if (entry == &journal->j_journal_list)
  				return 0;
  		} else {
  			return 0;
  		}
  	}
  	return 0;
  }
  
  static int reiserfs_async_progress_wait(struct super_block *s)
  {
  	struct reiserfs_journal *j = SB_JOURNAL(s);
  
  	if (atomic_read(&j->j_async_throttle)) {
  		int depth;
  
  		depth = reiserfs_write_unlock_nested(s);
  		congestion_wait(BLK_RW_ASYNC, HZ / 10);
  		reiserfs_write_lock_nested(s, depth);
  	}
  
  	return 0;
  }
  
  /*
   * if this journal list still has commit blocks unflushed, send them to disk.
   *
   * log areas must be flushed in order (transaction 2 can't commit before
   * transaction 1) Before the commit block can by written, every other log
   * block must be safely on disk
   */
  static int flush_commit_list(struct super_block *s,
  			     struct reiserfs_journal_list *jl, int flushall)
  {
  	int i;
  	b_blocknr_t bn;
  	struct buffer_head *tbh = NULL;
  	unsigned int trans_id = jl->j_trans_id;
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	int retval = 0;
  	int write_len;
  	int depth;
  
  	reiserfs_check_lock_depth(s, "flush_commit_list");
  
  	if (atomic_read(&jl->j_older_commits_done)) {
  		return 0;
  	}
  
  	/*
  	 * before we can put our commit blocks on disk, we have to make
  	 * sure everyone older than us is on disk too
  	 */
  	BUG_ON(jl->j_len <= 0);
  	BUG_ON(trans_id == journal->j_trans_id);
  
  	get_journal_list(jl);
  	if (flushall) {
  		if (flush_older_commits(s, jl) == 1) {
  			/*
  			 * list disappeared during flush_older_commits.
  			 * return
  			 */
  			goto put_jl;
  		}
  	}
  
  	/* make sure nobody is trying to flush this one at the same time */
  	reiserfs_mutex_lock_safe(&jl->j_commit_mutex, s);
  
  	if (!journal_list_still_alive(s, trans_id)) {
  		mutex_unlock(&jl->j_commit_mutex);
  		goto put_jl;
  	}
  	BUG_ON(jl->j_trans_id == 0);
  
  	/* this commit is done, exit */
  	if (atomic_read(&jl->j_commit_left) <= 0) {
  		if (flushall) {
  			atomic_set(&jl->j_older_commits_done, 1);
  		}
  		mutex_unlock(&jl->j_commit_mutex);
  		goto put_jl;
  	}
  
  	if (!list_empty(&jl->j_bh_list)) {
  		int ret;
  
  		/*
  		 * We might sleep in numerous places inside
  		 * write_ordered_buffers. Relax the write lock.
  		 */
  		depth = reiserfs_write_unlock_nested(s);
  		ret = write_ordered_buffers(&journal->j_dirty_buffers_lock,
  					    journal, jl, &jl->j_bh_list);
  		if (ret < 0 && retval == 0)
  			retval = ret;
  		reiserfs_write_lock_nested(s, depth);
  	}
  	BUG_ON(!list_empty(&jl->j_bh_list));
  	/*
  	 * for the description block and all the log blocks, submit any buffers
  	 * that haven't already reached the disk.  Try to write at least 256
  	 * log blocks. later on, we will only wait on blocks that correspond
  	 * to this transaction, but while we're unplugging we might as well
  	 * get a chunk of data on there.
  	 */
  	atomic_inc(&journal->j_async_throttle);
  	write_len = jl->j_len + 1;
  	if (write_len < 256)
  		write_len = 256;
  	for (i = 0 ; i < write_len ; i++) {
  		bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) + (jl->j_start + i) %
  		    SB_ONDISK_JOURNAL_SIZE(s);
  		tbh = journal_find_get_block(s, bn);
  		if (tbh) {
  			if (buffer_dirty(tbh)) {
  		            depth = reiserfs_write_unlock_nested(s);
  			    ll_rw_block(WRITE, 1, &tbh);
  			    reiserfs_write_lock_nested(s, depth);
  			}
  			put_bh(tbh) ;
  		}
  	}
  	atomic_dec(&journal->j_async_throttle);
  
  	for (i = 0; i < (jl->j_len + 1); i++) {
  		bn = SB_ONDISK_JOURNAL_1st_BLOCK(s) +
  		    (jl->j_start + i) % SB_ONDISK_JOURNAL_SIZE(s);
  		tbh = journal_find_get_block(s, bn);
  
  		depth = reiserfs_write_unlock_nested(s);
  		__wait_on_buffer(tbh);
  		reiserfs_write_lock_nested(s, depth);
  		/*
  		 * since we're using ll_rw_blk above, it might have skipped
  		 * over a locked buffer.  Double check here
  		 */
  		/* redundant, sync_dirty_buffer() checks */
  		if (buffer_dirty(tbh)) {
  			depth = reiserfs_write_unlock_nested(s);
  			sync_dirty_buffer(tbh);
  			reiserfs_write_lock_nested(s, depth);
  		}
  		if (unlikely(!buffer_uptodate(tbh))) {
  #ifdef CONFIG_REISERFS_CHECK
  			reiserfs_warning(s, "journal-601",
  					 "buffer write failed");
  #endif
  			retval = -EIO;
  		}
  		/* once for journal_find_get_block */
  		put_bh(tbh);
  		/* once due to original getblk in do_journal_end */
  		put_bh(tbh);
  		atomic_dec(&jl->j_commit_left);
  	}
  
  	BUG_ON(atomic_read(&jl->j_commit_left) != 1);
  
  	/*
  	 * If there was a write error in the journal - we can't commit
  	 * this transaction - it will be invalid and, if successful,
  	 * will just end up propagating the write error out to
  	 * the file system.
  	 */
  	if (likely(!retval && !reiserfs_is_journal_aborted (journal))) {
  		if (buffer_dirty(jl->j_commit_bh))
  			BUG();
  		mark_buffer_dirty(jl->j_commit_bh) ;
  		depth = reiserfs_write_unlock_nested(s);
  		if (reiserfs_barrier_flush(s))
  			__sync_dirty_buffer(jl->j_commit_bh, WRITE_FLUSH_FUA);
  		else
  			sync_dirty_buffer(jl->j_commit_bh);
  		reiserfs_write_lock_nested(s, depth);
  	}
  
  	/*
  	 * If there was a write error in the journal - we can't commit this
  	 * transaction - it will be invalid and, if successful, will just end
  	 * up propagating the write error out to the filesystem.
  	 */
  	if (unlikely(!buffer_uptodate(jl->j_commit_bh))) {
  #ifdef CONFIG_REISERFS_CHECK
  		reiserfs_warning(s, "journal-615", "buffer write failed");
  #endif
  		retval = -EIO;
  	}
  	bforget(jl->j_commit_bh);
  	if (journal->j_last_commit_id != 0 &&
  	    (jl->j_trans_id - journal->j_last_commit_id) != 1) {
  		reiserfs_warning(s, "clm-2200", "last commit %lu, current %lu",
  				 journal->j_last_commit_id, jl->j_trans_id);
  	}
  	journal->j_last_commit_id = jl->j_trans_id;
  
  	/*
  	 * now, every commit block is on the disk.  It is safe to allow
  	 * blocks freed during this transaction to be reallocated
  	 */
  	cleanup_freed_for_journal_list(s, jl);
  
  	retval = retval ? retval : journal->j_errno;
  
  	/* mark the metadata dirty */
  	if (!retval)
  		dirty_one_transaction(s, jl);
  	atomic_dec(&jl->j_commit_left);
  
  	if (flushall) {
  		atomic_set(&jl->j_older_commits_done, 1);
  	}
  	mutex_unlock(&jl->j_commit_mutex);
  put_jl:
  	put_journal_list(s, jl);
  
  	if (retval)
  		reiserfs_abort(s, retval, "Journal write error in %s",
  			       __func__);
  	return retval;
  }
  
  /*
   * flush_journal_list frequently needs to find a newer transaction for a
   * given block.  This does that, or returns NULL if it can't find anything
   */
  static struct reiserfs_journal_list *find_newer_jl_for_cn(struct
  							  reiserfs_journal_cnode
  							  *cn)
  {
  	struct super_block *sb = cn->sb;
  	b_blocknr_t blocknr = cn->blocknr;
  
  	cn = cn->hprev;
  	while (cn) {
  		if (cn->sb == sb && cn->blocknr == blocknr && cn->jlist) {
  			return cn->jlist;
  		}
  		cn = cn->hprev;
  	}
  	return NULL;
  }
  
  static void remove_journal_hash(struct super_block *,
  				struct reiserfs_journal_cnode **,
  				struct reiserfs_journal_list *, unsigned long,
  				int);
  
  /*
   * once all the real blocks have been flushed, it is safe to remove them
   * from the journal list for this transaction.  Aside from freeing the
   * cnode, this also allows the block to be reallocated for data blocks
   * if it had been deleted.
   */
  static void remove_all_from_journal_list(struct super_block *sb,
  					 struct reiserfs_journal_list *jl,
  					 int debug)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_cnode *cn, *last;
  	cn = jl->j_realblock;
  
  	/*
  	 * which is better, to lock once around the whole loop, or
  	 * to lock for each call to remove_journal_hash?
  	 */
  	while (cn) {
  		if (cn->blocknr != 0) {
  			if (debug) {
  				reiserfs_warning(sb, "reiserfs-2201",
  						 "block %u, bh is %d, state %ld",
  						 cn->blocknr, cn->bh ? 1 : 0,
  						 cn->state);
  			}
  			cn->state = 0;
  			remove_journal_hash(sb, journal->j_list_hash_table,
  					    jl, cn->blocknr, 1);
  		}
  		last = cn;
  		cn = cn->next;
  		free_cnode(sb, last);
  	}
  	jl->j_realblock = NULL;
  }
  
  /*
   * if this timestamp is greater than the timestamp we wrote last to the
   * header block, write it to the header block.  once this is done, I can
   * safely say the log area for this transaction won't ever be replayed,
   * and I can start releasing blocks in this transaction for reuse as data
   * blocks.  called by flush_journal_list, before it calls
   * remove_all_from_journal_list
   */
  static int _update_journal_header_block(struct super_block *sb,
  					unsigned long offset,
  					unsigned int trans_id)
  {
  	struct reiserfs_journal_header *jh;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	int depth;
  
  	if (reiserfs_is_journal_aborted(journal))
  		return -EIO;
  
  	if (trans_id >= journal->j_last_flush_trans_id) {
  		if (buffer_locked((journal->j_header_bh))) {
  			depth = reiserfs_write_unlock_nested(sb);
  			__wait_on_buffer(journal->j_header_bh);
  			reiserfs_write_lock_nested(sb, depth);
  			if (unlikely(!buffer_uptodate(journal->j_header_bh))) {
  #ifdef CONFIG_REISERFS_CHECK
  				reiserfs_warning(sb, "journal-699",
  						 "buffer write failed");
  #endif
  				return -EIO;
  			}
  		}
  		journal->j_last_flush_trans_id = trans_id;
  		journal->j_first_unflushed_offset = offset;
  		jh = (struct reiserfs_journal_header *)(journal->j_header_bh->
  							b_data);
  		jh->j_last_flush_trans_id = cpu_to_le32(trans_id);
  		jh->j_first_unflushed_offset = cpu_to_le32(offset);
  		jh->j_mount_id = cpu_to_le32(journal->j_mount_id);
  
  		set_buffer_dirty(journal->j_header_bh);
  		depth = reiserfs_write_unlock_nested(sb);
  
  		if (reiserfs_barrier_flush(sb))
  			__sync_dirty_buffer(journal->j_header_bh, WRITE_FLUSH_FUA);
  		else
  			sync_dirty_buffer(journal->j_header_bh);
  
  		reiserfs_write_lock_nested(sb, depth);
  		if (!buffer_uptodate(journal->j_header_bh)) {
  			reiserfs_warning(sb, "journal-837",
  					 "IO error during journal replay");
  			return -EIO;
  		}
  	}
  	return 0;
  }
  
  static int update_journal_header_block(struct super_block *sb,
  				       unsigned long offset,
  				       unsigned int trans_id)
  {
  	return _update_journal_header_block(sb, offset, trans_id);
  }
  
  /*
  ** flush any and all journal lists older than you are
  ** can only be called from flush_journal_list
  */
  static int flush_older_journal_lists(struct super_block *sb,
  				     struct reiserfs_journal_list *jl)
  {
  	struct list_head *entry;
  	struct reiserfs_journal_list *other_jl;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	unsigned int trans_id = jl->j_trans_id;
  
  	/*
  	 * we know we are the only ones flushing things, no extra race
  	 * protection is required.
  	 */
  restart:
  	entry = journal->j_journal_list.next;
  	/* Did we wrap? */
  	if (entry == &journal->j_journal_list)
  		return 0;
  	other_jl = JOURNAL_LIST_ENTRY(entry);
  	if (other_jl->j_trans_id < trans_id) {
  		BUG_ON(other_jl->j_refcount <= 0);
  		/* do not flush all */
  		flush_journal_list(sb, other_jl, 0);
  
  		/* other_jl is now deleted from the list */
  		goto restart;
  	}
  	return 0;
  }
  
  static void del_from_work_list(struct super_block *s,
  			       struct reiserfs_journal_list *jl)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	if (!list_empty(&jl->j_working_list)) {
  		list_del_init(&jl->j_working_list);
  		journal->j_num_work_lists--;
  	}
  }
  
  /*
   * flush a journal list, both commit and real blocks
   *
   * always set flushall to 1, unless you are calling from inside
   * flush_journal_list
   *
   * IMPORTANT.  This can only be called while there are no journal writers,
   * and the journal is locked.  That means it can only be called from
   * do_journal_end, or by journal_release
   */
  static int flush_journal_list(struct super_block *s,
  			      struct reiserfs_journal_list *jl, int flushall)
  {
  	struct reiserfs_journal_list *pjl;
  	struct reiserfs_journal_cnode *cn, *last;
  	int count;
  	int was_jwait = 0;
  	int was_dirty = 0;
  	struct buffer_head *saved_bh;
  	unsigned long j_len_saved = jl->j_len;
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	int err = 0;
  	int depth;
  
  	BUG_ON(j_len_saved <= 0);
  
  	if (atomic_read(&journal->j_wcount) != 0) {
  		reiserfs_warning(s, "clm-2048", "called with wcount %d",
  				 atomic_read(&journal->j_wcount));
  	}
  
  	/* if flushall == 0, the lock is already held */
  	if (flushall) {
  		reiserfs_mutex_lock_safe(&journal->j_flush_mutex, s);
  	} else if (mutex_trylock(&journal->j_flush_mutex)) {
  		BUG();
  	}
  
  	count = 0;
  	if (j_len_saved > journal->j_trans_max) {
  		reiserfs_panic(s, "journal-715", "length is %lu, trans id %lu",
  			       j_len_saved, jl->j_trans_id);
  		return 0;
  	}
  
  	/* if all the work is already done, get out of here */
  	if (atomic_read(&jl->j_nonzerolen) <= 0 &&
  	    atomic_read(&jl->j_commit_left) <= 0) {
  		goto flush_older_and_return;
  	}
  
  	/*
  	 * start by putting the commit list on disk.  This will also flush
  	 * the commit lists of any olders transactions
  	 */
  	flush_commit_list(s, jl, 1);
  
  	if (!(jl->j_state & LIST_DIRTY)
  	    && !reiserfs_is_journal_aborted(journal))
  		BUG();
  
  	/* are we done now? */
  	if (atomic_read(&jl->j_nonzerolen) <= 0 &&
  	    atomic_read(&jl->j_commit_left) <= 0) {
  		goto flush_older_and_return;
  	}
  
  	/*
  	 * loop through each cnode, see if we need to write it,
  	 * or wait on a more recent transaction, or just ignore it
  	 */
  	if (atomic_read(&journal->j_wcount) != 0) {
  		reiserfs_panic(s, "journal-844", "journal list is flushing, "
  			       "wcount is not 0");
  	}
  	cn = jl->j_realblock;
  	while (cn) {
  		was_jwait = 0;
  		was_dirty = 0;
  		saved_bh = NULL;
  		/* blocknr of 0 is no longer in the hash, ignore it */
  		if (cn->blocknr == 0) {
  			goto free_cnode;
  		}
  
  		/*
  		 * This transaction failed commit.
  		 * Don't write out to the disk
  		 */
  		if (!(jl->j_state & LIST_DIRTY))
  			goto free_cnode;
  
  		pjl = find_newer_jl_for_cn(cn);
  		/*
  		 * the order is important here.  We check pjl to make sure we
  		 * don't clear BH_JDirty_wait if we aren't the one writing this
  		 * block to disk
  		 */
  		if (!pjl && cn->bh) {
  			saved_bh = cn->bh;
  
  			/*
  			 * we do this to make sure nobody releases the
  			 * buffer while we are working with it
  			 */
  			get_bh(saved_bh);
  
  			if (buffer_journal_dirty(saved_bh)) {
  				BUG_ON(!can_dirty(cn));
  				was_jwait = 1;
  				was_dirty = 1;
  			} else if (can_dirty(cn)) {
  				/*
  				 * everything with !pjl && jwait
  				 * should be writable
  				 */
  				BUG();
  			}
  		}
  
  		/*
  		 * if someone has this block in a newer transaction, just make
  		 * sure they are committed, and don't try writing it to disk
  		 */
  		if (pjl) {
  			if (atomic_read(&pjl->j_commit_left))
  				flush_commit_list(s, pjl, 1);
  			goto free_cnode;
  		}
  
  		/*
  		 * bh == NULL when the block got to disk on its own, OR,
  		 * the block got freed in a future transaction
  		 */
  		if (saved_bh == NULL) {
  			goto free_cnode;
  		}
  
  		/*
  		 * this should never happen.  kupdate_one_transaction has
  		 * this list locked while it works, so we should never see a
  		 * buffer here that is not marked JDirty_wait
  		 */
  		if ((!was_jwait) && !buffer_locked(saved_bh)) {
  			reiserfs_warning(s, "journal-813",
  					 "BAD! buffer %llu %cdirty %cjwait, "
  					 "not in a newer tranasction",
  					 (unsigned long long)saved_bh->
  					 b_blocknr, was_dirty ? ' ' : '!',
  					 was_jwait ? ' ' : '!');
  		}
  		if (was_dirty) {
  			/*
  			 * we inc again because saved_bh gets decremented
  			 * at free_cnode
  			 */
  			get_bh(saved_bh);
  			set_bit(BLOCK_NEEDS_FLUSH, &cn->state);
  			lock_buffer(saved_bh);
  			BUG_ON(cn->blocknr != saved_bh->b_blocknr);
  			if (buffer_dirty(saved_bh))
  				submit_logged_buffer(saved_bh);
  			else
  				unlock_buffer(saved_bh);
  			count++;
  		} else {
  			reiserfs_warning(s, "clm-2082",
  					 "Unable to flush buffer %llu in %s",
  					 (unsigned long long)saved_bh->
  					 b_blocknr, __func__);
  		}
  free_cnode:
  		last = cn;
  		cn = cn->next;
  		if (saved_bh) {
  			/*
  			 * we incremented this to keep others from
  			 * taking the buffer head away
  			 */
  			put_bh(saved_bh);
  			if (atomic_read(&saved_bh->b_count) < 0) {
  				reiserfs_warning(s, "journal-945",
  						 "saved_bh->b_count < 0");
  			}
  		}
  	}
  	if (count > 0) {
  		cn = jl->j_realblock;
  		while (cn) {
  			if (test_bit(BLOCK_NEEDS_FLUSH, &cn->state)) {
  				if (!cn->bh) {
  					reiserfs_panic(s, "journal-1011",
  						       "cn->bh is NULL");
  				}
  
  				depth = reiserfs_write_unlock_nested(s);
  				__wait_on_buffer(cn->bh);
  				reiserfs_write_lock_nested(s, depth);
  
  				if (!cn->bh) {
  					reiserfs_panic(s, "journal-1012",
  						       "cn->bh is NULL");
  				}
  				if (unlikely(!buffer_uptodate(cn->bh))) {
  #ifdef CONFIG_REISERFS_CHECK
  					reiserfs_warning(s, "journal-949",
  							 "buffer write failed");
  #endif
  					err = -EIO;
  				}
  				/*
  				 * note, we must clear the JDirty_wait bit
  				 * after the up to date check, otherwise we
  				 * race against our flushpage routine
  				 */
  				BUG_ON(!test_clear_buffer_journal_dirty
  				       (cn->bh));
  
  				/* drop one ref for us */
  				put_bh(cn->bh);
  				/* drop one ref for journal_mark_dirty */
  				release_buffer_page(cn->bh);
  			}
  			cn = cn->next;
  		}
  	}
  
  	if (err)
  		reiserfs_abort(s, -EIO,
  			       "Write error while pushing transaction to disk in %s",
  			       __func__);
  flush_older_and_return:
  
  	/*
  	 * before we can update the journal header block, we _must_ flush all
  	 * real blocks from all older transactions to disk.  This is because
  	 * once the header block is updated, this transaction will not be
  	 * replayed after a crash
  	 */
  	if (flushall) {
  		flush_older_journal_lists(s, jl);
  	}
  
  	err = journal->j_errno;
  	/*
  	 * before we can remove everything from the hash tables for this
  	 * transaction, we must make sure it can never be replayed
  	 *
  	 * since we are only called from do_journal_end, we know for sure there
  	 * are no allocations going on while we are flushing journal lists.  So,
  	 * we only need to update the journal header block for the last list
  	 * being flushed
  	 */
  	if (!err && flushall) {
  		err =
  		    update_journal_header_block(s,
  						(jl->j_start + jl->j_len +
  						 2) % SB_ONDISK_JOURNAL_SIZE(s),
  						jl->j_trans_id);
  		if (err)
  			reiserfs_abort(s, -EIO,
  				       "Write error while updating journal header in %s",
  				       __func__);
  	}
  	remove_all_from_journal_list(s, jl, 0);
  	list_del_init(&jl->j_list);
  	journal->j_num_lists--;
  	del_from_work_list(s, jl);
  
  	if (journal->j_last_flush_id != 0 &&
  	    (jl->j_trans_id - journal->j_last_flush_id) != 1) {
  		reiserfs_warning(s, "clm-2201", "last flush %lu, current %lu",
  				 journal->j_last_flush_id, jl->j_trans_id);
  	}
  	journal->j_last_flush_id = jl->j_trans_id;
  
  	/*
  	 * not strictly required since we are freeing the list, but it should
  	 * help find code using dead lists later on
  	 */
  	jl->j_len = 0;
  	atomic_set(&jl->j_nonzerolen, 0);
  	jl->j_start = 0;
  	jl->j_realblock = NULL;
  	jl->j_commit_bh = NULL;
  	jl->j_trans_id = 0;
  	jl->j_state = 0;
  	put_journal_list(s, jl);
  	if (flushall)
  		mutex_unlock(&journal->j_flush_mutex);
  	return err;
  }
  
  static int write_one_transaction(struct super_block *s,
  				 struct reiserfs_journal_list *jl,
  				 struct buffer_chunk *chunk)
  {
  	struct reiserfs_journal_cnode *cn;
  	int ret = 0;
  
  	jl->j_state |= LIST_TOUCHED;
  	del_from_work_list(s, jl);
  	if (jl->j_len == 0 || atomic_read(&jl->j_nonzerolen) == 0) {
  		return 0;
  	}
  
  	cn = jl->j_realblock;
  	while (cn) {
  		/*
  		 * if the blocknr == 0, this has been cleared from the hash,
  		 * skip it
  		 */
  		if (cn->blocknr == 0) {
  			goto next;
  		}
  		if (cn->bh && can_dirty(cn) && buffer_dirty(cn->bh)) {
  			struct buffer_head *tmp_bh;
  			/*
  			 * we can race against journal_mark_freed when we try
  			 * to lock_buffer(cn->bh), so we have to inc the buffer
  			 * count, and recheck things after locking
  			 */
  			tmp_bh = cn->bh;
  			get_bh(tmp_bh);
  			lock_buffer(tmp_bh);
  			if (cn->bh && can_dirty(cn) && buffer_dirty(tmp_bh)) {
  				if (!buffer_journal_dirty(tmp_bh) ||
  				    buffer_journal_prepared(tmp_bh))
  					BUG();
  				add_to_chunk(chunk, tmp_bh, NULL, write_chunk);
  				ret++;
  			} else {
  				/* note, cn->bh might be null now */
  				unlock_buffer(tmp_bh);
  			}
  			put_bh(tmp_bh);
  		}
  next:
  		cn = cn->next;
  		cond_resched();
  	}
  	return ret;
  }
  
  /* used by flush_commit_list */
  static int dirty_one_transaction(struct super_block *s,
  				 struct reiserfs_journal_list *jl)
  {
  	struct reiserfs_journal_cnode *cn;
  	struct reiserfs_journal_list *pjl;
  	int ret = 0;
  
  	jl->j_state |= LIST_DIRTY;
  	cn = jl->j_realblock;
  	while (cn) {
  		/*
  		 * look for a more recent transaction that logged this
  		 * buffer.  Only the most recent transaction with a buffer in
  		 * it is allowed to send that buffer to disk
  		 */
  		pjl = find_newer_jl_for_cn(cn);
  		if (!pjl && cn->blocknr && cn->bh
  		    && buffer_journal_dirty(cn->bh)) {
  			BUG_ON(!can_dirty(cn));
  			/*
  			 * if the buffer is prepared, it will either be logged
  			 * or restored.  If restored, we need to make sure
  			 * it actually gets marked dirty
  			 */
  			clear_buffer_journal_new(cn->bh);
  			if (buffer_journal_prepared(cn->bh)) {
  				set_buffer_journal_restore_dirty(cn->bh);
  			} else {
  				set_buffer_journal_test(cn->bh);
  				mark_buffer_dirty(cn->bh);
  			}
  		}
  		cn = cn->next;
  	}
  	return ret;
  }
  
  static int kupdate_transactions(struct super_block *s,
  				struct reiserfs_journal_list *jl,
  				struct reiserfs_journal_list **next_jl,
  				unsigned int *next_trans_id,
  				int num_blocks, int num_trans)
  {
  	int ret = 0;
  	int written = 0;
  	int transactions_flushed = 0;
  	unsigned int orig_trans_id = jl->j_trans_id;
  	struct buffer_chunk chunk;
  	struct list_head *entry;
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	chunk.nr = 0;
  
  	reiserfs_mutex_lock_safe(&journal->j_flush_mutex, s);
  	if (!journal_list_still_alive(s, orig_trans_id)) {
  		goto done;
  	}
  
  	/*
  	 * we've got j_flush_mutex held, nobody is going to delete any
  	 * of these lists out from underneath us
  	 */
  	while ((num_trans && transactions_flushed < num_trans) ||
  	       (!num_trans && written < num_blocks)) {
  
  		if (jl->j_len == 0 || (jl->j_state & LIST_TOUCHED) ||
  		    atomic_read(&jl->j_commit_left)
  		    || !(jl->j_state & LIST_DIRTY)) {
  			del_from_work_list(s, jl);
  			break;
  		}
  		ret = write_one_transaction(s, jl, &chunk);
  
  		if (ret < 0)
  			goto done;
  		transactions_flushed++;
  		written += ret;
  		entry = jl->j_list.next;
  
  		/* did we wrap? */
  		if (entry == &journal->j_journal_list) {
  			break;
  		}
  		jl = JOURNAL_LIST_ENTRY(entry);
  
  		/* don't bother with older transactions */
  		if (jl->j_trans_id <= orig_trans_id)
  			break;
  	}
  	if (chunk.nr) {
  		write_chunk(&chunk);
  	}
  
  done:
  	mutex_unlock(&journal->j_flush_mutex);
  	return ret;
  }
  
  /*
   * for o_sync and fsync heavy applications, they tend to use
   * all the journa list slots with tiny transactions.  These
   * trigger lots and lots of calls to update the header block, which
   * adds seeks and slows things down.
   *
   * This function tries to clear out a large chunk of the journal lists
   * at once, which makes everything faster since only the newest journal
   * list updates the header block
   */
  static int flush_used_journal_lists(struct super_block *s,
  				    struct reiserfs_journal_list *jl)
  {
  	unsigned long len = 0;
  	unsigned long cur_len;
  	int ret;
  	int i;
  	int limit = 256;
  	struct reiserfs_journal_list *tjl;
  	struct reiserfs_journal_list *flush_jl;
  	unsigned int trans_id;
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  
  	flush_jl = tjl = jl;
  
  	/* in data logging mode, try harder to flush a lot of blocks */
  	if (reiserfs_data_log(s))
  		limit = 1024;
  	/* flush for 256 transactions or limit blocks, whichever comes first */
  	for (i = 0; i < 256 && len < limit; i++) {
  		if (atomic_read(&tjl->j_commit_left) ||
  		    tjl->j_trans_id < jl->j_trans_id) {
  			break;
  		}
  		cur_len = atomic_read(&tjl->j_nonzerolen);
  		if (cur_len > 0) {
  			tjl->j_state &= ~LIST_TOUCHED;
  		}
  		len += cur_len;
  		flush_jl = tjl;
  		if (tjl->j_list.next == &journal->j_journal_list)
  			break;
  		tjl = JOURNAL_LIST_ENTRY(tjl->j_list.next);
  	}
  	get_journal_list(jl);
  	get_journal_list(flush_jl);
  
  	/*
  	 * try to find a group of blocks we can flush across all the
  	 * transactions, but only bother if we've actually spanned
  	 * across multiple lists
  	 */
  	if (flush_jl != jl) {
  		ret = kupdate_transactions(s, jl, &tjl, &trans_id, len, i);
  	}
  	flush_journal_list(s, flush_jl, 1);
  	put_journal_list(s, flush_jl);
  	put_journal_list(s, jl);
  	return 0;
  }
  
  /*
   * removes any nodes in table with name block and dev as bh.
   * only touchs the hnext and hprev pointers.
   */
  void remove_journal_hash(struct super_block *sb,
  			 struct reiserfs_journal_cnode **table,
  			 struct reiserfs_journal_list *jl,
  			 unsigned long block, int remove_freed)
  {
  	struct reiserfs_journal_cnode *cur;
  	struct reiserfs_journal_cnode **head;
  
  	head = &(journal_hash(table, sb, block));
  	if (!head) {
  		return;
  	}
  	cur = *head;
  	while (cur) {
  		if (cur->blocknr == block && cur->sb == sb
  		    && (jl == NULL || jl == cur->jlist)
  		    && (!test_bit(BLOCK_FREED, &cur->state) || remove_freed)) {
  			if (cur->hnext) {
  				cur->hnext->hprev = cur->hprev;
  			}
  			if (cur->hprev) {
  				cur->hprev->hnext = cur->hnext;
  			} else {
  				*head = cur->hnext;
  			}
  			cur->blocknr = 0;
  			cur->sb = NULL;
  			cur->state = 0;
  			/*
  			 * anybody who clears the cur->bh will also
  			 * dec the nonzerolen
  			 */
  			if (cur->bh && cur->jlist)
  				atomic_dec(&cur->jlist->j_nonzerolen);
  			cur->bh = NULL;
  			cur->jlist = NULL;
  		}
  		cur = cur->hnext;
  	}
  }
  
  static void free_journal_ram(struct super_block *sb)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	kfree(journal->j_current_jl);
  	journal->j_num_lists--;
  
  	vfree(journal->j_cnode_free_orig);
  	free_list_bitmaps(sb, journal->j_list_bitmap);
  	free_bitmap_nodes(sb);	/* must be after free_list_bitmaps */
  	if (journal->j_header_bh) {
  		brelse(journal->j_header_bh);
  	}
  	/*
  	 * j_header_bh is on the journal dev, make sure
  	 * not to release the journal dev until we brelse j_header_bh
  	 */
  	release_journal_dev(sb, journal);
  	vfree(journal);
  }
  
  /*
   * call on unmount.  Only set error to 1 if you haven't made your way out
   * of read_super() yet.  Any other caller must keep error at 0.
   */
  static int do_journal_release(struct reiserfs_transaction_handle *th,
  			      struct super_block *sb, int error)
  {
  	struct reiserfs_transaction_handle myth;
  	int flushed = 0;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  
  	/*
  	 * we only want to flush out transactions if we were
  	 * called with error == 0
  	 */
  	if (!error && !(sb->s_flags & MS_RDONLY)) {
  		/* end the current trans */
  		BUG_ON(!th->t_trans_id);
  		do_journal_end(th, FLUSH_ALL);
  
  		/*
  		 * make sure something gets logged to force
  		 * our way into the flush code
  		 */
  		if (!journal_join(&myth, sb)) {
  			reiserfs_prepare_for_journal(sb,
  						     SB_BUFFER_WITH_SB(sb),
  						     1);
  			journal_mark_dirty(&myth, SB_BUFFER_WITH_SB(sb));
  			do_journal_end(&myth, FLUSH_ALL);
  			flushed = 1;
  		}
  	}
  
  	/* this also catches errors during the do_journal_end above */
  	if (!error && reiserfs_is_journal_aborted(journal)) {
  		memset(&myth, 0, sizeof(myth));
  		if (!journal_join_abort(&myth, sb)) {
  			reiserfs_prepare_for_journal(sb,
  						     SB_BUFFER_WITH_SB(sb),
  						     1);
  			journal_mark_dirty(&myth, SB_BUFFER_WITH_SB(sb));
  			do_journal_end(&myth, FLUSH_ALL);
  		}
  	}
  
  
  	/*
  	 * We must release the write lock here because
  	 * the workqueue job (flush_async_commit) needs this lock
  	 */
  	reiserfs_write_unlock(sb);
  
  	/*
  	 * Cancel flushing of old commits. Note that neither of these works
  	 * will be requeued because superblock is being shutdown and doesn't
  	 * have MS_ACTIVE set.
  	 */
  	cancel_delayed_work_sync(&REISERFS_SB(sb)->old_work);
  	/* wait for all commits to finish */
  	cancel_delayed_work_sync(&SB_JOURNAL(sb)->j_work);
  
  	free_journal_ram(sb);
  
  	reiserfs_write_lock(sb);
  
  	return 0;
  }
  
  /* * call on unmount.  flush all journal trans, release all alloc'd ram */
  int journal_release(struct reiserfs_transaction_handle *th,
  		    struct super_block *sb)
  {
  	return do_journal_release(th, sb, 0);
  }
  
  /* only call from an error condition inside reiserfs_read_super!  */
  int journal_release_error(struct reiserfs_transaction_handle *th,
  			  struct super_block *sb)
  {
  	return do_journal_release(th, sb, 1);
  }
  
  /*
   * compares description block with commit block.
   * returns 1 if they differ, 0 if they are the same
   */
  static int journal_compare_desc_commit(struct super_block *sb,
  				       struct reiserfs_journal_desc *desc,
  				       struct reiserfs_journal_commit *commit)
  {
  	if (get_commit_trans_id(commit) != get_desc_trans_id(desc) ||
  	    get_commit_trans_len(commit) != get_desc_trans_len(desc) ||
  	    get_commit_trans_len(commit) > SB_JOURNAL(sb)->j_trans_max ||
  	    get_commit_trans_len(commit) <= 0) {
  		return 1;
  	}
  	return 0;
  }
  
  /*
   * returns 0 if it did not find a description block
   * returns -1 if it found a corrupt commit block
   * returns 1 if both desc and commit were valid
   * NOTE: only called during fs mount
   */
  static int journal_transaction_is_valid(struct super_block *sb,
  					struct buffer_head *d_bh,
  					unsigned int *oldest_invalid_trans_id,
  					unsigned long *newest_mount_id)
  {
  	struct reiserfs_journal_desc *desc;
  	struct reiserfs_journal_commit *commit;
  	struct buffer_head *c_bh;
  	unsigned long offset;
  
  	if (!d_bh)
  		return 0;
  
  	desc = (struct reiserfs_journal_desc *)d_bh->b_data;
  	if (get_desc_trans_len(desc) > 0
  	    && !memcmp(get_journal_desc_magic(d_bh), JOURNAL_DESC_MAGIC, 8)) {
  		if (oldest_invalid_trans_id && *oldest_invalid_trans_id
  		    && get_desc_trans_id(desc) > *oldest_invalid_trans_id) {
  			reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  				       "journal-986: transaction "
  				       "is valid returning because trans_id %d is greater than "
  				       "oldest_invalid %lu",
  				       get_desc_trans_id(desc),
  				       *oldest_invalid_trans_id);
  			return 0;
  		}
  		if (newest_mount_id
  		    && *newest_mount_id > get_desc_mount_id(desc)) {
  			reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  				       "journal-1087: transaction "
  				       "is valid returning because mount_id %d is less than "
  				       "newest_mount_id %lu",
  				       get_desc_mount_id(desc),
  				       *newest_mount_id);
  			return -1;
  		}
  		if (get_desc_trans_len(desc) > SB_JOURNAL(sb)->j_trans_max) {
  			reiserfs_warning(sb, "journal-2018",
  					 "Bad transaction length %d "
  					 "encountered, ignoring transaction",
  					 get_desc_trans_len(desc));
  			return -1;
  		}
  		offset = d_bh->b_blocknr - SB_ONDISK_JOURNAL_1st_BLOCK(sb);
  
  		/*
  		 * ok, we have a journal description block,
  		 * let's see if the transaction was valid
  		 */
  		c_bh =
  		    journal_bread(sb,
  				  SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  				  ((offset + get_desc_trans_len(desc) +
  				    1) % SB_ONDISK_JOURNAL_SIZE(sb)));
  		if (!c_bh)
  			return 0;
  		commit = (struct reiserfs_journal_commit *)c_bh->b_data;
  		if (journal_compare_desc_commit(sb, desc, commit)) {
  			reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  				       "journal_transaction_is_valid, commit offset %ld had bad "
  				       "time %d or length %d",
  				       c_bh->b_blocknr -
  				       SB_ONDISK_JOURNAL_1st_BLOCK(sb),
  				       get_commit_trans_id(commit),
  				       get_commit_trans_len(commit));
  			brelse(c_bh);
  			if (oldest_invalid_trans_id) {
  				*oldest_invalid_trans_id =
  				    get_desc_trans_id(desc);
  				reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  					       "journal-1004: "
  					       "transaction_is_valid setting oldest invalid trans_id "
  					       "to %d",
  					       get_desc_trans_id(desc));
  			}
  			return -1;
  		}
  		brelse(c_bh);
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  			       "journal-1006: found valid "
  			       "transaction start offset %llu, len %d id %d",
  			       d_bh->b_blocknr -
  			       SB_ONDISK_JOURNAL_1st_BLOCK(sb),
  			       get_desc_trans_len(desc),
  			       get_desc_trans_id(desc));
  		return 1;
  	} else {
  		return 0;
  	}
  }
  
  static void brelse_array(struct buffer_head **heads, int num)
  {
  	int i;
  	for (i = 0; i < num; i++) {
  		brelse(heads[i]);
  	}
  }
  
  /*
   * given the start, and values for the oldest acceptable transactions,
   * this either reads in a replays a transaction, or returns because the
   * transaction is invalid, or too old.
   * NOTE: only called during fs mount
   */
  static int journal_read_transaction(struct super_block *sb,
  				    unsigned long cur_dblock,
  				    unsigned long oldest_start,
  				    unsigned int oldest_trans_id,
  				    unsigned long newest_mount_id)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_desc *desc;
  	struct reiserfs_journal_commit *commit;
  	unsigned int trans_id = 0;
  	struct buffer_head *c_bh;
  	struct buffer_head *d_bh;
  	struct buffer_head **log_blocks = NULL;
  	struct buffer_head **real_blocks = NULL;
  	unsigned int trans_offset;
  	int i;
  	int trans_half;
  
  	d_bh = journal_bread(sb, cur_dblock);
  	if (!d_bh)
  		return 1;
  	desc = (struct reiserfs_journal_desc *)d_bh->b_data;
  	trans_offset = d_bh->b_blocknr - SB_ONDISK_JOURNAL_1st_BLOCK(sb);
  	reiserfs_debug(sb, REISERFS_DEBUG_CODE, "journal-1037: "
  		       "journal_read_transaction, offset %llu, len %d mount_id %d",
  		       d_bh->b_blocknr - SB_ONDISK_JOURNAL_1st_BLOCK(sb),
  		       get_desc_trans_len(desc), get_desc_mount_id(desc));
  	if (get_desc_trans_id(desc) < oldest_trans_id) {
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE, "journal-1039: "
  			       "journal_read_trans skipping because %lu is too old",
  			       cur_dblock -
  			       SB_ONDISK_JOURNAL_1st_BLOCK(sb));
  		brelse(d_bh);
  		return 1;
  	}
  	if (get_desc_mount_id(desc) != newest_mount_id) {
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE, "journal-1146: "
  			       "journal_read_trans skipping because %d is != "
  			       "newest_mount_id %lu", get_desc_mount_id(desc),
  			       newest_mount_id);
  		brelse(d_bh);
  		return 1;
  	}
  	c_bh = journal_bread(sb, SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  			     ((trans_offset + get_desc_trans_len(desc) + 1) %
  			      SB_ONDISK_JOURNAL_SIZE(sb)));
  	if (!c_bh) {
  		brelse(d_bh);
  		return 1;
  	}
  	commit = (struct reiserfs_journal_commit *)c_bh->b_data;
  	if (journal_compare_desc_commit(sb, desc, commit)) {
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  			       "journal_read_transaction, "
  			       "commit offset %llu had bad time %d or length %d",
  			       c_bh->b_blocknr -
  			       SB_ONDISK_JOURNAL_1st_BLOCK(sb),
  			       get_commit_trans_id(commit),
  			       get_commit_trans_len(commit));
  		brelse(c_bh);
  		brelse(d_bh);
  		return 1;
  	}
  
  	if (bdev_read_only(sb->s_bdev)) {
  		reiserfs_warning(sb, "clm-2076",
  				 "device is readonly, unable to replay log");
  		brelse(c_bh);
  		brelse(d_bh);
  		return -EROFS;
  	}
  
  	trans_id = get_desc_trans_id(desc);
  	/*
  	 * now we know we've got a good transaction, and it was
  	 * inside the valid time ranges
  	 */
  	log_blocks = kmalloc(get_desc_trans_len(desc) *
  			     sizeof(struct buffer_head *), GFP_NOFS);
  	real_blocks = kmalloc(get_desc_trans_len(desc) *
  			      sizeof(struct buffer_head *), GFP_NOFS);
  	if (!log_blocks || !real_blocks) {
  		brelse(c_bh);
  		brelse(d_bh);
  		kfree(log_blocks);
  		kfree(real_blocks);
  		reiserfs_warning(sb, "journal-1169",
  				 "kmalloc failed, unable to mount FS");
  		return -1;
  	}
  	/* get all the buffer heads */
  	trans_half = journal_trans_half(sb->s_blocksize);
  	for (i = 0; i < get_desc_trans_len(desc); i++) {
  		log_blocks[i] =
  		    journal_getblk(sb,
  				   SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  				   (trans_offset + 1 +
  				    i) % SB_ONDISK_JOURNAL_SIZE(sb));
  		if (i < trans_half) {
  			real_blocks[i] =
  			    sb_getblk(sb,
  				      le32_to_cpu(desc->j_realblock[i]));
  		} else {
  			real_blocks[i] =
  			    sb_getblk(sb,
  				      le32_to_cpu(commit->
  						  j_realblock[i - trans_half]));
  		}
  		if (real_blocks[i]->b_blocknr > SB_BLOCK_COUNT(sb)) {
  			reiserfs_warning(sb, "journal-1207",
  					 "REPLAY FAILURE fsck required! "
  					 "Block to replay is outside of "
  					 "filesystem");
  			goto abort_replay;
  		}
  		/* make sure we don't try to replay onto log or reserved area */
  		if (is_block_in_log_or_reserved_area
  		    (sb, real_blocks[i]->b_blocknr)) {
  			reiserfs_warning(sb, "journal-1204",
  					 "REPLAY FAILURE fsck required! "
  					 "Trying to replay onto a log block");
  abort_replay:
  			brelse_array(log_blocks, i);
  			brelse_array(real_blocks, i);
  			brelse(c_bh);
  			brelse(d_bh);
  			kfree(log_blocks);
  			kfree(real_blocks);
  			return -1;
  		}
  	}
  	/* read in the log blocks, memcpy to the corresponding real block */
  	ll_rw_block(READ, get_desc_trans_len(desc), log_blocks);
  	for (i = 0; i < get_desc_trans_len(desc); i++) {
  
  		wait_on_buffer(log_blocks[i]);
  		if (!buffer_uptodate(log_blocks[i])) {
  			reiserfs_warning(sb, "journal-1212",
  					 "REPLAY FAILURE fsck required! "
  					 "buffer write failed");
  			brelse_array(log_blocks + i,
  				     get_desc_trans_len(desc) - i);
  			brelse_array(real_blocks, get_desc_trans_len(desc));
  			brelse(c_bh);
  			brelse(d_bh);
  			kfree(log_blocks);
  			kfree(real_blocks);
  			return -1;
  		}
  		memcpy(real_blocks[i]->b_data, log_blocks[i]->b_data,
  		       real_blocks[i]->b_size);
  		set_buffer_uptodate(real_blocks[i]);
  		brelse(log_blocks[i]);
  	}
  	/* flush out the real blocks */
  	for (i = 0; i < get_desc_trans_len(desc); i++) {
  		set_buffer_dirty(real_blocks[i]);
  		write_dirty_buffer(real_blocks[i], WRITE);
  	}
  	for (i = 0; i < get_desc_trans_len(desc); i++) {
  		wait_on_buffer(real_blocks[i]);
  		if (!buffer_uptodate(real_blocks[i])) {
  			reiserfs_warning(sb, "journal-1226",
  					 "REPLAY FAILURE, fsck required! "
  					 "buffer write failed");
  			brelse_array(real_blocks + i,
  				     get_desc_trans_len(desc) - i);
  			brelse(c_bh);
  			brelse(d_bh);
  			kfree(log_blocks);
  			kfree(real_blocks);
  			return -1;
  		}
  		brelse(real_blocks[i]);
  	}
  	cur_dblock =
  	    SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  	    ((trans_offset + get_desc_trans_len(desc) +
  	      2) % SB_ONDISK_JOURNAL_SIZE(sb));
  	reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  		       "journal-1095: setting journal " "start to offset %ld",
  		       cur_dblock - SB_ONDISK_JOURNAL_1st_BLOCK(sb));
  
  	/*
  	 * init starting values for the first transaction, in case
  	 * this is the last transaction to be replayed.
  	 */
  	journal->j_start = cur_dblock - SB_ONDISK_JOURNAL_1st_BLOCK(sb);
  	journal->j_last_flush_trans_id = trans_id;
  	journal->j_trans_id = trans_id + 1;
  	/* check for trans_id overflow */
  	if (journal->j_trans_id == 0)
  		journal->j_trans_id = 10;
  	brelse(c_bh);
  	brelse(d_bh);
  	kfree(log_blocks);
  	kfree(real_blocks);
  	return 0;
  }
  
  /*
   * This function reads blocks starting from block and to max_block of bufsize
   * size (but no more than BUFNR blocks at a time). This proved to improve
   * mounting speed on self-rebuilding raid5 arrays at least.
   * Right now it is only used from journal code. But later we might use it
   * from other places.
   * Note: Do not use journal_getblk/sb_getblk functions here!
   */
  static struct buffer_head *reiserfs_breada(struct block_device *dev,
  					   b_blocknr_t block, int bufsize,
  					   b_blocknr_t max_block)
  {
  	struct buffer_head *bhlist[BUFNR];
  	unsigned int blocks = BUFNR;
  	struct buffer_head *bh;
  	int i, j;
  
  	bh = __getblk(dev, block, bufsize);
  	if (buffer_uptodate(bh))
  		return (bh);
  
  	if (block + BUFNR > max_block) {
  		blocks = max_block - block;
  	}
  	bhlist[0] = bh;
  	j = 1;
  	for (i = 1; i < blocks; i++) {
  		bh = __getblk(dev, block + i, bufsize);
  		if (buffer_uptodate(bh)) {
  			brelse(bh);
  			break;
  		} else
  			bhlist[j++] = bh;
  	}
  	ll_rw_block(READ, j, bhlist);
  	for (i = 1; i < j; i++)
  		brelse(bhlist[i]);
  	bh = bhlist[0];
  	wait_on_buffer(bh);
  	if (buffer_uptodate(bh))
  		return bh;
  	brelse(bh);
  	return NULL;
  }
  
  /*
   * read and replay the log
   * on a clean unmount, the journal header's next unflushed pointer will be
   * to an invalid transaction.  This tests that before finding all the
   * transactions in the log, which makes normal mount times fast.
   *
   * After a crash, this starts with the next unflushed transaction, and
   * replays until it finds one too old, or invalid.
   *
   * On exit, it sets things up so the first transaction will work correctly.
   * NOTE: only called during fs mount
   */
  static int journal_read(struct super_block *sb)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_desc *desc;
  	unsigned int oldest_trans_id = 0;
  	unsigned int oldest_invalid_trans_id = 0;
  	time_t start;
  	unsigned long oldest_start = 0;
  	unsigned long cur_dblock = 0;
  	unsigned long newest_mount_id = 9;
  	struct buffer_head *d_bh;
  	struct reiserfs_journal_header *jh;
  	int valid_journal_header = 0;
  	int replay_count = 0;
  	int continue_replay = 1;
  	int ret;
  
  	cur_dblock = SB_ONDISK_JOURNAL_1st_BLOCK(sb);
  	reiserfs_info(sb, "checking transaction log (%pg)\n",
  		      journal->j_dev_bd);
  	start = get_seconds();
  
  	/*
  	 * step 1, read in the journal header block.  Check the transaction
  	 * it says is the first unflushed, and if that transaction is not
  	 * valid, replay is done
  	 */
  	journal->j_header_bh = journal_bread(sb,
  					     SB_ONDISK_JOURNAL_1st_BLOCK(sb)
  					     + SB_ONDISK_JOURNAL_SIZE(sb));
  	if (!journal->j_header_bh) {
  		return 1;
  	}
  	jh = (struct reiserfs_journal_header *)(journal->j_header_bh->b_data);
  	if (le32_to_cpu(jh->j_first_unflushed_offset) <
  	    SB_ONDISK_JOURNAL_SIZE(sb)
  	    && le32_to_cpu(jh->j_last_flush_trans_id) > 0) {
  		oldest_start =
  		    SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  		    le32_to_cpu(jh->j_first_unflushed_offset);
  		oldest_trans_id = le32_to_cpu(jh->j_last_flush_trans_id) + 1;
  		newest_mount_id = le32_to_cpu(jh->j_mount_id);
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  			       "journal-1153: found in "
  			       "header: first_unflushed_offset %d, last_flushed_trans_id "
  			       "%lu", le32_to_cpu(jh->j_first_unflushed_offset),
  			       le32_to_cpu(jh->j_last_flush_trans_id));
  		valid_journal_header = 1;
  
  		/*
  		 * now, we try to read the first unflushed offset.  If it
  		 * is not valid, there is nothing more we can do, and it
  		 * makes no sense to read through the whole log.
  		 */
  		d_bh =
  		    journal_bread(sb,
  				  SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  				  le32_to_cpu(jh->j_first_unflushed_offset));
  		ret = journal_transaction_is_valid(sb, d_bh, NULL, NULL);
  		if (!ret) {
  			continue_replay = 0;
  		}
  		brelse(d_bh);
  		goto start_log_replay;
  	}
  
  	/*
  	 * ok, there are transactions that need to be replayed.  start
  	 * with the first log block, find all the valid transactions, and
  	 * pick out the oldest.
  	 */
  	while (continue_replay
  	       && cur_dblock <
  	       (SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  		SB_ONDISK_JOURNAL_SIZE(sb))) {
  		/*
  		 * Note that it is required for blocksize of primary fs
  		 * device and journal device to be the same
  		 */
  		d_bh =
  		    reiserfs_breada(journal->j_dev_bd, cur_dblock,
  				    sb->s_blocksize,
  				    SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  				    SB_ONDISK_JOURNAL_SIZE(sb));
  		ret =
  		    journal_transaction_is_valid(sb, d_bh,
  						 &oldest_invalid_trans_id,
  						 &newest_mount_id);
  		if (ret == 1) {
  			desc = (struct reiserfs_journal_desc *)d_bh->b_data;
  			if (oldest_start == 0) {	/* init all oldest_ values */
  				oldest_trans_id = get_desc_trans_id(desc);
  				oldest_start = d_bh->b_blocknr;
  				newest_mount_id = get_desc_mount_id(desc);
  				reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  					       "journal-1179: Setting "
  					       "oldest_start to offset %llu, trans_id %lu",
  					       oldest_start -
  					       SB_ONDISK_JOURNAL_1st_BLOCK
  					       (sb), oldest_trans_id);
  			} else if (oldest_trans_id > get_desc_trans_id(desc)) {
  				/* one we just read was older */
  				oldest_trans_id = get_desc_trans_id(desc);
  				oldest_start = d_bh->b_blocknr;
  				reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  					       "journal-1180: Resetting "
  					       "oldest_start to offset %lu, trans_id %lu",
  					       oldest_start -
  					       SB_ONDISK_JOURNAL_1st_BLOCK
  					       (sb), oldest_trans_id);
  			}
  			if (newest_mount_id < get_desc_mount_id(desc)) {
  				newest_mount_id = get_desc_mount_id(desc);
  				reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  					       "journal-1299: Setting "
  					       "newest_mount_id to %d",
  					       get_desc_mount_id(desc));
  			}
  			cur_dblock += get_desc_trans_len(desc) + 2;
  		} else {
  			cur_dblock++;
  		}
  		brelse(d_bh);
  	}
  
  start_log_replay:
  	cur_dblock = oldest_start;
  	if (oldest_trans_id) {
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  			       "journal-1206: Starting replay "
  			       "from offset %llu, trans_id %lu",
  			       cur_dblock - SB_ONDISK_JOURNAL_1st_BLOCK(sb),
  			       oldest_trans_id);
  
  	}
  	replay_count = 0;
  	while (continue_replay && oldest_trans_id > 0) {
  		ret =
  		    journal_read_transaction(sb, cur_dblock, oldest_start,
  					     oldest_trans_id, newest_mount_id);
  		if (ret < 0) {
  			return ret;
  		} else if (ret != 0) {
  			break;
  		}
  		cur_dblock =
  		    SB_ONDISK_JOURNAL_1st_BLOCK(sb) + journal->j_start;
  		replay_count++;
  		if (cur_dblock == oldest_start)
  			break;
  	}
  
  	if (oldest_trans_id == 0) {
  		reiserfs_debug(sb, REISERFS_DEBUG_CODE,
  			       "journal-1225: No valid " "transactions found");
  	}
  	/*
  	 * j_start does not get set correctly if we don't replay any
  	 * transactions.  if we had a valid journal_header, set j_start
  	 * to the first unflushed transaction value, copy the trans_id
  	 * from the header
  	 */
  	if (valid_journal_header && replay_count == 0) {
  		journal->j_start = le32_to_cpu(jh->j_first_unflushed_offset);
  		journal->j_trans_id =
  		    le32_to_cpu(jh->j_last_flush_trans_id) + 1;
  		/* check for trans_id overflow */
  		if (journal->j_trans_id == 0)
  			journal->j_trans_id = 10;
  		journal->j_last_flush_trans_id =
  		    le32_to_cpu(jh->j_last_flush_trans_id);
  		journal->j_mount_id = le32_to_cpu(jh->j_mount_id) + 1;
  	} else {
  		journal->j_mount_id = newest_mount_id + 1;
  	}
  	reiserfs_debug(sb, REISERFS_DEBUG_CODE, "journal-1299: Setting "
  		       "newest_mount_id to %lu", journal->j_mount_id);
  	journal->j_first_unflushed_offset = journal->j_start;
  	if (replay_count > 0) {
  		reiserfs_info(sb,
  			      "replayed %d transactions in %lu seconds\n",
  			      replay_count, get_seconds() - start);
  	}
  	/* needed to satisfy the locking in _update_journal_header_block */
  	reiserfs_write_lock(sb);
  	if (!bdev_read_only(sb->s_bdev) &&
  	    _update_journal_header_block(sb, journal->j_start,
  					 journal->j_last_flush_trans_id)) {
  		reiserfs_write_unlock(sb);
  		/*
  		 * replay failed, caller must call free_journal_ram and abort
  		 * the mount
  		 */
  		return -1;
  	}
  	reiserfs_write_unlock(sb);
  	return 0;
  }
  
  static struct reiserfs_journal_list *alloc_journal_list(struct super_block *s)
  {
  	struct reiserfs_journal_list *jl;
  	jl = kzalloc(sizeof(struct reiserfs_journal_list),
  		     GFP_NOFS | __GFP_NOFAIL);
  	INIT_LIST_HEAD(&jl->j_list);
  	INIT_LIST_HEAD(&jl->j_working_list);
  	INIT_LIST_HEAD(&jl->j_tail_bh_list);
  	INIT_LIST_HEAD(&jl->j_bh_list);
  	mutex_init(&jl->j_commit_mutex);
  	SB_JOURNAL(s)->j_num_lists++;
  	get_journal_list(jl);
  	return jl;
  }
  
  static void journal_list_init(struct super_block *sb)
  {
  	SB_JOURNAL(sb)->j_current_jl = alloc_journal_list(sb);
  }
  
  static void release_journal_dev(struct super_block *super,
  			       struct reiserfs_journal *journal)
  {
  	if (journal->j_dev_bd != NULL) {
  		blkdev_put(journal->j_dev_bd, journal->j_dev_mode);
  		journal->j_dev_bd = NULL;
  	}
  }
  
  static int journal_init_dev(struct super_block *super,
  			    struct reiserfs_journal *journal,
  			    const char *jdev_name)
  {
  	int result;
  	dev_t jdev;
  	fmode_t blkdev_mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
  	char b[BDEVNAME_SIZE];
  
  	result = 0;
  
  	journal->j_dev_bd = NULL;
  	jdev = SB_ONDISK_JOURNAL_DEVICE(super) ?
  	    new_decode_dev(SB_ONDISK_JOURNAL_DEVICE(super)) : super->s_dev;
  
  	if (bdev_read_only(super->s_bdev))
  		blkdev_mode = FMODE_READ;
  
  	/* there is no "jdev" option and journal is on separate device */
  	if ((!jdev_name || !jdev_name[0])) {
  		if (jdev == super->s_dev)
  			blkdev_mode &= ~FMODE_EXCL;
  		journal->j_dev_bd = blkdev_get_by_dev(jdev, blkdev_mode,
  						      journal);
  		journal->j_dev_mode = blkdev_mode;
  		if (IS_ERR(journal->j_dev_bd)) {
  			result = PTR_ERR(journal->j_dev_bd);
  			journal->j_dev_bd = NULL;
  			reiserfs_warning(super, "sh-458",
  					 "cannot init journal device '%s': %i",
  					 __bdevname(jdev, b), result);
  			return result;
  		} else if (jdev != super->s_dev)
  			set_blocksize(journal->j_dev_bd, super->s_blocksize);
  
  		return 0;
  	}
  
  	journal->j_dev_mode = blkdev_mode;
  	journal->j_dev_bd = blkdev_get_by_path(jdev_name, blkdev_mode, journal);
  	if (IS_ERR(journal->j_dev_bd)) {
  		result = PTR_ERR(journal->j_dev_bd);
  		journal->j_dev_bd = NULL;
  		reiserfs_warning(super,
  				 "journal_init_dev: Cannot open '%s': %i",
  				 jdev_name, result);
  		return result;
  	}
  
  	set_blocksize(journal->j_dev_bd, super->s_blocksize);
  	reiserfs_info(super,
  		      "journal_init_dev: journal device: %pg\n",
  		      journal->j_dev_bd);
  	return 0;
  }
  
  /*
   * When creating/tuning a file system user can assign some
   * journal params within boundaries which depend on the ratio
   * blocksize/standard_blocksize.
   *
   * For blocks >= standard_blocksize transaction size should
   * be not less then JOURNAL_TRANS_MIN_DEFAULT, and not more
   * then JOURNAL_TRANS_MAX_DEFAULT.
   *
   * For blocks < standard_blocksize these boundaries should be
   * decreased proportionally.
   */
  #define REISERFS_STANDARD_BLKSIZE (4096)
  
  static int check_advise_trans_params(struct super_block *sb,
  				     struct reiserfs_journal *journal)
  {
          if (journal->j_trans_max) {
  		/* Non-default journal params.  Do sanity check for them. */
  	        int ratio = 1;
  		if (sb->s_blocksize < REISERFS_STANDARD_BLKSIZE)
  		        ratio = REISERFS_STANDARD_BLKSIZE / sb->s_blocksize;
  
  		if (journal->j_trans_max > JOURNAL_TRANS_MAX_DEFAULT / ratio ||
  		    journal->j_trans_max < JOURNAL_TRANS_MIN_DEFAULT / ratio ||
  		    SB_ONDISK_JOURNAL_SIZE(sb) / journal->j_trans_max <
  		    JOURNAL_MIN_RATIO) {
  			reiserfs_warning(sb, "sh-462",
  					 "bad transaction max size (%u). "
  					 "FSCK?", journal->j_trans_max);
  			return 1;
  		}
  		if (journal->j_max_batch != (journal->j_trans_max) *
  		        JOURNAL_MAX_BATCH_DEFAULT/JOURNAL_TRANS_MAX_DEFAULT) {
  			reiserfs_warning(sb, "sh-463",
  					 "bad transaction max batch (%u). "
  					 "FSCK?", journal->j_max_batch);
  			return 1;
  		}
  	} else {
  		/*
  		 * Default journal params.
  		 * The file system was created by old version
  		 * of mkreiserfs, so some fields contain zeros,
  		 * and we need to advise proper values for them
  		 */
  		if (sb->s_blocksize != REISERFS_STANDARD_BLKSIZE) {
  			reiserfs_warning(sb, "sh-464", "bad blocksize (%u)",
  					 sb->s_blocksize);
  			return 1;
  		}
  		journal->j_trans_max = JOURNAL_TRANS_MAX_DEFAULT;
  		journal->j_max_batch = JOURNAL_MAX_BATCH_DEFAULT;
  		journal->j_max_commit_age = JOURNAL_MAX_COMMIT_AGE;
  	}
  	return 0;
  }
  
  /* must be called once on fs mount.  calls journal_read for you */
  int journal_init(struct super_block *sb, const char *j_dev_name,
  		 int old_format, unsigned int commit_max_age)
  {
  	int num_cnodes = SB_ONDISK_JOURNAL_SIZE(sb) * 2;
  	struct buffer_head *bhjh;
  	struct reiserfs_super_block *rs;
  	struct reiserfs_journal_header *jh;
  	struct reiserfs_journal *journal;
  	struct reiserfs_journal_list *jl;
  	int ret;
  
  	journal = SB_JOURNAL(sb) = vzalloc(sizeof(struct reiserfs_journal));
  	if (!journal) {
  		reiserfs_warning(sb, "journal-1256",
  				 "unable to get memory for journal structure");
  		return 1;
  	}
  	INIT_LIST_HEAD(&journal->j_bitmap_nodes);
  	INIT_LIST_HEAD(&journal->j_prealloc_list);
  	INIT_LIST_HEAD(&journal->j_working_list);
  	INIT_LIST_HEAD(&journal->j_journal_list);
  	journal->j_persistent_trans = 0;
  	if (reiserfs_allocate_list_bitmaps(sb, journal->j_list_bitmap,
  					   reiserfs_bmap_count(sb)))
  		goto free_and_return;
  
  	allocate_bitmap_nodes(sb);
  
  	/* reserved for journal area support */
  	SB_JOURNAL_1st_RESERVED_BLOCK(sb) = (old_format ?
  						 REISERFS_OLD_DISK_OFFSET_IN_BYTES
  						 / sb->s_blocksize +
  						 reiserfs_bmap_count(sb) +
  						 1 :
  						 REISERFS_DISK_OFFSET_IN_BYTES /
  						 sb->s_blocksize + 2);
  
  	/*
  	 * Sanity check to see is the standard journal fitting
  	 * within first bitmap (actual for small blocksizes)
  	 */
  	if (!SB_ONDISK_JOURNAL_DEVICE(sb) &&
  	    (SB_JOURNAL_1st_RESERVED_BLOCK(sb) +
  	     SB_ONDISK_JOURNAL_SIZE(sb) > sb->s_blocksize * 8)) {
  		reiserfs_warning(sb, "journal-1393",
  				 "journal does not fit for area addressed "
  				 "by first of bitmap blocks. It starts at "
  				 "%u and its size is %u. Block size %ld",
  				 SB_JOURNAL_1st_RESERVED_BLOCK(sb),
  				 SB_ONDISK_JOURNAL_SIZE(sb),
  				 sb->s_blocksize);
  		goto free_and_return;
  	}
  
  	if (journal_init_dev(sb, journal, j_dev_name) != 0) {
  		reiserfs_warning(sb, "sh-462",
  				 "unable to initialize journal device");
  		goto free_and_return;
  	}
  
  	rs = SB_DISK_SUPER_BLOCK(sb);
  
  	/* read journal header */
  	bhjh = journal_bread(sb,
  			     SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  			     SB_ONDISK_JOURNAL_SIZE(sb));
  	if (!bhjh) {
  		reiserfs_warning(sb, "sh-459",
  				 "unable to read journal header");
  		goto free_and_return;
  	}
  	jh = (struct reiserfs_journal_header *)(bhjh->b_data);
  
  	/* make sure that journal matches to the super block */
  	if (is_reiserfs_jr(rs)
  	    && (le32_to_cpu(jh->jh_journal.jp_journal_magic) !=
  		sb_jp_journal_magic(rs))) {
  		reiserfs_warning(sb, "sh-460",
  				 "journal header magic %x (device %pg) does "
  				 "not match to magic found in super block %x",
  				 jh->jh_journal.jp_journal_magic,
  				 journal->j_dev_bd,
  				 sb_jp_journal_magic(rs));
  		brelse(bhjh);
  		goto free_and_return;
  	}
  
  	journal->j_trans_max = le32_to_cpu(jh->jh_journal.jp_journal_trans_max);
  	journal->j_max_batch = le32_to_cpu(jh->jh_journal.jp_journal_max_batch);
  	journal->j_max_commit_age =
  	    le32_to_cpu(jh->jh_journal.jp_journal_max_commit_age);
  	journal->j_max_trans_age = JOURNAL_MAX_TRANS_AGE;
  
  	if (check_advise_trans_params(sb, journal) != 0)
  	        goto free_and_return;
  	journal->j_default_max_commit_age = journal->j_max_commit_age;
  
  	if (commit_max_age != 0) {
  		journal->j_max_commit_age = commit_max_age;
  		journal->j_max_trans_age = commit_max_age;
  	}
  
  	reiserfs_info(sb, "journal params: device %pg, size %u, "
  		      "journal first block %u, max trans len %u, max batch %u, "
  		      "max commit age %u, max trans age %u\n",
  		      journal->j_dev_bd,
  		      SB_ONDISK_JOURNAL_SIZE(sb),
  		      SB_ONDISK_JOURNAL_1st_BLOCK(sb),
  		      journal->j_trans_max,
  		      journal->j_max_batch,
  		      journal->j_max_commit_age, journal->j_max_trans_age);
  
  	brelse(bhjh);
  
  	journal->j_list_bitmap_index = 0;
  	journal_list_init(sb);
  
  	memset(journal->j_list_hash_table, 0,
  	       JOURNAL_HASH_SIZE * sizeof(struct reiserfs_journal_cnode *));
  
  	INIT_LIST_HEAD(&journal->j_dirty_buffers);
  	spin_lock_init(&journal->j_dirty_buffers_lock);
  
  	journal->j_start = 0;
  	journal->j_len = 0;
  	journal->j_len_alloc = 0;
  	atomic_set(&journal->j_wcount, 0);
  	atomic_set(&journal->j_async_throttle, 0);
  	journal->j_bcount = 0;
  	journal->j_trans_start_time = 0;
  	journal->j_last = NULL;
  	journal->j_first = NULL;
  	init_waitqueue_head(&journal->j_join_wait);
  	mutex_init(&journal->j_mutex);
  	mutex_init(&journal->j_flush_mutex);
  
  	journal->j_trans_id = 10;
  	journal->j_mount_id = 10;
  	journal->j_state = 0;
  	atomic_set(&journal->j_jlock, 0);
  	journal->j_cnode_free_list = allocate_cnodes(num_cnodes);
  	journal->j_cnode_free_orig = journal->j_cnode_free_list;
  	journal->j_cnode_free = journal->j_cnode_free_list ? num_cnodes : 0;
  	journal->j_cnode_used = 0;
  	journal->j_must_wait = 0;
  
  	if (journal->j_cnode_free == 0) {
  		reiserfs_warning(sb, "journal-2004", "Journal cnode memory "
  		                 "allocation failed (%ld bytes). Journal is "
  		                 "too large for available memory. Usually "
  		                 "this is due to a journal that is too large.",
  		                 sizeof (struct reiserfs_journal_cnode) * num_cnodes);
          	goto free_and_return;
  	}
  
  	init_journal_hash(sb);
  	jl = journal->j_current_jl;
  
  	/*
  	 * get_list_bitmap() may call flush_commit_list() which
  	 * requires the lock. Calling flush_commit_list() shouldn't happen
  	 * this early but I like to be paranoid.
  	 */
  	reiserfs_write_lock(sb);
  	jl->j_list_bitmap = get_list_bitmap(sb, jl);
  	reiserfs_write_unlock(sb);
  	if (!jl->j_list_bitmap) {
  		reiserfs_warning(sb, "journal-2005",
  				 "get_list_bitmap failed for journal list 0");
  		goto free_and_return;
  	}
  
  	ret = journal_read(sb);
  	if (ret < 0) {
  		reiserfs_warning(sb, "reiserfs-2006",
  				 "Replay Failure, unable to mount");
  		goto free_and_return;
  	}
  
  	INIT_DELAYED_WORK(&journal->j_work, flush_async_commits);
  	journal->j_work_sb = sb;
  	return 0;
  free_and_return:
  	free_journal_ram(sb);
  	return 1;
  }
  
  /*
   * test for a polite end of the current transaction.  Used by file_write,
   * and should be used by delete to make sure they don't write more than
   * can fit inside a single transaction
   */
  int journal_transaction_should_end(struct reiserfs_transaction_handle *th,
  				   int new_alloc)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(th->t_super);
  	time_t now = get_seconds();
  	/* cannot restart while nested */
  	BUG_ON(!th->t_trans_id);
  	if (th->t_refcount > 1)
  		return 0;
  	if (journal->j_must_wait > 0 ||
  	    (journal->j_len_alloc + new_alloc) >= journal->j_max_batch ||
  	    atomic_read(&journal->j_jlock) ||
  	    (now - journal->j_trans_start_time) > journal->j_max_trans_age ||
  	    journal->j_cnode_free < (journal->j_trans_max * 3)) {
  		return 1;
  	}
  
  	journal->j_len_alloc += new_alloc;
  	th->t_blocks_allocated += new_alloc ;
  	return 0;
  }
  
  /* this must be called inside a transaction */
  void reiserfs_block_writes(struct reiserfs_transaction_handle *th)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(th->t_super);
  	BUG_ON(!th->t_trans_id);
  	journal->j_must_wait = 1;
  	set_bit(J_WRITERS_BLOCKED, &journal->j_state);
  	return;
  }
  
  /* this must be called without a transaction started */
  void reiserfs_allow_writes(struct super_block *s)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	clear_bit(J_WRITERS_BLOCKED, &journal->j_state);
  	wake_up(&journal->j_join_wait);
  }
  
  /* this must be called without a transaction started */
  void reiserfs_wait_on_write_block(struct super_block *s)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	wait_event(journal->j_join_wait,
  		   !test_bit(J_WRITERS_BLOCKED, &journal->j_state));
  }
  
  static void queue_log_writer(struct super_block *s)
  {
  	wait_queue_t wait;
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	set_bit(J_WRITERS_QUEUED, &journal->j_state);
  
  	/*
  	 * we don't want to use wait_event here because
  	 * we only want to wait once.
  	 */
  	init_waitqueue_entry(&wait, current);
  	add_wait_queue(&journal->j_join_wait, &wait);
  	set_current_state(TASK_UNINTERRUPTIBLE);
  	if (test_bit(J_WRITERS_QUEUED, &journal->j_state)) {
  		int depth = reiserfs_write_unlock_nested(s);
  		schedule();
  		reiserfs_write_lock_nested(s, depth);
  	}
  	__set_current_state(TASK_RUNNING);
  	remove_wait_queue(&journal->j_join_wait, &wait);
  }
  
  static void wake_queued_writers(struct super_block *s)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(s);
  	if (test_and_clear_bit(J_WRITERS_QUEUED, &journal->j_state))
  		wake_up(&journal->j_join_wait);
  }
  
  static void let_transaction_grow(struct super_block *sb, unsigned int trans_id)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	unsigned long bcount = journal->j_bcount;
  	while (1) {
  		int depth;
  
  		depth = reiserfs_write_unlock_nested(sb);
  		schedule_timeout_uninterruptible(1);
  		reiserfs_write_lock_nested(sb, depth);
  
  		journal->j_current_jl->j_state |= LIST_COMMIT_PENDING;
  		while ((atomic_read(&journal->j_wcount) > 0 ||
  			atomic_read(&journal->j_jlock)) &&
  		       journal->j_trans_id == trans_id) {
  			queue_log_writer(sb);
  		}
  		if (journal->j_trans_id != trans_id)
  			break;
  		if (bcount == journal->j_bcount)
  			break;
  		bcount = journal->j_bcount;
  	}
  }
  
  /*
   * join == true if you must join an existing transaction.
   * join == false if you can deal with waiting for others to finish
   *
   * this will block until the transaction is joinable.  send the number of
   * blocks you expect to use in nblocks.
  */
  static int do_journal_begin_r(struct reiserfs_transaction_handle *th,
  			      struct super_block *sb, unsigned long nblocks,
  			      int join)
  {
  	time_t now = get_seconds();
  	unsigned int old_trans_id;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_transaction_handle myth;
  	int sched_count = 0;
  	int retval;
  	int depth;
  
  	reiserfs_check_lock_depth(sb, "journal_begin");
  	BUG_ON(nblocks > journal->j_trans_max);
  
  	PROC_INFO_INC(sb, journal.journal_being);
  	/* set here for journal_join */
  	th->t_refcount = 1;
  	th->t_super = sb;
  
  relock:
  	lock_journal(sb);
  	if (join != JBEGIN_ABORT && reiserfs_is_journal_aborted(journal)) {
  		unlock_journal(sb);
  		retval = journal->j_errno;
  		goto out_fail;
  	}
  	journal->j_bcount++;
  
  	if (test_bit(J_WRITERS_BLOCKED, &journal->j_state)) {
  		unlock_journal(sb);
  		depth = reiserfs_write_unlock_nested(sb);
  		reiserfs_wait_on_write_block(sb);
  		reiserfs_write_lock_nested(sb, depth);
  		PROC_INFO_INC(sb, journal.journal_relock_writers);
  		goto relock;
  	}
  	now = get_seconds();
  
  	/*
  	 * if there is no room in the journal OR
  	 * if this transaction is too old, and we weren't called joinable,
  	 * wait for it to finish before beginning we don't sleep if there
  	 * aren't other writers
  	 */
  
  	if ((!join && journal->j_must_wait > 0) ||
  	    (!join
  	     && (journal->j_len_alloc + nblocks + 2) >= journal->j_max_batch)
  	    || (!join && atomic_read(&journal->j_wcount) > 0
  		&& journal->j_trans_start_time > 0
  		&& (now - journal->j_trans_start_time) >
  		journal->j_max_trans_age) || (!join
  					      && atomic_read(&journal->j_jlock))
  	    || (!join && journal->j_cnode_free < (journal->j_trans_max * 3))) {
  
  		old_trans_id = journal->j_trans_id;
  		/* allow others to finish this transaction */
  		unlock_journal(sb);
  
  		if (!join && (journal->j_len_alloc + nblocks + 2) >=
  		    journal->j_max_batch &&
  		    ((journal->j_len + nblocks + 2) * 100) <
  		    (journal->j_len_alloc * 75)) {
  			if (atomic_read(&journal->j_wcount) > 10) {
  				sched_count++;
  				queue_log_writer(sb);
  				goto relock;
  			}
  		}
  		/*
  		 * don't mess with joining the transaction if all we
  		 * have to do is wait for someone else to do a commit
  		 */
  		if (atomic_read(&journal->j_jlock)) {
  			while (journal->j_trans_id == old_trans_id &&
  			       atomic_read(&journal->j_jlock)) {
  				queue_log_writer(sb);
  			}
  			goto relock;
  		}
  		retval = journal_join(&myth, sb);
  		if (retval)
  			goto out_fail;
  
  		/* someone might have ended the transaction while we joined */
  		if (old_trans_id != journal->j_trans_id) {
  			retval = do_journal_end(&myth, 0);
  		} else {
  			retval = do_journal_end(&myth, COMMIT_NOW);
  		}
  
  		if (retval)
  			goto out_fail;
  
  		PROC_INFO_INC(sb, journal.journal_relock_wcount);
  		goto relock;
  	}
  	/* we are the first writer, set trans_id */
  	if (journal->j_trans_start_time == 0) {
  		journal->j_trans_start_time = get_seconds();
  	}
  	atomic_inc(&journal->j_wcount);
  	journal->j_len_alloc += nblocks;
  	th->t_blocks_logged = 0;
  	th->t_blocks_allocated = nblocks;
  	th->t_trans_id = journal->j_trans_id;
  	unlock_journal(sb);
  	INIT_LIST_HEAD(&th->t_list);
  	return 0;
  
  out_fail:
  	memset(th, 0, sizeof(*th));
  	/*
  	 * Re-set th->t_super, so we can properly keep track of how many
  	 * persistent transactions there are. We need to do this so if this
  	 * call is part of a failed restart_transaction, we can free it later
  	 */
  	th->t_super = sb;
  	return retval;
  }
  
  struct reiserfs_transaction_handle *reiserfs_persistent_transaction(struct
  								    super_block
  								    *s,
  								    int nblocks)
  {
  	int ret;
  	struct reiserfs_transaction_handle *th;
  
  	/*
  	 * if we're nesting into an existing transaction.  It will be
  	 * persistent on its own
  	 */
  	if (reiserfs_transaction_running(s)) {
  		th = current->journal_info;
  		th->t_refcount++;
  		BUG_ON(th->t_refcount < 2);
  
  		return th;
  	}
  	th = kmalloc(sizeof(struct reiserfs_transaction_handle), GFP_NOFS);
  	if (!th)
  		return NULL;
  	ret = journal_begin(th, s, nblocks);
  	if (ret) {
  		kfree(th);
  		return NULL;
  	}
  
  	SB_JOURNAL(s)->j_persistent_trans++;
  	return th;
  }
  
  int reiserfs_end_persistent_transaction(struct reiserfs_transaction_handle *th)
  {
  	struct super_block *s = th->t_super;
  	int ret = 0;
  	if (th->t_trans_id)
  		ret = journal_end(th);
  	else
  		ret = -EIO;
  	if (th->t_refcount == 0) {
  		SB_JOURNAL(s)->j_persistent_trans--;
  		kfree(th);
  	}
  	return ret;
  }
  
  static int journal_join(struct reiserfs_transaction_handle *th,
  			struct super_block *sb)
  {
  	struct reiserfs_transaction_handle *cur_th = current->journal_info;
  
  	/*
  	 * this keeps do_journal_end from NULLing out the
  	 * current->journal_info pointer
  	 */
  	th->t_handle_save = cur_th;
  	BUG_ON(cur_th && cur_th->t_refcount > 1);
  	return do_journal_begin_r(th, sb, 1, JBEGIN_JOIN);
  }
  
  int journal_join_abort(struct reiserfs_transaction_handle *th,
  		       struct super_block *sb)
  {
  	struct reiserfs_transaction_handle *cur_th = current->journal_info;
  
  	/*
  	 * this keeps do_journal_end from NULLing out the
  	 * current->journal_info pointer
  	 */
  	th->t_handle_save = cur_th;
  	BUG_ON(cur_th && cur_th->t_refcount > 1);
  	return do_journal_begin_r(th, sb, 1, JBEGIN_ABORT);
  }
  
  int journal_begin(struct reiserfs_transaction_handle *th,
  		  struct super_block *sb, unsigned long nblocks)
  {
  	struct reiserfs_transaction_handle *cur_th = current->journal_info;
  	int ret;
  
  	th->t_handle_save = NULL;
  	if (cur_th) {
  		/* we are nesting into the current transaction */
  		if (cur_th->t_super == sb) {
  			BUG_ON(!cur_th->t_refcount);
  			cur_th->t_refcount++;
  			memcpy(th, cur_th, sizeof(*th));
  			if (th->t_refcount <= 1)
  				reiserfs_warning(sb, "reiserfs-2005",
  						 "BAD: refcount <= 1, but "
  						 "journal_info != 0");
  			return 0;
  		} else {
  			/*
  			 * we've ended up with a handle from a different
  			 * filesystem.  save it and restore on journal_end.
  			 * This should never really happen...
  			 */
  			reiserfs_warning(sb, "clm-2100",
  					 "nesting info a different FS");
  			th->t_handle_save = current->journal_info;
  			current->journal_info = th;
  		}
  	} else {
  		current->journal_info = th;
  	}
  	ret = do_journal_begin_r(th, sb, nblocks, JBEGIN_REG);
  	BUG_ON(current->journal_info != th);
  
  	/*
  	 * I guess this boils down to being the reciprocal of clm-2100 above.
  	 * If do_journal_begin_r fails, we need to put it back, since
  	 * journal_end won't be called to do it. */
  	if (ret)
  		current->journal_info = th->t_handle_save;
  	else
  		BUG_ON(!th->t_refcount);
  
  	return ret;
  }
  
  /*
   * puts bh into the current transaction.  If it was already there, reorders
   * removes the old pointers from the hash, and puts new ones in (to make
   * sure replay happen in the right order).
   *
   * if it was dirty, cleans and files onto the clean list.  I can't let it
   * be dirty again until the transaction is committed.
   *
   * if j_len, is bigger than j_len_alloc, it pushes j_len_alloc to 10 + j_len.
   */
  int journal_mark_dirty(struct reiserfs_transaction_handle *th,
  		       struct buffer_head *bh)
  {
  	struct super_block *sb = th->t_super;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_cnode *cn = NULL;
  	int count_already_incd = 0;
  	int prepared = 0;
  	BUG_ON(!th->t_trans_id);
  
  	PROC_INFO_INC(sb, journal.mark_dirty);
  	if (th->t_trans_id != journal->j_trans_id) {
  		reiserfs_panic(th->t_super, "journal-1577",
  			       "handle trans id %ld != current trans id %ld",
  			       th->t_trans_id, journal->j_trans_id);
  	}
  
  	prepared = test_clear_buffer_journal_prepared(bh);
  	clear_buffer_journal_restore_dirty(bh);
  	/* already in this transaction, we are done */
  	if (buffer_journaled(bh)) {
  		PROC_INFO_INC(sb, journal.mark_dirty_already);
  		return 0;
  	}
  
  	/*
  	 * this must be turned into a panic instead of a warning.  We can't
  	 * allow a dirty or journal_dirty or locked buffer to be logged, as
  	 * some changes could get to disk too early.  NOT GOOD.
  	 */
  	if (!prepared || buffer_dirty(bh)) {
  		reiserfs_warning(sb, "journal-1777",
  				 "buffer %llu bad state "
  				 "%cPREPARED %cLOCKED %cDIRTY %cJDIRTY_WAIT",
  				 (unsigned long long)bh->b_blocknr,
  				 prepared ? ' ' : '!',
  				 buffer_locked(bh) ? ' ' : '!',
  				 buffer_dirty(bh) ? ' ' : '!',
  				 buffer_journal_dirty(bh) ? ' ' : '!');
  	}
  
  	if (atomic_read(&journal->j_wcount) <= 0) {
  		reiserfs_warning(sb, "journal-1409",
  				 "returning because j_wcount was %d",
  				 atomic_read(&journal->j_wcount));
  		return 1;
  	}
  	/*
  	 * this error means I've screwed up, and we've overflowed
  	 * the transaction.  Nothing can be done here, except make the
  	 * FS readonly or panic.
  	 */
  	if (journal->j_len >= journal->j_trans_max) {
  		reiserfs_panic(th->t_super, "journal-1413",
  			       "j_len (%lu) is too big",
  			       journal->j_len);
  	}
  
  	if (buffer_journal_dirty(bh)) {
  		count_already_incd = 1;
  		PROC_INFO_INC(sb, journal.mark_dirty_notjournal);
  		clear_buffer_journal_dirty(bh);
  	}
  
  	if (journal->j_len > journal->j_len_alloc) {
  		journal->j_len_alloc = journal->j_len + JOURNAL_PER_BALANCE_CNT;
  	}
  
  	set_buffer_journaled(bh);
  
  	/* now put this guy on the end */
  	if (!cn) {
  		cn = get_cnode(sb);
  		if (!cn) {
  			reiserfs_panic(sb, "journal-4", "get_cnode failed!");
  		}
  
  		if (th->t_blocks_logged == th->t_blocks_allocated) {
  			th->t_blocks_allocated += JOURNAL_PER_BALANCE_CNT;
  			journal->j_len_alloc += JOURNAL_PER_BALANCE_CNT;
  		}
  		th->t_blocks_logged++;
  		journal->j_len++;
  
  		cn->bh = bh;
  		cn->blocknr = bh->b_blocknr;
  		cn->sb = sb;
  		cn->jlist = NULL;
  		insert_journal_hash(journal->j_hash_table, cn);
  		if (!count_already_incd) {
  			get_bh(bh);
  		}
  	}
  	cn->next = NULL;
  	cn->prev = journal->j_last;
  	cn->bh = bh;
  	if (journal->j_last) {
  		journal->j_last->next = cn;
  		journal->j_last = cn;
  	} else {
  		journal->j_first = cn;
  		journal->j_last = cn;
  	}
  	reiserfs_schedule_old_flush(sb);
  	return 0;
  }
  
  int journal_end(struct reiserfs_transaction_handle *th)
  {
  	struct super_block *sb = th->t_super;
  	if (!current->journal_info && th->t_refcount > 1)
  		reiserfs_warning(sb, "REISER-NESTING",
  				 "th NULL, refcount %d", th->t_refcount);
  
  	if (!th->t_trans_id) {
  		WARN_ON(1);
  		return -EIO;
  	}
  
  	th->t_refcount--;
  	if (th->t_refcount > 0) {
  		struct reiserfs_transaction_handle *cur_th =
  		    current->journal_info;
  
  		/*
  		 * we aren't allowed to close a nested transaction on a
  		 * different filesystem from the one in the task struct
  		 */
  		BUG_ON(cur_th->t_super != th->t_super);
  
  		if (th != cur_th) {
  			memcpy(current->journal_info, th, sizeof(*th));
  			th->t_trans_id = 0;
  		}
  		return 0;
  	} else {
  		return do_journal_end(th, 0);
  	}
  }
  
  /*
   * removes from the current transaction, relsing and descrementing any counters.
   * also files the removed buffer directly onto the clean list
   *
   * called by journal_mark_freed when a block has been deleted
   *
   * returns 1 if it cleaned and relsed the buffer. 0 otherwise
   */
  static int remove_from_transaction(struct super_block *sb,
  				   b_blocknr_t blocknr, int already_cleaned)
  {
  	struct buffer_head *bh;
  	struct reiserfs_journal_cnode *cn;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	int ret = 0;
  
  	cn = get_journal_hash_dev(sb, journal->j_hash_table, blocknr);
  	if (!cn || !cn->bh) {
  		return ret;
  	}
  	bh = cn->bh;
  	if (cn->prev) {
  		cn->prev->next = cn->next;
  	}
  	if (cn->next) {
  		cn->next->prev = cn->prev;
  	}
  	if (cn == journal->j_first) {
  		journal->j_first = cn->next;
  	}
  	if (cn == journal->j_last) {
  		journal->j_last = cn->prev;
  	}
  	if (bh)
  		remove_journal_hash(sb, journal->j_hash_table, NULL,
  				    bh->b_blocknr, 0);
  	clear_buffer_journaled(bh);	/* don't log this one */
  
  	if (!already_cleaned) {
  		clear_buffer_journal_dirty(bh);
  		clear_buffer_dirty(bh);
  		clear_buffer_journal_test(bh);
  		put_bh(bh);
  		if (atomic_read(&bh->b_count) < 0) {
  			reiserfs_warning(sb, "journal-1752",
  					 "b_count < 0");
  		}
  		ret = 1;
  	}
  	journal->j_len--;
  	journal->j_len_alloc--;
  	free_cnode(sb, cn);
  	return ret;
  }
  
  /*
   * for any cnode in a journal list, it can only be dirtied of all the
   * transactions that include it are committed to disk.
   * this checks through each transaction, and returns 1 if you are allowed
   * to dirty, and 0 if you aren't
   *
   * it is called by dirty_journal_list, which is called after
   * flush_commit_list has gotten all the log blocks for a given
   * transaction on disk
   *
   */
  static int can_dirty(struct reiserfs_journal_cnode *cn)
  {
  	struct super_block *sb = cn->sb;
  	b_blocknr_t blocknr = cn->blocknr;
  	struct reiserfs_journal_cnode *cur = cn->hprev;
  	int can_dirty = 1;
  
  	/*
  	 * first test hprev.  These are all newer than cn, so any node here
  	 * with the same block number and dev means this node can't be sent
  	 * to disk right now.
  	 */
  	while (cur && can_dirty) {
  		if (cur->jlist && cur->bh && cur->blocknr && cur->sb == sb &&
  		    cur->blocknr == blocknr) {
  			can_dirty = 0;
  		}
  		cur = cur->hprev;
  	}
  	/*
  	 * then test hnext.  These are all older than cn.  As long as they
  	 * are committed to the log, it is safe to write cn to disk
  	 */
  	cur = cn->hnext;
  	while (cur && can_dirty) {
  		if (cur->jlist && cur->jlist->j_len > 0 &&
  		    atomic_read(&cur->jlist->j_commit_left) > 0 && cur->bh &&
  		    cur->blocknr && cur->sb == sb && cur->blocknr == blocknr) {
  			can_dirty = 0;
  		}
  		cur = cur->hnext;
  	}
  	return can_dirty;
  }
  
  /*
   * syncs the commit blocks, but does not force the real buffers to disk
   * will wait until the current transaction is done/committed before returning
   */
  int journal_end_sync(struct reiserfs_transaction_handle *th)
  {
  	struct super_block *sb = th->t_super;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  
  	BUG_ON(!th->t_trans_id);
  	/* you can sync while nested, very, very bad */
  	BUG_ON(th->t_refcount > 1);
  	if (journal->j_len == 0) {
  		reiserfs_prepare_for_journal(sb, SB_BUFFER_WITH_SB(sb),
  					     1);
  		journal_mark_dirty(th, SB_BUFFER_WITH_SB(sb));
  	}
  	return do_journal_end(th, COMMIT_NOW | WAIT);
  }
  
  /* writeback the pending async commits to disk */
  static void flush_async_commits(struct work_struct *work)
  {
  	struct reiserfs_journal *journal =
  		container_of(work, struct reiserfs_journal, j_work.work);
  	struct super_block *sb = journal->j_work_sb;
  	struct reiserfs_journal_list *jl;
  	struct list_head *entry;
  
  	reiserfs_write_lock(sb);
  	if (!list_empty(&journal->j_journal_list)) {
  		/* last entry is the youngest, commit it and you get everything */
  		entry = journal->j_journal_list.prev;
  		jl = JOURNAL_LIST_ENTRY(entry);
  		flush_commit_list(sb, jl, 1);
  	}
  	reiserfs_write_unlock(sb);
  }
  
  /*
   * flushes any old transactions to disk
   * ends the current transaction if it is too old
   */
  void reiserfs_flush_old_commits(struct super_block *sb)
  {
  	time_t now;
  	struct reiserfs_transaction_handle th;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  
  	now = get_seconds();
  	/*
  	 * safety check so we don't flush while we are replaying the log during
  	 * mount
  	 */
  	if (list_empty(&journal->j_journal_list))
  		return;
  
  	/*
  	 * check the current transaction.  If there are no writers, and it is
  	 * too old, finish it, and force the commit blocks to disk
  	 */
  	if (atomic_read(&journal->j_wcount) <= 0 &&
  	    journal->j_trans_start_time > 0 &&
  	    journal->j_len > 0 &&
  	    (now - journal->j_trans_start_time) > journal->j_max_trans_age) {
  		if (!journal_join(&th, sb)) {
  			reiserfs_prepare_for_journal(sb,
  						     SB_BUFFER_WITH_SB(sb),
  						     1);
  			journal_mark_dirty(&th, SB_BUFFER_WITH_SB(sb));
  
  			/*
  			 * we're only being called from kreiserfsd, it makes
  			 * no sense to do an async commit so that kreiserfsd
  			 * can do it later
  			 */
  			do_journal_end(&th, COMMIT_NOW | WAIT);
  		}
  	}
  }
  
  /*
   * returns 0 if do_journal_end should return right away, returns 1 if
   * do_journal_end should finish the commit
   *
   * if the current transaction is too old, but still has writers, this will
   * wait on j_join_wait until all the writers are done.  By the time it
   * wakes up, the transaction it was called has already ended, so it just
   * flushes the commit list and returns 0.
   *
   * Won't batch when flush or commit_now is set.  Also won't batch when
   * others are waiting on j_join_wait.
   *
   * Note, we can't allow the journal_end to proceed while there are still
   * writers in the log.
   */
  static int check_journal_end(struct reiserfs_transaction_handle *th, int flags)
  {
  
  	time_t now;
  	int flush = flags & FLUSH_ALL;
  	int commit_now = flags & COMMIT_NOW;
  	int wait_on_commit = flags & WAIT;
  	struct reiserfs_journal_list *jl;
  	struct super_block *sb = th->t_super;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  
  	BUG_ON(!th->t_trans_id);
  
  	if (th->t_trans_id != journal->j_trans_id) {
  		reiserfs_panic(th->t_super, "journal-1577",
  			       "handle trans id %ld != current trans id %ld",
  			       th->t_trans_id, journal->j_trans_id);
  	}
  
  	journal->j_len_alloc -= (th->t_blocks_allocated - th->t_blocks_logged);
  	/* <= 0 is allowed.  unmounting might not call begin */
  	if (atomic_read(&journal->j_wcount) > 0)
  		atomic_dec(&journal->j_wcount);
  
  	/*
  	 * BUG, deal with case where j_len is 0, but people previously
  	 * freed blocks need to be released will be dealt with by next
  	 * transaction that actually writes something, but should be taken
  	 * care of in this trans
  	 */
  	BUG_ON(journal->j_len == 0);
  
  	/*
  	 * if wcount > 0, and we are called to with flush or commit_now,
  	 * we wait on j_join_wait.  We will wake up when the last writer has
  	 * finished the transaction, and started it on its way to the disk.
  	 * Then, we flush the commit or journal list, and just return 0
  	 * because the rest of journal end was already done for this
  	 * transaction.
  	 */
  	if (atomic_read(&journal->j_wcount) > 0) {
  		if (flush || commit_now) {
  			unsigned trans_id;
  
  			jl = journal->j_current_jl;
  			trans_id = jl->j_trans_id;
  			if (wait_on_commit)
  				jl->j_state |= LIST_COMMIT_PENDING;
  			atomic_set(&journal->j_jlock, 1);
  			if (flush) {
  				journal->j_next_full_flush = 1;
  			}
  			unlock_journal(sb);
  
  			/*
  			 * sleep while the current transaction is
  			 * still j_jlocked
  			 */
  			while (journal->j_trans_id == trans_id) {
  				if (atomic_read(&journal->j_jlock)) {
  					queue_log_writer(sb);
  				} else {
  					lock_journal(sb);
  					if (journal->j_trans_id == trans_id) {
  						atomic_set(&journal->j_jlock,
  							   1);
  					}
  					unlock_journal(sb);
  				}
  			}
  			BUG_ON(journal->j_trans_id == trans_id);
  
  			if (commit_now
  			    && journal_list_still_alive(sb, trans_id)
  			    && wait_on_commit) {
  				flush_commit_list(sb, jl, 1);
  			}
  			return 0;
  		}
  		unlock_journal(sb);
  		return 0;
  	}
  
  	/* deal with old transactions where we are the last writers */
  	now = get_seconds();
  	if ((now - journal->j_trans_start_time) > journal->j_max_trans_age) {
  		commit_now = 1;
  		journal->j_next_async_flush = 1;
  	}
  	/* don't batch when someone is waiting on j_join_wait */
  	/* don't batch when syncing the commit or flushing the whole trans */
  	if (!(journal->j_must_wait > 0) && !(atomic_read(&journal->j_jlock))
  	    && !flush && !commit_now && (journal->j_len < journal->j_max_batch)
  	    && journal->j_len_alloc < journal->j_max_batch
  	    && journal->j_cnode_free > (journal->j_trans_max * 3)) {
  		journal->j_bcount++;
  		unlock_journal(sb);
  		return 0;
  	}
  
  	if (journal->j_start > SB_ONDISK_JOURNAL_SIZE(sb)) {
  		reiserfs_panic(sb, "journal-003",
  			       "j_start (%ld) is too high",
  			       journal->j_start);
  	}
  	return 1;
  }
  
  /*
   * Does all the work that makes deleting blocks safe.
   * when deleting a block mark BH_JNew, just remove it from the current
   * transaction, clean it's buffer_head and move on.
   *
   * otherwise:
   * set a bit for the block in the journal bitmap.  That will prevent it from
   * being allocated for unformatted nodes before this transaction has finished.
   *
   * mark any cnodes for this block as BLOCK_FREED, and clear their bh pointers.
   * That will prevent any old transactions with this block from trying to flush
   * to the real location.  Since we aren't removing the cnode from the
   * journal_list_hash, *the block can't be reallocated yet.
   *
   * Then remove it from the current transaction, decrementing any counters and
   * filing it on the clean list.
   */
  int journal_mark_freed(struct reiserfs_transaction_handle *th,
  		       struct super_block *sb, b_blocknr_t blocknr)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_cnode *cn = NULL;
  	struct buffer_head *bh = NULL;
  	struct reiserfs_list_bitmap *jb = NULL;
  	int cleaned = 0;
  	BUG_ON(!th->t_trans_id);
  
  	cn = get_journal_hash_dev(sb, journal->j_hash_table, blocknr);
  	if (cn && cn->bh) {
  		bh = cn->bh;
  		get_bh(bh);
  	}
  	/* if it is journal new, we just remove it from this transaction */
  	if (bh && buffer_journal_new(bh)) {
  		clear_buffer_journal_new(bh);
  		clear_prepared_bits(bh);
  		reiserfs_clean_and_file_buffer(bh);
  		cleaned = remove_from_transaction(sb, blocknr, cleaned);
  	} else {
  		/*
  		 * set the bit for this block in the journal bitmap
  		 * for this transaction
  		 */
  		jb = journal->j_current_jl->j_list_bitmap;
  		if (!jb) {
  			reiserfs_panic(sb, "journal-1702",
  				       "journal_list_bitmap is NULL");
  		}
  		set_bit_in_list_bitmap(sb, blocknr, jb);
  
  		/* Note, the entire while loop is not allowed to schedule.  */
  
  		if (bh) {
  			clear_prepared_bits(bh);
  			reiserfs_clean_and_file_buffer(bh);
  		}
  		cleaned = remove_from_transaction(sb, blocknr, cleaned);
  
  		/*
  		 * find all older transactions with this block,
  		 * make sure they don't try to write it out
  		 */
  		cn = get_journal_hash_dev(sb, journal->j_list_hash_table,
  					  blocknr);
  		while (cn) {
  			if (sb == cn->sb && blocknr == cn->blocknr) {
  				set_bit(BLOCK_FREED, &cn->state);
  				if (cn->bh) {
  					/*
  					 * remove_from_transaction will brelse
  					 * the buffer if it was in the current
  					 * trans
  					 */
  					if (!cleaned) {
  						clear_buffer_journal_dirty(cn->
  									   bh);
  						clear_buffer_dirty(cn->bh);
  						clear_buffer_journal_test(cn->
  									  bh);
  						cleaned = 1;
  						put_bh(cn->bh);
  						if (atomic_read
  						    (&cn->bh->b_count) < 0) {
  							reiserfs_warning(sb,
  								 "journal-2138",
  								 "cn->bh->b_count < 0");
  						}
  					}
  					/*
  					 * since we are clearing the bh,
  					 * we MUST dec nonzerolen
  					 */
  					if (cn->jlist) {
  						atomic_dec(&cn->jlist->
  							   j_nonzerolen);
  					}
  					cn->bh = NULL;
  				}
  			}
  			cn = cn->hnext;
  		}
  	}
  
  	if (bh)
  		release_buffer_page(bh); /* get_hash grabs the buffer */
  	return 0;
  }
  
  void reiserfs_update_inode_transaction(struct inode *inode)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(inode->i_sb);
  	REISERFS_I(inode)->i_jl = journal->j_current_jl;
  	REISERFS_I(inode)->i_trans_id = journal->j_trans_id;
  }
  
  /*
   * returns -1 on error, 0 if no commits/barriers were done and 1
   * if a transaction was actually committed and the barrier was done
   */
  static int __commit_trans_jl(struct inode *inode, unsigned long id,
  			     struct reiserfs_journal_list *jl)
  {
  	struct reiserfs_transaction_handle th;
  	struct super_block *sb = inode->i_sb;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	int ret = 0;
  
  	/*
  	 * is it from the current transaction,
  	 * or from an unknown transaction?
  	 */
  	if (id == journal->j_trans_id) {
  		jl = journal->j_current_jl;
  		/*
  		 * try to let other writers come in and
  		 * grow this transaction
  		 */
  		let_transaction_grow(sb, id);
  		if (journal->j_trans_id != id) {
  			goto flush_commit_only;
  		}
  
  		ret = journal_begin(&th, sb, 1);
  		if (ret)
  			return ret;
  
  		/* someone might have ended this transaction while we joined */
  		if (journal->j_trans_id != id) {
  			reiserfs_prepare_for_journal(sb, SB_BUFFER_WITH_SB(sb),
  						     1);
  			journal_mark_dirty(&th, SB_BUFFER_WITH_SB(sb));
  			ret = journal_end(&th);
  			goto flush_commit_only;
  		}
  
  		ret = journal_end_sync(&th);
  		if (!ret)
  			ret = 1;
  
  	} else {
  		/*
  		 * this gets tricky, we have to make sure the journal list in
  		 * the inode still exists.  We know the list is still around
  		 * if we've got a larger transaction id than the oldest list
  		 */
  flush_commit_only:
  		if (journal_list_still_alive(inode->i_sb, id)) {
  			/*
  			 * we only set ret to 1 when we know for sure
  			 * the barrier hasn't been started yet on the commit
  			 * block.
  			 */
  			if (atomic_read(&jl->j_commit_left) > 1)
  				ret = 1;
  			flush_commit_list(sb, jl, 1);
  			if (journal->j_errno)
  				ret = journal->j_errno;
  		}
  	}
  	/* otherwise the list is gone, and long since committed */
  	return ret;
  }
  
  int reiserfs_commit_for_inode(struct inode *inode)
  {
  	unsigned int id = REISERFS_I(inode)->i_trans_id;
  	struct reiserfs_journal_list *jl = REISERFS_I(inode)->i_jl;
  
  	/*
  	 * for the whole inode, assume unset id means it was
  	 * changed in the current transaction.  More conservative
  	 */
  	if (!id || !jl) {
  		reiserfs_update_inode_transaction(inode);
  		id = REISERFS_I(inode)->i_trans_id;
  		/* jl will be updated in __commit_trans_jl */
  	}
  
  	return __commit_trans_jl(inode, id, jl);
  }
  
  void reiserfs_restore_prepared_buffer(struct super_block *sb,
  				      struct buffer_head *bh)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	PROC_INFO_INC(sb, journal.restore_prepared);
  	if (!bh) {
  		return;
  	}
  	if (test_clear_buffer_journal_restore_dirty(bh) &&
  	    buffer_journal_dirty(bh)) {
  		struct reiserfs_journal_cnode *cn;
  		reiserfs_write_lock(sb);
  		cn = get_journal_hash_dev(sb,
  					  journal->j_list_hash_table,
  					  bh->b_blocknr);
  		if (cn && can_dirty(cn)) {
  			set_buffer_journal_test(bh);
  			mark_buffer_dirty(bh);
  		}
  		reiserfs_write_unlock(sb);
  	}
  	clear_buffer_journal_prepared(bh);
  }
  
  extern struct tree_balance *cur_tb;
  /*
   * before we can change a metadata block, we have to make sure it won't
   * be written to disk while we are altering it.  So, we must:
   * clean it
   * wait on it.
   */
  int reiserfs_prepare_for_journal(struct super_block *sb,
  				 struct buffer_head *bh, int wait)
  {
  	PROC_INFO_INC(sb, journal.prepare);
  
  	if (!trylock_buffer(bh)) {
  		if (!wait)
  			return 0;
  		lock_buffer(bh);
  	}
  	set_buffer_journal_prepared(bh);
  	if (test_clear_buffer_dirty(bh) && buffer_journal_dirty(bh)) {
  		clear_buffer_journal_test(bh);
  		set_buffer_journal_restore_dirty(bh);
  	}
  	unlock_buffer(bh);
  	return 1;
  }
  
  /*
   * long and ugly.  If flush, will not return until all commit
   * blocks and all real buffers in the trans are on disk.
   * If no_async, won't return until all commit blocks are on disk.
   *
   * keep reading, there are comments as you go along
   *
   * If the journal is aborted, we just clean up. Things like flushing
   * journal lists, etc just won't happen.
   */
  static int do_journal_end(struct reiserfs_transaction_handle *th, int flags)
  {
  	struct super_block *sb = th->t_super;
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	struct reiserfs_journal_cnode *cn, *next, *jl_cn;
  	struct reiserfs_journal_cnode *last_cn = NULL;
  	struct reiserfs_journal_desc *desc;
  	struct reiserfs_journal_commit *commit;
  	struct buffer_head *c_bh;	/* commit bh */
  	struct buffer_head *d_bh;	/* desc bh */
  	int cur_write_start = 0;	/* start index of current log write */
  	int old_start;
  	int i;
  	int flush;
  	int wait_on_commit;
  	struct reiserfs_journal_list *jl, *temp_jl;
  	struct list_head *entry, *safe;
  	unsigned long jindex;
  	unsigned int commit_trans_id;
  	int trans_half;
  	int depth;
  
  	BUG_ON(th->t_refcount > 1);
  	BUG_ON(!th->t_trans_id);
  	BUG_ON(!th->t_super);
  
  	/*
  	 * protect flush_older_commits from doing mistakes if the
  	 * transaction ID counter gets overflowed.
  	 */
  	if (th->t_trans_id == ~0U)
  		flags |= FLUSH_ALL | COMMIT_NOW | WAIT;
  	flush = flags & FLUSH_ALL;
  	wait_on_commit = flags & WAIT;
  
  	current->journal_info = th->t_handle_save;
  	reiserfs_check_lock_depth(sb, "journal end");
  	if (journal->j_len == 0) {
  		reiserfs_prepare_for_journal(sb, SB_BUFFER_WITH_SB(sb),
  					     1);
  		journal_mark_dirty(th, SB_BUFFER_WITH_SB(sb));
  	}
  
  	lock_journal(sb);
  	if (journal->j_next_full_flush) {
  		flags |= FLUSH_ALL;
  		flush = 1;
  	}
  	if (journal->j_next_async_flush) {
  		flags |= COMMIT_NOW | WAIT;
  		wait_on_commit = 1;
  	}
  
  	/*
  	 * check_journal_end locks the journal, and unlocks if it does
  	 * not return 1 it tells us if we should continue with the
  	 * journal_end, or just return
  	 */
  	if (!check_journal_end(th, flags)) {
  		reiserfs_schedule_old_flush(sb);
  		wake_queued_writers(sb);
  		reiserfs_async_progress_wait(sb);
  		goto out;
  	}
  
  	/* check_journal_end might set these, check again */
  	if (journal->j_next_full_flush) {
  		flush = 1;
  	}
  
  	/*
  	 * j must wait means we have to flush the log blocks, and the
  	 * real blocks for this transaction
  	 */
  	if (journal->j_must_wait > 0) {
  		flush = 1;
  	}
  #ifdef REISERFS_PREALLOCATE
  	/*
  	 * quota ops might need to nest, setup the journal_info pointer
  	 * for them and raise the refcount so that it is > 0.
  	 */
  	current->journal_info = th;
  	th->t_refcount++;
  
  	/* it should not involve new blocks into the transaction */
  	reiserfs_discard_all_prealloc(th);
  
  	th->t_refcount--;
  	current->journal_info = th->t_handle_save;
  #endif
  
  	/* setup description block */
  	d_bh =
  	    journal_getblk(sb,
  			   SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  			   journal->j_start);
  	set_buffer_uptodate(d_bh);
  	desc = (struct reiserfs_journal_desc *)(d_bh)->b_data;
  	memset(d_bh->b_data, 0, d_bh->b_size);
  	memcpy(get_journal_desc_magic(d_bh), JOURNAL_DESC_MAGIC, 8);
  	set_desc_trans_id(desc, journal->j_trans_id);
  
  	/*
  	 * setup commit block.  Don't write (keep it clean too) this one
  	 * until after everyone else is written
  	 */
  	c_bh = journal_getblk(sb, SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  			      ((journal->j_start + journal->j_len +
  				1) % SB_ONDISK_JOURNAL_SIZE(sb)));
  	commit = (struct reiserfs_journal_commit *)c_bh->b_data;
  	memset(c_bh->b_data, 0, c_bh->b_size);
  	set_commit_trans_id(commit, journal->j_trans_id);
  	set_buffer_uptodate(c_bh);
  
  	/* init this journal list */
  	jl = journal->j_current_jl;
  
  	/*
  	 * we lock the commit before doing anything because
  	 * we want to make sure nobody tries to run flush_commit_list until
  	 * the new transaction is fully setup, and we've already flushed the
  	 * ordered bh list
  	 */
  	reiserfs_mutex_lock_safe(&jl->j_commit_mutex, sb);
  
  	/* save the transaction id in case we need to commit it later */
  	commit_trans_id = jl->j_trans_id;
  
  	atomic_set(&jl->j_older_commits_done, 0);
  	jl->j_trans_id = journal->j_trans_id;
  	jl->j_timestamp = journal->j_trans_start_time;
  	jl->j_commit_bh = c_bh;
  	jl->j_start = journal->j_start;
  	jl->j_len = journal->j_len;
  	atomic_set(&jl->j_nonzerolen, journal->j_len);
  	atomic_set(&jl->j_commit_left, journal->j_len + 2);
  	jl->j_realblock = NULL;
  
  	/*
  	 * The ENTIRE FOR LOOP MUST not cause schedule to occur.
  	 * for each real block, add it to the journal list hash,
  	 * copy into real block index array in the commit or desc block
  	 */
  	trans_half = journal_trans_half(sb->s_blocksize);
  	for (i = 0, cn = journal->j_first; cn; cn = cn->next, i++) {
  		if (buffer_journaled(cn->bh)) {
  			jl_cn = get_cnode(sb);
  			if (!jl_cn) {
  				reiserfs_panic(sb, "journal-1676",
  					       "get_cnode returned NULL");
  			}
  			if (i == 0) {
  				jl->j_realblock = jl_cn;
  			}
  			jl_cn->prev = last_cn;
  			jl_cn->next = NULL;
  			if (last_cn) {
  				last_cn->next = jl_cn;
  			}
  			last_cn = jl_cn;
  			/*
  			 * make sure the block we are trying to log
  			 * is not a block of journal or reserved area
  			 */
  			if (is_block_in_log_or_reserved_area
  			    (sb, cn->bh->b_blocknr)) {
  				reiserfs_panic(sb, "journal-2332",
  					       "Trying to log block %lu, "
  					       "which is a log block",
  					       cn->bh->b_blocknr);
  			}
  			jl_cn->blocknr = cn->bh->b_blocknr;
  			jl_cn->state = 0;
  			jl_cn->sb = sb;
  			jl_cn->bh = cn->bh;
  			jl_cn->jlist = jl;
  			insert_journal_hash(journal->j_list_hash_table, jl_cn);
  			if (i < trans_half) {
  				desc->j_realblock[i] =
  				    cpu_to_le32(cn->bh->b_blocknr);
  			} else {
  				commit->j_realblock[i - trans_half] =
  				    cpu_to_le32(cn->bh->b_blocknr);
  			}
  		} else {
  			i--;
  		}
  	}
  	set_desc_trans_len(desc, journal->j_len);
  	set_desc_mount_id(desc, journal->j_mount_id);
  	set_desc_trans_id(desc, journal->j_trans_id);
  	set_commit_trans_len(commit, journal->j_len);
  
  	/*
  	 * special check in case all buffers in the journal
  	 * were marked for not logging
  	 */
  	BUG_ON(journal->j_len == 0);
  
  	/*
  	 * we're about to dirty all the log blocks, mark the description block
  	 * dirty now too.  Don't mark the commit block dirty until all the
  	 * others are on disk
  	 */
  	mark_buffer_dirty(d_bh);
  
  	/*
  	 * first data block is j_start + 1, so add one to
  	 * cur_write_start wherever you use it
  	 */
  	cur_write_start = journal->j_start;
  	cn = journal->j_first;
  	jindex = 1;	/* start at one so we don't get the desc again */
  	while (cn) {
  		clear_buffer_journal_new(cn->bh);
  		/* copy all the real blocks into log area.  dirty log blocks */
  		if (buffer_journaled(cn->bh)) {
  			struct buffer_head *tmp_bh;
  			char *addr;
  			struct page *page;
  			tmp_bh =
  			    journal_getblk(sb,
  					   SB_ONDISK_JOURNAL_1st_BLOCK(sb) +
  					   ((cur_write_start +
  					     jindex) %
  					    SB_ONDISK_JOURNAL_SIZE(sb)));
  			set_buffer_uptodate(tmp_bh);
  			page = cn->bh->b_page;
  			addr = kmap(page);
  			memcpy(tmp_bh->b_data,
  			       addr + offset_in_page(cn->bh->b_data),
  			       cn->bh->b_size);
  			kunmap(page);
  			mark_buffer_dirty(tmp_bh);
  			jindex++;
  			set_buffer_journal_dirty(cn->bh);
  			clear_buffer_journaled(cn->bh);
  		} else {
  			/*
  			 * JDirty cleared sometime during transaction.
  			 * don't log this one
  			 */
  			reiserfs_warning(sb, "journal-2048",
  					 "BAD, buffer in journal hash, "
  					 "but not JDirty!");
  			brelse(cn->bh);
  		}
  		next = cn->next;
  		free_cnode(sb, cn);
  		cn = next;
  		reiserfs_cond_resched(sb);
  	}
  
  	/*
  	 * we are done with both the c_bh and d_bh, but
  	 * c_bh must be written after all other commit blocks,
  	 * so we dirty/relse c_bh in flush_commit_list, with commit_left <= 1.
  	 */
  
  	journal->j_current_jl = alloc_journal_list(sb);
  
  	/* now it is safe to insert this transaction on the main list */
  	list_add_tail(&jl->j_list, &journal->j_journal_list);
  	list_add_tail(&jl->j_working_list, &journal->j_working_list);
  	journal->j_num_work_lists++;
  
  	/* reset journal values for the next transaction */
  	old_start = journal->j_start;
  	journal->j_start =
  	    (journal->j_start + journal->j_len +
  	     2) % SB_ONDISK_JOURNAL_SIZE(sb);
  	atomic_set(&journal->j_wcount, 0);
  	journal->j_bcount = 0;
  	journal->j_last = NULL;
  	journal->j_first = NULL;
  	journal->j_len = 0;
  	journal->j_trans_start_time = 0;
  	/* check for trans_id overflow */
  	if (++journal->j_trans_id == 0)
  		journal->j_trans_id = 10;
  	journal->j_current_jl->j_trans_id = journal->j_trans_id;
  	journal->j_must_wait = 0;
  	journal->j_len_alloc = 0;
  	journal->j_next_full_flush = 0;
  	journal->j_next_async_flush = 0;
  	init_journal_hash(sb);
  
  	/*
  	 * make sure reiserfs_add_jh sees the new current_jl before we
  	 * write out the tails
  	 */
  	smp_mb();
  
  	/*
  	 * tail conversion targets have to hit the disk before we end the
  	 * transaction.  Otherwise a later transaction might repack the tail
  	 * before this transaction commits, leaving the data block unflushed
  	 * and clean, if we crash before the later transaction commits, the
  	 * data block is lost.
  	 */
  	if (!list_empty(&jl->j_tail_bh_list)) {
  		depth = reiserfs_write_unlock_nested(sb);
  		write_ordered_buffers(&journal->j_dirty_buffers_lock,
  				      journal, jl, &jl->j_tail_bh_list);
  		reiserfs_write_lock_nested(sb, depth);
  	}
  	BUG_ON(!list_empty(&jl->j_tail_bh_list));
  	mutex_unlock(&jl->j_commit_mutex);
  
  	/*
  	 * honor the flush wishes from the caller, simple commits can
  	 * be done outside the journal lock, they are done below
  	 *
  	 * if we don't flush the commit list right now, we put it into
  	 * the work queue so the people waiting on the async progress work
  	 * queue don't wait for this proc to flush journal lists and such.
  	 */
  	if (flush) {
  		flush_commit_list(sb, jl, 1);
  		flush_journal_list(sb, jl, 1);
  	} else if (!(jl->j_state & LIST_COMMIT_PENDING)) {
  		/*
  		 * Avoid queueing work when sb is being shut down. Transaction
  		 * will be flushed on journal shutdown.
  		 */
  		if (sb->s_flags & MS_ACTIVE)
  			queue_delayed_work(REISERFS_SB(sb)->commit_wq,
  					   &journal->j_work, HZ / 10);
  	}
  
  	/*
  	 * if the next transaction has any chance of wrapping, flush
  	 * transactions that might get overwritten.  If any journal lists
  	 * are very old flush them as well.
  	 */
  first_jl:
  	list_for_each_safe(entry, safe, &journal->j_journal_list) {
  		temp_jl = JOURNAL_LIST_ENTRY(entry);
  		if (journal->j_start <= temp_jl->j_start) {
  			if ((journal->j_start + journal->j_trans_max + 1) >=
  			    temp_jl->j_start) {
  				flush_used_journal_lists(sb, temp_jl);
  				goto first_jl;
  			} else if ((journal->j_start +
  				    journal->j_trans_max + 1) <
  				   SB_ONDISK_JOURNAL_SIZE(sb)) {
  				/*
  				 * if we don't cross into the next
  				 * transaction and we don't wrap, there is
  				 * no way we can overlap any later transactions
  				 * break now
  				 */
  				break;
  			}
  		} else if ((journal->j_start +
  			    journal->j_trans_max + 1) >
  			   SB_ONDISK_JOURNAL_SIZE(sb)) {
  			if (((journal->j_start + journal->j_trans_max + 1) %
  			     SB_ONDISK_JOURNAL_SIZE(sb)) >=
  			    temp_jl->j_start) {
  				flush_used_journal_lists(sb, temp_jl);
  				goto first_jl;
  			} else {
  				/*
  				* we don't overlap anything from out start
  				* to the end of the log, and our wrapped
  				* portion doesn't overlap anything at
  				* the start of the log.  We can break
  				*/
  				break;
  			}
  		}
  	}
  
  	journal->j_current_jl->j_list_bitmap =
  	    get_list_bitmap(sb, journal->j_current_jl);
  
  	if (!(journal->j_current_jl->j_list_bitmap)) {
  		reiserfs_panic(sb, "journal-1996",
  			       "could not get a list bitmap");
  	}
  
  	atomic_set(&journal->j_jlock, 0);
  	unlock_journal(sb);
  	/* wake up any body waiting to join. */
  	clear_bit(J_WRITERS_QUEUED, &journal->j_state);
  	wake_up(&journal->j_join_wait);
  
  	if (!flush && wait_on_commit &&
  	    journal_list_still_alive(sb, commit_trans_id)) {
  		flush_commit_list(sb, jl, 1);
  	}
  out:
  	reiserfs_check_lock_depth(sb, "journal end2");
  
  	memset(th, 0, sizeof(*th));
  	/*
  	 * Re-set th->t_super, so we can properly keep track of how many
  	 * persistent transactions there are. We need to do this so if this
  	 * call is part of a failed restart_transaction, we can free it later
  	 */
  	th->t_super = sb;
  
  	return journal->j_errno;
  }
  
  /* Send the file system read only and refuse new transactions */
  void reiserfs_abort_journal(struct super_block *sb, int errno)
  {
  	struct reiserfs_journal *journal = SB_JOURNAL(sb);
  	if (test_bit(J_ABORTED, &journal->j_state))
  		return;
  
  	if (!journal->j_errno)
  		journal->j_errno = errno;
  
  	sb->s_flags |= MS_RDONLY;
  	set_bit(J_ABORTED, &journal->j_state);
  
  #ifdef CONFIG_REISERFS_CHECK
  	dump_stack();
  #endif
  }
  