Index: linux-2.6.7/include/linux/jbd.h
===================================================================
--- linux-2.6.7.orig/include/linux/jbd.h	2004-08-26 17:12:16.000000000 +0400
+++ linux-2.6.7/include/linux/jbd.h	2005-01-19 17:08:33.144512008 +0300
@@ -826,6 +826,12 @@
 	struct jbd_revoke_table_s *j_revoke_table[2];
 
 	/*
+	 * array of bhs for journal_commit_transaction
+	 */
+	struct buffer_head	**j_wbuf;
+	int			j_wbufsize;
+
+	/*
 	 * An opaque pointer to fs-private information.  ext3 puts its
 	 * superblock pointer here
 	 */
Index: linux-2.6.7/include/linux/journal-head.h
===================================================================
--- linux-2.6.7.orig/include/linux/journal-head.h	2003-06-24 18:05:26.000000000 +0400
+++ linux-2.6.7/include/linux/journal-head.h	2005-01-19 14:09:59.000000000 +0300
@@ -80,6 +80,11 @@
 	 * [j_list_lock]
 	 */
 	struct journal_head *b_cpnext, *b_cpprev;
+
+	/*
+	 * counter to track users of the buffer in current transaction
+	 */
+	int b_tcount;
 };
 
 #endif		/* JOURNAL_HEAD_H_INCLUDED */
Index: linux-2.6.7/fs/jbd/commit.c
===================================================================
--- linux-2.6.7.orig/fs/jbd/commit.c	2004-08-26 17:12:40.000000000 +0400
+++ linux-2.6.7/fs/jbd/commit.c	2005-01-19 17:28:32.965111552 +0300
@@ -103,7 +103,7 @@
 {
 	transaction_t *commit_transaction;
 	struct journal_head *jh, *new_jh, *descriptor;
-	struct buffer_head *wbuf[64];
+	struct buffer_head **wbuf = journal->j_wbuf;
 	int bufs;
 	int flags;
 	int err;
@@ -271,7 +283,7 @@
 				BUFFER_TRACE(bh, "start journal writeout");
 				get_bh(bh);
 				wbuf[bufs++] = bh;
-				if (bufs == ARRAY_SIZE(wbuf)) {
+				if (bufs == journal->j_wbufsize) {
 					jbd_debug(2, "submit %d writes\n",
 							bufs);
 					spin_unlock(&journal->j_list_lock);
@@ -488,7 +500,7 @@
 		/* If there's no more to do, or if the descriptor is full,
 		   let the IO rip! */
 
-		if (bufs == ARRAY_SIZE(wbuf) ||
+		if (bufs == journal->j_wbufsize ||
 		    commit_transaction->t_buffers == NULL ||
 		    space_left < sizeof(journal_block_tag_t) + 16) {
 
Index: linux-2.6.7/fs/jbd/journal.c
===================================================================
--- linux-2.6.7.orig/fs/jbd/journal.c	2005-01-19 12:07:59.000000000 +0300
+++ linux-2.6.7/fs/jbd/journal.c	2005-01-19 17:11:08.589880720 +0300
@@ -687,6 +687,7 @@
 {
 	journal_t *journal = journal_init_common();
 	struct buffer_head *bh;
+	int n;
 
 	if (!journal)
 		return NULL;
@@ -702,6 +703,17 @@
 	journal->j_sb_buffer = bh;
 	journal->j_superblock = (journal_superblock_t *)bh->b_data;
 
+	/* journal descriptor can store upto n blocks -bzzz */
+	n = journal->j_blocksize / sizeof(journal_block_tag_t);
+	journal->j_wbufsize = n;
+	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
+	if (!journal->j_wbuf) {
+		printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
+			__FUNCTION__);
+		kfree(journal);
+		journal = NULL;
+	}
+	
 	return journal;
 }
  
@@ -717,7 +729,7 @@
 {
 	struct buffer_head *bh;
 	journal_t *journal = journal_init_common();
-	int err;
+	int err, n;
 	unsigned long blocknr;
 
 	if (!journal)
@@ -734,6 +746,17 @@
 	journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
 	journal->j_blocksize = inode->i_sb->s_blocksize;
 
+	/* journal descriptor can store upto n blocks -bzzz */
+	n = journal->j_blocksize / sizeof(journal_block_tag_t);
+	journal->j_wbufsize = n;
+	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
+	if (!journal->j_wbuf) {
+		printk(KERN_ERR "%s: Cant allocate bhs for commit thread\n",
+			__FUNCTION__);
+		kfree(journal);
+		return NULL;
+	}
+
 	err = journal_bmap(journal, 0, &blocknr);
 	/* If that failed, give up */
 	if (err) {
@@ -1107,6 +1130,10 @@
 		iput(journal->j_inode);
 	if (journal->j_revoke)
 		journal_destroy_revoke(journal);
+	if (journal->j_wbuf) {
+		kfree(journal->j_wbuf);
+		journal->j_wbuf = NULL;
+	}
 	kfree(journal);
 }
 
Index: linux-2.6.7/fs/jbd/transaction.c
===================================================================
--- linux-2.6.7.orig/fs/jbd/transaction.c	2004-08-26 17:12:40.000000000 +0400
+++ linux-2.6.7/fs/jbd/transaction.c	2005-01-19 17:23:30.058160408 +0300
@@ -611,6 +611,10 @@
 		handle->h_buffer_credits--;
 		if (credits)
 			(*credits)++;
+
+		/* the block's becoming member of the trasaction -bzzz */
+		jh->b_tcount = 0;
+
 		goto done;
 	}
 
@@ -694,6 +698,9 @@
 	if (credits)
 		(*credits)++;
 
+	/* the block's becoming member of the trasaction -bzzz */
+	jh->b_tcount = 0;
+
 	/*
 	 * Finally, if the buffer is not journaled right now, we need to make
 	 * sure it doesn't get written to disk before the caller actually
@@ -723,6 +730,11 @@
 		memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size);
 		kunmap_atomic(source, KM_USER0);
 	}
+
+	/* track all references to the block to be able to recognize the
+	 * situation when the buffer is not part of transaction -bzzz */
+	jh->b_tcount++;
+
 	jbd_unlock_bh_state(bh);
 
 	/*
@@ -822,11 +834,20 @@
 		jh->b_transaction = transaction;
 		JBUFFER_TRACE(jh, "file as BJ_Reserved");
 		__journal_file_buffer(jh, transaction, BJ_Reserved);
+		jh->b_tcount = 0;
 	} else if (jh->b_transaction == journal->j_committing_transaction) {
 		JBUFFER_TRACE(jh, "set next transaction");
 		jh->b_next_transaction = transaction;
+		jh->b_tcount = 0;
 	}
 	spin_unlock(&journal->j_list_lock);
+
+	/*
+	 * track all reference to the block to be able to recognize
+	 * the situation when the buffer is not part of transaction -bzzz
+	 */
+	jh->b_tcount++;
+
 	jbd_unlock_bh_state(bh);
 
 	/*
@@ -1178,8 +1199,40 @@
 void
 journal_release_buffer(handle_t *handle, struct buffer_head *bh, int credits)
 {
+	journal_t *journal = handle->h_transaction->t_journal;
+	struct journal_head *jh = bh2jh(bh);
+
 	BUFFER_TRACE(bh, "entry");
-	handle->h_buffer_credits += credits;
+
+	/* return credit back to the handle if it was really spent */
+	if (credits)
+		handle->h_buffer_credits++; 
+
+	jbd_lock_bh_state(bh);
+	J_ASSERT(jh->b_tcount > 0);
+
+	jh->b_tcount--;
+	if (jh->b_tcount == 0) {
+		/* we can drop it from the transaction -bzzz */
+		J_ASSERT(jh->b_transaction == handle->h_transaction ||
+				jh->b_next_transaction == handle->h_transaction);
+		if (jh->b_transaction == handle->h_transaction) {
+			spin_lock(&journal->j_list_lock);
+			__journal_unfile_buffer(jh);
+			spin_unlock(&journal->j_list_lock);
+		} else if(jh->b_next_transaction) {
+			jh->b_next_transaction = NULL;
+		}
+
+		/* 
+		 * this was last reference to the block from the current
+		 * transaction and we'd like to return credit to the
+		 * whole transaction -bzzz
+		 */
+		if (!credits)
+			handle->h_buffer_credits++; 
+	}
+	jbd_unlock_bh_state(bh);
 }
 
 /** 
@@ -1204,6 +1257,7 @@
 	transaction_t *transaction = handle->h_transaction;
 	journal_t *journal = transaction->t_journal;
 	struct journal_head *jh;
+	int drop_reserve = 0;
 
 	BUFFER_TRACE(bh, "entry");
 
@@ -1227,6 +1281,7 @@
 		J_ASSERT_JH(jh, !jh->b_committed_data);
 
 		__journal_unfile_buffer(jh);
+		drop_reserve = 1;
 
 		/* 
 		 * We are no longer going to journal this buffer.
@@ -1249,7 +1304,7 @@
 				spin_unlock(&journal->j_list_lock);
 				jbd_unlock_bh_state(bh);
 				__bforget(bh);
-				return;
+				goto drop;
 			}
 		}
 	} else if (jh->b_transaction) {
@@ -1264,6 +1319,7 @@
 		if (jh->b_next_transaction) {
 			J_ASSERT(jh->b_next_transaction == transaction);
 			jh->b_next_transaction = NULL;
+			drop_reserve = 1;
 		}
 	}
 
@@ -1271,6 +1327,15 @@
 	spin_unlock(&journal->j_list_lock);
 	jbd_unlock_bh_state(bh);
 	__brelse(bh);
+
+drop:
+	if (drop_reserve) {
+		/* no need to reserve log space for this block -bzzz */
+		spin_lock(&transaction->t_handle_lock);
+		transaction->t_outstanding_credits--;
+		spin_unlock(&transaction->t_handle_lock);
+	}
+
 	return;
 }