BACKPORT: ext4 from 3.18 to mtk-3.10

7 files changed, 844 insertions, 825 deletions

diff --git a/fs/jbd2/Kconfig b/fs/jbd2/Kconfig
index 69a48c294..5a9f5534d 100644
--- a/fs/jbd2/Kconfig
+++ b/fs/jbd2/Kconfig
@@ -20,7 +20,7 @@ config JBD2
 
 config JBD2_DEBUG
 	bool "JBD2 (ext4) debugging support"
-	depends on JBD2 && DEBUG_FS
+	depends on JBD2
 	help
 	  If you are using the ext4 journaled file system (or
 	  potentially any other filesystem/device using JBD2), this option
@@ -29,7 +29,7 @@ config JBD2_DEBUG
 	  By default, the debugging output will be turned off.
 
 	  If you select Y here, then you will be able to turn on debugging
-	  with "echo N > /sys/kernel/debug/jbd2/jbd2-debug", where N is a
+	  with "echo N > /sys/module/jbd2/parameters/jbd2_debug", where N is a
 	  number between 1 and 5. The higher the number, the more debugging
 	  output is generated.  To turn debugging off again, do
-	  "echo 0 > /sys/kernel/debug/jbd2/jbd2-debug".
+	  "echo 0 > /sys/module/jbd2/parameters/jbd2_debug".
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index 6bb52859c..988b32ed4 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -96,15 +96,8 @@ static int __try_to_free_cp_buf(struct journal_head *jh)
 
 	if (jh->b_transaction == NULL && !buffer_locked(bh) &&
 	    !buffer_dirty(bh) && !buffer_write_io_error(bh)) {
-		/*
-		 * Get our reference so that bh cannot be freed before
-		 * we unlock it
-		 */
-		get_bh(bh);
 		JBUFFER_TRACE(jh, "remove from checkpoint list");
 		ret = __jbd2_journal_remove_checkpoint(jh) + 1;
-		BUFFER_TRACE(bh, "release");
-		__brelse(bh);
 	}
 	return ret;
 }
@@ -120,10 +113,8 @@ void __jbd2_log_wait_for_space(journal_t *journal)
 	int nblocks, space_left;
 	/* assert_spin_locked(&journal->j_state_lock); */
 
-	nblocks = jbd_space_needed(journal);
-	while (__jbd2_log_space_left(journal) < nblocks) {
-		if (journal->j_flags & JBD2_ABORT)
-			return;
+	nblocks = jbd2_space_needed(journal);
+	while (jbd2_log_space_left(journal) < nblocks) {
 		write_unlock(&journal->j_state_lock);
 		mutex_lock(&journal->j_checkpoint_mutex);
 
@@ -139,9 +130,13 @@ void __jbd2_log_wait_for_space(journal_t *journal)
 		 * trace for forensic evidence.
 		 */
 		write_lock(&journal->j_state_lock);
+		if (journal->j_flags & JBD2_ABORT) {
+			mutex_unlock(&journal->j_checkpoint_mutex);
+			return;
+		}
 		spin_lock(&journal->j_list_lock);
-		nblocks = jbd_space_needed(journal);
-		space_left = __jbd2_log_space_left(journal);
+		nblocks = jbd2_space_needed(journal);
+		space_left = jbd2_log_space_left(journal);
 		if (space_left < nblocks) {
 			int chkpt = journal->j_checkpoint_transactions != NULL;
 			tid_t tid = 0;
@@ -156,7 +151,15 @@ void __jbd2_log_wait_for_space(journal_t *journal)
 				/* We were able to recover space; yay! */
 				;
 			} else if (tid) {
+				/*
+				 * jbd2_journal_commit_transaction() may want
+				 * to take the checkpoint_mutex if JBD2_FLUSHED
+				 * is set.  So we need to temporarily drop it.
+				 */
+				mutex_unlock(&journal->j_checkpoint_mutex);
 				jbd2_log_wait_commit(journal, tid);
+				write_lock(&journal->j_state_lock);
+				continue;
 			} else {
 				printk(KERN_ERR "%s: needed %d blocks and "
 				       "only had %d space available\n",
@@ -175,58 +178,6 @@ void __jbd2_log_wait_for_space(journal_t *journal)
 	}
 }
 
-/*
- * Clean up transaction's list of buffers submitted for io.
- * We wait for any pending IO to complete and remove any clean
- * buffers. Note that we take the buffers in the opposite ordering
- * from the one in which they were submitted for IO.
- *
- * Return 0 on success, and return <0 if some buffers have failed
- * to be written out.
- *
- * Called with j_list_lock held.
- */
-static int __wait_cp_io(journal_t *journal, transaction_t *transaction)
-{
-	struct journal_head *jh;
-	struct buffer_head *bh;
-	tid_t this_tid;
-	int released = 0;
-	int ret = 0;
-
-	this_tid = transaction->t_tid;
-restart:
-	/* Did somebody clean up the transaction in the meanwhile? */
-	if (journal->j_checkpoint_transactions != transaction ||
-			transaction->t_tid != this_tid)
-		return ret;
-	while (!released && transaction->t_checkpoint_io_list) {
-		jh = transaction->t_checkpoint_io_list;
-		bh = jh2bh(jh);
-		get_bh(bh);
-		if (buffer_locked(bh)) {
-			spin_unlock(&journal->j_list_lock);
-			wait_on_buffer(bh);
-			/* the journal_head may have gone by now */
-			BUFFER_TRACE(bh, "brelse");
-			__brelse(bh);
-			spin_lock(&journal->j_list_lock);
-			goto restart;
-		}
-		if (unlikely(buffer_write_io_error(bh)))
-			ret = -EIO;
-
-		/*
-		 * Now in whatever state the buffer currently is, we know that
-		 * it has been written out and so we can drop it from the list
-		 */
-		released = __jbd2_journal_remove_checkpoint(jh);
-		__brelse(bh);
-	}
-
-	return ret;
-}
-
 static void
 __flush_batch(journal_t *journal, int *batch_count)
 {
@@ -247,81 +198,6 @@ __flush_batch(journal_t *journal, int *batch_count)
 }
 
 /*
- * Try to flush one buffer from the checkpoint list to disk.
- *
- * Return 1 if something happened which requires us to abort the current
- * scan of the checkpoint list.  Return <0 if the buffer has failed to
- * be written out.
- *
- * Called with j_list_lock held and drops it if 1 is returned
- */
-static int __process_buffer(journal_t *journal, struct journal_head *jh,
-			    int *batch_count, transaction_t *transaction)
-{
-	struct buffer_head *bh = jh2bh(jh);
-	int ret = 0;
-
-	if (buffer_locked(bh)) {
-		get_bh(bh);
-		spin_unlock(&journal->j_list_lock);
-		wait_on_buffer(bh);
-		/* the journal_head may have gone by now */
-		BUFFER_TRACE(bh, "brelse");
-		__brelse(bh);
-		ret = 1;
-	} else if (jh->b_transaction != NULL) {
-		transaction_t *t = jh->b_transaction;
-		tid_t tid = t->t_tid;
-
-		transaction->t_chp_stats.cs_forced_to_close++;
-		spin_unlock(&journal->j_list_lock);
-		if (unlikely(journal->j_flags & JBD2_UNMOUNT))
-			/*
-			 * The journal thread is dead; so starting and
-			 * waiting for a commit to finish will cause
-			 * us to wait for a _very_ long time.
-			 */
-			printk(KERN_ERR "JBD2: %s: "
-			       "Waiting for Godot: block %llu\n",
-			       journal->j_devname,
-			       (unsigned long long) bh->b_blocknr);
-		jbd2_log_start_commit(journal, tid);
-		jbd2_log_wait_commit(journal, tid);
-		ret = 1;
-	} else if (!buffer_dirty(bh)) {
-		ret = 1;
-		if (unlikely(buffer_write_io_error(bh)))
-			ret = -EIO;
-		get_bh(bh);
-		BUFFER_TRACE(bh, "remove from checkpoint");
-		__jbd2_journal_remove_checkpoint(jh);
-		spin_unlock(&journal->j_list_lock);
-		__brelse(bh);
-	} else {
-		/*
-		 * Important: we are about to write the buffer, and
-		 * possibly block, while still holding the journal lock.
-		 * We cannot afford to let the transaction logic start
-		 * messing around with this buffer before we write it to
-		 * disk, as that would break recoverability.
-		 */
-		BUFFER_TRACE(bh, "queue");
-		get_bh(bh);
-		J_ASSERT_BH(bh, !buffer_jwrite(bh));
-		journal->j_chkpt_bhs[*batch_count] = bh;
-		__buffer_relink_io(jh);
-		transaction->t_chp_stats.cs_written++;
-		(*batch_count)++;
-		if (*batch_count == JBD2_NR_BATCH) {
-			spin_unlock(&journal->j_list_lock);
-			__flush_batch(journal, batch_count);
-			ret = 1;
-		}
-	}
-	return ret;
-}
-
-/*
  * Perform an actual checkpoint. We take the first transaction on the
  * list of transactions to be checkpointed and send all its buffers
  * to disk. We submit larger chunks of data at once.
@@ -331,9 +207,11 @@ static int __process_buffer(journal_t *journal, struct journal_head *jh,
  */
 int jbd2_log_do_checkpoint(journal_t *journal)
 {
-	transaction_t *transaction;
-	tid_t this_tid;
-	int result;
+	struct journal_head	*jh;
+	struct buffer_head	*bh;
+	transaction_t		*transaction;
+	tid_t			this_tid;
+	int			result, batch_count = 0;
 
 	jbd_debug(1, "Start checkpoint\n");
 
@@ -366,45 +244,117 @@ restart:
 	 * done (maybe it's a new transaction, but it fell at the same
 	 * address).
 	 */
-	if (journal->j_checkpoint_transactions == transaction &&
-			transaction->t_tid == this_tid) {
-		int batch_count = 0;
-		struct journal_head *jh;
-		int retry = 0, err;
-
-		while (!retry && transaction->t_checkpoint_list) {
-			jh = transaction->t_checkpoint_list;
-			retry = __process_buffer(journal, jh, &batch_count,
-						 transaction);
-			if (retry < 0 && !result)
-				result = retry;
-			if (!retry && (need_resched() ||
-				spin_needbreak(&journal->j_list_lock))) {
-				spin_unlock(&journal->j_list_lock);
-				retry = 1;
-				break;
-			}
+	if (journal->j_checkpoint_transactions != transaction ||
+	    transaction->t_tid != this_tid)
+		goto out;
+
+	/* checkpoint all of the transaction's buffers */
+	while (transaction->t_checkpoint_list) {
+		jh = transaction->t_checkpoint_list;
+		bh = jh2bh(jh);
+
+		if (buffer_locked(bh)) {
+			spin_unlock(&journal->j_list_lock);
+			get_bh(bh);
+			wait_on_buffer(bh);
+			/* the journal_head may have gone by now */
+			BUFFER_TRACE(bh, "brelse");
+			__brelse(bh);
+			goto retry;
 		}
+		if (jh->b_transaction != NULL) {
+			transaction_t *t = jh->b_transaction;
+			tid_t tid = t->t_tid;
 
-		if (batch_count) {
-			if (!retry) {
-				spin_unlock(&journal->j_list_lock);
-				retry = 1;
-			}
-			__flush_batch(journal, &batch_count);
+			transaction->t_chp_stats.cs_forced_to_close++;
+			spin_unlock(&journal->j_list_lock);
+			if (unlikely(journal->j_flags & JBD2_UNMOUNT))
+				/*
+				 * The journal thread is dead; so
+				 * starting and waiting for a commit
+				 * to finish will cause us to wait for
+				 * a _very_ long time.
+				 */
+				printk(KERN_ERR
+		"JBD2: %s: Waiting for Godot: block %llu\n",
+		journal->j_devname, (unsigned long long) bh->b_blocknr);
+
+			jbd2_log_start_commit(journal, tid);
+			jbd2_log_wait_commit(journal, tid);
+			goto retry;
 		}
+		if (!buffer_dirty(bh)) {
+			if (unlikely(buffer_write_io_error(bh)) && !result)
+				result = -EIO;
+			BUFFER_TRACE(bh, "remove from checkpoint");
+			if (__jbd2_journal_remove_checkpoint(jh))
+				/* The transaction was released; we're done */
+				goto out;
+			continue;
+		}
+		/*
+		 * Important: we are about to write the buffer, and
+		 * possibly block, while still holding the journal
+		 * lock.  We cannot afford to let the transaction
+		 * logic start messing around with this buffer before
+		 * we write it to disk, as that would break
+		 * recoverability.
+		 */
+		BUFFER_TRACE(bh, "queue");
+		get_bh(bh);
+		J_ASSERT_BH(bh, !buffer_jwrite(bh));
+		journal->j_chkpt_bhs[batch_count++] = bh;
+		__buffer_relink_io(jh);
+		transaction->t_chp_stats.cs_written++;
+		if ((batch_count == JBD2_NR_BATCH) ||
+		    need_resched() ||
+		    spin_needbreak(&journal->j_list_lock))
+			goto unlock_and_flush;
+	}
 
-		if (retry) {
+	if (batch_count) {
+		unlock_and_flush:
+			spin_unlock(&journal->j_list_lock);
+		retry:
+			if (batch_count)
+				__flush_batch(journal, &batch_count);
 			spin_lock(&journal->j_list_lock);
 			goto restart;
+	}
+
+	/*
+	 * Now we issued all of the transaction's buffers, let's deal
+	 * with the buffers that are out for I/O.
+	 */
+restart2:
+	/* Did somebody clean up the transaction in the meanwhile? */
+	if (journal->j_checkpoint_transactions != transaction ||
+	    transaction->t_tid != this_tid)
+		goto out;
+
+	while (transaction->t_checkpoint_io_list) {
+		jh = transaction->t_checkpoint_io_list;
+		bh = jh2bh(jh);
+		if (buffer_locked(bh)) {
+			spin_unlock(&journal->j_list_lock);
+			get_bh(bh);
+			wait_on_buffer(bh);
+			/* the journal_head may have gone by now */
+			BUFFER_TRACE(bh, "brelse");
+			__brelse(bh);
+			spin_lock(&journal->j_list_lock);
+			goto restart2;
 		}
+		if (unlikely(buffer_write_io_error(bh)) && !result)
+			result = -EIO;
+
 		/*
-		 * Now we have cleaned up the first transaction's checkpoint
-		 * list. Let's clean up the second one
+		 * Now in whatever state the buffer currently is, we
+		 * know that it has been written out and so we can
+		 * drop it from the list
 		 */
-		err = __wait_cp_io(journal, transaction);
-		if (!result)
-			result = err;
+		if (__jbd2_journal_remove_checkpoint(jh))
+			break;
 	}
 out:
 	spin_unlock(&journal->j_list_lock);
@@ -440,7 +390,7 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
 	unsigned long	blocknr;
 
 	if (is_journal_aborted(journal))
-		return -EIO;
+		return 1;
 
 	if (!jbd2_journal_get_log_tail(journal, &first_tid, &blocknr))
 		return 1;
@@ -455,9 +405,10 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
 	 * jbd2_cleanup_journal_tail() doesn't get called all that often.
 	 */
 	if (journal->j_flags & JBD2_BARRIER)
-		blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
+		blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
 
-	return __jbd2_update_log_tail(journal, first_tid, blocknr);
+	__jbd2_update_log_tail(journal, first_tid, blocknr);
+	return 0;
 }
 
 
@@ -469,18 +420,16 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
  * Find all the written-back checkpoint buffers in the given list and
  * release them.
  *
- * Called with the journal locked.
  * Called with j_list_lock held.
- * Returns number of buffers reaped (for debug)
+ * Returns 1 if we freed the transaction, 0 otherwise.
  */
-
-static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
+static int journal_clean_one_cp_list(struct journal_head *jh)
 {
 	struct journal_head *last_jh;
 	struct journal_head *next_jh = jh;
-	int ret, freed = 0;
+	int ret;
+	int freed = 0;
 
-	*released = 0;
 	if (!jh)
 		return 0;
 
@@ -489,13 +438,11 @@ static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
 		jh = next_jh;
 		next_jh = jh->b_cpnext;
 		ret = __try_to_free_cp_buf(jh);
-		if (ret) {
-			freed++;
-			if (ret == 2) {
-				*released = 1;
-				return freed;
-			}
-		}
+		if (!ret)
+			return freed;
+		if (ret == 2)
+			return 1;
+		freed = 1;
 		/*
 		 * This function only frees up some memory
 		 * if possible so we dont have an obligation
@@ -514,49 +461,49 @@ static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
  *
  * Find all the written-back checkpoint buffers in the journal and release them.
  *
- * Called with the journal locked.
  * Called with j_list_lock held.
- * Returns number of buffers reaped (for debug)
  */
-
-int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
+void __jbd2_journal_clean_checkpoint_list(journal_t *journal)
 {
 	transaction_t *transaction, *last_transaction, *next_transaction;
-	int ret = 0;
-	int released;
+	int ret;
 
 	transaction = journal->j_checkpoint_transactions;
 	if (!transaction)
-		goto out;
+		return;
 
 	last_transaction = transaction->t_cpprev;
 	next_transaction = transaction;
 	do {
 		transaction = next_transaction;
 		next_transaction = transaction->t_cpnext;
-		ret += journal_clean_one_cp_list(transaction->
-				t_checkpoint_list, &released);
+		ret = journal_clean_one_cp_list(transaction->t_checkpoint_list);
 		/*
 		 * This function only frees up some memory if possible so we
 		 * dont have an obligation to finish processing. Bail out if
 		 * preemption requested:
 		 */
 		if (need_resched())
-			goto out;
-		if (released)
+			return;
+		if (ret)
 			continue;
 		/*
 		 * It is essential that we are as careful as in the case of
 		 * t_checkpoint_list with removing the buffer from the list as
 		 * we can possibly see not yet submitted buffers on io_list
 		 */
-		ret += journal_clean_one_cp_list(transaction->
-				t_checkpoint_io_list, &released);
+		ret = journal_clean_one_cp_list(transaction->
+				t_checkpoint_io_list);
 		if (need_resched())
-			goto out;
+			return;
+		/*
+		 * Stop scanning if we couldn't free the transaction. This
+		 * avoids pointless scanning of transactions which still
+		 * weren't checkpointed.
+		 */
+		if (!ret)
+			return;
 	} while (transaction != last_transaction);
-out:
-	return ret;
 }
 
 /*
@@ -624,10 +571,6 @@ int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
 
 	__jbd2_journal_drop_transaction(journal, transaction);
 	jbd2_journal_free_transaction(transaction);
-
-	/* Just in case anybody was waiting for more transactions to be
-           checkpointed... */
-	wake_up(&journal->j_wait_logspace);
 	ret = 1;
 out:
 	return ret;
@@ -689,9 +632,7 @@ void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transact
 	J_ASSERT(transaction->t_state == T_FINISHED);
 	J_ASSERT(transaction->t_buffers == NULL);
 	J_ASSERT(transaction->t_forget == NULL);
-	J_ASSERT(transaction->t_iobuf_list == NULL);
 	J_ASSERT(transaction->t_shadow_list == NULL);
-	J_ASSERT(transaction->t_log_list == NULL);
 	J_ASSERT(transaction->t_checkpoint_list == NULL);
 	J_ASSERT(transaction->t_checkpoint_io_list == NULL);
 	J_ASSERT(atomic_read(&transaction->t_updates) == 0);
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 0f53946f1..b73e0215b 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -30,15 +30,22 @@
 #include <trace/events/jbd2.h>
 
 /*
- * Default IO end handler for temporary BJ_IO buffer_heads.
+ * IO end handler for temporary buffer_heads handling writes to the journal.
  */
 static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
 {
+	struct buffer_head *orig_bh = bh->b_private;
+
 	BUFFER_TRACE(bh, "");
 	if (uptodate)
 		set_buffer_uptodate(bh);
 	else
 		clear_buffer_uptodate(bh);
+	if (orig_bh) {
+		clear_bit_unlock(BH_Shadow, &orig_bh->b_state);
+		smp_mb__after_atomic();
+		wake_up_bit(&orig_bh->b_state, BH_Shadow);
+	}
 	unlock_buffer(bh);
 }
 
@@ -85,21 +92,19 @@ nope:
 	__brelse(bh);
 }
 
-static void jbd2_commit_block_csum_set(journal_t *j,
-				       struct journal_head *descriptor)
+static void jbd2_commit_block_csum_set(journal_t *j, struct buffer_head *bh)
 {
 	struct commit_header *h;
 	__u32 csum;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return;
 
-	h = (struct commit_header *)(jh2bh(descriptor)->b_data);
+	h = (struct commit_header *)(bh->b_data);
 	h->h_chksum_type = 0;
 	h->h_chksum_size = 0;
 	h->h_chksum[0] = 0;
-	csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
-			   j->j_blocksize);
+	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
 	h->h_chksum[0] = cpu_to_be32(csum);
 }
 
@@ -116,7 +121,6 @@ static int journal_submit_commit_record(journal_t *journal,
 					struct buffer_head **cbh,
 					__u32 crc32_sum)
 {
-	struct journal_head *descriptor;
 	struct commit_header *tmp;
 	struct buffer_head *bh;
 	int ret;
@@ -127,12 +131,10 @@ static int journal_submit_commit_record(journal_t *journal,
 	if (is_journal_aborted(journal))
 		return 0;
 
-	descriptor = jbd2_journal_get_descriptor_buffer(journal);
-	if (!descriptor)
+	bh = jbd2_journal_get_descriptor_buffer(journal);
+	if (!bh)
 		return 1;
 
-	bh = jh2bh(descriptor);
-
 	tmp = (struct commit_header *)bh->b_data;
 	tmp->h_magic = cpu_to_be32(JBD2_MAGIC_NUMBER);
 	tmp->h_blocktype = cpu_to_be32(JBD2_COMMIT_BLOCK);
@@ -146,9 +148,9 @@ static int journal_submit_commit_record(journal_t *journal,
 		tmp->h_chksum_size 	= JBD2_CRC32_CHKSUM_SIZE;
 		tmp->h_chksum[0] 	= cpu_to_be32(crc32_sum);
 	}
-	jbd2_commit_block_csum_set(journal, descriptor);
+	jbd2_commit_block_csum_set(journal, bh);
 
-	JBUFFER_TRACE(descriptor, "submit commit block");
+	BUFFER_TRACE(bh, "submit commit block");
 	lock_buffer(bh);
 	clear_buffer_dirty(bh);
 	set_buffer_uptodate(bh);
@@ -180,7 +182,6 @@ static int journal_wait_on_commit_record(journal_t *journal,
 	if (unlikely(!buffer_uptodate(bh)))
 		ret = -EIO;
 	put_bh(bh);            /* One for getblk() */
-	jbd2_journal_put_journal_head(bh2jh(bh));
 
 	return ret;
 }
@@ -238,7 +239,7 @@ static int journal_submit_data_buffers(journal_t *journal,
 		spin_lock(&journal->j_list_lock);
 		J_ASSERT(jinode->i_transaction == commit_transaction);
 		clear_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
-		smp_mb__after_clear_bit();
+		smp_mb__after_atomic();
 		wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
 	}
 	spin_unlock(&journal->j_list_lock);
@@ -276,7 +277,7 @@ static int journal_finish_inode_data_buffers(journal_t *journal,
 		}
 		spin_lock(&journal->j_list_lock);
 		clear_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
-		smp_mb__after_clear_bit();
+		smp_mb__after_atomic();
 		wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
 	}
 
@@ -312,51 +313,53 @@ static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
 	return checksum;
 }
 
-static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
+static void write_tag_block(journal_t *j, journal_block_tag_t *tag,
 				   unsigned long long block)
 {
 	tag->t_blocknr = cpu_to_be32(block & (u32)~0);
-	if (tag_bytes > JBD2_TAG_SIZE32)
+	if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_64BIT))
 		tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
 }
 
 static void jbd2_descr_block_csum_set(journal_t *j,
-				      struct journal_head *descriptor)
+				      struct buffer_head *bh)
 {
 	struct jbd2_journal_block_tail *tail;
 	__u32 csum;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return;
 
-	tail = (struct jbd2_journal_block_tail *)
-			(jh2bh(descriptor)->b_data + j->j_blocksize -
+	tail = (struct jbd2_journal_block_tail *)(bh->b_data + j->j_blocksize -
 			sizeof(struct jbd2_journal_block_tail));
 	tail->t_checksum = 0;
-	csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
-			   j->j_blocksize);
+	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
 	tail->t_checksum = cpu_to_be32(csum);
 }
 
 static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
 				    struct buffer_head *bh, __u32 sequence)
 {
+	journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
 	struct page *page = bh->b_page;
 	__u8 *addr;
-	__u32 csum;
+	__u32 csum32;
+	__be32 seq;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return;
 
-	sequence = cpu_to_be32(sequence);
+	seq = cpu_to_be32(sequence);
 	addr = kmap_atomic(page);
-	csum = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
-			  sizeof(sequence));
-	csum = jbd2_chksum(j, csum, addr + offset_in_page(bh->b_data),
-			  bh->b_size);
+	csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
+	csum32 = jbd2_chksum(j, csum32, addr + offset_in_page(bh->b_data),
+			     bh->b_size);
 	kunmap_atomic(addr);
 
-	tag->t_checksum = cpu_to_be32(csum);
+	if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+		tag3->t_checksum = cpu_to_be32(csum32);
+	else
+		tag->t_checksum = cpu_to_be16(csum32);
 }
 /*
  * jbd2_journal_commit_transaction
@@ -368,7 +371,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 {
 	struct transaction_stats_s stats;
 	transaction_t *commit_transaction;
-	struct journal_head *jh, *new_jh, *descriptor;
+	struct journal_head *jh;
+	struct buffer_head *descriptor;
 	struct buffer_head **wbuf = journal->j_wbuf;
 	int bufs;
 	int flags;
@@ -392,8 +396,10 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	tid_t first_tid;
 	int update_tail;
 	int csum_size = 0;
+	LIST_HEAD(io_bufs);
+	LIST_HEAD(log_bufs);
 
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (jbd2_journal_has_csum_v2or3(journal))
 		csum_size = sizeof(struct jbd2_journal_block_tail);
 
 	/*
@@ -424,13 +430,13 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	J_ASSERT(journal->j_committing_transaction == NULL);
 
 	commit_transaction = journal->j_running_transaction;
-	J_ASSERT(commit_transaction->t_state == T_RUNNING);
 
 	trace_jbd2_start_commit(journal, commit_transaction);
 	jbd_debug(1, "JBD2: starting commit of transaction %d\n",
 			commit_transaction->t_tid);
 
 	write_lock(&journal->j_state_lock);
+	J_ASSERT(commit_transaction->t_state == T_RUNNING);
 	commit_transaction->t_state = T_LOCKED;
 
 	trace_jbd2_commit_locking(journal, commit_transaction);
@@ -520,6 +526,12 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	 */
 	jbd2_journal_switch_revoke_table(journal);
 
+	/*
+	 * Reserved credits cannot be claimed anymore, free them
+	 */
+	atomic_sub(atomic_read(&journal->j_reserved_credits),
+		   &commit_transaction->t_outstanding_credits);
+
 	trace_jbd2_commit_flushing(journal, commit_transaction);
 	stats.run.rs_flushing = jiffies;
 	stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
@@ -533,7 +545,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	wake_up(&journal->j_wait_transaction_locked);
 	write_unlock(&journal->j_state_lock);
 
-	jbd_debug(3, "JBD2: commit phase 2\n");
+	jbd_debug(3, "JBD2: commit phase 2a\n");
 
 	/*
 	 * Now start flushing things to disk, in the order they appear
@@ -545,10 +557,9 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
 	blk_start_plug(&plug);
 	jbd2_journal_write_revoke_records(journal, commit_transaction,
-					  WRITE_SYNC);
-	blk_finish_plug(&plug);
+					  &log_bufs, WRITE_SYNC);
 
-	jbd_debug(3, "JBD2: commit phase 2\n");
+	jbd_debug(3, "JBD2: commit phase 2b\n");
 
 	/*
 	 * Way to go: we have now written out all of the data for a
@@ -571,9 +582,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 		 atomic_read(&commit_transaction->t_outstanding_credits));
 
 	err = 0;
-	descriptor = NULL;
 	bufs = 0;
-	blk_start_plug(&plug);
+	descriptor = NULL;
 	while (commit_transaction->t_buffers) {
 
 		/* Find the next buffer to be journaled... */
@@ -604,8 +614,6 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 		   record the metadata buffer. */
 
 		if (!descriptor) {
-			struct buffer_head *bh;
-
 			J_ASSERT (bufs == 0);
 
 			jbd_debug(4, "JBD2: get descriptor\n");
@@ -616,26 +624,26 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 				continue;
 			}
 
-			bh = jh2bh(descriptor);
 			jbd_debug(4, "JBD2: got buffer %llu (%p)\n",
-				(unsigned long long)bh->b_blocknr, bh->b_data);
-			header = (journal_header_t *)&bh->b_data[0];
+				(unsigned long long)descriptor->b_blocknr,
+				descriptor->b_data);
+			header = (journal_header_t *)descriptor->b_data;
 			header->h_magic     = cpu_to_be32(JBD2_MAGIC_NUMBER);
 			header->h_blocktype = cpu_to_be32(JBD2_DESCRIPTOR_BLOCK);
 			header->h_sequence  = cpu_to_be32(commit_transaction->t_tid);
 
-			tagp = &bh->b_data[sizeof(journal_header_t)];
-			space_left = bh->b_size - sizeof(journal_header_t);
+			tagp = &descriptor->b_data[sizeof(journal_header_t)];
+			space_left = descriptor->b_size -
+						sizeof(journal_header_t);
 			first_tag = 1;
-			set_buffer_jwrite(bh);
-			set_buffer_dirty(bh);
-			wbuf[bufs++] = bh;
+			set_buffer_jwrite(descriptor);
+			set_buffer_dirty(descriptor);
+			wbuf[bufs++] = descriptor;
 
 			/* Record it so that we can wait for IO
                            completion later */
-			BUFFER_TRACE(bh, "ph3: file as descriptor");
-			jbd2_journal_file_buffer(descriptor, commit_transaction,
-					BJ_LogCtl);
+			BUFFER_TRACE(descriptor, "ph3: file as descriptor");
+			jbd2_file_log_bh(&log_bufs, descriptor);
 		}
 
 		/* Where is the buffer to be written? */
@@ -658,29 +666,22 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 
 		/* Bump b_count to prevent truncate from stumbling over
                    the shadowed buffer!  @@@ This can go if we ever get
-                   rid of the BJ_IO/BJ_Shadow pairing of buffers. */
+                   rid of the shadow pairing of buffers. */
 		atomic_inc(&jh2bh(jh)->b_count);
 
-		/* Make a temporary IO buffer with which to write it out
-                   (this will requeue both the metadata buffer and the
-                   temporary IO buffer). new_bh goes on BJ_IO*/
-
-		set_bit(BH_JWrite, &jh2bh(jh)->b_state);
 		/*
-		 * akpm: jbd2_journal_write_metadata_buffer() sets
-		 * new_bh->b_transaction to commit_transaction.
-		 * We need to clean this up before we release new_bh
-		 * (which is of type BJ_IO)
+		 * Make a temporary IO buffer with which to write it out
+		 * (this will requeue the metadata buffer to BJ_Shadow).
 		 */
+		set_bit(BH_JWrite, &jh2bh(jh)->b_state);
 		JBUFFER_TRACE(jh, "ph3: write metadata");
 		flags = jbd2_journal_write_metadata_buffer(commit_transaction,
-						      jh, &new_jh, blocknr);
+						jh, &wbuf[bufs], blocknr);
 		if (flags < 0) {
 			jbd2_journal_abort(journal, flags);
 			continue;
 		}
-		set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
-		wbuf[bufs++] = jh2bh(new_jh);
+		jbd2_file_log_bh(&io_bufs, wbuf[bufs]);
 
 		/* Record the new block's tag in the current descriptor
                    buffer */
@@ -692,12 +693,13 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 			tag_flag |= JBD2_FLAG_SAME_UUID;
 
 		tag = (journal_block_tag_t *) tagp;
-		write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
+		write_tag_block(journal, tag, jh2bh(jh)->b_blocknr);
 		tag->t_flags = cpu_to_be16(tag_flag);
-		jbd2_block_tag_csum_set(journal, tag, jh2bh(new_jh),
+		jbd2_block_tag_csum_set(journal, tag, wbuf[bufs],
 					commit_transaction->t_tid);
 		tagp += tag_bytes;
 		space_left -= tag_bytes;
+		bufs++;
 
 		if (first_tag) {
 			memcpy (tagp, journal->j_uuid, 16);
@@ -809,7 +811,7 @@ start_journal_io:
            the log.  Before we can commit it, wait for the IO so far to
            complete.  Control buffers being written are on the
            transaction's t_log_list queue, and metadata buffers are on
-           the t_iobuf_list queue.
+           the io_bufs list.
 
 	   Wait for the buffers in reverse order.  That way we are
 	   less likely to be woken up until all IOs have completed, and
@@ -818,47 +820,33 @@ start_journal_io:
 
 	jbd_debug(3, "JBD2: commit phase 3\n");
 
-	/*
-	 * akpm: these are BJ_IO, and j_list_lock is not needed.
-	 * See __journal_try_to_free_buffer.
-	 */
-wait_for_iobuf:
-	while (commit_transaction->t_iobuf_list != NULL) {
-		struct buffer_head *bh;
+	while (!list_empty(&io_bufs)) {
+		struct buffer_head *bh = list_entry(io_bufs.prev,
+						    struct buffer_head,
+						    b_assoc_buffers);
 
-		jh = commit_transaction->t_iobuf_list->b_tprev;
-		bh = jh2bh(jh);
-		if (buffer_locked(bh)) {
-			wait_on_buffer(bh);
-			goto wait_for_iobuf;
-		}
-		if (cond_resched())
-			goto wait_for_iobuf;
+		wait_on_buffer(bh);
+		cond_resched();
 
 		if (unlikely(!buffer_uptodate(bh)))
 			err = -EIO;
-
-		clear_buffer_jwrite(bh);
-
-		JBUFFER_TRACE(jh, "ph4: unfile after journal write");
-		jbd2_journal_unfile_buffer(journal, jh);
+		jbd2_unfile_log_bh(bh);
 
 		/*
-		 * ->t_iobuf_list should contain only dummy buffer_heads
-		 * which were created by jbd2_journal_write_metadata_buffer().
+		 * The list contains temporary buffer heads created by
+		 * jbd2_journal_write_metadata_buffer().
 		 */
 		BUFFER_TRACE(bh, "dumping temporary bh");
-		jbd2_journal_put_journal_head(jh);
 		__brelse(bh);
 		J_ASSERT_BH(bh, atomic_read(&bh->b_count) == 0);
 		free_buffer_head(bh);
 
-		/* We also have to unlock and free the corresponding
-                   shadowed buffer */
+		/* We also have to refile the corresponding shadowed buffer */
 		jh = commit_transaction->t_shadow_list->b_tprev;
 		bh = jh2bh(jh);
-		clear_bit(BH_JWrite, &bh->b_state);
+		clear_buffer_jwrite(bh);
 		J_ASSERT_BH(bh, buffer_jbddirty(bh));
+		J_ASSERT_BH(bh, !buffer_shadow(bh));
 
 		/* The metadata is now released for reuse, but we need
                    to remember it against this transaction so that when
@@ -866,14 +854,6 @@ wait_for_iobuf:
                    required. */
 		JBUFFER_TRACE(jh, "file as BJ_Forget");
 		jbd2_journal_file_buffer(jh, commit_transaction, BJ_Forget);
-		/*
-		 * Wake up any transactions which were waiting for this IO to
-		 * complete. The barrier must be here so that changes by
-		 * jbd2_journal_file_buffer() take effect before wake_up_bit()
-		 * does the waitqueue check.
-		 */
-		smp_mb();
-		wake_up_bit(&bh->b_state, BH_Unshadow);
 		JBUFFER_TRACE(jh, "brelse shadowed buffer");
 		__brelse(bh);
 	}
@@ -883,26 +863,19 @@ wait_for_iobuf:
 	jbd_debug(3, "JBD2: commit phase 4\n");
 
 	/* Here we wait for the revoke record and descriptor record buffers */
- wait_for_ctlbuf:
-	while (commit_transaction->t_log_list != NULL) {
+	while (!list_empty(&log_bufs)) {
 		struct buffer_head *bh;
 
-		jh = commit_transaction->t_log_list->b_tprev;
-		bh = jh2bh(jh);
-		if (buffer_locked(bh)) {
-			wait_on_buffer(bh);
-			goto wait_for_ctlbuf;
-		}
-		if (cond_resched())
-			goto wait_for_ctlbuf;
+		bh = list_entry(log_bufs.prev, struct buffer_head, b_assoc_buffers);
+		wait_on_buffer(bh);
+		cond_resched();
 
 		if (unlikely(!buffer_uptodate(bh)))
 			err = -EIO;
 
 		BUFFER_TRACE(bh, "ph5: control buffer writeout done: unfile");
 		clear_buffer_jwrite(bh);
-		jbd2_journal_unfile_buffer(journal, jh);
-		jbd2_journal_put_journal_head(jh);
+		jbd2_unfile_log_bh(bh);
 		__brelse(bh);		/* One for getblk */
 		/* AKPM: bforget here */
 	}
@@ -952,9 +925,7 @@ wait_for_iobuf:
 	J_ASSERT(list_empty(&commit_transaction->t_inode_list));
 	J_ASSERT(commit_transaction->t_buffers == NULL);
 	J_ASSERT(commit_transaction->t_checkpoint_list == NULL);
-	J_ASSERT(commit_transaction->t_iobuf_list == NULL);
 	J_ASSERT(commit_transaction->t_shadow_list == NULL);
-	J_ASSERT(commit_transaction->t_log_list == NULL);
 
 restart_loop:
 	/*
@@ -1097,6 +1068,25 @@ restart_loop:
 		goto restart_loop;
 	}
 
+	/* Add the transaction to the checkpoint list
+	 * __journal_remove_checkpoint() can not destroy transaction
+	 * under us because it is not marked as T_FINISHED yet */
+	if (journal->j_checkpoint_transactions == NULL) {
+		journal->j_checkpoint_transactions = commit_transaction;
+		commit_transaction->t_cpnext = commit_transaction;
+		commit_transaction->t_cpprev = commit_transaction;
+	} else {
+		commit_transaction->t_cpnext =
+			journal->j_checkpoint_transactions;
+		commit_transaction->t_cpprev =
+			commit_transaction->t_cpnext->t_cpprev;
+		commit_transaction->t_cpnext->t_cpprev =
+			commit_transaction;
+		commit_transaction->t_cpprev->t_cpnext =
+				commit_transaction;
+	}
+	spin_unlock(&journal->j_list_lock);
+
 	/* Done with this transaction! */
 
 	jbd_debug(3, "JBD2: commit phase 7\n");
@@ -1115,24 +1105,7 @@ restart_loop:
 		atomic_read(&commit_transaction->t_handle_count);
 	trace_jbd2_run_stats(journal->j_fs_dev->bd_dev,
 			     commit_transaction->t_tid, &stats.run);
-
-	/*
-	 * Calculate overall stats
-	 */
-	spin_lock(&journal->j_history_lock);
-	journal->j_stats.ts_tid++;
-	if (commit_transaction->t_requested)
-		journal->j_stats.ts_requested++;
-	journal->j_stats.run.rs_wait += stats.run.rs_wait;
-	journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
-	journal->j_stats.run.rs_running += stats.run.rs_running;
-	journal->j_stats.run.rs_locked += stats.run.rs_locked;
-	journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
-	journal->j_stats.run.rs_logging += stats.run.rs_logging;
-	journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
-	journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
-	journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
-	spin_unlock(&journal->j_history_lock);
+	stats.ts_requested = (commit_transaction->t_requested) ? 1 : 0;
 
 	commit_transaction->t_state = T_COMMIT_CALLBACK;
 	J_ASSERT(commit_transaction == journal->j_committing_transaction);
@@ -1152,24 +1125,6 @@ restart_loop:
 
 	write_unlock(&journal->j_state_lock);
 
-	if (journal->j_checkpoint_transactions == NULL) {
-		journal->j_checkpoint_transactions = commit_transaction;
-		commit_transaction->t_cpnext = commit_transaction;
-		commit_transaction->t_cpprev = commit_transaction;
-	} else {
-		commit_transaction->t_cpnext =
-			journal->j_checkpoint_transactions;
-		commit_transaction->t_cpprev =
-			commit_transaction->t_cpnext->t_cpprev;
-		commit_transaction->t_cpnext->t_cpprev =
-			commit_transaction;
-		commit_transaction->t_cpprev->t_cpnext =
-				commit_transaction;
-	}
-	spin_unlock(&journal->j_list_lock);
-	/* Drop all spin_locks because commit_callback may be block.
-	 * __journal_remove_checkpoint() can not destroy transaction
-	 * under us because it is not marked as T_FINISHED yet */
 	if (journal->j_commit_callback)
 		journal->j_commit_callback(journal, commit_transaction);
 
@@ -1180,7 +1135,7 @@ restart_loop:
 	write_lock(&journal->j_state_lock);
 	spin_lock(&journal->j_list_lock);
 	commit_transaction->t_state = T_FINISHED;
-	/* Recheck checkpoint lists after j_list_lock was dropped */
+	/* Check if the transaction can be dropped now that we are finished */
 	if (commit_transaction->t_checkpoint_list == NULL &&
 	    commit_transaction->t_checkpoint_io_list == NULL) {
 		__jbd2_journal_drop_transaction(journal, commit_transaction);
@@ -1189,4 +1144,21 @@ restart_loop:
 	spin_unlock(&journal->j_list_lock);
 	write_unlock(&journal->j_state_lock);
 	wake_up(&journal->j_wait_done_commit);
+
+	/*
+	 * Calculate overall stats
+	 */
+	spin_lock(&journal->j_history_lock);
+	journal->j_stats.ts_tid++;
+	journal->j_stats.ts_requested += stats.ts_requested;
+	journal->j_stats.run.rs_wait += stats.run.rs_wait;
+	journal->j_stats.run.rs_request_delay += stats.run.rs_request_delay;
+	journal->j_stats.run.rs_running += stats.run.rs_running;
+	journal->j_stats.run.rs_locked += stats.run.rs_locked;
+	journal->j_stats.run.rs_flushing += stats.run.rs_flushing;
+	journal->j_stats.run.rs_logging += stats.run.rs_logging;
+	journal->j_stats.run.rs_handle_count += stats.run.rs_handle_count;
+	journal->j_stats.run.rs_blocks += stats.run.rs_blocks;
+	journal->j_stats.run.rs_blocks_logged += stats.run.rs_blocks_logged;
+	spin_unlock(&journal->j_history_lock);
 }
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 955781774..1df94fabe 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -103,18 +103,37 @@ EXPORT_SYMBOL(jbd2_inode_cache);
 static void __journal_abort_soft (journal_t *journal, int errno);
 static int jbd2_journal_create_slab(size_t slab_size);
 
+#ifdef CONFIG_JBD2_DEBUG
+void __jbd2_debug(int level, const char *file, const char *func,
+		  unsigned int line, const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	if (level > jbd2_journal_enable_debug)
+		return;
+	va_start(args, fmt);
+	vaf.fmt = fmt;
+	vaf.va = &args;
+	printk(KERN_DEBUG "%s: (%s, %u): %pV\n", file, func, line, &vaf);
+	va_end(args);
+}
+EXPORT_SYMBOL(__jbd2_debug);
+#endif
+
 /* Checksumming functions */
-int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
+static int jbd2_verify_csum_type(journal_t *j, journal_superblock_t *sb)
 {
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return 1;
 
 	return sb->s_checksum_type == JBD2_CRC32C_CHKSUM;
 }
 
-static __u32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
+static __be32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
 {
-	__u32 csum, old_csum;
+	__u32 csum;
+	__be32 old_csum;
 
 	old_csum = sb->s_checksum;
 	sb->s_checksum = 0;
@@ -124,17 +143,17 @@ static __u32 jbd2_superblock_csum(journal_t *j, journal_superblock_t *sb)
 	return cpu_to_be32(csum);
 }
 
-int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb)
+static int jbd2_superblock_csum_verify(journal_t *j, journal_superblock_t *sb)
 {
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return 1;
 
 	return sb->s_checksum == jbd2_superblock_csum(j, sb);
 }
 
-void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb)
+static void jbd2_superblock_csum_set(journal_t *j, journal_superblock_t *sb)
 {
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return;
 
 	sb->s_checksum = jbd2_superblock_csum(j, sb);
@@ -283,8 +302,8 @@ static void journal_kill_thread(journal_t *journal)
 	journal->j_flags |= JBD2_UNMOUNT;
 
 	while (journal->j_task) {
-		wake_up(&journal->j_wait_commit);
 		write_unlock(&journal->j_state_lock);
+		wake_up(&journal->j_wait_commit);
 		wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
 		write_lock(&journal->j_state_lock);
 	}
@@ -310,14 +329,12 @@ static void journal_kill_thread(journal_t *journal)
  *
  * If the source buffer has already been modified by a new transaction
  * since we took the last commit snapshot, we use the frozen copy of
- * that data for IO.  If we end up using the existing buffer_head's data
- * for the write, then we *have* to lock the buffer to prevent anyone
- * else from using and possibly modifying it while the IO is in
- * progress.
- *
- * The function returns a pointer to the buffer_heads to be used for IO.
+ * that data for IO. If we end up using the existing buffer_head's data
+ * for the write, then we have to make sure nobody modifies it while the
+ * IO is in progress. do_get_write_access() handles this.
  *
- * We assume that the journal has already been locked in this function.
+ * The function returns a pointer to the buffer_head to be used for IO.
+ * 
  *
  * Return value:
  *  <0: Error
@@ -330,15 +347,14 @@ static void journal_kill_thread(journal_t *journal)
 
 int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
 				  struct journal_head  *jh_in,
-				  struct journal_head **jh_out,
-				  unsigned long long blocknr)
+				  struct buffer_head **bh_out,
+				  sector_t blocknr)
 {
 	int need_copy_out = 0;
 	int done_copy_out = 0;
 	int do_escape = 0;
 	char *mapped_data;
 	struct buffer_head *new_bh;
-	struct journal_head *new_jh;
 	struct page *new_page;
 	unsigned int new_offset;
 	struct buffer_head *bh_in = jh2bh(jh_in);
@@ -368,14 +384,13 @@ retry_alloc:
 
 	/* keep subsequent assertions sane */
 	atomic_set(&new_bh->b_count, 1);
-	new_jh = jbd2_journal_add_journal_head(new_bh);	/* This sleeps */
 
+	jbd_lock_bh_state(bh_in);
+repeat:
 	/*
 	 * If a new transaction has already done a buffer copy-out, then
 	 * we use that version of the data for the commit.
 	 */
-	jbd_lock_bh_state(bh_in);
-repeat:
 	if (jh_in->b_frozen_data) {
 		done_copy_out = 1;
 		new_page = virt_to_page(jh_in->b_frozen_data);
@@ -415,7 +430,7 @@ repeat:
 		jbd_unlock_bh_state(bh_in);
 		tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
 		if (!tmp) {
-			jbd2_journal_put_journal_head(new_jh);
+			brelse(new_bh);
 			return -ENOMEM;
 		}
 		jbd_lock_bh_state(bh_in);
@@ -426,7 +441,7 @@ repeat:
 
 		jh_in->b_frozen_data = tmp;
 		mapped_data = kmap_atomic(new_page);
-		memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
+		memcpy(tmp, mapped_data + new_offset, bh_in->b_size);
 		kunmap_atomic(mapped_data);
 
 		new_page = virt_to_page(tmp);
@@ -452,14 +467,14 @@ repeat:
 	}
 
 	set_bh_page(new_bh, new_page, new_offset);
-	new_jh->b_transaction = NULL;
-	new_bh->b_size = jh2bh(jh_in)->b_size;
-	new_bh->b_bdev = transaction->t_journal->j_dev;
+	new_bh->b_size = bh_in->b_size;
+	new_bh->b_bdev = journal->j_dev;
 	new_bh->b_blocknr = blocknr;
+	new_bh->b_private = bh_in;
 	set_buffer_mapped(new_bh);
 	set_buffer_dirty(new_bh);
 
-	*jh_out = new_jh;
+	*bh_out = new_bh;
 
 	/*
 	 * The to-be-written buffer needs to get moved to the io queue,
@@ -470,11 +485,9 @@ repeat:
 	spin_lock(&journal->j_list_lock);
 	__jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
 	spin_unlock(&journal->j_list_lock);
+	set_buffer_shadow(bh_in);
 	jbd_unlock_bh_state(bh_in);
 
-	JBUFFER_TRACE(new_jh, "file as BJ_IO");
-	jbd2_journal_file_buffer(new_jh, transaction, BJ_IO);
-
 	return do_escape | (done_copy_out << 1);
 }
 
@@ -484,35 +497,6 @@ repeat:
  */
 
 /*
- * __jbd2_log_space_left: Return the number of free blocks left in the journal.
- *
- * Called with the journal already locked.
- *
- * Called under j_state_lock
- */
-
-int __jbd2_log_space_left(journal_t *journal)
-{
-	int left = journal->j_free;
-
-	/* assert_spin_locked(&journal->j_state_lock); */
-
-	/*
-	 * Be pessimistic here about the number of those free blocks which
-	 * might be required for log descriptor control blocks.
-	 */
-
-#define MIN_LOG_RESERVED_BLOCKS 32 /* Allow for rounding errors */
-
-	left -= MIN_LOG_RESERVED_BLOCKS;
-
-	if (left <= 0)
-		return 0;
-	left -= (left >> 3);
-	return left;
-}
-
-/*
  * Called with j_state_lock locked for writing.
  * Returns true if a transaction commit was started.
  */
@@ -564,20 +548,17 @@ int jbd2_log_start_commit(journal_t *journal, tid_t tid)
 }
 
 /*
- * Force and wait upon a commit if the calling process is not within
- * transaction.  This is used for forcing out undo-protected data which contains
- * bitmaps, when the fs is running out of space.
- *
- * We can only force the running transaction if we don't have an active handle;
- * otherwise, we will deadlock.
- *
- * Returns true if a transaction was started.
+ * Force and wait any uncommitted transactions.  We can only force the running
+ * transaction if we don't have an active handle, otherwise, we will deadlock.
+ * Returns: <0 in case of error,
+ *           0 if nothing to commit,
+ *           1 if transaction was successfully committed.
  */
-int jbd2_journal_force_commit_nested(journal_t *journal)
+static int __jbd2_journal_force_commit(journal_t *journal)
 {
 	transaction_t *transaction = NULL;
 	tid_t tid;
-	int need_to_start = 0;
+	int need_to_start = 0, ret = 0;
 
 	read_lock(&journal->j_state_lock);
 	if (journal->j_running_transaction && !current->journal_info) {
@@ -588,16 +569,53 @@ int jbd2_journal_force_commit_nested(journal_t *journal)
 		transaction = journal->j_committing_transaction;
 
 	if (!transaction) {
+		/* Nothing to commit */
 		read_unlock(&journal->j_state_lock);
-		return 0;	/* Nothing to retry */
+		return 0;
 	}
-
 	tid = transaction->t_tid;
 	read_unlock(&journal->j_state_lock);
 	if (need_to_start)
 		jbd2_log_start_commit(journal, tid);
-	jbd2_log_wait_commit(journal, tid);
-	return 1;
+	ret = jbd2_log_wait_commit(journal, tid);
+	if (!ret)
+		ret = 1;
+
+	return ret;
+}
+
+/**
+ * Force and wait upon a commit if the calling process is not within
+ * transaction.  This is used for forcing out undo-protected data which contains
+ * bitmaps, when the fs is running out of space.
+ *
+ * @journal: journal to force
+ * Returns true if progress was made.
+ */
+int jbd2_journal_force_commit_nested(journal_t *journal)
+{
+	int ret;
+
+	ret = __jbd2_journal_force_commit(journal);
+	return ret > 0;
+}
+
+/**
+ * int journal_force_commit() - force any uncommitted transactions
+ * @journal: journal to force
+ *
+ * Caller want unconditional commit. We can only force the running transaction
+ * if we don't have an active handle, otherwise, we will deadlock.
+ */
+int jbd2_journal_force_commit(journal_t *journal)
+{
+	int ret;
+
+	J_ASSERT(!current->journal_info);
+	ret = __jbd2_journal_force_commit(journal);
+	if (ret > 0)
+		ret = 0;
+	return ret;
 }
 
 /*
@@ -684,7 +702,7 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
 	read_lock(&journal->j_state_lock);
 #ifdef CONFIG_JBD2_DEBUG
 	if (!tid_geq(journal->j_commit_request, tid)) {
-		printk(KERN_EMERG
+		printk(KERN_ERR
 		       "%s: error: j_commit_request=%d, tid=%d\n",
 		       __func__, journal->j_commit_request, tid);
 	}
@@ -692,18 +710,16 @@ int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
 	while (tid_gt(tid, journal->j_commit_sequence)) {
 		jbd_debug(1, "JBD2: want %d, j_commit_sequence=%d\n",
 				  tid, journal->j_commit_sequence);
-		wake_up(&journal->j_wait_commit);
 		read_unlock(&journal->j_state_lock);
+		wake_up(&journal->j_wait_commit);
 		wait_event(journal->j_wait_done_commit,
 				!tid_gt(tid, journal->j_commit_sequence));
 		read_lock(&journal->j_state_lock);
 	}
 	read_unlock(&journal->j_state_lock);
 
-	if (unlikely(is_journal_aborted(journal))) {
-		printk(KERN_EMERG "journal commit I/O error\n");
+	if (unlikely(is_journal_aborted(journal)))
 		err = -EIO;
-	}
 	return err;
 }
 
@@ -798,7 +814,7 @@ int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
  * But we don't bother doing that, so there will be coherency problems with
  * mmaps of blockdevs which hold live JBD-controlled filesystems.
  */
-struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
+struct buffer_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
 {
 	struct buffer_head *bh;
 	unsigned long long blocknr;
@@ -817,7 +833,7 @@ struct journal_head *jbd2_journal_get_descriptor_buffer(journal_t *journal)
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 	BUFFER_TRACE(bh, "return this buffer");
-	return jbd2_journal_add_journal_head(bh);
+	return bh;
 }
 
 /*
@@ -869,10 +885,9 @@ int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
  *
  * Requires j_checkpoint_mutex
  */
-int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
+void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
 {
 	unsigned long freed;
-	int ret;
 
 	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
 
@@ -882,10 +897,7 @@ int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
 	 * space and if we lose sb update during power failure we'd replay
 	 * old transaction with possibly newly overwritten data.
 	 */
-	ret = jbd2_journal_update_sb_log_tail(journal, tid, block, WRITE_FUA);
-	if (ret)
-		goto out;
-
+	jbd2_journal_update_sb_log_tail(journal, tid, block, WRITE_FUA);
 	write_lock(&journal->j_state_lock);
 	freed = block - journal->j_tail;
 	if (block < journal->j_tail)
@@ -901,9 +913,6 @@ int __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
 	journal->j_tail_sequence = tid;
 	journal->j_tail = block;
 	write_unlock(&journal->j_state_lock);
-
-out:
-	return ret;
 }
 
 /*
@@ -1069,11 +1078,10 @@ static journal_t * journal_init_common (void)
 		return NULL;
 
 	init_waitqueue_head(&journal->j_wait_transaction_locked);
-	init_waitqueue_head(&journal->j_wait_logspace);
 	init_waitqueue_head(&journal->j_wait_done_commit);
-	init_waitqueue_head(&journal->j_wait_checkpoint);
 	init_waitqueue_head(&journal->j_wait_commit);
 	init_waitqueue_head(&journal->j_wait_updates);
+	init_waitqueue_head(&journal->j_wait_reserved);
 	mutex_init(&journal->j_barrier);
 	mutex_init(&journal->j_checkpoint_mutex);
 	spin_lock_init(&journal->j_revoke_lock);
@@ -1083,6 +1091,7 @@ static journal_t * journal_init_common (void)
 	journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
 	journal->j_min_batch_time = 0;
 	journal->j_max_batch_time = 15000; /* 15ms */
+	atomic_set(&journal->j_reserved_credits, 0);
 
 	/* The journal is marked for error until we succeed with recovery! */
 	journal->j_flags = JBD2_ABORT;
@@ -1228,11 +1237,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
 		goto out_err;
 	}
 
-#if defined(CONFIG_CMA) && defined(CONFIG_MTK_SVP)
 	bh = getblk_unmovable(journal->j_dev, blocknr, journal->j_blocksize);
-#else
-	bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-#endif
 	if (!bh) {
 		printk(KERN_ERR
 		       "%s: Cannot get buffer for journal superblock\n",
@@ -1326,7 +1331,7 @@ static int journal_reset(journal_t *journal)
 	return jbd2_journal_start_thread(journal);
 }
 
-static int jbd2_write_superblock(journal_t *journal, int write_op)
+static void jbd2_write_superblock(journal_t *journal, int write_op)
 {
 	struct buffer_head *bh = journal->j_sb_buffer;
 	journal_superblock_t *sb = journal->j_superblock;
@@ -1365,10 +1370,7 @@ static int jbd2_write_superblock(journal_t *journal, int write_op)
 		printk(KERN_ERR "JBD2: Error %d detected when updating "
 		       "journal superblock for %s.\n", ret,
 		       journal->j_devname);
-		jbd2_journal_abort(journal, ret);
 	}
-
-	return ret;
 }
 
 /**
@@ -1381,11 +1383,10 @@ static int jbd2_write_superblock(journal_t *journal, int write_op)
  * Update a journal's superblock information about log tail and write it to
  * disk, waiting for the IO to complete.
  */
-int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
+void jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
 				     unsigned long tail_block, int write_op)
 {
 	journal_superblock_t *sb = journal->j_superblock;
-	int ret;
 
 	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
 	jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
@@ -1394,29 +1395,23 @@ int jbd2_journal_update_sb_log_tail(journal_t *journal, tid_t tail_tid,
 	sb->s_sequence = cpu_to_be32(tail_tid);
 	sb->s_start    = cpu_to_be32(tail_block);
 
-	ret = jbd2_write_superblock(journal, write_op);
-	if (ret)
-		goto out;
+	jbd2_write_superblock(journal, write_op);
 
 	/* Log is no longer empty */
 	write_lock(&journal->j_state_lock);
 	WARN_ON(!sb->s_sequence);
 	journal->j_flags &= ~JBD2_FLUSHED;
 	write_unlock(&journal->j_state_lock);
-
-out:
-	return ret;
 }
 
 /**
  * jbd2_mark_journal_empty() - Mark on disk journal as empty.
  * @journal: The journal to update.
- * @write_op: With which operation should we write the journal sb
  *
  * Update a journal's dynamic superblock fields to show that journal is empty.
  * Write updated superblock to disk waiting for IO to complete.
  */
-static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
+static void jbd2_mark_journal_empty(journal_t *journal)
 {
 	journal_superblock_t *sb = journal->j_superblock;
 
@@ -1434,7 +1429,7 @@ static void jbd2_mark_journal_empty(journal_t *journal, int write_op)
 	sb->s_start    = cpu_to_be32(0);
 	read_unlock(&journal->j_state_lock);
 
-	jbd2_write_superblock(journal, write_op);
+	jbd2_write_superblock(journal, WRITE_FUA);
 
 	/* Log is no longer empty */
 	write_lock(&journal->j_state_lock);
@@ -1527,24 +1522,32 @@ static int journal_get_superblock(journal_t *journal)
 		goto out;
 	}
 
-	if (JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM) &&
-	    JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2) &&
+	    JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
+		/* Can't have checksum v2 and v3 at the same time! */
+		printk(KERN_ERR "JBD2: Can't enable checksumming v2 and v3 "
+		       "at the same time!\n");
+		goto out;
+	}
+
+	if (jbd2_journal_has_csum_v2or3(journal) &&
+	    JBD2_HAS_COMPAT_FEATURE(journal, JBD2_FEATURE_COMPAT_CHECKSUM)) {
 		/* Can't have checksum v1 and v2 on at the same time! */
-		printk(KERN_ERR "JBD: Can't enable checksumming v1 and v2 "
+		printk(KERN_ERR "JBD2: Can't enable checksumming v1 and v2/3 "
 		       "at the same time!\n");
 		goto out;
 	}
 
 	if (!jbd2_verify_csum_type(journal, sb)) {
-		printk(KERN_ERR "JBD: Unknown checksum type\n");
+		printk(KERN_ERR "JBD2: Unknown checksum type\n");
 		goto out;
 	}
 
 	/* Load the checksum driver */
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+	if (jbd2_journal_has_csum_v2or3(journal)) {
 		journal->j_chksum_driver = crypto_alloc_shash("crc32c", 0, 0);
 		if (IS_ERR(journal->j_chksum_driver)) {
-			printk(KERN_ERR "JBD: Cannot load crc32c driver.\n");
+			printk(KERN_ERR "JBD2: Cannot load crc32c driver.\n");
 			err = PTR_ERR(journal->j_chksum_driver);
 			journal->j_chksum_driver = NULL;
 			goto out;
@@ -1553,12 +1556,12 @@ static int journal_get_superblock(journal_t *journal)
 
 	/* Check superblock checksum */
 	if (!jbd2_superblock_csum_verify(journal, sb)) {
-		printk(KERN_ERR "JBD: journal checksum error\n");
+		printk(KERN_ERR "JBD2: journal checksum error\n");
 		goto out;
 	}
 
 	/* Precompute checksum seed for all metadata */
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (jbd2_journal_has_csum_v2or3(journal))
 		journal->j_csum_seed = jbd2_chksum(journal, ~0, sb->s_uuid,
 						   sizeof(sb->s_uuid));
 
@@ -1702,13 +1705,7 @@ int jbd2_journal_destroy(journal_t *journal)
 	if (journal->j_sb_buffer) {
 		if (!is_journal_aborted(journal)) {
 			mutex_lock(&journal->j_checkpoint_mutex);
-
-			write_lock(&journal->j_state_lock);
-			journal->j_tail_sequence =
-				++journal->j_transaction_sequence;
-			write_unlock(&journal->j_state_lock);
-
-			jbd2_mark_journal_empty(journal, WRITE_FLUSH_FUA);
+			jbd2_mark_journal_empty(journal);
 			mutex_unlock(&journal->j_checkpoint_mutex);
 		} else
 			err = -EIO;
@@ -1824,8 +1821,14 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 	if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
 		return 0;
 
-	/* Asking for checksumming v2 and v1?  Only give them v2. */
-	if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2 &&
+	/* If enabling v2 checksums, turn on v3 instead */
+	if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V2) {
+		incompat &= ~JBD2_FEATURE_INCOMPAT_CSUM_V2;
+		incompat |= JBD2_FEATURE_INCOMPAT_CSUM_V3;
+	}
+
+	/* Asking for checksumming v3 and v1?  Only give them v3. */
+	if (incompat & JBD2_FEATURE_INCOMPAT_CSUM_V3 &&
 	    compat & JBD2_FEATURE_COMPAT_CHECKSUM)
 		compat &= ~JBD2_FEATURE_COMPAT_CHECKSUM;
 
@@ -1834,8 +1837,8 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 
 	sb = journal->j_superblock;
 
-	/* If enabling v2 checksums, update superblock */
-	if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V2)) {
+	/* If enabling v3 checksums, update superblock */
+	if (INCOMPAT_FEATURE_ON(JBD2_FEATURE_INCOMPAT_CSUM_V3)) {
 		sb->s_checksum_type = JBD2_CRC32C_CHKSUM;
 		sb->s_feature_compat &=
 			~cpu_to_be32(JBD2_FEATURE_COMPAT_CHECKSUM);
@@ -1845,25 +1848,24 @@ int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
 			journal->j_chksum_driver = crypto_alloc_shash("crc32c",
 								      0, 0);
 			if (IS_ERR(journal->j_chksum_driver)) {
-				printk(KERN_ERR "JBD: Cannot load crc32c "
+				printk(KERN_ERR "JBD2: Cannot load crc32c "
 				       "driver.\n");
 				journal->j_chksum_driver = NULL;
 				return 0;
 			}
-		}
 
-		/* Precompute checksum seed for all metadata */
-		if (JBD2_HAS_INCOMPAT_FEATURE(journal,
-					      JBD2_FEATURE_INCOMPAT_CSUM_V2))
+			/* Precompute checksum seed for all metadata */
 			journal->j_csum_seed = jbd2_chksum(journal, ~0,
 							   sb->s_uuid,
 							   sizeof(sb->s_uuid));
+		}
 	}
 
 	/* If enabling v1 checksums, downgrade superblock */
 	if (COMPAT_FEATURE_ON(JBD2_FEATURE_COMPAT_CHECKSUM))
 		sb->s_feature_incompat &=
-			~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2);
+			~cpu_to_be32(JBD2_FEATURE_INCOMPAT_CSUM_V2 |
+				     JBD2_FEATURE_INCOMPAT_CSUM_V3);
 
 	sb->s_feature_compat    |= cpu_to_be32(compat);
 	sb->s_feature_ro_compat |= cpu_to_be32(ro);
@@ -1949,21 +1951,14 @@ int jbd2_journal_flush(journal_t *journal)
 		return -EIO;
 
 	mutex_lock(&journal->j_checkpoint_mutex);
-	if (!err) {
-		err = jbd2_cleanup_journal_tail(journal);
-		if (err < 0) {
-			mutex_unlock(&journal->j_checkpoint_mutex);
-			goto out;
-		}
-		err = 0;
-	}
+	jbd2_cleanup_journal_tail(journal);
 
 	/* Finally, mark the journal as really needing no recovery.
 	 * This sets s_start==0 in the underlying superblock, which is
 	 * the magic code for a fully-recovered superblock.  Any future
 	 * commits of data to the journal will restore the current
 	 * s_start value. */
-	jbd2_mark_journal_empty(journal, WRITE_FUA);
+	jbd2_mark_journal_empty(journal);
 	mutex_unlock(&journal->j_checkpoint_mutex);
 	write_lock(&journal->j_state_lock);
 	J_ASSERT(!journal->j_running_transaction);
@@ -1972,8 +1967,7 @@ int jbd2_journal_flush(journal_t *journal)
 	J_ASSERT(journal->j_head == journal->j_tail);
 	J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
 	write_unlock(&journal->j_state_lock);
-out:
-	return err;
+	return 0;
 }
 
 /**
@@ -2009,7 +2003,7 @@ int jbd2_journal_wipe(journal_t *journal, int write)
 	if (write) {
 		/* Lock to make assertions happy... */
 		mutex_lock(&journal->j_checkpoint_mutex);
-		jbd2_mark_journal_empty(journal, WRITE_FUA);
+		jbd2_mark_journal_empty(journal);
 		mutex_unlock(&journal->j_checkpoint_mutex);
 	}
 
@@ -2060,12 +2054,8 @@ static void __journal_abort_soft (journal_t *journal, int errno)
 
 	__jbd2_journal_abort_hard(journal);
 
-	if (errno) {
+	if (errno)
 		jbd2_journal_update_sb_errno(journal);
-		write_lock(&journal->j_state_lock);
-		journal->j_flags |= JBD2_REC_ERR;
-		write_unlock(&journal->j_state_lock);
-	}
 }
 
 /**
@@ -2188,16 +2178,20 @@ int jbd2_journal_blocks_per_page(struct inode *inode)
  */
 size_t journal_tag_bytes(journal_t *journal)
 {
-	journal_block_tag_t tag;
-	size_t x = 0;
+	size_t sz;
+
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+		return sizeof(journal_block_tag3_t);
+
+	sz = sizeof(journal_block_tag_t);
 
 	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
-		x += sizeof(tag.t_checksum);
+		sz += sizeof(__u16);
 
 	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
-		return x + JBD2_TAG_SIZE64;
+		return sz;
 	else
-		return x + JBD2_TAG_SIZE32;
+		return sz - sizeof(__u32);
 }
 
 /*
@@ -2365,13 +2359,13 @@ static struct journal_head *journal_alloc_journal_head(void)
 #ifdef CONFIG_JBD2_DEBUG
 	atomic_inc(&nr_journal_heads);
 #endif
-	ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
+	ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS);
 	if (!ret) {
 		jbd_debug(1, "out of memory for journal_head\n");
 		pr_notice_ratelimited("ENOMEM in %s, retrying.\n", __func__);
 		while (!ret) {
 			yield();
-			ret = kmem_cache_alloc(jbd2_journal_head_cache, GFP_NOFS);
+			ret = kmem_cache_zalloc(jbd2_journal_head_cache, GFP_NOFS);
 		}
 	}
 	return ret;
@@ -2433,10 +2427,8 @@ struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
 	struct journal_head *new_jh = NULL;
 
 repeat:
-	if (!buffer_jbd(bh)) {
+	if (!buffer_jbd(bh))
 		new_jh = journal_alloc_journal_head();
-		memset(new_jh, 0, sizeof(*new_jh));
-	}
 
 	jbd_lock_bh_journal_head(bh);
 	if (buffer_jbd(bh)) {
@@ -2668,7 +2660,7 @@ static void __exit journal_exit(void)
 #ifdef CONFIG_JBD2_DEBUG
 	int n = atomic_read(&nr_journal_heads);
 	if (n)
-		printk(KERN_EMERG "JBD2: leaked %d journal_heads!\n", n);
+		printk(KERN_ERR "JBD2: leaked %d journal_heads!\n", n);
 #endif
 	jbd2_remove_jbd_stats_proc_entry();
 	jbd2_journal_destroy_caches();
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 6e2fb5cba..bcbef08a4 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -178,9 +178,10 @@ static int jbd2_descr_block_csum_verify(journal_t *j,
 					void *buf)
 {
 	struct jbd2_journal_block_tail *tail;
-	__u32 provided, calculated;
+	__be32 provided;
+	__u32 calculated;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return 1;
 
 	tail = (struct jbd2_journal_block_tail *)(buf + j->j_blocksize -
@@ -190,8 +191,7 @@ static int jbd2_descr_block_csum_verify(journal_t *j,
 	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
 	tail->t_checksum = provided;
 
-	provided = be32_to_cpu(provided);
-	return provided == calculated;
+	return provided == cpu_to_be32(calculated);
 }
 
 /*
@@ -205,7 +205,7 @@ static int count_tags(journal_t *journal, struct buffer_head *bh)
 	int			nr = 0, size = journal->j_blocksize;
 	int			tag_bytes = journal_tag_bytes(journal);
 
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (jbd2_journal_has_csum_v2or3(journal))
 		size -= sizeof(struct jbd2_journal_block_tail);
 
 	tagp = &bh->b_data[sizeof(journal_header_t)];
@@ -338,10 +338,11 @@ int jbd2_journal_skip_recovery(journal_t *journal)
 	return err;
 }
 
-static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
+static inline unsigned long long read_tag_block(journal_t *journal,
+						journal_block_tag_t *tag)
 {
 	unsigned long long block = be32_to_cpu(tag->t_blocknr);
-	if (tag_bytes > JBD2_TAG_SIZE32)
+	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
 		block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
 	return block;
 }
@@ -381,9 +382,10 @@ static int calc_chksums(journal_t *journal, struct buffer_head *bh,
 static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 {
 	struct commit_header *h;
-	__u32 provided, calculated;
+	__be32 provided;
+	__u32 calculated;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return 1;
 
 	h = buf;
@@ -392,25 +394,27 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
 	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
 	h->h_chksum[0] = provided;
 
-	provided = be32_to_cpu(provided);
-	return provided == calculated;
+	return provided == cpu_to_be32(calculated);
 }
 
 static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
 				      void *buf, __u32 sequence)
 {
-	__u32 provided, calculated;
+	journal_block_tag3_t *tag3 = (journal_block_tag3_t *)tag;
+	__u32 csum32;
+	__be32 seq;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return 1;
 
-	sequence = cpu_to_be32(sequence);
-	calculated = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
-				 sizeof(sequence));
-	calculated = jbd2_chksum(j, calculated, buf, j->j_blocksize);
-	provided = be32_to_cpu(tag->t_checksum);
+	seq = cpu_to_be32(sequence);
+	csum32 = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&seq, sizeof(seq));
+	csum32 = jbd2_chksum(j, csum32, buf, j->j_blocksize);
 
-	return provided == cpu_to_be32(calculated);
+	if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V3))
+		return tag3->t_checksum == cpu_to_be32(csum32);
+	else
+		return tag->t_checksum == cpu_to_be16(csum32);
 }
 
 static int do_one_pass(journal_t *journal,
@@ -514,8 +518,7 @@ static int do_one_pass(journal_t *journal,
 		switch(blocktype) {
 		case JBD2_DESCRIPTOR_BLOCK:
 			/* Verify checksum first */
-			if (JBD2_HAS_INCOMPAT_FEATURE(journal,
-					JBD2_FEATURE_INCOMPAT_CSUM_V2))
+			if (jbd2_journal_has_csum_v2or3(journal))
 				descr_csum_size =
 					sizeof(struct jbd2_journal_block_tail);
 			if (descr_csum_size > 0 &&
@@ -577,7 +580,7 @@ static int do_one_pass(journal_t *journal,
 					unsigned long long blocknr;
 
 					J_ASSERT(obh != NULL);
-					blocknr = read_tag_block(tag_bytes,
+					blocknr = read_tag_block(journal,
 								 tag);
 
 					/* If the block has been
@@ -597,7 +600,7 @@ static int do_one_pass(journal_t *journal,
 						be32_to_cpu(tmp->h_sequence))) {
 						brelse(obh);
 						success = -EIO;
-						printk(KERN_ERR "JBD: Invalid "
+						printk(KERN_ERR "JBD2: Invalid "
 						       "checksum recovering "
 						       "block %llu in log\n",
 						       blocknr);
@@ -813,9 +816,10 @@ static int jbd2_revoke_block_csum_verify(journal_t *j,
 					 void *buf)
 {
 	struct jbd2_journal_revoke_tail *tail;
-	__u32 provided, calculated;
+	__be32 provided;
+	__u32 calculated;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return 1;
 
 	tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
@@ -825,8 +829,7 @@ static int jbd2_revoke_block_csum_verify(journal_t *j,
 	calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
 	tail->r_checksum = provided;
 
-	provided = be32_to_cpu(provided);
-	return provided == calculated;
+	return provided == cpu_to_be32(calculated);
 }
 
 /* Scan a revoke record, marking all blocks mentioned as revoked. */
diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index f30b80b4c..c6cbaef2b 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -91,8 +91,9 @@
 #include <linux/list.h>
 #include <linux/init.h>
 #include <linux/bio.h>
-#endif
 #include <linux/log2.h>
+#include <linux/hash.h>
+#endif
 
 static struct kmem_cache *jbd2_revoke_record_cache;
 static struct kmem_cache *jbd2_revoke_table_cache;
@@ -122,23 +123,17 @@ struct jbd2_revoke_table_s
 
 #ifdef __KERNEL__
 static void write_one_revoke_record(journal_t *, transaction_t *,
-				    struct journal_head **, int *,
+				    struct list_head *,
+				    struct buffer_head **, int *,
 				    struct jbd2_revoke_record_s *, int);
-static void flush_descriptor(journal_t *, struct journal_head *, int, int);
+static void flush_descriptor(journal_t *, struct buffer_head *, int, int);
 #endif
 
 /* Utility functions to maintain the revoke table */
 
-/* Borrowed from buffer.c: this is a tried and tested block hash function */
 static inline int hash(journal_t *journal, unsigned long long block)
 {
-	struct jbd2_revoke_table_s *table = journal->j_revoke;
-	int hash_shift = table->hash_shift;
-	int hash = (int)block ^ (int)((block >> 31) >> 1);
-
-	return ((hash << (hash_shift - 6)) ^
-		(hash >> 13) ^
-		(hash << (hash_shift - 12))) & (table->hash_size - 1);
+	return hash_64(block, journal->j_revoke->hash_shift);
 }
 
 static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr,
@@ -531,9 +526,10 @@ void jbd2_journal_switch_revoke_table(journal_t *journal)
  */
 void jbd2_journal_write_revoke_records(journal_t *journal,
 				       transaction_t *transaction,
+				       struct list_head *log_bufs,
 				       int write_op)
 {
-	struct journal_head *descriptor;
+	struct buffer_head *descriptor;
 	struct jbd2_revoke_record_s *record;
 	struct jbd2_revoke_table_s *revoke;
 	struct list_head *hash_list;
@@ -553,7 +549,7 @@ void jbd2_journal_write_revoke_records(journal_t *journal,
 		while (!list_empty(hash_list)) {
 			record = (struct jbd2_revoke_record_s *)
 				hash_list->next;
-			write_one_revoke_record(journal, transaction,
+			write_one_revoke_record(journal, transaction, log_bufs,
 						&descriptor, &offset,
 						record, write_op);
 			count++;
@@ -573,13 +569,14 @@ void jbd2_journal_write_revoke_records(journal_t *journal,
 
 static void write_one_revoke_record(journal_t *journal,
 				    transaction_t *transaction,
-				    struct journal_head **descriptorp,
+				    struct list_head *log_bufs,
+				    struct buffer_head **descriptorp,
 				    int *offsetp,
 				    struct jbd2_revoke_record_s *record,
 				    int write_op)
 {
 	int csum_size = 0;
-	struct journal_head *descriptor;
+	struct buffer_head *descriptor;
 	int offset;
 	journal_header_t *header;
 
@@ -594,7 +591,7 @@ static void write_one_revoke_record(journal_t *journal,
 	offset = *offsetp;
 
 	/* Do we need to leave space at the end for a checksum? */
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (jbd2_journal_has_csum_v2or3(journal))
 		csum_size = sizeof(struct jbd2_journal_revoke_tail);
 
 	/* Make sure we have a descriptor with space left for the record */
@@ -609,26 +606,26 @@ static void write_one_revoke_record(journal_t *journal,
 		descriptor = jbd2_journal_get_descriptor_buffer(journal);
 		if (!descriptor)
 			return;
-		header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
+		header = (journal_header_t *)descriptor->b_data;
 		header->h_magic     = cpu_to_be32(JBD2_MAGIC_NUMBER);
 		header->h_blocktype = cpu_to_be32(JBD2_REVOKE_BLOCK);
 		header->h_sequence  = cpu_to_be32(transaction->t_tid);
 
 		/* Record it so that we can wait for IO completion later */
-		JBUFFER_TRACE(descriptor, "file as BJ_LogCtl");
-		jbd2_journal_file_buffer(descriptor, transaction, BJ_LogCtl);
+		BUFFER_TRACE(descriptor, "file in log_bufs");
+		jbd2_file_log_bh(log_bufs, descriptor);
 
 		offset = sizeof(jbd2_journal_revoke_header_t);
 		*descriptorp = descriptor;
 	}
 
 	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) {
-		* ((__be64 *)(&jh2bh(descriptor)->b_data[offset])) =
+		* ((__be64 *)(&descriptor->b_data[offset])) =
 			cpu_to_be64(record->blocknr);
 		offset += 8;
 
 	} else {
-		* ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
+		* ((__be32 *)(&descriptor->b_data[offset])) =
 			cpu_to_be32(record->blocknr);
 		offset += 4;
 	}
@@ -636,21 +633,18 @@ static void write_one_revoke_record(journal_t *journal,
 	*offsetp = offset;
 }
 
-static void jbd2_revoke_csum_set(journal_t *j,
-				 struct journal_head *descriptor)
+static void jbd2_revoke_csum_set(journal_t *j, struct buffer_head *bh)
 {
 	struct jbd2_journal_revoke_tail *tail;
 	__u32 csum;
 
-	if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+	if (!jbd2_journal_has_csum_v2or3(j))
 		return;
 
-	tail = (struct jbd2_journal_revoke_tail *)
-			(jh2bh(descriptor)->b_data + j->j_blocksize -
+	tail = (struct jbd2_journal_revoke_tail *)(bh->b_data + j->j_blocksize -
 			sizeof(struct jbd2_journal_revoke_tail));
 	tail->r_checksum = 0;
-	csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
-			   j->j_blocksize);
+	csum = jbd2_chksum(j, j->j_csum_seed, bh->b_data, j->j_blocksize);
 	tail->r_checksum = cpu_to_be32(csum);
 }
 
@@ -662,25 +656,24 @@ static void jbd2_revoke_csum_set(journal_t *j,
  */
 
 static void flush_descriptor(journal_t *journal,
-			     struct journal_head *descriptor,
+			     struct buffer_head *descriptor,
 			     int offset, int write_op)
 {
 	jbd2_journal_revoke_header_t *header;
-	struct buffer_head *bh = jh2bh(descriptor);
 
 	if (is_journal_aborted(journal)) {
-		put_bh(bh);
+		put_bh(descriptor);
 		return;
 	}
 
-	header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
+	header = (jbd2_journal_revoke_header_t *)descriptor->b_data;
 	header->r_count = cpu_to_be32(offset);
 	jbd2_revoke_csum_set(journal, descriptor);
 
-	set_buffer_jwrite(bh);
-	BUFFER_TRACE(bh, "write");
-	set_buffer_dirty(bh);
-	write_dirty_buffer(bh, write_op);
+	set_buffer_jwrite(descriptor);
+	BUFFER_TRACE(descriptor, "write");
+	set_buffer_dirty(descriptor);
+	write_dirty_buffer(descriptor, write_op);
 }
 #endif
 
diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 21b828c71..5f09370c9 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -89,7 +89,8 @@ jbd2_get_transaction(journal_t *journal, transaction_t *transaction)
 	transaction->t_expires = jiffies + journal->j_commit_interval;
 	spin_lock_init(&transaction->t_handle_lock);
 	atomic_set(&transaction->t_updates, 0);
-	atomic_set(&transaction->t_outstanding_credits, 0);
+	atomic_set(&transaction->t_outstanding_credits,
+		   atomic_read(&journal->j_reserved_credits));
 	atomic_set(&transaction->t_handle_count, 0);
 	INIT_LIST_HEAD(&transaction->t_inode_list);
 	INIT_LIST_HEAD(&transaction->t_private_list);
@@ -141,6 +142,112 @@ static inline void update_t_max_wait(transaction_t *transaction,
 }
 
 /*
+ * Wait until running transaction passes T_LOCKED state. Also starts the commit
+ * if needed. The function expects running transaction to exist and releases
+ * j_state_lock.
+ */
+static void wait_transaction_locked(journal_t *journal)
+	__releases(journal->j_state_lock)
+{
+	DEFINE_WAIT(wait);
+	int need_to_start;
+	tid_t tid = journal->j_running_transaction->t_tid;
+
+	prepare_to_wait(&journal->j_wait_transaction_locked, &wait,
+			TASK_UNINTERRUPTIBLE);
+	need_to_start = !tid_geq(journal->j_commit_request, tid);
+	read_unlock(&journal->j_state_lock);
+	if (need_to_start)
+		jbd2_log_start_commit(journal, tid);
+	schedule();
+	finish_wait(&journal->j_wait_transaction_locked, &wait);
+}
+
+static void sub_reserved_credits(journal_t *journal, int blocks)
+{
+	atomic_sub(blocks, &journal->j_reserved_credits);
+	wake_up(&journal->j_wait_reserved);
+}
+
+/*
+ * Wait until we can add credits for handle to the running transaction.  Called
+ * with j_state_lock held for reading. Returns 0 if handle joined the running
+ * transaction. Returns 1 if we had to wait, j_state_lock is dropped, and
+ * caller must retry.
+ */
+static int add_transaction_credits(journal_t *journal, int blocks,
+				   int rsv_blocks)
+{
+	transaction_t *t = journal->j_running_transaction;
+	int needed;
+	int total = blocks + rsv_blocks;
+
+	/*
+	 * If the current transaction is locked down for commit, wait
+	 * for the lock to be released.
+	 */
+	if (t->t_state == T_LOCKED) {
+		wait_transaction_locked(journal);
+		return 1;
+	}
+
+	/*
+	 * If there is not enough space left in the log to write all
+	 * potential buffers requested by this operation, we need to
+	 * stall pending a log checkpoint to free some more log space.
+	 */
+	needed = atomic_add_return(total, &t->t_outstanding_credits);
+	if (needed > journal->j_max_transaction_buffers) {
+		/*
+		 * If the current transaction is already too large,
+		 * then start to commit it: we can then go back and
+		 * attach this handle to a new transaction.
+		 */
+		atomic_sub(total, &t->t_outstanding_credits);
+		wait_transaction_locked(journal);
+		return 1;
+	}
+
+	/*
+	 * The commit code assumes that it can get enough log space
+	 * without forcing a checkpoint.  This is *critical* for
+	 * correctness: a checkpoint of a buffer which is also
+	 * associated with a committing transaction creates a deadlock,
+	 * so commit simply cannot force through checkpoints.
+	 *
+	 * We must therefore ensure the necessary space in the journal
+	 * *before* starting to dirty potentially checkpointed buffers
+	 * in the new transaction.
+	 */
+	if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) {
+		atomic_sub(total, &t->t_outstanding_credits);
+		read_unlock(&journal->j_state_lock);
+		write_lock(&journal->j_state_lock);
+		if (jbd2_log_space_left(journal) < jbd2_space_needed(journal))
+			__jbd2_log_wait_for_space(journal);
+		write_unlock(&journal->j_state_lock);
+		return 1;
+	}
+
+	/* No reservation? We are done... */
+	if (!rsv_blocks)
+		return 0;
+
+	needed = atomic_add_return(rsv_blocks, &journal->j_reserved_credits);
+	/* We allow at most half of a transaction to be reserved */
+	if (needed > journal->j_max_transaction_buffers / 2) {
+		sub_reserved_credits(journal, rsv_blocks);
+		atomic_sub(total, &t->t_outstanding_credits);
+		read_unlock(&journal->j_state_lock);
+		wait_event(journal->j_wait_reserved,
+			 atomic_read(&journal->j_reserved_credits) + rsv_blocks
+			 <= journal->j_max_transaction_buffers / 2);
+		return 1;
+	}
+	return 0;
+}
+
+/*
  * start_this_handle: Given a handle, deal with any locking or stalling
  * needed to make sure that there is enough journal space for the handle
  * to begin.  Attach the handle to a transaction and set up the
@@ -151,18 +258,24 @@ static int start_this_handle(journal_t *journal, handle_t *handle,
 			     gfp_t gfp_mask)
 {
 	transaction_t	*transaction, *new_transaction = NULL;
-	tid_t		tid;
-	int		needed, need_to_start;
-	int		nblocks = handle->h_buffer_credits;
+	int		blocks = handle->h_buffer_credits;
+	int		rsv_blocks = 0;
 	unsigned long ts = jiffies;
 
-	if (nblocks > journal->j_max_transaction_buffers) {
+	/*
+	 * 1/2 of transaction can be reserved so we can practically handle
+	 * only 1/2 of maximum transaction size per operation
+	 */
+	if (WARN_ON(blocks > journal->j_max_transaction_buffers / 2)) {
 		printk(KERN_ERR "JBD2: %s wants too many credits (%d > %d)\n",
-		       current->comm, nblocks,
-		       journal->j_max_transaction_buffers);
+		       current->comm, blocks,
+		       journal->j_max_transaction_buffers / 2);
 		return -ENOSPC;
 	}
 
+	if (handle->h_rsv_handle)
+		rsv_blocks = handle->h_rsv_handle->h_buffer_credits;
+
 alloc_transaction:
 	if (!journal->j_running_transaction) {
 		new_transaction = kmem_cache_zalloc(transaction_cache,
@@ -199,8 +312,12 @@ repeat:
 		return -EROFS;
 	}
 
-	/* Wait on the journal's transaction barrier if necessary */
-	if (journal->j_barrier_count) {
+	/*
+	 * Wait on the journal's transaction barrier if necessary. Specifically
+	 * we allow reserved handles to proceed because otherwise commit could
+	 * deadlock on page writeback not being able to complete.
+	 */
+	if (!handle->h_reserved && journal->j_barrier_count) {
 		read_unlock(&journal->j_state_lock);
 		wait_event(journal->j_wait_transaction_locked,
 				journal->j_barrier_count == 0);
@@ -213,7 +330,7 @@ repeat:
 			goto alloc_transaction;
 		write_lock(&journal->j_state_lock);
 		if (!journal->j_running_transaction &&
-		    !journal->j_barrier_count) {
+		    (handle->h_reserved || !journal->j_barrier_count)) {
 			jbd2_get_transaction(journal, new_transaction);
 			new_transaction = NULL;
 		}
@@ -223,85 +340,18 @@ repeat:
 
 	transaction = journal->j_running_transaction;
 
-	/*
-	 * If the current transaction is locked down for commit, wait for the
-	 * lock to be released.
-	 */
-	if (transaction->t_state == T_LOCKED) {
-		DEFINE_WAIT(wait);
-
-		prepare_to_wait(&journal->j_wait_transaction_locked,
-					&wait, TASK_UNINTERRUPTIBLE);
-		read_unlock(&journal->j_state_lock);
-		schedule();
-		finish_wait(&journal->j_wait_transaction_locked, &wait);
-		goto repeat;
-	}
-
-	/*
-	 * If there is not enough space left in the log to write all potential
-	 * buffers requested by this operation, we need to stall pending a log
-	 * checkpoint to free some more log space.
-	 */
-	needed = atomic_add_return(nblocks,
-				   &transaction->t_outstanding_credits);
-
-	if (needed > journal->j_max_transaction_buffers) {
+	if (!handle->h_reserved) {
+		/* We may have dropped j_state_lock - restart in that case */
+		if (add_transaction_credits(journal, blocks, rsv_blocks))
+			goto repeat;
+	} else {
 		/*
-		 * If the current transaction is already too large, then start
-		 * to commit it: we can then go back and attach this handle to
-		 * a new transaction.
+		 * We have handle reserved so we are allowed to join T_LOCKED
+		 * transaction and we don't have to check for transaction size
+		 * and journal space.
 		 */
-		DEFINE_WAIT(wait);
-
-		jbd_debug(2, "Handle %p starting new commit...\n", handle);
-		atomic_sub(nblocks, &transaction->t_outstanding_credits);
-		prepare_to_wait(&journal->j_wait_transaction_locked, &wait,
-				TASK_UNINTERRUPTIBLE);
-		tid = transaction->t_tid;
-		need_to_start = !tid_geq(journal->j_commit_request, tid);
-		read_unlock(&journal->j_state_lock);
-		if (need_to_start)
-			jbd2_log_start_commit(journal, tid);
-		schedule();
-		finish_wait(&journal->j_wait_transaction_locked, &wait);
-		goto repeat;
-	}
-
-	/*
-	 * The commit code assumes that it can get enough log space
-	 * without forcing a checkpoint.  This is *critical* for
-	 * correctness: a checkpoint of a buffer which is also
-	 * associated with a committing transaction creates a deadlock,
-	 * so commit simply cannot force through checkpoints.
-	 *
-	 * We must therefore ensure the necessary space in the journal
-	 * *before* starting to dirty potentially checkpointed buffers
-	 * in the new transaction.
-	 *
-	 * The worst part is, any transaction currently committing can
-	 * reduce the free space arbitrarily.  Be careful to account for
-	 * those buffers when checkpointing.
-	 */
-
-	/*
-	 * @@@ AKPM: This seems rather over-defensive.  We're giving commit
-	 * a _lot_ of headroom: 1/4 of the journal plus the size of
-	 * the committing transaction.  Really, we only need to give it
-	 * committing_transaction->t_outstanding_credits plus "enough" for
-	 * the log control blocks.
-	 * Also, this test is inconsistent with the matching one in
-	 * jbd2_journal_extend().
-	 */
-	if (__jbd2_log_space_left(journal) < jbd_space_needed(journal)) {
-		jbd_debug(2, "Handle %p waiting for checkpoint...\n", handle);
-		atomic_sub(nblocks, &transaction->t_outstanding_credits);
-		read_unlock(&journal->j_state_lock);
-		write_lock(&journal->j_state_lock);
-		if (__jbd2_log_space_left(journal) < jbd_space_needed(journal))
-			__jbd2_log_wait_for_space(journal);
-		write_unlock(&journal->j_state_lock);
-		goto repeat;
+		sub_reserved_credits(journal, blocks);
+		handle->h_reserved = 0;
 	}
 
 	/* OK, account for the buffers that this operation expects to
@@ -309,15 +359,16 @@ repeat:
 	 */
 	update_t_max_wait(transaction, ts);
 	handle->h_transaction = transaction;
-	handle->h_requested_credits = nblocks;
+	handle->h_requested_credits = blocks;
 	handle->h_start_jiffies = jiffies;
 	atomic_inc(&transaction->t_updates);
 	atomic_inc(&transaction->t_handle_count);
-	jbd_debug(4, "Handle %p given %d credits (total %d, free %d)\n",
-		  handle, nblocks,
+	jbd_debug(4, "Handle %p given %d credits (total %d, free %lu)\n",
+		  handle, blocks,
 		  atomic_read(&transaction->t_outstanding_credits),
-		  __jbd2_log_space_left(journal));
+		  jbd2_log_space_left(journal));
 	read_unlock(&journal->j_state_lock);
+	current->journal_info = handle;
 
 	lock_map_acquire(&handle->h_lockdep_map);
 	jbd2_journal_free_transaction(new_transaction);
@@ -348,16 +399,21 @@ static handle_t *new_handle(int nblocks)
  *
  * We make sure that the transaction can guarantee at least nblocks of
  * modified buffers in the log.  We block until the log can guarantee
- * that much space.
- *
- * This function is visible to journal users (like ext3fs), so is not
- * called with the journal already locked.
+ * that much space. Additionally, if rsv_blocks > 0, we also create another
+ * handle with rsv_blocks reserved blocks in the journal. This handle is
+ * is stored in h_rsv_handle. It is not attached to any particular transaction
+ * and thus doesn't block transaction commit. If the caller uses this reserved
+ * handle, it has to set h_rsv_handle to NULL as otherwise jbd2_journal_stop()
+ * on the parent handle will dispose the reserved one. Reserved handle has to
+ * be converted to a normal handle using jbd2_journal_start_reserved() before
+ * it can be used.
  *
  * Return a pointer to a newly allocated handle, or an ERR_PTR() value
  * on failure.
  */
-handle_t *jbd2__journal_start(journal_t *journal, int nblocks, gfp_t gfp_mask,
-			      unsigned int type, unsigned int line_no)
+handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks,
+			      gfp_t gfp_mask, unsigned int type,
+			      unsigned int line_no)
 {
 	handle_t *handle = journal_current_handle();
 	int err;
@@ -374,13 +430,24 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, gfp_t gfp_mask,
 	handle = new_handle(nblocks);
 	if (!handle)
 		return ERR_PTR(-ENOMEM);
+	if (rsv_blocks) {
+		handle_t *rsv_handle;
 
-	current->journal_info = handle;
+		rsv_handle = new_handle(rsv_blocks);
+		if (!rsv_handle) {
+			jbd2_free_handle(handle);
+			return ERR_PTR(-ENOMEM);
+		}
+		rsv_handle->h_reserved = 1;
+		rsv_handle->h_journal = journal;
+		handle->h_rsv_handle = rsv_handle;
+	}
 
 	err = start_this_handle(journal, handle, gfp_mask);
 	if (err < 0) {
+		if (handle->h_rsv_handle)
+			jbd2_free_handle(handle->h_rsv_handle);
 		jbd2_free_handle(handle);
-		current->journal_info = NULL;
 		return ERR_PTR(err);
 	}
 	handle->h_type = type;
@@ -395,10 +462,67 @@ EXPORT_SYMBOL(jbd2__journal_start);
 
 handle_t *jbd2_journal_start(journal_t *journal, int nblocks)
 {
-	return jbd2__journal_start(journal, nblocks, GFP_NOFS, 0, 0);
+	return jbd2__journal_start(journal, nblocks, 0, GFP_NOFS, 0, 0);
 }
 EXPORT_SYMBOL(jbd2_journal_start);
 
+void jbd2_journal_free_reserved(handle_t *handle)
+{
+	journal_t *journal = handle->h_journal;
+
+	WARN_ON(!handle->h_reserved);
+	sub_reserved_credits(journal, handle->h_buffer_credits);
+	jbd2_free_handle(handle);
+}
+EXPORT_SYMBOL(jbd2_journal_free_reserved);
+
+/**
+ * int jbd2_journal_start_reserved(handle_t *handle) - start reserved handle
+ * @handle: handle to start
+ *
+ * Start handle that has been previously reserved with jbd2_journal_reserve().
+ * This attaches @handle to the running transaction (or creates one if there's
+ * not transaction running). Unlike jbd2_journal_start() this function cannot
+ * block on journal commit, checkpointing, or similar stuff. It can block on
+ * memory allocation or frozen journal though.
+ *
+ * Return 0 on success, non-zero on error - handle is freed in that case.
+ */
+int jbd2_journal_start_reserved(handle_t *handle, unsigned int type,
+				unsigned int line_no)
+{
+	journal_t *journal = handle->h_journal;
+	int ret = -EIO;
+
+	if (WARN_ON(!handle->h_reserved)) {
+		/* Someone passed in normal handle? Just stop it. */
+		jbd2_journal_stop(handle);
+		return ret;
+	}
+	/*
+	 * Usefulness of mixing of reserved and unreserved handles is
+	 * questionable. So far nobody seems to need it so just error out.
+	 */
+	if (WARN_ON(current->journal_info)) {
+		jbd2_journal_free_reserved(handle);
+		return ret;
+	}
+
+	handle->h_journal = NULL;
+	/*
+	 * GFP_NOFS is here because callers are likely from writeback or
+	 * similarly constrained call sites
+	 */
+	ret = start_this_handle(journal, handle, GFP_NOFS);
+	if (ret < 0) {
+		jbd2_journal_free_reserved(handle);
+		return ret;
+	}
+	handle->h_type = type;
+	handle->h_line_no = line_no;
+	return 0;
+}
+EXPORT_SYMBOL(jbd2_journal_start_reserved);
 
 /**
  * int jbd2_journal_extend() - extend buffer credits.
@@ -423,49 +547,53 @@ EXPORT_SYMBOL(jbd2_journal_start);
 int jbd2_journal_extend(handle_t *handle, int nblocks)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
+	journal_t *journal;
 	int result;
 	int wanted;
 
-	result = -EIO;
+	WARN_ON(!transaction);
 	if (is_handle_aborted(handle))
-		goto out;
+		return -EROFS;
+	journal = transaction->t_journal;
 
 	result = 1;
 
 	read_lock(&journal->j_state_lock);
 
 	/* Don't extend a locked-down transaction! */
-	if (handle->h_transaction->t_state != T_RUNNING) {
+	if (transaction->t_state != T_RUNNING) {
 		jbd_debug(3, "denied handle %p %d blocks: "
 			  "transaction not running\n", handle, nblocks);
 		goto error_out;
 	}
 
 	spin_lock(&transaction->t_handle_lock);
-	wanted = atomic_read(&transaction->t_outstanding_credits) + nblocks;
+	wanted = atomic_add_return(nblocks,
+				   &transaction->t_outstanding_credits);
 
 	if (wanted > journal->j_max_transaction_buffers) {
 		jbd_debug(3, "denied handle %p %d blocks: "
 			  "transaction too large\n", handle, nblocks);
+		atomic_sub(nblocks, &transaction->t_outstanding_credits);
 		goto unlock;
 	}
 
-	if (wanted > __jbd2_log_space_left(journal)) {
+	if (wanted + (wanted >> JBD2_CONTROL_BLOCKS_SHIFT) >
+	    jbd2_log_space_left(journal)) {
 		jbd_debug(3, "denied handle %p %d blocks: "
 			  "insufficient log space\n", handle, nblocks);
+		atomic_sub(nblocks, &transaction->t_outstanding_credits);
 		goto unlock;
 	}
 
 	trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev,
-				 handle->h_transaction->t_tid,
+				 transaction->t_tid,
 				 handle->h_type, handle->h_line_no,
 				 handle->h_buffer_credits,
 				 nblocks);
 
 	handle->h_buffer_credits += nblocks;
 	handle->h_requested_credits += nblocks;
-	atomic_add(nblocks, &transaction->t_outstanding_credits);
 	result = 0;
 
 	jbd_debug(3, "extended handle %p by %d\n", handle, nblocks);
@@ -473,7 +601,6 @@ unlock:
 	spin_unlock(&transaction->t_handle_lock);
 error_out:
 	read_unlock(&journal->j_state_lock);
-out:
 	return result;
 }
 
@@ -490,19 +617,22 @@ out:
  * to a running handle, a call to jbd2_journal_restart will commit the
  * handle's transaction so far and reattach the handle to a new
  * transaction capabable of guaranteeing the requested number of
- * credits.
+ * credits. We preserve reserved handle if there's any attached to the
+ * passed in handle.
  */
 int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
+	journal_t *journal;
 	tid_t		tid;
 	int		need_to_start, ret;
 
+	WARN_ON(!transaction);
 	/* If we've had an abort of any type, don't even think about
 	 * actually doing the restart! */
 	if (is_handle_aborted(handle))
 		return 0;
+	journal = transaction->t_journal;
 
 	/*
 	 * First unlink the handle from its current transaction, and start the
@@ -515,10 +645,16 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask)
 	spin_lock(&transaction->t_handle_lock);
 	atomic_sub(handle->h_buffer_credits,
 		   &transaction->t_outstanding_credits);
+	if (handle->h_rsv_handle) {
+		sub_reserved_credits(journal,
+				     handle->h_rsv_handle->h_buffer_credits);
+	}
 	if (atomic_dec_and_test(&transaction->t_updates))
 		wake_up(&journal->j_wait_updates);
 	tid = transaction->t_tid;
 	spin_unlock(&transaction->t_handle_lock);
+	handle->h_transaction = NULL;
+	current->journal_info = NULL;
 
 	jbd_debug(2, "restarting handle %p\n", handle);
 	need_to_start = !tid_geq(journal->j_commit_request, tid);
@@ -557,6 +693,14 @@ void jbd2_journal_lock_updates(journal_t *journal)
 	write_lock(&journal->j_state_lock);
 	++journal->j_barrier_count;
 
+	/* Wait until there are no reserved handles */
+	if (atomic_read(&journal->j_reserved_credits)) {
+		write_unlock(&journal->j_state_lock);
+		wait_event(journal->j_wait_reserved,
+			   atomic_read(&journal->j_reserved_credits) == 0);
+		write_lock(&journal->j_state_lock);
+	}
+
 	/* Wait until there are no running updates */
 	while (1) {
 		transaction_t *transaction = journal->j_running_transaction;
@@ -634,17 +778,16 @@ do_get_write_access(handle_t *handle, struct journal_head *jh,
 			int force_copy)
 {
 	struct buffer_head *bh;
-	transaction_t *transaction;
+	transaction_t *transaction = handle->h_transaction;
 	journal_t *journal;
 	int error;
 	char *frozen_buffer = NULL;
 	int need_copy = 0;
 	unsigned long start_lock, time_lock;
 
+	WARN_ON(!transaction);
 	if (is_handle_aborted(handle))
 		return -EROFS;
-
-	transaction = handle->h_transaction;
 	journal = transaction->t_journal;
 
 	jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy);
@@ -754,41 +897,29 @@ repeat:
 		 * journaled.  If the primary copy is already going to
 		 * disk then we cannot do copy-out here. */
 
-		if (jh->b_jlist == BJ_Shadow) {
-			DEFINE_WAIT_BIT(wait, &bh->b_state, BH_Unshadow);
-			wait_queue_head_t *wqh;
-
-			wqh = bit_waitqueue(&bh->b_state, BH_Unshadow);
-
+		if (buffer_shadow(bh)) {
 			JBUFFER_TRACE(jh, "on shadow: sleep");
 			jbd_unlock_bh_state(bh);
-			/* commit wakes up all shadow buffers after IO */
-			for ( ; ; ) {
-				prepare_to_wait(wqh, &wait.wait,
-						TASK_UNINTERRUPTIBLE);
-				if (jh->b_jlist != BJ_Shadow)
-					break;
-				schedule();
-			}
-			finish_wait(wqh, &wait.wait);
+			wait_on_bit_io(&bh->b_state, BH_Shadow,
+				       TASK_UNINTERRUPTIBLE);
 			goto repeat;
 		}
 
-		/* Only do the copy if the currently-owning transaction
-		 * still needs it.  If it is on the Forget list, the
-		 * committing transaction is past that stage.  The
-		 * buffer had better remain locked during the kmalloc,
-		 * but that should be true --- we hold the journal lock
-		 * still and the buffer is already on the BUF_JOURNAL
-		 * list so won't be flushed.
+		/*
+		 * Only do the copy if the currently-owning transaction still
+		 * needs it. If buffer isn't on BJ_Metadata list, the
+		 * committing transaction is past that stage (here we use the
+		 * fact that BH_Shadow is set under bh_state lock together with
+		 * refiling to BJ_Shadow list and at this point we know the
+		 * buffer doesn't have BH_Shadow set).
 		 *
 		 * Subtle point, though: if this is a get_undo_access,
 		 * then we will be relying on the frozen_data to contain
 		 * the new value of the committed_data record after the
 		 * transaction, so we HAVE to force the frozen_data copy
-		 * in that case. */
-
-		if (jh->b_jlist != BJ_Forget || force_copy) {
+		 * in that case.
+		 */
+		if (jh->b_jlist == BJ_Metadata || force_copy) {
 			JBUFFER_TRACE(jh, "generate frozen data");
 			if (!frozen_buffer) {
 				JBUFFER_TRACE(jh, "allocate memory for buffer");
@@ -797,7 +928,7 @@ repeat:
 					jbd2_alloc(jh2bh(jh)->b_size,
 							 GFP_NOFS);
 				if (!frozen_buffer) {
-					printk(KERN_EMERG
+					printk(KERN_ERR
 					       "%s: OOM for frozen_buffer\n",
 					       __func__);
 					JBUFFER_TRACE(jh, "oom!");
@@ -915,14 +1046,16 @@ int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh)
 int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
+	journal_t *journal;
 	struct journal_head *jh = jbd2_journal_add_journal_head(bh);
 	int err;
 
 	jbd_debug(5, "journal_head %p\n", jh);
+	WARN_ON(!transaction);
 	err = -EROFS;
 	if (is_handle_aborted(handle))
 		goto out;
+	journal = transaction->t_journal;
 	err = 0;
 
 	JBUFFER_TRACE(jh, "entry");
@@ -934,7 +1067,6 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
 	 * reused here.
 	 */
 	jbd_lock_bh_state(bh);
-	spin_lock(&journal->j_list_lock);
 	J_ASSERT_JH(jh, (jh->b_transaction == transaction ||
 		jh->b_transaction == NULL ||
 		(jh->b_transaction == journal->j_committing_transaction &&
@@ -957,12 +1089,14 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
 		jh->b_modified = 0;
 
 		JBUFFER_TRACE(jh, "file as BJ_Reserved");
+		spin_lock(&journal->j_list_lock);
 		__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
 	} else if (jh->b_transaction == journal->j_committing_transaction) {
 		/* first access by this transaction */
 		jh->b_modified = 0;
 
 		JBUFFER_TRACE(jh, "set next transaction");
+		spin_lock(&journal->j_list_lock);
 		jh->b_next_transaction = transaction;
 	}
 	spin_unlock(&journal->j_list_lock);
@@ -1029,7 +1163,7 @@ repeat:
 	if (!jh->b_committed_data) {
 		committed_data = jbd2_alloc(jh2bh(jh)->b_size, GFP_NOFS);
 		if (!committed_data) {
-			printk(KERN_EMERG "%s: No memory for committed data\n",
+			printk(KERN_ERR "%s: No memory for committed data\n",
 				__func__);
 			err = -ENOMEM;
 			goto out;
@@ -1128,12 +1262,14 @@ void jbd2_buffer_abort_trigger(struct journal_head *jh,
 int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
+	journal_t *journal;
 	struct journal_head *jh;
 	int ret = 0;
 
+	WARN_ON(!transaction);
 	if (is_handle_aborted(handle))
-		goto out;
+		return -EROFS;
+	journal = transaction->t_journal;
 	jh = jbd2_journal_grab_journal_head(bh);
 	if (!jh) {
 		ret = -EUCLEAN;
@@ -1169,9 +1305,9 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
 		JBUFFER_TRACE(jh, "fastpath");
 		if (unlikely(jh->b_transaction !=
 			     journal->j_running_transaction)) {
-			printk(KERN_EMERG "JBD: %s: "
+			printk(KERN_ERR "JBD2: %s: "
 			       "jh->b_transaction (%llu, %p, %u) != "
-			       "journal->j_running_transaction (%p, %u)",
+			       "journal->j_running_transaction (%p, %u)\n",
 			       journal->j_devname,
 			       (unsigned long long) bh->b_blocknr,
 			       jh->b_transaction,
@@ -1194,30 +1330,25 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
 	 */
 	if (jh->b_transaction != transaction) {
 		JBUFFER_TRACE(jh, "already on other transaction");
-		if (unlikely(jh->b_transaction !=
-			     journal->j_committing_transaction)) {
-			printk(KERN_EMERG "JBD: %s: "
-			       "jh->b_transaction (%llu, %p, %u) != "
-			       "journal->j_committing_transaction (%p, %u)",
+		if (unlikely(((jh->b_transaction !=
+			       journal->j_committing_transaction)) ||
+			     (jh->b_next_transaction != transaction))) {
+			printk(KERN_ERR "jbd2_journal_dirty_metadata: %s: "
+			       "bad jh for block %llu: "
+			       "transaction (%p, %u), "
+			       "jh->b_transaction (%p, %u), "
+			       "jh->b_next_transaction (%p, %u), jlist %u\n",
 			       journal->j_devname,
 			       (unsigned long long) bh->b_blocknr,
+			       transaction, transaction->t_tid,
 			       jh->b_transaction,
-			       jh->b_transaction ? jh->b_transaction->t_tid : 0,
-			       journal->j_committing_transaction,
-			       journal->j_committing_transaction ?
-			       journal->j_committing_transaction->t_tid : 0);
-			ret = -EINVAL;
-		}
-		if (unlikely(jh->b_next_transaction != transaction)) {
-			printk(KERN_EMERG "JBD: %s: "
-			       "jh->b_next_transaction (%llu, %p, %u) != "
-			       "transaction (%p, %u)",
-			       journal->j_devname,
-			       (unsigned long long) bh->b_blocknr,
+			       jh->b_transaction ?
+			       jh->b_transaction->t_tid : 0,
 			       jh->b_next_transaction,
 			       jh->b_next_transaction ?
 			       jh->b_next_transaction->t_tid : 0,
-			       transaction, transaction->t_tid);
+			       jh->b_jlist);
+			WARN_ON(1);
 			ret = -EINVAL;
 		}
 		/* And this case is illegal: we can't reuse another
@@ -1230,7 +1361,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
 
 	JBUFFER_TRACE(jh, "file as BJ_Metadata");
 	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata);
+	__jbd2_journal_file_buffer(jh, transaction, BJ_Metadata);
 	spin_unlock(&journal->j_list_lock);
 out_unlock_bh:
 	jbd_unlock_bh_state(bh);
@@ -1260,16 +1391,20 @@ out:
 int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
+	journal_t *journal;
 	struct journal_head *jh;
 	int drop_reserve = 0;
 	int err = 0;
 	int was_modified = 0;
 
+	WARN_ON(!transaction);
+	if (is_handle_aborted(handle))
+		return -EROFS;
+	journal = transaction->t_journal;
+
 	BUFFER_TRACE(bh, "entry");
 
 	jbd_lock_bh_state(bh);
-	spin_lock(&journal->j_list_lock);
 
 	if (!buffer_jbd(bh))
 		goto not_jbd;
@@ -1292,7 +1427,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 	 */
 	jh->b_modified = 0;
 
-	if (jh->b_transaction == handle->h_transaction) {
+	if (jh->b_transaction == transaction) {
 		J_ASSERT_JH(jh, !jh->b_frozen_data);
 
 		/* If we are forgetting a buffer which is already part
@@ -1322,6 +1457,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 		 * we know to remove the checkpoint after we commit.
 		 */
 
+		spin_lock(&journal->j_list_lock);
 		if (jh->b_cp_transaction) {
 			__jbd2_journal_temp_unlink_buffer(jh);
 			__jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
@@ -1334,6 +1470,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 				goto drop;
 			}
 		}
+		spin_unlock(&journal->j_list_lock);
 	} else if (jh->b_transaction) {
 		J_ASSERT_JH(jh, (jh->b_transaction ==
 				 journal->j_committing_transaction));
@@ -1345,7 +1482,9 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 
 		if (jh->b_next_transaction) {
 			J_ASSERT(jh->b_next_transaction == transaction);
+			spin_lock(&journal->j_list_lock);
 			jh->b_next_transaction = NULL;
+			spin_unlock(&journal->j_list_lock);
 
 			/*
 			 * only drop a reference if this transaction modified
@@ -1357,7 +1496,6 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
 	}
 
 not_jbd:
-	spin_unlock(&journal->j_list_lock);
 	jbd_unlock_bh_state(bh);
 	__brelse(bh);
 drop:
@@ -1387,19 +1525,21 @@ drop:
 int jbd2_journal_stop(handle_t *handle)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
-	int err, wait_for_commit = 0;
+	journal_t *journal;
+	int err = 0, wait_for_commit = 0;
 	tid_t tid;
 	pid_t pid;
 
+	if (!transaction)
+		goto free_and_exit;
+	journal = transaction->t_journal;
+
 	J_ASSERT(journal_current_handle() == handle);
 
 	if (is_handle_aborted(handle))
 		err = -EIO;
-	else {
+	else
 		J_ASSERT(atomic_read(&transaction->t_updates) > 0);
-		err = 0;
-	}
 
 	if (--handle->h_ref > 0) {
 		jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
@@ -1409,7 +1549,7 @@ int jbd2_journal_stop(handle_t *handle)
 
 	jbd_debug(4, "Handle %p going down\n", handle);
 	trace_jbd2_handle_stats(journal->j_fs_dev->bd_dev,
-				handle->h_transaction->t_tid,
+				transaction->t_tid,
 				handle->h_type, handle->h_line_no,
 				jiffies - handle->h_start_jiffies,
 				handle->h_sync, handle->h_requested_credits,
@@ -1523,33 +1663,13 @@ int jbd2_journal_stop(handle_t *handle)
 
 	lock_map_release(&handle->h_lockdep_map);
 
+	if (handle->h_rsv_handle)
+		jbd2_journal_free_reserved(handle->h_rsv_handle);
+free_and_exit:
 	jbd2_free_handle(handle);
 	return err;
 }
 
-/**
- * int jbd2_journal_force_commit() - force any uncommitted transactions
- * @journal: journal to force
- *
- * For synchronous operations: force any uncommitted transactions
- * to disk.  May seem kludgy, but it reuses all the handle batching
- * code in a very simple manner.
- */
-int jbd2_journal_force_commit(journal_t *journal)
-{
-	handle_t *handle;
-	int ret;
-
-	handle = jbd2_journal_start(journal, 1);
-	if (IS_ERR(handle)) {
-		ret = PTR_ERR(handle);
-	} else {
-		handle->h_sync = 1;
-		ret = jbd2_journal_stop(handle);
-	}
-	return ret;
-}
-
 /*
  *
  * List management code snippets: various functions for manipulating the
@@ -1606,10 +1726,10 @@ __blist_del_buffer(struct journal_head **list, struct journal_head *jh)
  * Remove a buffer from the appropriate transaction list.
  *
  * Note that this function can *change* the value of
- * bh->b_transaction->t_buffers, t_forget, t_iobuf_list, t_shadow_list,
- * t_log_list or t_reserved_list.  If the caller is holding onto a copy of one
- * of these pointers, it could go bad.  Generally the caller needs to re-read
- * the pointer from the transaction_t.
+ * bh->b_transaction->t_buffers, t_forget, t_shadow_list, t_log_list or
+ * t_reserved_list.  If the caller is holding onto a copy of one of these
+ * pointers, it could go bad.  Generally the caller needs to re-read the
+ * pointer from the transaction_t.
  *
  * Called under j_list_lock.
  */
@@ -1639,15 +1759,9 @@ static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
 	case BJ_Forget:
 		list = &transaction->t_forget;
 		break;
-	case BJ_IO:
-		list = &transaction->t_iobuf_list;
-		break;
 	case BJ_Shadow:
 		list = &transaction->t_shadow_list;
 		break;
-	case BJ_LogCtl:
-		list = &transaction->t_log_list;
-		break;
 	case BJ_Reserved:
 		list = &transaction->t_reserved_list;
 		break;
@@ -1702,11 +1816,11 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
 	if (buffer_locked(bh) || buffer_dirty(bh))
 		goto out;
 
-	if (jh->b_next_transaction != NULL)
+	if (jh->b_next_transaction != NULL || jh->b_transaction != NULL)
 		goto out;
 
 	spin_lock(&journal->j_list_lock);
-	if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
+	if (jh->b_cp_transaction != NULL) {
 		/* written-back checkpointed metadata buffer */
 		JBUFFER_TRACE(jh, "remove from checkpoint list");
 		__jbd2_journal_remove_checkpoint(jh);
@@ -1936,7 +2050,6 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh,
 
 		if (!buffer_dirty(bh)) {
 			/* bdflush has written it.  We can drop it now */
-			__jbd2_journal_remove_checkpoint(jh);
 			goto zap_buffer;
 		}
 
@@ -1966,7 +2079,6 @@ static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh,
 				/* The orphan record's transaction has
 				 * committed.  We can cleanse this buffer */
 				clear_buffer_jbddirty(bh);
-				__jbd2_journal_remove_checkpoint(jh);
 				goto zap_buffer;
 			}
 		}
@@ -2041,18 +2153,23 @@ zap_buffer_unlocked:
  * void jbd2_journal_invalidatepage()
  * @journal: journal to use for flush...
  * @page:    page to flush
- * @offset:  length of page to invalidate.
+ * @offset:  start of the range to invalidate
+ * @length:  length of the range to invalidate
  *
- * Reap page buffers containing data after offset in page. Can return -EBUSY
- * if buffers are part of the committing transaction and the page is straddling
- * i_size. Caller then has to wait for current commit and try again.
+ * Reap page buffers containing data after in the specified range in page.
+ * Can return -EBUSY if buffers are part of the committing transaction and
+ * the page is straddling i_size. Caller then has to wait for current commit
+ * and try again.
  */
 int jbd2_journal_invalidatepage(journal_t *journal,
 				struct page *page,
-				unsigned long offset)
+				unsigned int offset,
+				unsigned int length)
 {
 	struct buffer_head *head, *bh, *next;
+	unsigned int stop = offset + length;
 	unsigned int curr_off = 0;
+	int partial_page = (offset || length < PAGE_CACHE_SIZE);
 	int may_free = 1;
 	int ret = 0;
 
@@ -2061,6 +2178,8 @@ int jbd2_journal_invalidatepage(journal_t *journal,
 	if (!page_has_buffers(page))
 		return 0;
 
+	BUG_ON(stop > PAGE_CACHE_SIZE || stop < length);
+
 	/* We will potentially be playing with lists other than just the
 	 * data lists (especially for journaled data mode), so be
 	 * cautious in our locking. */
@@ -2070,10 +2189,13 @@ int jbd2_journal_invalidatepage(journal_t *journal,
 		unsigned int next_off = curr_off + bh->b_size;
 		next = bh->b_this_page;
 
+		if (next_off > stop)
+			return 0;
+
 		if (offset <= curr_off) {
 			/* This block is wholly outside the truncation point */
 			lock_buffer(bh);
-			ret = journal_unmap_buffer(journal, bh, offset > 0);
+			ret = journal_unmap_buffer(journal, bh, partial_page);
 			unlock_buffer(bh);
 			if (ret < 0)
 				return ret;
@@ -2084,7 +2206,7 @@ int jbd2_journal_invalidatepage(journal_t *journal,
 
 	} while (bh != head);
 
-	if (!offset) {
+	if (!partial_page) {
 		if (may_free && try_to_free_buffers(page))
 			J_ASSERT(!page_has_buffers(page));
 	}
@@ -2145,15 +2267,9 @@ void __jbd2_journal_file_buffer(struct journal_head *jh,
 	case BJ_Forget:
 		list = &transaction->t_forget;
 		break;
-	case BJ_IO:
-		list = &transaction->t_iobuf_list;
-		break;
 	case BJ_Shadow:
 		list = &transaction->t_shadow_list;
 		break;
-	case BJ_LogCtl:
-		list = &transaction->t_log_list;
-		break;
 	case BJ_Reserved:
 		list = &transaction->t_reserved_list;
 		break;
@@ -2255,10 +2371,12 @@ void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh)
 int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
 {
 	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
+	journal_t *journal;
 
+	WARN_ON(!transaction);
 	if (is_handle_aborted(handle))
-		return -EIO;
+		return -EROFS;
+	journal = transaction->t_journal;
 
 	jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,
 			transaction->t_tid);