Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

8 files changed, 0 insertions, 8130 deletions

diff --git a/ANDROID_3.4.5/fs/jbd2/Kconfig b/ANDROID_3.4.5/fs/jbd2/Kconfig
deleted file mode 100644
index f32f346f..00000000
--- a/ANDROID_3.4.5/fs/jbd2/Kconfig
+++ /dev/null
@@ -1,33 +0,0 @@
-config JBD2
-	tristate
-	select CRC32
-	help
-	  This is a generic journaling layer for block devices that support
-	  both 32-bit and 64-bit block numbers.  It is currently used by
-	  the ext4 and OCFS2 filesystems, but it could also be used to add
-	  journal support to other file systems or block devices such
-	  as RAID or LVM.
-
-	  If you are using ext4 or OCFS2, you need to say Y here.
-	  If you are not using ext4 or OCFS2 then you will
-	  probably want to say N.
-
-	  To compile this device as a module, choose M here. The module will be
-	  called jbd2.  If you are compiling ext4 or OCFS2 into the kernel,
-	  you cannot compile this code as a module.
-
-config JBD2_DEBUG
-	bool "JBD2 (ext4) debugging support"
-	depends on JBD2 && DEBUG_FS
-	help
-	  If you are using the ext4 journaled file system (or
-	  potentially any other filesystem/device using JBD2), this option
-	  allows you to enable debugging output while the system is running,
-	  in order to help track down any problems you are having.
-	  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
-	  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".
diff --git a/ANDROID_3.4.5/fs/jbd2/Makefile b/ANDROID_3.4.5/fs/jbd2/Makefile
deleted file mode 100644
index 802a3413..00000000
--- a/ANDROID_3.4.5/fs/jbd2/Makefile
+++ /dev/null
@@ -1,7 +0,0 @@
-#
-# Makefile for the linux journaling routines.
-#
-
-obj-$(CONFIG_JBD2) += jbd2.o
-
-jbd2-objs := transaction.o commit.o recovery.o checkpoint.o revoke.o journal.o
diff --git a/ANDROID_3.4.5/fs/jbd2/checkpoint.c b/ANDROID_3.4.5/fs/jbd2/checkpoint.c
deleted file mode 100644
index c78841ee..00000000
--- a/ANDROID_3.4.5/fs/jbd2/checkpoint.c
+++ /dev/null
@@ -1,705 +0,0 @@
-/*
- * linux/fs/jbd2/checkpoint.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
- *
- * Copyright 1999 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Checkpoint routines for the generic filesystem journaling code.
- * Part of the ext2fs journaling system.
- *
- * Checkpointing is the process of ensuring that a section of the log is
- * committed fully to disk, so that that portion of the log can be
- * reused.
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/blkdev.h>
-#include <trace/events/jbd2.h>
-
-/*
- * Unlink a buffer from a transaction checkpoint list.
- *
- * Called with j_list_lock held.
- */
-static inline void __buffer_unlink_first(struct journal_head *jh)
-{
-	transaction_t *transaction = jh->b_cp_transaction;
-
-	jh->b_cpnext->b_cpprev = jh->b_cpprev;
-	jh->b_cpprev->b_cpnext = jh->b_cpnext;
-	if (transaction->t_checkpoint_list == jh) {
-		transaction->t_checkpoint_list = jh->b_cpnext;
-		if (transaction->t_checkpoint_list == jh)
-			transaction->t_checkpoint_list = NULL;
-	}
-}
-
-/*
- * Unlink a buffer from a transaction checkpoint(io) list.
- *
- * Called with j_list_lock held.
- */
-static inline void __buffer_unlink(struct journal_head *jh)
-{
-	transaction_t *transaction = jh->b_cp_transaction;
-
-	__buffer_unlink_first(jh);
-	if (transaction->t_checkpoint_io_list == jh) {
-		transaction->t_checkpoint_io_list = jh->b_cpnext;
-		if (transaction->t_checkpoint_io_list == jh)
-			transaction->t_checkpoint_io_list = NULL;
-	}
-}
-
-/*
- * Move a buffer from the checkpoint list to the checkpoint io list
- *
- * Called with j_list_lock held
- */
-static inline void __buffer_relink_io(struct journal_head *jh)
-{
-	transaction_t *transaction = jh->b_cp_transaction;
-
-	__buffer_unlink_first(jh);
-
-	if (!transaction->t_checkpoint_io_list) {
-		jh->b_cpnext = jh->b_cpprev = jh;
-	} else {
-		jh->b_cpnext = transaction->t_checkpoint_io_list;
-		jh->b_cpprev = transaction->t_checkpoint_io_list->b_cpprev;
-		jh->b_cpprev->b_cpnext = jh;
-		jh->b_cpnext->b_cpprev = jh;
-	}
-	transaction->t_checkpoint_io_list = jh;
-}
-
-/*
- * Try to release a checkpointed buffer from its transaction.
- * Returns 1 if we released it and 2 if we also released the
- * whole transaction.
- *
- * Requires j_list_lock
- */
-static int __try_to_free_cp_buf(struct journal_head *jh)
-{
-	int ret = 0;
-	struct buffer_head *bh = jh2bh(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;
-}
-
-/*
- * __jbd2_log_wait_for_space: wait until there is space in the journal.
- *
- * Called under j-state_lock *only*.  It will be unlocked if we have to wait
- * for a checkpoint to free up some space in the log.
- */
-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;
-		write_unlock(&journal->j_state_lock);
-		mutex_lock(&journal->j_checkpoint_mutex);
-
-		/*
-		 * Test again, another process may have checkpointed while we
-		 * were waiting for the checkpoint lock. If there are no
-		 * transactions ready to be checkpointed, try to recover
-		 * journal space by calling cleanup_journal_tail(), and if
-		 * that doesn't work, by waiting for the currently committing
-		 * transaction to complete.  If there is absolutely no way
-		 * to make progress, this is either a BUG or corrupted
-		 * filesystem, so abort the journal and leave a stack
-		 * trace for forensic evidence.
-		 */
-		write_lock(&journal->j_state_lock);
-		spin_lock(&journal->j_list_lock);
-		nblocks = jbd_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;
-
-			if (journal->j_committing_transaction)
-				tid = journal->j_committing_transaction->t_tid;
-			spin_unlock(&journal->j_list_lock);
-			write_unlock(&journal->j_state_lock);
-			if (chkpt) {
-				jbd2_log_do_checkpoint(journal);
-			} else if (jbd2_cleanup_journal_tail(journal) == 0) {
-				/* We were able to recover space; yay! */
-				;
-			} else if (tid) {
-				jbd2_log_wait_commit(journal, tid);
-			} else {
-				printk(KERN_ERR "%s: needed %d blocks and "
-				       "only had %d space available\n",
-				       __func__, nblocks, space_left);
-				printk(KERN_ERR "%s: no way to get more "
-				       "journal space in %s\n", __func__,
-				       journal->j_devname);
-				WARN_ON(1);
-				jbd2_journal_abort(journal, 0);
-			}
-			write_lock(&journal->j_state_lock);
-		} else {
-			spin_unlock(&journal->j_list_lock);
-		}
-		mutex_unlock(&journal->j_checkpoint_mutex);
-	}
-}
-
-/*
- * 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)
-{
-	int i;
-	struct blk_plug plug;
-
-	blk_start_plug(&plug);
-	for (i = 0; i < *batch_count; i++)
-		write_dirty_buffer(journal->j_chkpt_bhs[i], WRITE_SYNC);
-	blk_finish_plug(&plug);
-
-	for (i = 0; i < *batch_count; i++) {
-		struct buffer_head *bh = journal->j_chkpt_bhs[i];
-		BUFFER_TRACE(bh, "brelse");
-		__brelse(bh);
-	}
-	*batch_count = 0;
-}
-
-/*
- * 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.
- *
- * The journal should be locked before calling this function.
- * Called with j_checkpoint_mutex held.
- */
-int jbd2_log_do_checkpoint(journal_t *journal)
-{
-	transaction_t *transaction;
-	tid_t this_tid;
-	int result;
-
-	jbd_debug(1, "Start checkpoint\n");
-
-	/*
-	 * First thing: if there are any transactions in the log which
-	 * don't need checkpointing, just eliminate them from the
-	 * journal straight away.
-	 */
-	result = jbd2_cleanup_journal_tail(journal);
-	trace_jbd2_checkpoint(journal, result);
-	jbd_debug(1, "cleanup_journal_tail returned %d\n", result);
-	if (result <= 0)
-		return result;
-
-	/*
-	 * OK, we need to start writing disk blocks.  Take one transaction
-	 * and write it.
-	 */
-	result = 0;
-	spin_lock(&journal->j_list_lock);
-	if (!journal->j_checkpoint_transactions)
-		goto out;
-	transaction = journal->j_checkpoint_transactions;
-	if (transaction->t_chp_stats.cs_chp_time == 0)
-		transaction->t_chp_stats.cs_chp_time = jiffies;
-	this_tid = transaction->t_tid;
-restart:
-	/*
-	 * If someone cleaned up this transaction while we slept, we're
-	 * 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 (batch_count) {
-			if (!retry) {
-				spin_unlock(&journal->j_list_lock);
-				retry = 1;
-			}
-			__flush_batch(journal, &batch_count);
-		}
-
-		if (retry) {
-			spin_lock(&journal->j_list_lock);
-			goto restart;
-		}
-		/*
-		 * Now we have cleaned up the first transaction's checkpoint
-		 * list. Let's clean up the second one
-		 */
-		err = __wait_cp_io(journal, transaction);
-		if (!result)
-			result = err;
-	}
-out:
-	spin_unlock(&journal->j_list_lock);
-	if (result < 0)
-		jbd2_journal_abort(journal, result);
-	else
-		result = jbd2_cleanup_journal_tail(journal);
-
-	return (result < 0) ? result : 0;
-}
-
-/*
- * Check the list of checkpoint transactions for the journal to see if
- * we have already got rid of any since the last update of the log tail
- * in the journal superblock.  If so, we can instantly roll the
- * superblock forward to remove those transactions from the log.
- *
- * Return <0 on error, 0 on success, 1 if there was nothing to clean up.
- *
- * Called with the journal lock held.
- *
- * This is the only part of the journaling code which really needs to be
- * aware of transaction aborts.  Checkpointing involves writing to the
- * main filesystem area rather than to the journal, so it can proceed
- * even in abort state, but we must not update the super block if
- * checkpointing may have failed.  Otherwise, we would lose some metadata
- * buffers which should be written-back to the filesystem.
- */
-
-int jbd2_cleanup_journal_tail(journal_t *journal)
-{
-	tid_t		first_tid;
-	unsigned long	blocknr;
-
-	if (is_journal_aborted(journal))
-		return 1;
-
-	if (!jbd2_journal_get_log_tail(journal, &first_tid, &blocknr))
-		return 1;
-	J_ASSERT(blocknr != 0);
-
-	/*
-	 * We need to make sure that any blocks that were recently written out
-	 * --- perhaps by jbd2_log_do_checkpoint() --- are flushed out before
-	 * we drop the transactions from the journal. It's unlikely this will
-	 * be necessary, especially with an appropriately sized journal, but we
-	 * need this to guarantee correctness.  Fortunately
-	 * 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_KERNEL, NULL);
-
-	__jbd2_update_log_tail(journal, first_tid, blocknr);
-	return 0;
-}
-
-
-/* Checkpoint list management */
-
-/*
- * journal_clean_one_cp_list
- *
- * 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)
- */
-
-static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
-{
-	struct journal_head *last_jh;
-	struct journal_head *next_jh = jh;
-	int ret, freed = 0;
-
-	*released = 0;
-	if (!jh)
-		return 0;
-
-	last_jh = jh->b_cpprev;
-	do {
-		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;
-			}
-		}
-		/*
-		 * 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())
-			return freed;
-	} while (jh != last_jh);
-
-	return freed;
-}
-
-/*
- * journal_clean_checkpoint_list
- *
- * 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)
-{
-	transaction_t *transaction, *last_transaction, *next_transaction;
-	int ret = 0;
-	int released;
-
-	transaction = journal->j_checkpoint_transactions;
-	if (!transaction)
-		goto out;
-
-	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);
-		/*
-		 * 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)
-			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);
-		if (need_resched())
-			goto out;
-	} while (transaction != last_transaction);
-out:
-	return ret;
-}
-
-/*
- * journal_remove_checkpoint: called after a buffer has been committed
- * to disk (either by being write-back flushed to disk, or being
- * committed to the log).
- *
- * We cannot safely clean a transaction out of the log until all of the
- * buffer updates committed in that transaction have safely been stored
- * elsewhere on disk.  To achieve this, all of the buffers in a
- * transaction need to be maintained on the transaction's checkpoint
- * lists until they have been rewritten, at which point this function is
- * called to remove the buffer from the existing transaction's
- * checkpoint lists.
- *
- * The function returns 1 if it frees the transaction, 0 otherwise.
- * The function can free jh and bh.
- *
- * This function is called with j_list_lock held.
- */
-int __jbd2_journal_remove_checkpoint(struct journal_head *jh)
-{
-	struct transaction_chp_stats_s *stats;
-	transaction_t *transaction;
-	journal_t *journal;
-	int ret = 0;
-
-	JBUFFER_TRACE(jh, "entry");
-
-	if ((transaction = jh->b_cp_transaction) == NULL) {
-		JBUFFER_TRACE(jh, "not on transaction");
-		goto out;
-	}
-	journal = transaction->t_journal;
-
-	JBUFFER_TRACE(jh, "removing from transaction");
-	__buffer_unlink(jh);
-	jh->b_cp_transaction = NULL;
-	jbd2_journal_put_journal_head(jh);
-
-	if (transaction->t_checkpoint_list != NULL ||
-	    transaction->t_checkpoint_io_list != NULL)
-		goto out;
-
-	/*
-	 * There is one special case to worry about: if we have just pulled the
-	 * buffer off a running or committing transaction's checkpoing list,
-	 * then even if the checkpoint list is empty, the transaction obviously
-	 * cannot be dropped!
-	 *
-	 * The locking here around t_state is a bit sleazy.
-	 * See the comment at the end of jbd2_journal_commit_transaction().
-	 */
-	if (transaction->t_state != T_FINISHED)
-		goto out;
-
-	/* OK, that was the last buffer for the transaction: we can now
-	   safely remove this transaction from the log */
-	stats = &transaction->t_chp_stats;
-	if (stats->cs_chp_time)
-		stats->cs_chp_time = jbd2_time_diff(stats->cs_chp_time,
-						    jiffies);
-	trace_jbd2_checkpoint_stats(journal->j_fs_dev->bd_dev,
-				    transaction->t_tid, stats);
-
-	__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;
-}
-
-/*
- * journal_insert_checkpoint: put a committed buffer onto a checkpoint
- * list so that we know when it is safe to clean the transaction out of
- * the log.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- */
-void __jbd2_journal_insert_checkpoint(struct journal_head *jh,
-			       transaction_t *transaction)
-{
-	JBUFFER_TRACE(jh, "entry");
-	J_ASSERT_JH(jh, buffer_dirty(jh2bh(jh)) || buffer_jbddirty(jh2bh(jh)));
-	J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
-
-	/* Get reference for checkpointing transaction */
-	jbd2_journal_grab_journal_head(jh2bh(jh));
-	jh->b_cp_transaction = transaction;
-
-	if (!transaction->t_checkpoint_list) {
-		jh->b_cpnext = jh->b_cpprev = jh;
-	} else {
-		jh->b_cpnext = transaction->t_checkpoint_list;
-		jh->b_cpprev = transaction->t_checkpoint_list->b_cpprev;
-		jh->b_cpprev->b_cpnext = jh;
-		jh->b_cpnext->b_cpprev = jh;
-	}
-	transaction->t_checkpoint_list = jh;
-}
-
-/*
- * We've finished with this transaction structure: adios...
- *
- * The transaction must have no links except for the checkpoint by this
- * point.
- *
- * Called with the journal locked.
- * Called with j_list_lock held.
- */
-
-void __jbd2_journal_drop_transaction(journal_t *journal, transaction_t *transaction)
-{
-	assert_spin_locked(&journal->j_list_lock);
-	if (transaction->t_cpnext) {
-		transaction->t_cpnext->t_cpprev = transaction->t_cpprev;
-		transaction->t_cpprev->t_cpnext = transaction->t_cpnext;
-		if (journal->j_checkpoint_transactions == transaction)
-			journal->j_checkpoint_transactions =
-				transaction->t_cpnext;
-		if (journal->j_checkpoint_transactions == transaction)
-			journal->j_checkpoint_transactions = NULL;
-	}
-
-	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);
-	J_ASSERT(journal->j_committing_transaction != transaction);
-	J_ASSERT(journal->j_running_transaction != transaction);
-
-	trace_jbd2_drop_transaction(journal, transaction);
-
-	jbd_debug(1, "Dropping transaction %d, all done\n", transaction->t_tid);
-}
diff --git a/ANDROID_3.4.5/fs/jbd2/commit.c b/ANDROID_3.4.5/fs/jbd2/commit.c
deleted file mode 100644
index 840f70f5..00000000
--- a/ANDROID_3.4.5/fs/jbd2/commit.c
+++ /dev/null
@@ -1,1096 +0,0 @@
-/*
- * linux/fs/jbd2/commit.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Journal commit routines for the generic filesystem journaling code;
- * part of the ext2fs journaling system.
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/mm.h>
-#include <linux/pagemap.h>
-#include <linux/jiffies.h>
-#include <linux/crc32.h>
-#include <linux/writeback.h>
-#include <linux/backing-dev.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/bitops.h>
-#include <trace/events/jbd2.h>
-
-/*
- * Default IO end handler for temporary BJ_IO buffer_heads.
- */
-static void journal_end_buffer_io_sync(struct buffer_head *bh, int uptodate)
-{
-	BUFFER_TRACE(bh, "");
-	if (uptodate)
-		set_buffer_uptodate(bh);
-	else
-		clear_buffer_uptodate(bh);
-	unlock_buffer(bh);
-}
-
-/*
- * When an ext4 file is truncated, it is possible that some pages are not
- * successfully freed, because they are attached to a committing transaction.
- * After the transaction commits, these pages are left on the LRU, with no
- * ->mapping, and with attached buffers.  These pages are trivially reclaimable
- * by the VM, but their apparent absence upsets the VM accounting, and it makes
- * the numbers in /proc/meminfo look odd.
- *
- * So here, we have a buffer which has just come off the forget list.  Look to
- * see if we can strip all buffers from the backing page.
- *
- * Called under lock_journal(), and possibly under journal_datalist_lock.  The
- * caller provided us with a ref against the buffer, and we drop that here.
- */
-static void release_buffer_page(struct buffer_head *bh)
-{
-	struct page *page;
-
-	if (buffer_dirty(bh))
-		goto nope;
-	if (atomic_read(&bh->b_count) != 1)
-		goto nope;
-	page = bh->b_page;
-	if (!page)
-		goto nope;
-	if (page->mapping)
-		goto nope;
-
-	/* OK, it's a truncated page */
-	if (!trylock_page(page))
-		goto nope;
-
-	page_cache_get(page);
-	__brelse(bh);
-	try_to_free_buffers(page);
-	unlock_page(page);
-	page_cache_release(page);
-	return;
-
-nope:
-	__brelse(bh);
-}
-
-/*
- * Done it all: now submit the commit record.  We should have
- * cleaned up our previous buffers by now, so if we are in abort
- * mode we can now just skip the rest of the journal write
- * entirely.
- *
- * Returns 1 if the journal needs to be aborted or 0 on success
- */
-static int journal_submit_commit_record(journal_t *journal,
-					transaction_t *commit_transaction,
-					struct buffer_head **cbh,
-					__u32 crc32_sum)
-{
-	struct journal_head *descriptor;
-	struct commit_header *tmp;
-	struct buffer_head *bh;
-	int ret;
-	struct timespec now = current_kernel_time();
-
-	*cbh = NULL;
-
-	if (is_journal_aborted(journal))
-		return 0;
-
-	descriptor = jbd2_journal_get_descriptor_buffer(journal);
-	if (!descriptor)
-		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);
-	tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
-	tmp->h_commit_sec = cpu_to_be64(now.tv_sec);
-	tmp->h_commit_nsec = cpu_to_be32(now.tv_nsec);
-
-	if (JBD2_HAS_COMPAT_FEATURE(journal,
-				    JBD2_FEATURE_COMPAT_CHECKSUM)) {
-		tmp->h_chksum_type 	= JBD2_CRC32_CHKSUM;
-		tmp->h_chksum_size 	= JBD2_CRC32_CHKSUM_SIZE;
-		tmp->h_chksum[0] 	= cpu_to_be32(crc32_sum);
-	}
-
-	JBUFFER_TRACE(descriptor, "submit commit block");
-	lock_buffer(bh);
-	clear_buffer_dirty(bh);
-	set_buffer_uptodate(bh);
-	bh->b_end_io = journal_end_buffer_io_sync;
-
-	if (journal->j_flags & JBD2_BARRIER &&
-	    !JBD2_HAS_INCOMPAT_FEATURE(journal,
-				       JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT))
-		ret = submit_bh(WRITE_SYNC | WRITE_FLUSH_FUA, bh);
-	else
-		ret = submit_bh(WRITE_SYNC, bh);
-
-	*cbh = bh;
-	return ret;
-}
-
-/*
- * This function along with journal_submit_commit_record
- * allows to write the commit record asynchronously.
- */
-static int journal_wait_on_commit_record(journal_t *journal,
-					 struct buffer_head *bh)
-{
-	int ret = 0;
-
-	clear_buffer_dirty(bh);
-	wait_on_buffer(bh);
-
-	if (unlikely(!buffer_uptodate(bh)))
-		ret = -EIO;
-	put_bh(bh);            /* One for getblk() */
-	jbd2_journal_put_journal_head(bh2jh(bh));
-
-	return ret;
-}
-
-/*
- * write the filemap data using writepage() address_space_operations.
- * We don't do block allocation here even for delalloc. We don't
- * use writepages() because with dealyed allocation we may be doing
- * block allocation in writepages().
- */
-static int journal_submit_inode_data_buffers(struct address_space *mapping)
-{
-	int ret;
-	struct writeback_control wbc = {
-		.sync_mode =  WB_SYNC_ALL,
-		.nr_to_write = mapping->nrpages * 2,
-		.range_start = 0,
-		.range_end = i_size_read(mapping->host),
-	};
-
-	ret = generic_writepages(mapping, &wbc);
-	return ret;
-}
-
-/*
- * Submit all the data buffers of inode associated with the transaction to
- * disk.
- *
- * We are in a committing transaction. Therefore no new inode can be added to
- * our inode list. We use JI_COMMIT_RUNNING flag to protect inode we currently
- * operate on from being released while we write out pages.
- */
-static int journal_submit_data_buffers(journal_t *journal,
-		transaction_t *commit_transaction)
-{
-	struct jbd2_inode *jinode;
-	int err, ret = 0;
-	struct address_space *mapping;
-
-	spin_lock(&journal->j_list_lock);
-	list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
-		mapping = jinode->i_vfs_inode->i_mapping;
-		set_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
-		spin_unlock(&journal->j_list_lock);
-		/*
-		 * submit the inode data buffers. We use writepage
-		 * instead of writepages. Because writepages can do
-		 * block allocation  with delalloc. We need to write
-		 * only allocated blocks here.
-		 */
-		trace_jbd2_submit_inode_data(jinode->i_vfs_inode);
-		err = journal_submit_inode_data_buffers(mapping);
-		if (!ret)
-			ret = err;
-		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();
-		wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
-	}
-	spin_unlock(&journal->j_list_lock);
-	return ret;
-}
-
-/*
- * Wait for data submitted for writeout, refile inodes to proper
- * transaction if needed.
- *
- */
-static int journal_finish_inode_data_buffers(journal_t *journal,
-		transaction_t *commit_transaction)
-{
-	struct jbd2_inode *jinode, *next_i;
-	int err, ret = 0;
-
-	/* For locking, see the comment in journal_submit_data_buffers() */
-	spin_lock(&journal->j_list_lock);
-	list_for_each_entry(jinode, &commit_transaction->t_inode_list, i_list) {
-		set_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
-		spin_unlock(&journal->j_list_lock);
-		err = filemap_fdatawait(jinode->i_vfs_inode->i_mapping);
-		if (err) {
-			/*
-			 * Because AS_EIO is cleared by
-			 * filemap_fdatawait_range(), set it again so
-			 * that user process can get -EIO from fsync().
-			 */
-			set_bit(AS_EIO,
-				&jinode->i_vfs_inode->i_mapping->flags);
-
-			if (!ret)
-				ret = err;
-		}
-		spin_lock(&journal->j_list_lock);
-		clear_bit(__JI_COMMIT_RUNNING, &jinode->i_flags);
-		smp_mb__after_clear_bit();
-		wake_up_bit(&jinode->i_flags, __JI_COMMIT_RUNNING);
-	}
-
-	/* Now refile inode to proper lists */
-	list_for_each_entry_safe(jinode, next_i,
-				 &commit_transaction->t_inode_list, i_list) {
-		list_del(&jinode->i_list);
-		if (jinode->i_next_transaction) {
-			jinode->i_transaction = jinode->i_next_transaction;
-			jinode->i_next_transaction = NULL;
-			list_add(&jinode->i_list,
-				&jinode->i_transaction->t_inode_list);
-		} else {
-			jinode->i_transaction = NULL;
-		}
-	}
-	spin_unlock(&journal->j_list_lock);
-
-	return ret;
-}
-
-static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
-{
-	struct page *page = bh->b_page;
-	char *addr;
-	__u32 checksum;
-
-	addr = kmap_atomic(page);
-	checksum = crc32_be(crc32_sum,
-		(void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
-	kunmap_atomic(addr);
-
-	return checksum;
-}
-
-static void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
-				   unsigned long long block)
-{
-	tag->t_blocknr = cpu_to_be32(block & (u32)~0);
-	if (tag_bytes > JBD2_TAG_SIZE32)
-		tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1);
-}
-
-/*
- * jbd2_journal_commit_transaction
- *
- * The primary function for committing a transaction to the log.  This
- * function is called by the journal thread to begin a complete commit.
- */
-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 buffer_head **wbuf = journal->j_wbuf;
-	int bufs;
-	int flags;
-	int err;
-	unsigned long long blocknr;
-	ktime_t start_time;
-	u64 commit_time;
-	char *tagp = NULL;
-	journal_header_t *header;
-	journal_block_tag_t *tag = NULL;
-	int space_left = 0;
-	int first_tag = 0;
-	int tag_flag;
-	int i, to_free = 0;
-	int tag_bytes = journal_tag_bytes(journal);
-	struct buffer_head *cbh = NULL; /* For transactional checksums */
-	__u32 crc32_sum = ~0;
-	struct blk_plug plug;
-	/* Tail of the journal */
-	unsigned long first_block;
-	tid_t first_tid;
-	int update_tail;
-
-	/*
-	 * First job: lock down the current transaction and wait for
-	 * all outstanding updates to complete.
-	 */
-
-	/* Do we need to erase the effects of a prior jbd2_journal_flush? */
-	if (journal->j_flags & JBD2_FLUSHED) {
-		jbd_debug(3, "super block updated\n");
-		mutex_lock(&journal->j_checkpoint_mutex);
-		/*
-		 * We hold j_checkpoint_mutex so tail cannot change under us.
-		 * We don't need any special data guarantees for writing sb
-		 * since journal is empty and it is ok for write to be
-		 * flushed only with transaction commit.
-		 */
-		jbd2_journal_update_sb_log_tail(journal,
-						journal->j_tail_sequence,
-						journal->j_tail,
-						WRITE_SYNC);
-		mutex_unlock(&journal->j_checkpoint_mutex);
-	} else {
-		jbd_debug(3, "superblock not updated\n");
-	}
-
-	J_ASSERT(journal->j_running_transaction != NULL);
-	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);
-	commit_transaction->t_state = T_LOCKED;
-
-	trace_jbd2_commit_locking(journal, commit_transaction);
-	stats.run.rs_wait = commit_transaction->t_max_wait;
-	stats.run.rs_locked = jiffies;
-	stats.run.rs_running = jbd2_time_diff(commit_transaction->t_start,
-					      stats.run.rs_locked);
-
-	spin_lock(&commit_transaction->t_handle_lock);
-	while (atomic_read(&commit_transaction->t_updates)) {
-		DEFINE_WAIT(wait);
-
-		prepare_to_wait(&journal->j_wait_updates, &wait,
-					TASK_UNINTERRUPTIBLE);
-		if (atomic_read(&commit_transaction->t_updates)) {
-			spin_unlock(&commit_transaction->t_handle_lock);
-			write_unlock(&journal->j_state_lock);
-			schedule();
-			write_lock(&journal->j_state_lock);
-			spin_lock(&commit_transaction->t_handle_lock);
-		}
-		finish_wait(&journal->j_wait_updates, &wait);
-	}
-	spin_unlock(&commit_transaction->t_handle_lock);
-
-	J_ASSERT (atomic_read(&commit_transaction->t_outstanding_credits) <=
-			journal->j_max_transaction_buffers);
-
-	/*
-	 * First thing we are allowed to do is to discard any remaining
-	 * BJ_Reserved buffers.  Note, it is _not_ permissible to assume
-	 * that there are no such buffers: if a large filesystem
-	 * operation like a truncate needs to split itself over multiple
-	 * transactions, then it may try to do a jbd2_journal_restart() while
-	 * there are still BJ_Reserved buffers outstanding.  These must
-	 * be released cleanly from the current transaction.
-	 *
-	 * In this case, the filesystem must still reserve write access
-	 * again before modifying the buffer in the new transaction, but
-	 * we do not require it to remember exactly which old buffers it
-	 * has reserved.  This is consistent with the existing behaviour
-	 * that multiple jbd2_journal_get_write_access() calls to the same
-	 * buffer are perfectly permissible.
-	 */
-	while (commit_transaction->t_reserved_list) {
-		jh = commit_transaction->t_reserved_list;
-		JBUFFER_TRACE(jh, "reserved, unused: refile");
-		/*
-		 * A jbd2_journal_get_undo_access()+jbd2_journal_release_buffer() may
-		 * leave undo-committed data.
-		 */
-		if (jh->b_committed_data) {
-			struct buffer_head *bh = jh2bh(jh);
-
-			jbd_lock_bh_state(bh);
-			jbd2_free(jh->b_committed_data, bh->b_size);
-			jh->b_committed_data = NULL;
-			jbd_unlock_bh_state(bh);
-		}
-		jbd2_journal_refile_buffer(journal, jh);
-	}
-
-	/*
-	 * Now try to drop any written-back buffers from the journal's
-	 * checkpoint lists.  We do this *before* commit because it potentially
-	 * frees some memory
-	 */
-	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_clean_checkpoint_list(journal);
-	spin_unlock(&journal->j_list_lock);
-
-	jbd_debug(3, "JBD2: commit phase 1\n");
-
-	/*
-	 * Clear revoked flag to reflect there is no revoked buffers
-	 * in the next transaction which is going to be started.
-	 */
-	jbd2_clear_buffer_revoked_flags(journal);
-
-	/*
-	 * Switch to a new revoke table.
-	 */
-	jbd2_journal_switch_revoke_table(journal);
-
-	trace_jbd2_commit_flushing(journal, commit_transaction);
-	stats.run.rs_flushing = jiffies;
-	stats.run.rs_locked = jbd2_time_diff(stats.run.rs_locked,
-					     stats.run.rs_flushing);
-
-	commit_transaction->t_state = T_FLUSH;
-	journal->j_committing_transaction = commit_transaction;
-	journal->j_running_transaction = NULL;
-	start_time = ktime_get();
-	commit_transaction->t_log_start = journal->j_head;
-	wake_up(&journal->j_wait_transaction_locked);
-	write_unlock(&journal->j_state_lock);
-
-	jbd_debug(3, "JBD2: commit phase 2\n");
-
-	/*
-	 * Now start flushing things to disk, in the order they appear
-	 * on the transaction lists.  Data blocks go first.
-	 */
-	err = journal_submit_data_buffers(journal, commit_transaction);
-	if (err)
-		jbd2_journal_abort(journal, err);
-
-	blk_start_plug(&plug);
-	jbd2_journal_write_revoke_records(journal, commit_transaction,
-					  WRITE_SYNC);
-	blk_finish_plug(&plug);
-
-	jbd_debug(3, "JBD2: commit phase 2\n");
-
-	/*
-	 * Way to go: we have now written out all of the data for a
-	 * transaction!  Now comes the tricky part: we need to write out
-	 * metadata.  Loop over the transaction's entire buffer list:
-	 */
-	write_lock(&journal->j_state_lock);
-	commit_transaction->t_state = T_COMMIT;
-	write_unlock(&journal->j_state_lock);
-
-	trace_jbd2_commit_logging(journal, commit_transaction);
-	stats.run.rs_logging = jiffies;
-	stats.run.rs_flushing = jbd2_time_diff(stats.run.rs_flushing,
-					       stats.run.rs_logging);
-	stats.run.rs_blocks =
-		atomic_read(&commit_transaction->t_outstanding_credits);
-	stats.run.rs_blocks_logged = 0;
-
-	J_ASSERT(commit_transaction->t_nr_buffers <=
-		 atomic_read(&commit_transaction->t_outstanding_credits));
-
-	err = 0;
-	descriptor = NULL;
-	bufs = 0;
-	blk_start_plug(&plug);
-	while (commit_transaction->t_buffers) {
-
-		/* Find the next buffer to be journaled... */
-
-		jh = commit_transaction->t_buffers;
-
-		/* If we're in abort mode, we just un-journal the buffer and
-		   release it. */
-
-		if (is_journal_aborted(journal)) {
-			clear_buffer_jbddirty(jh2bh(jh));
-			JBUFFER_TRACE(jh, "journal is aborting: refile");
-			jbd2_buffer_abort_trigger(jh,
-						  jh->b_frozen_data ?
-						  jh->b_frozen_triggers :
-						  jh->b_triggers);
-			jbd2_journal_refile_buffer(journal, jh);
-			/* If that was the last one, we need to clean up
-			 * any descriptor buffers which may have been
-			 * already allocated, even if we are now
-			 * aborting. */
-			if (!commit_transaction->t_buffers)
-				goto start_journal_io;
-			continue;
-		}
-
-		/* Make sure we have a descriptor block in which to
-		   record the metadata buffer. */
-
-		if (!descriptor) {
-			struct buffer_head *bh;
-
-			J_ASSERT (bufs == 0);
-
-			jbd_debug(4, "JBD2: get descriptor\n");
-
-			descriptor = jbd2_journal_get_descriptor_buffer(journal);
-			if (!descriptor) {
-				jbd2_journal_abort(journal, -EIO);
-				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];
-			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);
-			first_tag = 1;
-			set_buffer_jwrite(bh);
-			set_buffer_dirty(bh);
-			wbuf[bufs++] = bh;
-
-			/* 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);
-		}
-
-		/* Where is the buffer to be written? */
-
-		err = jbd2_journal_next_log_block(journal, &blocknr);
-		/* If the block mapping failed, just abandon the buffer
-		   and repeat this loop: we'll fall into the
-		   refile-on-abort condition above. */
-		if (err) {
-			jbd2_journal_abort(journal, err);
-			continue;
-		}
-
-		/*
-		 * start_this_handle() uses t_outstanding_credits to determine
-		 * the free space in the log, but this counter is changed
-		 * by jbd2_journal_next_log_block() also.
-		 */
-		atomic_dec(&commit_transaction->t_outstanding_credits);
-
-		/* 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. */
-		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)
-		 */
-		JBUFFER_TRACE(jh, "ph3: write metadata");
-		flags = jbd2_journal_write_metadata_buffer(commit_transaction,
-						      jh, &new_jh, blocknr);
-		if (flags < 0) {
-			jbd2_journal_abort(journal, flags);
-			continue;
-		}
-		set_bit(BH_JWrite, &jh2bh(new_jh)->b_state);
-		wbuf[bufs++] = jh2bh(new_jh);
-
-		/* Record the new block's tag in the current descriptor
-                   buffer */
-
-		tag_flag = 0;
-		if (flags & 1)
-			tag_flag |= JBD2_FLAG_ESCAPE;
-		if (!first_tag)
-			tag_flag |= JBD2_FLAG_SAME_UUID;
-
-		tag = (journal_block_tag_t *) tagp;
-		write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
-		tag->t_flags = cpu_to_be32(tag_flag);
-		tagp += tag_bytes;
-		space_left -= tag_bytes;
-
-		if (first_tag) {
-			memcpy (tagp, journal->j_uuid, 16);
-			tagp += 16;
-			space_left -= 16;
-			first_tag = 0;
-		}
-
-		/* If there's no more to do, or if the descriptor is full,
-		   let the IO rip! */
-
-		if (bufs == journal->j_wbufsize ||
-		    commit_transaction->t_buffers == NULL ||
-		    space_left < tag_bytes + 16) {
-
-			jbd_debug(4, "JBD2: Submit %d IOs\n", bufs);
-
-			/* Write an end-of-descriptor marker before
-                           submitting the IOs.  "tag" still points to
-                           the last tag we set up. */
-
-			tag->t_flags |= cpu_to_be32(JBD2_FLAG_LAST_TAG);
-
-start_journal_io:
-			for (i = 0; i < bufs; i++) {
-				struct buffer_head *bh = wbuf[i];
-				/*
-				 * Compute checksum.
-				 */
-				if (JBD2_HAS_COMPAT_FEATURE(journal,
-					JBD2_FEATURE_COMPAT_CHECKSUM)) {
-					crc32_sum =
-					    jbd2_checksum_data(crc32_sum, bh);
-				}
-
-				lock_buffer(bh);
-				clear_buffer_dirty(bh);
-				set_buffer_uptodate(bh);
-				bh->b_end_io = journal_end_buffer_io_sync;
-				submit_bh(WRITE_SYNC, bh);
-			}
-			cond_resched();
-			stats.run.rs_blocks_logged += bufs;
-
-			/* Force a new descriptor to be generated next
-                           time round the loop. */
-			descriptor = NULL;
-			bufs = 0;
-		}
-	}
-
-	err = journal_finish_inode_data_buffers(journal, commit_transaction);
-	if (err) {
-		printk(KERN_WARNING
-			"JBD2: Detected IO errors while flushing file data "
-		       "on %s\n", journal->j_devname);
-		if (journal->j_flags & JBD2_ABORT_ON_SYNCDATA_ERR)
-			jbd2_journal_abort(journal, err);
-		err = 0;
-	}
-
-	/*
-	 * Get current oldest transaction in the log before we issue flush
-	 * to the filesystem device. After the flush we can be sure that
-	 * blocks of all older transactions are checkpointed to persistent
-	 * storage and we will be safe to update journal start in the
-	 * superblock with the numbers we get here.
-	 */
-	update_tail =
-		jbd2_journal_get_log_tail(journal, &first_tid, &first_block);
-
-	write_lock(&journal->j_state_lock);
-	if (update_tail) {
-		long freed = first_block - journal->j_tail;
-
-		if (first_block < journal->j_tail)
-			freed += journal->j_last - journal->j_first;
-		/* Update tail only if we free significant amount of space */
-		if (freed < journal->j_maxlen / 4)
-			update_tail = 0;
-	}
-	J_ASSERT(commit_transaction->t_state == T_COMMIT);
-	commit_transaction->t_state = T_COMMIT_DFLUSH;
-	write_unlock(&journal->j_state_lock);
-
-	/* 
-	 * If the journal is not located on the file system device,
-	 * then we must flush the file system device before we issue
-	 * the commit record
-	 */
-	if (commit_transaction->t_need_data_flush &&
-	    (journal->j_fs_dev != journal->j_dev) &&
-	    (journal->j_flags & JBD2_BARRIER))
-		blkdev_issue_flush(journal->j_fs_dev, GFP_NOFS, NULL);
-
-	/* Done it all: now write the commit record asynchronously. */
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal,
-				      JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
-		err = journal_submit_commit_record(journal, commit_transaction,
-						 &cbh, crc32_sum);
-		if (err)
-			__jbd2_journal_abort_hard(journal);
-	}
-
-	blk_finish_plug(&plug);
-
-	/* Lo and behold: we have just managed to send a transaction to
-           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.
-
-	   Wait for the buffers in reverse order.  That way we are
-	   less likely to be woken up until all IOs have completed, and
-	   so we incur less scheduling load.
-	*/
-
-	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;
-
-		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;
-
-		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);
-
-		/*
-		 * ->t_iobuf_list should contain only dummy buffer_heads
-		 * which were 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 */
-		jh = commit_transaction->t_shadow_list->b_tprev;
-		bh = jh2bh(jh);
-		clear_bit(BH_JWrite, &bh->b_state);
-		J_ASSERT_BH(bh, buffer_jbddirty(bh));
-
-		/* The metadata is now released for reuse, but we need
-                   to remember it against this transaction so that when
-                   we finally commit, we can do any checkpointing
-                   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);
-	}
-
-	J_ASSERT (commit_transaction->t_shadow_list == NULL);
-
-	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) {
-		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;
-
-		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);
-		__brelse(bh);		/* One for getblk */
-		/* AKPM: bforget here */
-	}
-
-	if (err)
-		jbd2_journal_abort(journal, err);
-
-	jbd_debug(3, "JBD2: commit phase 5\n");
-	write_lock(&journal->j_state_lock);
-	J_ASSERT(commit_transaction->t_state == T_COMMIT_DFLUSH);
-	commit_transaction->t_state = T_COMMIT_JFLUSH;
-	write_unlock(&journal->j_state_lock);
-
-	if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
-				       JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
-		err = journal_submit_commit_record(journal, commit_transaction,
-						&cbh, crc32_sum);
-		if (err)
-			__jbd2_journal_abort_hard(journal);
-	}
-	if (cbh)
-		err = journal_wait_on_commit_record(journal, cbh);
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal,
-				      JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT) &&
-	    journal->j_flags & JBD2_BARRIER) {
-		blkdev_issue_flush(journal->j_dev, GFP_NOFS, NULL);
-	}
-
-	if (err)
-		jbd2_journal_abort(journal, err);
-
-	/*
-	 * Now disk caches for filesystem device are flushed so we are safe to
-	 * erase checkpointed transactions from the log by updating journal
-	 * superblock.
-	 */
-	if (update_tail)
-		jbd2_update_log_tail(journal, first_tid, first_block);
-
-	/* End of a transaction!  Finally, we can do checkpoint
-           processing: any buffers committed as a result of this
-           transaction can be removed from any checkpoint list it was on
-           before. */
-
-	jbd_debug(3, "JBD2: commit phase 6\n");
-
-	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:
-	/*
-	 * As there are other places (journal_unmap_buffer()) adding buffers
-	 * to this list we have to be careful and hold the j_list_lock.
-	 */
-	spin_lock(&journal->j_list_lock);
-	while (commit_transaction->t_forget) {
-		transaction_t *cp_transaction;
-		struct buffer_head *bh;
-		int try_to_free = 0;
-
-		jh = commit_transaction->t_forget;
-		spin_unlock(&journal->j_list_lock);
-		bh = jh2bh(jh);
-		/*
-		 * Get a reference so that bh cannot be freed before we are
-		 * done with it.
-		 */
-		get_bh(bh);
-		jbd_lock_bh_state(bh);
-		J_ASSERT_JH(jh,	jh->b_transaction == commit_transaction);
-
-		/*
-		 * If there is undo-protected committed data against
-		 * this buffer, then we can remove it now.  If it is a
-		 * buffer needing such protection, the old frozen_data
-		 * field now points to a committed version of the
-		 * buffer, so rotate that field to the new committed
-		 * data.
-		 *
-		 * Otherwise, we can just throw away the frozen data now.
-		 *
-		 * We also know that the frozen data has already fired
-		 * its triggers if they exist, so we can clear that too.
-		 */
-		if (jh->b_committed_data) {
-			jbd2_free(jh->b_committed_data, bh->b_size);
-			jh->b_committed_data = NULL;
-			if (jh->b_frozen_data) {
-				jh->b_committed_data = jh->b_frozen_data;
-				jh->b_frozen_data = NULL;
-				jh->b_frozen_triggers = NULL;
-			}
-		} else if (jh->b_frozen_data) {
-			jbd2_free(jh->b_frozen_data, bh->b_size);
-			jh->b_frozen_data = NULL;
-			jh->b_frozen_triggers = NULL;
-		}
-
-		spin_lock(&journal->j_list_lock);
-		cp_transaction = jh->b_cp_transaction;
-		if (cp_transaction) {
-			JBUFFER_TRACE(jh, "remove from old cp transaction");
-			cp_transaction->t_chp_stats.cs_dropped++;
-			__jbd2_journal_remove_checkpoint(jh);
-		}
-
-		/* Only re-checkpoint the buffer_head if it is marked
-		 * dirty.  If the buffer was added to the BJ_Forget list
-		 * by jbd2_journal_forget, it may no longer be dirty and
-		 * there's no point in keeping a checkpoint record for
-		 * it. */
-
-		/* A buffer which has been freed while still being
-		 * journaled by a previous transaction may end up still
-		 * being dirty here, but we want to avoid writing back
-		 * that buffer in the future after the "add to orphan"
-		 * operation been committed,  That's not only a performance
-		 * gain, it also stops aliasing problems if the buffer is
-		 * left behind for writeback and gets reallocated for another
-		 * use in a different page. */
-		if (buffer_freed(bh) && !jh->b_next_transaction) {
-			clear_buffer_freed(bh);
-			clear_buffer_jbddirty(bh);
-		}
-
-		if (buffer_jbddirty(bh)) {
-			JBUFFER_TRACE(jh, "add to new checkpointing trans");
-			__jbd2_journal_insert_checkpoint(jh, commit_transaction);
-			if (is_journal_aborted(journal))
-				clear_buffer_jbddirty(bh);
-		} else {
-			J_ASSERT_BH(bh, !buffer_dirty(bh));
-			/*
-			 * The buffer on BJ_Forget list and not jbddirty means
-			 * it has been freed by this transaction and hence it
-			 * could not have been reallocated until this
-			 * transaction has committed. *BUT* it could be
-			 * reallocated once we have written all the data to
-			 * disk and before we process the buffer on BJ_Forget
-			 * list.
-			 */
-			if (!jh->b_next_transaction)
-				try_to_free = 1;
-		}
-		JBUFFER_TRACE(jh, "refile or unfile buffer");
-		__jbd2_journal_refile_buffer(jh);
-		jbd_unlock_bh_state(bh);
-		if (try_to_free)
-			release_buffer_page(bh);	/* Drops bh reference */
-		else
-			__brelse(bh);
-		cond_resched_lock(&journal->j_list_lock);
-	}
-	spin_unlock(&journal->j_list_lock);
-	/*
-	 * This is a bit sleazy.  We use j_list_lock to protect transition
-	 * of a transaction into T_FINISHED state and calling
-	 * __jbd2_journal_drop_transaction(). Otherwise we could race with
-	 * other checkpointing code processing the transaction...
-	 */
-	write_lock(&journal->j_state_lock);
-	spin_lock(&journal->j_list_lock);
-	/*
-	 * Now recheck if some buffers did not get attached to the transaction
-	 * while the lock was dropped...
-	 */
-	if (commit_transaction->t_forget) {
-		spin_unlock(&journal->j_list_lock);
-		write_unlock(&journal->j_state_lock);
-		goto restart_loop;
-	}
-
-	/* Done with this transaction! */
-
-	jbd_debug(3, "JBD2: commit phase 7\n");
-
-	J_ASSERT(commit_transaction->t_state == T_COMMIT_JFLUSH);
-
-	commit_transaction->t_start = jiffies;
-	stats.run.rs_logging = jbd2_time_diff(stats.run.rs_logging,
-					      commit_transaction->t_start);
-
-	/*
-	 * File the transaction statistics
-	 */
-	stats.ts_tid = commit_transaction->t_tid;
-	stats.run.rs_handle_count =
-		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++;
-	journal->j_stats.run.rs_wait += stats.run.rs_wait;
-	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);
-
-	commit_transaction->t_state = T_FINISHED;
-	J_ASSERT(commit_transaction == journal->j_committing_transaction);
-	journal->j_commit_sequence = commit_transaction->t_tid;
-	journal->j_committing_transaction = NULL;
-	commit_time = ktime_to_ns(ktime_sub(ktime_get(), start_time));
-
-	/*
-	 * weight the commit time higher than the average time so we don't
-	 * react too strongly to vast changes in the commit time
-	 */
-	if (likely(journal->j_average_commit_time))
-		journal->j_average_commit_time = (commit_time +
-				journal->j_average_commit_time*3) / 4;
-	else
-		journal->j_average_commit_time = commit_time;
-	write_unlock(&journal->j_state_lock);
-
-	if (commit_transaction->t_checkpoint_list == NULL &&
-	    commit_transaction->t_checkpoint_io_list == NULL) {
-		__jbd2_journal_drop_transaction(journal, commit_transaction);
-		to_free = 1;
-	} else {
-		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);
-
-	if (journal->j_commit_callback)
-		journal->j_commit_callback(journal, commit_transaction);
-
-	trace_jbd2_end_commit(journal, commit_transaction);
-	jbd_debug(1, "JBD2: commit %d complete, head %d\n",
-		  journal->j_commit_sequence, journal->j_tail_sequence);
-	if (to_free)
-		jbd2_journal_free_transaction(commit_transaction);
-
-	wake_up(&journal->j_wait_done_commit);
-}
diff --git a/ANDROID_3.4.5/fs/jbd2/journal.c b/ANDROID_3.4.5/fs/jbd2/journal.c
deleted file mode 100644
index 1afb7016..00000000
--- a/ANDROID_3.4.5/fs/jbd2/journal.c
+++ /dev/null
@@ -1,2502 +0,0 @@
-/*
- * linux/fs/jbd2/journal.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Generic filesystem journal-writing code; part of the ext2fs
- * journaling system.
- *
- * This file manages journals: areas of disk reserved for logging
- * transactional updates.  This includes the kernel journaling thread
- * which is responsible for scheduling updates to the log.
- *
- * We do not actually manage the physical storage of the journal in this
- * file: that is left to a per-journal policy function, which allows us
- * to store the journal within a filesystem-specified area for ext2
- * journaling (ext2 can use a reserved inode for storing the log).
- */
-
-#include <linux/module.h>
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/freezer.h>
-#include <linux/pagemap.h>
-#include <linux/kthread.h>
-#include <linux/poison.h>
-#include <linux/proc_fs.h>
-#include <linux/debugfs.h>
-#include <linux/seq_file.h>
-#include <linux/math64.h>
-#include <linux/hash.h>
-#include <linux/log2.h>
-#include <linux/vmalloc.h>
-#include <linux/backing-dev.h>
-#include <linux/bitops.h>
-#include <linux/ratelimit.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/jbd2.h>
-
-#include <asm/uaccess.h>
-#include <asm/page.h>
-
-EXPORT_SYMBOL(jbd2_journal_extend);
-EXPORT_SYMBOL(jbd2_journal_stop);
-EXPORT_SYMBOL(jbd2_journal_lock_updates);
-EXPORT_SYMBOL(jbd2_journal_unlock_updates);
-EXPORT_SYMBOL(jbd2_journal_get_write_access);
-EXPORT_SYMBOL(jbd2_journal_get_create_access);
-EXPORT_SYMBOL(jbd2_journal_get_undo_access);
-EXPORT_SYMBOL(jbd2_journal_set_triggers);
-EXPORT_SYMBOL(jbd2_journal_dirty_metadata);
-EXPORT_SYMBOL(jbd2_journal_release_buffer);
-EXPORT_SYMBOL(jbd2_journal_forget);
-#if 0
-EXPORT_SYMBOL(journal_sync_buffer);
-#endif
-EXPORT_SYMBOL(jbd2_journal_flush);
-EXPORT_SYMBOL(jbd2_journal_revoke);
-
-EXPORT_SYMBOL(jbd2_journal_init_dev);
-EXPORT_SYMBOL(jbd2_journal_init_inode);
-EXPORT_SYMBOL(jbd2_journal_check_used_features);
-EXPORT_SYMBOL(jbd2_journal_check_available_features);
-EXPORT_SYMBOL(jbd2_journal_set_features);
-EXPORT_SYMBOL(jbd2_journal_load);
-EXPORT_SYMBOL(jbd2_journal_destroy);
-EXPORT_SYMBOL(jbd2_journal_abort);
-EXPORT_SYMBOL(jbd2_journal_errno);
-EXPORT_SYMBOL(jbd2_journal_ack_err);
-EXPORT_SYMBOL(jbd2_journal_clear_err);
-EXPORT_SYMBOL(jbd2_log_wait_commit);
-EXPORT_SYMBOL(jbd2_log_start_commit);
-EXPORT_SYMBOL(jbd2_journal_start_commit);
-EXPORT_SYMBOL(jbd2_journal_force_commit_nested);
-EXPORT_SYMBOL(jbd2_journal_wipe);
-EXPORT_SYMBOL(jbd2_journal_blocks_per_page);
-EXPORT_SYMBOL(jbd2_journal_invalidatepage);
-EXPORT_SYMBOL(jbd2_journal_try_to_free_buffers);
-EXPORT_SYMBOL(jbd2_journal_force_commit);
-EXPORT_SYMBOL(jbd2_journal_file_inode);
-EXPORT_SYMBOL(jbd2_journal_init_jbd_inode);
-EXPORT_SYMBOL(jbd2_journal_release_jbd_inode);
-EXPORT_SYMBOL(jbd2_journal_begin_ordered_truncate);
-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);
-
-/*
- * Helper function used to manage commit timeouts
- */
-
-static void commit_timeout(unsigned long __data)
-{
-	struct task_struct * p = (struct task_struct *) __data;
-
-	wake_up_process(p);
-}
-
-/*
- * kjournald2: The main thread function used to manage a logging device
- * journal.
- *
- * This kernel thread is responsible for two things:
- *
- * 1) COMMIT:  Every so often we need to commit the current state of the
- *    filesystem to disk.  The journal thread is responsible for writing
- *    all of the metadata buffers to disk.
- *
- * 2) CHECKPOINT: We cannot reuse a used section of the log file until all
- *    of the data in that part of the log has been rewritten elsewhere on
- *    the disk.  Flushing these old buffers to reclaim space in the log is
- *    known as checkpointing, and this thread is responsible for that job.
- */
-
-static int kjournald2(void *arg)
-{
-	journal_t *journal = arg;
-	transaction_t *transaction;
-
-	/*
-	 * Set up an interval timer which can be used to trigger a commit wakeup
-	 * after the commit interval expires
-	 */
-	setup_timer(&journal->j_commit_timer, commit_timeout,
-			(unsigned long)current);
-
-	set_freezable();
-
-	/* Record that the journal thread is running */
-	journal->j_task = current;
-	wake_up(&journal->j_wait_done_commit);
-
-	/*
-	 * And now, wait forever for commit wakeup events.
-	 */
-	write_lock(&journal->j_state_lock);
-
-loop:
-	if (journal->j_flags & JBD2_UNMOUNT)
-		goto end_loop;
-
-	jbd_debug(1, "commit_sequence=%d, commit_request=%d\n",
-		journal->j_commit_sequence, journal->j_commit_request);
-
-	if (journal->j_commit_sequence != journal->j_commit_request) {
-		jbd_debug(1, "OK, requests differ\n");
-		write_unlock(&journal->j_state_lock);
-		del_timer_sync(&journal->j_commit_timer);
-		jbd2_journal_commit_transaction(journal);
-		write_lock(&journal->j_state_lock);
-		goto loop;
-	}
-
-	wake_up(&journal->j_wait_done_commit);
-	if (freezing(current)) {
-		/*
-		 * The simpler the better. Flushing journal isn't a
-		 * good idea, because that depends on threads that may
-		 * be already stopped.
-		 */
-		jbd_debug(1, "Now suspending kjournald2\n");
-		write_unlock(&journal->j_state_lock);
-		try_to_freeze();
-		write_lock(&journal->j_state_lock);
-	} else {
-		/*
-		 * We assume on resume that commits are already there,
-		 * so we don't sleep
-		 */
-		DEFINE_WAIT(wait);
-		int should_sleep = 1;
-
-		prepare_to_wait(&journal->j_wait_commit, &wait,
-				TASK_INTERRUPTIBLE);
-		if (journal->j_commit_sequence != journal->j_commit_request)
-			should_sleep = 0;
-		transaction = journal->j_running_transaction;
-		if (transaction && time_after_eq(jiffies,
-						transaction->t_expires))
-			should_sleep = 0;
-		if (journal->j_flags & JBD2_UNMOUNT)
-			should_sleep = 0;
-		if (should_sleep) {
-			write_unlock(&journal->j_state_lock);
-			schedule();
-			write_lock(&journal->j_state_lock);
-		}
-		finish_wait(&journal->j_wait_commit, &wait);
-	}
-
-	jbd_debug(1, "kjournald2 wakes\n");
-
-	/*
-	 * Were we woken up by a commit wakeup event?
-	 */
-	transaction = journal->j_running_transaction;
-	if (transaction && time_after_eq(jiffies, transaction->t_expires)) {
-		journal->j_commit_request = transaction->t_tid;
-		jbd_debug(1, "woke because of timeout\n");
-	}
-	goto loop;
-
-end_loop:
-	write_unlock(&journal->j_state_lock);
-	del_timer_sync(&journal->j_commit_timer);
-	journal->j_task = NULL;
-	wake_up(&journal->j_wait_done_commit);
-	jbd_debug(1, "Journal thread exiting.\n");
-	return 0;
-}
-
-static int jbd2_journal_start_thread(journal_t *journal)
-{
-	struct task_struct *t;
-
-	t = kthread_run(kjournald2, journal, "jbd2/%s",
-			journal->j_devname);
-	if (IS_ERR(t))
-		return PTR_ERR(t);
-
-	wait_event(journal->j_wait_done_commit, journal->j_task != NULL);
-	return 0;
-}
-
-static void journal_kill_thread(journal_t *journal)
-{
-	write_lock(&journal->j_state_lock);
-	journal->j_flags |= JBD2_UNMOUNT;
-
-	while (journal->j_task) {
-		wake_up(&journal->j_wait_commit);
-		write_unlock(&journal->j_state_lock);
-		wait_event(journal->j_wait_done_commit, journal->j_task == NULL);
-		write_lock(&journal->j_state_lock);
-	}
-	write_unlock(&journal->j_state_lock);
-}
-
-/*
- * jbd2_journal_write_metadata_buffer: write a metadata buffer to the journal.
- *
- * Writes a metadata buffer to a given disk block.  The actual IO is not
- * performed but a new buffer_head is constructed which labels the data
- * to be written with the correct destination disk block.
- *
- * Any magic-number escaping which needs to be done will cause a
- * copy-out here.  If the buffer happens to start with the
- * JBD2_MAGIC_NUMBER, then we can't write it to the log directly: the
- * magic number is only written to the log for descripter blocks.  In
- * this case, we copy the data and replace the first word with 0, and we
- * return a result code which indicates that this buffer needs to be
- * marked as an escaped buffer in the corresponding log descriptor
- * block.  The missing word can then be restored when the block is read
- * during recovery.
- *
- * 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.
- *
- * We assume that the journal has already been locked in this function.
- *
- * Return value:
- *  <0: Error
- * >=0: Finished OK
- *
- * On success:
- * Bit 0 set == escape performed on the data
- * Bit 1 set == buffer copy-out performed (kfree the data after IO)
- */
-
-int jbd2_journal_write_metadata_buffer(transaction_t *transaction,
-				  struct journal_head  *jh_in,
-				  struct journal_head **jh_out,
-				  unsigned long long 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);
-	journal_t *journal = transaction->t_journal;
-
-	/*
-	 * The buffer really shouldn't be locked: only the current committing
-	 * transaction is allowed to write it, so nobody else is allowed
-	 * to do any IO.
-	 *
-	 * akpm: except if we're journalling data, and write() output is
-	 * also part of a shared mapping, and another thread has
-	 * decided to launch a writepage() against this buffer.
-	 */
-	J_ASSERT_BH(bh_in, buffer_jbddirty(bh_in));
-
-retry_alloc:
-	new_bh = alloc_buffer_head(GFP_NOFS);
-	if (!new_bh) {
-		/*
-		 * Failure is not an option, but __GFP_NOFAIL is going
-		 * away; so we retry ourselves here.
-		 */
-		congestion_wait(BLK_RW_ASYNC, HZ/50);
-		goto retry_alloc;
-	}
-
-	/* keep subsequent assertions sane */
-	new_bh->b_state = 0;
-	init_buffer(new_bh, NULL, NULL);
-	atomic_set(&new_bh->b_count, 1);
-	new_jh = jbd2_journal_add_journal_head(new_bh);	/* This sleeps */
-
-	/*
-	 * 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);
-		new_offset = offset_in_page(jh_in->b_frozen_data);
-	} else {
-		new_page = jh2bh(jh_in)->b_page;
-		new_offset = offset_in_page(jh2bh(jh_in)->b_data);
-	}
-
-	mapped_data = kmap_atomic(new_page);
-	/*
-	 * Fire data frozen trigger if data already wasn't frozen.  Do this
-	 * before checking for escaping, as the trigger may modify the magic
-	 * offset.  If a copy-out happens afterwards, it will have the correct
-	 * data in the buffer.
-	 */
-	if (!done_copy_out)
-		jbd2_buffer_frozen_trigger(jh_in, mapped_data + new_offset,
-					   jh_in->b_triggers);
-
-	/*
-	 * Check for escaping
-	 */
-	if (*((__be32 *)(mapped_data + new_offset)) ==
-				cpu_to_be32(JBD2_MAGIC_NUMBER)) {
-		need_copy_out = 1;
-		do_escape = 1;
-	}
-	kunmap_atomic(mapped_data);
-
-	/*
-	 * Do we need to do a data copy?
-	 */
-	if (need_copy_out && !done_copy_out) {
-		char *tmp;
-
-		jbd_unlock_bh_state(bh_in);
-		tmp = jbd2_alloc(bh_in->b_size, GFP_NOFS);
-		if (!tmp) {
-			jbd2_journal_put_journal_head(new_jh);
-			return -ENOMEM;
-		}
-		jbd_lock_bh_state(bh_in);
-		if (jh_in->b_frozen_data) {
-			jbd2_free(tmp, bh_in->b_size);
-			goto repeat;
-		}
-
-		jh_in->b_frozen_data = tmp;
-		mapped_data = kmap_atomic(new_page);
-		memcpy(tmp, mapped_data + new_offset, jh2bh(jh_in)->b_size);
-		kunmap_atomic(mapped_data);
-
-		new_page = virt_to_page(tmp);
-		new_offset = offset_in_page(tmp);
-		done_copy_out = 1;
-
-		/*
-		 * This isn't strictly necessary, as we're using frozen
-		 * data for the escaping, but it keeps consistency with
-		 * b_frozen_data usage.
-		 */
-		jh_in->b_frozen_triggers = jh_in->b_triggers;
-	}
-
-	/*
-	 * Did we need to do an escaping?  Now we've done all the
-	 * copying, we can finally do so.
-	 */
-	if (do_escape) {
-		mapped_data = kmap_atomic(new_page);
-		*((unsigned int *)(mapped_data + new_offset)) = 0;
-		kunmap_atomic(mapped_data);
-	}
-
-	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_blocknr = blocknr;
-	set_buffer_mapped(new_bh);
-	set_buffer_dirty(new_bh);
-
-	*jh_out = new_jh;
-
-	/*
-	 * The to-be-written buffer needs to get moved to the io queue,
-	 * and the original buffer whose contents we are shadowing or
-	 * copying is moved to the transaction's shadow queue.
-	 */
-	JBUFFER_TRACE(jh_in, "file as BJ_Shadow");
-	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_file_buffer(jh_in, transaction, BJ_Shadow);
-	spin_unlock(&journal->j_list_lock);
-	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);
-}
-
-/*
- * Allocation code for the journal file.  Manage the space left in the
- * journal, so that we can begin checkpointing when appropriate.
- */
-
-/*
- * __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.
- */
-int __jbd2_log_start_commit(journal_t *journal, tid_t target)
-{
-	/*
-	 * The only transaction we can possibly wait upon is the
-	 * currently running transaction (if it exists).  Otherwise,
-	 * the target tid must be an old one.
-	 */
-	if (journal->j_running_transaction &&
-	    journal->j_running_transaction->t_tid == target) {
-		/*
-		 * We want a new commit: OK, mark the request and wakeup the
-		 * commit thread.  We do _not_ do the commit ourselves.
-		 */
-
-		journal->j_commit_request = target;
-		jbd_debug(1, "JBD2: requesting commit %d/%d\n",
-			  journal->j_commit_request,
-			  journal->j_commit_sequence);
-		wake_up(&journal->j_wait_commit);
-		return 1;
-	} else if (!tid_geq(journal->j_commit_request, target))
-		/* This should never happen, but if it does, preserve
-		   the evidence before kjournald goes into a loop and
-		   increments j_commit_sequence beyond all recognition. */
-		WARN_ONCE(1, "JBD2: bad log_start_commit: %u %u %u %u\n",
-			  journal->j_commit_request,
-			  journal->j_commit_sequence,
-			  target, journal->j_running_transaction ? 
-			  journal->j_running_transaction->t_tid : 0);
-	return 0;
-}
-
-int jbd2_log_start_commit(journal_t *journal, tid_t tid)
-{
-	int ret;
-
-	write_lock(&journal->j_state_lock);
-	ret = __jbd2_log_start_commit(journal, tid);
-	write_unlock(&journal->j_state_lock);
-	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.
- *
- * 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.
- */
-int jbd2_journal_force_commit_nested(journal_t *journal)
-{
-	transaction_t *transaction = NULL;
-	tid_t tid;
-	int need_to_start = 0;
-
-	read_lock(&journal->j_state_lock);
-	if (journal->j_running_transaction && !current->journal_info) {
-		transaction = journal->j_running_transaction;
-		if (!tid_geq(journal->j_commit_request, transaction->t_tid))
-			need_to_start = 1;
-	} else if (journal->j_committing_transaction)
-		transaction = journal->j_committing_transaction;
-
-	if (!transaction) {
-		read_unlock(&journal->j_state_lock);
-		return 0;	/* Nothing to retry */
-	}
-
-	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;
-}
-
-/*
- * Start a commit of the current running transaction (if any).  Returns true
- * if a transaction is going to be committed (or is currently already
- * committing), and fills its tid in at *ptid
- */
-int jbd2_journal_start_commit(journal_t *journal, tid_t *ptid)
-{
-	int ret = 0;
-
-	write_lock(&journal->j_state_lock);
-	if (journal->j_running_transaction) {
-		tid_t tid = journal->j_running_transaction->t_tid;
-
-		__jbd2_log_start_commit(journal, tid);
-		/* There's a running transaction and we've just made sure
-		 * it's commit has been scheduled. */
-		if (ptid)
-			*ptid = tid;
-		ret = 1;
-	} else if (journal->j_committing_transaction) {
-		/*
-		 * If ext3_write_super() recently started a commit, then we
-		 * have to wait for completion of that transaction
-		 */
-		if (ptid)
-			*ptid = journal->j_committing_transaction->t_tid;
-		ret = 1;
-	}
-	write_unlock(&journal->j_state_lock);
-	return ret;
-}
-
-/*
- * Return 1 if a given transaction has not yet sent barrier request
- * connected with a transaction commit. If 0 is returned, transaction
- * may or may not have sent the barrier. Used to avoid sending barrier
- * twice in common cases.
- */
-int jbd2_trans_will_send_data_barrier(journal_t *journal, tid_t tid)
-{
-	int ret = 0;
-	transaction_t *commit_trans;
-
-	if (!(journal->j_flags & JBD2_BARRIER))
-		return 0;
-	read_lock(&journal->j_state_lock);
-	/* Transaction already committed? */
-	if (tid_geq(journal->j_commit_sequence, tid))
-		goto out;
-	commit_trans = journal->j_committing_transaction;
-	if (!commit_trans || commit_trans->t_tid != tid) {
-		ret = 1;
-		goto out;
-	}
-	/*
-	 * Transaction is being committed and we already proceeded to
-	 * submitting a flush to fs partition?
-	 */
-	if (journal->j_fs_dev != journal->j_dev) {
-		if (!commit_trans->t_need_data_flush ||
-		    commit_trans->t_state >= T_COMMIT_DFLUSH)
-			goto out;
-	} else {
-		if (commit_trans->t_state >= T_COMMIT_JFLUSH)
-			goto out;
-	}
-	ret = 1;
-out:
-	read_unlock(&journal->j_state_lock);
-	return ret;
-}
-EXPORT_SYMBOL(jbd2_trans_will_send_data_barrier);
-
-/*
- * Wait for a specified commit to complete.
- * The caller may not hold the journal lock.
- */
-int jbd2_log_wait_commit(journal_t *journal, tid_t tid)
-{
-	int err = 0;
-
-	read_lock(&journal->j_state_lock);
-#ifdef CONFIG_JBD2_DEBUG
-	if (!tid_geq(journal->j_commit_request, tid)) {
-		printk(KERN_EMERG
-		       "%s: error: j_commit_request=%d, tid=%d\n",
-		       __func__, journal->j_commit_request, tid);
-	}
-#endif
-	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);
-		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");
-		err = -EIO;
-	}
-	return err;
-}
-
-/*
- * Log buffer allocation routines:
- */
-
-int jbd2_journal_next_log_block(journal_t *journal, unsigned long long *retp)
-{
-	unsigned long blocknr;
-
-	write_lock(&journal->j_state_lock);
-	J_ASSERT(journal->j_free > 1);
-
-	blocknr = journal->j_head;
-	journal->j_head++;
-	journal->j_free--;
-	if (journal->j_head == journal->j_last)
-		journal->j_head = journal->j_first;
-	write_unlock(&journal->j_state_lock);
-	return jbd2_journal_bmap(journal, blocknr, retp);
-}
-
-/*
- * Conversion of logical to physical block numbers for the journal
- *
- * On external journals the journal blocks are identity-mapped, so
- * this is a no-op.  If needed, we can use j_blk_offset - everything is
- * ready.
- */
-int jbd2_journal_bmap(journal_t *journal, unsigned long blocknr,
-		 unsigned long long *retp)
-{
-	int err = 0;
-	unsigned long long ret;
-
-	if (journal->j_inode) {
-		ret = bmap(journal->j_inode, blocknr);
-		if (ret)
-			*retp = ret;
-		else {
-			printk(KERN_ALERT "%s: journal block not found "
-					"at offset %lu on %s\n",
-			       __func__, blocknr, journal->j_devname);
-			err = -EIO;
-			__journal_abort_soft(journal, err);
-		}
-	} else {
-		*retp = blocknr; /* +journal->j_blk_offset */
-	}
-	return err;
-}
-
-/*
- * We play buffer_head aliasing tricks to write data/metadata blocks to
- * the journal without copying their contents, but for journal
- * descriptor blocks we do need to generate bona fide buffers.
- *
- * After the caller of jbd2_journal_get_descriptor_buffer() has finished modifying
- * the buffer's contents they really should run flush_dcache_page(bh->b_page).
- * 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 *bh;
-	unsigned long long blocknr;
-	int err;
-
-	err = jbd2_journal_next_log_block(journal, &blocknr);
-
-	if (err)
-		return NULL;
-
-	bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-	if (!bh)
-		return NULL;
-	lock_buffer(bh);
-	memset(bh->b_data, 0, journal->j_blocksize);
-	set_buffer_uptodate(bh);
-	unlock_buffer(bh);
-	BUFFER_TRACE(bh, "return this buffer");
-	return jbd2_journal_add_journal_head(bh);
-}
-
-/*
- * Return tid of the oldest transaction in the journal and block in the journal
- * where the transaction starts.
- *
- * If the journal is now empty, return which will be the next transaction ID
- * we will write and where will that transaction start.
- *
- * The return value is 0 if journal tail cannot be pushed any further, 1 if
- * it can.
- */
-int jbd2_journal_get_log_tail(journal_t *journal, tid_t *tid,
-			      unsigned long *block)
-{
-	transaction_t *transaction;
-	int ret;
-
-	read_lock(&journal->j_state_lock);
-	spin_lock(&journal->j_list_lock);
-	transaction = journal->j_checkpoint_transactions;
-	if (transaction) {
-		*tid = transaction->t_tid;
-		*block = transaction->t_log_start;
-	} else if ((transaction = journal->j_committing_transaction) != NULL) {
-		*tid = transaction->t_tid;
-		*block = transaction->t_log_start;
-	} else if ((transaction = journal->j_running_transaction) != NULL) {
-		*tid = transaction->t_tid;
-		*block = journal->j_head;
-	} else {
-		*tid = journal->j_transaction_sequence;
-		*block = journal->j_head;
-	}
-	ret = tid_gt(*tid, journal->j_tail_sequence);
-	spin_unlock(&journal->j_list_lock);
-	read_unlock(&journal->j_state_lock);
-
-	return ret;
-}
-
-/*
- * Update information in journal structure and in on disk journal superblock
- * about log tail. This function does not check whether information passed in
- * really pushes log tail further. It's responsibility of the caller to make
- * sure provided log tail information is valid (e.g. by holding
- * j_checkpoint_mutex all the time between computing log tail and calling this
- * function as is the case with jbd2_cleanup_journal_tail()).
- *
- * Requires j_checkpoint_mutex
- */
-void __jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
-{
-	unsigned long freed;
-
-	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
-
-	/*
-	 * We cannot afford for write to remain in drive's caches since as
-	 * soon as we update j_tail, next transaction can start reusing journal
-	 * space and if we lose sb update during power failure we'd replay
-	 * old transaction with possibly newly overwritten data.
-	 */
-	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)
-		freed += journal->j_last - journal->j_first;
-
-	trace_jbd2_update_log_tail(journal, tid, block, freed);
-	jbd_debug(1,
-		  "Cleaning journal tail from %d to %d (offset %lu), "
-		  "freeing %lu\n",
-		  journal->j_tail_sequence, tid, block, freed);
-
-	journal->j_free += freed;
-	journal->j_tail_sequence = tid;
-	journal->j_tail = block;
-	write_unlock(&journal->j_state_lock);
-}
-
-/*
- * This is a variaon of __jbd2_update_log_tail which checks for validity of
- * provided log tail and locks j_checkpoint_mutex. So it is safe against races
- * with other threads updating log tail.
- */
-void jbd2_update_log_tail(journal_t *journal, tid_t tid, unsigned long block)
-{
-	mutex_lock(&journal->j_checkpoint_mutex);
-	if (tid_gt(tid, journal->j_tail_sequence))
-		__jbd2_update_log_tail(journal, tid, block);
-	mutex_unlock(&journal->j_checkpoint_mutex);
-}
-
-struct jbd2_stats_proc_session {
-	journal_t *journal;
-	struct transaction_stats_s *stats;
-	int start;
-	int max;
-};
-
-static void *jbd2_seq_info_start(struct seq_file *seq, loff_t *pos)
-{
-	return *pos ? NULL : SEQ_START_TOKEN;
-}
-
-static void *jbd2_seq_info_next(struct seq_file *seq, void *v, loff_t *pos)
-{
-	return NULL;
-}
-
-static int jbd2_seq_info_show(struct seq_file *seq, void *v)
-{
-	struct jbd2_stats_proc_session *s = seq->private;
-
-	if (v != SEQ_START_TOKEN)
-		return 0;
-	seq_printf(seq, "%lu transaction, each up to %u blocks\n",
-			s->stats->ts_tid,
-			s->journal->j_max_transaction_buffers);
-	if (s->stats->ts_tid == 0)
-		return 0;
-	seq_printf(seq, "average: \n  %ums waiting for transaction\n",
-	    jiffies_to_msecs(s->stats->run.rs_wait / s->stats->ts_tid));
-	seq_printf(seq, "  %ums running transaction\n",
-	    jiffies_to_msecs(s->stats->run.rs_running / s->stats->ts_tid));
-	seq_printf(seq, "  %ums transaction was being locked\n",
-	    jiffies_to_msecs(s->stats->run.rs_locked / s->stats->ts_tid));
-	seq_printf(seq, "  %ums flushing data (in ordered mode)\n",
-	    jiffies_to_msecs(s->stats->run.rs_flushing / s->stats->ts_tid));
-	seq_printf(seq, "  %ums logging transaction\n",
-	    jiffies_to_msecs(s->stats->run.rs_logging / s->stats->ts_tid));
-	seq_printf(seq, "  %lluus average transaction commit time\n",
-		   div_u64(s->journal->j_average_commit_time, 1000));
-	seq_printf(seq, "  %lu handles per transaction\n",
-	    s->stats->run.rs_handle_count / s->stats->ts_tid);
-	seq_printf(seq, "  %lu blocks per transaction\n",
-	    s->stats->run.rs_blocks / s->stats->ts_tid);
-	seq_printf(seq, "  %lu logged blocks per transaction\n",
-	    s->stats->run.rs_blocks_logged / s->stats->ts_tid);
-	return 0;
-}
-
-static void jbd2_seq_info_stop(struct seq_file *seq, void *v)
-{
-}
-
-static const struct seq_operations jbd2_seq_info_ops = {
-	.start  = jbd2_seq_info_start,
-	.next   = jbd2_seq_info_next,
-	.stop   = jbd2_seq_info_stop,
-	.show   = jbd2_seq_info_show,
-};
-
-static int jbd2_seq_info_open(struct inode *inode, struct file *file)
-{
-	journal_t *journal = PDE(inode)->data;
-	struct jbd2_stats_proc_session *s;
-	int rc, size;
-
-	s = kmalloc(sizeof(*s), GFP_KERNEL);
-	if (s == NULL)
-		return -ENOMEM;
-	size = sizeof(struct transaction_stats_s);
-	s->stats = kmalloc(size, GFP_KERNEL);
-	if (s->stats == NULL) {
-		kfree(s);
-		return -ENOMEM;
-	}
-	spin_lock(&journal->j_history_lock);
-	memcpy(s->stats, &journal->j_stats, size);
-	s->journal = journal;
-	spin_unlock(&journal->j_history_lock);
-
-	rc = seq_open(file, &jbd2_seq_info_ops);
-	if (rc == 0) {
-		struct seq_file *m = file->private_data;
-		m->private = s;
-	} else {
-		kfree(s->stats);
-		kfree(s);
-	}
-	return rc;
-
-}
-
-static int jbd2_seq_info_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *seq = file->private_data;
-	struct jbd2_stats_proc_session *s = seq->private;
-	kfree(s->stats);
-	kfree(s);
-	return seq_release(inode, file);
-}
-
-static const struct file_operations jbd2_seq_info_fops = {
-	.owner		= THIS_MODULE,
-	.open           = jbd2_seq_info_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.release        = jbd2_seq_info_release,
-};
-
-static struct proc_dir_entry *proc_jbd2_stats;
-
-static void jbd2_stats_proc_init(journal_t *journal)
-{
-	journal->j_proc_entry = proc_mkdir(journal->j_devname, proc_jbd2_stats);
-	if (journal->j_proc_entry) {
-		proc_create_data("info", S_IRUGO, journal->j_proc_entry,
-				 &jbd2_seq_info_fops, journal);
-	}
-}
-
-static void jbd2_stats_proc_exit(journal_t *journal)
-{
-	remove_proc_entry("info", journal->j_proc_entry);
-	remove_proc_entry(journal->j_devname, proc_jbd2_stats);
-}
-
-/*
- * Management for journal control blocks: functions to create and
- * destroy journal_t structures, and to initialise and read existing
- * journal blocks from disk.  */
-
-/* First: create and setup a journal_t object in memory.  We initialise
- * very few fields yet: that has to wait until we have created the
- * journal structures from from scratch, or loaded them from disk. */
-
-static journal_t * journal_init_common (void)
-{
-	journal_t *journal;
-	int err;
-
-	journal = kzalloc(sizeof(*journal), GFP_KERNEL);
-	if (!journal)
-		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);
-	mutex_init(&journal->j_barrier);
-	mutex_init(&journal->j_checkpoint_mutex);
-	spin_lock_init(&journal->j_revoke_lock);
-	spin_lock_init(&journal->j_list_lock);
-	rwlock_init(&journal->j_state_lock);
-
-	journal->j_commit_interval = (HZ * JBD2_DEFAULT_MAX_COMMIT_AGE);
-	journal->j_min_batch_time = 0;
-	journal->j_max_batch_time = 15000; /* 15ms */
-
-	/* The journal is marked for error until we succeed with recovery! */
-	journal->j_flags = JBD2_ABORT;
-
-	/* Set up a default-sized revoke table for the new mount. */
-	err = jbd2_journal_init_revoke(journal, JOURNAL_REVOKE_DEFAULT_HASH);
-	if (err) {
-		kfree(journal);
-		return NULL;
-	}
-
-	spin_lock_init(&journal->j_history_lock);
-
-	return journal;
-}
-
-/* jbd2_journal_init_dev and jbd2_journal_init_inode:
- *
- * Create a journal structure assigned some fixed set of disk blocks to
- * the journal.  We don't actually touch those disk blocks yet, but we
- * need to set up all of the mapping information to tell the journaling
- * system where the journal blocks are.
- *
- */
-
-/**
- *  journal_t * jbd2_journal_init_dev() - creates and initialises a journal structure
- *  @bdev: Block device on which to create the journal
- *  @fs_dev: Device which hold journalled filesystem for this journal.
- *  @start: Block nr Start of journal.
- *  @len:  Length of the journal in blocks.
- *  @blocksize: blocksize of journalling device
- *
- *  Returns: a newly created journal_t *
- *
- *  jbd2_journal_init_dev creates a journal which maps a fixed contiguous
- *  range of blocks on an arbitrary block device.
- *
- */
-journal_t * jbd2_journal_init_dev(struct block_device *bdev,
-			struct block_device *fs_dev,
-			unsigned long long start, int len, int blocksize)
-{
-	journal_t *journal = journal_init_common();
-	struct buffer_head *bh;
-	char *p;
-	int n;
-
-	if (!journal)
-		return NULL;
-
-	/* journal descriptor can store up to n blocks -bzzz */
-	journal->j_blocksize = blocksize;
-	journal->j_dev = bdev;
-	journal->j_fs_dev = fs_dev;
-	journal->j_blk_offset = start;
-	journal->j_maxlen = len;
-	bdevname(journal->j_dev, journal->j_devname);
-	p = journal->j_devname;
-	while ((p = strchr(p, '/')))
-		*p = '!';
-	jbd2_stats_proc_init(journal);
-	n = journal->j_blocksize / sizeof(journal_block_tag_t);
-	journal->j_wbufsize = n;
-	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
-	if (!journal->j_wbuf) {
-		printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
-			__func__);
-		goto out_err;
-	}
-
-	bh = __getblk(journal->j_dev, start, journal->j_blocksize);
-	if (!bh) {
-		printk(KERN_ERR
-		       "%s: Cannot get buffer for journal superblock\n",
-		       __func__);
-		goto out_err;
-	}
-	journal->j_sb_buffer = bh;
-	journal->j_superblock = (journal_superblock_t *)bh->b_data;
-
-	return journal;
-out_err:
-	kfree(journal->j_wbuf);
-	jbd2_stats_proc_exit(journal);
-	kfree(journal);
-	return NULL;
-}
-
-/**
- *  journal_t * jbd2_journal_init_inode () - creates a journal which maps to a inode.
- *  @inode: An inode to create the journal in
- *
- * jbd2_journal_init_inode creates a journal which maps an on-disk inode as
- * the journal.  The inode must exist already, must support bmap() and
- * must have all data blocks preallocated.
- */
-journal_t * jbd2_journal_init_inode (struct inode *inode)
-{
-	struct buffer_head *bh;
-	journal_t *journal = journal_init_common();
-	char *p;
-	int err;
-	int n;
-	unsigned long long blocknr;
-
-	if (!journal)
-		return NULL;
-
-	journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
-	journal->j_inode = inode;
-	bdevname(journal->j_dev, journal->j_devname);
-	p = journal->j_devname;
-	while ((p = strchr(p, '/')))
-		*p = '!';
-	p = journal->j_devname + strlen(journal->j_devname);
-	sprintf(p, "-%lu", journal->j_inode->i_ino);
-	jbd_debug(1,
-		  "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
-		  journal, inode->i_sb->s_id, inode->i_ino,
-		  (long long) inode->i_size,
-		  inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
-
-	journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
-	journal->j_blocksize = inode->i_sb->s_blocksize;
-	jbd2_stats_proc_init(journal);
-
-	/* journal descriptor can store up to n blocks -bzzz */
-	n = journal->j_blocksize / sizeof(journal_block_tag_t);
-	journal->j_wbufsize = n;
-	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
-	if (!journal->j_wbuf) {
-		printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
-			__func__);
-		goto out_err;
-	}
-
-	err = jbd2_journal_bmap(journal, 0, &blocknr);
-	/* If that failed, give up */
-	if (err) {
-		printk(KERN_ERR "%s: Cannot locate journal superblock\n",
-		       __func__);
-		goto out_err;
-	}
-
-	bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-	if (!bh) {
-		printk(KERN_ERR
-		       "%s: Cannot get buffer for journal superblock\n",
-		       __func__);
-		goto out_err;
-	}
-	journal->j_sb_buffer = bh;
-	journal->j_superblock = (journal_superblock_t *)bh->b_data;
-
-	return journal;
-out_err:
-	kfree(journal->j_wbuf);
-	jbd2_stats_proc_exit(journal);
-	kfree(journal);
-	return NULL;
-}
-
-/*
- * If the journal init or create aborts, we need to mark the journal
- * superblock as being NULL to prevent the journal destroy from writing
- * back a bogus superblock.
- */
-static void journal_fail_superblock (journal_t *journal)
-{
-	struct buffer_head *bh = journal->j_sb_buffer;
-	brelse(bh);
-	journal->j_sb_buffer = NULL;
-}
-
-/*
- * Given a journal_t structure, initialise the various fields for
- * startup of a new journaling session.  We use this both when creating
- * a journal, and after recovering an old journal to reset it for
- * subsequent use.
- */
-
-static int journal_reset(journal_t *journal)
-{
-	journal_superblock_t *sb = journal->j_superblock;
-	unsigned long long first, last;
-
-	first = be32_to_cpu(sb->s_first);
-	last = be32_to_cpu(sb->s_maxlen);
-	if (first + JBD2_MIN_JOURNAL_BLOCKS > last + 1) {
-		printk(KERN_ERR "JBD2: Journal too short (blocks %llu-%llu).\n",
-		       first, last);
-		journal_fail_superblock(journal);
-		return -EINVAL;
-	}
-
-	journal->j_first = first;
-	journal->j_last = last;
-
-	journal->j_head = first;
-	journal->j_tail = first;
-	journal->j_free = last - first;
-
-	journal->j_tail_sequence = journal->j_transaction_sequence;
-	journal->j_commit_sequence = journal->j_transaction_sequence - 1;
-	journal->j_commit_request = journal->j_commit_sequence;
-
-	journal->j_max_transaction_buffers = journal->j_maxlen / 4;
-
-	/*
-	 * As a special case, if the on-disk copy is already marked as needing
-	 * no recovery (s_start == 0), then we can safely defer the superblock
-	 * update until the next commit by setting JBD2_FLUSHED.  This avoids
-	 * attempting a write to a potential-readonly device.
-	 */
-	if (sb->s_start == 0) {
-		jbd_debug(1, "JBD2: Skipping superblock update on recovered sb "
-			"(start %ld, seq %d, errno %d)\n",
-			journal->j_tail, journal->j_tail_sequence,
-			journal->j_errno);
-		journal->j_flags |= JBD2_FLUSHED;
-	} else {
-		/* Lock here to make assertions happy... */
-		mutex_lock(&journal->j_checkpoint_mutex);
-		/*
-		 * Update log tail information. We use WRITE_FUA since new
-		 * transaction will start reusing journal space and so we
-		 * must make sure information about current log tail is on
-		 * disk before that.
-		 */
-		jbd2_journal_update_sb_log_tail(journal,
-						journal->j_tail_sequence,
-						journal->j_tail,
-						WRITE_FUA);
-		mutex_unlock(&journal->j_checkpoint_mutex);
-	}
-	return jbd2_journal_start_thread(journal);
-}
-
-static void jbd2_write_superblock(journal_t *journal, int write_op)
-{
-	struct buffer_head *bh = journal->j_sb_buffer;
-	int ret;
-
-	trace_jbd2_write_superblock(journal, write_op);
-	if (!(journal->j_flags & JBD2_BARRIER))
-		write_op &= ~(REQ_FUA | REQ_FLUSH);
-	lock_buffer(bh);
-	if (buffer_write_io_error(bh)) {
-		/*
-		 * Oh, dear.  A previous attempt to write the journal
-		 * superblock failed.  This could happen because the
-		 * USB device was yanked out.  Or it could happen to
-		 * be a transient write error and maybe the block will
-		 * be remapped.  Nothing we can do but to retry the
-		 * write and hope for the best.
-		 */
-		printk(KERN_ERR "JBD2: previous I/O error detected "
-		       "for journal superblock update for %s.\n",
-		       journal->j_devname);
-		clear_buffer_write_io_error(bh);
-		set_buffer_uptodate(bh);
-	}
-	get_bh(bh);
-	bh->b_end_io = end_buffer_write_sync;
-	ret = submit_bh(write_op, bh);
-	wait_on_buffer(bh);
-	if (buffer_write_io_error(bh)) {
-		clear_buffer_write_io_error(bh);
-		set_buffer_uptodate(bh);
-		ret = -EIO;
-	}
-	if (ret) {
-		printk(KERN_ERR "JBD2: Error %d detected when updating "
-		       "journal superblock for %s.\n", ret,
-		       journal->j_devname);
-	}
-}
-
-/**
- * jbd2_journal_update_sb_log_tail() - Update log tail in journal sb on disk.
- * @journal: The journal to update.
- * @tail_tid: TID of the new transaction at the tail of the log
- * @tail_block: The first block of the transaction at the tail of the log
- * @write_op: With which operation should we write the journal sb
- *
- * Update a journal's superblock information about log tail and write it to
- * disk, waiting for the IO to complete.
- */
-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;
-
-	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
-	jbd_debug(1, "JBD2: updating superblock (start %lu, seq %u)\n",
-		  tail_block, tail_tid);
-
-	sb->s_sequence = cpu_to_be32(tail_tid);
-	sb->s_start    = cpu_to_be32(tail_block);
-
-	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);
-}
-
-/**
- * jbd2_mark_journal_empty() - Mark on disk journal as empty.
- * @journal: The journal to update.
- *
- * 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)
-{
-	journal_superblock_t *sb = journal->j_superblock;
-
-	BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
-	read_lock(&journal->j_state_lock);
-	jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n",
-		  journal->j_tail_sequence);
-
-	sb->s_sequence = cpu_to_be32(journal->j_tail_sequence);
-	sb->s_start    = cpu_to_be32(0);
-	read_unlock(&journal->j_state_lock);
-
-	jbd2_write_superblock(journal, WRITE_FUA);
-
-	/* Log is no longer empty */
-	write_lock(&journal->j_state_lock);
-	journal->j_flags |= JBD2_FLUSHED;
-	write_unlock(&journal->j_state_lock);
-}
-
-
-/**
- * jbd2_journal_update_sb_errno() - Update error in the journal.
- * @journal: The journal to update.
- *
- * Update a journal's errno.  Write updated superblock to disk waiting for IO
- * to complete.
- */
-static void jbd2_journal_update_sb_errno(journal_t *journal)
-{
-	journal_superblock_t *sb = journal->j_superblock;
-
-	read_lock(&journal->j_state_lock);
-	jbd_debug(1, "JBD2: updating superblock error (errno %d)\n",
-		  journal->j_errno);
-	sb->s_errno    = cpu_to_be32(journal->j_errno);
-	read_unlock(&journal->j_state_lock);
-
-	jbd2_write_superblock(journal, WRITE_SYNC);
-}
-
-/*
- * Read the superblock for a given journal, performing initial
- * validation of the format.
- */
-static int journal_get_superblock(journal_t *journal)
-{
-	struct buffer_head *bh;
-	journal_superblock_t *sb;
-	int err = -EIO;
-
-	bh = journal->j_sb_buffer;
-
-	J_ASSERT(bh != NULL);
-	if (!buffer_uptodate(bh)) {
-		ll_rw_block(READ, 1, &bh);
-		wait_on_buffer(bh);
-		if (!buffer_uptodate(bh)) {
-			printk(KERN_ERR
-				"JBD2: IO error reading journal superblock\n");
-			goto out;
-		}
-	}
-
-	sb = journal->j_superblock;
-
-	err = -EINVAL;
-
-	if (sb->s_header.h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER) ||
-	    sb->s_blocksize != cpu_to_be32(journal->j_blocksize)) {
-		printk(KERN_WARNING "JBD2: no valid journal superblock found\n");
-		goto out;
-	}
-
-	switch(be32_to_cpu(sb->s_header.h_blocktype)) {
-	case JBD2_SUPERBLOCK_V1:
-		journal->j_format_version = 1;
-		break;
-	case JBD2_SUPERBLOCK_V2:
-		journal->j_format_version = 2;
-		break;
-	default:
-		printk(KERN_WARNING "JBD2: unrecognised superblock format ID\n");
-		goto out;
-	}
-
-	if (be32_to_cpu(sb->s_maxlen) < journal->j_maxlen)
-		journal->j_maxlen = be32_to_cpu(sb->s_maxlen);
-	else if (be32_to_cpu(sb->s_maxlen) > journal->j_maxlen) {
-		printk(KERN_WARNING "JBD2: journal file too short\n");
-		goto out;
-	}
-
-	if (be32_to_cpu(sb->s_first) == 0 ||
-	    be32_to_cpu(sb->s_first) >= journal->j_maxlen) {
-		printk(KERN_WARNING
-			"JBD2: Invalid start block of journal: %u\n",
-			be32_to_cpu(sb->s_first));
-		goto out;
-	}
-
-	return 0;
-
-out:
-	journal_fail_superblock(journal);
-	return err;
-}
-
-/*
- * Load the on-disk journal superblock and read the key fields into the
- * journal_t.
- */
-
-static int load_superblock(journal_t *journal)
-{
-	int err;
-	journal_superblock_t *sb;
-
-	err = journal_get_superblock(journal);
-	if (err)
-		return err;
-
-	sb = journal->j_superblock;
-
-	journal->j_tail_sequence = be32_to_cpu(sb->s_sequence);
-	journal->j_tail = be32_to_cpu(sb->s_start);
-	journal->j_first = be32_to_cpu(sb->s_first);
-	journal->j_last = be32_to_cpu(sb->s_maxlen);
-	journal->j_errno = be32_to_cpu(sb->s_errno);
-
-	return 0;
-}
-
-
-/**
- * int jbd2_journal_load() - Read journal from disk.
- * @journal: Journal to act on.
- *
- * Given a journal_t structure which tells us which disk blocks contain
- * a journal, read the journal from disk to initialise the in-memory
- * structures.
- */
-int jbd2_journal_load(journal_t *journal)
-{
-	int err;
-	journal_superblock_t *sb;
-
-	err = load_superblock(journal);
-	if (err)
-		return err;
-
-	sb = journal->j_superblock;
-	/* If this is a V2 superblock, then we have to check the
-	 * features flags on it. */
-
-	if (journal->j_format_version >= 2) {
-		if ((sb->s_feature_ro_compat &
-		     ~cpu_to_be32(JBD2_KNOWN_ROCOMPAT_FEATURES)) ||
-		    (sb->s_feature_incompat &
-		     ~cpu_to_be32(JBD2_KNOWN_INCOMPAT_FEATURES))) {
-			printk(KERN_WARNING
-				"JBD2: Unrecognised features on journal\n");
-			return -EINVAL;
-		}
-	}
-
-	/*
-	 * Create a slab for this blocksize
-	 */
-	err = jbd2_journal_create_slab(be32_to_cpu(sb->s_blocksize));
-	if (err)
-		return err;
-
-	/* Let the recovery code check whether it needs to recover any
-	 * data from the journal. */
-	if (jbd2_journal_recover(journal))
-		goto recovery_error;
-
-	if (journal->j_failed_commit) {
-		printk(KERN_ERR "JBD2: journal transaction %u on %s "
-		       "is corrupt.\n", journal->j_failed_commit,
-		       journal->j_devname);
-		return -EIO;
-	}
-
-	/* OK, we've finished with the dynamic journal bits:
-	 * reinitialise the dynamic contents of the superblock in memory
-	 * and reset them on disk. */
-	if (journal_reset(journal))
-		goto recovery_error;
-
-	journal->j_flags &= ~JBD2_ABORT;
-	journal->j_flags |= JBD2_LOADED;
-	return 0;
-
-recovery_error:
-	printk(KERN_WARNING "JBD2: recovery failed\n");
-	return -EIO;
-}
-
-/**
- * void jbd2_journal_destroy() - Release a journal_t structure.
- * @journal: Journal to act on.
- *
- * Release a journal_t structure once it is no longer in use by the
- * journaled object.
- * Return <0 if we couldn't clean up the journal.
- */
-int jbd2_journal_destroy(journal_t *journal)
-{
-	int err = 0;
-
-	/* Wait for the commit thread to wake up and die. */
-	journal_kill_thread(journal);
-
-	/* Force a final log commit */
-	if (journal->j_running_transaction)
-		jbd2_journal_commit_transaction(journal);
-
-	/* Force any old transactions to disk */
-
-	/* Totally anal locking here... */
-	spin_lock(&journal->j_list_lock);
-	while (journal->j_checkpoint_transactions != NULL) {
-		spin_unlock(&journal->j_list_lock);
-		mutex_lock(&journal->j_checkpoint_mutex);
-		jbd2_log_do_checkpoint(journal);
-		mutex_unlock(&journal->j_checkpoint_mutex);
-		spin_lock(&journal->j_list_lock);
-	}
-
-	J_ASSERT(journal->j_running_transaction == NULL);
-	J_ASSERT(journal->j_committing_transaction == NULL);
-	J_ASSERT(journal->j_checkpoint_transactions == NULL);
-	spin_unlock(&journal->j_list_lock);
-
-	if (journal->j_sb_buffer) {
-		if (!is_journal_aborted(journal)) {
-			mutex_lock(&journal->j_checkpoint_mutex);
-			jbd2_mark_journal_empty(journal);
-			mutex_unlock(&journal->j_checkpoint_mutex);
-		} else
-			err = -EIO;
-		brelse(journal->j_sb_buffer);
-	}
-
-	if (journal->j_proc_entry)
-		jbd2_stats_proc_exit(journal);
-	if (journal->j_inode)
-		iput(journal->j_inode);
-	if (journal->j_revoke)
-		jbd2_journal_destroy_revoke(journal);
-	kfree(journal->j_wbuf);
-	kfree(journal);
-
-	return err;
-}
-
-
-/**
- *int jbd2_journal_check_used_features () - Check if features specified are used.
- * @journal: Journal to check.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Check whether the journal uses all of a given set of
- * features.  Return true (non-zero) if it does.
- **/
-
-int jbd2_journal_check_used_features (journal_t *journal, unsigned long compat,
-				 unsigned long ro, unsigned long incompat)
-{
-	journal_superblock_t *sb;
-
-	if (!compat && !ro && !incompat)
-		return 1;
-	/* Load journal superblock if it is not loaded yet. */
-	if (journal->j_format_version == 0 &&
-	    journal_get_superblock(journal) != 0)
-		return 0;
-	if (journal->j_format_version == 1)
-		return 0;
-
-	sb = journal->j_superblock;
-
-	if (((be32_to_cpu(sb->s_feature_compat) & compat) == compat) &&
-	    ((be32_to_cpu(sb->s_feature_ro_compat) & ro) == ro) &&
-	    ((be32_to_cpu(sb->s_feature_incompat) & incompat) == incompat))
-		return 1;
-
-	return 0;
-}
-
-/**
- * int jbd2_journal_check_available_features() - Check feature set in journalling layer
- * @journal: Journal to check.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Check whether the journaling code supports the use of
- * all of a given set of features on this journal.  Return true
- * (non-zero) if it can. */
-
-int jbd2_journal_check_available_features (journal_t *journal, unsigned long compat,
-				      unsigned long ro, unsigned long incompat)
-{
-	if (!compat && !ro && !incompat)
-		return 1;
-
-	/* We can support any known requested features iff the
-	 * superblock is in version 2.  Otherwise we fail to support any
-	 * extended sb features. */
-
-	if (journal->j_format_version != 2)
-		return 0;
-
-	if ((compat   & JBD2_KNOWN_COMPAT_FEATURES) == compat &&
-	    (ro       & JBD2_KNOWN_ROCOMPAT_FEATURES) == ro &&
-	    (incompat & JBD2_KNOWN_INCOMPAT_FEATURES) == incompat)
-		return 1;
-
-	return 0;
-}
-
-/**
- * int jbd2_journal_set_features () - Mark a given journal feature in the superblock
- * @journal: Journal to act on.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Mark a given journal feature as present on the
- * superblock.  Returns true if the requested features could be set.
- *
- */
-
-int jbd2_journal_set_features (journal_t *journal, unsigned long compat,
-			  unsigned long ro, unsigned long incompat)
-{
-	journal_superblock_t *sb;
-
-	if (jbd2_journal_check_used_features(journal, compat, ro, incompat))
-		return 1;
-
-	if (!jbd2_journal_check_available_features(journal, compat, ro, incompat))
-		return 0;
-
-	jbd_debug(1, "Setting new features 0x%lx/0x%lx/0x%lx\n",
-		  compat, ro, incompat);
-
-	sb = journal->j_superblock;
-
-	sb->s_feature_compat    |= cpu_to_be32(compat);
-	sb->s_feature_ro_compat |= cpu_to_be32(ro);
-	sb->s_feature_incompat  |= cpu_to_be32(incompat);
-
-	return 1;
-}
-
-/*
- * jbd2_journal_clear_features () - Clear a given journal feature in the
- * 				    superblock
- * @journal: Journal to act on.
- * @compat: bitmask of compatible features
- * @ro: bitmask of features that force read-only mount
- * @incompat: bitmask of incompatible features
- *
- * Clear a given journal feature as present on the
- * superblock.
- */
-void jbd2_journal_clear_features(journal_t *journal, unsigned long compat,
-				unsigned long ro, unsigned long incompat)
-{
-	journal_superblock_t *sb;
-
-	jbd_debug(1, "Clear features 0x%lx/0x%lx/0x%lx\n",
-		  compat, ro, incompat);
-
-	sb = journal->j_superblock;
-
-	sb->s_feature_compat    &= ~cpu_to_be32(compat);
-	sb->s_feature_ro_compat &= ~cpu_to_be32(ro);
-	sb->s_feature_incompat  &= ~cpu_to_be32(incompat);
-}
-EXPORT_SYMBOL(jbd2_journal_clear_features);
-
-/**
- * int jbd2_journal_flush () - Flush journal
- * @journal: Journal to act on.
- *
- * Flush all data for a given journal to disk and empty the journal.
- * Filesystems can use this when remounting readonly to ensure that
- * recovery does not need to happen on remount.
- */
-
-int jbd2_journal_flush(journal_t *journal)
-{
-	int err = 0;
-	transaction_t *transaction = NULL;
-
-	write_lock(&journal->j_state_lock);
-
-	/* Force everything buffered to the log... */
-	if (journal->j_running_transaction) {
-		transaction = journal->j_running_transaction;
-		__jbd2_log_start_commit(journal, transaction->t_tid);
-	} else if (journal->j_committing_transaction)
-		transaction = journal->j_committing_transaction;
-
-	/* Wait for the log commit to complete... */
-	if (transaction) {
-		tid_t tid = transaction->t_tid;
-
-		write_unlock(&journal->j_state_lock);
-		jbd2_log_wait_commit(journal, tid);
-	} else {
-		write_unlock(&journal->j_state_lock);
-	}
-
-	/* ...and flush everything in the log out to disk. */
-	spin_lock(&journal->j_list_lock);
-	while (!err && journal->j_checkpoint_transactions != NULL) {
-		spin_unlock(&journal->j_list_lock);
-		mutex_lock(&journal->j_checkpoint_mutex);
-		err = jbd2_log_do_checkpoint(journal);
-		mutex_unlock(&journal->j_checkpoint_mutex);
-		spin_lock(&journal->j_list_lock);
-	}
-	spin_unlock(&journal->j_list_lock);
-
-	if (is_journal_aborted(journal))
-		return -EIO;
-
-	mutex_lock(&journal->j_checkpoint_mutex);
-	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);
-	mutex_unlock(&journal->j_checkpoint_mutex);
-	write_lock(&journal->j_state_lock);
-	J_ASSERT(!journal->j_running_transaction);
-	J_ASSERT(!journal->j_committing_transaction);
-	J_ASSERT(!journal->j_checkpoint_transactions);
-	J_ASSERT(journal->j_head == journal->j_tail);
-	J_ASSERT(journal->j_tail_sequence == journal->j_transaction_sequence);
-	write_unlock(&journal->j_state_lock);
-	return 0;
-}
-
-/**
- * int jbd2_journal_wipe() - Wipe journal contents
- * @journal: Journal to act on.
- * @write: flag (see below)
- *
- * Wipe out all of the contents of a journal, safely.  This will produce
- * a warning if the journal contains any valid recovery information.
- * Must be called between journal_init_*() and jbd2_journal_load().
- *
- * If 'write' is non-zero, then we wipe out the journal on disk; otherwise
- * we merely suppress recovery.
- */
-
-int jbd2_journal_wipe(journal_t *journal, int write)
-{
-	int err = 0;
-
-	J_ASSERT (!(journal->j_flags & JBD2_LOADED));
-
-	err = load_superblock(journal);
-	if (err)
-		return err;
-
-	if (!journal->j_tail)
-		goto no_recovery;
-
-	printk(KERN_WARNING "JBD2: %s recovery information on journal\n",
-		write ? "Clearing" : "Ignoring");
-
-	err = jbd2_journal_skip_recovery(journal);
-	if (write) {
-		/* Lock to make assertions happy... */
-		mutex_lock(&journal->j_checkpoint_mutex);
-		jbd2_mark_journal_empty(journal);
-		mutex_unlock(&journal->j_checkpoint_mutex);
-	}
-
- no_recovery:
-	return err;
-}
-
-/*
- * Journal abort has very specific semantics, which we describe
- * for journal abort.
- *
- * Two internal functions, which provide abort to the jbd layer
- * itself are here.
- */
-
-/*
- * Quick version for internal journal use (doesn't lock the journal).
- * Aborts hard --- we mark the abort as occurred, but do _nothing_ else,
- * and don't attempt to make any other journal updates.
- */
-void __jbd2_journal_abort_hard(journal_t *journal)
-{
-	transaction_t *transaction;
-
-	if (journal->j_flags & JBD2_ABORT)
-		return;
-
-	printk(KERN_ERR "Aborting journal on device %s.\n",
-	       journal->j_devname);
-
-	write_lock(&journal->j_state_lock);
-	journal->j_flags |= JBD2_ABORT;
-	transaction = journal->j_running_transaction;
-	if (transaction)
-		__jbd2_log_start_commit(journal, transaction->t_tid);
-	write_unlock(&journal->j_state_lock);
-}
-
-/* Soft abort: record the abort error status in the journal superblock,
- * but don't do any other IO. */
-static void __journal_abort_soft (journal_t *journal, int errno)
-{
-	if (journal->j_flags & JBD2_ABORT)
-		return;
-
-	if (!journal->j_errno)
-		journal->j_errno = errno;
-
-	__jbd2_journal_abort_hard(journal);
-
-	if (errno)
-		jbd2_journal_update_sb_errno(journal);
-}
-
-/**
- * void jbd2_journal_abort () - Shutdown the journal immediately.
- * @journal: the journal to shutdown.
- * @errno:   an error number to record in the journal indicating
- *           the reason for the shutdown.
- *
- * Perform a complete, immediate shutdown of the ENTIRE
- * journal (not of a single transaction).  This operation cannot be
- * undone without closing and reopening the journal.
- *
- * The jbd2_journal_abort function is intended to support higher level error
- * recovery mechanisms such as the ext2/ext3 remount-readonly error
- * mode.
- *
- * Journal abort has very specific semantics.  Any existing dirty,
- * unjournaled buffers in the main filesystem will still be written to
- * disk by bdflush, but the journaling mechanism will be suspended
- * immediately and no further transaction commits will be honoured.
- *
- * Any dirty, journaled buffers will be written back to disk without
- * hitting the journal.  Atomicity cannot be guaranteed on an aborted
- * filesystem, but we _do_ attempt to leave as much data as possible
- * behind for fsck to use for cleanup.
- *
- * Any attempt to get a new transaction handle on a journal which is in
- * ABORT state will just result in an -EROFS error return.  A
- * jbd2_journal_stop on an existing handle will return -EIO if we have
- * entered abort state during the update.
- *
- * Recursive transactions are not disturbed by journal abort until the
- * final jbd2_journal_stop, which will receive the -EIO error.
- *
- * Finally, the jbd2_journal_abort call allows the caller to supply an errno
- * which will be recorded (if possible) in the journal superblock.  This
- * allows a client to record failure conditions in the middle of a
- * transaction without having to complete the transaction to record the
- * failure to disk.  ext3_error, for example, now uses this
- * functionality.
- *
- * Errors which originate from within the journaling layer will NOT
- * supply an errno; a null errno implies that absolutely no further
- * writes are done to the journal (unless there are any already in
- * progress).
- *
- */
-
-void jbd2_journal_abort(journal_t *journal, int errno)
-{
-	__journal_abort_soft(journal, errno);
-}
-
-/**
- * int jbd2_journal_errno () - returns the journal's error state.
- * @journal: journal to examine.
- *
- * This is the errno number set with jbd2_journal_abort(), the last
- * time the journal was mounted - if the journal was stopped
- * without calling abort this will be 0.
- *
- * If the journal has been aborted on this mount time -EROFS will
- * be returned.
- */
-int jbd2_journal_errno(journal_t *journal)
-{
-	int err;
-
-	read_lock(&journal->j_state_lock);
-	if (journal->j_flags & JBD2_ABORT)
-		err = -EROFS;
-	else
-		err = journal->j_errno;
-	read_unlock(&journal->j_state_lock);
-	return err;
-}
-
-/**
- * int jbd2_journal_clear_err () - clears the journal's error state
- * @journal: journal to act on.
- *
- * An error must be cleared or acked to take a FS out of readonly
- * mode.
- */
-int jbd2_journal_clear_err(journal_t *journal)
-{
-	int err = 0;
-
-	write_lock(&journal->j_state_lock);
-	if (journal->j_flags & JBD2_ABORT)
-		err = -EROFS;
-	else
-		journal->j_errno = 0;
-	write_unlock(&journal->j_state_lock);
-	return err;
-}
-
-/**
- * void jbd2_journal_ack_err() - Ack journal err.
- * @journal: journal to act on.
- *
- * An error must be cleared or acked to take a FS out of readonly
- * mode.
- */
-void jbd2_journal_ack_err(journal_t *journal)
-{
-	write_lock(&journal->j_state_lock);
-	if (journal->j_errno)
-		journal->j_flags |= JBD2_ACK_ERR;
-	write_unlock(&journal->j_state_lock);
-}
-
-int jbd2_journal_blocks_per_page(struct inode *inode)
-{
-	return 1 << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
-}
-
-/*
- * helper functions to deal with 32 or 64bit block numbers.
- */
-size_t journal_tag_bytes(journal_t *journal)
-{
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
-		return JBD2_TAG_SIZE64;
-	else
-		return JBD2_TAG_SIZE32;
-}
-
-/*
- * JBD memory management
- *
- * These functions are used to allocate block-sized chunks of memory
- * used for making copies of buffer_head data.  Very often it will be
- * page-sized chunks of data, but sometimes it will be in
- * sub-page-size chunks.  (For example, 16k pages on Power systems
- * with a 4k block file system.)  For blocks smaller than a page, we
- * use a SLAB allocator.  There are slab caches for each block size,
- * which are allocated at mount time, if necessary, and we only free
- * (all of) the slab caches when/if the jbd2 module is unloaded.  For
- * this reason we don't need to a mutex to protect access to
- * jbd2_slab[] allocating or releasing memory; only in
- * jbd2_journal_create_slab().
- */
-#define JBD2_MAX_SLABS 8
-static struct kmem_cache *jbd2_slab[JBD2_MAX_SLABS];
-
-static const char *jbd2_slab_names[JBD2_MAX_SLABS] = {
-	"jbd2_1k", "jbd2_2k", "jbd2_4k", "jbd2_8k",
-	"jbd2_16k", "jbd2_32k", "jbd2_64k", "jbd2_128k"
-};
-
-
-static void jbd2_journal_destroy_slabs(void)
-{
-	int i;
-
-	for (i = 0; i < JBD2_MAX_SLABS; i++) {
-		if (jbd2_slab[i])
-			kmem_cache_destroy(jbd2_slab[i]);
-		jbd2_slab[i] = NULL;
-	}
-}
-
-static int jbd2_journal_create_slab(size_t size)
-{
-	static DEFINE_MUTEX(jbd2_slab_create_mutex);
-	int i = order_base_2(size) - 10;
-	size_t slab_size;
-
-	if (size == PAGE_SIZE)
-		return 0;
-
-	if (i >= JBD2_MAX_SLABS)
-		return -EINVAL;
-
-	if (unlikely(i < 0))
-		i = 0;
-	mutex_lock(&jbd2_slab_create_mutex);
-	if (jbd2_slab[i]) {
-		mutex_unlock(&jbd2_slab_create_mutex);
-		return 0;	/* Already created */
-	}
-
-	slab_size = 1 << (i+10);
-	jbd2_slab[i] = kmem_cache_create(jbd2_slab_names[i], slab_size,
-					 slab_size, 0, NULL);
-	mutex_unlock(&jbd2_slab_create_mutex);
-	if (!jbd2_slab[i]) {
-		printk(KERN_EMERG "JBD2: no memory for jbd2_slab cache\n");
-		return -ENOMEM;
-	}
-	return 0;
-}
-
-static struct kmem_cache *get_slab(size_t size)
-{
-	int i = order_base_2(size) - 10;
-
-	BUG_ON(i >= JBD2_MAX_SLABS);
-	if (unlikely(i < 0))
-		i = 0;
-	BUG_ON(jbd2_slab[i] == NULL);
-	return jbd2_slab[i];
-}
-
-void *jbd2_alloc(size_t size, gfp_t flags)
-{
-	void *ptr;
-
-	BUG_ON(size & (size-1)); /* Must be a power of 2 */
-
-	flags |= __GFP_REPEAT;
-	if (size == PAGE_SIZE)
-		ptr = (void *)__get_free_pages(flags, 0);
-	else if (size > PAGE_SIZE) {
-		int order = get_order(size);
-
-		if (order < 3)
-			ptr = (void *)__get_free_pages(flags, order);
-		else
-			ptr = vmalloc(size);
-	} else
-		ptr = kmem_cache_alloc(get_slab(size), flags);
-
-	/* Check alignment; SLUB has gotten this wrong in the past,
-	 * and this can lead to user data corruption! */
-	BUG_ON(((unsigned long) ptr) & (size-1));
-
-	return ptr;
-}
-
-void jbd2_free(void *ptr, size_t size)
-{
-	if (size == PAGE_SIZE) {
-		free_pages((unsigned long)ptr, 0);
-		return;
-	}
-	if (size > PAGE_SIZE) {
-		int order = get_order(size);
-
-		if (order < 3)
-			free_pages((unsigned long)ptr, order);
-		else
-			vfree(ptr);
-		return;
-	}
-	kmem_cache_free(get_slab(size), ptr);
-};
-
-/*
- * Journal_head storage management
- */
-static struct kmem_cache *jbd2_journal_head_cache;
-#ifdef CONFIG_JBD2_DEBUG
-static atomic_t nr_journal_heads = ATOMIC_INIT(0);
-#endif
-
-static int jbd2_journal_init_journal_head_cache(void)
-{
-	int retval;
-
-	J_ASSERT(jbd2_journal_head_cache == NULL);
-	jbd2_journal_head_cache = kmem_cache_create("jbd2_journal_head",
-				sizeof(struct journal_head),
-				0,		/* offset */
-				SLAB_TEMPORARY,	/* flags */
-				NULL);		/* ctor */
-	retval = 0;
-	if (!jbd2_journal_head_cache) {
-		retval = -ENOMEM;
-		printk(KERN_EMERG "JBD2: no memory for journal_head cache\n");
-	}
-	return retval;
-}
-
-static void jbd2_journal_destroy_journal_head_cache(void)
-{
-	if (jbd2_journal_head_cache) {
-		kmem_cache_destroy(jbd2_journal_head_cache);
-		jbd2_journal_head_cache = NULL;
-	}
-}
-
-/*
- * journal_head splicing and dicing
- */
-static struct journal_head *journal_alloc_journal_head(void)
-{
-	struct journal_head *ret;
-
-#ifdef CONFIG_JBD2_DEBUG
-	atomic_inc(&nr_journal_heads);
-#endif
-	ret = kmem_cache_alloc(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);
-		}
-	}
-	return ret;
-}
-
-static void journal_free_journal_head(struct journal_head *jh)
-{
-#ifdef CONFIG_JBD2_DEBUG
-	atomic_dec(&nr_journal_heads);
-	memset(jh, JBD2_POISON_FREE, sizeof(*jh));
-#endif
-	kmem_cache_free(jbd2_journal_head_cache, jh);
-}
-
-/*
- * A journal_head is attached to a buffer_head whenever JBD has an
- * interest in the buffer.
- *
- * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit
- * is set.  This bit is tested in core kernel code where we need to take
- * JBD-specific actions.  Testing the zeroness of ->b_private is not reliable
- * there.
- *
- * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one.
- *
- * When a buffer has its BH_JBD bit set it is immune from being released by
- * core kernel code, mainly via ->b_count.
- *
- * A journal_head is detached from its buffer_head when the journal_head's
- * b_jcount reaches zero. Running transaction (b_transaction) and checkpoint
- * transaction (b_cp_transaction) hold their references to b_jcount.
- *
- * Various places in the kernel want to attach a journal_head to a buffer_head
- * _before_ attaching the journal_head to a transaction.  To protect the
- * journal_head in this situation, jbd2_journal_add_journal_head elevates the
- * journal_head's b_jcount refcount by one.  The caller must call
- * jbd2_journal_put_journal_head() to undo this.
- *
- * So the typical usage would be:
- *
- *	(Attach a journal_head if needed.  Increments b_jcount)
- *	struct journal_head *jh = jbd2_journal_add_journal_head(bh);
- *	...
- *      (Get another reference for transaction)
- *	jbd2_journal_grab_journal_head(bh);
- *	jh->b_transaction = xxx;
- *	(Put original reference)
- *	jbd2_journal_put_journal_head(jh);
- */
-
-/*
- * Give a buffer_head a journal_head.
- *
- * May sleep.
- */
-struct journal_head *jbd2_journal_add_journal_head(struct buffer_head *bh)
-{
-	struct journal_head *jh;
-	struct journal_head *new_jh = NULL;
-
-repeat:
-	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)) {
-		jh = bh2jh(bh);
-	} else {
-		J_ASSERT_BH(bh,
-			(atomic_read(&bh->b_count) > 0) ||
-			(bh->b_page && bh->b_page->mapping));
-
-		if (!new_jh) {
-			jbd_unlock_bh_journal_head(bh);
-			goto repeat;
-		}
-
-		jh = new_jh;
-		new_jh = NULL;		/* We consumed it */
-		set_buffer_jbd(bh);
-		bh->b_private = jh;
-		jh->b_bh = bh;
-		get_bh(bh);
-		BUFFER_TRACE(bh, "added journal_head");
-	}
-	jh->b_jcount++;
-	jbd_unlock_bh_journal_head(bh);
-	if (new_jh)
-		journal_free_journal_head(new_jh);
-	return bh->b_private;
-}
-
-/*
- * Grab a ref against this buffer_head's journal_head.  If it ended up not
- * having a journal_head, return NULL
- */
-struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
-{
-	struct journal_head *jh = NULL;
-
-	jbd_lock_bh_journal_head(bh);
-	if (buffer_jbd(bh)) {
-		jh = bh2jh(bh);
-		jh->b_jcount++;
-	}
-	jbd_unlock_bh_journal_head(bh);
-	return jh;
-}
-
-static void __journal_remove_journal_head(struct buffer_head *bh)
-{
-	struct journal_head *jh = bh2jh(bh);
-
-	J_ASSERT_JH(jh, jh->b_jcount >= 0);
-	J_ASSERT_JH(jh, jh->b_transaction == NULL);
-	J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
-	J_ASSERT_JH(jh, jh->b_cp_transaction == NULL);
-	J_ASSERT_JH(jh, jh->b_jlist == BJ_None);
-	J_ASSERT_BH(bh, buffer_jbd(bh));
-	J_ASSERT_BH(bh, jh2bh(jh) == bh);
-	BUFFER_TRACE(bh, "remove journal_head");
-	if (jh->b_frozen_data) {
-		printk(KERN_WARNING "%s: freeing b_frozen_data\n", __func__);
-		jbd2_free(jh->b_frozen_data, bh->b_size);
-	}
-	if (jh->b_committed_data) {
-		printk(KERN_WARNING "%s: freeing b_committed_data\n", __func__);
-		jbd2_free(jh->b_committed_data, bh->b_size);
-	}
-	bh->b_private = NULL;
-	jh->b_bh = NULL;	/* debug, really */
-	clear_buffer_jbd(bh);
-	journal_free_journal_head(jh);
-}
-
-/*
- * Drop a reference on the passed journal_head.  If it fell to zero then
- * release the journal_head from the buffer_head.
- */
-void jbd2_journal_put_journal_head(struct journal_head *jh)
-{
-	struct buffer_head *bh = jh2bh(jh);
-
-	jbd_lock_bh_journal_head(bh);
-	J_ASSERT_JH(jh, jh->b_jcount > 0);
-	--jh->b_jcount;
-	if (!jh->b_jcount) {
-		__journal_remove_journal_head(bh);
-		jbd_unlock_bh_journal_head(bh);
-		__brelse(bh);
-	} else
-		jbd_unlock_bh_journal_head(bh);
-}
-
-/*
- * Initialize jbd inode head
- */
-void jbd2_journal_init_jbd_inode(struct jbd2_inode *jinode, struct inode *inode)
-{
-	jinode->i_transaction = NULL;
-	jinode->i_next_transaction = NULL;
-	jinode->i_vfs_inode = inode;
-	jinode->i_flags = 0;
-	INIT_LIST_HEAD(&jinode->i_list);
-}
-
-/*
- * Function to be called before we start removing inode from memory (i.e.,
- * clear_inode() is a fine place to be called from). It removes inode from
- * transaction's lists.
- */
-void jbd2_journal_release_jbd_inode(journal_t *journal,
-				    struct jbd2_inode *jinode)
-{
-	if (!journal)
-		return;
-restart:
-	spin_lock(&journal->j_list_lock);
-	/* Is commit writing out inode - we have to wait */
-	if (test_bit(__JI_COMMIT_RUNNING, &jinode->i_flags)) {
-		wait_queue_head_t *wq;
-		DEFINE_WAIT_BIT(wait, &jinode->i_flags, __JI_COMMIT_RUNNING);
-		wq = bit_waitqueue(&jinode->i_flags, __JI_COMMIT_RUNNING);
-		prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
-		spin_unlock(&journal->j_list_lock);
-		schedule();
-		finish_wait(wq, &wait.wait);
-		goto restart;
-	}
-
-	if (jinode->i_transaction) {
-		list_del(&jinode->i_list);
-		jinode->i_transaction = NULL;
-	}
-	spin_unlock(&journal->j_list_lock);
-}
-
-/*
- * debugfs tunables
- */
-#ifdef CONFIG_JBD2_DEBUG
-u8 jbd2_journal_enable_debug __read_mostly;
-EXPORT_SYMBOL(jbd2_journal_enable_debug);
-
-#define JBD2_DEBUG_NAME "jbd2-debug"
-
-static struct dentry *jbd2_debugfs_dir;
-static struct dentry *jbd2_debug;
-
-static void __init jbd2_create_debugfs_entry(void)
-{
-	jbd2_debugfs_dir = debugfs_create_dir("jbd2", NULL);
-	if (jbd2_debugfs_dir)
-		jbd2_debug = debugfs_create_u8(JBD2_DEBUG_NAME,
-					       S_IRUGO | S_IWUSR,
-					       jbd2_debugfs_dir,
-					       &jbd2_journal_enable_debug);
-}
-
-static void __exit jbd2_remove_debugfs_entry(void)
-{
-	debugfs_remove(jbd2_debug);
-	debugfs_remove(jbd2_debugfs_dir);
-}
-
-#else
-
-static void __init jbd2_create_debugfs_entry(void)
-{
-}
-
-static void __exit jbd2_remove_debugfs_entry(void)
-{
-}
-
-#endif
-
-#ifdef CONFIG_PROC_FS
-
-#define JBD2_STATS_PROC_NAME "fs/jbd2"
-
-static void __init jbd2_create_jbd_stats_proc_entry(void)
-{
-	proc_jbd2_stats = proc_mkdir(JBD2_STATS_PROC_NAME, NULL);
-}
-
-static void __exit jbd2_remove_jbd_stats_proc_entry(void)
-{
-	if (proc_jbd2_stats)
-		remove_proc_entry(JBD2_STATS_PROC_NAME, NULL);
-}
-
-#else
-
-#define jbd2_create_jbd_stats_proc_entry() do {} while (0)
-#define jbd2_remove_jbd_stats_proc_entry() do {} while (0)
-
-#endif
-
-struct kmem_cache *jbd2_handle_cache, *jbd2_inode_cache;
-
-static int __init jbd2_journal_init_handle_cache(void)
-{
-	jbd2_handle_cache = KMEM_CACHE(jbd2_journal_handle, SLAB_TEMPORARY);
-	if (jbd2_handle_cache == NULL) {
-		printk(KERN_EMERG "JBD2: failed to create handle cache\n");
-		return -ENOMEM;
-	}
-	jbd2_inode_cache = KMEM_CACHE(jbd2_inode, 0);
-	if (jbd2_inode_cache == NULL) {
-		printk(KERN_EMERG "JBD2: failed to create inode cache\n");
-		kmem_cache_destroy(jbd2_handle_cache);
-		return -ENOMEM;
-	}
-	return 0;
-}
-
-static void jbd2_journal_destroy_handle_cache(void)
-{
-	if (jbd2_handle_cache)
-		kmem_cache_destroy(jbd2_handle_cache);
-	if (jbd2_inode_cache)
-		kmem_cache_destroy(jbd2_inode_cache);
-
-}
-
-/*
- * Module startup and shutdown
- */
-
-static int __init journal_init_caches(void)
-{
-	int ret;
-
-	ret = jbd2_journal_init_revoke_caches();
-	if (ret == 0)
-		ret = jbd2_journal_init_journal_head_cache();
-	if (ret == 0)
-		ret = jbd2_journal_init_handle_cache();
-	if (ret == 0)
-		ret = jbd2_journal_init_transaction_cache();
-	return ret;
-}
-
-static void jbd2_journal_destroy_caches(void)
-{
-	jbd2_journal_destroy_revoke_caches();
-	jbd2_journal_destroy_journal_head_cache();
-	jbd2_journal_destroy_handle_cache();
-	jbd2_journal_destroy_transaction_cache();
-	jbd2_journal_destroy_slabs();
-}
-
-static int __init journal_init(void)
-{
-	int ret;
-
-	BUILD_BUG_ON(sizeof(struct journal_superblock_s) != 1024);
-
-	ret = journal_init_caches();
-	if (ret == 0) {
-		jbd2_create_debugfs_entry();
-		jbd2_create_jbd_stats_proc_entry();
-	} else {
-		jbd2_journal_destroy_caches();
-	}
-	return ret;
-}
-
-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);
-#endif
-	jbd2_remove_debugfs_entry();
-	jbd2_remove_jbd_stats_proc_entry();
-	jbd2_journal_destroy_caches();
-}
-
-MODULE_LICENSE("GPL");
-module_init(journal_init);
-module_exit(journal_exit);
-
diff --git a/ANDROID_3.4.5/fs/jbd2/recovery.c b/ANDROID_3.4.5/fs/jbd2/recovery.c
deleted file mode 100644
index c1a03354..00000000
--- a/ANDROID_3.4.5/fs/jbd2/recovery.c
+++ /dev/null
@@ -1,741 +0,0 @@
-/*
- * linux/fs/jbd2/recovery.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
- *
- * Copyright 1999-2000 Red Hat Software --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Journal recovery routines for the generic filesystem journaling code;
- * part of the ext2fs journaling system.
- */
-
-#ifndef __KERNEL__
-#include "jfs_user.h"
-#else
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/crc32.h>
-#include <linux/blkdev.h>
-#endif
-
-/*
- * Maintain information about the progress of the recovery job, so that
- * the different passes can carry information between them.
- */
-struct recovery_info
-{
-	tid_t		start_transaction;
-	tid_t		end_transaction;
-
-	int		nr_replays;
-	int		nr_revokes;
-	int		nr_revoke_hits;
-};
-
-enum passtype {PASS_SCAN, PASS_REVOKE, PASS_REPLAY};
-static int do_one_pass(journal_t *journal,
-				struct recovery_info *info, enum passtype pass);
-static int scan_revoke_records(journal_t *, struct buffer_head *,
-				tid_t, struct recovery_info *);
-
-#ifdef __KERNEL__
-
-/* Release readahead buffers after use */
-static void journal_brelse_array(struct buffer_head *b[], int n)
-{
-	while (--n >= 0)
-		brelse (b[n]);
-}
-
-
-/*
- * When reading from the journal, we are going through the block device
- * layer directly and so there is no readahead being done for us.  We
- * need to implement any readahead ourselves if we want it to happen at
- * all.  Recovery is basically one long sequential read, so make sure we
- * do the IO in reasonably large chunks.
- *
- * This is not so critical that we need to be enormously clever about
- * the readahead size, though.  128K is a purely arbitrary, good-enough
- * fixed value.
- */
-
-#define MAXBUF 8
-static int do_readahead(journal_t *journal, unsigned int start)
-{
-	int err;
-	unsigned int max, nbufs, next;
-	unsigned long long blocknr;
-	struct buffer_head *bh;
-
-	struct buffer_head * bufs[MAXBUF];
-
-	/* Do up to 128K of readahead */
-	max = start + (128 * 1024 / journal->j_blocksize);
-	if (max > journal->j_maxlen)
-		max = journal->j_maxlen;
-
-	/* Do the readahead itself.  We'll submit MAXBUF buffer_heads at
-	 * a time to the block device IO layer. */
-
-	nbufs = 0;
-
-	for (next = start; next < max; next++) {
-		err = jbd2_journal_bmap(journal, next, &blocknr);
-
-		if (err) {
-			printk(KERN_ERR "JBD2: bad block at offset %u\n",
-				next);
-			goto failed;
-		}
-
-		bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-		if (!bh) {
-			err = -ENOMEM;
-			goto failed;
-		}
-
-		if (!buffer_uptodate(bh) && !buffer_locked(bh)) {
-			bufs[nbufs++] = bh;
-			if (nbufs == MAXBUF) {
-				ll_rw_block(READ, nbufs, bufs);
-				journal_brelse_array(bufs, nbufs);
-				nbufs = 0;
-			}
-		} else
-			brelse(bh);
-	}
-
-	if (nbufs)
-		ll_rw_block(READ, nbufs, bufs);
-	err = 0;
-
-failed:
-	if (nbufs)
-		journal_brelse_array(bufs, nbufs);
-	return err;
-}
-
-#endif /* __KERNEL__ */
-
-
-/*
- * Read a block from the journal
- */
-
-static int jread(struct buffer_head **bhp, journal_t *journal,
-		 unsigned int offset)
-{
-	int err;
-	unsigned long long blocknr;
-	struct buffer_head *bh;
-
-	*bhp = NULL;
-
-	if (offset >= journal->j_maxlen) {
-		printk(KERN_ERR "JBD2: corrupted journal superblock\n");
-		return -EIO;
-	}
-
-	err = jbd2_journal_bmap(journal, offset, &blocknr);
-
-	if (err) {
-		printk(KERN_ERR "JBD2: bad block at offset %u\n",
-			offset);
-		return err;
-	}
-
-	bh = __getblk(journal->j_dev, blocknr, journal->j_blocksize);
-	if (!bh)
-		return -ENOMEM;
-
-	if (!buffer_uptodate(bh)) {
-		/* If this is a brand new buffer, start readahead.
-                   Otherwise, we assume we are already reading it.  */
-		if (!buffer_req(bh))
-			do_readahead(journal, offset);
-		wait_on_buffer(bh);
-	}
-
-	if (!buffer_uptodate(bh)) {
-		printk(KERN_ERR "JBD2: Failed to read block at offset %u\n",
-			offset);
-		brelse(bh);
-		return -EIO;
-	}
-
-	*bhp = bh;
-	return 0;
-}
-
-
-/*
- * Count the number of in-use tags in a journal descriptor block.
- */
-
-static int count_tags(journal_t *journal, struct buffer_head *bh)
-{
-	char *			tagp;
-	journal_block_tag_t *	tag;
-	int			nr = 0, size = journal->j_blocksize;
-	int			tag_bytes = journal_tag_bytes(journal);
-
-	tagp = &bh->b_data[sizeof(journal_header_t)];
-
-	while ((tagp - bh->b_data + tag_bytes) <= size) {
-		tag = (journal_block_tag_t *) tagp;
-
-		nr++;
-		tagp += tag_bytes;
-		if (!(tag->t_flags & cpu_to_be32(JBD2_FLAG_SAME_UUID)))
-			tagp += 16;
-
-		if (tag->t_flags & cpu_to_be32(JBD2_FLAG_LAST_TAG))
-			break;
-	}
-
-	return nr;
-}
-
-
-/* Make sure we wrap around the log correctly! */
-#define wrap(journal, var)						\
-do {									\
-	if (var >= (journal)->j_last)					\
-		var -= ((journal)->j_last - (journal)->j_first);	\
-} while (0)
-
-/**
- * jbd2_journal_recover - recovers a on-disk journal
- * @journal: the journal to recover
- *
- * The primary function for recovering the log contents when mounting a
- * journaled device.
- *
- * Recovery is done in three passes.  In the first pass, we look for the
- * end of the log.  In the second, we assemble the list of revoke
- * blocks.  In the third and final pass, we replay any un-revoked blocks
- * in the log.
- */
-int jbd2_journal_recover(journal_t *journal)
-{
-	int			err, err2;
-	journal_superblock_t *	sb;
-
-	struct recovery_info	info;
-
-	memset(&info, 0, sizeof(info));
-	sb = journal->j_superblock;
-
-	/*
-	 * The journal superblock's s_start field (the current log head)
-	 * is always zero if, and only if, the journal was cleanly
-	 * unmounted.
-	 */
-
-	if (!sb->s_start) {
-		jbd_debug(1, "No recovery required, last transaction %d\n",
-			  be32_to_cpu(sb->s_sequence));
-		journal->j_transaction_sequence = be32_to_cpu(sb->s_sequence) + 1;
-		return 0;
-	}
-
-	err = do_one_pass(journal, &info, PASS_SCAN);
-	if (!err)
-		err = do_one_pass(journal, &info, PASS_REVOKE);
-	if (!err)
-		err = do_one_pass(journal, &info, PASS_REPLAY);
-
-	jbd_debug(1, "JBD2: recovery, exit status %d, "
-		  "recovered transactions %u to %u\n",
-		  err, info.start_transaction, info.end_transaction);
-	jbd_debug(1, "JBD2: Replayed %d and revoked %d/%d blocks\n",
-		  info.nr_replays, info.nr_revoke_hits, info.nr_revokes);
-
-	/* Restart the log at the next transaction ID, thus invalidating
-	 * any existing commit records in the log. */
-	journal->j_transaction_sequence = ++info.end_transaction;
-
-	jbd2_journal_clear_revoke(journal);
-	err2 = sync_blockdev(journal->j_fs_dev);
-	if (!err)
-		err = err2;
-	/* Make sure all replayed data is on permanent storage */
-	if (journal->j_flags & JBD2_BARRIER)
-		blkdev_issue_flush(journal->j_fs_dev, GFP_KERNEL, NULL);
-	return err;
-}
-
-/**
- * jbd2_journal_skip_recovery - Start journal and wipe exiting records
- * @journal: journal to startup
- *
- * Locate any valid recovery information from the journal and set up the
- * journal structures in memory to ignore it (presumably because the
- * caller has evidence that it is out of date).
- * This function does'nt appear to be exorted..
- *
- * We perform one pass over the journal to allow us to tell the user how
- * much recovery information is being erased, and to let us initialise
- * the journal transaction sequence numbers to the next unused ID.
- */
-int jbd2_journal_skip_recovery(journal_t *journal)
-{
-	int			err;
-
-	struct recovery_info	info;
-
-	memset (&info, 0, sizeof(info));
-
-	err = do_one_pass(journal, &info, PASS_SCAN);
-
-	if (err) {
-		printk(KERN_ERR "JBD2: error %d scanning journal\n", err);
-		++journal->j_transaction_sequence;
-	} else {
-#ifdef CONFIG_JBD2_DEBUG
-		int dropped = info.end_transaction - 
-			be32_to_cpu(journal->j_superblock->s_sequence);
-		jbd_debug(1,
-			  "JBD2: ignoring %d transaction%s from the journal.\n",
-			  dropped, (dropped == 1) ? "" : "s");
-#endif
-		journal->j_transaction_sequence = ++info.end_transaction;
-	}
-
-	journal->j_tail = 0;
-	return err;
-}
-
-static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag_t *tag)
-{
-	unsigned long long block = be32_to_cpu(tag->t_blocknr);
-	if (tag_bytes > JBD2_TAG_SIZE32)
-		block |= (u64)be32_to_cpu(tag->t_blocknr_high) << 32;
-	return block;
-}
-
-/*
- * calc_chksums calculates the checksums for the blocks described in the
- * descriptor block.
- */
-static int calc_chksums(journal_t *journal, struct buffer_head *bh,
-			unsigned long *next_log_block, __u32 *crc32_sum)
-{
-	int i, num_blks, err;
-	unsigned long io_block;
-	struct buffer_head *obh;
-
-	num_blks = count_tags(journal, bh);
-	/* Calculate checksum of the descriptor block. */
-	*crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
-
-	for (i = 0; i < num_blks; i++) {
-		io_block = (*next_log_block)++;
-		wrap(journal, *next_log_block);
-		err = jread(&obh, journal, io_block);
-		if (err) {
-			printk(KERN_ERR "JBD2: IO error %d recovering block "
-				"%lu in log\n", err, io_block);
-			return 1;
-		} else {
-			*crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
-				     obh->b_size);
-		}
-		put_bh(obh);
-	}
-	return 0;
-}
-
-static int do_one_pass(journal_t *journal,
-			struct recovery_info *info, enum passtype pass)
-{
-	unsigned int		first_commit_ID, next_commit_ID;
-	unsigned long		next_log_block;
-	int			err, success = 0;
-	journal_superblock_t *	sb;
-	journal_header_t *	tmp;
-	struct buffer_head *	bh;
-	unsigned int		sequence;
-	int			blocktype;
-	int			tag_bytes = journal_tag_bytes(journal);
-	__u32			crc32_sum = ~0; /* Transactional Checksums */
-
-	/*
-	 * First thing is to establish what we expect to find in the log
-	 * (in terms of transaction IDs), and where (in terms of log
-	 * block offsets): query the superblock.
-	 */
-
-	sb = journal->j_superblock;
-	next_commit_ID = be32_to_cpu(sb->s_sequence);
-	next_log_block = be32_to_cpu(sb->s_start);
-
-	first_commit_ID = next_commit_ID;
-	if (pass == PASS_SCAN)
-		info->start_transaction = first_commit_ID;
-
-	jbd_debug(1, "Starting recovery pass %d\n", pass);
-
-	/*
-	 * Now we walk through the log, transaction by transaction,
-	 * making sure that each transaction has a commit block in the
-	 * expected place.  Each complete transaction gets replayed back
-	 * into the main filesystem.
-	 */
-
-	while (1) {
-		int			flags;
-		char *			tagp;
-		journal_block_tag_t *	tag;
-		struct buffer_head *	obh;
-		struct buffer_head *	nbh;
-
-		cond_resched();
-
-		/* If we already know where to stop the log traversal,
-		 * check right now that we haven't gone past the end of
-		 * the log. */
-
-		if (pass != PASS_SCAN)
-			if (tid_geq(next_commit_ID, info->end_transaction))
-				break;
-
-		jbd_debug(2, "Scanning for sequence ID %u at %lu/%lu\n",
-			  next_commit_ID, next_log_block, journal->j_last);
-
-		/* Skip over each chunk of the transaction looking
-		 * either the next descriptor block or the final commit
-		 * record. */
-
-		jbd_debug(3, "JBD2: checking block %ld\n", next_log_block);
-		err = jread(&bh, journal, next_log_block);
-		if (err)
-			goto failed;
-
-		next_log_block++;
-		wrap(journal, next_log_block);
-
-		/* What kind of buffer is it?
-		 *
-		 * If it is a descriptor block, check that it has the
-		 * expected sequence number.  Otherwise, we're all done
-		 * here. */
-
-		tmp = (journal_header_t *)bh->b_data;
-
-		if (tmp->h_magic != cpu_to_be32(JBD2_MAGIC_NUMBER)) {
-			brelse(bh);
-			break;
-		}
-
-		blocktype = be32_to_cpu(tmp->h_blocktype);
-		sequence = be32_to_cpu(tmp->h_sequence);
-		jbd_debug(3, "Found magic %d, sequence %d\n",
-			  blocktype, sequence);
-
-		if (sequence != next_commit_ID) {
-			brelse(bh);
-			break;
-		}
-
-		/* OK, we have a valid descriptor block which matches
-		 * all of the sequence number checks.  What are we going
-		 * to do with it?  That depends on the pass... */
-
-		switch(blocktype) {
-		case JBD2_DESCRIPTOR_BLOCK:
-			/* If it is a valid descriptor block, replay it
-			 * in pass REPLAY; if journal_checksums enabled, then
-			 * calculate checksums in PASS_SCAN, otherwise,
-			 * just skip over the blocks it describes. */
-			if (pass != PASS_REPLAY) {
-				if (pass == PASS_SCAN &&
-				    JBD2_HAS_COMPAT_FEATURE(journal,
-					    JBD2_FEATURE_COMPAT_CHECKSUM) &&
-				    !info->end_transaction) {
-					if (calc_chksums(journal, bh,
-							&next_log_block,
-							&crc32_sum)) {
-						put_bh(bh);
-						break;
-					}
-					put_bh(bh);
-					continue;
-				}
-				next_log_block += count_tags(journal, bh);
-				wrap(journal, next_log_block);
-				put_bh(bh);
-				continue;
-			}
-
-			/* A descriptor block: we can now write all of
-			 * the data blocks.  Yay, useful work is finally
-			 * getting done here! */
-
-			tagp = &bh->b_data[sizeof(journal_header_t)];
-			while ((tagp - bh->b_data + tag_bytes)
-			       <= journal->j_blocksize) {
-				unsigned long io_block;
-
-				tag = (journal_block_tag_t *) tagp;
-				flags = be32_to_cpu(tag->t_flags);
-
-				io_block = next_log_block++;
-				wrap(journal, next_log_block);
-				err = jread(&obh, journal, io_block);
-				if (err) {
-					/* Recover what we can, but
-					 * report failure at the end. */
-					success = err;
-					printk(KERN_ERR
-						"JBD2: IO error %d recovering "
-						"block %ld in log\n",
-						err, io_block);
-				} else {
-					unsigned long long blocknr;
-
-					J_ASSERT(obh != NULL);
-					blocknr = read_tag_block(tag_bytes,
-								 tag);
-
-					/* If the block has been
-					 * revoked, then we're all done
-					 * here. */
-					if (jbd2_journal_test_revoke
-					    (journal, blocknr,
-					     next_commit_ID)) {
-						brelse(obh);
-						++info->nr_revoke_hits;
-						goto skip_write;
-					}
-
-					/* Find a buffer for the new
-					 * data being restored */
-					nbh = __getblk(journal->j_fs_dev,
-							blocknr,
-							journal->j_blocksize);
-					if (nbh == NULL) {
-						printk(KERN_ERR
-						       "JBD2: Out of memory "
-						       "during recovery.\n");
-						err = -ENOMEM;
-						brelse(bh);
-						brelse(obh);
-						goto failed;
-					}
-
-					lock_buffer(nbh);
-					memcpy(nbh->b_data, obh->b_data,
-							journal->j_blocksize);
-					if (flags & JBD2_FLAG_ESCAPE) {
-						*((__be32 *)nbh->b_data) =
-						cpu_to_be32(JBD2_MAGIC_NUMBER);
-					}
-
-					BUFFER_TRACE(nbh, "marking dirty");
-					set_buffer_uptodate(nbh);
-					mark_buffer_dirty(nbh);
-					BUFFER_TRACE(nbh, "marking uptodate");
-					++info->nr_replays;
-					/* ll_rw_block(WRITE, 1, &nbh); */
-					unlock_buffer(nbh);
-					brelse(obh);
-					brelse(nbh);
-				}
-
-			skip_write:
-				tagp += tag_bytes;
-				if (!(flags & JBD2_FLAG_SAME_UUID))
-					tagp += 16;
-
-				if (flags & JBD2_FLAG_LAST_TAG)
-					break;
-			}
-
-			brelse(bh);
-			continue;
-
-		case JBD2_COMMIT_BLOCK:
-			/*     How to differentiate between interrupted commit
-			 *               and journal corruption ?
-			 *
-			 * {nth transaction}
-			 *        Checksum Verification Failed
-			 *			 |
-			 *		 ____________________
-			 *		|		     |
-			 * 	async_commit             sync_commit
-			 *     		|                    |
-			 *		| GO TO NEXT    "Journal Corruption"
-			 *		| TRANSACTION
-			 *		|
-			 * {(n+1)th transanction}
-			 *		|
-			 * 	 _______|______________
-			 * 	|	 	      |
-			 * Commit block found	Commit block not found
-			 *      |		      |
-			 * "Journal Corruption"       |
-			 *		 _____________|_________
-			 *     		|	           	|
-			 *	nth trans corrupt	OR   nth trans
-			 *	and (n+1)th interrupted     interrupted
-			 *	before commit block
-			 *      could reach the disk.
-			 *	(Cannot find the difference in above
-			 *	 mentioned conditions. Hence assume
-			 *	 "Interrupted Commit".)
-			 */
-
-			/* Found an expected commit block: if checksums
-			 * are present verify them in PASS_SCAN; else not
-			 * much to do other than move on to the next sequence
-			 * number. */
-			if (pass == PASS_SCAN &&
-			    JBD2_HAS_COMPAT_FEATURE(journal,
-				    JBD2_FEATURE_COMPAT_CHECKSUM)) {
-				int chksum_err, chksum_seen;
-				struct commit_header *cbh =
-					(struct commit_header *)bh->b_data;
-				unsigned found_chksum =
-					be32_to_cpu(cbh->h_chksum[0]);
-
-				chksum_err = chksum_seen = 0;
-
-				if (info->end_transaction) {
-					journal->j_failed_commit =
-						info->end_transaction;
-					brelse(bh);
-					break;
-				}
-
-				if (crc32_sum == found_chksum &&
-				    cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
-				    cbh->h_chksum_size ==
-						JBD2_CRC32_CHKSUM_SIZE)
-				       chksum_seen = 1;
-				else if (!(cbh->h_chksum_type == 0 &&
-					     cbh->h_chksum_size == 0 &&
-					     found_chksum == 0 &&
-					     !chksum_seen))
-				/*
-				 * If fs is mounted using an old kernel and then
-				 * kernel with journal_chksum is used then we
-				 * get a situation where the journal flag has
-				 * checksum flag set but checksums are not
-				 * present i.e chksum = 0, in the individual
-				 * commit blocks.
-				 * Hence to avoid checksum failures, in this
-				 * situation, this extra check is added.
-				 */
-						chksum_err = 1;
-
-				if (chksum_err) {
-					info->end_transaction = next_commit_ID;
-
-					if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
-					   JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
-						journal->j_failed_commit =
-							next_commit_ID;
-						brelse(bh);
-						break;
-					}
-				}
-				crc32_sum = ~0;
-			}
-			brelse(bh);
-			next_commit_ID++;
-			continue;
-
-		case JBD2_REVOKE_BLOCK:
-			/* If we aren't in the REVOKE pass, then we can
-			 * just skip over this block. */
-			if (pass != PASS_REVOKE) {
-				brelse(bh);
-				continue;
-			}
-
-			err = scan_revoke_records(journal, bh,
-						  next_commit_ID, info);
-			brelse(bh);
-			if (err)
-				goto failed;
-			continue;
-
-		default:
-			jbd_debug(3, "Unrecognised magic %d, end of scan.\n",
-				  blocktype);
-			brelse(bh);
-			goto done;
-		}
-	}
-
- done:
-	/*
-	 * We broke out of the log scan loop: either we came to the
-	 * known end of the log or we found an unexpected block in the
-	 * log.  If the latter happened, then we know that the "current"
-	 * transaction marks the end of the valid log.
-	 */
-
-	if (pass == PASS_SCAN) {
-		if (!info->end_transaction)
-			info->end_transaction = next_commit_ID;
-	} else {
-		/* It's really bad news if different passes end up at
-		 * different places (but possible due to IO errors). */
-		if (info->end_transaction != next_commit_ID) {
-			printk(KERN_ERR "JBD2: recovery pass %d ended at "
-				"transaction %u, expected %u\n",
-				pass, next_commit_ID, info->end_transaction);
-			if (!success)
-				success = -EIO;
-		}
-	}
-
-	return success;
-
- failed:
-	return err;
-}
-
-
-/* Scan a revoke record, marking all blocks mentioned as revoked. */
-
-static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
-			       tid_t sequence, struct recovery_info *info)
-{
-	jbd2_journal_revoke_header_t *header;
-	int offset, max;
-	int record_len = 4;
-
-	header = (jbd2_journal_revoke_header_t *) bh->b_data;
-	offset = sizeof(jbd2_journal_revoke_header_t);
-	max = be32_to_cpu(header->r_count);
-
-	if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
-		record_len = 8;
-
-	while (offset + record_len <= max) {
-		unsigned long long blocknr;
-		int err;
-
-		if (record_len == 4)
-			blocknr = be32_to_cpu(* ((__be32 *) (bh->b_data+offset)));
-		else
-			blocknr = be64_to_cpu(* ((__be64 *) (bh->b_data+offset)));
-		offset += record_len;
-		err = jbd2_journal_set_revoke(journal, blocknr, sequence);
-		if (err)
-			return err;
-		++info->nr_revokes;
-	}
-	return 0;
-}
diff --git a/ANDROID_3.4.5/fs/jbd2/revoke.c b/ANDROID_3.4.5/fs/jbd2/revoke.c
deleted file mode 100644
index 6973705d..00000000
--- a/ANDROID_3.4.5/fs/jbd2/revoke.c
+++ /dev/null
@@ -1,744 +0,0 @@
-/*
- * linux/fs/jbd2/revoke.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 2000
- *
- * Copyright 2000 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Journal revoke routines for the generic filesystem journaling code;
- * part of the ext2fs journaling system.
- *
- * Revoke is the mechanism used to prevent old log records for deleted
- * metadata from being replayed on top of newer data using the same
- * blocks.  The revoke mechanism is used in two separate places:
- *
- * + Commit: during commit we write the entire list of the current
- *   transaction's revoked blocks to the journal
- *
- * + Recovery: during recovery we record the transaction ID of all
- *   revoked blocks.  If there are multiple revoke records in the log
- *   for a single block, only the last one counts, and if there is a log
- *   entry for a block beyond the last revoke, then that log entry still
- *   gets replayed.
- *
- * We can get interactions between revokes and new log data within a
- * single transaction:
- *
- * Block is revoked and then journaled:
- *   The desired end result is the journaling of the new block, so we
- *   cancel the revoke before the transaction commits.
- *
- * Block is journaled and then revoked:
- *   The revoke must take precedence over the write of the block, so we
- *   need either to cancel the journal entry or to write the revoke
- *   later in the log than the log block.  In this case, we choose the
- *   latter: journaling a block cancels any revoke record for that block
- *   in the current transaction, so any revoke for that block in the
- *   transaction must have happened after the block was journaled and so
- *   the revoke must take precedence.
- *
- * Block is revoked and then written as data:
- *   The data write is allowed to succeed, but the revoke is _not_
- *   cancelled.  We still need to prevent old log records from
- *   overwriting the new data.  We don't even need to clear the revoke
- *   bit here.
- *
- * We cache revoke status of a buffer in the current transaction in b_states
- * bits.  As the name says, revokevalid flag indicates that the cached revoke
- * status of a buffer is valid and we can rely on the cached status.
- *
- * Revoke information on buffers is a tri-state value:
- *
- * RevokeValid clear:	no cached revoke status, need to look it up
- * RevokeValid set, Revoked clear:
- *			buffer has not been revoked, and cancel_revoke
- *			need do nothing.
- * RevokeValid set, Revoked set:
- *			buffer has been revoked.
- *
- * Locking rules:
- * We keep two hash tables of revoke records. One hashtable belongs to the
- * running transaction (is pointed to by journal->j_revoke), the other one
- * belongs to the committing transaction. Accesses to the second hash table
- * happen only from the kjournald and no other thread touches this table.  Also
- * journal_switch_revoke_table() which switches which hashtable belongs to the
- * running and which to the committing transaction is called only from
- * kjournald. Therefore we need no locks when accessing the hashtable belonging
- * to the committing transaction.
- *
- * All users operating on the hash table belonging to the running transaction
- * have a handle to the transaction. Therefore they are safe from kjournald
- * switching hash tables under them. For operations on the lists of entries in
- * the hash table j_revoke_lock is used.
- *
- * Finally, also replay code uses the hash tables but at this moment no one else
- * can touch them (filesystem isn't mounted yet) and hence no locking is
- * needed.
- */
-
-#ifndef __KERNEL__
-#include "jfs_user.h"
-#else
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/list.h>
-#include <linux/init.h>
-#include <linux/bio.h>
-#endif
-#include <linux/log2.h>
-
-static struct kmem_cache *jbd2_revoke_record_cache;
-static struct kmem_cache *jbd2_revoke_table_cache;
-
-/* Each revoke record represents one single revoked block.  During
-   journal replay, this involves recording the transaction ID of the
-   last transaction to revoke this block. */
-
-struct jbd2_revoke_record_s
-{
-	struct list_head  hash;
-	tid_t		  sequence;	/* Used for recovery only */
-	unsigned long long	  blocknr;
-};
-
-
-/* The revoke table is just a simple hash table of revoke records. */
-struct jbd2_revoke_table_s
-{
-	/* It is conceivable that we might want a larger hash table
-	 * for recovery.  Must be a power of two. */
-	int		  hash_size;
-	int		  hash_shift;
-	struct list_head *hash_table;
-};
-
-
-#ifdef __KERNEL__
-static void write_one_revoke_record(journal_t *, transaction_t *,
-				    struct journal_head **, int *,
-				    struct jbd2_revoke_record_s *, int);
-static void flush_descriptor(journal_t *, struct journal_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);
-}
-
-static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr,
-			      tid_t seq)
-{
-	struct list_head *hash_list;
-	struct jbd2_revoke_record_s *record;
-
-repeat:
-	record = kmem_cache_alloc(jbd2_revoke_record_cache, GFP_NOFS);
-	if (!record)
-		goto oom;
-
-	record->sequence = seq;
-	record->blocknr = blocknr;
-	hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
-	spin_lock(&journal->j_revoke_lock);
-	list_add(&record->hash, hash_list);
-	spin_unlock(&journal->j_revoke_lock);
-	return 0;
-
-oom:
-	if (!journal_oom_retry)
-		return -ENOMEM;
-	jbd_debug(1, "ENOMEM in %s, retrying\n", __func__);
-	yield();
-	goto repeat;
-}
-
-/* Find a revoke record in the journal's hash table. */
-
-static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal,
-						      unsigned long long blocknr)
-{
-	struct list_head *hash_list;
-	struct jbd2_revoke_record_s *record;
-
-	hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
-
-	spin_lock(&journal->j_revoke_lock);
-	record = (struct jbd2_revoke_record_s *) hash_list->next;
-	while (&(record->hash) != hash_list) {
-		if (record->blocknr == blocknr) {
-			spin_unlock(&journal->j_revoke_lock);
-			return record;
-		}
-		record = (struct jbd2_revoke_record_s *) record->hash.next;
-	}
-	spin_unlock(&journal->j_revoke_lock);
-	return NULL;
-}
-
-void jbd2_journal_destroy_revoke_caches(void)
-{
-	if (jbd2_revoke_record_cache) {
-		kmem_cache_destroy(jbd2_revoke_record_cache);
-		jbd2_revoke_record_cache = NULL;
-	}
-	if (jbd2_revoke_table_cache) {
-		kmem_cache_destroy(jbd2_revoke_table_cache);
-		jbd2_revoke_table_cache = NULL;
-	}
-}
-
-int __init jbd2_journal_init_revoke_caches(void)
-{
-	J_ASSERT(!jbd2_revoke_record_cache);
-	J_ASSERT(!jbd2_revoke_table_cache);
-
-	jbd2_revoke_record_cache = KMEM_CACHE(jbd2_revoke_record_s,
-					SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY);
-	if (!jbd2_revoke_record_cache)
-		goto record_cache_failure;
-
-	jbd2_revoke_table_cache = KMEM_CACHE(jbd2_revoke_table_s,
-					     SLAB_TEMPORARY);
-	if (!jbd2_revoke_table_cache)
-		goto table_cache_failure;
-	return 0;
-table_cache_failure:
-	jbd2_journal_destroy_revoke_caches();
-record_cache_failure:
-		return -ENOMEM;
-}
-
-static struct jbd2_revoke_table_s *jbd2_journal_init_revoke_table(int hash_size)
-{
-	int shift = 0;
-	int tmp = hash_size;
-	struct jbd2_revoke_table_s *table;
-
-	table = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL);
-	if (!table)
-		goto out;
-
-	while((tmp >>= 1UL) != 0UL)
-		shift++;
-
-	table->hash_size = hash_size;
-	table->hash_shift = shift;
-	table->hash_table =
-		kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL);
-	if (!table->hash_table) {
-		kmem_cache_free(jbd2_revoke_table_cache, table);
-		table = NULL;
-		goto out;
-	}
-
-	for (tmp = 0; tmp < hash_size; tmp++)
-		INIT_LIST_HEAD(&table->hash_table[tmp]);
-
-out:
-	return table;
-}
-
-static void jbd2_journal_destroy_revoke_table(struct jbd2_revoke_table_s *table)
-{
-	int i;
-	struct list_head *hash_list;
-
-	for (i = 0; i < table->hash_size; i++) {
-		hash_list = &table->hash_table[i];
-		J_ASSERT(list_empty(hash_list));
-	}
-
-	kfree(table->hash_table);
-	kmem_cache_free(jbd2_revoke_table_cache, table);
-}
-
-/* Initialise the revoke table for a given journal to a given size. */
-int jbd2_journal_init_revoke(journal_t *journal, int hash_size)
-{
-	J_ASSERT(journal->j_revoke_table[0] == NULL);
-	J_ASSERT(is_power_of_2(hash_size));
-
-	journal->j_revoke_table[0] = jbd2_journal_init_revoke_table(hash_size);
-	if (!journal->j_revoke_table[0])
-		goto fail0;
-
-	journal->j_revoke_table[1] = jbd2_journal_init_revoke_table(hash_size);
-	if (!journal->j_revoke_table[1])
-		goto fail1;
-
-	journal->j_revoke = journal->j_revoke_table[1];
-
-	spin_lock_init(&journal->j_revoke_lock);
-
-	return 0;
-
-fail1:
-	jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
-fail0:
-	return -ENOMEM;
-}
-
-/* Destroy a journal's revoke table.  The table must already be empty! */
-void jbd2_journal_destroy_revoke(journal_t *journal)
-{
-	journal->j_revoke = NULL;
-	if (journal->j_revoke_table[0])
-		jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]);
-	if (journal->j_revoke_table[1])
-		jbd2_journal_destroy_revoke_table(journal->j_revoke_table[1]);
-}
-
-
-#ifdef __KERNEL__
-
-/*
- * jbd2_journal_revoke: revoke a given buffer_head from the journal.  This
- * prevents the block from being replayed during recovery if we take a
- * crash after this current transaction commits.  Any subsequent
- * metadata writes of the buffer in this transaction cancel the
- * revoke.
- *
- * Note that this call may block --- it is up to the caller to make
- * sure that there are no further calls to journal_write_metadata
- * before the revoke is complete.  In ext3, this implies calling the
- * revoke before clearing the block bitmap when we are deleting
- * metadata.
- *
- * Revoke performs a jbd2_journal_forget on any buffer_head passed in as a
- * parameter, but does _not_ forget the buffer_head if the bh was only
- * found implicitly.
- *
- * bh_in may not be a journalled buffer - it may have come off
- * the hash tables without an attached journal_head.
- *
- * If bh_in is non-zero, jbd2_journal_revoke() will decrement its b_count
- * by one.
- */
-
-int jbd2_journal_revoke(handle_t *handle, unsigned long long blocknr,
-		   struct buffer_head *bh_in)
-{
-	struct buffer_head *bh = NULL;
-	journal_t *journal;
-	struct block_device *bdev;
-	int err;
-
-	might_sleep();
-	if (bh_in)
-		BUFFER_TRACE(bh_in, "enter");
-
-	journal = handle->h_transaction->t_journal;
-	if (!jbd2_journal_set_features(journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)){
-		J_ASSERT (!"Cannot set revoke feature!");
-		return -EINVAL;
-	}
-
-	bdev = journal->j_fs_dev;
-	bh = bh_in;
-
-	if (!bh) {
-		bh = __find_get_block(bdev, blocknr, journal->j_blocksize);
-		if (bh)
-			BUFFER_TRACE(bh, "found on hash");
-	}
-#ifdef JBD2_EXPENSIVE_CHECKING
-	else {
-		struct buffer_head *bh2;
-
-		/* If there is a different buffer_head lying around in
-		 * memory anywhere... */
-		bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize);
-		if (bh2) {
-			/* ... and it has RevokeValid status... */
-			if (bh2 != bh && buffer_revokevalid(bh2))
-				/* ...then it better be revoked too,
-				 * since it's illegal to create a revoke
-				 * record against a buffer_head which is
-				 * not marked revoked --- that would
-				 * risk missing a subsequent revoke
-				 * cancel. */
-				J_ASSERT_BH(bh2, buffer_revoked(bh2));
-			put_bh(bh2);
-		}
-	}
-#endif
-
-	/* We really ought not ever to revoke twice in a row without
-           first having the revoke cancelled: it's illegal to free a
-           block twice without allocating it in between! */
-	if (bh) {
-		if (!J_EXPECT_BH(bh, !buffer_revoked(bh),
-				 "inconsistent data on disk")) {
-			if (!bh_in)
-				brelse(bh);
-			return -EIO;
-		}
-		set_buffer_revoked(bh);
-		set_buffer_revokevalid(bh);
-		if (bh_in) {
-			BUFFER_TRACE(bh_in, "call jbd2_journal_forget");
-			jbd2_journal_forget(handle, bh_in);
-		} else {
-			BUFFER_TRACE(bh, "call brelse");
-			__brelse(bh);
-		}
-	}
-
-	jbd_debug(2, "insert revoke for block %llu, bh_in=%p\n",blocknr, bh_in);
-	err = insert_revoke_hash(journal, blocknr,
-				handle->h_transaction->t_tid);
-	BUFFER_TRACE(bh_in, "exit");
-	return err;
-}
-
-/*
- * Cancel an outstanding revoke.  For use only internally by the
- * journaling code (called from jbd2_journal_get_write_access).
- *
- * We trust buffer_revoked() on the buffer if the buffer is already
- * being journaled: if there is no revoke pending on the buffer, then we
- * don't do anything here.
- *
- * This would break if it were possible for a buffer to be revoked and
- * discarded, and then reallocated within the same transaction.  In such
- * a case we would have lost the revoked bit, but when we arrived here
- * the second time we would still have a pending revoke to cancel.  So,
- * do not trust the Revoked bit on buffers unless RevokeValid is also
- * set.
- */
-int jbd2_journal_cancel_revoke(handle_t *handle, struct journal_head *jh)
-{
-	struct jbd2_revoke_record_s *record;
-	journal_t *journal = handle->h_transaction->t_journal;
-	int need_cancel;
-	int did_revoke = 0;	/* akpm: debug */
-	struct buffer_head *bh = jh2bh(jh);
-
-	jbd_debug(4, "journal_head %p, cancelling revoke\n", jh);
-
-	/* Is the existing Revoke bit valid?  If so, we trust it, and
-	 * only perform the full cancel if the revoke bit is set.  If
-	 * not, we can't trust the revoke bit, and we need to do the
-	 * full search for a revoke record. */
-	if (test_set_buffer_revokevalid(bh)) {
-		need_cancel = test_clear_buffer_revoked(bh);
-	} else {
-		need_cancel = 1;
-		clear_buffer_revoked(bh);
-	}
-
-	if (need_cancel) {
-		record = find_revoke_record(journal, bh->b_blocknr);
-		if (record) {
-			jbd_debug(4, "cancelled existing revoke on "
-				  "blocknr %llu\n", (unsigned long long)bh->b_blocknr);
-			spin_lock(&journal->j_revoke_lock);
-			list_del(&record->hash);
-			spin_unlock(&journal->j_revoke_lock);
-			kmem_cache_free(jbd2_revoke_record_cache, record);
-			did_revoke = 1;
-		}
-	}
-
-#ifdef JBD2_EXPENSIVE_CHECKING
-	/* There better not be one left behind by now! */
-	record = find_revoke_record(journal, bh->b_blocknr);
-	J_ASSERT_JH(jh, record == NULL);
-#endif
-
-	/* Finally, have we just cleared revoke on an unhashed
-	 * buffer_head?  If so, we'd better make sure we clear the
-	 * revoked status on any hashed alias too, otherwise the revoke
-	 * state machine will get very upset later on. */
-	if (need_cancel) {
-		struct buffer_head *bh2;
-		bh2 = __find_get_block(bh->b_bdev, bh->b_blocknr, bh->b_size);
-		if (bh2) {
-			if (bh2 != bh)
-				clear_buffer_revoked(bh2);
-			__brelse(bh2);
-		}
-	}
-	return did_revoke;
-}
-
-/*
- * journal_clear_revoked_flag clears revoked flag of buffers in
- * revoke table to reflect there is no revoked buffers in the next
- * transaction which is going to be started.
- */
-void jbd2_clear_buffer_revoked_flags(journal_t *journal)
-{
-	struct jbd2_revoke_table_s *revoke = journal->j_revoke;
-	int i = 0;
-
-	for (i = 0; i < revoke->hash_size; i++) {
-		struct list_head *hash_list;
-		struct list_head *list_entry;
-		hash_list = &revoke->hash_table[i];
-
-		list_for_each(list_entry, hash_list) {
-			struct jbd2_revoke_record_s *record;
-			struct buffer_head *bh;
-			record = (struct jbd2_revoke_record_s *)list_entry;
-			bh = __find_get_block(journal->j_fs_dev,
-					      record->blocknr,
-					      journal->j_blocksize);
-			if (bh) {
-				clear_buffer_revoked(bh);
-				__brelse(bh);
-			}
-		}
-	}
-}
-
-/* journal_switch_revoke table select j_revoke for next transaction
- * we do not want to suspend any processing until all revokes are
- * written -bzzz
- */
-void jbd2_journal_switch_revoke_table(journal_t *journal)
-{
-	int i;
-
-	if (journal->j_revoke == journal->j_revoke_table[0])
-		journal->j_revoke = journal->j_revoke_table[1];
-	else
-		journal->j_revoke = journal->j_revoke_table[0];
-
-	for (i = 0; i < journal->j_revoke->hash_size; i++)
-		INIT_LIST_HEAD(&journal->j_revoke->hash_table[i]);
-}
-
-/*
- * Write revoke records to the journal for all entries in the current
- * revoke hash, deleting the entries as we go.
- */
-void jbd2_journal_write_revoke_records(journal_t *journal,
-				       transaction_t *transaction,
-				       int write_op)
-{
-	struct journal_head *descriptor;
-	struct jbd2_revoke_record_s *record;
-	struct jbd2_revoke_table_s *revoke;
-	struct list_head *hash_list;
-	int i, offset, count;
-
-	descriptor = NULL;
-	offset = 0;
-	count = 0;
-
-	/* select revoke table for committing transaction */
-	revoke = journal->j_revoke == journal->j_revoke_table[0] ?
-		journal->j_revoke_table[1] : journal->j_revoke_table[0];
-
-	for (i = 0; i < revoke->hash_size; i++) {
-		hash_list = &revoke->hash_table[i];
-
-		while (!list_empty(hash_list)) {
-			record = (struct jbd2_revoke_record_s *)
-				hash_list->next;
-			write_one_revoke_record(journal, transaction,
-						&descriptor, &offset,
-						record, write_op);
-			count++;
-			list_del(&record->hash);
-			kmem_cache_free(jbd2_revoke_record_cache, record);
-		}
-	}
-	if (descriptor)
-		flush_descriptor(journal, descriptor, offset, write_op);
-	jbd_debug(1, "Wrote %d revoke records\n", count);
-}
-
-/*
- * Write out one revoke record.  We need to create a new descriptor
- * block if the old one is full or if we have not already created one.
- */
-
-static void write_one_revoke_record(journal_t *journal,
-				    transaction_t *transaction,
-				    struct journal_head **descriptorp,
-				    int *offsetp,
-				    struct jbd2_revoke_record_s *record,
-				    int write_op)
-{
-	struct journal_head *descriptor;
-	int offset;
-	journal_header_t *header;
-
-	/* If we are already aborting, this all becomes a noop.  We
-           still need to go round the loop in
-           jbd2_journal_write_revoke_records in order to free all of the
-           revoke records: only the IO to the journal is omitted. */
-	if (is_journal_aborted(journal))
-		return;
-
-	descriptor = *descriptorp;
-	offset = *offsetp;
-
-	/* Make sure we have a descriptor with space left for the record */
-	if (descriptor) {
-		if (offset == journal->j_blocksize) {
-			flush_descriptor(journal, descriptor, offset, write_op);
-			descriptor = NULL;
-		}
-	}
-
-	if (!descriptor) {
-		descriptor = jbd2_journal_get_descriptor_buffer(journal);
-		if (!descriptor)
-			return;
-		header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
-		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);
-
-		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])) =
-			cpu_to_be64(record->blocknr);
-		offset += 8;
-
-	} else {
-		* ((__be32 *)(&jh2bh(descriptor)->b_data[offset])) =
-			cpu_to_be32(record->blocknr);
-		offset += 4;
-	}
-
-	*offsetp = offset;
-}
-
-/*
- * Flush a revoke descriptor out to the journal.  If we are aborting,
- * this is a noop; otherwise we are generating a buffer which needs to
- * be waited for during commit, so it has to go onto the appropriate
- * journal buffer list.
- */
-
-static void flush_descriptor(journal_t *journal,
-			     struct journal_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);
-		return;
-	}
-
-	header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
-	header->r_count = cpu_to_be32(offset);
-	set_buffer_jwrite(bh);
-	BUFFER_TRACE(bh, "write");
-	set_buffer_dirty(bh);
-	write_dirty_buffer(bh, write_op);
-}
-#endif
-
-/*
- * Revoke support for recovery.
- *
- * Recovery needs to be able to:
- *
- *  record all revoke records, including the tid of the latest instance
- *  of each revoke in the journal
- *
- *  check whether a given block in a given transaction should be replayed
- *  (ie. has not been revoked by a revoke record in that or a subsequent
- *  transaction)
- *
- *  empty the revoke table after recovery.
- */
-
-/*
- * First, setting revoke records.  We create a new revoke record for
- * every block ever revoked in the log as we scan it for recovery, and
- * we update the existing records if we find multiple revokes for a
- * single block.
- */
-
-int jbd2_journal_set_revoke(journal_t *journal,
-		       unsigned long long blocknr,
-		       tid_t sequence)
-{
-	struct jbd2_revoke_record_s *record;
-
-	record = find_revoke_record(journal, blocknr);
-	if (record) {
-		/* If we have multiple occurrences, only record the
-		 * latest sequence number in the hashed record */
-		if (tid_gt(sequence, record->sequence))
-			record->sequence = sequence;
-		return 0;
-	}
-	return insert_revoke_hash(journal, blocknr, sequence);
-}
-
-/*
- * Test revoke records.  For a given block referenced in the log, has
- * that block been revoked?  A revoke record with a given transaction
- * sequence number revokes all blocks in that transaction and earlier
- * ones, but later transactions still need replayed.
- */
-
-int jbd2_journal_test_revoke(journal_t *journal,
-			unsigned long long blocknr,
-			tid_t sequence)
-{
-	struct jbd2_revoke_record_s *record;
-
-	record = find_revoke_record(journal, blocknr);
-	if (!record)
-		return 0;
-	if (tid_gt(sequence, record->sequence))
-		return 0;
-	return 1;
-}
-
-/*
- * Finally, once recovery is over, we need to clear the revoke table so
- * that it can be reused by the running filesystem.
- */
-
-void jbd2_journal_clear_revoke(journal_t *journal)
-{
-	int i;
-	struct list_head *hash_list;
-	struct jbd2_revoke_record_s *record;
-	struct jbd2_revoke_table_s *revoke;
-
-	revoke = journal->j_revoke;
-
-	for (i = 0; i < revoke->hash_size; i++) {
-		hash_list = &revoke->hash_table[i];
-		while (!list_empty(hash_list)) {
-			record = (struct jbd2_revoke_record_s*) hash_list->next;
-			list_del(&record->hash);
-			kmem_cache_free(jbd2_revoke_record_cache, record);
-		}
-	}
-}
diff --git a/ANDROID_3.4.5/fs/jbd2/transaction.c b/ANDROID_3.4.5/fs/jbd2/transaction.c
deleted file mode 100644
index ddcd3549..00000000
--- a/ANDROID_3.4.5/fs/jbd2/transaction.c
+++ /dev/null
@@ -1,2302 +0,0 @@
-/*
- * linux/fs/jbd2/transaction.c
- *
- * Written by Stephen C. Tweedie <sct@redhat.com>, 1998
- *
- * Copyright 1998 Red Hat corp --- All Rights Reserved
- *
- * This file is part of the Linux kernel and is made available under
- * the terms of the GNU General Public License, version 2, or at your
- * option, any later version, incorporated herein by reference.
- *
- * Generic filesystem transaction handling code; part of the ext2fs
- * journaling system.
- *
- * This file manages transactions (compound commits managed by the
- * journaling code) and handles (individual atomic operations by the
- * filesystem).
- */
-
-#include <linux/time.h>
-#include <linux/fs.h>
-#include <linux/jbd2.h>
-#include <linux/errno.h>
-#include <linux/slab.h>
-#include <linux/timer.h>
-#include <linux/mm.h>
-#include <linux/highmem.h>
-#include <linux/hrtimer.h>
-#include <linux/backing-dev.h>
-#include <linux/bug.h>
-#include <linux/module.h>
-
-static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh);
-static void __jbd2_journal_unfile_buffer(struct journal_head *jh);
-
-static struct kmem_cache *transaction_cache;
-int __init jbd2_journal_init_transaction_cache(void)
-{
-	J_ASSERT(!transaction_cache);
-	transaction_cache = kmem_cache_create("jbd2_transaction_s",
-					sizeof(transaction_t),
-					0,
-					SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY,
-					NULL);
-	if (transaction_cache)
-		return 0;
-	return -ENOMEM;
-}
-
-void jbd2_journal_destroy_transaction_cache(void)
-{
-	if (transaction_cache) {
-		kmem_cache_destroy(transaction_cache);
-		transaction_cache = NULL;
-	}
-}
-
-void jbd2_journal_free_transaction(transaction_t *transaction)
-{
-	if (unlikely(ZERO_OR_NULL_PTR(transaction)))
-		return;
-	kmem_cache_free(transaction_cache, transaction);
-}
-
-/*
- * jbd2_get_transaction: obtain a new transaction_t object.
- *
- * Simply allocate and initialise a new transaction.  Create it in
- * RUNNING state and add it to the current journal (which should not
- * have an existing running transaction: we only make a new transaction
- * once we have started to commit the old one).
- *
- * Preconditions:
- *	The journal MUST be locked.  We don't perform atomic mallocs on the
- *	new transaction	and we can't block without protecting against other
- *	processes trying to touch the journal while it is in transition.
- *
- */
-
-static transaction_t *
-jbd2_get_transaction(journal_t *journal, transaction_t *transaction)
-{
-	transaction->t_journal = journal;
-	transaction->t_state = T_RUNNING;
-	transaction->t_start_time = ktime_get();
-	transaction->t_tid = journal->j_transaction_sequence++;
-	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_handle_count, 0);
-	INIT_LIST_HEAD(&transaction->t_inode_list);
-	INIT_LIST_HEAD(&transaction->t_private_list);
-
-	/* Set up the commit timer for the new transaction. */
-	journal->j_commit_timer.expires = round_jiffies_up(transaction->t_expires);
-	add_timer(&journal->j_commit_timer);
-
-	J_ASSERT(journal->j_running_transaction == NULL);
-	journal->j_running_transaction = transaction;
-	transaction->t_max_wait = 0;
-	transaction->t_start = jiffies;
-
-	return transaction;
-}
-
-/*
- * Handle management.
- *
- * A handle_t is an object which represents a single atomic update to a
- * filesystem, and which tracks all of the modifications which form part
- * of that one update.
- */
-
-/*
- * Update transaction's maximum wait time, if debugging is enabled.
- *
- * In order for t_max_wait to be reliable, it must be protected by a
- * lock.  But doing so will mean that start_this_handle() can not be
- * run in parallel on SMP systems, which limits our scalability.  So
- * unless debugging is enabled, we no longer update t_max_wait, which
- * means that maximum wait time reported by the jbd2_run_stats
- * tracepoint will always be zero.
- */
-static inline void update_t_max_wait(transaction_t *transaction,
-				     unsigned long ts)
-{
-#ifdef CONFIG_JBD2_DEBUG
-	if (jbd2_journal_enable_debug &&
-	    time_after(transaction->t_start, ts)) {
-		ts = jbd2_time_diff(ts, transaction->t_start);
-		spin_lock(&transaction->t_handle_lock);
-		if (ts > transaction->t_max_wait)
-			transaction->t_max_wait = ts;
-		spin_unlock(&transaction->t_handle_lock);
-	}
-#endif
-}
-
-/*
- * 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
- * transaction's buffer credits.
- */
-
-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;
-	unsigned long ts = jiffies;
-
-	if (nblocks > journal->j_max_transaction_buffers) {
-		printk(KERN_ERR "JBD2: %s wants too many credits (%d > %d)\n",
-		       current->comm, nblocks,
-		       journal->j_max_transaction_buffers);
-		return -ENOSPC;
-	}
-
-alloc_transaction:
-	if (!journal->j_running_transaction) {
-		new_transaction = kmem_cache_alloc(transaction_cache,
-						   gfp_mask | __GFP_ZERO);
-		if (!new_transaction) {
-			/*
-			 * If __GFP_FS is not present, then we may be
-			 * being called from inside the fs writeback
-			 * layer, so we MUST NOT fail.  Since
-			 * __GFP_NOFAIL is going away, we will arrange
-			 * to retry the allocation ourselves.
-			 */
-			if ((gfp_mask & __GFP_FS) == 0) {
-				congestion_wait(BLK_RW_ASYNC, HZ/50);
-				goto alloc_transaction;
-			}
-			return -ENOMEM;
-		}
-	}
-
-	jbd_debug(3, "New handle %p going live.\n", handle);
-
-	/*
-	 * We need to hold j_state_lock until t_updates has been incremented,
-	 * for proper journal barrier handling
-	 */
-repeat:
-	read_lock(&journal->j_state_lock);
-	BUG_ON(journal->j_flags & JBD2_UNMOUNT);
-	if (is_journal_aborted(journal) ||
-	    (journal->j_errno != 0 && !(journal->j_flags & JBD2_ACK_ERR))) {
-		read_unlock(&journal->j_state_lock);
-		jbd2_journal_free_transaction(new_transaction);
-		return -EROFS;
-	}
-
-	/* Wait on the journal's transaction barrier if necessary */
-	if (journal->j_barrier_count) {
-		read_unlock(&journal->j_state_lock);
-		wait_event(journal->j_wait_transaction_locked,
-				journal->j_barrier_count == 0);
-		goto repeat;
-	}
-
-	if (!journal->j_running_transaction) {
-		read_unlock(&journal->j_state_lock);
-		if (!new_transaction)
-			goto alloc_transaction;
-		write_lock(&journal->j_state_lock);
-		if (!journal->j_running_transaction) {
-			jbd2_get_transaction(journal, new_transaction);
-			new_transaction = NULL;
-		}
-		write_unlock(&journal->j_state_lock);
-		goto 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 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.
-		 */
-		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;
-	}
-
-	/* OK, account for the buffers that this operation expects to
-	 * use and add the handle to the running transaction. 
-	 */
-	update_t_max_wait(transaction, ts);
-	handle->h_transaction = transaction;
-	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,
-		  atomic_read(&transaction->t_outstanding_credits),
-		  __jbd2_log_space_left(journal));
-	read_unlock(&journal->j_state_lock);
-
-	lock_map_acquire(&handle->h_lockdep_map);
-	jbd2_journal_free_transaction(new_transaction);
-	return 0;
-}
-
-static struct lock_class_key jbd2_handle_key;
-
-/* Allocate a new handle.  This should probably be in a slab... */
-static handle_t *new_handle(int nblocks)
-{
-	handle_t *handle = jbd2_alloc_handle(GFP_NOFS);
-	if (!handle)
-		return NULL;
-	memset(handle, 0, sizeof(*handle));
-	handle->h_buffer_credits = nblocks;
-	handle->h_ref = 1;
-
-	lockdep_init_map(&handle->h_lockdep_map, "jbd2_handle",
-						&jbd2_handle_key, 0);
-
-	return handle;
-}
-
-/**
- * handle_t *jbd2_journal_start() - Obtain a new handle.
- * @journal: Journal to start transaction on.
- * @nblocks: number of block buffer we might modify
- *
- * 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.
- *
- * 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)
-{
-	handle_t *handle = journal_current_handle();
-	int err;
-
-	if (!journal)
-		return ERR_PTR(-EROFS);
-
-	if (handle) {
-		J_ASSERT(handle->h_transaction->t_journal == journal);
-		handle->h_ref++;
-		return handle;
-	}
-
-	handle = new_handle(nblocks);
-	if (!handle)
-		return ERR_PTR(-ENOMEM);
-
-	current->journal_info = handle;
-
-	err = start_this_handle(journal, handle, gfp_mask);
-	if (err < 0) {
-		jbd2_free_handle(handle);
-		current->journal_info = NULL;
-		handle = ERR_PTR(err);
-	}
-	return handle;
-}
-EXPORT_SYMBOL(jbd2__journal_start);
-
-
-handle_t *jbd2_journal_start(journal_t *journal, int nblocks)
-{
-	return jbd2__journal_start(journal, nblocks, GFP_NOFS);
-}
-EXPORT_SYMBOL(jbd2_journal_start);
-
-
-/**
- * int jbd2_journal_extend() - extend buffer credits.
- * @handle:  handle to 'extend'
- * @nblocks: nr blocks to try to extend by.
- *
- * Some transactions, such as large extends and truncates, can be done
- * atomically all at once or in several stages.  The operation requests
- * a credit for a number of buffer modications in advance, but can
- * extend its credit if it needs more.
- *
- * jbd2_journal_extend tries to give the running handle more buffer credits.
- * It does not guarantee that allocation - this is a best-effort only.
- * The calling process MUST be able to deal cleanly with a failure to
- * extend here.
- *
- * Return 0 on success, non-zero on failure.
- *
- * return code < 0 implies an error
- * return code > 0 implies normal transaction-full status.
- */
-int jbd2_journal_extend(handle_t *handle, int nblocks)
-{
-	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
-	int result;
-	int wanted;
-
-	result = -EIO;
-	if (is_handle_aborted(handle))
-		goto out;
-
-	result = 1;
-
-	read_lock(&journal->j_state_lock);
-
-	/* Don't extend a locked-down transaction! */
-	if (handle->h_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;
-
-	if (wanted > journal->j_max_transaction_buffers) {
-		jbd_debug(3, "denied handle %p %d blocks: "
-			  "transaction too large\n", handle, nblocks);
-		goto unlock;
-	}
-
-	if (wanted > __jbd2_log_space_left(journal)) {
-		jbd_debug(3, "denied handle %p %d blocks: "
-			  "insufficient log space\n", handle, nblocks);
-		goto unlock;
-	}
-
-	handle->h_buffer_credits += nblocks;
-	atomic_add(nblocks, &transaction->t_outstanding_credits);
-	result = 0;
-
-	jbd_debug(3, "extended handle %p by %d\n", handle, nblocks);
-unlock:
-	spin_unlock(&transaction->t_handle_lock);
-error_out:
-	read_unlock(&journal->j_state_lock);
-out:
-	return result;
-}
-
-
-/**
- * int jbd2_journal_restart() - restart a handle .
- * @handle:  handle to restart
- * @nblocks: nr credits requested
- *
- * Restart a handle for a multi-transaction filesystem
- * operation.
- *
- * If the jbd2_journal_extend() call above fails to grant new buffer credits
- * 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.
- */
-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;
-	tid_t		tid;
-	int		need_to_start, ret;
-
-	/* 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;
-
-	/*
-	 * First unlink the handle from its current transaction, and start the
-	 * commit on that.
-	 */
-	J_ASSERT(atomic_read(&transaction->t_updates) > 0);
-	J_ASSERT(journal_current_handle() == handle);
-
-	read_lock(&journal->j_state_lock);
-	spin_lock(&transaction->t_handle_lock);
-	atomic_sub(handle->h_buffer_credits,
-		   &transaction->t_outstanding_credits);
-	if (atomic_dec_and_test(&transaction->t_updates))
-		wake_up(&journal->j_wait_updates);
-	spin_unlock(&transaction->t_handle_lock);
-
-	jbd_debug(2, "restarting handle %p\n", handle);
-	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);
-
-	lock_map_release(&handle->h_lockdep_map);
-	handle->h_buffer_credits = nblocks;
-	ret = start_this_handle(journal, handle, gfp_mask);
-	return ret;
-}
-EXPORT_SYMBOL(jbd2__journal_restart);
-
-
-int jbd2_journal_restart(handle_t *handle, int nblocks)
-{
-	return jbd2__journal_restart(handle, nblocks, GFP_NOFS);
-}
-EXPORT_SYMBOL(jbd2_journal_restart);
-
-/**
- * void jbd2_journal_lock_updates () - establish a transaction barrier.
- * @journal:  Journal to establish a barrier on.
- *
- * This locks out any further updates from being started, and blocks
- * until all existing updates have completed, returning only once the
- * journal is in a quiescent state with no updates running.
- *
- * The journal lock should not be held on entry.
- */
-void jbd2_journal_lock_updates(journal_t *journal)
-{
-	DEFINE_WAIT(wait);
-
-	write_lock(&journal->j_state_lock);
-	++journal->j_barrier_count;
-
-	/* Wait until there are no running updates */
-	while (1) {
-		transaction_t *transaction = journal->j_running_transaction;
-
-		if (!transaction)
-			break;
-
-		spin_lock(&transaction->t_handle_lock);
-		prepare_to_wait(&journal->j_wait_updates, &wait,
-				TASK_UNINTERRUPTIBLE);
-		if (!atomic_read(&transaction->t_updates)) {
-			spin_unlock(&transaction->t_handle_lock);
-			finish_wait(&journal->j_wait_updates, &wait);
-			break;
-		}
-		spin_unlock(&transaction->t_handle_lock);
-		write_unlock(&journal->j_state_lock);
-		schedule();
-		finish_wait(&journal->j_wait_updates, &wait);
-		write_lock(&journal->j_state_lock);
-	}
-	write_unlock(&journal->j_state_lock);
-
-	/*
-	 * We have now established a barrier against other normal updates, but
-	 * we also need to barrier against other jbd2_journal_lock_updates() calls
-	 * to make sure that we serialise special journal-locked operations
-	 * too.
-	 */
-	mutex_lock(&journal->j_barrier);
-}
-
-/**
- * void jbd2_journal_unlock_updates (journal_t* journal) - release barrier
- * @journal:  Journal to release the barrier on.
- *
- * Release a transaction barrier obtained with jbd2_journal_lock_updates().
- *
- * Should be called without the journal lock held.
- */
-void jbd2_journal_unlock_updates (journal_t *journal)
-{
-	J_ASSERT(journal->j_barrier_count != 0);
-
-	mutex_unlock(&journal->j_barrier);
-	write_lock(&journal->j_state_lock);
-	--journal->j_barrier_count;
-	write_unlock(&journal->j_state_lock);
-	wake_up(&journal->j_wait_transaction_locked);
-}
-
-static void warn_dirty_buffer(struct buffer_head *bh)
-{
-	char b[BDEVNAME_SIZE];
-
-	printk(KERN_WARNING
-	       "JBD2: Spotted dirty metadata buffer (dev = %s, blocknr = %llu). "
-	       "There's a risk of filesystem corruption in case of system "
-	       "crash.\n",
-	       bdevname(bh->b_bdev, b), (unsigned long long)bh->b_blocknr);
-}
-
-/*
- * If the buffer is already part of the current transaction, then there
- * is nothing we need to do.  If it is already part of a prior
- * transaction which we are still committing to disk, then we need to
- * make sure that we do not overwrite the old copy: we do copy-out to
- * preserve the copy going to disk.  We also account the buffer against
- * the handle's metadata buffer credits (unless the buffer is already
- * part of the transaction, that is).
- *
- */
-static int
-do_get_write_access(handle_t *handle, struct journal_head *jh,
-			int force_copy)
-{
-	struct buffer_head *bh;
-	transaction_t *transaction;
-	journal_t *journal;
-	int error;
-	char *frozen_buffer = NULL;
-	int need_copy = 0;
-
-	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);
-
-	JBUFFER_TRACE(jh, "entry");
-repeat:
-	bh = jh2bh(jh);
-
-	/* @@@ Need to check for errors here at some point. */
-
-	lock_buffer(bh);
-	jbd_lock_bh_state(bh);
-
-	/* We now hold the buffer lock so it is safe to query the buffer
-	 * state.  Is the buffer dirty?
-	 *
-	 * If so, there are two possibilities.  The buffer may be
-	 * non-journaled, and undergoing a quite legitimate writeback.
-	 * Otherwise, it is journaled, and we don't expect dirty buffers
-	 * in that state (the buffers should be marked JBD_Dirty
-	 * instead.)  So either the IO is being done under our own
-	 * control and this is a bug, or it's a third party IO such as
-	 * dump(8) (which may leave the buffer scheduled for read ---
-	 * ie. locked but not dirty) or tune2fs (which may actually have
-	 * the buffer dirtied, ugh.)  */
-
-	if (buffer_dirty(bh)) {
-		/*
-		 * First question: is this buffer already part of the current
-		 * transaction or the existing committing transaction?
-		 */
-		if (jh->b_transaction) {
-			J_ASSERT_JH(jh,
-				jh->b_transaction == transaction ||
-				jh->b_transaction ==
-					journal->j_committing_transaction);
-			if (jh->b_next_transaction)
-				J_ASSERT_JH(jh, jh->b_next_transaction ==
-							transaction);
-			warn_dirty_buffer(bh);
-		}
-		/*
-		 * In any case we need to clean the dirty flag and we must
-		 * do it under the buffer lock to be sure we don't race
-		 * with running write-out.
-		 */
-		JBUFFER_TRACE(jh, "Journalling dirty buffer");
-		clear_buffer_dirty(bh);
-		set_buffer_jbddirty(bh);
-	}
-
-	unlock_buffer(bh);
-
-	error = -EROFS;
-	if (is_handle_aborted(handle)) {
-		jbd_unlock_bh_state(bh);
-		goto out;
-	}
-	error = 0;
-
-	/*
-	 * The buffer is already part of this transaction if b_transaction or
-	 * b_next_transaction points to it
-	 */
-	if (jh->b_transaction == transaction ||
-	    jh->b_next_transaction == transaction)
-		goto done;
-
-	/*
-	 * this is the first time this transaction is touching this buffer,
-	 * reset the modified flag
-	 */
-       jh->b_modified = 0;
-
-	/*
-	 * If there is already a copy-out version of this buffer, then we don't
-	 * need to make another one
-	 */
-	if (jh->b_frozen_data) {
-		JBUFFER_TRACE(jh, "has frozen data");
-		J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
-		jh->b_next_transaction = transaction;
-		goto done;
-	}
-
-	/* Is there data here we need to preserve? */
-
-	if (jh->b_transaction && jh->b_transaction != transaction) {
-		JBUFFER_TRACE(jh, "owned by older transaction");
-		J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
-		J_ASSERT_JH(jh, jh->b_transaction ==
-					journal->j_committing_transaction);
-
-		/* There is one case we have to be very careful about.
-		 * If the committing transaction is currently writing
-		 * this buffer out to disk and has NOT made a copy-out,
-		 * then we cannot modify the buffer contents at all
-		 * right now.  The essence of copy-out is that it is the
-		 * extra copy, not the primary copy, which gets
-		 * 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);
-
-			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);
-			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.
-		 *
-		 * 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) {
-			JBUFFER_TRACE(jh, "generate frozen data");
-			if (!frozen_buffer) {
-				JBUFFER_TRACE(jh, "allocate memory for buffer");
-				jbd_unlock_bh_state(bh);
-				frozen_buffer =
-					jbd2_alloc(jh2bh(jh)->b_size,
-							 GFP_NOFS);
-				if (!frozen_buffer) {
-					printk(KERN_EMERG
-					       "%s: OOM for frozen_buffer\n",
-					       __func__);
-					JBUFFER_TRACE(jh, "oom!");
-					error = -ENOMEM;
-					jbd_lock_bh_state(bh);
-					goto done;
-				}
-				goto repeat;
-			}
-			jh->b_frozen_data = frozen_buffer;
-			frozen_buffer = NULL;
-			need_copy = 1;
-		}
-		jh->b_next_transaction = transaction;
-	}
-
-
-	/*
-	 * Finally, if the buffer is not journaled right now, we need to make
-	 * sure it doesn't get written to disk before the caller actually
-	 * commits the new data
-	 */
-	if (!jh->b_transaction) {
-		JBUFFER_TRACE(jh, "no transaction");
-		J_ASSERT_JH(jh, !jh->b_next_transaction);
-		JBUFFER_TRACE(jh, "file as BJ_Reserved");
-		spin_lock(&journal->j_list_lock);
-		__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
-		spin_unlock(&journal->j_list_lock);
-	}
-
-done:
-	if (need_copy) {
-		struct page *page;
-		int offset;
-		char *source;
-
-		J_EXPECT_JH(jh, buffer_uptodate(jh2bh(jh)),
-			    "Possible IO failure.\n");
-		page = jh2bh(jh)->b_page;
-		offset = offset_in_page(jh2bh(jh)->b_data);
-		source = kmap_atomic(page);
-		/* Fire data frozen trigger just before we copy the data */
-		jbd2_buffer_frozen_trigger(jh, source + offset,
-					   jh->b_triggers);
-		memcpy(jh->b_frozen_data, source+offset, jh2bh(jh)->b_size);
-		kunmap_atomic(source);
-
-		/*
-		 * Now that the frozen data is saved off, we need to store
-		 * any matching triggers.
-		 */
-		jh->b_frozen_triggers = jh->b_triggers;
-	}
-	jbd_unlock_bh_state(bh);
-
-	/*
-	 * If we are about to journal a buffer, then any revoke pending on it is
-	 * no longer valid
-	 */
-	jbd2_journal_cancel_revoke(handle, jh);
-
-out:
-	if (unlikely(frozen_buffer))	/* It's usually NULL */
-		jbd2_free(frozen_buffer, bh->b_size);
-
-	JBUFFER_TRACE(jh, "exit");
-	return error;
-}
-
-/**
- * int jbd2_journal_get_write_access() - notify intent to modify a buffer for metadata (not data) update.
- * @handle: transaction to add buffer modifications to
- * @bh:     bh to be used for metadata writes
- *
- * Returns an error code or 0 on success.
- *
- * In full data journalling mode the buffer may be of type BJ_AsyncData,
- * because we're write()ing a buffer which is also part of a shared mapping.
- */
-
-int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh)
-{
-	struct journal_head *jh = jbd2_journal_add_journal_head(bh);
-	int rc;
-
-	/* We do not want to get caught playing with fields which the
-	 * log thread also manipulates.  Make sure that the buffer
-	 * completes any outstanding IO before proceeding. */
-	rc = do_get_write_access(handle, jh, 0);
-	jbd2_journal_put_journal_head(jh);
-	return rc;
-}
-
-
-/*
- * When the user wants to journal a newly created buffer_head
- * (ie. getblk() returned a new buffer and we are going to populate it
- * manually rather than reading off disk), then we need to keep the
- * buffer_head locked until it has been completely filled with new
- * data.  In this case, we should be able to make the assertion that
- * the bh is not already part of an existing transaction.
- *
- * The buffer should already be locked by the caller by this point.
- * There is no lock ranking violation: it was a newly created,
- * unlocked buffer beforehand. */
-
-/**
- * int jbd2_journal_get_create_access () - notify intent to use newly created bh
- * @handle: transaction to new buffer to
- * @bh: new buffer.
- *
- * Call this if you create a new 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;
-	struct journal_head *jh = jbd2_journal_add_journal_head(bh);
-	int err;
-
-	jbd_debug(5, "journal_head %p\n", jh);
-	err = -EROFS;
-	if (is_handle_aborted(handle))
-		goto out;
-	err = 0;
-
-	JBUFFER_TRACE(jh, "entry");
-	/*
-	 * The buffer may already belong to this transaction due to pre-zeroing
-	 * in the filesystem's new_block code.  It may also be on the previous,
-	 * committing transaction's lists, but it HAS to be in Forget state in
-	 * that case: the transaction must have deleted the buffer for it to be
-	 * 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 &&
-			  jh->b_jlist == BJ_Forget)));
-
-	J_ASSERT_JH(jh, jh->b_next_transaction == NULL);
-	J_ASSERT_JH(jh, buffer_locked(jh2bh(jh)));
-
-	if (jh->b_transaction == NULL) {
-		/*
-		 * Previous jbd2_journal_forget() could have left the buffer
-		 * with jbddirty bit set because it was being committed. When
-		 * the commit finished, we've filed the buffer for
-		 * checkpointing and marked it dirty. Now we are reallocating
-		 * the buffer so the transaction freeing it must have
-		 * committed and so it's safe to clear the dirty bit.
-		 */
-		clear_buffer_dirty(jh2bh(jh));
-		/* first access by this transaction */
-		jh->b_modified = 0;
-
-		JBUFFER_TRACE(jh, "file as BJ_Reserved");
-		__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");
-		jh->b_next_transaction = transaction;
-	}
-	spin_unlock(&journal->j_list_lock);
-	jbd_unlock_bh_state(bh);
-
-	/*
-	 * akpm: I added this.  ext3_alloc_branch can pick up new indirect
-	 * blocks which contain freed but then revoked metadata.  We need
-	 * to cancel the revoke in case we end up freeing it yet again
-	 * and the reallocating as data - this would cause a second revoke,
-	 * which hits an assertion error.
-	 */
-	JBUFFER_TRACE(jh, "cancelling revoke");
-	jbd2_journal_cancel_revoke(handle, jh);
-out:
-	jbd2_journal_put_journal_head(jh);
-	return err;
-}
-
-/**
- * int jbd2_journal_get_undo_access() -  Notify intent to modify metadata with
- *     non-rewindable consequences
- * @handle: transaction
- * @bh: buffer to undo
- *
- * Sometimes there is a need to distinguish between metadata which has
- * been committed to disk and that which has not.  The ext3fs code uses
- * this for freeing and allocating space, we have to make sure that we
- * do not reuse freed space until the deallocation has been committed,
- * since if we overwrote that space we would make the delete
- * un-rewindable in case of a crash.
- *
- * To deal with that, jbd2_journal_get_undo_access requests write access to a
- * buffer for parts of non-rewindable operations such as delete
- * operations on the bitmaps.  The journaling code must keep a copy of
- * the buffer's contents prior to the undo_access call until such time
- * as we know that the buffer has definitely been committed to disk.
- *
- * We never need to know which transaction the committed data is part
- * of, buffers touched here are guaranteed to be dirtied later and so
- * will be committed to a new transaction in due course, at which point
- * we can discard the old committed data pointer.
- *
- * Returns error number or 0 on success.
- */
-int jbd2_journal_get_undo_access(handle_t *handle, struct buffer_head *bh)
-{
-	int err;
-	struct journal_head *jh = jbd2_journal_add_journal_head(bh);
-	char *committed_data = NULL;
-
-	JBUFFER_TRACE(jh, "entry");
-
-	/*
-	 * Do this first --- it can drop the journal lock, so we want to
-	 * make sure that obtaining the committed_data is done
-	 * atomically wrt. completion of any outstanding commits.
-	 */
-	err = do_get_write_access(handle, jh, 1);
-	if (err)
-		goto out;
-
-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",
-				__func__);
-			err = -ENOMEM;
-			goto out;
-		}
-	}
-
-	jbd_lock_bh_state(bh);
-	if (!jh->b_committed_data) {
-		/* Copy out the current buffer contents into the
-		 * preserved, committed copy. */
-		JBUFFER_TRACE(jh, "generate b_committed data");
-		if (!committed_data) {
-			jbd_unlock_bh_state(bh);
-			goto repeat;
-		}
-
-		jh->b_committed_data = committed_data;
-		committed_data = NULL;
-		memcpy(jh->b_committed_data, bh->b_data, bh->b_size);
-	}
-	jbd_unlock_bh_state(bh);
-out:
-	jbd2_journal_put_journal_head(jh);
-	if (unlikely(committed_data))
-		jbd2_free(committed_data, bh->b_size);
-	return err;
-}
-
-/**
- * void jbd2_journal_set_triggers() - Add triggers for commit writeout
- * @bh: buffer to trigger on
- * @type: struct jbd2_buffer_trigger_type containing the trigger(s).
- *
- * Set any triggers on this journal_head.  This is always safe, because
- * triggers for a committing buffer will be saved off, and triggers for
- * a running transaction will match the buffer in that transaction.
- *
- * Call with NULL to clear the triggers.
- */
-void jbd2_journal_set_triggers(struct buffer_head *bh,
-			       struct jbd2_buffer_trigger_type *type)
-{
-	struct journal_head *jh = bh2jh(bh);
-
-	jh->b_triggers = type;
-}
-
-void jbd2_buffer_frozen_trigger(struct journal_head *jh, void *mapped_data,
-				struct jbd2_buffer_trigger_type *triggers)
-{
-	struct buffer_head *bh = jh2bh(jh);
-
-	if (!triggers || !triggers->t_frozen)
-		return;
-
-	triggers->t_frozen(triggers, bh, mapped_data, bh->b_size);
-}
-
-void jbd2_buffer_abort_trigger(struct journal_head *jh,
-			       struct jbd2_buffer_trigger_type *triggers)
-{
-	if (!triggers || !triggers->t_abort)
-		return;
-
-	triggers->t_abort(triggers, jh2bh(jh));
-}
-
-
-
-/**
- * int jbd2_journal_dirty_metadata() -  mark a buffer as containing dirty metadata
- * @handle: transaction to add buffer to.
- * @bh: buffer to mark
- *
- * mark dirty metadata which needs to be journaled as part of the current
- * transaction.
- *
- * The buffer must have previously had jbd2_journal_get_write_access()
- * called so that it has a valid journal_head attached to the buffer
- * head.
- *
- * The buffer is placed on the transaction's metadata list and is marked
- * as belonging to the transaction.
- *
- * Returns error number or 0 on success.
- *
- * Special care needs to be taken if the buffer already belongs to the
- * current committing transaction (in which case we should have frozen
- * data present for that commit).  In that case, we don't relink the
- * buffer: that only gets done when the old transaction finally
- * completes its commit.
- */
-int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)
-{
-	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
-	struct journal_head *jh = bh2jh(bh);
-	int ret = 0;
-
-	jbd_debug(5, "journal_head %p\n", jh);
-	JBUFFER_TRACE(jh, "entry");
-	if (is_handle_aborted(handle))
-		goto out;
-	if (!buffer_jbd(bh)) {
-		ret = -EUCLEAN;
-		goto out;
-	}
-
-	jbd_lock_bh_state(bh);
-
-	if (jh->b_modified == 0) {
-		/*
-		 * This buffer's got modified and becoming part
-		 * of the transaction. This needs to be done
-		 * once a transaction -bzzz
-		 */
-		jh->b_modified = 1;
-		J_ASSERT_JH(jh, handle->h_buffer_credits > 0);
-		handle->h_buffer_credits--;
-	}
-
-	/*
-	 * fastpath, to avoid expensive locking.  If this buffer is already
-	 * on the running transaction's metadata list there is nothing to do.
-	 * Nobody can take it off again because there is a handle open.
-	 * I _think_ we're OK here with SMP barriers - a mistaken decision will
-	 * result in this test being false, so we go in and take the locks.
-	 */
-	if (jh->b_transaction == transaction && jh->b_jlist == BJ_Metadata) {
-		JBUFFER_TRACE(jh, "fastpath");
-		if (unlikely(jh->b_transaction !=
-			     journal->j_running_transaction)) {
-			printk(KERN_EMERG "JBD: %s: "
-			       "jh->b_transaction (%llu, %p, %u) != "
-			       "journal->j_running_transaction (%p, %u)",
-			       journal->j_devname,
-			       (unsigned long long) bh->b_blocknr,
-			       jh->b_transaction,
-			       jh->b_transaction ? jh->b_transaction->t_tid : 0,
-			       journal->j_running_transaction,
-			       journal->j_running_transaction ?
-			       journal->j_running_transaction->t_tid : 0);
-			ret = -EINVAL;
-		}
-		goto out_unlock_bh;
-	}
-
-	set_buffer_jbddirty(bh);
-
-	/*
-	 * Metadata already on the current transaction list doesn't
-	 * need to be filed.  Metadata on another transaction's list must
-	 * be committing, and will be refiled once the commit completes:
-	 * leave it alone for now.
-	 */
-	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)",
-			       journal->j_devname,
-			       (unsigned long long) bh->b_blocknr,
-			       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_next_transaction,
-			       jh->b_next_transaction ?
-			       jh->b_next_transaction->t_tid : 0,
-			       transaction, transaction->t_tid);
-			ret = -EINVAL;
-		}
-		/* And this case is illegal: we can't reuse another
-		 * transaction's data buffer, ever. */
-		goto out_unlock_bh;
-	}
-
-	/* That test should have eliminated the following case: */
-	J_ASSERT_JH(jh, jh->b_frozen_data == NULL);
-
-	JBUFFER_TRACE(jh, "file as BJ_Metadata");
-	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata);
-	spin_unlock(&journal->j_list_lock);
-out_unlock_bh:
-	jbd_unlock_bh_state(bh);
-out:
-	JBUFFER_TRACE(jh, "exit");
-	WARN_ON(ret);	/* All errors are bugs, so dump the stack */
-	return ret;
-}
-
-/*
- * jbd2_journal_release_buffer: undo a get_write_access without any buffer
- * updates, if the update decided in the end that it didn't need access.
- *
- */
-void
-jbd2_journal_release_buffer(handle_t *handle, struct buffer_head *bh)
-{
-	BUFFER_TRACE(bh, "entry");
-}
-
-/**
- * void jbd2_journal_forget() - bforget() for potentially-journaled buffers.
- * @handle: transaction handle
- * @bh:     bh to 'forget'
- *
- * We can only do the bforget if there are no commits pending against the
- * buffer.  If the buffer is dirty in the current running transaction we
- * can safely unlink it.
- *
- * bh may not be a journalled buffer at all - it may be a non-JBD
- * buffer which came off the hashtable.  Check for this.
- *
- * Decrements bh->b_count by one.
- *
- * Allow this call even if the handle has aborted --- it may be part of
- * the caller's cleanup after an abort.
- */
-int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)
-{
-	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
-	struct journal_head *jh;
-	int drop_reserve = 0;
-	int err = 0;
-	int was_modified = 0;
-
-	BUFFER_TRACE(bh, "entry");
-
-	jbd_lock_bh_state(bh);
-	spin_lock(&journal->j_list_lock);
-
-	if (!buffer_jbd(bh))
-		goto not_jbd;
-	jh = bh2jh(bh);
-
-	/* Critical error: attempting to delete a bitmap buffer, maybe?
-	 * Don't do any jbd operations, and return an error. */
-	if (!J_EXPECT_JH(jh, !jh->b_committed_data,
-			 "inconsistent data on disk")) {
-		err = -EIO;
-		goto not_jbd;
-	}
-
-	/* keep track of wether or not this transaction modified us */
-	was_modified = jh->b_modified;
-
-	/*
-	 * The buffer's going from the transaction, we must drop
-	 * all references -bzzz
-	 */
-	jh->b_modified = 0;
-
-	if (jh->b_transaction == handle->h_transaction) {
-		J_ASSERT_JH(jh, !jh->b_frozen_data);
-
-		/* If we are forgetting a buffer which is already part
-		 * of this transaction, then we can just drop it from
-		 * the transaction immediately. */
-		clear_buffer_dirty(bh);
-		clear_buffer_jbddirty(bh);
-
-		JBUFFER_TRACE(jh, "belongs to current transaction: unfile");
-
-		/*
-		 * we only want to drop a reference if this transaction
-		 * modified the buffer
-		 */
-		if (was_modified)
-			drop_reserve = 1;
-
-		/*
-		 * We are no longer going to journal this buffer.
-		 * However, the commit of this transaction is still
-		 * important to the buffer: the delete that we are now
-		 * processing might obsolete an old log entry, so by
-		 * committing, we can satisfy the buffer's checkpoint.
-		 *
-		 * So, if we have a checkpoint on the buffer, we should
-		 * now refile the buffer on our BJ_Forget list so that
-		 * we know to remove the checkpoint after we commit.
-		 */
-
-		if (jh->b_cp_transaction) {
-			__jbd2_journal_temp_unlink_buffer(jh);
-			__jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
-		} else {
-			__jbd2_journal_unfile_buffer(jh);
-			if (!buffer_jbd(bh)) {
-				spin_unlock(&journal->j_list_lock);
-				jbd_unlock_bh_state(bh);
-				__bforget(bh);
-				goto drop;
-			}
-		}
-	} else if (jh->b_transaction) {
-		J_ASSERT_JH(jh, (jh->b_transaction ==
-				 journal->j_committing_transaction));
-		/* However, if the buffer is still owned by a prior
-		 * (committing) transaction, we can't drop it yet... */
-		JBUFFER_TRACE(jh, "belongs to older transaction");
-		/* ... but we CAN drop it from the new transaction if we
-		 * have also modified it since the original commit. */
-
-		if (jh->b_next_transaction) {
-			J_ASSERT(jh->b_next_transaction == transaction);
-			jh->b_next_transaction = NULL;
-
-			/*
-			 * only drop a reference if this transaction modified
-			 * the buffer
-			 */
-			if (was_modified)
-				drop_reserve = 1;
-		}
-	}
-
-not_jbd:
-	spin_unlock(&journal->j_list_lock);
-	jbd_unlock_bh_state(bh);
-	__brelse(bh);
-drop:
-	if (drop_reserve) {
-		/* no need to reserve log space for this block -bzzz */
-		handle->h_buffer_credits++;
-	}
-	return err;
-}
-
-/**
- * int jbd2_journal_stop() - complete a transaction
- * @handle: tranaction to complete.
- *
- * All done for a particular handle.
- *
- * There is not much action needed here.  We just return any remaining
- * buffer credits to the transaction and remove the handle.  The only
- * complication is that we need to start a commit operation if the
- * filesystem is marked for synchronous update.
- *
- * jbd2_journal_stop itself will not usually return an error, but it may
- * do so in unusual circumstances.  In particular, expect it to
- * return -EIO if a jbd2_journal_abort has been executed since the
- * transaction began.
- */
-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;
-	tid_t tid;
-	pid_t pid;
-
-	J_ASSERT(journal_current_handle() == handle);
-
-	if (is_handle_aborted(handle))
-		err = -EIO;
-	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,
-			  handle->h_ref);
-		return err;
-	}
-
-	jbd_debug(4, "Handle %p going down\n", handle);
-
-	/*
-	 * Implement synchronous transaction batching.  If the handle
-	 * was synchronous, don't force a commit immediately.  Let's
-	 * yield and let another thread piggyback onto this
-	 * transaction.  Keep doing that while new threads continue to
-	 * arrive.  It doesn't cost much - we're about to run a commit
-	 * and sleep on IO anyway.  Speeds up many-threaded, many-dir
-	 * operations by 30x or more...
-	 *
-	 * We try and optimize the sleep time against what the
-	 * underlying disk can do, instead of having a static sleep
-	 * time.  This is useful for the case where our storage is so
-	 * fast that it is more optimal to go ahead and force a flush
-	 * and wait for the transaction to be committed than it is to
-	 * wait for an arbitrary amount of time for new writers to
-	 * join the transaction.  We achieve this by measuring how
-	 * long it takes to commit a transaction, and compare it with
-	 * how long this transaction has been running, and if run time
-	 * < commit time then we sleep for the delta and commit.  This
-	 * greatly helps super fast disks that would see slowdowns as
-	 * more threads started doing fsyncs.
-	 *
-	 * But don't do this if this process was the most recent one
-	 * to perform a synchronous write.  We do this to detect the
-	 * case where a single process is doing a stream of sync
-	 * writes.  No point in waiting for joiners in that case.
-	 */
-	pid = current->pid;
-	if (handle->h_sync && journal->j_last_sync_writer != pid) {
-		u64 commit_time, trans_time;
-
-		journal->j_last_sync_writer = pid;
-
-		read_lock(&journal->j_state_lock);
-		commit_time = journal->j_average_commit_time;
-		read_unlock(&journal->j_state_lock);
-
-		trans_time = ktime_to_ns(ktime_sub(ktime_get(),
-						   transaction->t_start_time));
-
-		commit_time = max_t(u64, commit_time,
-				    1000*journal->j_min_batch_time);
-		commit_time = min_t(u64, commit_time,
-				    1000*journal->j_max_batch_time);
-
-		if (trans_time < commit_time) {
-			ktime_t expires = ktime_add_ns(ktime_get(),
-						       commit_time);
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			schedule_hrtimeout(&expires, HRTIMER_MODE_ABS);
-		}
-	}
-
-	if (handle->h_sync)
-		transaction->t_synchronous_commit = 1;
-	current->journal_info = NULL;
-	atomic_sub(handle->h_buffer_credits,
-		   &transaction->t_outstanding_credits);
-
-	/*
-	 * If the handle is marked SYNC, we need to set another commit
-	 * going!  We also want to force a commit if the current
-	 * transaction is occupying too much of the log, or if the
-	 * transaction is too old now.
-	 */
-	if (handle->h_sync ||
-	    (atomic_read(&transaction->t_outstanding_credits) >
-	     journal->j_max_transaction_buffers) ||
-	    time_after_eq(jiffies, transaction->t_expires)) {
-		/* Do this even for aborted journals: an abort still
-		 * completes the commit thread, it just doesn't write
-		 * anything to disk. */
-
-		jbd_debug(2, "transaction too old, requesting commit for "
-					"handle %p\n", handle);
-		/* This is non-blocking */
-		jbd2_log_start_commit(journal, transaction->t_tid);
-
-		/*
-		 * Special case: JBD2_SYNC synchronous updates require us
-		 * to wait for the commit to complete.
-		 */
-		if (handle->h_sync && !(current->flags & PF_MEMALLOC))
-			wait_for_commit = 1;
-	}
-
-	/*
-	 * Once we drop t_updates, if it goes to zero the transaction
-	 * could start committing on us and eventually disappear.  So
-	 * once we do this, we must not dereference transaction
-	 * pointer again.
-	 */
-	tid = transaction->t_tid;
-	if (atomic_dec_and_test(&transaction->t_updates)) {
-		wake_up(&journal->j_wait_updates);
-		if (journal->j_barrier_count)
-			wake_up(&journal->j_wait_transaction_locked);
-	}
-
-	if (wait_for_commit)
-		err = jbd2_log_wait_commit(journal, tid);
-
-	lock_map_release(&handle->h_lockdep_map);
-
-	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
- * transaction buffer lists.
- *
- */
-
-/*
- * Append a buffer to a transaction list, given the transaction's list head
- * pointer.
- *
- * j_list_lock is held.
- *
- * jbd_lock_bh_state(jh2bh(jh)) is held.
- */
-
-static inline void
-__blist_add_buffer(struct journal_head **list, struct journal_head *jh)
-{
-	if (!*list) {
-		jh->b_tnext = jh->b_tprev = jh;
-		*list = jh;
-	} else {
-		/* Insert at the tail of the list to preserve order */
-		struct journal_head *first = *list, *last = first->b_tprev;
-		jh->b_tprev = last;
-		jh->b_tnext = first;
-		last->b_tnext = first->b_tprev = jh;
-	}
-}
-
-/*
- * Remove a buffer from a transaction list, given the transaction's list
- * head pointer.
- *
- * Called with j_list_lock held, and the journal may not be locked.
- *
- * jbd_lock_bh_state(jh2bh(jh)) is held.
- */
-
-static inline void
-__blist_del_buffer(struct journal_head **list, struct journal_head *jh)
-{
-	if (*list == jh) {
-		*list = jh->b_tnext;
-		if (*list == jh)
-			*list = NULL;
-	}
-	jh->b_tprev->b_tnext = jh->b_tnext;
-	jh->b_tnext->b_tprev = jh->b_tprev;
-}
-
-/*
- * 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.
- *
- * Called under j_list_lock.
- */
-static void __jbd2_journal_temp_unlink_buffer(struct journal_head *jh)
-{
-	struct journal_head **list = NULL;
-	transaction_t *transaction;
-	struct buffer_head *bh = jh2bh(jh);
-
-	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
-	transaction = jh->b_transaction;
-	if (transaction)
-		assert_spin_locked(&transaction->t_journal->j_list_lock);
-
-	J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
-	if (jh->b_jlist != BJ_None)
-		J_ASSERT_JH(jh, transaction != NULL);
-
-	switch (jh->b_jlist) {
-	case BJ_None:
-		return;
-	case BJ_Metadata:
-		transaction->t_nr_buffers--;
-		J_ASSERT_JH(jh, transaction->t_nr_buffers >= 0);
-		list = &transaction->t_buffers;
-		break;
-	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;
-	}
-
-	__blist_del_buffer(list, jh);
-	jh->b_jlist = BJ_None;
-	if (test_clear_buffer_jbddirty(bh))
-		mark_buffer_dirty(bh);	/* Expose it to the VM */
-}
-
-/*
- * Remove buffer from all transactions.
- *
- * Called with bh_state lock and j_list_lock
- *
- * jh and bh may be already freed when this function returns.
- */
-static void __jbd2_journal_unfile_buffer(struct journal_head *jh)
-{
-	__jbd2_journal_temp_unlink_buffer(jh);
-	jh->b_transaction = NULL;
-	jbd2_journal_put_journal_head(jh);
-}
-
-void jbd2_journal_unfile_buffer(journal_t *journal, struct journal_head *jh)
-{
-	struct buffer_head *bh = jh2bh(jh);
-
-	/* Get reference so that buffer cannot be freed before we unlock it */
-	get_bh(bh);
-	jbd_lock_bh_state(bh);
-	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_unfile_buffer(jh);
-	spin_unlock(&journal->j_list_lock);
-	jbd_unlock_bh_state(bh);
-	__brelse(bh);
-}
-
-/*
- * Called from jbd2_journal_try_to_free_buffers().
- *
- * Called under jbd_lock_bh_state(bh)
- */
-static void
-__journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
-{
-	struct journal_head *jh;
-
-	jh = bh2jh(bh);
-
-	if (buffer_locked(bh) || buffer_dirty(bh))
-		goto out;
-
-	if (jh->b_next_transaction != NULL)
-		goto out;
-
-	spin_lock(&journal->j_list_lock);
-	if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
-		/* written-back checkpointed metadata buffer */
-		JBUFFER_TRACE(jh, "remove from checkpoint list");
-		__jbd2_journal_remove_checkpoint(jh);
-	}
-	spin_unlock(&journal->j_list_lock);
-out:
-	return;
-}
-
-/**
- * int jbd2_journal_try_to_free_buffers() - try to free page buffers.
- * @journal: journal for operation
- * @page: to try and free
- * @gfp_mask: we use the mask to detect how hard should we try to release
- * buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
- * release the buffers.
- *
- *
- * For all the buffers on this page,
- * if they are fully written out ordered data, move them onto BUF_CLEAN
- * so try_to_free_buffers() can reap them.
- *
- * This function returns non-zero if we wish try_to_free_buffers()
- * to be called. We do this if the page is releasable by try_to_free_buffers().
- * We also do it if the page has locked or dirty buffers and the caller wants
- * us to perform sync or async writeout.
- *
- * This complicates JBD locking somewhat.  We aren't protected by the
- * BKL here.  We wish to remove the buffer from its committing or
- * running transaction's ->t_datalist via __jbd2_journal_unfile_buffer.
- *
- * This may *change* the value of transaction_t->t_datalist, so anyone
- * who looks at t_datalist needs to lock against this function.
- *
- * Even worse, someone may be doing a jbd2_journal_dirty_data on this
- * buffer.  So we need to lock against that.  jbd2_journal_dirty_data()
- * will come out of the lock with the buffer dirty, which makes it
- * ineligible for release here.
- *
- * Who else is affected by this?  hmm...  Really the only contender
- * is do_get_write_access() - it could be looking at the buffer while
- * journal_try_to_free_buffer() is changing its state.  But that
- * cannot happen because we never reallocate freed data as metadata
- * while the data is part of a transaction.  Yes?
- *
- * Return 0 on failure, 1 on success
- */
-int jbd2_journal_try_to_free_buffers(journal_t *journal,
-				struct page *page, gfp_t gfp_mask)
-{
-	struct buffer_head *head;
-	struct buffer_head *bh;
-	int ret = 0;
-
-	J_ASSERT(PageLocked(page));
-
-	head = page_buffers(page);
-	bh = head;
-	do {
-		struct journal_head *jh;
-
-		/*
-		 * We take our own ref against the journal_head here to avoid
-		 * having to add tons of locking around each instance of
-		 * jbd2_journal_put_journal_head().
-		 */
-		jh = jbd2_journal_grab_journal_head(bh);
-		if (!jh)
-			continue;
-
-		jbd_lock_bh_state(bh);
-		__journal_try_to_free_buffer(journal, bh);
-		jbd2_journal_put_journal_head(jh);
-		jbd_unlock_bh_state(bh);
-		if (buffer_jbd(bh))
-			goto busy;
-	} while ((bh = bh->b_this_page) != head);
-
-	ret = try_to_free_buffers(page);
-
-busy:
-	return ret;
-}
-
-/*
- * This buffer is no longer needed.  If it is on an older transaction's
- * checkpoint list we need to record it on this transaction's forget list
- * to pin this buffer (and hence its checkpointing transaction) down until
- * this transaction commits.  If the buffer isn't on a checkpoint list, we
- * release it.
- * Returns non-zero if JBD no longer has an interest in the buffer.
- *
- * Called under j_list_lock.
- *
- * Called under jbd_lock_bh_state(bh).
- */
-static int __dispose_buffer(struct journal_head *jh, transaction_t *transaction)
-{
-	int may_free = 1;
-	struct buffer_head *bh = jh2bh(jh);
-
-	if (jh->b_cp_transaction) {
-		JBUFFER_TRACE(jh, "on running+cp transaction");
-		__jbd2_journal_temp_unlink_buffer(jh);
-		/*
-		 * We don't want to write the buffer anymore, clear the
-		 * bit so that we don't confuse checks in
-		 * __journal_file_buffer
-		 */
-		clear_buffer_dirty(bh);
-		__jbd2_journal_file_buffer(jh, transaction, BJ_Forget);
-		may_free = 0;
-	} else {
-		JBUFFER_TRACE(jh, "on running transaction");
-		__jbd2_journal_unfile_buffer(jh);
-	}
-	return may_free;
-}
-
-/*
- * jbd2_journal_invalidatepage
- *
- * This code is tricky.  It has a number of cases to deal with.
- *
- * There are two invariants which this code relies on:
- *
- * i_size must be updated on disk before we start calling invalidatepage on the
- * data.
- *
- *  This is done in ext3 by defining an ext3_setattr method which
- *  updates i_size before truncate gets going.  By maintaining this
- *  invariant, we can be sure that it is safe to throw away any buffers
- *  attached to the current transaction: once the transaction commits,
- *  we know that the data will not be needed.
- *
- *  Note however that we can *not* throw away data belonging to the
- *  previous, committing transaction!
- *
- * Any disk blocks which *are* part of the previous, committing
- * transaction (and which therefore cannot be discarded immediately) are
- * not going to be reused in the new running transaction
- *
- *  The bitmap committed_data images guarantee this: any block which is
- *  allocated in one transaction and removed in the next will be marked
- *  as in-use in the committed_data bitmap, so cannot be reused until
- *  the next transaction to delete the block commits.  This means that
- *  leaving committing buffers dirty is quite safe: the disk blocks
- *  cannot be reallocated to a different file and so buffer aliasing is
- *  not possible.
- *
- *
- * The above applies mainly to ordered data mode.  In writeback mode we
- * don't make guarantees about the order in which data hits disk --- in
- * particular we don't guarantee that new dirty data is flushed before
- * transaction commit --- so it is always safe just to discard data
- * immediately in that mode.  --sct
- */
-
-/*
- * The journal_unmap_buffer helper function returns zero if the buffer
- * concerned remains pinned as an anonymous buffer belonging to an older
- * transaction.
- *
- * We're outside-transaction here.  Either or both of j_running_transaction
- * and j_committing_transaction may be NULL.
- */
-static int journal_unmap_buffer(journal_t *journal, struct buffer_head *bh)
-{
-	transaction_t *transaction;
-	struct journal_head *jh;
-	int may_free = 1;
-	int ret;
-
-	BUFFER_TRACE(bh, "entry");
-
-	/*
-	 * It is safe to proceed here without the j_list_lock because the
-	 * buffers cannot be stolen by try_to_free_buffers as long as we are
-	 * holding the page lock. --sct
-	 */
-
-	if (!buffer_jbd(bh))
-		goto zap_buffer_unlocked;
-
-	/* OK, we have data buffer in journaled mode */
-	write_lock(&journal->j_state_lock);
-	jbd_lock_bh_state(bh);
-	spin_lock(&journal->j_list_lock);
-
-	jh = jbd2_journal_grab_journal_head(bh);
-	if (!jh)
-		goto zap_buffer_no_jh;
-
-	/*
-	 * We cannot remove the buffer from checkpoint lists until the
-	 * transaction adding inode to orphan list (let's call it T)
-	 * is committed.  Otherwise if the transaction changing the
-	 * buffer would be cleaned from the journal before T is
-	 * committed, a crash will cause that the correct contents of
-	 * the buffer will be lost.  On the other hand we have to
-	 * clear the buffer dirty bit at latest at the moment when the
-	 * transaction marking the buffer as freed in the filesystem
-	 * structures is committed because from that moment on the
-	 * buffer can be reallocated and used by a different page.
-	 * Since the block hasn't been freed yet but the inode has
-	 * already been added to orphan list, it is safe for us to add
-	 * the buffer to BJ_Forget list of the newest transaction.
-	 */
-	transaction = jh->b_transaction;
-	if (transaction == NULL) {
-		/* First case: not on any transaction.  If it
-		 * has no checkpoint link, then we can zap it:
-		 * it's a writeback-mode buffer so we don't care
-		 * if it hits disk safely. */
-		if (!jh->b_cp_transaction) {
-			JBUFFER_TRACE(jh, "not on any transaction: zap");
-			goto zap_buffer;
-		}
-
-		if (!buffer_dirty(bh)) {
-			/* bdflush has written it.  We can drop it now */
-			goto zap_buffer;
-		}
-
-		/* OK, it must be in the journal but still not
-		 * written fully to disk: it's metadata or
-		 * journaled data... */
-
-		if (journal->j_running_transaction) {
-			/* ... and once the current transaction has
-			 * committed, the buffer won't be needed any
-			 * longer. */
-			JBUFFER_TRACE(jh, "checkpointed: add to BJ_Forget");
-			ret = __dispose_buffer(jh,
-					journal->j_running_transaction);
-			jbd2_journal_put_journal_head(jh);
-			spin_unlock(&journal->j_list_lock);
-			jbd_unlock_bh_state(bh);
-			write_unlock(&journal->j_state_lock);
-			return ret;
-		} else {
-			/* There is no currently-running transaction. So the
-			 * orphan record which we wrote for this file must have
-			 * passed into commit.  We must attach this buffer to
-			 * the committing transaction, if it exists. */
-			if (journal->j_committing_transaction) {
-				JBUFFER_TRACE(jh, "give to committing trans");
-				ret = __dispose_buffer(jh,
-					journal->j_committing_transaction);
-				jbd2_journal_put_journal_head(jh);
-				spin_unlock(&journal->j_list_lock);
-				jbd_unlock_bh_state(bh);
-				write_unlock(&journal->j_state_lock);
-				return ret;
-			} else {
-				/* The orphan record's transaction has
-				 * committed.  We can cleanse this buffer */
-				clear_buffer_jbddirty(bh);
-				goto zap_buffer;
-			}
-		}
-	} else if (transaction == journal->j_committing_transaction) {
-		JBUFFER_TRACE(jh, "on committing transaction");
-		/*
-		 * The buffer is committing, we simply cannot touch
-		 * it. So we just set j_next_transaction to the
-		 * running transaction (if there is one) and mark
-		 * buffer as freed so that commit code knows it should
-		 * clear dirty bits when it is done with the buffer.
-		 */
-		set_buffer_freed(bh);
-		if (journal->j_running_transaction && buffer_jbddirty(bh))
-			jh->b_next_transaction = journal->j_running_transaction;
-		jbd2_journal_put_journal_head(jh);
-		spin_unlock(&journal->j_list_lock);
-		jbd_unlock_bh_state(bh);
-		write_unlock(&journal->j_state_lock);
-		return 0;
-	} else {
-		/* Good, the buffer belongs to the running transaction.
-		 * We are writing our own transaction's data, not any
-		 * previous one's, so it is safe to throw it away
-		 * (remember that we expect the filesystem to have set
-		 * i_size already for this truncate so recovery will not
-		 * expose the disk blocks we are discarding here.) */
-		J_ASSERT_JH(jh, transaction == journal->j_running_transaction);
-		JBUFFER_TRACE(jh, "on running transaction");
-		may_free = __dispose_buffer(jh, transaction);
-	}
-
-zap_buffer:
-	jbd2_journal_put_journal_head(jh);
-zap_buffer_no_jh:
-	spin_unlock(&journal->j_list_lock);
-	jbd_unlock_bh_state(bh);
-	write_unlock(&journal->j_state_lock);
-zap_buffer_unlocked:
-	clear_buffer_dirty(bh);
-	J_ASSERT_BH(bh, !buffer_jbddirty(bh));
-	clear_buffer_mapped(bh);
-	clear_buffer_req(bh);
-	clear_buffer_new(bh);
-	clear_buffer_delay(bh);
-	clear_buffer_unwritten(bh);
-	bh->b_bdev = NULL;
-	return may_free;
-}
-
-/**
- * void jbd2_journal_invalidatepage()
- * @journal: journal to use for flush...
- * @page:    page to flush
- * @offset:  length of page to invalidate.
- *
- * Reap page buffers containing data after offset in page.
- *
- */
-void jbd2_journal_invalidatepage(journal_t *journal,
-		      struct page *page,
-		      unsigned long offset)
-{
-	struct buffer_head *head, *bh, *next;
-	unsigned int curr_off = 0;
-	int may_free = 1;
-
-	if (!PageLocked(page))
-		BUG();
-	if (!page_has_buffers(page))
-		return;
-
-	/* We will potentially be playing with lists other than just the
-	 * data lists (especially for journaled data mode), so be
-	 * cautious in our locking. */
-
-	head = bh = page_buffers(page);
-	do {
-		unsigned int next_off = curr_off + bh->b_size;
-		next = bh->b_this_page;
-
-		if (offset <= curr_off) {
-			/* This block is wholly outside the truncation point */
-			lock_buffer(bh);
-			may_free &= journal_unmap_buffer(journal, bh);
-			unlock_buffer(bh);
-		}
-		curr_off = next_off;
-		bh = next;
-
-	} while (bh != head);
-
-	if (!offset) {
-		if (may_free && try_to_free_buffers(page))
-			J_ASSERT(!page_has_buffers(page));
-	}
-}
-
-/*
- * File a buffer on the given transaction list.
- */
-void __jbd2_journal_file_buffer(struct journal_head *jh,
-			transaction_t *transaction, int jlist)
-{
-	struct journal_head **list = NULL;
-	int was_dirty = 0;
-	struct buffer_head *bh = jh2bh(jh);
-
-	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
-	assert_spin_locked(&transaction->t_journal->j_list_lock);
-
-	J_ASSERT_JH(jh, jh->b_jlist < BJ_Types);
-	J_ASSERT_JH(jh, jh->b_transaction == transaction ||
-				jh->b_transaction == NULL);
-
-	if (jh->b_transaction && jh->b_jlist == jlist)
-		return;
-
-	if (jlist == BJ_Metadata || jlist == BJ_Reserved ||
-	    jlist == BJ_Shadow || jlist == BJ_Forget) {
-		/*
-		 * For metadata buffers, we track dirty bit in buffer_jbddirty
-		 * instead of buffer_dirty. We should not see a dirty bit set
-		 * here because we clear it in do_get_write_access but e.g.
-		 * tune2fs can modify the sb and set the dirty bit at any time
-		 * so we try to gracefully handle that.
-		 */
-		if (buffer_dirty(bh))
-			warn_dirty_buffer(bh);
-		if (test_clear_buffer_dirty(bh) ||
-		    test_clear_buffer_jbddirty(bh))
-			was_dirty = 1;
-	}
-
-	if (jh->b_transaction)
-		__jbd2_journal_temp_unlink_buffer(jh);
-	else
-		jbd2_journal_grab_journal_head(bh);
-	jh->b_transaction = transaction;
-
-	switch (jlist) {
-	case BJ_None:
-		J_ASSERT_JH(jh, !jh->b_committed_data);
-		J_ASSERT_JH(jh, !jh->b_frozen_data);
-		return;
-	case BJ_Metadata:
-		transaction->t_nr_buffers++;
-		list = &transaction->t_buffers;
-		break;
-	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;
-	}
-
-	__blist_add_buffer(list, jh);
-	jh->b_jlist = jlist;
-
-	if (was_dirty)
-		set_buffer_jbddirty(bh);
-}
-
-void jbd2_journal_file_buffer(struct journal_head *jh,
-				transaction_t *transaction, int jlist)
-{
-	jbd_lock_bh_state(jh2bh(jh));
-	spin_lock(&transaction->t_journal->j_list_lock);
-	__jbd2_journal_file_buffer(jh, transaction, jlist);
-	spin_unlock(&transaction->t_journal->j_list_lock);
-	jbd_unlock_bh_state(jh2bh(jh));
-}
-
-/*
- * Remove a buffer from its current buffer list in preparation for
- * dropping it from its current transaction entirely.  If the buffer has
- * already started to be used by a subsequent transaction, refile the
- * buffer on that transaction's metadata list.
- *
- * Called under j_list_lock
- * Called under jbd_lock_bh_state(jh2bh(jh))
- *
- * jh and bh may be already free when this function returns
- */
-void __jbd2_journal_refile_buffer(struct journal_head *jh)
-{
-	int was_dirty, jlist;
-	struct buffer_head *bh = jh2bh(jh);
-
-	J_ASSERT_JH(jh, jbd_is_locked_bh_state(bh));
-	if (jh->b_transaction)
-		assert_spin_locked(&jh->b_transaction->t_journal->j_list_lock);
-
-	/* If the buffer is now unused, just drop it. */
-	if (jh->b_next_transaction == NULL) {
-		__jbd2_journal_unfile_buffer(jh);
-		return;
-	}
-
-	/*
-	 * It has been modified by a later transaction: add it to the new
-	 * transaction's metadata list.
-	 */
-
-	was_dirty = test_clear_buffer_jbddirty(bh);
-	__jbd2_journal_temp_unlink_buffer(jh);
-	/*
-	 * We set b_transaction here because b_next_transaction will inherit
-	 * our jh reference and thus __jbd2_journal_file_buffer() must not
-	 * take a new one.
-	 */
-	jh->b_transaction = jh->b_next_transaction;
-	jh->b_next_transaction = NULL;
-	if (buffer_freed(bh))
-		jlist = BJ_Forget;
-	else if (jh->b_modified)
-		jlist = BJ_Metadata;
-	else
-		jlist = BJ_Reserved;
-	__jbd2_journal_file_buffer(jh, jh->b_transaction, jlist);
-	J_ASSERT_JH(jh, jh->b_transaction->t_state == T_RUNNING);
-
-	if (was_dirty)
-		set_buffer_jbddirty(bh);
-}
-
-/*
- * __jbd2_journal_refile_buffer() with necessary locking added. We take our
- * bh reference so that we can safely unlock bh.
- *
- * The jh and bh may be freed by this call.
- */
-void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh)
-{
-	struct buffer_head *bh = jh2bh(jh);
-
-	/* Get reference so that buffer cannot be freed before we unlock it */
-	get_bh(bh);
-	jbd_lock_bh_state(bh);
-	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_refile_buffer(jh);
-	jbd_unlock_bh_state(bh);
-	spin_unlock(&journal->j_list_lock);
-	__brelse(bh);
-}
-
-/*
- * File inode in the inode list of the handle's transaction
- */
-int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)
-{
-	transaction_t *transaction = handle->h_transaction;
-	journal_t *journal = transaction->t_journal;
-
-	if (is_handle_aborted(handle))
-		return -EIO;
-
-	jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,
-			transaction->t_tid);
-
-	/*
-	 * First check whether inode isn't already on the transaction's
-	 * lists without taking the lock. Note that this check is safe
-	 * without the lock as we cannot race with somebody removing inode
-	 * from the transaction. The reason is that we remove inode from the
-	 * transaction only in journal_release_jbd_inode() and when we commit
-	 * the transaction. We are guarded from the first case by holding
-	 * a reference to the inode. We are safe against the second case
-	 * because if jinode->i_transaction == transaction, commit code
-	 * cannot touch the transaction because we hold reference to it,
-	 * and if jinode->i_next_transaction == transaction, commit code
-	 * will only file the inode where we want it.
-	 */
-	if (jinode->i_transaction == transaction ||
-	    jinode->i_next_transaction == transaction)
-		return 0;
-
-	spin_lock(&journal->j_list_lock);
-
-	if (jinode->i_transaction == transaction ||
-	    jinode->i_next_transaction == transaction)
-		goto done;
-
-	/*
-	 * We only ever set this variable to 1 so the test is safe. Since
-	 * t_need_data_flush is likely to be set, we do the test to save some
-	 * cacheline bouncing
-	 */
-	if (!transaction->t_need_data_flush)
-		transaction->t_need_data_flush = 1;
-	/* On some different transaction's list - should be
-	 * the committing one */
-	if (jinode->i_transaction) {
-		J_ASSERT(jinode->i_next_transaction == NULL);
-		J_ASSERT(jinode->i_transaction ==
-					journal->j_committing_transaction);
-		jinode->i_next_transaction = transaction;
-		goto done;
-	}
-	/* Not on any transaction list... */
-	J_ASSERT(!jinode->i_next_transaction);
-	jinode->i_transaction = transaction;
-	list_add(&jinode->i_list, &transaction->t_inode_list);
-done:
-	spin_unlock(&journal->j_list_lock);
-
-	return 0;
-}
-
-/*
- * File truncate and transaction commit interact with each other in a
- * non-trivial way.  If a transaction writing data block A is
- * committing, we cannot discard the data by truncate until we have
- * written them.  Otherwise if we crashed after the transaction with
- * write has committed but before the transaction with truncate has
- * committed, we could see stale data in block A.  This function is a
- * helper to solve this problem.  It starts writeout of the truncated
- * part in case it is in the committing transaction.
- *
- * Filesystem code must call this function when inode is journaled in
- * ordered mode before truncation happens and after the inode has been
- * placed on orphan list with the new inode size. The second condition
- * avoids the race that someone writes new data and we start
- * committing the transaction after this function has been called but
- * before a transaction for truncate is started (and furthermore it
- * allows us to optimize the case where the addition to orphan list
- * happens in the same transaction as write --- we don't have to write
- * any data in such case).
- */
-int jbd2_journal_begin_ordered_truncate(journal_t *journal,
-					struct jbd2_inode *jinode,
-					loff_t new_size)
-{
-	transaction_t *inode_trans, *commit_trans;
-	int ret = 0;
-
-	/* This is a quick check to avoid locking if not necessary */
-	if (!jinode->i_transaction)
-		goto out;
-	/* Locks are here just to force reading of recent values, it is
-	 * enough that the transaction was not committing before we started
-	 * a transaction adding the inode to orphan list */
-	read_lock(&journal->j_state_lock);
-	commit_trans = journal->j_committing_transaction;
-	read_unlock(&journal->j_state_lock);
-	spin_lock(&journal->j_list_lock);
-	inode_trans = jinode->i_transaction;
-	spin_unlock(&journal->j_list_lock);
-	if (inode_trans == commit_trans) {
-		ret = filemap_fdatawrite_range(jinode->i_vfs_inode->i_mapping,
-			new_size, LLONG_MAX);
-		if (ret)
-			jbd2_journal_abort(journal, ret);
-	}
-out:
-	return ret;
-}