ext4: Allow ext4 to run without a journal

A few weeks ago I posted a patch for discussion that allowed ext4 to run
without a journal.  Since that time I've integrated the excellent
comments from Andreas and fixed several serious bugs.  We're currently
running with this patch and generating some performance numbers against
both ext2 (with backported reservations code) and ext4 with and without
a journal.  It just so happens that running without a journal is
slightly faster for most everything.

We did
	iozone -T -t 4 s 2g -r 256k -T -I -i0 -i1 -i2

which creates 4 threads, each of which create and do reads and writes on
a 2G file, with a buffer size of 256K, using O_DIRECT for all file opens
to bypass the page cache.  Results:

                     ext2        ext4, default   ext4, no journal
  initial writes   13.0 MB/s        15.4 MB/s          15.7 MB/s
  rewrites         13.1 MB/s        15.6 MB/s          15.9 MB/s
  reads            15.2 MB/s        16.9 MB/s          17.2 MB/s
  re-reads         15.3 MB/s        16.9 MB/s          17.2 MB/s
  random readers    5.6 MB/s         5.6 MB/s           5.7 MB/s
  random writers    5.1 MB/s         5.3 MB/s           5.4 MB/s 

So it seems that, so far, this was a useful exercise.

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

13 files changed, 452 insertions, 224 deletions

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 35f5f9a2772..31ebeb5e7b0 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -531,11 +531,11 @@ do_more:
 
 	/* We dirtied the bitmap block */
 	BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
-	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 
 	/* And the group descriptor block */
 	BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
-	ret = ext4_journal_dirty_metadata(handle, gd_bh);
+	ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
 	if (!err) err = ret;
 	*pdquot_freed_blocks += group_freed;
 
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c
index c75384b34f2..ad13a84644e 100644
--- a/fs/ext4/ext4_jbd2.c
+++ b/fs/ext4/ext4_jbd2.c
@@ -7,53 +7,96 @@
 int __ext4_journal_get_undo_access(const char *where, handle_t *handle,
 				struct buffer_head *bh)
 {
-	int err = jbd2_journal_get_undo_access(handle, bh);
-	if (err)
-		ext4_journal_abort_handle(where, __func__, bh, handle, err);
+	int err = 0;
+
+	if (ext4_handle_valid(handle)) {
+		err = jbd2_journal_get_undo_access(handle, bh);
+		if (err)
+			ext4_journal_abort_handle(where, __func__, bh,
+						  handle, err);
+	}
 	return err;
 }
 
 int __ext4_journal_get_write_access(const char *where, handle_t *handle,
 				struct buffer_head *bh)
 {
-	int err = jbd2_journal_get_write_access(handle, bh);
-	if (err)
-		ext4_journal_abort_handle(where, __func__, bh, handle, err);
+	int err = 0;
+
+	if (ext4_handle_valid(handle)) {
+		err = jbd2_journal_get_write_access(handle, bh);
+		if (err)
+			ext4_journal_abort_handle(where, __func__, bh,
+						  handle, err);
+	}
 	return err;
 }
 
 int __ext4_journal_forget(const char *where, handle_t *handle,
 				struct buffer_head *bh)
 {
-	int err = jbd2_journal_forget(handle, bh);
-	if (err)
-		ext4_journal_abort_handle(where, __func__, bh, handle, err);
+	int err = 0;
+
+	if (ext4_handle_valid(handle)) {
+		err = jbd2_journal_forget(handle, bh);
+		if (err)
+			ext4_journal_abort_handle(where, __func__, bh,
+						  handle, err);
+	}
 	return err;
 }
 
 int __ext4_journal_revoke(const char *where, handle_t *handle,
 				ext4_fsblk_t blocknr, struct buffer_head *bh)
 {
-	int err = jbd2_journal_revoke(handle, blocknr, bh);
-	if (err)
-		ext4_journal_abort_handle(where, __func__, bh, handle, err);
+	int err = 0;
+
+	if (ext4_handle_valid(handle)) {
+		err = jbd2_journal_revoke(handle, blocknr, bh);
+		if (err)
+			ext4_journal_abort_handle(where, __func__, bh,
+						  handle, err);
+	}
 	return err;
 }
 
 int __ext4_journal_get_create_access(const char *where,
 				handle_t *handle, struct buffer_head *bh)
 {
-	int err = jbd2_journal_get_create_access(handle, bh);
-	if (err)
-		ext4_journal_abort_handle(where, __func__, bh, handle, err);
+	int err = 0;
+
+	if (ext4_handle_valid(handle)) {
+		err = jbd2_journal_get_create_access(handle, bh);
+		if (err)
+			ext4_journal_abort_handle(where, __func__, bh,
+						  handle, err);
+	}
 	return err;
 }
 
-int __ext4_journal_dirty_metadata(const char *where,
-				handle_t *handle, struct buffer_head *bh)
+int __ext4_handle_dirty_metadata(const char *where, handle_t *handle,
+				 struct inode *inode, struct buffer_head *bh)
 {
-	int err = jbd2_journal_dirty_metadata(handle, bh);
-	if (err)
-		ext4_journal_abort_handle(where, __func__, bh, handle, err);
+	int err = 0;
+
+	if (ext4_handle_valid(handle)) {
+		err = jbd2_journal_dirty_metadata(handle, bh);
+		if (err)
+			ext4_journal_abort_handle(where, __func__, bh,
+						  handle, err);
+	} else {
+		mark_buffer_dirty(bh);
+		if (inode && inode_needs_sync(inode)) {
+			sync_dirty_buffer(bh);
+			if (buffer_req(bh) && !buffer_uptodate(bh)) {
+				ext4_error(inode->i_sb, __func__,
+					   "IO error syncing inode, "
+					   "inode=%lu, block=%llu",
+					   inode->i_ino,
+					   (unsigned long long) bh->b_blocknr);
+				err = -EIO;
+			}
+		}
+	}
 	return err;
 }
diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h
index b455c685a98..663197adae5 100644
--- a/fs/ext4/ext4_jbd2.h
+++ b/fs/ext4/ext4_jbd2.h
@@ -122,12 +122,6 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode);
  * been done yet.
  */
 
-static inline void ext4_journal_release_buffer(handle_t *handle,
-						struct buffer_head *bh)
-{
-	jbd2_journal_release_buffer(handle, bh);
-}
-
 void ext4_journal_abort_handle(const char *caller, const char *err_fn,
 		struct buffer_head *bh, handle_t *handle, int err);
 
@@ -146,8 +140,8 @@ int __ext4_journal_revoke(const char *where, handle_t *handle,
 int __ext4_journal_get_create_access(const char *where,
 				handle_t *handle, struct buffer_head *bh);
 
-int __ext4_journal_dirty_metadata(const char *where,
-				handle_t *handle, struct buffer_head *bh);
+int __ext4_handle_dirty_metadata(const char *where, handle_t *handle,
+				 struct inode *inode, struct buffer_head *bh);
 
 #define ext4_journal_get_undo_access(handle, bh) \
 	__ext4_journal_get_undo_access(__func__, (handle), (bh))
@@ -157,14 +151,57 @@ int __ext4_journal_dirty_metadata(const char *where,
 	__ext4_journal_revoke(__func__, (handle), (blocknr), (bh))
 #define ext4_journal_get_create_access(handle, bh) \
 	__ext4_journal_get_create_access(__func__, (handle), (bh))
-#define ext4_journal_dirty_metadata(handle, bh) \
-	__ext4_journal_dirty_metadata(__func__, (handle), (bh))
 #define ext4_journal_forget(handle, bh) \
 	__ext4_journal_forget(__func__, (handle), (bh))
+#define ext4_handle_dirty_metadata(handle, inode, bh) \
+	__ext4_handle_dirty_metadata(__func__, (handle), (inode), (bh))
 
 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);
 int __ext4_journal_stop(const char *where, handle_t *handle);
 
+#define EXT4_NOJOURNAL_HANDLE	((handle_t *) 0x1)
+
+static inline int ext4_handle_valid(handle_t *handle)
+{
+	if (handle == EXT4_NOJOURNAL_HANDLE)
+		return 0;
+	return 1;
+}
+
+static inline void ext4_handle_sync(handle_t *handle)
+{
+	if (ext4_handle_valid(handle))
+		handle->h_sync = 1;
+}
+
+static inline void ext4_handle_release_buffer(handle_t *handle,
+						struct buffer_head *bh)
+{
+	if (ext4_handle_valid(handle))
+		jbd2_journal_release_buffer(handle, bh);
+}
+
+static inline int ext4_handle_is_aborted(handle_t *handle)
+{
+	if (ext4_handle_valid(handle))
+		return is_handle_aborted(handle);
+	return 0;
+}
+
+static inline int ext4_handle_has_enough_credits(handle_t *handle, int needed)
+{
+	if (ext4_handle_valid(handle) && handle->h_buffer_credits < needed)
+		return 0;
+	return 1;
+}
+
+static inline void ext4_journal_release_buffer(handle_t *handle,
+						struct buffer_head *bh)
+{
+	if (ext4_handle_valid(handle))
+		jbd2_journal_release_buffer(handle, bh);
+}
+
 static inline handle_t *ext4_journal_start(struct inode *inode, int nblocks)
 {
 	return ext4_journal_start_sb(inode->i_sb, nblocks);
@@ -180,27 +217,37 @@ static inline handle_t *ext4_journal_current_handle(void)
 
 static inline int ext4_journal_extend(handle_t *handle, int nblocks)
 {
-	return jbd2_journal_extend(handle, nblocks);
+	if (ext4_handle_valid(handle))
+		return jbd2_journal_extend(handle, nblocks);
+	return 0;
 }
 
 static inline int ext4_journal_restart(handle_t *handle, int nblocks)
 {
-	return jbd2_journal_restart(handle, nblocks);
+	if (ext4_handle_valid(handle))
+		return jbd2_journal_restart(handle, nblocks);
+	return 0;
 }
 
 static inline int ext4_journal_blocks_per_page(struct inode *inode)
 {
-	return jbd2_journal_blocks_per_page(inode);
+	if (EXT4_JOURNAL(inode) != NULL)
+		return jbd2_journal_blocks_per_page(inode);
+	return 0;
 }
 
 static inline int ext4_journal_force_commit(journal_t *journal)
 {
-	return jbd2_journal_force_commit(journal);
+	if (journal)
+		return jbd2_journal_force_commit(journal);
+	return 0;
 }
 
 static inline int ext4_jbd2_file_inode(handle_t *handle, struct inode *inode)
 {
-	return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
+	if (ext4_handle_valid(handle))
+		return jbd2_journal_file_inode(handle, &EXT4_I(inode)->jinode);
+	return 0;
 }
 
 /* super.c */
@@ -208,6 +255,8 @@ int ext4_force_commit(struct super_block *sb);
 
 static inline int ext4_should_journal_data(struct inode *inode)
 {
+	if (EXT4_JOURNAL(inode) == NULL)
+		return 0;
 	if (!S_ISREG(inode->i_mode))
 		return 1;
 	if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
@@ -219,6 +268,8 @@ static inline int ext4_should_journal_data(struct inode *inode)
 
 static inline int ext4_should_order_data(struct inode *inode)
 {
+	if (EXT4_JOURNAL(inode) == NULL)
+		return 0;
 	if (!S_ISREG(inode->i_mode))
 		return 0;
 	if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
@@ -230,6 +281,8 @@ static inline int ext4_should_order_data(struct inode *inode)
 
 static inline int ext4_should_writeback_data(struct inode *inode)
 {
+	if (EXT4_JOURNAL(inode) == NULL)
+		return 0;
 	if (!S_ISREG(inode->i_mode))
 		return 0;
 	if (EXT4_I(inode)->i_flags & EXT4_JOURNAL_DATA_FL)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 0917be51f10..743e3feb3e5 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -97,6 +97,8 @@ static int ext4_ext_journal_restart(handle_t *handle, int needed)
 {
 	int err;
 
+	if (!ext4_handle_valid(handle))
+		return 0;
 	if (handle->h_buffer_credits > needed)
 		return 0;
 	err = ext4_journal_extend(handle, needed);
@@ -134,7 +136,7 @@ static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
 	int err;
 	if (path->p_bh) {
 		/* path points to block */
-		err = ext4_journal_dirty_metadata(handle, path->p_bh);
+		err = ext4_handle_dirty_metadata(handle, inode, path->p_bh);
 	} else {
 		/* path points to leaf/index in inode body */
 		err = ext4_mark_inode_dirty(handle, inode);
@@ -780,7 +782,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 
-	err = ext4_journal_dirty_metadata(handle, bh);
+	err = ext4_handle_dirty_metadata(handle, inode, bh);
 	if (err)
 		goto cleanup;
 	brelse(bh);
@@ -859,7 +861,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		set_buffer_uptodate(bh);
 		unlock_buffer(bh);
 
-		err = ext4_journal_dirty_metadata(handle, bh);
+		err = ext4_handle_dirty_metadata(handle, inode, bh);
 		if (err)
 			goto cleanup;
 		brelse(bh);
@@ -955,7 +957,7 @@ static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
 	set_buffer_uptodate(bh);
 	unlock_buffer(bh);
 
-	err = ext4_journal_dirty_metadata(handle, bh);
+	err = ext4_handle_dirty_metadata(handle, inode, bh);
 	if (err)
 		goto out;
 
@@ -2947,7 +2949,7 @@ void ext4_ext_truncate(struct inode *inode)
 	 * transaction synchronous.
 	 */
 	if (IS_SYNC(inode))
-		handle->h_sync = 1;
+		ext4_handle_sync(handle);
 
 out_stop:
 	up_write(&EXT4_I(inode)->i_data_sem);
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 6e6052879aa..9dd21b75f4b 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -253,12 +253,12 @@ void ext4_free_inode(handle_t *handle, struct inode *inode)
 				spin_unlock(sb_bgl_lock(sbi, flex_group));
 			}
 		}
-		BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
-		err = ext4_journal_dirty_metadata(handle, bh2);
+		BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
+		err = ext4_handle_dirty_metadata(handle, NULL, bh2);
 		if (!fatal) fatal = err;
 	}
-	BUFFER_TRACE(bitmap_bh, "call ext4_journal_dirty_metadata");
-	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+	BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 	if (!fatal)
 		fatal = err;
 	sb->s_dirt = 1;
@@ -656,15 +656,16 @@ repeat_in_this_group:
 						ino, bitmap_bh->b_data)) {
 				/* we won it */
 				BUFFER_TRACE(bitmap_bh,
-					"call ext4_journal_dirty_metadata");
-				err = ext4_journal_dirty_metadata(handle,
+					"call ext4_handle_dirty_metadata");
+				err = ext4_handle_dirty_metadata(handle,
+								inode,
 								bitmap_bh);
 				if (err)
 					goto fail;
 				goto got;
 			}
 			/* we lost it */
-			jbd2_journal_release_buffer(handle, bitmap_bh);
+			ext4_handle_release_buffer(handle, bitmap_bh);
 
 			if (++ino < EXT4_INODES_PER_GROUP(sb))
 				goto repeat_in_this_group;
@@ -726,7 +727,8 @@ got:
 		/* Don't need to dirty bitmap block if we didn't change it */
 		if (free) {
 			BUFFER_TRACE(block_bh, "dirty block bitmap");
-			err = ext4_journal_dirty_metadata(handle, block_bh);
+			err = ext4_handle_dirty_metadata(handle,
+							NULL, block_bh);
 		}
 
 		brelse(block_bh);
@@ -771,8 +773,8 @@ got:
 	}
 	gdp->bg_checksum = ext4_group_desc_csum(sbi, group, gdp);
 	spin_unlock(sb_bgl_lock(sbi, group));
-	BUFFER_TRACE(bh2, "call ext4_journal_dirty_metadata");
-	err = ext4_journal_dirty_metadata(handle, bh2);
+	BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_metadata(handle, NULL, bh2);
 	if (err) goto fail;
 
 	percpu_counter_dec(&sbi->s_freeinodes_counter);
@@ -825,7 +827,7 @@ got:
 
 	ext4_set_inode_flags(inode);
 	if (IS_DIRSYNC(inode))
-		handle->h_sync = 1;
+		ext4_handle_sync(handle);
 	if (insert_inode_locked(inode) < 0) {
 		err = -EINVAL;
 		goto fail_drop;
@@ -1028,4 +1030,3 @@ unsigned long ext4_count_dirs(struct super_block * sb)
 	}
 	return count;
 }
-
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c77a7ac753f..45d0f70a1f0 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -72,12 +72,17 @@ static int ext4_inode_is_fast_symlink(struct inode *inode)
  * "bh" may be NULL: a metadata block may have been freed from memory
  * but there may still be a record of it in the journal, and that record
  * still needs to be revoked.
+ *
+ * If the handle isn't valid we're not journaling so there's nothing to do.
  */
 int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
 			struct buffer_head *bh, ext4_fsblk_t blocknr)
 {
 	int err;
 
+	if (!ext4_handle_valid(handle))
+		return 0;
+
 	might_sleep();
 
 	BUFFER_TRACE(bh, "enter");
@@ -170,7 +175,9 @@ static handle_t *start_transaction(struct inode *inode)
  */
 static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
 {
-	if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS)
+	if (!ext4_handle_valid(handle))
+		return 0;
+	if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
 		return 0;
 	if (!ext4_journal_extend(handle, blocks_for_truncate(inode)))
 		return 0;
@@ -184,6 +191,7 @@ static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
  */
 static int ext4_journal_test_restart(handle_t *handle, struct inode *inode)
 {
+	BUG_ON(EXT4_JOURNAL(inode) == NULL);
 	jbd_debug(2, "restarting handle %p\n", handle);
 	return ext4_journal_restart(handle, blocks_for_truncate(inode));
 }
@@ -216,7 +224,7 @@ void ext4_delete_inode(struct inode *inode)
 	}
 
 	if (IS_SYNC(inode))
-		handle->h_sync = 1;
+		ext4_handle_sync(handle);
 	inode->i_size = 0;
 	err = ext4_mark_inode_dirty(handle, inode);
 	if (err) {
@@ -233,7 +241,7 @@ void ext4_delete_inode(struct inode *inode)
 	 * enough credits left in the handle to remove the inode from
 	 * the orphan list and set the dtime field.
 	 */
-	if (handle->h_buffer_credits < 3) {
+	if (!ext4_handle_has_enough_credits(handle, 3)) {
 		err = ext4_journal_extend(handle, 3);
 		if (err > 0)
 			err = ext4_journal_restart(handle, 3);
@@ -717,8 +725,8 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
 		set_buffer_uptodate(bh);
 		unlock_buffer(bh);
 
-		BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-		err = ext4_journal_dirty_metadata(handle, bh);
+		BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+		err = ext4_handle_dirty_metadata(handle, inode, bh);
 		if (err)
 			goto failed;
 	}
@@ -800,8 +808,8 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
 		 * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
 		 */
 		jbd_debug(5, "splicing indirect only\n");
-		BUFFER_TRACE(where->bh, "call ext4_journal_dirty_metadata");
-		err = ext4_journal_dirty_metadata(handle, where->bh);
+		BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
+		err = ext4_handle_dirty_metadata(handle, inode, where->bh);
 		if (err)
 			goto err_out;
 	} else {
@@ -1229,8 +1237,8 @@ struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
 				set_buffer_uptodate(bh);
 			}
 			unlock_buffer(bh);
-			BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-			err = ext4_journal_dirty_metadata(handle, bh);
+			BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+			err = ext4_handle_dirty_metadata(handle, inode, bh);
 			if (!fatal)
 				fatal = err;
 		} else {
@@ -1395,7 +1403,7 @@ static int write_end_fn(handle_t *handle, struct buffer_head *bh)
 	if (!buffer_mapped(bh) || buffer_freed(bh))
 		return 0;
 	set_buffer_uptodate(bh);
-	return ext4_journal_dirty_metadata(handle, bh);
+	return ext4_handle_dirty_metadata(handle, NULL, bh);
 }
 
 /*
@@ -2762,7 +2770,10 @@ static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
 		filemap_write_and_wait(mapping);
 	}
 
-	if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
+	BUG_ON(!EXT4_JOURNAL(inode) &&
+	       EXT4_I(inode)->i_state & EXT4_STATE_JDATA);
+
+	if (EXT4_JOURNAL(inode) && EXT4_I(inode)->i_state & EXT4_STATE_JDATA) {
 		/*
 		 * This is a REALLY heavyweight approach, but the use of
 		 * bmap on dirty files is expected to be extremely rare:
@@ -3033,7 +3044,10 @@ static void ext4_invalidatepage(struct page *page, unsigned long offset)
 	if (offset == 0)
 		ClearPageChecked(page);
 
-	jbd2_journal_invalidatepage(journal, page, offset);
+	if (journal)
+		jbd2_journal_invalidatepage(journal, page, offset);
+	else
+		block_invalidatepage(page, offset);
 }
 
 static int ext4_releasepage(struct page *page, gfp_t wait)
@@ -3043,7 +3057,10 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
 	WARN_ON(PageChecked(page));
 	if (!page_has_buffers(page))
 		return 0;
-	return jbd2_journal_try_to_free_buffers(journal, page, wait);
+	if (journal)
+		return jbd2_journal_try_to_free_buffers(journal, page, wait);
+	else
+		return try_to_free_buffers(page);
 }
 
 /*
@@ -3315,7 +3332,7 @@ int ext4_block_truncate_page(handle_t *handle,
 
 	err = 0;
 	if (ext4_should_journal_data(inode)) {
-		err = ext4_journal_dirty_metadata(handle, bh);
+		err = ext4_handle_dirty_metadata(handle, inode, bh);
 	} else {
 		if (ext4_should_order_data(inode))
 			err = ext4_jbd2_file_inode(handle, inode);
@@ -3439,8 +3456,8 @@ static void ext4_clear_blocks(handle_t *handle, struct inode *inode,
 	__le32 *p;
 	if (try_to_extend_transaction(handle, inode)) {
 		if (bh) {
-			BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-			ext4_journal_dirty_metadata(handle, bh);
+			BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+			ext4_handle_dirty_metadata(handle, inode, bh);
 		}
 		ext4_mark_inode_dirty(handle, inode);
 		ext4_journal_test_restart(handle, inode);
@@ -3540,7 +3557,7 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
 				  count, block_to_free_p, p);
 
 	if (this_bh) {
-		BUFFER_TRACE(this_bh, "call ext4_journal_dirty_metadata");
+		BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
 
 		/*
 		 * The buffer head should have an attached journal head at this
@@ -3549,7 +3566,7 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
 		 * the block was cleared. Check for this instead of OOPSing.
 		 */
 		if (bh2jh(this_bh))
-			ext4_journal_dirty_metadata(handle, this_bh);
+			ext4_handle_dirty_metadata(handle, inode, this_bh);
 		else
 			ext4_error(inode->i_sb, __func__,
 				   "circular indirect block detected, "
@@ -3579,7 +3596,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 	ext4_fsblk_t nr;
 	__le32 *p;
 
-	if (is_handle_aborted(handle))
+	if (ext4_handle_is_aborted(handle))
 		return;
 
 	if (depth--) {
@@ -3649,7 +3666,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 			 * will merely complain about releasing a free block,
 			 * rather than leaking blocks.
 			 */
-			if (is_handle_aborted(handle))
+			if (ext4_handle_is_aborted(handle))
 				return;
 			if (try_to_extend_transaction(handle, inode)) {
 				ext4_mark_inode_dirty(handle, inode);
@@ -3668,9 +3685,10 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 								   parent_bh)){
 					*p = 0;
 					BUFFER_TRACE(parent_bh,
-					"call ext4_journal_dirty_metadata");
-					ext4_journal_dirty_metadata(handle,
-								    parent_bh);
+					"call ext4_handle_dirty_metadata");
+					ext4_handle_dirty_metadata(handle,
+								   inode,
+								   parent_bh);
 				}
 			}
 		}
@@ -3858,7 +3876,7 @@ do_indirects:
 	 * synchronous
 	 */
 	if (IS_SYNC(inode))
-		handle->h_sync = 1;
+		ext4_handle_sync(handle);
 out_stop:
 	/*
 	 * If this was a simple ftruncate(), and the file will remain alive
@@ -4357,8 +4375,8 @@ static int ext4_do_update_inode(handle_t *handle,
 			EXT4_SET_RO_COMPAT_FEATURE(sb,
 					EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
 			sb->s_dirt = 1;
-			handle->h_sync = 1;
-			err = ext4_journal_dirty_metadata(handle,
+			ext4_handle_sync(handle);
+			err = ext4_handle_dirty_metadata(handle, inode,
 					EXT4_SB(sb)->s_sbh);
 		}
 	}
@@ -4385,9 +4403,8 @@ static int ext4_do_update_inode(handle_t *handle,
 		raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
 	}
 
-
-	BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-	rc = ext4_journal_dirty_metadata(handle, bh);
+	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+	rc = ext4_handle_dirty_metadata(handle, inode, bh);
 	if (!err)
 		err = rc;
 	ei->i_state &= ~EXT4_STATE_NEW;
@@ -4450,6 +4467,25 @@ int ext4_write_inode(struct inode *inode, int wait)
 	return ext4_force_commit(inode->i_sb);
 }
 
+int __ext4_write_dirty_metadata(struct inode *inode, struct buffer_head *bh)
+{
+	int err = 0;
+
+	mark_buffer_dirty(bh);
+	if (inode && inode_needs_sync(inode)) {
+		sync_dirty_buffer(bh);
+		if (buffer_req(bh) && !buffer_uptodate(bh)) {
+			ext4_error(inode->i_sb, __func__,
+				   "IO error syncing inode, "
+				   "inode=%lu, block=%llu",
+				   inode->i_ino,
+				   (unsigned long long)bh->b_blocknr);
+			err = -EIO;
+		}
+	}
+	return err;
+}
+
 /*
  * ext4_setattr()
  *
@@ -4754,16 +4790,15 @@ int
 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
 			 struct ext4_iloc *iloc)
 {
-	int err = 0;
-	if (handle) {
-		err = ext4_get_inode_loc(inode, iloc);
-		if (!err) {
-			BUFFER_TRACE(iloc->bh, "get_write_access");
-			err = ext4_journal_get_write_access(handle, iloc->bh);
-			if (err) {
-				brelse(iloc->bh);
-				iloc->bh = NULL;
-			}
+	int err;
+
+	err = ext4_get_inode_loc(inode, iloc);
+	if (!err) {
+		BUFFER_TRACE(iloc->bh, "get_write_access");
+		err = ext4_journal_get_write_access(handle, iloc->bh);
+		if (err) {
+			brelse(iloc->bh);
+			iloc->bh = NULL;
 		}
 	}
 	ext4_std_error(inode->i_sb, err);
@@ -4835,7 +4870,8 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
 
 	might_sleep();
 	err = ext4_reserve_inode_write(handle, inode, &iloc);
-	if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
+	if (ext4_handle_valid(handle) &&
+	    EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
 	    !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) {
 		/*
 		 * We need extra buffer credits since we may write into EA block
@@ -4887,6 +4923,11 @@ void ext4_dirty_inode(struct inode *inode)
 	handle_t *current_handle = ext4_journal_current_handle();
 	handle_t *handle;
 
+	if (!ext4_handle_valid(current_handle)) {
+		ext4_mark_inode_dirty(current_handle, inode);
+		return;
+	}
+
 	handle = ext4_journal_start(inode, 2);
 	if (IS_ERR(handle))
 		goto out;
@@ -4924,8 +4965,9 @@ static int ext4_pin_inode(handle_t *handle, struct inode *inode)
 			BUFFER_TRACE(iloc.bh, "get_write_access");
 			err = jbd2_journal_get_write_access(handle, iloc.bh);
 			if (!err)
-				err = ext4_journal_dirty_metadata(handle,
-								  iloc.bh);
+				err = ext4_handle_dirty_metadata(handle,
+								 inode,
+								 iloc.bh);
 			brelse(iloc.bh);
 		}
 	}
@@ -4951,6 +4993,8 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 	 */
 
 	journal = EXT4_JOURNAL(inode);
+	if (!journal)
+		return 0;
 	if (is_journal_aborted(journal))
 		return -EROFS;
 
@@ -4980,7 +5024,7 @@ int ext4_change_inode_journal_flag(struct inode *inode, int val)
 		return PTR_ERR(handle);
 
 	err = ext4_mark_inode_dirty(handle, inode);
-	handle->h_sync = 1;
+	ext4_handle_sync(handle);
 	ext4_journal_stop(handle);
 	ext4_std_error(inode->i_sb, err);
 
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index dc99b4776d5..42dc83fb247 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -99,7 +99,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			goto flags_out;
 		}
 		if (IS_SYNC(inode))
-			handle->h_sync = 1;
+			ext4_handle_sync(handle);
 		err = ext4_reserve_inode_write(handle, inode, &iloc);
 		if (err)
 			goto flags_err;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 7beab7141dd..edb512b2ec4 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2553,7 +2553,8 @@ int ext4_mb_init(struct super_block *sb, int needs_recovery)
 	ext4_mb_init_per_dev_proc(sb);
 	ext4_mb_history_init(sb);
 
-	sbi->s_journal->j_commit_callback = release_blocks_on_commit;
+	if (sbi->s_journal)
+		sbi->s_journal->j_commit_callback = release_blocks_on_commit;
 
 	printk(KERN_INFO "EXT4-fs: mballoc enabled\n");
 	return 0;
@@ -2854,7 +2855,7 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 		mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group),
 				bitmap_bh->b_data, ac->ac_b_ex.fe_start,
 				ac->ac_b_ex.fe_len);
-		err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+		err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 		if (!err)
 			err = -EAGAIN;
 		goto out_err;
@@ -2901,10 +2902,10 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 		spin_unlock(sb_bgl_lock(sbi, flex_group));
 	}
 
-	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 	if (err)
 		goto out_err;
-	err = ext4_journal_dirty_metadata(handle, gdp_bh);
+	err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);
 
 out_err:
 	sb->s_dirt = 1;
@@ -4414,7 +4415,7 @@ ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
 	struct rb_node **n = &db->bb_free_root.rb_node, *node;
 	struct rb_node *parent = NULL, *new_node;
 
-
+	BUG_ON(!ext4_handle_valid(handle));
 	BUG_ON(e4b->bd_bitmap_page == NULL);
 	BUG_ON(e4b->bd_buddy_page == NULL);
 
@@ -4600,7 +4601,7 @@ do_more:
 
 	/* We dirtied the bitmap block */
 	BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
-	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);
 
 	if (ac) {
 		ac->ac_b_ex.fe_group = block_group;
@@ -4609,7 +4610,7 @@ do_more:
 		ext4_mb_store_history(ac);
 	}
 
-	if (metadata) {
+	if (metadata && ext4_handle_valid(handle)) {
 		/* blocks being freed are metadata. these blocks shouldn't
 		 * be used until this transaction is committed */
 		ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
@@ -4639,7 +4640,7 @@ do_more:
 
 	/* And the group descriptor block */
 	BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
-	ret = ext4_journal_dirty_metadata(handle, gd_bh);
+	ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);
 	if (!err)
 		err = ret;
 
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index f2a9cf498ec..e7cd488da4b 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -59,7 +59,8 @@ static int finish_range(handle_t *handle, struct inode *inode,
 	/*
 	 * Make sure the credit we accumalated is not really high
 	 */
-	if (needed && handle->h_buffer_credits >= EXT4_RESERVE_TRANS_BLOCKS) {
+	if (needed && ext4_handle_has_enough_credits(handle,
+						EXT4_RESERVE_TRANS_BLOCKS)) {
 		retval = ext4_journal_restart(handle, needed);
 		if (retval)
 			goto err_out;
@@ -229,7 +230,7 @@ static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
 {
 	int retval = 0, needed;
 
-	if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS)
+	if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
 		return 0;
 	/*
 	 * We are freeing a blocks. During this we touch
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 84a68ae623c..08873e938ab 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1233,10 +1233,10 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 		de = de2;
 	}
 	dx_insert_block(frame, hash2 + continued, newblock);
-	err = ext4_journal_dirty_metadata(handle, bh2);
+	err = ext4_handle_dirty_metadata(handle, dir, bh2);
 	if (err)
 		goto journal_error;
-	err = ext4_journal_dirty_metadata(handle, frame->bh);
+	err = ext4_handle_dirty_metadata(handle, dir, frame->bh);
 	if (err)
 		goto journal_error;
 	brelse(bh2);
@@ -1340,8 +1340,8 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 	ext4_update_dx_flag(dir);
 	dir->i_version++;
 	ext4_mark_inode_dirty(handle, dir);
-	BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-	err = ext4_journal_dirty_metadata(handle, bh);
+	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+	err = ext4_handle_dirty_metadata(handle, dir, bh);
 	if (err)
 		ext4_std_error(dir->i_sb, err);
 	brelse(bh);
@@ -1581,7 +1581,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			dxtrace(dx_show_index("node", frames[1].entries));
 			dxtrace(dx_show_index("node",
 			       ((struct dx_node *) bh2->b_data)->entries));
-			err = ext4_journal_dirty_metadata(handle, bh2);
+			err = ext4_handle_dirty_metadata(handle, inode, bh2);
 			if (err)
 				goto journal_error;
 			brelse (bh2);
@@ -1607,7 +1607,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			if (err)
 				goto journal_error;
 		}
-		ext4_journal_dirty_metadata(handle, frames[0].bh);
+		ext4_handle_dirty_metadata(handle, inode, frames[0].bh);
 	}
 	de = do_split(handle, dir, &bh, frame, &hinfo, &err);
 	if (!de)
@@ -1653,8 +1653,8 @@ static int ext4_delete_entry(handle_t *handle,
 			else
 				de->inode = 0;
 			dir->i_version++;
-			BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
-			ext4_journal_dirty_metadata(handle, bh);
+			BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
+			ext4_handle_dirty_metadata(handle, dir, bh);
 			return 0;