ocfs2: Switch over to JBD2.

ocfs2 wants JBD2 for many reasons, not the least of which is that JBD is
limiting our maximum filesystem size.

It's a pretty trivial change.  Most functions are just renamed.  The
only functional change is moving to Jan's inode-based ordered data mode.
It's better, too.

Because JBD2 reads and writes JBD journals, this is compatible with any
existing filesystem.  It can even interact with JBD-based ocfs2 as long
as the journal is formated for JBD.

We provide a compatibility option so that paranoid people can still use
JBD for the time being.  This will go away shortly.

[ Moved call of ocfs2_begin_ordered_truncate() from ocfs2_delete_inode() to
  ocfs2_truncate_for_delete(). --Mark ]

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
diff --git a/fs/Kconfig b/fs/Kconfig
index f54a157..4be00d8 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -220,17 +220,16 @@
 	tristate
 	help
 	  This is a generic journalling layer for block devices.  It is
-	  currently used by the ext3 and OCFS2 file systems, but it could
-	  also be used to add journal support to other file systems or block
+	  currently used by the ext3 file system, 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 the ext3 or OCFS2 file systems, you need to
-	  say Y here. If you are not using ext3 OCFS2 then you will probably
-	  want to say N.
+	  If you are using the ext3 file system, you need to say Y here.
+	  If you are not using ext3 then you will probably want to say N.
 
 	  To compile this device as a module, choose M here: the module will be
-	  called jbd.  If you are compiling ext3 or OCFS2 into the kernel,
-	  you cannot compile this code as a module.
+	  called jbd.  If you are compiling ext3 into the kernel, you
+	  cannot compile this code as a module.
 
 config JBD_DEBUG
 	bool "JBD (ext3) debugging support"
@@ -254,15 +253,16 @@
 	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 filesystem, but it could also be used to add
+	  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, you need to say Y here. If you are not
-	  using ext4 then you will probably want to say N.
+	  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 into the kernel,
+	  called jbd2.  If you are compiling ext4 or OCFS2 into the kernel,
 	  you cannot compile this code as a module.
 
 config JBD2_DEBUG
@@ -440,7 +440,7 @@
 	tristate "OCFS2 file system support"
 	depends on NET && SYSFS
 	select CONFIGFS_FS
-	select JBD
+	select JBD2
 	select CRC32
 	help
 	  OCFS2 is a general purpose extent based shared disk cluster file
@@ -511,6 +511,16 @@
 	  this option for debugging only as it is likely to decrease
 	  performance of the filesystem.
 
+config OCFS2_COMPAT_JBD
+	bool "Use JBD for compatibility"
+	depends on OCFS2_FS
+	default n
+	select JBD
+	help
+	  The ocfs2 filesystem now uses JBD2 for its journalling.  JBD2
+	  is backwards compatible with JBD.  It is safe to say N here.
+	  However, if you really want to use the original JBD, say Y here.
+
 endif # BLOCK
 
 config DNOTIFY