GFS2: Merge lock_dlm module into GFS2

This is the big patch that I've been working on for some time
now. There are many reasons for wanting to make this change
such as:
 o Reducing overhead by eliminating duplicated fields between structures
 o Simplifcation of the code (reduces the code size by a fair bit)
 o The locking interface is now the DLM interface itself as proposed
   some time ago.
 o Fewer lookups of glocks when processing replies from the DLM
 o Fewer memory allocations/deallocations for each glock
 o Scope to do further optimisations in the future (but this patch is
   more than big enough for now!)

Please note that (a) this patch relates to the lock_dlm module and
not the DLM itself, that is still a separate module; and (b) that
we retain the ability to build GFS2 as a standalone single node
filesystem with out requiring the DLM.

This patch needs a lot of testing, hence my keeping it I restarted
my -git tree after the last merge window. That way, this has the maximum
exposure before its merged. This is (modulo a few minor bug fixes) the
same patch that I've been posting on and off the the last three months
and its passed a number of different tests so far.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/Kconfig

@@ -1,6 +1,10 @@
 config GFS2_FS
 	tristate "GFS2 file system support"
 	depends on EXPERIMENTAL && (64BIT || LBD)
+	select DLM if GFS2_FS_LOCKING_DLM
+	select CONFIGFS_FS if GFS2_FS_LOCKING_DLM
+	select SYSFS if GFS2_FS_LOCKING_DLM
+	select IP_SCTP if DLM_SCTP
 	select FS_POSIX_ACL
 	select CRC32
 	help
@@ -18,17 +22,16 @@ config GFS2_FS
 	  the locking module below. Documentation and utilities for GFS2 can
 	  be found here: http://sources.redhat.com/cluster
 
-	  The "nolock" lock module is now built in to GFS2 by default.
+	  The "nolock" lock module is now built in to GFS2 by default. If
+	  you want to use the DLM, be sure to enable HOTPLUG and IPv4/6
+	  networking.
 
 config GFS2_FS_LOCKING_DLM
-	tristate "GFS2 DLM locking module"
-	depends on GFS2_FS && SYSFS && NET && INET && (IPV6 || IPV6=n)
-	select IP_SCTP if DLM_SCTP
-	select CONFIGFS_FS
-	select DLM
+	bool "GFS2 DLM locking"
+	depends on (GFS2_FS!=n) && NET && INET && (IPV6 || IPV6=n) && HOTPLUG
 	help
 	  Multiple node locking module for GFS2
 
-	  Most users of GFS2 will require this module. It provides the locking
+	  Most users of GFS2 will require this. It provides the locking
 	  interface between GFS2 and the DLM, which is required to use GFS2
 	  in a cluster environment.

fs/gfs2/Makefile

@@ -1,9 +1,9 @@
 obj-$(CONFIG_GFS2_FS) += gfs2.o
 gfs2-y := acl.o bmap.o dir.o eaops.o eattr.o glock.o \
-	glops.o inode.o log.o lops.o locking.o main.o meta_io.o \
+	glops.o inode.o log.o lops.o main.o meta_io.o \
 	mount.o ops_address.o ops_dentry.o ops_export.o ops_file.o \
 	ops_fstype.o ops_inode.o ops_super.o quota.o \
 	recovery.o rgrp.o super.o sys.o trans.o util.o
 
-obj-$(CONFIG_GFS2_FS_LOCKING_DLM) += locking/dlm/
+gfs2-$(CONFIG_GFS2_FS_LOCKING_DLM) += lock_dlm.o
 

fs/gfs2/acl.c

@@ -15,7 +15,6 @@
 #include <linux/posix_acl.h>
 #include <linux/posix_acl_xattr.h>
 #include <linux/gfs2_ondisk.h>
-#include <linux/lm_interface.h>
 
 #include "gfs2.h"
 #include "incore.h"

fs/gfs2/bmap.c

@@ -13,7 +13,6 @@
 #include <linux/buffer_head.h>
 #include <linux/gfs2_ondisk.h>
 #include <linux/crc32.h>
-#include <linux/lm_interface.h>
 
 #include "gfs2.h"
 #include "incore.h"

fs/gfs2/dir.c

@@ -60,7 +60,6 @@
 #include <linux/gfs2_ondisk.h>
 #include <linux/crc32.h>
 #include <linux/vmalloc.h>
-#include <linux/lm_interface.h>
 
 #include "gfs2.h"
 #include "incore.h"

fs/gfs2/eaops.c

@@ -14,7 +14,6 @@
 #include <linux/capability.h>
 #include <linux/xattr.h>
 #include <linux/gfs2_ondisk.h>
-#include <linux/lm_interface.h>
 #include <asm/uaccess.h>
 
 #include "gfs2.h"

fs/gfs2/eattr.c

@@ -13,7 +13,6 @@
 #include <linux/buffer_head.h>
 #include <linux/xattr.h>
 #include <linux/gfs2_ondisk.h>
-#include <linux/lm_interface.h>
 #include <asm/uaccess.h>
 
 #include "gfs2.h"