[PATCH] md: merge raid5 and raid6 code

There is a lot of commonality between raid5.c and raid6main.c.  This patches
merges both into one module called raid456.  This saves a lot of code, and
paves the way for online raid5->raid6 migrations.

There is still duplication, e.g.  between handle_stripe5 and handle_stripe6.
This will probably be cleaned up later.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index d3efedf..34957a6 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -8,7 +8,7 @@
 dm-snapshot-objs := dm-snap.o dm-exception-store.o
 dm-mirror-objs	:= dm-log.o dm-raid1.o
 md-mod-objs     := md.o bitmap.o
-raid6-objs	:= raid6main.o raid6algos.o raid6recov.o raid6tables.o \
+raid456-objs	:= raid5.o raid6algos.o raid6recov.o raid6tables.o \
 		   raid6int1.o raid6int2.o raid6int4.o \
 		   raid6int8.o raid6int16.o raid6int32.o \
 		   raid6altivec1.o raid6altivec2.o raid6altivec4.o \
@@ -25,8 +25,7 @@
 obj-$(CONFIG_MD_RAID0)		+= raid0.o
 obj-$(CONFIG_MD_RAID1)		+= raid1.o
 obj-$(CONFIG_MD_RAID10)		+= raid10.o
-obj-$(CONFIG_MD_RAID5)		+= raid5.o xor.o
-obj-$(CONFIG_MD_RAID6)		+= raid6.o xor.o
+obj-$(CONFIG_MD_RAID456)	+= raid456.o xor.o
 obj-$(CONFIG_MD_MULTIPATH)	+= multipath.o
 obj-$(CONFIG_MD_FAULTY)		+= faulty.o
 obj-$(CONFIG_BLK_DEV_MD)	+= md-mod.o