[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/Kconfig b/drivers/md/Kconfig
index ac25a48..f657aa7 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -104,8 +104,8 @@
If unsure, say Y.
-config MD_RAID5
- tristate "RAID-4/RAID-5 mode"
+config MD_RAID456
+ tristate "RAID-4/RAID-5/RAID-6 mode"
depends on BLK_DEV_MD
---help---
A RAID-5 set of N drives with a capacity of C MB per drive provides
@@ -116,14 +116,22 @@
while a RAID-5 set distributes the parity across the drives in one
of the available parity distribution methods.
+ A RAID-6 set of N drives with a capacity of C MB per drive
+ provides the capacity of C * (N - 2) MB, and protects
+ against a failure of any two drives. For a given sector
+ (row) number, (N - 2) drives contain data sectors, and two
+ drives contains two independent redundancy syndromes. Like
+ RAID-5, RAID-6 distributes the syndromes across the drives
+ in one of the available parity distribution methods.
+
Information about Software RAID on Linux is contained in the
Software-RAID mini-HOWTO, available from
<http://www.tldp.org/docs.html#howto>. There you will also
learn where to get the supporting user space utilities raidtools.
- If you want to use such a RAID-4/RAID-5 set, say Y. To
+ If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To
compile this code as a module, choose M here: the module
- will be called raid5.
+ will be called raid456.
If unsure, say Y.
@@ -154,28 +162,6 @@
There should be enough spares already present to make the new
array workable.
-config MD_RAID6
- tristate "RAID-6 mode"
- depends on BLK_DEV_MD
- ---help---
- A RAID-6 set of N drives with a capacity of C MB per drive
- provides the capacity of C * (N - 2) MB, and protects
- against a failure of any two drives. For a given sector
- (row) number, (N - 2) drives contain data sectors, and two
- drives contains two independent redundancy syndromes. Like
- RAID-5, RAID-6 distributes the syndromes across the drives
- in one of the available parity distribution methods.
-
- RAID-6 requires mdadm-1.5.0 or later, available at:
-
- ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/
-
- If you want to use such a RAID-6 set, say Y. To compile
- this code as a module, choose M here: the module will be
- called raid6.
-
- If unsure, say Y.
-
config MD_MULTIPATH
tristate "Multipath I/O support"
depends on BLK_DEV_MD