btrfs-progs: raid56: Introduce raid56 header for later recovery usage

Introduce a new header, kernel-lib/raid56.h, for later raid56 works.

It contains 2 functions, from original btrfs-progs code:
void raid6_gen_syndrome(int disks, size_t bytes, void **ptrs);
int raid5_gen_result(int nr_devs, size_t stripe_len, int dest, void **data);

Will be expanded later and some part of it(RAID6 recover part) may keep
sync with kernel later.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[ unify gpl header, rename header macro ]
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/volumes.c b/volumes.c
index 8fc29552..af7e7892 100644
--- a/volumes.c
+++ b/volumes.c
@@ -28,6 +28,7 @@
 #include "print-tree.h"
 #include "volumes.h"
 #include "utils.h"
+#include "kernel-lib/raid56.h"
 
 struct stripe {
 	struct btrfs_device *dev;