Assemble: add support for replacement devices.

Need to possibly collect 2 devices for each slot, and
original and a replacement.

Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/md_p.h b/md_p.h
index 517b2041..c7c4388b 100644
--- a/md_p.h
+++ b/md_p.h
@@ -84,6 +84,8 @@
 				   * dire need
 				   */
 
+#define MD_DISK_REPLACEMENT	17
+
 typedef struct mdp_device_descriptor_s {
 	__u32 number;		/* 0 Device number in the entire set	      */
 	__u32 major;		/* 1 Device major number		      */