MD: replace special disk roles with macros

Add the following two macros for special roles: spare and faulty

MD_DISK_ROLE_SPARE	0xffff
MD_DISK_ROLE_FAULTY	0xfffe

Add MD_DISK_ROLE_MAX	0xff00 as the maximal possible regular role,
and minimal value of special role.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: NeilBrown <neilb@suse.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/uapi/linux/raid/md_p.h b/include/uapi/linux/raid/md_p.h
index 867ee874fa80..d1fc8a637368 100644
--- a/include/uapi/linux/raid/md_p.h
+++ b/include/uapi/linux/raid/md_p.h
@@ -90,6 +90,10 @@
                                    * dire need
                                    */
 
+#define MD_DISK_ROLE_SPARE      0xffff
+#define MD_DISK_ROLE_FAULTY     0xfffe
+#define MD_DISK_ROLE_MAX        0xff00 /* max value of regular disk role */
+
 typedef struct mdp_device_descriptor_s {
         __u32 number;           /* 0 Device number in the entire set          */
         __u32 major;            /* 1 Device major number                      */