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>

2 files changed, 11 insertions, 7 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 44d034246723..cfe5c8704a26 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1608,7 +1608,7 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
                 ++ev1;
                 if (rdev->desc_nr >= 0 &&
                     rdev->desc_nr < le32_to_cpu(sb->max_dev) &&
-                    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < 0xfffe)
+                    le16_to_cpu(sb->dev_roles[rdev->desc_nr]) < MD_DISK_ROLE_MAX)
                         if (ev1 < mddev->events)
                                 return -EINVAL;
         } else if (mddev->bitmap) {
@@ -1628,14 +1628,14 @@ static int super_1_validate(struct mddev *mddev, struct md_rdev *rdev)
                 int role;
                 if (rdev->desc_nr < 0 ||
                     rdev->desc_nr >= le32_to_cpu(sb->max_dev)) {
-                        role = 0xffff;
+                        role = MD_DISK_ROLE_SPARE;
                         rdev->desc_nr = -1;
                 } else
                         role = le16_to_cpu(sb->dev_roles[rdev->desc_nr]);
                 switch(role) {
-                case 0xffff: /* spare */
+                case MD_DISK_ROLE_SPARE: /* spare */
                         break;
-                case 0xfffe: /* faulty */
+                case MD_DISK_ROLE_FAULTY: /* faulty */
                         set_bit(Faulty, &rdev->flags);
                         break;
                 default:
@@ -1788,18 +1788,18 @@ retry:
                 max_dev = le32_to_cpu(sb->max_dev);
 
         for (i=0; i<max_dev;i++)
-                sb->dev_roles[i] = cpu_to_le16(0xfffe);
+                sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
 
         rdev_for_each(rdev2, mddev) {
                 i = rdev2->desc_nr;
                 if (test_bit(Faulty, &rdev2->flags))
-                        sb->dev_roles[i] = cpu_to_le16(0xfffe);
+                        sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_FAULTY);
                 else if (test_bit(In_sync, &rdev2->flags))
                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
                 else if (rdev2->raid_disk >= 0)
                         sb->dev_roles[i] = cpu_to_le16(rdev2->raid_disk);
                 else
-                        sb->dev_roles[i] = cpu_to_le16(0xffff);
+                        sb->dev_roles[i] = cpu_to_le16(MD_DISK_ROLE_SPARE);
         }
 
         sb->sb_csum = calc_sb_1_csum(sb);
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                      */