clustermd_tests: add test case to test manage_re-add against cluster-raid1

02r1_Manage_re-add:
2 active disk in array, set 1 disk 'fail' and 'remove' it from array,
then re-add the disk back to array and triggers recovery.

Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

clustermd_tests/02r1_Manage_re-add

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+mdadm -CR $md0 -l1 -b clustered -n2 $dev0 $dev1 --assume-clean
+ssh $NODE2 mdadm -A $md0 $dev0 $dev1
+check all nosync
+check all raid1
+check all bitmap
+check all state UU
+check all dmesg
+mdadm --manage $md0 --fail $dev0 --remove $dev0
+mdadm --manage $md0 --re-add $dev0
+check $NODE1 recovery
+check all wait
+check all state UU
+check all dmesg
+stop_md all $md0
+
+exit 0