mdadm/clustermd_tests: add test case to test grow_resize cluster-raid10

01r10_Grow_resize:
1. Create clustered raid10 with smaller size, then resize the
mddev to max size, finally change back to smaller size.
2. Create clustered raid10 with smaller chunk-size, then resize
it to larger, and trigger reshape.

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

clustermd_tests/01r10_Grow_resize

@@ -0,0 +1,38 @@
+#!/bin/bash
+
+size=20000
+
+mdadm -CR $md0 -l10 -b clustered --layout n2 --size $size --chunk=64 -n2 $dev0 $dev1 --assume-clean
+ssh $NODE2 mdadm -A $md0 $dev0 $dev1
+check all nosync
+check all raid10
+check all bitmap
+check all state UU
+
+mdadm --grow $md0 --size max
+check $NODE1 resync
+check $NODE1 wait
+check all state UU
+
+mdadm --grow $md0 --size $size
+check all nosync
+check all state UU
+check all dmesg
+stop_md all $md0
+
+mdadm -CR $md0 -l10 -b clustered --layout n2 --chunk=64 -n2 $dev0 $dev1 --assume-clean
+ssh $NODE2 mdadm -A $md0 $dev0 $dev1
+check all nosync
+check all raid10
+check all bitmap
+check all state UU
+
+mdadm --grow $md0 --chunk=128
+check $NODE1 reshape
+check $NODE1 wait
+check all chunk 128
+check all state UU
+check all dmesg
+stop_md all $md0
+
+exit 0