HBASE-22922 Lock all regions to be merged in case of multi region merge (#542)

* HBASE-22922 Lock all regions to be merged in case of multi region merge

* HBASE-22922 Lock all regions to be merged in case of multi region merge
 (addendum)

fix off-by-one error in patch
Signed-off-by: stack <stack@apache.org>

Author: stoty

hbase-server/src/main/java/org/apache/hadoop/hbase/master/assignment/MergeTableRegionsProcedure.java

@@ -402,8 +402,10 @@ public void toStringClassDetails(StringBuilder sb) {
 
   @Override
   protected LockState acquireLock(final MasterProcedureEnv env) {
-    if (env.getProcedureScheduler().waitRegions(this, getTableName(),
-        mergedRegion, regionsToMerge[0], regionsToMerge[1])) {
+    RegionInfo[] lockRegions = Arrays.copyOf(regionsToMerge, regionsToMerge.length + 1);
+    lockRegions[lockRegions.length - 1] = mergedRegion;
+
+    if (env.getProcedureScheduler().waitRegions(this, getTableName(), lockRegions)) {
       try {
         LOG.debug(LockState.LOCK_EVENT_WAIT + " " + env.getProcedureScheduler().dumpLocks());
       } catch (IOException e) {
@@ -416,8 +418,10 @@ protected LockState acquireLock(final MasterProcedureEnv env) {
 
   @Override
   protected void releaseLock(final MasterProcedureEnv env) {
-    env.getProcedureScheduler().wakeRegions(this, getTableName(),
-      mergedRegion, regionsToMerge[0], regionsToMerge[1]);
+    RegionInfo[] lockRegions = Arrays.copyOf(regionsToMerge, regionsToMerge.length + 1);
+    lockRegions[lockRegions.length - 1] = mergedRegion;
+
+    env.getProcedureScheduler().wakeRegions(this, getTableName(), lockRegions);
   }
 
   @Override