feat(disk_balance): support and validate disk migration rpc

include/dsn/dist/replication/replication.codes.h

@@ -158,6 +158,7 @@ MAKE_EVENT_CODE_RPC(RPC_SPLIT_NOTIFY_CATCH_UP, TASK_PRIORITY_COMMON)
 MAKE_EVENT_CODE_RPC(RPC_SPLIT_UPDATE_CHILD_PARTITION_COUNT, TASK_PRIORITY_COMMON)
 MAKE_EVENT_CODE_RPC(RPC_BULK_LOAD, TASK_PRIORITY_COMMON)
 MAKE_EVENT_CODE_RPC(RPC_GROUP_BULK_LOAD, TASK_PRIORITY_COMMON)
+MAKE_EVENT_CODE_RPC(RPC_MIGRATE_REPLICA, TASK_PRIORITY_COMMON)
 MAKE_EVENT_CODE(LPC_REPLICATION_LOW, TASK_PRIORITY_LOW)
 MAKE_EVENT_CODE(LPC_REPLICATION_COMMON, TASK_PRIORITY_COMMON)
 MAKE_EVENT_CODE(LPC_REPLICATION_HIGH, TASK_PRIORITY_HIGH)

include/dsn/dist/replication/replication_enums.h

@@ -107,4 +107,13 @@ ENUM_REG(replication::split_status::PAUSING)
 ENUM_REG(replication::split_status::PAUSED)
 ENUM_REG(replication::split_status::CANCELING)
 ENUM_END2(replication::split_status::type, split_status)
+
+ENUM_BEGIN2(replication::disk_replica_migration_status::type,
+            disk_replica_migration_status,
+            replication::disk_replica_migration_status::IDLE)
+ENUM_REG(replication::disk_replica_migration_status::IDLE)
+ENUM_REG(replication::disk_replica_migration_status::MOVING)
+ENUM_REG(replication::disk_replica_migration_status::MOVED)
+ENUM_REG(replication::disk_replica_migration_status::CLOSED)
+ENUM_END2(replication::disk_replica_migration_status::type, disk_replica_migration_status)
 }

src/common/fs_manager.h

@@ -127,6 +127,7 @@ class fs_manager
     perf_counter_wrapper _counter_max_available_ratio;
 
     friend class replica_stub;
+    friend class replica;
     friend class mock_replica_stub;
     friend class replica_disk_test;
 };