[HDFS-15505] Fix NullPointerException when call getAdditionalDatanode method with null extendedBlock parameter

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.0.0, 3.1.0, 3.0.1, 3.0.2, 3.2.0, 3.1.1, 3.0.3, 3.1.2, 3.3.0, 3.2.1, 3.1.3
• Component/s: dfsclient
• Target Version/s: 3.3.9
• Assignee: Unassigned
• Reporter: hang chen
• Created: 31/Jul/20 15:05
• Updated: 29/Nov/22 15:51

Description

When client call getAdditionalDatanode method, it will initialize GetAdditionalDatanodeRequestProto and send RPC request to Router/namenode. However, if we call getAdditionalDatanode method with null extendedBlock parameter, it will set GetAdditionalDatanodeRequestProto's blk field with null, which will cause NullPointerException. The code show as follow.

// code placeholder
GetAdditionalDatanodeRequestProto req = GetAdditionalDatanodeRequestProto
 .newBuilder()
 .setSrc(src)
 .setFileId(fileId)
 .setBlk(PBHelperClient.convert(blk))
 .addAllExistings(PBHelperClient.convert(existings))
 .addAllExistingStorageUuids(Arrays.asList(existingStorageIDs))
 .addAllExcludes(PBHelperClient.convert(excludes))
 .setNumAdditionalNodes(numAdditionalNodes)
 .setClientName(clientName)
 .build();