HDFS-11018. Incorrect check and message in FsDatasetImpl#invalidate. Contributed by Yiqun Lin.

(cherry picked from commit 6d2da38d16cebe9b82f1048f87127eecee33664c)

Conflicts:
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java

(cherry picked from commit 6f4192d77d0551b2ca847c8c1ee5b1c4a3380c36)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java

@@ -807,8 +807,14 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
       throws ReplicaNotFoundException {
     ReplicaInfo info = volumeMap.get(b.getBlockPoolId(), b.getLocalBlock());
     if (info == null) {
-      throw new ReplicaNotFoundException(
-          ReplicaNotFoundException.NON_EXISTENT_REPLICA + b);
+      if (volumeMap.get(b.getBlockPoolId(), b.getLocalBlock().getBlockId())
+          == null) {
+        throw new ReplicaNotFoundException(
+            ReplicaNotFoundException.NON_EXISTENT_REPLICA + b);
+      } else {
+        throw new ReplicaNotFoundException(
+            ReplicaNotFoundException.UNEXPECTED_GS_REPLICA + b);
+      }
     }
     return info;
   }
@@ -1994,14 +2000,18 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
       try(AutoCloseableLock lock = datasetLock.acquire()) {
         final ReplicaInfo info = volumeMap.get(bpid, invalidBlks[i]);
         if (info == null) {
-          // It is okay if the block is not found -- it may be deleted earlier.
-          LOG.info("Failed to delete replica " + invalidBlks[i]
-              + ": ReplicaInfo not found.");
-          continue;
-        }
-        if (info.getGenerationStamp() != invalidBlks[i].getGenerationStamp()) {
-          errors.add("Failed to delete replica " + invalidBlks[i]
-              + ": GenerationStamp not matched, info=" + info);
+          ReplicaInfo infoByBlockId =
+              volumeMap.get(bpid, invalidBlks[i].getBlockId());
+          if (infoByBlockId == null) {
+            // It is okay if the block is not found -- it
+            // may be deleted earlier.
+            LOG.info("Failed to delete replica " + invalidBlks[i]
+                + ": ReplicaInfo not found.");
+          } else {
+            errors.add("Failed to delete replica " + invalidBlks[i]
+                + ": GenerationStamp not matched, existing replica is "
+                + Block.toString(infoByBlockId));
+          }
           continue;
         }
         f = info.getBlockFile();