HDFS-17707. Optimize <op>WithExistsCheck methods in concurrent scenario.

Author: hfutatzhanghb

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/FileIoProvider.java

@@ -243,7 +243,7 @@ public boolean deleteWithExistsCheck(@Nullable FsVolumeSpi volume, File f) {
     final long begin = profilingEventHook.beforeMetadataOp(volume, DELETE);
     try {
       faultInjectorEventHook.beforeMetadataOp(volume, DELETE);
-      boolean deleted = !f.exists() || f.delete();
+      boolean deleted = !f.exists() || f.delete() || !f.exists();
       profilingEventHook.afterMetadataOp(volume, DELETE, begin);
       if (!deleted) {
         LOG.warn("Failed to delete file {}", f);
@@ -686,7 +686,7 @@ public void mkdirsWithExistsCheck(
     boolean succeeded = false;
     try {
       faultInjectorEventHook.beforeMetadataOp(volume, MKDIRS);
-      succeeded = dir.isDirectory() || dir.mkdirs();
+      succeeded = dir.isDirectory() || dir.mkdirs() || dir.isDirectory();
       profilingEventHook.afterMetadataOp(volume, MKDIRS, begin);
     } catch(Exception e) {
       onFailure(volume, begin);