[HDFS-14471] FSDirectory.resolveDotInodesPath() throws FileNotFoundException when the path is malformed

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Not A Problem
• Assignee: Unassigned
• Reporter: Haicheng Chen
• Created: 06/May/19 14:11
• Updated: 29/May/19 18:04
• Resolved: 29/May/19 18:04

Description

Dear HDFS developers, we are developing a tool to detect exception-related bugs in Java. Our prototype has spotted the following throw statement whose exception class and error message indicate different error conditions.

 

Version: Hadoop-3.1.2

File: HADOOP-ROOT/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java

Line: 1646-1651

try {
  id = Long.parseLong(inodeId);
} catch (NumberFormatException e) {
  throw new FileNotFoundException("Invalid inode path: " +
      DFSUtil.byteArray2PathString(pathComponents));
}

 

A FileNotFoundException means that a target file cannot be found. However, the error message indicates that the path is malformed (instead of well-formed but pointing to no file). This mismatch could be a problem. For example, the callers trying to handle other FileNotFoundException may accidentally (and incorrectly) handle the malformed path. Or, users/admins may be misled by the exception class name and wonder why the file is missing.

 

Maybe the FileNotFoundException can wrap the NumberFormatException, so that the callers and users will have more idea of why the inode path is invalid.