[FLINK-15244] FileUtils#deleteDirectoryQuietly will delete files in the symbolic link which point to a directory

• Type: Bug
• Status: Closed
• Priority: Blocker
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Fix Version/s: 1.10.0
• Component/s: FileSystems
• Labels: pull-request-available
• Assignee: Wei Zhong
• Reporter: Wei Zhong
• Created: 13/Dec/19 08:56
• Updated: 18/Dec/19 14:20
• Resolved: 18/Dec/19 14:20

Description

FileUtils.deleteDirectoryQuietly will delete files in symbolic link which point to a directory. Currently the PyFlink uses this method to delete temporary folders generated during the job submission and python UDF execution, which contains the symbolic links which may point to users' libraries and directories in distributed cache. 

To resolve this problem we need to check if the directory is symbolic link in FileUtils.deleteDirectoryInternal:

private static void deleteDirectoryInternal(File directory) throws IOException {
    // **We should check if the directory is symbolic link.**
    if (directory.isDirectory()) {
      // directory exists and is a directory

      // empty the directory first
      try {
         cleanDirectoryInternal(directory);
      }
      catch (FileNotFoundException ignored) {
         // someone concurrently deleted the directory, nothing to do for us
         return;
      }

      // delete the directory. this fails if the directory is not empty, meaning
      // if new files got concurrently created. we want to fail then.
      // if someone else deleted the empty directory concurrently, we don't mind
      // the result is the same for us, after all
      Files.deleteIfExists(directory.toPath());
   }
   else if (directory.exists()) {
      // exists but is file, not directory
      // either an error from the caller, or concurrently a file got created
      throw new IOException(directory + " is not a directory");
   }
   // else: does not exist, which is okay (as if deleted)
}

Issue Links

• links to: GitHub Pull Request #10567