[HDFS-15667] Audit log record the unexpected allowed result when delete called

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.3.0, 3.2.1
• Fix Version/s: 3.3.1, 3.4.0
• Component/s: hdfs
• Labels: pull-request-available
• Assignee: Baolong Mao
• Reporter: Baolong Mao
• Created: 05/Nov/20 03:07
• Updated: 02/Apr/21 06:08
• Resolved: 10/Nov/20 05:02

Description

I met this issue if rm root directory, for remove non-root and non-empty directory, toRemovedBlocks isn't null, its toDeleteList size is 0.

when will return null?

Through this screenshot, we can find that if fileRemoved = -1, then toRemovedBlocks = null

And when deleteAllowed(iip) return false, fileRemoved can be -1,

 private static boolean deleteAllowed(final INodesInPath iip) {
    if (iip.length() < 1 || iip.getLastINode() == null) {
      if (NameNode.stateChangeLog.isDebugEnabled()) {
        NameNode.stateChangeLog.debug(
            "DIR* FSDirectory.unprotectedDelete: failed to remove "
                + iip.getPath() + " because it does not exist");
      }
      return false;
    } else if (iip.length() == 1) { // src is the root
      NameNode.stateChangeLog.warn(
          "DIR* FSDirectory.unprotectedDelete: failed to remove " +
              iip.getPath() + " because the root is not allowed to be deleted");
      return false;
    }
    return true;
  }

Through the code of deleteAllowed, we can find that when src is the root, it can return false.

So without this PR, when I execute bin/hdfs dfs -rm -r /

I find the confusing auditlog line like following

2020-11-05 14:32:53,420 INFO FSNamesystem.audit (FSNamesystem.java:logAuditMessage(8102)) - allowed=true

Issue Links

• links to: GitHub Pull Request #2437