What is this PR for?

When note persistence fails because of file-system restrictions, the failed note can remain visible in Notebook Overview and newly created empty directories can be left behind.

This PR rolls back the in-memory note and authorization state when creation fails with an IOException or IllegalArgumentException, including invalid HDFS paths. It also removes temporary files and newly created empty directories after a failed VFS save while preserving directories that already existed.

What type of PR is it?

Bug Fix

Todos

• Roll back note and authorization state after a failed save
• Clean up VFS artifacts without removing existing directories
• Add regression tests for file-name length and unchecked file-system errors

What is the Jira issue?

https://issues.apache.org/jira/browse/ZEPPELIN-5450

How should this be tested?

Automated tests cover:

• A note name that exceeds the local file-system limit
• An HDFS-like invalid path failure that throws IllegalArgumentException
• Preservation of an existing parent directory after a failed save

./mvnw test -pl zeppelin-server -Dtest=NotebookServiceTest,VFSNotebookRepoTest
./mvnw clean org.apache.rat:apache-rat-plugin:check -Prat

Screenshots (if appropriate)

Not applicable

Questions:

• Does the license files need to update? No.
• Is there breaking changes for older versions? No.
• Does this needs documentation? No.