[HDDS-2682] OM File create request does not check for existing directory with the same name

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: Ozone Manager
• Labels: pull-request-available
• Assignee: Rakesh Radhakrishnan
• Reporter: Supratim Deka
• Created: 06/Dec/19 05:20
• Updated: 16/Apr/20 06:24
• Resolved: 16/Apr/20 06:24

Description

Assume the following sequence of operations/requests:
Req 1. create file -> /d1/d2/d3/d4/k1 (d3 implicitly is a sub-directory inside /d1/d2)
Req 2. create file -> /d1/d2/d3 (d3 as a file inside /d1/d2)

When processing request 2, OMFileCreateRequest needs to check if 'd1/d2/d3' is the name of an existing file or an existing directory. In which case the request has to fail.

Currently for request 2, OM will check explicitly if there is a key '/d1/d2/d3' in the key table.
Also for non-recursive create requests, OM will check if parent directory /d1/d2 already exists. For this, the OM iterates the key table to check if 'd1/d2' occurs as a prefix of any key in the key table - checkKeysUnderPath()

What is missing in current behaviour?
For OM File create, the table iterator must also determine if '/d1/d2/d3' exists as a prefix for any key in the key table - not just '/d1/d2'.

This fix is required for the correctness of OzoneFS namespace. There is a potential performance impact - which is outside the scope of this jira and will be addressed separately.

Issue Links

• links to: GitHub Pull Request #824