[LU-13437] rename may miss revoking LOOKUP lock to cause stale dentry on client

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.14.0, Lustre 2.12.6
• Affects Version/s: Lustre 2.10.0, Lustre 2.12.0, Lustre 2.13.0
• Labels: LTS12
• Severity: 3
• Assignee: Lai Siyao
• Reporter: Lai Siyao

Description

In rename, all objects involved but target may be remote, i.e. source, source parent, target parent may be remote object, herein to know whether source is a remote object on source parent, we need to compare which MDT they are located.

In mdt_getattr_name_lock(), if name is NULL, the LOOKUP lock can't be returned to client, because this object may be a remote object under its parent, and the remote LOOKUP lock is on the MDT where its parent is located.

Issue Links

• is related to: LU-14172 DIR Stat performance regression in striped dir