[LU-7829] Glimpse lock shouldn't match not granted locks

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.9.0
• Labels: patch
• Severity: 3
• Assignee: WC Triage
• Reporter: Andriy Skulysh

Description

A deadlock is possible during ccc_prep_size()->ldlm_lock_match() vs
cl_io_lock() which is waiting for a matched lock and conflicts with
already taken lock before ccc_prep_size().

It is better to send an aditional lock request to avoid deadlock.