[LU-17295] avoiding VFS exclusive locking on shared parent directory in ->atomic_open()

• Type: Improvement
• Resolution: Unresolved
• Priority: Minor
• Labels: IO500 performance
• Severity: 3
• Assignee: Qian Yingjin
• Reporter: Qian Yingjin

Description

This is an experimental feature to avoid the VFS exclusive locking on parent directory in ->atomic_open during file creations.

It converted the exclusive semaphore mutex into a shared lock to avoid waiting for the heavy creation RPC to finished