[LU-20148] Purge directories in parallel in ltrash_purge

• Type: Improvement
• Resolution: Unresolved
• Priority: Medium
• Severity: 3
• Assignee: Emoly Liu
• Reporter: Emoly Liu

Description

Now ltrash_purge uses two-phase process to purge files and directories:

• phase1: purge files during tree walk
• phase2: purge directories in DFS order in serial

To improve directory deletion, we can build a directory list in phase1 and then do directory deletion in parallel in phase2, like MPIFileUtils drm does.

Issue Links

• is related to: LU-19598 TCU: Clean up files from the Trash Can