[LU-12607] Use zfs internals to manage the zrlock

• Type: Bug
• Resolution: Unresolved
• Priority: Major
• Affects Version/s: Lustre 2.12.2
• Labels: ORNL
• Environment: lustre servers using ZFS 0.8.1+
• Severity: 3
• Assignee: Alex Zhuravlev
• Reporter: James A Simmons

Description

The fix for LU-12510 was only a temporary work around. Currently Lustre manages the zrlock directly but this can collide with ZFS doing with the same thing which can lead to dead locks. The proper fix it so use the ZFS lock management functions provided by ZFS. https://github.com/zfsonlinux/zfs/pull/9027 landed a patch to export the needed functions for Lustre to use. This ticket will track the proper locking implementation.