[LU-2261] Add cache stats to zfs osd

• Type: Improvement
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.8.0
• Affects Version/s: Lustre 2.4.0
• Labels: patch zfs

Epic

zfs

• Assignee: WC Triage
• Reporter: Nathaniel Clark

Description

Currently osd caching statistics are not reported or compiled for zfs.

Upon fixing this sanity test_156 should be re-enabled for ZFS (see LU-1956)

Issue Links

• is related to: LU-11889 sanity test 156 fails on ZFS: roc_hit not safe to use
• is related to: LU-5375 Failure on test suite sanity test_151 test_156: roc_hit is not safe to use
• is related to: LU-4259 No brw_stats on ZFS