[LU-3171] Imbalance of do_ref_add and do_ref_del calls

• Type: Bug
• Resolution: Not a Bug
• Priority: Major
• Affects Version/s: Lustre 2.4.0
• Severity: 3
• Assignee: WC Triage
• Reporter: Li Wei (Inactive)

Description

It looks the issue addressed by the one-year-old http://review.whamcloud.com/2399 (never landed anywhere) still exists on master. From the old commit message:

Every new object created by osd-ldiskfs has the link count one,
regardless of how many links it really has. This forces some OSD API
users, like MDD and LLog, to do an extra reference deletion when
destroying an object. The resulting caller code is asymmetric,
confusing, and potentially troublesome for other back ends. Moreover,
it requires some callers to do special checks to handle old (i.e.,
pre-OSD) objects. (So far osd-zfs does not explode because it does not
check link counts when destroying objects.) ...

do_create should return objects with actual link counts, while the callers should only take care of their own (rather than OSD-internal) links.