[LU-10877] dt_locate_at reference leak

• Type: Bug
• Resolution: Fixed
• Priority: Critical
• Fix Version/s: Lustre 2.12.0
• Affects Version/s: Lustre 2.9.0, Lustre 2.10.0, Lustre 2.11.0
• Environment: any. Test from LU-9699
• Severity: 3
• Assignee: WC Triage
• Reporter: Alexey Lyashkov

Description

commit f6d6a552398eb1e65857d9bf1afaaf98c8dc1a79 have rewrite a dt_locate_at function to different device tree handling, and this change introduce an object reference leak.

+       struct lu_object *lo, *n;
+       ENTRY;
+
+       lo = lu_object_find_at(env, top_dev, fid, NULL);
+       if (IS_ERR(lo))
+               return (void *)lo;
+
+       LASSERT(lo != NULL);
+
+       cfs_list_for_each_entry(n, &lo->lo_header->loh_layers, lo_linkage) {
+               if (n->lo_dev == &dev->dd_lu_dev)
+                       return container_of0(n, struct dt_object, do_lu);
+       }
+       return ERR_PTR(-ENOENT);

if some object not in expected tree we have return an ENOENT without an object reference release. It will cause a panic on unmount.

Issue Links

• is related to: LU-1301 MGS over OSD