getAdapterName: Lookup stable scsi_host

If a parentaddr was provided in the XML, have getAdapterName lookup
the stable address.  This allows virStorageBackendSCSICheckPool() and
virStorageBackendSCSIRefreshPool() to automagically find the scsi_host
by its PCI address and unique_id

src/storage/storage_backend_scsi.c

@@ -547,9 +547,29 @@ static char *
 getAdapterName(virStoragePoolSourceAdapter adapter)
 {
     char *name = NULL;
+    char *parentaddr = NULL;
 
     if (adapter.type == VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_SCSI_HOST) {
-        ignore_value(VIR_STRDUP(name, adapter.data.scsi_host.name));
+        if (adapter.data.scsi_host.has_parent) {
+            unsigned int unique_id = adapter.data.scsi_host.unique_id;
+
+            if (virAsprintf(&parentaddr, "%04x:%02x:%02x.%01x",
+                            adapter.data.scsi_host.parentaddr.domain,
+                            adapter.data.scsi_host.parentaddr.bus,
+                            adapter.data.scsi_host.parentaddr.slot,
+                            adapter.data.scsi_host.parentaddr.function) < 0)
+                goto cleanup;
+            if (!(name = virFindSCSIHostByPCI(NULL, parentaddr,
+                                              unique_id))) {
+                virReportError(VIR_ERR_XML_ERROR,
+                               _("Failed to find scsi_host using PCI '%s' "
+                                 "and unique_id='%u'"),
+                               parentaddr, unique_id);
+                goto cleanup;
+            }
+        } else {
+            ignore_value(VIR_STRDUP(name, adapter.data.scsi_host.name));
+        }
     } else if (adapter.type == VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_FC_HOST) {
         if (!(name = virGetFCHostNameByWWN(NULL,
                                            adapter.data.fchost.wwnn,
@@ -561,6 +581,8 @@ getAdapterName(virStoragePoolSourceAdapter adapter)
         }
     }
 
+ cleanup:
+    VIR_FREE(parentaddr);
     return name;
 }