CLEANUP: resolvers: replace all LIST_DELETE with LIST_DEL_INIT

The code as it is uses crossed lists between many elements, and at
many places the code relies on list iterators or emptiness checks,
which does not work with only LIST_DELETE. Further, it is quite
difficult to place debugging code and checks in the current situation,
and gdb is helpless.

This code replaces all LIST_DELETE calls with LIST_DEL_INIT so that
it becomes possible to trust the lists.

diff --git a/src/resolvers.c b/src/resolvers.c
index 1795ba2b5ca9dfbcdd2080bd5fd976fd1599417c..e205a561b578150cb6392b52edb982840615b553 100644 (file)
--- a/src/resolvers.c
+++ b/src/resolvers.c
@@ -370,7 +370,7 @@ static int resolv_send_query(struct resolv_resolution *resolution)
        }
 
        /* Push the resolution at the end of the active list */
-       LIST_DELETE(&resolution->list);
+       LIST_DEL_INIT(&resolution->list);
        LIST_APPEND(&resolvers->resolutions.curr, &resolution->list);
        return 0;
 }
@@ -580,7 +580,7 @@ static void resolv_srvrq_cleanup_srv(struct server *srv, int safe)
        ha_free(&srv->host_dn.key);
 
        HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
-       LIST_DELETE(&srv->srv_rec_item);
+       LIST_DEL_INIT(&srv->srv_rec_item);
        LIST_APPEND(&srv->srvrq->attached_servers, &srv->srv_rec_item);
 
        srv->srvrq_check->expire = TICK_ETERNITY;
@@ -641,7 +641,7 @@ static void resolv_check_response(struct resolv_resolution *res)
                                        resolv_srvrq_cleanup_srv(srv, 0);
                        }
 
-                       LIST_DELETE(&item->list);
+                       LIST_DEL_INIT(&item->list);
                        if (item->ar_item) {
                                pool_free(resolv_answer_item_pool, item->ar_item);
                                item->ar_item = NULL;
@@ -1605,7 +1605,7 @@ int resolv_get_ip_from_response(struct resolv_response *r_res,
        list_for_each_entry(record, &r_res->answer_list, list) {
                /* Move the first record to the end of the list, for internal
                 * round robin */
-               LIST_DELETE(&record->list);
+               LIST_DEL_INIT(&record->list);
                LIST_APPEND(&r_res->answer_list, &record->list);
                break;
        }
@@ -1808,7 +1808,7 @@ static void resolv_purge_resolution_answer_records(struct resolv_resolution *res
        struct resolv_answer_item *item, *itemback;
 
        list_for_each_entry_safe(item, itemback, &resolution->response.answer_list, list) {
-               LIST_DELETE(&item->list);
+               LIST_DEL_INIT(&item->list);
                pool_free(resolv_answer_item_pool, item->ar_item);
                pool_free(resolv_answer_item_pool, item);
        }
@@ -1834,13 +1834,13 @@ static void resolv_free_resolution(struct resolv_resolution *resolution)
        resolution->hostname_dn_len = 0;
 
        list_for_each_entry_safe(req, reqback, &resolution->requesters, list) {
-               LIST_DELETE(&req->list);
+               LIST_DEL_INIT(&req->list);
                req->resolution = NULL;
        }
        resolv_purge_resolution_answer_records(resolution);
        resolv_purge_resolution_query_items(resolution);
 
-       LIST_DELETE(&resolution->list);
+       LIST_DEL_INIT(&resolution->list);
        pool_free(resolv_resolution_pool, resolution);
 }
 
@@ -2008,7 +2008,7 @@ void resolv_unlink_resolution(struct resolv_requester *requester, int safe)
        resolv_detach_from_resolution_answer_items(res,  requester, safe);
 
        /* Clean up the requester */
-       LIST_DELETE(&requester->list);
+       LIST_DEL_INIT(&requester->list);
        requester->resolution = NULL;
 
        /* We need to find another requester linked on this resolution */
@@ -2214,7 +2214,7 @@ static int resolv_process_responses(struct dns_nameserver *ns)
                if (!keep_answer_items)
                        resolv_purge_resolution_answer_records(res);
                resolv_reset_resolution(res);
-               LIST_DELETE(&res->list);
+               LIST_DEL_INIT(&res->list);
                LIST_APPEND(&resolvers->resolutions.wait, &res->list);
                continue;
 
@@ -2234,7 +2234,7 @@ static int resolv_process_responses(struct dns_nameserver *ns)
                }
 
                resolv_reset_resolution(res);
-               LIST_DELETE(&res->list);
+               LIST_DEL_INIT(&res->list);
                LIST_APPEND(&resolvers->resolutions.wait, &res->list);
                continue;
        }
@@ -2287,7 +2287,7 @@ static struct task *process_resolvers(struct task *t, void *context, unsigned in
                        /* Clean up resolution info and remove it from the
                         * current list */
                        resolv_reset_resolution(res);
-                       LIST_DELETE(&res->list);
+                       LIST_DEL_INIT(&res->list);
                        LIST_APPEND(&resolvers->resolutions.wait, &res->list);
                }
                else {
@@ -2325,7 +2325,7 @@ static struct task *process_resolvers(struct task *t, void *context, unsigned in
 
                if (resolv_run_resolution(res) != 1) {
                        res->last_resolution = now_ms;
-                       LIST_DELETE(&res->list);
+                       LIST_DEL_INIT(&res->list);
                        LIST_APPEND(&resolvers->resolutions.wait, &res->list);
                }
        }
@@ -2366,14 +2366,14 @@ static void resolvers_deinit(void)
                                        task_destroy(ns->stream->task_rsp);
                                free(ns->stream);
                        }
-                       LIST_DELETE(&ns->list);
+                       LIST_DEL_INIT(&ns->list);
                        EXTRA_COUNTERS_FREE(ns->extra_counters);
                        free(ns);
                }
 
                list_for_each_entry_safe(res, resback, &resolvers->resolutions.curr, list) {
                        list_for_each_entry_safe(req, reqback, &res->requesters, list) {
-                               LIST_DELETE(&req->list);
+                               LIST_DEL_INIT(&req->list);
                                pool_free(resolv_requester_pool, req);
                        }
                        resolv_free_resolution(res);
@@ -2381,7 +2381,7 @@ static void resolvers_deinit(void)
 
                list_for_each_entry_safe(res, resback, &resolvers->resolutions.wait, list) {
                        list_for_each_entry_safe(req, reqback, &res->requesters, list) {
-                               LIST_DELETE(&req->list);
+                               LIST_DEL_INIT(&req->list);
                                pool_free(resolv_requester_pool, req);
                        }
                        resolv_free_resolution(res);
@@ -2390,14 +2390,14 @@ static void resolvers_deinit(void)
                free(resolvers->id);
                free((char *)resolvers->conf.file);
                task_destroy(resolvers->t);
-               LIST_DELETE(&resolvers->list);
+               LIST_DEL_INIT(&resolvers->list);
                free(resolvers);
        }
 
        list_for_each_entry_safe(srvrq, srvrqback, &resolv_srvrq_list, list) {
                free(srvrq->name);
                free(srvrq->hostname_dn);
-               LIST_DELETE(&srvrq->list);
+               LIST_DEL_INIT(&srvrq->list);
                free(srvrq);
        }
 }