Refactor dns_master_dump*async() to use offloaded work

The dns_master_dump*async() functions were using isc_async_run() to
schedule work on the active loop; use isc_work_enqueue() instead.

bin/named/server.c

@@ -11611,7 +11611,7 @@ resume:
 			result = dns_master_dumptostreamasync(
 				dctx->mctx, dctx->cache, NULL, style, dctx->fp,
 				named_g_mainloop, dumpdone, dctx, &dctx->mdctx);
-			if (result == DNS_R_CONTINUE) {
+			if (result == ISC_R_SUCCESS) {
 				return;
 			}
 			if (result == ISC_R_NOTIMPLEMENTED) {
@@ -11670,9 +11670,9 @@ resume:
 			dns_db_currentversion(dctx->db, &dctx->version);
 			result = dns_master_dumptostreamasync(
 				dctx->mctx, dctx->db, dctx->version, style,
-				dctx->fp, named_g_mainloop, dumpdone, dctx,
-				&dctx->mdctx);
-			if (result == DNS_R_CONTINUE) {
+				dctx->fp, dns_zone_getloop(dctx->zone->zone),
+				dumpdone, dctx, &dctx->mdctx);
+			if (result == ISC_R_SUCCESS) {
 				return;
 			}
 			if (result == ISC_R_NOTIMPLEMENTED) {

lib/dns/include/dns/zone.h

@@ -2753,6 +2753,16 @@ dns_zone_gettid(dns_zone_t *zone);
  * \return thread id associated with the zone
  */
 
+isc_loop_t *
+dns_zone_getloop(dns_zone_t *zone);
+/**<
+ * \brief Return loop associated with the zone.
+ *
+ * \param valid dns_zone_t object
+ *
+ * \return loop associated with the zone
+ */
+
 bool
 dns_zone_check_dnskey_nsec3(dns_zone_t *zone, dns_db_t *db,
 			    dns_dbversion_t *ver, dns_diff_t *diff,

lib/dns/masterdump.c

@@ -262,7 +262,6 @@ struct dns_dumpctx {
 	dns_dbversion_t *version;
 	dns_dbiterator_t *dbiter;
 	dns_totext_ctx_t tctx;
-	isc_loop_t *loop;
 	dns_dumpdonefunc_t done;
 	void *done_arg;
 	/* dns_master_dumpasync() */
@@ -1072,7 +1071,6 @@ again:
 		sorted[i] = &rdatasets[i];
 	}
 	n = i;
-	INSIST(n <= MAXSORT);
 
 	qsort(sorted, n, sizeof(sorted[0]), dump_order_compare);
 
@@ -1335,9 +1333,6 @@ dumpctx_destroy(dns_dumpctx_t *dctx) {
 		dns_db_closeversion(dctx->db, &dctx->version, false);
 	}
 	dns_db_detach(&dctx->db);
-	if (dctx->loop != NULL) {
-		isc_loop_detach(&dctx->loop);
-	}
 	if (dctx->file != NULL) {
 		isc_mem_free(dctx->mctx, dctx->file);
 	}
@@ -1507,18 +1502,6 @@ master_dump_done_cb(void *data) {
 	dns_dumpctx_detach(&dctx);
 }
 
-/*
- * This must be run from a loop manager thread.
- */
-static void
-setup_dump(void *arg) {
-	dns_dumpctx_t *dctx = (dns_dumpctx_t *)arg;
-
-	REQUIRE(DNS_DCTX_VALID(dctx));
-
-	isc_work_enqueue(dctx->loop, master_dump_cb, master_dump_done_cb, dctx);
-}
-
 static isc_result_t
 dumpctx_create(isc_mem_t *mctx, dns_db_t *db, dns_dbversion_t *version,
 	       const dns_master_style_t *style, FILE *f, dns_dumpctx_t **dctxp,
@@ -1761,13 +1744,13 @@ dns_master_dumptostreamasync(isc_mem_t *mctx, dns_db_t *db,
 	if (result != ISC_R_SUCCESS) {
 		return (result);
 	}
-	isc_loop_attach(loop, &dctx->loop);
 	dctx->done = done;
 	dctx->done_arg = done_arg;
 
-	isc_async_run(dctx->loop, setup_dump, dctx);
 	dns_dumpctx_attach(dctx, dctxp);
-	return (DNS_R_CONTINUE);
+	isc_work_enqueue(loop, master_dump_cb, master_dump_done_cb, dctx);
+
+	return (ISC_R_SUCCESS);
 }
 
 isc_result_t
@@ -1850,39 +1833,33 @@ dns_master_dumpasync(isc_mem_t *mctx, dns_db_t *db, dns_dbversion_t *version,
 
 	result = opentmp(mctx, format, filename, &tempname, &f);
 	if (result != ISC_R_SUCCESS) {
-		goto cleanup;
+		goto cleanup_file;
 	}
 
 	result = dumpctx_create(mctx, db, version, style, f, &dctx, format,
 				header);
 	if (result != ISC_R_SUCCESS) {
-		(void)isc_stdio_close(f);
-		(void)isc_file_remove(tempname);
-		goto cleanup;
+		goto cleanup_tempname;
 	}
 
-	isc_loop_attach(loop, &dctx->loop);
 	dctx->done = done;
 	dctx->done_arg = done_arg;
 	dctx->file = file;
-	file = NULL;
 	dctx->tmpfile = tempname;
-	tempname = NULL;
 
-	isc_async_run(dctx->loop, setup_dump, dctx);
 	dns_dumpctx_attach(dctx, dctxp);
-	return (DNS_R_CONTINUE);
+	isc_work_enqueue(loop, master_dump_cb, master_dump_done_cb, dctx);
+
+	return (ISC_R_SUCCESS);
+
+cleanup_tempname:
+	(void)isc_stdio_close(f);
+	(void)isc_file_remove(tempname);
+	isc_mem_free(mctx, tempname);
+
+cleanup_file:
+	isc_mem_free(mctx, file);
 
-cleanup:
-	if (dctx != NULL) {
-		dns_dumpctx_detach(&dctx);
-	}
-	if (file != NULL) {
-		isc_mem_free(mctx, file);
-	}
-	if (tempname != NULL) {
-		isc_mem_free(mctx, tempname);
-	}
 	return (result);
 }
 

lib/dns/zone.c

@@ -2701,7 +2701,7 @@ zone_gotwritehandle(isc_task_t *task, isc_event_t *event) {
 		dns_db_detach(&db);
 	}
 	UNLOCK_ZONE(zone);
-	if (result != DNS_R_CONTINUE) {
+	if (result != ISC_R_SUCCESS) {
 		goto fail;
 	}
 	return;
@@ -12174,8 +12174,6 @@ redo:
 				       &zone->writeio);
 		if (result != ISC_R_SUCCESS) {
 			zone_idetach(&dummy);
-		} else {
-			result = DNS_R_CONTINUE;
 		}
 		UNLOCK_ZONE(zone);
 	} else {
@@ -12205,7 +12203,7 @@ fail:
 	}
 	masterfile = NULL;
 
-	if (result == DNS_R_CONTINUE) {
+	if (result == ISC_R_SUCCESS) {
 		return (ISC_R_SUCCESS); /* XXXMPA */
 	}
 
@@ -23674,3 +23672,8 @@ unsigned int
 dns_zone_gettid(dns_zone_t *zone) {
 	return (zone->tid);
 }
+
+isc_loop_t *
+dns_zone_getloop(dns_zone_t *zone) {
+	return (zone->loop);
+}