Add open_cores parameter to ocf_mngt_cache_device_config

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

inc/ocf_mngt.h

@@ -301,6 +301,19 @@ struct ocf_mngt_cache_device_config {
 	 */
 	ocf_cache_line_size_t cache_line_size;
 
+	/**
+	 * @brief Automatically open core volumes when loading cache
+	 *
+	 * If set to false, cache load will not attempt to open core volumes,
+	 * and so cores will be marked "inactive" unless their volumes were
+	 * earlier added to the core pool. In such case user will be expected
+	 * to add cores later using function ocf_mngt_cache_add_core().
+	 *
+	 * @note This option is meaningful only with ocf_mngt_cache_load().
+	 *       When used with ocf_mngt_cache_attach() it's ignored.
+	 */
+	bool open_cores;
+
 	/**
 	 * @brief Ignore warnings and start cache
 	 *

src/mngt/ocf_mngt_cache.c

@@ -413,7 +413,7 @@ static int _ocf_mngt_init_instance_add_cores(
 			core->opened = true;
 			ocf_cache_log(cache, log_info,
 					"Attached core %u from pool\n", i);
-		} else {
+		} else if (context->cfg.open_cores) {
 			ret = ocf_volume_open(&core->volume, NULL);
 			if (ret == -OCF_ERR_NOT_OPEN_EXC) {
 				ocf_cache_log(cache, log_warn,