Enable cache detach

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@huawei.com>
Signed-off-by: Jan Musial <jan.musial@huawei.com>

casadm/cas_lib.c

@@ -1054,6 +1054,63 @@ int attach_cache(uint16_t cache_id, const char *cache_device, int force)
 			ocf_cache_mode_none, ocf_cache_line_size_none, force, false);
 }
 
+int detach_cache(uint16_t cache_id)
+{
+	int fd = 0;
+	struct kcas_stop_cache cmd = {};
+	int ioctl_code = KCAS_IOCTL_DETACH_CACHE;
+	int status;
+
+	fd = open_ctrl_device();
+	if (fd == -1)
+		return FAILURE;
+
+	cmd.cache_id = cache_id;
+	cmd.flush_data = true;
+
+	status = run_ioctl_interruptible_retry(
+			fd,
+			ioctl_code,
+			&cmd,
+			"Detaching the device from cache",
+			cache_id,
+			OCF_CORE_ID_INVALID);
+	close(fd);
+
+	if (status < 0) {
+		if (OCF_ERR_FLUSHING_INTERRUPTED == cmd.ext_err_code) {
+			cas_printf(LOG_ERR,
+				"You have interrupted detaching the device "
+				"from cache %d. CAS continues to operate "
+				"normally.\n",
+				cache_id
+				);
+			return INTERRUPTED;
+		} else if (OCF_ERR_WRITE_CACHE == cmd.ext_err_code) {
+			cas_printf(LOG_ERR,
+					"Detached the device from cache %d "
+					"with errors\n",
+					cache_id
+					);
+			print_err(cmd.ext_err_code);
+			return FAILURE;
+		} else {
+			cas_printf(LOG_ERR,
+					"Error while detaching the device from"
+					" cache %d\n",
+					cache_id
+					);
+			print_err(cmd.ext_err_code);
+			return FAILURE;
+		}
+	}
+
+	cas_printf(LOG_INFO, "Successfully detached device from cache %hu\n",
+			cache_id);
+
+	return SUCCESS;
+}
+
 int stop_cache(uint16_t cache_id, int flush)
 {
 	int fd = 0;
@@ -1082,7 +1139,6 @@ int stop_cache(uint16_t cache_id, int flush)
 	close(fd);
 
 	if (status < 0) {
-
 		if (OCF_ERR_FLUSHING_INTERRUPTED == cmd.ext_err_code) {
 			cas_printf(LOG_ERR,
 				"You have interrupted stopping of cache %d. "

casadm/cas_lib.h

@@ -117,6 +117,7 @@ int start_cache(uint16_t cache_id, unsigned int cache_init,
 		ocf_cache_line_size_t line_size, int force);
 int stop_cache(uint16_t cache_id, int flush);
 
+int detach_cache(uint16_t cache_id);
 int attach_cache(uint16_t cache_id, const char *cache_device, int force);
 
 #ifdef WI_AVAILABLE

casadm/cas_main.c

@@ -421,6 +421,11 @@ int handle_cache_attach(void)
 			);
 }
 
+int handle_cache_detach(void)
+{
+	return detach_cache(command_args_values.cache_id);
+}
+
 int handle_start()
 {
 	int status;
@@ -543,6 +548,11 @@ static cli_option stop_options[] = {
 	{0}
 };
 
+static cli_option detach_options[] = {
+	{'i', "cache-id", CACHE_ID_DESC, 1, "ID", CLI_OPTION_REQUIRED},
+	{0}
+};
+
 int handle_stop()
 {
 	return stop_cache(command_args_values.cache_id,
@@ -2230,6 +2240,16 @@ static cli_command cas_commands[] = {
 			.flags = CLI_SU_REQUIRED,
 			.help = NULL,
 		},
+		{
+			.name = "detach-cache",
+			.desc = "Detach cache device",
+			.long_desc = NULL,
+			.options = detach_options,
+			.command_handle_opts = command_handle_option,
+			.handle = handle_cache_detach,
+			.flags = CLI_SU_REQUIRED,
+			.help = NULL,
+		},
 		{
 			.name = "stop-cache",
 			.short_name = 'T',

modules/cas_cache/layer_cache_management.c

@@ -2509,6 +2509,22 @@ int cache_mngt_create_cache_standby_activate_cfg(
 	return 0;
 }
 
+static void _cache_mngt_detach_cache_complete(ocf_cache_t cache, void *priv,
+		int error)
+{
+	struct _cache_mngt_async_context *context = priv;
+	int result;
+
+	result = _cache_mngt_async_callee_set_result(context, error);
+
+	if (result != -KCAS_ERR_WAITING_INTERRUPTED)
+		return;
+
+	kfree(context);
+	ocf_mngt_cache_unlock(cache);
+	kfree(context);
+}
+
 int cache_mngt_attach_device(const char *cache_name, size_t name_len,
 		const char *device, struct ocf_mngt_cache_attach_config *attach_cfg)
 {
@@ -3113,6 +3129,53 @@ put:
 	return result;
 }
 
+int cache_mngt_detach_cache(const char *cache_name, size_t name_len)
+{
+	ocf_cache_t cache;
+	int status = 0;
+	struct _cache_mngt_async_context *context;
+
+	context = kmalloc(sizeof(*context), GFP_KERNEL);
+	if (!context)
+		return -ENOMEM;
+
+	_cache_mngt_async_context_init(context);
+
+	status = ocf_mngt_cache_get_by_name(cas_ctx, cache_name,
+					name_len, &cache);
+	if (status)
+		goto err_get_cache;
+
+	if (ocf_cache_is_running(cache))
+		status = _cache_flush_with_lock(cache);
+	if (status)
+		goto err_flush;
+
+	status = _cache_mngt_lock_sync(cache);
+	if (status)
+		goto err_lock;
+
+	ocf_mngt_cache_detach(cache, _cache_mngt_detach_cache_complete, context);
+
+	status = wait_for_completion_interruptible(&context->cmpl);
+	status = _cache_mngt_async_caller_set_result(context, status);
+
+	if (status == -KCAS_ERR_WAITING_INTERRUPTED) {
+		printk(KERN_WARNING "Waiting for cache detach interrupted. "
+				"The operation will finish asynchronously.\n");
+		goto err_int;
+	}
+
+	ocf_mngt_cache_unlock(cache);
+err_lock:
+err_flush:
+	ocf_mngt_cache_put(cache);
+err_get_cache:
+	kfree(context);
+err_int:
+	return status;
+}
+
 /**
  * @brief routine implements --stop-cache command.
  * @param[in] cache_name caching device name to be removed

modules/cas_cache/layer_cache_management.h

@@ -43,6 +43,8 @@ int cache_mngt_reset_stats(const char *cache_name, size_t cache_name_len,
 int cache_mngt_set_partitions(const char *cache_name, size_t name_len,
 		struct kcas_io_classes *cfg);
 
+int cache_mngt_detach_cache(const char *cache_name, size_t name_len);
+
 int cache_mngt_attach_device(const char *cache_name, size_t name_len,
 		const char *device, struct ocf_mngt_cache_attach_config *attach_cfg);
 

modules/cas_cache/service_ui_ioctl.c

@@ -99,6 +99,20 @@ long cas_service_ioctl_ctrl(struct file *filp, unsigned int cmd,
 		RETURN_CMD_RESULT(cmd_info, arg, retval);
 	}
 
+	case KCAS_IOCTL_DETACH_CACHE: {
+		struct kcas_stop_cache *cmd_info;
+		char cache_name[OCF_CACHE_NAME_SIZE];
+
+		GET_CMD_INFO(cmd_info, arg);
+
+		cache_name_from_id(cache_name, cmd_info->cache_id);
+
+		retval = cache_mngt_detach_cache(cache_name,
+				OCF_CACHE_NAME_SIZE);
+
+		RETURN_CMD_RESULT(cmd_info, arg, retval);
+	}
+
 	case KCAS_IOCTL_SET_CACHE_STATE: {
 		struct kcas_set_cache_state *cmd_info;
 		char cache_name[OCF_CACHE_NAME_SIZE];

modules/include/cas_ioctl_codes.h

@@ -406,6 +406,7 @@ struct kcas_standby_activate
  *    39    *    KCAS_IOCTL_STANDBY_ACTIVATE                *    OK            *
  *    40    *    KCAS_IOCTL_CORE_INFO                       *    OK            *
  *    41    *    KCAS_IOCTL_START_CACHE                     *    OK            *
+ *    42    *    KCAS_IOCTL_DETACH_CACHE                    *    OK            *
  *    43    *    KCAS_IOCTL_ATTACH_CACHE                    *    OK            *
  *******************************************************************************
  */
@@ -505,6 +506,9 @@ struct kcas_standby_activate
 /** Start new cache instance, load cache or recover cache */
 #define KCAS_IOCTL_START_CACHE _IOWR(KCAS_IOCTL_MAGIC, 41, struct kcas_start_cache)
 
+/** Detach cache device */
+#define KCAS_IOCTL_DETACH_CACHE _IOWR(KCAS_IOCTL_MAGIC, 42, struct kcas_stop_cache)
+
 /** Attach cache device */
 #define KCAS_IOCTL_ATTACH_CACHE _IOWR(KCAS_IOCTL_MAGIC, 43, struct kcas_start_cache)