Introduce composite volume

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

inc/ocf.h

@@ -1,5 +1,5 @@
 /*
- * Copyright(c) 2012-2021 Intel Corporation
+ * Copyright(c) 2012-2022 Intel Corporation
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -18,6 +18,7 @@
 #include "ocf_types.h"
 #include "ocf_io.h"
 #include "ocf_volume.h"
+#include "ocf_composite_volume.h"
 #include "ocf_cache.h"
 #include "ocf_core.h"
 #include "ocf_queue.h"

inc/ocf_composite_volume.h

@@ -0,0 +1,55 @@
+/*
+ * Copyright(c) 2022 Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __OCF_COMPOSITE_VOLUME_H__
+#define __OCF_COMPOSITE_VOLUME_H__
+
+/**
+ * @file
+ * @brief OCF composite volume API
+ */
+
+#include "ocf_types.h"
+#include "ocf_env_headers.h"
+#include "ocf_err.h"
+#include "ocf_volume.h"
+
+/**
+ * @brief handle to object designating composite volume
+ */
+typedef ocf_volume_t ocf_composite_volume_t;
+
+/**
+ * @brief Allocate and initialize composite volume
+ *
+ * @param[out] cvolume pointer to volume handle
+ * @param[in] ctx OCF context
+ *
+ * @return Zero when success, othewise an error
+ */
+int ocf_composite_volume_create(ocf_composite_volume_t *cvolume, ocf_ctx_t ctx);
+
+/**
+ * @brief Deinitialize and free composite volume
+ *
+ * @param[in] volume volume handle
+ */
+void ocf_composite_volume_destroy(ocf_composite_volume_t cvolume);
+
+/**
+ * @brief Add subvolume to composite volume
+ *
+ * @param[in] cvolume composite volume handle
+ * @param[in] type type of added subvolume
+ * @param[in] uuid UUID of added subvolume
+ * @param[in] volume_params params to be passed to subvolume open
+ *
+ * @return Zero when success, othewise an error
+ */
+int ocf_composite_volume_add(ocf_composite_volume_t cvolume,
+		ocf_volume_type_t type, struct ocf_volume_uuid *uuid,
+		void *volume_params);
+
+#endif /* __OCF_COMPOSITE_VOLUME_H__ */