Change get_effective_cache_mode to operate on req instead of io

Signed-off-by: Michal Rakowski <michal.rakowski@intel.com>

src/ocf_request.h

@@ -8,6 +8,7 @@
 
 #include "ocf_env.h"
 #include "ocf_io_priv.h"
+#include "engine/cache_engine.h"
 
 struct ocf_req_allocator;
 
@@ -149,6 +150,8 @@ struct ocf_request {
 	ctx_data_t *cp_data;
 	/*!< Copy of request data */
 
+	ocf_req_cache_mode_t cache_mode;
+
 	uint64_t byte_position;
 	/*!< LBA byte position of request in core domain */
 
@@ -326,6 +329,8 @@ void ocf_req_clear_map(struct ocf_request *req);
  */
 void ocf_req_hash(struct ocf_request *req);
 
+int ocf_req_set_dirty(struct ocf_request *req);
+
 /**
  * @brief Clear OCF request
  *