diff --git a/src/engine/cache_engine.c b/src/engine/cache_engine.c
index c2465a97..1ffde748 100644
--- a/src/engine/cache_engine.c
+++ b/src/engine/cache_engine.c
@@ -138,7 +138,7 @@ const char *ocf_get_io_iface_name(ocf_req_cache_mode_t cache_mode)
 	return cache_mode_io_if_map[cache_mode]->name;
 }
 
-static ocf_engine_cb ocf_io_if_type_to_engine_cb(
+static ocf_req_cb ocf_io_if_type_to_engine_cb(
 		enum ocf_io_if_type io_if_type, int rw)
 {
 	if (unlikely(io_if_type == OCF_IO_MAX_IF ||
@@ -149,7 +149,7 @@ static ocf_engine_cb ocf_io_if_type_to_engine_cb(
 	return IO_IFS[io_if_type].cbs[rw];
 }
 
-static ocf_engine_cb ocf_cache_mode_to_engine_cb(
+static ocf_req_cb ocf_cache_mode_to_engine_cb(
 		ocf_req_cache_mode_t req_cache_mode, int rw)
 {
 	if (req_cache_mode == ocf_req_cache_mode_max)
@@ -158,37 +158,6 @@ static ocf_engine_cb ocf_cache_mode_to_engine_cb(
 	return cache_mode_io_if_map[req_cache_mode]->cbs[rw];
 }
 
-struct ocf_request *ocf_engine_pop_req(ocf_queue_t q)
-{
-	unsigned long lock_flags = 0;
-	struct ocf_request *req;
-
-	OCF_CHECK_NULL(q);
-
-	/* LOCK */
-	env_spinlock_lock_irqsave(&q->io_list_lock, lock_flags);
-
-	if (list_empty(&q->io_list)) {
-		/* No items on the list */
-		env_spinlock_unlock_irqrestore(&q->io_list_lock,
-				lock_flags);
-		return NULL;
-	}
-
-	/* Get the first request and remove it from the list */
-	req = list_first_entry(&q->io_list, struct ocf_request, list);
-
-	env_atomic_dec(&q->io_no);
-	list_del(&req->list);
-
-	/* UNLOCK */
-	env_spinlock_unlock_irqrestore(&q->io_list_lock, lock_flags);
-
-	OCF_CHECK_NULL(req);
-
-	return req;
-}
-
 bool ocf_fallback_pt_is_on(ocf_cache_t cache)
 {
 	ENV_BUG_ON(env_atomic_read(&cache->fallback_pt_error_counter) < 0);
@@ -264,14 +233,14 @@ int ocf_engine_hndl_req(struct ocf_request *req)
 	 * to into OCF workers
 	 */
 
-	ocf_engine_push_req_back(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC);
 
 	return 0;
 }
 
 int ocf_engine_hndl_fast_req(struct ocf_request *req)
 {
-	ocf_engine_cb engine_cb;
+	ocf_req_cb engine_cb;
 	int ret;
 
 	engine_cb = ocf_cache_mode_to_engine_cb(req->cache_mode, req->rw);
@@ -313,7 +282,7 @@ void ocf_engine_hndl_ops_req(struct ocf_request *req)
 			ocf_io_if_type_to_engine_cb(OCF_IO_D2C_IF, req->rw) :
 			ocf_io_if_type_to_engine_cb(OCF_IO_OPS_IF, req->rw);
 
-	ocf_engine_push_req_back(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC);
 }
 
 bool ocf_req_cache_mode_has_lazy_write(ocf_req_cache_mode_t mode)
diff --git a/src/engine/cache_engine.h b/src/engine/cache_engine.h
index 6e211de1..bb61e79c 100644
--- a/src/engine/cache_engine.h
+++ b/src/engine/cache_engine.h
@@ -7,42 +7,22 @@
 #ifndef __CACHE_ENGINE_H_
 #define __CACHE_ENGINE_H_
 
+#include "../ocf_request.h"
+
 struct ocf_thread_priv;
-struct ocf_request;
 
 #define LOOKUP_HIT 5
 #define LOOKUP_MISS 6
 #define LOOKUP_REMAPPED 8
 
-typedef enum {
-	/* modes inherited from user API */
-	ocf_req_cache_mode_wt = ocf_cache_mode_wt,
-	ocf_req_cache_mode_wb = ocf_cache_mode_wb,
-	ocf_req_cache_mode_wa = ocf_cache_mode_wa,
-	ocf_req_cache_mode_pt = ocf_cache_mode_pt,
-	ocf_req_cache_mode_wi = ocf_cache_mode_wi,
-	ocf_req_cache_mode_wo = ocf_cache_mode_wo,
-
-	/* internal modes */
-	ocf_req_cache_mode_fast,
-		/*!< Fast path */
-	ocf_req_cache_mode_d2c,
-		/*!< Direct to Core - pass through to core without
-				touching cacheline metadata */
-
-	ocf_req_cache_mode_max,
-} ocf_req_cache_mode_t;
-
 static inline ocf_req_cache_mode_t ocf_cache_mode_to_req_cache_mode(
 		ocf_cache_mode_t mode)
 {
 	return (ocf_req_cache_mode_t)mode;
 }
 
-typedef int (*ocf_engine_cb)(struct ocf_request *req);
-
 struct ocf_io_if {
-	ocf_engine_cb cbs[2]; /* READ and WRITE */
+	ocf_req_cb cbs[2]; /* READ and WRITE */
 
 	const char *name;
 };
@@ -56,8 +36,6 @@ bool ocf_req_cache_mode_has_lazy_write(ocf_req_cache_mode_t mode);
 
 bool ocf_fallback_pt_is_on(ocf_cache_t cache);
 
-struct ocf_request *ocf_engine_pop_req(struct ocf_queue *q);
-
 int ocf_engine_hndl_req(struct ocf_request *req);
 
 #define OCF_FAST_PATH_YES	7
diff --git a/src/engine/engine_bf.c b/src/engine/engine_bf.c
index 60d2cea2..f6435cab 100644
--- a/src/engine/engine_bf.c
+++ b/src/engine/engine_bf.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -94,5 +95,6 @@ static int _ocf_backfill_do(struct ocf_request *req)
 void ocf_engine_backfill(struct ocf_request *req)
 {
 	backfill_queue_inc_block(req->cache);
-	ocf_engine_push_req_front_cb(req, _ocf_backfill_do, true);
+	ocf_queue_push_req_cb(req, _ocf_backfill_do,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
diff --git a/src/engine/engine_common.c b/src/engine/engine_common.c
index 24643f68..49d3dab2 100644
--- a/src/engine/engine_common.c
+++ b/src/engine/engine_common.c
@@ -1,6 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
- * Copyright(c) 2024 Huawei Technologies Co., Ltd.
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -381,7 +381,8 @@ static void _ocf_engine_clean_end(void *private_data, int error)
 	} else {
 		req->info.dirty_any = 0;
 		req->info.dirty_all = 0;
-		ocf_engine_push_req_front(req, true);
+		ocf_queue_push_req(req,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	}
 }
 
@@ -584,75 +585,6 @@ void ocf_engine_update_request_stats(struct ocf_request *req)
 			req->info.hit_no, req->core_line_count);
 }
 
-void ocf_engine_push_req_back(struct ocf_request *req, bool allow_sync)
-{
-	ocf_cache_t cache = req->cache;
-	ocf_queue_t q = NULL;
-	unsigned long lock_flags = 0;
-
-	INIT_LIST_HEAD(&req->list);
-
-	ENV_BUG_ON(!req->io_queue);
-	q = req->io_queue;
-
-	if (!req->info.internal) {
-		env_atomic_set(&cache->last_access_ms,
-				env_ticks_to_msecs(env_get_tick_count()));
-	}
-
-	env_spinlock_lock_irqsave(&q->io_list_lock, lock_flags);
-
-	list_add_tail(&req->list, &q->io_list);
-	env_atomic_inc(&q->io_no);
-
-	env_spinlock_unlock_irqrestore(&q->io_list_lock, lock_flags);
-
-	/* NOTE: do not dereference @req past this line, it might
-	 * be picked up by concurrent io thread and deallocated
-	 * at this point */
-
-	ocf_queue_kick(q, allow_sync);
-}
-
-void ocf_engine_push_req_front(struct ocf_request *req, bool allow_sync)
-{
-	ocf_cache_t cache = req->cache;
-	ocf_queue_t q = NULL;
-	unsigned long lock_flags = 0;
-
-	ENV_BUG_ON(!req->io_queue);
-	INIT_LIST_HEAD(&req->list);
-
-	q = req->io_queue;
-
-	if (!req->info.internal) {
-		env_atomic_set(&cache->last_access_ms,
-				env_ticks_to_msecs(env_get_tick_count()));
-	}
-
-	env_spinlock_lock_irqsave(&q->io_list_lock, lock_flags);
-
-	list_add(&req->list, &q->io_list);
-	env_atomic_inc(&q->io_no);
-
-	env_spinlock_unlock_irqrestore(&q->io_list_lock, lock_flags);
-
-	/* NOTE: do not dereference @req past this line, it might
-	 * be picked up by concurrent io thread and deallocated
-	 * at this point */
-
-	ocf_queue_kick(q, allow_sync);
-}
-
-void ocf_engine_push_req_front_cb(struct ocf_request *req,
-		ocf_engine_cb engine_cb,
-		bool allow_sync)
-{
-	req->error = 0; /* Please explain why!!! */
-	req->engine_handler = engine_cb;
-	ocf_engine_push_req_front(req, allow_sync);
-}
-
 void inc_fallback_pt_error_counter(ocf_cache_t cache)
 {
 	ENV_BUG_ON(env_atomic_read(&cache->fallback_pt_error_counter) < 0);
@@ -712,5 +644,5 @@ void ocf_engine_on_resume(struct ocf_request *req)
 
 	OCF_DEBUG_RQ(req, "On resume");
 
-	ocf_engine_push_req_front_cb(req, _ocf_engine_refresh, false);
+	ocf_queue_push_req_cb(req, _ocf_engine_refresh, OCF_QUEUE_PRIO_HIGH);
 }
diff --git a/src/engine/engine_common.h b/src/engine/engine_common.h
index 6f9c73fc..6c6946ee 100644
--- a/src/engine/engine_common.h
+++ b/src/engine/engine_common.h
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -280,38 +281,6 @@ void ocf_engine_update_block_stats(struct ocf_request *req);
  */
 void ocf_engine_update_request_stats(struct ocf_request *req);
 
-/**
- * @brief Push front OCF request to the OCF thread worker queue
- *
- * @param req OCF request
- * @param allow_sync caller allows for request from queue to be ran immediately
-		from push function in caller context
- */
-void ocf_engine_push_req_back(struct ocf_request *req,
-		bool allow_sync);
-
-/**
- * @brief Push back OCF request to the OCF thread worker queue
- *
- * @param req OCF request
- * @param allow_sync caller allows for request from queue to be ran immediately
-		from push function in caller context
- */
-void ocf_engine_push_req_front(struct ocf_request *req,
-		bool allow_sync);
-
-/**
- * @brief Set interface and push from request to the OCF thread worker queue
- *
- * @param req OCF request
- * @param engine_cb IO engine handler callback
- * @param allow_sync caller allows for request from queue to be ran immediately
-		from push function in caller context
- */
-void ocf_engine_push_req_front_cb(struct ocf_request *req,
-		ocf_engine_cb engine_cb,
-		bool allow_sync);
-
 void inc_fallback_pt_error_counter(ocf_cache_t cache);
 
 void ocf_engine_on_resume(struct ocf_request *req);
diff --git a/src/engine/engine_discard.c b/src/engine/engine_discard.c
index 38532de7..b5e975b0 100644
--- a/src/engine/engine_discard.c
+++ b/src/engine/engine_discard.c
@@ -74,7 +74,7 @@ static void _ocf_discard_cache_flush_complete(struct ocf_io *io, int error)
 	}
 
 	req->engine_handler = _ocf_discard_core;
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 
 	ocf_io_put(io);
 }
@@ -111,7 +111,7 @@ static void _ocf_discard_finish_step(struct ocf_request *req)
 	else
 		req->engine_handler = _ocf_discard_core;
 
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static void _ocf_discard_step_complete(struct ocf_request *req, int error)
@@ -182,7 +182,7 @@ static int _ocf_discard_step_do(struct ocf_request *req)
 static void _ocf_discard_on_resume(struct ocf_request *req)
 {
 	OCF_DEBUG_RQ(req, "On resume");
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static int _ocf_discard_step(struct ocf_request *req)
diff --git a/src/engine/engine_fast.c b/src/engine/engine_fast.c
index fc7e608d..5c2f4aa1 100644
--- a/src/engine/engine_fast.c
+++ b/src/engine/engine_fast.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -45,7 +46,7 @@ static void _ocf_read_fast_complete(struct ocf_request *req, int error)
 	if (req->error) {
 		OCF_DEBUG_RQ(req, "ERROR");
 
-		ocf_engine_push_req_front_pt(req);
+		ocf_queue_push_req_pt(req);
 	} else {
 		ocf_req_unlock(ocf_cache_line_concurrency(req->cache), req);
 
diff --git a/src/engine/engine_inv.c b/src/engine/engine_inv.c
index 4b60b2b3..d4c5e9eb 100644
--- a/src/engine/engine_inv.c
+++ b/src/engine/engine_inv.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -62,5 +63,6 @@ static int _ocf_invalidate_do(struct ocf_request *req)
 
 void ocf_engine_invalidate(struct ocf_request *req)
 {
-	ocf_engine_push_req_front_cb(req, _ocf_invalidate_do, true);
+	ocf_queue_push_req_cb(req, _ocf_invalidate_do,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
diff --git a/src/engine/engine_pt.c b/src/engine/engine_pt.c
index 6d3c53dd..dbb2d5e1 100644
--- a/src/engine/engine_pt.c
+++ b/src/engine/engine_pt.c
@@ -1,6 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
- * Copyright(c) 2023 Huawei Technologies
+ * Copyright(c) 2023-2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #include "ocf/ocf.h"
@@ -165,8 +165,9 @@ int ocf_read_pt(struct ocf_request *req)
 	return 0;
 }
 
-void ocf_engine_push_req_front_pt(struct ocf_request *req)
+void ocf_queue_push_req_pt(struct ocf_request *req)
 {
-	ocf_engine_push_req_front_cb(req, ocf_read_pt_do, true);
+	ocf_queue_push_req_cb(req, ocf_read_pt_do,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
diff --git a/src/engine/engine_pt.h b/src/engine/engine_pt.h
index 59da6ce4..9bea3bb1 100644
--- a/src/engine/engine_pt.h
+++ b/src/engine/engine_pt.h
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2021 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -10,6 +11,6 @@ int ocf_read_pt(struct ocf_request *req);
 
 int ocf_read_pt_do(struct ocf_request *req);
 
-void ocf_engine_push_req_front_pt(struct ocf_request *req);
+void ocf_queue_push_req_pt(struct ocf_request *req);
 
 #endif /* ENGINE_OFF_H_ */
diff --git a/src/engine/engine_rd.c b/src/engine/engine_rd.c
index 52fd4d3e..3cf67c75 100644
--- a/src/engine/engine_rd.c
+++ b/src/engine/engine_rd.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -41,7 +42,7 @@ static void _ocf_read_generic_hit_complete(struct ocf_request *req, int error)
 		OCF_DEBUG_RQ(req, "HIT completion");
 
 		if (req->error) {
-			ocf_engine_push_req_front_pt(req);
+			ocf_queue_push_req_pt(req);
 		} else {
 			ocf_req_unlock(c, req);
 
diff --git a/src/engine/engine_wb.c b/src/engine/engine_wb.c
index 9343360c..d419d504 100644
--- a/src/engine/engine_wb.c
+++ b/src/engine/engine_wb.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -102,8 +103,8 @@ static void _ocf_write_wb_complete(struct ocf_request *req, int error)
 
 		ocf_engine_invalidate(req);
 	} else {
-		ocf_engine_push_req_front_cb(req,
-				ocf_write_wb_do_flush_metadata, true);
+		ocf_queue_push_req_cb(req, ocf_write_wb_do_flush_metadata,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	}
 }
 
diff --git a/src/engine/engine_wi.c b/src/engine/engine_wi.c
index 6db17a47..0adf0fb3 100644
--- a/src/engine/engine_wi.c
+++ b/src/engine/engine_wi.c
@@ -56,8 +56,8 @@ static void _ocf_write_wi_io_flush_metadata(struct ocf_request *req, int error)
 
 	if (!req->error && !req->wi_second_pass && ocf_engine_is_miss(req)) {
 		/* need another pass */
-		ocf_engine_push_req_front_cb(req, _ocf_write_wi_next_pass,
-				true);
+		ocf_queue_push_req_cb(req, _ocf_write_wi_next_pass,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 		return;
 	}
 
@@ -123,8 +123,9 @@ static void _ocf_write_wi_core_complete(struct ocf_request *req, int error)
 
 		ocf_req_put(req);
 	} else {
-		ocf_engine_push_req_front_cb(req,
-				ocf_write_wi_update_and_flush_metadata, true);
+		ocf_queue_push_req_cb(req,
+				ocf_write_wi_update_and_flush_metadata,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	}
 }
 
@@ -155,7 +156,7 @@ static int _ocf_write_wi_core_write(struct ocf_request *req)
 static void _ocf_write_wi_on_resume(struct ocf_request *req)
 {
 	OCF_DEBUG_RQ(req, "On resume");
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 int ocf_write_wi(struct ocf_request *req)
diff --git a/src/engine/engine_wo.c b/src/engine/engine_wo.c
index 1b6afee3..9414bda9 100644
--- a/src/engine/engine_wo.c
+++ b/src/engine/engine_wo.c
@@ -171,7 +171,7 @@ static void _ocf_read_wo_core_complete(struct ocf_request *req, int error)
 	}
 
 	req->engine_handler = ocf_read_wo_cache_do;
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static int ocf_read_wo_do(struct ocf_request *req)
diff --git a/src/engine/engine_wt.c b/src/engine/engine_wt.c
index 95a2321c..4dcce9bd 100644
--- a/src/engine/engine_wt.c
+++ b/src/engine/engine_wt.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -112,8 +113,8 @@ static void _ocf_write_wt_req_complete(struct ocf_request *req)
 
 	if (req->info.dirty_any) {
 		/* Some of the request's cachelines changed its state to clean */
-		ocf_engine_push_req_front_cb(req,
-				ocf_write_wt_do_flush_metadata, true);
+		ocf_queue_push_req_cb(req, ocf_write_wt_do_flush_metadata,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	} else {
 		ocf_req_unlock_wr(ocf_cache_line_concurrency(req->cache), req);
 
diff --git a/src/engine/engine_zero.c b/src/engine/engine_zero.c
index 5d6352bc..cdd9b85d 100644
--- a/src/engine/engine_zero.c
+++ b/src/engine/engine_zero.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -50,7 +51,8 @@ static void _ocf_zero_io_flush_metadata(struct ocf_request *req, int error)
 	if (env_atomic_dec_return(&req->req_remaining))
 		return;
 
-	ocf_engine_push_req_front_cb(req, ocf_zero_purge, true);
+	ocf_queue_push_req_cb(req, ocf_zero_purge,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static inline void ocf_zero_map_info(struct ocf_request *req)
@@ -148,7 +150,8 @@ void ocf_engine_zero_line(struct ocf_request *req)
 
 	if (lock >= 0) {
 		ENV_BUG_ON(lock != OCF_LOCK_ACQUIRED);
-		ocf_engine_push_req_front_cb(req, _ocf_zero_do, true);
+		ocf_queue_push_req_cb(req, _ocf_zero_do,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	} else {
 		OCF_DEBUG_RQ(req, "LOCK ERROR %d", lock);
 		req->complete(req, lock);
diff --git a/src/metadata/metadata_io.c b/src/metadata/metadata_io.c
index 65a47787..9be1d2fe 100644
--- a/src/metadata/metadata_io.c
+++ b/src/metadata/metadata_io.c
@@ -93,7 +93,8 @@ static void metadata_io_read_i_atomic_step_end(struct ocf_io *io, int error)
 	context->curr_offset += context->curr_count;
 
 	if (context->count > 0)
-		ocf_engine_push_req_front(context->req, true);
+		ocf_queue_push_req(context->req,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	else
 		metadata_io_read_i_atomic_complete(context, 0);
 }
@@ -181,7 +182,8 @@ int metadata_io_read_i_atomic(ocf_cache_t cache, ocf_queue_t queue, void *priv,
 	context->compl_hndl = compl_hndl;
 	context->priv = priv;
 
-	ocf_engine_push_req_front(context->req, true);
+	ocf_queue_push_req(context->req,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 
 	return 0;
 }
@@ -269,7 +271,7 @@ static void metadata_io_req_finalize(struct metadata_io_request *m_req)
 
 static void metadata_io_page_lock_acquired(struct ocf_request *req)
 {
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static int metadata_io_restart_req(struct ocf_request *req)
@@ -401,7 +403,8 @@ void metadata_io_req_complete(struct metadata_io_request *m_req)
 	}
 
 	m_req->req.engine_handler = metadata_io_restart_req;
-	ocf_engine_push_req_front(&m_req->req, true);
+	ocf_queue_push_req(&m_req->req,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 /*
diff --git a/src/metadata/metadata_passive_update.c b/src/metadata/metadata_passive_update.c
index 8e84a6ad..c77fec40 100644
--- a/src/metadata/metadata_passive_update.c
+++ b/src/metadata/metadata_passive_update.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -70,7 +71,7 @@ static int passive_io_resume(struct ocf_request *req)
 
 static void passive_io_page_lock_acquired(struct ocf_request *req)
 {
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 int ocf_metadata_passive_update(ocf_cache_t cache, struct ocf_io *io,
diff --git a/src/metadata/metadata_raw_dynamic.c b/src/metadata/metadata_raw_dynamic.c
index fc064189..d426ff98 100644
--- a/src/metadata/metadata_raw_dynamic.c
+++ b/src/metadata/metadata_raw_dynamic.c
@@ -389,7 +389,8 @@ static void raw_dynamic_load_all_read_end(struct ocf_io *io, int error)
 	}
 
 	context->req->engine_handler = raw_dynamic_load_all_update;
-	ocf_engine_push_req_front(context->req, true);
+	ocf_queue_push_req(context->req,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static int raw_dynamic_load_all_read(struct ocf_request *req)
@@ -455,7 +456,8 @@ static int raw_dynamic_load_all_update(struct ocf_request *req)
 	}
 
 	context->req->engine_handler = raw_dynamic_load_all_read;
-	ocf_engine_push_req_front(context->req, true);
+	ocf_queue_push_req(context->req,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 
 	return 0;
 }
@@ -501,7 +503,8 @@ void raw_dynamic_load_all(ocf_cache_t cache, struct ocf_metadata_raw *raw,
 	context->req->priv = context;
 	context->req->engine_handler = raw_dynamic_load_all_read;
 
-	ocf_engine_push_req_front(context->req, true);
+	ocf_queue_push_req(context->req,
+			OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	return;
 
 err_req:
diff --git a/src/mngt/ocf_mngt_flush.c b/src/mngt/ocf_mngt_flush.c
index 2cfc5659..cccffc4e 100644
--- a/src/mngt/ocf_mngt_flush.c
+++ b/src/mngt/ocf_mngt_flush.c
@@ -402,7 +402,7 @@ static void _ocf_mngt_flush_portion_end(void *private_data, int error)
 		return;
 	}
 
-	ocf_engine_push_req_back(fc->req, false);
+	ocf_queue_push_req(fc->req, 0);
 }
 
 
@@ -452,7 +452,7 @@ static void _ocf_mngt_flush_container(
 	fc->ticks1 = 0;
 	fc->ticks2 = UINT_MAX;
 
-	ocf_engine_push_req_back(fc->req, true);
+	ocf_queue_push_req(fc->req, OCF_QUEUE_ALLOW_SYNC);
 	return;
 
 finish:
diff --git a/src/ocf_queue.c b/src/ocf_queue.c
index 120ed752..71203c98 100644
--- a/src/ocf_queue.c
+++ b/src/ocf_queue.c
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 #include "ocf/ocf.h"
@@ -39,7 +40,8 @@ int ocf_queue_create(ocf_cache_t cache, ocf_queue_t *queue,
 		return result;
 	}
 
-	INIT_LIST_HEAD(&tmp_queue->io_list);
+	INIT_LIST_HEAD(&tmp_queue->io_list_high);
+	INIT_LIST_HEAD(&tmp_queue->io_list_low);
 	env_atomic_set(&tmp_queue->ref_count, 1);
 	tmp_queue->cache = cache;
 	tmp_queue->ops = ops;
@@ -88,13 +90,48 @@ void ocf_io_handle(struct ocf_io *io, void *opaque)
 	req->engine_handler(req);
 }
 
+static struct ocf_request *ocf_queue_pop_req(ocf_queue_t q)
+{
+	unsigned long lock_flags = 0;
+	struct ocf_request *req;
+	struct list_head *io_list;
+
+	OCF_CHECK_NULL(q);
+
+	/* LOCK */
+	env_spinlock_lock_irqsave(&q->io_list_lock, lock_flags);
+
+	if (!list_empty(&q->io_list_high)) {
+		io_list = &q->io_list_high;
+	} else if (!list_empty(&q->io_list_low)) {
+		io_list = &q->io_list_low;
+	} else {	/* No items on the list */
+		env_spinlock_unlock_irqrestore(&q->io_list_lock,
+				lock_flags);
+		return NULL;
+	}
+
+	/* Get the first request and remove it from the list */
+	req = list_first_entry(io_list, struct ocf_request, list);
+
+	env_atomic_dec(&q->io_no);
+	list_del(&req->list);
+
+	/* UNLOCK */
+	env_spinlock_unlock_irqrestore(&q->io_list_lock, lock_flags);
+
+	OCF_CHECK_NULL(req);
+
+	return req;
+}
+
 void ocf_queue_run_single(ocf_queue_t q)
 {
 	struct ocf_request *io_req = NULL;
 
 	OCF_CHECK_NULL(q);
 
-	io_req = ocf_engine_pop_req(q);
+	io_req = ocf_queue_pop_req(q);
 
 	if (!io_req)
 		return;
@@ -141,3 +178,43 @@ ocf_cache_t ocf_queue_get_cache(ocf_queue_t q)
 	OCF_CHECK_NULL(q);
 	return q->cache;
 }
+
+void ocf_queue_push_req(struct ocf_request *req, uint flags)
+{
+	ocf_cache_t cache = req->cache;
+	ocf_queue_t q = NULL;
+	unsigned long lock_flags = 0;
+	struct list_head *io_list;
+
+	INIT_LIST_HEAD(&req->list);
+
+	ENV_BUG_ON(!req->io_queue);
+	q = req->io_queue;
+
+	if (!req->info.internal) {
+		env_atomic_set(&cache->last_access_ms,
+				env_ticks_to_msecs(env_get_tick_count()));
+	}
+
+	env_spinlock_lock_irqsave(&q->io_list_lock, lock_flags);
+
+	io_list = (flags & OCF_QUEUE_PRIO_HIGH) ? &q->io_list_high : &q->io_list_low;
+	list_add_tail(&req->list, io_list);
+	env_atomic_inc(&q->io_no);
+
+	env_spinlock_unlock_irqrestore(&q->io_list_lock, lock_flags);
+
+	/* NOTE: do not dereference @req past this line, it might
+	 * be picked up by concurrent io thread and deallocated
+	 * at this point */
+
+	ocf_queue_kick(q, (bool)(flags & OCF_QUEUE_ALLOW_SYNC));
+}
+
+void ocf_queue_push_req_cb(struct ocf_request *req,
+		ocf_req_cb req_cb, uint flags)
+{
+	req->error = 0; /* Please explain why!!! */
+	req->engine_handler = req_cb;
+	ocf_queue_push_req(req, flags);
+}
diff --git a/src/ocf_queue_priv.h b/src/ocf_queue_priv.h
index 50160c3a..8cf4725d 100644
--- a/src/ocf_queue_priv.h
+++ b/src/ocf_queue_priv.h
@@ -1,5 +1,6 @@
 /*
  * Copyright(c) 2012-2021 Intel Corporation
+ * Copyright(c) 2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -7,13 +8,19 @@
 #define OCF_QUEUE_PRIV_H_
 
 #include "ocf_env.h"
+#include "ocf_request.h"
+
+/* ocf_queue_push_req flags */
+#define	OCF_QUEUE_ALLOW_SYNC	0x01	/* Request can run immediately in caller context */
+#define	OCF_QUEUE_PRIO_HIGH	0x02	/* Push to the high priority queue */
 
 struct ocf_queue {
 	ocf_cache_t cache;
 
 	void *priv;
 
-	struct list_head io_list;
+	struct list_head io_list_high;
+	struct list_head io_list_low;
 
 	/* per-queue free running global metadata lock index */
 	unsigned lock_idx;
@@ -46,4 +53,22 @@ static inline void ocf_queue_kick(ocf_queue_t queue, bool allow_sync)
 		queue->ops->kick(queue);
 }
 
+/**
+ * @brief Push OCF request to the OCF thread worker queue
+ *
+ * @param req OCF request
+ * @param flags See ocf_queue_push_req flags above
+ */
+void ocf_queue_push_req(struct ocf_request *req, uint flags);
+
+/**
+ * @brief Set interface and push from request to the OCF thread worker queue
+ *
+ * @param req OCF request
+ * @param req_cb IO engine handler callback
+ * @param flags See ocf_queue_push_req flags above
+ */
+void ocf_queue_push_req_cb(struct ocf_request *req,
+		ocf_req_cb req_cb, uint flags);
+
 #endif
diff --git a/src/ocf_request.h b/src/ocf_request.h
index 5e05139f..53571761 100644
--- a/src/ocf_request.h
+++ b/src/ocf_request.h
@@ -9,9 +9,27 @@
 
 #include "ocf_env.h"
 #include "ocf_io_priv.h"
-#include "engine/cache_engine.h"
 #include "metadata/metadata_structs.h"
 
+typedef enum {
+	/* modes inherited from user API */
+	ocf_req_cache_mode_wt = ocf_cache_mode_wt,
+	ocf_req_cache_mode_wb = ocf_cache_mode_wb,
+	ocf_req_cache_mode_wa = ocf_cache_mode_wa,
+	ocf_req_cache_mode_pt = ocf_cache_mode_pt,
+	ocf_req_cache_mode_wi = ocf_cache_mode_wi,
+	ocf_req_cache_mode_wo = ocf_cache_mode_wo,
+
+	/* internal modes */
+	ocf_req_cache_mode_fast,
+		/*!< Fast path */
+	ocf_req_cache_mode_d2c,
+		/*!< Direct to Core - pass through to core without
+				touching cacheline metadata */
+
+	ocf_req_cache_mode_max,
+} ocf_req_cache_mode_t;
+
 struct ocf_req_allocator;
 
 struct ocf_req_info {
@@ -94,6 +112,12 @@ struct ocf_req_discard_info {
 		/*!< Number of processed sector during discard operation */
 };
 
+/**
+ * @brief OCF IO engine handler callback
+ */
+struct ocf_request;
+typedef int (*ocf_req_cb)(struct ocf_request *req);
+
 /**
  * @brief OCF IO request
  */
@@ -129,7 +153,7 @@ struct ocf_request {
 	ocf_core_t core;
 	/*!< Handle to core instance */
 
-	ocf_engine_cb engine_handler;
+	ocf_req_cb engine_handler;
 	/*!< IO engine handler */
 
 	void *priv;
diff --git a/src/utils/utils_cleaner.c b/src/utils/utils_cleaner.c
index 65112e59..210086d1 100644
--- a/src/utils/utils_cleaner.c
+++ b/src/utils/utils_cleaner.c
@@ -217,8 +217,8 @@ static void _ocf_cleaner_complete_req(struct ocf_request *req)
 
 	if (master->complete_queue) {
 		ocf_req_get(master);
-		ocf_engine_push_req_front_cb(master,
-				_ocf_cleaner_complete, true);
+		ocf_queue_push_req_cb(master, _ocf_cleaner_complete,
+				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	} else {
 		/* Only master contains completion function and priv */
 		cmpl = master->master_io_req;
@@ -232,7 +232,7 @@ static void _ocf_cleaner_complete_req(struct ocf_request *req)
 static void _ocf_cleaner_on_resume(struct ocf_request *req)
 {
 	OCF_DEBUG_TRACE(req->cache);
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 /*
@@ -336,7 +336,7 @@ static void _ocf_cleaner_metadata_io_end(struct ocf_request *req, int error)
 	OCF_DEBUG_MSG(req->cache, "Metadata flush finished");
 
 	req->engine_handler = _ocf_cleaner_fire_flush_cache;
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static int _ocf_cleaner_update_metadata(struct ocf_request *req)
@@ -415,7 +415,7 @@ static void _ocf_cleaner_flush_cores_io_end(struct ocf_map_info *map,
 	 * All core writes done, switch to post cleaning activities
 	 */
 	req->engine_handler = _ocf_cleaner_update_metadata;
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static void _ocf_cleaner_flush_cores_io_cmpl(struct ocf_io *io, int error)
@@ -487,7 +487,7 @@ static void _ocf_cleaner_core_io_end(struct ocf_request *req)
 	 * Move processing to thread, where IO will be (and can be) submitted
 	 */
 	req->engine_handler = _ocf_cleaner_fire_flush_cores;
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 }
 
 static void _ocf_cleaner_core_io_cmpl(struct ocf_io *io, int error)
@@ -645,7 +645,7 @@ static void _ocf_cleaner_cache_io_end(struct ocf_request *req)
 	 * Move processing to thread, where IO will be (and can be) submitted
 	 */
 	req->engine_handler = _ocf_cleaner_fire_core;
-	ocf_engine_push_req_front(req, true);
+	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 
 	OCF_DEBUG_MSG(req->cache, "Cache reads finished");
 }
diff --git a/src/utils/utils_parallelize.c b/src/utils/utils_parallelize.c
index a7dd383b..43983bdc 100644
--- a/src/utils/utils_parallelize.c
+++ b/src/utils/utils_parallelize.c
@@ -1,6 +1,6 @@
 /*
  * Copyright(c) 2012-2022 Intel Corporation
- * Copyright(c) 2023 Huawei Technologies
+ * Copyright(c) 2023-2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -142,5 +142,5 @@ void ocf_parallelize_run(ocf_parallelize_t parallelize)
 	int i;
 
 	for (i = 0; i < parallelize->shards_cnt; i++)
-		ocf_engine_push_req_front(parallelize->reqs[i], false);
+		ocf_queue_push_req(parallelize->reqs[i], OCF_QUEUE_PRIO_HIGH);
 }
diff --git a/src/utils/utils_pipeline.c b/src/utils/utils_pipeline.c
index c2a263aa..2e176161 100644
--- a/src/utils/utils_pipeline.c
+++ b/src/utils/utils_pipeline.c
@@ -1,6 +1,6 @@
 /*
  * Copyright(c) 2019-2022 Intel Corporation
- * Copyright(c) 2023 Huawei Technologies
+ * Copyright(c) 2023-2024 Huawei Technologies
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
@@ -47,7 +47,7 @@ static int _ocf_pipeline_run_step(struct ocf_request *req)
 			if (step->pred(pipeline, pipeline->priv, &step->arg)) {
 				step->hndl(pipeline, pipeline->priv, &step->arg);
 				return 0;
-			}	
+			}
 			continue;
 		case ocf_pipeline_step_foreach:
 			arg = &step->args[pipeline->next_arg++];
@@ -126,12 +126,12 @@ void *ocf_pipeline_get_priv(ocf_pipeline_t pipeline)
 
 void ocf_pipeline_next(ocf_pipeline_t pipeline)
 {
-	ocf_engine_push_req_front(pipeline->req, false);
+	ocf_queue_push_req(pipeline->req, OCF_QUEUE_PRIO_HIGH);
 }
 
 void ocf_pipeline_finish(ocf_pipeline_t pipeline, int error)
 {
 	pipeline->finish = true;
 	pipeline->error = error;
-	ocf_engine_push_req_front(pipeline->req, false);
+	ocf_queue_push_req(pipeline->req, OCF_QUEUE_PRIO_HIGH);
 }