Merge pull request #829 from mmichal10/d2c-improvement

D2C improvement

src/engine/cache_engine.c

@@ -21,7 +21,6 @@
 #include "engine_fast.h"
 #include "engine_flush.h"
 #include "engine_discard.h"
-#include "engine_d2c.h"
 #include "../utils/utils_user_part.h"
 #include "../utils/utils_refcnt.h"
 #include "../ocf_request.h"
@@ -42,9 +41,6 @@ enum ocf_io_if_type {
 	OCF_IO_FAST_IF,
 	OCF_IO_FLUSH_IF,
 	OCF_IO_DISCARD_IF,
-	OCF_IO_D2C_IF,
-	OCF_IO_D2C_FLUSH_IF,
-	OCF_IO_D2C_DISCARD_IF,
 	OCF_IO_PRIV_MAX_IF,
 };
 
@@ -112,27 +108,6 @@ static const struct ocf_io_if IO_IFS[OCF_IO_PRIV_MAX_IF] = {
 		},
 		.name = "Discard",
 	},
-	[OCF_IO_D2C_IF] = {
-		.cbs = {
-			[OCF_READ] = ocf_d2c_io,
-			[OCF_WRITE] = ocf_d2c_io,
-		},
-		.name = "Direct to core io",
-	},
-	[OCF_IO_D2C_FLUSH_IF] = {
-		.cbs = {
-			[OCF_READ] = ocf_d2c_flush,
-			[OCF_WRITE] = ocf_d2c_flush,
-		},
-		.name = "Direct to core flush",
-	},
-	[OCF_IO_D2C_DISCARD_IF] = {
-		.cbs = {
-			[OCF_READ] = ocf_d2c_discard,
-			[OCF_WRITE] = ocf_d2c_discard,
-		},
-		.name = "Direct to core discard",
-	},
 };
 
 static const struct ocf_io_if *cache_mode_io_if_map[ocf_req_cache_mode_max] = {
@@ -143,7 +118,6 @@ static const struct ocf_io_if *cache_mode_io_if_map[ocf_req_cache_mode_max] = {
 	[ocf_req_cache_mode_wo] = &IO_IFS[OCF_IO_WO_IF],
 	[ocf_req_cache_mode_pt] = &IO_IFS[OCF_IO_PT_IF],
 	[ocf_req_cache_mode_fast] = &IO_IFS[OCF_IO_FAST_IF],
-	[ocf_req_cache_mode_d2c] = &IO_IFS[OCF_IO_D2C_IF],
 };
 
 const char *ocf_get_io_iface_name(ocf_req_cache_mode_t cache_mode)
@@ -178,11 +152,6 @@ void ocf_resolve_effective_cache_mode(ocf_cache_t cache,
 {
 	ocf_cache_mode_t cache_mode;
 
-	if (req->d2c) {
-		req->cache_mode = ocf_req_cache_mode_d2c;
-		return;
-	}
-
 	if (ocf_fallback_pt_is_on(cache)){
 		req->cache_mode = ocf_req_cache_mode_pt;
 		return;
@@ -266,11 +235,6 @@ void ocf_engine_hndl_discard_req(struct ocf_request *req)
 {
 	ocf_req_get(req);
 
-	if (req->d2c) {
-		IO_IFS[OCF_IO_D2C_DISCARD_IF].cbs[req->rw](req);
-		return;
-	}
-
 	IO_IFS[OCF_IO_DISCARD_IF].cbs[req->rw](req);
 }
 
@@ -278,9 +242,7 @@ void ocf_engine_hndl_flush_req(struct ocf_request *req)
 {
 	ocf_req_get(req);
 
-	req->engine_handler = (req->d2c) ?
-			IO_IFS[OCF_IO_D2C_FLUSH_IF].cbs[req->rw] :
-			IO_IFS[OCF_IO_FLUSH_IF].cbs[req->rw];
+	req->engine_handler = IO_IFS[OCF_IO_FLUSH_IF].cbs[req->rw];
 
 	ocf_queue_push_req(req, OCF_QUEUE_ALLOW_SYNC);
 }

src/engine/engine_d2c.c

@@ -29,7 +29,7 @@ static void _ocf_d2c_completion(struct ocf_request *req, int error)
 	ocf_req_put(req);
 }
 
-int ocf_d2c_io(struct ocf_request *req)
+int ocf_d2c_io_fast(struct ocf_request *req)
 {
 	OCF_DEBUG_TRACE(req->cache);
 
@@ -46,13 +46,10 @@ int ocf_d2c_io(struct ocf_request *req)
 	ocf_core_stats_request_pt_update(req->core, req->part_id, req->rw,
 			req->info.hit_no, req->core_line_count);
 
-	/* Put OCF request - decrease reference counter */
-	ocf_req_put(req);
-
 	return 0;
 }
 
-int ocf_d2c_flush(struct ocf_request *req)
+int ocf_d2c_flush_fast(struct ocf_request *req)
 {
 	OCF_DEBUG_TRACE(req->cache);
 
@@ -69,13 +66,10 @@ int ocf_d2c_flush(struct ocf_request *req)
 	ocf_core_stats_request_pt_update(req->core, req->part_id, req->rw,
 			req->info.hit_no, req->core_line_count);
 
-	/* Put OCF request - decrease reference counter */
-	ocf_req_put(req);
-
 	return 0;
 }
 
-int ocf_d2c_discard(struct ocf_request *req)
+int ocf_d2c_discard_fast(struct ocf_request *req)
 {
 	OCF_DEBUG_TRACE(req->cache);
 
@@ -92,8 +86,5 @@ int ocf_d2c_discard(struct ocf_request *req)
 	ocf_core_stats_request_pt_update(req->core, req->part_id, req->rw,
 			req->info.hit_no, req->core_line_count);
 
-	/* Put OCF request - decrease reference counter */
-	ocf_req_put(req);
-
 	return 0;
 }

src/engine/engine_d2c.h

@@ -7,10 +7,10 @@
 #ifndef ENGINE_2DC_H_
 #define ENGINE_2DC_H_
 
-int ocf_d2c_io(struct ocf_request *req);
+int ocf_d2c_io_fast(struct ocf_request *req);
 
-int ocf_d2c_flush(struct ocf_request *req);
+int ocf_d2c_flush_fast(struct ocf_request *req);
 
-int ocf_d2c_discard(struct ocf_request *req);
+int ocf_d2c_discard_fast(struct ocf_request *req);
 
 #endif /* ENGINE_2DC_H_ */

src/ocf_core.c

@@ -10,6 +10,7 @@
 #include "ocf_io_priv.h"
 #include "metadata/metadata.h"
 #include "engine/cache_engine.h"
+#include "engine/engine_d2c.h"
 #include "utils/utils_user_part.h"
 #include "ocf_request.h"
 
@@ -241,10 +242,6 @@ static int ocf_core_submit_io_fast(struct ocf_io *io, struct ocf_request *req,
 	ocf_req_cache_mode_t original_mode, resolved_mode;
 	int ret;
 
-	if (req->d2c) {
-		return OCF_FAST_PATH_NO;
-	}
-
 	if (req->cache_mode == ocf_req_cache_mode_pt)
 		return OCF_FAST_PATH_NO;
 
@@ -286,21 +283,27 @@ static void ocf_core_volume_submit_io(struct ocf_io *io)
 		return;
 	}
 
-	ret = ocf_req_alloc_map(req);
-	if (ret) {
-		ocf_io_end(io, ret);
+	req->core = core;
+	req->complete = ocf_req_complete;
+
+	ocf_io_get(io);
+
+	if (unlikely(req->d2c)) {
+		ocf_core_update_stats(core, io);
+		ocf_d2c_io_fast(req);
 		return;
 	}
 
+	ret = ocf_req_alloc_map(req);
+	if (ret)
+		goto err;
+
 	req->part_id = ocf_user_part_class2id(cache, io->io_class);
-	req->core = core;
-	req->complete = ocf_req_complete;
 
 	ocf_resolve_effective_cache_mode(cache, core, req);
 
 	ocf_core_update_stats(core, io);
 
-	ocf_io_get(io);
 	/* Prevent race condition */
 	ocf_req_get(req);
 
@@ -317,9 +320,14 @@ static void ocf_core_volume_submit_io(struct ocf_io *io)
 	ret = ocf_engine_hndl_req(req);
 	if (ret) {
 		dec_counter_if_req_was_dirty(req);
+		goto err;
+	}
+
+	return;
+
+err:
 	ocf_io_end(io, ret);
 	ocf_io_put(io);
-	}
 }
 
 static void ocf_core_volume_submit_flush(struct ocf_io *io)
@@ -351,6 +359,11 @@ static void ocf_core_volume_submit_flush(struct ocf_io *io)
 
 	ocf_io_get(io);
 
+	if (unlikely(req->d2c)) {
+		ocf_d2c_flush_fast(req);
+		return;
+	}
+
 	ocf_engine_hndl_flush_req(req);
 }
 
@@ -383,17 +396,23 @@ static void ocf_core_volume_submit_discard(struct ocf_io *io)
 		return;
 	}
 
-	ret = ocf_req_alloc_map_discard(req);
-	if (ret) {
-		ocf_io_end(io, -OCF_ERR_NO_MEM);
-		return;
-	}
-
 	req->core = core;
 	req->complete = ocf_req_complete;
 
 	ocf_io_get(io);
 
+	if (unlikely(req->d2c)) {
+		ocf_d2c_discard_fast(req);
+		return;
+	}
+
+	ret = ocf_req_alloc_map_discard(req);
+	if (ret) {
+		ocf_io_end(io, -OCF_ERR_NO_MEM);
+		ocf_io_put(io);
+		return;
+	}
+
 	ocf_engine_hndl_discard_req(req);
 }