Merge pull request #826 from mmichal10/errors-in-engines

Errors in engines

src/engine/engine_d2c.c

@@ -21,10 +21,8 @@ static void _ocf_d2c_completion(struct ocf_request *req, int error)
 
 	OCF_DEBUG_RQ(req, "Completion");
 
-	if (req->error) {
-		req->info.core_error = 1;
+	if (req->error)
 		ocf_core_stats_core_error_update(req->core, req->rw);
-	}
 
 	/* Complete request */
 	req->complete(req, req->error);

src/engine/engine_pt.c

@@ -28,10 +28,8 @@ static void _ocf_read_pt_complete(struct ocf_request *req, int error)
 
 	OCF_DEBUG_RQ(req, "Completion");
 
-	if (req->error) {
-		req->info.core_error = 1;
+	if (req->error)
 		ocf_core_stats_core_error_update(req->core, OCF_READ);
-	}
 
 	/* Complete request */
 	req->complete(req, req->error);

src/engine/engine_rd.c

@@ -78,7 +78,6 @@ static void _ocf_read_generic_miss_complete(struct ocf_request *req, int error)
 			 */
 			req->complete(req, req->error);
 
-			req->info.core_error = 1;
 			ocf_core_stats_core_error_update(req->core, OCF_READ);
 
 			ctx_data_free(cache->owner, req->cp_data);

src/engine/engine_wi.c

@@ -107,7 +107,6 @@ static void _ocf_write_wi_core_complete(struct ocf_request *req, int error)
 {
 	if (error) {
 		req->error = error;
-		req->info.core_error = 1;
 		ocf_core_stats_core_error_update(req->core, OCF_WRITE);
 	}
 

src/engine/engine_wo.c

@@ -156,7 +156,6 @@ static void _ocf_read_wo_core_complete(struct ocf_request *req, int error)
 {
 	if (error) {
 		req->error |= error;
-		req->info.core_error = 1;
 		ocf_core_stats_core_error_update(req->core, OCF_READ);
 	}
 

src/engine/engine_wt.c

@@ -68,7 +68,7 @@ static void _ocf_write_wt_do_flush_metadata_compl(struct ocf_request *req,
 
 	ocf_req_unlock_wr(ocf_cache_line_concurrency(req->cache), req);
 
-	req->complete(req, req->info.core_error ? req->error : 0);
+	req->complete(req, error);
 
 	ocf_req_put(req);
 }
@@ -100,14 +100,9 @@ static void _ocf_write_wt_req_complete(struct ocf_request *req)
 
 	OCF_DEBUG_RQ(req, "Completion");
 
-	if (req->error) {
-		/* An error occured */
-
-		/* Complete request */
-		req->complete(req, req->info.core_error ? req->error : 0);
-
+	if (req->info.cache_error || req->info.core_error) {
+		req->complete(req, req->error);
 		ocf_engine_invalidate(req);
-
 		return;
 	}
 
@@ -117,21 +112,22 @@ static void _ocf_write_wt_req_complete(struct ocf_request *req)
 				OCF_QUEUE_ALLOW_SYNC | OCF_QUEUE_PRIO_HIGH);
 	} else {
 		ocf_req_unlock_wr(ocf_cache_line_concurrency(req->cache), req);
-
-		req->complete(req, req->info.core_error ? req->error : 0);
-
+		req->complete(req, 0);
 		ocf_req_put(req);
 	}
 }
 
 static void _ocf_write_wt_cache_complete(struct ocf_request *req, int error)
 {
 	if (error) {
-		req->error = req->error ?: error;
+		/* Cache error code is not propagated further to the user here
+		 * because data could be successfully written to the core device
+		 * despite the cache IO error.
+		 * Error flag is set though to indicate that the error occurred
+		 * and to invalidate the request in completion. */
+		req->info.cache_error = 1;
 		ocf_core_stats_cache_error_update(req->core, OCF_WRITE);
-
-		if (req->error)
-			inc_fallback_pt_error_counter(req->cache);
+		inc_fallback_pt_error_counter(req->cache);
 	}
 
 	_ocf_write_wt_req_complete(req);

src/ocf_request.h

@@ -55,8 +55,11 @@ struct ocf_req_info {
 	uint32_t cleaning_required : 1;
 	/*!< Eviction failed, need to request cleaning */
 
+	uint32_t cache_error : 1;
+	/*!< Error occurred during I/O on cache device */
+
 	uint32_t core_error : 1;
-	/*!< Error occured during I/O on core device */
+	/*!< Error occurred during I/O on core device */
 
 	uint32_t cleaner_cache_line_lock : 1;
 	/*!< Cleaner flag - acquire cache line lock */
@@ -192,6 +195,12 @@ struct ocf_request {
 	int error;
 	/*!< This filed indicates an error for OCF request */
 
+	int cache_error;
+	/*!< Indicator of forward IO cache device error */
+
+	int core_error;
+	/*!< Indicator of forward IO core device error */
+
 	ocf_part_id_t part_id;
 	/*!< Targeted partition of requests */