engine_rd: Ignore backfill buffer allocation errors

Signed-off-by: Michal Mielewczyk <michal.mielewczyk@huawei.com>

src/engine/engine_bf.c

@@ -60,10 +60,12 @@ static void _ocf_backfill_complete(struct ocf_request *req, int error)
 	backfill_queue_dec_unblock(req->cache);
 
 	/* We must free the pages we have allocated */
-	ctx_data_secure_erase(cache->owner, req->data);
-	ctx_data_munlock(cache->owner, req->data);
-	ctx_data_free(cache->owner, req->data);
-	req->data = NULL;
+	if (likely(req->data)) {
+		ctx_data_secure_erase(cache->owner, req->data);
+		ctx_data_munlock(cache->owner, req->data);
+		ctx_data_free(cache->owner, req->data);
+		req->data = NULL;
+	}
 
 	if (req->error) {
 		ocf_engine_invalidate(req);
@@ -79,13 +81,18 @@ static int _ocf_backfill_do(struct ocf_request *req)
 {
 	unsigned int reqs_to_issue;
 
+	req->data = req->cp_data;
+	if (unlikely(req->data == NULL)) {
+		env_atomic_set(&req->req_remaining, 1);
+		_ocf_backfill_complete(req, -OCF_ERR_NO_MEM);
+		return 0;
+	}
+
 	reqs_to_issue = ocf_engine_io_count(req);
 
 	/* There will be #reqs_to_issue completions */
 	env_atomic_set(&req->req_remaining, reqs_to_issue);
 
-	req->data = req->cp_data;
-
 	ocf_submit_cache_reqs(req->cache, req, OCF_WRITE, 0, req->byte_length,
 				reqs_to_issue, _ocf_backfill_complete);
 

src/engine/engine_rd.c

@@ -103,21 +103,25 @@ static inline void _ocf_read_generic_submit_miss(struct ocf_request *req)
 
 	req->cp_data = ctx_data_alloc(cache->owner,
 			BYTES_TO_PAGES(req->byte_length));
-	if (!req->cp_data)
+	if (!req->cp_data) {
+		/* If buffer allocation for backfill fails, ignore the error */
+		ocf_cache_log(cache, log_warn, "Backfill buffer allocation "
+				"error (size %u)\n",
+				req->byte_length);
 		goto err_alloc;
+	}
 
 	ret = ctx_data_mlock(cache->owner, req->cp_data);
-	if (ret)
-		goto err_alloc;
+	if (ret) {
+		ocf_cache_log(cache, log_warn, "Backfill error\n");
+		ctx_data_free(cache->owner, req->cp_data);
+		req->cp_data = NULL;
+	}
 
+err_alloc:
 	/* Submit read request to core device. */
 	ocf_submit_volume_req(&req->core->volume, req,
 			_ocf_read_generic_miss_complete);
-
-	return;
-
-err_alloc:
-	_ocf_read_generic_miss_complete(req, -OCF_ERR_NO_MEM);
 }
 
 static int _ocf_read_generic_do(struct ocf_request *req)