Fail cache recovery in case of erroneous mapping

Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>

src/metadata/metadata.c

@@ -1552,6 +1552,26 @@ void ocf_metadata_clear_dirty_if_invalid(struct ocf_cache *cache,
 	}
 }
 
+bool ocf_metadata_check(struct ocf_cache *cache, ocf_cache_line_t line)
+{
+	switch (cache->metadata.line_size) {
+		case ocf_cache_line_size_4:
+			return _ocf_metadata_check_u8(cache, line);
+		case ocf_cache_line_size_8:
+			return _ocf_metadata_check_u16(cache, line);
+		case ocf_cache_line_size_16:
+			return _ocf_metadata_check_u32(cache, line);
+		case ocf_cache_line_size_32:
+			return _ocf_metadata_check_u64(cache, line);
+		case ocf_cache_line_size_64:
+			return _ocf_metadata_check_u128(cache, line);
+		case ocf_cache_line_size_none:
+		default:
+			ENV_BUG_ON(1);
+			return false;
+	}
+}
+
 int ocf_metadata_init(struct ocf_cache *cache,
 		ocf_cache_line_size_t cache_line_size)
 {

src/metadata/metadata.h

@@ -220,4 +220,14 @@ static inline ocf_cache_line_t ocf_metadata_collision_table_entries(
 void ocf_metadata_zero_superblock(ocf_cache_t cache,
 		ocf_metadata_end_t cmpl, void *context);
 
+/**
+ * @brief Check for incorrect status bits combinations
+ *
+ * @param cache Cache instance
+ * @param line Cache line
+ * @return true - status bits are correct
+ * @return false - status bits have illegal value
+ */
+bool ocf_metadata_check(struct ocf_cache *cache, ocf_cache_line_t line);
+
 #endif /* METADATA_H_ */

src/metadata/metadata_bit.h

@@ -263,6 +263,23 @@ static void _ocf_metadata_clear_dirty_if_invalid_##type(struct ocf_cache *cache,
 \
 	map[line].dirty &= (mask & map[line].valid) | (~mask); \
 } \
+\
+/* true if no incorrect combination of status bits */ \
+static bool _ocf_metadata_check_##type(struct ocf_cache *cache, \
+		ocf_cache_line_t line) \
+{ \
+	struct ocf_metadata_ctrl *ctrl = \
+		(struct ocf_metadata_ctrl *) cache->metadata.priv; \
+\
+	struct ocf_metadata_raw *raw = \
+			&ctrl->raw_desc[metadata_segment_collision]; \
+\
+	struct ocf_metadata_map_##type *map = raw->mem_pool; \
+\
+	_raw_bug_on(raw, line); \
+\
+	return (map[line].dirty & (~map[line].valid)) == 0; \
+} \
 
 #define ocf_metadata_bit_funcs(type) \
 ocf_metadata_bit_struct(type); \

src/mngt/ocf_mngt_cache.c

@@ -495,7 +495,7 @@ static void _recovery_reset_cline_metadata(struct ocf_cache *cache,
 	ocf_cleaning_init_cache_block(cache, cline);
 }
 
-static void _ocf_mngt_rebuild_metadata(ocf_cache_t cache)
+static int _ocf_mngt_rebuild_metadata(ocf_cache_t cache)
 {
 	ocf_cache_line_t cline;
 	ocf_core_id_t core_id;
@@ -512,25 +512,40 @@ static void _ocf_mngt_rebuild_metadata(ocf_cache_t cache)
 		OCF_COND_RESCHED(step, 128);
 		ocf_metadata_get_core_info(cache, cline, &core_id, &core_line);
 
-		metadata_clear_dirty_if_invalid(cache, cline);
+		if (!ocf_metadata_check(cache, cline) ||
+				core_id > OCF_CORE_MAX) {
+			ocf_cache_log(cache, log_err, "Inconsistent mapping "
+					"detected in on-disk metadata - "
+					"refusing to recover cache.\n");
+			return -OCF_ERR_INVAL;
+		}
 
 		any_valid = metadata_clear_valid_if_clean(cache, cline);
-		if (!any_valid || core_id >= OCF_CORE_MAX) {
+		if (!any_valid || core_id == OCF_CORE_MAX) {
 			/* Reset metadata for not mapped or clean cache line */
 			_recovery_reset_cline_metadata(cache, cline);
 			continue;
 		}
 
+		if (!cache->core[core_id].added) {
+			ocf_cache_log(cache, log_err, "Stale mapping in "
+					"on-disk metadata - refusing to "
+					"recover cache.\n");
+			return -OCF_ERR_INVAL;
+		}
+
 		/* Rebuild metadata for mapped cache line */
 		ocf_cline_rebuild_metadata(cache, core_id, core_line, cline);
 	}
 
 	ocf_metadata_end_exclusive_access(&cache->metadata.lock);
+
+	return 0;
 }
 
-static void _ocf_mngt_recovery_rebuild_metadata(ocf_cache_t cache)
+static int _ocf_mngt_recovery_rebuild_metadata(ocf_cache_t cache)
 {
-	_ocf_mngt_rebuild_metadata(cache);
+	return _ocf_mngt_rebuild_metadata(cache);
 }
 
 static inline ocf_error_t _ocf_init_cleaning_policy(ocf_cache_t cache,
@@ -556,9 +571,12 @@ static void _ocf_mngt_load_post_metadata_load(ocf_pipeline_t pipeline,
 	struct ocf_cache_attach_context *context = priv;
 	ocf_cache_t cache = context->cache;
 	ocf_error_t result;
+	int ret;
 
 	if (context->metadata.shutdown_status != ocf_metadata_clean_shutdown) {
-		_ocf_mngt_recovery_rebuild_metadata(cache);
+		ret = _ocf_mngt_recovery_rebuild_metadata(cache);
+		if (ret)
+			OCF_PL_FINISH_RET(pipeline, ret);
 		__populate_free(cache);
 	}
 
@@ -2113,8 +2131,11 @@ static void _ocf_mngt_standby_recovery(ocf_pipeline_t pipeline,
 {
 	struct ocf_cache_attach_context *context = priv;
 	ocf_cache_t cache = context->cache;
+	int ret;
 
-	_ocf_mngt_recovery_rebuild_metadata(cache);
+	ret = _ocf_mngt_recovery_rebuild_metadata(cache);
+	if (ret)
+		OCF_PL_FINISH_RET(pipeline, ret);
 	__populate_free(cache);
 
 	ocf_pipeline_next(pipeline);