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); \