+ up_write(&(cmd)->root_lock)
+
+static bool cmd_read_lock(struct dm_cache_metadata *cmd)
+{
+ down_read(&cmd->root_lock);
+ if (cmd->fail_io) {
+ up_read(&cmd->root_lock);
+ return false;
+ }
+ return true;
+}
+
+#define READ_LOCK(cmd) \
+ do { \
+ if (!cmd_read_lock((cmd))) \
+ return -EINVAL; \
+ } while(0)
+
+#define READ_LOCK_VOID(cmd) \
+ do { \
+ if (!cmd_read_lock((cmd))) \
+ return; \
+ } while(0)
+
+#define READ_UNLOCK(cmd) \
+ up_read(&(cmd)->root_lock)