#val_type uint64_t
#unconditional
BTRFS_DEV_STAT_WRITE_ERRS
BTRFS_DEV_STAT_READ_ERRS
BTRFS_DEV_STAT_FLUSH_ERRS
BTRFS_DEV_STAT_CORRUPTION_ERRS
BTRFS_DEV_STAT_GENERATION_ERRS