MD_FEATURE_JOURNAL
if (le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)
(MD_FEATURE_BITMAP_OFFSET | MD_FEATURE_JOURNAL))
if (!(le32_to_cpu(sb->feature_map) & MD_FEATURE_JOURNAL)) {
sb->feature_map |= cpu_to_le32(MD_FEATURE_JOURNAL);
|MD_FEATURE_JOURNAL \