82ec0ae59d02 ("md: Make sure md_do_sync() will set MD_RECOVERY_DONE")
f97a5528b21e ("md: introduce md_ro_state")
d7a4783883d3 ("md: check for NULL ->meta_bdev before calling bdev_read_only")
118cf084adb3 ("md: implement ->set_read_only to hook into BLKROSET processing")