> The attached patch implement this:
> - don't rely on FS_FLAGS_UPDATED to see if we need to update new fields from
>   old fields.
> - when writing back the superblock, copy back the flags to the old location
>   if only old flags are set (FS_FLAGS_UPDATED won't be set in this case).
>   If mounted on other OS, the lack of FS_FLAGS_UPDATED will trigger the
>   compat code, but it shouldn't be a problem as the old fields are up to
>   date. It will also help for filesystems shared between old and new
>   kernels and fsck (one could think the filesystem is clean when it isn't).

	i'm not a filesystem guy, but it seems to be the right thing.  thank
	you! (i busted couple of harddisks by booting UFS2-capable kernel
	and UFS1-only fsck already)

itojun