Re: Exporting which partitions to md-configure

["H. Peter Anvin" <hpa@zytor.com>]

Neil Brown wrote:
> 
> Well, grepping through fs/partitions/*.c, the 'flags' thing is set by
>  efi.c, msdos.c sgi.c sun.c
> 
> Of these, efi compares something against PARTITION_LINUX_RAID_GUID,
> and msdos.c, sgi.c and sun. compare something against
> LINUX_RAID_PARTITION.
> 
> The former would look like
>   e6d6d379-f507-44c2-a23c-238f2a3df928
> in sysfs (I think);
> The latter would look like
>   fd
> (I suspect).
> 
> These are both easily recognisable with no real room for confusion.

Well, if we're going to have a generic facility it should make sense 
across the board.  If all we're doing is supporting legacy usage we 
might as well export a flag.

I guess we could have a single entry with a string of the form 
"efi:e6d6d379-f507-44c2-a23c-238f2a3df928" or "msdos:fd" etc -- it 
really doesn't make any difference to me, but it seems cleaner to have 
two pieces of data in two different sysfs entries.

> 
> And if other partition styles wanted to add support for raid auto
> detect, tell them "no". It is perfectly possible and even preferable
> to live without autodetect.   We should support legacy usage (those
> above) but should discourage any new usage.
> 

Why is that, keeping in mind this will all be done in userspace?

	-hpa