Re: bcache-tools package for Fedora / status probe-bcache

[Gabriel de Perthuis <g2p.code@gmail.com>]

>> I'm not a fan of a blkid csum check (I pointed it out on the 
>> bug[1]). If a superblock gets scribbled or corrupted, you want 
>> bcache to complain, and you don't want blkid to look for the next 
>> possible signature.
> 
> Having blkid also verify the csum was requested by Karel Zak, the 
> maintainer of util-linux. As a packager of bcache-tools I'm in favour
> of having blkid identify bcache, but I don't have a preference on
> using csum to identify bcache. I can pass the message to Karel, but
> it would be better if we both discuss it on the appropriate 
> (util-linux?) mail list.

Karel, are you okay if blkid doesn't do the csum verification discussed above?
Checksum failures will be reported by the kernel instead.
Alternatively, do you see a way libblkid can return good magic / bad checksum
results?

>>> So now I'm wondering: are there any particular reasons to keep 
>>> probe-bcache part of the package, or will it really be obsolete?
>> 
>> If you address the above and tweak the udev rules, why not.
>> 
>> The upstream repo will need to keep probe-bcache for a while 
>> longer, because we don't have a way to require a sufficiently 
>> recent libblkid.
> 
> I agree, f20 is a specific case, but in general probe-bcache will be 
> needed for a while.

For the record, the libblkid patch is a good thing in the long run:
common interface, less forks in udev.

>> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1001120#c9