[dm-devel] [PATCH] dm-raid: add RAID discard support

[Martin K. Petersen]

>>>>> "Neil" == NeilBrown  <neilb at suse.de> writes:

Neil> I would really rather that discard_zeroes_data were only set on
Neil> devices where it was actually true.  Then it wouldn't be my
Neil> problem any more.

Yeah. It's too late for 3.18 but I'll try to get a whitelist going for
3.19.

Neil>  Here is a question: if a region has been discarded, are we
Neil>  guaranteed that reads are at least stable.  i.e. if I read twice
Neil>  will I definitely get the same value?

If discard_zeroes_data=1, then yes.

-- 
Martin K. Petersen	Oracle Linux Engineering