On Mon, Jun 06, 2016 at 10:32:38PM -0400, Martin K. Petersen wrote: > >>>>> "Mike" == Mike Snitzer <snit...@redhat.com> writes: > > Mike> But hch was originally in favor of _always_ dropping EOPNOTSUPP on > Mike> the floor (that is what his commit 38f25255330 did). Then he said > Mike> he disagrees with these interfaces playing games with masking > Mike> EOPNOTSUPP -- to which you seemingly really don't agree. Unless > Mike> I'm completely misreading you. > > Userland apps rely on EOPNOTSUPP, we can't break that.
Rely on what exactly? Current we return EOPNOTSUPP if the device doesn't claim to support discards, but it returns 0 if the device first claims to support it but then fails the I/O.
