On Fri, 2018-07-06 at 19:48 -0700, Linus Torvalds wrote: > On Fri, Jul 6, 2018 at 7:39 PM Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > I'd rather add a deprecation warning to the whole "read/write > > to /dev/sg" itself > > In the meantime, I've pulled this, but do wonder why we actually > allow that crazy read/write that doesn't even work for any other > models (ie I guarantee you that cdrom writers etc don't use that > interface, because SG_IO is the only thing that works on most > hardware). We did discuss removing the r/w interface, but, as you say, it's been around for ages so it's not clear what regressions would surface if we did. It's mostly root only (with certain distro exceptions), so the consensus for a short term fix was to make sure it couldn't be exploited. Long term we'll absolutely look into removing it. The argument I've seen for the old interface is userspace programs that want multiple outstanding commands in the old event driven single threaded model (with SG_IO you need one thread for each command) but if you asked me to name any, I couldn't, so perhaps they're all gone by now. James
