On Sun, 2012-04-29 at 17:43 -0700, Linus Torvalds wrote: > On Sun, Apr 29, 2012 at 5:35 PM, H. Peter Anvin <hpa@xxxxxxxxx> wrote: > > > > Which is funny/sad, because that's actually the intended way the > > interface is meant to work. > > Well, the autofs packet model is actually horribly badly misdesigned > even for that: the header doesn't contain the size of the packet. It > contains the packet *type*, and from that you can then determine the > size (of course, every other program would determine it *wrongly* for > this whole x86-64 alignment reason), but that is actually a horrible > model because it assumes you know all the packet types. > > (There's a "len" field in the v5 packet, but that's not the packet > length, that's the length of the name component) > > And the reason nobody does that is that in practice there is only ever > one single type of packet that is possible anyway, so there's no point > in even reading the header to find the type. > > So a much nicer model is one where the actual *size* of the packet is > in the header. That would have allowed for not having that fixed > maximum size of a name etc, and would have avoided the whole problem > to begin with. > > Of course, the nicest model of all is to just use a packetized > interface to begin with, so that none of these issues exist. Which is > what we're now effectively moving to, unless we can find some horrible > program that makes that impossible due to it playing games and knowing > it's a "stream". > > Looking at am-utils, I think we're ok so far. But maybe you know of > yet another crazy user of the autofs interfaces. autodir looks ok as well. http://sourceforge.net/projects/intraperson/files/latest/download > > Linus -- To unsubscribe from this list: send the line "unsubscribe autofs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
