Messages in this thread | | | Date | Thu, 28 Aug 2008 20:02:44 +0200 | From | Tejun Heo <> | Subject | Re: [PATCH 5/7] FUSE: implement ioctl support |
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Tejun Heo wrote: > Greg KH wrote: >> Why do we need ioctls? For CUSE? In that case, would we need to copy >> the memory from userspace, into the kernel, and then back out into >> userspace again? Can't we just have a "pass-through" type fixed ioctl >> instead? > > Can you elaborate a bit? How the fixed ioctl would know how much to > copy in and out and from where?
If you're worried about the double copying due to performance reasons, what we can do is implementing userspace to userspace copying. I just took easier path of copying twice as u-u copy can't be done using the existing FUSE mechanics, but frankly, at this point, I think that would be an premature optimization.
-- tejun
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