Messages in this thread | | | Date | Thu, 28 Aug 2008 20:28:06 +0200 | From | Tejun Heo <> | Subject | Re: [PATCH 5/7] FUSE: implement ioctl support |
| |
H. Peter Anvin wrote: > Tejun Heo wrote: >> ioctl support is tricky to implement because only the ioctl >> implementation itself knows which memory regions need to be read >> and/or written. To support this, fuse client can request retry of >> ioctl specifying memory regions to read and write. Deep copying >> (nested pointers) can be implemented by retrying multiple times >> resolving one depth of dereference at a time. > > Okay, I'm going to say it... wouldn't it be better to have some kind of > data structure description language which the userspace can register > with the kernel to linearize the data on a per-ioctl basis (kind of like > rpcgen)?
Ah.... funky. If this retry thing is too repulsive, I guess the best alternative would be directly accessing caller's memory as Miklos suggested.
Thanks.
-- tejun
| |