H. Peter Anvin wrote:

quoted text
> 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

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