Re: fs: Use non-const iov in aio_read/aio_write

From: Herbert Xu
Date: Sun Nov 02 2014 - 19:22:22 EST


On Mon, Nov 03, 2014 at 12:16:34AM +0000, Al Viro wrote:
>
> NAK with extreme prejudice. The right way to deal with that is
> to convert the socket side of things to iov_iter. And give it a
> consistent behaviour, while we are at it (some protocols do advance
> the damn thing, so do not). There are _very_ good reasons to have those
> iovecs unchanged - if you look at the callers on the socket side, you'll
> see a bunch that has to _copy_ iovec just to avoid it being buggered.
> And you get rather suboptimal behaviour in memcpy_fromiovec() and friends,
> exactly because you have to skip through the emptied elements.
>
> IOW, no way in hell.

You're welcome to send patches fix every spot in the network stack
that writes to the iovec. But until the network stack is all fixed
up, having a const struct iovec in aio_read/aio_write is a delusion.

Cheers,
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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