Re: [PATCH 3/9 next] lib/iov_iter: Improved function for importing iovec[] from userpace.

From: Christoph Hellwig
Date: Mon Sep 21 2020 - 10:10:55 EST

On Tue, Sep 15, 2020 at 02:55:17PM +0000, David Laight wrote:
> import_iovec() has a 'pointer by reference' parameter to pass in the
> (on-stack) iov[] cache and return the address of a larger copy that
> the caller must free.
> This is non-intuitive, faffy to setup, and not that efficient.
> Instead just pass in the address of the cache and return the address
> to free (on success) or PTR_ERR() (on error).

To me it seems pretty sensible, and in fact the conversions to your
new API seem to add more lines than they remove.