Re: [PATCH 3/7] crypto: acomp - Add request chaining and virtual addresses

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Feb 27, 2025 at 06:15:00PM +0800, Herbert Xu wrote:
> This adds request chaining and virtual address support to the
> acomp interface.
> 
> It is identical to the ahash interface, except that a new flag
> CRYPTO_ACOMP_REQ_NONDMA has been added to indicate that the
> virtual addresses are not suitable for DMA.  This is because

As with ahash, the request chaining support is a huge mistake.  The problem is
much better solved by adding methods that explicitly take an array of data
buffers (i.e., batch_compress and batch_decompress in the case of compression).
"Request chaining" is unnecessarily complex and creates a lot of edge cases and
ambiguities.  E.g. it would make it ambiguous whether every function operates on
a single request or on the whole list of requests.  It also doesn't even work in
the expected way, as submitting a list of requests won't be equivalent to
submitting them individually.

And as usual for your submissions it's also undocumented and has no tests.

- Eric