linux-kernel - Re: [PATCH mm-unstable 3/5] mm: zpool: Remove object mapping APIs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <Z8nTa1yut6I0RS0a@google.com>
Date: Thu, 6 Mar 2025 16:55:07 +0000
From: Yosry Ahmed <yosry.ahmed@...ux.dev>
To: Herbert Xu <herbert@...dor.apana.org.au>,
	Sergey Senozhatsky <senozhatsky@...omium.org>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	Johannes Weiner <hannes@...xchg.org>, Nhat Pham <nphamcs@...il.com>,
	Chengming Zhou <chengming.zhou@...ux.dev>,
	Minchan Kim <minchan@...nel.org>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH mm-unstable 3/5] mm: zpool: Remove object mapping APIs

On Thu, Mar 06, 2025 at 12:19:19PM +0800, Herbert Xu wrote:
> On Thu, Mar 06, 2025 at 09:48:58AM +0800, Herbert Xu wrote:
> >
> > This patch breaks zbud and z3fold because they haven't been converted
> > to the new interface.
> 
> I've rebased my zswap SG patch on top of your series.  I've removed
> all the mapping code from zpool/zsmalloc and pushed it out to zram
> instead.
> 
> This patch depends on a new memcpy_sglist function which I've just
> posted a patch for:
> 
> https://patchwork.kernel.org/project/linux-crypto/patch/Z8kXhLb681E_FLzs@gondor.apana.org.au/
> 
> From a77ee529b831e7e606ed2a5b723b74ce234a3915 Mon Sep 17 00:00:00 2001
> From: Herbert Xu <herbert@...dor.apana.org.au>
> Date: Thu, 6 Mar 2025 12:13:58 +0800
> Subject: [PATCH] mm: zswap: Give non-linear objects to Crypto API
> 
> Instead of copying non-linear objects into a buffer, use the
> scatterlist to give them directly to the Crypto API.
> 
> Signed-off-by: Herbert Xu <herbert@...dor.apana.org.au>

The zswap and zsmalloc look good and the code is simpler. I am fine with
this approach if Sergey is fine with it, although I wonder if we should
update Sergey's patches in mm-unstable do this directly. Currently we
are switching from mapping APIs to read/write APIs, and then quickly to
the pinning APIs. The history will be confusing.

Sergey, do you prefer if we keep things as-is, or if you update your
series to incorporate Herbert's changes for zsmalloc/zram, then I can
update my series to incorporate the changes in zswap?

We can also combine the series into a single updated one with
zsmalloc/zram/zswap changes.

Let me know what you prefer.