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From:   Rui Salvaterra <rsalvaterra@gmail.com>
Date:   Thu, 22 Oct 2020 22:19:17 +0100
Message-ID: <CALjTZva495Lp39D=AKoRcdK2MbqwVRenaaMA+4KUPtLCXEeKJQ@mail.gmail.com>
Subject: Re: [PATCH] zram: break the strict dependency from lzo
To:     minchan@kernel.org, ngupta@vflare.org,
        sergey.senozhatsky.work@gmail.com
Cc:     linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
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Oops, this is broken, I'll send a v2 soon.

On Thu, 22 Oct 2020 at 17:11, Rui Salvaterra <rsalvaterra@gmail.com> wrote:
>
> There's nothing special about zram and lzo. It works just fine without it, so
> as long as at least one of the other supported compression algorithms is
> selected.
>
> Additionally, drop the explicit dependency from CRYPTO, as it's implied by the
> selection of the algorithms themselves.
>
> Signed-off-by: Rui Salvaterra <rsalvaterra@gmail.com>
> ---
>  drivers/block/zram/Kconfig | 8 ++++++--
>  drivers/block/zram/zcomp.c | 2 ++
>  2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
> index fe7a4b7d30cf..2641b86f8677 100644
> --- a/drivers/block/zram/Kconfig
> +++ b/drivers/block/zram/Kconfig
> @@ -1,8 +1,7 @@
>  # SPDX-License-Identifier: GPL-2.0
>  config ZRAM
>         tristate "Compressed RAM block device support"
> -       depends on BLOCK && SYSFS && ZSMALLOC && CRYPTO
> -       select CRYPTO_LZO
> +       depends on BLOCK && SYSFS && ZSMALLOC
>         help
>           Creates virtual block devices called /dev/zramX (X = 0, 1, ...).
>           Pages written to these disks are compressed and stored in memory
> @@ -37,3 +36,8 @@ config ZRAM_MEMORY_TRACKING
>           /sys/kernel/debug/zram/zramX/block_state.
>
>           See Documentation/admin-guide/blockdev/zram.rst for more information.
> +
> +config ZRAM_AUTOSEL_ALGO
> +       def_bool y
> +       depends on ZRAM && !(CRYPTO_LZ4 || CRYPTO_LZ4HC || CRYPTO_842 || CRYPTO_ZSTD)
> +       select CRYPTO_LZO
> diff --git a/drivers/block/zram/zcomp.c b/drivers/block/zram/zcomp.c
> index 33e3b76c4fa9..052aa3f65514 100644
> --- a/drivers/block/zram/zcomp.c
> +++ b/drivers/block/zram/zcomp.c
> @@ -15,8 +15,10 @@
>  #include "zcomp.h"
>
>  static const char * const backends[] = {
> +#if IS_ENABLED(CONFIG_CRYPTO_LZO)
>         "lzo",
>         "lzo-rle",
> +#endif
>  #if IS_ENABLED(CONFIG_CRYPTO_LZ4)
>         "lz4",
>  #endif
> --
> 2.28.0
>