Re: [PATCH v1 3/3] dm-inlinecrypt: Expose inline crypto caps to the device

[Eric Biggers <ebiggers@kernel.org>]

On Wed, Mar 04, 2026 at 04:17:28AM -0800, Linlin Zhang wrote:
> Add a new DM flag, which means the inline crypto capabilities
> from underlying devices can be exposed to the DM device, and
> the DM device consumes these capabilities, rather pass through
> them to the upper layer.
> 
> Signed-off-by: Linlin Zhang <linlin.zhang@oss.qualcomm.com>
> ---
>  drivers/md/dm-inlinecrypt.c   | 2 +-
>  drivers/md/dm-table.c         | 3 ++-
>  include/linux/device-mapper.h | 7 +++++++
>  3 files changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/md/dm-inlinecrypt.c b/drivers/md/dm-inlinecrypt.c
> index 251760da9f7e..eda56893d430 100644
> --- a/drivers/md/dm-inlinecrypt.c
> +++ b/drivers/md/dm-inlinecrypt.c
> @@ -396,7 +396,7 @@ static struct target_type inlinecrypt_target = {
>  	 * Do not set DM_TARGET_PASSES_CRYPTO, since dm-inlinecrypt consumes the
>  	 * crypto capability itself.
>  	 */
> -	.features		= DM_TARGET_ZONED_HM,
> +	.features		= DM_TARGET_CONSUME_CRYPTO | DM_TARGET_ZONED_HM,
>  	.module			= THIS_MODULE,
>  	.ctr			= inlinecrypt_ctr,
>  	.dtr			= inlinecrypt_dtr,
> diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
> index 7be1d8dc8bdd..f0580935394a 100644
> --- a/drivers/md/dm-table.c
> +++ b/drivers/md/dm-table.c
> @@ -1407,7 +1407,8 @@ static int dm_table_construct_crypto_profile(struct dm_table *t)
>  	for (i = 0; i < t->num_targets; i++) {
>  		struct dm_target *ti = dm_table_get_target(t, i);
>  
> -		if (!dm_target_passes_crypto(ti->type)) {
> +		if (!dm_target_passes_crypto(ti->type)
> +				&& !dm_target_consume_crypto(ti->type)) {
>  			blk_crypto_intersect_capabilities(profile, NULL);
>  			break;
>  		}
> diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
> index 38f625af6ab4..6abd1b4fcb76 100644
> --- a/include/linux/device-mapper.h
> +++ b/include/linux/device-mapper.h
> @@ -306,6 +306,13 @@ struct target_type {
>  #define dm_target_supports_mixed_zoned_model(type) (false)
>  #endif
>  
> +/*
> + * A target consumes inline crypto capabilities itself and doesn't support
> + * passing through inline crypto support.
> + */
> +#define DM_TARGET_CONSUME_CRYPTO		0x00000300
> +#define dm_target_consume_crypto(type) ((type)->features & DM_TARGET_CONSUME_CRYPTO)

This patch doesn't make any sense.  First, no new flag is needed, as the
behavior is already correct if you just leave DM_TARGET_PASSES_CRYPTO
unset, as far as I can tell.  Second, the new flag is numerically equal
to DM_TARGET_PASSES_CRYPTO|CONFIG_BLK_DEV_ZONED.  Third, even if it had
a unique bit as seems to have been intended, the behavior is the same as
DM_TARGET_PASSES_CRYPTO, which should not be used on this target.

- Eric