Re: [PATCH v6] block: sed-opal: Add ioctl to return device status

[Scott Bauer <sbauer@plzdonthack.me>]

On Wed, Aug 10, 2022 at 01:35:51PM +0100, luca.boccassi@gmail.com wrote:
> From: "dougmill@linux.vnet.ibm.com" <dougmill@linux.vnet.ibm.com>
> 
> Provide a mechanism to retrieve basic status information about
> the device, including the "supported" flag indicating whether
> SED-OPAL is supported. The information returned is from the various
> feature descriptors received during the discovery0 step, and so
> this ioctl does nothing more than perform the discovery0 step
> and then save the information received. See "struct opal_status"
> and OPAL_FL_* bits for the status information currently returned.
> 
> This is necessary to be able to check whether a device is OPAL
> enabled, set up, locked or unlocked from userspace programs
> like systemd-cryptsetup and libcryptsetup. Right now we just
> have to assume the user 'knows' or blindly attempt setup/lock/unlock
> operations.
> 
> Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com>
> Tested-by: Luca Boccassi <bluca@debian.org>
> ---
> v2: https://patchwork.kernel.org/project/linux-block/patch/612795b5.tj7FMS9wzchsMzrK%25dougmill@linux.vnet.ibm.com/
> v3: resend on request, after rebasing and testing on my machine
>     https://patchwork.kernel.org/project/linux-block/patch/20220125215248.6489-1-luca.boccassi@gmail.com/
> v4: it's been more than 7 months and no alternative approach has appeared.
>     we really need to be able to identify and query the status of a sed-opal
>     device, so rebased and resending.
> v5: as requested by reviewer, add __32 reserved to the UAPI ioctl struct to align to 64
>     bits and to reserve space for future expansion
> v6: as requested by reviewer, update commit message with use case
> 
>  block/opal_proto.h            |  5 ++
>  block/sed-opal.c              | 90 ++++++++++++++++++++++++++++++-----
>  include/linux/sed-opal.h      |  1 +
>  include/uapi/linux/sed-opal.h | 13 +++++
>  4 files changed, 97 insertions(+), 12 deletions(-)

looks fine
Reviewed-by: Scott Bauer <sbauer@plzdonthack.me>