RE: [PATCH 1/2] block: add bi_crypto_ctx variable in struct bio

[Parshuram Raju Thombare]

Hello Jens,

Thank you for a comment.

>-----Original Message-----
>From: Jens Axboe <axboe@xxxxxxxxx>
>Sent: Tuesday, December 11, 2018 7:07 PM
>To: Parshuram Raju Thombare <pthombar@xxxxxxxxxxx>; tj@xxxxxxxxxx;
>jbacik@xxxxxx; michaelcallahan@xxxxxx; snitzer@xxxxxxxxxx;
>osandov@xxxxxx; keith.busch@xxxxxxxxx; ming.lei@xxxxxxxxxx; shli@xxxxxx;
>dennisszhou@xxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
>Cc: Alan Douglas <adouglas@xxxxxxxxxxx>; Janek Kotas <jank@xxxxxxxxxxx>;
>Rafal Ciepiela <rafalc@xxxxxxxxxxx>
>Subject: Re: [PATCH 1/2] block: add bi_crypto_ctx variable in struct bio
>
>EXTERNAL MAIL
>
>
>On 12/11/18 2:50 AM, Parshuram Thombare wrote:
>> Add variable 'void *bi_crypt_ctx' in 'struct bio'. This will be used
>> to associate bio with crypto configuration of controller supporting
>> real time / inline encryption/decryption.
>>
>> Signed-off-by: Parshuram Thombare <pthombar@xxxxxxxxxxx>
>> ---
>>  include/linux/blk_types.h |    4 ++++
>>  1 files changed, 4 insertions(+), 0 deletions(-)
>>
>> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
>> index 1dcf652..bd77603 100644
>> --- a/include/linux/blk_types.h
>> +++ b/include/linux/blk_types.h
>> @@ -188,6 +188,10 @@ struct bio {
>>  #endif
>>  	};
>>
>> +#ifdef CONFIG_BLK_DEV_HW_RT_ENCRYPTION
>> +	void *bi_crypto_ctx;
>> +#endif
>> +
>>  	unsigned short		bi_vcnt;	/* how many bio_vec's */
>>
>>  	/*
>
>Pretty sure I mentioned this last time, but in case I didn't, don't add bio members
>for random drivers. Can you imagine how huge this thing would be if we allowed
>that?
>
>If you need per-io storage, put it in the payload for the blk-mq request. That way
>you are only bloating your own IO related data structures, not everyones.
Ok, I will look into using payload for the blk-mq request instead of adding variable 
in struct bio.
I thought this filed would be useful in enabling inline encryption for other type of
devices too.
>
>--
>Jens Axboe

Regards,
Parshuram Thombare