[dm-devel] [PATCH 15/15] block: split scsi_request out of struct request
Jens Axboe
axboe at fb.com
Thu Jan 12 03:59:11 UTC 2017
On Tue, Jan 10 2017, Christoph Hellwig wrote:
> And require all drivers that want to support BLOCK_PC to allocate it
> as the first thing of their private data. To support this the legacy
> IDE and BSG code is switched to set cmd_size on their queues to let
> the block layer allocate the additional space.
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index be23859..499728d 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -225,17 +225,7 @@ struct request {
> int tag;
> int errors;
>
> - /*
> - * when request is used as a packet command carrier
> - */
> - unsigned char __cmd[BLK_MAX_CDB];
> - unsigned char *cmd;
> - unsigned short cmd_len;
> -
> unsigned int extra_len; /* length of alignment and padding */
> - unsigned int sense_len;
> - unsigned int resid_len; /* residual count */
> - void *sense;
Oh yes, my mouth is watering. I've wanted to kill off ->cmd and friends
with fire for years.
On the block front, I think the solution is fine with mimicking the mq
solution of carrying an rq payload, and the implementation for the
legacy path looks fine.
--
Jens Axboe
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