Re: [PATCH v8 13/13] nvmet-passthru: support block accounting

[Sagi Grimberg]

> Support block disk accounting by setting the RQF_IO_STAT flag
> and gendisk in the request.
>
> After this change, IO counts will be reflected correctly in
> /proc/diskstats for drives being used by passthru.
>
> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> ---
>   drivers/nvme/target/io-cmd-passthru.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/target/io-cmd-passthru.c b/drivers/nvme/target/io-cmd-passthru.c
> index 7557927a3451..63f12750a80d 100644
> --- a/drivers/nvme/target/io-cmd-passthru.c
> +++ b/drivers/nvme/target/io-cmd-passthru.c
> @@ -410,6 +410,9 @@ static struct request *nvmet_passthru_blk_make_request(struct nvmet_req *req,
>   	if (unlikely(IS_ERR(rq)))
>   		return rq;
>   
> +	if (blk_queue_io_stat(q) && cmd->common.opcode != nvme_cmd_flush)
> +		rq->rq_flags |= RQF_IO_STAT;

Does flush has data bytes in the request? Why the special casing?