Commit ed0c31ae authored by Shin'ichiro Kawasaki's avatar Shin'ichiro Kawasaki Committed by Jens Axboe
Browse files

null_blk: pass transfer size to null_handle_rq() 



As preparation to support partial data transfer, add a new argument to
null_handle_rq() to pass the number of sectors to transfer. While at it,
rename the function from null_handle_rq to null_handle_data_transfer.
This commit does not change the behavior.

Reviewed-by: default avatarDamien Le Moal <dlemoal@kernel.org>
Reviewed-by: default avatarChaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20250226100613.1622564-5-shinichiro.kawasaki@wdc.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 4f235000

drivers/block/null_blk/main.c

+14 −2
Original line number Diff line number Diff line
@@ -1263,25 +1263,37 @@ static int null_transfer(struct nullb *nullb, struct page *page, 
	return err;

}



static blk_status_t null_handle_rq(struct nullb_cmd *cmd)

/*

 * Transfer data for the given request. The transfer size is capped with the

 * nr_sectors argument.

 */

static blk_status_t null_handle_data_transfer(struct nullb_cmd *cmd,

					      sector_t nr_sectors)

{

	struct request *rq = blk_mq_rq_from_pdu(cmd);

	struct nullb *nullb = cmd->nq->dev->nullb;

	int err = 0;

	unsigned int len;

	sector_t sector = blk_rq_pos(rq);

	unsigned int max_bytes = nr_sectors << SECTOR_SHIFT;

	unsigned int transferred_bytes = 0;

	struct req_iterator iter;

	struct bio_vec bvec;



	spin_lock_irq(&nullb->lock);

	rq_for_each_segment(bvec, rq, iter) {

		len = bvec.bv_len;

		if (transferred_bytes + len > max_bytes)

			len = max_bytes - transferred_bytes;

		err = null_transfer(nullb, bvec.bv_page, len, bvec.bv_offset,

				     op_is_write(req_op(rq)), sector,

				     rq->cmd_flags & REQ_FUA);

		if (err)

			break;

		sector += len >> SECTOR_SHIFT;

		transferred_bytes += len;

		if (transferred_bytes >= max_bytes)

			break;

	}

	spin_unlock_irq(&nullb->lock);
@@ -1333,7 +1345,7 @@ blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd, enum req_op op, 
	if (op == REQ_OP_DISCARD)

		return null_handle_discard(dev, sector, nr_sectors);



	return null_handle_rq(cmd);

	return null_handle_data_transfer(cmd, nr_sectors);

}



static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd)