Commit be82a890 authored by Stanley Zhang's avatar Stanley Zhang Committed by Jens Axboe
Browse files

ublk: implement integrity user copy 



Add a function ublk_copy_user_integrity() to copy integrity information
between a request and a user iov_iter. This mirrors the existing
ublk_copy_user_pages() but operates on request integrity data instead of
regular data. Check UBLKSRV_IO_INTEGRITY_FLAG in iocb->ki_pos in
ublk_user_copy() to choose between copying data or integrity data.

[csander: change offset units from data bytes to integrity data bytes,
 fix CONFIG_BLK_DEV_INTEGRITY=n build, rebase on user copy refactor]

Signed-off-by: default avatarStanley Zhang <stazhang@purestorage.com>
Signed-off-by: default avatarCaleb Sander Mateos <csander@purestorage.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent fd5a005f

drivers/block/ublk_drv.c

+51 −2
Original line number Diff line number Diff line
@@ -1040,6 +1040,33 @@ static size_t ublk_copy_user_pages(const struct request *req, 
	return done;

}



#ifdef CONFIG_BLK_DEV_INTEGRITY

static size_t ublk_copy_user_integrity(const struct request *req,

		unsigned offset, struct iov_iter *uiter, int dir)

{

	size_t done = 0;

	struct bio *bio = req->bio;

	struct bvec_iter iter;

	struct bio_vec iv;



	if (!blk_integrity_rq(req))

		return 0;



	bio_for_each_integrity_vec(iv, bio, iter) {

		if (!ublk_copy_user_bvec(&iv, &offset, uiter, dir, &done))

			break;

	}



	return done;

}

#else /* #ifdef CONFIG_BLK_DEV_INTEGRITY */

static size_t ublk_copy_user_integrity(const struct request *req,

		unsigned offset, struct iov_iter *uiter, int dir)

{

	return 0;

}

#endif /* #ifdef CONFIG_BLK_DEV_INTEGRITY */



static inline bool ublk_need_map_req(const struct request *req)

{

	return ublk_rq_has_data(req) && req_op(req) == REQ_OP_WRITE;
@@ -2668,6 +2695,8 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir) 
	struct ublk_queue *ubq;

	struct request *req;

	struct ublk_io *io;

	unsigned data_len;

	bool is_integrity;

	size_t buf_off;

	u16 tag, q_id;

	ssize_t ret;
@@ -2681,6 +2710,10 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir) 
	tag = ublk_pos_to_tag(iocb->ki_pos);

	q_id = ublk_pos_to_hwq(iocb->ki_pos);

	buf_off = ublk_pos_to_buf_off(iocb->ki_pos);

	is_integrity = !!(iocb->ki_pos & UBLKSRV_IO_INTEGRITY_FLAG);



	if (unlikely(!ublk_dev_support_integrity(ub) && is_integrity))

		return -EINVAL;



	if (q_id >= ub->dev_info.nr_hw_queues)

		return -EINVAL;
@@ -2697,7 +2730,14 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir) 
	if (!req)

		return -EINVAL;



	if (buf_off > blk_rq_bytes(req)) {

	if (is_integrity) {

		struct blk_integrity *bi = &req->q->limits.integrity;



		data_len = bio_integrity_bytes(bi, blk_rq_sectors(req));

	} else {

		data_len = blk_rq_bytes(req);

	}

	if (buf_off > data_len) {

		ret = -EINVAL;

		goto out;

	}
@@ -2707,6 +2747,9 @@ ublk_user_copy(struct kiocb *iocb, struct iov_iter *iter, int dir) 
		goto out;

	}



	if (is_integrity)

		ret = ublk_copy_user_integrity(req, buf_off, iter, dir);

	else

		ret = ublk_copy_user_pages(req, buf_off, iter, dir);



out:
@@ -3948,6 +3991,12 @@ static int __init ublk_init(void) 


	BUILD_BUG_ON((u64)UBLKSRV_IO_BUF_OFFSET +

			UBLKSRV_IO_BUF_TOTAL_SIZE < UBLKSRV_IO_BUF_OFFSET);

	/*

	 * Ensure UBLKSRV_IO_BUF_OFFSET + UBLKSRV_IO_BUF_TOTAL_SIZE

	 * doesn't overflow into UBLKSRV_IO_INTEGRITY_FLAG

	 */

	BUILD_BUG_ON(UBLKSRV_IO_BUF_OFFSET + UBLKSRV_IO_BUF_TOTAL_SIZE >=

		     UBLKSRV_IO_INTEGRITY_FLAG);

	BUILD_BUG_ON(sizeof(struct ublk_auto_buf_reg) != 8);



	init_waitqueue_head(&ublk_idr_wq);

include/uapi/linux/ublk_cmd.h

+4 −0
Original line number Diff line number Diff line
@@ -134,6 +134,10 @@ 
#define UBLKSRV_IO_BUF_TOTAL_BITS	(UBLK_QID_OFF + UBLK_QID_BITS)

#define UBLKSRV_IO_BUF_TOTAL_SIZE	(1ULL << UBLKSRV_IO_BUF_TOTAL_BITS)



/* Copy to/from request integrity buffer instead of data buffer */

#define UBLK_INTEGRITY_FLAG_OFF 62

#define UBLKSRV_IO_INTEGRITY_FLAG (1ULL << UBLK_INTEGRITY_FLAG_OFF)



/*

 * ublk server can register data buffers for incoming I/O requests with a sparse

 * io_uring buffer table. The request buffer can then be used as the data buffer