Commit 57ed58c1 authored by Ming Lei's avatar Ming Lei Committed by Jens Axboe
Browse files

selftests: ublk: enable zero copy for stripe target 



Use io_uring vectored fixed kernel buffer for handling stripe IO.

Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20250325135155.935398-5-ming.lei@redhat.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1045afae

tools/testing/selftests/ublk/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ TEST_PROGS += test_loop_05.sh 
TEST_PROGS += test_stripe_01.sh

TEST_PROGS += test_stripe_02.sh

TEST_PROGS += test_stripe_03.sh

TEST_PROGS += test_stripe_04.sh



TEST_PROGS += test_stress_01.sh

TEST_PROGS += test_stress_02.sh

tools/testing/selftests/ublk/stripe.c

+52 −17
Original line number Diff line number Diff line
@@ -111,43 +111,67 @@ static void calculate_stripe_array(const struct stripe_conf *conf, 
	}

}



static inline enum io_uring_op stripe_to_uring_op(const struct ublksrv_io_desc *iod)

static inline enum io_uring_op stripe_to_uring_op(

		const struct ublksrv_io_desc *iod, int zc)

{

	unsigned ublk_op = ublksrv_get_op(iod);



	if (ublk_op == UBLK_IO_OP_READ)

		return IORING_OP_READV;

		return zc ? IORING_OP_READV_FIXED : IORING_OP_READV;

	else if (ublk_op == UBLK_IO_OP_WRITE)

		return IORING_OP_WRITEV;

		return zc ? IORING_OP_WRITEV_FIXED : IORING_OP_WRITEV;

	assert(0);

}



static int stripe_queue_tgt_rw_io(struct ublk_queue *q, const struct ublksrv_io_desc *iod, int tag)

{

	const struct stripe_conf *conf = get_chunk_shift(q);

	enum io_uring_op op = stripe_to_uring_op(iod);

	int zc = !!(ublk_queue_use_zc(q) != 0);

	enum io_uring_op op = stripe_to_uring_op(iod, zc);

	struct io_uring_sqe *sqe[NR_STRIPE];

	struct stripe_array *s = alloc_stripe_array(conf, iod);

	struct ublk_io *io = ublk_get_io(q, tag);

	int i;

	int i, extra = zc ? 2 : 0;



	io->private_data = s;

	calculate_stripe_array(conf, iod, s);



	ublk_queue_alloc_sqes(q, sqe, s->nr);

	for (i = 0; i < s->nr; i++) {

		struct stripe *t = &s->s[i];

	ublk_queue_alloc_sqes(q, sqe, s->nr + extra);



	if (zc) {

		io_uring_prep_buf_register(sqe[0], 0, tag, q->q_id, tag);

		sqe[0]->flags |= IOSQE_CQE_SKIP_SUCCESS | IOSQE_IO_HARDLINK;

		sqe[0]->user_data = build_user_data(tag,

			ublk_cmd_op_nr(sqe[0]->cmd_op), 0, 1);

	}



	for (i = zc; i < s->nr + extra - zc; i++) {

		struct stripe *t = &s->s[i - zc];



		io_uring_prep_rw(op, sqe[i],

				t->seq + 1,

				(void *)t->vec,

				t->nr_vec,

				t->start << 9);

		if (zc) {

			sqe[i]->buf_index = tag;

			io_uring_sqe_set_flags(sqe[i],

					IOSQE_FIXED_FILE | IOSQE_IO_HARDLINK);

		} else {

			io_uring_sqe_set_flags(sqe[i], IOSQE_FIXED_FILE);

		}

		/* bit63 marks us as tgt io */

		sqe[i]->user_data = build_user_data(tag, ublksrv_get_op(iod), i, 1);

		sqe[i]->user_data = build_user_data(tag, ublksrv_get_op(iod), i - zc, 1);

	}

	return s->nr;

	if (zc) {

		struct io_uring_sqe *unreg = sqe[s->nr + 1];



		io_uring_prep_buf_unregister(unreg, 0, tag, q->q_id, tag);

		unreg->user_data = build_user_data(tag, ublk_cmd_op_nr(unreg->cmd_op), 0, 1);

	}



	/* register buffer is skip_success */

	return s->nr + zc;

}



static int handle_flush(struct ublk_queue *q, const struct ublksrv_io_desc *iod, int tag)
@@ -208,19 +232,27 @@ static void ublk_stripe_io_done(struct ublk_queue *q, int tag, 
	struct ublk_io *io = ublk_get_io(q, tag);

	int res = cqe->res;



	if (res < 0) {

	if (res < 0 || op != ublk_cmd_op_nr(UBLK_U_IO_UNREGISTER_IO_BUF)) {

		if (!io->result)

			io->result = res;

		if (res < 0)

			ublk_err("%s: io failure %d tag %u\n", __func__, res, tag);

	}



	/* buffer register op is IOSQE_CQE_SKIP_SUCCESS */

	if (op == ublk_cmd_op_nr(UBLK_U_IO_REGISTER_IO_BUF))

		io->tgt_ios += 1;



	/* fail short READ/WRITE simply */

	if (op == UBLK_IO_OP_READ || op == UBLK_IO_OP_WRITE) {

		unsigned seq = user_data_to_tgt_data(cqe->user_data);

		struct stripe_array *s = io->private_data;



		if (res < s->s[seq].vec->iov_len)

		if (res < s->s[seq].nr_sects << 9) {

			io->result = -EIO;

			ublk_err("%s: short rw op %u res %d exp %u tag %u\n",

					__func__, op, res, s->s[seq].vec->iov_len, tag);

		}

	}



	if (ublk_completed_tgt_io(q, tag)) {
@@ -253,7 +285,7 @@ static int ublk_stripe_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev) 
	struct stripe_conf *conf;

	unsigned chunk_shift;

	loff_t bytes = 0;

	int ret, i;

	int ret, i, mul = 1;



	if ((chunk_size & (chunk_size - 1)) || !chunk_size) {

		ublk_err("invalid chunk size %u\n", chunk_size);
@@ -295,8 +327,11 @@ static int ublk_stripe_tgt_init(const struct dev_ctx *ctx, struct ublk_dev *dev) 
	dev->tgt.dev_size = bytes;

	p.basic.dev_sectors = bytes >> 9;

	dev->tgt.params = p;

	dev->tgt.sq_depth = dev->dev_info.queue_depth * conf->nr_files;

	dev->tgt.cq_depth = dev->dev_info.queue_depth * conf->nr_files;



	if (dev->dev_info.flags & UBLK_F_SUPPORT_ZERO_COPY)

		mul = 2;

	dev->tgt.sq_depth = mul * dev->dev_info.queue_depth * conf->nr_files;

	dev->tgt.cq_depth = mul * dev->dev_info.queue_depth * conf->nr_files;



	printf("%s: shift %u files %u\n", __func__, conf->shift, conf->nr_files);