path: root/tools/testing/selftests/ublk/kublk.c

/* SPDX-License-Identifier: MIT */
/*
 * Description: uring_cmd based ublk
 */

#include "kublk.h"

unsigned int ublk_dbg_mask = UBLK_LOG;
static const struct ublk_tgt_ops *tgt_ops_list[] = {
	&null_tgt_ops,
	&loop_tgt_ops,
	&stripe_tgt_ops,
};

static const struct ublk_tgt_ops *ublk_find_tgt(const char *name)
{
	const struct ublk_tgt_ops *ops;
	int i;

	if (name == NULL)
		return NULL;

	for (i = 0; sizeof(tgt_ops_list) / sizeof(ops); i++)
		if (strcmp(tgt_ops_list[i]->name, name) == 0)
			return tgt_ops_list[i];
	return NULL;
}

static inline int ublk_setup_ring(struct io_uring *r, int depth,
		int cq_depth, unsigned flags)
{
	struct io_uring_params p;

	memset(&p, 0, sizeof(p));
	p.flags = flags | IORING_SETUP_CQSIZE;
	p.cq_entries = cq_depth;

	return io_uring_queue_init_params(depth, r, &p);
}

static void ublk_ctrl_init_cmd(struct ublk_dev *dev,
		struct io_uring_sqe *sqe,
		struct ublk_ctrl_cmd_data *data)
{
	struct ublksrv_ctrl_dev_info *info = &dev->dev_info;
	struct ublksrv_ctrl_cmd *cmd = (struct ublksrv_ctrl_cmd *)ublk_get_sqe_cmd(sqe);

	sqe->fd = dev->ctrl_fd;
	sqe->opcode = IORING_OP_URING_CMD;
	sqe->ioprio = 0;

	if (data->flags & CTRL_CMD_HAS_BUF) {
		cmd->addr = data->addr;
		cmd->len = data->len;
	}

	if (data->flags & CTRL_CMD_HAS_DATA)
		cmd->data[0] = data->data[0];

	cmd->dev_id = info->dev_id;
	cmd->queue_id = -1;

	ublk_set_sqe_cmd_op(sqe, data->cmd_op);

	io_uring_sqe_set_data(sqe, cmd);
}

static int __ublk_ctrl_cmd(struct ublk_dev *dev,
		struct ublk_ctrl_cmd_data *data)
{
	struct io_uring_sqe *sqe;
	struct io_uring_cqe *cqe;
	int ret = -EINVAL;

	sqe = io_uring_get_sqe(&dev->ring);
	if (!sqe) {
		ublk_err("%s: can't get sqe ret %d\n", __func__, ret);
		return ret;
	}

	ublk_ctrl_init_cmd(dev, sqe, data);

	ret = io_uring_submit(&dev->ring);
	if (ret < 0) {
		ublk_err("uring submit ret %d\n", ret);
		return ret;
	}

	ret = io_uring_wait_cqe(&dev->ring, &cqe);
	if (ret < 0) {
		ublk_err("wait cqe: %s\n", strerror(-ret));
		return ret;
	}
	io_uring_cqe_seen(&dev->ring, cqe);

	return cqe->res;
}

static int ublk_ctrl_stop_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_STOP_DEV,
	};

	return __ublk_ctrl_cmd(dev, &data);
}

static int ublk_ctrl_start_dev(struct ublk_dev *dev,
		int daemon_pid)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_START_DEV,
		.flags	= CTRL_CMD_HAS_DATA,
	};

	dev->dev_info.ublksrv_pid = data.data[0] = daemon_pid;

	return __ublk_ctrl_cmd(dev, &data);
}

static int ublk_ctrl_add_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op	= UBLK_U_CMD_ADD_DEV,
		.flags	= CTRL_CMD_HAS_BUF,
		.addr = (__u64) (uintptr_t) &dev->dev_info,
		.len = sizeof(struct ublksrv_ctrl_dev_info),
	};

	return __ublk_ctrl_cmd(dev, &data);
}

static int ublk_ctrl_del_dev(struct ublk_dev *dev)
{
	struct ublk_ctrl_cmd_data data = {
		.cmd_op = UBLK_U_CMD_DEL_DEV,
		.flags = 0,
	};

	return __ublk_ctrl_cmd(dev, &