engines/sg.c - platform/external/fio - Gitiles

 /*
  * scsi generic sg v3 io engine
  *
  */
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <assert.h>
 #include <sys/poll.h>

 #include "../fio.h"
 #include "../os.h"

 #ifdef FIO_HAVE_SGIO

 struct sgio_cmd {
 	unsigned char cdb[10];
 	int nr;
 };

 struct sgio_data {
 	struct sgio_cmd *cmds;
 	struct io_u **events;
 	struct pollfd *pfds;
 	int *fd_flags;
 	void *sgbuf;
 	unsigned int bs;
 };

 static void sgio_hdr_init(struct sgio_data *sd, struct sg_io_hdr *hdr,
 			  struct io_u *io_u, int fs)
 {
 	struct sgio_cmd *sc = &sd->cmds[io_u->index];

 	memset(hdr, 0, sizeof(*hdr));
 	memset(sc->cdb, 0, sizeof(sc->cdb));

 	hdr->interface_id = 'S';
 	hdr->cmdp = sc->cdb;
 	hdr->cmd_len = sizeof(sc->cdb);
 	hdr->pack_id = io_u->index;
 	hdr->usr_ptr = io_u;

 	if (fs) {
 		hdr->dxferp = io_u->xfer_buf;
 		hdr->dxfer_len = io_u->xfer_buflen;
 	}
 }

 static int pollin_events(struct pollfd *pfds, int fds)
 {
 	int i;

 	for (i = 0; i < fds; i++)
 		if (pfds[i].revents & POLLIN)
 			return 1;

 	return 0;
 }

 static int fio_sgio_getevents(struct thread_data *td, int min, int max,
 			      struct timespec fio_unused *t)
 {
 	/*
 	 * normally hard coding &td->files[0] is a bug that needs to be fixed,
 	 * but it's ok here as all files should point to the same device.
 	 */
 	struct fio_file *f = &td->files[0];
 	struct sgio_data *sd = td->io_ops->data;
 	int left = max, ret, events, i, r = 0;
 	void *buf = sd->sgbuf;

 	/*
 	 * Fill in the file descriptors
 	 */
 	for_each_file(td, f, i) {
 		/*
 		 * don't block for min events == 0
 		 */
 		if (!min) {
 			sd->fd_flags[i] = fcntl(f->fd, F_GETFL);
 			fcntl(f->fd, F_SETFL, sd->fd_flags[i] | O_NONBLOCK);
 		}
 		sd->pfds[i].fd = f->fd;
 		sd->pfds[i].events = POLLIN;
 	}

 	while (left) {
 		void *p;

 		do {
 			if (!min)
 				break;

 			ret = poll(sd->pfds, td->nr_files, -1);
 			if (ret < 0) {
 				if (!r)
 					r = -errno;
 				td_verror(td, errno);
 				break;
 			} else if (!ret)
 				continue;

 			if (pollin_events(sd->pfds, td->nr_files))
 				break;
 		} while (1);

 		if (r < 0)
 			break;

 re_read:
 		p = buf;
 		events = 0;
 		for_each_file(td, f, i) {
 			ret = read(f->fd, p, left * sizeof(struct sg_io_hdr));
 			if (ret < 0) {
 				if (errno == EAGAIN)
 					continue;
 				r = -errno;
 				td_verror(td, errno);
 				break;
 			} else if (ret) {
 				p += ret;
 				events += ret / sizeof(struct sg_io_hdr);
 			}
 		}

 		if (r < 0)
 			break;
 		if (!events) {
 			usleep(1000);
 			goto re_read;
 		}

 		left -= events;
 		r += events;

 		for (i = 0; i < events; i++) {
 			struct sg_io_hdr *hdr = (struct sg_io_hdr *) buf + i;

 			sd->events[i] = hdr->usr_ptr;
 		}
 	}

 	if (!min) {
 		for_each_file(td, f, i)
 			fcntl(f->fd, F_SETFL, sd->fd_flags[i]);
 	}

 	return r;
 }

 static int fio_sgio_ioctl_doio(struct thread_data *td,
 			       struct fio_file *f, struct io_u *io_u)
 {
 	struct sgio_data *sd = td->io_ops->data;
 	struct sg_io_hdr *hdr = &io_u->hdr;
 	int ret;

 	sd->events[0] = io_u;

 	ret = ioctl(f->fd, SG_IO, hdr);
 	if (ret < 0)
 		return -errno;

 	return FIO_Q_COMPLETED;
 }

 static int fio_sgio_rw_doio(struct fio_file *f, struct io_u *io_u, int sync)
 {
 	struct sg_io_hdr *hdr = &io_u->hdr;
 	int ret;

 	ret = write(f->fd, hdr, sizeof(*hdr));
 	if (ret < 0)
 		return errno;

 	if (sync) {
 		ret = read(f->fd, hdr, sizeof(*hdr));
 		if (ret < 0)
 			return -errno;
 		return FIO_Q_COMPLETED;
 	}

 	return FIO_Q_QUEUED;
 }

 static int fio_sgio_doio(struct thread_data *td, struct io_u *io_u, int sync)
 {
 	struct fio_file *f = io_u->file;

 	if (td->filetype == FIO_TYPE_BD)
 		return fio_sgio_ioctl_doio(td, f, io_u);

 	return fio_sgio_rw_doio(f, io_u, sync);
 }

 static int fio_sgio_prep(struct thread_data *td, struct io_u *io_u)
 {
 	struct sg_io_hdr *hdr = &io_u->hdr;
 	struct sgio_data *sd = td->io_ops->data;
 	int nr_blocks, lba;

 	if (io_u->xfer_buflen & (sd->bs - 1)) {
 		log_err("read/write not sector aligned\n");
 		return EINVAL;
 	}

 	if (io_u->ddir == DDIR_READ) {
 		sgio_hdr_init(sd, hdr, io_u, 1);

 		hdr->dxfer_direction = SG_DXFER_FROM_DEV;
 		hdr->cmdp[0] = 0x28;
 	} else if (io_u->ddir == DDIR_WRITE) {
 		sgio_hdr_init(sd, hdr, io_u, 1);

 		hdr->dxfer_direction = SG_DXFER_TO_DEV;
 		hdr->cmdp[0] = 0x2a;
 	} else {
 		sgio_hdr_init(sd, hdr, io_u, 0);

 		hdr->dxfer_direction = SG_DXFER_NONE;
 		hdr->cmdp[0] = 0x35;
 	}

 	if (hdr->dxfer_direction != SG_DXFER_NONE) {
 		nr_blocks = io_u->xfer_buflen / sd->bs;
 		lba = io_u->offset / sd->bs;
 		hdr->cmdp[2] = (unsigned char) ((lba >> 24) & 0xff);
 		hdr->cmdp[3] = (unsigned char) ((lba >> 16) & 0xff);
 		hdr->cmdp[4] = (unsigned char) ((lba >>  8) & 0xff);
 		hdr->cmdp[5] = (unsigned char) (lba & 0xff);
 		hdr->cmdp[7] = (unsigned char) ((nr_blocks >> 8) & 0xff);
 		hdr->cmdp[8] = (unsigned char) (nr_blocks & 0xff);
 	}

 	return 0;
 }

 static int fio_sgio_queue(struct thread_data *td, struct io_u *io_u)
 {
 	struct sg_io_hdr *hdr = &io_u->hdr;
 	int ret;

 	ret = fio_sgio_doio(td, io_u, io_u->ddir == DDIR_SYNC);

 	if (ret < 0)
 		io_u->error = errno;
 	else if (hdr->status) {
 		io_u->resid = hdr->resid;
 		io_u->error = EIO;
 	}

 	if (io_u->error) {
 		td_verror(td, io_u->error);
 		return FIO_Q_COMPLETED;
 	}

 	return ret;
 }

 static struct io_u *fio_sgio_event(struct thread_data *td, int event)
 {
 	struct sgio_data *sd = td->io_ops->data;

 	return sd->events[event];
 }

 static int fio_sgio_get_bs(struct thread_data *td, unsigned int *bs)
 {
 	struct sgio_data *sd = td->io_ops->data;
 	struct io_u *io_u;
 	struct sg_io_hdr *hdr;
 	unsigned char buf[8];
 	int ret;

 	io_u = __get_io_u(td);
 	io_u->file = &td->files[0];
 	assert(io_u);

 	hdr = &io_u->hdr;
 	sgio_hdr_init(sd, hdr, io_u, 0);
 	memset(buf, 0, sizeof(buf));

 	hdr->cmdp[0] = 0x25;
 	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
 	hdr->dxferp = buf;
 	hdr->dxfer_len = sizeof(buf);

 	ret = fio_sgio_doio(td, io_u, 1);
 	if (ret) {
 		put_io_u(td, io_u);
 		return ret;
 	}

 	*bs = (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
 	put_io_u(td, io_u);
 	return 0;
 }

 static void fio_sgio_cleanup(struct thread_data *td)
 {
 	struct sgio_data *sd = td->io_ops->data;

 	if (sd) {
 		free(sd->events);
 		free(sd->cmds);
 		free(sd->fd_flags);
 		free(sd->pfds);
 		free(sd->sgbuf);
 		free(sd);

 		td->io_ops->data = NULL;
 	}
 }

 static int fio_sgio_init(struct thread_data *td)
 {
 	struct fio_file *f = &td->files[0];
 	struct sgio_data *sd;
 	unsigned int bs;
 	int ret;

 	sd = malloc(sizeof(*sd));
 	memset(sd, 0, sizeof(*sd));
 	sd->cmds = malloc(td->iodepth * sizeof(struct sgio_cmd));
 	memset(sd->cmds, 0, td->iodepth * sizeof(struct sgio_cmd));
 	sd->events = malloc(td->iodepth * sizeof(struct io_u *));
 	memset(sd->events, 0, td->iodepth * sizeof(struct io_u *));
 	sd->pfds = malloc(sizeof(struct pollfd) * td->nr_files);
 	memset(sd->pfds, 0, sizeof(struct pollfd) * td->nr_files);
 	sd->fd_flags = malloc(sizeof(int) * td->nr_files);
 	memset(sd->fd_flags, 0, sizeof(int) * td->nr_files);
 	sd->sgbuf = malloc(sizeof(struct sg_io_hdr) * td->iodepth);
 	memset(sd->sgbuf, 0, sizeof(struct sg_io_hdr) * td->iodepth);

 	td->io_ops->data = sd;

 	if (td->filetype == FIO_TYPE_BD) {
 		if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
 			td_verror(td, errno);
 			goto err;
 		}
 	} else if (td->filetype == FIO_TYPE_CHAR) {
 		int version;

 		if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
 			td_verror(td, errno);
 			goto err;
 		}

 		ret = fio_sgio_get_bs(td, &bs);
 		if (ret)
 			goto err;
 	} else {
 		log_err("ioengine sgio only works on block devices\n");
 		goto err;
 	}

 	sd->bs = bs;

 	if (td->filetype == FIO_TYPE_BD) {
 		td->io_ops->getevents = NULL;
 		td->io_ops->event = NULL;
 	}

 	/*
 	 * we want to do it, regardless of whether odirect is set or not
 	 */
 	td->override_sync = 1;
 	return 0;
 err:
 	free(sd->events);
 	free(sd->cmds);
 	free(sd->fd_flags);
 	free(sd->pfds);
 	free(sd->sgbuf);
 	free(sd);
 	td->io_ops->data = NULL;
 	return 1;
 }

 static struct ioengine_ops ioengine = {
 	.name		= "sg",
 	.version	= FIO_IOOPS_VERSION,
 	.init		= fio_sgio_init,
 	.prep		= fio_sgio_prep,
 	.queue		= fio_sgio_queue,
 	.getevents	= fio_sgio_getevents,
 	.event		= fio_sgio_event,
 	.cleanup	= fio_sgio_cleanup,
 	.flags		= FIO_SYNCIO | FIO_RAWIO,
 };

 #else /* FIO_HAVE_SGIO */

 /*
  * When we have a proper configure system in place, we simply wont build
  * and install this io engine. For now install a crippled version that
  * just complains and fails to load.
  */
 static int fio_sgio_init(struct thread_data fio_unused *td)
 {
 	fprintf(stderr, "fio: sgio not available\n");
 	return 1;
 }

 static struct ioengine_ops ioengine = {
 	.name		= "sgio",
 	.version	= FIO_IOOPS_VERSION,
 	.init		= fio_sgio_init,
 };

 #endif

 static void fio_init fio_sgio_register(void)
 {
 	register_ioengine(&ioengine);
 }

 static void fio_exit fio_sgio_unregister(void)
 {
 	unregister_ioengine(&ioengine);
 }
	/*
	* scsi generic sg v3 io engine
	*
	*/
	#include <stdio.h>
	#include <stdlib.h>
	#include <unistd.h>
	#include <errno.h>
	#include <assert.h>
	#include <sys/poll.h>

	#include "../fio.h"
	#include "../os.h"

	#ifdef FIO_HAVE_SGIO

	struct sgio_cmd {
	unsigned char cdb[10];
	int nr;
	};

	struct sgio_data {
	struct sgio_cmd *cmds;
	struct io_u **events;
	struct pollfd *pfds;
	int *fd_flags;
	void *sgbuf;
	unsigned int bs;
	};

	static void sgio_hdr_init(struct sgio_data sd, struct sg_io_hdr hdr,
	struct io_u *io_u, int fs)
	{
	struct sgio_cmd *sc = &sd->cmds[io_u->index];

	memset(hdr, 0, sizeof(*hdr));
	memset(sc->cdb, 0, sizeof(sc->cdb));

	hdr->interface_id = 'S';
	hdr->cmdp = sc->cdb;
	hdr->cmd_len = sizeof(sc->cdb);
	hdr->pack_id = io_u->index;
	hdr->usr_ptr = io_u;

	if (fs) {
	hdr->dxferp = io_u->xfer_buf;
	hdr->dxfer_len = io_u->xfer_buflen;
	}
	}

	static int pollin_events(struct pollfd *pfds, int fds)
	{
	int i;

	for (i = 0; i < fds; i++)
	if (pfds[i].revents & POLLIN)
	return 1;

	return 0;
	}

	static int fio_sgio_getevents(struct thread_data *td, int min, int max,
	struct timespec fio_unused *t)
	{
	/*
	* normally hard coding &td->files[0] is a bug that needs to be fixed,
	* but it's ok here as all files should point to the same device.
	*/
	struct fio_file *f = &td->files[0];
	struct sgio_data *sd = td->io_ops->data;
	int left = max, ret, events, i, r = 0;
	void *buf = sd->sgbuf;

	/*
	* Fill in the file descriptors
	*/
	for_each_file(td, f, i) {
	/*
	* don't block for min events == 0
	*/
	if (!min) {
	sd->fd_flags[i] = fcntl(f->fd, F_GETFL);
	fcntl(f->fd, F_SETFL, sd->fd_flags[i] \| O_NONBLOCK);
	}
	sd->pfds[i].fd = f->fd;
	sd->pfds[i].events = POLLIN;
	}

	while (left) {
	void *p;

	do {
	if (!min)
	break;

	ret = poll(sd->pfds, td->nr_files, -1);
	if (ret < 0) {
	if (!r)
	r = -errno;
	td_verror(td, errno);
	break;
	} else if (!ret)
	continue;

	if (pollin_events(sd->pfds, td->nr_files))
	break;
	} while (1);

	if (r < 0)
	break;

	re_read:
	p = buf;
	events = 0;
	for_each_file(td, f, i) {
	ret = read(f->fd, p, left * sizeof(struct sg_io_hdr));
	if (ret < 0) {
	if (errno == EAGAIN)
	continue;
	r = -errno;
	td_verror(td, errno);
	break;
	} else if (ret) {
	p += ret;
	events += ret / sizeof(struct sg_io_hdr);
	}
	}

	if (r < 0)
	break;
	if (!events) {
	usleep(1000);
	goto re_read;
	}

	left -= events;
	r += events;

	for (i = 0; i < events; i++) {
	struct sg_io_hdr hdr = (struct sg_io_hdr ) buf + i;

	sd->events[i] = hdr->usr_ptr;
	}
	}

	if (!min) {
	for_each_file(td, f, i)
	fcntl(f->fd, F_SETFL, sd->fd_flags[i]);
	}

	return r;
	}

	static int fio_sgio_ioctl_doio(struct thread_data *td,
	struct fio_file f, struct io_u io_u)
	{
	struct sgio_data *sd = td->io_ops->data;
	struct sg_io_hdr *hdr = &io_u->hdr;
	int ret;

	sd->events[0] = io_u;

	ret = ioctl(f->fd, SG_IO, hdr);
	if (ret < 0)
	return -errno;

	return FIO_Q_COMPLETED;
	}

	static int fio_sgio_rw_doio(struct fio_file f, struct io_u io_u, int sync)
	{
	struct sg_io_hdr *hdr = &io_u->hdr;
	int ret;

	ret = write(f->fd, hdr, sizeof(*hdr));
	if (ret < 0)
	return errno;

	if (sync) {
	ret = read(f->fd, hdr, sizeof(*hdr));
	if (ret < 0)
	return -errno;
	return FIO_Q_COMPLETED;
	}

	return FIO_Q_QUEUED;
	}

	static int fio_sgio_doio(struct thread_data td, struct io_u io_u, int sync)
	{
	struct fio_file *f = io_u->file;

	if (td->filetype == FIO_TYPE_BD)
	return fio_sgio_ioctl_doio(td, f, io_u);

	return fio_sgio_rw_doio(f, io_u, sync);
	}

	static int fio_sgio_prep(struct thread_data td, struct io_u io_u)
	{
	struct sg_io_hdr *hdr = &io_u->hdr;
	struct sgio_data *sd = td->io_ops->data;
	int nr_blocks, lba;

	if (io_u->xfer_buflen & (sd->bs - 1)) {
	log_err("read/write not sector aligned\n");
	return EINVAL;
	}

	if (io_u->ddir == DDIR_READ) {
	sgio_hdr_init(sd, hdr, io_u, 1);

	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	hdr->cmdp[0] = 0x28;
	} else if (io_u->ddir == DDIR_WRITE) {
	sgio_hdr_init(sd, hdr, io_u, 1);

	hdr->dxfer_direction = SG_DXFER_TO_DEV;
	hdr->cmdp[0] = 0x2a;
	} else {
	sgio_hdr_init(sd, hdr, io_u, 0);

	hdr->dxfer_direction = SG_DXFER_NONE;
	hdr->cmdp[0] = 0x35;
	}

	if (hdr->dxfer_direction != SG_DXFER_NONE) {
	nr_blocks = io_u->xfer_buflen / sd->bs;
	lba = io_u->offset / sd->bs;
	hdr->cmdp[2] = (unsigned char) ((lba >> 24) & 0xff);
	hdr->cmdp[3] = (unsigned char) ((lba >> 16) & 0xff);
	hdr->cmdp[4] = (unsigned char) ((lba >> 8) & 0xff);
	hdr->cmdp[5] = (unsigned char) (lba & 0xff);
	hdr->cmdp[7] = (unsigned char) ((nr_blocks >> 8) & 0xff);
	hdr->cmdp[8] = (unsigned char) (nr_blocks & 0xff);
	}

	return 0;
	}

	static int fio_sgio_queue(struct thread_data td, struct io_u io_u)
	{
	struct sg_io_hdr *hdr = &io_u->hdr;
	int ret;

	ret = fio_sgio_doio(td, io_u, io_u->ddir == DDIR_SYNC);

	if (ret < 0)
	io_u->error = errno;
	else if (hdr->status) {
	io_u->resid = hdr->resid;
	io_u->error = EIO;
	}

	if (io_u->error) {
	td_verror(td, io_u->error);
	return FIO_Q_COMPLETED;
	}

	return ret;
	}

	static struct io_u fio_sgio_event(struct thread_data td, int event)
	{
	struct sgio_data *sd = td->io_ops->data;

	return sd->events[event];
	}

	static int fio_sgio_get_bs(struct thread_data td, unsigned int bs)
	{
	struct sgio_data *sd = td->io_ops->data;
	struct io_u *io_u;
	struct sg_io_hdr *hdr;
	unsigned char buf[8];
	int ret;

	io_u = __get_io_u(td);
	io_u->file = &td->files[0];
	assert(io_u);

	hdr = &io_u->hdr;
	sgio_hdr_init(sd, hdr, io_u, 0);
	memset(buf, 0, sizeof(buf));

	hdr->cmdp[0] = 0x25;
	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	hdr->dxferp = buf;
	hdr->dxfer_len = sizeof(buf);

	ret = fio_sgio_doio(td, io_u, 1);
	if (ret) {
	put_io_u(td, io_u);
	return ret;
	}

	*bs = (buf[4] << 24) \| (buf[5] << 16) \| (buf[6] << 8) \| buf[7];
	put_io_u(td, io_u);
	return 0;
	}

	static void fio_sgio_cleanup(struct thread_data *td)
	{
	struct sgio_data *sd = td->io_ops->data;

	if (sd) {
	free(sd->events);
	free(sd->cmds);
	free(sd->fd_flags);
	free(sd->pfds);
	free(sd->sgbuf);
	free(sd);

	td->io_ops->data = NULL;
	}
	}

	static int fio_sgio_init(struct thread_data *td)
	{
	struct fio_file *f = &td->files[0];
	struct sgio_data *sd;
	unsigned int bs;
	int ret;

	sd = malloc(sizeof(*sd));
	memset(sd, 0, sizeof(*sd));
	sd->cmds = malloc(td->iodepth * sizeof(struct sgio_cmd));
	memset(sd->cmds, 0, td->iodepth * sizeof(struct sgio_cmd));
	sd->events = malloc(td->iodepth * sizeof(struct io_u *));
	memset(sd->events, 0, td->iodepth * sizeof(struct io_u *));
	sd->pfds = malloc(sizeof(struct pollfd) * td->nr_files);
	memset(sd->pfds, 0, sizeof(struct pollfd) * td->nr_files);
	sd->fd_flags = malloc(sizeof(int) * td->nr_files);
	memset(sd->fd_flags, 0, sizeof(int) * td->nr_files);
	sd->sgbuf = malloc(sizeof(struct sg_io_hdr) * td->iodepth);
	memset(sd->sgbuf, 0, sizeof(struct sg_io_hdr) * td->iodepth);

	td->io_ops->data = sd;

	if (td->filetype == FIO_TYPE_BD) {
	if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
	td_verror(td, errno);
	goto err;
	}
	} else if (td->filetype == FIO_TYPE_CHAR) {
	int version;

	if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
	td_verror(td, errno);
	goto err;
	}

	ret = fio_sgio_get_bs(td, &bs);
	if (ret)
	goto err;
	} else {
	log_err("ioengine sgio only works on block devices\n");
	goto err;
	}

	sd->bs = bs;

	if (td->filetype == FIO_TYPE_BD) {
	td->io_ops->getevents = NULL;
	td->io_ops->event = NULL;
	}

	/*
	* we want to do it, regardless of whether odirect is set or not
	*/
	td->override_sync = 1;
	return 0;
	err:
	free(sd->events);
	free(sd->cmds);
	free(sd->fd_flags);
	free(sd->pfds);
	free(sd->sgbuf);
	free(sd);
	td->io_ops->data = NULL;
	return 1;
	}

	static struct ioengine_ops ioengine = {
	.name = "sg",
	.version = FIO_IOOPS_VERSION,
	.init = fio_sgio_init,
	.prep = fio_sgio_prep,
	.queue = fio_sgio_queue,
	.getevents = fio_sgio_getevents,
	.event = fio_sgio_event,
	.cleanup = fio_sgio_cleanup,
	.flags = FIO_SYNCIO \| FIO_RAWIO,
	};

	#else /* FIO_HAVE_SGIO */

	/*
	* When we have a proper configure system in place, we simply wont build
	* and install this io engine. For now install a crippled version that
	* just complains and fails to load.
	*/
	static int fio_sgio_init(struct thread_data fio_unused *td)
	{
	fprintf(stderr, "fio: sgio not available\n");
	return 1;
	}

	static struct ioengine_ops ioengine = {
	.name = "sgio",
	.version = FIO_IOOPS_VERSION,
	.init = fio_sgio_init,
	};

	#endif

	static void fio_init fio_sgio_register(void)
	{
	register_ioengine(&ioengine);
	}

	static void fio_exit fio_sgio_unregister(void)
	{
	unregister_ioengine(&ioengine);
	}