[fio.git] / engines / sg.c

/*
 * 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 fio_sgio_ioctl_getevents(struct thread_data *td, int fio_unused min,
				    int max, struct timespec fio_unused *t)
{
	assert(max <= 1);

	/*
	 * we can only have one finished io_u for sync io, since the depth
	 * is always 1
	 */
	if (list_empty(&td->io_u_busylist))
		return 0;

	return 1;
}

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) {
				td_verror(td, errno);
				if (!r)
					r = -1;
				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;
				td_verror(td, errno);
				r = -1;
				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;

	sd->events[0] = io_u;

	return ioctl(f->fd, SG_IO, hdr);
}

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 0;
}

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;
	}

	return io_u->error;
}

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 = fio_sgio_ioctl_getevents;
	else
		td->io_ops->getevents = fio_sgio_getevents;

	/*
	 * 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);
}
Commit	Line	Data
	1	/*
	2	* scsi generic sg v3 io engine
	3	*
	4	*/
	5	#include <stdio.h>
	6	#include <stdlib.h>
	7	#include <unistd.h>
	8	#include <errno.h>
	9	#include <assert.h>
	10	#include <sys/poll.h>
	11
	12	#include "../fio.h"
	13	#include "../os.h"
	14
	15	#ifdef FIO_HAVE_SGIO
	16
	17	struct sgio_cmd {
	18	unsigned char cdb[10];
	19	int nr;
	20	};
	21
	22	struct sgio_data {
	23	struct sgio_cmd *cmds;
	24	struct io_u **events;
	25	struct pollfd *pfds;
	26	int *fd_flags;
	27	void *sgbuf;
	28	unsigned int bs;
	29	};
	30
	31	static void sgio_hdr_init(struct sgio_data sd, struct sg_io_hdr hdr,
	32	struct io_u *io_u, int fs)
	33	{
	34	struct sgio_cmd *sc = &sd->cmds[io_u->index];
	35
	36	memset(hdr, 0, sizeof(*hdr));
	37	memset(sc->cdb, 0, sizeof(sc->cdb));
	38
	39	hdr->interface_id = 'S';
	40	hdr->cmdp = sc->cdb;
	41	hdr->cmd_len = sizeof(sc->cdb);
	42	hdr->pack_id = io_u->index;
	43	hdr->usr_ptr = io_u;
	44
	45	if (fs) {
	46	hdr->dxferp = io_u->xfer_buf;
	47	hdr->dxfer_len = io_u->xfer_buflen;
	48	}
	49	}
	50
	51	static int fio_sgio_ioctl_getevents(struct thread_data *td, int fio_unused min,
	52	int max, struct timespec fio_unused *t)
	53	{
	54	assert(max <= 1);
	55
	56	/*
	57	* we can only have one finished io_u for sync io, since the depth
	58	* is always 1
	59	*/
	60	if (list_empty(&td->io_u_busylist))
	61	return 0;
	62
	63	return 1;
	64	}
	65
	66	static int pollin_events(struct pollfd *pfds, int fds)
	67	{
	68	int i;
	69
	70	for (i = 0; i < fds; i++)
	71	if (pfds[i].revents & POLLIN)
	72	return 1;
	73
	74	return 0;
	75	}
	76
	77	static int fio_sgio_getevents(struct thread_data *td, int min, int max,
	78	struct timespec fio_unused *t)
	79	{
	80	/*
	81	* normally hard coding &td->files[0] is a bug that needs to be fixed,
	82	* but it's ok here as all files should point to the same device.
	83	*/
	84	struct fio_file *f = &td->files[0];
	85	struct sgio_data *sd = td->io_ops->data;
	86	int left = max, ret, events, i, r = 0;
	87	void *buf = sd->sgbuf;
	88
	89	/*
	90	* Fill in the file descriptors
	91	*/
	92	for_each_file(td, f, i) {
	93	/*
	94	* don't block for min events == 0
	95	*/
	96	if (!min) {
	97	sd->fd_flags[i] = fcntl(f->fd, F_GETFL);
	98	fcntl(f->fd, F_SETFL, sd->fd_flags[i] \| O_NONBLOCK);
	99	}
	100	sd->pfds[i].fd = f->fd;
	101	sd->pfds[i].events = POLLIN;
	102	}
	103
	104	while (left) {
	105	void *p;
	106
	107	do {
	108	if (!min)
	109	break;
	110
	111	ret = poll(sd->pfds, td->nr_files, -1);
	112	if (ret < 0) {
	113	td_verror(td, errno);
	114	if (!r)
	115	r = -1;
	116	break;
	117	} else if (!ret)
	118	continue;
	119
	120	if (pollin_events(sd->pfds, td->nr_files))
	121	break;
	122	} while (1);
	123
	124	if (r < 0)
	125	break;
	126
	127	re_read:
	128	p = buf;
	129	events = 0;
	130	for_each_file(td, f, i) {
	131	ret = read(f->fd, p, left * sizeof(struct sg_io_hdr));
	132	if (ret < 0) {
	133	if (errno == EAGAIN)
	134	continue;
	135	td_verror(td, errno);
	136	r = -1;
	137	break;
	138	} else if (ret) {
	139	p += ret;
	140	events += ret / sizeof(struct sg_io_hdr);
	141	}
	142	}
	143
	144	if (r < 0)
	145	break;
	146	if (!events) {
	147	usleep(1000);
	148	goto re_read;
	149	}
	150
	151	left -= events;
	152	r += events;
	153
	154	for (i = 0; i < events; i++) {
	155	struct sg_io_hdr hdr = (struct sg_io_hdr ) buf + i;
	156
	157	sd->events[i] = hdr->usr_ptr;
	158	}
	159	}
	160
	161	if (!min) {
	162	for_each_file(td, f, i)
	163	fcntl(f->fd, F_SETFL, sd->fd_flags[i]);
	164	}
	165
	166	return r;
	167	}
	168
	169	static int fio_sgio_ioctl_doio(struct thread_data *td,
	170	struct fio_file f, struct io_u io_u)
	171	{
	172	struct sgio_data *sd = td->io_ops->data;
	173	struct sg_io_hdr *hdr = &io_u->hdr;
	174
	175	sd->events[0] = io_u;
	176
	177	return ioctl(f->fd, SG_IO, hdr);
	178	}
	179
	180	static int fio_sgio_rw_doio(struct fio_file f, struct io_u io_u, int sync)
	181	{
	182	struct sg_io_hdr *hdr = &io_u->hdr;
	183	int ret;
	184
	185	ret = write(f->fd, hdr, sizeof(*hdr));
	186	if (ret < 0)
	187	return errno;
	188
	189	if (sync) {
	190	ret = read(f->fd, hdr, sizeof(*hdr));
	191	if (ret < 0)
	192	return errno;
	193	}
	194
	195	return 0;
	196	}
	197
	198	static int fio_sgio_doio(struct thread_data td, struct io_u io_u, int sync)
	199	{
	200	struct fio_file *f = io_u->file;
	201
	202	if (td->filetype == FIO_TYPE_BD)
	203	return fio_sgio_ioctl_doio(td, f, io_u);
	204
	205	return fio_sgio_rw_doio(f, io_u, sync);
	206	}
	207
	208	static int fio_sgio_prep(struct thread_data td, struct io_u io_u)
	209	{
	210	struct sg_io_hdr *hdr = &io_u->hdr;
	211	struct sgio_data *sd = td->io_ops->data;
	212	int nr_blocks, lba;
	213
	214	if (io_u->xfer_buflen & (sd->bs - 1)) {
	215	log_err("read/write not sector aligned\n");
	216	return EINVAL;
	217	}
	218
	219	if (io_u->ddir == DDIR_READ) {
	220	sgio_hdr_init(sd, hdr, io_u, 1);
	221
	222	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	223	hdr->cmdp[0] = 0x28;
	224	} else if (io_u->ddir == DDIR_WRITE) {
	225	sgio_hdr_init(sd, hdr, io_u, 1);
	226
	227	hdr->dxfer_direction = SG_DXFER_TO_DEV;
	228	hdr->cmdp[0] = 0x2a;
	229	} else {
	230	sgio_hdr_init(sd, hdr, io_u, 0);
	231
	232	hdr->dxfer_direction = SG_DXFER_NONE;
	233	hdr->cmdp[0] = 0x35;
	234	}
	235
	236	if (hdr->dxfer_direction != SG_DXFER_NONE) {
	237	nr_blocks = io_u->xfer_buflen / sd->bs;
	238	lba = io_u->offset / sd->bs;
	239	hdr->cmdp[2] = (unsigned char) ((lba >> 24) & 0xff);
	240	hdr->cmdp[3] = (unsigned char) ((lba >> 16) & 0xff);
	241	hdr->cmdp[4] = (unsigned char) ((lba >> 8) & 0xff);
	242	hdr->cmdp[5] = (unsigned char) (lba & 0xff);
	243	hdr->cmdp[7] = (unsigned char) ((nr_blocks >> 8) & 0xff);
	244	hdr->cmdp[8] = (unsigned char) (nr_blocks & 0xff);
	245	}
	246
	247	return 0;
	248	}
	249
	250	static int fio_sgio_queue(struct thread_data td, struct io_u io_u)
	251	{
	252	struct sg_io_hdr *hdr = &io_u->hdr;
	253	int ret;
	254
	255	ret = fio_sgio_doio(td, io_u, io_u->ddir == DDIR_SYNC);
	256
	257	if (ret < 0)
	258	io_u->error = errno;
	259	else if (hdr->status) {
	260	io_u->resid = hdr->resid;
	261	io_u->error = EIO;
	262	}
	263
	264	return io_u->error;
	265	}
	266
	267	static struct io_u fio_sgio_event(struct thread_data td, int event)
	268	{
	269	struct sgio_data *sd = td->io_ops->data;
	270
	271	return sd->events[event];
	272	}
	273
	274	static int fio_sgio_get_bs(struct thread_data td, unsigned int bs)
	275	{
	276	struct sgio_data *sd = td->io_ops->data;
	277	struct io_u *io_u;
	278	struct sg_io_hdr *hdr;
	279	unsigned char buf[8];
	280	int ret;
	281
	282	io_u = __get_io_u(td);
	283	io_u->file = &td->files[0];
	284	assert(io_u);
	285
	286	hdr = &io_u->hdr;
	287	sgio_hdr_init(sd, hdr, io_u, 0);
	288	memset(buf, 0, sizeof(buf));
	289
	290	hdr->cmdp[0] = 0x25;
	291	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	292	hdr->dxferp = buf;
	293	hdr->dxfer_len = sizeof(buf);
	294
	295	ret = fio_sgio_doio(td, io_u, 1);
	296	if (ret) {
	297	put_io_u(td, io_u);
	298	return ret;
	299	}
	300
	301	*bs = (buf[4] << 24) \| (buf[5] << 16) \| (buf[6] << 8) \| buf[7];
	302	put_io_u(td, io_u);
	303	return 0;
	304	}
	305
	306	static void fio_sgio_cleanup(struct thread_data *td)
	307	{
	308	struct sgio_data *sd = td->io_ops->data;
	309
	310	if (sd) {
	311	free(sd->events);
	312	free(sd->cmds);
	313	free(sd->fd_flags);
	314	free(sd->pfds);
	315	free(sd->sgbuf);
	316	free(sd);
	317
	318	td->io_ops->data = NULL;
	319	}
	320	}
	321
	322	static int fio_sgio_init(struct thread_data *td)
	323	{
	324	struct fio_file *f = &td->files[0];
	325	struct sgio_data *sd;
	326	unsigned int bs;
	327	int ret;
	328
	329	sd = malloc(sizeof(*sd));
	330	memset(sd, 0, sizeof(*sd));
	331	sd->cmds = malloc(td->iodepth * sizeof(struct sgio_cmd));
	332	memset(sd->cmds, 0, td->iodepth * sizeof(struct sgio_cmd));
	333	sd->events = malloc(td->iodepth * sizeof(struct io_u *));
	334	memset(sd->events, 0, td->iodepth * sizeof(struct io_u *));
	335	sd->pfds = malloc(sizeof(struct pollfd) * td->nr_files);
	336	memset(sd->pfds, 0, sizeof(struct pollfd) * td->nr_files);
	337	sd->fd_flags = malloc(sizeof(int) * td->nr_files);
	338	memset(sd->fd_flags, 0, sizeof(int) * td->nr_files);
	339	sd->sgbuf = malloc(sizeof(struct sg_io_hdr) * td->iodepth);
	340	memset(sd->sgbuf, 0, sizeof(struct sg_io_hdr) * td->iodepth);
	341
	342	td->io_ops->data = sd;
	343
	344	if (td->filetype == FIO_TYPE_BD) {
	345	if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
	346	td_verror(td, errno);
	347	goto err;
	348	}
	349	} else if (td->filetype == FIO_TYPE_CHAR) {
	350	int version;
	351
	352	if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
	353	td_verror(td, errno);
	354	goto err;
	355	}
	356
	357	ret = fio_sgio_get_bs(td, &bs);
	358	if (ret)
	359	goto err;
	360	} else {
	361	log_err("ioengine sgio only works on block devices\n");
	362	goto err;
	363	}
	364
	365	sd->bs = bs;
	366
	367	if (td->filetype == FIO_TYPE_BD)
	368	td->io_ops->getevents = fio_sgio_ioctl_getevents;
	369	else
	370	td->io_ops->getevents = fio_sgio_getevents;
	371
	372	/*
	373	* we want to do it, regardless of whether odirect is set or not
	374	*/
	375	td->override_sync = 1;
	376	return 0;
	377	err:
	378	free(sd->events);
	379	free(sd->cmds);
	380	free(sd->fd_flags);
	381	free(sd->pfds);
	382	free(sd->sgbuf);
	383	free(sd);
	384	td->io_ops->data = NULL;
	385	return 1;
	386	}
	387
	388	static struct ioengine_ops ioengine = {
	389	.name = "sg",
	390	.version = FIO_IOOPS_VERSION,
	391	.init = fio_sgio_init,
	392	.prep = fio_sgio_prep,
	393	.queue = fio_sgio_queue,
	394	.getevents = fio_sgio_getevents,
	395	.event = fio_sgio_event,
	396	.cleanup = fio_sgio_cleanup,
	397	.flags = FIO_SYNCIO \| FIO_RAWIO,
	398	};
	399
	400	#else /* FIO_HAVE_SGIO */
	401
	402	/*
	403	* When we have a proper configure system in place, we simply wont build
	404	* and install this io engine. For now install a crippled version that
	405	* just complains and fails to load.
	406	*/
	407	static int fio_sgio_init(struct thread_data fio_unused *td)
	408	{
	409	fprintf(stderr, "fio: sgio not available\n");
	410	return 1;
	411	}
	412
	413	static struct ioengine_ops ioengine = {
	414	.name = "sgio",
	415	.version = FIO_IOOPS_VERSION,
	416	.init = fio_sgio_init,
	417	};
	418
	419	#endif
	420
	421	static void fio_init fio_sgio_register(void)
	422	{
	423	register_ioengine(&ioengine);
	424	}
	425
	426	static void fio_exit fio_sgio_unregister(void)
	427	{
	428	unregister_ioengine(&ioengine);
	429	}