[fio.git] / engines / sg.c

/*
 * sg engine
 *
 * IO engine that uses the Linux SG v3 interface to talk to SCSI devices
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <assert.h>
#include <sys/poll.h>

#include "../fio.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;
	int type_checked;
};

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, unsigned int min,
			      unsigned int max, struct timespec fio_unused *t)
{
	struct sgio_data *sd = td->io_ops->data;
	int left = max, ret, r = 0;
	void *buf = sd->sgbuf;
	unsigned int i, events;
	struct fio_file *f;

	/*
	 * Fill in the file descriptors
	 */
	for_each_file(td, f, i) {
		/*
		 * don't block for min events == 0
		 */
		if (!min)
			fio_set_fd_nonblocking(f->fd, "sg");

		sd->pfds[i].fd = f->fd;
		sd->pfds[i].events = POLLIN;
	}

	while (left) {
		void *p;

		do {
			if (!min)
				break;

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

			if (pollin_events(sd->pfds, td->o.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, "read");
				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 ret;

	return FIO_Q_COMPLETED;
}

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

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

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

	return FIO_Q_QUEUED;
}

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

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

	return fio_sgio_rw_doio(f, io_u, do_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, do_sync = 0;

	fio_ro_check(td, io_u);

	if (td->o.sync_io || td->o.odirect || ddir_sync(io_u->ddir))
		do_sync = 1;

	ret = fio_sgio_doio(td, io_u, do_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, "xfer");
		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;

	memset(&io_u, 0, sizeof(io_u));
	io_u.file = td->files[0];

	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)
		return ret;

	*bs = (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
	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);
	}
}

static int fio_sgio_init(struct thread_data *td)
{
	struct sgio_data *sd;

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

	td->io_ops->data = sd;

	/*
	 * we want to do it, regardless of whether odirect is set or not
	 */
	td->o.override_sync = 1;
	return 0;
}

static int fio_sgio_type_check(struct thread_data *td, struct fio_file *f)
{
	struct sgio_data *sd = td->io_ops->data;
	unsigned int bs;

	if (f->filetype == FIO_TYPE_BD) {
		if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
			td_verror(td, errno, "ioctl");
			return 1;
		}
	} else if (f->filetype == FIO_TYPE_CHAR) {
		int version, ret;

		if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
			td_verror(td, errno, "ioctl");
			return 1;
		}

		ret = fio_sgio_get_bs(td, &bs);
		if (ret)
			return 1;
	} else {
		log_err("ioengine sg only works on block devices\n");
		return 1;
	}

	sd->bs = bs;

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

	return 0;
}

static int fio_sgio_open(struct thread_data *td, struct fio_file *f)
{
	struct sgio_data *sd = td->io_ops->data;
	int ret;

	ret = generic_open_file(td, f);
	if (ret)
		return ret;

	if (sd && !sd->type_checked && fio_sgio_type_check(td, f)) {
		ret = generic_close_file(td, f);
		return 1;
	}

	return 0;
}

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,
	.open_file	= fio_sgio_open,
	.close_file	= generic_close_file,
	.get_file_size	= generic_get_file_size,
	.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)
{
	log_err("fio: ioengine sg not available\n");
	return 1;
}

static struct ioengine_ops ioengine = {
	.name		= "sg",
	.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	* sg engine
	3	*
	4	* IO engine that uses the Linux SG v3 interface to talk to SCSI devices
	5	*
	6	*/
	7	#include <stdio.h>
	8	#include <stdlib.h>
	9	#include <unistd.h>
	10	#include <errno.h>
	11	#include <assert.h>
	12	#include <sys/poll.h>
	13
	14	#include "../fio.h"
	15
	16	#ifdef FIO_HAVE_SGIO
	17
	18	struct sgio_cmd {
	19	unsigned char cdb[10];
	20	int nr;
	21	};
	22
	23	struct sgio_data {
	24	struct sgio_cmd *cmds;
	25	struct io_u **events;
	26	struct pollfd *pfds;
	27	int *fd_flags;
	28	void *sgbuf;
	29	unsigned int bs;
	30	int type_checked;
	31	};
	32
	33	static void sgio_hdr_init(struct sgio_data sd, struct sg_io_hdr hdr,
	34	struct io_u *io_u, int fs)
	35	{
	36	struct sgio_cmd *sc = &sd->cmds[io_u->index];
	37
	38	memset(hdr, 0, sizeof(*hdr));
	39	memset(sc->cdb, 0, sizeof(sc->cdb));
	40
	41	hdr->interface_id = 'S';
	42	hdr->cmdp = sc->cdb;
	43	hdr->cmd_len = sizeof(sc->cdb);
	44	hdr->pack_id = io_u->index;
	45	hdr->usr_ptr = io_u;
	46
	47	if (fs) {
	48	hdr->dxferp = io_u->xfer_buf;
	49	hdr->dxfer_len = io_u->xfer_buflen;
	50	}
	51	}
	52
	53	static int pollin_events(struct pollfd *pfds, int fds)
	54	{
	55	int i;
	56
	57	for (i = 0; i < fds; i++)
	58	if (pfds[i].revents & POLLIN)
	59	return 1;
	60
	61	return 0;
	62	}
	63
	64	static int fio_sgio_getevents(struct thread_data *td, unsigned int min,
	65	unsigned int max, struct timespec fio_unused *t)
	66	{
	67	struct sgio_data *sd = td->io_ops->data;
	68	int left = max, ret, r = 0;
	69	void *buf = sd->sgbuf;
	70	unsigned int i, events;
	71	struct fio_file *f;
	72
	73	/*
	74	* Fill in the file descriptors
	75	*/
	76	for_each_file(td, f, i) {
	77	/*
	78	* don't block for min events == 0
	79	*/
	80	if (!min)
	81	fio_set_fd_nonblocking(f->fd, "sg");
	82
	83	sd->pfds[i].fd = f->fd;
	84	sd->pfds[i].events = POLLIN;
	85	}
	86
	87	while (left) {
	88	void *p;
	89
	90	do {
	91	if (!min)
	92	break;
	93
	94	ret = poll(sd->pfds, td->o.nr_files, -1);
	95	if (ret < 0) {
	96	if (!r)
	97	r = -errno;
	98	td_verror(td, errno, "poll");
	99	break;
	100	} else if (!ret)
	101	continue;
	102
	103	if (pollin_events(sd->pfds, td->o.nr_files))
	104	break;
	105	} while (1);
	106
	107	if (r < 0)
	108	break;
	109
	110	re_read:
	111	p = buf;
	112	events = 0;
	113	for_each_file(td, f, i) {
	114	ret = read(f->fd, p, left * sizeof(struct sg_io_hdr));
	115	if (ret < 0) {
	116	if (errno == EAGAIN)
	117	continue;
	118	r = -errno;
	119	td_verror(td, errno, "read");
	120	break;
	121	} else if (ret) {
	122	p += ret;
	123	events += ret / sizeof(struct sg_io_hdr);
	124	}
	125	}
	126
	127	if (r < 0)
	128	break;
	129	if (!events) {
	130	usleep(1000);
	131	goto re_read;
	132	}
	133
	134	left -= events;
	135	r += events;
	136
	137	for (i = 0; i < events; i++) {
	138	struct sg_io_hdr hdr = (struct sg_io_hdr ) buf + i;
	139
	140	sd->events[i] = hdr->usr_ptr;
	141	}
	142	}
	143
	144	if (!min) {
	145	for_each_file(td, f, i)
	146	fcntl(f->fd, F_SETFL, sd->fd_flags[i]);
	147	}
	148
	149	return r;
	150	}
	151
	152	static int fio_sgio_ioctl_doio(struct thread_data *td,
	153	struct fio_file f, struct io_u io_u)
	154	{
	155	struct sgio_data *sd = td->io_ops->data;
	156	struct sg_io_hdr *hdr = &io_u->hdr;
	157	int ret;
	158
	159	sd->events[0] = io_u;
	160
	161	ret = ioctl(f->fd, SG_IO, hdr);
	162	if (ret < 0)
	163	return ret;
	164
	165	return FIO_Q_COMPLETED;
	166	}
	167
	168	static int fio_sgio_rw_doio(struct fio_file f, struct io_u io_u, int do_sync)
	169	{
	170	struct sg_io_hdr *hdr = &io_u->hdr;
	171	int ret;
	172
	173	ret = write(f->fd, hdr, sizeof(*hdr));
	174	if (ret < 0)
	175	return ret;
	176
	177	if (do_sync) {
	178	ret = read(f->fd, hdr, sizeof(*hdr));
	179	if (ret < 0)
	180	return ret;
	181	return FIO_Q_COMPLETED;
	182	}
	183
	184	return FIO_Q_QUEUED;
	185	}
	186
	187	static int fio_sgio_doio(struct thread_data td, struct io_u io_u, int do_sync)
	188	{
	189	struct fio_file *f = io_u->file;
	190
	191	if (f->filetype == FIO_TYPE_BD)
	192	return fio_sgio_ioctl_doio(td, f, io_u);
	193
	194	return fio_sgio_rw_doio(f, io_u, do_sync);
	195	}
	196
	197	static int fio_sgio_prep(struct thread_data td, struct io_u io_u)
	198	{
	199	struct sg_io_hdr *hdr = &io_u->hdr;
	200	struct sgio_data *sd = td->io_ops->data;
	201	int nr_blocks, lba;
	202
	203	if (io_u->xfer_buflen & (sd->bs - 1)) {
	204	log_err("read/write not sector aligned\n");
	205	return EINVAL;
	206	}
	207
	208	if (io_u->ddir == DDIR_READ) {
	209	sgio_hdr_init(sd, hdr, io_u, 1);
	210
	211	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	212	hdr->cmdp[0] = 0x28;
	213	} else if (io_u->ddir == DDIR_WRITE) {
	214	sgio_hdr_init(sd, hdr, io_u, 1);
	215
	216	hdr->dxfer_direction = SG_DXFER_TO_DEV;
	217	hdr->cmdp[0] = 0x2a;
	218	} else {
	219	sgio_hdr_init(sd, hdr, io_u, 0);
	220
	221	hdr->dxfer_direction = SG_DXFER_NONE;
	222	hdr->cmdp[0] = 0x35;
	223	}
	224
	225	if (hdr->dxfer_direction != SG_DXFER_NONE) {
	226	nr_blocks = io_u->xfer_buflen / sd->bs;
	227	lba = io_u->offset / sd->bs;
	228	hdr->cmdp[2] = (unsigned char) ((lba >> 24) & 0xff);
	229	hdr->cmdp[3] = (unsigned char) ((lba >> 16) & 0xff);
	230	hdr->cmdp[4] = (unsigned char) ((lba >> 8) & 0xff);
	231	hdr->cmdp[5] = (unsigned char) (lba & 0xff);
	232	hdr->cmdp[7] = (unsigned char) ((nr_blocks >> 8) & 0xff);
	233	hdr->cmdp[8] = (unsigned char) (nr_blocks & 0xff);
	234	}
	235
	236	return 0;
	237	}
	238
	239	static int fio_sgio_queue(struct thread_data td, struct io_u io_u)
	240	{
	241	struct sg_io_hdr *hdr = &io_u->hdr;
	242	int ret, do_sync = 0;
	243
	244	fio_ro_check(td, io_u);
	245
	246	if (td->o.sync_io \|\| td->o.odirect \|\| ddir_sync(io_u->ddir))
	247	do_sync = 1;
	248
	249	ret = fio_sgio_doio(td, io_u, do_sync);
	250
	251	if (ret < 0)
	252	io_u->error = errno;
	253	else if (hdr->status) {
	254	io_u->resid = hdr->resid;
	255	io_u->error = EIO;
	256	}
	257
	258	if (io_u->error) {
	259	td_verror(td, io_u->error, "xfer");
	260	return FIO_Q_COMPLETED;
	261	}
	262
	263	return ret;
	264	}
	265
	266	static struct io_u fio_sgio_event(struct thread_data td, int event)
	267	{
	268	struct sgio_data *sd = td->io_ops->data;
	269
	270	return sd->events[event];
	271	}
	272
	273	static int fio_sgio_get_bs(struct thread_data td, unsigned int bs)
	274	{
	275	struct sgio_data *sd = td->io_ops->data;
	276	struct io_u io_u;
	277	struct sg_io_hdr *hdr;
	278	unsigned char buf[8];
	279	int ret;
	280
	281	memset(&io_u, 0, sizeof(io_u));
	282	io_u.file = td->files[0];
	283
	284	hdr = &io_u.hdr;
	285	sgio_hdr_init(sd, hdr, &io_u, 0);
	286	memset(buf, 0, sizeof(buf));
	287
	288	hdr->cmdp[0] = 0x25;
	289	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	290	hdr->dxferp = buf;
	291	hdr->dxfer_len = sizeof(buf);
	292
	293	ret = fio_sgio_doio(td, &io_u, 1);
	294	if (ret)
	295	return ret;
	296
	297	*bs = (buf[4] << 24) \| (buf[5] << 16) \| (buf[6] << 8) \| buf[7];
	298	return 0;
	299	}
	300
	301	static void fio_sgio_cleanup(struct thread_data *td)
	302	{
	303	struct sgio_data *sd = td->io_ops->data;
	304
	305	if (sd) {
	306	free(sd->events);
	307	free(sd->cmds);
	308	free(sd->fd_flags);
	309	free(sd->pfds);
	310	free(sd->sgbuf);
	311	free(sd);
	312	}
	313	}
	314
	315	static int fio_sgio_init(struct thread_data *td)
	316	{
	317	struct sgio_data *sd;
	318
	319	sd = malloc(sizeof(*sd));
	320	memset(sd, 0, sizeof(*sd));
	321	sd->cmds = malloc(td->o.iodepth * sizeof(struct sgio_cmd));
	322	memset(sd->cmds, 0, td->o.iodepth * sizeof(struct sgio_cmd));
	323	sd->events = malloc(td->o.iodepth * sizeof(struct io_u *));
	324	memset(sd->events, 0, td->o.iodepth * sizeof(struct io_u *));
	325	sd->pfds = malloc(sizeof(struct pollfd) * td->o.nr_files);
	326	memset(sd->pfds, 0, sizeof(struct pollfd) * td->o.nr_files);
	327	sd->fd_flags = malloc(sizeof(int) * td->o.nr_files);
	328	memset(sd->fd_flags, 0, sizeof(int) * td->o.nr_files);
	329	sd->sgbuf = malloc(sizeof(struct sg_io_hdr) * td->o.iodepth);
	330	memset(sd->sgbuf, 0, sizeof(struct sg_io_hdr) * td->o.iodepth);
	331
	332	td->io_ops->data = sd;
	333
	334	/*
	335	* we want to do it, regardless of whether odirect is set or not
	336	*/
	337	td->o.override_sync = 1;
	338	return 0;
	339	}
	340
	341	static int fio_sgio_type_check(struct thread_data td, struct fio_file f)
	342	{
	343	struct sgio_data *sd = td->io_ops->data;
	344	unsigned int bs;
	345
	346	if (f->filetype == FIO_TYPE_BD) {
	347	if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
	348	td_verror(td, errno, "ioctl");
	349	return 1;
	350	}
	351	} else if (f->filetype == FIO_TYPE_CHAR) {
	352	int version, ret;
	353
	354	if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
	355	td_verror(td, errno, "ioctl");
	356	return 1;
	357	}
	358
	359	ret = fio_sgio_get_bs(td, &bs);
	360	if (ret)
	361	return 1;
	362	} else {
	363	log_err("ioengine sg only works on block devices\n");
	364	return 1;
	365	}
	366
	367	sd->bs = bs;
	368
	369	if (f->filetype == FIO_TYPE_BD) {
	370	td->io_ops->getevents = NULL;
	371	td->io_ops->event = NULL;
	372	}
	373
	374	return 0;
	375	}
	376
	377	static int fio_sgio_open(struct thread_data td, struct fio_file f)
	378	{
	379	struct sgio_data *sd = td->io_ops->data;
	380	int ret;
	381
	382	ret = generic_open_file(td, f);
	383	if (ret)
	384	return ret;
	385
	386	if (sd && !sd->type_checked && fio_sgio_type_check(td, f)) {
	387	ret = generic_close_file(td, f);
	388	return 1;
	389	}
	390
	391	return 0;
	392	}
	393
	394	static struct ioengine_ops ioengine = {
	395	.name = "sg",
	396	.version = FIO_IOOPS_VERSION,
	397	.init = fio_sgio_init,
	398	.prep = fio_sgio_prep,
	399	.queue = fio_sgio_queue,
	400	.getevents = fio_sgio_getevents,
	401	.event = fio_sgio_event,
	402	.cleanup = fio_sgio_cleanup,
	403	.open_file = fio_sgio_open,
	404	.close_file = generic_close_file,
	405	.get_file_size = generic_get_file_size,
	406	.flags = FIO_SYNCIO \| FIO_RAWIO,
	407	};
	408
	409	#else /* FIO_HAVE_SGIO */
	410
	411	/*
	412	* When we have a proper configure system in place, we simply wont build
	413	* and install this io engine. For now install a crippled version that
	414	* just complains and fails to load.
	415	*/
	416	static int fio_sgio_init(struct thread_data fio_unused *td)
	417	{
	418	log_err("fio: ioengine sg not available\n");
	419	return 1;
	420	}
	421
	422	static struct ioengine_ops ioengine = {
	423	.name = "sg",
	424	.version = FIO_IOOPS_VERSION,
	425	.init = fio_sgio_init,
	426	};
	427
	428	#endif
	429
	430	static void fio_init fio_sgio_register(void)
	431	{
	432	register_ioengine(&ioengine);
	433	}
	434
	435	static void fio_exit fio_sgio_unregister(void)
	436	{
	437	unregister_ioengine(&ioengine);
	438	}