[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,
			      const 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)
			sd->fd_flags[i] = fio_set_fd_nonblocking(f->fd, "sg");
		else
			sd->fd_flags[i] = -1;

		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) {
			if (sd->fd_flags[i] == -1)
				continue;

			if (fcntl(f->fd, F_SETFL, sd->fd_flags[i]) < 0)
				log_err("fio: sg failed to restore fcntl flags: %s\n", strerror(errno));
		}
	}

	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,
	66	const struct timespec fio_unused *t)
	67	{
	68	struct sgio_data *sd = td->io_ops->data;
	69	int left = max, ret, r = 0;
	70	void *buf = sd->sgbuf;
	71	unsigned int i, events;
	72	struct fio_file *f;
	73
	74	/*
	75	* Fill in the file descriptors
	76	*/
	77	for_each_file(td, f, i) {
	78	/*
	79	* don't block for min events == 0
	80	*/
	81	if (!min)
	82	sd->fd_flags[i] = fio_set_fd_nonblocking(f->fd, "sg");
	83	else
	84	sd->fd_flags[i] = -1;
	85
	86	sd->pfds[i].fd = f->fd;
	87	sd->pfds[i].events = POLLIN;
	88	}
	89
	90	while (left) {
	91	void *p;
	92
	93	do {
	94	if (!min)
	95	break;
	96
	97	ret = poll(sd->pfds, td->o.nr_files, -1);
	98	if (ret < 0) {
	99	if (!r)
	100	r = -errno;
	101	td_verror(td, errno, "poll");
	102	break;
	103	} else if (!ret)
	104	continue;
	105
	106	if (pollin_events(sd->pfds, td->o.nr_files))
	107	break;
	108	} while (1);
	109
	110	if (r < 0)
	111	break;
	112
	113	re_read:
	114	p = buf;
	115	events = 0;
	116	for_each_file(td, f, i) {
	117	ret = read(f->fd, p, left * sizeof(struct sg_io_hdr));
	118	if (ret < 0) {
	119	if (errno == EAGAIN)
	120	continue;
	121	r = -errno;
	122	td_verror(td, errno, "read");
	123	break;
	124	} else if (ret) {
	125	p += ret;
	126	events += ret / sizeof(struct sg_io_hdr);
	127	}
	128	}
	129
	130	if (r < 0)
	131	break;
	132	if (!events) {
	133	usleep(1000);
	134	goto re_read;
	135	}
	136
	137	left -= events;
	138	r += events;
	139
	140	for (i = 0; i < events; i++) {
	141	struct sg_io_hdr hdr = (struct sg_io_hdr ) buf + i;
	142
	143	sd->events[i] = hdr->usr_ptr;
	144	}
	145	}
	146
	147	if (!min) {
	148	for_each_file(td, f, i) {
	149	if (sd->fd_flags[i] == -1)
	150	continue;
	151
	152	if (fcntl(f->fd, F_SETFL, sd->fd_flags[i]) < 0)
	153	log_err("fio: sg failed to restore fcntl flags: %s\n", strerror(errno));
	154	}
	155	}
	156
	157	return r;
	158	}
	159
	160	static int fio_sgio_ioctl_doio(struct thread_data *td,
	161	struct fio_file f, struct io_u io_u)
	162	{
	163	struct sgio_data *sd = td->io_ops->data;
	164	struct sg_io_hdr *hdr = &io_u->hdr;
	165	int ret;
	166
	167	sd->events[0] = io_u;
	168
	169	ret = ioctl(f->fd, SG_IO, hdr);
	170	if (ret < 0)
	171	return ret;
	172
	173	return FIO_Q_COMPLETED;
	174	}
	175
	176	static int fio_sgio_rw_doio(struct fio_file f, struct io_u io_u, int do_sync)
	177	{
	178	struct sg_io_hdr *hdr = &io_u->hdr;
	179	int ret;
	180
	181	ret = write(f->fd, hdr, sizeof(*hdr));
	182	if (ret < 0)
	183	return ret;
	184
	185	if (do_sync) {
	186	ret = read(f->fd, hdr, sizeof(*hdr));
	187	if (ret < 0)
	188	return ret;
	189	return FIO_Q_COMPLETED;
	190	}
	191
	192	return FIO_Q_QUEUED;
	193	}
	194
	195	static int fio_sgio_doio(struct thread_data td, struct io_u io_u, int do_sync)
	196	{
	197	struct fio_file *f = io_u->file;
	198
	199	if (f->filetype == FIO_TYPE_BD)
	200	return fio_sgio_ioctl_doio(td, f, io_u);
	201
	202	return fio_sgio_rw_doio(f, io_u, do_sync);
	203	}
	204
	205	static int fio_sgio_prep(struct thread_data td, struct io_u io_u)
	206	{
	207	struct sg_io_hdr *hdr = &io_u->hdr;
	208	struct sgio_data *sd = td->io_ops->data;
	209	int nr_blocks, lba;
	210
	211	if (io_u->xfer_buflen & (sd->bs - 1)) {
	212	log_err("read/write not sector aligned\n");
	213	return EINVAL;
	214	}
	215
	216	if (io_u->ddir == DDIR_READ) {
	217	sgio_hdr_init(sd, hdr, io_u, 1);
	218
	219	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	220	hdr->cmdp[0] = 0x28;
	221	} else if (io_u->ddir == DDIR_WRITE) {
	222	sgio_hdr_init(sd, hdr, io_u, 1);
	223
	224	hdr->dxfer_direction = SG_DXFER_TO_DEV;
	225	hdr->cmdp[0] = 0x2a;
	226	} else {
	227	sgio_hdr_init(sd, hdr, io_u, 0);
	228
	229	hdr->dxfer_direction = SG_DXFER_NONE;
	230	hdr->cmdp[0] = 0x35;
	231	}
	232
	233	if (hdr->dxfer_direction != SG_DXFER_NONE) {
	234	nr_blocks = io_u->xfer_buflen / sd->bs;
	235	lba = io_u->offset / sd->bs;
	236	hdr->cmdp[2] = (unsigned char) ((lba >> 24) & 0xff);
	237	hdr->cmdp[3] = (unsigned char) ((lba >> 16) & 0xff);
	238	hdr->cmdp[4] = (unsigned char) ((lba >> 8) & 0xff);
	239	hdr->cmdp[5] = (unsigned char) (lba & 0xff);
	240	hdr->cmdp[7] = (unsigned char) ((nr_blocks >> 8) & 0xff);
	241	hdr->cmdp[8] = (unsigned char) (nr_blocks & 0xff);
	242	}
	243
	244	return 0;
	245	}
	246
	247	static int fio_sgio_queue(struct thread_data td, struct io_u io_u)
	248	{
	249	struct sg_io_hdr *hdr = &io_u->hdr;
	250	int ret, do_sync = 0;
	251
	252	fio_ro_check(td, io_u);
	253
	254	if (td->o.sync_io \|\| td->o.odirect \|\| ddir_sync(io_u->ddir))
	255	do_sync = 1;
	256
	257	ret = fio_sgio_doio(td, io_u, do_sync);
	258
	259	if (ret < 0)
	260	io_u->error = errno;
	261	else if (hdr->status) {
	262	io_u->resid = hdr->resid;
	263	io_u->error = EIO;
	264	}
	265
	266	if (io_u->error) {
	267	td_verror(td, io_u->error, "xfer");
	268	return FIO_Q_COMPLETED;
	269	}
	270
	271	return ret;
	272	}
	273
	274	static struct io_u fio_sgio_event(struct thread_data td, int event)
	275	{
	276	struct sgio_data *sd = td->io_ops->data;
	277
	278	return sd->events[event];
	279	}
	280
	281	static int fio_sgio_get_bs(struct thread_data td, unsigned int bs)
	282	{
	283	struct sgio_data *sd = td->io_ops->data;
	284	struct io_u io_u;
	285	struct sg_io_hdr *hdr;
	286	unsigned char buf[8];
	287	int ret;
	288
	289	memset(&io_u, 0, sizeof(io_u));
	290	io_u.file = td->files[0];
	291
	292	hdr = &io_u.hdr;
	293	sgio_hdr_init(sd, hdr, &io_u, 0);
	294	memset(buf, 0, sizeof(buf));
	295
	296	hdr->cmdp[0] = 0x25;
	297	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
	298	hdr->dxferp = buf;
	299	hdr->dxfer_len = sizeof(buf);
	300
	301	ret = fio_sgio_doio(td, &io_u, 1);
	302	if (ret)
	303	return ret;
	304
	305	*bs = (buf[4] << 24) \| (buf[5] << 16) \| (buf[6] << 8) \| buf[7];
	306	return 0;
	307	}
	308
	309	static void fio_sgio_cleanup(struct thread_data *td)
	310	{
	311	struct sgio_data *sd = td->io_ops->data;
	312
	313	if (sd) {
	314	free(sd->events);
	315	free(sd->cmds);
	316	free(sd->fd_flags);
	317	free(sd->pfds);
	318	free(sd->sgbuf);
	319	free(sd);
	320	}
	321	}
	322
	323	static int fio_sgio_init(struct thread_data *td)
	324	{
	325	struct sgio_data *sd;
	326
	327	sd = malloc(sizeof(*sd));
	328	memset(sd, 0, sizeof(*sd));
	329	sd->cmds = malloc(td->o.iodepth * sizeof(struct sgio_cmd));
	330	memset(sd->cmds, 0, td->o.iodepth * sizeof(struct sgio_cmd));
	331	sd->events = malloc(td->o.iodepth * sizeof(struct io_u *));
	332	memset(sd->events, 0, td->o.iodepth * sizeof(struct io_u *));
	333	sd->pfds = malloc(sizeof(struct pollfd) * td->o.nr_files);
	334	memset(sd->pfds, 0, sizeof(struct pollfd) * td->o.nr_files);
	335	sd->fd_flags = malloc(sizeof(int) * td->o.nr_files);
	336	memset(sd->fd_flags, 0, sizeof(int) * td->o.nr_files);
	337	sd->sgbuf = malloc(sizeof(struct sg_io_hdr) * td->o.iodepth);
	338	memset(sd->sgbuf, 0, sizeof(struct sg_io_hdr) * td->o.iodepth);
	339
	340	td->io_ops->data = sd;
	341
	342	/*
	343	* we want to do it, regardless of whether odirect is set or not
	344	*/
	345	td->o.override_sync = 1;
	346	return 0;
	347	}
	348
	349	static int fio_sgio_type_check(struct thread_data td, struct fio_file f)
	350	{
	351	struct sgio_data *sd = td->io_ops->data;
	352	unsigned int bs;
	353
	354	if (f->filetype == FIO_TYPE_BD) {
	355	if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
	356	td_verror(td, errno, "ioctl");
	357	return 1;
	358	}
	359	} else if (f->filetype == FIO_TYPE_CHAR) {
	360	int version, ret;
	361
	362	if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
	363	td_verror(td, errno, "ioctl");
	364	return 1;
	365	}
	366
	367	ret = fio_sgio_get_bs(td, &bs);
	368	if (ret)
	369	return 1;
	370	} else {
	371	log_err("ioengine sg only works on block devices\n");
	372	return 1;
	373	}
	374
	375	sd->bs = bs;
	376
	377	if (f->filetype == FIO_TYPE_BD) {
	378	td->io_ops->getevents = NULL;
	379	td->io_ops->event = NULL;
	380	}
	381
	382	return 0;
	383	}
	384
	385	static int fio_sgio_open(struct thread_data td, struct fio_file f)
	386	{
	387	struct sgio_data *sd = td->io_ops->data;
	388	int ret;
	389
	390	ret = generic_open_file(td, f);
	391	if (ret)
	392	return ret;
	393
	394	if (sd && !sd->type_checked && fio_sgio_type_check(td, f)) {
	395	ret = generic_close_file(td, f);
	396	return 1;
	397	}
	398
	399	return 0;
	400	}
	401
	402	static struct ioengine_ops ioengine = {
	403	.name = "sg",
	404	.version = FIO_IOOPS_VERSION,
	405	.init = fio_sgio_init,
	406	.prep = fio_sgio_prep,
	407	.queue = fio_sgio_queue,
	408	.getevents = fio_sgio_getevents,
	409	.event = fio_sgio_event,
	410	.cleanup = fio_sgio_cleanup,
	411	.open_file = fio_sgio_open,
	412	.close_file = generic_close_file,
	413	.get_file_size = generic_get_file_size,
	414	.flags = FIO_SYNCIO \| FIO_RAWIO,
	415	};
	416
	417	#else /* FIO_HAVE_SGIO */
	418
	419	/*
	420	* When we have a proper configure system in place, we simply wont build
	421	* and install this io engine. For now install a crippled version that
	422	* just complains and fails to load.
	423	*/
	424	static int fio_sgio_init(struct thread_data fio_unused *td)
	425	{
	426	log_err("fio: ioengine sg not available\n");
	427	return 1;
	428	}
	429
	430	static struct ioengine_ops ioengine = {
	431	.name = "sg",
	432	.version = FIO_IOOPS_VERSION,
	433	.init = fio_sgio_init,
	434	};
	435
	436	#endif
	437
	438	static void fio_init fio_sgio_register(void)
	439	{
	440	register_ioengine(&ioengine);
	441	}
	442
	443	static void fio_exit fio_sgio_unregister(void)
	444	{
	445	unregister_ioengine(&ioengine);
	446	}