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
18struct sgio_cmd {
19	unsigned char cdb[10];
20	int nr;
21};
22
23struct 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
33static 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
53static 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
64static 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			sd->fd_flags[i] = fio_set_fd_nonblocking(f->fd, "sg");
82		else
83			sd->fd_flags[i] = -1;
84
85		sd->pfds[i].fd = f->fd;
86		sd->pfds[i].events = POLLIN;
87	}
88
89	while (left) {
90		void *p;
91
92		do {
93			if (!min)
94				break;
95
96			ret = poll(sd->pfds, td->o.nr_files, -1);
97			if (ret < 0) {
98				if (!r)
99					r = -errno;
100				td_verror(td, errno, "poll");
101				break;
102			} else if (!ret)
103				continue;
104
105			if (pollin_events(sd->pfds, td->o.nr_files))
106				break;
107		} while (1);
108
109		if (r < 0)
110			break;
111
112re_read:
113		p = buf;
114		events = 0;
115		for_each_file(td, f, i) {
116			ret = read(f->fd, p, left * sizeof(struct sg_io_hdr));
117			if (ret < 0) {
118				if (errno == EAGAIN)
119					continue;
120				r = -errno;
121				td_verror(td, errno, "read");
122				break;
123			} else if (ret) {
124				p += ret;
125				events += ret / sizeof(struct sg_io_hdr);
126			}
127		}
128
129		if (r < 0)
130			break;
131		if (!events) {
132			usleep(1000);
133			goto re_read;
134		}
135
136		left -= events;
137		r += events;
138
139		for (i = 0; i < events; i++) {
140			struct sg_io_hdr *hdr = (struct sg_io_hdr *) buf + i;
141
142			sd->events[i] = hdr->usr_ptr;
143		}
144	}
145
146	if (!min) {
147		for_each_file(td, f, i) {
148			if (sd->fd_flags[i] == -1)
149				continue;
150
151			if (fcntl(f->fd, F_SETFL, sd->fd_flags[i]) < 0)
152				log_err("fio: sg failed to restore fcntl flags: %s\n", strerror(errno));
153		}
154	}
155
156	return r;
157}
158
159static int fio_sgio_ioctl_doio(struct thread_data *td,
160			       struct fio_file *f, struct io_u *io_u)
161{
162	struct sgio_data *sd = td->io_ops->data;
163	struct sg_io_hdr *hdr = &io_u->hdr;
164	int ret;
165
166	sd->events[0] = io_u;
167
168	ret = ioctl(f->fd, SG_IO, hdr);
169	if (ret < 0)
170		return ret;
171
172	return FIO_Q_COMPLETED;
173}
174
175static int fio_sgio_rw_doio(struct fio_file *f, struct io_u *io_u, int do_sync)
176{
177	struct sg_io_hdr *hdr = &io_u->hdr;
178	int ret;
179
180	ret = write(f->fd, hdr, sizeof(*hdr));
181	if (ret < 0)
182		return ret;
183
184	if (do_sync) {
185		ret = read(f->fd, hdr, sizeof(*hdr));
186		if (ret < 0)
187			return ret;
188		return FIO_Q_COMPLETED;
189	}
190
191	return FIO_Q_QUEUED;
192}
193
194static int fio_sgio_doio(struct thread_data *td, struct io_u *io_u, int do_sync)
195{
196	struct fio_file *f = io_u->file;
197
198	if (f->filetype == FIO_TYPE_BD)
199		return fio_sgio_ioctl_doio(td, f, io_u);
200
201	return fio_sgio_rw_doio(f, io_u, do_sync);
202}
203
204static int fio_sgio_prep(struct thread_data *td, struct io_u *io_u)
205{
206	struct sg_io_hdr *hdr = &io_u->hdr;
207	struct sgio_data *sd = td->io_ops->data;
208	int nr_blocks, lba;
209
210	if (io_u->xfer_buflen & (sd->bs - 1)) {
211		log_err("read/write not sector aligned\n");
212		return EINVAL;
213	}
214
215	if (io_u->ddir == DDIR_READ) {
216		sgio_hdr_init(sd, hdr, io_u, 1);
217
218		hdr->dxfer_direction = SG_DXFER_FROM_DEV;
219		hdr->cmdp[0] = 0x28;
220	} else if (io_u->ddir == DDIR_WRITE) {
221		sgio_hdr_init(sd, hdr, io_u, 1);
222
223		hdr->dxfer_direction = SG_DXFER_TO_DEV;
224		hdr->cmdp[0] = 0x2a;
225	} else {
226		sgio_hdr_init(sd, hdr, io_u, 0);
227
228		hdr->dxfer_direction = SG_DXFER_NONE;
229		hdr->cmdp[0] = 0x35;
230	}
231
232	if (hdr->dxfer_direction != SG_DXFER_NONE) {
233		nr_blocks = io_u->xfer_buflen / sd->bs;
234		lba = io_u->offset / sd->bs;
235		hdr->cmdp[2] = (unsigned char) ((lba >> 24) & 0xff);
236		hdr->cmdp[3] = (unsigned char) ((lba >> 16) & 0xff);
237		hdr->cmdp[4] = (unsigned char) ((lba >>  8) & 0xff);
238		hdr->cmdp[5] = (unsigned char) (lba & 0xff);
239		hdr->cmdp[7] = (unsigned char) ((nr_blocks >> 8) & 0xff);
240		hdr->cmdp[8] = (unsigned char) (nr_blocks & 0xff);
241	}
242
243	return 0;
244}
245
246static int fio_sgio_queue(struct thread_data *td, struct io_u *io_u)
247{
248	struct sg_io_hdr *hdr = &io_u->hdr;
249	int ret, do_sync = 0;
250
251	fio_ro_check(td, io_u);
252
253	if (td->o.sync_io || td->o.odirect || ddir_sync(io_u->ddir))
254		do_sync = 1;
255
256	ret = fio_sgio_doio(td, io_u, do_sync);
257
258	if (ret < 0)
259		io_u->error = errno;
260	else if (hdr->status) {
261		io_u->resid = hdr->resid;
262		io_u->error = EIO;
263	}
264
265	if (io_u->error) {
266		td_verror(td, io_u->error, "xfer");
267		return FIO_Q_COMPLETED;
268	}
269
270	return ret;
271}
272
273static struct io_u *fio_sgio_event(struct thread_data *td, int event)
274{
275	struct sgio_data *sd = td->io_ops->data;
276
277	return sd->events[event];
278}
279
280static int fio_sgio_get_bs(struct thread_data *td, unsigned int *bs)
281{
282	struct sgio_data *sd = td->io_ops->data;
283	struct io_u io_u;
284	struct sg_io_hdr *hdr;
285	unsigned char buf[8];
286	int ret;
287
288	memset(&io_u, 0, sizeof(io_u));
289	io_u.file = td->files[0];
290
291	hdr = &io_u.hdr;
292	sgio_hdr_init(sd, hdr, &io_u, 0);
293	memset(buf, 0, sizeof(buf));
294
295	hdr->cmdp[0] = 0x25;
296	hdr->dxfer_direction = SG_DXFER_FROM_DEV;
297	hdr->dxferp = buf;
298	hdr->dxfer_len = sizeof(buf);
299
300	ret = fio_sgio_doio(td, &io_u, 1);
301	if (ret)
302		return ret;
303
304	*bs = (buf[4] << 24) | (buf[5] << 16) | (buf[6] << 8) | buf[7];
305	return 0;
306}
307
308static void fio_sgio_cleanup(struct thread_data *td)
309{
310	struct sgio_data *sd = td->io_ops->data;
311
312	if (sd) {
313		free(sd->events);
314		free(sd->cmds);
315		free(sd->fd_flags);
316		free(sd->pfds);
317		free(sd->sgbuf);
318		free(sd);
319	}
320}
321
322static int fio_sgio_init(struct thread_data *td)
323{
324	struct sgio_data *sd;
325
326	sd = malloc(sizeof(*sd));
327	memset(sd, 0, sizeof(*sd));
328	sd->cmds = malloc(td->o.iodepth * sizeof(struct sgio_cmd));
329	memset(sd->cmds, 0, td->o.iodepth * sizeof(struct sgio_cmd));
330	sd->events = malloc(td->o.iodepth * sizeof(struct io_u *));
331	memset(sd->events, 0, td->o.iodepth * sizeof(struct io_u *));
332	sd->pfds = malloc(sizeof(struct pollfd) * td->o.nr_files);
333	memset(sd->pfds, 0, sizeof(struct pollfd) * td->o.nr_files);
334	sd->fd_flags = malloc(sizeof(int) * td->o.nr_files);
335	memset(sd->fd_flags, 0, sizeof(int) * td->o.nr_files);
336	sd->sgbuf = malloc(sizeof(struct sg_io_hdr) * td->o.iodepth);
337	memset(sd->sgbuf, 0, sizeof(struct sg_io_hdr) * td->o.iodepth);
338
339	td->io_ops->data = sd;
340
341	/*
342	 * we want to do it, regardless of whether odirect is set or not
343	 */
344	td->o.override_sync = 1;
345	return 0;
346}
347
348static int fio_sgio_type_check(struct thread_data *td, struct fio_file *f)
349{
350	struct sgio_data *sd = td->io_ops->data;
351	unsigned int bs;
352
353	if (f->filetype == FIO_TYPE_BD) {
354		if (ioctl(f->fd, BLKSSZGET, &bs) < 0) {
355			td_verror(td, errno, "ioctl");
356			return 1;
357		}
358	} else if (f->filetype == FIO_TYPE_CHAR) {
359		int version, ret;
360
361		if (ioctl(f->fd, SG_GET_VERSION_NUM, &version) < 0) {
362			td_verror(td, errno, "ioctl");
363			return 1;
364		}
365
366		ret = fio_sgio_get_bs(td, &bs);
367		if (ret)
368			return 1;
369	} else {
370		log_err("ioengine sg only works on block devices\n");
371		return 1;
372	}
373
374	sd->bs = bs;
375
376	if (f->filetype == FIO_TYPE_BD) {
377		td->io_ops->getevents = NULL;
378		td->io_ops->event = NULL;
379	}
380
381	return 0;
382}
383
384static int fio_sgio_open(struct thread_data *td, struct fio_file *f)
385{
386	struct sgio_data *sd = td->io_ops->data;
387	int ret;
388
389	ret = generic_open_file(td, f);
390	if (ret)
391		return ret;
392
393	if (sd && !sd->type_checked && fio_sgio_type_check(td, f)) {
394		ret = generic_close_file(td, f);
395		return 1;
396	}
397
398	return 0;
399}
400
401static struct ioengine_ops ioengine = {
402	.name		= "sg",
403	.version	= FIO_IOOPS_VERSION,
404	.init		= fio_sgio_init,
405	.prep		= fio_sgio_prep,
406	.queue		= fio_sgio_queue,
407	.getevents	= fio_sgio_getevents,
408	.event		= fio_sgio_event,
409	.cleanup	= fio_sgio_cleanup,
410	.open_file	= fio_sgio_open,
411	.close_file	= generic_close_file,
412	.get_file_size	= generic_get_file_size,
413	.flags		= FIO_SYNCIO | FIO_RAWIO,
414};
415
416#else /* FIO_HAVE_SGIO */
417
418/*
419 * When we have a proper configure system in place, we simply wont build
420 * and install this io engine. For now install a crippled version that
421 * just complains and fails to load.
422 */
423static int fio_sgio_init(struct thread_data fio_unused *td)
424{
425	log_err("fio: ioengine sg not available\n");
426	return 1;
427}
428
429static struct ioengine_ops ioengine = {
430	.name		= "sg",
431	.version	= FIO_IOOPS_VERSION,
432	.init		= fio_sgio_init,
433};
434
435#endif
436
437static void fio_init fio_sgio_register(void)
438{
439	register_ioengine(&ioengine);
440}
441
442static void fio_exit fio_sgio_unregister(void)
443{
444	unregister_ioengine(&ioengine);
445}
446