xref: /freebsd/sys/geom/geom_dev.c (revision f5f7c05209ca2c3748fd8b27c5e80ffad49120eb)
1 /*-
2  * Copyright (c) 2002 Poul-Henning Kamp
3  * Copyright (c) 2002 Networks Associates Technology, Inc.
4  * All rights reserved.
5  *
6  * This software was developed for the FreeBSD Project by Poul-Henning Kamp
7  * and NAI Labs, the Security Research Division of Network Associates, Inc.
8  * under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
9  * DARPA CHATS research program.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. The names of the authors may not be used to endorse or promote
20  *    products derived from this software without specific prior written
21  *    permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 #include <sys/conf.h>
44 #include <sys/ctype.h>
45 #include <sys/bio.h>
46 #include <sys/bus.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/proc.h>
50 #include <sys/errno.h>
51 #include <sys/time.h>
52 #include <sys/disk.h>
53 #include <sys/fcntl.h>
54 #include <sys/limits.h>
55 #include <geom/geom.h>
56 #include <geom/geom_int.h>
57 #include <machine/stdarg.h>
58 
59 /*
60  * Use the consumer private field to reference a physdev alias (if any).
61  */
62 #define cp_alias_dev	private
63 
64 static d_open_t		g_dev_open;
65 static d_close_t	g_dev_close;
66 static d_strategy_t	g_dev_strategy;
67 static d_ioctl_t	g_dev_ioctl;
68 
69 static struct cdevsw g_dev_cdevsw = {
70 	.d_version =	D_VERSION,
71 	.d_open =	g_dev_open,
72 	.d_close =	g_dev_close,
73 	.d_read =	physread,
74 	.d_write =	physwrite,
75 	.d_ioctl =	g_dev_ioctl,
76 	.d_strategy =	g_dev_strategy,
77 	.d_name =	"g_dev",
78 	.d_flags =	D_DISK | D_TRACKCLOSE,
79 };
80 
81 static g_taste_t g_dev_taste;
82 static g_orphan_t g_dev_orphan;
83 static g_attrchanged_t g_dev_attrchanged;
84 
85 static struct g_class g_dev_class	= {
86 	.name = "DEV",
87 	.version = G_VERSION,
88 	.taste = g_dev_taste,
89 	.orphan = g_dev_orphan,
90 	.attrchanged = g_dev_attrchanged
91 };
92 
93 void
94 g_dev_print(void)
95 {
96 	struct g_geom *gp;
97 	char const *p = "";
98 
99 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
100 		printf("%s%s", p, gp->name);
101 		p = " ";
102 	}
103 	printf("\n");
104 }
105 
106 static void
107 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
108 {
109 	struct cdev *dev;
110 	char buf[SPECNAMELEN + 6];
111 
112 	if (strcmp(attr, "GEOM::media") == 0) {
113 		dev = cp->geom->softc;
114 		snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
115 		devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
116 		dev = cp->cp_alias_dev;
117 		if (dev != NULL) {
118 			snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
119 			devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf,
120 			    M_WAITOK);
121 		}
122 		return;
123 	}
124 
125 	if (strcmp(attr, "GEOM::physpath") != 0)
126 		return;
127 
128 	if (g_access(cp, 1, 0, 0) == 0) {
129 		char *physpath;
130 		int error, physpath_len;
131 
132 		physpath_len = MAXPATHLEN;
133 		physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
134 		error =
135 		    g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
136 		g_access(cp, -1, 0, 0);
137 		if (error == 0 && strlen(physpath) != 0) {
138 			struct cdev *old_alias_dev;
139 			struct cdev **alias_devp;
140 
141 			dev = cp->geom->softc;
142 			old_alias_dev = cp->cp_alias_dev;
143 			alias_devp = (struct cdev **)&cp->cp_alias_dev;
144 			make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
145 			    dev, old_alias_dev, physpath);
146 		} else if (cp->cp_alias_dev) {
147 			destroy_dev((struct cdev *)cp->cp_alias_dev);
148 			cp->cp_alias_dev = NULL;
149 		}
150 		g_free(physpath);
151 	}
152 }
153 
154 struct g_provider *
155 g_dev_getprovider(struct cdev *dev)
156 {
157 	struct g_consumer *cp;
158 
159 	g_topology_assert();
160 	if (dev == NULL)
161 		return (NULL);
162 	if (dev->si_devsw != &g_dev_cdevsw)
163 		return (NULL);
164 	cp = dev->si_drv2;
165 	return (cp->provider);
166 }
167 
168 static struct g_geom *
169 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
170 {
171 	struct g_geom *gp;
172 	struct g_consumer *cp;
173 	int error, len;
174 	struct cdev *dev, *adev;
175 	char buf[64], *val;
176 
177 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
178 	g_topology_assert();
179 	gp = g_new_geomf(mp, "%s", pp->name);
180 	cp = g_new_consumer(gp);
181 	error = g_attach(cp, pp);
182 	KASSERT(error == 0,
183 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
184 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
185 	    &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
186 	if (error != 0) {
187 		printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
188 		    __func__, gp->name, error);
189 		g_detach(cp);
190 		g_destroy_consumer(cp);
191 		g_destroy_geom(gp);
192 		return (NULL);
193 	}
194 
195 	/* Search for device alias name and create it if found. */
196 	adev = NULL;
197 	for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
198 		snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
199 		buf[14 + len] = 0;
200 		val = getenv(buf);
201 		if (val != NULL) {
202 			snprintf(buf, sizeof(buf), "%s%s",
203 			    val, gp->name + len);
204 			freeenv(val);
205 			make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
206 			    &adev, dev, "%s", buf);
207 			break;
208 		}
209 	}
210 
211 	dev->si_iosize_max = MAXPHYS;
212 	gp->softc = dev;
213 	dev->si_drv1 = gp;
214 	dev->si_drv2 = cp;
215 	if (adev != NULL) {
216 		adev->si_iosize_max = MAXPHYS;
217 		adev->si_drv1 = gp;
218 		adev->si_drv2 = cp;
219 	}
220 
221 	g_dev_attrchanged(cp, "GEOM::physpath");
222 
223 	return (gp);
224 }
225 
226 static int
227 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
228 {
229 	struct g_geom *gp;
230 	struct g_consumer *cp;
231 	int error, r, w, e;
232 
233 	gp = dev->si_drv1;
234 	cp = dev->si_drv2;
235 	if (gp == NULL || cp == NULL || gp->softc != dev)
236 		return(ENXIO);		/* g_dev_taste() not done yet */
237 
238 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
239 	    gp->name, flags, fmt, td);
240 
241 	r = flags & FREAD ? 1 : 0;
242 	w = flags & FWRITE ? 1 : 0;
243 #ifdef notyet
244 	e = flags & O_EXCL ? 1 : 0;
245 #else
246 	e = 0;
247 #endif
248 	if (w) {
249 		/*
250 		 * When running in very secure mode, do not allow
251 		 * opens for writing of any disks.
252 		 */
253 		error = securelevel_ge(td->td_ucred, 2);
254 		if (error)
255 			return (error);
256 	}
257 	g_topology_lock();
258 	if (dev->si_devsw == NULL)
259 		error = ENXIO;		/* We were orphaned */
260 	else
261 		error = g_access(cp, r, w, e);
262 	g_topology_unlock();
263 	return(error);
264 }
265 
266 static int
267 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
268 {
269 	struct g_geom *gp;
270 	struct g_consumer *cp;
271 	int error, r, w, e, i;
272 
273 	gp = dev->si_drv1;
274 	cp = dev->si_drv2;
275 	if (gp == NULL || cp == NULL)
276 		return(ENXIO);
277 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
278 	    gp->name, flags, fmt, td);
279 	r = flags & FREAD ? -1 : 0;
280 	w = flags & FWRITE ? -1 : 0;
281 #ifdef notyet
282 	e = flags & O_EXCL ? -1 : 0;
283 #else
284 	e = 0;
285 #endif
286 	g_topology_lock();
287 	if (dev->si_devsw == NULL)
288 		error = ENXIO;		/* We were orphaned */
289 	else
290 		error = g_access(cp, r, w, e);
291 	for (i = 0; i < 10 * hz;) {
292 		if (cp->acr != 0 || cp->acw != 0)
293 			break;
294  		if (cp->nstart == cp->nend)
295 			break;
296 		pause("gdevwclose", hz / 10);
297 		i += hz / 10;
298 	}
299 	if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
300 		printf("WARNING: Final close of geom_dev(%s) %s %s\n",
301 		    gp->name,
302 		    "still has outstanding I/O after 10 seconds.",
303 		    "Completing close anyway, panic may happen later.");
304 	}
305 	g_topology_unlock();
306 	return (error);
307 }
308 
309 /*
310  * XXX: Until we have unmessed the ioctl situation, there is a race against
311  * XXX: a concurrent orphanization.  We cannot close it by holding topology
312  * XXX: since that would prevent us from doing our job, and stalling events
313  * XXX: will break (actually: stall) the BSD disklabel hacks.
314  */
315 static int
316 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
317 {
318 	struct g_geom *gp;
319 	struct g_consumer *cp;
320 	struct g_provider *pp;
321 	struct g_kerneldump kd;
322 	off_t offset, length, chunk;
323 	int i, error;
324 	u_int u;
325 
326 	gp = dev->si_drv1;
327 	cp = dev->si_drv2;
328 	pp = cp->provider;
329 
330 	error = 0;
331 	KASSERT(cp->acr || cp->acw,
332 	    ("Consumer with zero access count in g_dev_ioctl"));
333 
334 	i = IOCPARM_LEN(cmd);
335 	switch (cmd) {
336 	case DIOCGSECTORSIZE:
337 		*(u_int *)data = cp->provider->sectorsize;
338 		if (*(u_int *)data == 0)
339 			error = ENOENT;
340 		break;
341 	case DIOCGMEDIASIZE:
342 		*(off_t *)data = cp->provider->mediasize;
343 		if (*(off_t *)data == 0)
344 			error = ENOENT;
345 		break;
346 	case DIOCGFWSECTORS:
347 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
348 		if (error == 0 && *(u_int *)data == 0)
349 			error = ENOENT;
350 		break;
351 	case DIOCGFWHEADS:
352 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
353 		if (error == 0 && *(u_int *)data == 0)
354 			error = ENOENT;
355 		break;
356 	case DIOCGFRONTSTUFF:
357 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
358 		break;
359 	case DIOCSKERNELDUMP:
360 		u = *((u_int *)data);
361 		if (!u) {
362 			set_dumper(NULL, NULL);
363 			error = 0;
364 			break;
365 		}
366 		kd.offset = 0;
367 		kd.length = OFF_MAX;
368 		i = sizeof kd;
369 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
370 		if (!error) {
371 			error = set_dumper(&kd.di, devtoname(dev));
372 			if (!error)
373 				dev->si_flags |= SI_DUMPDEV;
374 		}
375 		break;
376 	case DIOCGFLUSH:
377 		error = g_io_flush(cp);
378 		break;
379 	case DIOCGDELETE:
380 		offset = ((off_t *)data)[0];
381 		length = ((off_t *)data)[1];
382 		if ((offset % cp->provider->sectorsize) != 0 ||
383 		    (length % cp->provider->sectorsize) != 0 || length <= 0) {
384 			printf("%s: offset=%jd length=%jd\n", __func__, offset,
385 			    length);
386 			error = EINVAL;
387 			break;
388 		}
389 		while (length > 0) {
390 			chunk = length;
391 			if (chunk > 65536 * cp->provider->sectorsize)
392 				chunk = 65536 * cp->provider->sectorsize;
393 			error = g_delete_data(cp, offset, chunk);
394 			length -= chunk;
395 			offset += chunk;
396 			if (error)
397 				break;
398 			/*
399 			 * Since the request size is unbounded, the service
400 			 * time is likewise.  We make this ioctl interruptible
401 			 * by checking for signals for each bio.
402 			 */
403 			if (SIGPENDING(td))
404 				break;
405 		}
406 		break;
407 	case DIOCGIDENT:
408 		error = g_io_getattr("GEOM::ident", cp, &i, data);
409 		break;
410 	case DIOCGPROVIDERNAME:
411 		if (pp == NULL)
412 			return (ENOENT);
413 		strlcpy(data, pp->name, i);
414 		break;
415 	case DIOCGSTRIPESIZE:
416 		*(off_t *)data = cp->provider->stripesize;
417 		break;
418 	case DIOCGSTRIPEOFFSET:
419 		*(off_t *)data = cp->provider->stripeoffset;
420 		break;
421 	case DIOCGPHYSPATH:
422 		error = g_io_getattr("GEOM::physpath", cp, &i, data);
423 		if (error == 0 && *(char *)data == '\0')
424 			error = ENOENT;
425 		break;
426 	default:
427 		if (cp->provider->geom->ioctl != NULL) {
428 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
429 		} else {
430 			error = ENOIOCTL;
431 		}
432 	}
433 
434 	return (error);
435 }
436 
437 static void
438 g_dev_done(struct bio *bp2)
439 {
440 	struct bio *bp;
441 
442 	bp = bp2->bio_parent;
443 	bp->bio_error = bp2->bio_error;
444 	if (bp->bio_error != 0) {
445 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
446 		    bp2, bp->bio_error);
447 		bp->bio_flags |= BIO_ERROR;
448 	} else {
449 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
450 		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
451 	}
452 	bp->bio_resid = bp->bio_length - bp2->bio_completed;
453 	bp->bio_completed = bp2->bio_completed;
454 	g_destroy_bio(bp2);
455 	biodone(bp);
456 }
457 
458 static void
459 g_dev_strategy(struct bio *bp)
460 {
461 	struct g_consumer *cp;
462 	struct bio *bp2;
463 	struct cdev *dev;
464 
465 	KASSERT(bp->bio_cmd == BIO_READ ||
466 	        bp->bio_cmd == BIO_WRITE ||
467 	        bp->bio_cmd == BIO_DELETE,
468 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
469 	dev = bp->bio_dev;
470 	cp = dev->si_drv2;
471 	KASSERT(cp->acr || cp->acw,
472 	    ("Consumer with zero access count in g_dev_strategy"));
473 #ifdef INVARIANTS
474 	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
475 	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
476 		bp->bio_resid = bp->bio_bcount;
477 		biofinish(bp, NULL, EINVAL);
478 		return;
479 	}
480 #endif
481 	for (;;) {
482 		/*
483 		 * XXX: This is not an ideal solution, but I belive it to
484 		 * XXX: deadlock safe, all things considered.
485 		 */
486 		bp2 = g_clone_bio(bp);
487 		if (bp2 != NULL)
488 			break;
489 		pause("gdstrat", hz / 10);
490 	}
491 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
492 	bp2->bio_done = g_dev_done;
493 	g_trace(G_T_BIO,
494 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
495 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
496 	    bp2->bio_data, bp2->bio_cmd);
497 	g_io_request(bp2, cp);
498 	KASSERT(cp->acr || cp->acw,
499 	    ("g_dev_strategy raced with g_dev_close and lost"));
500 
501 }
502 
503 /*
504  * g_dev_orphan()
505  *
506  * Called from below when the provider orphaned us.
507  * - Clear any dump settings.
508  * - Destroy the struct cdev to prevent any more request from coming in.  The
509  *   provider is already marked with an error, so anything which comes in
510  *   in the interrim will be returned immediately.
511  * - Wait for any outstanding I/O to finish.
512  * - Set our access counts to zero, whatever they were.
513  * - Detach and self-destruct.
514  */
515 
516 static void
517 g_dev_orphan(struct g_consumer *cp)
518 {
519 	struct g_geom *gp;
520 	struct cdev *dev;
521 
522 	g_topology_assert();
523 	gp = cp->geom;
524 	dev = gp->softc;
525 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
526 
527 	/* Reset any dump-area set on this device */
528 	if (dev->si_flags & SI_DUMPDEV)
529 		set_dumper(NULL, NULL);
530 
531 	/* Destroy the struct cdev *so we get no more requests */
532 	destroy_dev(dev);
533 
534 	/* Wait for the cows to come home */
535 	while (cp->nstart != cp->nend)
536 		pause("gdevorphan", hz / 10);
537 
538 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
539 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
540 
541 	g_detach(cp);
542 	g_destroy_consumer(cp);
543 	g_destroy_geom(gp);
544 }
545 
546 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
547