xref: /freebsd/sys/geom/geom_dev.c (revision 675be9115aae86ad6b3d877155d4fd7822892105)
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/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/proc.h>
49 #include <sys/errno.h>
50 #include <sys/time.h>
51 #include <sys/disk.h>
52 #include <sys/fcntl.h>
53 #include <sys/limits.h>
54 #include <geom/geom.h>
55 #include <geom/geom_int.h>
56 #include <machine/stdarg.h>
57 
58 /*
59  * Use the consumer private field to reference a physdev alias (if any).
60  */
61 #define cp_alias_dev	private
62 
63 static d_open_t		g_dev_open;
64 static d_close_t	g_dev_close;
65 static d_strategy_t	g_dev_strategy;
66 static d_ioctl_t	g_dev_ioctl;
67 
68 static struct cdevsw g_dev_cdevsw = {
69 	.d_version =	D_VERSION,
70 	.d_open =	g_dev_open,
71 	.d_close =	g_dev_close,
72 	.d_read =	physread,
73 	.d_write =	physwrite,
74 	.d_ioctl =	g_dev_ioctl,
75 	.d_strategy =	g_dev_strategy,
76 	.d_name =	"g_dev",
77 	.d_flags =	D_DISK | D_TRACKCLOSE,
78 };
79 
80 static g_taste_t g_dev_taste;
81 static g_orphan_t g_dev_orphan;
82 static g_attrchanged_t g_dev_attrchanged;
83 
84 static struct g_class g_dev_class	= {
85 	.name = "DEV",
86 	.version = G_VERSION,
87 	.taste = g_dev_taste,
88 	.orphan = g_dev_orphan,
89 	.attrchanged = g_dev_attrchanged
90 };
91 
92 void
93 g_dev_print(void)
94 {
95 	struct g_geom *gp;
96 	char const *p = "";
97 
98 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
99 		printf("%s%s", p, gp->name);
100 		p = " ";
101 	}
102 	printf("\n");
103 }
104 
105 static void
106 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
107 {
108 
109 	if (strcmp(attr, "GEOM::physpath") != 0)
110 		return;
111 
112 	if (g_access(cp, 1, 0, 0) == 0) {
113 		char *physpath;
114 		int error, physpath_len;
115 
116 		physpath_len = MAXPATHLEN;
117 		physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
118 		error =
119 		    g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
120 		g_access(cp, -1, 0, 0);
121 		if (error == 0 && strlen(physpath) != 0) {
122 			struct cdev *dev;
123 			struct cdev *old_alias_dev;
124 			struct cdev **alias_devp;
125 
126 			dev = cp->geom->softc;
127 			old_alias_dev = cp->cp_alias_dev;
128 			alias_devp = (struct cdev **)&cp->cp_alias_dev;
129 			make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
130 			    dev, old_alias_dev, physpath);
131 		} else if (cp->cp_alias_dev) {
132 			destroy_dev((struct cdev *)cp->cp_alias_dev);
133 			cp->cp_alias_dev = NULL;
134 		}
135 		g_free(physpath);
136 	}
137 }
138 
139 struct g_provider *
140 g_dev_getprovider(struct cdev *dev)
141 {
142 	struct g_consumer *cp;
143 
144 	g_topology_assert();
145 	if (dev == NULL)
146 		return (NULL);
147 	if (dev->si_devsw != &g_dev_cdevsw)
148 		return (NULL);
149 	cp = dev->si_drv2;
150 	return (cp->provider);
151 }
152 
153 static struct g_geom *
154 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
155 {
156 	struct g_geom *gp;
157 	struct g_consumer *cp;
158 	int error, len;
159 	struct cdev *dev, *adev;
160 	char buf[64], *val;
161 
162 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
163 	g_topology_assert();
164 	LIST_FOREACH(cp, &pp->consumers, consumers)
165 		if (cp->geom->class == mp)
166 			return (NULL);
167 	gp = g_new_geomf(mp, pp->name);
168 	cp = g_new_consumer(gp);
169 	error = g_attach(cp, pp);
170 	KASSERT(error == 0,
171 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
172 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
173 	    &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
174 	if (error != 0) {
175 		printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
176 		    __func__, gp->name, error);
177 		g_detach(cp);
178 		g_destroy_consumer(cp);
179 		g_destroy_geom(gp);
180 		return (NULL);
181 	}
182 
183 	/* Search for device alias name and create it if found. */
184 	adev = NULL;
185 	for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
186 		snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
187 		buf[14 + len] = 0;
188 		val = getenv(buf);
189 		if (val != NULL) {
190 			snprintf(buf, sizeof(buf), "%s%s",
191 			    val, gp->name + len);
192 			freeenv(val);
193 			make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
194 			    &adev, dev, "%s", buf);
195 			break;
196 		}
197 	}
198 
199 	if (pp->flags & G_PF_CANDELETE)
200 		dev->si_flags |= SI_CANDELETE;
201 	dev->si_iosize_max = MAXPHYS;
202 	gp->softc = dev;
203 	dev->si_drv1 = gp;
204 	dev->si_drv2 = cp;
205 	if (adev != NULL) {
206 		if (pp->flags & G_PF_CANDELETE)
207 			adev->si_flags |= SI_CANDELETE;
208 		adev->si_iosize_max = MAXPHYS;
209 		adev->si_drv1 = gp;
210 		adev->si_drv2 = cp;
211 	}
212 
213 	g_dev_attrchanged(cp, "GEOM::physpath");
214 
215 	return (gp);
216 }
217 
218 static int
219 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
220 {
221 	struct g_geom *gp;
222 	struct g_consumer *cp;
223 	int error, r, w, e;
224 
225 	gp = dev->si_drv1;
226 	cp = dev->si_drv2;
227 	if (gp == NULL || cp == NULL || gp->softc != dev)
228 		return(ENXIO);		/* g_dev_taste() not done yet */
229 
230 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
231 	    gp->name, flags, fmt, td);
232 
233 	r = flags & FREAD ? 1 : 0;
234 	w = flags & FWRITE ? 1 : 0;
235 #ifdef notyet
236 	e = flags & O_EXCL ? 1 : 0;
237 #else
238 	e = 0;
239 #endif
240 	if (w) {
241 		/*
242 		 * When running in very secure mode, do not allow
243 		 * opens for writing of any disks.
244 		 */
245 		error = securelevel_ge(td->td_ucred, 2);
246 		if (error)
247 			return (error);
248 	}
249 	g_topology_lock();
250 	if (dev->si_devsw == NULL)
251 		error = ENXIO;		/* We were orphaned */
252 	else
253 		error = g_access(cp, r, w, e);
254 	g_topology_unlock();
255 	return(error);
256 }
257 
258 static int
259 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
260 {
261 	struct g_geom *gp;
262 	struct g_consumer *cp;
263 	int error, r, w, e, i;
264 
265 	gp = dev->si_drv1;
266 	cp = dev->si_drv2;
267 	if (gp == NULL || cp == NULL)
268 		return(ENXIO);
269 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
270 	    gp->name, flags, fmt, td);
271 	r = flags & FREAD ? -1 : 0;
272 	w = flags & FWRITE ? -1 : 0;
273 #ifdef notyet
274 	e = flags & O_EXCL ? -1 : 0;
275 #else
276 	e = 0;
277 #endif
278 	g_topology_lock();
279 	if (dev->si_devsw == NULL)
280 		error = ENXIO;		/* We were orphaned */
281 	else
282 		error = g_access(cp, r, w, e);
283 	for (i = 0; i < 10 * hz;) {
284 		if (cp->acr != 0 || cp->acw != 0)
285 			break;
286  		if (cp->nstart == cp->nend)
287 			break;
288 		pause("gdevwclose", hz / 10);
289 		i += hz / 10;
290 	}
291 	if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
292 		printf("WARNING: Final close of geom_dev(%s) %s %s\n",
293 		    gp->name,
294 		    "still has outstanding I/O after 10 seconds.",
295 		    "Completing close anyway, panic may happen later.");
296 	}
297 	g_topology_unlock();
298 	return (error);
299 }
300 
301 /*
302  * XXX: Until we have unmessed the ioctl situation, there is a race against
303  * XXX: a concurrent orphanization.  We cannot close it by holding topology
304  * XXX: since that would prevent us from doing our job, and stalling events
305  * XXX: will break (actually: stall) the BSD disklabel hacks.
306  */
307 static int
308 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
309 {
310 	struct g_geom *gp;
311 	struct g_consumer *cp;
312 	struct g_provider *pp;
313 	struct g_kerneldump kd;
314 	off_t offset, length, chunk;
315 	int i, error;
316 	u_int u;
317 
318 	gp = dev->si_drv1;
319 	cp = dev->si_drv2;
320 	pp = cp->provider;
321 
322 	error = 0;
323 	KASSERT(cp->acr || cp->acw,
324 	    ("Consumer with zero access count in g_dev_ioctl"));
325 
326 	i = IOCPARM_LEN(cmd);
327 	switch (cmd) {
328 	case DIOCGSECTORSIZE:
329 		*(u_int *)data = cp->provider->sectorsize;
330 		if (*(u_int *)data == 0)
331 			error = ENOENT;
332 		break;
333 	case DIOCGMEDIASIZE:
334 		*(off_t *)data = cp->provider->mediasize;
335 		if (*(off_t *)data == 0)
336 			error = ENOENT;
337 		break;
338 	case DIOCGFWSECTORS:
339 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
340 		if (error == 0 && *(u_int *)data == 0)
341 			error = ENOENT;
342 		break;
343 	case DIOCGFWHEADS:
344 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
345 		if (error == 0 && *(u_int *)data == 0)
346 			error = ENOENT;
347 		break;
348 	case DIOCGFRONTSTUFF:
349 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
350 		break;
351 	case DIOCSKERNELDUMP:
352 		u = *((u_int *)data);
353 		if (!u) {
354 			set_dumper(NULL);
355 			error = 0;
356 			break;
357 		}
358 		kd.offset = 0;
359 		kd.length = OFF_MAX;
360 		i = sizeof kd;
361 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
362 		if (!error) {
363 			error = set_dumper(&kd.di);
364 			if (!error)
365 				dev->si_flags |= SI_DUMPDEV;
366 		}
367 		break;
368 	case DIOCGFLUSH:
369 		error = g_io_flush(cp);
370 		break;
371 	case DIOCGDELETE:
372 		offset = ((off_t *)data)[0];
373 		length = ((off_t *)data)[1];
374 		if ((offset % cp->provider->sectorsize) != 0 ||
375 		    (length % cp->provider->sectorsize) != 0 || length <= 0) {
376 			printf("%s: offset=%jd length=%jd\n", __func__, offset,
377 			    length);
378 			error = EINVAL;
379 			break;
380 		}
381 		while (length > 0) {
382 			chunk = length;
383 			if (chunk > 65536 * cp->provider->sectorsize)
384 				chunk = 65536 * cp->provider->sectorsize;
385 			error = g_delete_data(cp, offset, chunk);
386 			length -= chunk;
387 			offset += chunk;
388 			if (error)
389 				break;
390 			/*
391 			 * Since the request size is unbounded, the service
392 			 * time is likewise.  We make this ioctl interruptible
393 			 * by checking for signals for each bio.
394 			 */
395 			if (SIGPENDING(td))
396 				break;
397 		}
398 		break;
399 	case DIOCGIDENT:
400 		error = g_io_getattr("GEOM::ident", cp, &i, data);
401 		break;
402 	case DIOCGPROVIDERNAME:
403 		if (pp == NULL)
404 			return (ENOENT);
405 		strlcpy(data, pp->name, i);
406 		break;
407 	case DIOCGSTRIPESIZE:
408 		*(off_t *)data = cp->provider->stripesize;
409 		break;
410 	case DIOCGSTRIPEOFFSET:
411 		*(off_t *)data = cp->provider->stripeoffset;
412 		break;
413 	case DIOCGPHYSPATH:
414 		error = g_io_getattr("GEOM::physpath", cp, &i, data);
415 		if (error == 0 && *(char *)data == '\0')
416 			error = ENOENT;
417 		break;
418 	default:
419 		if (cp->provider->geom->ioctl != NULL) {
420 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
421 		} else {
422 			error = ENOIOCTL;
423 		}
424 	}
425 
426 	return (error);
427 }
428 
429 static void
430 g_dev_done(struct bio *bp2)
431 {
432 	struct bio *bp;
433 
434 	bp = bp2->bio_parent;
435 	bp->bio_error = bp2->bio_error;
436 	if (bp->bio_error != 0) {
437 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
438 		    bp2, bp->bio_error);
439 		bp->bio_flags |= BIO_ERROR;
440 	} else {
441 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
442 		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
443 	}
444 	bp->bio_resid = bp->bio_length - bp2->bio_completed;
445 	bp->bio_completed = bp2->bio_completed;
446 	g_destroy_bio(bp2);
447 	biodone(bp);
448 }
449 
450 static void
451 g_dev_strategy(struct bio *bp)
452 {
453 	struct g_consumer *cp;
454 	struct bio *bp2;
455 	struct cdev *dev;
456 
457 	KASSERT(bp->bio_cmd == BIO_READ ||
458 	        bp->bio_cmd == BIO_WRITE ||
459 	        bp->bio_cmd == BIO_DELETE,
460 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
461 	dev = bp->bio_dev;
462 	cp = dev->si_drv2;
463 	KASSERT(cp->acr || cp->acw,
464 	    ("Consumer with zero access count in g_dev_strategy"));
465 #ifdef INVARIANTS
466 	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
467 	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
468 		bp->bio_resid = bp->bio_bcount;
469 		biofinish(bp, NULL, EINVAL);
470 		return;
471 	}
472 #endif
473 	for (;;) {
474 		/*
475 		 * XXX: This is not an ideal solution, but I belive it to
476 		 * XXX: deadlock safe, all things considered.
477 		 */
478 		bp2 = g_clone_bio(bp);
479 		if (bp2 != NULL)
480 			break;
481 		pause("gdstrat", hz / 10);
482 	}
483 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
484 	bp2->bio_done = g_dev_done;
485 	g_trace(G_T_BIO,
486 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
487 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
488 	    bp2->bio_data, bp2->bio_cmd);
489 	g_io_request(bp2, cp);
490 	KASSERT(cp->acr || cp->acw,
491 	    ("g_dev_strategy raced with g_dev_close and lost"));
492 
493 }
494 
495 /*
496  * g_dev_orphan()
497  *
498  * Called from below when the provider orphaned us.
499  * - Clear any dump settings.
500  * - Destroy the struct cdev *to prevent any more request from coming in.  The
501  *   provider is already marked with an error, so anything which comes in
502  *   in the interrim will be returned immediately.
503  * - Wait for any outstanding I/O to finish.
504  * - Set our access counts to zero, whatever they were.
505  * - Detach and self-destruct.
506  */
507 
508 static void
509 g_dev_orphan(struct g_consumer *cp)
510 {
511 	struct g_geom *gp;
512 	struct cdev *dev;
513 
514 	g_topology_assert();
515 	gp = cp->geom;
516 	dev = gp->softc;
517 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
518 
519 	/* Reset any dump-area set on this device */
520 	if (dev->si_flags & SI_DUMPDEV)
521 		set_dumper(NULL);
522 
523 	/* Destroy the struct cdev *so we get no more requests */
524 	destroy_dev(dev);
525 
526 	/* Wait for the cows to come home */
527 	while (cp->nstart != cp->nend)
528 		pause("gdevorphan", hz / 10);
529 
530 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
531 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
532 
533 	g_detach(cp);
534 	g_destroy_consumer(cp);
535 	g_destroy_geom(gp);
536 }
537 
538 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
539