xref: /freebsd/sys/geom/geom_dev.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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/bio.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/proc.h>
48 #include <sys/errno.h>
49 #include <sys/time.h>
50 #include <sys/disk.h>
51 #include <sys/fcntl.h>
52 #include <sys/limits.h>
53 #include <geom/geom.h>
54 #include <geom/geom_int.h>
55 
56 static d_open_t		g_dev_open;
57 static d_close_t	g_dev_close;
58 static d_strategy_t	g_dev_strategy;
59 static d_ioctl_t	g_dev_ioctl;
60 
61 static struct cdevsw g_dev_cdevsw = {
62 	.d_version =	D_VERSION,
63 	.d_open =	g_dev_open,
64 	.d_close =	g_dev_close,
65 	.d_read =	physread,
66 	.d_write =	physwrite,
67 	.d_ioctl =	g_dev_ioctl,
68 	.d_strategy =	g_dev_strategy,
69 	.d_name =	"g_dev",
70 	.d_flags =	D_DISK | D_TRACKCLOSE,
71 };
72 
73 static g_taste_t g_dev_taste;
74 static g_orphan_t g_dev_orphan;
75 
76 static struct g_class g_dev_class	= {
77 	.name = "DEV",
78 	.version = G_VERSION,
79 	.taste = g_dev_taste,
80 	.orphan = g_dev_orphan,
81 };
82 
83 void
84 g_dev_print(void)
85 {
86 	struct g_geom *gp;
87 	char const *p = "";
88 
89 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
90 		printf("%s%s", p, gp->name);
91 		p = " ";
92 	}
93 	printf("\n");
94 }
95 
96 struct g_provider *
97 g_dev_getprovider(struct cdev *dev)
98 {
99 	struct g_consumer *cp;
100 
101 	g_topology_assert();
102 	if (dev == NULL)
103 		return (NULL);
104 	if (dev->si_devsw != &g_dev_cdevsw)
105 		return (NULL);
106 	cp = dev->si_drv2;
107 	return (cp->provider);
108 }
109 
110 
111 static struct g_geom *
112 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
113 {
114 	struct g_geom *gp;
115 	struct g_consumer *cp;
116 	int error, len;
117 	struct cdev *dev, *adev;
118 	char buf[64], *val;
119 
120 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
121 	g_topology_assert();
122 	LIST_FOREACH(cp, &pp->consumers, consumers)
123 		if (cp->geom->class == mp)
124 			return (NULL);
125 	gp = g_new_geomf(mp, pp->name);
126 	cp = g_new_consumer(gp);
127 	error = g_attach(cp, pp);
128 	KASSERT(error == 0,
129 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
130 	error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
131 	    &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
132 	if (error != 0) {
133 		printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
134 		    __func__, gp->name, error);
135 		g_detach(cp);
136 		g_destroy_consumer(cp);
137 		g_destroy_geom(gp);
138 		return (NULL);
139 	}
140 
141 	/* Search for device alias name and create it if found. */
142 	adev = NULL;
143 	for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
144 		snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
145 		buf[14 + len] = 0;
146 		val = getenv(buf);
147 		if (val != NULL) {
148 			snprintf(buf, sizeof(buf), "%s%s",
149 			    val, gp->name + len);
150 			freeenv(val);
151 			make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
152 			    &adev, dev, "%s", buf);
153 			break;
154 		}
155 	}
156 
157 	if (pp->flags & G_PF_CANDELETE)
158 		dev->si_flags |= SI_CANDELETE;
159 	dev->si_iosize_max = MAXPHYS;
160 	gp->softc = dev;
161 	dev->si_drv1 = gp;
162 	dev->si_drv2 = cp;
163 	if (adev != NULL) {
164 		if (pp->flags & G_PF_CANDELETE)
165 			adev->si_flags |= SI_CANDELETE;
166 		adev->si_iosize_max = MAXPHYS;
167 		adev->si_drv1 = gp;
168 		adev->si_drv2 = cp;
169 	}
170 	return (gp);
171 }
172 
173 static int
174 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
175 {
176 	struct g_geom *gp;
177 	struct g_consumer *cp;
178 	int error, r, w, e;
179 
180 	gp = dev->si_drv1;
181 	cp = dev->si_drv2;
182 	if (gp == NULL || cp == NULL || gp->softc != dev)
183 		return(ENXIO);		/* g_dev_taste() not done yet */
184 
185 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
186 	    gp->name, flags, fmt, td);
187 
188 	r = flags & FREAD ? 1 : 0;
189 	w = flags & FWRITE ? 1 : 0;
190 #ifdef notyet
191 	e = flags & O_EXCL ? 1 : 0;
192 #else
193 	e = 0;
194 #endif
195 	if (w) {
196 		/*
197 		 * When running in very secure mode, do not allow
198 		 * opens for writing of any disks.
199 		 */
200 		error = securelevel_ge(td->td_ucred, 2);
201 		if (error)
202 			return (error);
203 	}
204 	g_topology_lock();
205 	if (dev->si_devsw == NULL)
206 		error = ENXIO;		/* We were orphaned */
207 	else
208 		error = g_access(cp, r, w, e);
209 	g_topology_unlock();
210 	return(error);
211 }
212 
213 static int
214 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
215 {
216 	struct g_geom *gp;
217 	struct g_consumer *cp;
218 	int error, r, w, e, i;
219 
220 	gp = dev->si_drv1;
221 	cp = dev->si_drv2;
222 	if (gp == NULL || cp == NULL)
223 		return(ENXIO);
224 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
225 	    gp->name, flags, fmt, td);
226 	r = flags & FREAD ? -1 : 0;
227 	w = flags & FWRITE ? -1 : 0;
228 #ifdef notyet
229 	e = flags & O_EXCL ? -1 : 0;
230 #else
231 	e = 0;
232 #endif
233 	g_topology_lock();
234 	if (dev->si_devsw == NULL)
235 		error = ENXIO;		/* We were orphaned */
236 	else
237 		error = g_access(cp, r, w, e);
238 	for (i = 0; i < 10 * hz;) {
239 		if (cp->acr != 0 || cp->acw != 0)
240 			break;
241  		if (cp->nstart == cp->nend)
242 			break;
243 		pause("gdevwclose", hz / 10);
244 		i += hz / 10;
245 	}
246 	if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
247 		printf("WARNING: Final close of geom_dev(%s) %s %s\n",
248 		    gp->name,
249 		    "still has outstanding I/O after 10 seconds.",
250 		    "Completing close anyway, panic may happen later.");
251 	}
252 	g_topology_unlock();
253 	return (error);
254 }
255 
256 /*
257  * XXX: Until we have unmessed the ioctl situation, there is a race against
258  * XXX: a concurrent orphanization.  We cannot close it by holding topology
259  * XXX: since that would prevent us from doing our job, and stalling events
260  * XXX: will break (actually: stall) the BSD disklabel hacks.
261  */
262 static int
263 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
264 {
265 	struct g_geom *gp;
266 	struct g_consumer *cp;
267 	struct g_provider *pp;
268 	struct g_kerneldump kd;
269 	off_t offset, length, chunk;
270 	int i, error;
271 	u_int u;
272 
273 	gp = dev->si_drv1;
274 	cp = dev->si_drv2;
275 	pp = cp->provider;
276 
277 	error = 0;
278 	KASSERT(cp->acr || cp->acw,
279 	    ("Consumer with zero access count in g_dev_ioctl"));
280 
281 	i = IOCPARM_LEN(cmd);
282 	switch (cmd) {
283 	case DIOCGSECTORSIZE:
284 		*(u_int *)data = cp->provider->sectorsize;
285 		if (*(u_int *)data == 0)
286 			error = ENOENT;
287 		break;
288 	case DIOCGMEDIASIZE:
289 		*(off_t *)data = cp->provider->mediasize;
290 		if (*(off_t *)data == 0)
291 			error = ENOENT;
292 		break;
293 	case DIOCGFWSECTORS:
294 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
295 		if (error == 0 && *(u_int *)data == 0)
296 			error = ENOENT;
297 		break;
298 	case DIOCGFWHEADS:
299 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
300 		if (error == 0 && *(u_int *)data == 0)
301 			error = ENOENT;
302 		break;
303 	case DIOCGFRONTSTUFF:
304 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
305 		break;
306 	case DIOCSKERNELDUMP:
307 		u = *((u_int *)data);
308 		if (!u) {
309 			set_dumper(NULL);
310 			error = 0;
311 			break;
312 		}
313 		kd.offset = 0;
314 		kd.length = OFF_MAX;
315 		i = sizeof kd;
316 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
317 		if (!error) {
318 			error = set_dumper(&kd.di);
319 			if (!error)
320 				dev->si_flags |= SI_DUMPDEV;
321 		}
322 		break;
323 	case DIOCGFLUSH:
324 		error = g_io_flush(cp);
325 		break;
326 	case DIOCGDELETE:
327 		offset = ((off_t *)data)[0];
328 		length = ((off_t *)data)[1];
329 		if ((offset % cp->provider->sectorsize) != 0 ||
330 		    (length % cp->provider->sectorsize) != 0 || length <= 0) {
331 			printf("%s: offset=%jd length=%jd\n", __func__, offset,
332 			    length);
333 			error = EINVAL;
334 			break;
335 		}
336 		while (length > 0) {
337 			chunk = length;
338 			if (chunk > 65536 * cp->provider->sectorsize)
339 				chunk = 65536 * cp->provider->sectorsize;
340 			error = g_delete_data(cp, offset, chunk);
341 			length -= chunk;
342 			offset += chunk;
343 			if (error)
344 				break;
345 			/*
346 			 * Since the request size is unbounded, the service
347 			 * time is likewise.  We make this ioctl interruptible
348 			 * by checking for signals for each bio.
349 			 */
350 			if (SIGPENDING(td))
351 				break;
352 		}
353 		break;
354 	case DIOCGIDENT:
355 		error = g_io_getattr("GEOM::ident", cp, &i, data);
356 		break;
357 	case DIOCGPROVIDERNAME:
358 		if (pp == NULL)
359 			return (ENOENT);
360 		strlcpy(data, pp->name, i);
361 		break;
362 	case DIOCGSTRIPESIZE:
363 		*(off_t *)data = cp->provider->stripesize;
364 		break;
365 	case DIOCGSTRIPEOFFSET:
366 		*(off_t *)data = cp->provider->stripeoffset;
367 		break;
368 	default:
369 		if (cp->provider->geom->ioctl != NULL) {
370 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
371 		} else {
372 			error = ENOIOCTL;
373 		}
374 	}
375 
376 	return (error);
377 }
378 
379 static void
380 g_dev_done(struct bio *bp2)
381 {
382 	struct bio *bp;
383 
384 	bp = bp2->bio_parent;
385 	bp->bio_error = bp2->bio_error;
386 	if (bp->bio_error != 0) {
387 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
388 		    bp2, bp->bio_error);
389 		bp->bio_flags |= BIO_ERROR;
390 	} else {
391 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
392 		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
393 	}
394 	bp->bio_resid = bp->bio_length - bp2->bio_completed;
395 	bp->bio_completed = bp2->bio_completed;
396 	g_destroy_bio(bp2);
397 	biodone(bp);
398 }
399 
400 static void
401 g_dev_strategy(struct bio *bp)
402 {
403 	struct g_consumer *cp;
404 	struct bio *bp2;
405 	struct cdev *dev;
406 
407 	KASSERT(bp->bio_cmd == BIO_READ ||
408 	        bp->bio_cmd == BIO_WRITE ||
409 	        bp->bio_cmd == BIO_DELETE,
410 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
411 	dev = bp->bio_dev;
412 	cp = dev->si_drv2;
413 	KASSERT(cp->acr || cp->acw,
414 	    ("Consumer with zero access count in g_dev_strategy"));
415 #ifdef INVARIANTS
416 	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
417 	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
418 		bp->bio_resid = bp->bio_bcount;
419 		biofinish(bp, NULL, EINVAL);
420 		return;
421 	}
422 #endif
423 	for (;;) {
424 		/*
425 		 * XXX: This is not an ideal solution, but I belive it to
426 		 * XXX: deadlock safe, all things considered.
427 		 */
428 		bp2 = g_clone_bio(bp);
429 		if (bp2 != NULL)
430 			break;
431 		pause("gdstrat", hz / 10);
432 	}
433 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
434 	bp2->bio_done = g_dev_done;
435 	g_trace(G_T_BIO,
436 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
437 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
438 	    bp2->bio_data, bp2->bio_cmd);
439 	g_io_request(bp2, cp);
440 	KASSERT(cp->acr || cp->acw,
441 	    ("g_dev_strategy raced with g_dev_close and lost"));
442 
443 }
444 
445 /*
446  * g_dev_orphan()
447  *
448  * Called from below when the provider orphaned us.
449  * - Clear any dump settings.
450  * - Destroy the struct cdev *to prevent any more request from coming in.  The
451  *   provider is already marked with an error, so anything which comes in
452  *   in the interrim will be returned immediately.
453  * - Wait for any outstanding I/O to finish.
454  * - Set our access counts to zero, whatever they were.
455  * - Detach and self-destruct.
456  */
457 
458 static void
459 g_dev_orphan(struct g_consumer *cp)
460 {
461 	struct g_geom *gp;
462 	struct cdev *dev;
463 
464 	g_topology_assert();
465 	gp = cp->geom;
466 	dev = gp->softc;
467 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
468 
469 	/* Reset any dump-area set on this device */
470 	if (dev->si_flags & SI_DUMPDEV)
471 		set_dumper(NULL);
472 
473 	/* Destroy the struct cdev *so we get no more requests */
474 	destroy_dev(dev);
475 
476 	/* Wait for the cows to come home */
477 	while (cp->nstart != cp->nend)
478 		pause("gdevorphan", hz / 10);
479 
480 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
481 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
482 
483 	g_detach(cp);
484 	g_destroy_consumer(cp);
485 	g_destroy_geom(gp);
486 }
487 
488 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
489