xref: /freebsd/sys/geom/geom_dev.c (revision 9fd69f37d28cfd7438cac3eeb45fe9dd46b4d7dd)
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;
117 	struct cdev *dev;
118 
119 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
120 	g_topology_assert();
121 	LIST_FOREACH(cp, &pp->consumers, consumers)
122 		if (cp->geom->class == mp)
123 			return (NULL);
124 	gp = g_new_geomf(mp, pp->name);
125 	cp = g_new_consumer(gp);
126 	error = g_attach(cp, pp);
127 	KASSERT(error == 0,
128 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
129 	dev = make_dev(&g_dev_cdevsw, 0,
130 	    UID_ROOT, GID_OPERATOR, 0640, gp->name);
131 	if (pp->flags & G_PF_CANDELETE)
132 		dev->si_flags |= SI_CANDELETE;
133 	dev->si_iosize_max = MAXPHYS;
134 	gp->softc = dev;
135 	dev->si_drv1 = gp;
136 	dev->si_drv2 = cp;
137 	return (gp);
138 }
139 
140 static int
141 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
142 {
143 	struct g_geom *gp;
144 	struct g_consumer *cp;
145 	int error, r, w, e;
146 
147 	gp = dev->si_drv1;
148 	cp = dev->si_drv2;
149 	if (gp == NULL || cp == NULL || gp->softc != dev)
150 		return(ENXIO);		/* g_dev_taste() not done yet */
151 
152 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
153 	    gp->name, flags, fmt, td);
154 
155 	r = flags & FREAD ? 1 : 0;
156 	w = flags & FWRITE ? 1 : 0;
157 #ifdef notyet
158 	e = flags & O_EXCL ? 1 : 0;
159 #else
160 	e = 0;
161 #endif
162 	if (w) {
163 		/*
164 		 * When running in very secure mode, do not allow
165 		 * opens for writing of any disks.
166 		 */
167 		error = securelevel_ge(td->td_ucred, 2);
168 		if (error)
169 			return (error);
170 	}
171 	g_topology_lock();
172 	if (dev->si_devsw == NULL)
173 		error = ENXIO;		/* We were orphaned */
174 	else
175 		error = g_access(cp, r, w, e);
176 	g_topology_unlock();
177 	return(error);
178 }
179 
180 static int
181 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
182 {
183 	struct g_geom *gp;
184 	struct g_consumer *cp;
185 	int error, r, w, e, i;
186 
187 	gp = dev->si_drv1;
188 	cp = dev->si_drv2;
189 	if (gp == NULL || cp == NULL)
190 		return(ENXIO);
191 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
192 	    gp->name, flags, fmt, td);
193 	r = flags & FREAD ? -1 : 0;
194 	w = flags & FWRITE ? -1 : 0;
195 #ifdef notyet
196 	e = flags & O_EXCL ? -1 : 0;
197 #else
198 	e = 0;
199 #endif
200 	g_topology_lock();
201 	if (dev->si_devsw == NULL)
202 		error = ENXIO;		/* We were orphaned */
203 	else
204 		error = g_access(cp, r, w, e);
205 	for (i = 0; i < 10 * hz;) {
206 		if (cp->acr != 0 || cp->acw != 0)
207 			break;
208  		if (cp->nstart == cp->nend)
209 			break;
210 		pause("gdevwclose", hz / 10);
211 		i += hz / 10;
212 	}
213 	if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
214 		printf("WARNING: Final close of geom_dev(%s) %s %s\n",
215 		    gp->name,
216 		    "still has outstanding I/O after 10 seconds.",
217 		    "Completing close anyway, panic may happen later.");
218 	}
219 	g_topology_unlock();
220 	return (error);
221 }
222 
223 /*
224  * XXX: Until we have unmessed the ioctl situation, there is a race against
225  * XXX: a concurrent orphanization.  We cannot close it by holding topology
226  * XXX: since that would prevent us from doing our job, and stalling events
227  * XXX: will break (actually: stall) the BSD disklabel hacks.
228  */
229 static int
230 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
231 {
232 	struct g_geom *gp;
233 	struct g_consumer *cp;
234 	struct g_provider *pp;
235 	struct g_kerneldump kd;
236 	off_t offset, length, chunk;
237 	int i, error;
238 	u_int u;
239 
240 	gp = dev->si_drv1;
241 	cp = dev->si_drv2;
242 	pp = cp->provider;
243 
244 	error = 0;
245 	KASSERT(cp->acr || cp->acw,
246 	    ("Consumer with zero access count in g_dev_ioctl"));
247 
248 	i = IOCPARM_LEN(cmd);
249 	switch (cmd) {
250 	case DIOCGSECTORSIZE:
251 		*(u_int *)data = cp->provider->sectorsize;
252 		if (*(u_int *)data == 0)
253 			error = ENOENT;
254 		break;
255 	case DIOCGMEDIASIZE:
256 		*(off_t *)data = cp->provider->mediasize;
257 		if (*(off_t *)data == 0)
258 			error = ENOENT;
259 		break;
260 	case DIOCGFWSECTORS:
261 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
262 		if (error == 0 && *(u_int *)data == 0)
263 			error = ENOENT;
264 		break;
265 	case DIOCGFWHEADS:
266 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
267 		if (error == 0 && *(u_int *)data == 0)
268 			error = ENOENT;
269 		break;
270 	case DIOCGFRONTSTUFF:
271 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
272 		break;
273 	case DIOCSKERNELDUMP:
274 		u = *((u_int *)data);
275 		if (!u) {
276 			set_dumper(NULL);
277 			error = 0;
278 			break;
279 		}
280 		kd.offset = 0;
281 		kd.length = OFF_MAX;
282 		i = sizeof kd;
283 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
284 		if (!error)
285 			dev->si_flags |= SI_DUMPDEV;
286 		break;
287 	case DIOCGFLUSH:
288 		error = g_io_flush(cp);
289 		break;
290 	case DIOCGDELETE:
291 		offset = ((off_t *)data)[0];
292 		length = ((off_t *)data)[1];
293 		if ((offset % cp->provider->sectorsize) != 0 ||
294 		    (length % cp->provider->sectorsize) != 0 || length <= 0) {
295 			printf("%s: offset=%jd length=%jd\n", __func__, offset,
296 			    length);
297 			error = EINVAL;
298 			break;
299 		}
300 		while (length > 0) {
301 			chunk = length;
302 			if (chunk > 65536 * cp->provider->sectorsize)
303 				chunk = 65536 * cp->provider->sectorsize;
304 			error = g_delete_data(cp, offset, chunk);
305 			length -= chunk;
306 			offset += chunk;
307 			if (error)
308 				break;
309 			/*
310 			 * Since the request size is unbounded, the service
311 			 * time is likewise.  We make this ioctl interruptible
312 			 * by checking for signals for each bio.
313 			 */
314 			if (SIGPENDING(td))
315 				break;
316 		}
317 		break;
318 	case DIOCGIDENT:
319 		error = g_io_getattr("GEOM::ident", cp, &i, data);
320 		break;
321 	case DIOCGPROVIDERNAME:
322 		if (pp == NULL)
323 			return (ENOENT);
324 		strlcpy(data, pp->name, i);
325 		break;
326 	case DIOCGSTRIPESIZE:
327 		*(off_t *)data = cp->provider->stripesize;
328 		break;
329 	case DIOCGSTRIPEOFFSET:
330 		*(off_t *)data = cp->provider->stripeoffset;
331 		break;
332 	default:
333 		if (cp->provider->geom->ioctl != NULL) {
334 			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
335 		} else {
336 			error = ENOIOCTL;
337 		}
338 	}
339 
340 	return (error);
341 }
342 
343 static void
344 g_dev_done(struct bio *bp2)
345 {
346 	struct bio *bp;
347 
348 	bp = bp2->bio_parent;
349 	bp->bio_error = bp2->bio_error;
350 	if (bp->bio_error != 0) {
351 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
352 		    bp2, bp->bio_error);
353 		bp->bio_flags |= BIO_ERROR;
354 	} else {
355 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
356 		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
357 	}
358 	bp->bio_resid = bp->bio_length - bp2->bio_completed;
359 	bp->bio_completed = bp2->bio_completed;
360 	g_destroy_bio(bp2);
361 	biodone(bp);
362 }
363 
364 static void
365 g_dev_strategy(struct bio *bp)
366 {
367 	struct g_consumer *cp;
368 	struct bio *bp2;
369 	struct cdev *dev;
370 
371 	KASSERT(bp->bio_cmd == BIO_READ ||
372 	        bp->bio_cmd == BIO_WRITE ||
373 	        bp->bio_cmd == BIO_DELETE,
374 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
375 	dev = bp->bio_dev;
376 	cp = dev->si_drv2;
377 	KASSERT(cp->acr || cp->acw,
378 	    ("Consumer with zero access count in g_dev_strategy"));
379 #ifdef INVARIANTS
380 	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
381 	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
382 		bp->bio_resid = bp->bio_bcount;
383 		biofinish(bp, NULL, EINVAL);
384 		return;
385 	}
386 #endif
387 	for (;;) {
388 		/*
389 		 * XXX: This is not an ideal solution, but I belive it to
390 		 * XXX: deadlock safe, all things considered.
391 		 */
392 		bp2 = g_clone_bio(bp);
393 		if (bp2 != NULL)
394 			break;
395 		pause("gdstrat", hz / 10);
396 	}
397 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
398 	bp2->bio_done = g_dev_done;
399 	g_trace(G_T_BIO,
400 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
401 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
402 	    bp2->bio_data, bp2->bio_cmd);
403 	g_io_request(bp2, cp);
404 	KASSERT(cp->acr || cp->acw,
405 	    ("g_dev_strategy raced with g_dev_close and lost"));
406 
407 }
408 
409 /*
410  * g_dev_orphan()
411  *
412  * Called from below when the provider orphaned us.
413  * - Clear any dump settings.
414  * - Destroy the struct cdev *to prevent any more request from coming in.  The
415  *   provider is already marked with an error, so anything which comes in
416  *   in the interrim will be returned immediately.
417  * - Wait for any outstanding I/O to finish.
418  * - Set our access counts to zero, whatever they were.
419  * - Detach and self-destruct.
420  */
421 
422 static void
423 g_dev_orphan(struct g_consumer *cp)
424 {
425 	struct g_geom *gp;
426 	struct cdev *dev;
427 
428 	g_topology_assert();
429 	gp = cp->geom;
430 	dev = gp->softc;
431 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
432 
433 	/* Reset any dump-area set on this device */
434 	if (dev->si_flags & SI_DUMPDEV)
435 		set_dumper(NULL);
436 
437 	/* Destroy the struct cdev *so we get no more requests */
438 	destroy_dev(dev);
439 
440 	/* Wait for the cows to come home */
441 	while (cp->nstart != cp->nend)
442 		pause("gdevorphan", hz / 10);
443 
444 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
445 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
446 
447 	g_detach(cp);
448 	g_destroy_consumer(cp);
449 	g_destroy_geom(gp);
450 }
451 
452 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
453