xref: /freebsd/sys/geom/geom_dev.c (revision 77b7cdf1999ee965ad494fddd184b18f532ac91a)
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  * $FreeBSD$
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/malloc.h>
41 #include <sys/kernel.h>
42 #include <sys/conf.h>
43 #include <sys/bio.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/errno.h>
47 #include <sys/time.h>
48 #include <sys/disk.h>
49 #include <sys/fcntl.h>
50 #include <sys/limits.h>
51 #include <geom/geom.h>
52 #include <geom/geom_int.h>
53 
54 static d_open_t		g_dev_open;
55 static d_close_t	g_dev_close;
56 static d_strategy_t	g_dev_strategy;
57 static d_ioctl_t	g_dev_ioctl;
58 
59 static struct cdevsw g_dev_cdevsw = {
60 	.d_open =	g_dev_open,
61 	.d_close =	g_dev_close,
62 	.d_read =	physread,
63 	.d_write =	physwrite,
64 	.d_ioctl =	g_dev_ioctl,
65 	.d_strategy =	g_dev_strategy,
66 	.d_name =	"g_dev",
67 	.d_maj =	GEOM_MAJOR,
68 	.d_flags =	D_DISK | D_TRACKCLOSE,
69 };
70 
71 static g_taste_t g_dev_taste;
72 static g_orphan_t g_dev_orphan;
73 
74 static struct g_class g_dev_class	= {
75 	.name = "DEV",
76 	.taste = g_dev_taste,
77 	G_CLASS_INITIALIZER
78 };
79 
80 int
81 g_dev_print(void)
82 {
83 	struct g_geom *gp;
84 
85 	if (LIST_EMPTY(&g_dev_class.geom))
86 		return (0);
87 	printf("List of GEOM disk devices:\n  ");
88 	LIST_FOREACH(gp, &g_dev_class.geom, geom)
89 		printf(" %s", gp->name);
90 	printf("\n");
91 	return (1);
92 }
93 
94 /*
95  * XXX: This is disgusting and wrong in every way imaginable:  The only reason
96  * XXX: we have a clone function is because of the root-mount hack we currently
97  * XXX: employ.  An improvment would be to unregister this cloner once we know
98  * XXX: we no longer need it.  Ideally, root-fs would be mounted through DEVFS
99  * XXX: eliminating the need for this hack.
100  */
101 static void
102 g_dev_clone(void *arg __unused, char *name, int namelen __unused, dev_t *dev)
103 {
104 	struct g_geom *gp;
105 
106 	if (*dev != NODEV)
107 		return;
108 
109 	g_waitidle();
110 
111 	/* g_topology_lock(); */
112 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
113 		if (strcmp(gp->name, name))
114 			continue;
115 		*dev = gp->softc;
116 		g_trace(G_T_TOPOLOGY, "g_dev_clone(%s) = %p", name, *dev);
117 		return;
118 	}
119 	/* g_topology_unlock(); */
120 	return;
121 }
122 
123 static void
124 g_dev_register_cloner(void *foo __unused)
125 {
126 	static int once;
127 
128 	/* XXX: why would this happen more than once ?? */
129 	if (!once) {
130 		EVENTHANDLER_REGISTER(dev_clone, g_dev_clone, 0, 1000);
131 		once++;
132 	}
133 }
134 
135 SYSINIT(geomdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,g_dev_register_cloner,NULL);
136 
137 static struct g_geom *
138 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
139 {
140 	struct g_geom *gp;
141 	struct g_consumer *cp;
142 	static int unit = GEOM_MINOR_PROVIDERS;
143 	int error;
144 	dev_t dev;
145 
146 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
147 	g_topology_assert();
148 	LIST_FOREACH(cp, &pp->consumers, consumers)
149 		if (cp->geom->class == mp)
150 			return (NULL);
151 	gp = g_new_geomf(mp, pp->name);
152 	gp->orphan = g_dev_orphan;
153 	cp = g_new_consumer(gp);
154 	error = g_attach(cp, pp);
155 	KASSERT(error == 0,
156 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
157 	/*
158 	 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
159 	 * yet.  Once we can, we don't need to drop topology here either.
160 	 */
161 	g_topology_unlock();
162 	mtx_lock(&Giant);
163 	dev = make_dev(&g_dev_cdevsw, unit2minor(unit++),
164 	    UID_ROOT, GID_OPERATOR, 0640, gp->name);
165 	if (pp->flags & G_PF_CANDELETE)
166 		dev->si_flags |= SI_CANDELETE;
167 	mtx_unlock(&Giant);
168 	g_topology_lock();
169 	dev->si_iosize_max = MAXPHYS;
170 	dev->si_stripesize = pp->stripesize;
171 	dev->si_stripeoffset = pp->stripeoffset;
172 	gp->softc = dev;
173 	dev->si_drv1 = gp;
174 	dev->si_drv2 = cp;
175 	return (gp);
176 }
177 
178 static int
179 g_dev_open(dev_t dev, int flags, int fmt, struct thread *td)
180 {
181 	struct g_geom *gp;
182 	struct g_consumer *cp;
183 	int error, r, w, e;
184 
185 	gp = dev->si_drv1;
186 	cp = dev->si_drv2;
187 	if (gp == NULL || cp == NULL || gp->softc != dev)
188 		return(ENXIO);		/* g_dev_taste() not done yet */
189 
190 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
191 	    gp->name, flags, fmt, td);
192 	r = flags & FREAD ? 1 : 0;
193 	w = flags & FWRITE ? 1 : 0;
194 #ifdef notyet
195 	e = flags & O_EXCL ? 1 : 0;
196 #else
197 	e = 0;
198 #endif
199 	DROP_GIANT();
200 	g_topology_lock();
201 	if (dev->si_devsw == NULL)
202 		error = ENXIO;		/* We were orphaned */
203 	else
204 		error = g_access_rel(cp, r, w, e);
205 	g_topology_unlock();
206 	PICKUP_GIANT();
207 	g_waitidle();
208 	if (!error)
209 		dev->si_bsize_phys = cp->provider->sectorsize;
210 	return(error);
211 }
212 
213 static int
214 g_dev_close(dev_t 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;
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 	DROP_GIANT();
234 	g_topology_lock();
235 	if (dev->si_devsw == NULL)
236 		error = ENXIO;		/* We were orphaned */
237 	else
238 		error = g_access_rel(cp, r, w, e);
239 	KASSERT((cp->acr || cp->acw) || (cp->nstart == cp->nend),
240 	    ("final g_dev_close() with outstanding bios"));
241 	g_topology_unlock();
242 	PICKUP_GIANT();
243 	g_waitidle();
244 	return (error);
245 }
246 
247 /*
248  * XXX: Until we have unmessed the ioctl situation, there is a race against
249  * XXX: a concurrent orphanization.  We cannot close it by holding topology
250  * XXX: since that would prevent us from doing our job, and stalling events
251  * XXX: will break (actually: stall) the BSD disklabel hacks.
252  */
253 static int
254 g_dev_ioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
255 {
256 	struct g_geom *gp, *gp2;
257 	struct g_consumer *cp;
258 	struct g_provider *pp2;
259 	struct g_kerneldump kd;
260 	int i, error;
261 	u_int u;
262 	struct g_ioctl *gio;
263 
264 	gp = dev->si_drv1;
265 	cp = dev->si_drv2;
266 	pp2 = cp->provider;
267 	gp2 = pp2->geom;
268 	gio = NULL;
269 
270 	error = 0;
271 	KASSERT(cp->acr || cp->acw,
272 	    ("Consumer with zero access count in g_dev_ioctl"));
273 	DROP_GIANT();
274 
275 	gio = NULL;
276 	i = IOCPARM_LEN(cmd);
277 	switch (cmd) {
278 	case DIOCGSECTORSIZE:
279 		*(u_int *)data = cp->provider->sectorsize;
280 		if (*(u_int *)data == 0)
281 			error = ENOENT;
282 		break;
283 	case DIOCGMEDIASIZE:
284 		*(off_t *)data = cp->provider->mediasize;
285 		if (*(off_t *)data == 0)
286 			error = ENOENT;
287 		break;
288 	case DIOCGFWSECTORS:
289 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
290 		if (error == 0 && *(u_int *)data == 0)
291 			error = ENOENT;
292 		break;
293 	case DIOCGFWHEADS:
294 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
295 		if (error == 0 && *(u_int *)data == 0)
296 			error = ENOENT;
297 		break;
298 	case DIOCGFRONTSTUFF:
299 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
300 		break;
301 	case DIOCSKERNELDUMP:
302 		u = *((u_int *)data);
303 		if (!u) {
304 			set_dumper(NULL);
305 			error = 0;
306 			break;
307 		}
308 		kd.offset = 0;
309 		kd.length = OFF_MAX;
310 		i = sizeof kd;
311 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
312 		if (!error)
313 			dev->si_flags |= SI_DUMPDEV;
314 		break;
315 
316 	default:
317 		gio = g_malloc(sizeof *gio, M_WAITOK | M_ZERO);
318 		gio->cmd = cmd;
319 		gio->data = data;
320 		gio->fflag = fflag;
321 		gio->td = td;
322 		i = sizeof *gio;
323 		/*
324 		 * We always issue ioctls as getattr since the direction of data
325 		 * movement in ioctl is no indication of the ioctl being a "set"
326 		 * or "get" type ioctl or if such simplistic terms even apply
327 		 */
328 		error = g_io_getattr("GEOM::ioctl", cp, &i, gio);
329 		break;
330 	}
331 
332 	PICKUP_GIANT();
333 	if (error == EDIRIOCTL) {
334 		KASSERT(gio != NULL, ("NULL gio but EDIRIOCTL"));
335 		KASSERT(gio->func != NULL, ("NULL function but EDIRIOCTL"));
336 		error = (gio->func)(gio->dev, cmd, data, fflag, td);
337 	}
338 	g_waitidle();
339 	if (gio != NULL && (error == EOPNOTSUPP || error == ENOIOCTL)) {
340 		if (g_debugflags & G_T_TOPOLOGY) {
341 			i = IOCGROUP(cmd);
342 			printf("IOCTL(0x%lx) \"%s\"", cmd, gp->name);
343 			if (i > ' ' && i <= '~')
344 				printf(" '%c'", (int)IOCGROUP(cmd));
345 			else
346 				printf(" 0x%lx", IOCGROUP(cmd));
347 			printf("/%ld ", cmd & 0xff);
348 			if (cmd & IOC_IN)
349 				printf("I");
350 			if (cmd & IOC_OUT)
351 				printf("O");
352 			printf("(%ld) = ENOIOCTL\n", IOCPARM_LEN(cmd));
353 		}
354 		error = ENOTTY;
355 	}
356 	if (gio != NULL)
357 		g_free(gio);
358 	return (error);
359 }
360 
361 static void
362 g_dev_done(struct bio *bp2)
363 {
364 	struct bio *bp;
365 
366 	bp = bp2->bio_parent;
367 	bp->bio_error = bp2->bio_error;
368 	if (bp->bio_error != 0) {
369 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
370 		    bp2, bp->bio_error);
371 		bp->bio_flags |= BIO_ERROR;
372 	} else {
373 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
374 		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
375 	}
376 	bp->bio_resid = bp->bio_bcount - bp2->bio_completed;
377 	g_destroy_bio(bp2);
378 	mtx_lock(&Giant);
379 	biodone(bp);
380 	mtx_unlock(&Giant);
381 }
382 
383 static void
384 g_dev_strategy(struct bio *bp)
385 {
386 	struct g_geom *gp;
387 	struct g_consumer *cp;
388 	struct bio *bp2;
389 	dev_t dev;
390 
391 	KASSERT(bp->bio_cmd == BIO_READ ||
392 	        bp->bio_cmd == BIO_WRITE ||
393 	        bp->bio_cmd == BIO_DELETE,
394 		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
395 	dev = bp->bio_dev;
396 	gp = dev->si_drv1;
397 	cp = dev->si_drv2;
398 	KASSERT(cp->acr || cp->acw,
399 	    ("Consumer with zero access count in g_dev_strategy"));
400 
401 	bp2 = g_clone_bio(bp);
402 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
403 	bp2->bio_offset = (off_t)bp->bio_blkno << DEV_BSHIFT;
404 	KASSERT(bp2->bio_offset >= 0,
405 	    ("Negative bio_offset (%jd) on bio %p",
406 	    (intmax_t)bp2->bio_offset, bp));
407 	bp2->bio_length = (off_t)bp->bio_bcount;
408 	bp2->bio_done = g_dev_done;
409 	g_trace(G_T_BIO,
410 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
411 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
412 	    bp2->bio_data, bp2->bio_cmd);
413 	g_io_request(bp2, cp);
414 	KASSERT(cp->acr || cp->acw,
415 	    ("g_dev_strategy raced with g_dev_close and lost"));
416 
417 }
418 
419 /*
420  * g_dev_orphan()
421  *
422  * Called from below when the provider orphaned us.
423  * - Clear any dump settings.
424  * - Destroy the dev_t to prevent any more request from coming in.  The
425  *   provider is already marked with an error, so anything which comes in
426  *   in the interrim will be returned immediately.
427  * - Wait for any outstanding I/O to finish.
428  * - Set our access counts to zero, whatever they were.
429  * - Detach and self-destruct.
430  */
431 
432 static void
433 g_dev_orphan(struct g_consumer *cp)
434 {
435 	struct g_geom *gp;
436 	dev_t dev;
437 
438 	g_topology_assert();
439 	gp = cp->geom;
440 	dev = gp->softc;
441 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
442 
443 	/* Reset any dump-area set on this device */
444 	if (dev->si_flags & SI_DUMPDEV)
445 		set_dumper(NULL);
446 
447 	/* Destroy the dev_t so we get no more requests */
448 	destroy_dev(dev);
449 
450 	/* Wait for the cows to come home */
451 	while (cp->nstart != cp->nend)
452 		msleep(&dev, NULL, PRIBIO, "gdevorphan", hz / 10);
453 
454 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
455 		g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
456 
457 	g_detach(cp);
458 	g_destroy_consumer(cp);
459 	g_destroy_geom(gp);
460 }
461 
462 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
463