xref: /freebsd/sys/geom/geom_dev.c (revision 71fe318b852b8dfb3e799cb12ef184750f7f8eac)
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/stdint.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/errno.h>
48 #include <sys/time.h>
49 #include <sys/disk.h>
50 #include <sys/fcntl.h>
51 #include <geom/geom.h>
52 #include <geom/geom_int.h>
53 #include <machine/limits.h>
54 
55 #define CDEV_MAJOR	4
56 
57 static d_open_t		g_dev_open;
58 static d_close_t	g_dev_close;
59 static d_strategy_t	g_dev_strategy;
60 static d_ioctl_t	g_dev_ioctl;
61 static d_psize_t	g_dev_psize;
62 
63 static struct cdevsw g_dev_cdevsw = {
64 	/* open */      g_dev_open,
65 	/* close */     g_dev_close,
66 	/* read */      physread,
67 	/* write */     physwrite,
68 	/* ioctl */     g_dev_ioctl,
69 	/* poll */      nopoll,
70 	/* mmap */      nommap,
71 	/* strategy */  g_dev_strategy,
72 	/* name */      "g_dev",
73 	/* maj */       CDEV_MAJOR,
74 	/* dump */      nodump,
75 	/* psize */     g_dev_psize,
76 	/* flags */     D_DISK | D_CANFREE | D_TRACKCLOSE,
77 	/* kqfilter */	nokqfilter
78 };
79 
80 static g_taste_t g_dev_taste;
81 static g_orphan_t g_dev_orphan;
82 
83 static struct g_class g_dev_class	= {
84 	"DEV",
85 	g_dev_taste,
86 	NULL,
87 	G_CLASS_INITIALIZER
88 };
89 
90 int
91 g_dev_print(void)
92 {
93 	struct g_geom *gp;
94 
95 	if (LIST_EMPTY(&g_dev_class.geom))
96 		return (0);
97 	printf("List of GEOM disk devices:\n  ");
98 	LIST_FOREACH(gp, &g_dev_class.geom, geom)
99 		printf(" %s", gp->name);
100 	printf("\n");
101 	return (1);
102 }
103 
104 static void
105 g_dev_clone(void *arg __unused, char *name, int namelen __unused, dev_t *dev)
106 {
107 	struct g_geom *gp;
108 
109 	if (*dev != NODEV)
110 		return;
111 
112 	g_waitidle();
113 
114 	/* XXX: can I drop Giant here ??? */
115 	/* g_topology_lock(); */
116 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
117 		if (strcmp(gp->name, name))
118 			continue;
119 		*dev = gp->softc;
120 		g_trace(G_T_TOPOLOGY, "g_dev_clone(%s) = %p", name, *dev);
121 		return;
122 	}
123 	/* g_topology_unlock(); */
124 	return;
125 }
126 
127 static void
128 g_dev_register_cloner(void *foo __unused)
129 {
130 	static int once;
131 
132 	/* XXX: why would this happen more than once ?? */
133 	if (!once) {
134 		EVENTHANDLER_REGISTER(dev_clone, g_dev_clone, 0, 1000);
135 		once++;
136 	}
137 }
138 
139 SYSINIT(geomdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,g_dev_register_cloner,NULL);
140 
141 static struct g_geom *
142 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
143 {
144 	struct g_geom *gp;
145 	struct g_consumer *cp;
146 	static int unit;
147 	int error;
148 	dev_t dev;
149 
150 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
151 	g_topology_assert();
152 	LIST_FOREACH(cp, &pp->consumers, consumers)
153 		if (cp->geom->class == mp)
154 			return (NULL);
155 	gp = g_new_geomf(mp, pp->name);
156 	gp->orphan = g_dev_orphan;
157 	cp = g_new_consumer(gp);
158 	error = g_attach(cp, pp);
159 	KASSERT(error == 0,
160 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
161 	/*
162 	 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
163 	 * yet.  Once we can, we don't need to drop topology here either.
164 	 */
165 	g_topology_unlock();
166 	mtx_lock(&Giant);
167 	dev = make_dev(&g_dev_cdevsw, unit2minor(unit++),
168 	    UID_ROOT, GID_OPERATOR, 0640, gp->name);
169 	mtx_unlock(&Giant);
170 	g_topology_lock();
171 
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)
188 		return(ENXIO);
189 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
190 	    gp->name, flags, fmt, td);
191 	DROP_GIANT();
192 	g_topology_lock();
193 	g_silence();
194 	r = flags & FREAD ? 1 : 0;
195 	w = flags & FWRITE ? 1 : 0;
196 #ifdef notyet
197 	e = flags & O_EXCL ? 1 : 0;
198 #else
199 	e = 0;
200 #endif
201 	error = g_access_rel(cp, r, w, e);
202 	g_topology_unlock();
203 	PICKUP_GIANT();
204 	g_waitidle();
205 	return(error);
206 }
207 
208 static int
209 g_dev_close(dev_t dev, int flags, int fmt, struct thread *td)
210 {
211 	struct g_geom *gp;
212 	struct g_consumer *cp;
213 	int error, r, w, e;
214 
215 	gp = dev->si_drv1;
216 	cp = dev->si_drv2;
217 	if (gp == NULL || cp == NULL)
218 		return(ENXIO);
219 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
220 	    gp->name, flags, fmt, td);
221 	DROP_GIANT();
222 	g_topology_lock();
223 	g_silence();
224 	r = flags & FREAD ? -1 : 0;
225 	w = flags & FWRITE ? -1 : 0;
226 #ifdef notyet
227 	e = flags & O_EXCL ? -1 : 0;
228 #else
229 	e = 0;
230 #endif
231 	error = g_access_rel(cp, r, w, e);
232 	g_topology_unlock();
233 	PICKUP_GIANT();
234 	g_waitidle();
235 	return (error);
236 }
237 
238 static int
239 g_dev_ioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
240 {
241 	struct g_geom *gp, *gp2;
242 	struct g_consumer *cp;
243 	struct g_provider *pp2;
244 	struct g_kerneldump kd;
245 	int i, error;
246 	u_int u;
247 	struct g_ioctl *gio;
248 
249 	gp = dev->si_drv1;
250 	cp = dev->si_drv2;
251 	pp2 = cp->provider;
252 	gp2 = pp2->geom;
253 	gio = NULL;
254 
255 	error = 0;
256 	DROP_GIANT();
257 
258 	i = IOCPARM_LEN(cmd);
259 	switch (cmd) {
260 	case DIOCGSECTORSIZE:
261 		*(u_int *)data = cp->provider->sectorsize;
262 		if (*(u_int *)data == 0)
263 			error = ENOENT;
264 		break;
265 	case DIOCGMEDIASIZE:
266 		*(off_t *)data = cp->provider->mediasize;
267 		if (*(off_t *)data == 0)
268 			error = ENOENT;
269 		break;
270 	case DIOCGFWSECTORS:
271 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
272 		if (error == 0 && *(u_int *)data == 0)
273 			error = ENOENT;
274 		break;
275 	case DIOCGFWHEADS:
276 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
277 		if (error == 0 && *(u_int *)data == 0)
278 			error = ENOENT;
279 		break;
280 	case DIOCGFRONTSTUFF:
281 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
282 		break;
283 	case DIOCSKERNELDUMP:
284 		u = *((u_int *)data);
285 		if (!u) {
286 			set_dumper(NULL);
287 			error = 0;
288 			break;
289 		}
290 		kd.offset = 0;
291 		kd.length = OFF_MAX;
292 		i = sizeof kd;
293 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
294 		if (!error)
295 			dev->si_flags |= SI_DUMPDEV;
296 		break;
297 
298 	default:
299 		gio = g_malloc(sizeof *gio, M_WAITOK | M_ZERO);
300 		gio->cmd = cmd;
301 		gio->data = data;
302 		gio->fflag = fflag;
303 		gio->td = td;
304 		i = sizeof *gio;
305 		if (cmd & IOC_IN)
306 			error = g_io_setattr("GEOM::ioctl", cp, i, gio);
307 		else
308 			error = g_io_getattr("GEOM::ioctl", cp, &i, gio);
309 		break;
310 	}
311 
312 	PICKUP_GIANT();
313 	if (error == EDIRIOCTL) {
314 		KASSERT(gio != NULL, ("NULL gio but EDIRIOCTL"));
315 		KASSERT(gio->func != NULL, ("NULL function but EDIRIOCTL"));
316 		error = (gio->func)(gio->dev, cmd, data, fflag, td);
317 	}
318 	if (gio != NULL)
319 		g_free(gio);
320 	g_waitidle();
321 	if (error == ENOIOCTL) {
322 		if (g_debugflags & G_T_TOPOLOGY) {
323 			i = IOCGROUP(cmd);
324 			printf("IOCTL(0x%lx) \"%s\"", cmd, gp->name);
325 			if (i > ' ' && i <= '~')
326 				printf(" '%c'", (int)IOCGROUP(cmd));
327 			else
328 				printf(" 0x%lx", IOCGROUP(cmd));
329 			printf("/%ld ", cmd & 0xff);
330 			if (cmd & IOC_IN)
331 				printf("I");
332 			if (cmd & IOC_OUT)
333 				printf("O");
334 			printf("(%ld) = ENOIOCTL\n", IOCPARM_LEN(cmd));
335 		}
336 		error = ENOTTY;
337 	}
338 	return (error);
339 }
340 
341 static int
342 g_dev_psize(dev_t dev)
343 {
344 	struct g_consumer *cp;
345 	off_t mediasize;
346 
347 	cp = dev->si_drv2;
348 
349 	mediasize = cp->provider->mediasize;
350 	return (mediasize >> DEV_BSHIFT);
351 }
352 
353 static void
354 g_dev_done(struct bio *bp2)
355 {
356 	struct bio *bp;
357 
358 	bp = bp2->bio_linkage;
359 	bp->bio_error = bp2->bio_error;
360 	if (bp->bio_error != 0) {
361 		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
362 		    bp2, bp->bio_error);
363 		bp->bio_flags |= BIO_ERROR;
364 	} else {
365 		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
366 		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
367 	}
368 	bp->bio_resid = bp->bio_bcount - bp2->bio_completed;
369 	g_destroy_bio(bp2);
370 	mtx_lock(&Giant);
371 	biodone(bp);
372 	mtx_unlock(&Giant);
373 }
374 
375 static void
376 g_dev_strategy(struct bio *bp)
377 {
378 	struct g_geom *gp;
379 	struct g_consumer *cp;
380 	struct bio *bp2;
381 	dev_t dev;
382 
383 	dev = bp->bio_dev;
384 	gp = dev->si_drv1;
385 	cp = dev->si_drv2;
386 	bp2 = g_clone_bio(bp);
387 	bp2->bio_offset = (off_t)bp->bio_blkno << DEV_BSHIFT;
388 	bp2->bio_length = (off_t)bp->bio_bcount;
389 	bp2->bio_done = g_dev_done;
390 	g_trace(G_T_BIO,
391 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
392 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
393 	    bp2->bio_data, bp2->bio_cmd);
394 	g_io_request(bp2, cp);
395 }
396 
397 /*
398  * g_dev_orphan()
399  *
400  * Called from below when the provider orphaned us.  It is our responsibility
401  * to get the access counts back to zero, until we do so the stack below will
402  * not unravel.  We must clear the kernel-dump settings, if this is the
403  * current dumpdev.  We call destroy_dev(9) to send our dev_t the way of
404  * punched cards and if we have non-zero access counts, we call down with
405  * them negated before we detattch and selfdestruct.
406  */
407 
408 static void
409 g_dev_orphan(struct g_consumer *cp)
410 {
411 	struct g_geom *gp;
412 	dev_t dev;
413 
414 	gp = cp->geom;
415 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
416 	g_topology_assert();
417 	if (cp->biocount > 0)
418 		return;
419 	dev = gp->softc;
420 	if (dev->si_flags & SI_DUMPDEV)
421 		set_dumper(NULL);
422 	/* XXX: we may need Giant for now */
423 	destroy_dev(dev);
424 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
425 		g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
426 	g_detach(cp);
427 	g_destroy_consumer(cp);
428 	g_destroy_geom(gp);
429 }
430 
431 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
432