xref: /freebsd/sys/geom/geom_dev.c (revision 936cc4614b5187681f3a1c76a7740ead4845a548)
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 /*
105  * XXX: This is disgusting and wrong in every way imaginable:  The only reason
106  * XXX: we have a clone function is because of the root-mount hack we currently
107  * XXX: employ.  An improvment would be to unregister this cloner once we know
108  * XXX: we no longer need it.  Ideally, root-fs would be mounted through DEVFS
109  * XXX: eliminating the need for this hack.
110  */
111 static void
112 g_dev_clone(void *arg __unused, char *name, int namelen __unused, dev_t *dev)
113 {
114 	struct g_geom *gp;
115 
116 	if (*dev != NODEV)
117 		return;
118 
119 	g_waitidle();
120 
121 	/* g_topology_lock(); */
122 	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
123 		if (strcmp(gp->name, name))
124 			continue;
125 		*dev = gp->softc;
126 		g_trace(G_T_TOPOLOGY, "g_dev_clone(%s) = %p", name, *dev);
127 		return;
128 	}
129 	/* g_topology_unlock(); */
130 	return;
131 }
132 
133 static void
134 g_dev_register_cloner(void *foo __unused)
135 {
136 	static int once;
137 
138 	/* XXX: why would this happen more than once ?? */
139 	if (!once) {
140 		EVENTHANDLER_REGISTER(dev_clone, g_dev_clone, 0, 1000);
141 		once++;
142 	}
143 }
144 
145 SYSINIT(geomdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,g_dev_register_cloner,NULL);
146 
147 static struct g_geom *
148 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
149 {
150 	struct g_geom *gp;
151 	struct g_consumer *cp;
152 	static int unit;
153 	int error;
154 	dev_t dev;
155 
156 	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
157 	g_topology_assert();
158 	LIST_FOREACH(cp, &pp->consumers, consumers)
159 		if (cp->geom->class == mp)
160 			return (NULL);
161 	gp = g_new_geomf(mp, pp->name);
162 	gp->orphan = g_dev_orphan;
163 	cp = g_new_consumer(gp);
164 	error = g_attach(cp, pp);
165 	KASSERT(error == 0,
166 	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
167 	/*
168 	 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
169 	 * yet.  Once we can, we don't need to drop topology here either.
170 	 */
171 	g_topology_unlock();
172 	mtx_lock(&Giant);
173 	dev = make_dev(&g_dev_cdevsw, unit2minor(unit++),
174 	    UID_ROOT, GID_OPERATOR, 0640, gp->name);
175 	mtx_unlock(&Giant);
176 	g_topology_lock();
177 
178 	gp->softc = dev;
179 	dev->si_drv1 = gp;
180 	dev->si_drv2 = cp;
181 	return (gp);
182 }
183 
184 static int
185 g_dev_open(dev_t dev, int flags, int fmt, struct thread *td)
186 {
187 	struct g_geom *gp;
188 	struct g_consumer *cp;
189 	int error, r, w, e;
190 
191 	gp = dev->si_drv1;
192 	cp = dev->si_drv2;
193 	if (gp == NULL || cp == NULL)
194 		return(ENXIO);
195 	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
196 	    gp->name, flags, fmt, td);
197 	DROP_GIANT();
198 	g_topology_lock();
199 	r = flags & FREAD ? 1 : 0;
200 	w = flags & FWRITE ? 1 : 0;
201 #ifdef notyet
202 	e = flags & O_EXCL ? 1 : 0;
203 #else
204 	e = 0;
205 #endif
206 	error = g_access_rel(cp, r, w, e);
207 	g_topology_unlock();
208 	PICKUP_GIANT();
209 	g_waitidle();
210 	dev->si_bsize_phys = cp->provider->sectorsize;
211 	return(error);
212 }
213 
214 static int
215 g_dev_close(dev_t dev, int flags, int fmt, struct thread *td)
216 {
217 	struct g_geom *gp;
218 	struct g_consumer *cp;
219 	int error, r, w, e;
220 
221 	gp = dev->si_drv1;
222 	cp = dev->si_drv2;
223 	if (gp == NULL || cp == NULL)
224 		return(ENXIO);
225 	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
226 	    gp->name, flags, fmt, td);
227 	DROP_GIANT();
228 	g_topology_lock();
229 	r = flags & FREAD ? -1 : 0;
230 	w = flags & FWRITE ? -1 : 0;
231 #ifdef notyet
232 	e = flags & O_EXCL ? -1 : 0;
233 #else
234 	e = 0;
235 #endif
236 	error = g_access_rel(cp, r, w, e);
237 	g_topology_unlock();
238 	PICKUP_GIANT();
239 	g_waitidle();
240 	return (error);
241 }
242 
243 static int
244 g_dev_ioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
245 {
246 	struct g_geom *gp, *gp2;
247 	struct g_consumer *cp;
248 	struct g_provider *pp2;
249 	struct g_kerneldump kd;
250 	int i, error;
251 	u_int u;
252 	struct g_ioctl *gio;
253 
254 	gp = dev->si_drv1;
255 	cp = dev->si_drv2;
256 	pp2 = cp->provider;
257 	gp2 = pp2->geom;
258 	gio = NULL;
259 
260 	error = 0;
261 	DROP_GIANT();
262 
263 	gio = NULL;
264 	i = IOCPARM_LEN(cmd);
265 	switch (cmd) {
266 	case DIOCGSECTORSIZE:
267 		*(u_int *)data = cp->provider->sectorsize;
268 		if (*(u_int *)data == 0)
269 			error = ENOENT;
270 		break;
271 	case DIOCGMEDIASIZE:
272 		*(off_t *)data = cp->provider->mediasize;
273 		if (*(off_t *)data == 0)
274 			error = ENOENT;
275 		break;
276 	case DIOCGFWSECTORS:
277 		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
278 		if (error == 0 && *(u_int *)data == 0)
279 			error = ENOENT;
280 		break;
281 	case DIOCGFWHEADS:
282 		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
283 		if (error == 0 && *(u_int *)data == 0)
284 			error = ENOENT;
285 		break;
286 	case DIOCGFRONTSTUFF:
287 		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
288 		break;
289 	case DIOCSKERNELDUMP:
290 		u = *((u_int *)data);
291 		if (!u) {
292 			set_dumper(NULL);
293 			error = 0;
294 			break;
295 		}
296 		kd.offset = 0;
297 		kd.length = OFF_MAX;
298 		i = sizeof kd;
299 		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
300 		if (!error)
301 			dev->si_flags |= SI_DUMPDEV;
302 		break;
303 
304 	default:
305 		gio = g_malloc(sizeof *gio, M_ZERO);
306 		gio->cmd = cmd;
307 		gio->data = data;
308 		gio->fflag = fflag;
309 		gio->td = td;
310 		i = sizeof *gio;
311 		/*
312 		 * We always issue ioctls as getattr since the direction of data
313 		 * movement in ioctl is no indication of the ioctl being a "set"
314 		 * or "get" type ioctl or if such simplistic terms even apply
315 		 */
316 		error = g_io_getattr("GEOM::ioctl", cp, &i, gio);
317 		break;
318 	}
319 
320 	PICKUP_GIANT();
321 	if (error == EDIRIOCTL) {
322 		KASSERT(gio != NULL, ("NULL gio but EDIRIOCTL"));
323 		KASSERT(gio->func != NULL, ("NULL function but EDIRIOCTL"));
324 		error = (gio->func)(gio->dev, cmd, data, fflag, td);
325 	}
326 	g_waitidle();
327 	if (gio != NULL && (error == EOPNOTSUPP || error == ENOIOCTL)) {
328 		if (g_debugflags & G_T_TOPOLOGY) {
329 			i = IOCGROUP(cmd);
330 			printf("IOCTL(0x%lx) \"%s\"", cmd, gp->name);
331 			if (i > ' ' && i <= '~')
332 				printf(" '%c'", (int)IOCGROUP(cmd));
333 			else
334 				printf(" 0x%lx", IOCGROUP(cmd));
335 			printf("/%ld ", cmd & 0xff);
336 			if (cmd & IOC_IN)
337 				printf("I");
338 			if (cmd & IOC_OUT)
339 				printf("O");
340 			printf("(%ld) = ENOIOCTL\n", IOCPARM_LEN(cmd));
341 		}
342 		error = ENOTTY;
343 	}
344 	if (gio != NULL)
345 		g_free(gio);
346 	return (error);
347 }
348 
349 static int
350 g_dev_psize(dev_t dev)
351 {
352 	struct g_consumer *cp;
353 	off_t mediasize;
354 
355 	cp = dev->si_drv2;
356 
357 	mediasize = cp->provider->mediasize;
358 	return (mediasize >> DEV_BSHIFT);
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 	bp2 = g_clone_bio(bp);
399 	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
400 	bp2->bio_offset = (off_t)bp->bio_blkno << DEV_BSHIFT;
401 	KASSERT(bp2->bio_offset >= 0,
402 	    ("Negative bio_offset (%jd) on bio %p",
403 	    (intmax_t)bp2->bio_offset, bp));
404 	bp2->bio_length = (off_t)bp->bio_bcount;
405 	bp2->bio_done = g_dev_done;
406 	g_trace(G_T_BIO,
407 	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
408 	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
409 	    bp2->bio_data, bp2->bio_cmd);
410 	g_io_request(bp2, cp);
411 }
412 
413 /*
414  * g_dev_orphan()
415  *
416  * Called from below when the provider orphaned us.  It is our responsibility
417  * to get the access counts back to zero, until we do so the stack below will
418  * not unravel.  We must clear the kernel-dump settings, if this is the
419  * current dumpdev.  We call destroy_dev(9) to send our dev_t the way of
420  * punched cards and if we have non-zero access counts, we call down with
421  * them negated before we detattch and selfdestruct.
422  */
423 
424 static void
425 g_dev_orphan(struct g_consumer *cp)
426 {
427 	struct g_geom *gp;
428 	dev_t dev;
429 
430 	gp = cp->geom;
431 	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
432 	g_topology_assert();
433 	if (cp->biocount > 0)
434 		return;
435 	dev = gp->softc;
436 	if (dev->si_flags & SI_DUMPDEV)
437 		set_dumper(NULL);
438 	/* XXX: we may need Giant for now */
439 	destroy_dev(dev);
440 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
441 		g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
442 	g_detach(cp);
443 	g_destroy_consumer(cp);
444 	g_destroy_geom(gp);
445 }
446 
447 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
448