geom_dev.c revision 138732 
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: head/sys/geom/geom_dev.c 138732 2004-12-12 10:09:05Z phk $");
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
56static d_open_t		g_dev_open;
57static d_close_t	g_dev_close;
58static d_strategy_t	g_dev_strategy;
59static d_ioctl_t	g_dev_ioctl;
60
61static 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
73static g_taste_t g_dev_taste;
74static g_orphan_t g_dev_orphan;
75static g_init_t		g_dev_init;
76
77static struct g_class g_dev_class	= {
78	.name = "DEV",
79	.version = G_VERSION,
80	.taste = g_dev_taste,
81	.orphan = g_dev_orphan,
82	.init = g_dev_init,
83};
84
85static struct unrhdr *unithdr;	/* Locked by topology */
86
87static void
88g_dev_init(struct g_class *mp)
89{
90
91	/* XXX: should have a #define MAX_UNIT_MINOR */
92	unithdr = new_unrhdr(0, 0xffffff);
93}
94
95void
96g_dev_print(void)
97{
98	struct g_geom *gp;
99	char const *p = "";
100
101	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
102		printf("%s%s", p, gp->name);
103		p = " ";
104	}
105	printf("\n");
106}
107
108struct g_provider *
109g_dev_getprovider(struct cdev *dev)
110{
111	struct g_consumer *cp;
112
113	g_topology_assert();
114	if (dev == NULL)
115		return (NULL);
116	if (dev->si_devsw != &g_dev_cdevsw)
117		cp = NULL;
118	else
119		cp = dev->si_drv2;
120	return (cp->provider);
121}
122
123
124static struct g_geom *
125g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
126{
127	struct g_geom *gp;
128	struct g_consumer *cp;
129	int error;
130	struct cdev *dev;
131	u_int unit;
132
133	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
134	g_topology_assert();
135	LIST_FOREACH(cp, &pp->consumers, consumers)
136		if (cp->geom->class == mp)
137			return (NULL);
138	gp = g_new_geomf(mp, pp->name);
139	cp = g_new_consumer(gp);
140	error = g_attach(cp, pp);
141	KASSERT(error == 0,
142	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
143	/*
144	 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
145	 * yet.  Once we can, we don't need to drop topology here either.
146	 */
147	unit = alloc_unr(unithdr);
148	g_topology_unlock();
149	mtx_lock(&Giant);
150	dev = make_dev(&g_dev_cdevsw, unit2minor(unit),
151	    UID_ROOT, GID_OPERATOR, 0640, gp->name);
152	if (pp->flags & G_PF_CANDELETE)
153		dev->si_flags |= SI_CANDELETE;
154	mtx_unlock(&Giant);
155	g_topology_lock();
156	dev->si_iosize_max = MAXPHYS;
157	gp->softc = dev;
158	dev->si_drv1 = gp;
159	dev->si_drv2 = cp;
160	return (gp);
161}
162
163static int
164g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
165{
166	struct g_geom *gp;
167	struct g_consumer *cp;
168	int error, r, w, e;
169
170	gp = dev->si_drv1;
171	cp = dev->si_drv2;
172	if (gp == NULL || cp == NULL || gp->softc != dev)
173		return(ENXIO);		/* g_dev_taste() not done yet */
174
175	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
176	    gp->name, flags, fmt, td);
177
178	r = flags & FREAD ? 1 : 0;
179	w = flags & FWRITE ? 1 : 0;
180#ifdef notyet
181	e = flags & O_EXCL ? 1 : 0;
182#else
183	e = 0;
184#endif
185	if (w) {
186		/*
187		 * When running in very secure mode, do not allow
188		 * opens for writing of any disks.
189		 */
190		error = securelevel_ge(td->td_ucred, 2);
191		if (error)
192			return (error);
193	}
194	g_topology_lock();
195	if (dev->si_devsw == NULL)
196		error = ENXIO;		/* We were orphaned */
197	else
198		error = g_access(cp, r, w, e);
199	g_topology_unlock();
200	return(error);
201}
202
203static int
204g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
205{
206	struct g_geom *gp;
207	struct g_consumer *cp;
208	int error, r, w, e, i;
209
210	gp = dev->si_drv1;
211	cp = dev->si_drv2;
212	if (gp == NULL || cp == NULL)
213		return(ENXIO);
214	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
215	    gp->name, flags, fmt, td);
216	r = flags & FREAD ? -1 : 0;
217	w = flags & FWRITE ? -1 : 0;
218#ifdef notyet
219	e = flags & O_EXCL ? -1 : 0;
220#else
221	e = 0;
222#endif
223	g_topology_lock();
224	if (dev->si_devsw == NULL)
225		error = ENXIO;		/* We were orphaned */
226	else
227		error = g_access(cp, r, w, e);
228	for (i = 0; i < 10 * hz;) {
229		if (cp->acr != 0 || cp->acw != 0)
230			break;
231 		if (cp->nstart == cp->nend)
232			break;
233		tsleep(&i, PRIBIO, "gdevwclose", hz / 10);
234		i += hz / 10;
235	}
236	if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
237		printf("WARNING: Final close of geom_dev(%s) %s %s\n",
238		    gp->name,
239		    "still has outstanding I/O after 10 seconds.",
240		    "Completing close anyway, panic may happen later.");
241	}
242	g_topology_unlock();
243	return (error);
244}
245
246/*
247 * XXX: Until we have unmessed the ioctl situation, there is a race against
248 * XXX: a concurrent orphanization.  We cannot close it by holding topology
249 * XXX: since that would prevent us from doing our job, and stalling events
250 * XXX: will break (actually: stall) the BSD disklabel hacks.
251 */
252static int
253g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
254{
255	struct g_geom *gp;
256	struct g_consumer *cp;
257	struct g_kerneldump kd;
258	int i, error;
259	u_int u;
260
261	gp = dev->si_drv1;
262	cp = dev->si_drv2;
263
264	error = 0;
265	KASSERT(cp->acr || cp->acw,
266	    ("Consumer with zero access count in g_dev_ioctl"));
267
268	i = IOCPARM_LEN(cmd);
269	switch (cmd) {
270	case DIOCGSECTORSIZE:
271		*(u_int *)data = cp->provider->sectorsize;
272		if (*(u_int *)data == 0)
273			error = ENOENT;
274		break;
275	case DIOCGMEDIASIZE:
276		*(off_t *)data = cp->provider->mediasize;
277		if (*(off_t *)data == 0)
278			error = ENOENT;
279		break;
280	case DIOCGFWSECTORS:
281		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
282		if (error == 0 && *(u_int *)data == 0)
283			error = ENOENT;
284		break;
285	case DIOCGFWHEADS:
286		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
287		if (error == 0 && *(u_int *)data == 0)
288			error = ENOENT;
289		break;
290	case DIOCGFRONTSTUFF:
291		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
292		break;
293	case DIOCSKERNELDUMP:
294		u = *((u_int *)data);
295		if (!u) {
296			set_dumper(NULL);
297			error = 0;
298			break;
299		}
300		kd.offset = 0;
301		kd.length = OFF_MAX;
302		i = sizeof kd;
303		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
304		if (!error)
305			dev->si_flags |= SI_DUMPDEV;
306		break;
307
308	default:
309		if (cp->provider->geom->ioctl != NULL) {
310			error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
311		} else {
312			error = ENOIOCTL;
313		}
314	}
315
316	return (error);
317}
318
319static void
320g_dev_done(struct bio *bp2)
321{
322	struct bio *bp;
323
324	bp = bp2->bio_parent;
325	bp->bio_error = bp2->bio_error;
326	if (bp->bio_error != 0) {
327		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
328		    bp2, bp->bio_error);
329		bp->bio_flags |= BIO_ERROR;
330	} else {
331		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
332		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
333	}
334	bp->bio_resid = bp->bio_length - bp2->bio_completed;
335	bp->bio_completed = bp2->bio_completed;
336	g_destroy_bio(bp2);
337	biodone(bp);
338}
339
340static void
341g_dev_strategy(struct bio *bp)
342{
343	struct g_consumer *cp;
344	struct bio *bp2;
345	struct cdev *dev;
346
347	KASSERT(bp->bio_cmd == BIO_READ ||
348	        bp->bio_cmd == BIO_WRITE ||
349	        bp->bio_cmd == BIO_DELETE,
350		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
351	dev = bp->bio_dev;
352	cp = dev->si_drv2;
353	KASSERT(cp->acr || cp->acw,
354	    ("Consumer with zero access count in g_dev_strategy"));
355
356	if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
357	    (bp->bio_bcount % cp->provider->sectorsize) != 0) {
358		biofinish(bp, NULL, EINVAL);
359		return;
360	}
361
362	for (;;) {
363		/*
364		 * XXX: This is not an ideal solution, but I belive it to
365		 * XXX: deadlock safe, all things considered.
366		 */
367		bp2 = g_clone_bio(bp);
368		if (bp2 != NULL)
369			break;
370		tsleep(&bp, PRIBIO, "gdstrat", hz / 10);
371	}
372	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
373	bp2->bio_done = g_dev_done;
374	g_trace(G_T_BIO,
375	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
376	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
377	    bp2->bio_data, bp2->bio_cmd);
378	g_io_request(bp2, cp);
379	KASSERT(cp->acr || cp->acw,
380	    ("g_dev_strategy raced with g_dev_close and lost"));
381
382}
383
384/*
385 * g_dev_orphan()
386 *
387 * Called from below when the provider orphaned us.
388 * - Clear any dump settings.
389 * - Destroy the struct cdev *to prevent any more request from coming in.  The
390 *   provider is already marked with an error, so anything which comes in
391 *   in the interrim will be returned immediately.
392 * - Wait for any outstanding I/O to finish.
393 * - Set our access counts to zero, whatever they were.
394 * - Detach and self-destruct.
395 */
396
397static void
398g_dev_orphan(struct g_consumer *cp)
399{
400	struct g_geom *gp;
401	struct cdev *dev;
402	u_int unit;
403
404	g_topology_assert();
405	gp = cp->geom;
406	dev = gp->softc;
407	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
408
409	/* Reset any dump-area set on this device */
410	if (dev->si_flags & SI_DUMPDEV)
411		set_dumper(NULL);
412
413	/* Destroy the struct cdev *so we get no more requests */
414	unit = dev2unit(dev);
415	destroy_dev(dev);
416	free_unr(unithdr, unit);
417
418	/* Wait for the cows to come home */
419	while (cp->nstart != cp->nend)
420		msleep(&dev, NULL, PRIBIO, "gdevorphan", hz / 10);
421
422	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
423		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
424
425	g_detach(cp);
426	g_destroy_consumer(cp);
427	g_destroy_geom(gp);
428}
429
430DECLARE_GEOM_CLASS(g_dev_class, g_dev);
431