geom_dev.c revision 107834 
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: head/sys/geom/geom_dev.c 107834 2002-12-13 22:04:45Z phk $
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
57static d_open_t		g_dev_open;
58static d_close_t	g_dev_close;
59static d_strategy_t	g_dev_strategy;
60static d_ioctl_t	g_dev_ioctl;
61static d_psize_t	g_dev_psize;
62
63static 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
80static g_taste_t g_dev_taste;
81static g_orphan_t g_dev_orphan;
82
83static struct g_class g_dev_class	= {
84	"DEV",
85	g_dev_taste,
86	NULL,
87	G_CLASS_INITIALIZER
88};
89
90int
91g_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
104static void
105g_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
127static void
128g_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
139SYSINIT(geomdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,g_dev_register_cloner,NULL);
140
141static struct g_geom *
142g_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
178static int
179g_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
208static int
209g_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
238static int
239g_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
341static int
342g_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
353static void
354g_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
375static void
376g_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	KASSERT(bp->bio_cmd == BIO_READ ||
384	        bp->bio_cmd == BIO_WRITE ||
385	        bp->bio_cmd == BIO_DELETE,
386		("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
387	dev = bp->bio_dev;
388	gp = dev->si_drv1;
389	cp = dev->si_drv2;
390	bp2 = g_clone_bio(bp);
391	KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
392	bp2->bio_offset = (off_t)bp->bio_blkno << DEV_BSHIFT;
393	KASSERT(bp2->bio_offset >= 0,
394	    ("Negative bio_offset (%jd) on bio %p",
395	    (intmax_t)bp2->bio_offset, bp));
396	bp2->bio_length = (off_t)bp->bio_bcount;
397	bp2->bio_done = g_dev_done;
398	g_trace(G_T_BIO,
399	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
400	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
401	    bp2->bio_data, bp2->bio_cmd);
402	g_io_request(bp2, cp);
403}
404
405/*
406 * g_dev_orphan()
407 *
408 * Called from below when the provider orphaned us.  It is our responsibility
409 * to get the access counts back to zero, until we do so the stack below will
410 * not unravel.  We must clear the kernel-dump settings, if this is the
411 * current dumpdev.  We call destroy_dev(9) to send our dev_t the way of
412 * punched cards and if we have non-zero access counts, we call down with
413 * them negated before we detattch and selfdestruct.
414 */
415
416static void
417g_dev_orphan(struct g_consumer *cp)
418{
419	struct g_geom *gp;
420	dev_t dev;
421
422	gp = cp->geom;
423	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
424	g_topology_assert();
425	if (cp->biocount > 0)
426		return;
427	dev = gp->softc;
428	if (dev->si_flags & SI_DUMPDEV)
429		set_dumper(NULL);
430	/* XXX: we may need Giant for now */
431	destroy_dev(dev);
432	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
433		g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
434	g_detach(cp);
435	g_destroy_consumer(cp);
436	g_destroy_geom(gp);
437}
438
439DECLARE_GEOM_CLASS(g_dev_class, g_dev);
440