geom_dev.c revision 104087 
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 104087 2002-09-28 11:57:20Z phk $
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 <geom/geom.h>
51#include <geom/geom_int.h>
52#include <machine/limits.h>
53
54#define CDEV_MAJOR	4
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;
60static d_psize_t	g_dev_psize;
61
62static struct cdevsw g_dev_cdevsw = {
63	/* open */      g_dev_open,
64	/* close */     g_dev_close,
65	/* read */      physread,
66	/* write */     physwrite,
67	/* ioctl */     g_dev_ioctl,
68	/* poll */      nopoll,
69	/* mmap */      nommap,
70	/* strategy */  g_dev_strategy,
71	/* name */      "g_dev",
72	/* maj */       CDEV_MAJOR,
73	/* dump */      nodump,
74	/* psize */     g_dev_psize,
75	/* flags */     D_DISK | D_CANFREE | D_TRACKCLOSE,
76	/* kqfilter */	nokqfilter
77};
78
79static g_taste_t g_dev_taste;
80static g_orphan_t g_dev_orphan;
81
82static struct g_class g_dev_class	= {
83	"DEV",
84	g_dev_taste,
85	NULL,
86	G_CLASS_INITIALIZER
87};
88
89static void
90g_dev_clone(void *arg __unused, char *name, int namelen __unused, dev_t *dev)
91{
92	struct g_geom *gp;
93
94	if (*dev != NODEV)
95		return;
96
97	g_trace(G_T_TOPOLOGY, "g_dev_clone(%s)", name);
98	g_waitidle();
99
100	/* XXX: can I drop Giant here ??? */
101	/* g_topology_lock(); */
102	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
103		if (strcmp(gp->name, name))
104			continue;
105		*dev = gp->softc;
106		g_trace(G_T_TOPOLOGY, "g_dev_clone(%s) = %p", name, *dev);
107		return;
108	}
109	/* g_topology_unlock(); */
110	return;
111}
112
113static void
114g_dev_register_cloner(void *foo __unused)
115{
116	static int once;
117
118	/* XXX: why would this happen more than once ?? */
119	if (!once) {
120		EVENTHANDLER_REGISTER(dev_clone, g_dev_clone, 0, 1000);
121		once++;
122	}
123}
124
125SYSINIT(geomdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,g_dev_register_cloner,NULL);
126
127static struct g_geom *
128g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
129{
130	struct g_geom *gp;
131	struct g_consumer *cp;
132	static int unit;
133	int error;
134	dev_t dev;
135
136	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
137	g_topology_assert();
138	LIST_FOREACH(cp, &pp->consumers, consumers)
139		if (cp->geom->class == mp)
140			return (NULL);
141	gp = g_new_geomf(mp, pp->name);
142	gp->orphan = g_dev_orphan;
143	cp = g_new_consumer(gp);
144	error = g_attach(cp, pp);
145	KASSERT(error == 0,
146	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
147	/*
148	 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
149	 * yet.  Once we can, we don't need to drop topology here either.
150	 */
151	g_topology_unlock();
152	mtx_lock(&Giant);
153	dev = make_dev(&g_dev_cdevsw, unit2minor(unit++),
154	    UID_ROOT, GID_WHEEL, 0600, gp->name);
155	mtx_unlock(&Giant);
156	g_topology_lock();
157
158	gp->softc = dev;
159	dev->si_drv1 = gp;
160	dev->si_drv2 = cp;
161	return (gp);
162}
163
164static int
165g_dev_open(dev_t dev, int flags, int fmt, struct thread *td)
166{
167	struct g_geom *gp;
168	struct g_consumer *cp;
169	int error, r, w, e;
170
171	gp = dev->si_drv1;
172	cp = dev->si_drv2;
173	if (gp == NULL || cp == NULL)
174		return(ENXIO);
175	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
176	    gp->name, flags, fmt, td);
177	DROP_GIANT();
178	g_topology_lock();
179	g_silence();
180	r = flags & FREAD ? 1 : 0;
181	w = flags & FWRITE ? 1 : 0;
182#ifdef notyet
183	e = flags & O_EXCL ? 1 : 0;
184#else
185	e = 0;
186#endif
187	error = g_access_rel(cp, r, w, e);
188	g_topology_unlock();
189	PICKUP_GIANT();
190	g_waitidle();
191	return(error);
192}
193
194static int
195g_dev_close(dev_t dev, int flags, int fmt, struct thread *td)
196{
197	struct g_geom *gp;
198	struct g_consumer *cp;
199	int error, r, w, e;
200
201	gp = dev->si_drv1;
202	cp = dev->si_drv2;
203	if (gp == NULL || cp == NULL)
204		return(ENXIO);
205	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
206	    gp->name, flags, fmt, td);
207	DROP_GIANT();
208	g_topology_lock();
209	g_silence();
210	r = flags & FREAD ? -1 : 0;
211	w = flags & FWRITE ? -1 : 0;
212#ifdef notyet
213	e = flags & O_EXCL ? -1 : 0;
214#else
215	e = 0;
216#endif
217	error = g_access_rel(cp, r, w, e);
218	g_topology_unlock();
219	PICKUP_GIANT();
220	g_waitidle();
221	return (error);
222}
223
224static int
225g_dev_ioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
226{
227	struct g_geom *gp, *gp2;
228	struct g_consumer *cp;
229	struct g_provider *pp2;
230	struct g_kerneldump kd;
231	int i, error;
232	u_int u;
233	struct g_ioctl *gio;
234	struct sbuf *usb, *sb;
235
236	gp = dev->si_drv1;
237	cp = dev->si_drv2;
238	pp2 = cp->provider;
239	gp2 = pp2->geom;
240
241	error = 0;
242	DROP_GIANT();
243
244	i = IOCPARM_LEN(cmd);
245	switch (cmd) {
246	case DIOCGSECTORSIZE:
247		error = g_io_getattr("GEOM::sectorsize", cp, &i, data);
248		break;
249	case DIOCGMEDIASIZE:
250		error = g_io_getattr("GEOM::mediasize", cp, &i, data);
251		break;
252	case DIOCGFWSECTORS:
253		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
254		break;
255	case DIOCGFWHEADS:
256		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
257		break;
258	case DIOCGFRONTSTUFF:
259		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
260		break;
261	case DIOCSKERNELDUMP:
262		u = *((u_int *)data);
263		if (!u) {
264			set_dumper(NULL);
265			error = 0;
266			break;
267		}
268		kd.offset = 0;
269		kd.length = OFF_MAX;
270		i = sizeof kd;
271		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
272		if (!error)
273			dev->si_flags |= SI_DUMPDEV;
274		break;
275	case GEOMGETCONF:
276		/* we bogusly pass cp to avoid getting any consumers listed */
277		sb = g_conf_specific(gp2->class, gp2, pp2, cp);
278		usb = (struct sbuf *)data;
279		if (usb->s_size - 1 < sbuf_len(sb))
280			error = ENOMEM;
281		else
282			error = copyout(sbuf_data(sb), usb->s_buf, sbuf_len(sb) + 1);
283		if (!error)
284			usb->s_len = sbuf_len(sb);
285		break;
286	default:
287		gio = g_malloc(sizeof *gio, M_WAITOK);
288		gio->cmd = cmd;
289		gio->data = data;
290		gio->fflag = fflag;
291		gio->td = td;
292		i = sizeof *gio;
293		if (cmd & IOC_IN)
294			error = g_io_setattr("GEOM::ioctl", cp, i, gio);
295		else
296			error = g_io_getattr("GEOM::ioctl", cp, &i, gio);
297		g_free(gio);
298		break;
299	}
300
301	PICKUP_GIANT();
302	g_waitidle();
303	if (error == ENOIOCTL) {
304		i = IOCGROUP(cmd);
305		printf("IOCTL(0x%lx) \"%s\"", cmd, gp->name);
306		if (i > ' ' && i <= '~')
307			printf(" '%c'", (int)IOCGROUP(cmd));
308		else
309			printf(" 0x%lx", IOCGROUP(cmd));
310		printf("/%ld ", cmd & 0xff);
311		if (cmd & IOC_IN)
312			printf("I");
313		if (cmd & IOC_OUT)
314			printf("O");
315		printf("(%ld) = ENOIOCTL\n", IOCPARM_LEN(cmd));
316		error = ENOTTY;
317	}
318	return (error);
319}
320
321static int
322g_dev_psize(dev_t dev)
323{
324	struct g_consumer *cp;
325	int i, error;
326	off_t mediasize;
327
328	cp = dev->si_drv2;
329
330	i = sizeof mediasize;
331	error = g_io_getattr("GEOM::mediasize", cp, &i, &mediasize);
332	if (error)
333		return (-1);
334	return (mediasize >> DEV_BSHIFT);
335}
336
337static void
338g_dev_done(struct bio *bp2)
339{
340	struct bio *bp;
341
342	bp = bp2->bio_linkage;
343	bp->bio_error = bp2->bio_error;
344	if (bp->bio_error != 0) {
345		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
346		    bp2, bp->bio_error);
347		bp->bio_flags |= BIO_ERROR;
348	} else {
349		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %lld",
350		    bp2, bp, bp->bio_resid, bp2->bio_completed);
351	}
352	bp->bio_resid = bp->bio_bcount - bp2->bio_completed;
353	g_destroy_bio(bp2);
354	mtx_lock(&Giant);
355	biodone(bp);
356	mtx_unlock(&Giant);
357}
358
359static void
360g_dev_strategy(struct bio *bp)
361{
362	struct g_geom *gp;
363	struct g_consumer *cp;
364	struct bio *bp2;
365	dev_t dev;
366
367	dev = bp->bio_dev;
368	gp = dev->si_drv1;
369	cp = dev->si_drv2;
370	bp2 = g_clone_bio(bp);
371	bp2->bio_offset = (off_t)bp->bio_blkno << DEV_BSHIFT;
372	bp2->bio_length = (off_t)bp->bio_bcount;
373	bp2->bio_done = g_dev_done;
374	g_trace(G_T_BIO,
375	    "g_dev_strategy(%p/%p) offset %lld length %lld data %p cmd %d",
376	    bp, bp2, bp->bio_offset, bp2->bio_length, bp2->bio_data,
377	    bp2->bio_cmd);
378	g_io_request(bp2, cp);
379}
380
381/*
382 * g_dev_orphan()
383 *
384 * Called from below when the provider orphaned us.  It is our responsibility
385 * to get the access counts back to zero, until we do so the stack below will
386 * not unravel.  We must clear the kernel-dump settings, if this is the
387 * current dumpdev.  We call destroy_dev(9) to send our dev_t the way of
388 * punched cards and if we have non-zero access counts, we call down with
389 * them negated before we detattch and selfdestruct.
390 */
391
392static void
393g_dev_orphan(struct g_consumer *cp)
394{
395	struct g_geom *gp;
396	dev_t dev;
397
398	gp = cp->geom;
399	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
400	g_topology_assert();
401	if (cp->biocount > 0)
402		return;
403	dev = gp->softc;
404	if (dev->si_flags & SI_DUMPDEV)
405		set_dumper(NULL);
406	/* XXX: we may need Giant for now */
407	destroy_dev(dev);
408	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
409		g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
410	g_detach(cp);
411	g_destroy_consumer(cp);
412	g_destroy_geom(gp);
413}
414
415DECLARE_GEOM_CLASS(g_dev_class, g_dev);
416