geom_dev.c revision 105540 
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 105540 2002-10-20 18:48:12Z 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
90static void
91g_dev_clone(void *arg __unused, char *name, int namelen __unused, dev_t *dev)
92{
93	struct g_geom *gp;
94
95	if (*dev != NODEV)
96		return;
97
98	g_trace(G_T_TOPOLOGY, "g_dev_clone(%s)", name);
99	g_waitidle();
100
101	/* XXX: can I drop Giant here ??? */
102	/* g_topology_lock(); */
103	LIST_FOREACH(gp, &g_dev_class.geom, geom) {
104		if (strcmp(gp->name, name))
105			continue;
106		*dev = gp->softc;
107		g_trace(G_T_TOPOLOGY, "g_dev_clone(%s) = %p", name, *dev);
108		return;
109	}
110	/* g_topology_unlock(); */
111	return;
112}
113
114static void
115g_dev_register_cloner(void *foo __unused)
116{
117	static int once;
118
119	/* XXX: why would this happen more than once ?? */
120	if (!once) {
121		EVENTHANDLER_REGISTER(dev_clone, g_dev_clone, 0, 1000);
122		once++;
123	}
124}
125
126SYSINIT(geomdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE,g_dev_register_cloner,NULL);
127
128static struct g_geom *
129g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
130{
131	struct g_geom *gp;
132	struct g_consumer *cp;
133	static int unit;
134	int error;
135	dev_t dev;
136
137	g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
138	g_topology_assert();
139	LIST_FOREACH(cp, &pp->consumers, consumers)
140		if (cp->geom->class == mp)
141			return (NULL);
142	gp = g_new_geomf(mp, pp->name);
143	gp->orphan = g_dev_orphan;
144	cp = g_new_consumer(gp);
145	error = g_attach(cp, pp);
146	KASSERT(error == 0,
147	    ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
148	/*
149	 * XXX: I'm not 100% sure we can call make_dev(9) without Giant
150	 * yet.  Once we can, we don't need to drop topology here either.
151	 */
152	g_topology_unlock();
153	mtx_lock(&Giant);
154	dev = make_dev(&g_dev_cdevsw, unit2minor(unit++),
155	    UID_ROOT, GID_OPERATOR, 0640, gp->name);
156	mtx_unlock(&Giant);
157	g_topology_lock();
158
159	gp->softc = dev;
160	dev->si_drv1 = gp;
161	dev->si_drv2 = cp;
162	return (gp);
163}
164
165static int
166g_dev_open(dev_t dev, int flags, int fmt, struct thread *td)
167{
168	struct g_geom *gp;
169	struct g_consumer *cp;
170	int error, r, w, e;
171
172	gp = dev->si_drv1;
173	cp = dev->si_drv2;
174	if (gp == NULL || cp == NULL)
175		return(ENXIO);
176	g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
177	    gp->name, flags, fmt, td);
178	DROP_GIANT();
179	g_topology_lock();
180	g_silence();
181	r = flags & FREAD ? 1 : 0;
182	w = flags & FWRITE ? 1 : 0;
183#ifdef notyet
184	e = flags & O_EXCL ? 1 : 0;
185#else
186	e = 0;
187#endif
188	error = g_access_rel(cp, r, w, e);
189	g_topology_unlock();
190	PICKUP_GIANT();
191	g_waitidle();
192	return(error);
193}
194
195static int
196g_dev_close(dev_t dev, int flags, int fmt, struct thread *td)
197{
198	struct g_geom *gp;
199	struct g_consumer *cp;
200	int error, r, w, e;
201
202	gp = dev->si_drv1;
203	cp = dev->si_drv2;
204	if (gp == NULL || cp == NULL)
205		return(ENXIO);
206	g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
207	    gp->name, flags, fmt, td);
208	DROP_GIANT();
209	g_topology_lock();
210	g_silence();
211	r = flags & FREAD ? -1 : 0;
212	w = flags & FWRITE ? -1 : 0;
213#ifdef notyet
214	e = flags & O_EXCL ? -1 : 0;
215#else
216	e = 0;
217#endif
218	error = g_access_rel(cp, r, w, e);
219	g_topology_unlock();
220	PICKUP_GIANT();
221	g_waitidle();
222	return (error);
223}
224
225static int
226g_dev_ioctl(dev_t dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
227{
228	struct g_geom *gp, *gp2;
229	struct g_consumer *cp;
230	struct g_provider *pp2;
231	struct g_kerneldump kd;
232	int i, error;
233	u_int u;
234	struct g_ioctl *gio;
235
236	gp = dev->si_drv1;
237	cp = dev->si_drv2;
238	pp2 = cp->provider;
239	gp2 = pp2->geom;
240	gio = NULL;
241
242	error = 0;
243	DROP_GIANT();
244
245	i = IOCPARM_LEN(cmd);
246	switch (cmd) {
247	case DIOCGSECTORSIZE:
248		error = g_io_getattr("GEOM::sectorsize", cp, &i, data);
249		if (error == 0 && *(u_int *)data == 0)
250			error = ENOENT;
251		break;
252	case DIOCGMEDIASIZE:
253		error = g_io_getattr("GEOM::mediasize", cp, &i, data);
254		if (error == 0 && *(off_t *)data == 0)
255			error = ENOENT;
256		break;
257	case DIOCGFWSECTORS:
258		error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
259		if (error == 0 && *(u_int *)data == 0)
260			error = ENOENT;
261		break;
262	case DIOCGFWHEADS:
263		error = g_io_getattr("GEOM::fwheads", cp, &i, data);
264		if (error == 0 && *(u_int *)data == 0)
265			error = ENOENT;
266		break;
267	case DIOCGFRONTSTUFF:
268		error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
269		break;
270	case DIOCSKERNELDUMP:
271		u = *((u_int *)data);
272		if (!u) {
273			set_dumper(NULL);
274			error = 0;
275			break;
276		}
277		kd.offset = 0;
278		kd.length = OFF_MAX;
279		i = sizeof kd;
280		error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
281		if (!error)
282			dev->si_flags |= SI_DUMPDEV;
283		break;
284
285	default:
286		gio = g_malloc(sizeof *gio, M_WAITOK | M_ZERO);
287		gio->cmd = cmd;
288		gio->data = data;
289		gio->fflag = fflag;
290		gio->td = td;
291		i = sizeof *gio;
292		if (cmd & IOC_IN)
293			error = g_io_setattr("GEOM::ioctl", cp, i, gio);
294		else
295			error = g_io_getattr("GEOM::ioctl", cp, &i, gio);
296		break;
297	}
298
299	PICKUP_GIANT();
300	if (error == EDIRIOCTL) {
301		KASSERT(gio != NULL, ("NULL gio but EDIRIOCTL"));
302		KASSERT(gio->func != NULL, ("NULL function but EDIRIOCTL"));
303		error = (gio->func)(gio->dev, cmd, data, fflag, td);
304	}
305	if (gio != NULL)
306		g_free(gio);
307	g_waitidle();
308	if (error == ENOIOCTL) {
309		if (g_debugflags & G_T_TOPOLOGY) {
310			i = IOCGROUP(cmd);
311			printf("IOCTL(0x%lx) \"%s\"", cmd, gp->name);
312			if (i > ' ' && i <= '~')
313				printf(" '%c'", (int)IOCGROUP(cmd));
314			else
315				printf(" 0x%lx", IOCGROUP(cmd));
316			printf("/%ld ", cmd & 0xff);
317			if (cmd & IOC_IN)
318				printf("I");
319			if (cmd & IOC_OUT)
320				printf("O");
321			printf("(%ld) = ENOIOCTL\n", IOCPARM_LEN(cmd));
322		}
323		error = ENOTTY;
324	}
325	return (error);
326}
327
328static int
329g_dev_psize(dev_t dev)
330{
331	struct g_consumer *cp;
332	int i, error;
333	off_t mediasize;
334
335	cp = dev->si_drv2;
336
337	i = sizeof mediasize;
338	error = g_io_getattr("GEOM::mediasize", cp, &i, &mediasize);
339	if (error)
340		return (-1);
341	return (mediasize >> DEV_BSHIFT);
342}
343
344static void
345g_dev_done(struct bio *bp2)
346{
347	struct bio *bp;
348
349	bp = bp2->bio_linkage;
350	bp->bio_error = bp2->bio_error;
351	if (bp->bio_error != 0) {
352		g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
353		    bp2, bp->bio_error);
354		bp->bio_flags |= BIO_ERROR;
355	} else {
356		g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
357		    bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
358	}
359	bp->bio_resid = bp->bio_bcount - bp2->bio_completed;
360	g_destroy_bio(bp2);
361	mtx_lock(&Giant);
362	biodone(bp);
363	mtx_unlock(&Giant);
364}
365
366static void
367g_dev_strategy(struct bio *bp)
368{
369	struct g_geom *gp;
370	struct g_consumer *cp;
371	struct bio *bp2;
372	dev_t dev;
373
374	dev = bp->bio_dev;
375	gp = dev->si_drv1;
376	cp = dev->si_drv2;
377	bp2 = g_clone_bio(bp);
378	bp2->bio_offset = (off_t)bp->bio_blkno << DEV_BSHIFT;
379	bp2->bio_length = (off_t)bp->bio_bcount;
380	bp2->bio_done = g_dev_done;
381	g_trace(G_T_BIO,
382	    "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
383	    bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
384	    bp2->bio_data, bp2->bio_cmd);
385	g_io_request(bp2, cp);
386}
387
388/*
389 * g_dev_orphan()
390 *
391 * Called from below when the provider orphaned us.  It is our responsibility
392 * to get the access counts back to zero, until we do so the stack below will
393 * not unravel.  We must clear the kernel-dump settings, if this is the
394 * current dumpdev.  We call destroy_dev(9) to send our dev_t the way of
395 * punched cards and if we have non-zero access counts, we call down with
396 * them negated before we detattch and selfdestruct.
397 */
398
399static void
400g_dev_orphan(struct g_consumer *cp)
401{
402	struct g_geom *gp;
403	dev_t dev;
404
405	gp = cp->geom;
406	g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
407	g_topology_assert();
408	if (cp->biocount > 0)
409		return;
410	dev = gp->softc;
411	if (dev->si_flags & SI_DUMPDEV)
412		set_dumper(NULL);
413	/* XXX: we may need Giant for now */
414	destroy_dev(dev);
415	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
416		g_access_rel(cp, -cp->acr, -cp->acw, -cp->ace);
417	g_detach(cp);
418	g_destroy_consumer(cp);
419	g_destroy_geom(gp);
420}
421
422DECLARE_GEOM_CLASS(g_dev_class, g_dev);
423