FreeBSD/Linux Kernel Cross Reference
sys/geom/geom_dev.c
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: releng/7.4/sys/geom/geom_dev.c 212879 2010-09-19 20:02:31Z mav $");
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
56 static d_open_t g_dev_open;
57 static d_close_t g_dev_close;
58 static d_strategy_t g_dev_strategy;
59 static d_ioctl_t g_dev_ioctl;
60
61 static 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
73 static g_taste_t g_dev_taste;
74 static g_orphan_t g_dev_orphan;
75 static g_init_t g_dev_init;
76
77 static 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
85 static struct unrhdr *unithdr; /* Locked by topology */
86
87 static void
88 g_dev_init(struct g_class *mp)
89 {
90
91 unithdr = new_unrhdr(0, minor2unit(MAXMINOR), NULL);
92 }
93
94 void
95 g_dev_print(void)
96 {
97 struct g_geom *gp;
98 char const *p = "";
99
100 LIST_FOREACH(gp, &g_dev_class.geom, geom) {
101 printf("%s%s", p, gp->name);
102 p = " ";
103 }
104 printf("\n");
105 }
106
107 struct g_provider *
108 g_dev_getprovider(struct cdev *dev)
109 {
110 struct g_consumer *cp;
111
112 g_topology_assert();
113 if (dev == NULL)
114 return (NULL);
115 if (dev->si_devsw != &g_dev_cdevsw)
116 return (NULL);
117 cp = dev->si_drv2;
118 return (cp->provider);
119 }
120
121
122 static struct g_geom *
123 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
124 {
125 struct g_geom *gp;
126 struct g_consumer *cp;
127 char *alias;
128 int error;
129 struct cdev *dev;
130 u_int unit;
131
132 g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
133 g_topology_assert();
134 LIST_FOREACH(cp, &pp->consumers, consumers)
135 if (cp->geom->class == mp)
136 return (NULL);
137 gp = g_new_geomf(mp, pp->name);
138 cp = g_new_consumer(gp);
139 error = g_attach(cp, pp);
140 KASSERT(error == 0,
141 ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
142 unit = alloc_unr(unithdr);
143 dev = make_dev(&g_dev_cdevsw, unit2minor(unit),
144 UID_ROOT, GID_OPERATOR, 0640, gp->name);
145 if (pp->flags & G_PF_CANDELETE)
146 dev->si_flags |= SI_CANDELETE;
147 dev->si_iosize_max = MAXPHYS;
148 gp->softc = dev;
149 dev->si_drv1 = gp;
150 dev->si_drv2 = cp;
151
152 g_topology_unlock();
153
154 alias = g_malloc(MAXPATHLEN, M_WAITOK | M_ZERO);
155 error = (pp->geom->ioctl == NULL) ? ENODEV :
156 pp->geom->ioctl(pp, DIOCGPROVIDERALIAS, alias, 0, curthread);
157 if (!error && alias[0] != '\0')
158 make_dev_alias(dev, "%s", alias);
159 g_free(alias);
160
161 g_topology_lock();
162 return (gp);
163 }
164
165 static int
166 g_dev_open(struct cdev *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 || gp->softc != dev)
175 return(ENXIO); /* g_dev_taste() not done yet */
176
177 g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
178 gp->name, flags, fmt, td);
179
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 if (w) {
188 /*
189 * When running in very secure mode, do not allow
190 * opens for writing of any disks.
191 */
192 error = securelevel_ge(td->td_ucred, 2);
193 if (error)
194 return (error);
195 }
196 g_topology_lock();
197 if (dev->si_devsw == NULL)
198 error = ENXIO; /* We were orphaned */
199 else
200 error = g_access(cp, r, w, e);
201 g_topology_unlock();
202 return(error);
203 }
204
205 static int
206 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
207 {
208 struct g_geom *gp;
209 struct g_consumer *cp;
210 int error, r, w, e, i;
211
212 gp = dev->si_drv1;
213 cp = dev->si_drv2;
214 if (gp == NULL || cp == NULL)
215 return(ENXIO);
216 g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
217 gp->name, flags, fmt, td);
218 r = flags & FREAD ? -1 : 0;
219 w = flags & FWRITE ? -1 : 0;
220 #ifdef notyet
221 e = flags & O_EXCL ? -1 : 0;
222 #else
223 e = 0;
224 #endif
225 g_topology_lock();
226 if (dev->si_devsw == NULL)
227 error = ENXIO; /* We were orphaned */
228 else
229 error = g_access(cp, r, w, e);
230 for (i = 0; i < 10 * hz;) {
231 if (cp->acr != 0 || cp->acw != 0)
232 break;
233 if (cp->nstart == cp->nend)
234 break;
235 pause("gdevwclose", hz / 10);
236 i += hz / 10;
237 }
238 if (cp->acr == 0 && cp->acw == 0 && cp->nstart != cp->nend) {
239 printf("WARNING: Final close of geom_dev(%s) %s %s\n",
240 gp->name,
241 "still has outstanding I/O after 10 seconds.",
242 "Completing close anyway, panic may happen later.");
243 }
244 g_topology_unlock();
245 return (error);
246 }
247
248 /*
249 * XXX: Until we have unmessed the ioctl situation, there is a race against
250 * XXX: a concurrent orphanization. We cannot close it by holding topology
251 * XXX: since that would prevent us from doing our job, and stalling events
252 * XXX: will break (actually: stall) the BSD disklabel hacks.
253 */
254 static int
255 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
256 {
257 struct g_geom *gp;
258 struct g_consumer *cp;
259 struct g_kerneldump kd;
260 off_t offset, length;
261 int i, error;
262 u_int u;
263
264 gp = dev->si_drv1;
265 cp = dev->si_drv2;
266
267 error = 0;
268 KASSERT(cp->acr || cp->acw,
269 ("Consumer with zero access count in g_dev_ioctl"));
270
271 i = IOCPARM_LEN(cmd);
272 switch (cmd) {
273 case DIOCGSECTORSIZE:
274 *(u_int *)data = cp->provider->sectorsize;
275 if (*(u_int *)data == 0)
276 error = ENOENT;
277 break;
278 case DIOCGMEDIASIZE:
279 *(off_t *)data = cp->provider->mediasize;
280 if (*(off_t *)data == 0)
281 error = ENOENT;
282 break;
283 case DIOCGFWSECTORS:
284 error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
285 if (error == 0 && *(u_int *)data == 0)
286 error = ENOENT;
287 break;
288 case DIOCGFWHEADS:
289 error = g_io_getattr("GEOM::fwheads", cp, &i, data);
290 if (error == 0 && *(u_int *)data == 0)
291 error = ENOENT;
292 break;
293 case DIOCGFRONTSTUFF:
294 error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
295 break;
296 case DIOCSKERNELDUMP:
297 u = *((u_int *)data);
298 if (!u) {
299 set_dumper(NULL);
300 error = 0;
301 break;
302 }
303 kd.offset = 0;
304 kd.length = OFF_MAX;
305 i = sizeof kd;
306 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
307 if (!error)
308 dev->si_flags |= SI_DUMPDEV;
309 break;
310 case DIOCGFLUSH:
311 error = g_io_flush(cp);
312 break;
313 case DIOCGDELETE:
314 offset = ((off_t *)data)[0];
315 length = ((off_t *)data)[1];
316 if ((offset % cp->provider->sectorsize) != 0 ||
317 (length % cp->provider->sectorsize) != 0 || length <= 0) {
318 printf("%s: offset=%jd length=%jd\n", __func__, offset,
319 length);
320 error = EINVAL;
321 break;
322 }
323 error = g_delete_data(cp, offset, length);
324 break;
325 case DIOCGIDENT:
326 error = g_io_getattr("GEOM::ident", cp, &i, data);
327 break;
328
329 default:
330 if (cp->provider->geom->ioctl != NULL) {
331 error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
332 } else {
333 error = ENOIOCTL;
334 }
335 }
336
337 return (error);
338 }
339
340 static void
341 g_dev_done(struct bio *bp2)
342 {
343 struct bio *bp;
344
345 bp = bp2->bio_parent;
346 bp->bio_error = bp2->bio_error;
347 if (bp->bio_error != 0) {
348 g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
349 bp2, bp->bio_error);
350 bp->bio_flags |= BIO_ERROR;
351 } else {
352 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
353 bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
354 }
355 bp->bio_resid = bp->bio_length - bp2->bio_completed;
356 bp->bio_completed = bp2->bio_completed;
357 g_destroy_bio(bp2);
358 biodone(bp);
359 }
360
361 static void
362 g_dev_strategy(struct bio *bp)
363 {
364 struct g_consumer *cp;
365 struct bio *bp2;
366 struct cdev *dev;
367
368 KASSERT(bp->bio_cmd == BIO_READ ||
369 bp->bio_cmd == BIO_WRITE ||
370 bp->bio_cmd == BIO_DELETE,
371 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
372 dev = bp->bio_dev;
373 cp = dev->si_drv2;
374 KASSERT(cp->acr || cp->acw,
375 ("Consumer with zero access count in g_dev_strategy"));
376 #ifdef INVARIANTS
377 if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
378 (bp->bio_bcount % cp->provider->sectorsize) != 0) {
379 bp->bio_resid = bp->bio_bcount;
380 biofinish(bp, NULL, EINVAL);
381 return;
382 }
383 #endif
384 for (;;) {
385 /*
386 * XXX: This is not an ideal solution, but I belive it to
387 * XXX: deadlock safe, all things considered.
388 */
389 bp2 = g_clone_bio(bp);
390 if (bp2 != NULL)
391 break;
392 pause("gdstrat", hz / 10);
393 }
394 KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
395 bp2->bio_done = g_dev_done;
396 g_trace(G_T_BIO,
397 "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
398 bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
399 bp2->bio_data, bp2->bio_cmd);
400 g_io_request(bp2, cp);
401 KASSERT(cp->acr || cp->acw,
402 ("g_dev_strategy raced with g_dev_close and lost"));
403
404 }
405
406 /*
407 * g_dev_orphan()
408 *
409 * Called from below when the provider orphaned us.
410 * - Clear any dump settings.
411 * - Destroy the struct cdev *to prevent any more request from coming in. The
412 * provider is already marked with an error, so anything which comes in
413 * in the interrim will be returned immediately.
414 * - Wait for any outstanding I/O to finish.
415 * - Set our access counts to zero, whatever they were.
416 * - Detach and self-destruct.
417 */
418
419 static void
420 g_dev_orphan(struct g_consumer *cp)
421 {
422 struct g_geom *gp;
423 struct cdev *dev;
424 u_int unit;
425
426 g_topology_assert();
427 gp = cp->geom;
428 dev = gp->softc;
429 g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, gp->name);
430
431 /* Reset any dump-area set on this device */
432 if (dev->si_flags & SI_DUMPDEV)
433 set_dumper(NULL);
434
435 /* Destroy the struct cdev *so we get no more requests */
436 unit = dev2unit(dev);
437 destroy_dev(dev);
438 free_unr(unithdr, unit);
439
440 /* Wait for the cows to come home */
441 while (cp->nstart != cp->nend)
442 pause("gdevorphan", hz / 10);
443
444 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
445 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
446
447 g_detach(cp);
448 g_destroy_consumer(cp);
449 g_destroy_geom(gp);
450 }
451
452 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
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