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/9.2/sys/geom/geom_dev.c 251942 2013-06-18 14:46:42Z scottl $");
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/ctype.h>
45 #include <sys/bio.h>
46 #include <sys/bus.h>
47 #include <sys/lock.h>
48 #include <sys/mutex.h>
49 #include <sys/proc.h>
50 #include <sys/errno.h>
51 #include <sys/time.h>
52 #include <sys/disk.h>
53 #include <sys/fcntl.h>
54 #include <sys/limits.h>
55 #include <sys/sysctl.h>
56 #include <geom/geom.h>
57 #include <geom/geom_int.h>
58 #include <machine/stdarg.h>
59
60 struct g_dev_softc {
61 struct mtx sc_mtx;
62 struct cdev *sc_dev;
63 struct cdev *sc_alias;
64 int sc_open;
65 int sc_active;
66 };
67
68 static d_open_t g_dev_open;
69 static d_close_t g_dev_close;
70 static d_strategy_t g_dev_strategy;
71 static d_ioctl_t g_dev_ioctl;
72
73 static struct cdevsw g_dev_cdevsw = {
74 .d_version = D_VERSION,
75 .d_open = g_dev_open,
76 .d_close = g_dev_close,
77 .d_read = physread,
78 .d_write = physwrite,
79 .d_ioctl = g_dev_ioctl,
80 .d_strategy = g_dev_strategy,
81 .d_name = "g_dev",
82 .d_flags = D_DISK | D_TRACKCLOSE | D_UNMAPPED_IO,
83 };
84
85 static g_taste_t g_dev_taste;
86 static g_orphan_t g_dev_orphan;
87 static g_attrchanged_t g_dev_attrchanged;
88
89 static struct g_class g_dev_class = {
90 .name = "DEV",
91 .version = G_VERSION,
92 .taste = g_dev_taste,
93 .orphan = g_dev_orphan,
94 .attrchanged = g_dev_attrchanged
95 };
96
97 /*
98 * We target 262144 (8 x 32768) sectors by default as this significantly
99 * increases the throughput on commonly used SSD's with a marginal
100 * increase in non-interruptible request latency.
101 */
102 static uint64_t g_dev_del_max_sectors = 262144;
103 SYSCTL_DECL(_kern_geom);
104 SYSCTL_NODE(_kern_geom, OID_AUTO, dev, CTLFLAG_RW, 0, "GEOM_DEV stuff");
105 SYSCTL_QUAD(_kern_geom_dev, OID_AUTO, delete_max_sectors, CTLFLAG_RW,
106 &g_dev_del_max_sectors, 0, "Maximum number of sectors in a single "
107 "delete request sent to the provider. Larger requests are chunked "
108 "so they can be interrupted. (0 = disable chunking)");
109
110 static void
111 g_dev_destroy(void *arg, int flags __unused)
112 {
113 struct g_consumer *cp;
114 struct g_geom *gp;
115 struct g_dev_softc *sc;
116
117 g_topology_assert();
118 cp = arg;
119 gp = cp->geom;
120 sc = cp->private;
121 g_trace(G_T_TOPOLOGY, "g_dev_destroy(%p(%s))", cp, gp->name);
122 if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
123 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
124 g_detach(cp);
125 g_destroy_consumer(cp);
126 g_destroy_geom(gp);
127 mtx_destroy(&sc->sc_mtx);
128 g_free(sc);
129 }
130
131 void
132 g_dev_print(void)
133 {
134 struct g_geom *gp;
135 char const *p = "";
136
137 LIST_FOREACH(gp, &g_dev_class.geom, geom) {
138 printf("%s%s", p, gp->name);
139 p = " ";
140 }
141 printf("\n");
142 }
143
144 static void
145 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
146 {
147 struct g_dev_softc *sc;
148 struct cdev *dev;
149 char buf[SPECNAMELEN + 6];
150
151 sc = cp->private;
152 if (strcmp(attr, "GEOM::media") == 0) {
153 dev = sc->sc_dev;
154 snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
155 devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
156 dev = sc->sc_alias;
157 if (dev != NULL) {
158 snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
159 devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf,
160 M_WAITOK);
161 }
162 return;
163 }
164
165 if (strcmp(attr, "GEOM::physpath") != 0)
166 return;
167
168 if (g_access(cp, 1, 0, 0) == 0) {
169 char *physpath;
170 int error, physpath_len;
171
172 physpath_len = MAXPATHLEN;
173 physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
174 error =
175 g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
176 g_access(cp, -1, 0, 0);
177 if (error == 0 && strlen(physpath) != 0) {
178 struct cdev *old_alias_dev;
179 struct cdev **alias_devp;
180
181 dev = sc->sc_dev;
182 old_alias_dev = sc->sc_alias;
183 alias_devp = (struct cdev **)&sc->sc_alias;
184 make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
185 dev, old_alias_dev, physpath);
186 } else if (sc->sc_alias) {
187 destroy_dev((struct cdev *)sc->sc_alias);
188 sc->sc_alias = NULL;
189 }
190 g_free(physpath);
191 }
192 }
193
194 struct g_provider *
195 g_dev_getprovider(struct cdev *dev)
196 {
197 struct g_consumer *cp;
198
199 g_topology_assert();
200 if (dev == NULL)
201 return (NULL);
202 if (dev->si_devsw != &g_dev_cdevsw)
203 return (NULL);
204 cp = dev->si_drv2;
205 return (cp->provider);
206 }
207
208 static struct g_geom *
209 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
210 {
211 struct g_geom *gp;
212 struct g_consumer *cp;
213 struct g_dev_softc *sc;
214 int error, len;
215 struct cdev *dev, *adev;
216 char buf[64], *val;
217
218 g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
219 g_topology_assert();
220 gp = g_new_geomf(mp, "%s", pp->name);
221 sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
222 mtx_init(&sc->sc_mtx, "g_dev", NULL, MTX_DEF);
223 cp = g_new_consumer(gp);
224 cp->private = sc;
225 error = g_attach(cp, pp);
226 KASSERT(error == 0,
227 ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
228 error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
229 &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
230 if (error != 0) {
231 printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
232 __func__, gp->name, error);
233 g_detach(cp);
234 g_destroy_consumer(cp);
235 g_destroy_geom(gp);
236 mtx_destroy(&sc->sc_mtx);
237 g_free(sc);
238 return (NULL);
239 }
240 sc->sc_dev = dev;
241
242 /* Search for device alias name and create it if found. */
243 adev = NULL;
244 for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
245 snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
246 buf[14 + len] = 0;
247 val = getenv(buf);
248 if (val != NULL) {
249 snprintf(buf, sizeof(buf), "%s%s",
250 val, gp->name + len);
251 freeenv(val);
252 make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
253 &adev, dev, "%s", buf);
254 break;
255 }
256 }
257
258 if (pp->flags & G_PF_CANDELETE)
259 dev->si_flags |= SI_CANDELETE;
260 dev->si_iosize_max = MAXPHYS;
261 dev->si_drv2 = cp;
262 if (adev != NULL) {
263 if (pp->flags & G_PF_CANDELETE)
264 adev->si_flags |= SI_CANDELETE;
265 adev->si_iosize_max = MAXPHYS;
266 adev->si_drv2 = cp;
267 }
268
269 g_dev_attrchanged(cp, "GEOM::physpath");
270
271 return (gp);
272 }
273
274 static int
275 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
276 {
277 struct g_consumer *cp;
278 struct g_dev_softc *sc;
279 int error, r, w, e;
280
281 cp = dev->si_drv2;
282 if (cp == NULL)
283 return(ENXIO); /* g_dev_taste() not done yet */
284 g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
285 cp->geom->name, flags, fmt, td);
286
287 r = flags & FREAD ? 1 : 0;
288 w = flags & FWRITE ? 1 : 0;
289 #ifdef notyet
290 e = flags & O_EXCL ? 1 : 0;
291 #else
292 e = 0;
293 #endif
294 if (w) {
295 /*
296 * When running in very secure mode, do not allow
297 * opens for writing of any disks.
298 */
299 error = securelevel_ge(td->td_ucred, 2);
300 if (error)
301 return (error);
302 }
303 g_topology_lock();
304 error = g_access(cp, r, w, e);
305 g_topology_unlock();
306 if (error == 0) {
307 sc = cp->private;
308 mtx_lock(&sc->sc_mtx);
309 if (sc->sc_open == 0 && sc->sc_active != 0)
310 wakeup(&sc->sc_active);
311 sc->sc_open += r + w + e;
312 mtx_unlock(&sc->sc_mtx);
313 }
314 return(error);
315 }
316
317 static int
318 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
319 {
320 struct g_consumer *cp;
321 struct g_dev_softc *sc;
322 int error, r, w, e;
323
324 cp = dev->si_drv2;
325 if (cp == NULL)
326 return(ENXIO);
327 g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
328 cp->geom->name, flags, fmt, td);
329
330 r = flags & FREAD ? -1 : 0;
331 w = flags & FWRITE ? -1 : 0;
332 #ifdef notyet
333 e = flags & O_EXCL ? -1 : 0;
334 #else
335 e = 0;
336 #endif
337 sc = cp->private;
338 mtx_lock(&sc->sc_mtx);
339 sc->sc_open += r + w + e;
340 while (sc->sc_open == 0 && sc->sc_active != 0)
341 msleep(&sc->sc_active, &sc->sc_mtx, 0, "PRIBIO", 0);
342 mtx_unlock(&sc->sc_mtx);
343 g_topology_lock();
344 error = g_access(cp, r, w, e);
345 g_topology_unlock();
346 return (error);
347 }
348
349 /*
350 * XXX: Until we have unmessed the ioctl situation, there is a race against
351 * XXX: a concurrent orphanization. We cannot close it by holding topology
352 * XXX: since that would prevent us from doing our job, and stalling events
353 * XXX: will break (actually: stall) the BSD disklabel hacks.
354 */
355 static int
356 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
357 {
358 struct g_consumer *cp;
359 struct g_provider *pp;
360 struct g_kerneldump kd;
361 off_t offset, length, chunk;
362 int i, error;
363 u_int u;
364
365 cp = dev->si_drv2;
366 pp = cp->provider;
367
368 error = 0;
369 KASSERT(cp->acr || cp->acw,
370 ("Consumer with zero access count in g_dev_ioctl"));
371
372 i = IOCPARM_LEN(cmd);
373 switch (cmd) {
374 case DIOCGSECTORSIZE:
375 *(u_int *)data = cp->provider->sectorsize;
376 if (*(u_int *)data == 0)
377 error = ENOENT;
378 break;
379 case DIOCGMEDIASIZE:
380 *(off_t *)data = cp->provider->mediasize;
381 if (*(off_t *)data == 0)
382 error = ENOENT;
383 break;
384 case DIOCGFWSECTORS:
385 error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
386 if (error == 0 && *(u_int *)data == 0)
387 error = ENOENT;
388 break;
389 case DIOCGFWHEADS:
390 error = g_io_getattr("GEOM::fwheads", cp, &i, data);
391 if (error == 0 && *(u_int *)data == 0)
392 error = ENOENT;
393 break;
394 case DIOCGFRONTSTUFF:
395 error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
396 break;
397 case DIOCSKERNELDUMP:
398 u = *((u_int *)data);
399 if (!u) {
400 set_dumper(NULL);
401 error = 0;
402 break;
403 }
404 kd.offset = 0;
405 kd.length = OFF_MAX;
406 i = sizeof kd;
407 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
408 if (!error) {
409 error = set_dumper(&kd.di);
410 if (!error)
411 dev->si_flags |= SI_DUMPDEV;
412 }
413 break;
414 case DIOCGFLUSH:
415 error = g_io_flush(cp);
416 break;
417 case DIOCGDELETE:
418 offset = ((off_t *)data)[0];
419 length = ((off_t *)data)[1];
420 if ((offset % cp->provider->sectorsize) != 0 ||
421 (length % cp->provider->sectorsize) != 0 || length <= 0) {
422 printf("%s: offset=%jd length=%jd\n", __func__, offset,
423 length);
424 error = EINVAL;
425 break;
426 }
427 while (length > 0) {
428 chunk = length;
429 if (g_dev_del_max_sectors != 0 && chunk >
430 g_dev_del_max_sectors * cp->provider->sectorsize) {
431 chunk = g_dev_del_max_sectors *
432 cp->provider->sectorsize;
433 }
434 error = g_delete_data(cp, offset, chunk);
435 length -= chunk;
436 offset += chunk;
437 if (error)
438 break;
439 /*
440 * Since the request size can be large, the service
441 * time can be is likewise. We make this ioctl
442 * interruptible by checking for signals for each bio.
443 */
444 if (SIGPENDING(td))
445 break;
446 }
447 break;
448 case DIOCGIDENT:
449 error = g_io_getattr("GEOM::ident", cp, &i, data);
450 break;
451 case DIOCGPROVIDERNAME:
452 if (pp == NULL)
453 return (ENOENT);
454 strlcpy(data, pp->name, i);
455 break;
456 case DIOCGSTRIPESIZE:
457 *(off_t *)data = cp->provider->stripesize;
458 break;
459 case DIOCGSTRIPEOFFSET:
460 *(off_t *)data = cp->provider->stripeoffset;
461 break;
462 case DIOCGPHYSPATH:
463 error = g_io_getattr("GEOM::physpath", cp, &i, data);
464 if (error == 0 && *(char *)data == '\0')
465 error = ENOENT;
466 break;
467 default:
468 if (cp->provider->geom->ioctl != NULL) {
469 error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
470 } else {
471 error = ENOIOCTL;
472 }
473 }
474
475 return (error);
476 }
477
478 static void
479 g_dev_done(struct bio *bp2)
480 {
481 struct g_consumer *cp;
482 struct g_dev_softc *sc;
483 struct bio *bp;
484 int destroy;
485
486 cp = bp2->bio_from;
487 sc = cp->private;
488 bp = bp2->bio_parent;
489 bp->bio_error = bp2->bio_error;
490 if (bp->bio_error != 0) {
491 g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
492 bp2, bp->bio_error);
493 bp->bio_flags |= BIO_ERROR;
494 } else {
495 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
496 bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
497 }
498 bp->bio_resid = bp->bio_length - bp2->bio_completed;
499 bp->bio_completed = bp2->bio_completed;
500 g_destroy_bio(bp2);
501 destroy = 0;
502 mtx_lock(&sc->sc_mtx);
503 if ((--sc->sc_active) == 0) {
504 if (sc->sc_open == 0)
505 wakeup(&sc->sc_active);
506 if (sc->sc_dev == NULL)
507 destroy = 1;
508 }
509 mtx_unlock(&sc->sc_mtx);
510 if (destroy)
511 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
512 biodone(bp);
513 }
514
515 static void
516 g_dev_strategy(struct bio *bp)
517 {
518 struct g_consumer *cp;
519 struct bio *bp2;
520 struct cdev *dev;
521 struct g_dev_softc *sc;
522
523 KASSERT(bp->bio_cmd == BIO_READ ||
524 bp->bio_cmd == BIO_WRITE ||
525 bp->bio_cmd == BIO_DELETE ||
526 bp->bio_cmd == BIO_FLUSH,
527 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
528 dev = bp->bio_dev;
529 cp = dev->si_drv2;
530 sc = cp->private;
531 KASSERT(cp->acr || cp->acw,
532 ("Consumer with zero access count in g_dev_strategy"));
533 #ifdef INVARIANTS
534 if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
535 (bp->bio_bcount % cp->provider->sectorsize) != 0) {
536 bp->bio_resid = bp->bio_bcount;
537 biofinish(bp, NULL, EINVAL);
538 return;
539 }
540 #endif
541 mtx_lock(&sc->sc_mtx);
542 KASSERT(sc->sc_open > 0, ("Closed device in g_dev_strategy"));
543 sc->sc_active++;
544 mtx_unlock(&sc->sc_mtx);
545
546 for (;;) {
547 /*
548 * XXX: This is not an ideal solution, but I belive it to
549 * XXX: deadlock safe, all things considered.
550 */
551 bp2 = g_clone_bio(bp);
552 if (bp2 != NULL)
553 break;
554 pause("gdstrat", hz / 10);
555 }
556 KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
557 bp2->bio_done = g_dev_done;
558 g_trace(G_T_BIO,
559 "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
560 bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
561 bp2->bio_data, bp2->bio_cmd);
562 g_io_request(bp2, cp);
563 KASSERT(cp->acr || cp->acw,
564 ("g_dev_strategy raced with g_dev_close and lost"));
565
566 }
567
568 /*
569 * g_dev_callback()
570 *
571 * Called by devfs when asynchronous device destruction is completed.
572 * - Mark that we have no attached device any more.
573 * - If there are no outstanding requests, schedule geom destruction.
574 * Otherwise destruction will be scheduled later by g_dev_done().
575 */
576
577 static void
578 g_dev_callback(void *arg)
579 {
580 struct g_consumer *cp;
581 struct g_dev_softc *sc;
582 int destroy;
583
584 cp = arg;
585 sc = cp->private;
586 g_trace(G_T_TOPOLOGY, "g_dev_callback(%p(%s))", cp, cp->geom->name);
587
588 mtx_lock(&sc->sc_mtx);
589 sc->sc_dev = NULL;
590 sc->sc_alias = NULL;
591 destroy = (sc->sc_active == 0);
592 mtx_unlock(&sc->sc_mtx);
593 if (destroy)
594 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
595 }
596
597 /*
598 * g_dev_orphan()
599 *
600 * Called from below when the provider orphaned us.
601 * - Clear any dump settings.
602 * - Request asynchronous device destruction to prevent any more requests
603 * from coming in. The provider is already marked with an error, so
604 * anything which comes in in the interrim will be returned immediately.
605 */
606
607 static void
608 g_dev_orphan(struct g_consumer *cp)
609 {
610 struct cdev *dev;
611 struct g_dev_softc *sc;
612
613 g_topology_assert();
614 sc = cp->private;
615 dev = sc->sc_dev;
616 g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, cp->geom->name);
617
618 /* Reset any dump-area set on this device */
619 if (dev->si_flags & SI_DUMPDEV)
620 set_dumper(NULL);
621
622 /* Destroy the struct cdev *so we get no more requests */
623 destroy_dev_sched_cb(dev, g_dev_callback, cp);
624 }
625
626 DECLARE_GEOM_CLASS(g_dev_class, g_dev);
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