geom_dev.c revision 259065
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/10.0/sys/geom/geom_dev.c 254389 2013-08-15 22:52:39Z ken $"); 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 60struct 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 68static d_open_t g_dev_open; 69static d_close_t g_dev_close; 70static d_strategy_t g_dev_strategy; 71static d_ioctl_t g_dev_ioctl; 72 73static 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, 83}; 84 85static g_taste_t g_dev_taste; 86static g_orphan_t g_dev_orphan; 87static g_attrchanged_t g_dev_attrchanged; 88 89static 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 */ 102static uint64_t g_dev_del_max_sectors = 262144; 103SYSCTL_DECL(_kern_geom); 104SYSCTL_NODE(_kern_geom, OID_AUTO, dev, CTLFLAG_RW, 0, "GEOM_DEV stuff"); 105SYSCTL_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 110static void 111g_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 131void 132g_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 144static void 145g_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 194struct g_provider * 195g_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 208static struct g_geom * 209g_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 dev->si_flags |= SI_UNMAPPED; 241 sc->sc_dev = dev; 242 243 /* Search for device alias name and create it if found. */ 244 adev = NULL; 245 for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) { 246 snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name); 247 buf[14 + len] = 0; 248 val = getenv(buf); 249 if (val != NULL) { 250 snprintf(buf, sizeof(buf), "%s%s", 251 val, gp->name + len); 252 freeenv(val); 253 make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, 254 &adev, dev, "%s", buf); 255 adev->si_flags |= SI_UNMAPPED; 256 break; 257 } 258 } 259 260 dev->si_iosize_max = MAXPHYS; 261 dev->si_drv2 = cp; 262 if (adev != NULL) { 263 adev->si_iosize_max = MAXPHYS; 264 adev->si_drv2 = cp; 265 } 266 267 g_dev_attrchanged(cp, "GEOM::physpath"); 268 269 return (gp); 270} 271 272static int 273g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td) 274{ 275 struct g_consumer *cp; 276 struct g_dev_softc *sc; 277 int error, r, w, e; 278 279 cp = dev->si_drv2; 280 if (cp == NULL) 281 return(ENXIO); /* g_dev_taste() not done yet */ 282 g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)", 283 cp->geom->name, flags, fmt, td); 284 285 r = flags & FREAD ? 1 : 0; 286 w = flags & FWRITE ? 1 : 0; 287#ifdef notyet 288 e = flags & O_EXCL ? 1 : 0; 289#else 290 e = 0; 291#endif 292 if (w) { 293 /* 294 * When running in very secure mode, do not allow 295 * opens for writing of any disks. 296 */ 297 error = securelevel_ge(td->td_ucred, 2); 298 if (error) 299 return (error); 300 } 301 g_topology_lock(); 302 error = g_access(cp, r, w, e); 303 g_topology_unlock(); 304 if (error == 0) { 305 sc = cp->private; 306 mtx_lock(&sc->sc_mtx); 307 if (sc->sc_open == 0 && sc->sc_active != 0) 308 wakeup(&sc->sc_active); 309 sc->sc_open += r + w + e; 310 mtx_unlock(&sc->sc_mtx); 311 } 312 return(error); 313} 314 315static int 316g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td) 317{ 318 struct g_consumer *cp; 319 struct g_dev_softc *sc; 320 int error, r, w, e; 321 322 cp = dev->si_drv2; 323 if (cp == NULL) 324 return(ENXIO); 325 g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)", 326 cp->geom->name, flags, fmt, td); 327 328 r = flags & FREAD ? -1 : 0; 329 w = flags & FWRITE ? -1 : 0; 330#ifdef notyet 331 e = flags & O_EXCL ? -1 : 0; 332#else 333 e = 0; 334#endif 335 sc = cp->private; 336 mtx_lock(&sc->sc_mtx); 337 sc->sc_open += r + w + e; 338 while (sc->sc_open == 0 && sc->sc_active != 0) 339 msleep(&sc->sc_active, &sc->sc_mtx, 0, "PRIBIO", 0); 340 mtx_unlock(&sc->sc_mtx); 341 g_topology_lock(); 342 error = g_access(cp, r, w, e); 343 g_topology_unlock(); 344 return (error); 345} 346 347/* 348 * XXX: Until we have unmessed the ioctl situation, there is a race against 349 * XXX: a concurrent orphanization. We cannot close it by holding topology 350 * XXX: since that would prevent us from doing our job, and stalling events 351 * XXX: will break (actually: stall) the BSD disklabel hacks. 352 */ 353static int 354g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td) 355{ 356 struct g_consumer *cp; 357 struct g_provider *pp; 358 struct g_kerneldump kd; 359 off_t offset, length, chunk; 360 int i, error; 361 u_int u; 362 363 cp = dev->si_drv2; 364 pp = cp->provider; 365 366 error = 0; 367 KASSERT(cp->acr || cp->acw, 368 ("Consumer with zero access count in g_dev_ioctl")); 369 370 i = IOCPARM_LEN(cmd); 371 switch (cmd) { 372 case DIOCGSECTORSIZE: 373 *(u_int *)data = cp->provider->sectorsize; 374 if (*(u_int *)data == 0) 375 error = ENOENT; 376 break; 377 case DIOCGMEDIASIZE: 378 *(off_t *)data = cp->provider->mediasize; 379 if (*(off_t *)data == 0) 380 error = ENOENT; 381 break; 382 case DIOCGFWSECTORS: 383 error = g_io_getattr("GEOM::fwsectors", cp, &i, data); 384 if (error == 0 && *(u_int *)data == 0) 385 error = ENOENT; 386 break; 387 case DIOCGFWHEADS: 388 error = g_io_getattr("GEOM::fwheads", cp, &i, data); 389 if (error == 0 && *(u_int *)data == 0) 390 error = ENOENT; 391 break; 392 case DIOCGFRONTSTUFF: 393 error = g_io_getattr("GEOM::frontstuff", cp, &i, data); 394 break; 395 case DIOCSKERNELDUMP: 396 u = *((u_int *)data); 397 if (!u) { 398 set_dumper(NULL, NULL); 399 error = 0; 400 break; 401 } 402 kd.offset = 0; 403 kd.length = OFF_MAX; 404 i = sizeof kd; 405 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd); 406 if (!error) { 407 error = set_dumper(&kd.di, devtoname(dev)); 408 if (!error) 409 dev->si_flags |= SI_DUMPDEV; 410 } 411 break; 412 case DIOCGFLUSH: 413 error = g_io_flush(cp); 414 break; 415 case DIOCGDELETE: 416 offset = ((off_t *)data)[0]; 417 length = ((off_t *)data)[1]; 418 if ((offset % cp->provider->sectorsize) != 0 || 419 (length % cp->provider->sectorsize) != 0 || length <= 0) { 420 printf("%s: offset=%jd length=%jd\n", __func__, offset, 421 length); 422 error = EINVAL; 423 break; 424 } 425 while (length > 0) { 426 chunk = length; 427 if (g_dev_del_max_sectors != 0 && chunk > 428 g_dev_del_max_sectors * cp->provider->sectorsize) { 429 chunk = g_dev_del_max_sectors * 430 cp->provider->sectorsize; 431 } 432 error = g_delete_data(cp, offset, chunk); 433 length -= chunk; 434 offset += chunk; 435 if (error) 436 break; 437 /* 438 * Since the request size can be large, the service 439 * time can be is likewise. We make this ioctl 440 * interruptible by checking for signals for each bio. 441 */ 442 if (SIGPENDING(td)) 443 break; 444 } 445 break; 446 case DIOCGIDENT: 447 error = g_io_getattr("GEOM::ident", cp, &i, data); 448 break; 449 case DIOCGPROVIDERNAME: 450 if (pp == NULL) 451 return (ENOENT); 452 strlcpy(data, pp->name, i); 453 break; 454 case DIOCGSTRIPESIZE: 455 *(off_t *)data = cp->provider->stripesize; 456 break; 457 case DIOCGSTRIPEOFFSET: 458 *(off_t *)data = cp->provider->stripeoffset; 459 break; 460 case DIOCGPHYSPATH: 461 error = g_io_getattr("GEOM::physpath", cp, &i, data); 462 if (error == 0 && *(char *)data == '\0') 463 error = ENOENT; 464 break; 465 default: 466 if (cp->provider->geom->ioctl != NULL) { 467 error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td); 468 } else { 469 error = ENOIOCTL; 470 } 471 } 472 473 return (error); 474} 475 476static void 477g_dev_done(struct bio *bp2) 478{ 479 struct g_consumer *cp; 480 struct g_dev_softc *sc; 481 struct bio *bp; 482 int destroy; 483 484 cp = bp2->bio_from; 485 sc = cp->private; 486 bp = bp2->bio_parent; 487 bp->bio_error = bp2->bio_error; 488 if (bp->bio_error != 0) { 489 g_trace(G_T_BIO, "g_dev_done(%p) had error %d", 490 bp2, bp->bio_error); 491 bp->bio_flags |= BIO_ERROR; 492 } else { 493 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd", 494 bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed); 495 } 496 bp->bio_resid = bp->bio_length - bp2->bio_completed; 497 bp->bio_completed = bp2->bio_completed; 498 g_destroy_bio(bp2); 499 destroy = 0; 500 mtx_lock(&sc->sc_mtx); 501 if ((--sc->sc_active) == 0) { 502 if (sc->sc_open == 0) 503 wakeup(&sc->sc_active); 504 if (sc->sc_dev == NULL) 505 destroy = 1; 506 } 507 mtx_unlock(&sc->sc_mtx); 508 if (destroy) 509 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL); 510 biodone(bp); 511} 512 513static void 514g_dev_strategy(struct bio *bp) 515{ 516 struct g_consumer *cp; 517 struct bio *bp2; 518 struct cdev *dev; 519 struct g_dev_softc *sc; 520 521 KASSERT(bp->bio_cmd == BIO_READ || 522 bp->bio_cmd == BIO_WRITE || 523 bp->bio_cmd == BIO_DELETE || 524 bp->bio_cmd == BIO_FLUSH, 525 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd)); 526 dev = bp->bio_dev; 527 cp = dev->si_drv2; 528 sc = cp->private; 529 KASSERT(cp->acr || cp->acw, 530 ("Consumer with zero access count in g_dev_strategy")); 531#ifdef INVARIANTS 532 if ((bp->bio_offset % cp->provider->sectorsize) != 0 || 533 (bp->bio_bcount % cp->provider->sectorsize) != 0) { 534 bp->bio_resid = bp->bio_bcount; 535 biofinish(bp, NULL, EINVAL); 536 return; 537 } 538#endif 539 mtx_lock(&sc->sc_mtx); 540 KASSERT(sc->sc_open > 0, ("Closed device in g_dev_strategy")); 541 sc->sc_active++; 542 mtx_unlock(&sc->sc_mtx); 543 544 for (;;) { 545 /* 546 * XXX: This is not an ideal solution, but I belive it to 547 * XXX: deadlock safe, all things considered. 548 */ 549 bp2 = g_clone_bio(bp); 550 if (bp2 != NULL) 551 break; 552 pause("gdstrat", hz / 10); 553 } 554 KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place")); 555 bp2->bio_done = g_dev_done; 556 g_trace(G_T_BIO, 557 "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d", 558 bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length, 559 bp2->bio_data, bp2->bio_cmd); 560 g_io_request(bp2, cp); 561 KASSERT(cp->acr || cp->acw, 562 ("g_dev_strategy raced with g_dev_close and lost")); 563 564} 565 566/* 567 * g_dev_callback() 568 * 569 * Called by devfs when asynchronous device destruction is completed. 570 * - Mark that we have no attached device any more. 571 * - If there are no outstanding requests, schedule geom destruction. 572 * Otherwise destruction will be scheduled later by g_dev_done(). 573 */ 574 575static void 576g_dev_callback(void *arg) 577{ 578 struct g_consumer *cp; 579 struct g_dev_softc *sc; 580 int destroy; 581 582 cp = arg; 583 sc = cp->private; 584 g_trace(G_T_TOPOLOGY, "g_dev_callback(%p(%s))", cp, cp->geom->name); 585 586 mtx_lock(&sc->sc_mtx); 587 sc->sc_dev = NULL; 588 sc->sc_alias = NULL; 589 destroy = (sc->sc_active == 0); 590 mtx_unlock(&sc->sc_mtx); 591 if (destroy) 592 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL); 593} 594 595/* 596 * g_dev_orphan() 597 * 598 * Called from below when the provider orphaned us. 599 * - Clear any dump settings. 600 * - Request asynchronous device destruction to prevent any more requests 601 * from coming in. The provider is already marked with an error, so 602 * anything which comes in in the interrim will be returned immediately. 603 */ 604 605static void 606g_dev_orphan(struct g_consumer *cp) 607{ 608 struct cdev *dev; 609 struct g_dev_softc *sc; 610 611 g_topology_assert(); 612 sc = cp->private; 613 dev = sc->sc_dev; 614 g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, cp->geom->name); 615 616 /* Reset any dump-area set on this device */ 617 if (dev->si_flags & SI_DUMPDEV) 618 set_dumper(NULL, NULL); 619 620 /* Destroy the struct cdev *so we get no more requests */ 621 destroy_dev_sched_cb(dev, g_dev_callback, cp); 622} 623 624DECLARE_GEOM_CLASS(g_dev_class, g_dev); 625