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("$FreeBSD$");
  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 <geom/geom.h>
  56 #include <geom/geom_int.h>
  57 #include <machine/stdarg.h>
  58
  59 struct g_dev_softc {
  60         struct mtx       sc_mtx;
  61         struct cdev     *sc_dev;
  62         struct cdev     *sc_alias;
  63         int              sc_open;
  64         int              sc_active;
  65 };
  66
  67 static d_open_t         g_dev_open;
  68 static d_close_t        g_dev_close;
  69 static d_strategy_t     g_dev_strategy;
  70 static d_ioctl_t        g_dev_ioctl;
  71
  72 static struct cdevsw g_dev_cdevsw = {
  73         .d_version =    D_VERSION,
  74         .d_open =       g_dev_open,
  75         .d_close =      g_dev_close,
  76         .d_read =       physread,
  77         .d_write =      physwrite,
  78         .d_ioctl =      g_dev_ioctl,
  79         .d_strategy =   g_dev_strategy,
  80         .d_name =       "g_dev",
  81         .d_flags =      D_DISK | D_TRACKCLOSE,
  82 };
  83
  84 static g_taste_t g_dev_taste;
  85 static g_orphan_t g_dev_orphan;
  86 static g_attrchanged_t g_dev_attrchanged;
  87
  88 static struct g_class g_dev_class       = {
  89         .name = "DEV",
  90         .version = G_VERSION,
  91         .taste = g_dev_taste,
  92         .orphan = g_dev_orphan,
  93         .attrchanged = g_dev_attrchanged
  94 };
  95
  96 static void
  97 g_dev_destroy(void *arg, int flags __unused)
  98 {
  99         struct g_consumer *cp;
 100         struct g_geom *gp;
 101         struct g_dev_softc *sc;
 102
 103         g_topology_assert();
 104         cp = arg;
 105         gp = cp->geom;
 106         sc = cp->private;
 107         g_trace(G_T_TOPOLOGY, "g_dev_destroy(%p(%s))", cp, gp->name);
 108         if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
 109                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
 110         g_detach(cp);
 111         g_destroy_consumer(cp);
 112         g_destroy_geom(gp);
 113         mtx_destroy(&sc->sc_mtx);
 114         g_free(sc);
 115 }
 116
 117 void
 118 g_dev_print(void)
 119 {
 120         struct g_geom *gp;
 121         char const *p = "";
 122
 123         LIST_FOREACH(gp, &g_dev_class.geom, geom) {
 124                 printf("%s%s", p, gp->name);
 125                 p = " ";
 126         }
 127         printf("\n");
 128 }
 129
 130 static void
 131 g_dev_attrchanged(struct g_consumer *cp, const char *attr)
 132 {
 133         struct g_dev_softc *sc;
 134         struct cdev *dev;
 135         char buf[SPECNAMELEN + 6];
 136
 137         sc = cp->private;
 138         if (strcmp(attr, "GEOM::media") == 0) {
 139                 dev = sc->sc_dev;
 140                 snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
 141                 devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf, M_WAITOK);
 142                 dev = sc->sc_alias;
 143                 if (dev != NULL) {
 144                         snprintf(buf, sizeof(buf), "cdev=%s", dev->si_name);
 145                         devctl_notify_f("DEVFS", "CDEV", "MEDIACHANGE", buf,
 146                             M_WAITOK);
 147                 }
 148                 return;
 149         }
 150
 151         if (strcmp(attr, "GEOM::physpath") != 0)
 152                 return;
 153
 154         if (g_access(cp, 1, 0, 0) == 0) {
 155                 char *physpath;
 156                 int error, physpath_len;
 157
 158                 physpath_len = MAXPATHLEN;
 159                 physpath = g_malloc(physpath_len, M_WAITOK|M_ZERO);
 160                 error =
 161                     g_io_getattr("GEOM::physpath", cp, &physpath_len, physpath);
 162                 g_access(cp, -1, 0, 0);
 163                 if (error == 0 && strlen(physpath) != 0) {
 164                         struct cdev *old_alias_dev;
 165                         struct cdev **alias_devp;
 166
 167                         dev = sc->sc_dev;
 168                         old_alias_dev = sc->sc_alias;
 169                         alias_devp = (struct cdev **)&sc->sc_alias;
 170                         make_dev_physpath_alias(MAKEDEV_WAITOK, alias_devp,
 171                             dev, old_alias_dev, physpath);
 172                 } else if (sc->sc_alias) {
 173                         destroy_dev((struct cdev *)sc->sc_alias);
 174                         sc->sc_alias = NULL;
 175                 }
 176                 g_free(physpath);
 177         }
 178 }
 179
 180 struct g_provider *
 181 g_dev_getprovider(struct cdev *dev)
 182 {
 183         struct g_consumer *cp;
 184
 185         g_topology_assert();
 186         if (dev == NULL)
 187                 return (NULL);
 188         if (dev->si_devsw != &g_dev_cdevsw)
 189                 return (NULL);
 190         cp = dev->si_drv2;
 191         return (cp->provider);
 192 }
 193
 194 static struct g_geom *
 195 g_dev_taste(struct g_class *mp, struct g_provider *pp, int insist __unused)
 196 {
 197         struct g_geom *gp;
 198         struct g_consumer *cp;
 199         struct g_dev_softc *sc;
 200         int error, len;
 201         struct cdev *dev, *adev;
 202         char buf[64], *val;
 203
 204         g_trace(G_T_TOPOLOGY, "dev_taste(%s,%s)", mp->name, pp->name);
 205         g_topology_assert();
 206         gp = g_new_geomf(mp, "%s", pp->name);
 207         sc = g_malloc(sizeof(*sc), M_WAITOK | M_ZERO);
 208         mtx_init(&sc->sc_mtx, "g_dev", NULL, MTX_DEF);
 209         cp = g_new_consumer(gp);
 210         cp->private = sc;
 211         error = g_attach(cp, pp);
 212         KASSERT(error == 0,
 213             ("g_dev_taste(%s) failed to g_attach, err=%d", pp->name, error));
 214         error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &dev,
 215             &g_dev_cdevsw, NULL, UID_ROOT, GID_OPERATOR, 0640, "%s", gp->name);
 216         if (error != 0) {
 217                 printf("%s: make_dev_p() failed (gp->name=%s, error=%d)\n",
 218                     __func__, gp->name, error);
 219                 g_detach(cp);
 220                 g_destroy_consumer(cp);
 221                 g_destroy_geom(gp);
 222                 mtx_destroy(&sc->sc_mtx);
 223                 g_free(sc);
 224                 return (NULL);
 225         }
 226         sc->sc_dev = dev;
 227
 228         /* Search for device alias name and create it if found. */
 229         adev = NULL;
 230         for (len = MIN(strlen(gp->name), sizeof(buf) - 15); len > 0; len--) {
 231                 snprintf(buf, sizeof(buf), "kern.devalias.%s", gp->name);
 232                 buf[14 + len] = 0;
 233                 val = getenv(buf);
 234                 if (val != NULL) {
 235                         snprintf(buf, sizeof(buf), "%s%s",
 236                             val, gp->name + len);
 237                         freeenv(val);
 238                         make_dev_alias_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK,
 239                             &adev, dev, "%s", buf);
 240                         break;
 241                 }
 242         }
 243
 244         if (pp->flags & G_PF_CANDELETE)
 245                 dev->si_flags |= SI_CANDELETE;
 246         dev->si_iosize_max = MAXPHYS;
 247         dev->si_drv2 = cp;
 248         if (adev != NULL) {
 249                 if (pp->flags & G_PF_CANDELETE)
 250                         adev->si_flags |= SI_CANDELETE;
 251                 adev->si_iosize_max = MAXPHYS;
 252                 adev->si_drv2 = cp;
 253         }
 254
 255         g_dev_attrchanged(cp, "GEOM::physpath");
 256
 257         return (gp);
 258 }
 259
 260 static int
 261 g_dev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
 262 {
 263         struct g_consumer *cp;
 264         struct g_dev_softc *sc;
 265         int error, r, w, e;
 266
 267         cp = dev->si_drv2;
 268         if (cp == NULL)
 269                 return(ENXIO);          /* g_dev_taste() not done yet */
 270         g_trace(G_T_ACCESS, "g_dev_open(%s, %d, %d, %p)",
 271             cp->geom->name, flags, fmt, td);
 272
 273         r = flags & FREAD ? 1 : 0;
 274         w = flags & FWRITE ? 1 : 0;
 275 #ifdef notyet
 276         e = flags & O_EXCL ? 1 : 0;
 277 #else
 278         e = 0;
 279 #endif
 280         if (w) {
 281                 /*
 282                  * When running in very secure mode, do not allow
 283                  * opens for writing of any disks.
 284                  */
 285                 error = securelevel_ge(td->td_ucred, 2);
 286                 if (error)
 287                         return (error);
 288         }
 289         g_topology_lock();
 290         error = g_access(cp, r, w, e);
 291         g_topology_unlock();
 292         if (error == 0) {
 293                 sc = cp->private;
 294                 mtx_lock(&sc->sc_mtx);
 295                 if (sc->sc_open == 0 && sc->sc_active != 0)
 296                         wakeup(&sc->sc_active);
 297                 sc->sc_open += r + w + e;
 298                 mtx_unlock(&sc->sc_mtx);
 299         }
 300         return(error);
 301 }
 302
 303 static int
 304 g_dev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
 305 {
 306         struct g_consumer *cp;
 307         struct g_dev_softc *sc;
 308         int error, r, w, e;
 309
 310         cp = dev->si_drv2;
 311         if (cp == NULL)
 312                 return(ENXIO);
 313         g_trace(G_T_ACCESS, "g_dev_close(%s, %d, %d, %p)",
 314             cp->geom->name, flags, fmt, td);
 315
 316         r = flags & FREAD ? -1 : 0;
 317         w = flags & FWRITE ? -1 : 0;
 318 #ifdef notyet
 319         e = flags & O_EXCL ? -1 : 0;
 320 #else
 321         e = 0;
 322 #endif
 323         sc = cp->private;
 324         mtx_lock(&sc->sc_mtx);
 325         sc->sc_open += r + w + e;
 326         while (sc->sc_open == 0 && sc->sc_active != 0)
 327                 msleep(&sc->sc_active, &sc->sc_mtx, 0, "PRIBIO", 0);
 328         mtx_unlock(&sc->sc_mtx);
 329         g_topology_lock();
 330         error = g_access(cp, r, w, e);
 331         g_topology_unlock();
 332         return (error);
 333 }
 334
 335 /*
 336  * XXX: Until we have unmessed the ioctl situation, there is a race against
 337  * XXX: a concurrent orphanization.  We cannot close it by holding topology
 338  * XXX: since that would prevent us from doing our job, and stalling events
 339  * XXX: will break (actually: stall) the BSD disklabel hacks.
 340  */
 341 static int
 342 g_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag, struct thread *td)
 343 {
 344         struct g_consumer *cp;
 345         struct g_provider *pp;
 346         struct g_kerneldump kd;
 347         off_t offset, length, chunk;
 348         int i, error;
 349         u_int u;
 350
 351         cp = dev->si_drv2;
 352         pp = cp->provider;
 353
 354         error = 0;
 355         KASSERT(cp->acr || cp->acw,
 356             ("Consumer with zero access count in g_dev_ioctl"));
 357
 358         i = IOCPARM_LEN(cmd);
 359         switch (cmd) {
 360         case DIOCGSECTORSIZE:
 361                 *(u_int *)data = cp->provider->sectorsize;
 362                 if (*(u_int *)data == 0)
 363                         error = ENOENT;
 364                 break;
 365         case DIOCGMEDIASIZE:
 366                 *(off_t *)data = cp->provider->mediasize;
 367                 if (*(off_t *)data == 0)
 368                         error = ENOENT;
 369                 break;
 370         case DIOCGFWSECTORS:
 371                 error = g_io_getattr("GEOM::fwsectors", cp, &i, data);
 372                 if (error == 0 && *(u_int *)data == 0)
 373                         error = ENOENT;
 374                 break;
 375         case DIOCGFWHEADS:
 376                 error = g_io_getattr("GEOM::fwheads", cp, &i, data);
 377                 if (error == 0 && *(u_int *)data == 0)
 378                         error = ENOENT;
 379                 break;
 380         case DIOCGFRONTSTUFF:
 381                 error = g_io_getattr("GEOM::frontstuff", cp, &i, data);
 382                 break;
 383         case DIOCSKERNELDUMP:
 384                 u = *((u_int *)data);
 385                 if (!u) {
 386                         set_dumper(NULL);
 387                         error = 0;
 388                         break;
 389                 }
 390                 kd.offset = 0;
 391                 kd.length = OFF_MAX;
 392                 i = sizeof kd;
 393                 error = g_io_getattr("GEOM::kerneldump", cp, &i, &kd);
 394                 if (!error) {
 395                         error = set_dumper(&kd.di);
 396                         if (!error)
 397                                 dev->si_flags |= SI_DUMPDEV;
 398                 }
 399                 break;
 400         case DIOCGFLUSH:
 401                 error = g_io_flush(cp);
 402                 break;
 403         case DIOCGDELETE:
 404                 offset = ((off_t *)data)[0];
 405                 length = ((off_t *)data)[1];
 406                 if ((offset % cp->provider->sectorsize) != 0 ||
 407                     (length % cp->provider->sectorsize) != 0 || length <= 0) {
 408                         printf("%s: offset=%jd length=%jd\n", __func__, offset,
 409                             length);
 410                         error = EINVAL;
 411                         break;
 412                 }
 413                 while (length > 0) {
 414                         chunk = length;
 415                         if (chunk > 65536 * cp->provider->sectorsize)
 416                                 chunk = 65536 * cp->provider->sectorsize;
 417                         error = g_delete_data(cp, offset, chunk);
 418                         length -= chunk;
 419                         offset += chunk;
 420                         if (error)
 421                                 break;
 422                         /*
 423                          * Since the request size is unbounded, the service
 424                          * time is likewise.  We make this ioctl interruptible
 425                          * by checking for signals for each bio.
 426                          */
 427                         if (SIGPENDING(td))
 428                                 break;
 429                 }
 430                 break;
 431         case DIOCGIDENT:
 432                 error = g_io_getattr("GEOM::ident", cp, &i, data);
 433                 break;
 434         case DIOCGPROVIDERNAME:
 435                 if (pp == NULL)
 436                         return (ENOENT);
 437                 strlcpy(data, pp->name, i);
 438                 break;
 439         case DIOCGSTRIPESIZE:
 440                 *(off_t *)data = cp->provider->stripesize;
 441                 break;
 442         case DIOCGSTRIPEOFFSET:
 443                 *(off_t *)data = cp->provider->stripeoffset;
 444                 break;
 445         case DIOCGPHYSPATH:
 446                 error = g_io_getattr("GEOM::physpath", cp, &i, data);
 447                 if (error == 0 && *(char *)data == '\0')
 448                         error = ENOENT;
 449                 break;
 450         default:
 451                 if (cp->provider->geom->ioctl != NULL) {
 452                         error = cp->provider->geom->ioctl(cp->provider, cmd, data, fflag, td);
 453                 } else {
 454                         error = ENOIOCTL;
 455                 }
 456         }
 457
 458         return (error);
 459 }
 460
 461 static void
 462 g_dev_done(struct bio *bp2)
 463 {
 464         struct g_consumer *cp;
 465         struct g_dev_softc *sc;
 466         struct bio *bp;
 467         int destroy;
 468
 469         cp = bp2->bio_from;
 470         sc = cp->private;
 471         bp = bp2->bio_parent;
 472         bp->bio_error = bp2->bio_error;
 473         if (bp->bio_error != 0) {
 474                 g_trace(G_T_BIO, "g_dev_done(%p) had error %d",
 475                     bp2, bp->bio_error);
 476                 bp->bio_flags |= BIO_ERROR;
 477         } else {
 478                 g_trace(G_T_BIO, "g_dev_done(%p/%p) resid %ld completed %jd",
 479                     bp2, bp, bp->bio_resid, (intmax_t)bp2->bio_completed);
 480         }
 481         bp->bio_resid = bp->bio_length - bp2->bio_completed;
 482         bp->bio_completed = bp2->bio_completed;
 483         g_destroy_bio(bp2);
 484         destroy = 0;
 485         mtx_lock(&sc->sc_mtx);
 486         if ((--sc->sc_active) == 0) {
 487                 if (sc->sc_open == 0)
 488                         wakeup(&sc->sc_active);
 489                 if (sc->sc_dev == NULL)
 490                         destroy = 1;
 491         }
 492         mtx_unlock(&sc->sc_mtx);
 493         if (destroy)
 494                 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
 495         biodone(bp);
 496 }
 497
 498 static void
 499 g_dev_strategy(struct bio *bp)
 500 {
 501         struct g_consumer *cp;
 502         struct bio *bp2;
 503         struct cdev *dev;
 504         struct g_dev_softc *sc;
 505
 506         KASSERT(bp->bio_cmd == BIO_READ ||
 507                 bp->bio_cmd == BIO_WRITE ||
 508                 bp->bio_cmd == BIO_DELETE,
 509                 ("Wrong bio_cmd bio=%p cmd=%d", bp, bp->bio_cmd));
 510         dev = bp->bio_dev;
 511         cp = dev->si_drv2;
 512         sc = cp->private;
 513         KASSERT(cp->acr || cp->acw,
 514             ("Consumer with zero access count in g_dev_strategy"));
 515 #ifdef INVARIANTS
 516         if ((bp->bio_offset % cp->provider->sectorsize) != 0 ||
 517             (bp->bio_bcount % cp->provider->sectorsize) != 0) {
 518                 bp->bio_resid = bp->bio_bcount;
 519                 biofinish(bp, NULL, EINVAL);
 520                 return;
 521         }
 522 #endif
 523         mtx_lock(&sc->sc_mtx);
 524         KASSERT(sc->sc_open > 0, ("Closed device in g_dev_strategy"));
 525         sc->sc_active++;
 526         mtx_unlock(&sc->sc_mtx);
 527
 528         for (;;) {
 529                 /*
 530                  * XXX: This is not an ideal solution, but I belive it to
 531                  * XXX: deadlock safe, all things considered.
 532                  */
 533                 bp2 = g_clone_bio(bp);
 534                 if (bp2 != NULL)
 535                         break;
 536                 pause("gdstrat", hz / 10);
 537         }
 538         KASSERT(bp2 != NULL, ("XXX: ENOMEM in a bad place"));
 539         bp2->bio_done = g_dev_done;
 540         g_trace(G_T_BIO,
 541             "g_dev_strategy(%p/%p) offset %jd length %jd data %p cmd %d",
 542             bp, bp2, (intmax_t)bp->bio_offset, (intmax_t)bp2->bio_length,
 543             bp2->bio_data, bp2->bio_cmd);
 544         g_io_request(bp2, cp);
 545         KASSERT(cp->acr || cp->acw,
 546             ("g_dev_strategy raced with g_dev_close and lost"));
 547
 548 }
 549
 550 /*
 551  * g_dev_callback()
 552  *
 553  * Called by devfs when asynchronous device destruction is completed.
 554  * - Mark that we have no attached device any more.
 555  * - If there are no outstanding requests, schedule geom destruction.
 556  *   Otherwise destruction will be scheduled later by g_dev_done().
 557  */
 558
 559 static void
 560 g_dev_callback(void *arg)
 561 {
 562         struct g_consumer *cp;
 563         struct g_dev_softc *sc;
 564         int destroy;
 565
 566         cp = arg;
 567         sc = cp->private;
 568         g_trace(G_T_TOPOLOGY, "g_dev_callback(%p(%s))", cp, cp->geom->name);
 569
 570         mtx_lock(&sc->sc_mtx);
 571         sc->sc_dev = NULL;
 572         sc->sc_alias = NULL;
 573         destroy = (sc->sc_active == 0);
 574         mtx_unlock(&sc->sc_mtx);
 575         if (destroy)
 576                 g_post_event(g_dev_destroy, cp, M_WAITOK, NULL);
 577 }
 578
 579 /*
 580  * g_dev_orphan()
 581  *
 582  * Called from below when the provider orphaned us.
 583  * - Clear any dump settings.
 584  * - Request asynchronous device destruction to prevent any more requests
 585  *   from coming in.  The provider is already marked with an error, so
 586  *   anything which comes in in the interrim will be returned immediately.
 587  */
 588
 589 static void
 590 g_dev_orphan(struct g_consumer *cp)
 591 {
 592         struct cdev *dev;
 593         struct g_dev_softc *sc;
 594
 595         g_topology_assert();
 596         sc = cp->private;
 597         dev = sc->sc_dev;
 598         g_trace(G_T_TOPOLOGY, "g_dev_orphan(%p(%s))", cp, cp->geom->name);
 599
 600         /* Reset any dump-area set on this device */
 601         if (dev->si_flags & SI_DUMPDEV)
 602                 set_dumper(NULL);
 603
 604         /* Destroy the struct cdev *so we get no more requests */
 605         destroy_dev_sched_cb(dev, g_dev_callback, cp);
 606 }
 607
 608 DECLARE_GEOM_CLASS(g_dev_class, g_dev);