sys/geom/gate/g_gate.c

   1 /*-
   2  * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  */
  26
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/bio.h>
  33 #include <sys/conf.h>
  34 #include <sys/kernel.h>
  35 #include <sys/kthread.h>
  36 #include <sys/fcntl.h>
  37 #include <sys/linker.h>
  38 #include <sys/lock.h>
  39 #include <sys/malloc.h>
  40 #include <sys/mutex.h>
  41 #include <sys/proc.h>
  42 #include <sys/limits.h>
  43 #include <sys/queue.h>
  44 #include <sys/sysctl.h>
  45 #include <sys/signalvar.h>
  46 #include <sys/time.h>
  47 #include <machine/atomic.h>
  48
  49 #include <geom/geom.h>
  50 #include <geom/gate/g_gate.h>
  51
  52 static MALLOC_DEFINE(M_GATE, "gg_data", "GEOM Gate Data");
  53
  54 SYSCTL_DECL(_kern_geom);
  55 SYSCTL_NODE(_kern_geom, OID_AUTO, gate, CTLFLAG_RW, 0, "GEOM_GATE stuff");
  56 static u_int g_gate_debug = 0;
  57 SYSCTL_UINT(_kern_geom_gate, OID_AUTO, debug, CTLFLAG_RW, &g_gate_debug, 0,
  58     "Debug level");
  59
  60 struct g_class g_gate_class = {
  61         .name = G_GATE_CLASS_NAME,
  62         .version = G_VERSION,
  63 };
  64
  65 static struct cdev *status_dev;
  66 static d_ioctl_t g_gate_ioctl;
  67 static struct cdevsw g_gate_cdevsw = {
  68         .d_version =    D_VERSION,
  69         .d_ioctl =      g_gate_ioctl,
  70         .d_name =       G_GATE_CTL_NAME
  71 };
  72
  73
  74 static LIST_HEAD(, g_gate_softc) g_gate_list =
  75     LIST_HEAD_INITIALIZER(&g_gate_list);
  76 static struct mtx g_gate_list_mtx;
  77
  78
  79 static int
  80 g_gate_destroy(struct g_gate_softc *sc, boolean_t force)
  81 {
  82         struct g_provider *pp;
  83         struct g_geom *gp;
  84         struct bio *bp;
  85
  86         g_topology_assert();
  87         mtx_assert(&g_gate_list_mtx, MA_OWNED);
  88         pp = sc->sc_provider;
  89         if (!force && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
  90                 mtx_unlock(&g_gate_list_mtx);
  91                 return (EBUSY);
  92         }
  93         mtx_unlock(&g_gate_list_mtx);
  94         mtx_lock(&sc->sc_queue_mtx);
  95         if ((sc->sc_flags & G_GATE_FLAG_DESTROY) == 0)
  96                 sc->sc_flags |= G_GATE_FLAG_DESTROY;
  97         wakeup(sc);
  98         mtx_unlock(&sc->sc_queue_mtx);
  99         gp = pp->geom;
 100         pp->flags |= G_PF_WITHER;
 101         g_orphan_provider(pp, ENXIO);
 102         callout_drain(&sc->sc_callout);
 103         mtx_lock(&sc->sc_queue_mtx);
 104         for (;;) {
 105                 bp = bioq_first(&sc->sc_inqueue);
 106                 if (bp != NULL) {
 107                         bioq_remove(&sc->sc_inqueue, bp);
 108                         sc->sc_queue_count--;
 109                         G_GATE_LOGREQ(1, bp, "Request canceled.");
 110                         g_io_deliver(bp, ENXIO);
 111                 } else {
 112                         break;
 113                 }
 114         }
 115         for (;;) {
 116                 bp = bioq_first(&sc->sc_outqueue);
 117                 if (bp != NULL) {
 118                         bioq_remove(&sc->sc_outqueue, bp);
 119                         sc->sc_queue_count--;
 120                         G_GATE_LOGREQ(1, bp, "Request canceled.");
 121                         g_io_deliver(bp, ENXIO);
 122                 } else {
 123                         break;
 124                 }
 125         }
 126         mtx_unlock(&sc->sc_queue_mtx);
 127         g_topology_unlock();
 128         mtx_lock(&g_gate_list_mtx);
 129         /* One reference is ours. */
 130         sc->sc_ref--;
 131         while (sc->sc_ref > 0) {
 132                 msleep(&sc->sc_ref, &g_gate_list_mtx, 0, "gg:destroy", 0);
 133         }
 134         LIST_REMOVE(sc, sc_next);
 135         mtx_unlock(&g_gate_list_mtx);
 136         mtx_destroy(&sc->sc_queue_mtx);
 137         g_topology_lock();
 138         G_GATE_DEBUG(0, "Device %s destroyed.", gp->name);
 139         gp->softc = NULL;
 140         g_wither_geom(gp, ENXIO);
 141         sc->sc_provider = NULL;
 142         free(sc, M_GATE);
 143         return (0);
 144 }
 145
 146 static int
 147 g_gate_access(struct g_provider *pp, int dr, int dw, int de)
 148 {
 149         struct g_gate_softc *sc;
 150
 151         if (dr <= 0 && dw <= 0 && de <= 0)
 152                 return (0);
 153         sc = pp->geom->softc;
 154         if (sc == NULL || (sc->sc_flags & G_GATE_FLAG_DESTROY) != 0)
 155                 return (ENXIO);
 156         /* XXX: Hack to allow read-only mounts. */
 157 #if 0
 158         if ((sc->sc_flags & G_GATE_FLAG_READONLY) != 0 && dw > 0)
 159                 return (EPERM);
 160 #endif
 161         if ((sc->sc_flags & G_GATE_FLAG_WRITEONLY) != 0 && dr > 0)
 162                 return (EPERM);
 163         return (0);
 164 }
 165
 166 static void
 167 g_gate_start(struct bio *bp)
 168 {
 169         struct g_gate_softc *sc;
 170
 171         sc = bp->bio_to->geom->softc;
 172         if (sc == NULL || (sc->sc_flags & G_GATE_FLAG_DESTROY) != 0) {
 173                 g_io_deliver(bp, ENXIO);
 174                 return;
 175         }
 176         G_GATE_LOGREQ(2, bp, "Request received.");
 177         switch (bp->bio_cmd) {
 178         case BIO_READ:
 179                 break;
 180         case BIO_DELETE:
 181         case BIO_WRITE:
 182                 /* XXX: Hack to allow read-only mounts. */
 183                 if ((sc->sc_flags & G_GATE_FLAG_READONLY) != 0) {
 184                         g_io_deliver(bp, EPERM);
 185                         return;
 186                 }
 187                 break;
 188         case BIO_GETATTR:
 189         default:
 190                 G_GATE_LOGREQ(2, bp, "Ignoring request.");
 191                 g_io_deliver(bp, EOPNOTSUPP);
 192                 return;
 193         }
 194
 195         mtx_lock(&sc->sc_queue_mtx);
 196         if (sc->sc_queue_count > sc->sc_queue_size) {
 197                 mtx_unlock(&sc->sc_queue_mtx);
 198                 G_GATE_LOGREQ(1, bp, "Queue full, request canceled.");
 199                 g_io_deliver(bp, EIO);
 200                 return;
 201         }
 202
 203         bp->bio_driver1 = (void *)sc->sc_seq;
 204         sc->sc_seq++;
 205         sc->sc_queue_count++;
 206
 207         bioq_insert_tail(&sc->sc_inqueue, bp);
 208         wakeup(sc);
 209
 210         mtx_unlock(&sc->sc_queue_mtx);
 211 }
 212
 213 static struct g_gate_softc *
 214 g_gate_hold(u_int unit)
 215 {
 216         struct g_gate_softc *sc;
 217
 218         mtx_lock(&g_gate_list_mtx);
 219         LIST_FOREACH(sc, &g_gate_list, sc_next) {
 220                 if (sc->sc_unit == unit)
 221                         break;
 222         }
 223         if (sc != NULL)
 224                 sc->sc_ref++;
 225         mtx_unlock(&g_gate_list_mtx);
 226         return (sc);
 227 }
 228
 229 static void
 230 g_gate_release(struct g_gate_softc *sc)
 231 {
 232
 233         g_topology_assert_not();
 234         mtx_lock(&g_gate_list_mtx);
 235         sc->sc_ref--;
 236         KASSERT(sc->sc_ref >= 0, ("Negative sc_ref for %s.", sc->sc_name));
 237         if (sc->sc_ref == 0 && (sc->sc_flags & G_GATE_FLAG_DESTROY) != 0) {
 238                 wakeup(&sc->sc_ref);
 239                 mtx_unlock(&g_gate_list_mtx);
 240         } else {
 241                 mtx_unlock(&g_gate_list_mtx);
 242         }
 243 }
 244
 245 static int
 246 g_gate_getunit(int unit)
 247 {
 248         struct g_gate_softc *sc;
 249
 250         mtx_assert(&g_gate_list_mtx, MA_OWNED);
 251         if (unit >= 0) {
 252                 LIST_FOREACH(sc, &g_gate_list, sc_next) {
 253                         if (sc->sc_unit == unit)
 254                                 return (-1);
 255                 }
 256         } else {
 257                 unit = 0;
 258 once_again:
 259                 LIST_FOREACH(sc, &g_gate_list, sc_next) {
 260                         if (sc->sc_unit == unit) {
 261                                 if (++unit > 666)
 262                                         return (-1);
 263                                 goto once_again;
 264                         }
 265                 }
 266         }
 267         return (unit);
 268 }
 269
 270 static void
 271 g_gate_guard(void *arg)
 272 {
 273         struct g_gate_softc *sc;
 274         struct bintime curtime;
 275         struct bio *bp, *bp2;
 276
 277         sc = arg;
 278         binuptime(&curtime);
 279         g_gate_hold(sc->sc_unit);
 280         mtx_lock(&sc->sc_queue_mtx);
 281         TAILQ_FOREACH_SAFE(bp, &sc->sc_inqueue.queue, bio_queue, bp2) {
 282                 if (curtime.sec - bp->bio_t0.sec < 5)
 283                         continue;
 284                 bioq_remove(&sc->sc_inqueue, bp);
 285                 sc->sc_queue_count--;
 286                 G_GATE_LOGREQ(1, bp, "Request timeout.");
 287                 g_io_deliver(bp, EIO);
 288         }
 289         TAILQ_FOREACH_SAFE(bp, &sc->sc_outqueue.queue, bio_queue, bp2) {
 290                 if (curtime.sec - bp->bio_t0.sec < 5)
 291                         continue;
 292                 bioq_remove(&sc->sc_outqueue, bp);
 293                 sc->sc_queue_count--;
 294                 G_GATE_LOGREQ(1, bp, "Request timeout.");
 295                 g_io_deliver(bp, EIO);
 296         }
 297         mtx_unlock(&sc->sc_queue_mtx);
 298         if ((sc->sc_flags & G_GATE_FLAG_DESTROY) == 0) {
 299                 callout_reset(&sc->sc_callout, sc->sc_timeout * hz,
 300                     g_gate_guard, sc);
 301         }
 302         g_gate_release(sc);
 303 }
 304
 305 static void
 306 g_gate_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
 307     struct g_consumer *cp, struct g_provider *pp)
 308 {
 309         struct g_gate_softc *sc;
 310
 311         sc = gp->softc;
 312         if (sc == NULL || pp != NULL || cp != NULL)
 313                 return;
 314         g_gate_hold(sc->sc_unit);
 315         if ((sc->sc_flags & G_GATE_FLAG_READONLY) != 0) {
 316                 sbuf_printf(sb, "%s<access>%s</access>\n", indent, "read-only");
 317         } else if ((sc->sc_flags & G_GATE_FLAG_WRITEONLY) != 0) {
 318                 sbuf_printf(sb, "%s<access>%s</access>\n", indent,
 319                     "write-only");
 320         } else {
 321                 sbuf_printf(sb, "%s<access>%s</access>\n", indent,
 322                     "read-write");
 323         }
 324         sbuf_printf(sb, "%s<timeout>%u</timeout>\n", indent, sc->sc_timeout);
 325         sbuf_printf(sb, "%s<info>%s</info>\n", indent, sc->sc_info);
 326         sbuf_printf(sb, "%s<queue_count>%u</queue_count>\n", indent,
 327             sc->sc_queue_count);
 328         sbuf_printf(sb, "%s<queue_size>%u</queue_size>\n", indent,
 329             sc->sc_queue_size);
 330         sbuf_printf(sb, "%s<ref>%u</ref>\n", indent, sc->sc_ref);
 331         g_topology_unlock();
 332         g_gate_release(sc);
 333         g_topology_lock();
 334 }
 335
 336 static int
 337 g_gate_create(struct g_gate_ctl_create *ggio)
 338 {
 339         struct g_gate_softc *sc;
 340         struct g_geom *gp;
 341         struct g_provider *pp;
 342
 343         if (ggio->gctl_mediasize == 0) {
 344                 G_GATE_DEBUG(1, "Invalid media size.");
 345                 return (EINVAL);
 346         }
 347         if (ggio->gctl_sectorsize > 0 && !powerof2(ggio->gctl_sectorsize)) {
 348                 G_GATE_DEBUG(1, "Invalid sector size.");
 349                 return (EINVAL);
 350         }
 351         if ((ggio->gctl_mediasize % ggio->gctl_sectorsize) != 0) {
 352                 G_GATE_DEBUG(1, "Invalid media size.");
 353                 return (EINVAL);
 354         }
 355         if ((ggio->gctl_flags & G_GATE_FLAG_READONLY) != 0 &&
 356             (ggio->gctl_flags & G_GATE_FLAG_WRITEONLY) != 0) {
 357                 G_GATE_DEBUG(1, "Invalid flags.");
 358                 return (EINVAL);
 359         }
 360         if (ggio->gctl_unit < -1) {
 361                 G_GATE_DEBUG(1, "Invalid unit number.");
 362                 return (EINVAL);
 363         }
 364
 365         sc = malloc(sizeof(*sc), M_GATE, M_WAITOK | M_ZERO);
 366         sc->sc_flags = (ggio->gctl_flags & G_GATE_USERFLAGS);
 367         strlcpy(sc->sc_info, ggio->gctl_info, sizeof(sc->sc_info));
 368         sc->sc_seq = 0;
 369         bioq_init(&sc->sc_inqueue);
 370         bioq_init(&sc->sc_outqueue);
 371         mtx_init(&sc->sc_queue_mtx, "gg:queue", NULL, MTX_DEF);
 372         sc->sc_queue_count = 0;
 373         sc->sc_queue_size = ggio->gctl_maxcount;
 374         if (sc->sc_queue_size > G_GATE_MAX_QUEUE_SIZE)
 375                 sc->sc_queue_size = G_GATE_MAX_QUEUE_SIZE;
 376         sc->sc_timeout = ggio->gctl_timeout;
 377         callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
 378         mtx_lock(&g_gate_list_mtx);
 379         ggio->gctl_unit = g_gate_getunit(ggio->gctl_unit);
 380         if (ggio->gctl_unit == -1) {
 381                 mtx_unlock(&g_gate_list_mtx);
 382                 mtx_destroy(&sc->sc_queue_mtx);
 383                 free(sc, M_GATE);
 384                 return (EBUSY);
 385         }
 386         sc->sc_unit = ggio->gctl_unit;
 387         LIST_INSERT_HEAD(&g_gate_list, sc, sc_next);
 388         mtx_unlock(&g_gate_list_mtx);
 389
 390         g_topology_lock();
 391         gp = g_new_geomf(&g_gate_class, "%s%d", G_GATE_PROVIDER_NAME,
 392             sc->sc_unit);
 393         gp->start = g_gate_start;
 394         gp->access = g_gate_access;
 395         gp->dumpconf = g_gate_dumpconf;
 396         gp->softc = sc;
 397         pp = g_new_providerf(gp, "%s%d", G_GATE_PROVIDER_NAME, sc->sc_unit);
 398         pp->mediasize = ggio->gctl_mediasize;
 399         pp->sectorsize = ggio->gctl_sectorsize;
 400         sc->sc_provider = pp;
 401         g_error_provider(pp, 0);
 402         g_topology_unlock();
 403
 404         if (sc->sc_timeout > 0) {
 405                 callout_reset(&sc->sc_callout, sc->sc_timeout * hz,
 406                     g_gate_guard, sc);
 407         }
 408         return (0);
 409 }
 410
 411 #define G_GATE_CHECK_VERSION(ggio)      do {                            \
 412         if ((ggio)->gctl_version != G_GATE_VERSION) {                   \
 413                 printf("Version mismatch %d != %d.\n",                  \
 414                     ggio->gctl_version, G_GATE_VERSION);                \
 415                 return (EINVAL);                                        \
 416         }                                                               \
 417 } while (0)
 418 static int
 419 g_gate_ioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
 420 {
 421         struct g_gate_softc *sc;
 422         struct bio *bp;
 423         int error = 0;
 424
 425         G_GATE_DEBUG(4, "ioctl(%s, %lx, %p, %x, %p)", devtoname(dev), cmd, addr,
 426             flags, td);
 427
 428         switch (cmd) {
 429         case G_GATE_CMD_CREATE:
 430             {
 431                 struct g_gate_ctl_create *ggio = (void *)addr;
 432
 433                 G_GATE_CHECK_VERSION(ggio);
 434                 error = g_gate_create(ggio);
 435                 /*
 436                  * Reset TDP_GEOM flag.
 437                  * There are pending events for sure, because we just created
 438                  * new provider and other classes want to taste it, but we
 439                  * cannot answer on I/O requests until we're here.
 440                  */
 441                 td->td_pflags &= ~TDP_GEOM;
 442                 return (error);
 443             }
 444         case G_GATE_CMD_DESTROY:
 445             {
 446                 struct g_gate_ctl_destroy *ggio = (void *)addr;
 447
 448                 G_GATE_CHECK_VERSION(ggio);
 449                 sc = g_gate_hold(ggio->gctl_unit);
 450                 if (sc == NULL)
 451                         return (ENXIO);
 452                 g_topology_lock();
 453                 mtx_lock(&g_gate_list_mtx);
 454                 error = g_gate_destroy(sc, ggio->gctl_force);
 455                 g_topology_unlock();
 456                 if (error != 0)
 457                         g_gate_release(sc);
 458                 return (error);
 459             }
 460         case G_GATE_CMD_CANCEL:
 461             {
 462                 struct g_gate_ctl_cancel *ggio = (void *)addr;
 463                 struct bio *tbp, *lbp;
 464
 465                 G_GATE_CHECK_VERSION(ggio);
 466                 sc = g_gate_hold(ggio->gctl_unit);
 467                 if (sc == NULL)
 468                         return (ENXIO);
 469                 lbp = NULL;
 470                 mtx_lock(&sc->sc_queue_mtx);
 471                 TAILQ_FOREACH_SAFE(bp, &sc->sc_outqueue.queue, bio_queue, tbp) {
 472                         if (ggio->gctl_seq == 0 ||
 473                             ggio->gctl_seq == (uintptr_t)bp->bio_driver1) {
 474                                 G_GATE_LOGREQ(1, bp, "Request canceled.");
 475                                 bioq_remove(&sc->sc_outqueue, bp);
 476                                 /*
 477                                  * Be sure to put requests back onto incoming
 478                                  * queue in the proper order.
 479                                  */
 480                                 if (lbp == NULL)
 481                                         bioq_insert_head(&sc->sc_inqueue, bp);
 482                                 else {
 483                                         TAILQ_INSERT_AFTER(&sc->sc_inqueue.queue,
 484                                             lbp, bp, bio_queue);
 485                                 }
 486                                 lbp = bp;
 487                                 /*
 488                                  * If only one request was canceled, leave now.
 489                                  */
 490                                 if (ggio->gctl_seq != 0)
 491                                         break;
 492                         }
 493                 }
 494                 mtx_unlock(&sc->sc_queue_mtx);
 495                 g_gate_release(sc);
 496                 return (error);
 497             }
 498         case G_GATE_CMD_START:
 499             {
 500                 struct g_gate_ctl_io *ggio = (void *)addr;
 501
 502                 G_GATE_CHECK_VERSION(ggio);
 503                 sc = g_gate_hold(ggio->gctl_unit);
 504                 if (sc == NULL)
 505                         return (ENXIO);
 506                 error = 0;
 507                 for (;;) {
 508                         mtx_lock(&sc->sc_queue_mtx);
 509                         bp = bioq_first(&sc->sc_inqueue);
 510                         if (bp != NULL)
 511                                 break;
 512                         if ((sc->sc_flags & G_GATE_FLAG_DESTROY) != 0) {
 513                                 ggio->gctl_error = ECANCELED;
 514                                 mtx_unlock(&sc->sc_queue_mtx);
 515                                 goto start_end;
 516                         }
 517                         if (msleep(sc, &sc->sc_queue_mtx,
 518                             PPAUSE | PDROP | PCATCH, "ggwait", 0) != 0) {
 519                                 ggio->gctl_error = ECANCELED;
 520                                 goto start_end;
 521                         }
 522                 }
 523                 ggio->gctl_cmd = bp->bio_cmd;
 524                 if ((bp->bio_cmd == BIO_DELETE || bp->bio_cmd == BIO_WRITE) &&
 525                     bp->bio_length > ggio->gctl_length) {
 526                         mtx_unlock(&sc->sc_queue_mtx);
 527                         ggio->gctl_length = bp->bio_length;
 528                         ggio->gctl_error = ENOMEM;
 529                         goto start_end;
 530                 }
 531                 bioq_remove(&sc->sc_inqueue, bp);
 532                 bioq_insert_tail(&sc->sc_outqueue, bp);
 533                 mtx_unlock(&sc->sc_queue_mtx);
 534
 535                 ggio->gctl_seq = (uintptr_t)bp->bio_driver1;
 536                 ggio->gctl_offset = bp->bio_offset;
 537                 ggio->gctl_length = bp->bio_length;
 538
 539                 switch (bp->bio_cmd) {
 540                 case BIO_READ:
 541                         break;
 542                 case BIO_DELETE:
 543                 case BIO_WRITE:
 544                         error = copyout(bp->bio_data, ggio->gctl_data,
 545                             bp->bio_length);
 546                         if (error != 0) {
 547                                 mtx_lock(&sc->sc_queue_mtx);
 548                                 bioq_remove(&sc->sc_outqueue, bp);
 549                                 bioq_insert_head(&sc->sc_inqueue, bp);
 550                                 mtx_unlock(&sc->sc_queue_mtx);
 551                                 goto start_end;
 552                         }
 553                         break;
 554                 }
 555 start_end:
 556                 g_gate_release(sc);
 557                 return (error);
 558             }
 559         case G_GATE_CMD_DONE:
 560             {
 561                 struct g_gate_ctl_io *ggio = (void *)addr;
 562
 563                 G_GATE_CHECK_VERSION(ggio);
 564                 sc = g_gate_hold(ggio->gctl_unit);
 565                 if (sc == NULL)
 566                         return (ENOENT);
 567                 error = 0;
 568                 mtx_lock(&sc->sc_queue_mtx);
 569                 TAILQ_FOREACH(bp, &sc->sc_outqueue.queue, bio_queue) {
 570                         if (ggio->gctl_seq == (uintptr_t)bp->bio_driver1)
 571                                 break;
 572                 }
 573                 if (bp != NULL) {
 574                         bioq_remove(&sc->sc_outqueue, bp);
 575                         sc->sc_queue_count--;
 576                 }
 577                 mtx_unlock(&sc->sc_queue_mtx);
 578                 if (bp == NULL) {
 579                         /*
 580                          * Request was probably canceled.
 581                          */
 582                         goto done_end;
 583                 }
 584                 if (ggio->gctl_error == EAGAIN) {
 585                         bp->bio_error = 0;
 586                         G_GATE_LOGREQ(1, bp, "Request desisted.");
 587                         mtx_lock(&sc->sc_queue_mtx);
 588                         sc->sc_queue_count++;
 589                         bioq_insert_head(&sc->sc_inqueue, bp);
 590                         wakeup(sc);
 591                         mtx_unlock(&sc->sc_queue_mtx);
 592                 } else {
 593                         bp->bio_error = ggio->gctl_error;
 594                         if (bp->bio_error == 0) {
 595                                 bp->bio_completed = bp->bio_length;
 596                                 switch (bp->bio_cmd) {
 597                                 case BIO_READ:
 598                                         error = copyin(ggio->gctl_data,
 599                                             bp->bio_data, bp->bio_length);
 600                                         if (error != 0)
 601                                                 bp->bio_error = error;
 602                                         break;
 603                                 case BIO_DELETE:
 604                                 case BIO_WRITE:
 605                                         break;
 606                                 }
 607                         }
 608                         G_GATE_LOGREQ(2, bp, "Request done.");
 609                         g_io_deliver(bp, bp->bio_error);
 610                 }
 611 done_end:
 612                 g_gate_release(sc);
 613                 return (error);
 614             }
 615         }
 616         return (ENOIOCTL);
 617 }
 618
 619 static void
 620 g_gate_device(void)
 621 {
 622
 623         status_dev = make_dev(&g_gate_cdevsw, 0x0, UID_ROOT, GID_WHEEL, 0600,
 624             G_GATE_CTL_NAME);
 625 }
 626
 627 static int
 628 g_gate_modevent(module_t mod, int type, void *data)
 629 {
 630         int error = 0;
 631
 632         switch (type) {
 633         case MOD_LOAD:
 634                 mtx_init(&g_gate_list_mtx, "gg_list_lock", NULL, MTX_DEF);
 635                 g_gate_device();
 636                 break;
 637         case MOD_UNLOAD:
 638                 mtx_lock(&g_gate_list_mtx);
 639                 if (!LIST_EMPTY(&g_gate_list)) {
 640                         mtx_unlock(&g_gate_list_mtx);
 641                         error = EBUSY;
 642                         break;
 643                 }
 644                 mtx_unlock(&g_gate_list_mtx);
 645                 mtx_destroy(&g_gate_list_mtx);
 646                 if (status_dev != 0)
 647                         destroy_dev(status_dev);
 648                 break;
 649         default:
 650                 return (EOPNOTSUPP);
 651                 break;
 652         }
 653
 654         return (error);
 655 }
 656 static moduledata_t g_gate_module = {
 657         G_GATE_MOD_NAME,
 658         g_gate_modevent,
 659         NULL
 660 };
 661 DECLARE_MODULE(geom_gate, g_gate_module, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
 662 DECLARE_GEOM_CLASS(g_gate_class, g_gate);