sys/geom/mirror/g_mirror.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/fail.h>
  33 #include <sys/kernel.h>
  34 #include <sys/module.h>
  35 #include <sys/limits.h>
  36 #include <sys/lock.h>
  37 #include <sys/mutex.h>
  38 #include <sys/bio.h>
  39 #include <sys/sbuf.h>
  40 #include <sys/sysctl.h>
  41 #include <sys/malloc.h>
  42 #include <sys/eventhandler.h>
  43 #include <vm/uma.h>
  44 #include <geom/geom.h>
  45 #include <sys/proc.h>
  46 #include <sys/kthread.h>
  47 #include <sys/sched.h>
  48 #include <geom/mirror/g_mirror.h>
  49
  50 FEATURE(geom_mirror, "GEOM mirroring support");
  51
  52 static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
  53
  54 SYSCTL_DECL(_kern_geom);
  55 static SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW, 0,
  56     "GEOM_MIRROR stuff");
  57 u_int g_mirror_debug = 0;
  58 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RWTUN, &g_mirror_debug, 0,
  59     "Debug level");
  60 static u_int g_mirror_timeout = 4;
  61 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RWTUN, &g_mirror_timeout,
  62     0, "Time to wait on all mirror components");
  63 static u_int g_mirror_idletime = 5;
  64 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RWTUN,
  65     &g_mirror_idletime, 0, "Mark components as clean when idling");
  66 static u_int g_mirror_disconnect_on_failure = 1;
  67 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RWTUN,
  68     &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
  69 static u_int g_mirror_syncreqs = 2;
  70 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
  71     &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
  72
  73 #define MSLEEP(ident, mtx, priority, wmesg, timeout)    do {            \
  74         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));       \
  75         msleep((ident), (mtx), (priority), (wmesg), (timeout));         \
  76         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));       \
  77 } while (0)
  78
  79 static eventhandler_tag g_mirror_post_sync = NULL;
  80 static int g_mirror_shutdown = 0;
  81
  82 static g_ctl_destroy_geom_t g_mirror_destroy_geom;
  83 static g_taste_t g_mirror_taste;
  84 static g_init_t g_mirror_init;
  85 static g_fini_t g_mirror_fini;
  86 static g_provgone_t g_mirror_providergone;
  87 static g_resize_t g_mirror_resize;
  88
  89 struct g_class g_mirror_class = {
  90         .name = G_MIRROR_CLASS_NAME,
  91         .version = G_VERSION,
  92         .ctlreq = g_mirror_config,
  93         .taste = g_mirror_taste,
  94         .destroy_geom = g_mirror_destroy_geom,
  95         .init = g_mirror_init,
  96         .fini = g_mirror_fini,
  97         .providergone = g_mirror_providergone,
  98         .resize = g_mirror_resize
  99 };
 100
 101
 102 static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
 103 static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
 104 static void g_mirror_update_device(struct g_mirror_softc *sc, bool force);
 105 static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
 106     struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
 107 static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
 108 static void g_mirror_register_request(struct bio *bp);
 109 static void g_mirror_sync_release(struct g_mirror_softc *sc);
 110
 111
 112 static const char *
 113 g_mirror_disk_state2str(int state)
 114 {
 115
 116         switch (state) {
 117         case G_MIRROR_DISK_STATE_NONE:
 118                 return ("NONE");
 119         case G_MIRROR_DISK_STATE_NEW:
 120                 return ("NEW");
 121         case G_MIRROR_DISK_STATE_ACTIVE:
 122                 return ("ACTIVE");
 123         case G_MIRROR_DISK_STATE_STALE:
 124                 return ("STALE");
 125         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 126                 return ("SYNCHRONIZING");
 127         case G_MIRROR_DISK_STATE_DISCONNECTED:
 128                 return ("DISCONNECTED");
 129         case G_MIRROR_DISK_STATE_DESTROY:
 130                 return ("DESTROY");
 131         default:
 132                 return ("INVALID");
 133         }
 134 }
 135
 136 static const char *
 137 g_mirror_device_state2str(int state)
 138 {
 139
 140         switch (state) {
 141         case G_MIRROR_DEVICE_STATE_STARTING:
 142                 return ("STARTING");
 143         case G_MIRROR_DEVICE_STATE_RUNNING:
 144                 return ("RUNNING");
 145         default:
 146                 return ("INVALID");
 147         }
 148 }
 149
 150 static const char *
 151 g_mirror_get_diskname(struct g_mirror_disk *disk)
 152 {
 153
 154         if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
 155                 return ("[unknown]");
 156         return (disk->d_name);
 157 }
 158
 159 /*
 160  * --- Events handling functions ---
 161  * Events in geom_mirror are used to maintain disks and device status
 162  * from one thread to simplify locking.
 163  */
 164 static void
 165 g_mirror_event_free(struct g_mirror_event *ep)
 166 {
 167
 168         free(ep, M_MIRROR);
 169 }
 170
 171 int
 172 g_mirror_event_send(void *arg, int state, int flags)
 173 {
 174         struct g_mirror_softc *sc;
 175         struct g_mirror_disk *disk;
 176         struct g_mirror_event *ep;
 177         int error;
 178
 179         ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
 180         G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
 181         if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
 182                 disk = NULL;
 183                 sc = arg;
 184         } else {
 185                 disk = arg;
 186                 sc = disk->d_softc;
 187         }
 188         ep->e_disk = disk;
 189         ep->e_state = state;
 190         ep->e_flags = flags;
 191         ep->e_error = 0;
 192         mtx_lock(&sc->sc_events_mtx);
 193         TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
 194         mtx_unlock(&sc->sc_events_mtx);
 195         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 196         mtx_lock(&sc->sc_queue_mtx);
 197         wakeup(sc);
 198         mtx_unlock(&sc->sc_queue_mtx);
 199         if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 200                 return (0);
 201         sx_assert(&sc->sc_lock, SX_XLOCKED);
 202         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
 203         sx_xunlock(&sc->sc_lock);
 204         while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
 205                 mtx_lock(&sc->sc_events_mtx);
 206                 MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
 207                     hz * 5);
 208         }
 209         error = ep->e_error;
 210         g_mirror_event_free(ep);
 211         sx_xlock(&sc->sc_lock);
 212         return (error);
 213 }
 214
 215 static struct g_mirror_event *
 216 g_mirror_event_get(struct g_mirror_softc *sc)
 217 {
 218         struct g_mirror_event *ep;
 219
 220         mtx_lock(&sc->sc_events_mtx);
 221         ep = TAILQ_FIRST(&sc->sc_events);
 222         mtx_unlock(&sc->sc_events_mtx);
 223         return (ep);
 224 }
 225
 226 static void
 227 g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
 228 {
 229
 230         mtx_lock(&sc->sc_events_mtx);
 231         TAILQ_REMOVE(&sc->sc_events, ep, e_next);
 232         mtx_unlock(&sc->sc_events_mtx);
 233 }
 234
 235 static void
 236 g_mirror_event_cancel(struct g_mirror_disk *disk)
 237 {
 238         struct g_mirror_softc *sc;
 239         struct g_mirror_event *ep, *tmpep;
 240
 241         sc = disk->d_softc;
 242         sx_assert(&sc->sc_lock, SX_XLOCKED);
 243
 244         mtx_lock(&sc->sc_events_mtx);
 245         TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
 246                 if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
 247                         continue;
 248                 if (ep->e_disk != disk)
 249                         continue;
 250                 TAILQ_REMOVE(&sc->sc_events, ep, e_next);
 251                 if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 252                         g_mirror_event_free(ep);
 253                 else {
 254                         ep->e_error = ECANCELED;
 255                         wakeup(ep);
 256                 }
 257         }
 258         mtx_unlock(&sc->sc_events_mtx);
 259 }
 260
 261 /*
 262  * Return the number of disks in given state.
 263  * If state is equal to -1, count all connected disks.
 264  */
 265 u_int
 266 g_mirror_ndisks(struct g_mirror_softc *sc, int state)
 267 {
 268         struct g_mirror_disk *disk;
 269         u_int n = 0;
 270
 271         sx_assert(&sc->sc_lock, SX_LOCKED);
 272
 273         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 274                 if (state == -1 || disk->d_state == state)
 275                         n++;
 276         }
 277         return (n);
 278 }
 279
 280 /*
 281  * Find a disk in mirror by its disk ID.
 282  */
 283 static struct g_mirror_disk *
 284 g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
 285 {
 286         struct g_mirror_disk *disk;
 287
 288         sx_assert(&sc->sc_lock, SX_XLOCKED);
 289
 290         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 291                 if (disk->d_id == id)
 292                         return (disk);
 293         }
 294         return (NULL);
 295 }
 296
 297 static u_int
 298 g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
 299 {
 300         struct bio *bp;
 301         u_int nreqs = 0;
 302
 303         mtx_lock(&sc->sc_queue_mtx);
 304         TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
 305                 if (bp->bio_from == cp)
 306                         nreqs++;
 307         }
 308         mtx_unlock(&sc->sc_queue_mtx);
 309         return (nreqs);
 310 }
 311
 312 static int
 313 g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
 314 {
 315
 316         if (cp->index > 0) {
 317                 G_MIRROR_DEBUG(2,
 318                     "I/O requests for %s exist, can't destroy it now.",
 319                     cp->provider->name);
 320                 return (1);
 321         }
 322         if (g_mirror_nrequests(sc, cp) > 0) {
 323                 G_MIRROR_DEBUG(2,
 324                     "I/O requests for %s in queue, can't destroy it now.",
 325                     cp->provider->name);
 326                 return (1);
 327         }
 328         return (0);
 329 }
 330
 331 static void
 332 g_mirror_destroy_consumer(void *arg, int flags __unused)
 333 {
 334         struct g_consumer *cp;
 335
 336         g_topology_assert();
 337
 338         cp = arg;
 339         G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
 340         g_detach(cp);
 341         g_destroy_consumer(cp);
 342 }
 343
 344 static void
 345 g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
 346 {
 347         struct g_provider *pp;
 348         int retaste_wait;
 349
 350         g_topology_assert();
 351
 352         cp->private = NULL;
 353         if (g_mirror_is_busy(sc, cp))
 354                 return;
 355         pp = cp->provider;
 356         retaste_wait = 0;
 357         if (cp->acw == 1) {
 358                 if ((pp->geom->flags & G_GEOM_WITHER) == 0)
 359                         retaste_wait = 1;
 360         }
 361         G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
 362             -cp->acw, -cp->ace, 0);
 363         if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
 364                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
 365         if (retaste_wait) {
 366                 /*
 367                  * After retaste event was send (inside g_access()), we can send
 368                  * event to detach and destroy consumer.
 369                  * A class, which has consumer to the given provider connected
 370                  * will not receive retaste event for the provider.
 371                  * This is the way how I ignore retaste events when I close
 372                  * consumers opened for write: I detach and destroy consumer
 373                  * after retaste event is sent.
 374                  */
 375                 g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
 376                 return;
 377         }
 378         G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
 379         g_detach(cp);
 380         g_destroy_consumer(cp);
 381 }
 382
 383 static int
 384 g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
 385 {
 386         struct g_consumer *cp;
 387         int error;
 388
 389         g_topology_assert_not();
 390         KASSERT(disk->d_consumer == NULL,
 391             ("Disk already connected (device %s).", disk->d_softc->sc_name));
 392
 393         g_topology_lock();
 394         cp = g_new_consumer(disk->d_softc->sc_geom);
 395         cp->flags |= G_CF_DIRECT_RECEIVE;
 396         error = g_attach(cp, pp);
 397         if (error != 0) {
 398                 g_destroy_consumer(cp);
 399                 g_topology_unlock();
 400                 return (error);
 401         }
 402         error = g_access(cp, 1, 1, 1);
 403         if (error != 0) {
 404                 g_detach(cp);
 405                 g_destroy_consumer(cp);
 406                 g_topology_unlock();
 407                 G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
 408                     pp->name, error);
 409                 return (error);
 410         }
 411         g_topology_unlock();
 412         disk->d_consumer = cp;
 413         disk->d_consumer->private = disk;
 414         disk->d_consumer->index = 0;
 415
 416         G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
 417         return (0);
 418 }
 419
 420 static void
 421 g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
 422 {
 423
 424         g_topology_assert();
 425
 426         if (cp == NULL)
 427                 return;
 428         if (cp->provider != NULL)
 429                 g_mirror_kill_consumer(sc, cp);
 430         else
 431                 g_destroy_consumer(cp);
 432 }
 433
 434 /*
 435  * Initialize disk. This means allocate memory, create consumer, attach it
 436  * to the provider and open access (r1w1e1) to it.
 437  */
 438 static struct g_mirror_disk *
 439 g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
 440     struct g_mirror_metadata *md, int *errorp)
 441 {
 442         struct g_mirror_disk *disk;
 443         int i, error;
 444
 445         disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
 446         if (disk == NULL) {
 447                 error = ENOMEM;
 448                 goto fail;
 449         }
 450         disk->d_softc = sc;
 451         error = g_mirror_connect_disk(disk, pp);
 452         if (error != 0)
 453                 goto fail;
 454         disk->d_id = md->md_did;
 455         disk->d_state = G_MIRROR_DISK_STATE_NONE;
 456         disk->d_priority = md->md_priority;
 457         disk->d_flags = md->md_dflags;
 458         error = g_getattr("GEOM::candelete", disk->d_consumer, &i);
 459         if (error == 0 && i != 0)
 460                 disk->d_flags |= G_MIRROR_DISK_FLAG_CANDELETE;
 461         if (md->md_provider[0] != '\0')
 462                 disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
 463         disk->d_sync.ds_consumer = NULL;
 464         disk->d_sync.ds_offset = md->md_sync_offset;
 465         disk->d_sync.ds_offset_done = md->md_sync_offset;
 466         disk->d_genid = md->md_genid;
 467         disk->d_sync.ds_syncid = md->md_syncid;
 468         if (errorp != NULL)
 469                 *errorp = 0;
 470         return (disk);
 471 fail:
 472         if (errorp != NULL)
 473                 *errorp = error;
 474         if (disk != NULL)
 475                 free(disk, M_MIRROR);
 476         return (NULL);
 477 }
 478
 479 static void
 480 g_mirror_destroy_disk(struct g_mirror_disk *disk)
 481 {
 482         struct g_mirror_softc *sc;
 483
 484         g_topology_assert_not();
 485         sc = disk->d_softc;
 486         sx_assert(&sc->sc_lock, SX_XLOCKED);
 487
 488         LIST_REMOVE(disk, d_next);
 489         g_mirror_event_cancel(disk);
 490         if (sc->sc_hint == disk)
 491                 sc->sc_hint = NULL;
 492         switch (disk->d_state) {
 493         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 494                 g_mirror_sync_stop(disk, 1);
 495                 /* FALLTHROUGH */
 496         case G_MIRROR_DISK_STATE_NEW:
 497         case G_MIRROR_DISK_STATE_STALE:
 498         case G_MIRROR_DISK_STATE_ACTIVE:
 499                 g_topology_lock();
 500                 g_mirror_disconnect_consumer(sc, disk->d_consumer);
 501                 g_topology_unlock();
 502                 free(disk, M_MIRROR);
 503                 break;
 504         default:
 505                 KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
 506                     g_mirror_get_diskname(disk),
 507                     g_mirror_disk_state2str(disk->d_state)));
 508         }
 509 }
 510
 511 static void
 512 g_mirror_free_device(struct g_mirror_softc *sc)
 513 {
 514
 515         mtx_destroy(&sc->sc_queue_mtx);
 516         mtx_destroy(&sc->sc_events_mtx);
 517         mtx_destroy(&sc->sc_done_mtx);
 518         sx_destroy(&sc->sc_lock);
 519         free(sc, M_MIRROR);
 520 }
 521
 522 static void
 523 g_mirror_providergone(struct g_provider *pp)
 524 {
 525         struct g_mirror_softc *sc = pp->private;
 526
 527         if ((--sc->sc_refcnt) == 0)
 528                 g_mirror_free_device(sc);
 529 }
 530
 531 static void
 532 g_mirror_destroy_device(struct g_mirror_softc *sc)
 533 {
 534         struct g_mirror_disk *disk;
 535         struct g_mirror_event *ep;
 536         struct g_geom *gp;
 537         struct g_consumer *cp, *tmpcp;
 538
 539         g_topology_assert_not();
 540         sx_assert(&sc->sc_lock, SX_XLOCKED);
 541
 542         gp = sc->sc_geom;
 543         if (sc->sc_provider != NULL)
 544                 g_mirror_destroy_provider(sc);
 545         for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
 546             disk = LIST_FIRST(&sc->sc_disks)) {
 547                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 548                 g_mirror_update_metadata(disk);
 549                 g_mirror_destroy_disk(disk);
 550         }
 551         while ((ep = g_mirror_event_get(sc)) != NULL) {
 552                 g_mirror_event_remove(sc, ep);
 553                 if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 554                         g_mirror_event_free(ep);
 555                 else {
 556                         ep->e_error = ECANCELED;
 557                         ep->e_flags |= G_MIRROR_EVENT_DONE;
 558                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
 559                         mtx_lock(&sc->sc_events_mtx);
 560                         wakeup(ep);
 561                         mtx_unlock(&sc->sc_events_mtx);
 562                 }
 563         }
 564         callout_drain(&sc->sc_callout);
 565
 566         g_topology_lock();
 567         LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
 568                 g_mirror_disconnect_consumer(sc, cp);
 569         }
 570         g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
 571         G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
 572         g_wither_geom(gp, ENXIO);
 573         sx_xunlock(&sc->sc_lock);
 574         if ((--sc->sc_refcnt) == 0)
 575                 g_mirror_free_device(sc);
 576         g_topology_unlock();
 577 }
 578
 579 static void
 580 g_mirror_orphan(struct g_consumer *cp)
 581 {
 582         struct g_mirror_disk *disk;
 583
 584         g_topology_assert();
 585
 586         disk = cp->private;
 587         if (disk == NULL)
 588                 return;
 589         disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 590         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
 591             G_MIRROR_EVENT_DONTWAIT);
 592 }
 593
 594 /*
 595  * Function should return the next active disk on the list.
 596  * It is possible that it will be the same disk as given.
 597  * If there are no active disks on list, NULL is returned.
 598  */
 599 static __inline struct g_mirror_disk *
 600 g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
 601 {
 602         struct g_mirror_disk *dp;
 603
 604         for (dp = LIST_NEXT(disk, d_next); dp != disk;
 605             dp = LIST_NEXT(dp, d_next)) {
 606                 if (dp == NULL)
 607                         dp = LIST_FIRST(&sc->sc_disks);
 608                 if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
 609                         break;
 610         }
 611         if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 612                 return (NULL);
 613         return (dp);
 614 }
 615
 616 static struct g_mirror_disk *
 617 g_mirror_get_disk(struct g_mirror_softc *sc)
 618 {
 619         struct g_mirror_disk *disk;
 620
 621         if (sc->sc_hint == NULL) {
 622                 sc->sc_hint = LIST_FIRST(&sc->sc_disks);
 623                 if (sc->sc_hint == NULL)
 624                         return (NULL);
 625         }
 626         disk = sc->sc_hint;
 627         if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
 628                 disk = g_mirror_find_next(sc, disk);
 629                 if (disk == NULL)
 630                         return (NULL);
 631         }
 632         sc->sc_hint = g_mirror_find_next(sc, disk);
 633         return (disk);
 634 }
 635
 636 static int
 637 g_mirror_write_metadata(struct g_mirror_disk *disk,
 638     struct g_mirror_metadata *md)
 639 {
 640         struct g_mirror_softc *sc;
 641         struct g_consumer *cp;
 642         off_t offset, length;
 643         u_char *sector;
 644         int error = 0;
 645
 646         g_topology_assert_not();
 647         sc = disk->d_softc;
 648         sx_assert(&sc->sc_lock, SX_LOCKED);
 649
 650         cp = disk->d_consumer;
 651         KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
 652         KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
 653         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 654             ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
 655             cp->acw, cp->ace));
 656         length = cp->provider->sectorsize;
 657         offset = cp->provider->mediasize - length;
 658         sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
 659         if (md != NULL &&
 660             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0) {
 661                 /*
 662                  * Handle the case, when the size of parent provider reduced.
 663                  */
 664                 if (offset < md->md_mediasize)
 665                         error = ENOSPC;
 666                 else
 667                         mirror_metadata_encode(md, sector);
 668         }
 669         KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_metadata_write, error);
 670         if (error == 0)
 671                 error = g_write_data(cp, offset, sector, length);
 672         free(sector, M_MIRROR);
 673         if (error != 0) {
 674                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
 675                         disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
 676                         G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
 677                             "(device=%s, error=%d).",
 678                             g_mirror_get_diskname(disk), sc->sc_name, error);
 679                 } else {
 680                         G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
 681                             "(device=%s, error=%d).",
 682                             g_mirror_get_diskname(disk), sc->sc_name, error);
 683                 }
 684                 if (g_mirror_disconnect_on_failure &&
 685                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
 686                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 687                         g_mirror_event_send(disk,
 688                             G_MIRROR_DISK_STATE_DISCONNECTED,
 689                             G_MIRROR_EVENT_DONTWAIT);
 690                 }
 691         }
 692         return (error);
 693 }
 694
 695 static int
 696 g_mirror_clear_metadata(struct g_mirror_disk *disk)
 697 {
 698         int error;
 699
 700         g_topology_assert_not();
 701         sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
 702
 703         if (disk->d_softc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
 704                 return (0);
 705         error = g_mirror_write_metadata(disk, NULL);
 706         if (error == 0) {
 707                 G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
 708                     g_mirror_get_diskname(disk));
 709         } else {
 710                 G_MIRROR_DEBUG(0,
 711                     "Cannot clear metadata on disk %s (error=%d).",
 712                     g_mirror_get_diskname(disk), error);
 713         }
 714         return (error);
 715 }
 716
 717 void
 718 g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
 719     struct g_mirror_metadata *md)
 720 {
 721
 722         strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
 723         md->md_version = G_MIRROR_VERSION;
 724         strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
 725         md->md_mid = sc->sc_id;
 726         md->md_all = sc->sc_ndisks;
 727         md->md_slice = sc->sc_slice;
 728         md->md_balance = sc->sc_balance;
 729         md->md_genid = sc->sc_genid;
 730         md->md_mediasize = sc->sc_mediasize;
 731         md->md_sectorsize = sc->sc_sectorsize;
 732         md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
 733         bzero(md->md_provider, sizeof(md->md_provider));
 734         if (disk == NULL) {
 735                 md->md_did = arc4random();
 736                 md->md_priority = 0;
 737                 md->md_syncid = 0;
 738                 md->md_dflags = 0;
 739                 md->md_sync_offset = 0;
 740                 md->md_provsize = 0;
 741         } else {
 742                 md->md_did = disk->d_id;
 743                 md->md_priority = disk->d_priority;
 744                 md->md_syncid = disk->d_sync.ds_syncid;
 745                 md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
 746                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
 747                         md->md_sync_offset = disk->d_sync.ds_offset_done;
 748                 else
 749                         md->md_sync_offset = 0;
 750                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
 751                         strlcpy(md->md_provider,
 752                             disk->d_consumer->provider->name,
 753                             sizeof(md->md_provider));
 754                 }
 755                 md->md_provsize = disk->d_consumer->provider->mediasize;
 756         }
 757 }
 758
 759 void
 760 g_mirror_update_metadata(struct g_mirror_disk *disk)
 761 {
 762         struct g_mirror_softc *sc;
 763         struct g_mirror_metadata md;
 764         int error;
 765
 766         g_topology_assert_not();
 767         sc = disk->d_softc;
 768         sx_assert(&sc->sc_lock, SX_LOCKED);
 769
 770         if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
 771                 return;
 772         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0)
 773                 g_mirror_fill_metadata(sc, disk, &md);
 774         error = g_mirror_write_metadata(disk, &md);
 775         if (error == 0) {
 776                 G_MIRROR_DEBUG(2, "Metadata on %s updated.",
 777                     g_mirror_get_diskname(disk));
 778         } else {
 779                 G_MIRROR_DEBUG(0,
 780                     "Cannot update metadata on disk %s (error=%d).",
 781                     g_mirror_get_diskname(disk), error);
 782         }
 783 }
 784
 785 static void
 786 g_mirror_bump_syncid(struct g_mirror_softc *sc)
 787 {
 788         struct g_mirror_disk *disk;
 789
 790         g_topology_assert_not();
 791         sx_assert(&sc->sc_lock, SX_XLOCKED);
 792         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
 793             ("%s called with no active disks (device=%s).", __func__,
 794             sc->sc_name));
 795
 796         sc->sc_syncid++;
 797         G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
 798             sc->sc_syncid);
 799         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 800                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 801                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 802                         disk->d_sync.ds_syncid = sc->sc_syncid;
 803                         g_mirror_update_metadata(disk);
 804                 }
 805         }
 806 }
 807
 808 static void
 809 g_mirror_bump_genid(struct g_mirror_softc *sc)
 810 {
 811         struct g_mirror_disk *disk;
 812
 813         g_topology_assert_not();
 814         sx_assert(&sc->sc_lock, SX_XLOCKED);
 815         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
 816             ("%s called with no active disks (device=%s).", __func__,
 817             sc->sc_name));
 818
 819         sc->sc_genid++;
 820         G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
 821             sc->sc_genid);
 822         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 823                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 824                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 825                         disk->d_genid = sc->sc_genid;
 826                         g_mirror_update_metadata(disk);
 827                 }
 828         }
 829 }
 830
 831 static int
 832 g_mirror_idle(struct g_mirror_softc *sc, int acw)
 833 {
 834         struct g_mirror_disk *disk;
 835         int timeout;
 836
 837         g_topology_assert_not();
 838         sx_assert(&sc->sc_lock, SX_XLOCKED);
 839
 840         if (sc->sc_provider == NULL)
 841                 return (0);
 842         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 843                 return (0);
 844         if (sc->sc_idle)
 845                 return (0);
 846         if (sc->sc_writes > 0)
 847                 return (0);
 848         if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
 849                 timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
 850                 if (!g_mirror_shutdown && timeout > 0)
 851                         return (timeout);
 852         }
 853         sc->sc_idle = 1;
 854         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 855                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 856                         continue;
 857                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
 858                     g_mirror_get_diskname(disk), sc->sc_name);
 859                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 860                 g_mirror_update_metadata(disk);
 861         }
 862         return (0);
 863 }
 864
 865 static void
 866 g_mirror_unidle(struct g_mirror_softc *sc)
 867 {
 868         struct g_mirror_disk *disk;
 869
 870         g_topology_assert_not();
 871         sx_assert(&sc->sc_lock, SX_XLOCKED);
 872
 873         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 874                 return;
 875         sc->sc_idle = 0;
 876         sc->sc_last_write = time_uptime;
 877         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 878                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 879                         continue;
 880                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
 881                     g_mirror_get_diskname(disk), sc->sc_name);
 882                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
 883                 g_mirror_update_metadata(disk);
 884         }
 885 }
 886
 887 static void
 888 g_mirror_flush_done(struct bio *bp)
 889 {
 890         struct g_mirror_softc *sc;
 891         struct bio *pbp;
 892
 893         pbp = bp->bio_parent;
 894         sc = pbp->bio_to->private;
 895         mtx_lock(&sc->sc_done_mtx);
 896         if (pbp->bio_error == 0)
 897                 pbp->bio_error = bp->bio_error;
 898         pbp->bio_completed += bp->bio_completed;
 899         pbp->bio_inbed++;
 900         if (pbp->bio_children == pbp->bio_inbed) {
 901                 mtx_unlock(&sc->sc_done_mtx);
 902                 g_io_deliver(pbp, pbp->bio_error);
 903         } else
 904                 mtx_unlock(&sc->sc_done_mtx);
 905         g_destroy_bio(bp);
 906 }
 907
 908 static void
 909 g_mirror_done(struct bio *bp)
 910 {
 911         struct g_mirror_softc *sc;
 912
 913         sc = bp->bio_from->geom->softc;
 914         bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
 915         mtx_lock(&sc->sc_queue_mtx);
 916         bioq_insert_tail(&sc->sc_queue, bp);
 917         mtx_unlock(&sc->sc_queue_mtx);
 918         wakeup(sc);
 919 }
 920
 921 static void
 922 g_mirror_regular_request(struct bio *bp)
 923 {
 924         struct g_mirror_softc *sc;
 925         struct g_mirror_disk *disk;
 926         struct bio *pbp;
 927
 928         g_topology_assert_not();
 929
 930         pbp = bp->bio_parent;
 931         sc = pbp->bio_to->private;
 932         bp->bio_from->index--;
 933         if (bp->bio_cmd == BIO_WRITE)
 934                 sc->sc_writes--;
 935         disk = bp->bio_from->private;
 936         if (disk == NULL) {
 937                 g_topology_lock();
 938                 g_mirror_kill_consumer(sc, bp->bio_from);
 939                 g_topology_unlock();
 940         }
 941
 942         if (bp->bio_cmd == BIO_READ)
 943                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_read,
 944                     bp->bio_error);
 945         else if (bp->bio_cmd == BIO_WRITE)
 946                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_write,
 947                     bp->bio_error);
 948
 949         pbp->bio_inbed++;
 950         KASSERT(pbp->bio_inbed <= pbp->bio_children,
 951             ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
 952             pbp->bio_children));
 953         if (bp->bio_error == 0 && pbp->bio_error == 0) {
 954                 G_MIRROR_LOGREQ(3, bp, "Request delivered.");
 955                 g_destroy_bio(bp);
 956                 if (pbp->bio_children == pbp->bio_inbed) {
 957                         G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
 958                         pbp->bio_completed = pbp->bio_length;
 959                         if (pbp->bio_cmd == BIO_WRITE ||
 960                             pbp->bio_cmd == BIO_DELETE) {
 961                                 bioq_remove(&sc->sc_inflight, pbp);
 962                                 /* Release delayed sync requests if possible. */
 963                                 g_mirror_sync_release(sc);
 964                         }
 965                         g_io_deliver(pbp, pbp->bio_error);
 966                 }
 967                 return;
 968         } else if (bp->bio_error != 0) {
 969                 if (pbp->bio_error == 0)
 970                         pbp->bio_error = bp->bio_error;
 971                 if (disk != NULL) {
 972                         if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
 973                                 disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
 974                                 G_MIRROR_LOGREQ(0, bp,
 975                                     "Request failed (error=%d).",
 976                                     bp->bio_error);
 977                         } else {
 978                                 G_MIRROR_LOGREQ(1, bp,
 979                                     "Request failed (error=%d).",
 980                                     bp->bio_error);
 981                         }
 982                         if (g_mirror_disconnect_on_failure &&
 983                             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1)
 984                         {
 985                                 sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 986                                 g_mirror_event_send(disk,
 987                                     G_MIRROR_DISK_STATE_DISCONNECTED,
 988                                     G_MIRROR_EVENT_DONTWAIT);
 989                         }
 990                 }
 991                 switch (pbp->bio_cmd) {
 992                 case BIO_DELETE:
 993                 case BIO_WRITE:
 994                         pbp->bio_inbed--;
 995                         pbp->bio_children--;
 996                         break;
 997                 }
 998         }
 999         g_destroy_bio(bp);
1000
1001         switch (pbp->bio_cmd) {
1002         case BIO_READ:
1003                 if (pbp->bio_inbed < pbp->bio_children)
1004                         break;
1005                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
1006                         g_io_deliver(pbp, pbp->bio_error);
1007                 else {
1008                         pbp->bio_error = 0;
1009                         mtx_lock(&sc->sc_queue_mtx);
1010                         bioq_insert_tail(&sc->sc_queue, pbp);
1011                         mtx_unlock(&sc->sc_queue_mtx);
1012                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1013                         wakeup(sc);
1014                 }
1015                 break;
1016         case BIO_DELETE:
1017         case BIO_WRITE:
1018                 if (pbp->bio_children == 0) {
1019                         /*
1020                          * All requests failed.
1021                          */
1022                 } else if (pbp->bio_inbed < pbp->bio_children) {
1023                         /* Do nothing. */
1024                         break;
1025                 } else if (pbp->bio_children == pbp->bio_inbed) {
1026                         /* Some requests succeeded. */
1027                         pbp->bio_error = 0;
1028                         pbp->bio_completed = pbp->bio_length;
1029                 }
1030                 bioq_remove(&sc->sc_inflight, pbp);
1031                 /* Release delayed sync requests if possible. */
1032                 g_mirror_sync_release(sc);
1033                 g_io_deliver(pbp, pbp->bio_error);
1034                 break;
1035         default:
1036                 KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
1037                 break;
1038         }
1039 }
1040
1041 static void
1042 g_mirror_sync_done(struct bio *bp)
1043 {
1044         struct g_mirror_softc *sc;
1045
1046         G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
1047         sc = bp->bio_from->geom->softc;
1048         bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
1049         mtx_lock(&sc->sc_queue_mtx);
1050         bioq_insert_tail(&sc->sc_queue, bp);
1051         mtx_unlock(&sc->sc_queue_mtx);
1052         wakeup(sc);
1053 }
1054
1055 static void
1056 g_mirror_candelete(struct bio *bp)
1057 {
1058         struct g_mirror_softc *sc;
1059         struct g_mirror_disk *disk;
1060         int *val;
1061
1062         sc = bp->bio_to->private;
1063         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1064                 if (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE)
1065                         break;
1066         }
1067         val = (int *)bp->bio_data;
1068         *val = (disk != NULL);
1069         g_io_deliver(bp, 0);
1070 }
1071
1072 static void
1073 g_mirror_kernel_dump(struct bio *bp)
1074 {
1075         struct g_mirror_softc *sc;
1076         struct g_mirror_disk *disk;
1077         struct bio *cbp;
1078         struct g_kerneldump *gkd;
1079
1080         /*
1081          * We configure dumping to the first component, because this component
1082          * will be used for reading with 'prefer' balance algorithm.
1083          * If the component with the highest priority is currently disconnected
1084          * we will not be able to read the dump after the reboot if it will be
1085          * connected and synchronized later. Can we do something better?
1086          */
1087         sc = bp->bio_to->private;
1088         disk = LIST_FIRST(&sc->sc_disks);
1089
1090         gkd = (struct g_kerneldump *)bp->bio_data;
1091         if (gkd->length > bp->bio_to->mediasize)
1092                 gkd->length = bp->bio_to->mediasize;
1093         cbp = g_clone_bio(bp);
1094         if (cbp == NULL) {
1095                 g_io_deliver(bp, ENOMEM);
1096                 return;
1097         }
1098         cbp->bio_done = g_std_done;
1099         g_io_request(cbp, disk->d_consumer);
1100         G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1101             g_mirror_get_diskname(disk));
1102 }
1103
1104 static void
1105 g_mirror_flush(struct g_mirror_softc *sc, struct bio *bp)
1106 {
1107         struct bio_queue_head queue;
1108         struct g_mirror_disk *disk;
1109         struct g_consumer *cp;
1110         struct bio *cbp;
1111
1112         bioq_init(&queue);
1113         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1114                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1115                         continue;
1116                 cbp = g_clone_bio(bp);
1117                 if (cbp == NULL) {
1118                         while ((cbp = bioq_takefirst(&queue)) != NULL)
1119                                 g_destroy_bio(cbp);
1120                         if (bp->bio_error == 0)
1121                                 bp->bio_error = ENOMEM;
1122                         g_io_deliver(bp, bp->bio_error);
1123                         return;
1124                 }
1125                 bioq_insert_tail(&queue, cbp);
1126                 cbp->bio_done = g_mirror_flush_done;
1127                 cbp->bio_caller1 = disk;
1128                 cbp->bio_to = disk->d_consumer->provider;
1129         }
1130         while ((cbp = bioq_takefirst(&queue)) != NULL) {
1131                 G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1132                 disk = cbp->bio_caller1;
1133                 cbp->bio_caller1 = NULL;
1134                 cp = disk->d_consumer;
1135                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1136                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1137                     cp->acr, cp->acw, cp->ace));
1138                 g_io_request(cbp, disk->d_consumer);
1139         }
1140 }
1141
1142 static void
1143 g_mirror_start(struct bio *bp)
1144 {
1145         struct g_mirror_softc *sc;
1146
1147         sc = bp->bio_to->private;
1148         /*
1149          * If sc == NULL or there are no valid disks, provider's error
1150          * should be set and g_mirror_start() should not be called at all.
1151          */
1152         KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1153             ("Provider's error should be set (error=%d)(mirror=%s).",
1154             bp->bio_to->error, bp->bio_to->name));
1155         G_MIRROR_LOGREQ(3, bp, "Request received.");
1156
1157         switch (bp->bio_cmd) {
1158         case BIO_READ:
1159         case BIO_WRITE:
1160         case BIO_DELETE:
1161                 break;
1162         case BIO_FLUSH:
1163                 g_mirror_flush(sc, bp);
1164                 return;
1165         case BIO_GETATTR:
1166                 if (!strcmp(bp->bio_attribute, "GEOM::candelete")) {
1167                         g_mirror_candelete(bp);
1168                         return;
1169                 } else if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1170                         g_mirror_kernel_dump(bp);
1171                         return;
1172                 }
1173                 /* FALLTHROUGH */
1174         default:
1175                 g_io_deliver(bp, EOPNOTSUPP);
1176                 return;
1177         }
1178         mtx_lock(&sc->sc_queue_mtx);
1179         bioq_insert_tail(&sc->sc_queue, bp);
1180         mtx_unlock(&sc->sc_queue_mtx);
1181         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1182         wakeup(sc);
1183 }
1184
1185 /*
1186  * Return TRUE if the given request is colliding with a in-progress
1187  * synchronization request.
1188  */
1189 static int
1190 g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1191 {
1192         struct g_mirror_disk *disk;
1193         struct bio *sbp;
1194         off_t rstart, rend, sstart, send;
1195         u_int i;
1196
1197         if (sc->sc_sync.ds_ndisks == 0)
1198                 return (0);
1199         rstart = bp->bio_offset;
1200         rend = bp->bio_offset + bp->bio_length;
1201         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1202                 if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1203                         continue;
1204                 for (i = 0; i < g_mirror_syncreqs; i++) {
1205                         sbp = disk->d_sync.ds_bios[i];
1206                         if (sbp == NULL)
1207                                 continue;
1208                         sstart = sbp->bio_offset;
1209                         send = sbp->bio_offset + sbp->bio_length;
1210                         if (rend > sstart && rstart < send)
1211                                 return (1);
1212                 }
1213         }
1214         return (0);
1215 }
1216
1217 /*
1218  * Return TRUE if the given sync request is colliding with a in-progress regular
1219  * request.
1220  */
1221 static int
1222 g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1223 {
1224         off_t rstart, rend, sstart, send;
1225         struct bio *bp;
1226
1227         if (sc->sc_sync.ds_ndisks == 0)
1228                 return (0);
1229         sstart = sbp->bio_offset;
1230         send = sbp->bio_offset + sbp->bio_length;
1231         TAILQ_FOREACH(bp, &sc->sc_inflight.queue, bio_queue) {
1232                 rstart = bp->bio_offset;
1233                 rend = bp->bio_offset + bp->bio_length;
1234                 if (rend > sstart && rstart < send)
1235                         return (1);
1236         }
1237         return (0);
1238 }
1239
1240 /*
1241  * Puts request onto delayed queue.
1242  */
1243 static void
1244 g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1245 {
1246
1247         G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1248         bioq_insert_head(&sc->sc_regular_delayed, bp);
1249 }
1250
1251 /*
1252  * Puts synchronization request onto delayed queue.
1253  */
1254 static void
1255 g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1256 {
1257
1258         G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1259         bioq_insert_tail(&sc->sc_sync_delayed, bp);
1260 }
1261
1262 /*
1263  * Releases delayed regular requests which don't collide anymore with sync
1264  * requests.
1265  */
1266 static void
1267 g_mirror_regular_release(struct g_mirror_softc *sc)
1268 {
1269         struct bio *bp, *bp2;
1270
1271         TAILQ_FOREACH_SAFE(bp, &sc->sc_regular_delayed.queue, bio_queue, bp2) {
1272                 if (g_mirror_sync_collision(sc, bp))
1273                         continue;
1274                 bioq_remove(&sc->sc_regular_delayed, bp);
1275                 G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
1276                 mtx_lock(&sc->sc_queue_mtx);
1277                 bioq_insert_head(&sc->sc_queue, bp);
1278                 mtx_unlock(&sc->sc_queue_mtx);
1279         }
1280 }
1281
1282 /*
1283  * Releases delayed sync requests which don't collide anymore with regular
1284  * requests.
1285  */
1286 static void
1287 g_mirror_sync_release(struct g_mirror_softc *sc)
1288 {
1289         struct bio *bp, *bp2;
1290
1291         TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed.queue, bio_queue, bp2) {
1292                 if (g_mirror_regular_collision(sc, bp))
1293                         continue;
1294                 bioq_remove(&sc->sc_sync_delayed, bp);
1295                 G_MIRROR_LOGREQ(2, bp,
1296                     "Releasing delayed synchronization request.");
1297                 g_io_request(bp, bp->bio_from);
1298         }
1299 }
1300
1301 /*
1302  * Free a synchronization request and clear its slot in the array.
1303  */
1304 static void
1305 g_mirror_sync_request_free(struct g_mirror_disk *disk, struct bio *bp)
1306 {
1307         int i;
1308
1309         if (disk != NULL && disk->d_sync.ds_bios != NULL) {
1310                 i = (int)(uintptr_t)bp->bio_caller1;
1311                 disk->d_sync.ds_bios[i] = NULL;
1312         }
1313         free(bp->bio_data, M_MIRROR);
1314         g_destroy_bio(bp);
1315 }
1316
1317 /*
1318  * Handle synchronization requests.
1319  * Every synchronization request is two-steps process: first, READ request is
1320  * send to active provider and then WRITE request (with read data) to the provider
1321  * being synchronized. When WRITE is finished, new synchronization request is
1322  * send.
1323  */
1324 static void
1325 g_mirror_sync_request(struct bio *bp)
1326 {
1327         struct g_mirror_softc *sc;
1328         struct g_mirror_disk *disk;
1329         struct g_mirror_disk_sync *sync;
1330
1331         bp->bio_from->index--;
1332         sc = bp->bio_from->geom->softc;
1333         disk = bp->bio_from->private;
1334         if (disk == NULL) {
1335                 sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1336                 g_topology_lock();
1337                 g_mirror_kill_consumer(sc, bp->bio_from);
1338                 g_topology_unlock();
1339                 g_mirror_sync_request_free(NULL, bp);
1340                 sx_xlock(&sc->sc_lock);
1341                 return;
1342         }
1343
1344         /*
1345          * Synchronization request.
1346          */
1347         switch (bp->bio_cmd) {
1348         case BIO_READ:
1349             {
1350                 struct g_consumer *cp;
1351
1352                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_read,
1353                     bp->bio_error);
1354
1355                 if (bp->bio_error != 0) {
1356                         G_MIRROR_LOGREQ(0, bp,
1357                             "Synchronization request failed (error=%d).",
1358                             bp->bio_error);
1359                         g_mirror_sync_request_free(disk, bp);
1360                         return;
1361                 }
1362                 G_MIRROR_LOGREQ(3, bp,
1363                     "Synchronization request half-finished.");
1364                 bp->bio_cmd = BIO_WRITE;
1365                 bp->bio_cflags = 0;
1366                 cp = disk->d_consumer;
1367                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1368                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1369                     cp->acr, cp->acw, cp->ace));
1370                 cp->index++;
1371                 g_io_request(bp, cp);
1372                 return;
1373             }
1374         case BIO_WRITE:
1375             {
1376                 off_t offset;
1377                 void *data;
1378                 int i;
1379
1380                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_write,
1381                     bp->bio_error);
1382
1383                 if (bp->bio_error != 0) {
1384                         G_MIRROR_LOGREQ(0, bp,
1385                             "Synchronization request failed (error=%d).",
1386                             bp->bio_error);
1387                         g_mirror_sync_request_free(disk, bp);
1388                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1389                         g_mirror_event_send(disk,
1390                             G_MIRROR_DISK_STATE_DISCONNECTED,
1391                             G_MIRROR_EVENT_DONTWAIT);
1392                         return;
1393                 }
1394                 G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1395                 sync = &disk->d_sync;
1396                 if (sync->ds_offset >= sc->sc_mediasize ||
1397                     sync->ds_consumer == NULL ||
1398                     (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1399                         /* Don't send more synchronization requests. */
1400                         sync->ds_inflight--;
1401                         g_mirror_sync_request_free(disk, bp);
1402                         if (sync->ds_inflight > 0)
1403                                 return;
1404                         if (sync->ds_consumer == NULL ||
1405                             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1406                                 return;
1407                         }
1408                         /* Disk up-to-date, activate it. */
1409                         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1410                             G_MIRROR_EVENT_DONTWAIT);
1411                         return;
1412                 }
1413
1414                 /* Send next synchronization request. */
1415                 data = bp->bio_data;
1416                 g_reset_bio(bp);
1417                 bp->bio_cmd = BIO_READ;
1418                 bp->bio_offset = sync->ds_offset;
1419                 bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1420                 sync->ds_offset += bp->bio_length;
1421                 bp->bio_done = g_mirror_sync_done;
1422                 bp->bio_data = data;
1423                 bp->bio_from = sync->ds_consumer;
1424                 bp->bio_to = sc->sc_provider;
1425                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1426                 sync->ds_consumer->index++;
1427                 /*
1428                  * Delay the request if it is colliding with a regular request.
1429                  */
1430                 if (g_mirror_regular_collision(sc, bp))
1431                         g_mirror_sync_delay(sc, bp);
1432                 else
1433                         g_io_request(bp, sync->ds_consumer);
1434
1435                 /* Release delayed requests if possible. */
1436                 g_mirror_regular_release(sc);
1437
1438                 /* Find the smallest offset */
1439                 offset = sc->sc_mediasize;
1440                 for (i = 0; i < g_mirror_syncreqs; i++) {
1441                         bp = sync->ds_bios[i];
1442                         if (bp->bio_offset < offset)
1443                                 offset = bp->bio_offset;
1444                 }
1445                 if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
1446                         /* Update offset_done on every 100 blocks. */
1447                         sync->ds_offset_done = offset;
1448                         g_mirror_update_metadata(disk);
1449                 }
1450                 return;
1451             }
1452         default:
1453                 KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1454                     bp->bio_cmd, sc->sc_name));
1455                 break;
1456         }
1457 }
1458
1459 static void
1460 g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1461 {
1462         struct g_mirror_disk *disk;
1463         struct g_consumer *cp;
1464         struct bio *cbp;
1465
1466         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1467                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1468                         break;
1469         }
1470         if (disk == NULL) {
1471                 if (bp->bio_error == 0)
1472                         bp->bio_error = ENXIO;
1473                 g_io_deliver(bp, bp->bio_error);
1474                 return;
1475         }
1476         cbp = g_clone_bio(bp);
1477         if (cbp == NULL) {
1478                 if (bp->bio_error == 0)
1479                         bp->bio_error = ENOMEM;
1480                 g_io_deliver(bp, bp->bio_error);
1481                 return;
1482         }
1483         /*
1484          * Fill in the component buf structure.
1485          */
1486         cp = disk->d_consumer;
1487         cbp->bio_done = g_mirror_done;
1488         cbp->bio_to = cp->provider;
1489         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1490         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1491             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1492             cp->acw, cp->ace));
1493         cp->index++;
1494         g_io_request(cbp, cp);
1495 }
1496
1497 static void
1498 g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1499 {
1500         struct g_mirror_disk *disk;
1501         struct g_consumer *cp;
1502         struct bio *cbp;
1503
1504         disk = g_mirror_get_disk(sc);
1505         if (disk == NULL) {
1506                 if (bp->bio_error == 0)
1507                         bp->bio_error = ENXIO;
1508                 g_io_deliver(bp, bp->bio_error);
1509                 return;
1510         }
1511         cbp = g_clone_bio(bp);
1512         if (cbp == NULL) {
1513                 if (bp->bio_error == 0)
1514                         bp->bio_error = ENOMEM;
1515                 g_io_deliver(bp, bp->bio_error);
1516                 return;
1517         }
1518         /*
1519          * Fill in the component buf structure.
1520          */
1521         cp = disk->d_consumer;
1522         cbp->bio_done = g_mirror_done;
1523         cbp->bio_to = cp->provider;
1524         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1525         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1526             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1527             cp->acw, cp->ace));
1528         cp->index++;
1529         g_io_request(cbp, cp);
1530 }
1531
1532 #define TRACK_SIZE  (1 * 1024 * 1024)
1533 #define LOAD_SCALE      256
1534 #define ABS(x)          (((x) >= 0) ? (x) : (-(x)))
1535
1536 static void
1537 g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1538 {
1539         struct g_mirror_disk *disk, *dp;
1540         struct g_consumer *cp;
1541         struct bio *cbp;
1542         int prio, best;
1543
1544         /* Find a disk with the smallest load. */
1545         disk = NULL;
1546         best = INT_MAX;
1547         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1548                 if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1549                         continue;
1550                 prio = dp->load;
1551                 /* If disk head is precisely in position - highly prefer it. */
1552                 if (dp->d_last_offset == bp->bio_offset)
1553                         prio -= 2 * LOAD_SCALE;
1554                 else
1555                 /* If disk head is close to position - prefer it. */
1556                 if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
1557                         prio -= 1 * LOAD_SCALE;
1558                 if (prio <= best) {
1559                         disk = dp;
1560                         best = prio;
1561                 }
1562         }
1563         KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1564         cbp = g_clone_bio(bp);
1565         if (cbp == NULL) {
1566                 if (bp->bio_error == 0)
1567                         bp->bio_error = ENOMEM;
1568                 g_io_deliver(bp, bp->bio_error);
1569                 return;
1570         }
1571         /*
1572          * Fill in the component buf structure.
1573          */
1574         cp = disk->d_consumer;
1575         cbp->bio_done = g_mirror_done;
1576         cbp->bio_to = cp->provider;
1577         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1578         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1579             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1580             cp->acw, cp->ace));
1581         cp->index++;
1582         /* Remember last head position */
1583         disk->d_last_offset = bp->bio_offset + bp->bio_length;
1584         /* Update loads. */
1585         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1586                 dp->load = (dp->d_consumer->index * LOAD_SCALE +
1587                     dp->load * 7) / 8;
1588         }
1589         g_io_request(cbp, cp);
1590 }
1591
1592 static void
1593 g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1594 {
1595         struct bio_queue_head queue;
1596         struct g_mirror_disk *disk;
1597         struct g_consumer *cp;
1598         struct bio *cbp;
1599         off_t left, mod, offset, slice;
1600         u_char *data;
1601         u_int ndisks;
1602
1603         if (bp->bio_length <= sc->sc_slice) {
1604                 g_mirror_request_round_robin(sc, bp);
1605                 return;
1606         }
1607         ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1608         slice = bp->bio_length / ndisks;
1609         mod = slice % sc->sc_provider->sectorsize;
1610         if (mod != 0)
1611                 slice += sc->sc_provider->sectorsize - mod;
1612         /*
1613          * Allocate all bios before sending any request, so we can
1614          * return ENOMEM in nice and clean way.
1615          */
1616         left = bp->bio_length;
1617         offset = bp->bio_offset;
1618         data = bp->bio_data;
1619         bioq_init(&queue);
1620         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1621                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1622                         continue;
1623                 cbp = g_clone_bio(bp);
1624                 if (cbp == NULL) {
1625                         while ((cbp = bioq_takefirst(&queue)) != NULL)
1626                                 g_destroy_bio(cbp);
1627                         if (bp->bio_error == 0)
1628                                 bp->bio_error = ENOMEM;
1629                         g_io_deliver(bp, bp->bio_error);
1630                         return;
1631                 }
1632                 bioq_insert_tail(&queue, cbp);
1633                 cbp->bio_done = g_mirror_done;
1634                 cbp->bio_caller1 = disk;
1635                 cbp->bio_to = disk->d_consumer->provider;
1636                 cbp->bio_offset = offset;
1637                 cbp->bio_data = data;
1638                 cbp->bio_length = MIN(left, slice);
1639                 left -= cbp->bio_length;
1640                 if (left == 0)
1641                         break;
1642                 offset += cbp->bio_length;
1643                 data += cbp->bio_length;
1644         }
1645         while ((cbp = bioq_takefirst(&queue)) != NULL) {
1646                 G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1647                 disk = cbp->bio_caller1;
1648                 cbp->bio_caller1 = NULL;
1649                 cp = disk->d_consumer;
1650                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1651                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1652                     cp->acr, cp->acw, cp->ace));
1653                 disk->d_consumer->index++;
1654                 g_io_request(cbp, disk->d_consumer);
1655         }
1656 }
1657
1658 static void
1659 g_mirror_register_request(struct bio *bp)
1660 {
1661         struct g_mirror_softc *sc;
1662
1663         sc = bp->bio_to->private;
1664         switch (bp->bio_cmd) {
1665         case BIO_READ:
1666                 switch (sc->sc_balance) {
1667                 case G_MIRROR_BALANCE_LOAD:
1668                         g_mirror_request_load(sc, bp);
1669                         break;
1670                 case G_MIRROR_BALANCE_PREFER:
1671                         g_mirror_request_prefer(sc, bp);
1672                         break;
1673                 case G_MIRROR_BALANCE_ROUND_ROBIN:
1674                         g_mirror_request_round_robin(sc, bp);
1675                         break;
1676                 case G_MIRROR_BALANCE_SPLIT:
1677                         g_mirror_request_split(sc, bp);
1678                         break;
1679                 }
1680                 return;
1681         case BIO_WRITE:
1682         case BIO_DELETE:
1683             {
1684                 struct g_mirror_disk *disk;
1685                 struct g_mirror_disk_sync *sync;
1686                 struct bio_queue_head queue;
1687                 struct g_consumer *cp;
1688                 struct bio *cbp;
1689
1690                 /*
1691                  * Delay the request if it is colliding with a synchronization
1692                  * request.
1693                  */
1694                 if (g_mirror_sync_collision(sc, bp)) {
1695                         g_mirror_regular_delay(sc, bp);
1696                         return;
1697                 }
1698
1699                 if (sc->sc_idle)
1700                         g_mirror_unidle(sc);
1701                 else
1702                         sc->sc_last_write = time_uptime;
1703
1704                 /*
1705                  * Bump syncid on first write.
1706                  */
1707                 if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1708                         sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1709                         g_mirror_bump_syncid(sc);
1710                 }
1711
1712                 /*
1713                  * Allocate all bios before sending any request, so we can
1714                  * return ENOMEM in nice and clean way.
1715                  */
1716                 bioq_init(&queue);
1717                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1718                         sync = &disk->d_sync;
1719                         switch (disk->d_state) {
1720                         case G_MIRROR_DISK_STATE_ACTIVE:
1721                                 break;
1722                         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1723                                 if (bp->bio_offset >= sync->ds_offset)
1724                                         continue;
1725                                 break;
1726                         default:
1727                                 continue;
1728                         }
1729                         if (bp->bio_cmd == BIO_DELETE &&
1730                             (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE) == 0)
1731                                 continue;
1732                         cbp = g_clone_bio(bp);
1733                         if (cbp == NULL) {
1734                                 while ((cbp = bioq_takefirst(&queue)) != NULL)
1735                                         g_destroy_bio(cbp);
1736                                 if (bp->bio_error == 0)
1737                                         bp->bio_error = ENOMEM;
1738                                 g_io_deliver(bp, bp->bio_error);
1739                                 return;
1740                         }
1741                         bioq_insert_tail(&queue, cbp);
1742                         cbp->bio_done = g_mirror_done;
1743                         cp = disk->d_consumer;
1744                         cbp->bio_caller1 = cp;
1745                         cbp->bio_to = cp->provider;
1746                         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1747                             ("Consumer %s not opened (r%dw%de%d).",
1748                             cp->provider->name, cp->acr, cp->acw, cp->ace));
1749                 }
1750                 if (bioq_first(&queue) == NULL) {
1751                         g_io_deliver(bp, EOPNOTSUPP);
1752                         return;
1753                 }
1754                 while ((cbp = bioq_takefirst(&queue)) != NULL) {
1755                         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1756                         cp = cbp->bio_caller1;
1757                         cbp->bio_caller1 = NULL;
1758                         cp->index++;
1759                         sc->sc_writes++;
1760                         g_io_request(cbp, cp);
1761                 }
1762                 /*
1763                  * Put request onto inflight queue, so we can check if new
1764                  * synchronization requests don't collide with it.
1765                  */
1766                 bioq_insert_tail(&sc->sc_inflight, bp);
1767                 return;
1768             }
1769         default:
1770                 KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1771                     bp->bio_cmd, sc->sc_name));
1772                 break;
1773         }
1774 }
1775
1776 static int
1777 g_mirror_can_destroy(struct g_mirror_softc *sc)
1778 {
1779         struct g_geom *gp;
1780         struct g_consumer *cp;
1781
1782         g_topology_assert();
1783         gp = sc->sc_geom;
1784         if (gp->softc == NULL)
1785                 return (1);
1786         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_TASTING) != 0)
1787                 return (0);
1788         LIST_FOREACH(cp, &gp->consumer, consumer) {
1789                 if (g_mirror_is_busy(sc, cp))
1790                         return (0);
1791         }
1792         gp = sc->sc_sync.ds_geom;
1793         LIST_FOREACH(cp, &gp->consumer, consumer) {
1794                 if (g_mirror_is_busy(sc, cp))
1795                         return (0);
1796         }
1797         G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1798             sc->sc_name);
1799         return (1);
1800 }
1801
1802 static int
1803 g_mirror_try_destroy(struct g_mirror_softc *sc)
1804 {
1805
1806         if (sc->sc_rootmount != NULL) {
1807                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1808                     sc->sc_rootmount);
1809                 root_mount_rel(sc->sc_rootmount);
1810                 sc->sc_rootmount = NULL;
1811         }
1812         g_topology_lock();
1813         if (!g_mirror_can_destroy(sc)) {
1814                 g_topology_unlock();
1815                 return (0);
1816         }
1817         sc->sc_geom->softc = NULL;
1818         sc->sc_sync.ds_geom->softc = NULL;
1819         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WAIT) != 0) {
1820                 g_topology_unlock();
1821                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1822                     &sc->sc_worker);
1823                 /* Unlock sc_lock here, as it can be destroyed after wakeup. */
1824                 sx_xunlock(&sc->sc_lock);
1825                 wakeup(&sc->sc_worker);
1826                 sc->sc_worker = NULL;
1827         } else {
1828                 g_topology_unlock();
1829                 g_mirror_destroy_device(sc);
1830         }
1831         return (1);
1832 }
1833
1834 /*
1835  * Worker thread.
1836  */
1837 static void
1838 g_mirror_worker(void *arg)
1839 {
1840         struct g_mirror_softc *sc;
1841         struct g_mirror_event *ep;
1842         struct bio *bp;
1843         int timeout;
1844
1845         sc = arg;
1846         thread_lock(curthread);
1847         sched_prio(curthread, PRIBIO);
1848         thread_unlock(curthread);
1849
1850         sx_xlock(&sc->sc_lock);
1851         for (;;) {
1852                 G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1853                 /*
1854                  * First take a look at events.
1855                  * This is important to handle events before any I/O requests.
1856                  */
1857                 ep = g_mirror_event_get(sc);
1858                 if (ep != NULL) {
1859                         g_mirror_event_remove(sc, ep);
1860                         if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1861                                 /* Update only device status. */
1862                                 G_MIRROR_DEBUG(3,
1863                                     "Running event for device %s.",
1864                                     sc->sc_name);
1865                                 ep->e_error = 0;
1866                                 g_mirror_update_device(sc, true);
1867                         } else {
1868                                 /* Update disk status. */
1869                                 G_MIRROR_DEBUG(3, "Running event for disk %s.",
1870                                      g_mirror_get_diskname(ep->e_disk));
1871                                 ep->e_error = g_mirror_update_disk(ep->e_disk,
1872                                     ep->e_state);
1873                                 if (ep->e_error == 0)
1874                                         g_mirror_update_device(sc, false);
1875                         }
1876                         if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1877                                 KASSERT(ep->e_error == 0,
1878                                     ("Error cannot be handled."));
1879                                 g_mirror_event_free(ep);
1880                         } else {
1881                                 ep->e_flags |= G_MIRROR_EVENT_DONE;
1882                                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1883                                     ep);
1884                                 mtx_lock(&sc->sc_events_mtx);
1885                                 wakeup(ep);
1886                                 mtx_unlock(&sc->sc_events_mtx);
1887                         }
1888                         if ((sc->sc_flags &
1889                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1890                                 if (g_mirror_try_destroy(sc)) {
1891                                         curthread->td_pflags &= ~TDP_GEOM;
1892                                         G_MIRROR_DEBUG(1, "Thread exiting.");
1893                                         kproc_exit(0);
1894                                 }
1895                         }
1896                         G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1897                         continue;
1898                 }
1899                 /*
1900                  * Check if we can mark array as CLEAN and if we can't take
1901                  * how much seconds should we wait.
1902                  */
1903                 timeout = g_mirror_idle(sc, -1);
1904                 /*
1905                  * Now I/O requests.
1906                  */
1907                 /* Get first request from the queue. */
1908                 mtx_lock(&sc->sc_queue_mtx);
1909                 bp = bioq_takefirst(&sc->sc_queue);
1910                 if (bp == NULL) {
1911                         if ((sc->sc_flags &
1912                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1913                                 mtx_unlock(&sc->sc_queue_mtx);
1914                                 if (g_mirror_try_destroy(sc)) {
1915                                         curthread->td_pflags &= ~TDP_GEOM;
1916                                         G_MIRROR_DEBUG(1, "Thread exiting.");
1917                                         kproc_exit(0);
1918                                 }
1919                                 mtx_lock(&sc->sc_queue_mtx);
1920                         }
1921                         sx_xunlock(&sc->sc_lock);
1922                         /*
1923                          * XXX: We can miss an event here, because an event
1924                          *      can be added without sx-device-lock and without
1925                          *      mtx-queue-lock. Maybe I should just stop using
1926                          *      dedicated mutex for events synchronization and
1927                          *      stick with the queue lock?
1928                          *      The event will hang here until next I/O request
1929                          *      or next event is received.
1930                          */
1931                         MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
1932                             timeout * hz);
1933                         sx_xlock(&sc->sc_lock);
1934                         G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
1935                         continue;
1936                 }
1937                 mtx_unlock(&sc->sc_queue_mtx);
1938
1939                 if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
1940                     (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
1941                         g_mirror_sync_request(bp);      /* READ */
1942                 } else if (bp->bio_to != sc->sc_provider) {
1943                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
1944                                 g_mirror_regular_request(bp);
1945                         else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
1946                                 g_mirror_sync_request(bp);      /* WRITE */
1947                         else {
1948                                 KASSERT(0,
1949                                     ("Invalid request cflags=0x%hx to=%s.",
1950                                     bp->bio_cflags, bp->bio_to->name));
1951                         }
1952                 } else {
1953                         g_mirror_register_request(bp);
1954                 }
1955                 G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
1956         }
1957 }
1958
1959 static void
1960 g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
1961 {
1962
1963         sx_assert(&sc->sc_lock, SX_LOCKED);
1964
1965         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
1966                 return;
1967         if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
1968                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
1969                     g_mirror_get_diskname(disk), sc->sc_name);
1970                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1971         } else if (sc->sc_idle &&
1972             (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
1973                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
1974                     g_mirror_get_diskname(disk), sc->sc_name);
1975                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
1976         }
1977 }
1978
1979 static void
1980 g_mirror_sync_start(struct g_mirror_disk *disk)
1981 {
1982         struct g_mirror_softc *sc;
1983         struct g_consumer *cp;
1984         struct bio *bp;
1985         int error, i;
1986
1987         g_topology_assert_not();
1988         sc = disk->d_softc;
1989         sx_assert(&sc->sc_lock, SX_LOCKED);
1990
1991         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1992             ("Disk %s is not marked for synchronization.",
1993             g_mirror_get_diskname(disk)));
1994         KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1995             ("Device not in RUNNING state (%s, %u).", sc->sc_name,
1996             sc->sc_state));
1997
1998         sx_xunlock(&sc->sc_lock);
1999         g_topology_lock();
2000         cp = g_new_consumer(sc->sc_sync.ds_geom);
2001         cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
2002         error = g_attach(cp, sc->sc_provider);
2003         KASSERT(error == 0,
2004             ("Cannot attach to %s (error=%d).", sc->sc_name, error));
2005         error = g_access(cp, 1, 0, 0);
2006         KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
2007         g_topology_unlock();
2008         sx_xlock(&sc->sc_lock);
2009
2010         G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
2011             g_mirror_get_diskname(disk));
2012         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
2013                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
2014         KASSERT(disk->d_sync.ds_consumer == NULL,
2015             ("Sync consumer already exists (device=%s, disk=%s).",
2016             sc->sc_name, g_mirror_get_diskname(disk)));
2017
2018         disk->d_sync.ds_consumer = cp;
2019         disk->d_sync.ds_consumer->private = disk;
2020         disk->d_sync.ds_consumer->index = 0;
2021
2022         /*
2023          * Allocate memory for synchronization bios and initialize them.
2024          */
2025         disk->d_sync.ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
2026             M_MIRROR, M_WAITOK);
2027         for (i = 0; i < g_mirror_syncreqs; i++) {
2028                 bp = g_alloc_bio();
2029                 disk->d_sync.ds_bios[i] = bp;
2030                 bp->bio_parent = NULL;
2031                 bp->bio_cmd = BIO_READ;
2032                 bp->bio_data = malloc(MAXPHYS, M_MIRROR, M_WAITOK);
2033                 bp->bio_cflags = 0;
2034                 bp->bio_offset = disk->d_sync.ds_offset;
2035                 bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
2036                 disk->d_sync.ds_offset += bp->bio_length;
2037                 bp->bio_done = g_mirror_sync_done;
2038                 bp->bio_from = disk->d_sync.ds_consumer;
2039                 bp->bio_to = sc->sc_provider;
2040                 bp->bio_caller1 = (void *)(uintptr_t)i;
2041         }
2042
2043         /* Increase the number of disks in SYNCHRONIZING state. */
2044         sc->sc_sync.ds_ndisks++;
2045         /* Set the number of in-flight synchronization requests. */
2046         disk->d_sync.ds_inflight = g_mirror_syncreqs;
2047
2048         /*
2049          * Fire off first synchronization requests.
2050          */
2051         for (i = 0; i < g_mirror_syncreqs; i++) {
2052                 bp = disk->d_sync.ds_bios[i];
2053                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
2054                 disk->d_sync.ds_consumer->index++;
2055                 /*
2056                  * Delay the request if it is colliding with a regular request.
2057                  */
2058                 if (g_mirror_regular_collision(sc, bp))
2059                         g_mirror_sync_delay(sc, bp);
2060                 else
2061                         g_io_request(bp, disk->d_sync.ds_consumer);
2062         }
2063 }
2064
2065 /*
2066  * Stop synchronization process.
2067  * type: 0 - synchronization finished
2068  *       1 - synchronization stopped
2069  */
2070 static void
2071 g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
2072 {
2073         struct g_mirror_softc *sc;
2074         struct g_consumer *cp;
2075
2076         g_topology_assert_not();
2077         sc = disk->d_softc;
2078         sx_assert(&sc->sc_lock, SX_LOCKED);
2079
2080         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2081             ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2082             g_mirror_disk_state2str(disk->d_state)));
2083         if (disk->d_sync.ds_consumer == NULL)
2084                 return;
2085
2086         if (type == 0) {
2087                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
2088                     sc->sc_name, g_mirror_get_diskname(disk));
2089         } else /* if (type == 1) */ {
2090                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
2091                     sc->sc_name, g_mirror_get_diskname(disk));
2092         }
2093         g_mirror_regular_release(sc);
2094         free(disk->d_sync.ds_bios, M_MIRROR);
2095         disk->d_sync.ds_bios = NULL;
2096         cp = disk->d_sync.ds_consumer;
2097         disk->d_sync.ds_consumer = NULL;
2098         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2099         sc->sc_sync.ds_ndisks--;
2100         sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2101         g_topology_lock();
2102         g_mirror_kill_consumer(sc, cp);
2103         g_topology_unlock();
2104         sx_xlock(&sc->sc_lock);
2105 }
2106
2107 static void
2108 g_mirror_launch_provider(struct g_mirror_softc *sc)
2109 {
2110         struct g_mirror_disk *disk;
2111         struct g_provider *pp, *dp;
2112
2113         sx_assert(&sc->sc_lock, SX_LOCKED);
2114
2115         g_topology_lock();
2116         pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2117         pp->flags |= G_PF_DIRECT_RECEIVE;
2118         pp->mediasize = sc->sc_mediasize;
2119         pp->sectorsize = sc->sc_sectorsize;
2120         pp->stripesize = 0;
2121         pp->stripeoffset = 0;
2122
2123         /* Splitting of unmapped BIO's could work but isn't implemented now */
2124         if (sc->sc_balance != G_MIRROR_BALANCE_SPLIT)
2125                 pp->flags |= G_PF_ACCEPT_UNMAPPED;
2126
2127         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2128                 if (disk->d_consumer && disk->d_consumer->provider) {
2129                         dp = disk->d_consumer->provider;
2130                         if (dp->stripesize > pp->stripesize) {
2131                                 pp->stripesize = dp->stripesize;
2132                                 pp->stripeoffset = dp->stripeoffset;
2133                         }
2134                         /* A provider underneath us doesn't support unmapped */
2135                         if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
2136                                 G_MIRROR_DEBUG(0, "Cancelling unmapped "
2137                                     "because of %s.", dp->name);
2138                                 pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
2139                         }
2140                 }
2141         }
2142         pp->private = sc;
2143         sc->sc_refcnt++;
2144         sc->sc_provider = pp;
2145         g_error_provider(pp, 0);
2146         g_topology_unlock();
2147         G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2148             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2149         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2150                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2151                         g_mirror_sync_start(disk);
2152         }
2153 }
2154
2155 static void
2156 g_mirror_destroy_provider(struct g_mirror_softc *sc)
2157 {
2158         struct g_mirror_disk *disk;
2159         struct bio *bp;
2160
2161         g_topology_assert_not();
2162         KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2163             sc->sc_name));
2164
2165         g_topology_lock();
2166         g_error_provider(sc->sc_provider, ENXIO);
2167         mtx_lock(&sc->sc_queue_mtx);
2168         while ((bp = bioq_takefirst(&sc->sc_queue)) != NULL) {
2169                 /*
2170                  * Abort any pending I/O that wasn't generated by us.
2171                  * Synchronization requests and requests destined for individual
2172                  * mirror components can be destroyed immediately.
2173                  */
2174                 if (bp->bio_to == sc->sc_provider &&
2175                     bp->bio_from->geom != sc->sc_sync.ds_geom) {
2176                         g_io_deliver(bp, ENXIO);
2177                 } else {
2178                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
2179                                 free(bp->bio_data, M_MIRROR);
2180                         g_destroy_bio(bp);
2181                 }
2182         }
2183         mtx_unlock(&sc->sc_queue_mtx);
2184         g_wither_provider(sc->sc_provider, ENXIO);
2185         sc->sc_provider = NULL;
2186         G_MIRROR_DEBUG(0, "Device %s: provider destroyed.", sc->sc_name);
2187         g_topology_unlock();
2188         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2189                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2190                         g_mirror_sync_stop(disk, 1);
2191         }
2192 }
2193
2194 static void
2195 g_mirror_go(void *arg)
2196 {
2197         struct g_mirror_softc *sc;
2198
2199         sc = arg;
2200         G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2201         g_mirror_event_send(sc, 0,
2202             G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2203 }
2204
2205 static u_int
2206 g_mirror_determine_state(struct g_mirror_disk *disk)
2207 {
2208         struct g_mirror_softc *sc;
2209         u_int state;
2210
2211         sc = disk->d_softc;
2212         if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2213                 if ((disk->d_flags &
2214                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2215                         /* Disk does not need synchronization. */
2216                         state = G_MIRROR_DISK_STATE_ACTIVE;
2217                 } else {
2218                         if ((sc->sc_flags &
2219                              G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2220                             (disk->d_flags &
2221                              G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2222                                 /*
2223                                  * We can start synchronization from
2224                                  * the stored offset.
2225                                  */
2226                                 state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2227                         } else {
2228                                 state = G_MIRROR_DISK_STATE_STALE;
2229                         }
2230                 }
2231         } else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2232                 /*
2233                  * Reset all synchronization data for this disk,
2234                  * because if it even was synchronized, it was
2235                  * synchronized to disks with different syncid.
2236                  */
2237                 disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2238                 disk->d_sync.ds_offset = 0;
2239                 disk->d_sync.ds_offset_done = 0;
2240                 disk->d_sync.ds_syncid = sc->sc_syncid;
2241                 if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2242                     (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2243                         state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2244                 } else {
2245                         state = G_MIRROR_DISK_STATE_STALE;
2246                 }
2247         } else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2248                 /*
2249                  * Not good, NOT GOOD!
2250                  * It means that mirror was started on stale disks
2251                  * and more fresh disk just arrive.
2252                  * If there were writes, mirror is broken, sorry.
2253                  * I think the best choice here is don't touch
2254                  * this disk and inform the user loudly.
2255                  */
2256                 G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2257                     "disk (%s) arrives!! It will not be connected to the "
2258                     "running device.", sc->sc_name,
2259                     g_mirror_get_diskname(disk));
2260                 g_mirror_destroy_disk(disk);
2261                 state = G_MIRROR_DISK_STATE_NONE;
2262                 /* Return immediately, because disk was destroyed. */
2263                 return (state);
2264         }
2265         G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2266             g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2267         return (state);
2268 }
2269
2270 /*
2271  * Update device state.
2272  */
2273 static void
2274 g_mirror_update_device(struct g_mirror_softc *sc, bool force)
2275 {
2276         struct g_mirror_disk *disk;
2277         u_int state;
2278
2279         sx_assert(&sc->sc_lock, SX_XLOCKED);
2280
2281         switch (sc->sc_state) {
2282         case G_MIRROR_DEVICE_STATE_STARTING:
2283             {
2284                 struct g_mirror_disk *pdisk, *tdisk;
2285                 u_int dirty, ndisks, genid, syncid;
2286                 bool broken;
2287
2288                 KASSERT(sc->sc_provider == NULL,
2289                     ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2290                 /*
2291                  * Are we ready? We are, if all disks are connected or
2292                  * if we have any disks and 'force' is true.
2293                  */
2294                 ndisks = g_mirror_ndisks(sc, -1);
2295                 if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2296                         ;
2297                 } else if (ndisks == 0) {
2298                         /*
2299                          * Disks went down in starting phase, so destroy
2300                          * device.
2301                          */
2302                         callout_drain(&sc->sc_callout);
2303                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2304                         G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2305                             sc->sc_rootmount);
2306                         root_mount_rel(sc->sc_rootmount);
2307                         sc->sc_rootmount = NULL;
2308                         return;
2309                 } else {
2310                         return;
2311                 }
2312
2313                 /*
2314                  * Activate all disks with the biggest syncid.
2315                  */
2316                 if (force) {
2317                         /*
2318                          * If 'force' is true, we have been called due to
2319                          * timeout, so don't bother canceling timeout.
2320                          */
2321                         ndisks = 0;
2322                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2323                                 if ((disk->d_flags &
2324                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2325                                         ndisks++;
2326                                 }
2327                         }
2328                         if (ndisks == 0) {
2329                                 /* No valid disks found, destroy device. */
2330                                 sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2331                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2332                                     __LINE__, sc->sc_rootmount);
2333                                 root_mount_rel(sc->sc_rootmount);
2334                                 sc->sc_rootmount = NULL;
2335                                 return;
2336                         }
2337                 } else {
2338                         /* Cancel timeout. */
2339                         callout_drain(&sc->sc_callout);
2340                 }
2341
2342                 /*
2343                  * Find the biggest genid.
2344                  */
2345                 genid = 0;
2346                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2347                         if (disk->d_genid > genid)
2348                                 genid = disk->d_genid;
2349                 }
2350                 sc->sc_genid = genid;
2351                 /*
2352                  * Remove all disks without the biggest genid.
2353                  */
2354                 broken = false;
2355                 LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2356                         if (disk->d_genid < genid) {
2357                                 G_MIRROR_DEBUG(0,
2358                                     "Component %s (device %s) broken, skipping.",
2359                                     g_mirror_get_diskname(disk), sc->sc_name);
2360                                 g_mirror_destroy_disk(disk);
2361                                 /*
2362                                  * Bump the syncid in case we discover a healthy
2363                                  * replacement disk after starting the mirror.
2364                                  */
2365                                 broken = true;
2366                         }
2367                 }
2368
2369                 /*
2370                  * Find the biggest syncid.
2371                  */
2372                 syncid = 0;
2373                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2374                         if (disk->d_sync.ds_syncid > syncid)
2375                                 syncid = disk->d_sync.ds_syncid;
2376                 }
2377
2378                 /*
2379                  * Here we need to look for dirty disks and if all disks
2380                  * with the biggest syncid are dirty, we have to choose
2381                  * one with the biggest priority and rebuild the rest.
2382                  */
2383                 /*
2384                  * Find the number of dirty disks with the biggest syncid.
2385                  * Find the number of disks with the biggest syncid.
2386                  * While here, find a disk with the biggest priority.
2387                  */
2388                 dirty = ndisks = 0;
2389                 pdisk = NULL;
2390                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2391                         if (disk->d_sync.ds_syncid != syncid)
2392                                 continue;
2393                         if ((disk->d_flags &
2394                             G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2395                                 continue;
2396                         }
2397                         ndisks++;
2398                         if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2399                                 dirty++;
2400                                 if (pdisk == NULL ||
2401                                     pdisk->d_priority < disk->d_priority) {
2402                                         pdisk = disk;
2403                                 }
2404                         }
2405                 }
2406                 if (dirty == 0) {
2407                         /* No dirty disks at all, great. */
2408                 } else if (dirty == ndisks) {
2409                         /*
2410                          * Force synchronization for all dirty disks except one
2411                          * with the biggest priority.
2412                          */
2413                         KASSERT(pdisk != NULL, ("pdisk == NULL"));
2414                         G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2415                             "master disk for synchronization.",
2416                             g_mirror_get_diskname(pdisk), sc->sc_name);
2417                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2418                                 if (disk->d_sync.ds_syncid != syncid)
2419                                         continue;
2420                                 if ((disk->d_flags &
2421                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2422                                         continue;
2423                                 }
2424                                 KASSERT((disk->d_flags &
2425                                     G_MIRROR_DISK_FLAG_DIRTY) != 0,
2426                                     ("Disk %s isn't marked as dirty.",
2427                                     g_mirror_get_diskname(disk)));
2428                                 /* Skip the disk with the biggest priority. */
2429                                 if (disk == pdisk)
2430                                         continue;
2431                                 disk->d_sync.ds_syncid = 0;
2432                         }
2433                 } else if (dirty < ndisks) {
2434                         /*
2435                          * Force synchronization for all dirty disks.
2436                          * We have some non-dirty disks.
2437                          */
2438                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2439                                 if (disk->d_sync.ds_syncid != syncid)
2440                                         continue;
2441                                 if ((disk->d_flags &
2442                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2443                                         continue;
2444                                 }
2445                                 if ((disk->d_flags &
2446                                     G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2447                                         continue;
2448                                 }
2449                                 disk->d_sync.ds_syncid = 0;
2450                         }
2451                 }
2452
2453                 /* Reset hint. */
2454                 sc->sc_hint = NULL;
2455                 sc->sc_syncid = syncid;
2456                 if (force || broken) {
2457                         /* Remember to bump syncid on first write. */
2458                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2459                 }
2460                 state = G_MIRROR_DEVICE_STATE_RUNNING;
2461                 G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2462                     sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2463                     g_mirror_device_state2str(state));
2464                 sc->sc_state = state;
2465                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2466                         state = g_mirror_determine_state(disk);
2467                         g_mirror_event_send(disk, state,
2468                             G_MIRROR_EVENT_DONTWAIT);
2469                         if (state == G_MIRROR_DISK_STATE_STALE)
2470                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2471                 }
2472                 break;
2473             }
2474         case G_MIRROR_DEVICE_STATE_RUNNING:
2475                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2476                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2477                         /*
2478                          * No active disks or no disks at all,
2479                          * so destroy device.
2480                          */
2481                         if (sc->sc_provider != NULL)
2482                                 g_mirror_destroy_provider(sc);
2483                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2484                         break;
2485                 } else if (g_mirror_ndisks(sc,
2486                     G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2487                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2488                         /*
2489                          * We have active disks, launch provider if it doesn't
2490                          * exist.
2491                          */
2492                         if (sc->sc_provider == NULL)
2493                                 g_mirror_launch_provider(sc);
2494                         if (sc->sc_rootmount != NULL) {
2495                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2496                                     __LINE__, sc->sc_rootmount);
2497                                 root_mount_rel(sc->sc_rootmount);
2498                                 sc->sc_rootmount = NULL;
2499                         }
2500                 }
2501                 /*
2502                  * Genid should be bumped immediately, so do it here.
2503                  */
2504                 if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2505                         sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2506                         g_mirror_bump_genid(sc);
2507                 }
2508                 break;
2509         default:
2510                 KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2511                     sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2512                 break;
2513         }
2514 }
2515
2516 /*
2517  * Update disk state and device state if needed.
2518  */
2519 #define DISK_STATE_CHANGED()    G_MIRROR_DEBUG(1,                       \
2520         "Disk %s state changed from %s to %s (device %s).",             \
2521         g_mirror_get_diskname(disk),                                    \
2522         g_mirror_disk_state2str(disk->d_state),                         \
2523         g_mirror_disk_state2str(state), sc->sc_name)
2524 static int
2525 g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2526 {
2527         struct g_mirror_softc *sc;
2528
2529         sc = disk->d_softc;
2530         sx_assert(&sc->sc_lock, SX_XLOCKED);
2531
2532 again:
2533         G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2534             g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2535             g_mirror_disk_state2str(state));
2536         switch (state) {
2537         case G_MIRROR_DISK_STATE_NEW:
2538                 /*
2539                  * Possible scenarios:
2540                  * 1. New disk arrive.
2541                  */
2542                 /* Previous state should be NONE. */
2543                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2544                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2545                     g_mirror_disk_state2str(disk->d_state)));
2546                 DISK_STATE_CHANGED();
2547
2548                 disk->d_state = state;
2549                 if (LIST_EMPTY(&sc->sc_disks))
2550                         LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2551                 else {
2552                         struct g_mirror_disk *dp;
2553
2554                         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2555                                 if (disk->d_priority >= dp->d_priority) {
2556                                         LIST_INSERT_BEFORE(dp, disk, d_next);
2557                                         dp = NULL;
2558                                         break;
2559                                 }
2560                                 if (LIST_NEXT(dp, d_next) == NULL)
2561                                         break;
2562                         }
2563                         if (dp != NULL)
2564                                 LIST_INSERT_AFTER(dp, disk, d_next);
2565                 }
2566                 G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2567                     sc->sc_name, g_mirror_get_diskname(disk));
2568                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2569                         break;
2570                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2571                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2572                     g_mirror_device_state2str(sc->sc_state),
2573                     g_mirror_get_diskname(disk),
2574                     g_mirror_disk_state2str(disk->d_state)));
2575                 state = g_mirror_determine_state(disk);
2576                 if (state != G_MIRROR_DISK_STATE_NONE)
2577                         goto again;
2578                 break;
2579         case G_MIRROR_DISK_STATE_ACTIVE:
2580                 /*
2581                  * Possible scenarios:
2582                  * 1. New disk does not need synchronization.
2583                  * 2. Synchronization process finished successfully.
2584                  */
2585                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2586                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2587                     g_mirror_device_state2str(sc->sc_state),
2588                     g_mirror_get_diskname(disk),
2589                     g_mirror_disk_state2str(disk->d_state)));
2590                 /* Previous state should be NEW or SYNCHRONIZING. */
2591                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2592                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2593                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2594                     g_mirror_disk_state2str(disk->d_state)));
2595                 DISK_STATE_CHANGED();
2596
2597                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2598                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2599                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2600                         g_mirror_sync_stop(disk, 0);
2601                 }
2602                 disk->d_state = state;
2603                 disk->d_sync.ds_offset = 0;
2604                 disk->d_sync.ds_offset_done = 0;
2605                 g_mirror_update_idle(sc, disk);
2606                 g_mirror_update_metadata(disk);
2607                 G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2608                     sc->sc_name, g_mirror_get_diskname(disk));
2609                 break;
2610         case G_MIRROR_DISK_STATE_STALE:
2611                 /*
2612                  * Possible scenarios:
2613                  * 1. Stale disk was connected.
2614                  */
2615                 /* Previous state should be NEW. */
2616                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2617                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2618                     g_mirror_disk_state2str(disk->d_state)));
2619                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2620                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2621                     g_mirror_device_state2str(sc->sc_state),
2622                     g_mirror_get_diskname(disk),
2623                     g_mirror_disk_state2str(disk->d_state)));
2624                 /*
2625                  * STALE state is only possible if device is marked
2626                  * NOAUTOSYNC.
2627                  */
2628                 KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2629                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2630                     g_mirror_device_state2str(sc->sc_state),
2631                     g_mirror_get_diskname(disk),
2632                     g_mirror_disk_state2str(disk->d_state)));
2633                 DISK_STATE_CHANGED();
2634
2635                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2636                 disk->d_state = state;
2637                 g_mirror_update_metadata(disk);
2638                 G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2639                     sc->sc_name, g_mirror_get_diskname(disk));
2640                 break;
2641         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2642                 /*
2643                  * Possible scenarios:
2644                  * 1. Disk which needs synchronization was connected.
2645                  */
2646                 /* Previous state should be NEW. */
2647                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2648                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2649                     g_mirror_disk_state2str(disk->d_state)));
2650                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2651                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2652                     g_mirror_device_state2str(sc->sc_state),
2653                     g_mirror_get_diskname(disk),
2654                     g_mirror_disk_state2str(disk->d_state)));
2655                 DISK_STATE_CHANGED();
2656
2657                 if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2658                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2659                 disk->d_state = state;
2660                 if (sc->sc_provider != NULL) {
2661                         g_mirror_sync_start(disk);
2662                         g_mirror_update_metadata(disk);
2663                 }
2664                 break;
2665         case G_MIRROR_DISK_STATE_DISCONNECTED:
2666                 /*
2667                  * Possible scenarios:
2668                  * 1. Device wasn't running yet, but disk disappear.
2669                  * 2. Disk was active and disapppear.
2670                  * 3. Disk disappear during synchronization process.
2671                  */
2672                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2673                         /*
2674                          * Previous state should be ACTIVE, STALE or
2675                          * SYNCHRONIZING.
2676                          */
2677                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2678                             disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2679                             disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2680                             ("Wrong disk state (%s, %s).",
2681                             g_mirror_get_diskname(disk),
2682                             g_mirror_disk_state2str(disk->d_state)));
2683                 } else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2684                         /* Previous state should be NEW. */
2685                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2686                             ("Wrong disk state (%s, %s).",
2687                             g_mirror_get_diskname(disk),
2688                             g_mirror_disk_state2str(disk->d_state)));
2689                         /*
2690                          * Reset bumping syncid if disk disappeared in STARTING
2691                          * state.
2692                          */
2693                         if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2694                                 sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2695 #ifdef  INVARIANTS
2696                 } else {
2697                         KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2698                             sc->sc_name,
2699                             g_mirror_device_state2str(sc->sc_state),
2700                             g_mirror_get_diskname(disk),
2701                             g_mirror_disk_state2str(disk->d_state)));
2702 #endif
2703                 }
2704                 DISK_STATE_CHANGED();
2705                 G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2706                     sc->sc_name, g_mirror_get_diskname(disk));
2707
2708                 g_mirror_destroy_disk(disk);
2709                 break;
2710         case G_MIRROR_DISK_STATE_DESTROY:
2711             {
2712                 int error;
2713
2714                 error = g_mirror_clear_metadata(disk);
2715                 if (error != 0) {
2716                         G_MIRROR_DEBUG(0,
2717                             "Device %s: failed to clear metadata on %s: %d.",
2718                             sc->sc_name, g_mirror_get_diskname(disk), error);
2719                         break;
2720                 }
2721                 DISK_STATE_CHANGED();
2722                 G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2723                     sc->sc_name, g_mirror_get_diskname(disk));
2724
2725                 g_mirror_destroy_disk(disk);
2726                 sc->sc_ndisks--;
2727                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2728                         g_mirror_update_metadata(disk);
2729                 }
2730                 break;
2731             }
2732         default:
2733                 KASSERT(1 == 0, ("Unknown state (%u).", state));
2734                 break;
2735         }
2736         return (0);
2737 }
2738 #undef  DISK_STATE_CHANGED
2739
2740 int
2741 g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2742 {
2743         struct g_provider *pp;
2744         u_char *buf;
2745         int error;
2746
2747         g_topology_assert();
2748
2749         error = g_access(cp, 1, 0, 0);
2750         if (error != 0)
2751                 return (error);
2752         pp = cp->provider;
2753         g_topology_unlock();
2754         /* Metadata are stored on last sector. */
2755         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2756             &error);
2757         g_topology_lock();
2758         g_access(cp, -1, 0, 0);
2759         if (buf == NULL) {
2760                 G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2761                     cp->provider->name, error);
2762                 return (error);
2763         }
2764
2765         /* Decode metadata. */
2766         error = mirror_metadata_decode(buf, md);
2767         g_free(buf);
2768         if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2769                 return (EINVAL);
2770         if (md->md_version > G_MIRROR_VERSION) {
2771                 G_MIRROR_DEBUG(0,
2772                     "Kernel module is too old to handle metadata from %s.",
2773                     cp->provider->name);
2774                 return (EINVAL);
2775         }
2776         if (error != 0) {
2777                 G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2778                     cp->provider->name);
2779                 return (error);
2780         }
2781
2782         return (0);
2783 }
2784
2785 static int
2786 g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2787     struct g_mirror_metadata *md)
2788 {
2789
2790         if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2791                 G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2792                     pp->name, md->md_did);
2793                 return (EEXIST);
2794         }
2795         if (md->md_all != sc->sc_ndisks) {
2796                 G_MIRROR_DEBUG(1,
2797                     "Invalid '%s' field on disk %s (device %s), skipping.",
2798                     "md_all", pp->name, sc->sc_name);
2799                 return (EINVAL);
2800         }
2801         if (md->md_slice != sc->sc_slice) {
2802                 G_MIRROR_DEBUG(1,
2803                     "Invalid '%s' field on disk %s (device %s), skipping.",
2804                     "md_slice", pp->name, sc->sc_name);
2805                 return (EINVAL);
2806         }
2807         if (md->md_balance != sc->sc_balance) {
2808                 G_MIRROR_DEBUG(1,
2809                     "Invalid '%s' field on disk %s (device %s), skipping.",
2810                     "md_balance", pp->name, sc->sc_name);
2811                 return (EINVAL);
2812         }
2813 #if 0
2814         if (md->md_mediasize != sc->sc_mediasize) {
2815                 G_MIRROR_DEBUG(1,
2816                     "Invalid '%s' field on disk %s (device %s), skipping.",
2817                     "md_mediasize", pp->name, sc->sc_name);
2818                 return (EINVAL);
2819         }
2820 #endif
2821         if (sc->sc_mediasize > pp->mediasize) {
2822                 G_MIRROR_DEBUG(1,
2823                     "Invalid size of disk %s (device %s), skipping.", pp->name,
2824                     sc->sc_name);
2825                 return (EINVAL);
2826         }
2827         if (md->md_sectorsize != sc->sc_sectorsize) {
2828                 G_MIRROR_DEBUG(1,
2829                     "Invalid '%s' field on disk %s (device %s), skipping.",
2830                     "md_sectorsize", pp->name, sc->sc_name);
2831                 return (EINVAL);
2832         }
2833         if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2834                 G_MIRROR_DEBUG(1,
2835                     "Invalid sector size of disk %s (device %s), skipping.",
2836                     pp->name, sc->sc_name);
2837                 return (EINVAL);
2838         }
2839         if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2840                 G_MIRROR_DEBUG(1,
2841                     "Invalid device flags on disk %s (device %s), skipping.",
2842                     pp->name, sc->sc_name);
2843                 return (EINVAL);
2844         }
2845         if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2846                 G_MIRROR_DEBUG(1,
2847                     "Invalid disk flags on disk %s (device %s), skipping.",
2848                     pp->name, sc->sc_name);
2849                 return (EINVAL);
2850         }
2851         return (0);
2852 }
2853
2854 int
2855 g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2856     struct g_mirror_metadata *md)
2857 {
2858         struct g_mirror_disk *disk;
2859         int error;
2860
2861         g_topology_assert_not();
2862         G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2863
2864         error = g_mirror_check_metadata(sc, pp, md);
2865         if (error != 0)
2866                 return (error);
2867         if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2868             md->md_genid < sc->sc_genid) {
2869                 G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2870                     pp->name, sc->sc_name);
2871                 return (EINVAL);
2872         }
2873         disk = g_mirror_init_disk(sc, pp, md, &error);
2874         if (disk == NULL)
2875                 return (error);
2876         error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2877             G_MIRROR_EVENT_WAIT);
2878         if (error != 0)
2879                 return (error);
2880         if (md->md_version < G_MIRROR_VERSION) {
2881                 G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2882                     pp->name, md->md_version, G_MIRROR_VERSION);
2883                 g_mirror_update_metadata(disk);
2884         }
2885         return (0);
2886 }
2887
2888 static void
2889 g_mirror_destroy_delayed(void *arg, int flag)
2890 {
2891         struct g_mirror_softc *sc;
2892         int error;
2893
2894         if (flag == EV_CANCEL) {
2895                 G_MIRROR_DEBUG(1, "Destroying canceled.");
2896                 return;
2897         }
2898         sc = arg;
2899         g_topology_unlock();
2900         sx_xlock(&sc->sc_lock);
2901         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2902             ("DESTROY flag set on %s.", sc->sc_name));
2903         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0,
2904             ("DESTROYING flag not set on %s.", sc->sc_name));
2905         G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2906         error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2907         if (error != 0) {
2908                 G_MIRROR_DEBUG(0, "Cannot destroy %s (error=%d).",
2909                     sc->sc_name, error);
2910                 sx_xunlock(&sc->sc_lock);
2911         }
2912         g_topology_lock();
2913 }
2914
2915 static int
2916 g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2917 {
2918         struct g_mirror_softc *sc;
2919         int error = 0;
2920
2921         g_topology_assert();
2922         G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2923             acw, ace);
2924
2925         sc = pp->private;
2926         KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2927
2928         g_topology_unlock();
2929         sx_xlock(&sc->sc_lock);
2930         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2931             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0 ||
2932             LIST_EMPTY(&sc->sc_disks)) {
2933                 if (acr > 0 || acw > 0 || ace > 0)
2934                         error = ENXIO;
2935                 goto end;
2936         }
2937         sc->sc_provider_open += acr + acw + ace;
2938         if (pp->acw + acw == 0)
2939                 g_mirror_idle(sc, 0);
2940         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0 &&
2941             sc->sc_provider_open == 0)
2942                 g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK, sc, NULL);
2943 end:
2944         sx_xunlock(&sc->sc_lock);
2945         g_topology_lock();
2946         return (error);
2947 }
2948
2949 struct g_geom *
2950 g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md,
2951     u_int type)
2952 {
2953         struct g_mirror_softc *sc;
2954         struct g_geom *gp;
2955         int error, timeout;
2956
2957         g_topology_assert();
2958         G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2959             md->md_mid);
2960
2961         /* One disk is minimum. */
2962         if (md->md_all < 1)
2963                 return (NULL);
2964         /*
2965          * Action geom.
2966          */
2967         gp = g_new_geomf(mp, "%s", md->md_name);
2968         sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2969         gp->start = g_mirror_start;
2970         gp->orphan = g_mirror_orphan;
2971         gp->access = g_mirror_access;
2972         gp->dumpconf = g_mirror_dumpconf;
2973
2974         sc->sc_type = type;
2975         sc->sc_id = md->md_mid;
2976         sc->sc_slice = md->md_slice;
2977         sc->sc_balance = md->md_balance;
2978         sc->sc_mediasize = md->md_mediasize;
2979         sc->sc_sectorsize = md->md_sectorsize;
2980         sc->sc_ndisks = md->md_all;
2981         sc->sc_flags = md->md_mflags;
2982         sc->sc_bump_id = 0;
2983         sc->sc_idle = 1;
2984         sc->sc_last_write = time_uptime;
2985         sc->sc_writes = 0;
2986         sc->sc_refcnt = 1;
2987         sx_init(&sc->sc_lock, "gmirror:lock");
2988         bioq_init(&sc->sc_queue);
2989         mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
2990         bioq_init(&sc->sc_regular_delayed);
2991         bioq_init(&sc->sc_inflight);
2992         bioq_init(&sc->sc_sync_delayed);
2993         LIST_INIT(&sc->sc_disks);
2994         TAILQ_INIT(&sc->sc_events);
2995         mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
2996         callout_init(&sc->sc_callout, 1);
2997         mtx_init(&sc->sc_done_mtx, "gmirror:done", NULL, MTX_DEF);
2998         sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
2999         gp->softc = sc;
3000         sc->sc_geom = gp;
3001         sc->sc_provider = NULL;
3002         sc->sc_provider_open = 0;
3003         /*
3004          * Synchronization geom.
3005          */
3006         gp = g_new_geomf(mp, "%s.sync", md->md_name);
3007         gp->softc = sc;
3008         gp->orphan = g_mirror_orphan;
3009         sc->sc_sync.ds_geom = gp;
3010         sc->sc_sync.ds_ndisks = 0;
3011         error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
3012             "g_mirror %s", md->md_name);
3013         if (error != 0) {
3014                 G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
3015                     sc->sc_name);
3016                 g_destroy_geom(sc->sc_sync.ds_geom);
3017                 g_destroy_geom(sc->sc_geom);
3018                 g_mirror_free_device(sc);
3019                 return (NULL);
3020         }
3021
3022         G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
3023             sc->sc_name, sc->sc_ndisks, sc->sc_id);
3024
3025         sc->sc_rootmount = root_mount_hold("GMIRROR");
3026         G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
3027         /*
3028          * Run timeout.
3029          */
3030         timeout = g_mirror_timeout * hz;
3031         callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
3032         return (sc->sc_geom);
3033 }
3034
3035 int
3036 g_mirror_destroy(struct g_mirror_softc *sc, int how)
3037 {
3038         struct g_mirror_disk *disk;
3039
3040         g_topology_assert_not();
3041         sx_assert(&sc->sc_lock, SX_XLOCKED);
3042
3043         if (sc->sc_provider_open != 0 || SCHEDULER_STOPPED()) {
3044                 switch (how) {
3045                 case G_MIRROR_DESTROY_SOFT:
3046                         G_MIRROR_DEBUG(1,
3047                             "Device %s is still open (%d).", sc->sc_name,
3048                             sc->sc_provider_open);
3049                         return (EBUSY);
3050                 case G_MIRROR_DESTROY_DELAYED:
3051                         G_MIRROR_DEBUG(1,
3052                             "Device %s will be destroyed on last close.",
3053                             sc->sc_name);
3054                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
3055                                 if (disk->d_state ==
3056                                     G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3057                                         g_mirror_sync_stop(disk, 1);
3058                                 }
3059                         }
3060                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROYING;
3061                         return (EBUSY);
3062                 case G_MIRROR_DESTROY_HARD:
3063                         G_MIRROR_DEBUG(1, "Device %s is still open, so it "
3064                             "can't be definitely removed.", sc->sc_name);
3065                 }
3066         }
3067
3068         g_topology_lock();
3069         if (sc->sc_geom->softc == NULL) {
3070                 g_topology_unlock();
3071                 return (0);
3072         }
3073         sc->sc_geom->softc = NULL;
3074         sc->sc_sync.ds_geom->softc = NULL;
3075         g_topology_unlock();
3076
3077         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
3078         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WAIT;
3079         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
3080         sx_xunlock(&sc->sc_lock);
3081         mtx_lock(&sc->sc_queue_mtx);
3082         wakeup(sc);
3083         mtx_unlock(&sc->sc_queue_mtx);
3084         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
3085         while (sc->sc_worker != NULL)
3086                 tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
3087         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
3088         sx_xlock(&sc->sc_lock);
3089         g_mirror_destroy_device(sc);
3090         return (0);
3091 }
3092
3093 static void
3094 g_mirror_taste_orphan(struct g_consumer *cp)
3095 {
3096
3097         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
3098             cp->provider->name));
3099 }
3100
3101 static struct g_geom *
3102 g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
3103 {
3104         struct g_mirror_metadata md;
3105         struct g_mirror_softc *sc;
3106         struct g_consumer *cp;
3107         struct g_geom *gp;
3108         int error;
3109
3110         g_topology_assert();
3111         g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
3112         G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
3113
3114         gp = g_new_geomf(mp, "mirror:taste");
3115         /*
3116          * This orphan function should be never called.
3117          */
3118         gp->orphan = g_mirror_taste_orphan;
3119         cp = g_new_consumer(gp);
3120         g_attach(cp, pp);
3121         error = g_mirror_read_metadata(cp, &md);
3122         g_detach(cp);
3123         g_destroy_consumer(cp);
3124         g_destroy_geom(gp);
3125         if (error != 0)
3126                 return (NULL);
3127         gp = NULL;
3128
3129         if (md.md_provider[0] != '\0' &&
3130             !g_compare_names(md.md_provider, pp->name))
3131                 return (NULL);
3132         if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3133                 return (NULL);
3134         if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3135                 G_MIRROR_DEBUG(0,
3136                     "Device %s: provider %s marked as inactive, skipping.",
3137                     md.md_name, pp->name);
3138                 return (NULL);
3139         }
3140         if (g_mirror_debug >= 2)
3141                 mirror_metadata_dump(&md);
3142
3143         /*
3144          * Let's check if device already exists.
3145          */
3146         sc = NULL;
3147         LIST_FOREACH(gp, &mp->geom, geom) {
3148                 sc = gp->softc;
3149                 if (sc == NULL)
3150                         continue;
3151                 if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
3152                         continue;
3153                 if (sc->sc_sync.ds_geom == gp)
3154                         continue;
3155                 if (strcmp(md.md_name, sc->sc_name) != 0)
3156                         continue;
3157                 if (md.md_mid != sc->sc_id) {
3158                         G_MIRROR_DEBUG(0, "Device %s already configured.",
3159                             sc->sc_name);
3160                         return (NULL);
3161                 }
3162                 break;
3163         }
3164         if (gp == NULL) {
3165                 gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_AUTOMATIC);
3166                 if (gp == NULL) {
3167                         G_MIRROR_DEBUG(0, "Cannot create device %s.",
3168                             md.md_name);
3169                         return (NULL);
3170                 }
3171                 sc = gp->softc;
3172         }
3173         G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3174         g_topology_unlock();
3175         sx_xlock(&sc->sc_lock);
3176         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
3177         error = g_mirror_add_disk(sc, pp, &md);
3178         if (error != 0) {
3179                 G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3180                     pp->name, gp->name, error);
3181                 if (LIST_EMPTY(&sc->sc_disks)) {
3182                         g_cancel_event(sc);
3183                         g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3184                         g_topology_lock();
3185                         return (NULL);
3186                 }
3187                 gp = NULL;
3188         }
3189         sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
3190         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
3191                 g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3192                 g_topology_lock();
3193                 return (NULL);
3194         }
3195         sx_xunlock(&sc->sc_lock);
3196         g_topology_lock();
3197         return (gp);
3198 }
3199
3200 static void
3201 g_mirror_resize(struct g_consumer *cp)
3202 {
3203         struct g_mirror_disk *disk;
3204
3205         g_topology_assert();
3206         g_trace(G_T_TOPOLOGY, "%s(%s)", __func__, cp->provider->name);
3207
3208         disk = cp->private;
3209         if (disk == NULL)
3210                 return;
3211         g_topology_unlock();
3212         g_mirror_update_metadata(disk);
3213         g_topology_lock();
3214 }
3215
3216 static int
3217 g_mirror_destroy_geom(struct gctl_req *req __unused,
3218     struct g_class *mp __unused, struct g_geom *gp)
3219 {
3220         struct g_mirror_softc *sc;
3221         int error;
3222
3223         g_topology_unlock();
3224         sc = gp->softc;
3225         sx_xlock(&sc->sc_lock);
3226         g_cancel_event(sc);
3227         error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3228         if (error != 0)
3229                 sx_xunlock(&sc->sc_lock);
3230         g_topology_lock();
3231         return (error);
3232 }
3233
3234 static void
3235 g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3236     struct g_consumer *cp, struct g_provider *pp)
3237 {
3238         struct g_mirror_softc *sc;
3239
3240         g_topology_assert();
3241
3242         sc = gp->softc;
3243         if (sc == NULL)
3244                 return;
3245         /* Skip synchronization geom. */
3246         if (gp == sc->sc_sync.ds_geom)
3247                 return;
3248         if (pp != NULL) {
3249                 /* Nothing here. */
3250         } else if (cp != NULL) {
3251                 struct g_mirror_disk *disk;
3252
3253                 disk = cp->private;
3254                 if (disk == NULL)
3255                         return;
3256                 g_topology_unlock();
3257                 sx_xlock(&sc->sc_lock);
3258                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3259                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3260                         sbuf_printf(sb, "%s<Synchronized>", indent);
3261                         if (disk->d_sync.ds_offset == 0)
3262                                 sbuf_printf(sb, "0%%");
3263                         else {
3264                                 sbuf_printf(sb, "%u%%",
3265                                     (u_int)((disk->d_sync.ds_offset * 100) /
3266                                     sc->sc_provider->mediasize));
3267                         }
3268                         sbuf_printf(sb, "</Synchronized>\n");
3269                         if (disk->d_sync.ds_offset > 0) {
3270                                 sbuf_printf(sb, "%s<BytesSynced>%jd"
3271                                     "</BytesSynced>\n", indent,
3272                                     (intmax_t)disk->d_sync.ds_offset);
3273                         }
3274                 }
3275                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3276                     disk->d_sync.ds_syncid);
3277                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3278                     disk->d_genid);
3279                 sbuf_printf(sb, "%s<Flags>", indent);
3280                 if (disk->d_flags == 0)
3281                         sbuf_printf(sb, "NONE");
3282                 else {
3283                         int first = 1;
3284
3285 #define ADD_FLAG(flag, name)    do {                                    \
3286         if ((disk->d_flags & (flag)) != 0) {                            \
3287                 if (!first)                                             \
3288                         sbuf_printf(sb, ", ");                          \
3289                 else                                                    \
3290                         first = 0;                                      \
3291                 sbuf_printf(sb, name);                                  \
3292         }                                                               \
3293 } while (0)
3294                         ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3295                         ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3296                         ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3297                         ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3298                             "SYNCHRONIZING");
3299                         ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3300                         ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3301 #undef  ADD_FLAG
3302                 }
3303                 sbuf_printf(sb, "</Flags>\n");
3304                 sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3305                     disk->d_priority);
3306                 sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3307                     g_mirror_disk_state2str(disk->d_state));
3308                 sx_xunlock(&sc->sc_lock);
3309                 g_topology_lock();
3310         } else {
3311                 g_topology_unlock();
3312                 sx_xlock(&sc->sc_lock);
3313                 sbuf_printf(sb, "%s<Type>", indent);
3314                 switch (sc->sc_type) {
3315                 case G_MIRROR_TYPE_AUTOMATIC:
3316                         sbuf_printf(sb, "AUTOMATIC");
3317                         break;
3318                 case G_MIRROR_TYPE_MANUAL:
3319                         sbuf_printf(sb, "MANUAL");
3320                         break;
3321                 default:
3322                         sbuf_printf(sb, "UNKNOWN");
3323                         break;
3324                 }
3325                 sbuf_printf(sb, "</Type>\n");
3326                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3327                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3328                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3329                 sbuf_printf(sb, "%s<Flags>", indent);
3330                 if (sc->sc_flags == 0)
3331                         sbuf_printf(sb, "NONE");
3332                 else {
3333                         int first = 1;
3334
3335 #define ADD_FLAG(flag, name)    do {                                    \
3336         if ((sc->sc_flags & (flag)) != 0) {                             \
3337                 if (!first)                                             \
3338                         sbuf_printf(sb, ", ");                          \
3339                 else                                                    \
3340                         first = 0;                                      \
3341                 sbuf_printf(sb, name);                                  \
3342         }                                                               \
3343 } while (0)
3344                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3345                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3346 #undef  ADD_FLAG
3347                 }
3348                 sbuf_printf(sb, "</Flags>\n");
3349                 sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3350                     (u_int)sc->sc_slice);
3351                 sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3352                     balance_name(sc->sc_balance));
3353                 sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3354                     sc->sc_ndisks);
3355                 sbuf_printf(sb, "%s<State>", indent);
3356                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3357                         sbuf_printf(sb, "%s", "STARTING");
3358                 else if (sc->sc_ndisks ==
3359                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3360                         sbuf_printf(sb, "%s", "COMPLETE");
3361                 else
3362                         sbuf_printf(sb, "%s", "DEGRADED");
3363                 sbuf_printf(sb, "</State>\n");
3364                 sx_xunlock(&sc->sc_lock);
3365                 g_topology_lock();
3366         }
3367 }
3368
3369 static void
3370 g_mirror_shutdown_post_sync(void *arg, int howto)
3371 {
3372         struct g_class *mp;
3373         struct g_geom *gp, *gp2;
3374         struct g_mirror_softc *sc;
3375         int error;
3376
3377         mp = arg;
3378         g_topology_lock();
3379         g_mirror_shutdown = 1;
3380         LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3381                 if ((sc = gp->softc) == NULL)
3382                         continue;
3383                 /* Skip synchronization geom. */
3384                 if (gp == sc->sc_sync.ds_geom)
3385                         continue;
3386                 g_topology_unlock();
3387                 sx_xlock(&sc->sc_lock);
3388                 g_mirror_idle(sc, -1);
3389                 g_cancel_event(sc);
3390                 error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3391                 if (error != 0)
3392                         sx_xunlock(&sc->sc_lock);
3393                 g_topology_lock();
3394         }
3395         g_topology_unlock();
3396 }
3397
3398 static void
3399 g_mirror_init(struct g_class *mp)
3400 {
3401
3402         g_mirror_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
3403             g_mirror_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
3404         if (g_mirror_post_sync == NULL)
3405                 G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3406 }
3407
3408 static void
3409 g_mirror_fini(struct g_class *mp)
3410 {
3411
3412         if (g_mirror_post_sync != NULL)
3413                 EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_mirror_post_sync);
3414 }
3415
3416 DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);