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/kernel.h>
  33 #include <sys/module.h>
  34 #include <sys/limits.h>
  35 #include <sys/lock.h>
  36 #include <sys/mutex.h>
  37 #include <sys/bio.h>
  38 #include <sys/sysctl.h>
  39 #include <sys/malloc.h>
  40 #include <sys/eventhandler.h>
  41 #include <vm/uma.h>
  42 #include <geom/geom.h>
  43 #include <sys/proc.h>
  44 #include <sys/kthread.h>
  45 #include <sys/sched.h>
  46 #include <geom/mirror/g_mirror.h>
  47
  48
  49 static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
  50
  51 SYSCTL_DECL(_kern_geom);
  52 SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW, 0, "GEOM_MIRROR stuff");
  53 u_int g_mirror_debug = 0;
  54 TUNABLE_INT("kern.geom.mirror.debug", &g_mirror_debug);
  55 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RW, &g_mirror_debug, 0,
  56     "Debug level");
  57 static u_int g_mirror_timeout = 4;
  58 TUNABLE_INT("kern.geom.mirror.timeout", &g_mirror_timeout);
  59 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RW, &g_mirror_timeout,
  60     0, "Time to wait on all mirror components");
  61 static u_int g_mirror_idletime = 5;
  62 TUNABLE_INT("kern.geom.mirror.idletime", &g_mirror_idletime);
  63 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RW,
  64     &g_mirror_idletime, 0, "Mark components as clean when idling");
  65 static u_int g_mirror_disconnect_on_failure = 1;
  66 TUNABLE_INT("kern.geom.mirror.disconnect_on_failure",
  67     &g_mirror_disconnect_on_failure);
  68 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RW,
  69     &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
  70 static u_int g_mirror_syncreqs = 2;
  71 TUNABLE_INT("kern.geom.mirror.sync_requests", &g_mirror_syncreqs);
  72 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
  73     &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
  74
  75 #define MSLEEP(ident, mtx, priority, wmesg, timeout)    do {            \
  76         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));       \
  77         msleep((ident), (mtx), (priority), (wmesg), (timeout));         \
  78         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));       \
  79 } while (0)
  80
  81 static eventhandler_tag g_mirror_pre_sync = NULL;
  82
  83 static int g_mirror_destroy_geom(struct gctl_req *req, struct g_class *mp,
  84     struct g_geom *gp);
  85 static g_taste_t g_mirror_taste;
  86 static void g_mirror_init(struct g_class *mp);
  87 static void g_mirror_fini(struct g_class *mp);
  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 };
  98
  99
 100 static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
 101 static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
 102 static void g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force);
 103 static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
 104     struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
 105 static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
 106 static void g_mirror_register_request(struct bio *bp);
 107 static void g_mirror_sync_release(struct g_mirror_softc *sc);
 108
 109
 110 static const char *
 111 g_mirror_disk_state2str(int state)
 112 {
 113
 114         switch (state) {
 115         case G_MIRROR_DISK_STATE_NONE:
 116                 return ("NONE");
 117         case G_MIRROR_DISK_STATE_NEW:
 118                 return ("NEW");
 119         case G_MIRROR_DISK_STATE_ACTIVE:
 120                 return ("ACTIVE");
 121         case G_MIRROR_DISK_STATE_STALE:
 122                 return ("STALE");
 123         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 124                 return ("SYNCHRONIZING");
 125         case G_MIRROR_DISK_STATE_DISCONNECTED:
 126                 return ("DISCONNECTED");
 127         case G_MIRROR_DISK_STATE_DESTROY:
 128                 return ("DESTROY");
 129         default:
 130                 return ("INVALID");
 131         }
 132 }
 133
 134 static const char *
 135 g_mirror_device_state2str(int state)
 136 {
 137
 138         switch (state) {
 139         case G_MIRROR_DEVICE_STATE_STARTING:
 140                 return ("STARTING");
 141         case G_MIRROR_DEVICE_STATE_RUNNING:
 142                 return ("RUNNING");
 143         default:
 144                 return ("INVALID");
 145         }
 146 }
 147
 148 static const char *
 149 g_mirror_get_diskname(struct g_mirror_disk *disk)
 150 {
 151
 152         if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
 153                 return ("[unknown]");
 154         return (disk->d_name);
 155 }
 156
 157 /*
 158  * --- Events handling functions ---
 159  * Events in geom_mirror are used to maintain disks and device status
 160  * from one thread to simplify locking.
 161  */
 162 static void
 163 g_mirror_event_free(struct g_mirror_event *ep)
 164 {
 165
 166         free(ep, M_MIRROR);
 167 }
 168
 169 int
 170 g_mirror_event_send(void *arg, int state, int flags)
 171 {
 172         struct g_mirror_softc *sc;
 173         struct g_mirror_disk *disk;
 174         struct g_mirror_event *ep;
 175         int error;
 176
 177         ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
 178         G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
 179         if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
 180                 disk = NULL;
 181                 sc = arg;
 182         } else {
 183                 disk = arg;
 184                 sc = disk->d_softc;
 185         }
 186         ep->e_disk = disk;
 187         ep->e_state = state;
 188         ep->e_flags = flags;
 189         ep->e_error = 0;
 190         mtx_lock(&sc->sc_events_mtx);
 191         TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
 192         mtx_unlock(&sc->sc_events_mtx);
 193         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 194         mtx_lock(&sc->sc_queue_mtx);
 195         wakeup(sc);
 196         mtx_unlock(&sc->sc_queue_mtx);
 197         if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 198                 return (0);
 199         sx_assert(&sc->sc_lock, SX_XLOCKED);
 200         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
 201         sx_xunlock(&sc->sc_lock);
 202         while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
 203                 mtx_lock(&sc->sc_events_mtx);
 204                 MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
 205                     hz * 5);
 206         }
 207         error = ep->e_error;
 208         g_mirror_event_free(ep);
 209         sx_xlock(&sc->sc_lock);
 210         return (error);
 211 }
 212
 213 static struct g_mirror_event *
 214 g_mirror_event_get(struct g_mirror_softc *sc)
 215 {
 216         struct g_mirror_event *ep;
 217
 218         mtx_lock(&sc->sc_events_mtx);
 219         ep = TAILQ_FIRST(&sc->sc_events);
 220         mtx_unlock(&sc->sc_events_mtx);
 221         return (ep);
 222 }
 223
 224 static void
 225 g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
 226 {
 227
 228         mtx_lock(&sc->sc_events_mtx);
 229         TAILQ_REMOVE(&sc->sc_events, ep, e_next);
 230         mtx_unlock(&sc->sc_events_mtx);
 231 }
 232
 233 static void
 234 g_mirror_event_cancel(struct g_mirror_disk *disk)
 235 {
 236         struct g_mirror_softc *sc;
 237         struct g_mirror_event *ep, *tmpep;
 238
 239         sc = disk->d_softc;
 240         sx_assert(&sc->sc_lock, SX_XLOCKED);
 241
 242         mtx_lock(&sc->sc_events_mtx);
 243         TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
 244                 if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
 245                         continue;
 246                 if (ep->e_disk != disk)
 247                         continue;
 248                 TAILQ_REMOVE(&sc->sc_events, ep, e_next);
 249                 if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 250                         g_mirror_event_free(ep);
 251                 else {
 252                         ep->e_error = ECANCELED;
 253                         wakeup(ep);
 254                 }
 255         }
 256         mtx_unlock(&sc->sc_events_mtx);
 257 }
 258
 259 /*
 260  * Return the number of disks in given state.
 261  * If state is equal to -1, count all connected disks.
 262  */
 263 u_int
 264 g_mirror_ndisks(struct g_mirror_softc *sc, int state)
 265 {
 266         struct g_mirror_disk *disk;
 267         u_int n = 0;
 268
 269         sx_assert(&sc->sc_lock, SX_LOCKED);
 270
 271         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 272                 if (state == -1 || disk->d_state == state)
 273                         n++;
 274         }
 275         return (n);
 276 }
 277
 278 /*
 279  * Find a disk in mirror by its disk ID.
 280  */
 281 static struct g_mirror_disk *
 282 g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
 283 {
 284         struct g_mirror_disk *disk;
 285
 286         sx_assert(&sc->sc_lock, SX_XLOCKED);
 287
 288         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 289                 if (disk->d_id == id)
 290                         return (disk);
 291         }
 292         return (NULL);
 293 }
 294
 295 static u_int
 296 g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
 297 {
 298         struct bio *bp;
 299         u_int nreqs = 0;
 300
 301         mtx_lock(&sc->sc_queue_mtx);
 302         TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
 303                 if (bp->bio_from == cp)
 304                         nreqs++;
 305         }
 306         mtx_unlock(&sc->sc_queue_mtx);
 307         return (nreqs);
 308 }
 309
 310 static int
 311 g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
 312 {
 313
 314         if (cp->index > 0) {
 315                 G_MIRROR_DEBUG(2,
 316                     "I/O requests for %s exist, can't destroy it now.",
 317                     cp->provider->name);
 318                 return (1);
 319         }
 320         if (g_mirror_nrequests(sc, cp) > 0) {
 321                 G_MIRROR_DEBUG(2,
 322                     "I/O requests for %s in queue, can't destroy it now.",
 323                     cp->provider->name);
 324                 return (1);
 325         }
 326         return (0);
 327 }
 328
 329 static void
 330 g_mirror_destroy_consumer(void *arg, int flags __unused)
 331 {
 332         struct g_consumer *cp;
 333
 334         g_topology_assert();
 335
 336         cp = arg;
 337         G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
 338         g_detach(cp);
 339         g_destroy_consumer(cp);
 340 }
 341
 342 static void
 343 g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
 344 {
 345         struct g_provider *pp;
 346         int retaste_wait;
 347
 348         g_topology_assert();
 349
 350         cp->private = NULL;
 351         if (g_mirror_is_busy(sc, cp))
 352                 return;
 353         pp = cp->provider;
 354         retaste_wait = 0;
 355         if (cp->acw == 1) {
 356                 if ((pp->geom->flags & G_GEOM_WITHER) == 0)
 357                         retaste_wait = 1;
 358         }
 359         G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
 360             -cp->acw, -cp->ace, 0);
 361         if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
 362                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
 363         if (retaste_wait) {
 364                 /*
 365                  * After retaste event was send (inside g_access()), we can send
 366                  * event to detach and destroy consumer.
 367                  * A class, which has consumer to the given provider connected
 368                  * will not receive retaste event for the provider.
 369                  * This is the way how I ignore retaste events when I close
 370                  * consumers opened for write: I detach and destroy consumer
 371                  * after retaste event is sent.
 372                  */
 373                 g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
 374                 return;
 375         }
 376         G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
 377         g_detach(cp);
 378         g_destroy_consumer(cp);
 379 }
 380
 381 static int
 382 g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
 383 {
 384         struct g_consumer *cp;
 385         int error;
 386
 387         g_topology_assert_not();
 388         KASSERT(disk->d_consumer == NULL,
 389             ("Disk already connected (device %s).", disk->d_softc->sc_name));
 390
 391         g_topology_lock();
 392         cp = g_new_consumer(disk->d_softc->sc_geom);
 393         error = g_attach(cp, pp);
 394         if (error != 0) {
 395                 g_destroy_consumer(cp);
 396                 g_topology_unlock();
 397                 return (error);
 398         }
 399         error = g_access(cp, 1, 1, 1);
 400         if (error != 0) {
 401                 g_detach(cp);
 402                 g_destroy_consumer(cp);
 403                 g_topology_unlock();
 404                 G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
 405                     pp->name, error);
 406                 return (error);
 407         }
 408         g_topology_unlock();
 409         disk->d_consumer = cp;
 410         disk->d_consumer->private = disk;
 411         disk->d_consumer->index = 0;
 412
 413         G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
 414         return (0);
 415 }
 416
 417 static void
 418 g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
 419 {
 420
 421         g_topology_assert();
 422
 423         if (cp == NULL)
 424                 return;
 425         if (cp->provider != NULL)
 426                 g_mirror_kill_consumer(sc, cp);
 427         else
 428                 g_destroy_consumer(cp);
 429 }
 430
 431 /*
 432  * Initialize disk. This means allocate memory, create consumer, attach it
 433  * to the provider and open access (r1w1e1) to it.
 434  */
 435 static struct g_mirror_disk *
 436 g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
 437     struct g_mirror_metadata *md, int *errorp)
 438 {
 439         struct g_mirror_disk *disk;
 440         int error;
 441
 442         disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
 443         if (disk == NULL) {
 444                 error = ENOMEM;
 445                 goto fail;
 446         }
 447         disk->d_softc = sc;
 448         error = g_mirror_connect_disk(disk, pp);
 449         if (error != 0)
 450                 goto fail;
 451         disk->d_id = md->md_did;
 452         disk->d_state = G_MIRROR_DISK_STATE_NONE;
 453         disk->d_priority = md->md_priority;
 454         disk->d_flags = md->md_dflags;
 455         if (md->md_provider[0] != '\0')
 456                 disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
 457         disk->d_sync.ds_consumer = NULL;
 458         disk->d_sync.ds_offset = md->md_sync_offset;
 459         disk->d_sync.ds_offset_done = md->md_sync_offset;
 460         disk->d_genid = md->md_genid;
 461         disk->d_sync.ds_syncid = md->md_syncid;
 462         if (errorp != NULL)
 463                 *errorp = 0;
 464         return (disk);
 465 fail:
 466         if (errorp != NULL)
 467                 *errorp = error;
 468         if (disk != NULL)
 469                 free(disk, M_MIRROR);
 470         return (NULL);
 471 }
 472
 473 static void
 474 g_mirror_destroy_disk(struct g_mirror_disk *disk)
 475 {
 476         struct g_mirror_softc *sc;
 477
 478         g_topology_assert_not();
 479         sc = disk->d_softc;
 480         sx_assert(&sc->sc_lock, SX_XLOCKED);
 481
 482         LIST_REMOVE(disk, d_next);
 483         g_mirror_event_cancel(disk);
 484         if (sc->sc_hint == disk)
 485                 sc->sc_hint = NULL;
 486         switch (disk->d_state) {
 487         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 488                 g_mirror_sync_stop(disk, 1);
 489                 /* FALLTHROUGH */
 490         case G_MIRROR_DISK_STATE_NEW:
 491         case G_MIRROR_DISK_STATE_STALE:
 492         case G_MIRROR_DISK_STATE_ACTIVE:
 493                 g_topology_lock();
 494                 g_mirror_disconnect_consumer(sc, disk->d_consumer);
 495                 g_topology_unlock();
 496                 free(disk, M_MIRROR);
 497                 break;
 498         default:
 499                 KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
 500                     g_mirror_get_diskname(disk),
 501                     g_mirror_disk_state2str(disk->d_state)));
 502         }
 503 }
 504
 505 static void
 506 g_mirror_destroy_device(struct g_mirror_softc *sc)
 507 {
 508         struct g_mirror_disk *disk;
 509         struct g_mirror_event *ep;
 510         struct g_geom *gp;
 511         struct g_consumer *cp, *tmpcp;
 512
 513         g_topology_assert_not();
 514         sx_assert(&sc->sc_lock, SX_XLOCKED);
 515
 516         gp = sc->sc_geom;
 517         if (sc->sc_provider != NULL)
 518                 g_mirror_destroy_provider(sc);
 519         for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
 520             disk = LIST_FIRST(&sc->sc_disks)) {
 521                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 522                 g_mirror_update_metadata(disk);
 523                 g_mirror_destroy_disk(disk);
 524         }
 525         while ((ep = g_mirror_event_get(sc)) != NULL) {
 526                 g_mirror_event_remove(sc, ep);
 527                 if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 528                         g_mirror_event_free(ep);
 529                 else {
 530                         ep->e_error = ECANCELED;
 531                         ep->e_flags |= G_MIRROR_EVENT_DONE;
 532                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
 533                         mtx_lock(&sc->sc_events_mtx);
 534                         wakeup(ep);
 535                         mtx_unlock(&sc->sc_events_mtx);
 536                 }
 537         }
 538         callout_drain(&sc->sc_callout);
 539
 540         g_topology_lock();
 541         LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
 542                 g_mirror_disconnect_consumer(sc, cp);
 543         }
 544         g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
 545         G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
 546         g_wither_geom(gp, ENXIO);
 547         g_topology_unlock();
 548         mtx_destroy(&sc->sc_queue_mtx);
 549         mtx_destroy(&sc->sc_events_mtx);
 550         sx_xunlock(&sc->sc_lock);
 551         sx_destroy(&sc->sc_lock);
 552 }
 553
 554 static void
 555 g_mirror_orphan(struct g_consumer *cp)
 556 {
 557         struct g_mirror_disk *disk;
 558
 559         g_topology_assert();
 560
 561         disk = cp->private;
 562         if (disk == NULL)
 563                 return;
 564         disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 565         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
 566             G_MIRROR_EVENT_DONTWAIT);
 567 }
 568
 569 /*
 570  * Function should return the next active disk on the list.
 571  * It is possible that it will be the same disk as given.
 572  * If there are no active disks on list, NULL is returned.
 573  */
 574 static __inline struct g_mirror_disk *
 575 g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
 576 {
 577         struct g_mirror_disk *dp;
 578
 579         for (dp = LIST_NEXT(disk, d_next); dp != disk;
 580             dp = LIST_NEXT(dp, d_next)) {
 581                 if (dp == NULL)
 582                         dp = LIST_FIRST(&sc->sc_disks);
 583                 if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
 584                         break;
 585         }
 586         if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 587                 return (NULL);
 588         return (dp);
 589 }
 590
 591 static struct g_mirror_disk *
 592 g_mirror_get_disk(struct g_mirror_softc *sc)
 593 {
 594         struct g_mirror_disk *disk;
 595
 596         if (sc->sc_hint == NULL) {
 597                 sc->sc_hint = LIST_FIRST(&sc->sc_disks);
 598                 if (sc->sc_hint == NULL)
 599                         return (NULL);
 600         }
 601         disk = sc->sc_hint;
 602         if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
 603                 disk = g_mirror_find_next(sc, disk);
 604                 if (disk == NULL)
 605                         return (NULL);
 606         }
 607         sc->sc_hint = g_mirror_find_next(sc, disk);
 608         return (disk);
 609 }
 610
 611 static int
 612 g_mirror_write_metadata(struct g_mirror_disk *disk,
 613     struct g_mirror_metadata *md)
 614 {
 615         struct g_mirror_softc *sc;
 616         struct g_consumer *cp;
 617         off_t offset, length;
 618         u_char *sector;
 619         int error = 0;
 620
 621         g_topology_assert_not();
 622         sc = disk->d_softc;
 623         sx_assert(&sc->sc_lock, SX_LOCKED);
 624
 625         cp = disk->d_consumer;
 626         KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
 627         KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
 628         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 629             ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
 630             cp->acw, cp->ace));
 631         length = cp->provider->sectorsize;
 632         offset = cp->provider->mediasize - length;
 633         sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
 634         if (md != NULL)
 635                 mirror_metadata_encode(md, sector);
 636         error = g_write_data(cp, offset, sector, length);
 637         free(sector, M_MIRROR);
 638         if (error != 0) {
 639                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
 640                         disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
 641                         G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
 642                             "(device=%s, error=%d).",
 643                             g_mirror_get_diskname(disk), sc->sc_name, error);
 644                 } else {
 645                         G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
 646                             "(device=%s, error=%d).",
 647                             g_mirror_get_diskname(disk), sc->sc_name, error);
 648                 }
 649                 if (g_mirror_disconnect_on_failure &&
 650                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
 651                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 652                         g_mirror_event_send(disk,
 653                             G_MIRROR_DISK_STATE_DISCONNECTED,
 654                             G_MIRROR_EVENT_DONTWAIT);
 655                 }
 656         }
 657         return (error);
 658 }
 659
 660 static int
 661 g_mirror_clear_metadata(struct g_mirror_disk *disk)
 662 {
 663         int error;
 664
 665         g_topology_assert_not();
 666         sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
 667
 668         error = g_mirror_write_metadata(disk, NULL);
 669         if (error == 0) {
 670                 G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
 671                     g_mirror_get_diskname(disk));
 672         } else {
 673                 G_MIRROR_DEBUG(0,
 674                     "Cannot clear metadata on disk %s (error=%d).",
 675                     g_mirror_get_diskname(disk), error);
 676         }
 677         return (error);
 678 }
 679
 680 void
 681 g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
 682     struct g_mirror_metadata *md)
 683 {
 684
 685         strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
 686         md->md_version = G_MIRROR_VERSION;
 687         strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
 688         md->md_mid = sc->sc_id;
 689         md->md_all = sc->sc_ndisks;
 690         md->md_slice = sc->sc_slice;
 691         md->md_balance = sc->sc_balance;
 692         md->md_genid = sc->sc_genid;
 693         md->md_mediasize = sc->sc_mediasize;
 694         md->md_sectorsize = sc->sc_sectorsize;
 695         md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
 696         bzero(md->md_provider, sizeof(md->md_provider));
 697         if (disk == NULL) {
 698                 md->md_did = arc4random();
 699                 md->md_priority = 0;
 700                 md->md_syncid = 0;
 701                 md->md_dflags = 0;
 702                 md->md_sync_offset = 0;
 703                 md->md_provsize = 0;
 704         } else {
 705                 md->md_did = disk->d_id;
 706                 md->md_priority = disk->d_priority;
 707                 md->md_syncid = disk->d_sync.ds_syncid;
 708                 md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
 709                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
 710                         md->md_sync_offset = disk->d_sync.ds_offset_done;
 711                 else
 712                         md->md_sync_offset = 0;
 713                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
 714                         strlcpy(md->md_provider,
 715                             disk->d_consumer->provider->name,
 716                             sizeof(md->md_provider));
 717                 }
 718                 md->md_provsize = disk->d_consumer->provider->mediasize;
 719         }
 720 }
 721
 722 void
 723 g_mirror_update_metadata(struct g_mirror_disk *disk)
 724 {
 725         struct g_mirror_softc *sc;
 726         struct g_mirror_metadata md;
 727         int error;
 728
 729         g_topology_assert_not();
 730         sc = disk->d_softc;
 731         sx_assert(&sc->sc_lock, SX_LOCKED);
 732
 733         g_mirror_fill_metadata(sc, disk, &md);
 734         error = g_mirror_write_metadata(disk, &md);
 735         if (error == 0) {
 736                 G_MIRROR_DEBUG(2, "Metadata on %s updated.",
 737                     g_mirror_get_diskname(disk));
 738         } else {
 739                 G_MIRROR_DEBUG(0,
 740                     "Cannot update metadata on disk %s (error=%d).",
 741                     g_mirror_get_diskname(disk), error);
 742         }
 743 }
 744
 745 static void
 746 g_mirror_bump_syncid(struct g_mirror_softc *sc)
 747 {
 748         struct g_mirror_disk *disk;
 749
 750         g_topology_assert_not();
 751         sx_assert(&sc->sc_lock, SX_XLOCKED);
 752         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
 753             ("%s called with no active disks (device=%s).", __func__,
 754             sc->sc_name));
 755
 756         sc->sc_syncid++;
 757         G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
 758             sc->sc_syncid);
 759         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 760                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 761                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 762                         disk->d_sync.ds_syncid = sc->sc_syncid;
 763                         g_mirror_update_metadata(disk);
 764                 }
 765         }
 766 }
 767
 768 static void
 769 g_mirror_bump_genid(struct g_mirror_softc *sc)
 770 {
 771         struct g_mirror_disk *disk;
 772
 773         g_topology_assert_not();
 774         sx_assert(&sc->sc_lock, SX_XLOCKED);
 775         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
 776             ("%s called with no active disks (device=%s).", __func__,
 777             sc->sc_name));
 778
 779         sc->sc_genid++;
 780         G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
 781             sc->sc_genid);
 782         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 783                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 784                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 785                         disk->d_genid = sc->sc_genid;
 786                         g_mirror_update_metadata(disk);
 787                 }
 788         }
 789 }
 790
 791 static int
 792 g_mirror_idle(struct g_mirror_softc *sc, int acw)
 793 {
 794         struct g_mirror_disk *disk;
 795         int timeout;
 796
 797         g_topology_assert_not();
 798         sx_assert(&sc->sc_lock, SX_XLOCKED);
 799
 800         if (sc->sc_provider == NULL)
 801                 return (0);
 802         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 803                 return (0);
 804         if (sc->sc_idle)
 805                 return (0);
 806         if (sc->sc_writes > 0)
 807                 return (0);
 808         if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
 809                 timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
 810                 if (timeout > 0)
 811                         return (timeout);
 812         }
 813         sc->sc_idle = 1;
 814         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 815                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 816                         continue;
 817                 G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
 818                     g_mirror_get_diskname(disk), sc->sc_name);
 819                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 820                 g_mirror_update_metadata(disk);
 821         }
 822         return (0);
 823 }
 824
 825 static void
 826 g_mirror_unidle(struct g_mirror_softc *sc)
 827 {
 828         struct g_mirror_disk *disk;
 829
 830         g_topology_assert_not();
 831         sx_assert(&sc->sc_lock, SX_XLOCKED);
 832
 833         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 834                 return;
 835         sc->sc_idle = 0;
 836         sc->sc_last_write = time_uptime;
 837         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 838                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 839                         continue;
 840                 G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
 841                     g_mirror_get_diskname(disk), sc->sc_name);
 842                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
 843                 g_mirror_update_metadata(disk);
 844         }
 845 }
 846
 847 static __inline int
 848 bintime_cmp(struct bintime *bt1, struct bintime *bt2)
 849 {
 850
 851         if (bt1->sec < bt2->sec)
 852                 return (-1);
 853         else if (bt1->sec > bt2->sec)
 854                 return (1);
 855         if (bt1->frac < bt2->frac)
 856                 return (-1);
 857         else if (bt1->frac > bt2->frac)
 858                 return (1);
 859         return (0);
 860 }
 861
 862 static void
 863 g_mirror_done(struct bio *bp)
 864 {
 865         struct g_mirror_softc *sc;
 866
 867         sc = bp->bio_from->geom->softc;
 868         bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
 869         mtx_lock(&sc->sc_queue_mtx);
 870         bioq_disksort(&sc->sc_queue, bp);
 871         mtx_unlock(&sc->sc_queue_mtx);
 872         wakeup(sc);
 873 }
 874
 875 static void
 876 g_mirror_regular_request(struct bio *bp)
 877 {
 878         struct g_mirror_softc *sc;
 879         struct g_mirror_disk *disk;
 880         struct bio *pbp;
 881
 882         g_topology_assert_not();
 883
 884         pbp = bp->bio_parent;
 885         sc = pbp->bio_to->geom->softc;
 886         bp->bio_from->index--;
 887         if (bp->bio_cmd == BIO_WRITE)
 888                 sc->sc_writes--;
 889         disk = bp->bio_from->private;
 890         if (disk == NULL) {
 891                 g_topology_lock();
 892                 g_mirror_kill_consumer(sc, bp->bio_from);
 893                 g_topology_unlock();
 894         }
 895
 896         pbp->bio_inbed++;
 897         KASSERT(pbp->bio_inbed <= pbp->bio_children,
 898             ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
 899             pbp->bio_children));
 900         if (bp->bio_error == 0 && pbp->bio_error == 0) {
 901                 G_MIRROR_LOGREQ(3, bp, "Request delivered.");
 902                 g_destroy_bio(bp);
 903                 if (pbp->bio_children == pbp->bio_inbed) {
 904                         G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
 905                         pbp->bio_completed = pbp->bio_length;
 906                         if (pbp->bio_cmd == BIO_WRITE) {
 907                                 bioq_remove(&sc->sc_inflight, pbp);
 908                                 /* Release delayed sync requests if possible. */
 909                                 g_mirror_sync_release(sc);
 910                         }
 911                         g_io_deliver(pbp, pbp->bio_error);
 912                 }
 913                 return;
 914         } else if (bp->bio_error != 0) {
 915                 if (pbp->bio_error == 0)
 916                         pbp->bio_error = bp->bio_error;
 917                 if (disk != NULL) {
 918                         if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
 919                                 disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
 920                                 G_MIRROR_LOGREQ(0, bp,
 921                                     "Request failed (error=%d).",
 922                                     bp->bio_error);
 923                         } else {
 924                                 G_MIRROR_LOGREQ(1, bp,
 925                                     "Request failed (error=%d).",
 926                                     bp->bio_error);
 927                         }
 928                         if (g_mirror_disconnect_on_failure &&
 929                             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1)
 930                         {
 931                                 sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 932                                 g_mirror_event_send(disk,
 933                                     G_MIRROR_DISK_STATE_DISCONNECTED,
 934                                     G_MIRROR_EVENT_DONTWAIT);
 935                         }
 936                 }
 937                 switch (pbp->bio_cmd) {
 938                 case BIO_DELETE:
 939                 case BIO_WRITE:
 940                         pbp->bio_inbed--;
 941                         pbp->bio_children--;
 942                         break;
 943                 }
 944         }
 945         g_destroy_bio(bp);
 946
 947         switch (pbp->bio_cmd) {
 948         case BIO_READ:
 949                 if (pbp->bio_inbed < pbp->bio_children)
 950                         break;
 951                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
 952                         g_io_deliver(pbp, pbp->bio_error);
 953                 else {
 954                         pbp->bio_error = 0;
 955                         mtx_lock(&sc->sc_queue_mtx);
 956                         bioq_disksort(&sc->sc_queue, pbp);
 957                         mtx_unlock(&sc->sc_queue_mtx);
 958                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 959                         wakeup(sc);
 960                 }
 961                 break;
 962         case BIO_DELETE:
 963         case BIO_WRITE:
 964                 if (pbp->bio_children == 0) {
 965                         /*
 966                          * All requests failed.
 967                          */
 968                 } else if (pbp->bio_inbed < pbp->bio_children) {
 969                         /* Do nothing. */
 970                         break;
 971                 } else if (pbp->bio_children == pbp->bio_inbed) {
 972                         /* Some requests succeeded. */
 973                         pbp->bio_error = 0;
 974                         pbp->bio_completed = pbp->bio_length;
 975                 }
 976                 bioq_remove(&sc->sc_inflight, pbp);
 977                 /* Release delayed sync requests if possible. */
 978                 g_mirror_sync_release(sc);
 979                 g_io_deliver(pbp, pbp->bio_error);
 980                 break;
 981         default:
 982                 KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
 983                 break;
 984         }
 985 }
 986
 987 static void
 988 g_mirror_sync_done(struct bio *bp)
 989 {
 990         struct g_mirror_softc *sc;
 991
 992         G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
 993         sc = bp->bio_from->geom->softc;
 994         bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
 995         mtx_lock(&sc->sc_queue_mtx);
 996         bioq_disksort(&sc->sc_queue, bp);
 997         mtx_unlock(&sc->sc_queue_mtx);
 998         wakeup(sc);
 999 }
1000
1001 static void
1002 g_mirror_kernel_dump(struct bio *bp)
1003 {
1004         struct g_mirror_softc *sc;
1005         struct g_mirror_disk *disk;
1006         struct bio *cbp;
1007         struct g_kerneldump *gkd;
1008
1009         /*
1010          * We configure dumping to the first component, because this component
1011          * will be used for reading with 'prefer' balance algorithm.
1012          * If the component with the higest priority is currently disconnected
1013          * we will not be able to read the dump after the reboot if it will be
1014          * connected and synchronized later. Can we do something better?
1015          */
1016         sc = bp->bio_to->geom->softc;
1017         disk = LIST_FIRST(&sc->sc_disks);
1018
1019         gkd = (struct g_kerneldump *)bp->bio_data;
1020         if (gkd->length > bp->bio_to->mediasize)
1021                 gkd->length = bp->bio_to->mediasize;
1022         cbp = g_clone_bio(bp);
1023         if (cbp == NULL) {
1024                 g_io_deliver(bp, ENOMEM);
1025                 return;
1026         }
1027         cbp->bio_done = g_std_done;
1028         g_io_request(cbp, disk->d_consumer);
1029         G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1030             g_mirror_get_diskname(disk));
1031 }
1032
1033 static void
1034 g_mirror_flush(struct g_mirror_softc *sc, struct bio *bp)
1035 {
1036         struct bio_queue_head queue;
1037         struct g_mirror_disk *disk;
1038         struct g_consumer *cp;
1039         struct bio *cbp;
1040
1041         bioq_init(&queue);
1042         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1043                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1044                         continue;
1045                 cbp = g_clone_bio(bp);
1046                 if (cbp == NULL) {
1047                         for (cbp = bioq_first(&queue); cbp != NULL;
1048                             cbp = bioq_first(&queue)) {
1049                                 bioq_remove(&queue, cbp);
1050                                 g_destroy_bio(cbp);
1051                         }
1052                         if (bp->bio_error == 0)
1053                                 bp->bio_error = ENOMEM;
1054                         g_io_deliver(bp, bp->bio_error);
1055                         return;
1056                 }
1057                 bioq_insert_tail(&queue, cbp);
1058                 cbp->bio_done = g_std_done;
1059                 cbp->bio_caller1 = disk;
1060                 cbp->bio_to = disk->d_consumer->provider;
1061         }
1062         for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1063                 bioq_remove(&queue, cbp);
1064                 G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1065                 disk = cbp->bio_caller1;
1066                 cbp->bio_caller1 = NULL;
1067                 cp = disk->d_consumer;
1068                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1069                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1070                     cp->acr, cp->acw, cp->ace));
1071                 g_io_request(cbp, disk->d_consumer);
1072         }
1073 }
1074
1075 static void
1076 g_mirror_start(struct bio *bp)
1077 {
1078         struct g_mirror_softc *sc;
1079
1080         sc = bp->bio_to->geom->softc;
1081         /*
1082          * If sc == NULL or there are no valid disks, provider's error
1083          * should be set and g_mirror_start() should not be called at all.
1084          */
1085         KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1086             ("Provider's error should be set (error=%d)(mirror=%s).",
1087             bp->bio_to->error, bp->bio_to->name));
1088         G_MIRROR_LOGREQ(3, bp, "Request received.");
1089
1090         switch (bp->bio_cmd) {
1091         case BIO_READ:
1092         case BIO_WRITE:
1093         case BIO_DELETE:
1094                 break;
1095         case BIO_FLUSH:
1096                 g_mirror_flush(sc, bp);
1097                 return;
1098         case BIO_GETATTR:
1099                 if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1100                         g_mirror_kernel_dump(bp);
1101                         return;
1102                 }
1103                 /* FALLTHROUGH */
1104         default:
1105                 g_io_deliver(bp, EOPNOTSUPP);
1106                 return;
1107         }
1108         mtx_lock(&sc->sc_queue_mtx);
1109         bioq_disksort(&sc->sc_queue, bp);
1110         mtx_unlock(&sc->sc_queue_mtx);
1111         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1112         wakeup(sc);
1113 }
1114
1115 /*
1116  * Return TRUE if the given request is colliding with a in-progress
1117  * synchronization request.
1118  */
1119 static int
1120 g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1121 {
1122         struct g_mirror_disk *disk;
1123         struct bio *sbp;
1124         off_t rstart, rend, sstart, send;
1125         int i;
1126
1127         if (sc->sc_sync.ds_ndisks == 0)
1128                 return (0);
1129         rstart = bp->bio_offset;
1130         rend = bp->bio_offset + bp->bio_length;
1131         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1132                 if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1133                         continue;
1134                 for (i = 0; i < g_mirror_syncreqs; i++) {
1135                         sbp = disk->d_sync.ds_bios[i];
1136                         if (sbp == NULL)
1137                                 continue;
1138                         sstart = sbp->bio_offset;
1139                         send = sbp->bio_offset + sbp->bio_length;
1140                         if (rend > sstart && rstart < send)
1141                                 return (1);
1142                 }
1143         }
1144         return (0);
1145 }
1146
1147 /*
1148  * Return TRUE if the given sync request is colliding with a in-progress regular
1149  * request.
1150  */
1151 static int
1152 g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1153 {
1154         off_t rstart, rend, sstart, send;
1155         struct bio *bp;
1156
1157         if (sc->sc_sync.ds_ndisks == 0)
1158                 return (0);
1159         sstart = sbp->bio_offset;
1160         send = sbp->bio_offset + sbp->bio_length;
1161         TAILQ_FOREACH(bp, &sc->sc_inflight.queue, bio_queue) {
1162                 rstart = bp->bio_offset;
1163                 rend = bp->bio_offset + bp->bio_length;
1164                 if (rend > sstart && rstart < send)
1165                         return (1);
1166         }
1167         return (0);
1168 }
1169
1170 /*
1171  * Puts request onto delayed queue.
1172  */
1173 static void
1174 g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1175 {
1176
1177         G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1178         bioq_insert_head(&sc->sc_regular_delayed, bp);
1179 }
1180
1181 /*
1182  * Puts synchronization request onto delayed queue.
1183  */
1184 static void
1185 g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1186 {
1187
1188         G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1189         bioq_insert_tail(&sc->sc_sync_delayed, bp);
1190 }
1191
1192 /*
1193  * Releases delayed regular requests which don't collide anymore with sync
1194  * requests.
1195  */
1196 static void
1197 g_mirror_regular_release(struct g_mirror_softc *sc)
1198 {
1199         struct bio *bp, *bp2;
1200
1201         TAILQ_FOREACH_SAFE(bp, &sc->sc_regular_delayed.queue, bio_queue, bp2) {
1202                 if (g_mirror_sync_collision(sc, bp))
1203                         continue;
1204                 bioq_remove(&sc->sc_regular_delayed, bp);
1205                 G_MIRROR_LOGREQ(2, bp, "Releasing delayed request (%p).", bp);
1206                 mtx_lock(&sc->sc_queue_mtx);
1207                 bioq_insert_head(&sc->sc_queue, bp);
1208 #if 0
1209                 /*
1210                  * wakeup() is not needed, because this function is called from
1211                  * the worker thread.
1212                  */
1213                 wakeup(&sc->sc_queue);
1214 #endif
1215                 mtx_unlock(&sc->sc_queue_mtx);
1216         }
1217 }
1218
1219 /*
1220  * Releases delayed sync requests which don't collide anymore with regular
1221  * requests.
1222  */
1223 static void
1224 g_mirror_sync_release(struct g_mirror_softc *sc)
1225 {
1226         struct bio *bp, *bp2;
1227
1228         TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed.queue, bio_queue, bp2) {
1229                 if (g_mirror_regular_collision(sc, bp))
1230                         continue;
1231                 bioq_remove(&sc->sc_sync_delayed, bp);
1232                 G_MIRROR_LOGREQ(2, bp,
1233                     "Releasing delayed synchronization request.");
1234                 g_io_request(bp, bp->bio_from);
1235         }
1236 }
1237
1238 /*
1239  * Handle synchronization requests.
1240  * Every synchronization request is two-steps process: first, READ request is
1241  * send to active provider and then WRITE request (with read data) to the provider
1242  * beeing synchronized. When WRITE is finished, new synchronization request is
1243  * send.
1244  */
1245 static void
1246 g_mirror_sync_request(struct bio *bp)
1247 {
1248         struct g_mirror_softc *sc;
1249         struct g_mirror_disk *disk;
1250
1251         bp->bio_from->index--;
1252         sc = bp->bio_from->geom->softc;
1253         disk = bp->bio_from->private;
1254         if (disk == NULL) {
1255                 sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1256                 g_topology_lock();
1257                 g_mirror_kill_consumer(sc, bp->bio_from);
1258                 g_topology_unlock();
1259                 free(bp->bio_data, M_MIRROR);
1260                 g_destroy_bio(bp);
1261                 sx_xlock(&sc->sc_lock);
1262                 return;
1263         }
1264
1265         /*
1266          * Synchronization request.
1267          */
1268         switch (bp->bio_cmd) {
1269         case BIO_READ:
1270             {
1271                 struct g_consumer *cp;
1272
1273                 if (bp->bio_error != 0) {
1274                         G_MIRROR_LOGREQ(0, bp,
1275                             "Synchronization request failed (error=%d).",
1276                             bp->bio_error);
1277                         g_destroy_bio(bp);
1278                         return;
1279                 }
1280                 G_MIRROR_LOGREQ(3, bp,
1281                     "Synchronization request half-finished.");
1282                 bp->bio_cmd = BIO_WRITE;
1283                 bp->bio_cflags = 0;
1284                 cp = disk->d_consumer;
1285                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1286                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1287                     cp->acr, cp->acw, cp->ace));
1288                 cp->index++;
1289                 g_io_request(bp, cp);
1290                 return;
1291             }
1292         case BIO_WRITE:
1293             {
1294                 struct g_mirror_disk_sync *sync;
1295                 off_t offset;
1296                 void *data;
1297                 int i;
1298
1299                 if (bp->bio_error != 0) {
1300                         G_MIRROR_LOGREQ(0, bp,
1301                             "Synchronization request failed (error=%d).",
1302                             bp->bio_error);
1303                         g_destroy_bio(bp);
1304                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1305                         g_mirror_event_send(disk,
1306                             G_MIRROR_DISK_STATE_DISCONNECTED,
1307                             G_MIRROR_EVENT_DONTWAIT);
1308                         return;
1309                 }
1310                 G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1311                 sync = &disk->d_sync;
1312                 if (sync->ds_offset == sc->sc_mediasize ||
1313                     sync->ds_consumer == NULL ||
1314                     (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1315                         /* Don't send more synchronization requests. */
1316                         sync->ds_inflight--;
1317                         if (sync->ds_bios != NULL) {
1318                                 i = (int)(uintptr_t)bp->bio_caller1;
1319                                 sync->ds_bios[i] = NULL;
1320                         }
1321                         free(bp->bio_data, M_MIRROR);
1322                         g_destroy_bio(bp);
1323                         if (sync->ds_inflight > 0)
1324                                 return;
1325                         if (sync->ds_consumer == NULL ||
1326                             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1327                                 return;
1328                         }
1329                         /* Disk up-to-date, activate it. */
1330                         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1331                             G_MIRROR_EVENT_DONTWAIT);
1332                         return;
1333                 }
1334
1335                 /* Send next synchronization request. */
1336                 data = bp->bio_data;
1337                 bzero(bp, sizeof(*bp));
1338                 bp->bio_cmd = BIO_READ;
1339                 bp->bio_offset = sync->ds_offset;
1340                 bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1341                 sync->ds_offset += bp->bio_length;
1342                 bp->bio_done = g_mirror_sync_done;
1343                 bp->bio_data = data;
1344                 bp->bio_from = sync->ds_consumer;
1345                 bp->bio_to = sc->sc_provider;
1346                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1347                 sync->ds_consumer->index++;
1348                 /*
1349                  * Delay the request if it is colliding with a regular request.
1350                  */
1351                 if (g_mirror_regular_collision(sc, bp))
1352                         g_mirror_sync_delay(sc, bp);
1353                 else
1354                         g_io_request(bp, sync->ds_consumer);
1355
1356                 /* Release delayed requests if possible. */
1357                 g_mirror_regular_release(sc);
1358
1359                 /* Find the smallest offset */
1360                 offset = sc->sc_mediasize;
1361                 for (i = 0; i < g_mirror_syncreqs; i++) {
1362                         bp = sync->ds_bios[i];
1363                         if (bp->bio_offset < offset)
1364                                 offset = bp->bio_offset;
1365                 }
1366                 if (sync->ds_offset_done + (MAXPHYS * 100) < offset) {
1367                         /* Update offset_done on every 100 blocks. */
1368                         sync->ds_offset_done = offset;
1369                         g_mirror_update_metadata(disk);
1370                 }
1371                 return;
1372             }
1373         default:
1374                 KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1375                     bp->bio_cmd, sc->sc_name));
1376                 break;
1377         }
1378 }
1379
1380 static void
1381 g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1382 {
1383         struct g_mirror_disk *disk;
1384         struct g_consumer *cp;
1385         struct bio *cbp;
1386
1387         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1388                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1389                         break;
1390         }
1391         if (disk == NULL) {
1392                 if (bp->bio_error == 0)
1393                         bp->bio_error = ENXIO;
1394                 g_io_deliver(bp, bp->bio_error);
1395                 return;
1396         }
1397         cbp = g_clone_bio(bp);
1398         if (cbp == NULL) {
1399                 if (bp->bio_error == 0)
1400                         bp->bio_error = ENOMEM;
1401                 g_io_deliver(bp, bp->bio_error);
1402                 return;
1403         }
1404         /*
1405          * Fill in the component buf structure.
1406          */
1407         cp = disk->d_consumer;
1408         cbp->bio_done = g_mirror_done;
1409         cbp->bio_to = cp->provider;
1410         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1411         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1412             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1413             cp->acw, cp->ace));
1414         cp->index++;
1415         g_io_request(cbp, cp);
1416 }
1417
1418 static void
1419 g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1420 {
1421         struct g_mirror_disk *disk;
1422         struct g_consumer *cp;
1423         struct bio *cbp;
1424
1425         disk = g_mirror_get_disk(sc);
1426         if (disk == NULL) {
1427                 if (bp->bio_error == 0)
1428                         bp->bio_error = ENXIO;
1429                 g_io_deliver(bp, bp->bio_error);
1430                 return;
1431         }
1432         cbp = g_clone_bio(bp);
1433         if (cbp == NULL) {
1434                 if (bp->bio_error == 0)
1435                         bp->bio_error = ENOMEM;
1436                 g_io_deliver(bp, bp->bio_error);
1437                 return;
1438         }
1439         /*
1440          * Fill in the component buf structure.
1441          */
1442         cp = disk->d_consumer;
1443         cbp->bio_done = g_mirror_done;
1444         cbp->bio_to = cp->provider;
1445         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1446         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1447             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1448             cp->acw, cp->ace));
1449         cp->index++;
1450         g_io_request(cbp, cp);
1451 }
1452
1453 #define TRACK_SIZE  (1 * 1024 * 1024)
1454 #define LOAD_SCALE      256
1455 #define ABS(x)          (((x) >= 0) ? (x) : (-(x)))
1456
1457 static void
1458 g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1459 {
1460         struct g_mirror_disk *disk, *dp;
1461         struct g_consumer *cp;
1462         struct bio *cbp;
1463         int prio, best;
1464
1465         /* Find a disk with the smallest load. */
1466         disk = NULL;
1467         best = INT_MAX;
1468         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1469                 if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1470                         continue;
1471                 prio = dp->load;
1472                 /* If disk head is precisely in position - highly prefer it. */
1473                 if (dp->d_last_offset == bp->bio_offset)
1474                         prio -= 2 * LOAD_SCALE;
1475                 else
1476                 /* If disk head is close to position - prefer it. */
1477                 if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
1478                         prio -= 1 * LOAD_SCALE;
1479                 if (prio <= best) {
1480                         disk = dp;
1481                         best = prio;
1482                 }
1483         }
1484         KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1485         cbp = g_clone_bio(bp);
1486         if (cbp == NULL) {
1487                 if (bp->bio_error == 0)
1488                         bp->bio_error = ENOMEM;
1489                 g_io_deliver(bp, bp->bio_error);
1490                 return;
1491         }
1492         /*
1493          * Fill in the component buf structure.
1494          */
1495         cp = disk->d_consumer;
1496         cbp->bio_done = g_mirror_done;
1497         cbp->bio_to = cp->provider;
1498         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1499         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1500             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1501             cp->acw, cp->ace));
1502         cp->index++;
1503         /* Remember last head position */
1504         disk->d_last_offset = bp->bio_offset + bp->bio_length;
1505         /* Update loads. */
1506         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1507                 dp->load = (dp->d_consumer->index * LOAD_SCALE +
1508                     dp->load * 7) / 8;
1509         }
1510         g_io_request(cbp, cp);
1511 }
1512
1513 static void
1514 g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1515 {
1516         struct bio_queue_head queue;
1517         struct g_mirror_disk *disk;
1518         struct g_consumer *cp;
1519         struct bio *cbp;
1520         off_t left, mod, offset, slice;
1521         u_char *data;
1522         u_int ndisks;
1523
1524         if (bp->bio_length <= sc->sc_slice) {
1525                 g_mirror_request_round_robin(sc, bp);
1526                 return;
1527         }
1528         ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1529         slice = bp->bio_length / ndisks;
1530         mod = slice % sc->sc_provider->sectorsize;
1531         if (mod != 0)
1532                 slice += sc->sc_provider->sectorsize - mod;
1533         /*
1534          * Allocate all bios before sending any request, so we can
1535          * return ENOMEM in nice and clean way.
1536          */
1537         left = bp->bio_length;
1538         offset = bp->bio_offset;
1539         data = bp->bio_data;
1540         bioq_init(&queue);
1541         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1542                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1543                         continue;
1544                 cbp = g_clone_bio(bp);
1545                 if (cbp == NULL) {
1546                         for (cbp = bioq_first(&queue); cbp != NULL;
1547                             cbp = bioq_first(&queue)) {
1548                                 bioq_remove(&queue, cbp);
1549                                 g_destroy_bio(cbp);
1550                         }
1551                         if (bp->bio_error == 0)
1552                                 bp->bio_error = ENOMEM;
1553                         g_io_deliver(bp, bp->bio_error);
1554                         return;
1555                 }
1556                 bioq_insert_tail(&queue, cbp);
1557                 cbp->bio_done = g_mirror_done;
1558                 cbp->bio_caller1 = disk;
1559                 cbp->bio_to = disk->d_consumer->provider;
1560                 cbp->bio_offset = offset;
1561                 cbp->bio_data = data;
1562                 cbp->bio_length = MIN(left, slice);
1563                 left -= cbp->bio_length;
1564                 if (left == 0)
1565                         break;
1566                 offset += cbp->bio_length;
1567                 data += cbp->bio_length;
1568         }
1569         for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
1570                 bioq_remove(&queue, cbp);
1571                 G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1572                 disk = cbp->bio_caller1;
1573                 cbp->bio_caller1 = NULL;
1574                 cp = disk->d_consumer;
1575                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1576                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1577                     cp->acr, cp->acw, cp->ace));
1578                 disk->d_consumer->index++;
1579                 g_io_request(cbp, disk->d_consumer);
1580         }
1581 }
1582
1583 static void
1584 g_mirror_register_request(struct bio *bp)
1585 {
1586         struct g_mirror_softc *sc;
1587
1588         sc = bp->bio_to->geom->softc;
1589         switch (bp->bio_cmd) {
1590         case BIO_READ:
1591                 switch (sc->sc_balance) {
1592                 case G_MIRROR_BALANCE_LOAD:
1593                         g_mirror_request_load(sc, bp);
1594                         break;
1595                 case G_MIRROR_BALANCE_PREFER:
1596                         g_mirror_request_prefer(sc, bp);
1597                         break;
1598                 case G_MIRROR_BALANCE_ROUND_ROBIN:
1599                         g_mirror_request_round_robin(sc, bp);
1600                         break;
1601                 case G_MIRROR_BALANCE_SPLIT:
1602                         g_mirror_request_split(sc, bp);
1603                         break;
1604                 }
1605                 return;
1606         case BIO_WRITE:
1607         case BIO_DELETE:
1608             {
1609                 struct g_mirror_disk *disk;
1610                 struct g_mirror_disk_sync *sync;
1611                 struct bio_queue_head queue;
1612                 struct g_consumer *cp;
1613                 struct bio *cbp;
1614
1615                 /*
1616                  * Delay the request if it is colliding with a synchronization
1617                  * request.
1618                  */
1619                 if (g_mirror_sync_collision(sc, bp)) {
1620                         g_mirror_regular_delay(sc, bp);
1621                         return;
1622                 }
1623
1624                 if (sc->sc_idle)
1625                         g_mirror_unidle(sc);
1626                 else
1627                         sc->sc_last_write = time_uptime;
1628
1629                 /*
1630                  * Allocate all bios before sending any request, so we can
1631                  * return ENOMEM in nice and clean way.
1632                  */
1633                 bioq_init(&queue);
1634                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1635                         sync = &disk->d_sync;
1636                         switch (disk->d_state) {
1637                         case G_MIRROR_DISK_STATE_ACTIVE:
1638                                 break;
1639                         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1640                                 if (bp->bio_offset >= sync->ds_offset)
1641                                         continue;
1642                                 break;
1643                         default:
1644                                 continue;
1645                         }
1646                         cbp = g_clone_bio(bp);
1647                         if (cbp == NULL) {
1648                                 for (cbp = bioq_first(&queue); cbp != NULL;
1649                                     cbp = bioq_first(&queue)) {
1650                                         bioq_remove(&queue, cbp);
1651                                         g_destroy_bio(cbp);
1652                                 }
1653                                 if (bp->bio_error == 0)
1654                                         bp->bio_error = ENOMEM;
1655                                 g_io_deliver(bp, bp->bio_error);
1656                                 return;
1657                         }
1658                         bioq_insert_tail(&queue, cbp);
1659                         cbp->bio_done = g_mirror_done;
1660                         cp = disk->d_consumer;
1661                         cbp->bio_caller1 = cp;
1662                         cbp->bio_to = cp->provider;
1663                         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1664                             ("Consumer %s not opened (r%dw%de%d).",
1665                             cp->provider->name, cp->acr, cp->acw, cp->ace));
1666                 }
1667                 for (cbp = bioq_first(&queue); cbp != NULL;
1668                     cbp = bioq_first(&queue)) {
1669                         bioq_remove(&queue, cbp);
1670                         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1671                         cp = cbp->bio_caller1;
1672                         cbp->bio_caller1 = NULL;
1673                         cp->index++;
1674                         sc->sc_writes++;
1675                         g_io_request(cbp, cp);
1676                 }
1677                 /*
1678                  * Put request onto inflight queue, so we can check if new
1679                  * synchronization requests don't collide with it.
1680                  */
1681                 bioq_insert_tail(&sc->sc_inflight, bp);
1682                 /*
1683                  * Bump syncid on first write.
1684                  */
1685                 if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1686                         sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1687                         g_mirror_bump_syncid(sc);
1688                 }
1689                 return;
1690             }
1691         default:
1692                 KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1693                     bp->bio_cmd, sc->sc_name));
1694                 break;
1695         }
1696 }
1697
1698 static int
1699 g_mirror_can_destroy(struct g_mirror_softc *sc)
1700 {
1701         struct g_geom *gp;
1702         struct g_consumer *cp;
1703
1704         g_topology_assert();
1705         gp = sc->sc_geom;
1706         if (gp->softc == NULL)
1707                 return (1);
1708         LIST_FOREACH(cp, &gp->consumer, consumer) {
1709                 if (g_mirror_is_busy(sc, cp))
1710                         return (0);
1711         }
1712         gp = sc->sc_sync.ds_geom;
1713         LIST_FOREACH(cp, &gp->consumer, consumer) {
1714                 if (g_mirror_is_busy(sc, cp))
1715                         return (0);
1716         }
1717         G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1718             sc->sc_name);
1719         return (1);
1720 }
1721
1722 static int
1723 g_mirror_try_destroy(struct g_mirror_softc *sc)
1724 {
1725
1726         if (sc->sc_rootmount != NULL) {
1727                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1728                     sc->sc_rootmount);
1729                 root_mount_rel(sc->sc_rootmount);
1730                 sc->sc_rootmount = NULL;
1731         }
1732         g_topology_lock();
1733         if (!g_mirror_can_destroy(sc)) {
1734                 g_topology_unlock();
1735                 return (0);
1736         }
1737         sc->sc_geom->softc = NULL;
1738         sc->sc_sync.ds_geom->softc = NULL;
1739         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WAIT) != 0) {
1740                 g_topology_unlock();
1741                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1742                     &sc->sc_worker);
1743                 /* Unlock sc_lock here, as it can be destroyed after wakeup. */
1744                 sx_xunlock(&sc->sc_lock);
1745                 wakeup(&sc->sc_worker);
1746                 sc->sc_worker = NULL;
1747         } else {
1748                 g_topology_unlock();
1749                 g_mirror_destroy_device(sc);
1750                 free(sc, M_MIRROR);
1751         }
1752         return (1);
1753 }
1754
1755 /*
1756  * Worker thread.
1757  */
1758 static void
1759 g_mirror_worker(void *arg)
1760 {
1761         struct g_mirror_softc *sc;
1762         struct g_mirror_event *ep;
1763         struct bio *bp;
1764         int timeout;
1765
1766         sc = arg;
1767         thread_lock(curthread);
1768         sched_prio(curthread, PRIBIO);
1769         thread_unlock(curthread);
1770
1771         sx_xlock(&sc->sc_lock);
1772         for (;;) {
1773                 G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1774                 /*
1775                  * First take a look at events.
1776                  * This is important to handle events before any I/O requests.
1777                  */
1778                 ep = g_mirror_event_get(sc);
1779                 if (ep != NULL) {
1780                         g_mirror_event_remove(sc, ep);
1781                         if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1782                                 /* Update only device status. */
1783                                 G_MIRROR_DEBUG(3,
1784                                     "Running event for device %s.",
1785                                     sc->sc_name);
1786                                 ep->e_error = 0;
1787                                 g_mirror_update_device(sc, 1);
1788                         } else {
1789                                 /* Update disk status. */
1790                                 G_MIRROR_DEBUG(3, "Running event for disk %s.",
1791                                      g_mirror_get_diskname(ep->e_disk));
1792                                 ep->e_error = g_mirror_update_disk(ep->e_disk,
1793                                     ep->e_state);
1794                                 if (ep->e_error == 0)
1795                                         g_mirror_update_device(sc, 0);
1796                         }
1797                         if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1798                                 KASSERT(ep->e_error == 0,
1799                                     ("Error cannot be handled."));
1800                                 g_mirror_event_free(ep);
1801                         } else {
1802                                 ep->e_flags |= G_MIRROR_EVENT_DONE;
1803                                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1804                                     ep);
1805                                 mtx_lock(&sc->sc_events_mtx);
1806                                 wakeup(ep);
1807                                 mtx_unlock(&sc->sc_events_mtx);
1808                         }
1809                         if ((sc->sc_flags &
1810                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1811                                 if (g_mirror_try_destroy(sc)) {
1812                                         curthread->td_pflags &= ~TDP_GEOM;
1813                                         G_MIRROR_DEBUG(1, "Thread exiting.");
1814                                         kproc_exit(0);
1815                                 }
1816                         }
1817                         G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1818                         continue;
1819                 }
1820                 /*
1821                  * Check if we can mark array as CLEAN and if we can't take
1822                  * how much seconds should we wait.
1823                  */
1824                 timeout = g_mirror_idle(sc, -1);
1825                 /*
1826                  * Now I/O requests.
1827                  */
1828                 /* Get first request from the queue. */
1829                 mtx_lock(&sc->sc_queue_mtx);
1830                 bp = bioq_first(&sc->sc_queue);
1831                 if (bp == NULL) {
1832                         if ((sc->sc_flags &
1833                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1834                                 mtx_unlock(&sc->sc_queue_mtx);
1835                                 if (g_mirror_try_destroy(sc)) {
1836                                         curthread->td_pflags &= ~TDP_GEOM;
1837                                         G_MIRROR_DEBUG(1, "Thread exiting.");
1838                                         kproc_exit(0);
1839                                 }
1840                                 mtx_lock(&sc->sc_queue_mtx);
1841                         }
1842                         sx_xunlock(&sc->sc_lock);
1843                         /*
1844                          * XXX: We can miss an event here, because an event
1845                          *      can be added without sx-device-lock and without
1846                          *      mtx-queue-lock. Maybe I should just stop using
1847                          *      dedicated mutex for events synchronization and
1848                          *      stick with the queue lock?
1849                          *      The event will hang here until next I/O request
1850                          *      or next event is received.
1851                          */
1852                         MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
1853                             timeout * hz);
1854                         sx_xlock(&sc->sc_lock);
1855                         G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
1856                         continue;
1857                 }
1858                 bioq_remove(&sc->sc_queue, bp);
1859                 mtx_unlock(&sc->sc_queue_mtx);
1860
1861                 if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
1862                     (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
1863                         g_mirror_sync_request(bp);      /* READ */
1864                 } else if (bp->bio_to != sc->sc_provider) {
1865                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
1866                                 g_mirror_regular_request(bp);
1867                         else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
1868                                 g_mirror_sync_request(bp);      /* WRITE */
1869                         else {
1870                                 KASSERT(0,
1871                                     ("Invalid request cflags=0x%hhx to=%s.",
1872                                     bp->bio_cflags, bp->bio_to->name));
1873                         }
1874                 } else {
1875                         g_mirror_register_request(bp);
1876                 }
1877                 G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
1878         }
1879 }
1880
1881 static void
1882 g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
1883 {
1884
1885         sx_assert(&sc->sc_lock, SX_LOCKED);
1886
1887         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
1888                 return;
1889         if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
1890                 G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as dirty.",
1891                     g_mirror_get_diskname(disk), sc->sc_name);
1892                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1893         } else if (sc->sc_idle &&
1894             (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
1895                 G_MIRROR_DEBUG(1, "Disk %s (device %s) marked as clean.",
1896                     g_mirror_get_diskname(disk), sc->sc_name);
1897                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
1898         }
1899 }
1900
1901 static void
1902 g_mirror_sync_start(struct g_mirror_disk *disk)
1903 {
1904         struct g_mirror_softc *sc;
1905         struct g_consumer *cp;
1906         struct bio *bp;
1907         int error, i;
1908
1909         g_topology_assert_not();
1910         sc = disk->d_softc;
1911         sx_assert(&sc->sc_lock, SX_LOCKED);
1912
1913         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
1914             ("Disk %s is not marked for synchronization.",
1915             g_mirror_get_diskname(disk)));
1916         KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1917             ("Device not in RUNNING state (%s, %u).", sc->sc_name,
1918             sc->sc_state));
1919
1920         sx_xunlock(&sc->sc_lock);
1921         g_topology_lock();
1922         cp = g_new_consumer(sc->sc_sync.ds_geom);
1923         error = g_attach(cp, sc->sc_provider);
1924         KASSERT(error == 0,
1925             ("Cannot attach to %s (error=%d).", sc->sc_name, error));
1926         error = g_access(cp, 1, 0, 0);
1927         KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
1928         g_topology_unlock();
1929         sx_xlock(&sc->sc_lock);
1930
1931         G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
1932             g_mirror_get_diskname(disk));
1933         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
1934                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
1935         KASSERT(disk->d_sync.ds_consumer == NULL,
1936             ("Sync consumer already exists (device=%s, disk=%s).",
1937             sc->sc_name, g_mirror_get_diskname(disk)));
1938
1939         disk->d_sync.ds_consumer = cp;
1940         disk->d_sync.ds_consumer->private = disk;
1941         disk->d_sync.ds_consumer->index = 0;
1942
1943         /*
1944          * Allocate memory for synchronization bios and initialize them.
1945          */
1946         disk->d_sync.ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
1947             M_MIRROR, M_WAITOK);
1948         for (i = 0; i < g_mirror_syncreqs; i++) {
1949                 bp = g_alloc_bio();
1950                 disk->d_sync.ds_bios[i] = bp;
1951                 bp->bio_parent = NULL;
1952                 bp->bio_cmd = BIO_READ;
1953                 bp->bio_data = malloc(MAXPHYS, M_MIRROR, M_WAITOK);
1954                 bp->bio_cflags = 0;
1955                 bp->bio_offset = disk->d_sync.ds_offset;
1956                 bp->bio_length = MIN(MAXPHYS, sc->sc_mediasize - bp->bio_offset);
1957                 disk->d_sync.ds_offset += bp->bio_length;
1958                 bp->bio_done = g_mirror_sync_done;
1959                 bp->bio_from = disk->d_sync.ds_consumer;
1960                 bp->bio_to = sc->sc_provider;
1961                 bp->bio_caller1 = (void *)(uintptr_t)i;
1962         }
1963
1964         /* Increase the number of disks in SYNCHRONIZING state. */
1965         sc->sc_sync.ds_ndisks++;
1966         /* Set the number of in-flight synchronization requests. */
1967         disk->d_sync.ds_inflight = g_mirror_syncreqs;
1968
1969         /*
1970          * Fire off first synchronization requests.
1971          */
1972         for (i = 0; i < g_mirror_syncreqs; i++) {
1973                 bp = disk->d_sync.ds_bios[i];
1974                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1975                 disk->d_sync.ds_consumer->index++;
1976                 /*
1977                  * Delay the request if it is colliding with a regular request.
1978                  */
1979                 if (g_mirror_regular_collision(sc, bp))
1980                         g_mirror_sync_delay(sc, bp);
1981                 else
1982                         g_io_request(bp, disk->d_sync.ds_consumer);
1983         }
1984 }
1985
1986 /*
1987  * Stop synchronization process.
1988  * type: 0 - synchronization finished
1989  *       1 - synchronization stopped
1990  */
1991 static void
1992 g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
1993 {
1994         struct g_mirror_softc *sc;
1995         struct g_consumer *cp;
1996
1997         g_topology_assert_not();
1998         sc = disk->d_softc;
1999         sx_assert(&sc->sc_lock, SX_LOCKED);
2000
2001         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2002             ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2003             g_mirror_disk_state2str(disk->d_state)));
2004         if (disk->d_sync.ds_consumer == NULL)
2005                 return;
2006
2007         if (type == 0) {
2008                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
2009                     sc->sc_name, g_mirror_get_diskname(disk));
2010         } else /* if (type == 1) */ {
2011                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
2012                     sc->sc_name, g_mirror_get_diskname(disk));
2013         }
2014         free(disk->d_sync.ds_bios, M_MIRROR);
2015         disk->d_sync.ds_bios = NULL;
2016         cp = disk->d_sync.ds_consumer;
2017         disk->d_sync.ds_consumer = NULL;
2018         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2019         sc->sc_sync.ds_ndisks--;
2020         sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2021         g_topology_lock();
2022         g_mirror_kill_consumer(sc, cp);
2023         g_topology_unlock();
2024         sx_xlock(&sc->sc_lock);
2025 }
2026
2027 static void
2028 g_mirror_launch_provider(struct g_mirror_softc *sc)
2029 {
2030         struct g_mirror_disk *disk;
2031         struct g_provider *pp;
2032
2033         sx_assert(&sc->sc_lock, SX_LOCKED);
2034
2035         g_topology_lock();
2036         pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2037         pp->mediasize = sc->sc_mediasize;
2038         pp->sectorsize = sc->sc_sectorsize;
2039         pp->stripesize = 0;
2040         pp->stripeoffset = 0;
2041         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2042                 if (disk->d_consumer && disk->d_consumer->provider &&
2043                     disk->d_consumer->provider->stripesize > pp->stripesize) {
2044                         pp->stripesize = disk->d_consumer->provider->stripesize;
2045                         pp->stripeoffset = disk->d_consumer->provider->stripeoffset;
2046                 }
2047         }
2048         sc->sc_provider = pp;
2049         g_error_provider(pp, 0);
2050         g_topology_unlock();
2051         G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2052             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2053         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2054                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2055                         g_mirror_sync_start(disk);
2056         }
2057 }
2058
2059 static void
2060 g_mirror_destroy_provider(struct g_mirror_softc *sc)
2061 {
2062         struct g_mirror_disk *disk;
2063         struct bio *bp;
2064
2065         g_topology_assert_not();
2066         KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2067             sc->sc_name));
2068
2069         g_topology_lock();
2070         g_error_provider(sc->sc_provider, ENXIO);
2071         mtx_lock(&sc->sc_queue_mtx);
2072         while ((bp = bioq_first(&sc->sc_queue)) != NULL) {
2073                 bioq_remove(&sc->sc_queue, bp);
2074                 g_io_deliver(bp, ENXIO);
2075         }
2076         mtx_unlock(&sc->sc_queue_mtx);
2077         G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.", sc->sc_name,
2078             sc->sc_provider->name);
2079         sc->sc_provider->flags |= G_PF_WITHER;
2080         g_orphan_provider(sc->sc_provider, ENXIO);
2081         g_topology_unlock();
2082         sc->sc_provider = NULL;
2083         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2084                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2085                         g_mirror_sync_stop(disk, 1);
2086         }
2087 }
2088
2089 static void
2090 g_mirror_go(void *arg)
2091 {
2092         struct g_mirror_softc *sc;
2093
2094         sc = arg;
2095         G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2096         g_mirror_event_send(sc, 0,
2097             G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2098 }
2099
2100 static u_int
2101 g_mirror_determine_state(struct g_mirror_disk *disk)
2102 {
2103         struct g_mirror_softc *sc;
2104         u_int state;
2105
2106         sc = disk->d_softc;
2107         if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2108                 if ((disk->d_flags &
2109                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2110                         /* Disk does not need synchronization. */
2111                         state = G_MIRROR_DISK_STATE_ACTIVE;
2112                 } else {
2113                         if ((sc->sc_flags &
2114                              G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2115                             (disk->d_flags &
2116                              G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2117                                 /*
2118                                  * We can start synchronization from
2119                                  * the stored offset.
2120                                  */
2121                                 state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2122                         } else {
2123                                 state = G_MIRROR_DISK_STATE_STALE;
2124                         }
2125                 }
2126         } else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2127                 /*
2128                  * Reset all synchronization data for this disk,
2129                  * because if it even was synchronized, it was
2130                  * synchronized to disks with different syncid.
2131                  */
2132                 disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2133                 disk->d_sync.ds_offset = 0;
2134                 disk->d_sync.ds_offset_done = 0;
2135                 disk->d_sync.ds_syncid = sc->sc_syncid;
2136                 if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2137                     (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2138                         state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2139                 } else {
2140                         state = G_MIRROR_DISK_STATE_STALE;
2141                 }
2142         } else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2143                 /*
2144                  * Not good, NOT GOOD!
2145                  * It means that mirror was started on stale disks
2146                  * and more fresh disk just arrive.
2147                  * If there were writes, mirror is broken, sorry.
2148                  * I think the best choice here is don't touch
2149                  * this disk and inform the user loudly.
2150                  */
2151                 G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2152                     "disk (%s) arrives!! It will not be connected to the "
2153                     "running device.", sc->sc_name,
2154                     g_mirror_get_diskname(disk));
2155                 g_mirror_destroy_disk(disk);
2156                 state = G_MIRROR_DISK_STATE_NONE;
2157                 /* Return immediately, because disk was destroyed. */
2158                 return (state);
2159         }
2160         G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2161             g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2162         return (state);
2163 }
2164
2165 /*
2166  * Update device state.
2167  */
2168 static void
2169 g_mirror_update_device(struct g_mirror_softc *sc, boolean_t force)
2170 {
2171         struct g_mirror_disk *disk;
2172         u_int state;
2173
2174         sx_assert(&sc->sc_lock, SX_XLOCKED);
2175
2176         switch (sc->sc_state) {
2177         case G_MIRROR_DEVICE_STATE_STARTING:
2178             {
2179                 struct g_mirror_disk *pdisk, *tdisk;
2180                 u_int dirty, ndisks, genid, syncid;
2181
2182                 KASSERT(sc->sc_provider == NULL,
2183                     ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2184                 /*
2185                  * Are we ready? We are, if all disks are connected or
2186                  * if we have any disks and 'force' is true.
2187                  */
2188                 ndisks = g_mirror_ndisks(sc, -1);
2189                 if (sc->sc_ndisks == ndisks || (force && ndisks > 0)) {
2190                         ;
2191                 } else if (ndisks == 0) {
2192                         /*
2193                          * Disks went down in starting phase, so destroy
2194                          * device.
2195                          */
2196                         callout_drain(&sc->sc_callout);
2197                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2198                         G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2199                             sc->sc_rootmount);
2200                         root_mount_rel(sc->sc_rootmount);
2201                         sc->sc_rootmount = NULL;
2202                         return;
2203                 } else {
2204                         return;
2205                 }
2206
2207                 /*
2208                  * Activate all disks with the biggest syncid.
2209                  */
2210                 if (force) {
2211                         /*
2212                          * If 'force' is true, we have been called due to
2213                          * timeout, so don't bother canceling timeout.
2214                          */
2215                         ndisks = 0;
2216                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2217                                 if ((disk->d_flags &
2218                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2219                                         ndisks++;
2220                                 }
2221                         }
2222                         if (ndisks == 0) {
2223                                 /* No valid disks found, destroy device. */
2224                                 sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2225                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2226                                     __LINE__, sc->sc_rootmount);
2227                                 root_mount_rel(sc->sc_rootmount);
2228                                 sc->sc_rootmount = NULL;
2229                                 return;
2230                         }
2231                 } else {
2232                         /* Cancel timeout. */
2233                         callout_drain(&sc->sc_callout);
2234                 }
2235
2236                 /*
2237                  * Find the biggest genid.
2238                  */
2239                 genid = 0;
2240                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2241                         if (disk->d_genid > genid)
2242                                 genid = disk->d_genid;
2243                 }
2244                 sc->sc_genid = genid;
2245                 /*
2246                  * Remove all disks without the biggest genid.
2247                  */
2248                 LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2249                         if (disk->d_genid < genid) {
2250                                 G_MIRROR_DEBUG(0,
2251                                     "Component %s (device %s) broken, skipping.",
2252                                     g_mirror_get_diskname(disk), sc->sc_name);
2253                                 g_mirror_destroy_disk(disk);
2254                         }
2255                 }
2256
2257                 /*
2258                  * Find the biggest syncid.
2259                  */
2260                 syncid = 0;
2261                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2262                         if (disk->d_sync.ds_syncid > syncid)
2263                                 syncid = disk->d_sync.ds_syncid;
2264                 }
2265
2266                 /*
2267                  * Here we need to look for dirty disks and if all disks
2268                  * with the biggest syncid are dirty, we have to choose
2269                  * one with the biggest priority and rebuild the rest.
2270                  */
2271                 /*
2272                  * Find the number of dirty disks with the biggest syncid.
2273                  * Find the number of disks with the biggest syncid.
2274                  * While here, find a disk with the biggest priority.
2275                  */
2276                 dirty = ndisks = 0;
2277                 pdisk = NULL;
2278                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2279                         if (disk->d_sync.ds_syncid != syncid)
2280                                 continue;
2281                         if ((disk->d_flags &
2282                             G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2283                                 continue;
2284                         }
2285                         ndisks++;
2286                         if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2287                                 dirty++;
2288                                 if (pdisk == NULL ||
2289                                     pdisk->d_priority < disk->d_priority) {
2290                                         pdisk = disk;
2291                                 }
2292                         }
2293                 }
2294                 if (dirty == 0) {
2295                         /* No dirty disks at all, great. */
2296                 } else if (dirty == ndisks) {
2297                         /*
2298                          * Force synchronization for all dirty disks except one
2299                          * with the biggest priority.
2300                          */
2301                         KASSERT(pdisk != NULL, ("pdisk == NULL"));
2302                         G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2303                             "master disk for synchronization.",
2304                             g_mirror_get_diskname(pdisk), sc->sc_name);
2305                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2306                                 if (disk->d_sync.ds_syncid != syncid)
2307                                         continue;
2308                                 if ((disk->d_flags &
2309                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2310                                         continue;
2311                                 }
2312                                 KASSERT((disk->d_flags &
2313                                     G_MIRROR_DISK_FLAG_DIRTY) != 0,
2314                                     ("Disk %s isn't marked as dirty.",
2315                                     g_mirror_get_diskname(disk)));
2316                                 /* Skip the disk with the biggest priority. */
2317                                 if (disk == pdisk)
2318                                         continue;
2319                                 disk->d_sync.ds_syncid = 0;
2320                         }
2321                 } else if (dirty < ndisks) {
2322                         /*
2323                          * Force synchronization for all dirty disks.
2324                          * We have some non-dirty disks.
2325                          */
2326                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2327                                 if (disk->d_sync.ds_syncid != syncid)
2328                                         continue;
2329                                 if ((disk->d_flags &
2330                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2331                                         continue;
2332                                 }
2333                                 if ((disk->d_flags &
2334                                     G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2335                                         continue;
2336                                 }
2337                                 disk->d_sync.ds_syncid = 0;
2338                         }
2339                 }
2340
2341                 /* Reset hint. */
2342                 sc->sc_hint = NULL;
2343                 sc->sc_syncid = syncid;
2344                 if (force) {
2345                         /* Remember to bump syncid on first write. */
2346                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2347                 }
2348                 state = G_MIRROR_DEVICE_STATE_RUNNING;
2349                 G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2350                     sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2351                     g_mirror_device_state2str(state));
2352                 sc->sc_state = state;
2353                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2354                         state = g_mirror_determine_state(disk);
2355                         g_mirror_event_send(disk, state,
2356                             G_MIRROR_EVENT_DONTWAIT);
2357                         if (state == G_MIRROR_DISK_STATE_STALE)
2358                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2359                 }
2360                 break;
2361             }
2362         case G_MIRROR_DEVICE_STATE_RUNNING:
2363                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2364                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2365                         /*
2366                          * No active disks or no disks at all,
2367                          * so destroy device.
2368                          */
2369                         if (sc->sc_provider != NULL)
2370                                 g_mirror_destroy_provider(sc);
2371                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2372                         break;
2373                 } else if (g_mirror_ndisks(sc,
2374                     G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2375                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2376                         /*
2377                          * We have active disks, launch provider if it doesn't
2378                          * exist.
2379                          */
2380                         if (sc->sc_provider == NULL)
2381                                 g_mirror_launch_provider(sc);
2382                         if (sc->sc_rootmount != NULL) {
2383                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2384                                     __LINE__, sc->sc_rootmount);
2385                                 root_mount_rel(sc->sc_rootmount);
2386                                 sc->sc_rootmount = NULL;
2387                         }
2388                 }
2389                 /*
2390                  * Genid should be bumped immediately, so do it here.
2391                  */
2392                 if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2393                         sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2394                         g_mirror_bump_genid(sc);
2395                 }
2396                 break;
2397         default:
2398                 KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2399                     sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2400                 break;
2401         }
2402 }
2403
2404 /*
2405  * Update disk state and device state if needed.
2406  */
2407 #define DISK_STATE_CHANGED()    G_MIRROR_DEBUG(1,                       \
2408         "Disk %s state changed from %s to %s (device %s).",             \
2409         g_mirror_get_diskname(disk),                                    \
2410         g_mirror_disk_state2str(disk->d_state),                         \
2411         g_mirror_disk_state2str(state), sc->sc_name)
2412 static int
2413 g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2414 {
2415         struct g_mirror_softc *sc;
2416
2417         sc = disk->d_softc;
2418         sx_assert(&sc->sc_lock, SX_XLOCKED);
2419
2420 again:
2421         G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2422             g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2423             g_mirror_disk_state2str(state));
2424         switch (state) {
2425         case G_MIRROR_DISK_STATE_NEW:
2426                 /*
2427                  * Possible scenarios:
2428                  * 1. New disk arrive.
2429                  */
2430                 /* Previous state should be NONE. */
2431                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2432                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2433                     g_mirror_disk_state2str(disk->d_state)));
2434                 DISK_STATE_CHANGED();
2435
2436                 disk->d_state = state;
2437                 if (LIST_EMPTY(&sc->sc_disks))
2438                         LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2439                 else {
2440                         struct g_mirror_disk *dp;
2441
2442                         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2443                                 if (disk->d_priority >= dp->d_priority) {
2444                                         LIST_INSERT_BEFORE(dp, disk, d_next);
2445                                         dp = NULL;
2446                                         break;
2447                                 }
2448                                 if (LIST_NEXT(dp, d_next) == NULL)
2449                                         break;
2450                         }
2451                         if (dp != NULL)
2452                                 LIST_INSERT_AFTER(dp, disk, d_next);
2453                 }
2454                 G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2455                     sc->sc_name, g_mirror_get_diskname(disk));
2456                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2457                         break;
2458                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2459                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2460                     g_mirror_device_state2str(sc->sc_state),
2461                     g_mirror_get_diskname(disk),
2462                     g_mirror_disk_state2str(disk->d_state)));
2463                 state = g_mirror_determine_state(disk);
2464                 if (state != G_MIRROR_DISK_STATE_NONE)
2465                         goto again;
2466                 break;
2467         case G_MIRROR_DISK_STATE_ACTIVE:
2468                 /*
2469                  * Possible scenarios:
2470                  * 1. New disk does not need synchronization.
2471                  * 2. Synchronization process finished successfully.
2472                  */
2473                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2474                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2475                     g_mirror_device_state2str(sc->sc_state),
2476                     g_mirror_get_diskname(disk),
2477                     g_mirror_disk_state2str(disk->d_state)));
2478                 /* Previous state should be NEW or SYNCHRONIZING. */
2479                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2480                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2481                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2482                     g_mirror_disk_state2str(disk->d_state)));
2483                 DISK_STATE_CHANGED();
2484
2485                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2486                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2487                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2488                         g_mirror_sync_stop(disk, 0);
2489                 }
2490                 disk->d_state = state;
2491                 disk->d_sync.ds_offset = 0;
2492                 disk->d_sync.ds_offset_done = 0;
2493                 g_mirror_update_idle(sc, disk);
2494                 g_mirror_update_metadata(disk);
2495                 G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2496                     sc->sc_name, g_mirror_get_diskname(disk));
2497                 break;
2498         case G_MIRROR_DISK_STATE_STALE:
2499                 /*
2500                  * Possible scenarios:
2501                  * 1. Stale disk was connected.
2502                  */
2503                 /* Previous state should be NEW. */
2504                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2505                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2506                     g_mirror_disk_state2str(disk->d_state)));
2507                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2508                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2509                     g_mirror_device_state2str(sc->sc_state),
2510                     g_mirror_get_diskname(disk),
2511                     g_mirror_disk_state2str(disk->d_state)));
2512                 /*
2513                  * STALE state is only possible if device is marked
2514                  * NOAUTOSYNC.
2515                  */
2516                 KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2517                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2518                     g_mirror_device_state2str(sc->sc_state),
2519                     g_mirror_get_diskname(disk),
2520                     g_mirror_disk_state2str(disk->d_state)));
2521                 DISK_STATE_CHANGED();
2522
2523                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2524                 disk->d_state = state;
2525                 g_mirror_update_metadata(disk);
2526                 G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2527                     sc->sc_name, g_mirror_get_diskname(disk));
2528                 break;
2529         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2530                 /*
2531                  * Possible scenarios:
2532                  * 1. Disk which needs synchronization was connected.
2533                  */
2534                 /* Previous state should be NEW. */
2535                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2536                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2537                     g_mirror_disk_state2str(disk->d_state)));
2538                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2539                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2540                     g_mirror_device_state2str(sc->sc_state),
2541                     g_mirror_get_diskname(disk),
2542                     g_mirror_disk_state2str(disk->d_state)));
2543                 DISK_STATE_CHANGED();
2544
2545                 if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2546                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2547                 disk->d_state = state;
2548                 if (sc->sc_provider != NULL) {
2549                         g_mirror_sync_start(disk);
2550                         g_mirror_update_metadata(disk);
2551                 }
2552                 break;
2553         case G_MIRROR_DISK_STATE_DISCONNECTED:
2554                 /*
2555                  * Possible scenarios:
2556                  * 1. Device wasn't running yet, but disk disappear.
2557                  * 2. Disk was active and disapppear.
2558                  * 3. Disk disappear during synchronization process.
2559                  */
2560                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2561                         /*
2562                          * Previous state should be ACTIVE, STALE or
2563                          * SYNCHRONIZING.
2564                          */
2565                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2566                             disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2567                             disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2568                             ("Wrong disk state (%s, %s).",
2569                             g_mirror_get_diskname(disk),
2570                             g_mirror_disk_state2str(disk->d_state)));
2571                 } else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2572                         /* Previous state should be NEW. */
2573                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2574                             ("Wrong disk state (%s, %s).",
2575                             g_mirror_get_diskname(disk),
2576                             g_mirror_disk_state2str(disk->d_state)));
2577                         /*
2578                          * Reset bumping syncid if disk disappeared in STARTING
2579                          * state.
2580                          */
2581                         if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2582                                 sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2583 #ifdef  INVARIANTS
2584                 } else {
2585                         KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2586                             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 #endif
2591                 }
2592                 DISK_STATE_CHANGED();
2593                 G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2594                     sc->sc_name, g_mirror_get_diskname(disk));
2595
2596                 g_mirror_destroy_disk(disk);
2597                 break;
2598         case G_MIRROR_DISK_STATE_DESTROY:
2599             {
2600                 int error;
2601
2602                 error = g_mirror_clear_metadata(disk);
2603                 if (error != 0)
2604                         return (error);
2605                 DISK_STATE_CHANGED();
2606                 G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2607                     sc->sc_name, g_mirror_get_diskname(disk));
2608
2609                 g_mirror_destroy_disk(disk);
2610                 sc->sc_ndisks--;
2611                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2612                         g_mirror_update_metadata(disk);
2613                 }
2614                 break;
2615             }
2616         default:
2617                 KASSERT(1 == 0, ("Unknown state (%u).", state));
2618                 break;
2619         }
2620         return (0);
2621 }
2622 #undef  DISK_STATE_CHANGED
2623
2624 int
2625 g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2626 {
2627         struct g_provider *pp;
2628         u_char *buf;
2629         int error;
2630
2631         g_topology_assert();
2632
2633         error = g_access(cp, 1, 0, 0);
2634         if (error != 0)
2635                 return (error);
2636         pp = cp->provider;
2637         g_topology_unlock();
2638         /* Metadata are stored on last sector. */
2639         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2640             &error);
2641         g_topology_lock();
2642         g_access(cp, -1, 0, 0);
2643         if (buf == NULL) {
2644                 G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2645                     cp->provider->name, error);
2646                 return (error);
2647         }
2648
2649         /* Decode metadata. */
2650         error = mirror_metadata_decode(buf, md);
2651         g_free(buf);
2652         if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2653                 return (EINVAL);
2654         if (md->md_version > G_MIRROR_VERSION) {
2655                 G_MIRROR_DEBUG(0,
2656                     "Kernel module is too old to handle metadata from %s.",
2657                     cp->provider->name);
2658                 return (EINVAL);
2659         }
2660         if (error != 0) {
2661                 G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2662                     cp->provider->name);
2663                 return (error);
2664         }
2665
2666         return (0);
2667 }
2668
2669 static int
2670 g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2671     struct g_mirror_metadata *md)
2672 {
2673
2674         if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2675                 G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2676                     pp->name, md->md_did);
2677                 return (EEXIST);
2678         }
2679         if (md->md_all != sc->sc_ndisks) {
2680                 G_MIRROR_DEBUG(1,
2681                     "Invalid '%s' field on disk %s (device %s), skipping.",
2682                     "md_all", pp->name, sc->sc_name);
2683                 return (EINVAL);
2684         }
2685         if (md->md_slice != sc->sc_slice) {
2686                 G_MIRROR_DEBUG(1,
2687                     "Invalid '%s' field on disk %s (device %s), skipping.",
2688                     "md_slice", pp->name, sc->sc_name);
2689                 return (EINVAL);
2690         }
2691         if (md->md_balance != sc->sc_balance) {
2692                 G_MIRROR_DEBUG(1,
2693                     "Invalid '%s' field on disk %s (device %s), skipping.",
2694                     "md_balance", pp->name, sc->sc_name);
2695                 return (EINVAL);
2696         }
2697         if (md->md_mediasize != sc->sc_mediasize) {
2698                 G_MIRROR_DEBUG(1,
2699                     "Invalid '%s' field on disk %s (device %s), skipping.",
2700                     "md_mediasize", pp->name, sc->sc_name);
2701                 return (EINVAL);
2702         }
2703         if (sc->sc_mediasize > pp->mediasize) {
2704                 G_MIRROR_DEBUG(1,
2705                     "Invalid size of disk %s (device %s), skipping.", pp->name,
2706                     sc->sc_name);
2707                 return (EINVAL);
2708         }
2709         if (md->md_sectorsize != sc->sc_sectorsize) {
2710                 G_MIRROR_DEBUG(1,
2711                     "Invalid '%s' field on disk %s (device %s), skipping.",
2712                     "md_sectorsize", pp->name, sc->sc_name);
2713                 return (EINVAL);
2714         }
2715         if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2716                 G_MIRROR_DEBUG(1,
2717                     "Invalid sector size of disk %s (device %s), skipping.",
2718                     pp->name, sc->sc_name);
2719                 return (EINVAL);
2720         }
2721         if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2722                 G_MIRROR_DEBUG(1,
2723                     "Invalid device flags on disk %s (device %s), skipping.",
2724                     pp->name, sc->sc_name);
2725                 return (EINVAL);
2726         }
2727         if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2728                 G_MIRROR_DEBUG(1,
2729                     "Invalid disk flags on disk %s (device %s), skipping.",
2730                     pp->name, sc->sc_name);
2731                 return (EINVAL);
2732         }
2733         return (0);
2734 }
2735
2736 int
2737 g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2738     struct g_mirror_metadata *md)
2739 {
2740         struct g_mirror_disk *disk;
2741         int error;
2742
2743         g_topology_assert_not();
2744         G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2745
2746         error = g_mirror_check_metadata(sc, pp, md);
2747         if (error != 0)
2748                 return (error);
2749         if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING &&
2750             md->md_genid < sc->sc_genid) {
2751                 G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
2752                     pp->name, sc->sc_name);
2753                 return (EINVAL);
2754         }
2755         disk = g_mirror_init_disk(sc, pp, md, &error);
2756         if (disk == NULL)
2757                 return (error);
2758         error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
2759             G_MIRROR_EVENT_WAIT);
2760         if (error != 0)
2761                 return (error);
2762         if (md->md_version < G_MIRROR_VERSION) {
2763                 G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
2764                     pp->name, md->md_version, G_MIRROR_VERSION);
2765                 g_mirror_update_metadata(disk);
2766         }
2767         return (0);
2768 }
2769
2770 static void
2771 g_mirror_destroy_delayed(void *arg, int flag)
2772 {
2773         struct g_mirror_softc *sc;
2774         int error;
2775
2776         if (flag == EV_CANCEL) {
2777                 G_MIRROR_DEBUG(1, "Destroying canceled.");
2778                 return;
2779         }
2780         sc = arg;
2781         g_topology_unlock();
2782         sx_xlock(&sc->sc_lock);
2783         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
2784             ("DESTROY flag set on %s.", sc->sc_name));
2785         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0,
2786             ("DESTROYING flag not set on %s.", sc->sc_name));
2787         G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
2788         error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
2789         if (error != 0) {
2790                 G_MIRROR_DEBUG(0, "Cannot destroy %s.", sc->sc_name);
2791                 sx_xunlock(&sc->sc_lock);
2792         }
2793         g_topology_lock();
2794 }
2795
2796 static int
2797 g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
2798 {
2799         struct g_mirror_softc *sc;
2800         int dcr, dcw, dce, error = 0;
2801
2802         g_topology_assert();
2803         G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
2804             acw, ace);
2805
2806         sc = pp->geom->softc;
2807         if (sc == NULL && acr <= 0 && acw <= 0 && ace <= 0)
2808                 return (0);
2809         KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
2810
2811         dcr = pp->acr + acr;
2812         dcw = pp->acw + acw;
2813         dce = pp->ace + ace;
2814
2815         g_topology_unlock();
2816         sx_xlock(&sc->sc_lock);
2817         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
2818             LIST_EMPTY(&sc->sc_disks)) {
2819                 if (acr > 0 || acw > 0 || ace > 0)
2820                         error = ENXIO;
2821                 goto end;
2822         }
2823         if (dcw == 0 && !sc->sc_idle)
2824                 g_mirror_idle(sc, dcw);
2825         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROYING) != 0) {
2826                 if (acr > 0 || acw > 0 || ace > 0) {
2827                         error = ENXIO;
2828                         goto end;
2829                 }
2830                 if (dcr == 0 && dcw == 0 && dce == 0) {
2831                         g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK,
2832                             sc, NULL);
2833                 }
2834         }
2835 end:
2836         sx_xunlock(&sc->sc_lock);
2837         g_topology_lock();
2838         return (error);
2839 }
2840
2841 static struct g_geom *
2842 g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md)
2843 {
2844         struct g_mirror_softc *sc;
2845         struct g_geom *gp;
2846         int error, timeout;
2847
2848         g_topology_assert();
2849         G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
2850             md->md_mid);
2851
2852         /* One disk is minimum. */
2853         if (md->md_all < 1)
2854                 return (NULL);
2855         /*
2856          * Action geom.
2857          */
2858         gp = g_new_geomf(mp, "%s", md->md_name);
2859         sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
2860         gp->start = g_mirror_start;
2861         gp->orphan = g_mirror_orphan;
2862         gp->access = g_mirror_access;
2863         gp->dumpconf = g_mirror_dumpconf;
2864
2865         sc->sc_id = md->md_mid;
2866         sc->sc_slice = md->md_slice;
2867         sc->sc_balance = md->md_balance;
2868         sc->sc_mediasize = md->md_mediasize;
2869         sc->sc_sectorsize = md->md_sectorsize;
2870         sc->sc_ndisks = md->md_all;
2871         sc->sc_flags = md->md_mflags;
2872         sc->sc_bump_id = 0;
2873         sc->sc_idle = 1;
2874         sc->sc_last_write = time_uptime;
2875         sc->sc_writes = 0;
2876         sx_init(&sc->sc_lock, "gmirror:lock");
2877         bioq_init(&sc->sc_queue);
2878         mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
2879         bioq_init(&sc->sc_regular_delayed);
2880         bioq_init(&sc->sc_inflight);
2881         bioq_init(&sc->sc_sync_delayed);
2882         LIST_INIT(&sc->sc_disks);
2883         TAILQ_INIT(&sc->sc_events);
2884         mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
2885         callout_init(&sc->sc_callout, CALLOUT_MPSAFE);
2886         sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
2887         gp->softc = sc;
2888         sc->sc_geom = gp;
2889         sc->sc_provider = NULL;
2890         /*
2891          * Synchronization geom.
2892          */
2893         gp = g_new_geomf(mp, "%s.sync", md->md_name);
2894         gp->softc = sc;
2895         gp->orphan = g_mirror_orphan;
2896         sc->sc_sync.ds_geom = gp;
2897         sc->sc_sync.ds_ndisks = 0;
2898         error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
2899             "g_mirror %s", md->md_name);
2900         if (error != 0) {
2901                 G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
2902                     sc->sc_name);
2903                 g_destroy_geom(sc->sc_sync.ds_geom);
2904                 mtx_destroy(&sc->sc_events_mtx);
2905                 mtx_destroy(&sc->sc_queue_mtx);
2906                 sx_destroy(&sc->sc_lock);
2907                 g_destroy_geom(sc->sc_geom);
2908                 free(sc, M_MIRROR);
2909                 return (NULL);
2910         }
2911
2912         G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
2913             sc->sc_name, sc->sc_ndisks, sc->sc_id);
2914
2915         sc->sc_rootmount = root_mount_hold("GMIRROR");
2916         G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
2917         /*
2918          * Run timeout.
2919          */
2920         timeout = g_mirror_timeout * hz;
2921         callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
2922         return (sc->sc_geom);
2923 }
2924
2925 int
2926 g_mirror_destroy(struct g_mirror_softc *sc, int how)
2927 {
2928         struct g_mirror_disk *disk;
2929         struct g_provider *pp;
2930
2931         g_topology_assert_not();
2932         if (sc == NULL)
2933                 return (ENXIO);
2934         sx_assert(&sc->sc_lock, SX_XLOCKED);
2935
2936         pp = sc->sc_provider;
2937         if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
2938                 switch (how) {
2939                 case G_MIRROR_DESTROY_SOFT:
2940                         G_MIRROR_DEBUG(1,
2941                             "Device %s is still open (r%dw%de%d).", pp->name,
2942                             pp->acr, pp->acw, pp->ace);
2943                         return (EBUSY);
2944                 case G_MIRROR_DESTROY_DELAYED:
2945                         G_MIRROR_DEBUG(1,
2946                             "Device %s will be destroyed on last close.",
2947                             pp->name);
2948                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2949                                 if (disk->d_state ==
2950                                     G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2951                                         g_mirror_sync_stop(disk, 1);
2952                                 }
2953                         }
2954                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROYING;
2955                         return (EBUSY);
2956                 case G_MIRROR_DESTROY_HARD:
2957                         G_MIRROR_DEBUG(1, "Device %s is still open, so it "
2958                             "can't be definitely removed.", pp->name);
2959                 }
2960         }
2961
2962         g_topology_lock();
2963         if (sc->sc_geom->softc == NULL) {
2964                 g_topology_unlock();
2965                 return (0);
2966         }
2967         sc->sc_geom->softc = NULL;
2968         sc->sc_sync.ds_geom->softc = NULL;
2969         g_topology_unlock();
2970
2971         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2972         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WAIT;
2973         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
2974         sx_xunlock(&sc->sc_lock);
2975         mtx_lock(&sc->sc_queue_mtx);
2976         wakeup(sc);
2977         mtx_unlock(&sc->sc_queue_mtx);
2978         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
2979         while (sc->sc_worker != NULL)
2980                 tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
2981         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
2982         sx_xlock(&sc->sc_lock);
2983         g_mirror_destroy_device(sc);
2984         free(sc, M_MIRROR);
2985         return (0);
2986 }
2987
2988 static void
2989 g_mirror_taste_orphan(struct g_consumer *cp)
2990 {
2991
2992         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
2993             cp->provider->name));
2994 }
2995
2996 static struct g_geom *
2997 g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
2998 {
2999         struct g_mirror_metadata md;
3000         struct g_mirror_softc *sc;
3001         struct g_consumer *cp;
3002         struct g_geom *gp;
3003         int error;
3004
3005         g_topology_assert();
3006         g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
3007         G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
3008
3009         gp = g_new_geomf(mp, "mirror:taste");
3010         /*
3011          * This orphan function should be never called.
3012          */
3013         gp->orphan = g_mirror_taste_orphan;
3014         cp = g_new_consumer(gp);
3015         g_attach(cp, pp);
3016         error = g_mirror_read_metadata(cp, &md);
3017         g_detach(cp);
3018         g_destroy_consumer(cp);
3019         g_destroy_geom(gp);
3020         if (error != 0)
3021                 return (NULL);
3022         gp = NULL;
3023
3024         if (md.md_provider[0] != '\0' && strcmp(md.md_provider, pp->name) != 0)
3025                 return (NULL);
3026         if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3027                 return (NULL);
3028         if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3029                 G_MIRROR_DEBUG(0,
3030                     "Device %s: provider %s marked as inactive, skipping.",
3031                     md.md_name, pp->name);
3032                 return (NULL);
3033         }
3034         if (g_mirror_debug >= 2)
3035                 mirror_metadata_dump(&md);
3036
3037         /*
3038          * Let's check if device already exists.
3039          */
3040         sc = NULL;
3041         LIST_FOREACH(gp, &mp->geom, geom) {
3042                 sc = gp->softc;
3043                 if (sc == NULL)
3044                         continue;
3045                 if (sc->sc_sync.ds_geom == gp)
3046                         continue;
3047                 if (strcmp(md.md_name, sc->sc_name) != 0)
3048                         continue;
3049                 if (md.md_mid != sc->sc_id) {
3050                         G_MIRROR_DEBUG(0, "Device %s already configured.",
3051                             sc->sc_name);
3052                         return (NULL);
3053                 }
3054                 break;
3055         }
3056         if (gp == NULL) {
3057                 gp = g_mirror_create(mp, &md);
3058                 if (gp == NULL) {
3059                         G_MIRROR_DEBUG(0, "Cannot create device %s.",
3060                             md.md_name);
3061                         return (NULL);
3062                 }
3063                 sc = gp->softc;
3064         }
3065         G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3066         g_topology_unlock();
3067         sx_xlock(&sc->sc_lock);
3068         error = g_mirror_add_disk(sc, pp, &md);
3069         if (error != 0) {
3070                 G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3071                     pp->name, gp->name, error);
3072                 if (LIST_EMPTY(&sc->sc_disks)) {
3073                         g_cancel_event(sc);
3074                         g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3075                         g_topology_lock();
3076                         return (NULL);
3077                 }
3078                 gp = NULL;
3079         }
3080         sx_xunlock(&sc->sc_lock);
3081         g_topology_lock();
3082         return (gp);
3083 }
3084
3085 static int
3086 g_mirror_destroy_geom(struct gctl_req *req __unused,
3087     struct g_class *mp __unused, struct g_geom *gp)
3088 {
3089         struct g_mirror_softc *sc;
3090         int error;
3091
3092         g_topology_unlock();
3093         sc = gp->softc;
3094         sx_xlock(&sc->sc_lock);
3095         g_cancel_event(sc);
3096         error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3097         if (error != 0)
3098                 sx_xunlock(&sc->sc_lock);
3099         g_topology_lock();
3100         return (error);
3101 }
3102
3103 static void
3104 g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3105     struct g_consumer *cp, struct g_provider *pp)
3106 {
3107         struct g_mirror_softc *sc;
3108
3109         g_topology_assert();
3110
3111         sc = gp->softc;
3112         if (sc == NULL)
3113                 return;
3114         /* Skip synchronization geom. */
3115         if (gp == sc->sc_sync.ds_geom)
3116                 return;
3117         if (pp != NULL) {
3118                 /* Nothing here. */
3119         } else if (cp != NULL) {
3120                 struct g_mirror_disk *disk;
3121
3122                 disk = cp->private;
3123                 if (disk == NULL)
3124                         return;
3125                 g_topology_unlock();
3126                 sx_xlock(&sc->sc_lock);
3127                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3128                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3129                         sbuf_printf(sb, "%s<Synchronized>", indent);
3130                         if (disk->d_sync.ds_offset == 0)
3131                                 sbuf_printf(sb, "0%%");
3132                         else {
3133                                 sbuf_printf(sb, "%u%%",
3134                                     (u_int)((disk->d_sync.ds_offset * 100) /
3135                                     sc->sc_provider->mediasize));
3136                         }
3137                         sbuf_printf(sb, "</Synchronized>\n");
3138                 }
3139                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3140                     disk->d_sync.ds_syncid);
3141                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3142                     disk->d_genid);
3143                 sbuf_printf(sb, "%s<Flags>", indent);
3144                 if (disk->d_flags == 0)
3145                         sbuf_printf(sb, "NONE");
3146                 else {
3147                         int first = 1;
3148
3149 #define ADD_FLAG(flag, name)    do {                                    \
3150         if ((disk->d_flags & (flag)) != 0) {                            \
3151                 if (!first)                                             \
3152                         sbuf_printf(sb, ", ");                          \
3153                 else                                                    \
3154                         first = 0;                                      \
3155                 sbuf_printf(sb, name);                                  \
3156         }                                                               \
3157 } while (0)
3158                         ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3159                         ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3160                         ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3161                         ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3162                             "SYNCHRONIZING");
3163                         ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3164                         ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3165 #undef  ADD_FLAG
3166                 }
3167                 sbuf_printf(sb, "</Flags>\n");
3168                 sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3169                     disk->d_priority);
3170                 sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3171                     g_mirror_disk_state2str(disk->d_state));
3172                 sx_xunlock(&sc->sc_lock);
3173                 g_topology_lock();
3174         } else {
3175                 g_topology_unlock();
3176                 sx_xlock(&sc->sc_lock);
3177                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3178                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3179                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3180                 sbuf_printf(sb, "%s<Flags>", indent);
3181                 if (sc->sc_flags == 0)
3182                         sbuf_printf(sb, "NONE");
3183                 else {
3184                         int first = 1;
3185
3186 #define ADD_FLAG(flag, name)    do {                                    \
3187         if ((sc->sc_flags & (flag)) != 0) {                             \
3188                 if (!first)                                             \
3189                         sbuf_printf(sb, ", ");                          \
3190                 else                                                    \
3191                         first = 0;                                      \
3192                 sbuf_printf(sb, name);                                  \
3193         }                                                               \
3194 } while (0)
3195                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3196                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3197 #undef  ADD_FLAG
3198                 }
3199                 sbuf_printf(sb, "</Flags>\n");
3200                 sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3201                     (u_int)sc->sc_slice);
3202                 sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3203                     balance_name(sc->sc_balance));
3204                 sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3205                     sc->sc_ndisks);
3206                 sbuf_printf(sb, "%s<State>", indent);
3207                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3208                         sbuf_printf(sb, "%s", "STARTING");
3209                 else if (sc->sc_ndisks ==
3210                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3211                         sbuf_printf(sb, "%s", "COMPLETE");
3212                 else
3213                         sbuf_printf(sb, "%s", "DEGRADED");
3214                 sbuf_printf(sb, "</State>\n");
3215                 sx_xunlock(&sc->sc_lock);
3216                 g_topology_lock();
3217         }
3218 }
3219
3220 static void
3221 g_mirror_shutdown_pre_sync(void *arg, int howto)
3222 {
3223         struct g_class *mp;
3224         struct g_geom *gp, *gp2;
3225         struct g_mirror_softc *sc;
3226         int error;
3227
3228         mp = arg;
3229         DROP_GIANT();
3230         g_topology_lock();
3231         LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3232                 if ((sc = gp->softc) == NULL)
3233                         continue;
3234                 /* Skip synchronization geom. */
3235                 if (gp == sc->sc_sync.ds_geom)
3236                         continue;
3237                 g_topology_unlock();
3238                 sx_xlock(&sc->sc_lock);
3239                 g_cancel_event(sc);
3240                 error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3241                 if (error != 0)
3242                         sx_xunlock(&sc->sc_lock);
3243                 g_topology_lock();
3244         }
3245         g_topology_unlock();
3246         PICKUP_GIANT();
3247 }
3248
3249 static void
3250 g_mirror_init(struct g_class *mp)
3251 {
3252
3253         g_mirror_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
3254             g_mirror_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
3255         if (g_mirror_pre_sync == NULL)
3256                 G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3257 }
3258
3259 static void
3260 g_mirror_fini(struct g_class *mp)
3261 {
3262
3263         if (g_mirror_pre_sync != NULL)
3264                 EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_mirror_pre_sync);
3265 }
3266
3267 DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);