sys/geom/mirror/g_mirror.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2004-2006 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/param.h>
  33 #include <sys/systm.h>
  34 #include <sys/bio.h>
  35 #include <sys/eventhandler.h>
  36 #include <sys/fail.h>
  37 #include <sys/kernel.h>
  38 #include <sys/kthread.h>
  39 #include <sys/limits.h>
  40 #include <sys/lock.h>
  41 #include <sys/malloc.h>
  42 #include <sys/mutex.h>
  43 #include <sys/proc.h>
  44 #include <sys/sbuf.h>
  45 #include <sys/sched.h>
  46 #include <sys/sx.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <geom/geom.h>
  50 #include <geom/geom_dbg.h>
  51 #include <geom/mirror/g_mirror.h>
  52
  53 FEATURE(geom_mirror, "GEOM mirroring support");
  54
  55 static MALLOC_DEFINE(M_MIRROR, "mirror_data", "GEOM_MIRROR Data");
  56
  57 SYSCTL_DECL(_kern_geom);
  58 static SYSCTL_NODE(_kern_geom, OID_AUTO, mirror, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
  59     "GEOM_MIRROR stuff");
  60 int g_mirror_debug = 0;
  61 SYSCTL_INT(_kern_geom_mirror, OID_AUTO, debug, CTLFLAG_RWTUN, &g_mirror_debug, 0,
  62     "Debug level");
  63 bool g_launch_mirror_before_timeout = true;
  64 SYSCTL_BOOL(_kern_geom_mirror, OID_AUTO, launch_mirror_before_timeout,
  65     CTLFLAG_RWTUN, &g_launch_mirror_before_timeout, 0,
  66     "If false, force gmirror to wait out the full kern.geom.mirror.timeout "
  67     "before launching mirrors");
  68 static u_int g_mirror_timeout = 4;
  69 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, timeout, CTLFLAG_RWTUN, &g_mirror_timeout,
  70     0, "Time to wait on all mirror components");
  71 static u_int g_mirror_idletime = 5;
  72 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, idletime, CTLFLAG_RWTUN,
  73     &g_mirror_idletime, 0, "Mark components as clean when idling");
  74 static u_int g_mirror_disconnect_on_failure = 1;
  75 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, disconnect_on_failure, CTLFLAG_RWTUN,
  76     &g_mirror_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
  77 static u_int g_mirror_syncreqs = 2;
  78 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_requests, CTLFLAG_RDTUN,
  79     &g_mirror_syncreqs, 0, "Parallel synchronization I/O requests.");
  80 static u_int g_mirror_sync_period = 5;
  81 SYSCTL_UINT(_kern_geom_mirror, OID_AUTO, sync_update_period, CTLFLAG_RWTUN,
  82     &g_mirror_sync_period, 0,
  83     "Metadata update period during synchronization, in seconds");
  84
  85 #define MSLEEP(ident, mtx, priority, wmesg, timeout)    do {            \
  86         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));       \
  87         msleep((ident), (mtx), (priority), (wmesg), (timeout));         \
  88         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, (ident));       \
  89 } while (0)
  90
  91 static eventhandler_tag g_mirror_post_sync = NULL;
  92 static int g_mirror_shutdown = 0;
  93
  94 static g_ctl_destroy_geom_t g_mirror_destroy_geom;
  95 static g_taste_t g_mirror_taste;
  96 static g_init_t g_mirror_init;
  97 static g_fini_t g_mirror_fini;
  98 static g_provgone_t g_mirror_providergone;
  99 static g_resize_t g_mirror_resize;
 100
 101 struct g_class g_mirror_class = {
 102         .name = G_MIRROR_CLASS_NAME,
 103         .version = G_VERSION,
 104         .ctlreq = g_mirror_config,
 105         .taste = g_mirror_taste,
 106         .destroy_geom = g_mirror_destroy_geom,
 107         .init = g_mirror_init,
 108         .fini = g_mirror_fini,
 109         .providergone = g_mirror_providergone,
 110         .resize = g_mirror_resize
 111 };
 112
 113 static void g_mirror_destroy_provider(struct g_mirror_softc *sc);
 114 static int g_mirror_update_disk(struct g_mirror_disk *disk, u_int state);
 115 static void g_mirror_update_device(struct g_mirror_softc *sc, bool force);
 116 static void g_mirror_dumpconf(struct sbuf *sb, const char *indent,
 117     struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
 118 static void g_mirror_timeout_drain(struct g_mirror_softc *sc);
 119 static int g_mirror_refresh_device(struct g_mirror_softc *sc,
 120     const struct g_provider *pp, const struct g_mirror_metadata *md);
 121 static void g_mirror_sync_reinit(const struct g_mirror_disk *disk,
 122     struct bio *bp, off_t offset);
 123 static void g_mirror_sync_stop(struct g_mirror_disk *disk, int type);
 124 static void g_mirror_register_request(struct g_mirror_softc *sc,
 125     struct bio *bp);
 126 static void g_mirror_sync_release(struct g_mirror_softc *sc);
 127
 128 static const char *
 129 g_mirror_disk_state2str(int state)
 130 {
 131
 132         switch (state) {
 133         case G_MIRROR_DISK_STATE_NONE:
 134                 return ("NONE");
 135         case G_MIRROR_DISK_STATE_NEW:
 136                 return ("NEW");
 137         case G_MIRROR_DISK_STATE_ACTIVE:
 138                 return ("ACTIVE");
 139         case G_MIRROR_DISK_STATE_STALE:
 140                 return ("STALE");
 141         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 142                 return ("SYNCHRONIZING");
 143         case G_MIRROR_DISK_STATE_DISCONNECTED:
 144                 return ("DISCONNECTED");
 145         case G_MIRROR_DISK_STATE_DESTROY:
 146                 return ("DESTROY");
 147         default:
 148                 return ("INVALID");
 149         }
 150 }
 151
 152 static const char *
 153 g_mirror_device_state2str(int state)
 154 {
 155
 156         switch (state) {
 157         case G_MIRROR_DEVICE_STATE_STARTING:
 158                 return ("STARTING");
 159         case G_MIRROR_DEVICE_STATE_RUNNING:
 160                 return ("RUNNING");
 161         default:
 162                 return ("INVALID");
 163         }
 164 }
 165
 166 static const char *
 167 g_mirror_get_diskname(struct g_mirror_disk *disk)
 168 {
 169
 170         if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
 171                 return ("[unknown]");
 172         return (disk->d_name);
 173 }
 174
 175 /*
 176  * --- Events handling functions ---
 177  * Events in geom_mirror are used to maintain disks and device status
 178  * from one thread to simplify locking.
 179  */
 180 static void
 181 g_mirror_event_free(struct g_mirror_event *ep)
 182 {
 183
 184         free(ep, M_MIRROR);
 185 }
 186
 187 static int
 188 g_mirror_event_dispatch(struct g_mirror_event *ep, void *arg, int state,
 189     int flags)
 190 {
 191         struct g_mirror_softc *sc;
 192         struct g_mirror_disk *disk;
 193         int error;
 194
 195         G_MIRROR_DEBUG(4, "%s: Sending event %p.", __func__, ep);
 196         if ((flags & G_MIRROR_EVENT_DEVICE) != 0) {
 197                 disk = NULL;
 198                 sc = arg;
 199         } else {
 200                 disk = arg;
 201                 sc = disk->d_softc;
 202         }
 203         ep->e_disk = disk;
 204         ep->e_state = state;
 205         ep->e_flags = flags;
 206         ep->e_error = 0;
 207         mtx_lock(&sc->sc_events_mtx);
 208         TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
 209         mtx_unlock(&sc->sc_events_mtx);
 210         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 211         mtx_lock(&sc->sc_queue_mtx);
 212         wakeup(sc);
 213         mtx_unlock(&sc->sc_queue_mtx);
 214         if ((flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 215                 return (0);
 216         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, ep);
 217         sx_xunlock(&sc->sc_lock);
 218         while ((ep->e_flags & G_MIRROR_EVENT_DONE) == 0) {
 219                 mtx_lock(&sc->sc_events_mtx);
 220                 MSLEEP(ep, &sc->sc_events_mtx, PRIBIO | PDROP, "m:event",
 221                     hz * 5);
 222         }
 223         error = ep->e_error;
 224         g_mirror_event_free(ep);
 225         sx_xlock(&sc->sc_lock);
 226         return (error);
 227 }
 228
 229 int
 230 g_mirror_event_send(void *arg, int state, int flags)
 231 {
 232         struct g_mirror_event *ep;
 233
 234         ep = malloc(sizeof(*ep), M_MIRROR, M_WAITOK);
 235         return (g_mirror_event_dispatch(ep, arg, state, flags));
 236 }
 237
 238 static struct g_mirror_event *
 239 g_mirror_event_first(struct g_mirror_softc *sc)
 240 {
 241         struct g_mirror_event *ep;
 242
 243         mtx_lock(&sc->sc_events_mtx);
 244         ep = TAILQ_FIRST(&sc->sc_events);
 245         mtx_unlock(&sc->sc_events_mtx);
 246         return (ep);
 247 }
 248
 249 static void
 250 g_mirror_event_remove(struct g_mirror_softc *sc, struct g_mirror_event *ep)
 251 {
 252
 253         mtx_lock(&sc->sc_events_mtx);
 254         TAILQ_REMOVE(&sc->sc_events, ep, e_next);
 255         mtx_unlock(&sc->sc_events_mtx);
 256 }
 257
 258 static void
 259 g_mirror_event_cancel(struct g_mirror_disk *disk)
 260 {
 261         struct g_mirror_softc *sc;
 262         struct g_mirror_event *ep, *tmpep;
 263
 264         sc = disk->d_softc;
 265         sx_assert(&sc->sc_lock, SX_XLOCKED);
 266
 267         mtx_lock(&sc->sc_events_mtx);
 268         TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
 269                 if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0)
 270                         continue;
 271                 if (ep->e_disk != disk)
 272                         continue;
 273                 TAILQ_REMOVE(&sc->sc_events, ep, e_next);
 274                 if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 275                         g_mirror_event_free(ep);
 276                 else {
 277                         ep->e_error = ECANCELED;
 278                         wakeup(ep);
 279                 }
 280         }
 281         mtx_unlock(&sc->sc_events_mtx);
 282 }
 283
 284 /*
 285  * Return the number of disks in given state.
 286  * If state is equal to -1, count all connected disks.
 287  */
 288 u_int
 289 g_mirror_ndisks(struct g_mirror_softc *sc, int state)
 290 {
 291         struct g_mirror_disk *disk;
 292         u_int n = 0;
 293
 294         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 295                 if (state == -1 || disk->d_state == state)
 296                         n++;
 297         }
 298         return (n);
 299 }
 300
 301 /*
 302  * Find a disk in mirror by its disk ID.
 303  */
 304 static struct g_mirror_disk *
 305 g_mirror_id2disk(struct g_mirror_softc *sc, uint32_t id)
 306 {
 307         struct g_mirror_disk *disk;
 308
 309         sx_assert(&sc->sc_lock, SX_XLOCKED);
 310
 311         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 312                 if (disk->d_id == id)
 313                         return (disk);
 314         }
 315         return (NULL);
 316 }
 317
 318 static u_int
 319 g_mirror_nrequests(struct g_mirror_softc *sc, struct g_consumer *cp)
 320 {
 321         struct bio *bp;
 322         u_int nreqs = 0;
 323
 324         mtx_lock(&sc->sc_queue_mtx);
 325         TAILQ_FOREACH(bp, &sc->sc_queue, bio_queue) {
 326                 if (bp->bio_from == cp)
 327                         nreqs++;
 328         }
 329         mtx_unlock(&sc->sc_queue_mtx);
 330         return (nreqs);
 331 }
 332
 333 static int
 334 g_mirror_is_busy(struct g_mirror_softc *sc, struct g_consumer *cp)
 335 {
 336
 337         if (cp->index > 0) {
 338                 G_MIRROR_DEBUG(2,
 339                     "I/O requests for %s exist, can't destroy it now.",
 340                     cp->provider->name);
 341                 return (1);
 342         }
 343         if (g_mirror_nrequests(sc, cp) > 0) {
 344                 G_MIRROR_DEBUG(2,
 345                     "I/O requests for %s in queue, can't destroy it now.",
 346                     cp->provider->name);
 347                 return (1);
 348         }
 349         return (0);
 350 }
 351
 352 static void
 353 g_mirror_destroy_consumer(void *arg, int flags __unused)
 354 {
 355         struct g_consumer *cp;
 356
 357         g_topology_assert();
 358
 359         cp = arg;
 360         G_MIRROR_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
 361         g_detach(cp);
 362         g_destroy_consumer(cp);
 363 }
 364
 365 static void
 366 g_mirror_kill_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
 367 {
 368         struct g_provider *pp;
 369         int retaste_wait;
 370
 371         g_topology_assert();
 372
 373         cp->private = NULL;
 374         if (g_mirror_is_busy(sc, cp))
 375                 return;
 376         pp = cp->provider;
 377         retaste_wait = 0;
 378         if (cp->acw == 1) {
 379                 if ((pp->geom->flags & G_GEOM_WITHER) == 0)
 380                         retaste_wait = 1;
 381         }
 382         G_MIRROR_DEBUG(2, "Access %s r%dw%de%d = %d", pp->name, -cp->acr,
 383             -cp->acw, -cp->ace, 0);
 384         if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
 385                 g_access(cp, -cp->acr, -cp->acw, -cp->ace);
 386         if (retaste_wait) {
 387                 /*
 388                  * After retaste event was send (inside g_access()), we can send
 389                  * event to detach and destroy consumer.
 390                  * A class, which has consumer to the given provider connected
 391                  * will not receive retaste event for the provider.
 392                  * This is the way how I ignore retaste events when I close
 393                  * consumers opened for write: I detach and destroy consumer
 394                  * after retaste event is sent.
 395                  */
 396                 g_post_event(g_mirror_destroy_consumer, cp, M_WAITOK, NULL);
 397                 return;
 398         }
 399         G_MIRROR_DEBUG(1, "Consumer %s destroyed.", pp->name);
 400         g_detach(cp);
 401         g_destroy_consumer(cp);
 402 }
 403
 404 static int
 405 g_mirror_connect_disk(struct g_mirror_disk *disk, struct g_provider *pp)
 406 {
 407         struct g_consumer *cp;
 408         int error;
 409
 410         g_topology_assert_not();
 411         KASSERT(disk->d_consumer == NULL,
 412             ("Disk already connected (device %s).", disk->d_softc->sc_name));
 413
 414         g_topology_lock();
 415         cp = g_new_consumer(disk->d_softc->sc_geom);
 416         cp->flags |= G_CF_DIRECT_RECEIVE;
 417         error = g_attach(cp, pp);
 418         if (error != 0) {
 419                 g_destroy_consumer(cp);
 420                 g_topology_unlock();
 421                 return (error);
 422         }
 423         error = g_access(cp, 1, 1, 1);
 424         if (error != 0) {
 425                 g_detach(cp);
 426                 g_destroy_consumer(cp);
 427                 g_topology_unlock();
 428                 G_MIRROR_DEBUG(0, "Cannot open consumer %s (error=%d).",
 429                     pp->name, error);
 430                 return (error);
 431         }
 432         g_topology_unlock();
 433         disk->d_consumer = cp;
 434         disk->d_consumer->private = disk;
 435         disk->d_consumer->index = 0;
 436
 437         G_MIRROR_DEBUG(2, "Disk %s connected.", g_mirror_get_diskname(disk));
 438         return (0);
 439 }
 440
 441 static void
 442 g_mirror_disconnect_consumer(struct g_mirror_softc *sc, struct g_consumer *cp)
 443 {
 444
 445         g_topology_assert();
 446
 447         if (cp == NULL)
 448                 return;
 449         if (cp->provider != NULL)
 450                 g_mirror_kill_consumer(sc, cp);
 451         else
 452                 g_destroy_consumer(cp);
 453 }
 454
 455 /*
 456  * Initialize disk. This means allocate memory, create consumer, attach it
 457  * to the provider and open access (r1w1e1) to it.
 458  */
 459 static struct g_mirror_disk *
 460 g_mirror_init_disk(struct g_mirror_softc *sc, struct g_provider *pp,
 461     struct g_mirror_metadata *md, int *errorp)
 462 {
 463         struct g_mirror_disk *disk;
 464         int i, error;
 465
 466         disk = malloc(sizeof(*disk), M_MIRROR, M_NOWAIT | M_ZERO);
 467         if (disk == NULL) {
 468                 error = ENOMEM;
 469                 goto fail;
 470         }
 471         disk->d_softc = sc;
 472         error = g_mirror_connect_disk(disk, pp);
 473         if (error != 0)
 474                 goto fail;
 475         disk->d_id = md->md_did;
 476         disk->d_state = G_MIRROR_DISK_STATE_NONE;
 477         disk->d_priority = md->md_priority;
 478         disk->d_flags = md->md_dflags;
 479         error = g_getattr("GEOM::candelete", disk->d_consumer, &i);
 480         if (error == 0 && i != 0)
 481                 disk->d_flags |= G_MIRROR_DISK_FLAG_CANDELETE;
 482         if (md->md_provider[0] != '\0')
 483                 disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
 484         disk->d_sync.ds_consumer = NULL;
 485         disk->d_sync.ds_offset = md->md_sync_offset;
 486         disk->d_sync.ds_offset_done = md->md_sync_offset;
 487         disk->d_sync.ds_update_ts = time_uptime;
 488         disk->d_genid = md->md_genid;
 489         disk->d_sync.ds_syncid = md->md_syncid;
 490         disk->d_init_ndisks = md->md_all;
 491         disk->d_init_slice = md->md_slice;
 492         disk->d_init_balance = md->md_balance;
 493         disk->d_init_mediasize = md->md_mediasize;
 494         if (errorp != NULL)
 495                 *errorp = 0;
 496         return (disk);
 497 fail:
 498         if (errorp != NULL)
 499                 *errorp = error;
 500         if (disk != NULL)
 501                 free(disk, M_MIRROR);
 502         return (NULL);
 503 }
 504
 505 static void
 506 g_mirror_destroy_disk(struct g_mirror_disk *disk)
 507 {
 508         struct g_mirror_softc *sc;
 509
 510         g_topology_assert_not();
 511         sc = disk->d_softc;
 512         sx_assert(&sc->sc_lock, SX_XLOCKED);
 513
 514         g_topology_lock();
 515         LIST_REMOVE(disk, d_next);
 516         g_topology_unlock();
 517         g_mirror_event_cancel(disk);
 518         if (sc->sc_hint == disk)
 519                 sc->sc_hint = NULL;
 520         switch (disk->d_state) {
 521         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 522                 g_mirror_sync_stop(disk, 1);
 523                 /* FALLTHROUGH */
 524         case G_MIRROR_DISK_STATE_NEW:
 525         case G_MIRROR_DISK_STATE_STALE:
 526         case G_MIRROR_DISK_STATE_ACTIVE:
 527                 g_topology_lock();
 528                 g_mirror_disconnect_consumer(sc, disk->d_consumer);
 529                 g_topology_unlock();
 530                 free(disk, M_MIRROR);
 531                 break;
 532         default:
 533                 KASSERT(0 == 1, ("Wrong disk state (%s, %s).",
 534                     g_mirror_get_diskname(disk),
 535                     g_mirror_disk_state2str(disk->d_state)));
 536         }
 537 }
 538
 539 static void
 540 g_mirror_free_device(struct g_mirror_softc *sc)
 541 {
 542
 543         g_topology_assert();
 544
 545         mtx_destroy(&sc->sc_queue_mtx);
 546         mtx_destroy(&sc->sc_events_mtx);
 547         mtx_destroy(&sc->sc_done_mtx);
 548         sx_destroy(&sc->sc_lock);
 549         free(sc, M_MIRROR);
 550 }
 551
 552 static void
 553 g_mirror_providergone(struct g_provider *pp)
 554 {
 555         struct g_mirror_softc *sc = pp->private;
 556
 557         if ((--sc->sc_refcnt) == 0)
 558                 g_mirror_free_device(sc);
 559 }
 560
 561 static void
 562 g_mirror_destroy_device(struct g_mirror_softc *sc)
 563 {
 564         struct g_mirror_disk *disk;
 565         struct g_mirror_event *ep;
 566         struct g_geom *gp;
 567         struct g_consumer *cp, *tmpcp;
 568
 569         g_topology_assert_not();
 570         sx_assert(&sc->sc_lock, SX_XLOCKED);
 571
 572         gp = sc->sc_geom;
 573         if (sc->sc_provider != NULL)
 574                 g_mirror_destroy_provider(sc);
 575         for (disk = LIST_FIRST(&sc->sc_disks); disk != NULL;
 576             disk = LIST_FIRST(&sc->sc_disks)) {
 577                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 578                 g_mirror_update_metadata(disk);
 579                 g_mirror_destroy_disk(disk);
 580         }
 581         while ((ep = g_mirror_event_first(sc)) != NULL) {
 582                 g_mirror_event_remove(sc, ep);
 583                 if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0)
 584                         g_mirror_event_free(ep);
 585                 else {
 586                         ep->e_error = ECANCELED;
 587                         ep->e_flags |= G_MIRROR_EVENT_DONE;
 588                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, ep);
 589                         mtx_lock(&sc->sc_events_mtx);
 590                         wakeup(ep);
 591                         mtx_unlock(&sc->sc_events_mtx);
 592                 }
 593         }
 594         g_mirror_timeout_drain(sc);
 595
 596         g_topology_lock();
 597         LIST_FOREACH_SAFE(cp, &sc->sc_sync.ds_geom->consumer, consumer, tmpcp) {
 598                 g_mirror_disconnect_consumer(sc, cp);
 599         }
 600         g_wither_geom(sc->sc_sync.ds_geom, ENXIO);
 601         G_MIRROR_DEBUG(0, "Device %s destroyed.", gp->name);
 602         g_wither_geom(gp, ENXIO);
 603         sx_xunlock(&sc->sc_lock);
 604         if ((--sc->sc_refcnt) == 0)
 605                 g_mirror_free_device(sc);
 606         g_topology_unlock();
 607 }
 608
 609 static void
 610 g_mirror_orphan(struct g_consumer *cp)
 611 {
 612         struct g_mirror_disk *disk;
 613
 614         g_topology_assert();
 615
 616         disk = cp->private;
 617         if (disk == NULL)
 618                 return;
 619         disk->d_softc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 620         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
 621             G_MIRROR_EVENT_DONTWAIT);
 622 }
 623
 624 /*
 625  * Function should return the next active disk on the list.
 626  * It is possible that it will be the same disk as given.
 627  * If there are no active disks on list, NULL is returned.
 628  */
 629 static __inline struct g_mirror_disk *
 630 g_mirror_find_next(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
 631 {
 632         struct g_mirror_disk *dp;
 633
 634         for (dp = LIST_NEXT(disk, d_next); dp != disk;
 635             dp = LIST_NEXT(dp, d_next)) {
 636                 if (dp == NULL)
 637                         dp = LIST_FIRST(&sc->sc_disks);
 638                 if (dp->d_state == G_MIRROR_DISK_STATE_ACTIVE)
 639                         break;
 640         }
 641         if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 642                 return (NULL);
 643         return (dp);
 644 }
 645
 646 static struct g_mirror_disk *
 647 g_mirror_get_disk(struct g_mirror_softc *sc)
 648 {
 649         struct g_mirror_disk *disk;
 650
 651         if (sc->sc_hint == NULL) {
 652                 sc->sc_hint = LIST_FIRST(&sc->sc_disks);
 653                 if (sc->sc_hint == NULL)
 654                         return (NULL);
 655         }
 656         disk = sc->sc_hint;
 657         if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE) {
 658                 disk = g_mirror_find_next(sc, disk);
 659                 if (disk == NULL)
 660                         return (NULL);
 661         }
 662         sc->sc_hint = g_mirror_find_next(sc, disk);
 663         return (disk);
 664 }
 665
 666 static int
 667 g_mirror_write_metadata(struct g_mirror_disk *disk,
 668     struct g_mirror_metadata *md)
 669 {
 670         struct g_mirror_softc *sc;
 671         struct g_consumer *cp;
 672         off_t offset, length;
 673         u_char *sector;
 674         int error = 0;
 675
 676         g_topology_assert_not();
 677         sc = disk->d_softc;
 678         sx_assert(&sc->sc_lock, SX_LOCKED);
 679
 680         cp = disk->d_consumer;
 681         KASSERT(cp != NULL, ("NULL consumer (%s).", sc->sc_name));
 682         KASSERT(cp->provider != NULL, ("NULL provider (%s).", sc->sc_name));
 683         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 684             ("Consumer %s closed? (r%dw%de%d).", cp->provider->name, cp->acr,
 685             cp->acw, cp->ace));
 686         length = cp->provider->sectorsize;
 687         offset = cp->provider->mediasize - length;
 688         sector = malloc((size_t)length, M_MIRROR, M_WAITOK | M_ZERO);
 689         if (md != NULL &&
 690             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0) {
 691                 /*
 692                  * Handle the case, when the size of parent provider reduced.
 693                  */
 694                 if (offset < md->md_mediasize)
 695                         error = ENOSPC;
 696                 else
 697                         mirror_metadata_encode(md, sector);
 698         }
 699         KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_metadata_write, error);
 700         if (error == 0)
 701                 error = g_write_data(cp, offset, sector, length);
 702         free(sector, M_MIRROR);
 703         if (error != 0) {
 704                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
 705                         disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
 706                         G_MIRROR_DEBUG(0, "Cannot write metadata on %s "
 707                             "(device=%s, error=%d).",
 708                             g_mirror_get_diskname(disk), sc->sc_name, error);
 709                 } else {
 710                         G_MIRROR_DEBUG(1, "Cannot write metadata on %s "
 711                             "(device=%s, error=%d).",
 712                             g_mirror_get_diskname(disk), sc->sc_name, error);
 713                 }
 714                 if (g_mirror_disconnect_on_failure &&
 715                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
 716                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 717                         g_mirror_event_send(disk,
 718                             G_MIRROR_DISK_STATE_DISCONNECTED,
 719                             G_MIRROR_EVENT_DONTWAIT);
 720                 }
 721         }
 722         return (error);
 723 }
 724
 725 static int
 726 g_mirror_clear_metadata(struct g_mirror_disk *disk)
 727 {
 728         int error;
 729
 730         g_topology_assert_not();
 731         sx_assert(&disk->d_softc->sc_lock, SX_LOCKED);
 732
 733         if (disk->d_softc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
 734                 return (0);
 735         error = g_mirror_write_metadata(disk, NULL);
 736         if (error == 0) {
 737                 G_MIRROR_DEBUG(2, "Metadata on %s cleared.",
 738                     g_mirror_get_diskname(disk));
 739         } else {
 740                 G_MIRROR_DEBUG(0,
 741                     "Cannot clear metadata on disk %s (error=%d).",
 742                     g_mirror_get_diskname(disk), error);
 743         }
 744         return (error);
 745 }
 746
 747 void
 748 g_mirror_fill_metadata(struct g_mirror_softc *sc, struct g_mirror_disk *disk,
 749     struct g_mirror_metadata *md)
 750 {
 751
 752         strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
 753         md->md_version = G_MIRROR_VERSION;
 754         strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
 755         md->md_mid = sc->sc_id;
 756         md->md_all = sc->sc_ndisks;
 757         md->md_slice = sc->sc_slice;
 758         md->md_balance = sc->sc_balance;
 759         md->md_genid = sc->sc_genid;
 760         md->md_mediasize = sc->sc_mediasize;
 761         md->md_sectorsize = sc->sc_sectorsize;
 762         md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
 763         bzero(md->md_provider, sizeof(md->md_provider));
 764         if (disk == NULL) {
 765                 md->md_did = arc4random();
 766                 md->md_priority = 0;
 767                 md->md_syncid = 0;
 768                 md->md_dflags = 0;
 769                 md->md_sync_offset = 0;
 770                 md->md_provsize = 0;
 771         } else {
 772                 md->md_did = disk->d_id;
 773                 md->md_priority = disk->d_priority;
 774                 md->md_syncid = disk->d_sync.ds_syncid;
 775                 md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
 776                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
 777                         md->md_sync_offset = disk->d_sync.ds_offset_done;
 778                 else
 779                         md->md_sync_offset = 0;
 780                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
 781                         strlcpy(md->md_provider,
 782                             disk->d_consumer->provider->name,
 783                             sizeof(md->md_provider));
 784                 }
 785                 md->md_provsize = disk->d_consumer->provider->mediasize;
 786         }
 787 }
 788
 789 void
 790 g_mirror_update_metadata(struct g_mirror_disk *disk)
 791 {
 792         struct g_mirror_softc *sc;
 793         struct g_mirror_metadata md;
 794         int error;
 795
 796         g_topology_assert_not();
 797         sc = disk->d_softc;
 798         sx_assert(&sc->sc_lock, SX_LOCKED);
 799
 800         if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
 801                 return;
 802         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0)
 803                 g_mirror_fill_metadata(sc, disk, &md);
 804         error = g_mirror_write_metadata(disk, &md);
 805         if (error == 0) {
 806                 G_MIRROR_DEBUG(2, "Metadata on %s updated.",
 807                     g_mirror_get_diskname(disk));
 808         } else {
 809                 G_MIRROR_DEBUG(0,
 810                     "Cannot update metadata on disk %s (error=%d).",
 811                     g_mirror_get_diskname(disk), error);
 812         }
 813 }
 814
 815 static void
 816 g_mirror_bump_syncid(struct g_mirror_softc *sc)
 817 {
 818         struct g_mirror_disk *disk;
 819
 820         g_topology_assert_not();
 821         sx_assert(&sc->sc_lock, SX_XLOCKED);
 822         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
 823             ("%s called with no active disks (device=%s).", __func__,
 824             sc->sc_name));
 825
 826         sc->sc_syncid++;
 827         G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
 828             sc->sc_syncid);
 829         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 830                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 831                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 832                         disk->d_sync.ds_syncid = sc->sc_syncid;
 833                         g_mirror_update_metadata(disk);
 834                 }
 835         }
 836 }
 837
 838 static void
 839 g_mirror_bump_genid(struct g_mirror_softc *sc)
 840 {
 841         struct g_mirror_disk *disk;
 842
 843         g_topology_assert_not();
 844         sx_assert(&sc->sc_lock, SX_XLOCKED);
 845         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
 846             ("%s called with no active disks (device=%s).", __func__,
 847             sc->sc_name));
 848
 849         sc->sc_genid++;
 850         G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
 851             sc->sc_genid);
 852         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 853                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 854                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 855                         disk->d_genid = sc->sc_genid;
 856                         g_mirror_update_metadata(disk);
 857                 }
 858         }
 859 }
 860
 861 static int
 862 g_mirror_idle(struct g_mirror_softc *sc, int acw)
 863 {
 864         struct g_mirror_disk *disk;
 865         int timeout;
 866
 867         g_topology_assert_not();
 868         sx_assert(&sc->sc_lock, SX_XLOCKED);
 869
 870         if (sc->sc_provider == NULL)
 871                 return (0);
 872         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 873                 return (0);
 874         if (sc->sc_idle)
 875                 return (0);
 876         if (sc->sc_writes > 0)
 877                 return (0);
 878         if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
 879                 timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
 880                 if (!g_mirror_shutdown && timeout > 0)
 881                         return (timeout);
 882         }
 883         sc->sc_idle = 1;
 884         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 885                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 886                         continue;
 887                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
 888                     g_mirror_get_diskname(disk), sc->sc_name);
 889                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 890                 g_mirror_update_metadata(disk);
 891         }
 892         return (0);
 893 }
 894
 895 static void
 896 g_mirror_unidle(struct g_mirror_softc *sc)
 897 {
 898         struct g_mirror_disk *disk;
 899
 900         g_topology_assert_not();
 901         sx_assert(&sc->sc_lock, SX_XLOCKED);
 902
 903         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 904                 return;
 905         sc->sc_idle = 0;
 906         sc->sc_last_write = time_uptime;
 907         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 908                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 909                         continue;
 910                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
 911                     g_mirror_get_diskname(disk), sc->sc_name);
 912                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
 913                 g_mirror_update_metadata(disk);
 914         }
 915 }
 916
 917 static void
 918 g_mirror_done(struct bio *bp)
 919 {
 920         struct g_mirror_softc *sc;
 921
 922         sc = bp->bio_from->geom->softc;
 923         bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
 924         mtx_lock(&sc->sc_queue_mtx);
 925         TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
 926         mtx_unlock(&sc->sc_queue_mtx);
 927         wakeup(sc);
 928 }
 929
 930 static void
 931 g_mirror_regular_request_error(struct g_mirror_softc *sc,
 932     struct g_mirror_disk *disk, struct bio *bp)
 933 {
 934
 935         if ((bp->bio_cmd == BIO_FLUSH || bp->bio_cmd == BIO_SPEEDUP) &&
 936             bp->bio_error == EOPNOTSUPP)
 937                 return;
 938
 939         if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
 940                 disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
 941                 G_MIRROR_LOGREQ(0, bp, "Request failed (error=%d).",
 942                     bp->bio_error);
 943         } else {
 944                 G_MIRROR_LOGREQ(1, bp, "Request failed (error=%d).",
 945                     bp->bio_error);
 946         }
 947         if (g_mirror_disconnect_on_failure &&
 948             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
 949                 if (bp->bio_error == ENXIO &&
 950                     bp->bio_cmd == BIO_READ)
 951                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 952                 else if (bp->bio_error == ENXIO)
 953                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID_NOW;
 954                 else
 955                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 956                 g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
 957                     G_MIRROR_EVENT_DONTWAIT);
 958         }
 959 }
 960
 961 static void
 962 g_mirror_regular_request(struct g_mirror_softc *sc, struct bio *bp)
 963 {
 964         struct g_mirror_disk *disk;
 965         struct bio *pbp;
 966
 967         g_topology_assert_not();
 968         KASSERT(sc->sc_provider == bp->bio_parent->bio_to,
 969             ("regular request %p with unexpected origin", bp));
 970
 971         pbp = bp->bio_parent;
 972         bp->bio_from->index--;
 973         if (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_DELETE)
 974                 sc->sc_writes--;
 975         disk = bp->bio_from->private;
 976         if (disk == NULL) {
 977                 g_topology_lock();
 978                 g_mirror_kill_consumer(sc, bp->bio_from);
 979                 g_topology_unlock();
 980         }
 981
 982         switch (bp->bio_cmd) {
 983         case BIO_READ:
 984                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_read,
 985                     bp->bio_error);
 986                 break;
 987         case BIO_WRITE:
 988                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_write,
 989                     bp->bio_error);
 990                 break;
 991         case BIO_DELETE:
 992                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_delete,
 993                     bp->bio_error);
 994                 break;
 995         case BIO_FLUSH:
 996                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_flush,
 997                     bp->bio_error);
 998                 break;
 999         case BIO_SPEEDUP:
1000                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_speedup,
1001                     bp->bio_error);
1002                 break;
1003         }
1004
1005         pbp->bio_inbed++;
1006         KASSERT(pbp->bio_inbed <= pbp->bio_children,
1007             ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
1008             pbp->bio_children));
1009         if (bp->bio_error == 0 && pbp->bio_error == 0) {
1010                 G_MIRROR_LOGREQ(3, bp, "Request delivered.");
1011                 g_destroy_bio(bp);
1012                 if (pbp->bio_children == pbp->bio_inbed) {
1013                         G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
1014                         pbp->bio_completed = pbp->bio_length;
1015                         if (pbp->bio_cmd == BIO_WRITE ||
1016                             pbp->bio_cmd == BIO_DELETE) {
1017                                 TAILQ_REMOVE(&sc->sc_inflight, pbp, bio_queue);
1018                                 /* Release delayed sync requests if possible. */
1019                                 g_mirror_sync_release(sc);
1020                         }
1021                         g_io_deliver(pbp, pbp->bio_error);
1022                 }
1023                 return;
1024         } else if (bp->bio_error != 0) {
1025                 if (pbp->bio_error == 0)
1026                         pbp->bio_error = bp->bio_error;
1027                 if (disk != NULL)
1028                         g_mirror_regular_request_error(sc, disk, bp);
1029                 switch (pbp->bio_cmd) {
1030                 case BIO_DELETE:
1031                 case BIO_WRITE:
1032                 case BIO_FLUSH:
1033                 case BIO_SPEEDUP:
1034                         pbp->bio_inbed--;
1035                         pbp->bio_children--;
1036                         break;
1037                 }
1038         }
1039         g_destroy_bio(bp);
1040
1041         switch (pbp->bio_cmd) {
1042         case BIO_READ:
1043                 if (pbp->bio_inbed < pbp->bio_children)
1044                         break;
1045                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1)
1046                         g_io_deliver(pbp, pbp->bio_error);
1047                 else {
1048                         pbp->bio_error = 0;
1049                         mtx_lock(&sc->sc_queue_mtx);
1050                         TAILQ_INSERT_TAIL(&sc->sc_queue, pbp, bio_queue);
1051                         mtx_unlock(&sc->sc_queue_mtx);
1052                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1053                         wakeup(sc);
1054                 }
1055                 break;
1056         case BIO_DELETE:
1057         case BIO_WRITE:
1058         case BIO_FLUSH:
1059         case BIO_SPEEDUP:
1060                 if (pbp->bio_children == 0) {
1061                         /*
1062                          * All requests failed.
1063                          */
1064                 } else if (pbp->bio_inbed < pbp->bio_children) {
1065                         /* Do nothing. */
1066                         break;
1067                 } else if (pbp->bio_children == pbp->bio_inbed) {
1068                         /* Some requests succeeded. */
1069                         pbp->bio_error = 0;
1070                         pbp->bio_completed = pbp->bio_length;
1071                 }
1072                 if (pbp->bio_cmd == BIO_WRITE || pbp->bio_cmd == BIO_DELETE) {
1073                         TAILQ_REMOVE(&sc->sc_inflight, pbp, bio_queue);
1074                         /* Release delayed sync requests if possible. */
1075                         g_mirror_sync_release(sc);
1076                 }
1077                 g_io_deliver(pbp, pbp->bio_error);
1078                 break;
1079         default:
1080                 KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
1081                 break;
1082         }
1083 }
1084
1085 static void
1086 g_mirror_sync_done(struct bio *bp)
1087 {
1088         struct g_mirror_softc *sc;
1089
1090         G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
1091         sc = bp->bio_from->geom->softc;
1092         bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
1093         mtx_lock(&sc->sc_queue_mtx);
1094         TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
1095         mtx_unlock(&sc->sc_queue_mtx);
1096         wakeup(sc);
1097 }
1098
1099 static void
1100 g_mirror_candelete(struct bio *bp)
1101 {
1102         struct g_mirror_softc *sc;
1103         struct g_mirror_disk *disk;
1104         int val;
1105
1106         sc = bp->bio_to->private;
1107         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1108                 if (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE)
1109                         break;
1110         }
1111         val = disk != NULL;
1112         g_handleattr(bp, "GEOM::candelete", &val, sizeof(val));
1113 }
1114
1115 static void
1116 g_mirror_kernel_dump(struct bio *bp)
1117 {
1118         struct g_mirror_softc *sc;
1119         struct g_mirror_disk *disk;
1120         struct bio *cbp;
1121         struct g_kerneldump *gkd;
1122
1123         /*
1124          * We configure dumping to the first component, because this component
1125          * will be used for reading with 'prefer' balance algorithm.
1126          * If the component with the highest priority is currently disconnected
1127          * we will not be able to read the dump after the reboot if it will be
1128          * connected and synchronized later. Can we do something better?
1129          */
1130         sc = bp->bio_to->private;
1131         disk = LIST_FIRST(&sc->sc_disks);
1132
1133         gkd = (struct g_kerneldump *)bp->bio_data;
1134         if (gkd->length > bp->bio_to->mediasize)
1135                 gkd->length = bp->bio_to->mediasize;
1136         cbp = g_clone_bio(bp);
1137         if (cbp == NULL) {
1138                 g_io_deliver(bp, ENOMEM);
1139                 return;
1140         }
1141         cbp->bio_done = g_std_done;
1142         g_io_request(cbp, disk->d_consumer);
1143         G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
1144             g_mirror_get_diskname(disk));
1145 }
1146
1147 static void
1148 g_mirror_start(struct bio *bp)
1149 {
1150         struct g_mirror_softc *sc;
1151
1152         sc = bp->bio_to->private;
1153         /*
1154          * If sc == NULL or there are no valid disks, provider's error
1155          * should be set and g_mirror_start() should not be called at all.
1156          */
1157         KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
1158             ("Provider's error should be set (error=%d)(mirror=%s).",
1159             bp->bio_to->error, bp->bio_to->name));
1160         G_MIRROR_LOGREQ(3, bp, "Request received.");
1161
1162         switch (bp->bio_cmd) {
1163         case BIO_READ:
1164         case BIO_WRITE:
1165         case BIO_DELETE:
1166         case BIO_SPEEDUP:
1167         case BIO_FLUSH:
1168                 break;
1169         case BIO_GETATTR:
1170                 if (!strcmp(bp->bio_attribute, "GEOM::candelete")) {
1171                         g_mirror_candelete(bp);
1172                         return;
1173                 } else if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
1174                         g_mirror_kernel_dump(bp);
1175                         return;
1176                 }
1177                 /* FALLTHROUGH */
1178         default:
1179                 g_io_deliver(bp, EOPNOTSUPP);
1180                 return;
1181         }
1182         mtx_lock(&sc->sc_queue_mtx);
1183         if (bp->bio_to->error != 0) {
1184                 mtx_unlock(&sc->sc_queue_mtx);
1185                 g_io_deliver(bp, bp->bio_to->error);
1186                 return;
1187         }
1188         TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
1189         mtx_unlock(&sc->sc_queue_mtx);
1190         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
1191         wakeup(sc);
1192 }
1193
1194 /*
1195  * Return TRUE if the given request is colliding with a in-progress
1196  * synchronization request.
1197  */
1198 static bool
1199 g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
1200 {
1201         struct g_mirror_disk *disk;
1202         struct bio *sbp;
1203         off_t rstart, rend, sstart, send;
1204         u_int i;
1205
1206         if (sc->sc_sync.ds_ndisks == 0)
1207                 return (false);
1208         rstart = bp->bio_offset;
1209         rend = bp->bio_offset + bp->bio_length;
1210         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1211                 if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
1212                         continue;
1213                 for (i = 0; i < g_mirror_syncreqs; i++) {
1214                         sbp = disk->d_sync.ds_bios[i];
1215                         if (sbp == NULL)
1216                                 continue;
1217                         sstart = sbp->bio_offset;
1218                         send = sbp->bio_offset + sbp->bio_length;
1219                         if (rend > sstart && rstart < send)
1220                                 return (true);
1221                 }
1222         }
1223         return (false);
1224 }
1225
1226 /*
1227  * Return TRUE if the given sync request is colliding with a in-progress regular
1228  * request.
1229  */
1230 static bool
1231 g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
1232 {
1233         off_t rstart, rend, sstart, send;
1234         struct bio *bp;
1235
1236         if (sc->sc_sync.ds_ndisks == 0)
1237                 return (false);
1238         sstart = sbp->bio_offset;
1239         send = sbp->bio_offset + sbp->bio_length;
1240         TAILQ_FOREACH(bp, &sc->sc_inflight, bio_queue) {
1241                 rstart = bp->bio_offset;
1242                 rend = bp->bio_offset + bp->bio_length;
1243                 if (rend > sstart && rstart < send)
1244                         return (true);
1245         }
1246         return (false);
1247 }
1248
1249 /*
1250  * Puts regular request onto delayed queue.
1251  */
1252 static void
1253 g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
1254 {
1255
1256         G_MIRROR_LOGREQ(2, bp, "Delaying request.");
1257         TAILQ_INSERT_TAIL(&sc->sc_regular_delayed, bp, bio_queue);
1258 }
1259
1260 /*
1261  * Puts synchronization request onto delayed queue.
1262  */
1263 static void
1264 g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
1265 {
1266
1267         G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
1268         TAILQ_INSERT_TAIL(&sc->sc_sync_delayed, bp, bio_queue);
1269 }
1270
1271 /*
1272  * Requeue delayed regular requests.
1273  */
1274 static void
1275 g_mirror_regular_release(struct g_mirror_softc *sc)
1276 {
1277         struct bio *bp;
1278
1279         if ((bp = TAILQ_FIRST(&sc->sc_regular_delayed)) == NULL)
1280                 return;
1281         if (g_mirror_sync_collision(sc, bp))
1282                 return;
1283
1284         G_MIRROR_DEBUG(2, "Requeuing regular requests after collision.");
1285         mtx_lock(&sc->sc_queue_mtx);
1286         TAILQ_CONCAT(&sc->sc_regular_delayed, &sc->sc_queue, bio_queue);
1287         TAILQ_SWAP(&sc->sc_regular_delayed, &sc->sc_queue, bio, bio_queue);
1288         mtx_unlock(&sc->sc_queue_mtx);
1289 }
1290
1291 /*
1292  * Releases delayed sync requests which don't collide anymore with regular
1293  * requests.
1294  */
1295 static void
1296 g_mirror_sync_release(struct g_mirror_softc *sc)
1297 {
1298         struct bio *bp, *bp2;
1299
1300         TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed, bio_queue, bp2) {
1301                 if (g_mirror_regular_collision(sc, bp))
1302                         continue;
1303                 TAILQ_REMOVE(&sc->sc_sync_delayed, bp, bio_queue);
1304                 G_MIRROR_LOGREQ(2, bp,
1305                     "Releasing delayed synchronization request.");
1306                 g_io_request(bp, bp->bio_from);
1307         }
1308 }
1309
1310 /*
1311  * Free a synchronization request and clear its slot in the array.
1312  */
1313 static void
1314 g_mirror_sync_request_free(struct g_mirror_disk *disk, struct bio *bp)
1315 {
1316         int idx;
1317
1318         if (disk != NULL && disk->d_sync.ds_bios != NULL) {
1319                 idx = (int)(uintptr_t)bp->bio_caller1;
1320                 KASSERT(disk->d_sync.ds_bios[idx] == bp,
1321                     ("unexpected sync BIO at %p:%d", disk, idx));
1322                 disk->d_sync.ds_bios[idx] = NULL;
1323         }
1324         free(bp->bio_data, M_MIRROR);
1325         g_destroy_bio(bp);
1326 }
1327
1328 /*
1329  * Handle synchronization requests.
1330  * Every synchronization request is a two-step process: first, a read request is
1331  * sent to the mirror provider via the sync consumer. If that request completes
1332  * successfully, it is converted to a write and sent to the disk being
1333  * synchronized. If the write also completes successfully, the synchronization
1334  * offset is advanced and a new read request is submitted.
1335  */
1336 static void
1337 g_mirror_sync_request(struct g_mirror_softc *sc, struct bio *bp)
1338 {
1339         struct g_mirror_disk *disk;
1340         struct g_mirror_disk_sync *sync;
1341
1342         KASSERT((bp->bio_cmd == BIO_READ &&
1343             bp->bio_from->geom == sc->sc_sync.ds_geom) ||
1344             (bp->bio_cmd == BIO_WRITE && bp->bio_from->geom == sc->sc_geom),
1345             ("Sync BIO %p with unexpected origin", bp));
1346
1347         bp->bio_from->index--;
1348         disk = bp->bio_from->private;
1349         if (disk == NULL) {
1350                 sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
1351                 g_topology_lock();
1352                 g_mirror_kill_consumer(sc, bp->bio_from);
1353                 g_topology_unlock();
1354                 g_mirror_sync_request_free(NULL, bp);
1355                 sx_xlock(&sc->sc_lock);
1356                 return;
1357         }
1358
1359         sync = &disk->d_sync;
1360
1361         /*
1362          * Synchronization request.
1363          */
1364         switch (bp->bio_cmd) {
1365         case BIO_READ: {
1366                 struct g_consumer *cp;
1367
1368                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_read,
1369                     bp->bio_error);
1370
1371                 if (bp->bio_error != 0) {
1372                         G_MIRROR_LOGREQ(0, bp,
1373                             "Synchronization request failed (error=%d).",
1374                             bp->bio_error);
1375
1376                         /*
1377                          * The read error will trigger a syncid bump, so there's
1378                          * no need to do that here.
1379                          *
1380                          * The read error handling for regular requests will
1381                          * retry the read from all active mirrors before passing
1382                          * the error back up, so there's no need to retry here.
1383                          */
1384                         g_mirror_sync_request_free(disk, bp);
1385                         g_mirror_event_send(disk,
1386                             G_MIRROR_DISK_STATE_DISCONNECTED,
1387                             G_MIRROR_EVENT_DONTWAIT);
1388                         return;
1389                 }
1390                 G_MIRROR_LOGREQ(3, bp,
1391                     "Synchronization request half-finished.");
1392                 bp->bio_cmd = BIO_WRITE;
1393                 bp->bio_cflags = 0;
1394                 cp = disk->d_consumer;
1395                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1396                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1397                     cp->acr, cp->acw, cp->ace));
1398                 cp->index++;
1399                 g_io_request(bp, cp);
1400                 return;
1401         }
1402         case BIO_WRITE: {
1403                 off_t offset;
1404                 int i;
1405
1406                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_write,
1407                     bp->bio_error);
1408
1409                 if (bp->bio_error != 0) {
1410                         G_MIRROR_LOGREQ(0, bp,
1411                             "Synchronization request failed (error=%d).",
1412                             bp->bio_error);
1413                         g_mirror_sync_request_free(disk, bp);
1414                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
1415                         g_mirror_event_send(disk,
1416                             G_MIRROR_DISK_STATE_DISCONNECTED,
1417                             G_MIRROR_EVENT_DONTWAIT);
1418                         return;
1419                 }
1420                 G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
1421                 if (sync->ds_offset >= sc->sc_mediasize ||
1422                     sync->ds_consumer == NULL ||
1423                     (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1424                         /* Don't send more synchronization requests. */
1425                         sync->ds_inflight--;
1426                         g_mirror_sync_request_free(disk, bp);
1427                         if (sync->ds_inflight > 0)
1428                                 return;
1429                         if (sync->ds_consumer == NULL ||
1430                             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1431                                 return;
1432                         }
1433                         /* Disk up-to-date, activate it. */
1434                         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
1435                             G_MIRROR_EVENT_DONTWAIT);
1436                         return;
1437                 }
1438
1439                 /* Send next synchronization request. */
1440                 g_mirror_sync_reinit(disk, bp, sync->ds_offset);
1441                 sync->ds_offset += bp->bio_length;
1442
1443                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
1444                 sync->ds_consumer->index++;
1445
1446                 /*
1447                  * Delay the request if it is colliding with a regular request.
1448                  */
1449                 if (g_mirror_regular_collision(sc, bp))
1450                         g_mirror_sync_delay(sc, bp);
1451                 else
1452                         g_io_request(bp, sync->ds_consumer);
1453
1454                 /* Requeue delayed requests if possible. */
1455                 g_mirror_regular_release(sc);
1456
1457                 /* Find the smallest offset */
1458                 offset = sc->sc_mediasize;
1459                 for (i = 0; i < g_mirror_syncreqs; i++) {
1460                         bp = sync->ds_bios[i];
1461                         if (bp != NULL && bp->bio_offset < offset)
1462                                 offset = bp->bio_offset;
1463                 }
1464                 if (g_mirror_sync_period > 0 &&
1465                     time_uptime - sync->ds_update_ts > g_mirror_sync_period) {
1466                         sync->ds_offset_done = offset;
1467                         g_mirror_update_metadata(disk);
1468                         sync->ds_update_ts = time_uptime;
1469                 }
1470                 return;
1471         }
1472         default:
1473                 panic("Invalid I/O request %p", bp);
1474         }
1475 }
1476
1477 static void
1478 g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
1479 {
1480         struct g_mirror_disk *disk;
1481         struct g_consumer *cp;
1482         struct bio *cbp;
1483
1484         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1485                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
1486                         break;
1487         }
1488         if (disk == NULL) {
1489                 if (bp->bio_error == 0)
1490                         bp->bio_error = ENXIO;
1491                 g_io_deliver(bp, bp->bio_error);
1492                 return;
1493         }
1494         cbp = g_clone_bio(bp);
1495         if (cbp == NULL) {
1496                 if (bp->bio_error == 0)
1497                         bp->bio_error = ENOMEM;
1498                 g_io_deliver(bp, bp->bio_error);
1499                 return;
1500         }
1501         /*
1502          * Fill in the component buf structure.
1503          */
1504         cp = disk->d_consumer;
1505         cbp->bio_done = g_mirror_done;
1506         cbp->bio_to = cp->provider;
1507         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1508         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1509             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1510             cp->acw, cp->ace));
1511         cp->index++;
1512         g_io_request(cbp, cp);
1513 }
1514
1515 static void
1516 g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
1517 {
1518         struct g_mirror_disk *disk;
1519         struct g_consumer *cp;
1520         struct bio *cbp;
1521
1522         disk = g_mirror_get_disk(sc);
1523         if (disk == NULL) {
1524                 if (bp->bio_error == 0)
1525                         bp->bio_error = ENXIO;
1526                 g_io_deliver(bp, bp->bio_error);
1527                 return;
1528         }
1529         cbp = g_clone_bio(bp);
1530         if (cbp == NULL) {
1531                 if (bp->bio_error == 0)
1532                         bp->bio_error = ENOMEM;
1533                 g_io_deliver(bp, bp->bio_error);
1534                 return;
1535         }
1536         /*
1537          * Fill in the component buf structure.
1538          */
1539         cp = disk->d_consumer;
1540         cbp->bio_done = g_mirror_done;
1541         cbp->bio_to = cp->provider;
1542         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1543         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1544             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1545             cp->acw, cp->ace));
1546         cp->index++;
1547         g_io_request(cbp, cp);
1548 }
1549
1550 #define TRACK_SIZE  (1 * 1024 * 1024)
1551 #define LOAD_SCALE      256
1552 #define ABS(x)          (((x) >= 0) ? (x) : (-(x)))
1553
1554 static void
1555 g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
1556 {
1557         struct g_mirror_disk *disk, *dp;
1558         struct g_consumer *cp;
1559         struct bio *cbp;
1560         int prio, best;
1561
1562         /* Find a disk with the smallest load. */
1563         disk = NULL;
1564         best = INT_MAX;
1565         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1566                 if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1567                         continue;
1568                 prio = dp->load;
1569                 /* If disk head is precisely in position - highly prefer it. */
1570                 if (dp->d_last_offset == bp->bio_offset)
1571                         prio -= 2 * LOAD_SCALE;
1572                 else
1573                 /* If disk head is close to position - prefer it. */
1574                 if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
1575                         prio -= 1 * LOAD_SCALE;
1576                 if (prio <= best) {
1577                         disk = dp;
1578                         best = prio;
1579                 }
1580         }
1581         KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
1582         cbp = g_clone_bio(bp);
1583         if (cbp == NULL) {
1584                 if (bp->bio_error == 0)
1585                         bp->bio_error = ENOMEM;
1586                 g_io_deliver(bp, bp->bio_error);
1587                 return;
1588         }
1589         /*
1590          * Fill in the component buf structure.
1591          */
1592         cp = disk->d_consumer;
1593         cbp->bio_done = g_mirror_done;
1594         cbp->bio_to = cp->provider;
1595         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1596         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1597             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
1598             cp->acw, cp->ace));
1599         cp->index++;
1600         /* Remember last head position */
1601         disk->d_last_offset = bp->bio_offset + bp->bio_length;
1602         /* Update loads. */
1603         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
1604                 dp->load = (dp->d_consumer->index * LOAD_SCALE +
1605                     dp->load * 7) / 8;
1606         }
1607         g_io_request(cbp, cp);
1608 }
1609
1610 static void
1611 g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
1612 {
1613         struct bio_queue queue;
1614         struct g_mirror_disk *disk;
1615         struct g_consumer *cp;
1616         struct bio *cbp;
1617         off_t left, mod, offset, slice;
1618         u_char *data;
1619         u_int ndisks;
1620
1621         if (bp->bio_length <= sc->sc_slice) {
1622                 g_mirror_request_round_robin(sc, bp);
1623                 return;
1624         }
1625         ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
1626         slice = bp->bio_length / ndisks;
1627         mod = slice % sc->sc_provider->sectorsize;
1628         if (mod != 0)
1629                 slice += sc->sc_provider->sectorsize - mod;
1630         /*
1631          * Allocate all bios before sending any request, so we can
1632          * return ENOMEM in nice and clean way.
1633          */
1634         left = bp->bio_length;
1635         offset = bp->bio_offset;
1636         data = bp->bio_data;
1637         TAILQ_INIT(&queue);
1638         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1639                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1640                         continue;
1641                 cbp = g_clone_bio(bp);
1642                 if (cbp == NULL) {
1643                         while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
1644                                 TAILQ_REMOVE(&queue, cbp, bio_queue);
1645                                 g_destroy_bio(cbp);
1646                         }
1647                         if (bp->bio_error == 0)
1648                                 bp->bio_error = ENOMEM;
1649                         g_io_deliver(bp, bp->bio_error);
1650                         return;
1651                 }
1652                 TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
1653                 cbp->bio_done = g_mirror_done;
1654                 cbp->bio_caller1 = disk;
1655                 cbp->bio_to = disk->d_consumer->provider;
1656                 cbp->bio_offset = offset;
1657                 cbp->bio_data = data;
1658                 cbp->bio_length = MIN(left, slice);
1659                 left -= cbp->bio_length;
1660                 if (left == 0)
1661                         break;
1662                 offset += cbp->bio_length;
1663                 data += cbp->bio_length;
1664         }
1665         while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
1666                 TAILQ_REMOVE(&queue, cbp, bio_queue);
1667                 G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1668                 disk = cbp->bio_caller1;
1669                 cbp->bio_caller1 = NULL;
1670                 cp = disk->d_consumer;
1671                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1672                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1673                     cp->acr, cp->acw, cp->ace));
1674                 disk->d_consumer->index++;
1675                 g_io_request(cbp, disk->d_consumer);
1676         }
1677 }
1678
1679 static void
1680 g_mirror_register_request(struct g_mirror_softc *sc, struct bio *bp)
1681 {
1682         struct bio_queue queue;
1683         struct bio *cbp;
1684         struct g_consumer *cp;
1685         struct g_mirror_disk *disk;
1686
1687         sx_assert(&sc->sc_lock, SA_XLOCKED);
1688
1689         /*
1690          * To avoid ordering issues, if a write is deferred because of a
1691          * collision with a sync request, all I/O is deferred until that
1692          * write is initiated.
1693          */
1694         if (bp->bio_from->geom != sc->sc_sync.ds_geom &&
1695             !TAILQ_EMPTY(&sc->sc_regular_delayed)) {
1696                 g_mirror_regular_delay(sc, bp);
1697                 return;
1698         }
1699
1700         switch (bp->bio_cmd) {
1701         case BIO_READ:
1702                 switch (sc->sc_balance) {
1703                 case G_MIRROR_BALANCE_LOAD:
1704                         g_mirror_request_load(sc, bp);
1705                         break;
1706                 case G_MIRROR_BALANCE_PREFER:
1707                         g_mirror_request_prefer(sc, bp);
1708                         break;
1709                 case G_MIRROR_BALANCE_ROUND_ROBIN:
1710                         g_mirror_request_round_robin(sc, bp);
1711                         break;
1712                 case G_MIRROR_BALANCE_SPLIT:
1713                         g_mirror_request_split(sc, bp);
1714                         break;
1715                 }
1716                 return;
1717         case BIO_WRITE:
1718         case BIO_DELETE:
1719                 /*
1720                  * Delay the request if it is colliding with a synchronization
1721                  * request.
1722                  */
1723                 if (g_mirror_sync_collision(sc, bp)) {
1724                         g_mirror_regular_delay(sc, bp);
1725                         return;
1726                 }
1727
1728                 if (sc->sc_idle)
1729                         g_mirror_unidle(sc);
1730                 else
1731                         sc->sc_last_write = time_uptime;
1732
1733                 /*
1734                  * Bump syncid on first write.
1735                  */
1736                 if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
1737                         sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
1738                         g_mirror_bump_syncid(sc);
1739                 }
1740
1741                 /*
1742                  * Allocate all bios before sending any request, so we can
1743                  * return ENOMEM in nice and clean way.
1744                  */
1745                 TAILQ_INIT(&queue);
1746                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1747                         switch (disk->d_state) {
1748                         case G_MIRROR_DISK_STATE_ACTIVE:
1749                                 break;
1750                         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
1751                                 if (bp->bio_offset >= disk->d_sync.ds_offset)
1752                                         continue;
1753                                 break;
1754                         default:
1755                                 continue;
1756                         }
1757                         if (bp->bio_cmd == BIO_DELETE &&
1758                             (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE) == 0)
1759                                 continue;
1760                         cbp = g_clone_bio(bp);
1761                         if (cbp == NULL) {
1762                                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
1763                                         TAILQ_REMOVE(&queue, cbp, bio_queue);
1764                                         g_destroy_bio(cbp);
1765                                 }
1766                                 if (bp->bio_error == 0)
1767                                         bp->bio_error = ENOMEM;
1768                                 g_io_deliver(bp, bp->bio_error);
1769                                 return;
1770                         }
1771                         TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
1772                         cbp->bio_done = g_mirror_done;
1773                         cp = disk->d_consumer;
1774                         cbp->bio_caller1 = cp;
1775                         cbp->bio_to = cp->provider;
1776                         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1777                             ("Consumer %s not opened (r%dw%de%d).",
1778                             cp->provider->name, cp->acr, cp->acw, cp->ace));
1779                 }
1780                 if (TAILQ_EMPTY(&queue)) {
1781                         KASSERT(bp->bio_cmd == BIO_DELETE,
1782                             ("No consumers for regular request %p", bp));
1783                         g_io_deliver(bp, EOPNOTSUPP);
1784                         return;
1785                 }
1786                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
1787                         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1788                         TAILQ_REMOVE(&queue, cbp, bio_queue);
1789                         cp = cbp->bio_caller1;
1790                         cbp->bio_caller1 = NULL;
1791                         cp->index++;
1792                         sc->sc_writes++;
1793                         g_io_request(cbp, cp);
1794                 }
1795                 /*
1796                  * Put request onto inflight queue, so we can check if new
1797                  * synchronization requests don't collide with it.
1798                  */
1799                 TAILQ_INSERT_TAIL(&sc->sc_inflight, bp, bio_queue);
1800                 return;
1801         case BIO_SPEEDUP:
1802         case BIO_FLUSH:
1803                 TAILQ_INIT(&queue);
1804                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
1805                         if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
1806                                 continue;
1807                         cbp = g_clone_bio(bp);
1808                         if (cbp == NULL) {
1809                                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
1810                                         TAILQ_REMOVE(&queue, cbp, bio_queue);
1811                                         g_destroy_bio(cbp);
1812                                 }
1813                                 if (bp->bio_error == 0)
1814                                         bp->bio_error = ENOMEM;
1815                                 g_io_deliver(bp, bp->bio_error);
1816                                 return;
1817                         }
1818                         TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
1819                         cbp->bio_done = g_mirror_done;
1820                         cbp->bio_caller1 = disk;
1821                         cbp->bio_to = disk->d_consumer->provider;
1822                 }
1823                 KASSERT(!TAILQ_EMPTY(&queue),
1824                     ("No consumers for regular request %p", bp));
1825                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
1826                         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
1827                         TAILQ_REMOVE(&queue, cbp, bio_queue);
1828                         disk = cbp->bio_caller1;
1829                         cbp->bio_caller1 = NULL;
1830                         cp = disk->d_consumer;
1831                         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
1832                             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
1833                             cp->acr, cp->acw, cp->ace));
1834                         cp->index++;
1835                         g_io_request(cbp, cp);
1836                 }
1837                 break;
1838         default:
1839                 KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
1840                     bp->bio_cmd, sc->sc_name));
1841                 break;
1842         }
1843 }
1844
1845 static int
1846 g_mirror_can_destroy(struct g_mirror_softc *sc)
1847 {
1848         struct g_geom *gp;
1849         struct g_consumer *cp;
1850
1851         g_topology_assert();
1852         gp = sc->sc_geom;
1853         if (gp->softc == NULL)
1854                 return (1);
1855         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_TASTING) != 0)
1856                 return (0);
1857         LIST_FOREACH(cp, &gp->consumer, consumer) {
1858                 if (g_mirror_is_busy(sc, cp))
1859                         return (0);
1860         }
1861         gp = sc->sc_sync.ds_geom;
1862         LIST_FOREACH(cp, &gp->consumer, consumer) {
1863                 if (g_mirror_is_busy(sc, cp))
1864                         return (0);
1865         }
1866         G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
1867             sc->sc_name);
1868         return (1);
1869 }
1870
1871 static int
1872 g_mirror_try_destroy(struct g_mirror_softc *sc)
1873 {
1874
1875         if (sc->sc_rootmount != NULL) {
1876                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
1877                     sc->sc_rootmount);
1878                 root_mount_rel(sc->sc_rootmount);
1879                 sc->sc_rootmount = NULL;
1880         }
1881         g_topology_lock();
1882         if (!g_mirror_can_destroy(sc)) {
1883                 g_topology_unlock();
1884                 return (0);
1885         }
1886         sc->sc_geom->softc = NULL;
1887         sc->sc_sync.ds_geom->softc = NULL;
1888         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DRAIN) != 0) {
1889                 g_topology_unlock();
1890                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1891                     &sc->sc_worker);
1892                 /* Unlock sc_lock here, as it can be destroyed after wakeup. */
1893                 sx_xunlock(&sc->sc_lock);
1894                 wakeup(&sc->sc_worker);
1895                 sc->sc_worker = NULL;
1896         } else {
1897                 g_topology_unlock();
1898                 g_mirror_destroy_device(sc);
1899         }
1900         return (1);
1901 }
1902
1903 /*
1904  * Worker thread.
1905  */
1906 static void
1907 g_mirror_worker(void *arg)
1908 {
1909         struct g_mirror_softc *sc;
1910         struct g_mirror_event *ep;
1911         struct bio *bp;
1912         int timeout;
1913
1914         sc = arg;
1915         thread_lock(curthread);
1916         sched_prio(curthread, PRIBIO);
1917         thread_unlock(curthread);
1918
1919         sx_xlock(&sc->sc_lock);
1920         for (;;) {
1921                 G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
1922                 /*
1923                  * First take a look at events.
1924                  * This is important to handle events before any I/O requests.
1925                  */
1926                 ep = g_mirror_event_first(sc);
1927                 if (ep != NULL) {
1928                         g_mirror_event_remove(sc, ep);
1929                         if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
1930                                 /* Update only device status. */
1931                                 G_MIRROR_DEBUG(3,
1932                                     "Running event for device %s.",
1933                                     sc->sc_name);
1934                                 ep->e_error = 0;
1935                                 g_mirror_update_device(sc, true);
1936                         } else {
1937                                 /* Update disk status. */
1938                                 G_MIRROR_DEBUG(3, "Running event for disk %s.",
1939                                      g_mirror_get_diskname(ep->e_disk));
1940                                 ep->e_error = g_mirror_update_disk(ep->e_disk,
1941                                     ep->e_state);
1942                                 if (ep->e_error == 0)
1943                                         g_mirror_update_device(sc, false);
1944                         }
1945                         if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
1946                                 KASSERT(ep->e_error == 0,
1947                                     ("Error cannot be handled."));
1948                                 g_mirror_event_free(ep);
1949                         } else {
1950                                 ep->e_flags |= G_MIRROR_EVENT_DONE;
1951                                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
1952                                     ep);
1953                                 mtx_lock(&sc->sc_events_mtx);
1954                                 wakeup(ep);
1955                                 mtx_unlock(&sc->sc_events_mtx);
1956                         }
1957                         if ((sc->sc_flags &
1958                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1959                                 if (g_mirror_try_destroy(sc)) {
1960                                         curthread->td_pflags &= ~TDP_GEOM;
1961                                         G_MIRROR_DEBUG(1, "Thread exiting.");
1962                                         kproc_exit(0);
1963                                 }
1964                         }
1965                         G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
1966                         continue;
1967                 }
1968
1969                 /*
1970                  * Check if we can mark array as CLEAN and if we can't take
1971                  * how much seconds should we wait.
1972                  */
1973                 timeout = g_mirror_idle(sc, -1);
1974
1975                 /*
1976                  * Handle I/O requests.
1977                  */
1978                 mtx_lock(&sc->sc_queue_mtx);
1979                 bp = TAILQ_FIRST(&sc->sc_queue);
1980                 if (bp != NULL)
1981                         TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
1982                 else {
1983                         if ((sc->sc_flags &
1984                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
1985                                 mtx_unlock(&sc->sc_queue_mtx);
1986                                 if (g_mirror_try_destroy(sc)) {
1987                                         curthread->td_pflags &= ~TDP_GEOM;
1988                                         G_MIRROR_DEBUG(1, "Thread exiting.");
1989                                         kproc_exit(0);
1990                                 }
1991                                 mtx_lock(&sc->sc_queue_mtx);
1992                                 if (!TAILQ_EMPTY(&sc->sc_queue)) {
1993                                         mtx_unlock(&sc->sc_queue_mtx);
1994                                         continue;
1995                                 }
1996                         }
1997                         if (g_mirror_event_first(sc) != NULL) {
1998                                 mtx_unlock(&sc->sc_queue_mtx);
1999                                 continue;
2000                         }
2001                         sx_xunlock(&sc->sc_lock);
2002                         MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
2003                             timeout * hz);
2004                         sx_xlock(&sc->sc_lock);
2005                         G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
2006                         continue;
2007                 }
2008                 mtx_unlock(&sc->sc_queue_mtx);
2009
2010                 if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
2011                     (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
2012                         /*
2013                          * Handle completion of the first half (the read) of a
2014                          * block synchronization operation.
2015                          */
2016                         g_mirror_sync_request(sc, bp);
2017                 } else if (bp->bio_to != sc->sc_provider) {
2018                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
2019                                 /*
2020                                  * Handle completion of a regular I/O request.
2021                                  */
2022                                 g_mirror_regular_request(sc, bp);
2023                         else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
2024                                 /*
2025                                  * Handle completion of the second half (the
2026                                  * write) of a block synchronization operation.
2027                                  */
2028                                 g_mirror_sync_request(sc, bp);
2029                         else {
2030                                 KASSERT(0,
2031                                     ("Invalid request cflags=0x%hx to=%s.",
2032                                     bp->bio_cflags, bp->bio_to->name));
2033                         }
2034                 } else {
2035                         /*
2036                          * Initiate an I/O request.
2037                          */
2038                         g_mirror_register_request(sc, bp);
2039                 }
2040                 G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
2041         }
2042 }
2043
2044 static void
2045 g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
2046 {
2047
2048         sx_assert(&sc->sc_lock, SX_LOCKED);
2049
2050         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
2051                 return;
2052         if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2053                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
2054                     g_mirror_get_diskname(disk), sc->sc_name);
2055                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
2056         } else if (sc->sc_idle &&
2057             (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2058                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
2059                     g_mirror_get_diskname(disk), sc->sc_name);
2060                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2061         }
2062 }
2063
2064 static void
2065 g_mirror_sync_reinit(const struct g_mirror_disk *disk, struct bio *bp,
2066     off_t offset)
2067 {
2068         void *data;
2069         int idx;
2070
2071         data = bp->bio_data;
2072         idx = (int)(uintptr_t)bp->bio_caller1;
2073         g_reset_bio(bp);
2074
2075         bp->bio_cmd = BIO_READ;
2076         bp->bio_data = data;
2077         bp->bio_done = g_mirror_sync_done;
2078         bp->bio_from = disk->d_sync.ds_consumer;
2079         bp->bio_to = disk->d_softc->sc_provider;
2080         bp->bio_caller1 = (void *)(uintptr_t)idx;
2081         bp->bio_offset = offset;
2082         bp->bio_length = MIN(maxphys,
2083             disk->d_softc->sc_mediasize - bp->bio_offset);
2084 }
2085
2086 static void
2087 g_mirror_sync_start(struct g_mirror_disk *disk)
2088 {
2089         struct g_mirror_softc *sc;
2090         struct g_mirror_disk_sync *sync;
2091         struct g_consumer *cp;
2092         struct bio *bp;
2093         int error, i;
2094
2095         g_topology_assert_not();
2096         sc = disk->d_softc;
2097         sync = &disk->d_sync;
2098         sx_assert(&sc->sc_lock, SX_LOCKED);
2099
2100         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2101             ("Disk %s is not marked for synchronization.",
2102             g_mirror_get_diskname(disk)));
2103         KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2104             ("Device not in RUNNING state (%s, %u).", sc->sc_name,
2105             sc->sc_state));
2106
2107         sx_xunlock(&sc->sc_lock);
2108         g_topology_lock();
2109         cp = g_new_consumer(sc->sc_sync.ds_geom);
2110         cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
2111         error = g_attach(cp, sc->sc_provider);
2112         KASSERT(error == 0,
2113             ("Cannot attach to %s (error=%d).", sc->sc_name, error));
2114         error = g_access(cp, 1, 0, 0);
2115         KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
2116         g_topology_unlock();
2117         sx_xlock(&sc->sc_lock);
2118
2119         G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
2120             g_mirror_get_diskname(disk));
2121         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
2122                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
2123         KASSERT(sync->ds_consumer == NULL,
2124             ("Sync consumer already exists (device=%s, disk=%s).",
2125             sc->sc_name, g_mirror_get_diskname(disk)));
2126
2127         sync->ds_consumer = cp;
2128         sync->ds_consumer->private = disk;
2129         sync->ds_consumer->index = 0;
2130
2131         /*
2132          * Allocate memory for synchronization bios and initialize them.
2133          */
2134         sync->ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
2135             M_MIRROR, M_WAITOK);
2136         for (i = 0; i < g_mirror_syncreqs; i++) {
2137                 bp = g_alloc_bio();
2138                 sync->ds_bios[i] = bp;
2139
2140                 bp->bio_data = malloc(maxphys, M_MIRROR, M_WAITOK);
2141                 bp->bio_caller1 = (void *)(uintptr_t)i;
2142                 g_mirror_sync_reinit(disk, bp, sync->ds_offset);
2143                 sync->ds_offset += bp->bio_length;
2144         }
2145
2146         /* Increase the number of disks in SYNCHRONIZING state. */
2147         sc->sc_sync.ds_ndisks++;
2148         /* Set the number of in-flight synchronization requests. */
2149         sync->ds_inflight = g_mirror_syncreqs;
2150
2151         /*
2152          * Fire off first synchronization requests.
2153          */
2154         for (i = 0; i < g_mirror_syncreqs; i++) {
2155                 bp = sync->ds_bios[i];
2156                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
2157                 sync->ds_consumer->index++;
2158                 /*
2159                  * Delay the request if it is colliding with a regular request.
2160                  */
2161                 if (g_mirror_regular_collision(sc, bp))
2162                         g_mirror_sync_delay(sc, bp);
2163                 else
2164                         g_io_request(bp, sync->ds_consumer);
2165         }
2166 }
2167
2168 /*
2169  * Stop synchronization process.
2170  * type: 0 - synchronization finished
2171  *       1 - synchronization stopped
2172  */
2173 static void
2174 g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
2175 {
2176         struct g_mirror_softc *sc;
2177         struct g_consumer *cp;
2178
2179         g_topology_assert_not();
2180         sc = disk->d_softc;
2181         sx_assert(&sc->sc_lock, SX_LOCKED);
2182
2183         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2184             ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2185             g_mirror_disk_state2str(disk->d_state)));
2186         if (disk->d_sync.ds_consumer == NULL)
2187                 return;
2188
2189         if (type == 0) {
2190                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
2191                     sc->sc_name, g_mirror_get_diskname(disk));
2192         } else /* if (type == 1) */ {
2193                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
2194                     sc->sc_name, g_mirror_get_diskname(disk));
2195         }
2196         g_mirror_regular_release(sc);
2197         free(disk->d_sync.ds_bios, M_MIRROR);
2198         disk->d_sync.ds_bios = NULL;
2199         cp = disk->d_sync.ds_consumer;
2200         disk->d_sync.ds_consumer = NULL;
2201         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2202         sc->sc_sync.ds_ndisks--;
2203         sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
2204         g_topology_lock();
2205         g_mirror_kill_consumer(sc, cp);
2206         g_topology_unlock();
2207         sx_xlock(&sc->sc_lock);
2208 }
2209
2210 static void
2211 g_mirror_launch_provider(struct g_mirror_softc *sc)
2212 {
2213         struct g_mirror_disk *disk;
2214         struct g_provider *pp, *dp;
2215
2216         sx_assert(&sc->sc_lock, SX_LOCKED);
2217
2218         g_topology_lock();
2219         pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
2220         pp->flags |= G_PF_DIRECT_RECEIVE;
2221         pp->mediasize = sc->sc_mediasize;
2222         pp->sectorsize = sc->sc_sectorsize;
2223         pp->stripesize = 0;
2224         pp->stripeoffset = 0;
2225
2226         /* Splitting of unmapped BIO's could work but isn't implemented now */
2227         if (sc->sc_balance != G_MIRROR_BALANCE_SPLIT)
2228                 pp->flags |= G_PF_ACCEPT_UNMAPPED;
2229
2230         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2231                 if (disk->d_consumer && disk->d_consumer->provider) {
2232                         dp = disk->d_consumer->provider;
2233                         if (dp->stripesize > pp->stripesize) {
2234                                 pp->stripesize = dp->stripesize;
2235                                 pp->stripeoffset = dp->stripeoffset;
2236                         }
2237                         /* A provider underneath us doesn't support unmapped */
2238                         if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
2239                                 G_MIRROR_DEBUG(0, "Cancelling unmapped "
2240                                     "because of %s.", dp->name);
2241                                 pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
2242                         }
2243                 }
2244         }
2245         pp->private = sc;
2246         sc->sc_refcnt++;
2247         sc->sc_provider = pp;
2248         g_error_provider(pp, 0);
2249         g_topology_unlock();
2250         G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
2251             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
2252         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2253                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2254                         g_mirror_sync_start(disk);
2255         }
2256 }
2257
2258 static void
2259 g_mirror_destroy_provider(struct g_mirror_softc *sc)
2260 {
2261         struct g_mirror_disk *disk;
2262         struct bio *bp;
2263
2264         g_topology_assert_not();
2265         KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
2266             sc->sc_name));
2267
2268         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2269                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
2270                         g_mirror_sync_stop(disk, 1);
2271         }
2272
2273         g_topology_lock();
2274         g_error_provider(sc->sc_provider, ENXIO);
2275         mtx_lock(&sc->sc_queue_mtx);
2276         while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL) {
2277                 TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
2278                 /*
2279                  * Abort any pending I/O that wasn't generated by us.
2280                  * Synchronization requests and requests destined for individual
2281                  * mirror components can be destroyed immediately.
2282                  */
2283                 if (bp->bio_to == sc->sc_provider &&
2284                     bp->bio_from->geom != sc->sc_sync.ds_geom) {
2285                         g_io_deliver(bp, ENXIO);
2286                 } else {
2287                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
2288                                 free(bp->bio_data, M_MIRROR);
2289                         g_destroy_bio(bp);
2290                 }
2291         }
2292         mtx_unlock(&sc->sc_queue_mtx);
2293         g_wither_provider(sc->sc_provider, ENXIO);
2294         sc->sc_provider = NULL;
2295         G_MIRROR_DEBUG(0, "Device %s: provider destroyed.", sc->sc_name);
2296         g_topology_unlock();
2297 }
2298
2299 static void
2300 g_mirror_go(void *arg)
2301 {
2302         struct g_mirror_softc *sc;
2303         struct g_mirror_event *ep;
2304
2305         sc = arg;
2306         G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
2307         ep = sc->sc_timeout_event;
2308         sc->sc_timeout_event = NULL;
2309         g_mirror_event_dispatch(ep, sc, 0,
2310             G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
2311 }
2312
2313 static void
2314 g_mirror_timeout_drain(struct g_mirror_softc *sc)
2315 {
2316         sx_assert(&sc->sc_lock, SX_XLOCKED);
2317
2318         callout_drain(&sc->sc_callout);
2319         g_mirror_event_free(sc->sc_timeout_event);
2320         sc->sc_timeout_event = NULL;
2321 }
2322
2323 static u_int
2324 g_mirror_determine_state(struct g_mirror_disk *disk)
2325 {
2326         struct g_mirror_softc *sc;
2327         u_int state;
2328
2329         sc = disk->d_softc;
2330         if (sc->sc_syncid == disk->d_sync.ds_syncid) {
2331                 if ((disk->d_flags &
2332                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0 &&
2333                     (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 ||
2334                      (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0)) {
2335                         /* Disk does not need synchronization. */
2336                         state = G_MIRROR_DISK_STATE_ACTIVE;
2337                 } else {
2338                         if ((sc->sc_flags &
2339                              G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2340                             (disk->d_flags &
2341                              G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2342                                 /*
2343                                  * We can start synchronization from
2344                                  * the stored offset.
2345                                  */
2346                                 state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2347                         } else {
2348                                 state = G_MIRROR_DISK_STATE_STALE;
2349                         }
2350                 }
2351         } else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
2352                 /*
2353                  * Reset all synchronization data for this disk,
2354                  * because if it even was synchronized, it was
2355                  * synchronized to disks with different syncid.
2356                  */
2357                 disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2358                 disk->d_sync.ds_offset = 0;
2359                 disk->d_sync.ds_offset_done = 0;
2360                 disk->d_sync.ds_syncid = sc->sc_syncid;
2361                 if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
2362                     (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
2363                         state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
2364                 } else {
2365                         state = G_MIRROR_DISK_STATE_STALE;
2366                 }
2367         } else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
2368                 /*
2369                  * Not good, NOT GOOD!
2370                  * It means that mirror was started on stale disks
2371                  * and more fresh disk just arrive.
2372                  * If there were writes, mirror is broken, sorry.
2373                  * I think the best choice here is don't touch
2374                  * this disk and inform the user loudly.
2375                  */
2376                 G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
2377                     "disk (%s) arrives!! It will not be connected to the "
2378                     "running device.", sc->sc_name,
2379                     g_mirror_get_diskname(disk));
2380                 g_mirror_destroy_disk(disk);
2381                 state = G_MIRROR_DISK_STATE_NONE;
2382                 /* Return immediately, because disk was destroyed. */
2383                 return (state);
2384         }
2385         G_MIRROR_DEBUG(3, "State for %s disk: %s.",
2386             g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
2387         return (state);
2388 }
2389
2390 /*
2391  * Update device state.
2392  */
2393 static void
2394 g_mirror_update_device(struct g_mirror_softc *sc, bool force)
2395 {
2396         struct g_mirror_disk *disk;
2397         u_int state;
2398
2399         sx_assert(&sc->sc_lock, SX_XLOCKED);
2400
2401         switch (sc->sc_state) {
2402         case G_MIRROR_DEVICE_STATE_STARTING:
2403             {
2404                 struct g_mirror_disk *pdisk, *tdisk;
2405                 const char *mismatch;
2406                 uintmax_t found, newest;
2407                 u_int dirty, ndisks;
2408
2409                 /* Pre-flight checks */
2410                 LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
2411                         /*
2412                          * Confirm we already detected the newest genid.
2413                          */
2414                         KASSERT(sc->sc_genid >= disk->d_genid,
2415                             ("%s: found newer genid %u (sc:%p had %u).", __func__,
2416                             disk->d_genid, sc, sc->sc_genid));
2417
2418                         /* Kick out any previously tasted stale components. */
2419                         if (disk->d_genid < sc->sc_genid) {
2420                                 G_MIRROR_DEBUG(0, "Stale 'genid' field on %s "
2421                                     "(device %s) (component=%u latest=%u), skipping.",
2422                                     g_mirror_get_diskname(disk), sc->sc_name,
2423                                     disk->d_genid, sc->sc_genid);
2424                                 g_mirror_destroy_disk(disk);
2425                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2426                                 continue;
2427                         }
2428
2429                         /*
2430                          * Confirm we already detected the newest syncid.
2431                          */
2432                         KASSERT(sc->sc_syncid >= disk->d_sync.ds_syncid,
2433                             ("%s: found newer syncid %u (sc:%p had %u).",
2434                              __func__, disk->d_sync.ds_syncid, sc,
2435                              sc->sc_syncid));
2436
2437 #define DETECT_MISMATCH(field, name) \
2438                         if (mismatch == NULL &&                                 \
2439                             disk->d_init_ ## field != sc->sc_ ## field) {       \
2440                                 mismatch = name;                                \
2441                                 found = (intmax_t)disk->d_init_ ## field;       \
2442                                 newest = (intmax_t)sc->sc_ ## field;            \
2443                         }
2444                         mismatch = NULL;
2445                         DETECT_MISMATCH(ndisks, "md_all");
2446                         DETECT_MISMATCH(balance, "md_balance");
2447                         DETECT_MISMATCH(slice, "md_slice");
2448                         DETECT_MISMATCH(mediasize, "md_mediasize");
2449 #undef DETECT_MISMATCH
2450                         if (mismatch != NULL) {
2451                                 G_MIRROR_DEBUG(0, "Found a mismatching '%s' "
2452                                     "field on %s (device %s) (found=%ju "
2453                                     "newest=%ju).", mismatch,
2454                                     g_mirror_get_diskname(disk), sc->sc_name,
2455                                     found, newest);
2456                                 g_mirror_destroy_disk(disk);
2457                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2458                                 continue;
2459                         }
2460                 }
2461
2462                 KASSERT(sc->sc_provider == NULL,
2463                     ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
2464                 /*
2465                  * Are we ready? If the timeout (force is true) has expired, and
2466                  * any disks are present, then yes. If we're permitted to launch
2467                  * before the timeout has expired and the expected number of
2468                  * current-generation mirror disks have been tasted, then yes.
2469                  */
2470                 ndisks = g_mirror_ndisks(sc, -1);
2471                 if ((force && ndisks > 0) ||
2472                     (g_launch_mirror_before_timeout && ndisks == sc->sc_ndisks)) {
2473                         ;
2474                 } else if (ndisks == 0) {
2475                         /*
2476                          * Disks went down in starting phase, so destroy
2477                          * device.
2478                          */
2479                         g_mirror_timeout_drain(sc);
2480                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2481                         G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
2482                             sc->sc_rootmount);
2483                         root_mount_rel(sc->sc_rootmount);
2484                         sc->sc_rootmount = NULL;
2485                         return;
2486                 } else {
2487                         return;
2488                 }
2489
2490                 /*
2491                  * Activate all disks with the biggest syncid.
2492                  */
2493                 if (force) {
2494                         /*
2495                          * If 'force' is true, we have been called due to
2496                          * timeout, so don't bother canceling timeout.
2497                          */
2498                         ndisks = 0;
2499                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2500                                 if ((disk->d_flags &
2501                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
2502                                         ndisks++;
2503                                 }
2504                         }
2505                         if (ndisks == 0) {
2506                                 /* No valid disks found, destroy device. */
2507                                 sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2508                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2509                                     __LINE__, sc->sc_rootmount);
2510                                 root_mount_rel(sc->sc_rootmount);
2511                                 sc->sc_rootmount = NULL;
2512                                 return;
2513                         }
2514                 } else {
2515                         /* Cancel timeout. */
2516                         g_mirror_timeout_drain(sc);
2517                 }
2518
2519                 /*
2520                  * Here we need to look for dirty disks and if all disks
2521                  * with the biggest syncid are dirty, we have to choose
2522                  * one with the biggest priority and rebuild the rest.
2523                  */
2524                 /*
2525                  * Find the number of dirty disks with the biggest syncid.
2526                  * Find the number of disks with the biggest syncid.
2527                  * While here, find a disk with the biggest priority.
2528                  */
2529                 dirty = ndisks = 0;
2530                 pdisk = NULL;
2531                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2532                         if (disk->d_sync.ds_syncid != sc->sc_syncid)
2533                                 continue;
2534                         if ((disk->d_flags &
2535                             G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2536                                 continue;
2537                         }
2538                         ndisks++;
2539                         if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
2540                                 dirty++;
2541                                 if (pdisk == NULL ||
2542                                     pdisk->d_priority < disk->d_priority) {
2543                                         pdisk = disk;
2544                                 }
2545                         }
2546                 }
2547                 if (dirty == 0) {
2548                         /* No dirty disks at all, great. */
2549                 } else if (dirty == ndisks) {
2550                         /*
2551                          * Force synchronization for all dirty disks except one
2552                          * with the biggest priority.
2553                          */
2554                         KASSERT(pdisk != NULL, ("pdisk == NULL"));
2555                         G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
2556                             "master disk for synchronization.",
2557                             g_mirror_get_diskname(pdisk), sc->sc_name);
2558                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2559                                 if (disk->d_sync.ds_syncid != sc->sc_syncid)
2560                                         continue;
2561                                 if ((disk->d_flags &
2562                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2563                                         continue;
2564                                 }
2565                                 KASSERT((disk->d_flags &
2566                                     G_MIRROR_DISK_FLAG_DIRTY) != 0,
2567                                     ("Disk %s isn't marked as dirty.",
2568                                     g_mirror_get_diskname(disk)));
2569                                 /* Skip the disk with the biggest priority. */
2570                                 if (disk == pdisk)
2571                                         continue;
2572                                 disk->d_sync.ds_syncid = 0;
2573                         }
2574                 } else if (dirty < ndisks) {
2575                         /*
2576                          * Force synchronization for all dirty disks.
2577                          * We have some non-dirty disks.
2578                          */
2579                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2580                                 if (disk->d_sync.ds_syncid != sc->sc_syncid)
2581                                         continue;
2582                                 if ((disk->d_flags &
2583                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
2584                                         continue;
2585                                 }
2586                                 if ((disk->d_flags &
2587                                     G_MIRROR_DISK_FLAG_DIRTY) == 0) {
2588                                         continue;
2589                                 }
2590                                 disk->d_sync.ds_syncid = 0;
2591                         }
2592                 }
2593
2594                 /* Reset hint. */
2595                 sc->sc_hint = NULL;
2596                 if (force) {
2597                         /* Remember to bump syncid on first write. */
2598                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2599                 }
2600                 state = G_MIRROR_DEVICE_STATE_RUNNING;
2601                 G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
2602                     sc->sc_name, g_mirror_device_state2str(sc->sc_state),
2603                     g_mirror_device_state2str(state));
2604                 sc->sc_state = state;
2605                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2606                         state = g_mirror_determine_state(disk);
2607                         g_mirror_event_send(disk, state,
2608                             G_MIRROR_EVENT_DONTWAIT);
2609                         if (state == G_MIRROR_DISK_STATE_STALE)
2610                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
2611                 }
2612                 break;
2613             }
2614         case G_MIRROR_DEVICE_STATE_RUNNING:
2615                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
2616                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2617                         /*
2618                          * No usable disks, so destroy the device.
2619                          */
2620                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
2621                         break;
2622                 } else if (g_mirror_ndisks(sc,
2623                     G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
2624                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
2625                         /*
2626                          * We have active disks, launch provider if it doesn't
2627                          * exist.
2628                          */
2629                         if (sc->sc_provider == NULL)
2630                                 g_mirror_launch_provider(sc);
2631                         if (sc->sc_rootmount != NULL) {
2632                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
2633                                     __LINE__, sc->sc_rootmount);
2634                                 root_mount_rel(sc->sc_rootmount);
2635                                 sc->sc_rootmount = NULL;
2636                         }
2637                 }
2638                 /*
2639                  * Genid should be bumped immediately, so do it here.
2640                  */
2641                 if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
2642                         sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
2643                         g_mirror_bump_genid(sc);
2644                 }
2645                 if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID_NOW) != 0) {
2646                         sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID_NOW;
2647                         g_mirror_bump_syncid(sc);
2648                 }
2649                 break;
2650         default:
2651                 KASSERT(1 == 0, ("Wrong device state (%s, %s).",
2652                     sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
2653                 break;
2654         }
2655 }
2656
2657 /*
2658  * Update disk state and device state if needed.
2659  */
2660 #define DISK_STATE_CHANGED()    G_MIRROR_DEBUG(1,                       \
2661         "Disk %s state changed from %s to %s (device %s).",             \
2662         g_mirror_get_diskname(disk),                                    \
2663         g_mirror_disk_state2str(disk->d_state),                         \
2664         g_mirror_disk_state2str(state), sc->sc_name)
2665 static int
2666 g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
2667 {
2668         struct g_mirror_softc *sc;
2669
2670         sc = disk->d_softc;
2671         sx_assert(&sc->sc_lock, SX_XLOCKED);
2672
2673 again:
2674         G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
2675             g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
2676             g_mirror_disk_state2str(state));
2677         switch (state) {
2678         case G_MIRROR_DISK_STATE_NEW:
2679                 /*
2680                  * Possible scenarios:
2681                  * 1. New disk arrive.
2682                  */
2683                 /* Previous state should be NONE. */
2684                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
2685                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2686                     g_mirror_disk_state2str(disk->d_state)));
2687                 DISK_STATE_CHANGED();
2688
2689                 disk->d_state = state;
2690                 g_topology_lock();
2691                 if (LIST_EMPTY(&sc->sc_disks))
2692                         LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
2693                 else {
2694                         struct g_mirror_disk *dp;
2695
2696                         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
2697                                 if (disk->d_priority >= dp->d_priority) {
2698                                         LIST_INSERT_BEFORE(dp, disk, d_next);
2699                                         dp = NULL;
2700                                         break;
2701                                 }
2702                                 if (LIST_NEXT(dp, d_next) == NULL)
2703                                         break;
2704                         }
2705                         if (dp != NULL)
2706                                 LIST_INSERT_AFTER(dp, disk, d_next);
2707                 }
2708                 g_topology_unlock();
2709                 G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
2710                     sc->sc_name, g_mirror_get_diskname(disk));
2711                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
2712                         break;
2713                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2714                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2715                     g_mirror_device_state2str(sc->sc_state),
2716                     g_mirror_get_diskname(disk),
2717                     g_mirror_disk_state2str(disk->d_state)));
2718                 state = g_mirror_determine_state(disk);
2719                 if (state != G_MIRROR_DISK_STATE_NONE)
2720                         goto again;
2721                 break;
2722         case G_MIRROR_DISK_STATE_ACTIVE:
2723                 /*
2724                  * Possible scenarios:
2725                  * 1. New disk does not need synchronization.
2726                  * 2. Synchronization process finished successfully.
2727                  */
2728                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2729                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2730                     g_mirror_device_state2str(sc->sc_state),
2731                     g_mirror_get_diskname(disk),
2732                     g_mirror_disk_state2str(disk->d_state)));
2733                 /* Previous state should be NEW or SYNCHRONIZING. */
2734                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
2735                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2736                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2737                     g_mirror_disk_state2str(disk->d_state)));
2738                 DISK_STATE_CHANGED();
2739
2740                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
2741                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
2742                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
2743                         g_mirror_sync_stop(disk, 0);
2744                 }
2745                 disk->d_state = state;
2746                 disk->d_sync.ds_offset = 0;
2747                 disk->d_sync.ds_offset_done = 0;
2748                 g_mirror_update_idle(sc, disk);
2749                 g_mirror_update_metadata(disk);
2750                 G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
2751                     sc->sc_name, g_mirror_get_diskname(disk));
2752                 break;
2753         case G_MIRROR_DISK_STATE_STALE:
2754                 /*
2755                  * Possible scenarios:
2756                  * 1. Stale disk was connected.
2757                  */
2758                 /* Previous state should be NEW. */
2759                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2760                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2761                     g_mirror_disk_state2str(disk->d_state)));
2762                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2763                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2764                     g_mirror_device_state2str(sc->sc_state),
2765                     g_mirror_get_diskname(disk),
2766                     g_mirror_disk_state2str(disk->d_state)));
2767                 /*
2768                  * STALE state is only possible if device is marked
2769                  * NOAUTOSYNC.
2770                  */
2771                 KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
2772                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2773                     g_mirror_device_state2str(sc->sc_state),
2774                     g_mirror_get_diskname(disk),
2775                     g_mirror_disk_state2str(disk->d_state)));
2776                 DISK_STATE_CHANGED();
2777
2778                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2779                 disk->d_state = state;
2780                 g_mirror_update_metadata(disk);
2781                 G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
2782                     sc->sc_name, g_mirror_get_diskname(disk));
2783                 break;
2784         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
2785                 /*
2786                  * Possible scenarios:
2787                  * 1. Disk which needs synchronization was connected.
2788                  */
2789                 /* Previous state should be NEW. */
2790                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2791                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
2792                     g_mirror_disk_state2str(disk->d_state)));
2793                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
2794                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
2795                     g_mirror_device_state2str(sc->sc_state),
2796                     g_mirror_get_diskname(disk),
2797                     g_mirror_disk_state2str(disk->d_state)));
2798                 DISK_STATE_CHANGED();
2799
2800                 if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
2801                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
2802                 disk->d_state = state;
2803                 if (sc->sc_provider != NULL) {
2804                         g_mirror_sync_start(disk);
2805                         g_mirror_update_metadata(disk);
2806                 }
2807                 break;
2808         case G_MIRROR_DISK_STATE_DISCONNECTED:
2809                 /*
2810                  * Possible scenarios:
2811                  * 1. Device wasn't running yet, but disk disappear.
2812                  * 2. Disk was active and disapppear.
2813                  * 3. Disk disappear during synchronization process.
2814                  */
2815                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
2816                         /*
2817                          * Previous state should be ACTIVE, STALE or
2818                          * SYNCHRONIZING.
2819                          */
2820                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
2821                             disk->d_state == G_MIRROR_DISK_STATE_STALE ||
2822                             disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
2823                             ("Wrong disk state (%s, %s).",
2824                             g_mirror_get_diskname(disk),
2825                             g_mirror_disk_state2str(disk->d_state)));
2826                 } else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
2827                         /* Previous state should be NEW. */
2828                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
2829                             ("Wrong disk state (%s, %s).",
2830                             g_mirror_get_diskname(disk),
2831                             g_mirror_disk_state2str(disk->d_state)));
2832                         /*
2833                          * Reset bumping syncid if disk disappeared in STARTING
2834                          * state.
2835                          */
2836                         if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
2837                                 sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
2838 #ifdef  INVARIANTS
2839                 } else {
2840                         KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
2841                             sc->sc_name,
2842                             g_mirror_device_state2str(sc->sc_state),
2843                             g_mirror_get_diskname(disk),
2844                             g_mirror_disk_state2str(disk->d_state)));
2845 #endif
2846                 }
2847                 DISK_STATE_CHANGED();
2848                 G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
2849                     sc->sc_name, g_mirror_get_diskname(disk));
2850
2851                 g_mirror_destroy_disk(disk);
2852                 break;
2853         case G_MIRROR_DISK_STATE_DESTROY:
2854             {
2855                 int error;
2856
2857                 error = g_mirror_clear_metadata(disk);
2858                 if (error != 0) {
2859                         G_MIRROR_DEBUG(0,
2860                             "Device %s: failed to clear metadata on %s: %d.",
2861                             sc->sc_name, g_mirror_get_diskname(disk), error);
2862                         break;
2863                 }
2864                 DISK_STATE_CHANGED();
2865                 G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
2866                     sc->sc_name, g_mirror_get_diskname(disk));
2867
2868                 g_mirror_destroy_disk(disk);
2869                 sc->sc_ndisks--;
2870                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
2871                         g_mirror_update_metadata(disk);
2872                 }
2873                 break;
2874             }
2875         default:
2876                 KASSERT(1 == 0, ("Unknown state (%u).", state));
2877                 break;
2878         }
2879         return (0);
2880 }
2881 #undef  DISK_STATE_CHANGED
2882
2883 int
2884 g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
2885 {
2886         struct g_provider *pp;
2887         u_char *buf;
2888         int error;
2889
2890         g_topology_assert();
2891
2892         error = g_access(cp, 1, 0, 0);
2893         if (error != 0)
2894                 return (error);
2895         pp = cp->provider;
2896         g_topology_unlock();
2897         /* Metadata are stored on last sector. */
2898         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
2899             &error);
2900         g_topology_lock();
2901         g_access(cp, -1, 0, 0);
2902         if (buf == NULL) {
2903                 G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
2904                     cp->provider->name, error);
2905                 return (error);
2906         }
2907
2908         /* Decode metadata. */
2909         error = mirror_metadata_decode(buf, md);
2910         g_free(buf);
2911         if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
2912                 return (EINVAL);
2913         if (md->md_version > G_MIRROR_VERSION) {
2914                 G_MIRROR_DEBUG(0,
2915                     "Kernel module is too old to handle metadata from %s.",
2916                     cp->provider->name);
2917                 return (EINVAL);
2918         }
2919         if (error != 0) {
2920                 G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
2921                     cp->provider->name);
2922                 return (error);
2923         }
2924
2925         return (0);
2926 }
2927
2928 static int
2929 g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
2930     struct g_mirror_metadata *md)
2931 {
2932
2933         G_MIRROR_DEBUG(2, "%s: md_did 0x%u disk %s device %s md_all 0x%x "
2934             "sc_ndisks 0x%x md_slice 0x%x sc_slice 0x%x md_balance 0x%x "
2935             "sc_balance 0x%x sc_mediasize 0x%jx pp_mediasize 0x%jx "
2936             "md_sectorsize 0x%x sc_sectorsize 0x%x md_mflags 0x%jx "
2937             "md_dflags 0x%jx md_syncid 0x%x md_genid 0x%x md_priority 0x%x "
2938             "sc_state 0x%x.",
2939             __func__, md->md_did, pp->name, sc->sc_name, md->md_all,
2940             sc->sc_ndisks, md->md_slice, sc->sc_slice, md->md_balance,
2941             sc->sc_balance, (uintmax_t)sc->sc_mediasize,
2942             (uintmax_t)pp->mediasize, md->md_sectorsize, sc->sc_sectorsize,
2943             (uintmax_t)md->md_mflags, (uintmax_t)md->md_dflags, md->md_syncid,
2944             md->md_genid, md->md_priority, sc->sc_state);
2945
2946         if (g_mirror_id2disk(sc, md->md_did) != NULL) {
2947                 G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
2948                     pp->name, md->md_did);
2949                 return (EEXIST);
2950         }
2951         if (sc->sc_mediasize > pp->mediasize) {
2952                 G_MIRROR_DEBUG(1,
2953                     "Invalid size of disk %s (device %s), skipping.", pp->name,
2954                     sc->sc_name);
2955                 return (EINVAL);
2956         }
2957         if (md->md_sectorsize != sc->sc_sectorsize) {
2958                 G_MIRROR_DEBUG(1,
2959                     "Invalid '%s' field on disk %s (device %s), skipping.",
2960                     "md_sectorsize", pp->name, sc->sc_name);
2961                 return (EINVAL);
2962         }
2963         if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
2964                 G_MIRROR_DEBUG(1,
2965                     "Invalid sector size of disk %s (device %s), skipping.",
2966                     pp->name, sc->sc_name);
2967                 return (EINVAL);
2968         }
2969         if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
2970                 G_MIRROR_DEBUG(1,
2971                     "Invalid device flags on disk %s (device %s), skipping.",
2972                     pp->name, sc->sc_name);
2973                 return (EINVAL);
2974         }
2975         if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
2976                 G_MIRROR_DEBUG(1,
2977                     "Invalid disk flags on disk %s (device %s), skipping.",
2978                     pp->name, sc->sc_name);
2979                 return (EINVAL);
2980         }
2981         return (0);
2982 }
2983
2984 int
2985 g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
2986     struct g_mirror_metadata *md)
2987 {
2988         struct g_mirror_disk *disk;
2989         int error;
2990
2991         g_topology_assert_not();
2992         G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
2993
2994         error = g_mirror_check_metadata(sc, pp, md);
2995         if (error != 0)
2996                 return (error);
2997
2998         if (md->md_genid < sc->sc_genid) {
2999                 G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
3000                     pp->name, sc->sc_name);
3001                 return (EINVAL);
3002         }
3003
3004         /*
3005          * If the component disk we're tasting has newer metadata than the
3006          * STARTING gmirror device, refresh the device from the component.
3007          */
3008         error = g_mirror_refresh_device(sc, pp, md);
3009         if (error != 0)
3010                 return (error);
3011
3012         disk = g_mirror_init_disk(sc, pp, md, &error);
3013         if (disk == NULL)
3014                 return (error);
3015         error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
3016             G_MIRROR_EVENT_WAIT);
3017         if (error != 0)
3018                 return (error);
3019         if (md->md_version < G_MIRROR_VERSION) {
3020                 G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
3021                     pp->name, md->md_version, G_MIRROR_VERSION);
3022                 g_mirror_update_metadata(disk);
3023         }
3024         return (0);
3025 }
3026
3027 static void
3028 g_mirror_destroy_delayed(void *arg, int flag)
3029 {
3030         struct g_mirror_softc *sc;
3031         int error;
3032
3033         if (flag == EV_CANCEL) {
3034                 G_MIRROR_DEBUG(1, "Destroying canceled.");
3035                 return;
3036         }
3037         sc = arg;
3038         g_topology_unlock();
3039         sx_xlock(&sc->sc_lock);
3040         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
3041             ("DESTROY flag set on %s.", sc->sc_name));
3042         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0,
3043             ("CLOSEWAIT flag not set on %s.", sc->sc_name));
3044         G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
3045         error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
3046         if (error != 0) {
3047                 G_MIRROR_DEBUG(0, "Cannot destroy %s (error=%d).",
3048                     sc->sc_name, error);
3049                 sx_xunlock(&sc->sc_lock);
3050         }
3051         g_topology_lock();
3052 }
3053
3054 static int
3055 g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
3056 {
3057         struct g_mirror_softc *sc;
3058         int error = 0;
3059
3060         g_topology_assert();
3061         G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
3062             acw, ace);
3063
3064         sc = pp->private;
3065         KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
3066
3067         g_topology_unlock();
3068         sx_xlock(&sc->sc_lock);
3069         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
3070             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0 ||
3071             LIST_EMPTY(&sc->sc_disks)) {
3072                 if (acr > 0 || acw > 0 || ace > 0)
3073                         error = ENXIO;
3074                 goto end;
3075         }
3076         sc->sc_provider_open += acr + acw + ace;
3077         if (pp->acw + acw == 0)
3078                 g_mirror_idle(sc, 0);
3079         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0 &&
3080             sc->sc_provider_open == 0)
3081                 g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK, sc, NULL);
3082 end:
3083         sx_xunlock(&sc->sc_lock);
3084         g_topology_lock();
3085         return (error);
3086 }
3087
3088 static void
3089 g_mirror_reinit_from_metadata(struct g_mirror_softc *sc,
3090     const struct g_mirror_metadata *md)
3091 {
3092
3093         sc->sc_genid = md->md_genid;
3094         sc->sc_syncid = md->md_syncid;
3095
3096         sc->sc_slice = md->md_slice;
3097         sc->sc_balance = md->md_balance;
3098         sc->sc_mediasize = md->md_mediasize;
3099         sc->sc_ndisks = md->md_all;
3100         sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_MASK;
3101         sc->sc_flags |= (md->md_mflags & G_MIRROR_DEVICE_FLAG_MASK);
3102 }
3103
3104 struct g_geom *
3105 g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md,
3106     u_int type)
3107 {
3108         struct g_mirror_softc *sc;
3109         struct g_geom *gp;
3110         int error, timeout;
3111
3112         g_topology_assert();
3113         G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
3114             md->md_mid);
3115
3116         /* One disk is minimum. */
3117         if (md->md_all < 1)
3118                 return (NULL);
3119         /*
3120          * Action geom.
3121          */
3122         gp = g_new_geomf(mp, "%s", md->md_name);
3123         sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
3124         gp->start = g_mirror_start;
3125         gp->orphan = g_mirror_orphan;
3126         gp->access = g_mirror_access;
3127         gp->dumpconf = g_mirror_dumpconf;
3128
3129         sc->sc_type = type;
3130         sc->sc_id = md->md_mid;
3131         g_mirror_reinit_from_metadata(sc, md);
3132         sc->sc_sectorsize = md->md_sectorsize;
3133         sc->sc_bump_id = 0;
3134         sc->sc_idle = 1;
3135         sc->sc_last_write = time_uptime;
3136         sc->sc_writes = 0;
3137         sc->sc_refcnt = 1;
3138         sx_init(&sc->sc_lock, "gmirror:lock");
3139         TAILQ_INIT(&sc->sc_queue);
3140         mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
3141         TAILQ_INIT(&sc->sc_regular_delayed);
3142         TAILQ_INIT(&sc->sc_inflight);
3143         TAILQ_INIT(&sc->sc_sync_delayed);
3144         LIST_INIT(&sc->sc_disks);
3145         TAILQ_INIT(&sc->sc_events);
3146         mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
3147         callout_init(&sc->sc_callout, 1);
3148         mtx_init(&sc->sc_done_mtx, "gmirror:done", NULL, MTX_DEF);
3149         sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
3150         gp->softc = sc;
3151         sc->sc_geom = gp;
3152         sc->sc_provider = NULL;
3153         sc->sc_provider_open = 0;
3154         /*
3155          * Synchronization geom.
3156          */
3157         gp = g_new_geomf(mp, "%s.sync", md->md_name);
3158         gp->softc = sc;
3159         gp->orphan = g_mirror_orphan;
3160         sc->sc_sync.ds_geom = gp;
3161         sc->sc_sync.ds_ndisks = 0;
3162         error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
3163             "g_mirror %s", md->md_name);
3164         if (error != 0) {
3165                 G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
3166                     sc->sc_name);
3167                 g_destroy_geom(sc->sc_sync.ds_geom);
3168                 g_destroy_geom(sc->sc_geom);
3169                 g_mirror_free_device(sc);
3170                 return (NULL);
3171         }
3172
3173         G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
3174             sc->sc_name, sc->sc_ndisks, sc->sc_id);
3175
3176         sc->sc_rootmount = root_mount_hold("GMIRROR");
3177         G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
3178
3179         /*
3180          * Schedule startup timeout.
3181          */
3182         timeout = g_mirror_timeout * hz;
3183         sc->sc_timeout_event = malloc(sizeof(struct g_mirror_event), M_MIRROR,
3184             M_WAITOK);
3185         callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
3186         return (sc->sc_geom);
3187 }
3188
3189 int
3190 g_mirror_destroy(struct g_mirror_softc *sc, int how)
3191 {
3192         struct g_mirror_disk *disk;
3193
3194         g_topology_assert_not();
3195         sx_assert(&sc->sc_lock, SX_XLOCKED);
3196
3197         if (sc->sc_provider_open != 0) {
3198                 switch (how) {
3199                 case G_MIRROR_DESTROY_SOFT:
3200                         G_MIRROR_DEBUG(1,
3201                             "Device %s is still open (%d).", sc->sc_name,
3202                             sc->sc_provider_open);
3203                         return (EBUSY);
3204                 case G_MIRROR_DESTROY_DELAYED:
3205                         G_MIRROR_DEBUG(1,
3206                             "Device %s will be destroyed on last close.",
3207                             sc->sc_name);
3208                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
3209                                 if (disk->d_state ==
3210                                     G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3211                                         g_mirror_sync_stop(disk, 1);
3212                                 }
3213                         }
3214                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_CLOSEWAIT;
3215                         return (EBUSY);
3216                 case G_MIRROR_DESTROY_HARD:
3217                         G_MIRROR_DEBUG(1, "Device %s is still open, so it "
3218                             "can't be definitely removed.", sc->sc_name);
3219                 }
3220         }
3221
3222         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
3223                 sx_xunlock(&sc->sc_lock);
3224                 return (0);
3225         }
3226         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
3227         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DRAIN;
3228         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
3229         sx_xunlock(&sc->sc_lock);
3230         mtx_lock(&sc->sc_queue_mtx);
3231         wakeup(sc);
3232         mtx_unlock(&sc->sc_queue_mtx);
3233         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
3234         while (sc->sc_worker != NULL)
3235                 tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
3236         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
3237         sx_xlock(&sc->sc_lock);
3238         g_mirror_destroy_device(sc);
3239         return (0);
3240 }
3241
3242 static void
3243 g_mirror_taste_orphan(struct g_consumer *cp)
3244 {
3245
3246         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
3247             cp->provider->name));
3248 }
3249
3250 static struct g_geom *
3251 g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
3252 {
3253         struct g_mirror_metadata md;
3254         struct g_mirror_softc *sc;
3255         struct g_consumer *cp;
3256         struct g_geom *gp;
3257         int error;
3258
3259         g_topology_assert();
3260         g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
3261         G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
3262
3263         gp = g_new_geomf(mp, "mirror:taste");
3264         /*
3265          * This orphan function should be never called.
3266          */
3267         gp->orphan = g_mirror_taste_orphan;
3268         cp = g_new_consumer(gp);
3269         error = g_attach(cp, pp);
3270         if (error == 0) {
3271                 error = g_mirror_read_metadata(cp, &md);
3272                 g_detach(cp);
3273         }
3274         g_destroy_consumer(cp);
3275         g_destroy_geom(gp);
3276         if (error != 0)
3277                 return (NULL);
3278         gp = NULL;
3279
3280         if (md.md_provider[0] != '\0' &&
3281             !g_compare_names(md.md_provider, pp->name))
3282                 return (NULL);
3283         if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
3284                 return (NULL);
3285         if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
3286                 G_MIRROR_DEBUG(0,
3287                     "Device %s: provider %s marked as inactive, skipping.",
3288                     md.md_name, pp->name);
3289                 return (NULL);
3290         }
3291         if (g_mirror_debug >= 2)
3292                 mirror_metadata_dump(&md);
3293
3294         /*
3295          * Let's check if device already exists.
3296          */
3297         sc = NULL;
3298         LIST_FOREACH(gp, &mp->geom, geom) {
3299                 sc = gp->softc;
3300                 if (sc == NULL)
3301                         continue;
3302                 if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
3303                         continue;
3304                 if (sc->sc_sync.ds_geom == gp)
3305                         continue;
3306                 if (strcmp(md.md_name, sc->sc_name) != 0)
3307                         continue;
3308                 if (md.md_mid != sc->sc_id) {
3309                         G_MIRROR_DEBUG(0, "Device %s already configured.",
3310                             sc->sc_name);
3311                         return (NULL);
3312                 }
3313                 break;
3314         }
3315         if (gp == NULL) {
3316                 gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_AUTOMATIC);
3317                 if (gp == NULL) {
3318                         G_MIRROR_DEBUG(0, "Cannot create device %s.",
3319                             md.md_name);
3320                         return (NULL);
3321                 }
3322                 sc = gp->softc;
3323         }
3324         G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
3325         g_topology_unlock();
3326         sx_xlock(&sc->sc_lock);
3327         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
3328         error = g_mirror_add_disk(sc, pp, &md);
3329         sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
3330         if (error != 0) {
3331                 G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
3332                     pp->name, gp->name, error);
3333                 if (LIST_EMPTY(&sc->sc_disks)) {
3334                         g_cancel_event(sc);
3335                         g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3336                         g_topology_lock();
3337                         return (NULL);
3338                 }
3339                 gp = NULL;
3340         }
3341         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
3342                 g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
3343                 g_topology_lock();
3344                 return (NULL);
3345         }
3346         sx_xunlock(&sc->sc_lock);
3347         g_topology_lock();
3348         return (gp);
3349 }
3350
3351 static void
3352 g_mirror_resize(struct g_consumer *cp)
3353 {
3354         struct g_mirror_disk *disk;
3355
3356         g_topology_assert();
3357         g_trace(G_T_TOPOLOGY, "%s(%s)", __func__, cp->provider->name);
3358
3359         disk = cp->private;
3360         if (disk == NULL)
3361                 return;
3362         g_topology_unlock();
3363         g_mirror_update_metadata(disk);
3364         g_topology_lock();
3365 }
3366
3367 static int
3368 g_mirror_destroy_geom(struct gctl_req *req __unused,
3369     struct g_class *mp __unused, struct g_geom *gp)
3370 {
3371         struct g_mirror_softc *sc;
3372         int error;
3373
3374         g_topology_unlock();
3375         sc = gp->softc;
3376         sx_xlock(&sc->sc_lock);
3377         g_cancel_event(sc);
3378         error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
3379         if (error != 0)
3380                 sx_xunlock(&sc->sc_lock);
3381         g_topology_lock();
3382         return (error);
3383 }
3384
3385 static void
3386 g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
3387     struct g_consumer *cp, struct g_provider *pp)
3388 {
3389         struct g_mirror_softc *sc;
3390
3391         g_topology_assert();
3392
3393         sc = gp->softc;
3394         if (sc == NULL)
3395                 return;
3396         /* Skip synchronization geom. */
3397         if (gp == sc->sc_sync.ds_geom)
3398                 return;
3399         if (pp != NULL) {
3400                 /* Nothing here. */
3401         } else if (cp != NULL) {
3402                 struct g_mirror_disk *disk;
3403
3404                 disk = cp->private;
3405                 if (disk == NULL)
3406                         return;
3407                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
3408                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
3409                         sbuf_printf(sb, "%s<Synchronized>", indent);
3410                         if (disk->d_sync.ds_offset == 0)
3411                                 sbuf_cat(sb, "0%");
3412                         else
3413                                 sbuf_printf(sb, "%u%%",
3414                                     (u_int)((disk->d_sync.ds_offset * 100) /
3415                                     sc->sc_mediasize));
3416                         sbuf_cat(sb, "</Synchronized>\n");
3417                         if (disk->d_sync.ds_offset > 0)
3418                                 sbuf_printf(sb, "%s<BytesSynced>%jd"
3419                                     "</BytesSynced>\n", indent,
3420                                     (intmax_t)disk->d_sync.ds_offset);
3421                 }
3422                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
3423                     disk->d_sync.ds_syncid);
3424                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
3425                     disk->d_genid);
3426                 sbuf_printf(sb, "%s<Flags>", indent);
3427                 if (disk->d_flags == 0)
3428                         sbuf_cat(sb, "NONE");
3429                 else {
3430                         int first = 1;
3431
3432 #define ADD_FLAG(flag, name)    do {                                    \
3433         if ((disk->d_flags & (flag)) != 0) {                            \
3434                 if (!first)                                             \
3435                         sbuf_cat(sb, ", ");                             \
3436                 else                                                    \
3437                         first = 0;                                      \
3438                 sbuf_cat(sb, name);                                     \
3439         }                                                               \
3440 } while (0)
3441                         ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
3442                         ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
3443                         ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
3444                         ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
3445                             "SYNCHRONIZING");
3446                         ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
3447                         ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
3448 #undef  ADD_FLAG
3449                 }
3450                 sbuf_cat(sb, "</Flags>\n");
3451                 sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
3452                     disk->d_priority);
3453                 sbuf_printf(sb, "%s<State>%s</State>\n", indent,
3454                     g_mirror_disk_state2str(disk->d_state));
3455         } else {
3456                 sbuf_printf(sb, "%s<Type>", indent);
3457                 switch (sc->sc_type) {
3458                 case G_MIRROR_TYPE_AUTOMATIC:
3459                         sbuf_cat(sb, "AUTOMATIC");
3460                         break;
3461                 case G_MIRROR_TYPE_MANUAL:
3462                         sbuf_cat(sb, "MANUAL");
3463                         break;
3464                 default:
3465                         sbuf_cat(sb, "UNKNOWN");
3466                         break;
3467                 }
3468                 sbuf_cat(sb, "</Type>\n");
3469                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
3470                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
3471                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
3472                 sbuf_printf(sb, "%s<Flags>", indent);
3473                 if (sc->sc_flags == 0)
3474                         sbuf_cat(sb, "NONE");
3475                 else {
3476                         int first = 1;
3477
3478 #define ADD_FLAG(flag, name)    do {                                    \
3479         if ((sc->sc_flags & (flag)) != 0) {                             \
3480                 if (!first)                                             \
3481                         sbuf_cat(sb, ", ");                             \
3482                 else                                                    \
3483                         first = 0;                                      \
3484                 sbuf_cat(sb, name);                                     \
3485         }                                                               \
3486 } while (0)
3487                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
3488                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
3489 #undef  ADD_FLAG
3490                 }
3491                 sbuf_cat(sb, "</Flags>\n");
3492                 sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
3493                     (u_int)sc->sc_slice);
3494                 sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
3495                     balance_name(sc->sc_balance));
3496                 sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
3497                     sc->sc_ndisks);
3498                 sbuf_printf(sb, "%s<State>", indent);
3499                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
3500                         sbuf_printf(sb, "%s", "STARTING");
3501                 else if (sc->sc_ndisks ==
3502                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
3503                         sbuf_printf(sb, "%s", "COMPLETE");
3504                 else
3505                         sbuf_printf(sb, "%s", "DEGRADED");
3506                 sbuf_cat(sb, "</State>\n");
3507         }
3508 }
3509
3510 static void
3511 g_mirror_shutdown_post_sync(void *arg, int howto)
3512 {
3513         struct g_class *mp;
3514         struct g_geom *gp, *gp2;
3515         struct g_mirror_softc *sc;
3516         int error;
3517
3518         if (KERNEL_PANICKED())
3519                 return;
3520
3521         mp = arg;
3522         g_topology_lock();
3523         g_mirror_shutdown = 1;
3524         LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
3525                 if ((sc = gp->softc) == NULL)
3526                         continue;
3527                 /* Skip synchronization geom. */
3528                 if (gp == sc->sc_sync.ds_geom)
3529                         continue;
3530                 g_topology_unlock();
3531                 sx_xlock(&sc->sc_lock);
3532                 g_mirror_idle(sc, -1);
3533                 g_cancel_event(sc);
3534                 error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
3535                 if (error != 0)
3536                         sx_xunlock(&sc->sc_lock);
3537                 g_topology_lock();
3538         }
3539         g_topology_unlock();
3540 }
3541
3542 static void
3543 g_mirror_init(struct g_class *mp)
3544 {
3545
3546         g_mirror_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
3547             g_mirror_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
3548         if (g_mirror_post_sync == NULL)
3549                 G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
3550 }
3551
3552 static void
3553 g_mirror_fini(struct g_class *mp)
3554 {
3555
3556         if (g_mirror_post_sync != NULL)
3557                 EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_mirror_post_sync);
3558 }
3559
3560 /*
3561  * Refresh the mirror device's metadata when gmirror encounters a newer
3562  * generation as the individual components are being added to the mirror set.
3563  */
3564 static int
3565 g_mirror_refresh_device(struct g_mirror_softc *sc, const struct g_provider *pp,
3566     const struct g_mirror_metadata *md)
3567 {
3568
3569         g_topology_assert_not();
3570         sx_assert(&sc->sc_lock, SX_XLOCKED);
3571
3572         KASSERT(sc->sc_genid <= md->md_genid,
3573             ("%s: attempted to refresh from stale component %s (device %s) "
3574             "(%u < %u).", __func__, pp->name, sc->sc_name, md->md_genid,
3575             sc->sc_genid));
3576
3577         if (sc->sc_genid > md->md_genid || (sc->sc_genid == md->md_genid &&
3578             sc->sc_syncid >= md->md_syncid))
3579                 return (0);
3580
3581         G_MIRROR_DEBUG(0, "Found newer version for device %s (genid: curr=%u "
3582             "new=%u; syncid: curr=%u new=%u; ndisks: curr=%u new=%u; "
3583             "provider=%s).", sc->sc_name, sc->sc_genid, md->md_genid,
3584             sc->sc_syncid, md->md_syncid, sc->sc_ndisks, md->md_all, pp->name);
3585
3586         if (sc->sc_state != G_MIRROR_DEVICE_STATE_STARTING) {
3587                 /* Probable data corruption detected */
3588                 G_MIRROR_DEBUG(0, "Cannot refresh metadata in %s state "
3589                     "(device=%s genid=%u). A stale mirror device was launched.",
3590                     g_mirror_device_state2str(sc->sc_state), sc->sc_name,
3591                     sc->sc_genid);
3592                 return (EINVAL);
3593         }
3594
3595         /* Update softc */
3596         g_mirror_reinit_from_metadata(sc, md);
3597
3598         G_MIRROR_DEBUG(1, "Refresh device %s (id=%u, state=%s) from disk %s "
3599             "(genid=%u syncid=%u md_all=%u).", sc->sc_name, md->md_mid,
3600             g_mirror_device_state2str(sc->sc_state), pp->name, md->md_genid,
3601             md->md_syncid, (unsigned)md->md_all);
3602
3603         return (0);
3604 }
3605
3606 DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
3607 MODULE_VERSION(geom_mirror, 0);