g_mirror.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    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         bzero(md, sizeof(*md));
  753         strlcpy(md->md_magic, G_MIRROR_MAGIC, sizeof(md->md_magic));
  754         md->md_version = G_MIRROR_VERSION;
  755         strlcpy(md->md_name, sc->sc_name, sizeof(md->md_name));
  756         md->md_mid = sc->sc_id;
  757         md->md_all = sc->sc_ndisks;
  758         md->md_slice = sc->sc_slice;
  759         md->md_balance = sc->sc_balance;
  760         md->md_genid = sc->sc_genid;
  761         md->md_mediasize = sc->sc_mediasize;
  762         md->md_sectorsize = sc->sc_sectorsize;
  763         md->md_mflags = (sc->sc_flags & G_MIRROR_DEVICE_FLAG_MASK);
  764         if (disk == NULL) {
  765                 md->md_did = arc4random();
  766         } else {
  767                 md->md_did = disk->d_id;
  768                 md->md_priority = disk->d_priority;
  769                 md->md_syncid = disk->d_sync.ds_syncid;
  770                 md->md_dflags = (disk->d_flags & G_MIRROR_DISK_FLAG_MASK);
  771                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
  772                         md->md_sync_offset = disk->d_sync.ds_offset_done;
  773                 if ((disk->d_flags & G_MIRROR_DISK_FLAG_HARDCODED) != 0) {
  774                         strlcpy(md->md_provider,
  775                             disk->d_consumer->provider->name,
  776                             sizeof(md->md_provider));
  777                 }
  778                 md->md_provsize = disk->d_consumer->provider->mediasize;
  779         }
  780 }
  781 
  782 void
  783 g_mirror_update_metadata(struct g_mirror_disk *disk)
  784 {
  785         struct g_mirror_softc *sc;
  786         struct g_mirror_metadata md;
  787         int error;
  788 
  789         g_topology_assert_not();
  790         sc = disk->d_softc;
  791         sx_assert(&sc->sc_lock, SX_LOCKED);
  792 
  793         if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
  794                 return;
  795         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_WIPE) == 0)
  796                 g_mirror_fill_metadata(sc, disk, &md);
  797         error = g_mirror_write_metadata(disk, &md);
  798         if (error == 0) {
  799                 G_MIRROR_DEBUG(2, "Metadata on %s updated.",
  800                     g_mirror_get_diskname(disk));
  801         } else {
  802                 G_MIRROR_DEBUG(0,
  803                     "Cannot update metadata on disk %s (error=%d).",
  804                     g_mirror_get_diskname(disk), error);
  805         }
  806 }
  807 
  808 static void
  809 g_mirror_bump_syncid(struct g_mirror_softc *sc)
  810 {
  811         struct g_mirror_disk *disk;
  812 
  813         g_topology_assert_not();
  814         sx_assert(&sc->sc_lock, SX_XLOCKED);
  815         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
  816             ("%s called with no active disks (device=%s).", __func__,
  817             sc->sc_name));
  818 
  819         sc->sc_syncid++;
  820         G_MIRROR_DEBUG(1, "Device %s: syncid bumped to %u.", sc->sc_name,
  821             sc->sc_syncid);
  822         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
  823                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
  824                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
  825                         disk->d_sync.ds_syncid = sc->sc_syncid;
  826                         g_mirror_update_metadata(disk);
  827                 }
  828         }
  829 }
  830 
  831 static void
  832 g_mirror_bump_genid(struct g_mirror_softc *sc)
  833 {
  834         struct g_mirror_disk *disk;
  835 
  836         g_topology_assert_not();
  837         sx_assert(&sc->sc_lock, SX_XLOCKED);
  838         KASSERT(g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 0,
  839             ("%s called with no active disks (device=%s).", __func__,
  840             sc->sc_name));
  841 
  842         sc->sc_genid++;
  843         G_MIRROR_DEBUG(1, "Device %s: genid bumped to %u.", sc->sc_name,
  844             sc->sc_genid);
  845         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
  846                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
  847                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
  848                         disk->d_genid = sc->sc_genid;
  849                         g_mirror_update_metadata(disk);
  850                 }
  851         }
  852 }
  853 
  854 static int
  855 g_mirror_idle(struct g_mirror_softc *sc, int acw)
  856 {
  857         struct g_mirror_disk *disk;
  858         int timeout;
  859 
  860         g_topology_assert_not();
  861         sx_assert(&sc->sc_lock, SX_XLOCKED);
  862 
  863         if (sc->sc_provider == NULL)
  864                 return (0);
  865         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
  866                 return (0);
  867         if (sc->sc_idle)
  868                 return (0);
  869         if (sc->sc_writes > 0)
  870                 return (0);
  871         if (acw > 0 || (acw == -1 && sc->sc_provider->acw > 0)) {
  872                 timeout = g_mirror_idletime - (time_uptime - sc->sc_last_write);
  873                 if (!g_mirror_shutdown && timeout > 0)
  874                         return (timeout);
  875         }
  876         sc->sc_idle = 1;
  877         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
  878                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
  879                         continue;
  880                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
  881                     g_mirror_get_diskname(disk), sc->sc_name);
  882                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
  883                 g_mirror_update_metadata(disk);
  884         }
  885         return (0);
  886 }
  887 
  888 static void
  889 g_mirror_unidle(struct g_mirror_softc *sc)
  890 {
  891         struct g_mirror_disk *disk;
  892 
  893         g_topology_assert_not();
  894         sx_assert(&sc->sc_lock, SX_XLOCKED);
  895 
  896         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
  897                 return;
  898         sc->sc_idle = 0;
  899         sc->sc_last_write = time_uptime;
  900         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
  901                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
  902                         continue;
  903                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
  904                     g_mirror_get_diskname(disk), sc->sc_name);
  905                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
  906                 g_mirror_update_metadata(disk);
  907         }
  908 }
  909 
  910 static void
  911 g_mirror_done(struct bio *bp)
  912 {
  913         struct g_mirror_softc *sc;
  914 
  915         sc = bp->bio_from->geom->softc;
  916         bp->bio_cflags = G_MIRROR_BIO_FLAG_REGULAR;
  917         mtx_lock(&sc->sc_queue_mtx);
  918         TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
  919         mtx_unlock(&sc->sc_queue_mtx);
  920         wakeup(sc);
  921 }
  922 
  923 static void
  924 g_mirror_regular_request_error(struct g_mirror_softc *sc,
  925     struct g_mirror_disk *disk, struct bio *bp)
  926 {
  927 
  928         if ((bp->bio_cmd == BIO_FLUSH || bp->bio_cmd == BIO_SPEEDUP) &&
  929             bp->bio_error == EOPNOTSUPP)
  930                 return;
  931 
  932         if ((disk->d_flags & G_MIRROR_DISK_FLAG_BROKEN) == 0) {
  933                 disk->d_flags |= G_MIRROR_DISK_FLAG_BROKEN;
  934                 G_MIRROR_LOGREQ(0, bp, "Request failed (error=%d).",
  935                     bp->bio_error);
  936         } else {
  937                 G_MIRROR_LOGREQ(1, bp, "Request failed (error=%d).",
  938                     bp->bio_error);
  939         }
  940         if (g_mirror_disconnect_on_failure &&
  941             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) > 1) {
  942                 if (bp->bio_error == ENXIO &&
  943                     bp->bio_cmd == BIO_READ)
  944                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
  945                 else if (bp->bio_error == ENXIO)
  946                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID_NOW;
  947                 else
  948                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
  949                 g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
  950                     G_MIRROR_EVENT_DONTWAIT);
  951         }
  952 }
  953 
  954 static void
  955 g_mirror_regular_request(struct g_mirror_softc *sc, struct bio *bp)
  956 {
  957         struct g_mirror_disk *disk;
  958         struct bio *pbp;
  959 
  960         g_topology_assert_not();
  961         KASSERT(sc->sc_provider == bp->bio_parent->bio_to,
  962             ("regular request %p with unexpected origin", bp));
  963 
  964         pbp = bp->bio_parent;
  965         bp->bio_from->index--;
  966         if (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_DELETE)
  967                 sc->sc_writes--;
  968         disk = bp->bio_from->private;
  969         if (disk == NULL) {
  970                 g_topology_lock();
  971                 g_mirror_kill_consumer(sc, bp->bio_from);
  972                 g_topology_unlock();
  973         }
  974 
  975         switch (bp->bio_cmd) {
  976         case BIO_READ:
  977                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_read,
  978                     bp->bio_error);
  979                 break;
  980         case BIO_WRITE:
  981                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_write,
  982                     bp->bio_error);
  983                 break;
  984         case BIO_DELETE:
  985                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_delete,
  986                     bp->bio_error);
  987                 break;
  988         case BIO_FLUSH:
  989                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_flush,
  990                     bp->bio_error);
  991                 break;
  992         case BIO_SPEEDUP:
  993                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_regular_request_speedup,
  994                     bp->bio_error);
  995                 break;
  996         }
  997 
  998         pbp->bio_inbed++;
  999         KASSERT(pbp->bio_inbed <= pbp->bio_children,
 1000             ("bio_inbed (%u) is bigger than bio_children (%u).", pbp->bio_inbed,
 1001             pbp->bio_children));
 1002         if (bp->bio_error == 0 && pbp->bio_error == 0) {
 1003                 G_MIRROR_LOGREQ(3, bp, "Request delivered.");
 1004                 g_destroy_bio(bp);
 1005                 if (pbp->bio_children == pbp->bio_inbed) {
 1006                         G_MIRROR_LOGREQ(3, pbp, "Request delivered.");
 1007                         pbp->bio_completed = pbp->bio_length;
 1008                         if (pbp->bio_cmd == BIO_WRITE ||
 1009                             pbp->bio_cmd == BIO_DELETE) {
 1010                                 TAILQ_REMOVE(&sc->sc_inflight, pbp, bio_queue);
 1011                                 /* Release delayed sync requests if possible. */
 1012                                 g_mirror_sync_release(sc);
 1013                         }
 1014                         g_io_deliver(pbp, pbp->bio_error);
 1015                 }
 1016                 return;
 1017         } else if (bp->bio_error != 0) {
 1018                 if (pbp->bio_error == 0)
 1019                         pbp->bio_error = bp->bio_error;
 1020                 if (disk != NULL)
 1021                         g_mirror_regular_request_error(sc, disk, bp);
 1022                 switch (pbp->bio_cmd) {
 1023                 case BIO_DELETE:
 1024                 case BIO_WRITE:
 1025                 case BIO_FLUSH:
 1026                 case BIO_SPEEDUP:
 1027                         pbp->bio_inbed--;
 1028                         pbp->bio_children--;
 1029                         break;
 1030                 }
 1031         }
 1032         g_destroy_bio(bp);
 1033 
 1034         switch (pbp->bio_cmd) {
 1035         case BIO_READ:
 1036                 if (pbp->bio_inbed < pbp->bio_children)
 1037                         break;
 1038 
 1039                 /*
 1040                  * If there is only one active disk we want to double-check that
 1041                  * it is, in fact, the disk that we already tried.  This is
 1042                  * necessary because we might have just lost a race with a
 1043                  * removal of the tried disk (likely because of the same error)
 1044                  * and the only remaining disk is still viable for a retry.
 1045                  */
 1046                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1 &&
 1047                     disk != NULL &&
 1048                     disk->d_state == G_MIRROR_DISK_STATE_ACTIVE) {
 1049                         g_io_deliver(pbp, pbp->bio_error);
 1050                 } else {
 1051                         pbp->bio_error = 0;
 1052                         mtx_lock(&sc->sc_queue_mtx);
 1053                         TAILQ_INSERT_TAIL(&sc->sc_queue, pbp, bio_queue);
 1054                         mtx_unlock(&sc->sc_queue_mtx);
 1055                         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 1056                         wakeup(sc);
 1057                 }
 1058                 break;
 1059         case BIO_DELETE:
 1060         case BIO_WRITE:
 1061         case BIO_FLUSH:
 1062         case BIO_SPEEDUP:
 1063                 if (pbp->bio_children == 0) {
 1064                         /*
 1065                          * All requests failed.
 1066                          */
 1067                 } else if (pbp->bio_inbed < pbp->bio_children) {
 1068                         /* Do nothing. */
 1069                         break;
 1070                 } else if (pbp->bio_children == pbp->bio_inbed) {
 1071                         /* Some requests succeeded. */
 1072                         pbp->bio_error = 0;
 1073                         pbp->bio_completed = pbp->bio_length;
 1074                 }
 1075                 if (pbp->bio_cmd == BIO_WRITE || pbp->bio_cmd == BIO_DELETE) {
 1076                         TAILQ_REMOVE(&sc->sc_inflight, pbp, bio_queue);
 1077                         /* Release delayed sync requests if possible. */
 1078                         g_mirror_sync_release(sc);
 1079                 }
 1080                 g_io_deliver(pbp, pbp->bio_error);
 1081                 break;
 1082         default:
 1083                 KASSERT(1 == 0, ("Invalid request: %u.", pbp->bio_cmd));
 1084                 break;
 1085         }
 1086 }
 1087 
 1088 static void
 1089 g_mirror_sync_done(struct bio *bp)
 1090 {
 1091         struct g_mirror_softc *sc;
 1092 
 1093         G_MIRROR_LOGREQ(3, bp, "Synchronization request delivered.");
 1094         sc = bp->bio_from->geom->softc;
 1095         bp->bio_cflags = G_MIRROR_BIO_FLAG_SYNC;
 1096         mtx_lock(&sc->sc_queue_mtx);
 1097         TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
 1098         mtx_unlock(&sc->sc_queue_mtx);
 1099         wakeup(sc);
 1100 }
 1101 
 1102 static void
 1103 g_mirror_candelete(struct bio *bp)
 1104 {
 1105         struct g_mirror_softc *sc;
 1106         struct g_mirror_disk *disk;
 1107         int val;
 1108 
 1109         sc = bp->bio_to->private;
 1110         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 1111                 if (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE)
 1112                         break;
 1113         }
 1114         val = disk != NULL;
 1115         g_handleattr(bp, "GEOM::candelete", &val, sizeof(val));
 1116 }
 1117 
 1118 static void
 1119 g_mirror_kernel_dump(struct bio *bp)
 1120 {
 1121         struct g_mirror_softc *sc;
 1122         struct g_mirror_disk *disk;
 1123         struct bio *cbp;
 1124         struct g_kerneldump *gkd;
 1125 
 1126         /*
 1127          * We configure dumping to the first component, because this component
 1128          * will be used for reading with 'prefer' balance algorithm.
 1129          * If the component with the highest priority is currently disconnected
 1130          * we will not be able to read the dump after the reboot if it will be
 1131          * connected and synchronized later. Can we do something better?
 1132          */
 1133         sc = bp->bio_to->private;
 1134         disk = LIST_FIRST(&sc->sc_disks);
 1135 
 1136         gkd = (struct g_kerneldump *)bp->bio_data;
 1137         if (gkd->length > bp->bio_to->mediasize)
 1138                 gkd->length = bp->bio_to->mediasize;
 1139         cbp = g_clone_bio(bp);
 1140         if (cbp == NULL) {
 1141                 g_io_deliver(bp, ENOMEM);
 1142                 return;
 1143         }
 1144         cbp->bio_done = g_std_done;
 1145         g_io_request(cbp, disk->d_consumer);
 1146         G_MIRROR_DEBUG(1, "Kernel dump will go to %s.",
 1147             g_mirror_get_diskname(disk));
 1148 }
 1149 
 1150 static void
 1151 g_mirror_start(struct bio *bp)
 1152 {
 1153         struct g_mirror_softc *sc;
 1154 
 1155         sc = bp->bio_to->private;
 1156         /*
 1157          * If sc == NULL or there are no valid disks, provider's error
 1158          * should be set and g_mirror_start() should not be called at all.
 1159          */
 1160         KASSERT(sc != NULL && sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
 1161             ("Provider's error should be set (error=%d)(mirror=%s).",
 1162             bp->bio_to->error, bp->bio_to->name));
 1163         G_MIRROR_LOGREQ(3, bp, "Request received.");
 1164 
 1165         switch (bp->bio_cmd) {
 1166         case BIO_READ:
 1167         case BIO_WRITE:
 1168         case BIO_DELETE:
 1169         case BIO_SPEEDUP:
 1170         case BIO_FLUSH:
 1171                 break;
 1172         case BIO_GETATTR:
 1173                 if (!strcmp(bp->bio_attribute, "GEOM::candelete")) {
 1174                         g_mirror_candelete(bp);
 1175                         return;
 1176                 } else if (strcmp("GEOM::kerneldump", bp->bio_attribute) == 0) {
 1177                         g_mirror_kernel_dump(bp);
 1178                         return;
 1179                 }
 1180                 /* FALLTHROUGH */
 1181         default:
 1182                 g_io_deliver(bp, EOPNOTSUPP);
 1183                 return;
 1184         }
 1185         mtx_lock(&sc->sc_queue_mtx);
 1186         if (bp->bio_to->error != 0) {
 1187                 mtx_unlock(&sc->sc_queue_mtx);
 1188                 g_io_deliver(bp, bp->bio_to->error);
 1189                 return;
 1190         }
 1191         TAILQ_INSERT_TAIL(&sc->sc_queue, bp, bio_queue);
 1192         mtx_unlock(&sc->sc_queue_mtx);
 1193         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 1194         wakeup(sc);
 1195 }
 1196 
 1197 /*
 1198  * Return TRUE if the given request is colliding with a in-progress
 1199  * synchronization request.
 1200  */
 1201 static bool
 1202 g_mirror_sync_collision(struct g_mirror_softc *sc, struct bio *bp)
 1203 {
 1204         struct g_mirror_disk *disk;
 1205         struct bio *sbp;
 1206         off_t rstart, rend, sstart, send;
 1207         u_int i;
 1208 
 1209         if (sc->sc_sync.ds_ndisks == 0)
 1210                 return (false);
 1211         rstart = bp->bio_offset;
 1212         rend = bp->bio_offset + bp->bio_length;
 1213         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 1214                 if (disk->d_state != G_MIRROR_DISK_STATE_SYNCHRONIZING)
 1215                         continue;
 1216                 for (i = 0; i < g_mirror_syncreqs; i++) {
 1217                         sbp = disk->d_sync.ds_bios[i];
 1218                         if (sbp == NULL)
 1219                                 continue;
 1220                         sstart = sbp->bio_offset;
 1221                         send = sbp->bio_offset + sbp->bio_length;
 1222                         if (rend > sstart && rstart < send)
 1223                                 return (true);
 1224                 }
 1225         }
 1226         return (false);
 1227 }
 1228 
 1229 /*
 1230  * Return TRUE if the given sync request is colliding with a in-progress regular
 1231  * request.
 1232  */
 1233 static bool
 1234 g_mirror_regular_collision(struct g_mirror_softc *sc, struct bio *sbp)
 1235 {
 1236         off_t rstart, rend, sstart, send;
 1237         struct bio *bp;
 1238 
 1239         if (sc->sc_sync.ds_ndisks == 0)
 1240                 return (false);
 1241         sstart = sbp->bio_offset;
 1242         send = sbp->bio_offset + sbp->bio_length;
 1243         TAILQ_FOREACH(bp, &sc->sc_inflight, bio_queue) {
 1244                 rstart = bp->bio_offset;
 1245                 rend = bp->bio_offset + bp->bio_length;
 1246                 if (rend > sstart && rstart < send)
 1247                         return (true);
 1248         }
 1249         return (false);
 1250 }
 1251 
 1252 /*
 1253  * Puts regular request onto delayed queue.
 1254  */
 1255 static void
 1256 g_mirror_regular_delay(struct g_mirror_softc *sc, struct bio *bp)
 1257 {
 1258 
 1259         G_MIRROR_LOGREQ(2, bp, "Delaying request.");
 1260         TAILQ_INSERT_TAIL(&sc->sc_regular_delayed, bp, bio_queue);
 1261 }
 1262 
 1263 /*
 1264  * Puts synchronization request onto delayed queue.
 1265  */
 1266 static void
 1267 g_mirror_sync_delay(struct g_mirror_softc *sc, struct bio *bp)
 1268 {
 1269 
 1270         G_MIRROR_LOGREQ(2, bp, "Delaying synchronization request.");
 1271         TAILQ_INSERT_TAIL(&sc->sc_sync_delayed, bp, bio_queue);
 1272 }
 1273 
 1274 /*
 1275  * Requeue delayed regular requests.
 1276  */
 1277 static void
 1278 g_mirror_regular_release(struct g_mirror_softc *sc)
 1279 {
 1280         struct bio *bp;
 1281 
 1282         if ((bp = TAILQ_FIRST(&sc->sc_regular_delayed)) == NULL)
 1283                 return;
 1284         if (g_mirror_sync_collision(sc, bp))
 1285                 return;
 1286 
 1287         G_MIRROR_DEBUG(2, "Requeuing regular requests after collision.");
 1288         mtx_lock(&sc->sc_queue_mtx);
 1289         TAILQ_CONCAT(&sc->sc_regular_delayed, &sc->sc_queue, bio_queue);
 1290         TAILQ_SWAP(&sc->sc_regular_delayed, &sc->sc_queue, bio, bio_queue);
 1291         mtx_unlock(&sc->sc_queue_mtx);
 1292 }
 1293 
 1294 /*
 1295  * Releases delayed sync requests which don't collide anymore with regular
 1296  * requests.
 1297  */
 1298 static void
 1299 g_mirror_sync_release(struct g_mirror_softc *sc)
 1300 {
 1301         struct bio *bp, *bp2;
 1302 
 1303         TAILQ_FOREACH_SAFE(bp, &sc->sc_sync_delayed, bio_queue, bp2) {
 1304                 if (g_mirror_regular_collision(sc, bp))
 1305                         continue;
 1306                 TAILQ_REMOVE(&sc->sc_sync_delayed, bp, bio_queue);
 1307                 G_MIRROR_LOGREQ(2, bp,
 1308                     "Releasing delayed synchronization request.");
 1309                 g_io_request(bp, bp->bio_from);
 1310         }
 1311 }
 1312 
 1313 /*
 1314  * Free a synchronization request and clear its slot in the array.
 1315  */
 1316 static void
 1317 g_mirror_sync_request_free(struct g_mirror_disk *disk, struct bio *bp)
 1318 {
 1319         int idx;
 1320 
 1321         if (disk != NULL && disk->d_sync.ds_bios != NULL) {
 1322                 idx = (int)(uintptr_t)bp->bio_caller1;
 1323                 KASSERT(disk->d_sync.ds_bios[idx] == bp,
 1324                     ("unexpected sync BIO at %p:%d", disk, idx));
 1325                 disk->d_sync.ds_bios[idx] = NULL;
 1326         }
 1327         free(bp->bio_data, M_MIRROR);
 1328         g_destroy_bio(bp);
 1329 }
 1330 
 1331 /*
 1332  * Handle synchronization requests.
 1333  * Every synchronization request is a two-step process: first, a read request is
 1334  * sent to the mirror provider via the sync consumer. If that request completes
 1335  * successfully, it is converted to a write and sent to the disk being
 1336  * synchronized. If the write also completes successfully, the synchronization
 1337  * offset is advanced and a new read request is submitted.
 1338  */
 1339 static void
 1340 g_mirror_sync_request(struct g_mirror_softc *sc, struct bio *bp)
 1341 {
 1342         struct g_mirror_disk *disk;
 1343         struct g_mirror_disk_sync *sync;
 1344 
 1345         KASSERT((bp->bio_cmd == BIO_READ &&
 1346             bp->bio_from->geom == sc->sc_sync.ds_geom) ||
 1347             (bp->bio_cmd == BIO_WRITE && bp->bio_from->geom == sc->sc_geom),
 1348             ("Sync BIO %p with unexpected origin", bp));
 1349 
 1350         bp->bio_from->index--;
 1351         disk = bp->bio_from->private;
 1352         if (disk == NULL) {
 1353                 sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
 1354                 g_topology_lock();
 1355                 g_mirror_kill_consumer(sc, bp->bio_from);
 1356                 g_topology_unlock();
 1357                 g_mirror_sync_request_free(NULL, bp);
 1358                 sx_xlock(&sc->sc_lock);
 1359                 return;
 1360         }
 1361 
 1362         sync = &disk->d_sync;
 1363 
 1364         /*
 1365          * Synchronization request.
 1366          */
 1367         switch (bp->bio_cmd) {
 1368         case BIO_READ: {
 1369                 struct g_consumer *cp;
 1370 
 1371                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_read,
 1372                     bp->bio_error);
 1373 
 1374                 if (bp->bio_error != 0) {
 1375                         G_MIRROR_LOGREQ(0, bp,
 1376                             "Synchronization request failed (error=%d).",
 1377                             bp->bio_error);
 1378 
 1379                         /*
 1380                          * The read error will trigger a syncid bump, so there's
 1381                          * no need to do that here.
 1382                          *
 1383                          * The read error handling for regular requests will
 1384                          * retry the read from all active mirrors before passing
 1385                          * the error back up, so there's no need to retry here.
 1386                          */
 1387                         g_mirror_sync_request_free(disk, bp);
 1388                         g_mirror_event_send(disk,
 1389                             G_MIRROR_DISK_STATE_DISCONNECTED,
 1390                             G_MIRROR_EVENT_DONTWAIT);
 1391                         return;
 1392                 }
 1393                 G_MIRROR_LOGREQ(3, bp,
 1394                     "Synchronization request half-finished.");
 1395                 bp->bio_cmd = BIO_WRITE;
 1396                 bp->bio_cflags = 0;
 1397                 cp = disk->d_consumer;
 1398                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1399                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
 1400                     cp->acr, cp->acw, cp->ace));
 1401                 cp->index++;
 1402                 g_io_request(bp, cp);
 1403                 return;
 1404         }
 1405         case BIO_WRITE: {
 1406                 off_t offset;
 1407                 int i;
 1408 
 1409                 KFAIL_POINT_ERROR(DEBUG_FP, g_mirror_sync_request_write,
 1410                     bp->bio_error);
 1411 
 1412                 if (bp->bio_error != 0) {
 1413                         G_MIRROR_LOGREQ(0, bp,
 1414                             "Synchronization request failed (error=%d).",
 1415                             bp->bio_error);
 1416                         g_mirror_sync_request_free(disk, bp);
 1417                         sc->sc_bump_id |= G_MIRROR_BUMP_GENID;
 1418                         g_mirror_event_send(disk,
 1419                             G_MIRROR_DISK_STATE_DISCONNECTED,
 1420                             G_MIRROR_EVENT_DONTWAIT);
 1421                         return;
 1422                 }
 1423                 G_MIRROR_LOGREQ(3, bp, "Synchronization request finished.");
 1424                 if (sync->ds_offset >= sc->sc_mediasize ||
 1425                     sync->ds_consumer == NULL ||
 1426                     (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
 1427                         /* Don't send more synchronization requests. */
 1428                         sync->ds_inflight--;
 1429                         g_mirror_sync_request_free(disk, bp);
 1430                         if (sync->ds_inflight > 0)
 1431                                 return;
 1432                         if (sync->ds_consumer == NULL ||
 1433                             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
 1434                                 return;
 1435                         }
 1436                         /* Disk up-to-date, activate it. */
 1437                         g_mirror_event_send(disk, G_MIRROR_DISK_STATE_ACTIVE,
 1438                             G_MIRROR_EVENT_DONTWAIT);
 1439                         return;
 1440                 }
 1441 
 1442                 /* Send next synchronization request. */
 1443                 g_mirror_sync_reinit(disk, bp, sync->ds_offset);
 1444                 sync->ds_offset += bp->bio_length;
 1445 
 1446                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
 1447                 sync->ds_consumer->index++;
 1448 
 1449                 /*
 1450                  * Delay the request if it is colliding with a regular request.
 1451                  */
 1452                 if (g_mirror_regular_collision(sc, bp))
 1453                         g_mirror_sync_delay(sc, bp);
 1454                 else
 1455                         g_io_request(bp, sync->ds_consumer);
 1456 
 1457                 /* Requeue delayed requests if possible. */
 1458                 g_mirror_regular_release(sc);
 1459 
 1460                 /* Find the smallest offset */
 1461                 offset = sc->sc_mediasize;
 1462                 for (i = 0; i < g_mirror_syncreqs; i++) {
 1463                         bp = sync->ds_bios[i];
 1464                         if (bp != NULL && bp->bio_offset < offset)
 1465                                 offset = bp->bio_offset;
 1466                 }
 1467                 if (g_mirror_sync_period > 0 &&
 1468                     time_uptime - sync->ds_update_ts > g_mirror_sync_period) {
 1469                         sync->ds_offset_done = offset;
 1470                         g_mirror_update_metadata(disk);
 1471                         sync->ds_update_ts = time_uptime;
 1472                 }
 1473                 return;
 1474         }
 1475         default:
 1476                 panic("Invalid I/O request %p", bp);
 1477         }
 1478 }
 1479 
 1480 static void
 1481 g_mirror_request_prefer(struct g_mirror_softc *sc, struct bio *bp)
 1482 {
 1483         struct g_mirror_disk *disk;
 1484         struct g_consumer *cp;
 1485         struct bio *cbp;
 1486 
 1487         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 1488                 if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE)
 1489                         break;
 1490         }
 1491         if (disk == NULL) {
 1492                 if (bp->bio_error == 0)
 1493                         bp->bio_error = ENXIO;
 1494                 g_io_deliver(bp, bp->bio_error);
 1495                 return;
 1496         }
 1497         cbp = g_clone_bio(bp);
 1498         if (cbp == NULL) {
 1499                 if (bp->bio_error == 0)
 1500                         bp->bio_error = ENOMEM;
 1501                 g_io_deliver(bp, bp->bio_error);
 1502                 return;
 1503         }
 1504         /*
 1505          * Fill in the component buf structure.
 1506          */
 1507         cp = disk->d_consumer;
 1508         cbp->bio_done = g_mirror_done;
 1509         cbp->bio_to = cp->provider;
 1510         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
 1511         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1512             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
 1513             cp->acw, cp->ace));
 1514         cp->index++;
 1515         g_io_request(cbp, cp);
 1516 }
 1517 
 1518 static void
 1519 g_mirror_request_round_robin(struct g_mirror_softc *sc, struct bio *bp)
 1520 {
 1521         struct g_mirror_disk *disk;
 1522         struct g_consumer *cp;
 1523         struct bio *cbp;
 1524 
 1525         disk = g_mirror_get_disk(sc);
 1526         if (disk == NULL) {
 1527                 if (bp->bio_error == 0)
 1528                         bp->bio_error = ENXIO;
 1529                 g_io_deliver(bp, bp->bio_error);
 1530                 return;
 1531         }
 1532         cbp = g_clone_bio(bp);
 1533         if (cbp == NULL) {
 1534                 if (bp->bio_error == 0)
 1535                         bp->bio_error = ENOMEM;
 1536                 g_io_deliver(bp, bp->bio_error);
 1537                 return;
 1538         }
 1539         /*
 1540          * Fill in the component buf structure.
 1541          */
 1542         cp = disk->d_consumer;
 1543         cbp->bio_done = g_mirror_done;
 1544         cbp->bio_to = cp->provider;
 1545         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
 1546         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1547             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
 1548             cp->acw, cp->ace));
 1549         cp->index++;
 1550         g_io_request(cbp, cp);
 1551 }
 1552 
 1553 #define TRACK_SIZE  (1 * 1024 * 1024)
 1554 #define LOAD_SCALE      256
 1555 #define ABS(x)          (((x) >= 0) ? (x) : (-(x)))
 1556 
 1557 static void
 1558 g_mirror_request_load(struct g_mirror_softc *sc, struct bio *bp)
 1559 {
 1560         struct g_mirror_disk *disk, *dp;
 1561         struct g_consumer *cp;
 1562         struct bio *cbp;
 1563         int prio, best;
 1564 
 1565         /* Find a disk with the smallest load. */
 1566         disk = NULL;
 1567         best = INT_MAX;
 1568         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
 1569                 if (dp->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 1570                         continue;
 1571                 prio = dp->load;
 1572                 /* If disk head is precisely in position - highly prefer it. */
 1573                 if (dp->d_last_offset == bp->bio_offset)
 1574                         prio -= 2 * LOAD_SCALE;
 1575                 else
 1576                 /* If disk head is close to position - prefer it. */
 1577                 if (ABS(dp->d_last_offset - bp->bio_offset) < TRACK_SIZE)
 1578                         prio -= 1 * LOAD_SCALE;
 1579                 if (prio <= best) {
 1580                         disk = dp;
 1581                         best = prio;
 1582                 }
 1583         }
 1584         KASSERT(disk != NULL, ("NULL disk for %s.", sc->sc_name));
 1585         cbp = g_clone_bio(bp);
 1586         if (cbp == NULL) {
 1587                 if (bp->bio_error == 0)
 1588                         bp->bio_error = ENOMEM;
 1589                 g_io_deliver(bp, bp->bio_error);
 1590                 return;
 1591         }
 1592         /*
 1593          * Fill in the component buf structure.
 1594          */
 1595         cp = disk->d_consumer;
 1596         cbp->bio_done = g_mirror_done;
 1597         cbp->bio_to = cp->provider;
 1598         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
 1599         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1600             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name, cp->acr,
 1601             cp->acw, cp->ace));
 1602         cp->index++;
 1603         /* Remember last head position */
 1604         disk->d_last_offset = bp->bio_offset + bp->bio_length;
 1605         /* Update loads. */
 1606         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
 1607                 dp->load = (dp->d_consumer->index * LOAD_SCALE +
 1608                     dp->load * 7) / 8;
 1609         }
 1610         g_io_request(cbp, cp);
 1611 }
 1612 
 1613 static void
 1614 g_mirror_request_split(struct g_mirror_softc *sc, struct bio *bp)
 1615 {
 1616         struct bio_queue queue;
 1617         struct g_mirror_disk *disk;
 1618         struct g_consumer *cp __diagused;
 1619         struct bio *cbp;
 1620         off_t left, mod, offset, slice;
 1621         u_char *data;
 1622         u_int ndisks;
 1623 
 1624         if (bp->bio_length <= sc->sc_slice) {
 1625                 g_mirror_request_round_robin(sc, bp);
 1626                 return;
 1627         }
 1628         ndisks = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
 1629         slice = bp->bio_length / ndisks;
 1630         mod = slice % sc->sc_provider->sectorsize;
 1631         if (mod != 0)
 1632                 slice += sc->sc_provider->sectorsize - mod;
 1633         /*
 1634          * Allocate all bios before sending any request, so we can
 1635          * return ENOMEM in nice and clean way.
 1636          */
 1637         left = bp->bio_length;
 1638         offset = bp->bio_offset;
 1639         data = bp->bio_data;
 1640         TAILQ_INIT(&queue);
 1641         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 1642                 if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 1643                         continue;
 1644                 cbp = g_clone_bio(bp);
 1645                 if (cbp == NULL) {
 1646                         while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
 1647                                 TAILQ_REMOVE(&queue, cbp, bio_queue);
 1648                                 g_destroy_bio(cbp);
 1649                         }
 1650                         if (bp->bio_error == 0)
 1651                                 bp->bio_error = ENOMEM;
 1652                         g_io_deliver(bp, bp->bio_error);
 1653                         return;
 1654                 }
 1655                 TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
 1656                 cbp->bio_done = g_mirror_done;
 1657                 cbp->bio_caller1 = disk;
 1658                 cbp->bio_to = disk->d_consumer->provider;
 1659                 cbp->bio_offset = offset;
 1660                 cbp->bio_data = data;
 1661                 cbp->bio_length = MIN(left, slice);
 1662                 left -= cbp->bio_length;
 1663                 if (left == 0)
 1664                         break;
 1665                 offset += cbp->bio_length;
 1666                 data += cbp->bio_length;
 1667         }
 1668         while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
 1669                 TAILQ_REMOVE(&queue, cbp, bio_queue);
 1670                 G_MIRROR_LOGREQ(3, cbp, "Sending request.");
 1671                 disk = cbp->bio_caller1;
 1672                 cbp->bio_caller1 = NULL;
 1673                 cp = disk->d_consumer;
 1674                 KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1675                     ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
 1676                     cp->acr, cp->acw, cp->ace));
 1677                 disk->d_consumer->index++;
 1678                 g_io_request(cbp, disk->d_consumer);
 1679         }
 1680 }
 1681 
 1682 static void
 1683 g_mirror_register_request(struct g_mirror_softc *sc, struct bio *bp)
 1684 {
 1685         struct bio_queue queue;
 1686         struct bio *cbp;
 1687         struct g_consumer *cp;
 1688         struct g_mirror_disk *disk;
 1689 
 1690         sx_assert(&sc->sc_lock, SA_XLOCKED);
 1691 
 1692         /*
 1693          * To avoid ordering issues, if a write is deferred because of a
 1694          * collision with a sync request, all I/O is deferred until that
 1695          * write is initiated.
 1696          */
 1697         if (bp->bio_from->geom != sc->sc_sync.ds_geom &&
 1698             !TAILQ_EMPTY(&sc->sc_regular_delayed)) {
 1699                 g_mirror_regular_delay(sc, bp);
 1700                 return;
 1701         }
 1702 
 1703         switch (bp->bio_cmd) {
 1704         case BIO_READ:
 1705                 switch (sc->sc_balance) {
 1706                 case G_MIRROR_BALANCE_LOAD:
 1707                         g_mirror_request_load(sc, bp);
 1708                         break;
 1709                 case G_MIRROR_BALANCE_PREFER:
 1710                         g_mirror_request_prefer(sc, bp);
 1711                         break;
 1712                 case G_MIRROR_BALANCE_ROUND_ROBIN:
 1713                         g_mirror_request_round_robin(sc, bp);
 1714                         break;
 1715                 case G_MIRROR_BALANCE_SPLIT:
 1716                         g_mirror_request_split(sc, bp);
 1717                         break;
 1718                 }
 1719                 return;
 1720         case BIO_WRITE:
 1721         case BIO_DELETE:
 1722                 /*
 1723                  * Delay the request if it is colliding with a synchronization
 1724                  * request.
 1725                  */
 1726                 if (g_mirror_sync_collision(sc, bp)) {
 1727                         g_mirror_regular_delay(sc, bp);
 1728                         return;
 1729                 }
 1730 
 1731                 if (sc->sc_idle)
 1732                         g_mirror_unidle(sc);
 1733                 else
 1734                         sc->sc_last_write = time_uptime;
 1735 
 1736                 /*
 1737                  * Bump syncid on first write.
 1738                  */
 1739                 if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0) {
 1740                         sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
 1741                         g_mirror_bump_syncid(sc);
 1742                 }
 1743 
 1744                 /*
 1745                  * Allocate all bios before sending any request, so we can
 1746                  * return ENOMEM in nice and clean way.
 1747                  */
 1748                 TAILQ_INIT(&queue);
 1749                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 1750                         switch (disk->d_state) {
 1751                         case G_MIRROR_DISK_STATE_ACTIVE:
 1752                                 break;
 1753                         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 1754                                 if (bp->bio_offset >= disk->d_sync.ds_offset)
 1755                                         continue;
 1756                                 break;
 1757                         default:
 1758                                 continue;
 1759                         }
 1760                         if (bp->bio_cmd == BIO_DELETE &&
 1761                             (disk->d_flags & G_MIRROR_DISK_FLAG_CANDELETE) == 0)
 1762                                 continue;
 1763                         cbp = g_clone_bio(bp);
 1764                         if (cbp == NULL) {
 1765                                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
 1766                                         TAILQ_REMOVE(&queue, cbp, bio_queue);
 1767                                         g_destroy_bio(cbp);
 1768                                 }
 1769                                 if (bp->bio_error == 0)
 1770                                         bp->bio_error = ENOMEM;
 1771                                 g_io_deliver(bp, bp->bio_error);
 1772                                 return;
 1773                         }
 1774                         TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
 1775                         cbp->bio_done = g_mirror_done;
 1776                         cp = disk->d_consumer;
 1777                         cbp->bio_caller1 = cp;
 1778                         cbp->bio_to = cp->provider;
 1779                         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1780                             ("Consumer %s not opened (r%dw%de%d).",
 1781                             cp->provider->name, cp->acr, cp->acw, cp->ace));
 1782                 }
 1783                 if (TAILQ_EMPTY(&queue)) {
 1784                         KASSERT(bp->bio_cmd == BIO_DELETE,
 1785                             ("No consumers for regular request %p", bp));
 1786                         g_io_deliver(bp, EOPNOTSUPP);
 1787                         return;
 1788                 }
 1789                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
 1790                         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
 1791                         TAILQ_REMOVE(&queue, cbp, bio_queue);
 1792                         cp = cbp->bio_caller1;
 1793                         cbp->bio_caller1 = NULL;
 1794                         cp->index++;
 1795                         sc->sc_writes++;
 1796                         g_io_request(cbp, cp);
 1797                 }
 1798                 /*
 1799                  * Put request onto inflight queue, so we can check if new
 1800                  * synchronization requests don't collide with it.
 1801                  */
 1802                 TAILQ_INSERT_TAIL(&sc->sc_inflight, bp, bio_queue);
 1803                 return;
 1804         case BIO_SPEEDUP:
 1805         case BIO_FLUSH:
 1806                 TAILQ_INIT(&queue);
 1807                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 1808                         if (disk->d_state != G_MIRROR_DISK_STATE_ACTIVE)
 1809                                 continue;
 1810                         cbp = g_clone_bio(bp);
 1811                         if (cbp == NULL) {
 1812                                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
 1813                                         TAILQ_REMOVE(&queue, cbp, bio_queue);
 1814                                         g_destroy_bio(cbp);
 1815                                 }
 1816                                 if (bp->bio_error == 0)
 1817                                         bp->bio_error = ENOMEM;
 1818                                 g_io_deliver(bp, bp->bio_error);
 1819                                 return;
 1820                         }
 1821                         TAILQ_INSERT_TAIL(&queue, cbp, bio_queue);
 1822                         cbp->bio_done = g_mirror_done;
 1823                         cbp->bio_caller1 = disk;
 1824                         cbp->bio_to = disk->d_consumer->provider;
 1825                 }
 1826                 KASSERT(!TAILQ_EMPTY(&queue),
 1827                     ("No consumers for regular request %p", bp));
 1828                 while ((cbp = TAILQ_FIRST(&queue)) != NULL) {
 1829                         G_MIRROR_LOGREQ(3, cbp, "Sending request.");
 1830                         TAILQ_REMOVE(&queue, cbp, bio_queue);
 1831                         disk = cbp->bio_caller1;
 1832                         cbp->bio_caller1 = NULL;
 1833                         cp = disk->d_consumer;
 1834                         KASSERT(cp->acr >= 1 && cp->acw >= 1 && cp->ace >= 1,
 1835                             ("Consumer %s not opened (r%dw%de%d).", cp->provider->name,
 1836                             cp->acr, cp->acw, cp->ace));
 1837                         cp->index++;
 1838                         g_io_request(cbp, cp);
 1839                 }
 1840                 break;
 1841         default:
 1842                 KASSERT(1 == 0, ("Invalid command here: %u (device=%s)",
 1843                     bp->bio_cmd, sc->sc_name));
 1844                 break;
 1845         }
 1846 }
 1847 
 1848 static int
 1849 g_mirror_can_destroy(struct g_mirror_softc *sc)
 1850 {
 1851         struct g_geom *gp;
 1852         struct g_consumer *cp;
 1853 
 1854         g_topology_assert();
 1855         gp = sc->sc_geom;
 1856         if (gp->softc == NULL)
 1857                 return (1);
 1858         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_TASTING) != 0)
 1859                 return (0);
 1860         LIST_FOREACH(cp, &gp->consumer, consumer) {
 1861                 if (g_mirror_is_busy(sc, cp))
 1862                         return (0);
 1863         }
 1864         gp = sc->sc_sync.ds_geom;
 1865         LIST_FOREACH(cp, &gp->consumer, consumer) {
 1866                 if (g_mirror_is_busy(sc, cp))
 1867                         return (0);
 1868         }
 1869         G_MIRROR_DEBUG(2, "No I/O requests for %s, it can be destroyed.",
 1870             sc->sc_name);
 1871         return (1);
 1872 }
 1873 
 1874 static int
 1875 g_mirror_try_destroy(struct g_mirror_softc *sc)
 1876 {
 1877 
 1878         if (sc->sc_rootmount != NULL) {
 1879                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
 1880                     sc->sc_rootmount);
 1881                 root_mount_rel(sc->sc_rootmount);
 1882                 sc->sc_rootmount = NULL;
 1883         }
 1884         g_topology_lock();
 1885         if (!g_mirror_can_destroy(sc)) {
 1886                 g_topology_unlock();
 1887                 return (0);
 1888         }
 1889         sc->sc_geom->softc = NULL;
 1890         sc->sc_sync.ds_geom->softc = NULL;
 1891         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DRAIN) != 0) {
 1892                 g_topology_unlock();
 1893                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
 1894                     &sc->sc_worker);
 1895                 /* Unlock sc_lock here, as it can be destroyed after wakeup. */
 1896                 sx_xunlock(&sc->sc_lock);
 1897                 wakeup(&sc->sc_worker);
 1898                 sc->sc_worker = NULL;
 1899         } else {
 1900                 g_topology_unlock();
 1901                 g_mirror_destroy_device(sc);
 1902         }
 1903         return (1);
 1904 }
 1905 
 1906 /*
 1907  * Worker thread.
 1908  */
 1909 static void
 1910 g_mirror_worker(void *arg)
 1911 {
 1912         struct g_mirror_softc *sc;
 1913         struct g_mirror_event *ep;
 1914         struct bio *bp;
 1915         int timeout;
 1916 
 1917         sc = arg;
 1918         thread_lock(curthread);
 1919         sched_prio(curthread, PRIBIO);
 1920         thread_unlock(curthread);
 1921 
 1922         sx_xlock(&sc->sc_lock);
 1923         for (;;) {
 1924                 G_MIRROR_DEBUG(5, "%s: Let's see...", __func__);
 1925                 /*
 1926                  * First take a look at events.
 1927                  * This is important to handle events before any I/O requests.
 1928                  */
 1929                 ep = g_mirror_event_first(sc);
 1930                 if (ep != NULL) {
 1931                         g_mirror_event_remove(sc, ep);
 1932                         if ((ep->e_flags & G_MIRROR_EVENT_DEVICE) != 0) {
 1933                                 /* Update only device status. */
 1934                                 G_MIRROR_DEBUG(3,
 1935                                     "Running event for device %s.",
 1936                                     sc->sc_name);
 1937                                 ep->e_error = 0;
 1938                                 g_mirror_update_device(sc, true);
 1939                         } else {
 1940                                 /* Update disk status. */
 1941                                 G_MIRROR_DEBUG(3, "Running event for disk %s.",
 1942                                      g_mirror_get_diskname(ep->e_disk));
 1943                                 ep->e_error = g_mirror_update_disk(ep->e_disk,
 1944                                     ep->e_state);
 1945                                 if (ep->e_error == 0)
 1946                                         g_mirror_update_device(sc, false);
 1947                         }
 1948                         if ((ep->e_flags & G_MIRROR_EVENT_DONTWAIT) != 0) {
 1949                                 KASSERT(ep->e_error == 0,
 1950                                     ("Error cannot be handled."));
 1951                                 g_mirror_event_free(ep);
 1952                         } else {
 1953                                 ep->e_flags |= G_MIRROR_EVENT_DONE;
 1954                                 G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__,
 1955                                     ep);
 1956                                 mtx_lock(&sc->sc_events_mtx);
 1957                                 wakeup(ep);
 1958                                 mtx_unlock(&sc->sc_events_mtx);
 1959                         }
 1960                         if ((sc->sc_flags &
 1961                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
 1962                                 if (g_mirror_try_destroy(sc)) {
 1963                                         curthread->td_pflags &= ~TDP_GEOM;
 1964                                         G_MIRROR_DEBUG(1, "Thread exiting.");
 1965                                         kproc_exit(0);
 1966                                 }
 1967                         }
 1968                         G_MIRROR_DEBUG(5, "%s: I'm here 1.", __func__);
 1969                         continue;
 1970                 }
 1971 
 1972                 /*
 1973                  * Check if we can mark array as CLEAN and if we can't take
 1974                  * how much seconds should we wait.
 1975                  */
 1976                 timeout = g_mirror_idle(sc, -1);
 1977 
 1978                 /*
 1979                  * Handle I/O requests.
 1980                  */
 1981                 mtx_lock(&sc->sc_queue_mtx);
 1982                 bp = TAILQ_FIRST(&sc->sc_queue);
 1983                 if (bp != NULL)
 1984                         TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
 1985                 else {
 1986                         if ((sc->sc_flags &
 1987                             G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
 1988                                 mtx_unlock(&sc->sc_queue_mtx);
 1989                                 if (g_mirror_try_destroy(sc)) {
 1990                                         curthread->td_pflags &= ~TDP_GEOM;
 1991                                         G_MIRROR_DEBUG(1, "Thread exiting.");
 1992                                         kproc_exit(0);
 1993                                 }
 1994                                 mtx_lock(&sc->sc_queue_mtx);
 1995                                 if (!TAILQ_EMPTY(&sc->sc_queue)) {
 1996                                         mtx_unlock(&sc->sc_queue_mtx);
 1997                                         continue;
 1998                                 }
 1999                         }
 2000                         if (g_mirror_event_first(sc) != NULL) {
 2001                                 mtx_unlock(&sc->sc_queue_mtx);
 2002                                 continue;
 2003                         }
 2004                         sx_xunlock(&sc->sc_lock);
 2005                         MSLEEP(sc, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:w1",
 2006                             timeout * hz);
 2007                         sx_xlock(&sc->sc_lock);
 2008                         G_MIRROR_DEBUG(5, "%s: I'm here 4.", __func__);
 2009                         continue;
 2010                 }
 2011                 mtx_unlock(&sc->sc_queue_mtx);
 2012 
 2013                 if (bp->bio_from->geom == sc->sc_sync.ds_geom &&
 2014                     (bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0) {
 2015                         /*
 2016                          * Handle completion of the first half (the read) of a
 2017                          * block synchronization operation.
 2018                          */
 2019                         g_mirror_sync_request(sc, bp);
 2020                 } else if (bp->bio_to != sc->sc_provider) {
 2021                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_REGULAR) != 0)
 2022                                 /*
 2023                                  * Handle completion of a regular I/O request.
 2024                                  */
 2025                                 g_mirror_regular_request(sc, bp);
 2026                         else if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
 2027                                 /*
 2028                                  * Handle completion of the second half (the
 2029                                  * write) of a block synchronization operation.
 2030                                  */
 2031                                 g_mirror_sync_request(sc, bp);
 2032                         else {
 2033                                 KASSERT(0,
 2034                                     ("Invalid request cflags=0x%hx to=%s.",
 2035                                     bp->bio_cflags, bp->bio_to->name));
 2036                         }
 2037                 } else {
 2038                         /*
 2039                          * Initiate an I/O request.
 2040                          */
 2041                         g_mirror_register_request(sc, bp);
 2042                 }
 2043                 G_MIRROR_DEBUG(5, "%s: I'm here 9.", __func__);
 2044         }
 2045 }
 2046 
 2047 static void
 2048 g_mirror_update_idle(struct g_mirror_softc *sc, struct g_mirror_disk *disk)
 2049 {
 2050 
 2051         sx_assert(&sc->sc_lock, SX_LOCKED);
 2052 
 2053         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0)
 2054                 return;
 2055         if (!sc->sc_idle && (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0) {
 2056                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as dirty.",
 2057                     g_mirror_get_diskname(disk), sc->sc_name);
 2058                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
 2059         } else if (sc->sc_idle &&
 2060             (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
 2061                 G_MIRROR_DEBUG(2, "Disk %s (device %s) marked as clean.",
 2062                     g_mirror_get_diskname(disk), sc->sc_name);
 2063                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 2064         }
 2065 }
 2066 
 2067 static void
 2068 g_mirror_sync_reinit(const struct g_mirror_disk *disk, struct bio *bp,
 2069     off_t offset)
 2070 {
 2071         void *data;
 2072         int idx;
 2073 
 2074         data = bp->bio_data;
 2075         idx = (int)(uintptr_t)bp->bio_caller1;
 2076         g_reset_bio(bp);
 2077 
 2078         bp->bio_cmd = BIO_READ;
 2079         bp->bio_data = data;
 2080         bp->bio_done = g_mirror_sync_done;
 2081         bp->bio_from = disk->d_sync.ds_consumer;
 2082         bp->bio_to = disk->d_softc->sc_provider;
 2083         bp->bio_caller1 = (void *)(uintptr_t)idx;
 2084         bp->bio_offset = offset;
 2085         bp->bio_length = MIN(maxphys,
 2086             disk->d_softc->sc_mediasize - bp->bio_offset);
 2087 }
 2088 
 2089 static void
 2090 g_mirror_sync_start(struct g_mirror_disk *disk)
 2091 {
 2092         struct g_mirror_softc *sc;
 2093         struct g_mirror_disk_sync *sync;
 2094         struct g_consumer *cp;
 2095         struct bio *bp;
 2096         int error __diagused, i;
 2097 
 2098         g_topology_assert_not();
 2099         sc = disk->d_softc;
 2100         sync = &disk->d_sync;
 2101         sx_assert(&sc->sc_lock, SX_LOCKED);
 2102 
 2103         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
 2104             ("Disk %s is not marked for synchronization.",
 2105             g_mirror_get_diskname(disk)));
 2106         KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
 2107             ("Device not in RUNNING state (%s, %u).", sc->sc_name,
 2108             sc->sc_state));
 2109 
 2110         sx_xunlock(&sc->sc_lock);
 2111         g_topology_lock();
 2112         cp = g_new_consumer(sc->sc_sync.ds_geom);
 2113         cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
 2114         error = g_attach(cp, sc->sc_provider);
 2115         KASSERT(error == 0,
 2116             ("Cannot attach to %s (error=%d).", sc->sc_name, error));
 2117         error = g_access(cp, 1, 0, 0);
 2118         KASSERT(error == 0, ("Cannot open %s (error=%d).", sc->sc_name, error));
 2119         g_topology_unlock();
 2120         sx_xlock(&sc->sc_lock);
 2121 
 2122         G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s.", sc->sc_name,
 2123             g_mirror_get_diskname(disk));
 2124         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) == 0)
 2125                 disk->d_flags |= G_MIRROR_DISK_FLAG_DIRTY;
 2126         KASSERT(sync->ds_consumer == NULL,
 2127             ("Sync consumer already exists (device=%s, disk=%s).",
 2128             sc->sc_name, g_mirror_get_diskname(disk)));
 2129 
 2130         sync->ds_consumer = cp;
 2131         sync->ds_consumer->private = disk;
 2132         sync->ds_consumer->index = 0;
 2133 
 2134         /*
 2135          * Allocate memory for synchronization bios and initialize them.
 2136          */
 2137         sync->ds_bios = malloc(sizeof(struct bio *) * g_mirror_syncreqs,
 2138             M_MIRROR, M_WAITOK);
 2139         for (i = 0; i < g_mirror_syncreqs; i++) {
 2140                 bp = g_alloc_bio();
 2141                 sync->ds_bios[i] = bp;
 2142 
 2143                 bp->bio_data = malloc(maxphys, M_MIRROR, M_WAITOK);
 2144                 bp->bio_caller1 = (void *)(uintptr_t)i;
 2145                 g_mirror_sync_reinit(disk, bp, sync->ds_offset);
 2146                 sync->ds_offset += bp->bio_length;
 2147         }
 2148 
 2149         /* Increase the number of disks in SYNCHRONIZING state. */
 2150         sc->sc_sync.ds_ndisks++;
 2151         /* Set the number of in-flight synchronization requests. */
 2152         sync->ds_inflight = g_mirror_syncreqs;
 2153 
 2154         /*
 2155          * Fire off first synchronization requests.
 2156          */
 2157         for (i = 0; i < g_mirror_syncreqs; i++) {
 2158                 bp = sync->ds_bios[i];
 2159                 G_MIRROR_LOGREQ(3, bp, "Sending synchronization request.");
 2160                 sync->ds_consumer->index++;
 2161                 /*
 2162                  * Delay the request if it is colliding with a regular request.
 2163                  */
 2164                 if (g_mirror_regular_collision(sc, bp))
 2165                         g_mirror_sync_delay(sc, bp);
 2166                 else
 2167                         g_io_request(bp, sync->ds_consumer);
 2168         }
 2169 }
 2170 
 2171 /*
 2172  * Stop synchronization process.
 2173  * type: 0 - synchronization finished
 2174  *       1 - synchronization stopped
 2175  */
 2176 static void
 2177 g_mirror_sync_stop(struct g_mirror_disk *disk, int type)
 2178 {
 2179         struct g_mirror_softc *sc;
 2180         struct g_consumer *cp;
 2181 
 2182         g_topology_assert_not();
 2183         sc = disk->d_softc;
 2184         sx_assert(&sc->sc_lock, SX_LOCKED);
 2185 
 2186         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
 2187             ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
 2188             g_mirror_disk_state2str(disk->d_state)));
 2189         if (disk->d_sync.ds_consumer == NULL)
 2190                 return;
 2191 
 2192         if (type == 0) {
 2193                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s finished.",
 2194                     sc->sc_name, g_mirror_get_diskname(disk));
 2195         } else /* if (type == 1) */ {
 2196                 G_MIRROR_DEBUG(0, "Device %s: rebuilding provider %s stopped.",
 2197                     sc->sc_name, g_mirror_get_diskname(disk));
 2198         }
 2199         g_mirror_regular_release(sc);
 2200         free(disk->d_sync.ds_bios, M_MIRROR);
 2201         disk->d_sync.ds_bios = NULL;
 2202         cp = disk->d_sync.ds_consumer;
 2203         disk->d_sync.ds_consumer = NULL;
 2204         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 2205         sc->sc_sync.ds_ndisks--;
 2206         sx_xunlock(&sc->sc_lock); /* Avoid recursion on sc_lock. */
 2207         g_topology_lock();
 2208         g_mirror_kill_consumer(sc, cp);
 2209         g_topology_unlock();
 2210         sx_xlock(&sc->sc_lock);
 2211 }
 2212 
 2213 static void
 2214 g_mirror_launch_provider(struct g_mirror_softc *sc)
 2215 {
 2216         struct g_mirror_disk *disk;
 2217         struct g_provider *pp, *dp;
 2218 
 2219         sx_assert(&sc->sc_lock, SX_LOCKED);
 2220 
 2221         g_topology_lock();
 2222         pp = g_new_providerf(sc->sc_geom, "mirror/%s", sc->sc_name);
 2223         pp->flags |= G_PF_DIRECT_RECEIVE;
 2224         pp->mediasize = sc->sc_mediasize;
 2225         pp->sectorsize = sc->sc_sectorsize;
 2226         pp->stripesize = 0;
 2227         pp->stripeoffset = 0;
 2228 
 2229         /* Splitting of unmapped BIO's could work but isn't implemented now */
 2230         if (sc->sc_balance != G_MIRROR_BALANCE_SPLIT)
 2231                 pp->flags |= G_PF_ACCEPT_UNMAPPED;
 2232 
 2233         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2234                 if (disk->d_consumer && disk->d_consumer->provider) {
 2235                         dp = disk->d_consumer->provider;
 2236                         if (dp->stripesize > pp->stripesize) {
 2237                                 pp->stripesize = dp->stripesize;
 2238                                 pp->stripeoffset = dp->stripeoffset;
 2239                         }
 2240                         /* A provider underneath us doesn't support unmapped */
 2241                         if ((dp->flags & G_PF_ACCEPT_UNMAPPED) == 0) {
 2242                                 G_MIRROR_DEBUG(0, "Cancelling unmapped "
 2243                                     "because of %s.", dp->name);
 2244                                 pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
 2245                         }
 2246                 }
 2247         }
 2248         pp->private = sc;
 2249         sc->sc_refcnt++;
 2250         sc->sc_provider = pp;
 2251         g_error_provider(pp, 0);
 2252         g_topology_unlock();
 2253         G_MIRROR_DEBUG(0, "Device %s launched (%u/%u).", pp->name,
 2254             g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE), sc->sc_ndisks);
 2255         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2256                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
 2257                         g_mirror_sync_start(disk);
 2258         }
 2259 }
 2260 
 2261 static void
 2262 g_mirror_destroy_provider(struct g_mirror_softc *sc)
 2263 {
 2264         struct g_mirror_disk *disk;
 2265         struct bio *bp;
 2266 
 2267         g_topology_assert_not();
 2268         KASSERT(sc->sc_provider != NULL, ("NULL provider (device=%s).",
 2269             sc->sc_name));
 2270 
 2271         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2272                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
 2273                         g_mirror_sync_stop(disk, 1);
 2274         }
 2275 
 2276         g_topology_lock();
 2277         g_error_provider(sc->sc_provider, ENXIO);
 2278         mtx_lock(&sc->sc_queue_mtx);
 2279         while ((bp = TAILQ_FIRST(&sc->sc_queue)) != NULL) {
 2280                 TAILQ_REMOVE(&sc->sc_queue, bp, bio_queue);
 2281                 /*
 2282                  * Abort any pending I/O that wasn't generated by us.
 2283                  * Synchronization requests and requests destined for individual
 2284                  * mirror components can be destroyed immediately.
 2285                  */
 2286                 if (bp->bio_to == sc->sc_provider &&
 2287                     bp->bio_from->geom != sc->sc_sync.ds_geom) {
 2288                         g_io_deliver(bp, ENXIO);
 2289                 } else {
 2290                         if ((bp->bio_cflags & G_MIRROR_BIO_FLAG_SYNC) != 0)
 2291                                 free(bp->bio_data, M_MIRROR);
 2292                         g_destroy_bio(bp);
 2293                 }
 2294         }
 2295         mtx_unlock(&sc->sc_queue_mtx);
 2296         g_wither_provider(sc->sc_provider, ENXIO);
 2297         sc->sc_provider = NULL;
 2298         G_MIRROR_DEBUG(0, "Device %s: provider destroyed.", sc->sc_name);
 2299         g_topology_unlock();
 2300 }
 2301 
 2302 static void
 2303 g_mirror_go(void *arg)
 2304 {
 2305         struct g_mirror_softc *sc;
 2306         struct g_mirror_event *ep;
 2307 
 2308         sc = arg;
 2309         G_MIRROR_DEBUG(0, "Force device %s start due to timeout.", sc->sc_name);
 2310         ep = sc->sc_timeout_event;
 2311         sc->sc_timeout_event = NULL;
 2312         g_mirror_event_dispatch(ep, sc, 0,
 2313             G_MIRROR_EVENT_DONTWAIT | G_MIRROR_EVENT_DEVICE);
 2314 }
 2315 
 2316 static void
 2317 g_mirror_timeout_drain(struct g_mirror_softc *sc)
 2318 {
 2319         sx_assert(&sc->sc_lock, SX_XLOCKED);
 2320 
 2321         callout_drain(&sc->sc_callout);
 2322         g_mirror_event_free(sc->sc_timeout_event);
 2323         sc->sc_timeout_event = NULL;
 2324 }
 2325 
 2326 static u_int
 2327 g_mirror_determine_state(struct g_mirror_disk *disk)
 2328 {
 2329         struct g_mirror_softc *sc;
 2330         u_int state;
 2331 
 2332         sc = disk->d_softc;
 2333         if (sc->sc_syncid == disk->d_sync.ds_syncid) {
 2334                 if ((disk->d_flags &
 2335                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0 &&
 2336                     (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 ||
 2337                      (disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) == 0)) {
 2338                         /* Disk does not need synchronization. */
 2339                         state = G_MIRROR_DISK_STATE_ACTIVE;
 2340                 } else {
 2341                         if ((sc->sc_flags &
 2342                              G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
 2343                             (disk->d_flags &
 2344                              G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
 2345                                 /*
 2346                                  * We can start synchronization from
 2347                                  * the stored offset.
 2348                                  */
 2349                                 state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
 2350                         } else {
 2351                                 state = G_MIRROR_DISK_STATE_STALE;
 2352                         }
 2353                 }
 2354         } else if (disk->d_sync.ds_syncid < sc->sc_syncid) {
 2355                 /*
 2356                  * Reset all synchronization data for this disk,
 2357                  * because if it even was synchronized, it was
 2358                  * synchronized to disks with different syncid.
 2359                  */
 2360                 disk->d_flags |= G_MIRROR_DISK_FLAG_SYNCHRONIZING;
 2361                 disk->d_sync.ds_offset = 0;
 2362                 disk->d_sync.ds_offset_done = 0;
 2363                 disk->d_sync.ds_syncid = sc->sc_syncid;
 2364                 if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) == 0 ||
 2365                     (disk->d_flags & G_MIRROR_DISK_FLAG_FORCE_SYNC) != 0) {
 2366                         state = G_MIRROR_DISK_STATE_SYNCHRONIZING;
 2367                 } else {
 2368                         state = G_MIRROR_DISK_STATE_STALE;
 2369                 }
 2370         } else /* if (sc->sc_syncid < disk->d_sync.ds_syncid) */ {
 2371                 /*
 2372                  * Not good, NOT GOOD!
 2373                  * It means that mirror was started on stale disks
 2374                  * and more fresh disk just arrive.
 2375                  * If there were writes, mirror is broken, sorry.
 2376                  * I think the best choice here is don't touch
 2377                  * this disk and inform the user loudly.
 2378                  */
 2379                 G_MIRROR_DEBUG(0, "Device %s was started before the freshest "
 2380                     "disk (%s) arrives!! It will not be connected to the "
 2381                     "running device.", sc->sc_name,
 2382                     g_mirror_get_diskname(disk));
 2383                 g_mirror_destroy_disk(disk);
 2384                 state = G_MIRROR_DISK_STATE_NONE;
 2385                 /* Return immediately, because disk was destroyed. */
 2386                 return (state);
 2387         }
 2388         G_MIRROR_DEBUG(3, "State for %s disk: %s.",
 2389             g_mirror_get_diskname(disk), g_mirror_disk_state2str(state));
 2390         return (state);
 2391 }
 2392 
 2393 /*
 2394  * Update device state.
 2395  */
 2396 static void
 2397 g_mirror_update_device(struct g_mirror_softc *sc, bool force)
 2398 {
 2399         struct g_mirror_disk *disk;
 2400         u_int state;
 2401 
 2402         sx_assert(&sc->sc_lock, SX_XLOCKED);
 2403 
 2404         switch (sc->sc_state) {
 2405         case G_MIRROR_DEVICE_STATE_STARTING:
 2406             {
 2407                 struct g_mirror_disk *pdisk, *tdisk;
 2408                 const char *mismatch;
 2409                 uintmax_t found, newest;
 2410                 u_int dirty, ndisks;
 2411 
 2412                 /* Pre-flight checks */
 2413                 LIST_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tdisk) {
 2414                         /*
 2415                          * Confirm we already detected the newest genid.
 2416                          */
 2417                         KASSERT(sc->sc_genid >= disk->d_genid,
 2418                             ("%s: found newer genid %u (sc:%p had %u).", __func__,
 2419                             disk->d_genid, sc, sc->sc_genid));
 2420 
 2421                         /* Kick out any previously tasted stale components. */
 2422                         if (disk->d_genid < sc->sc_genid) {
 2423                                 G_MIRROR_DEBUG(0, "Stale 'genid' field on %s "
 2424                                     "(device %s) (component=%u latest=%u), skipping.",
 2425                                     g_mirror_get_diskname(disk), sc->sc_name,
 2426                                     disk->d_genid, sc->sc_genid);
 2427                                 g_mirror_destroy_disk(disk);
 2428                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 2429                                 continue;
 2430                         }
 2431 
 2432                         /*
 2433                          * Confirm we already detected the newest syncid.
 2434                          */
 2435                         KASSERT(sc->sc_syncid >= disk->d_sync.ds_syncid,
 2436                             ("%s: found newer syncid %u (sc:%p had %u).",
 2437                              __func__, disk->d_sync.ds_syncid, sc,
 2438                              sc->sc_syncid));
 2439 
 2440 #define DETECT_MISMATCH(field, name) \
 2441                         if (mismatch == NULL &&                                 \
 2442                             disk->d_init_ ## field != sc->sc_ ## field) {       \
 2443                                 mismatch = name;                                \
 2444                                 found = (intmax_t)disk->d_init_ ## field;       \
 2445                                 newest = (intmax_t)sc->sc_ ## field;            \
 2446                         }
 2447                         mismatch = NULL;
 2448                         DETECT_MISMATCH(ndisks, "md_all");
 2449                         DETECT_MISMATCH(balance, "md_balance");
 2450                         DETECT_MISMATCH(slice, "md_slice");
 2451                         DETECT_MISMATCH(mediasize, "md_mediasize");
 2452 #undef DETECT_MISMATCH
 2453                         if (mismatch != NULL) {
 2454                                 G_MIRROR_DEBUG(0, "Found a mismatching '%s' "
 2455                                     "field on %s (device %s) (found=%ju "
 2456                                     "newest=%ju).", mismatch,
 2457                                     g_mirror_get_diskname(disk), sc->sc_name,
 2458                                     found, newest);
 2459                                 g_mirror_destroy_disk(disk);
 2460                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 2461                                 continue;
 2462                         }
 2463                 }
 2464 
 2465                 KASSERT(sc->sc_provider == NULL,
 2466                     ("Non-NULL provider in STARTING state (%s).", sc->sc_name));
 2467                 /*
 2468                  * Are we ready? If the timeout (force is true) has expired, and
 2469                  * any disks are present, then yes. If we're permitted to launch
 2470                  * before the timeout has expired and the expected number of
 2471                  * current-generation mirror disks have been tasted, then yes.
 2472                  */
 2473                 ndisks = g_mirror_ndisks(sc, -1);
 2474                 if ((force && ndisks > 0) ||
 2475                     (g_launch_mirror_before_timeout && ndisks == sc->sc_ndisks)) {
 2476                         ;
 2477                 } else if (ndisks == 0) {
 2478                         /*
 2479                          * Disks went down in starting phase, so destroy
 2480                          * device.
 2481                          */
 2482                         g_mirror_timeout_drain(sc);
 2483                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
 2484                         G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p", __LINE__,
 2485                             sc->sc_rootmount);
 2486                         root_mount_rel(sc->sc_rootmount);
 2487                         sc->sc_rootmount = NULL;
 2488                         return;
 2489                 } else {
 2490                         return;
 2491                 }
 2492 
 2493                 /*
 2494                  * Activate all disks with the biggest syncid.
 2495                  */
 2496                 if (force) {
 2497                         /*
 2498                          * If 'force' is true, we have been called due to
 2499                          * timeout, so don't bother canceling timeout.
 2500                          */
 2501                         ndisks = 0;
 2502                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2503                                 if ((disk->d_flags &
 2504                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) == 0) {
 2505                                         ndisks++;
 2506                                 }
 2507                         }
 2508                         if (ndisks == 0) {
 2509                                 /* No valid disks found, destroy device. */
 2510                                 sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
 2511                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
 2512                                     __LINE__, sc->sc_rootmount);
 2513                                 root_mount_rel(sc->sc_rootmount);
 2514                                 sc->sc_rootmount = NULL;
 2515                                 return;
 2516                         }
 2517                 } else {
 2518                         /* Cancel timeout. */
 2519                         g_mirror_timeout_drain(sc);
 2520                 }
 2521 
 2522                 /*
 2523                  * Here we need to look for dirty disks and if all disks
 2524                  * with the biggest syncid are dirty, we have to choose
 2525                  * one with the biggest priority and rebuild the rest.
 2526                  */
 2527                 /*
 2528                  * Find the number of dirty disks with the biggest syncid.
 2529                  * Find the number of disks with the biggest syncid.
 2530                  * While here, find a disk with the biggest priority.
 2531                  */
 2532                 dirty = ndisks = 0;
 2533                 pdisk = NULL;
 2534                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2535                         if (disk->d_sync.ds_syncid != sc->sc_syncid)
 2536                                 continue;
 2537                         if ((disk->d_flags &
 2538                             G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
 2539                                 continue;
 2540                         }
 2541                         ndisks++;
 2542                         if ((disk->d_flags & G_MIRROR_DISK_FLAG_DIRTY) != 0) {
 2543                                 dirty++;
 2544                                 if (pdisk == NULL ||
 2545                                     pdisk->d_priority < disk->d_priority) {
 2546                                         pdisk = disk;
 2547                                 }
 2548                         }
 2549                 }
 2550                 if (dirty == 0) {
 2551                         /* No dirty disks at all, great. */
 2552                 } else if (dirty == ndisks) {
 2553                         /*
 2554                          * Force synchronization for all dirty disks except one
 2555                          * with the biggest priority.
 2556                          */
 2557                         KASSERT(pdisk != NULL, ("pdisk == NULL"));
 2558                         G_MIRROR_DEBUG(1, "Using disk %s (device %s) as a "
 2559                             "master disk for synchronization.",
 2560                             g_mirror_get_diskname(pdisk), sc->sc_name);
 2561                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2562                                 if (disk->d_sync.ds_syncid != sc->sc_syncid)
 2563                                         continue;
 2564                                 if ((disk->d_flags &
 2565                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
 2566                                         continue;
 2567                                 }
 2568                                 KASSERT((disk->d_flags &
 2569                                     G_MIRROR_DISK_FLAG_DIRTY) != 0,
 2570                                     ("Disk %s isn't marked as dirty.",
 2571                                     g_mirror_get_diskname(disk)));
 2572                                 /* Skip the disk with the biggest priority. */
 2573                                 if (disk == pdisk)
 2574                                         continue;
 2575                                 disk->d_sync.ds_syncid = 0;
 2576                         }
 2577                 } else if (dirty < ndisks) {
 2578                         /*
 2579                          * Force synchronization for all dirty disks.
 2580                          * We have some non-dirty disks.
 2581                          */
 2582                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2583                                 if (disk->d_sync.ds_syncid != sc->sc_syncid)
 2584                                         continue;
 2585                                 if ((disk->d_flags &
 2586                                     G_MIRROR_DISK_FLAG_SYNCHRONIZING) != 0) {
 2587                                         continue;
 2588                                 }
 2589                                 if ((disk->d_flags &
 2590                                     G_MIRROR_DISK_FLAG_DIRTY) == 0) {
 2591                                         continue;
 2592                                 }
 2593                                 disk->d_sync.ds_syncid = 0;
 2594                         }
 2595                 }
 2596 
 2597                 /* Reset hint. */
 2598                 sc->sc_hint = NULL;
 2599                 if (force) {
 2600                         /* Remember to bump syncid on first write. */
 2601                         sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 2602                 }
 2603                 state = G_MIRROR_DEVICE_STATE_RUNNING;
 2604                 G_MIRROR_DEBUG(1, "Device %s state changed from %s to %s.",
 2605                     sc->sc_name, g_mirror_device_state2str(sc->sc_state),
 2606                     g_mirror_device_state2str(state));
 2607                 sc->sc_state = state;
 2608                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2609                         state = g_mirror_determine_state(disk);
 2610                         g_mirror_event_send(disk, state,
 2611                             G_MIRROR_EVENT_DONTWAIT);
 2612                         if (state == G_MIRROR_DISK_STATE_STALE)
 2613                                 sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
 2614                 }
 2615                 break;
 2616             }
 2617         case G_MIRROR_DEVICE_STATE_RUNNING:
 2618                 if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 0 &&
 2619                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
 2620                         /*
 2621                          * No usable disks, so destroy the device.
 2622                          */
 2623                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
 2624                         break;
 2625                 } else if (g_mirror_ndisks(sc,
 2626                     G_MIRROR_DISK_STATE_ACTIVE) > 0 &&
 2627                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_NEW) == 0) {
 2628                         /*
 2629                          * We have active disks, launch provider if it doesn't
 2630                          * exist.
 2631                          */
 2632                         if (sc->sc_provider == NULL)
 2633                                 g_mirror_launch_provider(sc);
 2634                         if (sc->sc_rootmount != NULL) {
 2635                                 G_MIRROR_DEBUG(1, "root_mount_rel[%u] %p",
 2636                                     __LINE__, sc->sc_rootmount);
 2637                                 root_mount_rel(sc->sc_rootmount);
 2638                                 sc->sc_rootmount = NULL;
 2639                         }
 2640                 }
 2641                 /*
 2642                  * Genid should be bumped immediately, so do it here.
 2643                  */
 2644                 if ((sc->sc_bump_id & G_MIRROR_BUMP_GENID) != 0) {
 2645                         sc->sc_bump_id &= ~G_MIRROR_BUMP_GENID;
 2646                         g_mirror_bump_genid(sc);
 2647                 }
 2648                 if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID_NOW) != 0) {
 2649                         sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID_NOW;
 2650                         g_mirror_bump_syncid(sc);
 2651                 }
 2652                 break;
 2653         default:
 2654                 KASSERT(1 == 0, ("Wrong device state (%s, %s).",
 2655                     sc->sc_name, g_mirror_device_state2str(sc->sc_state)));
 2656                 break;
 2657         }
 2658 }
 2659 
 2660 /*
 2661  * Update disk state and device state if needed.
 2662  */
 2663 #define DISK_STATE_CHANGED()    G_MIRROR_DEBUG(1,                       \
 2664         "Disk %s state changed from %s to %s (device %s).",             \
 2665         g_mirror_get_diskname(disk),                                    \
 2666         g_mirror_disk_state2str(disk->d_state),                         \
 2667         g_mirror_disk_state2str(state), sc->sc_name)
 2668 static int
 2669 g_mirror_update_disk(struct g_mirror_disk *disk, u_int state)
 2670 {
 2671         struct g_mirror_softc *sc;
 2672 
 2673         sc = disk->d_softc;
 2674         sx_assert(&sc->sc_lock, SX_XLOCKED);
 2675 
 2676 again:
 2677         G_MIRROR_DEBUG(3, "Changing disk %s state from %s to %s.",
 2678             g_mirror_get_diskname(disk), g_mirror_disk_state2str(disk->d_state),
 2679             g_mirror_disk_state2str(state));
 2680         switch (state) {
 2681         case G_MIRROR_DISK_STATE_NEW:
 2682                 /*
 2683                  * Possible scenarios:
 2684                  * 1. New disk arrive.
 2685                  */
 2686                 /* Previous state should be NONE. */
 2687                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NONE,
 2688                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
 2689                     g_mirror_disk_state2str(disk->d_state)));
 2690                 DISK_STATE_CHANGED();
 2691 
 2692                 disk->d_state = state;
 2693                 g_topology_lock();
 2694                 if (LIST_EMPTY(&sc->sc_disks))
 2695                         LIST_INSERT_HEAD(&sc->sc_disks, disk, d_next);
 2696                 else {
 2697                         struct g_mirror_disk *dp;
 2698 
 2699                         LIST_FOREACH(dp, &sc->sc_disks, d_next) {
 2700                                 if (disk->d_priority >= dp->d_priority) {
 2701                                         LIST_INSERT_BEFORE(dp, disk, d_next);
 2702                                         dp = NULL;
 2703                                         break;
 2704                                 }
 2705                                 if (LIST_NEXT(dp, d_next) == NULL)
 2706                                         break;
 2707                         }
 2708                         if (dp != NULL)
 2709                                 LIST_INSERT_AFTER(dp, disk, d_next);
 2710                 }
 2711                 g_topology_unlock();
 2712                 G_MIRROR_DEBUG(1, "Device %s: provider %s detected.",
 2713                     sc->sc_name, g_mirror_get_diskname(disk));
 2714                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
 2715                         break;
 2716                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
 2717                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
 2718                     g_mirror_device_state2str(sc->sc_state),
 2719                     g_mirror_get_diskname(disk),
 2720                     g_mirror_disk_state2str(disk->d_state)));
 2721                 state = g_mirror_determine_state(disk);
 2722                 if (state != G_MIRROR_DISK_STATE_NONE)
 2723                         goto again;
 2724                 break;
 2725         case G_MIRROR_DISK_STATE_ACTIVE:
 2726                 /*
 2727                  * Possible scenarios:
 2728                  * 1. New disk does not need synchronization.
 2729                  * 2. Synchronization process finished successfully.
 2730                  */
 2731                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
 2732                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
 2733                     g_mirror_device_state2str(sc->sc_state),
 2734                     g_mirror_get_diskname(disk),
 2735                     g_mirror_disk_state2str(disk->d_state)));
 2736                 /* Previous state should be NEW or SYNCHRONIZING. */
 2737                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW ||
 2738                     disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
 2739                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
 2740                     g_mirror_disk_state2str(disk->d_state)));
 2741                 DISK_STATE_CHANGED();
 2742 
 2743                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 2744                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_SYNCHRONIZING;
 2745                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
 2746                         g_mirror_sync_stop(disk, 0);
 2747                 }
 2748                 disk->d_state = state;
 2749                 disk->d_sync.ds_offset = 0;
 2750                 disk->d_sync.ds_offset_done = 0;
 2751                 g_mirror_update_idle(sc, disk);
 2752                 g_mirror_update_metadata(disk);
 2753                 G_MIRROR_DEBUG(1, "Device %s: provider %s activated.",
 2754                     sc->sc_name, g_mirror_get_diskname(disk));
 2755                 break;
 2756         case G_MIRROR_DISK_STATE_STALE:
 2757                 /*
 2758                  * Possible scenarios:
 2759                  * 1. Stale disk was connected.
 2760                  */
 2761                 /* Previous state should be NEW. */
 2762                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
 2763                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
 2764                     g_mirror_disk_state2str(disk->d_state)));
 2765                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
 2766                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
 2767                     g_mirror_device_state2str(sc->sc_state),
 2768                     g_mirror_get_diskname(disk),
 2769                     g_mirror_disk_state2str(disk->d_state)));
 2770                 /*
 2771                  * STALE state is only possible if device is marked
 2772                  * NOAUTOSYNC.
 2773                  */
 2774                 KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0,
 2775                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
 2776                     g_mirror_device_state2str(sc->sc_state),
 2777                     g_mirror_get_diskname(disk),
 2778                     g_mirror_disk_state2str(disk->d_state)));
 2779                 DISK_STATE_CHANGED();
 2780 
 2781                 disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 2782                 disk->d_state = state;
 2783                 g_mirror_update_metadata(disk);
 2784                 G_MIRROR_DEBUG(0, "Device %s: provider %s is stale.",
 2785                     sc->sc_name, g_mirror_get_diskname(disk));
 2786                 break;
 2787         case G_MIRROR_DISK_STATE_SYNCHRONIZING:
 2788                 /*
 2789                  * Possible scenarios:
 2790                  * 1. Disk which needs synchronization was connected.
 2791                  */
 2792                 /* Previous state should be NEW. */
 2793                 KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
 2794                     ("Wrong disk state (%s, %s).", g_mirror_get_diskname(disk),
 2795                     g_mirror_disk_state2str(disk->d_state)));
 2796                 KASSERT(sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING,
 2797                     ("Wrong device state (%s, %s, %s, %s).", sc->sc_name,
 2798                     g_mirror_device_state2str(sc->sc_state),
 2799                     g_mirror_get_diskname(disk),
 2800                     g_mirror_disk_state2str(disk->d_state)));
 2801                 DISK_STATE_CHANGED();
 2802 
 2803                 if (disk->d_state == G_MIRROR_DISK_STATE_NEW)
 2804                         disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
 2805                 disk->d_state = state;
 2806                 if (sc->sc_provider != NULL) {
 2807                         g_mirror_sync_start(disk);
 2808                         g_mirror_update_metadata(disk);
 2809                 }
 2810                 break;
 2811         case G_MIRROR_DISK_STATE_DISCONNECTED:
 2812                 /*
 2813                  * Possible scenarios:
 2814                  * 1. Device wasn't running yet, but disk disappear.
 2815                  * 2. Disk was active and disapppear.
 2816                  * 3. Disk disappear during synchronization process.
 2817                  */
 2818                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_RUNNING) {
 2819                         /*
 2820                          * Previous state should be ACTIVE, STALE or
 2821                          * SYNCHRONIZING.
 2822                          */
 2823                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_ACTIVE ||
 2824                             disk->d_state == G_MIRROR_DISK_STATE_STALE ||
 2825                             disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING,
 2826                             ("Wrong disk state (%s, %s).",
 2827                             g_mirror_get_diskname(disk),
 2828                             g_mirror_disk_state2str(disk->d_state)));
 2829                 } else if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING) {
 2830                         /* Previous state should be NEW. */
 2831                         KASSERT(disk->d_state == G_MIRROR_DISK_STATE_NEW,
 2832                             ("Wrong disk state (%s, %s).",
 2833                             g_mirror_get_diskname(disk),
 2834                             g_mirror_disk_state2str(disk->d_state)));
 2835                         /*
 2836                          * Reset bumping syncid if disk disappeared in STARTING
 2837                          * state.
 2838                          */
 2839                         if ((sc->sc_bump_id & G_MIRROR_BUMP_SYNCID) != 0)
 2840                                 sc->sc_bump_id &= ~G_MIRROR_BUMP_SYNCID;
 2841 #ifdef  INVARIANTS
 2842                 } else {
 2843                         KASSERT(1 == 0, ("Wrong device state (%s, %s, %s, %s).",
 2844                             sc->sc_name,
 2845                             g_mirror_device_state2str(sc->sc_state),
 2846                             g_mirror_get_diskname(disk),
 2847                             g_mirror_disk_state2str(disk->d_state)));
 2848 #endif
 2849                 }
 2850                 DISK_STATE_CHANGED();
 2851                 G_MIRROR_DEBUG(0, "Device %s: provider %s disconnected.",
 2852                     sc->sc_name, g_mirror_get_diskname(disk));
 2853 
 2854                 g_mirror_destroy_disk(disk);
 2855                 break;
 2856         case G_MIRROR_DISK_STATE_DESTROY:
 2857             {
 2858                 int error;
 2859 
 2860                 error = g_mirror_clear_metadata(disk);
 2861                 if (error != 0) {
 2862                         G_MIRROR_DEBUG(0,
 2863                             "Device %s: failed to clear metadata on %s: %d.",
 2864                             sc->sc_name, g_mirror_get_diskname(disk), error);
 2865                         break;
 2866                 }
 2867                 DISK_STATE_CHANGED();
 2868                 G_MIRROR_DEBUG(0, "Device %s: provider %s destroyed.",
 2869                     sc->sc_name, g_mirror_get_diskname(disk));
 2870 
 2871                 g_mirror_destroy_disk(disk);
 2872                 sc->sc_ndisks--;
 2873                 LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 2874                         g_mirror_update_metadata(disk);
 2875                 }
 2876                 break;
 2877             }
 2878         default:
 2879                 KASSERT(1 == 0, ("Unknown state (%u).", state));
 2880                 break;
 2881         }
 2882         return (0);
 2883 }
 2884 #undef  DISK_STATE_CHANGED
 2885 
 2886 int
 2887 g_mirror_read_metadata(struct g_consumer *cp, struct g_mirror_metadata *md)
 2888 {
 2889         struct g_provider *pp;
 2890         u_char *buf;
 2891         int error;
 2892 
 2893         g_topology_assert();
 2894 
 2895         error = g_access(cp, 1, 0, 0);
 2896         if (error != 0)
 2897                 return (error);
 2898         pp = cp->provider;
 2899         g_topology_unlock();
 2900         /* Metadata are stored on last sector. */
 2901         buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
 2902             &error);
 2903         g_topology_lock();
 2904         g_access(cp, -1, 0, 0);
 2905         if (buf == NULL) {
 2906                 G_MIRROR_DEBUG(1, "Cannot read metadata from %s (error=%d).",
 2907                     cp->provider->name, error);
 2908                 return (error);
 2909         }
 2910 
 2911         /* Decode metadata. */
 2912         error = mirror_metadata_decode(buf, md);
 2913         g_free(buf);
 2914         if (strcmp(md->md_magic, G_MIRROR_MAGIC) != 0)
 2915                 return (EINVAL);
 2916         if (md->md_version > G_MIRROR_VERSION) {
 2917                 G_MIRROR_DEBUG(0,
 2918                     "Kernel module is too old to handle metadata from %s.",
 2919                     cp->provider->name);
 2920                 return (EINVAL);
 2921         }
 2922         if (error != 0) {
 2923                 G_MIRROR_DEBUG(1, "MD5 metadata hash mismatch for provider %s.",
 2924                     cp->provider->name);
 2925                 return (error);
 2926         }
 2927 
 2928         return (0);
 2929 }
 2930 
 2931 static int
 2932 g_mirror_check_metadata(struct g_mirror_softc *sc, struct g_provider *pp,
 2933     struct g_mirror_metadata *md)
 2934 {
 2935 
 2936         G_MIRROR_DEBUG(2, "%s: md_did 0x%u disk %s device %s md_all 0x%x "
 2937             "sc_ndisks 0x%x md_slice 0x%x sc_slice 0x%x md_balance 0x%x "
 2938             "sc_balance 0x%x sc_mediasize 0x%jx pp_mediasize 0x%jx "
 2939             "md_sectorsize 0x%x sc_sectorsize 0x%x md_mflags 0x%jx "
 2940             "md_dflags 0x%jx md_syncid 0x%x md_genid 0x%x md_priority 0x%x "
 2941             "sc_state 0x%x.",
 2942             __func__, md->md_did, pp->name, sc->sc_name, md->md_all,
 2943             sc->sc_ndisks, md->md_slice, sc->sc_slice, md->md_balance,
 2944             sc->sc_balance, (uintmax_t)sc->sc_mediasize,
 2945             (uintmax_t)pp->mediasize, md->md_sectorsize, sc->sc_sectorsize,
 2946             (uintmax_t)md->md_mflags, (uintmax_t)md->md_dflags, md->md_syncid,
 2947             md->md_genid, md->md_priority, sc->sc_state);
 2948 
 2949         if (g_mirror_id2disk(sc, md->md_did) != NULL) {
 2950                 G_MIRROR_DEBUG(1, "Disk %s (id=%u) already exists, skipping.",
 2951                     pp->name, md->md_did);
 2952                 return (EEXIST);
 2953         }
 2954         if (sc->sc_mediasize > pp->mediasize) {
 2955                 G_MIRROR_DEBUG(1,
 2956                     "Invalid size of disk %s (device %s), skipping.", pp->name,
 2957                     sc->sc_name);
 2958                 return (EINVAL);
 2959         }
 2960         if (md->md_sectorsize != sc->sc_sectorsize) {
 2961                 G_MIRROR_DEBUG(1,
 2962                     "Invalid '%s' field on disk %s (device %s), skipping.",
 2963                     "md_sectorsize", pp->name, sc->sc_name);
 2964                 return (EINVAL);
 2965         }
 2966         if ((sc->sc_sectorsize % pp->sectorsize) != 0) {
 2967                 G_MIRROR_DEBUG(1,
 2968                     "Invalid sector size of disk %s (device %s), skipping.",
 2969                     pp->name, sc->sc_name);
 2970                 return (EINVAL);
 2971         }
 2972         if ((md->md_mflags & ~G_MIRROR_DEVICE_FLAG_MASK) != 0) {
 2973                 G_MIRROR_DEBUG(1,
 2974                     "Invalid device flags on disk %s (device %s), skipping.",
 2975                     pp->name, sc->sc_name);
 2976                 return (EINVAL);
 2977         }
 2978         if ((md->md_dflags & ~G_MIRROR_DISK_FLAG_MASK) != 0) {
 2979                 G_MIRROR_DEBUG(1,
 2980                     "Invalid disk flags on disk %s (device %s), skipping.",
 2981                     pp->name, sc->sc_name);
 2982                 return (EINVAL);
 2983         }
 2984         return (0);
 2985 }
 2986 
 2987 int
 2988 g_mirror_add_disk(struct g_mirror_softc *sc, struct g_provider *pp,
 2989     struct g_mirror_metadata *md)
 2990 {
 2991         struct g_mirror_disk *disk;
 2992         int error;
 2993 
 2994         g_topology_assert_not();
 2995         G_MIRROR_DEBUG(2, "Adding disk %s.", pp->name);
 2996 
 2997         error = g_mirror_check_metadata(sc, pp, md);
 2998         if (error != 0)
 2999                 return (error);
 3000 
 3001         if (md->md_genid < sc->sc_genid) {
 3002                 G_MIRROR_DEBUG(0, "Component %s (device %s) broken, skipping.",
 3003                     pp->name, sc->sc_name);
 3004                 return (EINVAL);
 3005         }
 3006 
 3007         /*
 3008          * If the component disk we're tasting has newer metadata than the
 3009          * STARTING gmirror device, refresh the device from the component.
 3010          */
 3011         error = g_mirror_refresh_device(sc, pp, md);
 3012         if (error != 0)
 3013                 return (error);
 3014 
 3015         disk = g_mirror_init_disk(sc, pp, md, &error);
 3016         if (disk == NULL)
 3017                 return (error);
 3018         error = g_mirror_event_send(disk, G_MIRROR_DISK_STATE_NEW,
 3019             G_MIRROR_EVENT_WAIT);
 3020         if (error != 0)
 3021                 return (error);
 3022         if (md->md_version < G_MIRROR_VERSION) {
 3023                 G_MIRROR_DEBUG(0, "Upgrading metadata on %s (v%d->v%d).",
 3024                     pp->name, md->md_version, G_MIRROR_VERSION);
 3025                 g_mirror_update_metadata(disk);
 3026         }
 3027         return (0);
 3028 }
 3029 
 3030 static void
 3031 g_mirror_destroy_delayed(void *arg, int flag)
 3032 {
 3033         struct g_mirror_softc *sc;
 3034         int error;
 3035 
 3036         if (flag == EV_CANCEL) {
 3037                 G_MIRROR_DEBUG(1, "Destroying canceled.");
 3038                 return;
 3039         }
 3040         sc = arg;
 3041         g_topology_unlock();
 3042         sx_xlock(&sc->sc_lock);
 3043         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) == 0,
 3044             ("DESTROY flag set on %s.", sc->sc_name));
 3045         KASSERT((sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0,
 3046             ("CLOSEWAIT flag not set on %s.", sc->sc_name));
 3047         G_MIRROR_DEBUG(1, "Destroying %s (delayed).", sc->sc_name);
 3048         error = g_mirror_destroy(sc, G_MIRROR_DESTROY_SOFT);
 3049         if (error != 0) {
 3050                 G_MIRROR_DEBUG(0, "Cannot destroy %s (error=%d).",
 3051                     sc->sc_name, error);
 3052                 sx_xunlock(&sc->sc_lock);
 3053         }
 3054         g_topology_lock();
 3055 }
 3056 
 3057 static int
 3058 g_mirror_access(struct g_provider *pp, int acr, int acw, int ace)
 3059 {
 3060         struct g_mirror_softc *sc;
 3061         int error = 0;
 3062 
 3063         g_topology_assert();
 3064         G_MIRROR_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
 3065             acw, ace);
 3066 
 3067         sc = pp->private;
 3068         KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
 3069 
 3070         g_topology_unlock();
 3071         sx_xlock(&sc->sc_lock);
 3072         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0 ||
 3073             (sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0 ||
 3074             LIST_EMPTY(&sc->sc_disks)) {
 3075                 if (acr > 0 || acw > 0 || ace > 0)
 3076                         error = ENXIO;
 3077                 goto end;
 3078         }
 3079         sc->sc_provider_open += acr + acw + ace;
 3080         if (pp->acw + acw == 0)
 3081                 g_mirror_idle(sc, 0);
 3082         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_CLOSEWAIT) != 0 &&
 3083             sc->sc_provider_open == 0)
 3084                 g_post_event(g_mirror_destroy_delayed, sc, M_WAITOK, sc, NULL);
 3085 end:
 3086         sx_xunlock(&sc->sc_lock);
 3087         g_topology_lock();
 3088         return (error);
 3089 }
 3090 
 3091 static void
 3092 g_mirror_reinit_from_metadata(struct g_mirror_softc *sc,
 3093     const struct g_mirror_metadata *md)
 3094 {
 3095 
 3096         sc->sc_genid = md->md_genid;
 3097         sc->sc_syncid = md->md_syncid;
 3098 
 3099         sc->sc_slice = md->md_slice;
 3100         sc->sc_balance = md->md_balance;
 3101         sc->sc_mediasize = md->md_mediasize;
 3102         sc->sc_ndisks = md->md_all;
 3103         sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_MASK;
 3104         sc->sc_flags |= (md->md_mflags & G_MIRROR_DEVICE_FLAG_MASK);
 3105 }
 3106 
 3107 struct g_geom *
 3108 g_mirror_create(struct g_class *mp, const struct g_mirror_metadata *md,
 3109     u_int type)
 3110 {
 3111         struct g_mirror_softc *sc;
 3112         struct g_geom *gp;
 3113         int error, timeout;
 3114 
 3115         g_topology_assert();
 3116         G_MIRROR_DEBUG(1, "Creating device %s (id=%u).", md->md_name,
 3117             md->md_mid);
 3118 
 3119         /* One disk is minimum. */
 3120         if (md->md_all < 1)
 3121                 return (NULL);
 3122         /*
 3123          * Action geom.
 3124          */
 3125         gp = g_new_geomf(mp, "%s", md->md_name);
 3126         sc = malloc(sizeof(*sc), M_MIRROR, M_WAITOK | M_ZERO);
 3127         gp->start = g_mirror_start;
 3128         gp->orphan = g_mirror_orphan;
 3129         gp->access = g_mirror_access;
 3130         gp->dumpconf = g_mirror_dumpconf;
 3131 
 3132         sc->sc_type = type;
 3133         sc->sc_id = md->md_mid;
 3134         g_mirror_reinit_from_metadata(sc, md);
 3135         sc->sc_sectorsize = md->md_sectorsize;
 3136         sc->sc_bump_id = 0;
 3137         sc->sc_idle = 1;
 3138         sc->sc_last_write = time_uptime;
 3139         sc->sc_writes = 0;
 3140         sc->sc_refcnt = 1;
 3141         sx_init(&sc->sc_lock, "gmirror:lock");
 3142         TAILQ_INIT(&sc->sc_queue);
 3143         mtx_init(&sc->sc_queue_mtx, "gmirror:queue", NULL, MTX_DEF);
 3144         TAILQ_INIT(&sc->sc_regular_delayed);
 3145         TAILQ_INIT(&sc->sc_inflight);
 3146         TAILQ_INIT(&sc->sc_sync_delayed);
 3147         LIST_INIT(&sc->sc_disks);
 3148         TAILQ_INIT(&sc->sc_events);
 3149         mtx_init(&sc->sc_events_mtx, "gmirror:events", NULL, MTX_DEF);
 3150         callout_init(&sc->sc_callout, 1);
 3151         mtx_init(&sc->sc_done_mtx, "gmirror:done", NULL, MTX_DEF);
 3152         sc->sc_state = G_MIRROR_DEVICE_STATE_STARTING;
 3153         gp->softc = sc;
 3154         sc->sc_geom = gp;
 3155         sc->sc_provider = NULL;
 3156         sc->sc_provider_open = 0;
 3157         /*
 3158          * Synchronization geom.
 3159          */
 3160         gp = g_new_geomf(mp, "%s.sync", md->md_name);
 3161         gp->softc = sc;
 3162         gp->orphan = g_mirror_orphan;
 3163         sc->sc_sync.ds_geom = gp;
 3164         sc->sc_sync.ds_ndisks = 0;
 3165         error = kproc_create(g_mirror_worker, sc, &sc->sc_worker, 0, 0,
 3166             "g_mirror %s", md->md_name);
 3167         if (error != 0) {
 3168                 G_MIRROR_DEBUG(1, "Cannot create kernel thread for %s.",
 3169                     sc->sc_name);
 3170                 g_destroy_geom(sc->sc_sync.ds_geom);
 3171                 g_destroy_geom(sc->sc_geom);
 3172                 g_mirror_free_device(sc);
 3173                 return (NULL);
 3174         }
 3175 
 3176         G_MIRROR_DEBUG(1, "Device %s created (%u components, id=%u).",
 3177             sc->sc_name, sc->sc_ndisks, sc->sc_id);
 3178 
 3179         sc->sc_rootmount = root_mount_hold("GMIRROR");
 3180         G_MIRROR_DEBUG(1, "root_mount_hold %p", sc->sc_rootmount);
 3181 
 3182         /*
 3183          * Schedule startup timeout.
 3184          */
 3185         timeout = g_mirror_timeout * hz;
 3186         sc->sc_timeout_event = malloc(sizeof(struct g_mirror_event), M_MIRROR,
 3187             M_WAITOK);
 3188         callout_reset(&sc->sc_callout, timeout, g_mirror_go, sc);
 3189         return (sc->sc_geom);
 3190 }
 3191 
 3192 int
 3193 g_mirror_destroy(struct g_mirror_softc *sc, int how)
 3194 {
 3195         struct g_mirror_disk *disk;
 3196 
 3197         g_topology_assert_not();
 3198         sx_assert(&sc->sc_lock, SX_XLOCKED);
 3199 
 3200         if (sc->sc_provider_open != 0) {
 3201                 switch (how) {
 3202                 case G_MIRROR_DESTROY_SOFT:
 3203                         G_MIRROR_DEBUG(1,
 3204                             "Device %s is still open (%d).", sc->sc_name,
 3205                             sc->sc_provider_open);
 3206                         return (EBUSY);
 3207                 case G_MIRROR_DESTROY_DELAYED:
 3208                         G_MIRROR_DEBUG(1,
 3209                             "Device %s will be destroyed on last close.",
 3210                             sc->sc_name);
 3211                         LIST_FOREACH(disk, &sc->sc_disks, d_next) {
 3212                                 if (disk->d_state ==
 3213                                     G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 3214                                         g_mirror_sync_stop(disk, 1);
 3215                                 }
 3216                         }
 3217                         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_CLOSEWAIT;
 3218                         return (EBUSY);
 3219                 case G_MIRROR_DESTROY_HARD:
 3220                         G_MIRROR_DEBUG(1, "Device %s is still open, so it "
 3221                             "can't be definitely removed.", sc->sc_name);
 3222                 }
 3223         }
 3224 
 3225         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
 3226                 sx_xunlock(&sc->sc_lock);
 3227                 return (0);
 3228         }
 3229         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DESTROY;
 3230         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_DRAIN;
 3231         G_MIRROR_DEBUG(4, "%s: Waking up %p.", __func__, sc);
 3232         sx_xunlock(&sc->sc_lock);
 3233         mtx_lock(&sc->sc_queue_mtx);
 3234         wakeup(sc);
 3235         mtx_unlock(&sc->sc_queue_mtx);
 3236         G_MIRROR_DEBUG(4, "%s: Sleeping %p.", __func__, &sc->sc_worker);
 3237         while (sc->sc_worker != NULL)
 3238                 tsleep(&sc->sc_worker, PRIBIO, "m:destroy", hz / 5);
 3239         G_MIRROR_DEBUG(4, "%s: Woken up %p.", __func__, &sc->sc_worker);
 3240         sx_xlock(&sc->sc_lock);
 3241         g_mirror_destroy_device(sc);
 3242         return (0);
 3243 }
 3244 
 3245 static void
 3246 g_mirror_taste_orphan(struct g_consumer *cp)
 3247 {
 3248 
 3249         KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
 3250             cp->provider->name));
 3251 }
 3252 
 3253 static struct g_geom *
 3254 g_mirror_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
 3255 {
 3256         struct g_mirror_metadata md;
 3257         struct g_mirror_softc *sc;
 3258         struct g_consumer *cp;
 3259         struct g_geom *gp;
 3260         int error;
 3261 
 3262         g_topology_assert();
 3263         g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
 3264         G_MIRROR_DEBUG(2, "Tasting %s.", pp->name);
 3265 
 3266         gp = g_new_geomf(mp, "mirror:taste");
 3267         /*
 3268          * This orphan function should be never called.
 3269          */
 3270         gp->orphan = g_mirror_taste_orphan;
 3271         cp = g_new_consumer(gp);
 3272         cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
 3273         error = g_attach(cp, pp);
 3274         if (error == 0) {
 3275                 error = g_mirror_read_metadata(cp, &md);
 3276                 g_detach(cp);
 3277         }
 3278         g_destroy_consumer(cp);
 3279         g_destroy_geom(gp);
 3280         if (error != 0)
 3281                 return (NULL);
 3282         gp = NULL;
 3283 
 3284         if (md.md_provider[0] != '\0' &&
 3285             !g_compare_names(md.md_provider, pp->name))
 3286                 return (NULL);
 3287         if (md.md_provsize != 0 && md.md_provsize != pp->mediasize)
 3288                 return (NULL);
 3289         if ((md.md_dflags & G_MIRROR_DISK_FLAG_INACTIVE) != 0) {
 3290                 G_MIRROR_DEBUG(0,
 3291                     "Device %s: provider %s marked as inactive, skipping.",
 3292                     md.md_name, pp->name);
 3293                 return (NULL);
 3294         }
 3295         if (g_mirror_debug >= 2)
 3296                 mirror_metadata_dump(&md);
 3297 
 3298         /*
 3299          * Let's check if device already exists.
 3300          */
 3301         sc = NULL;
 3302         LIST_FOREACH(gp, &mp->geom, geom) {
 3303                 sc = gp->softc;
 3304                 if (sc == NULL)
 3305                         continue;
 3306                 if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC)
 3307                         continue;
 3308                 if (sc->sc_sync.ds_geom == gp)
 3309                         continue;
 3310                 if (strcmp(md.md_name, sc->sc_name) != 0)
 3311                         continue;
 3312                 if (md.md_mid != sc->sc_id) {
 3313                         G_MIRROR_DEBUG(0, "Device %s already configured.",
 3314                             sc->sc_name);
 3315                         return (NULL);
 3316                 }
 3317                 break;
 3318         }
 3319         if (gp == NULL) {
 3320                 gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_AUTOMATIC);
 3321                 if (gp == NULL) {
 3322                         G_MIRROR_DEBUG(0, "Cannot create device %s.",
 3323                             md.md_name);
 3324                         return (NULL);
 3325                 }
 3326                 sc = gp->softc;
 3327         }
 3328         G_MIRROR_DEBUG(1, "Adding disk %s to %s.", pp->name, gp->name);
 3329         g_topology_unlock();
 3330         sx_xlock(&sc->sc_lock);
 3331         sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
 3332         error = g_mirror_add_disk(sc, pp, &md);
 3333         sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
 3334         if (error != 0) {
 3335                 G_MIRROR_DEBUG(0, "Cannot add disk %s to %s (error=%d).",
 3336                     pp->name, gp->name, error);
 3337                 if (LIST_EMPTY(&sc->sc_disks)) {
 3338                         g_cancel_event(sc);
 3339                         g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
 3340                         g_topology_lock();
 3341                         return (NULL);
 3342                 }
 3343                 gp = NULL;
 3344         }
 3345         if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
 3346                 g_mirror_destroy(sc, G_MIRROR_DESTROY_HARD);
 3347                 g_topology_lock();
 3348                 return (NULL);
 3349         }
 3350         sx_xunlock(&sc->sc_lock);
 3351         g_topology_lock();
 3352         return (gp);
 3353 }
 3354 
 3355 static void
 3356 g_mirror_resize(struct g_consumer *cp)
 3357 {
 3358         struct g_mirror_disk *disk;
 3359 
 3360         g_topology_assert();
 3361         g_trace(G_T_TOPOLOGY, "%s(%s)", __func__, cp->provider->name);
 3362 
 3363         disk = cp->private;
 3364         if (disk == NULL)
 3365                 return;
 3366         g_topology_unlock();
 3367         g_mirror_update_metadata(disk);
 3368         g_topology_lock();
 3369 }
 3370 
 3371 static int
 3372 g_mirror_destroy_geom(struct gctl_req *req __unused,
 3373     struct g_class *mp __unused, struct g_geom *gp)
 3374 {
 3375         struct g_mirror_softc *sc;
 3376         int error;
 3377 
 3378         g_topology_unlock();
 3379         sc = gp->softc;
 3380         sx_xlock(&sc->sc_lock);
 3381         g_cancel_event(sc);
 3382         error = g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_SOFT);
 3383         if (error != 0)
 3384                 sx_xunlock(&sc->sc_lock);
 3385         g_topology_lock();
 3386         return (error);
 3387 }
 3388 
 3389 static void
 3390 g_mirror_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
 3391     struct g_consumer *cp, struct g_provider *pp)
 3392 {
 3393         struct g_mirror_softc *sc;
 3394 
 3395         g_topology_assert();
 3396 
 3397         sc = gp->softc;
 3398         if (sc == NULL)
 3399                 return;
 3400         /* Skip synchronization geom. */
 3401         if (gp == sc->sc_sync.ds_geom)
 3402                 return;
 3403         if (pp != NULL) {
 3404                 /* Nothing here. */
 3405         } else if (cp != NULL) {
 3406                 struct g_mirror_disk *disk;
 3407 
 3408                 disk = cp->private;
 3409                 if (disk == NULL)
 3410                         return;
 3411                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)disk->d_id);
 3412                 if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING) {
 3413                         sbuf_printf(sb, "%s<Synchronized>", indent);
 3414                         if (disk->d_sync.ds_offset == 0)
 3415                                 sbuf_cat(sb, "0%");
 3416                         else
 3417                                 sbuf_printf(sb, "%u%%",
 3418                                     (u_int)((disk->d_sync.ds_offset * 100) /
 3419                                     sc->sc_mediasize));
 3420                         sbuf_cat(sb, "</Synchronized>\n");
 3421                         if (disk->d_sync.ds_offset > 0)
 3422                                 sbuf_printf(sb, "%s<BytesSynced>%jd"
 3423                                     "</BytesSynced>\n", indent,
 3424                                     (intmax_t)disk->d_sync.ds_offset);
 3425                 }
 3426                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent,
 3427                     disk->d_sync.ds_syncid);
 3428                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent,
 3429                     disk->d_genid);
 3430                 sbuf_printf(sb, "%s<Flags>", indent);
 3431                 if (disk->d_flags == 0)
 3432                         sbuf_cat(sb, "NONE");
 3433                 else {
 3434                         int first = 1;
 3435 
 3436 #define ADD_FLAG(flag, name)    do {                                    \
 3437         if ((disk->d_flags & (flag)) != 0) {                            \
 3438                 if (!first)                                             \
 3439                         sbuf_cat(sb, ", ");                             \
 3440                 else                                                    \
 3441                         first = 0;                                      \
 3442                 sbuf_cat(sb, name);                                     \
 3443         }                                                               \
 3444 } while (0)
 3445                         ADD_FLAG(G_MIRROR_DISK_FLAG_DIRTY, "DIRTY");
 3446                         ADD_FLAG(G_MIRROR_DISK_FLAG_HARDCODED, "HARDCODED");
 3447                         ADD_FLAG(G_MIRROR_DISK_FLAG_INACTIVE, "INACTIVE");
 3448                         ADD_FLAG(G_MIRROR_DISK_FLAG_SYNCHRONIZING,
 3449                             "SYNCHRONIZING");
 3450                         ADD_FLAG(G_MIRROR_DISK_FLAG_FORCE_SYNC, "FORCE_SYNC");
 3451                         ADD_FLAG(G_MIRROR_DISK_FLAG_BROKEN, "BROKEN");
 3452 #undef  ADD_FLAG
 3453                 }
 3454                 sbuf_cat(sb, "</Flags>\n");
 3455                 sbuf_printf(sb, "%s<Priority>%u</Priority>\n", indent,
 3456                     disk->d_priority);
 3457                 sbuf_printf(sb, "%s<State>%s</State>\n", indent,
 3458                     g_mirror_disk_state2str(disk->d_state));
 3459         } else {
 3460                 sbuf_printf(sb, "%s<Type>", indent);
 3461                 switch (sc->sc_type) {
 3462                 case G_MIRROR_TYPE_AUTOMATIC:
 3463                         sbuf_cat(sb, "AUTOMATIC");
 3464                         break;
 3465                 case G_MIRROR_TYPE_MANUAL:
 3466                         sbuf_cat(sb, "MANUAL");
 3467                         break;
 3468                 default:
 3469                         sbuf_cat(sb, "UNKNOWN");
 3470                         break;
 3471                 }
 3472                 sbuf_cat(sb, "</Type>\n");
 3473                 sbuf_printf(sb, "%s<ID>%u</ID>\n", indent, (u_int)sc->sc_id);
 3474                 sbuf_printf(sb, "%s<SyncID>%u</SyncID>\n", indent, sc->sc_syncid);
 3475                 sbuf_printf(sb, "%s<GenID>%u</GenID>\n", indent, sc->sc_genid);
 3476                 sbuf_printf(sb, "%s<Flags>", indent);
 3477                 if (sc->sc_flags == 0)
 3478                         sbuf_cat(sb, "NONE");
 3479                 else {
 3480                         int first = 1;
 3481 
 3482 #define ADD_FLAG(flag, name)    do {                                    \
 3483         if ((sc->sc_flags & (flag)) != 0) {                             \
 3484                 if (!first)                                             \
 3485                         sbuf_cat(sb, ", ");                             \
 3486                 else                                                    \
 3487                         first = 0;                                      \
 3488                 sbuf_cat(sb, name);                                     \
 3489         }                                                               \
 3490 } while (0)
 3491                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOFAILSYNC, "NOFAILSYNC");
 3492                         ADD_FLAG(G_MIRROR_DEVICE_FLAG_NOAUTOSYNC, "NOAUTOSYNC");
 3493 #undef  ADD_FLAG
 3494                 }
 3495                 sbuf_cat(sb, "</Flags>\n");
 3496                 sbuf_printf(sb, "%s<Slice>%u</Slice>\n", indent,
 3497                     (u_int)sc->sc_slice);
 3498                 sbuf_printf(sb, "%s<Balance>%s</Balance>\n", indent,
 3499                     balance_name(sc->sc_balance));
 3500                 sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
 3501                     sc->sc_ndisks);
 3502                 sbuf_printf(sb, "%s<State>", indent);
 3503                 if (sc->sc_state == G_MIRROR_DEVICE_STATE_STARTING)
 3504                         sbuf_printf(sb, "%s", "STARTING");
 3505                 else if (sc->sc_ndisks ==
 3506                     g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE))
 3507                         sbuf_printf(sb, "%s", "COMPLETE");
 3508                 else
 3509                         sbuf_printf(sb, "%s", "DEGRADED");
 3510                 sbuf_cat(sb, "</State>\n");
 3511         }
 3512 }
 3513 
 3514 static void
 3515 g_mirror_shutdown_post_sync(void *arg, int howto)
 3516 {
 3517         struct g_class *mp;
 3518         struct g_geom *gp, *gp2;
 3519         struct g_mirror_softc *sc;
 3520         int error;
 3521 
 3522         if (KERNEL_PANICKED())
 3523                 return;
 3524 
 3525         mp = arg;
 3526         g_topology_lock();
 3527         g_mirror_shutdown = 1;
 3528         LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
 3529                 if ((sc = gp->softc) == NULL)
 3530                         continue;
 3531                 /* Skip synchronization geom. */
 3532                 if (gp == sc->sc_sync.ds_geom)
 3533                         continue;
 3534                 g_topology_unlock();
 3535                 sx_xlock(&sc->sc_lock);
 3536                 g_mirror_idle(sc, -1);
 3537                 g_cancel_event(sc);
 3538                 error = g_mirror_destroy(sc, G_MIRROR_DESTROY_DELAYED);
 3539                 if (error != 0)
 3540                         sx_xunlock(&sc->sc_lock);
 3541                 g_topology_lock();
 3542         }
 3543         g_topology_unlock();
 3544 }
 3545 
 3546 static void
 3547 g_mirror_init(struct g_class *mp)
 3548 {
 3549 
 3550         g_mirror_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
 3551             g_mirror_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
 3552         if (g_mirror_post_sync == NULL)
 3553                 G_MIRROR_DEBUG(0, "Warning! Cannot register shutdown event.");
 3554 }
 3555 
 3556 static void
 3557 g_mirror_fini(struct g_class *mp)
 3558 {
 3559 
 3560         if (g_mirror_post_sync != NULL)
 3561                 EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_mirror_post_sync);
 3562 }
 3563 
 3564 /*
 3565  * Refresh the mirror device's metadata when gmirror encounters a newer
 3566  * generation as the individual components are being added to the mirror set.
 3567  */
 3568 static int
 3569 g_mirror_refresh_device(struct g_mirror_softc *sc, const struct g_provider *pp,
 3570     const struct g_mirror_metadata *md)
 3571 {
 3572 
 3573         g_topology_assert_not();
 3574         sx_assert(&sc->sc_lock, SX_XLOCKED);
 3575 
 3576         KASSERT(sc->sc_genid <= md->md_genid,
 3577             ("%s: attempted to refresh from stale component %s (device %s) "
 3578             "(%u < %u).", __func__, pp->name, sc->sc_name, md->md_genid,
 3579             sc->sc_genid));
 3580 
 3581         if (sc->sc_genid > md->md_genid || (sc->sc_genid == md->md_genid &&
 3582             sc->sc_syncid >= md->md_syncid))
 3583                 return (0);
 3584 
 3585         G_MIRROR_DEBUG(0, "Found newer version for device %s (genid: curr=%u "
 3586             "new=%u; syncid: curr=%u new=%u; ndisks: curr=%u new=%u; "
 3587             "provider=%s).", sc->sc_name, sc->sc_genid, md->md_genid,
 3588             sc->sc_syncid, md->md_syncid, sc->sc_ndisks, md->md_all, pp->name);
 3589 
 3590         if (sc->sc_state != G_MIRROR_DEVICE_STATE_STARTING) {
 3591                 /* Probable data corruption detected */
 3592                 G_MIRROR_DEBUG(0, "Cannot refresh metadata in %s state "
 3593                     "(device=%s genid=%u). A stale mirror device was launched.",
 3594                     g_mirror_device_state2str(sc->sc_state), sc->sc_name,
 3595                     sc->sc_genid);
 3596                 return (EINVAL);
 3597         }
 3598 
 3599         /* Update softc */
 3600         g_mirror_reinit_from_metadata(sc, md);
 3601 
 3602         G_MIRROR_DEBUG(1, "Refresh device %s (id=%u, state=%s) from disk %s "
 3603             "(genid=%u syncid=%u md_all=%u).", sc->sc_name, md->md_mid,
 3604             g_mirror_device_state2str(sc->sc_state), pp->name, md->md_genid,
 3605             md->md_syncid, (unsigned)md->md_all);
 3606 
 3607         return (0);
 3608 }
 3609 
 3610 DECLARE_GEOM_CLASS(g_mirror_class, g_mirror);
 3611 MODULE_VERSION(geom_mirror, 0);
Cache object: cd0b65dda609dd23d479a148ad108748
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/geom/mirror/g_mirror.c

FreeBSD/Linux Kernel Cross Reference
sys/geom/mirror/g_mirror.c
