The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/geom/raid/tr_raid1.c

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    1 /*-
    2  * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org>
    3  * All rights reserved.
    4  *
    5  * Redistribution and use in source and binary forms, with or without
    6  * modification, are permitted provided that the following conditions
    7  * are met:
    8  * 1. Redistributions of source code must retain the above copyright
    9  *    notice, this list of conditions and the following disclaimer.
   10  * 2. Redistributions in binary form must reproduce the above copyright
   11  *    notice, this list of conditions and the following disclaimer in the
   12  *    documentation and/or other materials provided with the distribution.
   13  *
   14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
   15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
   18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   24  * SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/10.2/sys/geom/raid/tr_raid1.c 260385 2014-01-07 01:32:23Z scottl $");
   29 
   30 #include <sys/param.h>
   31 #include <sys/bio.h>
   32 #include <sys/endian.h>
   33 #include <sys/kernel.h>
   34 #include <sys/kobj.h>
   35 #include <sys/limits.h>
   36 #include <sys/lock.h>
   37 #include <sys/malloc.h>
   38 #include <sys/mutex.h>
   39 #include <sys/sysctl.h>
   40 #include <sys/systm.h>
   41 #include <geom/geom.h>
   42 #include "geom/raid/g_raid.h"
   43 #include "g_raid_tr_if.h"
   44 
   45 SYSCTL_DECL(_kern_geom_raid_raid1);
   46 
   47 #define RAID1_REBUILD_SLAB      (1 << 20) /* One transation in a rebuild */
   48 static int g_raid1_rebuild_slab = RAID1_REBUILD_SLAB;
   49 TUNABLE_INT("kern.geom.raid.raid1.rebuild_slab_size",
   50     &g_raid1_rebuild_slab);
   51 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_slab_size, CTLFLAG_RW,
   52     &g_raid1_rebuild_slab, 0,
   53     "Amount of the disk to rebuild each read/write cycle of the rebuild.");
   54 
   55 #define RAID1_REBUILD_FAIR_IO 20 /* use 1/x of the available I/O */
   56 static int g_raid1_rebuild_fair_io = RAID1_REBUILD_FAIR_IO;
   57 TUNABLE_INT("kern.geom.raid.raid1.rebuild_fair_io",
   58     &g_raid1_rebuild_fair_io);
   59 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_fair_io, CTLFLAG_RW,
   60     &g_raid1_rebuild_fair_io, 0,
   61     "Fraction of the I/O bandwidth to use when disk busy for rebuild.");
   62 
   63 #define RAID1_REBUILD_CLUSTER_IDLE 100
   64 static int g_raid1_rebuild_cluster_idle = RAID1_REBUILD_CLUSTER_IDLE;
   65 TUNABLE_INT("kern.geom.raid.raid1.rebuild_cluster_idle",
   66     &g_raid1_rebuild_cluster_idle);
   67 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_cluster_idle, CTLFLAG_RW,
   68     &g_raid1_rebuild_cluster_idle, 0,
   69     "Number of slabs to do each time we trigger a rebuild cycle");
   70 
   71 #define RAID1_REBUILD_META_UPDATE 1024 /* update meta data every 1GB or so */
   72 static int g_raid1_rebuild_meta_update = RAID1_REBUILD_META_UPDATE;
   73 TUNABLE_INT("kern.geom.raid.raid1.rebuild_meta_update",
   74     &g_raid1_rebuild_meta_update);
   75 SYSCTL_UINT(_kern_geom_raid_raid1, OID_AUTO, rebuild_meta_update, CTLFLAG_RW,
   76     &g_raid1_rebuild_meta_update, 0,
   77     "When to update the meta data.");
   78 
   79 static MALLOC_DEFINE(M_TR_RAID1, "tr_raid1_data", "GEOM_RAID RAID1 data");
   80 
   81 #define TR_RAID1_NONE 0
   82 #define TR_RAID1_REBUILD 1
   83 #define TR_RAID1_RESYNC 2
   84 
   85 #define TR_RAID1_F_DOING_SOME   0x1
   86 #define TR_RAID1_F_LOCKED       0x2
   87 #define TR_RAID1_F_ABORT        0x4
   88 
   89 struct g_raid_tr_raid1_object {
   90         struct g_raid_tr_object  trso_base;
   91         int                      trso_starting;
   92         int                      trso_stopping;
   93         int                      trso_type;
   94         int                      trso_recover_slabs; /* slabs before rest */
   95         int                      trso_fair_io;
   96         int                      trso_meta_update;
   97         int                      trso_flags;
   98         struct g_raid_subdisk   *trso_failed_sd; /* like per volume */
   99         void                    *trso_buffer;    /* Buffer space */
  100         struct bio               trso_bio;
  101 };
  102 
  103 static g_raid_tr_taste_t g_raid_tr_taste_raid1;
  104 static g_raid_tr_event_t g_raid_tr_event_raid1;
  105 static g_raid_tr_start_t g_raid_tr_start_raid1;
  106 static g_raid_tr_stop_t g_raid_tr_stop_raid1;
  107 static g_raid_tr_iostart_t g_raid_tr_iostart_raid1;
  108 static g_raid_tr_iodone_t g_raid_tr_iodone_raid1;
  109 static g_raid_tr_kerneldump_t g_raid_tr_kerneldump_raid1;
  110 static g_raid_tr_locked_t g_raid_tr_locked_raid1;
  111 static g_raid_tr_idle_t g_raid_tr_idle_raid1;
  112 static g_raid_tr_free_t g_raid_tr_free_raid1;
  113 
  114 static kobj_method_t g_raid_tr_raid1_methods[] = {
  115         KOBJMETHOD(g_raid_tr_taste,     g_raid_tr_taste_raid1),
  116         KOBJMETHOD(g_raid_tr_event,     g_raid_tr_event_raid1),
  117         KOBJMETHOD(g_raid_tr_start,     g_raid_tr_start_raid1),
  118         KOBJMETHOD(g_raid_tr_stop,      g_raid_tr_stop_raid1),
  119         KOBJMETHOD(g_raid_tr_iostart,   g_raid_tr_iostart_raid1),
  120         KOBJMETHOD(g_raid_tr_iodone,    g_raid_tr_iodone_raid1),
  121         KOBJMETHOD(g_raid_tr_kerneldump, g_raid_tr_kerneldump_raid1),
  122         KOBJMETHOD(g_raid_tr_locked,    g_raid_tr_locked_raid1),
  123         KOBJMETHOD(g_raid_tr_idle,      g_raid_tr_idle_raid1),
  124         KOBJMETHOD(g_raid_tr_free,      g_raid_tr_free_raid1),
  125         { 0, 0 }
  126 };
  127 
  128 static struct g_raid_tr_class g_raid_tr_raid1_class = {
  129         "RAID1",
  130         g_raid_tr_raid1_methods,
  131         sizeof(struct g_raid_tr_raid1_object),
  132         .trc_enable = 1,
  133         .trc_priority = 100,
  134         .trc_accept_unmapped = 1
  135 };
  136 
  137 static void g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr);
  138 static void g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
  139     struct g_raid_subdisk *sd);
  140 
  141 static int
  142 g_raid_tr_taste_raid1(struct g_raid_tr_object *tr, struct g_raid_volume *vol)
  143 {
  144         struct g_raid_tr_raid1_object *trs;
  145 
  146         trs = (struct g_raid_tr_raid1_object *)tr;
  147         if (tr->tro_volume->v_raid_level != G_RAID_VOLUME_RL_RAID1 ||
  148             (tr->tro_volume->v_raid_level_qualifier != G_RAID_VOLUME_RLQ_R1SM &&
  149              tr->tro_volume->v_raid_level_qualifier != G_RAID_VOLUME_RLQ_R1MM))
  150                 return (G_RAID_TR_TASTE_FAIL);
  151         trs->trso_starting = 1;
  152         return (G_RAID_TR_TASTE_SUCCEED);
  153 }
  154 
  155 static int
  156 g_raid_tr_update_state_raid1(struct g_raid_volume *vol,
  157     struct g_raid_subdisk *sd)
  158 {
  159         struct g_raid_tr_raid1_object *trs;
  160         struct g_raid_softc *sc;
  161         struct g_raid_subdisk *tsd, *bestsd;
  162         u_int s;
  163         int i, na, ns;
  164 
  165         sc = vol->v_softc;
  166         trs = (struct g_raid_tr_raid1_object *)vol->v_tr;
  167         if (trs->trso_stopping &&
  168             (trs->trso_flags & TR_RAID1_F_DOING_SOME) == 0)
  169                 s = G_RAID_VOLUME_S_STOPPED;
  170         else if (trs->trso_starting)
  171                 s = G_RAID_VOLUME_S_STARTING;
  172         else {
  173                 /* Make sure we have at least one ACTIVE disk. */
  174                 na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
  175                 if (na == 0) {
  176                         /*
  177                          * Critical situation! We have no any active disk!
  178                          * Choose the best disk we have to make it active.
  179                          */
  180                         bestsd = &vol->v_subdisks[0];
  181                         for (i = 1; i < vol->v_disks_count; i++) {
  182                                 tsd = &vol->v_subdisks[i];
  183                                 if (tsd->sd_state > bestsd->sd_state)
  184                                         bestsd = tsd;
  185                                 else if (tsd->sd_state == bestsd->sd_state &&
  186                                     (tsd->sd_state == G_RAID_SUBDISK_S_REBUILD ||
  187                                      tsd->sd_state == G_RAID_SUBDISK_S_RESYNC) &&
  188                                     tsd->sd_rebuild_pos > bestsd->sd_rebuild_pos)
  189                                         bestsd = tsd;
  190                         }
  191                         if (bestsd->sd_state >= G_RAID_SUBDISK_S_UNINITIALIZED) {
  192                                 /* We found reasonable candidate. */
  193                                 G_RAID_DEBUG1(1, sc,
  194                                     "Promote subdisk %s:%d from %s to ACTIVE.",
  195                                     vol->v_name, bestsd->sd_pos,
  196                                     g_raid_subdisk_state2str(bestsd->sd_state));
  197                                 g_raid_change_subdisk_state(bestsd,
  198                                     G_RAID_SUBDISK_S_ACTIVE);
  199                                 g_raid_write_metadata(sc,
  200                                     vol, bestsd, bestsd->sd_disk);
  201                         }
  202                 }
  203                 na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
  204                 ns = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
  205                      g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
  206                 if (na == vol->v_disks_count)
  207                         s = G_RAID_VOLUME_S_OPTIMAL;
  208                 else if (na + ns == vol->v_disks_count)
  209                         s = G_RAID_VOLUME_S_SUBOPTIMAL;
  210                 else if (na > 0)
  211                         s = G_RAID_VOLUME_S_DEGRADED;
  212                 else
  213                         s = G_RAID_VOLUME_S_BROKEN;
  214                 g_raid_tr_raid1_maybe_rebuild(vol->v_tr, sd);
  215         }
  216         if (s != vol->v_state) {
  217                 g_raid_event_send(vol, G_RAID_VOLUME_S_ALIVE(s) ?
  218                     G_RAID_VOLUME_E_UP : G_RAID_VOLUME_E_DOWN,
  219                     G_RAID_EVENT_VOLUME);
  220                 g_raid_change_volume_state(vol, s);
  221                 if (!trs->trso_starting && !trs->trso_stopping)
  222                         g_raid_write_metadata(sc, vol, NULL, NULL);
  223         }
  224         return (0);
  225 }
  226 
  227 static void
  228 g_raid_tr_raid1_fail_disk(struct g_raid_softc *sc, struct g_raid_subdisk *sd,
  229     struct g_raid_disk *disk)
  230 {
  231         /*
  232          * We don't fail the last disk in the pack, since it still has decent
  233          * data on it and that's better than failing the disk if it is the root
  234          * file system.
  235          *
  236          * XXX should this be controlled via a tunable?  It makes sense for
  237          * the volume that has / on it.  I can't think of a case where we'd
  238          * want the volume to go away on this kind of event.
  239          */
  240         if (g_raid_nsubdisks(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE) == 1 &&
  241             g_raid_get_subdisk(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE) == sd)
  242                 return;
  243         g_raid_fail_disk(sc, sd, disk);
  244 }
  245 
  246 static void
  247 g_raid_tr_raid1_rebuild_some(struct g_raid_tr_object *tr)
  248 {
  249         struct g_raid_tr_raid1_object *trs;
  250         struct g_raid_subdisk *sd, *good_sd;
  251         struct bio *bp;
  252 
  253         trs = (struct g_raid_tr_raid1_object *)tr;
  254         if (trs->trso_flags & TR_RAID1_F_DOING_SOME)
  255                 return;
  256         sd = trs->trso_failed_sd;
  257         good_sd = g_raid_get_subdisk(sd->sd_volume, G_RAID_SUBDISK_S_ACTIVE);
  258         if (good_sd == NULL) {
  259                 g_raid_tr_raid1_rebuild_abort(tr);
  260                 return;
  261         }
  262         bp = &trs->trso_bio;
  263         memset(bp, 0, sizeof(*bp));
  264         bp->bio_offset = sd->sd_rebuild_pos;
  265         bp->bio_length = MIN(g_raid1_rebuild_slab,
  266             sd->sd_size - sd->sd_rebuild_pos);
  267         bp->bio_data = trs->trso_buffer;
  268         bp->bio_cmd = BIO_READ;
  269         bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
  270         bp->bio_caller1 = good_sd;
  271         trs->trso_flags |= TR_RAID1_F_DOING_SOME;
  272         trs->trso_flags |= TR_RAID1_F_LOCKED;
  273         g_raid_lock_range(sd->sd_volume,        /* Lock callback starts I/O */
  274            bp->bio_offset, bp->bio_length, NULL, bp);
  275 }
  276 
  277 static void
  278 g_raid_tr_raid1_rebuild_done(struct g_raid_tr_raid1_object *trs)
  279 {
  280         struct g_raid_volume *vol;
  281         struct g_raid_subdisk *sd;
  282 
  283         vol = trs->trso_base.tro_volume;
  284         sd = trs->trso_failed_sd;
  285         g_raid_write_metadata(vol->v_softc, vol, sd, sd->sd_disk);
  286         free(trs->trso_buffer, M_TR_RAID1);
  287         trs->trso_buffer = NULL;
  288         trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
  289         trs->trso_type = TR_RAID1_NONE;
  290         trs->trso_recover_slabs = 0;
  291         trs->trso_failed_sd = NULL;
  292         g_raid_tr_update_state_raid1(vol, NULL);
  293 }
  294 
  295 static void
  296 g_raid_tr_raid1_rebuild_finish(struct g_raid_tr_object *tr)
  297 {
  298         struct g_raid_tr_raid1_object *trs;
  299         struct g_raid_subdisk *sd;
  300 
  301         trs = (struct g_raid_tr_raid1_object *)tr;
  302         sd = trs->trso_failed_sd;
  303         G_RAID_DEBUG1(0, tr->tro_volume->v_softc,
  304             "Subdisk %s:%d-%s rebuild completed.",
  305             sd->sd_volume->v_name, sd->sd_pos,
  306             sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
  307         g_raid_change_subdisk_state(sd, G_RAID_SUBDISK_S_ACTIVE);
  308         sd->sd_rebuild_pos = 0;
  309         g_raid_tr_raid1_rebuild_done(trs);
  310 }
  311 
  312 static void
  313 g_raid_tr_raid1_rebuild_abort(struct g_raid_tr_object *tr)
  314 {
  315         struct g_raid_tr_raid1_object *trs;
  316         struct g_raid_subdisk *sd;
  317         struct g_raid_volume *vol;
  318         off_t len;
  319 
  320         vol = tr->tro_volume;
  321         trs = (struct g_raid_tr_raid1_object *)tr;
  322         sd = trs->trso_failed_sd;
  323         if (trs->trso_flags & TR_RAID1_F_DOING_SOME) {
  324                 G_RAID_DEBUG1(1, vol->v_softc,
  325                     "Subdisk %s:%d-%s rebuild is aborting.",
  326                     sd->sd_volume->v_name, sd->sd_pos,
  327                     sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
  328                 trs->trso_flags |= TR_RAID1_F_ABORT;
  329         } else {
  330                 G_RAID_DEBUG1(0, vol->v_softc,
  331                     "Subdisk %s:%d-%s rebuild aborted.",
  332                     sd->sd_volume->v_name, sd->sd_pos,
  333                     sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
  334                 trs->trso_flags &= ~TR_RAID1_F_ABORT;
  335                 if (trs->trso_flags & TR_RAID1_F_LOCKED) {
  336                         trs->trso_flags &= ~TR_RAID1_F_LOCKED;
  337                         len = MIN(g_raid1_rebuild_slab,
  338                             sd->sd_size - sd->sd_rebuild_pos);
  339                         g_raid_unlock_range(tr->tro_volume,
  340                             sd->sd_rebuild_pos, len);
  341                 }
  342                 g_raid_tr_raid1_rebuild_done(trs);
  343         }
  344 }
  345 
  346 static void
  347 g_raid_tr_raid1_rebuild_start(struct g_raid_tr_object *tr)
  348 {
  349         struct g_raid_volume *vol;
  350         struct g_raid_tr_raid1_object *trs;
  351         struct g_raid_subdisk *sd, *fsd;
  352 
  353         vol = tr->tro_volume;
  354         trs = (struct g_raid_tr_raid1_object *)tr;
  355         if (trs->trso_failed_sd) {
  356                 G_RAID_DEBUG1(1, vol->v_softc,
  357                     "Already rebuild in start rebuild. pos %jd\n",
  358                     (intmax_t)trs->trso_failed_sd->sd_rebuild_pos);
  359                 return;
  360         }
  361         sd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_ACTIVE);
  362         if (sd == NULL) {
  363                 G_RAID_DEBUG1(1, vol->v_softc,
  364                     "No active disk to rebuild.  night night.");
  365                 return;
  366         }
  367         fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_RESYNC);
  368         if (fsd == NULL)
  369                 fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_REBUILD);
  370         if (fsd == NULL) {
  371                 fsd = g_raid_get_subdisk(vol, G_RAID_SUBDISK_S_STALE);
  372                 if (fsd != NULL) {
  373                         fsd->sd_rebuild_pos = 0;
  374                         g_raid_change_subdisk_state(fsd,
  375                             G_RAID_SUBDISK_S_RESYNC);
  376                         g_raid_write_metadata(vol->v_softc, vol, fsd, NULL);
  377                 } else {
  378                         fsd = g_raid_get_subdisk(vol,
  379                             G_RAID_SUBDISK_S_UNINITIALIZED);
  380                         if (fsd == NULL)
  381                                 fsd = g_raid_get_subdisk(vol,
  382                                     G_RAID_SUBDISK_S_NEW);
  383                         if (fsd != NULL) {
  384                                 fsd->sd_rebuild_pos = 0;
  385                                 g_raid_change_subdisk_state(fsd,
  386                                     G_RAID_SUBDISK_S_REBUILD);
  387                                 g_raid_write_metadata(vol->v_softc,
  388                                     vol, fsd, NULL);
  389                         }
  390                 }
  391         }
  392         if (fsd == NULL) {
  393                 G_RAID_DEBUG1(1, vol->v_softc,
  394                     "No failed disk to rebuild.  night night.");
  395                 return;
  396         }
  397         trs->trso_failed_sd = fsd;
  398         G_RAID_DEBUG1(0, vol->v_softc,
  399             "Subdisk %s:%d-%s rebuild start at %jd.",
  400             fsd->sd_volume->v_name, fsd->sd_pos,
  401             fsd->sd_disk ? g_raid_get_diskname(fsd->sd_disk) : "[none]",
  402             trs->trso_failed_sd->sd_rebuild_pos);
  403         trs->trso_type = TR_RAID1_REBUILD;
  404         trs->trso_buffer = malloc(g_raid1_rebuild_slab, M_TR_RAID1, M_WAITOK);
  405         trs->trso_meta_update = g_raid1_rebuild_meta_update;
  406         g_raid_tr_raid1_rebuild_some(tr);
  407 }
  408 
  409 
  410 static void
  411 g_raid_tr_raid1_maybe_rebuild(struct g_raid_tr_object *tr,
  412     struct g_raid_subdisk *sd)
  413 {
  414         struct g_raid_volume *vol;
  415         struct g_raid_tr_raid1_object *trs;
  416         int na, nr;
  417         
  418         /*
  419          * If we're stopping, don't do anything.  If we don't have at least one
  420          * good disk and one bad disk, we don't do anything.  And if there's a
  421          * 'good disk' stored in the trs, then we're in progress and we punt.
  422          * If we make it past all these checks, we need to rebuild.
  423          */
  424         vol = tr->tro_volume;
  425         trs = (struct g_raid_tr_raid1_object *)tr;
  426         if (trs->trso_stopping)
  427                 return;
  428         na = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_ACTIVE);
  429         nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_REBUILD) +
  430             g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_RESYNC);
  431         switch(trs->trso_type) {
  432         case TR_RAID1_NONE:
  433                 if (na == 0)
  434                         return;
  435                 if (nr == 0) {
  436                         nr = g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_NEW) +
  437                             g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_STALE) +
  438                             g_raid_nsubdisks(vol, G_RAID_SUBDISK_S_UNINITIALIZED);
  439                         if (nr == 0)
  440                                 return;
  441                 }
  442                 g_raid_tr_raid1_rebuild_start(tr);
  443                 break;
  444         case TR_RAID1_REBUILD:
  445                 if (na == 0 || nr == 0 || trs->trso_failed_sd == sd)
  446                         g_raid_tr_raid1_rebuild_abort(tr);
  447                 break;
  448         case TR_RAID1_RESYNC:
  449                 break;
  450         }
  451 }
  452 
  453 static int
  454 g_raid_tr_event_raid1(struct g_raid_tr_object *tr,
  455     struct g_raid_subdisk *sd, u_int event)
  456 {
  457 
  458         g_raid_tr_update_state_raid1(tr->tro_volume, sd);
  459         return (0);
  460 }
  461 
  462 static int
  463 g_raid_tr_start_raid1(struct g_raid_tr_object *tr)
  464 {
  465         struct g_raid_tr_raid1_object *trs;
  466         struct g_raid_volume *vol;
  467 
  468         trs = (struct g_raid_tr_raid1_object *)tr;
  469         vol = tr->tro_volume;
  470         trs->trso_starting = 0;
  471         g_raid_tr_update_state_raid1(vol, NULL);
  472         return (0);
  473 }
  474 
  475 static int
  476 g_raid_tr_stop_raid1(struct g_raid_tr_object *tr)
  477 {
  478         struct g_raid_tr_raid1_object *trs;
  479         struct g_raid_volume *vol;
  480 
  481         trs = (struct g_raid_tr_raid1_object *)tr;
  482         vol = tr->tro_volume;
  483         trs->trso_starting = 0;
  484         trs->trso_stopping = 1;
  485         g_raid_tr_update_state_raid1(vol, NULL);
  486         return (0);
  487 }
  488 
  489 /*
  490  * Select the disk to read from.  Take into account: subdisk state, running
  491  * error recovery, average disk load, head position and possible cache hits.
  492  */
  493 #define ABS(x)          (((x) >= 0) ? (x) : (-(x)))
  494 static struct g_raid_subdisk *
  495 g_raid_tr_raid1_select_read_disk(struct g_raid_volume *vol, struct bio *bp,
  496     u_int mask)
  497 {
  498         struct g_raid_subdisk *sd, *best;
  499         int i, prio, bestprio;
  500 
  501         best = NULL;
  502         bestprio = INT_MAX;
  503         for (i = 0; i < vol->v_disks_count; i++) {
  504                 sd = &vol->v_subdisks[i];
  505                 if (sd->sd_state != G_RAID_SUBDISK_S_ACTIVE &&
  506                     ((sd->sd_state != G_RAID_SUBDISK_S_REBUILD &&
  507                       sd->sd_state != G_RAID_SUBDISK_S_RESYNC) ||
  508                      bp->bio_offset + bp->bio_length > sd->sd_rebuild_pos))
  509                         continue;
  510                 if ((mask & (1 << i)) != 0)
  511                         continue;
  512                 prio = G_RAID_SUBDISK_LOAD(sd);
  513                 prio += min(sd->sd_recovery, 255) << 22;
  514                 prio += (G_RAID_SUBDISK_S_ACTIVE - sd->sd_state) << 16;
  515                 /* If disk head is precisely in position - highly prefer it. */
  516                 if (G_RAID_SUBDISK_POS(sd) == bp->bio_offset)
  517                         prio -= 2 * G_RAID_SUBDISK_LOAD_SCALE;
  518                 else
  519                 /* If disk head is close to position - prefer it. */
  520                 if (ABS(G_RAID_SUBDISK_POS(sd) - bp->bio_offset) <
  521                     G_RAID_SUBDISK_TRACK_SIZE)
  522                         prio -= 1 * G_RAID_SUBDISK_LOAD_SCALE;
  523                 if (prio < bestprio) {
  524                         best = sd;
  525                         bestprio = prio;
  526                 }
  527         }
  528         return (best);
  529 }
  530 
  531 static void
  532 g_raid_tr_iostart_raid1_read(struct g_raid_tr_object *tr, struct bio *bp)
  533 {
  534         struct g_raid_subdisk *sd;
  535         struct bio *cbp;
  536 
  537         sd = g_raid_tr_raid1_select_read_disk(tr->tro_volume, bp, 0);
  538         KASSERT(sd != NULL, ("No active disks in volume %s.",
  539                 tr->tro_volume->v_name));
  540 
  541         cbp = g_clone_bio(bp);
  542         if (cbp == NULL) {
  543                 g_raid_iodone(bp, ENOMEM);
  544                 return;
  545         }
  546 
  547         g_raid_subdisk_iostart(sd, cbp);
  548 }
  549 
  550 static void
  551 g_raid_tr_iostart_raid1_write(struct g_raid_tr_object *tr, struct bio *bp)
  552 {
  553         struct g_raid_volume *vol;
  554         struct g_raid_subdisk *sd;
  555         struct bio_queue_head queue;
  556         struct bio *cbp;
  557         int i;
  558 
  559         vol = tr->tro_volume;
  560 
  561         /*
  562          * Allocate all bios before sending any request, so we can return
  563          * ENOMEM in nice and clean way.
  564          */
  565         bioq_init(&queue);
  566         for (i = 0; i < vol->v_disks_count; i++) {
  567                 sd = &vol->v_subdisks[i];
  568                 switch (sd->sd_state) {
  569                 case G_RAID_SUBDISK_S_ACTIVE:
  570                         break;
  571                 case G_RAID_SUBDISK_S_REBUILD:
  572                         /*
  573                          * When rebuilding, only part of this subdisk is
  574                          * writable, the rest will be written as part of the
  575                          * that process.
  576                          */
  577                         if (bp->bio_offset >= sd->sd_rebuild_pos)
  578                                 continue;
  579                         break;
  580                 case G_RAID_SUBDISK_S_STALE:
  581                 case G_RAID_SUBDISK_S_RESYNC:
  582                         /*
  583                          * Resyncing still writes on the theory that the
  584                          * resync'd disk is very close and writing it will
  585                          * keep it that way better if we keep up while
  586                          * resyncing.
  587                          */
  588                         break;
  589                 default:
  590                         continue;
  591                 }
  592                 cbp = g_clone_bio(bp);
  593                 if (cbp == NULL)
  594                         goto failure;
  595                 cbp->bio_caller1 = sd;
  596                 bioq_insert_tail(&queue, cbp);
  597         }
  598         while ((cbp = bioq_takefirst(&queue)) != NULL) {
  599                 sd = cbp->bio_caller1;
  600                 cbp->bio_caller1 = NULL;
  601                 g_raid_subdisk_iostart(sd, cbp);
  602         }
  603         return;
  604 failure:
  605         while ((cbp = bioq_takefirst(&queue)) != NULL)
  606                 g_destroy_bio(cbp);
  607         if (bp->bio_error == 0)
  608                 bp->bio_error = ENOMEM;
  609         g_raid_iodone(bp, bp->bio_error);
  610 }
  611 
  612 static void
  613 g_raid_tr_iostart_raid1(struct g_raid_tr_object *tr, struct bio *bp)
  614 {
  615         struct g_raid_volume *vol;
  616         struct g_raid_tr_raid1_object *trs;
  617 
  618         vol = tr->tro_volume;
  619         trs = (struct g_raid_tr_raid1_object *)tr;
  620         if (vol->v_state != G_RAID_VOLUME_S_OPTIMAL &&
  621             vol->v_state != G_RAID_VOLUME_S_SUBOPTIMAL &&
  622             vol->v_state != G_RAID_VOLUME_S_DEGRADED) {
  623                 g_raid_iodone(bp, EIO);
  624                 return;
  625         }
  626         /*
  627          * If we're rebuilding, squeeze in rebuild activity every so often,
  628          * even when the disk is busy.  Be sure to only count real I/O
  629          * to the disk.  All 'SPECIAL' I/O is traffic generated to the disk
  630          * by this module.
  631          */
  632         if (trs->trso_failed_sd != NULL &&
  633             !(bp->bio_cflags & G_RAID_BIO_FLAG_SPECIAL)) {
  634                 /* Make this new or running now round short. */
  635                 trs->trso_recover_slabs = 0;
  636                 if (--trs->trso_fair_io <= 0) {
  637                         trs->trso_fair_io = g_raid1_rebuild_fair_io;
  638                         g_raid_tr_raid1_rebuild_some(tr);
  639                 }
  640         }
  641         switch (bp->bio_cmd) {
  642         case BIO_READ:
  643                 g_raid_tr_iostart_raid1_read(tr, bp);
  644                 break;
  645         case BIO_WRITE:
  646         case BIO_DELETE:
  647                 g_raid_tr_iostart_raid1_write(tr, bp);
  648                 break;
  649         case BIO_FLUSH:
  650                 g_raid_tr_flush_common(tr, bp);
  651                 break;
  652         default:
  653                 KASSERT(1 == 0, ("Invalid command here: %u (volume=%s)",
  654                     bp->bio_cmd, vol->v_name));
  655                 break;
  656         }
  657 }
  658 
  659 static void
  660 g_raid_tr_iodone_raid1(struct g_raid_tr_object *tr,
  661     struct g_raid_subdisk *sd, struct bio *bp)
  662 {
  663         struct bio *cbp;
  664         struct g_raid_subdisk *nsd;
  665         struct g_raid_volume *vol;
  666         struct bio *pbp;
  667         struct g_raid_tr_raid1_object *trs;
  668         uintptr_t *mask;
  669         int error, do_write;
  670 
  671         trs = (struct g_raid_tr_raid1_object *)tr;
  672         vol = tr->tro_volume;
  673         if (bp->bio_cflags & G_RAID_BIO_FLAG_SYNC) {
  674                 /*
  675                  * This operation is part of a rebuild or resync operation.
  676                  * See what work just got done, then schedule the next bit of
  677                  * work, if any.  Rebuild/resync is done a little bit at a
  678                  * time.  Either when a timeout happens, or after we get a
  679                  * bunch of I/Os to the disk (to make sure an active system
  680                  * will complete in a sane amount of time).
  681                  *
  682                  * We are setup to do differing amounts of work for each of
  683                  * these cases.  so long as the slabs is smallish (less than
  684                  * 50 or so, I'd guess, but that's just a WAG), we shouldn't
  685                  * have any bio starvation issues.  For active disks, we do
  686                  * 5MB of data, for inactive ones, we do 50MB.
  687                  */
  688                 if (trs->trso_type == TR_RAID1_REBUILD) {
  689                         if (bp->bio_cmd == BIO_READ) {
  690 
  691                                 /* Immediately abort rebuild, if requested. */
  692                                 if (trs->trso_flags & TR_RAID1_F_ABORT) {
  693                                         trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
  694                                         g_raid_tr_raid1_rebuild_abort(tr);
  695                                         return;
  696                                 }
  697 
  698                                 /* On read error, skip and cross fingers. */
  699                                 if (bp->bio_error != 0) {
  700                                         G_RAID_LOGREQ(0, bp,
  701                                             "Read error during rebuild (%d), "
  702                                             "possible data loss!",
  703                                             bp->bio_error);
  704                                         goto rebuild_round_done;
  705                                 }
  706 
  707                                 /*
  708                                  * The read operation finished, queue the
  709                                  * write and get out.
  710                                  */
  711                                 G_RAID_LOGREQ(4, bp, "rebuild read done. %d",
  712                                     bp->bio_error);
  713                                 bp->bio_cmd = BIO_WRITE;
  714                                 bp->bio_cflags = G_RAID_BIO_FLAG_SYNC;
  715                                 G_RAID_LOGREQ(4, bp, "Queueing rebuild write.");
  716                                 g_raid_subdisk_iostart(trs->trso_failed_sd, bp);
  717                         } else {
  718                                 /*
  719                                  * The write operation just finished.  Do
  720                                  * another.  We keep cloning the master bio
  721                                  * since it has the right buffers allocated to
  722                                  * it.
  723                                  */
  724                                 G_RAID_LOGREQ(4, bp,
  725                                     "rebuild write done. Error %d",
  726                                     bp->bio_error);
  727                                 nsd = trs->trso_failed_sd;
  728                                 if (bp->bio_error != 0 ||
  729                                     trs->trso_flags & TR_RAID1_F_ABORT) {
  730                                         if ((trs->trso_flags &
  731                                             TR_RAID1_F_ABORT) == 0) {
  732                                                 g_raid_tr_raid1_fail_disk(sd->sd_softc,
  733                                                     nsd, nsd->sd_disk);
  734                                         }
  735                                         trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
  736                                         g_raid_tr_raid1_rebuild_abort(tr);
  737                                         return;
  738                                 }
  739 rebuild_round_done:
  740                                 nsd = trs->trso_failed_sd;
  741                                 trs->trso_flags &= ~TR_RAID1_F_LOCKED;
  742                                 g_raid_unlock_range(sd->sd_volume,
  743                                     bp->bio_offset, bp->bio_length);
  744                                 nsd->sd_rebuild_pos += bp->bio_length;
  745                                 if (nsd->sd_rebuild_pos >= nsd->sd_size) {
  746                                         g_raid_tr_raid1_rebuild_finish(tr);
  747                                         return;
  748                                 }
  749 
  750                                 /* Abort rebuild if we are stopping */
  751                                 if (trs->trso_stopping) {
  752                                         trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
  753                                         g_raid_tr_raid1_rebuild_abort(tr);
  754                                         return;
  755                                 }
  756 
  757                                 if (--trs->trso_meta_update <= 0) {
  758                                         g_raid_write_metadata(vol->v_softc,
  759                                             vol, nsd, nsd->sd_disk);
  760                                         trs->trso_meta_update =
  761                                             g_raid1_rebuild_meta_update;
  762                                 }
  763                                 trs->trso_flags &= ~TR_RAID1_F_DOING_SOME;
  764                                 if (--trs->trso_recover_slabs <= 0)
  765                                         return;
  766                                 g_raid_tr_raid1_rebuild_some(tr);
  767                         }
  768                 } else if (trs->trso_type == TR_RAID1_RESYNC) {
  769                         /*
  770                          * read good sd, read bad sd in parallel.  when both
  771                          * done, compare the buffers.  write good to the bad
  772                          * if different.  do the next bit of work.
  773                          */
  774                         panic("Somehow, we think we're doing a resync");
  775                 }
  776                 return;
  777         }
  778         pbp = bp->bio_parent;
  779         pbp->bio_inbed++;
  780         if (bp->bio_cmd == BIO_READ && bp->bio_error != 0) {
  781                 /*
  782                  * Read failed on first drive.  Retry the read error on
  783                  * another disk drive, if available, before erroring out the
  784                  * read.
  785                  */
  786                 sd->sd_disk->d_read_errs++;
  787                 G_RAID_LOGREQ(0, bp,
  788                     "Read error (%d), %d read errors total",
  789                     bp->bio_error, sd->sd_disk->d_read_errs);
  790 
  791                 /*
  792                  * If there are too many read errors, we move to degraded.
  793                  * XXX Do we want to FAIL the drive (eg, make the user redo
  794                  * everything to get it back in sync), or just degrade the
  795                  * drive, which kicks off a resync?
  796                  */
  797                 do_write = 1;
  798                 if (sd->sd_disk->d_read_errs > g_raid_read_err_thresh) {
  799                         g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
  800                         if (pbp->bio_children == 1)
  801                                 do_write = 0;
  802                 }
  803 
  804                 /*
  805                  * Find the other disk, and try to do the I/O to it.
  806                  */
  807                 mask = (uintptr_t *)(&pbp->bio_driver2);
  808                 if (pbp->bio_children == 1) {
  809                         /* Save original subdisk. */
  810                         pbp->bio_driver1 = do_write ? sd : NULL;
  811                         *mask = 0;
  812                 }
  813                 *mask |= 1 << sd->sd_pos;
  814                 nsd = g_raid_tr_raid1_select_read_disk(vol, pbp, *mask);
  815                 if (nsd != NULL && (cbp = g_clone_bio(pbp)) != NULL) {
  816                         g_destroy_bio(bp);
  817                         G_RAID_LOGREQ(2, cbp, "Retrying read from %d",
  818                             nsd->sd_pos);
  819                         if (pbp->bio_children == 2 && do_write) {
  820                                 sd->sd_recovery++;
  821                                 cbp->bio_caller1 = nsd;
  822                                 pbp->bio_pflags = G_RAID_BIO_FLAG_LOCKED;
  823                                 /* Lock callback starts I/O */
  824                                 g_raid_lock_range(sd->sd_volume,
  825                                     cbp->bio_offset, cbp->bio_length, pbp, cbp);
  826                         } else {
  827                                 g_raid_subdisk_iostart(nsd, cbp);
  828                         }
  829                         return;
  830                 }
  831                 /*
  832                  * We can't retry.  Return the original error by falling
  833                  * through.  This will happen when there's only one good disk.
  834                  * We don't need to fail the raid, since its actual state is
  835                  * based on the state of the subdisks.
  836                  */
  837                 G_RAID_LOGREQ(2, bp, "Couldn't retry read, failing it");
  838         }
  839         if (bp->bio_cmd == BIO_READ &&
  840             bp->bio_error == 0 &&
  841             pbp->bio_children > 1 &&
  842             pbp->bio_driver1 != NULL) {
  843                 /*
  844                  * If it was a read, and bio_children is >1, then we just
  845                  * recovered the data from the second drive.  We should try to
  846                  * write that data to the first drive if sector remapping is
  847                  * enabled.  A write should put the data in a new place on the
  848                  * disk, remapping the bad sector.  Do we need to do that by
  849                  * queueing a request to the main worker thread?  It doesn't
  850                  * affect the return code of this current read, and can be
  851                  * done at our liesure.  However, to make the code simpler, it
  852                  * is done syncrhonously.
  853                  */
  854                 G_RAID_LOGREQ(3, bp, "Recovered data from other drive");
  855                 cbp = g_clone_bio(pbp);
  856                 if (cbp != NULL) {
  857                         g_destroy_bio(bp);
  858                         cbp->bio_cmd = BIO_WRITE;
  859                         cbp->bio_cflags = G_RAID_BIO_FLAG_REMAP;
  860                         G_RAID_LOGREQ(2, cbp,
  861                             "Attempting bad sector remap on failing drive.");
  862                         g_raid_subdisk_iostart(pbp->bio_driver1, cbp);
  863                         return;
  864                 }
  865         }
  866         if (pbp->bio_pflags & G_RAID_BIO_FLAG_LOCKED) {
  867                 /*
  868                  * We're done with a recovery, mark the range as unlocked.
  869                  * For any write errors, we agressively fail the disk since
  870                  * there was both a READ and a WRITE error at this location.
  871                  * Both types of errors generally indicates the drive is on
  872                  * the verge of total failure anyway.  Better to stop trusting
  873                  * it now.  However, we need to reset error to 0 in that case
  874                  * because we're not failing the original I/O which succeeded.
  875                  */
  876                 if (bp->bio_cmd == BIO_WRITE && bp->bio_error) {
  877                         G_RAID_LOGREQ(0, bp, "Remap write failed: "
  878                             "failing subdisk.");
  879                         g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
  880                         bp->bio_error = 0;
  881                 }
  882                 if (pbp->bio_driver1 != NULL) {
  883                         ((struct g_raid_subdisk *)pbp->bio_driver1)
  884                             ->sd_recovery--;
  885                 }
  886                 G_RAID_LOGREQ(2, bp, "REMAP done %d.", bp->bio_error);
  887                 g_raid_unlock_range(sd->sd_volume, bp->bio_offset,
  888                     bp->bio_length);
  889         }
  890         if (pbp->bio_cmd != BIO_READ) {
  891                 if (pbp->bio_inbed == 1 || pbp->bio_error != 0)
  892                         pbp->bio_error = bp->bio_error;
  893                 if (pbp->bio_cmd == BIO_WRITE && bp->bio_error != 0) {
  894                         G_RAID_LOGREQ(0, bp, "Write failed: failing subdisk.");
  895                         g_raid_tr_raid1_fail_disk(sd->sd_softc, sd, sd->sd_disk);
  896                 }
  897                 error = pbp->bio_error;
  898         } else
  899                 error = bp->bio_error;
  900         g_destroy_bio(bp);
  901         if (pbp->bio_children == pbp->bio_inbed) {
  902                 pbp->bio_completed = pbp->bio_length;
  903                 g_raid_iodone(pbp, error);
  904         }
  905 }
  906 
  907 static int
  908 g_raid_tr_kerneldump_raid1(struct g_raid_tr_object *tr,
  909     void *virtual, vm_offset_t physical, off_t offset, size_t length)
  910 {
  911         struct g_raid_volume *vol;
  912         struct g_raid_subdisk *sd;
  913         int error, i, ok;
  914 
  915         vol = tr->tro_volume;
  916         error = 0;
  917         ok = 0;
  918         for (i = 0; i < vol->v_disks_count; i++) {
  919                 sd = &vol->v_subdisks[i];
  920                 switch (sd->sd_state) {
  921                 case G_RAID_SUBDISK_S_ACTIVE:
  922                         break;
  923                 case G_RAID_SUBDISK_S_REBUILD:
  924                         /*
  925                          * When rebuilding, only part of this subdisk is
  926                          * writable, the rest will be written as part of the
  927                          * that process.
  928                          */
  929                         if (offset >= sd->sd_rebuild_pos)
  930                                 continue;
  931                         break;
  932                 case G_RAID_SUBDISK_S_STALE:
  933                 case G_RAID_SUBDISK_S_RESYNC:
  934                         /*
  935                          * Resyncing still writes on the theory that the
  936                          * resync'd disk is very close and writing it will
  937                          * keep it that way better if we keep up while
  938                          * resyncing.
  939                          */
  940                         break;
  941                 default:
  942                         continue;
  943                 }
  944                 error = g_raid_subdisk_kerneldump(sd,
  945                     virtual, physical, offset, length);
  946                 if (error == 0)
  947                         ok++;
  948         }
  949         return (ok > 0 ? 0 : error);
  950 }
  951 
  952 static int
  953 g_raid_tr_locked_raid1(struct g_raid_tr_object *tr, void *argp)
  954 {
  955         struct bio *bp;
  956         struct g_raid_subdisk *sd;
  957 
  958         bp = (struct bio *)argp;
  959         sd = (struct g_raid_subdisk *)bp->bio_caller1;
  960         g_raid_subdisk_iostart(sd, bp);
  961 
  962         return (0);
  963 }
  964 
  965 static int
  966 g_raid_tr_idle_raid1(struct g_raid_tr_object *tr)
  967 {
  968         struct g_raid_tr_raid1_object *trs;
  969 
  970         trs = (struct g_raid_tr_raid1_object *)tr;
  971         trs->trso_fair_io = g_raid1_rebuild_fair_io;
  972         trs->trso_recover_slabs = g_raid1_rebuild_cluster_idle;
  973         if (trs->trso_type == TR_RAID1_REBUILD)
  974                 g_raid_tr_raid1_rebuild_some(tr);
  975         return (0);
  976 }
  977 
  978 static int
  979 g_raid_tr_free_raid1(struct g_raid_tr_object *tr)
  980 {
  981         struct g_raid_tr_raid1_object *trs;
  982 
  983         trs = (struct g_raid_tr_raid1_object *)tr;
  984 
  985         if (trs->trso_buffer != NULL) {
  986                 free(trs->trso_buffer, M_TR_RAID1);
  987                 trs->trso_buffer = NULL;
  988         }
  989         return (0);
  990 }
  991 
  992 G_RAID_TR_DECLARE(raid1, "RAID1");

Cache object: 8b2634d0ab526810ba39b3b361d4f4f1


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