/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/sbuf.h>
#include <sys/sched.h>
#include <sys/sysctl.h>

#include <vm/uma.h>

#include <geom/geom.h>
#include <geom/geom_dbg.h>
#include <geom/raid/g_raid.h>
#include "g_raid_md_if.h"
#include "g_raid_tr_if.h"

static MALLOC_DEFINE(M_RAID, "raid_data", "GEOM_RAID Data");

SYSCTL_DECL(_kern_geom);
SYSCTL_NODE(_kern_geom, OID_AUTO, raid, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
    "GEOM_RAID stuff");
int g_raid_enable = 1;
SYSCTL_INT(_kern_geom_raid, OID_AUTO, enable, CTLFLAG_RWTUN,
    &g_raid_enable, 0, "Enable on-disk metadata taste");
u_int g_raid_aggressive_spare = 0;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, aggressive_spare, CTLFLAG_RWTUN,
    &g_raid_aggressive_spare, 0, "Use disks without metadata as spare");
u_int g_raid_debug = 0;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, debug, CTLFLAG_RWTUN, &g_raid_debug, 0,
    "Debug level");
int g_raid_read_err_thresh = 10;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, read_err_thresh, CTLFLAG_RWTUN,
    &g_raid_read_err_thresh, 0,
    "Number of read errors equated to disk failure");
u_int g_raid_start_timeout = 30;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, start_timeout, CTLFLAG_RWTUN,
    &g_raid_start_timeout, 0,
    "Time to wait for all array components");
static u_int g_raid_clean_time = 5;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, clean_time, CTLFLAG_RWTUN,
    &g_raid_clean_time, 0, "Mark volume as clean when idling");
static u_int g_raid_disconnect_on_failure = 1;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, disconnect_on_failure, CTLFLAG_RWTUN,
    &g_raid_disconnect_on_failure, 0, "Disconnect component on I/O failure.");
static u_int g_raid_name_format = 0;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, name_format, CTLFLAG_RWTUN,
    &g_raid_name_format, 0, "Providers name format.");
static u_int g_raid_idle_threshold = 1000000;
SYSCTL_UINT(_kern_geom_raid, OID_AUTO, idle_threshold, CTLFLAG_RWTUN,
    &g_raid_idle_threshold, 1000000,
    "Time in microseconds to consider a volume idle.");

#define MSLEEP(rv, ident, mtx, priority, wmesg, timeout)        do {    \
        G_RAID_DEBUG(4, "%s: Sleeping %p.", __func__, (ident));         \
        rv = msleep((ident), (mtx), (priority), (wmesg), (timeout));    \
        G_RAID_DEBUG(4, "%s: Woken up %p.", __func__, (ident));         \
} while (0)

LIST_HEAD(, g_raid_md_class) g_raid_md_classes =
    LIST_HEAD_INITIALIZER(g_raid_md_classes);

LIST_HEAD(, g_raid_tr_class) g_raid_tr_classes =
    LIST_HEAD_INITIALIZER(g_raid_tr_classes);

LIST_HEAD(, g_raid_volume) g_raid_volumes =
    LIST_HEAD_INITIALIZER(g_raid_volumes);

static eventhandler_tag g_raid_post_sync = NULL;
static int g_raid_started = 0;
static int g_raid_shutdown = 0;

static int g_raid_destroy_geom(struct gctl_req *req, struct g_class *mp,
    struct g_geom *gp);
static g_taste_t g_raid_taste;
static void g_raid_init(struct g_class *mp);
static void g_raid_fini(struct g_class *mp);

struct g_class g_raid_class = {
        .name = G_RAID_CLASS_NAME,
        .version = G_VERSION,
        .ctlreq = g_raid_ctl,
        .taste = g_raid_taste,
        .destroy_geom = g_raid_destroy_geom,
        .init = g_raid_init,
        .fini = g_raid_fini
};

static void g_raid_destroy_provider(struct g_raid_volume *vol);
static int g_raid_update_disk(struct g_raid_disk *disk, u_int event);
static int g_raid_update_subdisk(struct g_raid_subdisk *subdisk, u_int event);
static int g_raid_update_volume(struct g_raid_volume *vol, u_int event);
static int g_raid_update_node(struct g_raid_softc *sc, u_int event);
static void g_raid_dumpconf(struct sbuf *sb, const char *indent,
    struct g_geom *gp, struct g_consumer *cp, struct g_provider *pp);
static void g_raid_start(struct bio *bp);
static void g_raid_start_request(struct bio *bp);
static void g_raid_disk_done(struct bio *bp);
static void g_raid_poll(struct g_raid_softc *sc);

static const char *
g_raid_node_event2str(int event)
{

        switch (event) {
        case G_RAID_NODE_E_WAKE:
                return ("WAKE");
        case G_RAID_NODE_E_START:
                return ("START");
        default:
                return ("INVALID");
        }
}

const char *
g_raid_disk_state2str(int state)
{

        switch (state) {
        case G_RAID_DISK_S_NONE:
                return ("NONE");
        case G_RAID_DISK_S_OFFLINE:
                return ("OFFLINE");
        case G_RAID_DISK_S_DISABLED:
                return ("DISABLED");
        case G_RAID_DISK_S_FAILED:
                return ("FAILED");
        case G_RAID_DISK_S_STALE_FAILED:
                return ("STALE_FAILED");
        case G_RAID_DISK_S_SPARE:
                return ("SPARE");
        case G_RAID_DISK_S_STALE:
                return ("STALE");
        case G_RAID_DISK_S_ACTIVE:
                return ("ACTIVE");
        default:
                return ("INVALID");
        }
}

static const char *
g_raid_disk_event2str(int event)
{

        switch (event) {
        case G_RAID_DISK_E_DISCONNECTED:
                return ("DISCONNECTED");
        default:
                return ("INVALID");
        }
}

const char *
g_raid_subdisk_state2str(int state)
{

        switch (state) {
        case G_RAID_SUBDISK_S_NONE:
                return ("NONE");
        case G_RAID_SUBDISK_S_FAILED:
                return ("FAILED");
        case G_RAID_SUBDISK_S_NEW:
                return ("NEW");
        case G_RAID_SUBDISK_S_REBUILD:
                return ("REBUILD");
        case G_RAID_SUBDISK_S_UNINITIALIZED:
                return ("UNINITIALIZED");
        case G_RAID_SUBDISK_S_STALE:
                return ("STALE");
        case G_RAID_SUBDISK_S_RESYNC:
                return ("RESYNC");
        case G_RAID_SUBDISK_S_ACTIVE:
                return ("ACTIVE");
        default:
                return ("INVALID");
        }
}

static const char *
g_raid_subdisk_event2str(int event)
{

        switch (event) {
        case G_RAID_SUBDISK_E_NEW:
                return ("NEW");
        case G_RAID_SUBDISK_E_FAILED:
                return ("FAILED");
        case G_RAID_SUBDISK_E_DISCONNECTED:
                return ("DISCONNECTED");
        default:
                return ("INVALID");
        }
}

const char *
g_raid_volume_state2str(int state)
{

        switch (state) {
        case G_RAID_VOLUME_S_STARTING:
                return ("STARTING");
        case G_RAID_VOLUME_S_BROKEN:
                return ("BROKEN");
        case G_RAID_VOLUME_S_DEGRADED:
                return ("DEGRADED");
        case G_RAID_VOLUME_S_SUBOPTIMAL:
                return ("SUBOPTIMAL");
        case G_RAID_VOLUME_S_OPTIMAL:
                return ("OPTIMAL");
        case G_RAID_VOLUME_S_UNSUPPORTED:
                return ("UNSUPPORTED");
        case G_RAID_VOLUME_S_STOPPED:
                return ("STOPPED");
        default:
                return ("INVALID");
        }
}

static const char *
g_raid_volume_event2str(int event)
{

        switch (event) {
        case G_RAID_VOLUME_E_UP:
                return ("UP");
        case G_RAID_VOLUME_E_DOWN:
                return ("DOWN");
        case G_RAID_VOLUME_E_START:
                return ("START");
        case G_RAID_VOLUME_E_STARTMD:
                return ("STARTMD");
        default:
                return ("INVALID");
        }
}

const char *
g_raid_volume_level2str(int level, int qual)
{

        switch (level) {
        case G_RAID_VOLUME_RL_RAID0:
                return ("RAID0");
        case G_RAID_VOLUME_RL_RAID1:
                return ("RAID1");
        case G_RAID_VOLUME_RL_RAID3:
                if (qual == G_RAID_VOLUME_RLQ_R3P0)
                        return ("RAID3-P0");
                if (qual == G_RAID_VOLUME_RLQ_R3PN)
                        return ("RAID3-PN");
                return ("RAID3");
        case G_RAID_VOLUME_RL_RAID4:
                if (qual == G_RAID_VOLUME_RLQ_R4P0)
                        return ("RAID4-P0");
                if (qual == G_RAID_VOLUME_RLQ_R4PN)
                        return ("RAID4-PN");
                return ("RAID4");
        case G_RAID_VOLUME_RL_RAID5:
                if (qual == G_RAID_VOLUME_RLQ_R5RA)
                        return ("RAID5-RA");
                if (qual == G_RAID_VOLUME_RLQ_R5RS)
                        return ("RAID5-RS");
                if (qual == G_RAID_VOLUME_RLQ_R5LA)
                        return ("RAID5-LA");
                if (qual == G_RAID_VOLUME_RLQ_R5LS)
                        return ("RAID5-LS");
                return ("RAID5");
        case G_RAID_VOLUME_RL_RAID6:
                if (qual == G_RAID_VOLUME_RLQ_R6RA)
                        return ("RAID6-RA");
                if (qual == G_RAID_VOLUME_RLQ_R6RS)
                        return ("RAID6-RS");
                if (qual == G_RAID_VOLUME_RLQ_R6LA)
                        return ("RAID6-LA");
                if (qual == G_RAID_VOLUME_RLQ_R6LS)
                        return ("RAID6-LS");
                return ("RAID6");
        case G_RAID_VOLUME_RL_RAIDMDF:
                if (qual == G_RAID_VOLUME_RLQ_RMDFRA)
                        return ("RAIDMDF-RA");
                if (qual == G_RAID_VOLUME_RLQ_RMDFRS)
                        return ("RAIDMDF-RS");
                if (qual == G_RAID_VOLUME_RLQ_RMDFLA)
                        return ("RAIDMDF-LA");
                if (qual == G_RAID_VOLUME_RLQ_RMDFLS)
                        return ("RAIDMDF-LS");
                return ("RAIDMDF");
        case G_RAID_VOLUME_RL_RAID1E:
                if (qual == G_RAID_VOLUME_RLQ_R1EA)
                        return ("RAID1E-A");
                if (qual == G_RAID_VOLUME_RLQ_R1EO)
                        return ("RAID1E-O");
                return ("RAID1E");
        case G_RAID_VOLUME_RL_SINGLE:
                return ("SINGLE");
        case G_RAID_VOLUME_RL_CONCAT:
                return ("CONCAT");
        case G_RAID_VOLUME_RL_RAID5E:
                if (qual == G_RAID_VOLUME_RLQ_R5ERA)
                        return ("RAID5E-RA");
                if (qual == G_RAID_VOLUME_RLQ_R5ERS)
                        return ("RAID5E-RS");
                if (qual == G_RAID_VOLUME_RLQ_R5ELA)
                        return ("RAID5E-LA");
                if (qual == G_RAID_VOLUME_RLQ_R5ELS)
                        return ("RAID5E-LS");
                return ("RAID5E");
        case G_RAID_VOLUME_RL_RAID5EE:
                if (qual == G_RAID_VOLUME_RLQ_R5EERA)
                        return ("RAID5EE-RA");
                if (qual == G_RAID_VOLUME_RLQ_R5EERS)
                        return ("RAID5EE-RS");
                if (qual == G_RAID_VOLUME_RLQ_R5EELA)
                        return ("RAID5EE-LA");
                if (qual == G_RAID_VOLUME_RLQ_R5EELS)
                        return ("RAID5EE-LS");
                return ("RAID5EE");
        case G_RAID_VOLUME_RL_RAID5R:
                if (qual == G_RAID_VOLUME_RLQ_R5RRA)
                        return ("RAID5R-RA");
                if (qual == G_RAID_VOLUME_RLQ_R5RRS)
                        return ("RAID5R-RS");
                if (qual == G_RAID_VOLUME_RLQ_R5RLA)
                        return ("RAID5R-LA");
                if (qual == G_RAID_VOLUME_RLQ_R5RLS)
                        return ("RAID5R-LS");
                return ("RAID5E");
        default:
                return ("UNKNOWN");
        }
}

int
g_raid_volume_str2level(const char *str, int *level, int *qual)
{

        *level = G_RAID_VOLUME_RL_UNKNOWN;
        *qual = G_RAID_VOLUME_RLQ_NONE;
        if (strcasecmp(str, "RAID0") == 0)
                *level = G_RAID_VOLUME_RL_RAID0;
        else if (strcasecmp(str, "RAID1") == 0)
                *level = G_RAID_VOLUME_RL_RAID1;
        else if (strcasecmp(str, "RAID3-P0") == 0) {
                *level = G_RAID_VOLUME_RL_RAID3;
                *qual = G_RAID_VOLUME_RLQ_R3P0;
        } else if (strcasecmp(str, "RAID3-PN") == 0 ||
                   strcasecmp(str, "RAID3") == 0) {
                *level = G_RAID_VOLUME_RL_RAID3;
                *qual = G_RAID_VOLUME_RLQ_R3PN;
        } else if (strcasecmp(str, "RAID4-P0") == 0) {
                *level = G_RAID_VOLUME_RL_RAID4;
                *qual = G_RAID_VOLUME_RLQ_R4P0;
        } else if (strcasecmp(str, "RAID4-PN") == 0 ||
                   strcasecmp(str, "RAID4") == 0) {
                *level = G_RAID_VOLUME_RL_RAID4;
                *qual = G_RAID_VOLUME_RLQ_R4PN;
        } else if (strcasecmp(str, "RAID5-RA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5;
                *qual = G_RAID_VOLUME_RLQ_R5RA;
        } else if (strcasecmp(str, "RAID5-RS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5;
                *qual = G_RAID_VOLUME_RLQ_R5RS;
        } else if (strcasecmp(str, "RAID5") == 0 ||
                   strcasecmp(str, "RAID5-LA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5;
                *qual = G_RAID_VOLUME_RLQ_R5LA;
        } else if (strcasecmp(str, "RAID5-LS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5;
                *qual = G_RAID_VOLUME_RLQ_R5LS;
        } else if (strcasecmp(str, "RAID6-RA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID6;
                *qual = G_RAID_VOLUME_RLQ_R6RA;
        } else if (strcasecmp(str, "RAID6-RS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID6;
                *qual = G_RAID_VOLUME_RLQ_R6RS;
        } else if (strcasecmp(str, "RAID6") == 0 ||
                   strcasecmp(str, "RAID6-LA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID6;
                *qual = G_RAID_VOLUME_RLQ_R6LA;
        } else if (strcasecmp(str, "RAID6-LS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID6;
                *qual = G_RAID_VOLUME_RLQ_R6LS;
        } else if (strcasecmp(str, "RAIDMDF-RA") == 0) {
                *level = G_RAID_VOLUME_RL_RAIDMDF;
                *qual = G_RAID_VOLUME_RLQ_RMDFRA;
        } else if (strcasecmp(str, "RAIDMDF-RS") == 0) {
                *level = G_RAID_VOLUME_RL_RAIDMDF;
                *qual = G_RAID_VOLUME_RLQ_RMDFRS;
        } else if (strcasecmp(str, "RAIDMDF") == 0 ||
                   strcasecmp(str, "RAIDMDF-LA") == 0) {
                *level = G_RAID_VOLUME_RL_RAIDMDF;
                *qual = G_RAID_VOLUME_RLQ_RMDFLA;
        } else if (strcasecmp(str, "RAIDMDF-LS") == 0) {
                *level = G_RAID_VOLUME_RL_RAIDMDF;
                *qual = G_RAID_VOLUME_RLQ_RMDFLS;
        } else if (strcasecmp(str, "RAID10") == 0 ||
                   strcasecmp(str, "RAID1E") == 0 ||
                   strcasecmp(str, "RAID1E-A") == 0) {
                *level = G_RAID_VOLUME_RL_RAID1E;
                *qual = G_RAID_VOLUME_RLQ_R1EA;
        } else if (strcasecmp(str, "RAID1E-O") == 0) {
                *level = G_RAID_VOLUME_RL_RAID1E;
                *qual = G_RAID_VOLUME_RLQ_R1EO;
        } else if (strcasecmp(str, "SINGLE") == 0)
                *level = G_RAID_VOLUME_RL_SINGLE;
        else if (strcasecmp(str, "CONCAT") == 0)
                *level = G_RAID_VOLUME_RL_CONCAT;
        else if (strcasecmp(str, "RAID5E-RA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5E;
                *qual = G_RAID_VOLUME_RLQ_R5ERA;
        } else if (strcasecmp(str, "RAID5E-RS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5E;
                *qual = G_RAID_VOLUME_RLQ_R5ERS;
        } else if (strcasecmp(str, "RAID5E") == 0 ||
                   strcasecmp(str, "RAID5E-LA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5E;
                *qual = G_RAID_VOLUME_RLQ_R5ELA;
        } else if (strcasecmp(str, "RAID5E-LS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5E;
                *qual = G_RAID_VOLUME_RLQ_R5ELS;
        } else if (strcasecmp(str, "RAID5EE-RA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5EE;
                *qual = G_RAID_VOLUME_RLQ_R5EERA;
        } else if (strcasecmp(str, "RAID5EE-RS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5EE;
                *qual = G_RAID_VOLUME_RLQ_R5EERS;
        } else if (strcasecmp(str, "RAID5EE") == 0 ||
                   strcasecmp(str, "RAID5EE-LA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5EE;
                *qual = G_RAID_VOLUME_RLQ_R5EELA;
        } else if (strcasecmp(str, "RAID5EE-LS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5EE;
                *qual = G_RAID_VOLUME_RLQ_R5EELS;
        } else if (strcasecmp(str, "RAID5R-RA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5R;
                *qual = G_RAID_VOLUME_RLQ_R5RRA;
        } else if (strcasecmp(str, "RAID5R-RS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5R;
                *qual = G_RAID_VOLUME_RLQ_R5RRS;
        } else if (strcasecmp(str, "RAID5R") == 0 ||
                   strcasecmp(str, "RAID5R-LA") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5R;
                *qual = G_RAID_VOLUME_RLQ_R5RLA;
        } else if (strcasecmp(str, "RAID5R-LS") == 0) {
                *level = G_RAID_VOLUME_RL_RAID5R;
                *qual = G_RAID_VOLUME_RLQ_R5RLS;
        } else
                return (-1);
        return (0);
}

const char *
g_raid_get_diskname(struct g_raid_disk *disk)
{

        if (disk->d_consumer == NULL || disk->d_consumer->provider == NULL)
                return ("[unknown]");
        return (disk->d_consumer->provider->name);
}

void
g_raid_get_disk_info(struct g_raid_disk *disk)
{
        struct g_consumer *cp = disk->d_consumer;
        int error, len;

        /* Read kernel dumping information. */
        disk->d_kd.offset = 0;
        disk->d_kd.length = OFF_MAX;
        len = sizeof(disk->d_kd);
        error = g_io_getattr("GEOM::kerneldump", cp, &len, &disk->d_kd);
        if (error)
                disk->d_kd.di.dumper = NULL;
        if (disk->d_kd.di.dumper == NULL)
                G_RAID_DEBUG1(2, disk->d_softc,
                    "Dumping not supported by %s: %d.", 
                    cp->provider->name, error);

        /* Read BIO_DELETE support. */
        error = g_getattr("GEOM::candelete", cp, &disk->d_candelete);
        if (error)
                disk->d_candelete = 0;
        if (!disk->d_candelete)
                G_RAID_DEBUG1(2, disk->d_softc,
                    "BIO_DELETE not supported by %s: %d.", 
                    cp->provider->name, error);
}

void
g_raid_report_disk_state(struct g_raid_disk *disk)
{
        struct g_raid_subdisk *sd;
        int len, state;
        uint32_t s;

        if (disk->d_consumer == NULL)
                return;
        if (disk->d_state == G_RAID_DISK_S_DISABLED) {
                s = G_STATE_ACTIVE; /* XXX */
        } else if (disk->d_state == G_RAID_DISK_S_FAILED ||
            disk->d_state == G_RAID_DISK_S_STALE_FAILED) {
                s = G_STATE_FAILED;
        } else {
                state = G_RAID_SUBDISK_S_ACTIVE;
                TAILQ_FOREACH(sd, &disk->d_subdisks, sd_next) {
                        if (sd->sd_state < state)
                                state = sd->sd_state;
                }
                if (state == G_RAID_SUBDISK_S_FAILED)
                        s = G_STATE_FAILED;
                else if (state == G_RAID_SUBDISK_S_NEW ||
                    state == G_RAID_SUBDISK_S_REBUILD)
                        s = G_STATE_REBUILD;
                else if (state == G_RAID_SUBDISK_S_STALE ||
                    state == G_RAID_SUBDISK_S_RESYNC)
                        s = G_STATE_RESYNC;
                else
                        s = G_STATE_ACTIVE;
        }
        len = sizeof(s);
        g_io_getattr("GEOM::setstate", disk->d_consumer, &len, &s);
        G_RAID_DEBUG1(2, disk->d_softc, "Disk %s state reported as %d.",
            g_raid_get_diskname(disk), s);
}

void
g_raid_change_disk_state(struct g_raid_disk *disk, int state)
{

        G_RAID_DEBUG1(0, disk->d_softc, "Disk %s state changed from %s to %s.",
            g_raid_get_diskname(disk),
            g_raid_disk_state2str(disk->d_state),
            g_raid_disk_state2str(state));
        disk->d_state = state;
        g_raid_report_disk_state(disk);
}

void
g_raid_change_subdisk_state(struct g_raid_subdisk *sd, int state)
{

        G_RAID_DEBUG1(0, sd->sd_softc,
            "Subdisk %s:%d-%s state changed from %s to %s.",
            sd->sd_volume->v_name, sd->sd_pos,
            sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]",
            g_raid_subdisk_state2str(sd->sd_state),
            g_raid_subdisk_state2str(state));
        sd->sd_state = state;
        if (sd->sd_disk)
                g_raid_report_disk_state(sd->sd_disk);
}

void
g_raid_change_volume_state(struct g_raid_volume *vol, int state)
{

        G_RAID_DEBUG1(0, vol->v_softc,
            "Volume %s state changed from %s to %s.",
            vol->v_name,
            g_raid_volume_state2str(vol->v_state),
            g_raid_volume_state2str(state));
        vol->v_state = state;
}

/*
 * --- Events handling functions ---
 * Events in geom_raid are used to maintain subdisks and volumes status
 * from one thread to simplify locking.
 */
static void
g_raid_event_free(struct g_raid_event *ep)
{

        free(ep, M_RAID);
}

int
g_raid_event_send(void *arg, int event, int flags)
{
        struct g_raid_softc *sc;
        struct g_raid_event *ep;
        int error;

        if ((flags & G_RAID_EVENT_VOLUME) != 0) {
                sc = ((struct g_raid_volume *)arg)->v_softc;
        } else if ((flags & G_RAID_EVENT_DISK) != 0) {
                sc = ((struct g_raid_disk *)arg)->d_softc;
        } else if ((flags & G_RAID_EVENT_SUBDISK) != 0) {
                sc = ((struct g_raid_subdisk *)arg)->sd_softc;
        } else {
                sc = arg;
        }
        ep = malloc(sizeof(*ep), M_RAID,
            sx_xlocked(&sc->sc_lock) ? M_WAITOK : M_NOWAIT);
        if (ep == NULL)
                return (ENOMEM);
        ep->e_tgt = arg;
        ep->e_event = event;
        ep->e_flags = flags;
        ep->e_error = 0;
        G_RAID_DEBUG1(4, sc, "Sending event %p. Waking up %p.", ep, sc);
        mtx_lock(&sc->sc_queue_mtx);
        TAILQ_INSERT_TAIL(&sc->sc_events, ep, e_next);
        mtx_unlock(&sc->sc_queue_mtx);
        wakeup(sc);

        if ((flags & G_RAID_EVENT_WAIT) == 0)
                return (0);

        sx_assert(&sc->sc_lock, SX_XLOCKED);
        G_RAID_DEBUG1(4, sc, "Sleeping on %p.", ep);
        sx_xunlock(&sc->sc_lock);
        while ((ep->e_flags & G_RAID_EVENT_DONE) == 0) {
                mtx_lock(&sc->sc_queue_mtx);
                MSLEEP(error, ep, &sc->sc_queue_mtx, PRIBIO | PDROP, "m:event",
                    hz * 5);
        }
        error = ep->e_error;
        g_raid_event_free(ep);
        sx_xlock(&sc->sc_lock);
        return (error);
}

static void
g_raid_event_cancel(struct g_raid_softc *sc, void *tgt)
{
        struct g_raid_event *ep, *tmpep;

        sx_assert(&sc->sc_lock, SX_XLOCKED);

        mtx_lock(&sc->sc_queue_mtx);
        TAILQ_FOREACH_SAFE(ep, &sc->sc_events, e_next, tmpep) {
                if (ep->e_tgt != tgt)
                        continue;
                TAILQ_REMOVE(&sc->sc_events, ep, e_next);
                if ((ep->e_flags & G_RAID_EVENT_WAIT) == 0)
                        g_raid_event_free(ep);
                else {
                        ep->e_error = ECANCELED;
                        wakeup(ep);
                }
        }
        mtx_unlock(&sc->sc_queue_mtx);
}

static int
g_raid_event_check(struct g_raid_softc *sc, void *tgt)
{
        struct g_raid_event *ep;
        int     res = 0;

        sx_assert(&sc->sc_lock, SX_XLOCKED);

        mtx_lock(&sc->sc_queue_mtx);
        TAILQ_FOREACH(ep, &sc->sc_events, e_next) {
                if (ep->e_tgt != tgt)
                        continue;
                res = 1;
                break;
        }
        mtx_unlock(&sc->sc_queue_mtx);
        return (res);
}

/*
 * Return the number of disks in given state.
 * If state is equal to -1, count all connected disks.
 */
u_int
g_raid_ndisks(struct g_raid_softc *sc, int state)
{
        struct g_raid_disk *disk;
        u_int n;

        sx_assert(&sc->sc_lock, SX_LOCKED);

        n = 0;
        TAILQ_FOREACH(disk, &sc->sc_disks, d_next) {
                if (disk->d_state == state || state == -1)
                        n++;
        }
        return (n);
}

/*
 * Return the number of subdisks in given state.
 * If state is equal to -1, count all connected disks.
 */
u_int
g_raid_nsubdisks(struct g_raid_volume *vol, int state)
{
        struct g_raid_subdisk *subdisk;
        struct g_raid_softc *sc __diagused;
        u_int i, n ;

        sc = vol->v_softc;
        sx_assert(&sc->sc_lock, SX_LOCKED);

        n = 0;
        for (i = 0; i < vol->v_disks_count; i++) {
                subdisk = &vol->v_subdisks[i];
                if ((state == -1 &&
                     subdisk->sd_state != G_RAID_SUBDISK_S_NONE) ||
                    subdisk->sd_state == state)
                        n++;
        }
        return (n);
}

/*
 * Return the first subdisk in given state.
 * If state is equal to -1, then the first connected disks.
 */
struct g_raid_subdisk *
g_raid_get_subdisk(struct g_raid_volume *vol, int state)
{
        struct g_raid_subdisk *sd;
        struct g_raid_softc *sc __diagused;
        u_int i;

        sc = vol->v_softc;
        sx_assert(&sc->sc_lock, SX_LOCKED);

        for (i = 0; i < vol->v_disks_count; i++) {
                sd = &vol->v_subdisks[i];
                if ((state == -1 &&
                     sd->sd_state != G_RAID_SUBDISK_S_NONE) ||
                    sd->sd_state == state)
                        return (sd);
        }
        return (NULL);
}

struct g_consumer *
g_raid_open_consumer(struct g_raid_softc *sc, const char *name)
{
        struct g_consumer *cp;
        struct g_provider *pp;

        g_topology_assert();

        pp = g_provider_by_name(name);
        if (pp == NULL)
                return (NULL);
        cp = g_new_consumer(sc->sc_geom);
        cp->flags |= G_CF_DIRECT_RECEIVE;
        if (g_attach(cp, pp) != 0) {
                g_destroy_consumer(cp);
                return (NULL);
        }
        if (g_access(cp, 1, 1, 1) != 0) {
                g_detach(cp);
                g_destroy_consumer(cp);
                return (NULL);
        }
        return (cp);
}

static u_int
g_raid_nrequests(struct g_raid_softc *sc, struct g_consumer *cp)
{
        struct bio *bp;
        u_int nreqs = 0;

        mtx_lock(&sc->sc_queue_mtx);
        TAILQ_FOREACH(bp, &sc->sc_queue.queue, bio_queue) {
                if (bp->bio_from == cp)
                        nreqs++;
        }
        mtx_unlock(&sc->sc_queue_mtx);
        return (nreqs);
}

u_int
g_raid_nopens(struct g_raid_softc *sc)
{
        struct g_raid_volume *vol;
        u_int opens;

        opens = 0;
        TAILQ_FOREACH(vol, &sc->sc_volumes, v_next) {
                if (vol->v_provider_open != 0)
                        opens++;
        }
        return (opens);
}

static int
g_raid_consumer_is_busy(struct g_raid_softc *sc, struct g_consumer *cp)
{

        if (cp->index > 0) {
                G_RAID_DEBUG1(2, sc,
                    "I/O requests for %s exist, can't destroy it now.",
                    cp->provider->name);
                return (1);
        }
        if (g_raid_nrequests(sc, cp) > 0) {
                G_RAID_DEBUG1(2, sc,
                    "I/O requests for %s in queue, can't destroy it now.",
                    cp->provider->name);
                return (1);
        }
        return (0);
}

static void
g_raid_destroy_consumer(void *arg, int flags __unused)
{
        struct g_consumer *cp;

        g_topology_assert();

        cp = arg;
        G_RAID_DEBUG(1, "Consumer %s destroyed.", cp->provider->name);
        g_detach(cp);
        g_destroy_consumer(cp);
}

void
g_raid_kill_consumer(struct g_raid_softc *sc, struct g_consumer *cp)
{
        struct g_provider *pp;
        int retaste_wait;

        g_topology_assert_not();

        g_topology_lock();
        cp->private = NULL;
        if (g_raid_consumer_is_busy(sc, cp))
                goto out;
        pp = cp->provider;
        retaste_wait = 0;
        if (cp->acw == 1) {
                if ((pp->geom->flags & G_GEOM_WITHER) == 0)
                        retaste_wait = 1;
        }
        if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
                g_access(cp, -cp->acr, -cp->acw, -cp->ace);
        if (retaste_wait) {
                /*
                 * After retaste event was send (inside g_access()), we can send
                 * event to detach and destroy consumer.
                 * A class, which has consumer to the given provider connected
                 * will not receive retaste event for the provider.
                 * This is the way how I ignore retaste events when I close
                 * consumers opened for write: I detach and destroy consumer
                 * after retaste event is sent.
                 */
                g_post_event(g_raid_destroy_consumer, cp, M_WAITOK, NULL);
                goto out;
        }
        G_RAID_DEBUG(1, "Consumer %s destroyed.", pp->name);
        g_detach(cp);
        g_destroy_consumer(cp);
out:
        g_topology_unlock();
}

static void
g_raid_orphan(struct g_consumer *cp)
{
        struct g_raid_disk *disk;

        g_topology_assert();

        disk = cp->private;
        if (disk == NULL)
                return;
        g_raid_event_send(disk, G_RAID_DISK_E_DISCONNECTED,
            G_RAID_EVENT_DISK);
}

static void
g_raid_clean(struct g_raid_volume *vol, int acw)
{
        struct g_raid_softc *sc;
        int timeout;

        sc = vol->v_softc;
        g_topology_assert_not();
        sx_assert(&sc->sc_lock, SX_XLOCKED);

//      if ((sc->sc_flags & G_RAID_DEVICE_FLAG_NOFAILSYNC) != 0)
//              return;
        if (!vol->v_dirty)
                return;
        if (vol->v_writes > 0)
                return;
        if (acw > 0 || (acw == -1 &&
            vol->v_provider != NULL && vol->v_provider->acw > 0)) {
                timeout = g_raid_clean_time - (time_uptime - vol->v_last_write);
                if (!g_raid_shutdown && timeout > 0)
                        return;
        }
        vol->v_dirty = 0;
        G_RAID_DEBUG1(1, sc, "Volume %s marked as clean.",
            vol->v_name);
        g_raid_write_metadata(sc, vol, NULL, NULL);
}

static void
g_raid_dirty(struct g_raid_volume *vol)
{
        struct g_raid_softc *sc;

        sc = vol->v_softc;
        g_topology_assert_not();
        sx_assert(&sc->sc_lock, SX_XLOCKED);

//      if ((sc->sc_flags & G_RAID_DEVICE_FLAG_NOFAILSYNC) != 0)
//              return;
        vol->v_dirty = 1;
        G_RAID_DEBUG1(1, sc, "Volume %s marked as dirty.",
            vol->v_name);
        g_raid_write_metadata(sc, vol, NULL, NULL);
}

void
g_raid_tr_flush_common(struct g_raid_tr_object *tr, struct bio *bp)
{
        struct g_raid_volume *vol;
        struct g_raid_subdisk *sd;
        struct bio_queue_head queue;
        struct bio *cbp;
        int i;

        vol = tr->tro_volume;

        /*
         * Allocate all bios before sending any request, so we can return
         * ENOMEM in nice and clean way.
         */
        bioq_init(&queue);
        for (i = 0; i < vol->v_disks_count; i++) {
                sd = &vol->v_subdisks[i];
                if (sd->sd_state == G_RAID_SUBDISK_S_NONE ||
                    sd->sd_state == G_RAID_SUBDISK_S_FAILED)
                        continue;
                cbp = g_clone_bio(bp);
                if (cbp == NULL)
                        goto failure;
                cbp->bio_caller1 = sd;
                bioq_insert_tail(&queue, cbp);
        }
        while ((cbp = bioq_takefirst(&queue)) != NULL) {
                sd = cbp->bio_caller1;
                cbp->bio_caller1 = NULL;
                g_raid_subdisk_iostart(sd, cbp);
        }
        return;
failure:
        while ((cbp = bioq_takefirst(&queue)) != NULL)
                g_destroy_bio(cbp);
        if (bp->bio_error == 0)
                bp->bio_error = ENOMEM;
        g_raid_iodone(bp, bp->bio_error);
}

static void
g_raid_tr_kerneldump_common_done(struct bio *bp)
{

        bp->bio_flags |= BIO_DONE;
}

int
g_raid_tr_kerneldump_common(struct g_raid_tr_object *tr,
    void *virtual, vm_offset_t physical, off_t offset, size_t length)
{
        struct g_raid_softc *sc;
        struct g_raid_volume *vol;
        struct bio bp;

        vol = tr->tro_volume;
        sc = vol->v_softc;

        g_reset_bio(&bp);
        bp.bio_cmd = BIO_WRITE;
        bp.bio_done = g_raid_tr_kerneldump_common_done;
        bp.bio_attribute = NULL;
        bp.bio_offset = offset;
        bp.bio_length = length;
        bp.bio_data = virtual;
        bp.bio_to = vol->v_provider;

        g_raid_start(&bp);
        while (!(bp.bio_flags & BIO_DONE)) {
                G_RAID_DEBUG1(4, sc, "Poll...");
                g_raid_poll(sc);
                DELAY(10);
        }

        return (bp.bio_error != 0 ? EIO : 0);
}

static int
g_raid_dump(void *arg, void *virtual, off_t offset, size_t length)
{
        struct g_raid_volume *vol;
        int error;

        vol = (struct g_raid_volume *)arg;
        G_RAID_DEBUG1(3, vol->v_softc, "Dumping at off %llu len %llu.",
            (long long unsigned)offset, (long long unsigned)length);

        error = G_RAID_TR_KERNELDUMP(vol->v_tr, virtual, offset, length);
        return (error);
}

static void
g_raid_kerneldump(struct g_raid_softc *sc, struct bio *bp)
{
        struct g_kerneldump *gkd;
        struct g_provider *pp;
        struct g_raid_volume *vol;

        gkd = (struct g_kerneldump*)bp->bio_data;
        pp = bp->bio_to;
        vol = pp->private;
        g_trace(G_T_TOPOLOGY, "g_raid_kerneldump(%s, %jd, %jd)",
                pp->name, (intmax_t)gkd->offset, (intmax_t)gkd->length);
        gkd->di.dumper = g_raid_dump;
        gkd->di.priv = vol;
        gkd->di.blocksize = vol->v_sectorsize;
        gkd->di.maxiosize = DFLTPHYS;
        gkd->di.mediaoffset = gkd->offset;
        if ((gkd->offset + gkd->length) > vol->v_mediasize)
                gkd->length = vol->v_mediasize - gkd->offset;
        gkd->di.mediasize = gkd->length;
        g_io_deliver(bp, 0);
}

static void
g_raid_candelete(struct g_raid_softc *sc, struct bio *bp)
{
        struct g_provider *pp;
        struct g_raid_volume *vol;
        struct g_raid_subdisk *sd;
        int i, val;

        pp = bp->bio_to;
        vol = pp->private;
        for (i = 0; i < vol->v_disks_count; i++) {
                sd = &vol->v_subdisks[i];
                if (sd->sd_state == G_RAID_SUBDISK_S_NONE)
                        continue;
                if (sd->sd_disk->d_candelete)
                        break;
        }
        val = i < vol->v_disks_count;
        g_handleattr(bp, "GEOM::candelete", &val, sizeof(val));
}

static void
g_raid_start(struct bio *bp)
{
        struct g_raid_softc *sc;

        sc = bp->bio_to->geom->softc;
        /*
         * If sc == NULL or there are no valid disks, provider's error
         * should be set and g_raid_start() should not be called at all.
         */
//      KASSERT(sc != NULL && sc->sc_state == G_RAID_VOLUME_S_RUNNING,
//          ("Provider's error should be set (error=%d)(mirror=%s).",
//          bp->bio_to->error, bp->bio_to->name));
        G_RAID_LOGREQ(3, bp, "Request received.");

        switch (bp->bio_cmd) {
        case BIO_READ:
        case BIO_WRITE:
        case BIO_DELETE:
        case BIO_FLUSH:
        case BIO_SPEEDUP:
                break;
        case BIO_GETATTR:
                if (!strcmp(bp->bio_attribute, "GEOM::candelete"))
                        g_raid_candelete(sc, bp);
                else if (!strcmp(bp->bio_attribute, "GEOM::kerneldump"))
                        g_raid_kerneldump(sc, bp);
                else
                        g_io_deliver(bp, EOPNOTSUPP);
                return;
        default:
                g_io_deliver(bp, EOPNOTSUPP);
                return;
        }
        mtx_lock(&sc->sc_queue_mtx);
        bioq_insert_tail(&sc->sc_queue, bp);
        mtx_unlock(&sc->sc_queue_mtx);
        if (!dumping) {
                G_RAID_DEBUG1(4, sc, "Waking up %p.", sc);
                wakeup(sc);
        }
}

static int
g_raid_bio_overlaps(const struct bio *bp, off_t lstart, off_t len)
{
        /*
         * 5 cases:
         * (1) bp entirely below NO
         * (2) bp entirely above NO
         * (3) bp start below, but end in range YES
         * (4) bp entirely within YES
         * (5) bp starts within, ends above YES
         *
         * lock range 10-19 (offset 10 length 10)
         * (1) 1-5: first if kicks it out
         * (2) 30-35: second if kicks it out
         * (3) 5-15: passes both ifs
         * (4) 12-14: passes both ifs
         * (5) 19-20: passes both
         */
        off_t lend = lstart + len - 1;
        off_t bstart = bp->bio_offset;
        off_t bend = bp->bio_offset + bp->bio_length - 1;

        if (bend < lstart)
                return (0);
        if (lend < bstart)
                return (0);
        return (1);
}

static int
g_raid_is_in_locked_range(struct g_raid_volume *vol, const struct bio *bp)
{
        struct g_raid_lock *lp;

        sx_assert(&vol->v_softc->sc_lock, SX_LOCKED);

        LIST_FOREACH(lp, &vol->v_locks, l_next) {
                if (g_raid_bio_overlaps(bp, lp->l_offset, lp->l_length))
                        return (1);
        }
        return (0);
}

static void
g_raid_start_request(struct bio *bp)
{
        struct g_raid_softc *sc __diagused;
        struct g_raid_volume *vol;

        sc = bp->bio_to->geom->softc;
        sx_assert(&sc->sc_lock, SX_LOCKED);
        vol = bp->bio_to->private;

        /*
         * Check to see if this item is in a locked range.  If so,
         * queue it to our locked queue and return.  We'll requeue
         * it when the range is unlocked.  Internal I/O for the
         * rebuild/rescan/recovery process is excluded from this
         * check so we can actually do the recovery.
         */
        if (!(bp->bio_cflags & G_RAID_BIO_FLAG_SPECIAL) &&
            g_raid_is_in_locked_range(vol, bp)) {
                G_RAID_LOGREQ(3, bp, "Defer request.");
                bioq_insert_tail(&vol->v_locked, bp);
                return;
        }

        /*
         * If we're actually going to do the write/delete, then
         * update the idle stats for the volume.
         */
        if (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_DELETE) {
                if (!vol->v_dirty)
                        g_raid_dirty(vol);
                vol->v_writes++;
        }

        /*
         * Put request onto inflight queue, so we can check if new
         * synchronization requests don't collide with it.  Then tell
         * the transformation layer to start the I/O.
         */
        bioq_insert_tail(&vol->v_inflight, bp);
        G_RAID_LOGREQ(4, bp, "Request started");
        G_RAID_TR_IOSTART(vol->v_tr, bp);
}

static void
g_raid_finish_with_locked_ranges(struct g_raid_volume *vol, struct bio *bp)
{
        off_t off, len;
        struct bio *nbp;
        struct g_raid_lock *lp;

        vol->v_pending_lock = 0;
        LIST_FOREACH(lp, &vol->v_locks, l_next) {
                if (lp->l_pending) {
                        off = lp->l_offset;
                        len = lp->l_length;
                        lp->l_pending = 0;
                        TAILQ_FOREACH(nbp, &vol->v_inflight.queue, bio_queue) {
                                if (g_raid_bio_overlaps(nbp, off, len))
                                        lp->l_pending++;
                        }
                        if (lp->l_pending) {
                                vol->v_pending_lock = 1;
                                G_RAID_DEBUG1(4, vol->v_softc,
                                    "Deferred lock(%jd, %jd) has %d pending",
                                    (intmax_t)off, (intmax_t)(off + len),
                                    lp->l_pending);
                                continue;
                        }
                        G_RAID_DEBUG1(4, vol->v_softc,
                            "Deferred lock of %jd to %jd completed",
                            (intmax_t)off, (intmax_t)(off + len));
                        G_RAID_TR_LOCKED(vol->v_tr, lp->l_callback_arg);
                }
        }
}

void
g_raid_iodone(struct bio *bp, int error)
{
        struct g_raid_softc *sc __diagused;
        struct g_raid_volume *vol;

        sc = bp->bio_to->geom->softc;
        sx_assert(&sc->sc_lock, SX_LOCKED);
        vol = bp->bio_to->private;
        G_RAID_LOGREQ(3, bp, "Request done: %d.", error);

        /* Update stats if we done write/delete. */
        if (bp->bio_cmd == BIO_WRITE || bp->bio_cmd == BIO_DELETE) {
                vol->v_writes--;
                vol->v_last_write = time_uptime;
        }

        bioq_remove(&vol->v_inflight, bp);
        if (vol->v_pending_lock && g_raid_is_in_locked_range(vol, bp))
                g_raid_finish_with_locked_ranges(vol, bp);
        getmicrouptime(&vol->v_last_done);
        g_io_deliver(bp, error);
}

int
g_raid_lock_range(struct g_raid_volume *vol, off_t off, off_t len,
    struct bio *ignore, void *argp)
{
        struct g_raid_softc *sc;
        struct g_raid_lock *lp;
        struct bio *bp;

        sc = vol->v_softc;
        lp = malloc(sizeof(*lp), M_RAID, M_WAITOK | M_ZERO);
        LIST_INSERT_HEAD(&vol->v_locks, lp, l_next);
        lp->l_offset = off;
        lp->l_length = len;
        lp->l_callback_arg = argp;

        lp->l_pending = 0;
        TAILQ_FOREACH(bp, &vol->v_inflight.queue, bio_queue) {
                if (bp != ignore && g_raid_bio_overlaps(bp, off, len))
                        lp->l_pending++;
        }       

        /*
         * If there are any writes that are pending, we return EBUSY.  All
         * callers will have to wait until all pending writes clear.
         */
        if (lp->l_pending > 0) {
                vol->v_pending_lock = 1;
                G_RAID_DEBUG1(4, sc, "Locking range %jd to %jd deferred %d pend",
                    (intmax_t)off, (intmax_t)(off+len), lp->l_pending);
                return (EBUSY);
        }
        G_RAID_DEBUG1(4, sc, "Locking range %jd to %jd",
            (intmax_t)off, (intmax_t)(off+len));
        G_RAID_TR_LOCKED(vol->v_tr, lp->l_callback_arg);
        return (0);
}

int
g_raid_unlock_range(struct g_raid_volume *vol, off_t off, off_t len)
{
        struct g_raid_lock *lp;
        struct g_raid_softc *sc;
        struct bio *bp;

        sc = vol->v_softc;
        LIST_FOREACH(lp, &vol->v_locks, l_next) {
                if (lp->l_offset == off && lp->l_length == len) {
                        LIST_REMOVE(lp, l_next);
                        /* XXX
                         * Right now we just put them all back on the queue
                         * and hope for the best.  We hope this because any
                         * locked ranges will go right back on this list
                         * when the worker thread runs.
                         * XXX
                         */
                        G_RAID_DEBUG1(4, sc, "Unlocked %jd to %jd",
                            (intmax_t)lp->l_offset,
                            (intmax_t)(lp->l_offset+lp->l_length));
                        mtx_lock(&sc->sc_queue_mtx);
                        while ((bp = bioq_takefirst(&vol->v_locked)) != NULL)
                                bioq_insert_tail(&sc->sc_queue, bp);
                        mtx_unlock(&sc->sc_queue_mtx);
                        free(lp, M_RAID);
                        return (0);
                }
        }
        return (EINVAL);
}

void
g_raid_subdisk_iostart(struct g_raid_subdisk *sd, struct bio *bp)
{
        struct g_consumer *cp;
        struct g_raid_disk *disk, *tdisk;

        bp->bio_caller1 = sd;

        /*
         * Make sure that the disk is present. Generally it is a task of
         * transformation layers to not send requests to absent disks, but
         * it is better to be safe and report situation then sorry.
         */
        if (sd->sd_disk == NULL) {
                G_RAID_LOGREQ(0, bp, "Warning! I/O request to an absent disk!");
nodisk:
                bp->bio_from = NULL;
                bp->bio_to = NULL;
                bp->bio_error = ENXIO;
                g_raid_disk_done(bp);
                return;
        }
        disk = sd->sd_disk;
        if (disk->d_state != G_RAID_DISK_S_ACTIVE &&
            disk->d_state != G_RAID_DISK_S_FAILED) {
                G_RAID_LOGREQ(0, bp, "Warning! I/O request to a disk in a "
                    "wrong state (%s)!", g_raid_disk_state2str(disk->d_state));
                goto nodisk;
        }

        cp = disk->d_consumer;
        bp->bio_from = cp;
        bp->bio_to = cp->provider;
        cp->index++;

        /* Update average disks load. */
        TAILQ_FOREACH(tdisk, &sd->sd_softc->sc_disks, d_next) {
                if (tdisk->d_consumer == NULL)
                        tdisk->d_load = 0;
                else
                        tdisk->d_load = (tdisk->d_consumer->index *
                            G_RAID_SUBDISK_LOAD_SCALE + tdisk->d_load * 7) / 8;
        }

        disk->d_last_offset = bp->bio_offset + bp->bio_length;
        if (dumping) {
                G_RAID_LOGREQ(3, bp, "Sending dumping request.");
                if (bp->bio_cmd == BIO_WRITE) {
                        bp->bio_error = g_raid_subdisk_kerneldump(sd,
                            bp->bio_data, bp->bio_offset, bp->bio_length);
                } else
                        bp->bio_error = EOPNOTSUPP;
                g_raid_disk_done(bp);
        } else {
                bp->bio_done = g_raid_disk_done;
                bp->bio_offset += sd->sd_offset;
                G_RAID_LOGREQ(3, bp, "Sending request.");
                g_io_request(bp, cp);
        }
}

int
g_raid_subdisk_kerneldump(struct g_raid_subdisk *sd, void *virtual,
    off_t offset, size_t length)
{

        if (sd->sd_disk == NULL)
                return (ENXIO);
        if (sd->sd_disk->d_kd.di.dumper == NULL)
                return (EOPNOTSUPP);
        return (dump_write(&sd->sd_disk->d_kd.di, virtual,
            sd->sd_disk->d_kd.di.mediaoffset + sd->sd_offset + offset, length));
}

static void
g_raid_disk_done(struct bio *bp)
{
        struct g_raid_softc *sc;
        struct g_raid_subdisk *sd;

        sd = bp->bio_caller1;
        sc = sd->sd_softc;
        mtx_lock(&sc->sc_queue_mtx);
        bioq_insert_tail(&sc->sc_queue, bp);
        mtx_unlock(&sc->sc_queue_mtx);
        if (!dumping)
                wakeup(sc);
}

static void
g_raid_disk_done_request(struct bio *bp)
{
        struct g_raid_softc *sc;
        struct g_raid_disk *disk;
        struct g_raid_subdisk *sd;
        struct g_raid_volume *vol;

        g_topology_assert_not();

        G_RAID_LOGREQ(3, bp, "Disk request done: %d.", bp->bio_error);
        sd = bp->bio_caller1;
        sc = sd->sd_softc;
        vol = sd->sd_volume;
        if (bp->bio_from != NULL) {
                bp->bio_from->index--;
                disk = bp->bio_from->private;
                if (disk == NULL)
                        g_raid_kill_consumer(sc, bp->bio_from);
        }
        bp->bio_offset -= sd->sd_offset;

        G_RAID_TR_IODONE(vol->v_tr, sd, bp);
}

static void
g_raid_handle_event(struct g_raid_softc *sc, struct g_raid_event *ep)
{

        if ((ep->e_flags & G_RAID_EVENT_VOLUME) != 0)
                ep->e_error = g_raid_update_volume(ep->e_tgt, ep->e_event);
        else if ((ep->e_flags & G_RAID_EVENT_DISK) != 0)
                ep->e_error = g_raid_update_disk(ep->e_tgt, ep->e_event);
        else if ((ep->e_flags & G_RAID_EVENT_SUBDISK) != 0)
                ep->e_error = g_raid_update_subdisk(ep->e_tgt, ep->e_event);
        else
                ep->e_error = g_raid_update_node(ep->e_tgt, ep->e_event);
        if ((ep->e_flags & G_RAID_EVENT_WAIT) == 0) {
                KASSERT(ep->e_error == 0,
                    ("Error cannot be handled."));
                g_raid_event_free(ep);
        } else {
                ep->e_flags |= G_RAID_EVENT_DONE;
                G_RAID_DEBUG1(4, sc, "Waking up %p.", ep);
                mtx_lock(&sc->sc_queue_mtx);
                wakeup(ep);
                mtx_unlock(&sc->sc_queue_mtx);
        }
}

/*
 * Worker thread.
 */
static void
g_raid_worker(void *arg)
{
        struct g_raid_softc *sc;
        struct g_raid_event *ep;
        struct g_raid_volume *vol;
        struct bio *bp;
        struct timeval now, t;
        int timeout, rv;

        sc = arg;
        thread_lock(curthread);
        sched_prio(curthread, PRIBIO);
        thread_unlock(curthread);

        sx_xlock(&sc->sc_lock);
        for (;;) {
                mtx_lock(&sc->sc_queue_mtx);
                /*
                 * First take a look at events.
                 * This is important to handle events before any I/O requests.
                 */
                bp = NULL;
                vol = NULL;
                rv = 0;
                ep = TAILQ_FIRST(&sc->sc_events);
                if (ep != NULL)
                        TAILQ_REMOVE(&sc->sc_events, ep, e_next);
                else if ((bp = bioq_takefirst(&sc->sc_queue)) != NULL)
                        ;
                else {
                        getmicrouptime(&now);
                        t = now;
                        TAILQ_FOREACH(vol, &sc->sc_volumes, v_next) {
                                if (bioq_first(&vol->v_inflight) == NULL &&
                                    vol->v_tr &&
                                    timevalcmp(&vol->v_last_done, &t, < ))
                                        t = vol->v_last_done;
                        }
                        timevalsub(&t, &now);
                        timeout = g_raid_idle_threshold +
                            t.tv_sec * 1000000 + t.tv_usec;
                        if (timeout > 0) {
                                /*
                                 * Two steps to avoid overflows at HZ=1000
                                 * and idle timeouts > 2.1s.  Some rounding
                                 * errors can occur, but they are < 1tick,
                                 * which is deemed to be close enough for
                                 * this purpose.
                                 */
                                int micpertic = 1000000 / hz;
                                timeout = (timeout + micpertic - 1) / micpertic;
                                sx_xunlock(&sc->sc_lock);
                                MSLEEP(rv, sc, &sc->sc_queue_mtx,
                                    PRIBIO | PDROP, "-", timeout);
                                sx_xlock(&sc->sc_lock);
                                goto process;
                        } else
                                rv = EWOULDBLOCK;
                }
                mtx_unlock(&sc->sc_queue_mtx);
process:
                if (ep != NULL) {
                        g_raid_handle_event(sc, ep);
                } else if (bp != NULL) {
                        if (bp->bio_to != NULL &&
                            bp->bio_to->geom == sc->sc_geom)
                                g_raid_start_request(bp);
                        else
                                g_raid_disk_done_request(bp);
                } else if (rv == EWOULDBLOCK) {
                        TAILQ_FOREACH(vol, &sc->sc_volumes, v_next) {
                                g_raid_clean(vol, -1);
                                if (bioq_first(&vol->v_inflight) == NULL &&
                                    vol->v_tr) {
                                        t.tv_sec = g_raid_idle_threshold / 1000000;
                                        t.tv_usec = g_raid_idle_threshold % 1000000;
                                        timevaladd(&t, &vol->v_last_done);
                                        getmicrouptime(&now);
                                        if (timevalcmp(&t, &now, <= )) {
                                                G_RAID_TR_IDLE(vol->v_tr);
                                                vol->v_last_done = now;
                                        }
                                }
                        }
                }
                if (sc->sc_stopping == G_RAID_DESTROY_HARD)
                        g_raid_destroy_node(sc, 1);     /* May not return. */
        }
}

static void
g_raid_poll(struct g_raid_softc *sc)
{
        struct g_raid_event *ep;
        struct bio *bp;

        sx_xlock(&sc->sc_lock);
        mtx_lock(&sc->sc_queue_mtx);
        /*
         * First take a look at events.
         * This is important to handle events before any I/O requests.
         */
        ep = TAILQ_FIRST(&sc->sc_events);
        if (ep != NULL) {
                TAILQ_REMOVE(&sc->sc_events, ep, e_next);
                mtx_unlock(&sc->sc_queue_mtx);
                g_raid_handle_event(sc, ep);
                goto out;
        }
        bp = bioq_takefirst(&sc->sc_queue);
        if (bp != NULL) {
                mtx_unlock(&sc->sc_queue_mtx);
                if (bp->bio_from == NULL ||
                    bp->bio_from->geom != sc->sc_geom)
                        g_raid_start_request(bp);
                else
                        g_raid_disk_done_request(bp);
        }
out:
        sx_xunlock(&sc->sc_lock);
}

static void
g_raid_launch_provider(struct g_raid_volume *vol)
{
        struct g_raid_disk *disk;
        struct g_raid_subdisk *sd;
        struct g_raid_softc *sc;
        struct g_provider *pp;
        char name[G_RAID_MAX_VOLUMENAME];
        off_t off;
        int i;

        sc = vol->v_softc;
        sx_assert(&sc->sc_lock, SX_LOCKED);

        g_topology_lock();
        /* Try to name provider with volume name. */
        snprintf(name, sizeof(name), "raid/%s", vol->v_name);
        if (g_raid_name_format == 0 || vol->v_name[0] == 0 ||
            g_provider_by_name(name) != NULL) {
                /* Otherwise use sequential volume number. */
                snprintf(name, sizeof(name), "raid/r%d", vol->v_global_id);
        }

        pp = g_new_providerf(sc->sc_geom, "%s", name);
        pp->flags |= G_PF_DIRECT_RECEIVE;
        if (vol->v_tr->tro_class->trc_accept_unmapped) {
                pp->flags |= G_PF_ACCEPT_UNMAPPED;
                for (i = 0; i < vol->v_disks_count; i++) {
                        sd = &vol->v_subdisks[i];
                        if (sd->sd_state == G_RAID_SUBDISK_S_NONE)
                                continue;
                        if ((sd->sd_disk->d_consumer->provider->flags &
                            G_PF_ACCEPT_UNMAPPED) == 0)
                                pp->flags &= ~G_PF_ACCEPT_UNMAPPED;
                }
        }
        pp->private = vol;
        pp->mediasize = vol->v_mediasize;
        pp->sectorsize = vol->v_sectorsize;
        pp->stripesize = 0;
        pp->stripeoffset = 0;
        if (vol->v_raid_level == G_RAID_VOLUME_RL_RAID1 ||
            vol->v_raid_level == G_RAID_VOLUME_RL_RAID3 ||
            vol->v_raid_level == G_RAID_VOLUME_RL_SINGLE ||
            vol->v_raid_level == G_RAID_VOLUME_RL_CONCAT) {
                if ((disk = vol->v_subdisks[0].sd_disk) != NULL &&
                    disk->d_consumer != NULL &&
                    disk->d_consumer->provider != NULL) {
                        pp->stripesize = disk->d_consumer->provider->stripesize;
                        off = disk->d_consumer->provider->stripeoffset;
                        pp->stripeoffset = off + vol->v_subdisks[0].sd_offset;
                        if (off > 0)
                                pp->stripeoffset %= off;
                }
                if (vol->v_raid_level == G_RAID_VOLUME_RL_RAID3) {
                        pp->stripesize *= (vol->v_disks_count - 1);
                        pp->stripeoffset *= (vol->v_disks_count - 1);
                }
        } else
                pp->stripesize = vol->v_strip_size;
        vol->v_provider = pp;
        g_error_provider(pp, 0);
        g_topology_unlock();
        G_RAID_DEBUG1(0, sc, "Provider %s for volume %s created.",
            pp->name, vol->v_name);
}

static void
g_raid_destroy_provider(struct g_raid_volume *vol)
{
        struct g_raid_softc *sc;
        struct g_provider *pp;
        struct bio *bp, *tmp;

        g_topology_assert_not();
        sc = vol->v_softc;
        pp = vol->v_provider;
        KASSERT(pp != NULL, ("NULL provider (volume=%s).", vol->v_name));

        g_topology_lock();
        g_error_provider(pp, ENXIO);
        mtx_lock(&sc->sc_queue_mtx);
        TAILQ_FOREACH_SAFE(bp, &sc->sc_queue.queue, bio_queue, tmp) {
                if (bp->bio_to != pp)
                        continue;
                bioq_remove(&sc->sc_queue, bp);
                g_io_deliver(bp, ENXIO);
        }
        mtx_unlock(&sc->sc_queue_mtx);
        G_RAID_DEBUG1(0, sc, "Provider %s for volume %s destroyed.",
            pp->name, vol->v_name);
        g_wither_provider(pp, ENXIO);
        g_topology_unlock();
        vol->v_provider = NULL;
}

/*
 * Update device state.
 */
static int
g_raid_update_volume(struct g_raid_volume *vol, u_int event)
{
        struct g_raid_softc *sc;

        sc = vol->v_softc;
        sx_assert(&sc->sc_lock, SX_XLOCKED);

        G_RAID_DEBUG1(2, sc, "Event %s for volume %s.",
            g_raid_volume_event2str(event),
            vol->v_name);
        switch (event) {
        case G_RAID_VOLUME_E_DOWN:
                if (vol->v_provider != NULL)
                        g_raid_destroy_provider(vol);
                break;
        case G_RAID_VOLUME_E_UP:
                if (vol->v_provider == NULL)
                        g_raid_launch_provider(vol);
                break;
        case G_RAID_VOLUME_E_START:
                if (vol->v_tr)
                        G_RAID_TR_START(vol->v_tr);
                return (0);
        default:
                if (sc->sc_md)
                        G_RAID_MD_VOLUME_EVENT(sc->sc_md, vol, event);
                return (0);
        }

        /* Manage root mount release. */
        if (vol->v_starting) {
                vol->v_starting = 0;
                G_RAID_DEBUG1(1, sc, "root_mount_rel %p", vol->v_rootmount);
                root_mount_rel(vol->v_rootmount);
                vol->v_rootmount = NULL;
        }
        if (vol->v_stopping && vol->v_provider_open == 0)
                g_raid_destroy_volume(vol);
        return (0);
}

/*
 * Update subdisk state.
 */
static int
g_raid_update_subdisk(struct g_raid_subdisk *sd, u_int event)
{
        struct g_raid_softc *sc;
        struct g_raid_volume *vol;

        sc = sd->sd_softc;
        vol = sd->sd_volume;
        sx_assert(&sc->sc_lock, SX_XLOCKED);

        G_RAID_DEBUG1(2, sc, "Event %s for subdisk %s:%d-%s.",
            g_raid_subdisk_event2str(event),
            vol->v_name, sd->sd_pos,
            sd->sd_disk ? g_raid_get_diskname(sd->sd_disk) : "[none]");
        if (vol->v_tr)
                G_RAID_TR_EVENT(vol->v_tr, sd, event);

        return (0);
}

/*
 * Update disk state.
 */
static int
g_raid_update_disk(struct g_raid_disk *disk, u_int event)
{
        struct g_raid_softc *sc;

        sc = disk->d_softc;
        sx_assert(&sc->sc_lock, SX_XLOCKED);

        G_RAID_DEBUG1(2, sc, "Event %s for disk %s.",
            g_raid_disk_event2str(event),
            g_raid_get_diskname(disk));

        if (sc->sc_md)
                G_RAID_MD_EVENT(sc->sc_md, disk, event);
        return (0);
}

/*
 * Node event.
 */
static int
g_raid_update_node(struct g_raid_softc *sc, u_int event)
{
        sx_assert(&sc->sc_lock, SX_XLOCKED);

        G_RAID_DEBUG1(2, sc, "Event %s for the array.",
            g_raid_node_event2str(event));

        if (event == G_RAID_NODE_E_WAKE)
                return (0);
        if (sc->sc_md)
                G_RAID_MD_EVENT(sc->sc_md, NULL, event);
        return (0);
}

static int
g_raid_access(struct g_provider *pp, int acr, int acw, int ace)
{
        struct g_raid_volume *vol;
        struct g_raid_softc *sc;
        int dcw, opens, error = 0;

        g_topology_assert();
        sc = pp->geom->softc;
        vol = pp->private;
        KASSERT(sc != NULL, ("NULL softc (provider=%s).", pp->name));
        KASSERT(vol != NULL, ("NULL volume (provider=%s).", pp->name));

        G_RAID_DEBUG1(2, sc, "Access request for %s: r%dw%de%d.", pp->name,
            acr, acw, ace);
        dcw = pp->acw + acw;

        g_topology_unlock();
        sx_xlock(&sc->sc_lock);
        /* Deny new opens while dying. */
        if (sc->sc_stopping != 0 && (acr > 0 || acw > 0 || ace > 0)) {
                error = ENXIO;
                goto out;
        }
        /* Deny write opens for read-only volumes. */
        if (vol->v_read_only && acw > 0) {
                error = EROFS;
                goto out;
        }
        if (dcw == 0)
                g_raid_clean(vol, dcw);
        vol->v_provider_open += acr + acw + ace;
        /* Handle delayed node destruction. */
        if (sc->sc_stopping == G_RAID_DESTROY_DELAYED &&
            vol->v_provider_open == 0) {
                /* Count open volumes. */
                opens = g_raid_nopens(sc);
                if (opens == 0) {
                        sc->sc_stopping = G_RAID_DESTROY_HARD;
                        /* Wake up worker to make it selfdestruct. */
                        g_raid_event_send(sc, G_RAID_NODE_E_WAKE, 0);
                }
        }
        /* Handle open volume destruction. */
        if (vol->v_stopping && vol->v_provider_open == 0)
                g_raid_destroy_volume(vol);
out:
        sx_xunlock(&sc->sc_lock);
        g_topology_lock();
        return (error);
}

struct g_raid_softc *
g_raid_create_node(struct g_class *mp,
    const char *name, struct g_raid_md_object *md)
{
        struct g_raid_softc *sc;
        struct g_geom *gp;
        int error;

        g_topology_assert();
        G_RAID_DEBUG(1, "Creating array %s.", name);

        gp = g_new_geom(mp, name);
        sc = malloc(sizeof(*sc), M_RAID, M_WAITOK | M_ZERO);
        gp->start = g_raid_start;
        gp->orphan = g_raid_orphan;
        gp->access = g_raid_access;
        gp->dumpconf = g_raid_dumpconf;

        sc->sc_md = md;
        sc->sc_geom = gp;
        sc->sc_flags = 0;
        TAILQ_INIT(&sc->sc_volumes);
        TAILQ_INIT(&sc->sc_disks);
        sx_init(&sc->sc_lock, "graid:lock");
        mtx_init(&sc->sc_queue_mtx, "graid:queue", NULL, MTX_DEF);
        TAILQ_INIT(&sc->sc_events);
        bioq_init(&sc->sc_queue);
        gp->softc = sc;
        error = kproc_create(g_raid_worker, sc, &sc->sc_worker, 0, 0,
            "g_raid %s", name);
        if (error != 0) {
                G_RAID_DEBUG(0, "Cannot create kernel thread for %s.", name);
                mtx_destroy(&sc->sc_queue_mtx);
                sx_destroy(&sc->sc_lock);
                g_destroy_geom(sc->sc_geom);
                free(sc, M_RAID);
                return (NULL);
        }

        G_RAID_DEBUG1(0, sc, "Array %s created.", name);
        return (sc);
}

struct g_raid_volume *
g_raid_create_volume(struct g_raid_softc *sc, const char *name, int id)
{
        struct g_raid_volume    *vol, *vol1;
        int i;

        G_RAID_DEBUG1(1, sc, "Creating volume %s.", name);
        vol = malloc(sizeof(*vol), M_RAID, M_WAITOK | M_ZERO);
        vol->v_softc = sc;
        strlcpy(vol->v_name, name, G_RAID_MAX_VOLUMENAME);
        vol->v_state = G_RAID_VOLUME_S_STARTING;
        vol->v_raid_level = G_RAID_VOLUME_RL_UNKNOWN;
        vol->v_raid_level_qualifier = G_RAID_VOLUME_RLQ_UNKNOWN;
        vol->v_rotate_parity = 1;
        bioq_init(&vol->v_inflight);
        bioq_init(&vol->v_locked);
        LIST_INIT(&vol->v_locks);
        for (i = 0; i < G_RAID_MAX_SUBDISKS; i++) {
                vol->v_subdisks[i].sd_softc = sc;
                vol->v_subdisks[i].sd_volume = vol;
                vol->v_subdisks[i].sd_pos = i;
                vol->v_subdisks[i].sd_state = G_RAID_DISK_S_NONE;
        }

        /* Find free ID for this volume. */
        g_topology_lock();
        vol1 = vol;
        if (id >= 0) {
                LIST_FOREACH(vol1, &g_raid_volumes, v_global_next) {
                        if (vol1->v_global_id == id)
                                break;
                }
        }
        if (vol1 != NULL) {
                for (id = 0; ; id++) {
                        LIST_FOREACH(vol1, &g_raid_volumes, v_global_next) {
                                if (vol1->v_global_id == id)
                                        break;
                        }
                        if (vol1 == NULL)
                                break;
                }
        }
        vol->v_global_id = id;
        LIST_INSERT_HEAD(&g_raid_volumes, vol, v_global_next);
        g_topology_unlock();

        /* Delay root mounting. */
        vol->v_rootmount = root_mount_hold("GRAID");
        G_RAID_DEBUG1(1, sc, "root_mount_hold %p", vol->v_rootmount);
        vol->v_starting = 1;
        TAILQ_INSERT_TAIL(&sc->sc_volumes, vol, v_next);
        return (vol);
}

struct g_raid_disk *
g_raid_create_disk(struct g_raid_softc *sc)
{
        struct g_raid_disk      *disk;

        G_RAID_DEBUG1(1, sc, "Creating disk.");
        disk = malloc(sizeof(*disk), M_RAID, M_WAITOK | M_ZERO);
        disk->d_softc = sc;
        disk->d_state = G_RAID_DISK_S_NONE;
        TAILQ_INIT(&disk->d_subdisks);
        TAILQ_INSERT_TAIL(&sc->sc_disks, disk, d_next);
        return (disk);
}

int g_raid_start_volume(struct g_raid_volume *vol)
{
        struct g_raid_tr_class *class;
        struct g_raid_tr_object *obj;
        int status;

        G_RAID_DEBUG1(2, vol->v_softc, "Starting volume %s.", vol->v_name);
        LIST_FOREACH(class, &g_raid_tr_classes, trc_list) {
                if (!class->trc_enable)
                        continue;
                G_RAID_DEBUG1(2, vol->v_softc,
                    "Tasting volume %s for %s transformation.",
                    vol->v_name, class->name);
                obj = (void *)kobj_create((kobj_class_t)class, M_RAID,
                    M_WAITOK);
                obj->tro_class = class;
                obj->tro_volume = vol;
                status = G_RAID_TR_TASTE(obj, vol);
                if (status != G_RAID_TR_TASTE_FAIL)
                        break;
                kobj_delete((kobj_t)obj, M_RAID);
        }
        if (class == NULL) {
                G_RAID_DEBUG1(0, vol->v_softc,
                    "No transformation module found for %s.",
                    vol->v_name);
                vol->v_tr = NULL;
                g_raid_change_volume_state(vol, G_RAID_VOLUME_S_UNSUPPORTED);
                g_raid_event_send(vol, G_RAID_VOLUME_E_DOWN,
                    G_RAID_EVENT_VOLUME);
                return (-1);
        }
        G_RAID_DEBUG1(2, vol->v_softc,
            "Transformation module %s chosen for %s.",
            class->name, vol->v_name);
        vol->v_tr = obj;
        return (0);
}

int
g_raid_destroy_node(struct g_raid_softc *sc, int worker)
{
        struct g_raid_volume *vol, *tmpv;
        struct g_raid_disk *disk, *tmpd;
        int error = 0;

        sc->sc_stopping = G_RAID_DESTROY_HARD;
        TAILQ_FOREACH_SAFE(vol, &sc->sc_volumes, v_next, tmpv) {
                if (g_raid_destroy_volume(vol))
                        error = EBUSY;
        }
        if (error)
                return (error);
        TAILQ_FOREACH_SAFE(disk, &sc->sc_disks, d_next, tmpd) {
                if (g_raid_destroy_disk(disk))
                        error = EBUSY;
        }
        if (error)
                return (error);
        if (sc->sc_md) {
                G_RAID_MD_FREE(sc->sc_md);
                kobj_delete((kobj_t)sc->sc_md, M_RAID);
                sc->sc_md = NULL;
        }
        if (sc->sc_geom != NULL) {
                G_RAID_DEBUG1(0, sc, "Array %s destroyed.", sc->sc_name);
                g_topology_lock();
                sc->sc_geom->softc = NULL;
                g_wither_geom(sc->sc_geom, ENXIO);
                g_topology_unlock();
                sc->sc_geom = NULL;
        } else
                G_RAID_DEBUG(1, "Array destroyed.");
        if (worker) {
                g_raid_event_cancel(sc, sc);
                mtx_destroy(&sc->sc_queue_mtx);
                sx_xunlock(&sc->sc_lock);
                sx_destroy(&sc->sc_lock);
                wakeup(&sc->sc_stopping);
                free(sc, M_RAID);
                curthread->td_pflags &= ~TDP_GEOM;
                G_RAID_DEBUG(1, "Thread exiting.");
                kproc_exit(0);
        } else {
                /* Wake up worker to make it selfdestruct. */
                g_raid_event_send(sc, G_RAID_NODE_E_WAKE, 0);
        }
        return (0);
}

int
g_raid_destroy_volume(struct g_raid_volume *vol)
{
        struct g_raid_softc *sc;
        struct g_raid_disk *disk;
        int i;

        sc = vol->v_softc;
        G_RAID_DEBUG1(2, sc, "Destroying volume %s.", vol->v_name);
        vol->v_stopping = 1;
        if (vol->v_state != G_RAID_VOLUME_S_STOPPED) {
                if (vol->v_tr) {
                        G_RAID_TR_STOP(vol->v_tr);
                        return (EBUSY);
                } else
                        vol->v_state = G_RAID_VOLUME_S_STOPPED;
        }
        if (g_raid_event_check(sc, vol) != 0)
                return (EBUSY);
        if (vol->v_provider != NULL)
                return (EBUSY);
        if (vol->v_provider_open != 0)
                return (EBUSY);
        if (vol->v_tr) {
                G_RAID_TR_FREE(vol->v_tr);
                kobj_delete((kobj_t)vol->v_tr, M_RAID);
                vol->v_tr = NULL;
        }
        if (vol->v_rootmount)
                root_mount_rel(vol->v_rootmount);
        g_topology_lock();
        LIST_REMOVE(vol, v_global_next);
        g_topology_unlock();
        TAILQ_REMOVE(&sc->sc_volumes, vol, v_next);
        for (i = 0; i < G_RAID_MAX_SUBDISKS; i++) {
                g_raid_event_cancel(sc, &vol->v_subdisks[i]);
                disk = vol->v_subdisks[i].sd_disk;
                if (disk == NULL)
                        continue;
                TAILQ_REMOVE(&disk->d_subdisks, &vol->v_subdisks[i], sd_next);
        }
        G_RAID_DEBUG1(2, sc, "Volume %s destroyed.", vol->v_name);
        if (sc->sc_md)
                G_RAID_MD_FREE_VOLUME(sc->sc_md, vol);
        g_raid_event_cancel(sc, vol);
        free(vol, M_RAID);
        if (sc->sc_stopping == G_RAID_DESTROY_HARD) {
                /* Wake up worker to let it selfdestruct. */
                g_raid_event_send(sc, G_RAID_NODE_E_WAKE, 0);
        }
        return (0);
}

int
g_raid_destroy_disk(struct g_raid_disk *disk)
{
        struct g_raid_softc *sc;
        struct g_raid_subdisk *sd, *tmp;

        sc = disk->d_softc;
        G_RAID_DEBUG1(2, sc, "Destroying disk.");
        if (disk->d_consumer) {
                g_raid_kill_consumer(sc, disk->d_consumer);
                disk->d_consumer = NULL;
        }
        TAILQ_FOREACH_SAFE(sd, &disk->d_subdisks, sd_next, tmp) {
                g_raid_change_subdisk_state(sd, G_RAID_SUBDISK_S_NONE);
                g_raid_event_send(sd, G_RAID_SUBDISK_E_DISCONNECTED,
                    G_RAID_EVENT_SUBDISK);
                TAILQ_REMOVE(&disk->d_subdisks, sd, sd_next);
                sd->sd_disk = NULL;
        }
        TAILQ_REMOVE(&sc->sc_disks, disk, d_next);
        if (sc->sc_md)
                G_RAID_MD_FREE_DISK(sc->sc_md, disk);
        g_raid_event_cancel(sc, disk);
        free(disk, M_RAID);
        return (0);
}

int
g_raid_destroy(struct g_raid_softc *sc, int how)
{
        int error, opens;

        g_topology_assert_not();
        if (sc == NULL)
                return (ENXIO);
        sx_assert(&sc->sc_lock, SX_XLOCKED);

        /* Count open volumes. */
        opens = g_raid_nopens(sc);

        /* React on some opened volumes. */
        if (opens > 0) {
                switch (how) {
                case G_RAID_DESTROY_SOFT:
                        G_RAID_DEBUG1(1, sc,
                            "%d volumes are still open.",
                            opens);
                        sx_xunlock(&sc->sc_lock);
                        return (EBUSY);
                case G_RAID_DESTROY_DELAYED:
                        G_RAID_DEBUG1(1, sc,
                            "Array will be destroyed on last close.");
                        sc->sc_stopping = G_RAID_DESTROY_DELAYED;
                        sx_xunlock(&sc->sc_lock);
                        return (EBUSY);
                case G_RAID_DESTROY_HARD:
                        G_RAID_DEBUG1(1, sc,
                            "%d volumes are still open.",
                            opens);
                }
        }

        /* Mark node for destruction. */
        sc->sc_stopping = G_RAID_DESTROY_HARD;
        /* Wake up worker to let it selfdestruct. */
        g_raid_event_send(sc, G_RAID_NODE_E_WAKE, 0);
        /* Sleep until node destroyed. */
        error = sx_sleep(&sc->sc_stopping, &sc->sc_lock,
            PRIBIO | PDROP, "r:destroy", hz * 3);
        return (error == EWOULDBLOCK ? EBUSY : 0);
}

static void
g_raid_taste_orphan(struct g_consumer *cp)
{

        KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
            cp->provider->name));
}

static struct g_geom *
g_raid_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
{
        struct g_consumer *cp;
        struct g_geom *gp, *geom;
        struct g_raid_md_class *class;
        struct g_raid_md_object *obj;
        int status;

        g_topology_assert();
        g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
        if (!g_raid_enable)
                return (NULL);
        G_RAID_DEBUG(2, "Tasting provider %s.", pp->name);

        geom = NULL;
        status = G_RAID_MD_TASTE_FAIL;
        gp = g_new_geom(mp, "raid:taste");
        /*
         * This orphan function should be never called.
         */
        gp->orphan = g_raid_taste_orphan;
        cp = g_new_consumer(gp);
        cp->flags |= G_CF_DIRECT_SEND | G_CF_DIRECT_RECEIVE;
        if (g_attach(cp, pp) != 0)
                goto ofail2;
        if (g_access(cp, 1, 0, 0) != 0)
                goto ofail;

        LIST_FOREACH(class, &g_raid_md_classes, mdc_list) {
                if (!class->mdc_enable)
                        continue;
                G_RAID_DEBUG(2, "Tasting provider %s for %s metadata.",
                    pp->name, class->name);
                obj = (void *)kobj_create((kobj_class_t)class, M_RAID,
                    M_WAITOK);
                obj->mdo_class = class;
                status = G_RAID_MD_TASTE(obj, mp, cp, &geom);
                if (status != G_RAID_MD_TASTE_NEW)
                        kobj_delete((kobj_t)obj, M_RAID);
                if (status != G_RAID_MD_TASTE_FAIL)
                        break;
        }

        if (status == G_RAID_MD_TASTE_FAIL)
                (void)g_access(cp, -1, 0, 0);
ofail:
        g_detach(cp);
ofail2:
        g_destroy_consumer(cp);
        g_destroy_geom(gp);
        G_RAID_DEBUG(2, "Tasting provider %s done.", pp->name);
        return (geom);
}

int
g_raid_create_node_format(const char *format, struct gctl_req *req,
    struct g_geom **gp)
{
        struct g_raid_md_class *class;
        struct g_raid_md_object *obj;
        int status;

        G_RAID_DEBUG(2, "Creating array for %s metadata.", format);
        LIST_FOREACH(class, &g_raid_md_classes, mdc_list) {
                if (strcasecmp(class->name, format) == 0)
                        break;
        }
        if (class == NULL) {
                G_RAID_DEBUG(1, "No support for %s metadata.", format);
                return (G_RAID_MD_TASTE_FAIL);
        }
        obj = (void *)kobj_create((kobj_class_t)class, M_RAID,
            M_WAITOK);
        obj->mdo_class = class;
        status = G_RAID_MD_CREATE_REQ(obj, &g_raid_class, req, gp);
        if (status != G_RAID_MD_TASTE_NEW)
                kobj_delete((kobj_t)obj, M_RAID);
        return (status);
}

static int
g_raid_destroy_geom(struct gctl_req *req __unused,
    struct g_class *mp __unused, struct g_geom *gp)
{
        struct g_raid_softc *sc;
        int error;

        g_topology_unlock();
        sc = gp->softc;
        sx_xlock(&sc->sc_lock);
        g_cancel_event(sc);
        error = g_raid_destroy(gp->softc, G_RAID_DESTROY_SOFT);
        g_topology_lock();
        return (error);
}

void g_raid_write_metadata(struct g_raid_softc *sc, struct g_raid_volume *vol,
    struct g_raid_subdisk *sd, struct g_raid_disk *disk)
{

        if (sc->sc_stopping == G_RAID_DESTROY_HARD)
                return;
        if (sc->sc_md)
                G_RAID_MD_WRITE(sc->sc_md, vol, sd, disk);
}

void g_raid_fail_disk(struct g_raid_softc *sc,
    struct g_raid_subdisk *sd, struct g_raid_disk *disk)
{

        if (disk == NULL)
                disk = sd->sd_disk;
        if (disk == NULL) {
                G_RAID_DEBUG1(0, sc, "Warning! Fail request to an absent disk!");
                return;
        }
        if (disk->d_state != G_RAID_DISK_S_ACTIVE) {
                G_RAID_DEBUG1(0, sc, "Warning! Fail request to a disk in a "
                    "wrong state (%s)!", g_raid_disk_state2str(disk->d_state));
                return;
        }
        if (sc->sc_md)
                G_RAID_MD_FAIL_DISK(sc->sc_md, sd, disk);
}

static void
g_raid_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
    struct g_consumer *cp, struct g_provider *pp)
{
        struct g_raid_softc *sc;
        struct g_raid_volume *vol;
        struct g_raid_subdisk *sd;
        struct g_raid_disk *disk;
        int i, s;

        g_topology_assert();

        sc = gp->softc;
        if (sc == NULL)
                return;
        if (pp != NULL) {
                vol = pp->private;
                g_topology_unlock();
                sx_xlock(&sc->sc_lock);
                sbuf_printf(sb, "%s<descr>%s %s volume</descr>\n", indent,
                    sc->sc_md->mdo_class->name,
                    g_raid_volume_level2str(vol->v_raid_level,
                    vol->v_raid_level_qualifier));
                sbuf_printf(sb, "%s<Label>%s</Label>\n", indent,
                    vol->v_name);
                sbuf_printf(sb, "%s<RAIDLevel>%s</RAIDLevel>\n", indent,
                    g_raid_volume_level2str(vol->v_raid_level,
                    vol->v_raid_level_qualifier));
                sbuf_printf(sb,
                    "%s<Transformation>%s</Transformation>\n", indent,
                    vol->v_tr ? vol->v_tr->tro_class->name : "NONE");
                sbuf_printf(sb, "%s<Components>%u</Components>\n", indent,
                    vol->v_disks_count);
                sbuf_printf(sb, "%s<Strip>%u</Strip>\n", indent,
                    vol->v_strip_size);
                sbuf_printf(sb, "%s<State>%s</State>\n", indent,
                    g_raid_volume_state2str(vol->v_state));
                sbuf_printf(sb, "%s<Dirty>%s</Dirty>\n", indent,
                    vol->v_dirty ? "Yes" : "No");
                sbuf_printf(sb, "%s<Subdisks>", indent);
                for (i = 0; i < vol->v_disks_count; i++) {
                        sd = &vol->v_subdisks[i];
                        if (sd->sd_disk != NULL &&
                            sd->sd_disk->d_consumer != NULL) {
                                sbuf_printf(sb, "%s ",
                                    g_raid_get_diskname(sd->sd_disk));
                        } else {
                                sbuf_cat(sb, "NONE ");
                        }
                        sbuf_printf(sb, "(%s",
                            g_raid_subdisk_state2str(sd->sd_state));
                        if (sd->sd_state == G_RAID_SUBDISK_S_REBUILD ||
                            sd->sd_state == G_RAID_SUBDISK_S_RESYNC) {
                                sbuf_printf(sb, " %d%%",
                                    (int)(sd->sd_rebuild_pos * 100 /
                                     sd->sd_size));
                        }
                        sbuf_cat(sb, ")");
                        if (i + 1 < vol->v_disks_count)
                                sbuf_cat(sb, ", ");
                }
                sbuf_cat(sb, "</Subdisks>\n");
                sx_xunlock(&sc->sc_lock);
                g_topology_lock();
        } else if (cp != NULL) {
                disk = cp->private;
                if (disk == NULL)
                        return;
                g_topology_unlock();
                sx_xlock(&sc->sc_lock);
                sbuf_printf(sb, "%s<State>%s", indent,
                    g_raid_disk_state2str(disk->d_state));
                if (!TAILQ_EMPTY(&disk->d_subdisks)) {
                        sbuf_cat(sb, " (");
                        TAILQ_FOREACH(sd, &disk->d_subdisks, sd_next) {
                                sbuf_printf(sb, "%s",
                                    g_raid_subdisk_state2str(sd->sd_state));
                                if (sd->sd_state == G_RAID_SUBDISK_S_REBUILD ||
                                    sd->sd_state == G_RAID_SUBDISK_S_RESYNC) {
                                        sbuf_printf(sb, " %d%%",
                                            (int)(sd->sd_rebuild_pos * 100 /
                                             sd->sd_size));
                                }
                                if (TAILQ_NEXT(sd, sd_next))
                                        sbuf_cat(sb, ", ");
                        }
                        sbuf_cat(sb, ")");
                }
                sbuf_cat(sb, "</State>\n");
                sbuf_printf(sb, "%s<Subdisks>", indent);
                TAILQ_FOREACH(sd, &disk->d_subdisks, sd_next) {
                        sbuf_printf(sb, "r%d(%s):%d@%ju",
                            sd->sd_volume->v_global_id,
                            sd->sd_volume->v_name,
                            sd->sd_pos, (uintmax_t)sd->sd_offset);
                        if (TAILQ_NEXT(sd, sd_next))
                                sbuf_cat(sb, ", ");
                }
                sbuf_cat(sb, "</Subdisks>\n");
                sbuf_printf(sb, "%s<ReadErrors>%d</ReadErrors>\n", indent,
                    disk->d_read_errs);
                sx_xunlock(&sc->sc_lock);
                g_topology_lock();
        } else {
                g_topology_unlock();
                sx_xlock(&sc->sc_lock);
                if (sc->sc_md) {
                        sbuf_printf(sb, "%s<Metadata>%s</Metadata>\n", indent,
                            sc->sc_md->mdo_class->name);
                }
                if (!TAILQ_EMPTY(&sc->sc_volumes)) {
                        s = 0xff;
                        TAILQ_FOREACH(vol, &sc->sc_volumes, v_next) {
                                if (vol->v_state < s)
                                        s = vol->v_state;
                        }
                        sbuf_printf(sb, "%s<State>%s</State>\n", indent,
                            g_raid_volume_state2str(s));
                }
                sx_xunlock(&sc->sc_lock);
                g_topology_lock();
        }
}

static void
g_raid_shutdown_post_sync(void *arg, int howto)
{
        struct g_class *mp;
        struct g_geom *gp, *gp2;
        struct g_raid_softc *sc;
        struct g_raid_volume *vol;

        if ((howto & RB_NOSYNC) != 0)
                return;

        mp = arg;
        g_topology_lock();
        g_raid_shutdown = 1;
        LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
                if ((sc = gp->softc) == NULL)
                        continue;
                g_topology_unlock();
                sx_xlock(&sc->sc_lock);
                TAILQ_FOREACH(vol, &sc->sc_volumes, v_next)
                        g_raid_clean(vol, -1);
                g_cancel_event(sc);
                g_raid_destroy(sc, G_RAID_DESTROY_DELAYED);
                g_topology_lock();
        }
        g_topology_unlock();
}

static void
g_raid_init(struct g_class *mp)
{

        g_raid_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
            g_raid_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
        if (g_raid_post_sync == NULL)
                G_RAID_DEBUG(0, "Warning! Cannot register shutdown event.");
        g_raid_started = 1;
}

static void
g_raid_fini(struct g_class *mp)
{

        if (g_raid_post_sync != NULL)
                EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_raid_post_sync);
        g_raid_started = 0;
}

int
g_raid_md_modevent(module_t mod, int type, void *arg)
{
        struct g_raid_md_class *class, *c, *nc;
        int error;

        error = 0;
        class = arg;
        switch (type) {
        case MOD_LOAD:
                c = LIST_FIRST(&g_raid_md_classes);
                if (c == NULL || c->mdc_priority > class->mdc_priority)
                        LIST_INSERT_HEAD(&g_raid_md_classes, class, mdc_list);
                else {
                        while ((nc = LIST_NEXT(c, mdc_list)) != NULL &&
                            nc->mdc_priority < class->mdc_priority)
                                c = nc;
                        LIST_INSERT_AFTER(c, class, mdc_list);
                }
                if (g_raid_started)
                        g_retaste(&g_raid_class);
                break;
        case MOD_UNLOAD:
                LIST_REMOVE(class, mdc_list);
                break;
        default:
                error = EOPNOTSUPP;
                break;
        }

        return (error);
}

int
g_raid_tr_modevent(module_t mod, int type, void *arg)
{
        struct g_raid_tr_class *class, *c, *nc;
        int error;

        error = 0;
        class = arg;
        switch (type) {
        case MOD_LOAD:
                c = LIST_FIRST(&g_raid_tr_classes);
                if (c == NULL || c->trc_priority > class->trc_priority)
                        LIST_INSERT_HEAD(&g_raid_tr_classes, class, trc_list);
                else {
                        while ((nc = LIST_NEXT(c, trc_list)) != NULL &&
                            nc->trc_priority < class->trc_priority)
                                c = nc;
                        LIST_INSERT_AFTER(c, class, trc_list);
                }
                break;
        case MOD_UNLOAD:
                LIST_REMOVE(class, trc_list);
                break;
        default:
                error = EOPNOTSUPP;
                break;
        }

        return (error);
}

/*
 * Use local implementation of DECLARE_GEOM_CLASS(g_raid_class, g_raid)
 * to reduce module priority, allowing submodules to register them first.
 */
static moduledata_t g_raid_mod = {
        "g_raid",
        g_modevent,
        &g_raid_class
};
DECLARE_MODULE(g_raid, g_raid_mod, SI_SUB_DRIVERS, SI_ORDER_FOURTH);
MODULE_VERSION(geom_raid, 0);