/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2004-2009 Pawel Jakub Dawidek <pjd@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/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/sbuf.h>
#include <sys/sx.h>

#include <geom/geom.h>
#include <geom/geom_dbg.h>
#include <geom/geom_int.h>
#include <geom/mirror/g_mirror.h>

/*
 * Configure, Rebuild, Remove, Deactivate, Forget, and Stop operations do not
 * seem to depend on any particular g_mirror initialization state.
 */
static struct g_mirror_softc *
g_mirror_find_device(struct g_class *mp, const char *name)
{
        struct g_mirror_softc *sc;
        struct g_geom *gp;

        g_topology_lock();
        LIST_FOREACH(gp, &mp->geom, geom) {
                sc = gp->softc;
                if (sc == NULL)
                        continue;
                if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0)
                        continue;
                if (strcmp(gp->name, name) == 0 ||
                    strcmp(sc->sc_name, name) == 0) {
                        g_topology_unlock();
                        sx_xlock(&sc->sc_lock);
                        if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
                                sx_xunlock(&sc->sc_lock);
                                return (NULL);
                        }
                        return (sc);
                }
        }
        g_topology_unlock();
        return (NULL);
}

/* Insert and Resize operations depend on a launched GEOM (sc_provider). */
#define GMFL_VALID_FLAGS        (M_WAITOK | M_NOWAIT)
static struct g_mirror_softc *
g_mirror_find_launched_device(struct g_class *mp, const char *name, int flags)
{
        struct g_mirror_softc *sc;
        int error;

        KASSERT((flags & ~GMFL_VALID_FLAGS) == 0 &&
            flags != GMFL_VALID_FLAGS && flags != 0,
            ("%s: Invalid flags %x\n", __func__, (unsigned)flags));
#undef  GMFL_VALID_FLAGS

        while (true) {
                sc = g_mirror_find_device(mp, name);
                if (sc == NULL)
                        return (NULL);
                if (sc->sc_provider != NULL)
                        return (sc);
                if (flags & M_NOWAIT) {
                        sx_xunlock(&sc->sc_lock);
                        return (NULL);
                }

                /*
                 * This is a dumb hack.  G_mirror does not expose any real
                 * wakeup API for observing state changes, and even if it did,
                 * its "RUNNING" state does not actually reflect all softc
                 * elements being initialized.
                 *
                 * Revamping g_mirror to have a 3rd, ACTUALLY_RUNNING state and
                 * updating all assertions and sc_state checks is a large work
                 * and would be easy to introduce regressions.
                 *
                 * Revamping g_mirror to have a wakeup for state changes would
                 * be difficult if one wanted to capture more than just
                 * sc_state and sc_provider.
                 *
                 * For now, just dummy sleep-poll until sc_provider shows up,
                 * the user cancels, or the g_mirror is destroyed.
                 */
                error = sx_sleep(&sc, &sc->sc_lock, PRIBIO | PCATCH | PDROP,
                    "GM:launched", 1);
                if (error != 0 && error != EWOULDBLOCK)
                        return (NULL);
        }
        __unreachable();
}

static struct g_mirror_disk *
g_mirror_find_disk(struct g_mirror_softc *sc, const char *name)
{
        struct g_mirror_disk *disk;

        sx_assert(&sc->sc_lock, SX_XLOCKED);
        if (strncmp(name, _PATH_DEV, 5) == 0)
                name += 5;
        LIST_FOREACH(disk, &sc->sc_disks, d_next) {
                if (disk->d_consumer == NULL)
                        continue;
                if (disk->d_consumer->provider == NULL)
                        continue;
                if (strcmp(disk->d_consumer->provider->name, name) == 0)
                        return (disk);
        }
        return (NULL);
}

static void
g_mirror_ctl_configure(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        const char *name, *balancep, *prov;
        intmax_t *slicep, *priority;
        uint32_t slice;
        uint8_t balance;
        int *autosync, *noautosync, *failsync, *nofailsync, *hardcode, *dynamic;
        int *nargs, do_sync = 0, dirty = 1, do_priority = 0;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs != 1 && *nargs != 2) {
                gctl_error(req, "Invalid number of arguments.");
                return;
        }
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        balancep = gctl_get_asciiparam(req, "balance");
        if (balancep == NULL) {
                gctl_error(req, "No '%s' argument.", "balance");
                return;
        }
        autosync = gctl_get_paraml(req, "autosync", sizeof(*autosync));
        if (autosync == NULL) {
                gctl_error(req, "No '%s' argument.", "autosync");
                return;
        }
        noautosync = gctl_get_paraml(req, "noautosync", sizeof(*noautosync));
        if (noautosync == NULL) {
                gctl_error(req, "No '%s' argument.", "noautosync");
                return;
        }
        failsync = gctl_get_paraml(req, "failsync", sizeof(*failsync));
        if (failsync == NULL) {
                gctl_error(req, "No '%s' argument.", "failsync");
                return;
        }
        nofailsync = gctl_get_paraml(req, "nofailsync", sizeof(*nofailsync));
        if (nofailsync == NULL) {
                gctl_error(req, "No '%s' argument.", "nofailsync");
                return;
        }
        hardcode = gctl_get_paraml(req, "hardcode", sizeof(*hardcode));
        if (hardcode == NULL) {
                gctl_error(req, "No '%s' argument.", "hardcode");
                return;
        }
        dynamic = gctl_get_paraml(req, "dynamic", sizeof(*dynamic));
        if (dynamic == NULL) {
                gctl_error(req, "No '%s' argument.", "dynamic");
                return;
        }
        priority = gctl_get_paraml(req, "priority", sizeof(*priority));
        if (priority == NULL) {
                gctl_error(req, "No '%s' argument.", "priority");
                return;
        }
        if (*priority < -1 || *priority > 255) {
                gctl_error(req, "Priority range is 0 to 255, %jd given",
                    *priority);
                return;
        }
        /* 
         * Since we have a priority, we also need a provider now.
         * Note: be WARNS safe, by always assigning prov and only throw an
         * error if *priority != -1.
         */
        prov = gctl_get_asciiparam(req, "arg1");
        if (*priority > -1) {
                if (prov == NULL) {
                        gctl_error(req, "Priority needs a disk name");
                        return;
                }
                do_priority = 1;
        }
        if (*autosync && *noautosync) {
                gctl_error(req, "'%s' and '%s' specified.", "autosync",
                    "noautosync");
                return;
        }
        if (*failsync && *nofailsync) {
                gctl_error(req, "'%s' and '%s' specified.", "failsync",
                    "nofailsync");
                return;
        }
        if (*hardcode && *dynamic) {
                gctl_error(req, "'%s' and '%s' specified.", "hardcode",
                    "dynamic");
                return;
        }
        sc = g_mirror_find_device(mp, name);
        if (sc == NULL) {
                gctl_error(req, "No such device: %s.", name);
                return;
        }
        if (*balancep == '\0')
                balance = sc->sc_balance;
        else {
                if (balance_id(balancep) == -1) {
                        gctl_error(req, "Invalid balance algorithm.");
                        sx_xunlock(&sc->sc_lock);
                        return;
                }
                balance = balance_id(balancep);
        }
        slicep = gctl_get_paraml(req, "slice", sizeof(*slicep));
        if (slicep == NULL) {
                gctl_error(req, "No '%s' argument.", "slice");
                sx_xunlock(&sc->sc_lock);
                return;
        }
        if (*slicep == -1)
                slice = sc->sc_slice;
        else
                slice = *slicep;
        /* Enforce usage() of -p not allowing any other options. */
        if (do_priority && (*autosync || *noautosync || *failsync ||
            *nofailsync || *hardcode || *dynamic || *slicep != -1 ||
            *balancep != '\0')) {
                sx_xunlock(&sc->sc_lock);
                gctl_error(req, "only -p accepted when setting priority");
                return;
        }
        if (sc->sc_balance == balance && sc->sc_slice == slice && !*autosync &&
            !*noautosync && !*failsync && !*nofailsync && !*hardcode &&
            !*dynamic && !do_priority) {
                sx_xunlock(&sc->sc_lock);
                gctl_error(req, "Nothing has changed.");
                return;
        }
        if ((!do_priority && *nargs != 1) || (do_priority && *nargs != 2)) {
                sx_xunlock(&sc->sc_lock);
                gctl_error(req, "Invalid number of arguments.");
                return;
        }
        if (g_mirror_ndisks(sc, -1) < sc->sc_ndisks) {
                sx_xunlock(&sc->sc_lock);
                gctl_error(req, "Not all disks connected. Try 'forget' command "
                    "first.");
                return;
        }
        sc->sc_balance = balance;
        sc->sc_slice = slice;
        if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0) {
                if (*autosync) {
                        sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_NOAUTOSYNC;
                        do_sync = 1;
                }
        } else {
                if (*noautosync)
                        sc->sc_flags |= G_MIRROR_DEVICE_FLAG_NOAUTOSYNC;
        }
        if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOFAILSYNC) != 0) {
                if (*failsync)
                        sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_NOFAILSYNC;
        } else {
                if (*nofailsync) {
                        sc->sc_flags |= G_MIRROR_DEVICE_FLAG_NOFAILSYNC;
                        dirty = 0;
                }
        }
        LIST_FOREACH(disk, &sc->sc_disks, d_next) {
                /*
                 * Handle priority first, since we only need one disk, do one
                 * operation on it and then we're done. No need to check other
                 * flags, as usage doesn't allow it.
                 */
                if (do_priority) {
                        if (strcmp(disk->d_name, prov) == 0) {
                                if (disk->d_priority == *priority)
                                        gctl_error(req, "Nothing has changed.");
                                else {
                                        disk->d_priority = *priority;
                                        g_mirror_update_metadata(disk);
                                }
                                break;
                        }
                        continue;
                }
                if (do_sync) {
                        if (disk->d_state == G_MIRROR_DISK_STATE_SYNCHRONIZING)
                                disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
                }
                if (*hardcode)
                        disk->d_flags |= G_MIRROR_DISK_FLAG_HARDCODED;
                else if (*dynamic)
                        disk->d_flags &= ~G_MIRROR_DISK_FLAG_HARDCODED;
                if (!dirty)
                        disk->d_flags &= ~G_MIRROR_DISK_FLAG_DIRTY;
                g_mirror_update_metadata(disk);
                if (do_sync) {
                        if (disk->d_state == G_MIRROR_DISK_STATE_STALE) {
                                g_mirror_event_send(disk,
                                    G_MIRROR_DISK_STATE_DISCONNECTED,
                                    G_MIRROR_EVENT_DONTWAIT);
                        }
                }
        }
        sx_xunlock(&sc->sc_lock);
}

static void
g_mirror_create_orphan(struct g_consumer *cp)
{

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

static void
g_mirror_ctl_create(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_metadata md;
        struct g_geom *gp;
        struct g_consumer *cp;
        struct g_provider *pp;
        struct g_mirror_softc *sc;
        struct sbuf *sb;
        const char *name;
        char param[16];
        int *nargs;
        intmax_t *val;
        int *ival;
        const char *sval;
        int bal;
        unsigned attached, no, sectorsize;
        off_t mediasize;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs <= 2) {
                gctl_error(req, "Too few arguments.");
                return;
        }

        strlcpy(md.md_magic, G_MIRROR_MAGIC, sizeof(md.md_magic));
        md.md_version = G_MIRROR_VERSION;
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        strlcpy(md.md_name, name, sizeof(md.md_name));
        md.md_mid = arc4random();
        md.md_all = *nargs - 1;
        md.md_genid = 0;
        md.md_syncid = 1;
        md.md_sync_offset = 0;
        val = gctl_get_paraml(req, "slice", sizeof(*val));
        if (val == NULL) {
                gctl_error(req, "No slice argument.");
                return;
        }
        md.md_slice = *val;
        sval = gctl_get_asciiparam(req, "balance");
        if (sval == NULL) {
                gctl_error(req, "No balance argument.");
                return;
        }
        bal = balance_id(sval);
        if (bal < 0) {
                gctl_error(req, "Invalid balance algorithm.");
                return;
        }
        md.md_balance = bal;
        md.md_mflags = 0;
        md.md_dflags = 0;
        ival = gctl_get_paraml(req, "noautosync", sizeof(*ival));
        if (ival != NULL && *ival)
                md.md_mflags |= G_MIRROR_DEVICE_FLAG_NOAUTOSYNC;
        ival = gctl_get_paraml(req, "nofailsync", sizeof(*ival));
        if (ival != NULL && *ival)
                md.md_mflags |= G_MIRROR_DEVICE_FLAG_NOFAILSYNC;
        /* These fields not used in manual mode. */
        bzero(md.md_provider, sizeof(md.md_provider));
        md.md_provsize = 0;

        g_topology_lock();
        mediasize = OFF_MAX;
        sectorsize = 0;
        gp = g_new_geom(mp, md.md_name);
        gp->orphan = g_mirror_create_orphan;
        cp = g_new_consumer(gp);
        for (no = 1; no < *nargs; no++) {
                snprintf(param, sizeof(param), "arg%u", no);
                pp = gctl_get_provider(req, param);
                if (pp == NULL) {
err:
                        g_destroy_consumer(cp);
                        g_destroy_geom(gp);
                        g_topology_unlock();
                        return;
                }
                if (g_attach(cp, pp) != 0) {
                        G_MIRROR_DEBUG(1, "Can't attach disk %s.", pp->name);
                        gctl_error(req, "Can't attach disk %s.", pp->name);
                        goto err;
                }
                if (g_access(cp, 1, 0, 0) != 0) {
                        G_MIRROR_DEBUG(1, "Can't open disk %s.", pp->name);
                        gctl_error(req, "Can't open disk %s.", pp->name);
err2:
                        g_detach(cp);
                        goto err;
                }
                if (pp->mediasize == 0 || pp->sectorsize == 0) {
                        G_MIRROR_DEBUG(1, "Disk %s has no media.", pp->name);
                        gctl_error(req, "Disk %s has no media.", pp->name);
                        g_access(cp, -1, 0, 0);
                        goto err2;
                }
                if (pp->mediasize < mediasize)
                        mediasize = pp->mediasize;
                if (pp->sectorsize > sectorsize)
                        sectorsize = pp->sectorsize;
                g_access(cp, -1, 0, 0);
                g_detach(cp);
        }
        g_destroy_consumer(cp);
        g_destroy_geom(gp);
        md.md_mediasize = mediasize;
        md.md_sectorsize = sectorsize;
        md.md_mediasize -= (md.md_mediasize % md.md_sectorsize);

        gp = g_mirror_create(mp, &md, G_MIRROR_TYPE_MANUAL);
        if (gp == NULL) {
                gctl_error(req, "Can't create %s.", md.md_name);
                g_topology_unlock();
                return;
        }

        sc = gp->softc;
        g_topology_unlock();
        sx_xlock(&sc->sc_lock);
        sc->sc_flags |= G_MIRROR_DEVICE_FLAG_TASTING;
        sb = sbuf_new_auto();
        sbuf_printf(sb, "Can't attach disk(s) to %s:", gp->name);
        for (attached = 0, no = 1; no < *nargs; no++) {
                snprintf(param, sizeof(param), "arg%u", no);
                pp = gctl_get_provider(req, param);
                if (pp == NULL) {
                        name = gctl_get_asciiparam(req, param);
                        MPASS(name != NULL);
                        sbuf_printf(sb, " %s", name);
                        continue;
                }
                md.md_did = arc4random();
                md.md_priority = no - 1;
                if (g_mirror_add_disk(sc, pp, &md) != 0) {
                        G_MIRROR_DEBUG(1, "Disk %u (%s) not attached to %s.",
                            no, pp->name, gp->name);
                        sbuf_printf(sb, " %s", pp->name);
                        continue;
                }
                attached++;
        }
        sbuf_finish(sb);
        sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_TASTING;
        if (md.md_all != attached ||
            (sc->sc_flags & G_MIRROR_DEVICE_FLAG_DESTROY) != 0) {
                g_mirror_destroy(gp->softc, G_MIRROR_DESTROY_HARD);
                gctl_error(req, "%s", sbuf_data(sb));
        } else
                sx_xunlock(&sc->sc_lock);
        sbuf_delete(sb);
}

static void
g_mirror_ctl_rebuild(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_metadata md;
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        struct g_provider *pp;
        const char *name;
        char param[16];
        int error, *nargs;
        u_int i;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs < 2) {
                gctl_error(req, "Too few arguments.");
                return;
        }
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        sc = g_mirror_find_device(mp, name);
        if (sc == NULL) {
                gctl_error(req, "No such device: %s.", name);
                return;
        }
        for (i = 1; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%u' argument.", i);
                        continue;
                }
                disk = g_mirror_find_disk(sc, name);
                if (disk == NULL) {
                        gctl_error(req, "No such provider: %s.", name);
                        continue;
                }
                if (g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE) == 1 &&
                    disk->d_state == G_MIRROR_DISK_STATE_ACTIVE) {
                        /*
                         * This is the last active disk. There will be nothing
                         * to rebuild it from, so deny this request.
                         */
                        gctl_error(req,
                            "Provider %s is the last active provider in %s.",
                            name, sc->sc_geom->name);
                        break;
                }
                /*
                 * Do rebuild by resetting syncid, disconnecting the disk and
                 * connecting it again.
                 */
                disk->d_sync.ds_syncid = 0;
                if ((sc->sc_flags & G_MIRROR_DEVICE_FLAG_NOAUTOSYNC) != 0)
                        disk->d_flags |= G_MIRROR_DISK_FLAG_FORCE_SYNC;
                g_mirror_update_metadata(disk);
                pp = disk->d_consumer->provider;
                g_topology_lock();
                error = g_mirror_read_metadata(disk->d_consumer, &md);
                g_topology_unlock();
                g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
                    G_MIRROR_EVENT_WAIT);
                if (error != 0) {
                        gctl_error(req, "Cannot read metadata from %s.",
                            pp->name);
                        continue;
                }
                error = g_mirror_add_disk(sc, pp, &md);
                if (error != 0) {
                        gctl_error(req, "Cannot reconnect component %s.",
                            pp->name);
                        continue;
                }
        }
        sx_xunlock(&sc->sc_lock);
}

static void
g_mirror_ctl_insert(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        struct g_mirror_metadata md;
        struct g_provider *pp;
        struct g_consumer *cp;
        intmax_t *priority;
        const char *name;
        char param[16];
        u_char *sector;
        u_int i, n;
        int error, *nargs, *hardcode, *inactive;
        struct {
                struct g_provider       *provider;
                struct g_consumer       *consumer;
        } *disks;
        off_t mdsize;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs < 2) {
                gctl_error(req, "Too few arguments.");
                return;
        }
        priority = gctl_get_paraml(req, "priority", sizeof(*priority));
        if (priority == NULL) {
                gctl_error(req, "No '%s' argument.", "priority");
                return;
        }
        inactive = gctl_get_paraml(req, "inactive", sizeof(*inactive));
        if (inactive == NULL) {
                gctl_error(req, "No '%s' argument.", "inactive");
                return;
        }
        hardcode = gctl_get_paraml(req, "hardcode", sizeof(*hardcode));
        if (hardcode == NULL) {
                gctl_error(req, "No '%s' argument.", "hardcode");
                return;
        }
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        sc = g_mirror_find_launched_device(mp, name, M_WAITOK);
        if (sc == NULL) {
                gctl_error(req, "No such device: %s.", name);
                return;
        }
        if (g_mirror_ndisks(sc, -1) < sc->sc_ndisks) {
                gctl_error(req, "Not all disks connected.");
                sx_xunlock(&sc->sc_lock);
                return;
        }

        disks = g_malloc(sizeof(*disks) * (*nargs), M_WAITOK | M_ZERO);
        g_topology_lock();
        for (i = 1, n = 0; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                pp = gctl_get_provider(req, param);
                if (pp == NULL)
                        continue;
                if (g_mirror_find_disk(sc, pp->name) != NULL) {
                        gctl_error(req, "Provider %s already inserted.", pp->name);
                        continue;
                }
                cp = g_new_consumer(sc->sc_geom);
                if (g_attach(cp, pp) != 0) {
                        g_destroy_consumer(cp);
                        gctl_error(req, "Cannot attach to provider %s.", pp->name);
                        continue;
                }
                if (g_access(cp, 0, 1, 1) != 0) {
                        gctl_error(req, "Cannot access provider %s.", pp->name);
err:
                        g_detach(cp);
                        g_destroy_consumer(cp);
                        continue;
                }
                mdsize = (sc->sc_type == G_MIRROR_TYPE_AUTOMATIC) ?
                    pp->sectorsize : 0;
                if (sc->sc_provider->mediasize > pp->mediasize - mdsize) {
                        gctl_error(req, "Provider %s too small.", pp->name);
err2:
                        g_access(cp, 0, -1, -1);
                        goto err;
                }
                if ((sc->sc_provider->sectorsize % pp->sectorsize) != 0) {
                        gctl_error(req, "Invalid sectorsize of provider %s.",
                            pp->name);
                        goto err2;
                }
                if (sc->sc_type != G_MIRROR_TYPE_AUTOMATIC) {
                        g_access(cp, 0, -1, -1);
                        g_detach(cp);
                        g_destroy_consumer(cp);
                        g_topology_unlock();
                        sc->sc_ndisks++;
                        g_mirror_fill_metadata(sc, NULL, &md);
                        md.md_priority = *priority;
                        if (*inactive)
                                md.md_dflags |= G_MIRROR_DISK_FLAG_INACTIVE;
                        if (g_mirror_add_disk(sc, pp, &md) != 0) {
                                sc->sc_ndisks--;
                                gctl_error(req, "Disk %s not inserted.", pp->name);
                        }
                        g_topology_lock();
                        continue;
                }
                disks[n].provider = pp;
                disks[n].consumer = cp;
                n++;
        }
        if (n == 0) {
                g_topology_unlock();
                sx_xunlock(&sc->sc_lock);
                g_free(disks);
                return;
        }
        sc->sc_ndisks += n;
again:
        for (i = 0; i < n; i++) {
                if (disks[i].consumer == NULL)
                        continue;
                g_mirror_fill_metadata(sc, NULL, &md);
                md.md_priority = *priority;
                if (*inactive)
                        md.md_dflags |= G_MIRROR_DISK_FLAG_INACTIVE;
                pp = disks[i].provider;
                if (*hardcode) {
                        strlcpy(md.md_provider, pp->name,
                            sizeof(md.md_provider));
                } else {
                        bzero(md.md_provider, sizeof(md.md_provider));
                }
                md.md_provsize = pp->mediasize;
                sector = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
                mirror_metadata_encode(&md, sector);
                error = g_write_data(disks[i].consumer,
                    pp->mediasize - pp->sectorsize, sector, pp->sectorsize);
                g_free(sector);
                if (error != 0) {
                        gctl_error(req, "Cannot store metadata on %s.",
                            pp->name);
                        g_access(disks[i].consumer, 0, -1, -1);
                        g_detach(disks[i].consumer);
                        g_destroy_consumer(disks[i].consumer);
                        disks[i].consumer = NULL;
                        disks[i].provider = NULL;
                        sc->sc_ndisks--;
                        goto again;
                }
        }
        g_topology_unlock();
        if (i == 0) {
                /* All writes failed. */
                sx_xunlock(&sc->sc_lock);
                g_free(disks);
                return;
        }
        LIST_FOREACH(disk, &sc->sc_disks, d_next) {
                g_mirror_update_metadata(disk);
        }
        /*
         * Release provider and wait for retaste.
         */
        g_topology_lock();
        for (i = 0; i < n; i++) {
                if (disks[i].consumer == NULL)
                        continue;
                g_access(disks[i].consumer, 0, -1, -1);
                g_detach(disks[i].consumer);
                g_destroy_consumer(disks[i].consumer);
        }
        g_topology_unlock();
        sx_xunlock(&sc->sc_lock);
        g_free(disks);
}

static void
g_mirror_ctl_remove(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        const char *name;
        char param[16];
        int *nargs;
        u_int i, active;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs < 2) {
                gctl_error(req, "Too few arguments.");
                return;
        }
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        sc = g_mirror_find_device(mp, name);
        if (sc == NULL) {
                gctl_error(req, "No such device: %s.", name);
                return;
        }
        if (g_mirror_ndisks(sc, -1) < sc->sc_ndisks) {
                sx_xunlock(&sc->sc_lock);
                gctl_error(req, "Not all disks connected. Try 'forget' command "
                    "first.");
                return;
        }
        active = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
        for (i = 1; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%u' argument.", i);
                        continue;
                }
                disk = g_mirror_find_disk(sc, name);
                if (disk == NULL) {
                        gctl_error(req, "No such provider: %s.", name);
                        continue;
                }
                if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE) {
                        if (active > 1)
                                active--;
                        else {
                                gctl_error(req, "%s: Can't remove the last "
                                    "ACTIVE component %s.", sc->sc_geom->name,
                                    name);
                                continue;
                        }
                }
                g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DESTROY,
                    G_MIRROR_EVENT_DONTWAIT);
        }
        sx_xunlock(&sc->sc_lock);
}

static void
g_mirror_ctl_resize(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        uint64_t mediasize;
        const char *name, *s;
        char *x;
        int *nargs;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs != 1) {
                gctl_error(req, "Missing device.");
                return;
        }
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        s = gctl_get_asciiparam(req, "size");
        if (s == NULL) {
                gctl_error(req, "No '%s' argument.", "size");
                return;
        }
        mediasize = strtouq(s, &x, 0);
        if (*x != '\0' || mediasize == 0) {
                gctl_error(req, "Invalid '%s' argument.", "size");
                return;
        }
        sc = g_mirror_find_launched_device(mp, name, M_WAITOK);
        if (sc == NULL) {
                gctl_error(req, "No such device: %s.", name);
                return;
        }
        /* Deny shrinking of an opened provider */
        if ((g_debugflags & G_F_FOOTSHOOTING) == 0 && sc->sc_provider_open > 0) {
                if (sc->sc_mediasize > mediasize) {
                        gctl_error(req, "Device %s is busy.",
                            sc->sc_provider->name);
                        sx_xunlock(&sc->sc_lock);
                        return;
                }
        }
        LIST_FOREACH(disk, &sc->sc_disks, d_next) {
                if (mediasize > disk->d_consumer->provider->mediasize -
                    disk->d_consumer->provider->sectorsize) {
                        gctl_error(req, "Provider %s is too small.",
                            disk->d_name);
                        sx_xunlock(&sc->sc_lock);
                        return;
                }
        }
        /* Update the size. */
        sc->sc_mediasize = mediasize;
        LIST_FOREACH(disk, &sc->sc_disks, d_next) {
                g_mirror_update_metadata(disk);
        }
        g_topology_lock();
        g_resize_provider(sc->sc_provider, mediasize);
        g_topology_unlock();
        sx_xunlock(&sc->sc_lock);
}

static void
g_mirror_ctl_deactivate(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        const char *name;
        char param[16];
        int *nargs;
        u_int i, active;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs < 2) {
                gctl_error(req, "Too few arguments.");
                return;
        }
        name = gctl_get_asciiparam(req, "arg0");
        if (name == NULL) {
                gctl_error(req, "No 'arg%u' argument.", 0);
                return;
        }
        sc = g_mirror_find_device(mp, name);
        if (sc == NULL) {
                gctl_error(req, "No such device: %s.", name);
                return;
        }
        active = g_mirror_ndisks(sc, G_MIRROR_DISK_STATE_ACTIVE);
        for (i = 1; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%u' argument.", i);
                        continue;
                }
                disk = g_mirror_find_disk(sc, name);
                if (disk == NULL) {
                        gctl_error(req, "No such provider: %s.", name);
                        continue;
                }
                if (disk->d_state == G_MIRROR_DISK_STATE_ACTIVE) {
                        if (active > 1)
                                active--;
                        else {
                                gctl_error(req, "%s: Can't deactivate the "
                                    "last ACTIVE component %s.",
                                    sc->sc_geom->name, name);
                                continue;
                        }
                }
                disk->d_flags |= G_MIRROR_DISK_FLAG_INACTIVE;
                disk->d_flags &= ~G_MIRROR_DISK_FLAG_FORCE_SYNC;
                g_mirror_update_metadata(disk);
                sc->sc_bump_id |= G_MIRROR_BUMP_SYNCID;
                g_mirror_event_send(disk, G_MIRROR_DISK_STATE_DISCONNECTED,
                    G_MIRROR_EVENT_DONTWAIT);
        }
        sx_xunlock(&sc->sc_lock);
}

static void
g_mirror_ctl_forget(struct gctl_req *req, struct g_class *mp)
{
        struct g_mirror_softc *sc;
        struct g_mirror_disk *disk;
        const char *name;
        char param[16];
        int *nargs;
        u_int i;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs < 1) {
                gctl_error(req, "Missing device(s).");
                return;
        }

        for (i = 0; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%u' argument.", i);
                        return;
                }
                sc = g_mirror_find_device(mp, name);
                if (sc == NULL) {
                        gctl_error(req, "No such device: %s.", name);
                        return;
                }
                if (g_mirror_ndisks(sc, -1) == sc->sc_ndisks) {
                        sx_xunlock(&sc->sc_lock);
                        G_MIRROR_DEBUG(1,
                            "All disks connected in %s, skipping.",
                            sc->sc_name);
                        continue;
                }
                sc->sc_ndisks = g_mirror_ndisks(sc, -1);
                LIST_FOREACH(disk, &sc->sc_disks, d_next) {
                        g_mirror_update_metadata(disk);
                }
                sx_xunlock(&sc->sc_lock);
        }
}

static void
g_mirror_ctl_stop(struct gctl_req *req, struct g_class *mp, int wipe)
{
        struct g_mirror_softc *sc;
        int *force, *nargs, error;
        const char *name;
        char param[16];
        u_int i;
        int how;

        nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
        if (nargs == NULL) {
                gctl_error(req, "No '%s' argument.", "nargs");
                return;
        }
        if (*nargs < 1) {
                gctl_error(req, "Missing device(s).");
                return;
        }
        force = gctl_get_paraml(req, "force", sizeof(*force));
        if (force == NULL) {
                gctl_error(req, "No '%s' argument.", "force");
                return;
        }
        if (*force)
                how = G_MIRROR_DESTROY_HARD;
        else
                how = G_MIRROR_DESTROY_SOFT;

        for (i = 0; i < (u_int)*nargs; i++) {
                snprintf(param, sizeof(param), "arg%u", i);
                name = gctl_get_asciiparam(req, param);
                if (name == NULL) {
                        gctl_error(req, "No 'arg%u' argument.", i);
                        return;
                }
                sc = g_mirror_find_device(mp, name);
                if (sc == NULL) {
                        gctl_error(req, "No such device: %s.", name);
                        return;
                }
                g_cancel_event(sc);
                if (wipe)
                        sc->sc_flags |= G_MIRROR_DEVICE_FLAG_WIPE;
                error = g_mirror_destroy(sc, how);
                if (error != 0) {
                        gctl_error(req, "Cannot destroy device %s (error=%d).",
                            sc->sc_geom->name, error);
                        if (wipe)
                                sc->sc_flags &= ~G_MIRROR_DEVICE_FLAG_WIPE;
                        sx_xunlock(&sc->sc_lock);
                        return;
                }
                /* No need to unlock, because lock is already dead. */
        }
}

void
g_mirror_config(struct gctl_req *req, struct g_class *mp, const char *verb)
{
        uint32_t *version;

        g_topology_assert();

        version = gctl_get_paraml(req, "version", sizeof(*version));
        if (version == NULL) {
                gctl_error(req, "No '%s' argument.", "version");
                return;
        }
        if (*version != G_MIRROR_VERSION) {
                gctl_error(req, "Userland and kernel parts are out of sync.");
                return;
        }

        g_topology_unlock();
        if (strcmp(verb, "configure") == 0)
                g_mirror_ctl_configure(req, mp);
        else if (strcmp(verb, "create") == 0)
                g_mirror_ctl_create(req, mp);
        else if (strcmp(verb, "rebuild") == 0)
                g_mirror_ctl_rebuild(req, mp);
        else if (strcmp(verb, "insert") == 0)
                g_mirror_ctl_insert(req, mp);
        else if (strcmp(verb, "remove") == 0)
                g_mirror_ctl_remove(req, mp);
        else if (strcmp(verb, "resize") == 0)
                g_mirror_ctl_resize(req, mp);
        else if (strcmp(verb, "deactivate") == 0)
                g_mirror_ctl_deactivate(req, mp);
        else if (strcmp(verb, "forget") == 0)
                g_mirror_ctl_forget(req, mp);
        else if (strcmp(verb, "stop") == 0)
                g_mirror_ctl_stop(req, mp, 0);
        else if (strcmp(verb, "destroy") == 0)
                g_mirror_ctl_stop(req, mp, 1);
        else
                gctl_error(req, "Unknown verb.");
        g_topology_lock();
}