root/sys/dev/softraid.c
/* $OpenBSD: softraid.c,v 1.438 2025/10/18 15:33:19 deraadt Exp $ */
/*
 * Copyright (c) 2007, 2008, 2009 Marco Peereboom <marco@peereboom.us>
 * Copyright (c) 2008 Chris Kuethe <ckuethe@openbsd.org>
 * Copyright (c) 2009 Joel Sing <jsing@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "bio.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/device.h>
#include <sys/ioctl.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/kernel.h>
#include <sys/disk.h>
#include <sys/rwlock.h>
#include <sys/queue.h>
#include <sys/fcntl.h>
#include <sys/disklabel.h>
#include <sys/vnode.h>
#include <sys/lock.h>
#include <sys/mount.h>
#include <sys/sensors.h>
#include <sys/stat.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/task.h>
#include <sys/kthread.h>
#include <sys/dkio.h>
#include <sys/stdint.h>

#include <scsi/scsi_all.h>
#include <scsi/scsiconf.h>
#include <scsi/scsi_disk.h>

#include <dev/softraidvar.h>

#ifdef HIBERNATE
#include <lib/libsa/aes_xts.h>
#include <sys/hibernate.h>
#include <scsi/sdvar.h>
#endif /* HIBERNATE */

/* #define SR_FANCY_STATS */

#ifdef SR_DEBUG
#define SR_FANCY_STATS
uint32_t        sr_debug = 0
                    /* | SR_D_CMD */
                    /* | SR_D_MISC */
                    /* | SR_D_INTR */
                    /* | SR_D_IOCTL */
                    /* | SR_D_CCB */
                    /* | SR_D_WU */
                    /* | SR_D_META */
                    /* | SR_D_DIS */
                    /* | SR_D_STATE */
                    /* | SR_D_REBUILD */
                ;
#endif

struct sr_softc *softraid0;
struct sr_uuid  sr_bootuuid;
u_int8_t        sr_bootkey[SR_CRYPTO_MAXKEYBYTES];

int             sr_match(struct device *, void *, void *);
void            sr_attach(struct device *, struct device *, void *);
int             sr_detach(struct device *, int);
void            sr_map_root(void);

const struct cfattach softraid_ca = {
        sizeof(struct sr_softc), sr_match, sr_attach, sr_detach,
};

struct cfdriver softraid_cd = {
        NULL, "softraid", DV_DULL, CD_COCOVM
};

/* scsi & discipline */
void                    sr_scsi_cmd(struct scsi_xfer *);
int                     sr_scsi_probe(struct scsi_link *);
int                     sr_scsi_ioctl(struct scsi_link *, u_long,
                            caddr_t, int);
int                     sr_bio_ioctl(struct device *, u_long, caddr_t);
int                     sr_bio_handler(struct sr_softc *,
                            struct sr_discipline *, u_long, struct bio *);
int                     sr_ioctl_inq(struct sr_softc *, struct bioc_inq *);
int                     sr_ioctl_vol(struct sr_softc *, struct bioc_vol *);
int                     sr_ioctl_disk(struct sr_softc *, struct bioc_disk *);
int                     sr_ioctl_setstate(struct sr_softc *,
                            struct bioc_setstate *);
int                     sr_ioctl_createraid(struct sr_softc *,
                            struct bioc_createraid *, int, void *);
int                     sr_ioctl_deleteraid(struct sr_softc *,
                            struct sr_discipline *, struct bioc_deleteraid *);
int                     sr_ioctl_discipline(struct sr_softc *,
                            struct sr_discipline *, struct bioc_discipline *);
int                     sr_ioctl_installboot(struct sr_softc *,
                            struct sr_discipline *, struct bioc_installboot *);
void                    sr_chunks_unwind(struct sr_softc *,
                            struct sr_chunk_head *);
void                    sr_discipline_free(struct sr_discipline *);
void                    sr_discipline_shutdown(struct sr_discipline *, int, int);
int                     sr_discipline_init(struct sr_discipline *, int);
int                     sr_alloc_resources(struct sr_discipline *);
void                    sr_free_resources(struct sr_discipline *);
void                    sr_set_chunk_state(struct sr_discipline *, int, int);
void                    sr_set_vol_state(struct sr_discipline *);

/* utility functions */
void                    sr_shutdown(int);
void                    sr_uuid_generate(struct sr_uuid *);
char                    *sr_uuid_format(struct sr_uuid *);
void                    sr_uuid_print(struct sr_uuid *, int);
void                    sr_checksum_print(u_int8_t *);
int                     sr_boot_assembly(struct sr_softc *);
int                     sr_already_assembled(struct sr_discipline *);
int                     sr_hotspare(struct sr_softc *, dev_t);
void                    sr_hotspare_rebuild(struct sr_discipline *);
int                     sr_rebuild_init(struct sr_discipline *, dev_t, int);
void                    sr_rebuild_start(void *);
void                    sr_rebuild_thread(void *);
void                    sr_rebuild(struct sr_discipline *);
void                    sr_roam_chunks(struct sr_discipline *);
int                     sr_chunk_in_use(struct sr_softc *, dev_t);
int                     sr_rw(struct sr_softc *, dev_t, char *, size_t,
                            daddr_t, long);
void                    sr_wu_done_callback(void *);
struct sr_discipline    *sr_find_discipline(struct sr_softc *sc, const char *);

/* don't include these on RAMDISK */
#ifndef SMALL_KERNEL
void                    sr_sensors_refresh(void *);
int                     sr_sensors_create(struct sr_discipline *);
void                    sr_sensors_delete(struct sr_discipline *);
#endif

/* metadata */
int                     sr_meta_probe(struct sr_discipline *, dev_t *, int);
int                     sr_meta_attach(struct sr_discipline *, int, int);
int                     sr_meta_rw(struct sr_discipline *, dev_t, void *, long);
int                     sr_meta_clear(struct sr_discipline *);
void                    sr_meta_init(struct sr_discipline *, int, int);
void                    sr_meta_init_complete(struct sr_discipline *);
void                    sr_meta_opt_handler(struct sr_discipline *,
                            struct sr_meta_opt_hdr *);

/* hotplug magic */
void                    sr_disk_attach(struct disk *, int);

struct sr_hotplug_list {
        void                    (*sh_hotplug)(struct sr_discipline *,
                                    struct disk *, int);
        struct sr_discipline    *sh_sd;

        SLIST_ENTRY(sr_hotplug_list) shl_link;
};
SLIST_HEAD(sr_hotplug_list_head, sr_hotplug_list);

struct                  sr_hotplug_list_head    sr_hotplug_callbacks;
extern void             (*softraid_disk_attach)(struct disk *, int);

/* scsi glue */
const struct scsi_adapter sr_switch = {
        sr_scsi_cmd, NULL, sr_scsi_probe, NULL, sr_scsi_ioctl
};

/* native metadata format */
int                     sr_meta_native_bootprobe(struct sr_softc *, dev_t,
                            struct sr_boot_chunk_head *);
#define SR_META_NOTCLAIMED      (0)
#define SR_META_CLAIMED         (1)
int                     sr_meta_native_probe(struct sr_softc *,
                           struct sr_chunk *);
int                     sr_meta_native_attach(struct sr_discipline *, int);
int                     sr_meta_native_write(struct sr_discipline *, dev_t,
                            struct sr_metadata *,void *);

#ifdef SR_DEBUG
void                    sr_meta_print(struct sr_metadata *);
#else
#define                 sr_meta_print(m)
#endif

/* the metadata driver should remain stateless */
struct sr_meta_driver {
        daddr_t                 smd_offset;     /* metadata location */
        u_int32_t               smd_size;       /* size of metadata */

        int                     (*smd_probe)(struct sr_softc *,
                                   struct sr_chunk *);
        int                     (*smd_attach)(struct sr_discipline *, int);
        int                     (*smd_detach)(struct sr_discipline *);
        int                     (*smd_read)(struct sr_discipline *, dev_t,
                                    struct sr_metadata *, void *);
        int                     (*smd_write)(struct sr_discipline *, dev_t,
                                    struct sr_metadata *, void *);
        int                     (*smd_validate)(struct sr_discipline *,
                                    struct sr_metadata *, void *);
} smd[] = {
        { SR_META_OFFSET, SR_META_SIZE * DEV_BSIZE,
          sr_meta_native_probe, sr_meta_native_attach, NULL,
          sr_meta_native_read, sr_meta_native_write, NULL },
        { 0, 0, NULL, NULL, NULL, NULL }
};

int
sr_meta_attach(struct sr_discipline *sd, int chunk_no, int force)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk_head    *cl;
        struct sr_chunk         *ch_entry, *chunk1, *chunk2;
        int                     rv = 1, i = 0;

        DNPRINTF(SR_D_META, "%s: sr_meta_attach(%d)\n", DEVNAME(sc), chunk_no);

        /* in memory copy of metadata */
        sd->sd_meta = malloc(SR_META_SIZE * DEV_BSIZE, M_DEVBUF,
            M_ZERO | M_NOWAIT);
        if (!sd->sd_meta) {
                sr_error(sc, "could not allocate memory for metadata");
                goto bad;
        }

        if (sd->sd_meta_type != SR_META_F_NATIVE) {
                /* in memory copy of foreign metadata */
                sd->sd_meta_foreign = malloc(smd[sd->sd_meta_type].smd_size,
                    M_DEVBUF, M_ZERO | M_NOWAIT);
                if (!sd->sd_meta_foreign) {
                        /* unwind frees sd_meta */
                        sr_error(sc, "could not allocate memory for foreign "
                            "metadata");
                        goto bad;
                }
        }

        /* we have a valid list now create an array index */
        cl = &sd->sd_vol.sv_chunk_list;
        sd->sd_vol.sv_chunks = mallocarray(chunk_no, sizeof(struct sr_chunk *),
            M_DEVBUF, M_WAITOK | M_ZERO);

        /* fill out chunk array */
        i = 0;
        SLIST_FOREACH(ch_entry, cl, src_link)
                sd->sd_vol.sv_chunks[i++] = ch_entry;

        /* attach metadata */
        if (smd[sd->sd_meta_type].smd_attach(sd, force))
                goto bad;

        /* Force chunks into correct order now that metadata is attached. */
        SLIST_INIT(cl);
        for (i = 0; i < chunk_no; i++) {
                ch_entry = sd->sd_vol.sv_chunks[i];
                chunk2 = NULL;
                SLIST_FOREACH(chunk1, cl, src_link) {
                        if (chunk1->src_meta.scmi.scm_chunk_id >
                            ch_entry->src_meta.scmi.scm_chunk_id)
                                break;
                        chunk2 = chunk1;
                }
                if (chunk2 == NULL)
                        SLIST_INSERT_HEAD(cl, ch_entry, src_link);
                else
                        SLIST_INSERT_AFTER(chunk2, ch_entry, src_link);
        }
        i = 0;
        SLIST_FOREACH(ch_entry, cl, src_link)
                sd->sd_vol.sv_chunks[i++] = ch_entry;

        rv = 0;
bad:
        return (rv);
}

int
sr_meta_probe(struct sr_discipline *sd, dev_t *dt, int no_chunk)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct vnode            *vn;
        struct sr_chunk         *ch_entry, *ch_prev = NULL;
        struct sr_chunk_head    *cl;
        char                    devname[32];
        int                     i, d, type, found, prevf, error;
        dev_t                   dev;

        DNPRINTF(SR_D_META, "%s: sr_meta_probe(%d)\n", DEVNAME(sc), no_chunk);

        if (no_chunk == 0)
                goto unwind;

        cl = &sd->sd_vol.sv_chunk_list;

        for (d = 0, prevf = SR_META_F_INVALID; d < no_chunk; d++) {
                ch_entry = malloc(sizeof(struct sr_chunk), M_DEVBUF,
                    M_WAITOK | M_ZERO);
                /* keep disks in user supplied order */
                if (ch_prev)
                        SLIST_INSERT_AFTER(ch_prev, ch_entry, src_link);
                else
                        SLIST_INSERT_HEAD(cl, ch_entry, src_link);
                ch_prev = ch_entry;
                dev = dt[d];
                ch_entry->src_dev_mm = dev;

                if (dev == NODEV) {
                        ch_entry->src_meta.scm_status = BIOC_SDOFFLINE;
                        continue;
                } else {
                        sr_meta_getdevname(sc, dev, devname, sizeof(devname));
                        if (bdevvp(dev, &vn)) {
                                sr_error(sc, "sr_meta_probe: cannot allocate "
                                    "vnode");
                                goto unwind;
                        }

                        /*
                         * XXX leaving dev open for now; move this to attach
                         * and figure out the open/close dance for unwind.
                         */
                        error = VOP_OPEN(vn, FREAD | FWRITE, NOCRED, curproc);
                        if (error) {
                                DNPRINTF(SR_D_META,"%s: sr_meta_probe can't "
                                    "open %s\n", DEVNAME(sc), devname);
                                vput(vn);
                                goto unwind;
                        }

                        strlcpy(ch_entry->src_devname, devname,
                            sizeof(ch_entry->src_devname));
                        ch_entry->src_vn = vn;
                }

                /* determine if this is a device we understand */
                for (i = 0, found = SR_META_F_INVALID; smd[i].smd_probe; i++) {
                        type = smd[i].smd_probe(sc, ch_entry);
                        if (type == SR_META_F_INVALID)
                                continue;
                        else {
                                found = type;
                                break;
                        }
                }

                if (found == SR_META_F_INVALID)
                        goto unwind;
                if (prevf == SR_META_F_INVALID)
                        prevf = found;
                if (prevf != found) {
                        DNPRINTF(SR_D_META, "%s: prevf != found\n",
                            DEVNAME(sc));
                        goto unwind;
                }
        }

        return (prevf);
unwind:
        return (SR_META_F_INVALID);
}

void
sr_meta_getdevname(struct sr_softc *sc, dev_t dev, char *buf, int size)
{
        int                     maj, unit, part;
        char                    *name;

        DNPRINTF(SR_D_META, "%s: sr_meta_getdevname(%p, %d)\n",
            DEVNAME(sc), buf, size);

        if (!buf)
                return;

        maj = major(dev);
        part = DISKPART(dev);
        unit = DISKUNIT(dev);

        name = findblkname(maj);
        if (name == NULL)
                return;

        snprintf(buf, size, "%s%d%c", name, unit, DL_PARTNUM2NAME(part));
}

int
sr_rw(struct sr_softc *sc, dev_t dev, char *buf, size_t size, daddr_t blkno,
    long flags)
{
        struct vnode            *vp;
        struct buf              b;
        size_t                  bufsize, dma_bufsize;
        int                     rv = 1;
        char                    *dma_buf;
        int                     s;

        DNPRINTF(SR_D_MISC, "%s: sr_rw(0x%x, %p, %zu, %lld 0x%lx)\n",
            DEVNAME(sc), dev, buf, size, (long long)blkno, flags);

        dma_bufsize = (size > MAXPHYS) ? MAXPHYS : size;
        dma_buf = dma_alloc(dma_bufsize, PR_WAITOK);

        if (bdevvp(dev, &vp)) {
                printf("%s: sr_rw: failed to allocate vnode\n", DEVNAME(sc));
                goto done;
        }

        while (size > 0) {
                DNPRINTF(SR_D_MISC, "%s: dma_buf %p, size %zu, blkno %lld)\n",
                    DEVNAME(sc), dma_buf, size, (long long)blkno);

                bufsize = (size > MAXPHYS) ? MAXPHYS : size;
                if (flags == B_WRITE)
                        memcpy(dma_buf, buf, bufsize);

                bzero(&b, sizeof(b));
                b.b_flags = flags | B_PHYS;
                b.b_proc = curproc;
                b.b_dev = dev;
                b.b_iodone = NULL;
                b.b_error = 0;
                b.b_blkno = blkno;
                b.b_data = dma_buf;
                b.b_bcount = bufsize;
                b.b_bufsize = bufsize;
                b.b_resid = bufsize;
                b.b_vp = vp;

                if ((b.b_flags & B_READ) == 0) {
                        s = splbio();
                        vp->v_numoutput++;
                        splx(s);
                }

                VOP_STRATEGY(vp, &b);
                biowait(&b);

                if (b.b_flags & B_ERROR) {
                        printf("%s: I/O error %d on dev 0x%x at block %llu\n",
                            DEVNAME(sc), b.b_error, dev, b.b_blkno);
                        goto done;
                }

                if (flags == B_READ)
                        memcpy(buf, dma_buf, bufsize);

                size -= bufsize;
                buf += bufsize;
                blkno += howmany(bufsize, DEV_BSIZE);
        }

        rv = 0;

done:
        if (vp)
                vput(vp);

        dma_free(dma_buf, dma_bufsize);

        return (rv);
}

int
sr_meta_rw(struct sr_discipline *sd, dev_t dev, void *md, long flags)
{
        int                     rv = 1;

        DNPRINTF(SR_D_META, "%s: sr_meta_rw(0x%x, %p, 0x%lx)\n",
            DEVNAME(sd->sd_sc), dev, md, flags);

        if (md == NULL) {
                printf("%s: sr_meta_rw: invalid metadata pointer\n",
                    DEVNAME(sd->sd_sc));
                goto done;
        }

        rv = sr_rw(sd->sd_sc, dev, md, SR_META_SIZE * DEV_BSIZE,
            SR_META_OFFSET, flags);

done:
        return (rv);
}

int
sr_meta_clear(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk_head    *cl = &sd->sd_vol.sv_chunk_list;
        struct sr_chunk         *ch_entry;
        void                    *m;
        int                     rv = 1;

        DNPRINTF(SR_D_META, "%s: sr_meta_clear\n", DEVNAME(sc));

        if (sd->sd_meta_type != SR_META_F_NATIVE) {
                sr_error(sc, "cannot clear foreign metadata");
                goto done;
        }

        m = malloc(SR_META_SIZE * DEV_BSIZE, M_DEVBUF, M_WAITOK | M_ZERO);
        SLIST_FOREACH(ch_entry, cl, src_link) {
                if (sr_meta_native_write(sd, ch_entry->src_dev_mm, m, NULL)) {
                        /* XXX mark disk offline */
                        DNPRINTF(SR_D_META, "%s: sr_meta_clear failed to "
                            "clear %s\n", DEVNAME(sc), ch_entry->src_devname);
                        rv++;
                        continue;
                }
                bzero(&ch_entry->src_meta, sizeof(ch_entry->src_meta));
        }

        bzero(sd->sd_meta, SR_META_SIZE * DEV_BSIZE);

        free(m, M_DEVBUF, SR_META_SIZE * DEV_BSIZE);
        rv = 0;
done:
        return (rv);
}

void
sr_meta_init(struct sr_discipline *sd, int level, int no_chunk)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_metadata      *sm = sd->sd_meta;
        struct sr_chunk_head    *cl = &sd->sd_vol.sv_chunk_list;
        struct sr_meta_chunk    *scm;
        struct sr_chunk         *chunk;
        int                     cid = 0;
        u_int64_t               max_chunk_sz = 0, min_chunk_sz = 0;
        u_int32_t               secsize = DEV_BSIZE;

        DNPRINTF(SR_D_META, "%s: sr_meta_init\n", DEVNAME(sc));

        if (!sm)
                return;

        /* Initialise volume metadata. */
        sm->ssdi.ssd_magic = SR_MAGIC;
        sm->ssdi.ssd_version = SR_META_VERSION;
        sm->ssdi.ssd_vol_flags = sd->sd_meta_flags;
        sm->ssdi.ssd_volid = 0;
        sm->ssdi.ssd_chunk_no = no_chunk;
        sm->ssdi.ssd_level = level;

        sm->ssd_data_blkno = SR_DATA_OFFSET;
        sm->ssd_ondisk = 0;

        sr_uuid_generate(&sm->ssdi.ssd_uuid);

        /* Initialise chunk metadata and get min/max chunk sizes & secsize. */
        SLIST_FOREACH(chunk, cl, src_link) {
                scm = &chunk->src_meta;
                scm->scmi.scm_size = chunk->src_size;
                scm->scmi.scm_chunk_id = cid++;
                scm->scm_status = BIOC_SDONLINE;
                scm->scmi.scm_volid = 0;
                strlcpy(scm->scmi.scm_devname, chunk->src_devname,
                    sizeof(scm->scmi.scm_devname));
                memcpy(&scm->scmi.scm_uuid, &sm->ssdi.ssd_uuid,
                    sizeof(scm->scmi.scm_uuid));
                sr_checksum(sc, scm, &scm->scm_checksum,
                    sizeof(scm->scm_checksum));

                if (min_chunk_sz == 0)
                        min_chunk_sz = scm->scmi.scm_size;
                if (chunk->src_secsize > secsize)
                        secsize = chunk->src_secsize;
                min_chunk_sz = MIN(min_chunk_sz, scm->scmi.scm_size);
                max_chunk_sz = MAX(max_chunk_sz, scm->scmi.scm_size);
        }

        sm->ssdi.ssd_secsize = secsize;

        /* Equalize chunk sizes. */
        SLIST_FOREACH(chunk, cl, src_link)
                chunk->src_meta.scmi.scm_coerced_size = min_chunk_sz;

        sd->sd_vol.sv_chunk_minsz = min_chunk_sz;
        sd->sd_vol.sv_chunk_maxsz = max_chunk_sz;
}

void
sr_meta_init_complete(struct sr_discipline *sd)
{
#ifdef SR_DEBUG
        struct sr_softc         *sc = sd->sd_sc;
#endif
        struct sr_metadata      *sm = sd->sd_meta;

        DNPRINTF(SR_D_META, "%s: sr_meta_complete\n", DEVNAME(sc));

        /* Complete initialisation of volume metadata. */
        strlcpy(sm->ssdi.ssd_vendor, "OPENBSD", sizeof(sm->ssdi.ssd_vendor));
        snprintf(sm->ssdi.ssd_product, sizeof(sm->ssdi.ssd_product),
            "SR %s", sd->sd_name);
        snprintf(sm->ssdi.ssd_revision, sizeof(sm->ssdi.ssd_revision),
            "%03d", sm->ssdi.ssd_version);
}

void
sr_meta_opt_handler(struct sr_discipline *sd, struct sr_meta_opt_hdr *om)
{
        if (om->som_type != SR_OPT_BOOT)
                panic("unknown optional metadata type");
}

void
sr_meta_save_callback(void *xsd)
{
        struct sr_discipline    *sd = xsd;
        int                     s;

        s = splbio();

        if (sr_meta_save(sd, SR_META_DIRTY))
                printf("%s: save metadata failed\n", DEVNAME(sd->sd_sc));

        sd->sd_must_flush = 0;
        splx(s);
}

int
sr_meta_save(struct sr_discipline *sd, u_int32_t flags)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_metadata      *sm = sd->sd_meta, *m;
        struct sr_meta_driver   *s;
        struct sr_chunk         *src;
        struct sr_meta_chunk    *cm;
        struct sr_workunit      wu;
        struct sr_meta_opt_hdr  *omh;
        struct sr_meta_opt_item *omi;
        int                     i;

        DNPRINTF(SR_D_META, "%s: sr_meta_save %s\n",
            DEVNAME(sc), sd->sd_meta->ssd_devname);

        if (!sm) {
                printf("%s: no in memory copy of metadata\n", DEVNAME(sc));
                goto bad;
        }

        /* meta scratchpad */
        s = &smd[sd->sd_meta_type];
        m = malloc(SR_META_SIZE * DEV_BSIZE, M_DEVBUF, M_ZERO | M_NOWAIT);
        if (!m) {
                printf("%s: could not allocate metadata scratch area\n",
                    DEVNAME(sc));
                goto bad;
        }

        /* from here on out metadata is updated */
restart:
        sm->ssd_ondisk++;
        sm->ssd_meta_flags = flags;
        memcpy(m, sm, sizeof(*m));

        /* Chunk metadata. */
        cm = (struct sr_meta_chunk *)(m + 1);
        for (i = 0; i < sm->ssdi.ssd_chunk_no; i++) {
                src = sd->sd_vol.sv_chunks[i];
                memcpy(cm, &src->src_meta, sizeof(*cm));
                cm++;
        }

        /* Optional metadata. */
        omh = (struct sr_meta_opt_hdr *)(cm);
        SLIST_FOREACH(omi, &sd->sd_meta_opt, omi_link) {
                DNPRINTF(SR_D_META, "%s: saving optional metadata type %u with "
                    "length %u\n", DEVNAME(sc), omi->omi_som->som_type,
                    omi->omi_som->som_length);
                bzero(&omi->omi_som->som_checksum, MD5_DIGEST_LENGTH);
                sr_checksum(sc, omi->omi_som, &omi->omi_som->som_checksum,
                    omi->omi_som->som_length);
                memcpy(omh, omi->omi_som, omi->omi_som->som_length);
                omh = (struct sr_meta_opt_hdr *)((u_int8_t *)omh +
                    omi->omi_som->som_length);
        }

        for (i = 0; i < sm->ssdi.ssd_chunk_no; i++) {
                src = sd->sd_vol.sv_chunks[i];

                /* skip disks that are offline */
                if (src->src_meta.scm_status == BIOC_SDOFFLINE)
                        continue;

                /* calculate metadata checksum for correct chunk */
                m->ssdi.ssd_chunk_id = i;
                sr_checksum(sc, m, &m->ssd_checksum,
                    sizeof(struct sr_meta_invariant));

#ifdef SR_DEBUG
                DNPRINTF(SR_D_META, "%s: sr_meta_save %s: volid: %d "
                    "chunkid: %d checksum: ",
                    DEVNAME(sc), src->src_meta.scmi.scm_devname,
                    m->ssdi.ssd_volid, m->ssdi.ssd_chunk_id);

                if (sr_debug & SR_D_META)
                        sr_checksum_print((u_int8_t *)&m->ssd_checksum);
                DNPRINTF(SR_D_META, "\n");
                sr_meta_print(m);
#endif

                /* translate and write to disk */
                if (s->smd_write(sd, src->src_dev_mm, m, NULL /* XXX */)) {
                        printf("%s: could not write metadata to %s\n",
                            DEVNAME(sc), src->src_devname);
                        /* restart the meta write */
                        src->src_meta.scm_status = BIOC_SDOFFLINE;
                        /* XXX recalculate volume status */
                        goto restart;
                }
        }

        /* not all disciplines have sync */
        if (sd->sd_scsi_sync) {
                bzero(&wu, sizeof(wu));
                wu.swu_flags |= SR_WUF_FAKE;
                wu.swu_dis = sd;
                sd->sd_scsi_sync(&wu);
        }
        free(m, M_DEVBUF, SR_META_SIZE * DEV_BSIZE);
        return (0);
bad:
        return (1);
}

int
sr_meta_read(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk_head    *cl = &sd->sd_vol.sv_chunk_list;
        struct sr_metadata      *sm;
        struct sr_chunk         *ch_entry;
        struct sr_meta_chunk    *cp;
        struct sr_meta_driver   *s;
        void                    *fm = NULL;
        int                     no_disk = 0, got_meta = 0;

        DNPRINTF(SR_D_META, "%s: sr_meta_read\n", DEVNAME(sc));

        sm = malloc(SR_META_SIZE * DEV_BSIZE, M_DEVBUF, M_WAITOK | M_ZERO);
        s = &smd[sd->sd_meta_type];
        if (sd->sd_meta_type != SR_META_F_NATIVE)
                fm = malloc(s->smd_size, M_DEVBUF, M_WAITOK | M_ZERO);

        cp = (struct sr_meta_chunk *)(sm + 1);
        SLIST_FOREACH(ch_entry, cl, src_link) {
                /* skip disks that are offline */
                if (ch_entry->src_meta.scm_status == BIOC_SDOFFLINE) {
                        DNPRINTF(SR_D_META,
                            "%s: %s chunk marked offline, spoofing status\n",
                            DEVNAME(sc), ch_entry->src_devname);
                        cp++; /* adjust chunk pointer to match failure */
                        continue;
                } else if (s->smd_read(sd, ch_entry->src_dev_mm, sm, fm)) {
                        /* read and translate */
                        /* XXX mark chunk offline, elsewhere!! */
                        ch_entry->src_meta.scm_status = BIOC_SDOFFLINE;
                        cp++; /* adjust chunk pointer to match failure */
                        DNPRINTF(SR_D_META, "%s: sr_meta_read failed\n",
                            DEVNAME(sc));
                        continue;
                }

                if (sm->ssdi.ssd_magic != SR_MAGIC) {
                        DNPRINTF(SR_D_META, "%s: sr_meta_read !SR_MAGIC\n",
                            DEVNAME(sc));
                        continue;
                }

                /* validate metadata */
                if (sr_meta_validate(sd, ch_entry->src_dev_mm, sm, fm)) {
                        DNPRINTF(SR_D_META, "%s: invalid metadata\n",
                            DEVNAME(sc));
                        no_disk = -1;
                        goto done;
                }

                /* assume first chunk contains metadata */
                if (got_meta == 0) {
                        sr_meta_opt_load(sc, sm, &sd->sd_meta_opt);
                        memcpy(sd->sd_meta, sm, sizeof(*sd->sd_meta));
                        got_meta = 1;
                }

                memcpy(&ch_entry->src_meta, cp, sizeof(ch_entry->src_meta));

                no_disk++;
                cp++;
        }

        free(sm, M_DEVBUF, SR_META_SIZE * DEV_BSIZE);
        free(fm, M_DEVBUF, s->smd_size);

done:
        DNPRINTF(SR_D_META, "%s: sr_meta_read found %d parts\n", DEVNAME(sc),
            no_disk);
        return (no_disk);
}

void
sr_meta_opt_load(struct sr_softc *sc, struct sr_metadata *sm,
    struct sr_meta_opt_head *som)
{
        struct sr_meta_opt_hdr  *omh;
        struct sr_meta_opt_item *omi;
        u_int8_t                checksum[MD5_DIGEST_LENGTH];
        int                     i;

        /* Process optional metadata. */
        omh = (struct sr_meta_opt_hdr *)((u_int8_t *)(sm + 1) +
            sizeof(struct sr_meta_chunk) * sm->ssdi.ssd_chunk_no);
        for (i = 0; i < sm->ssdi.ssd_opt_no; i++) {

                omi = malloc(sizeof(struct sr_meta_opt_item), M_DEVBUF,
                    M_WAITOK | M_ZERO);
                SLIST_INSERT_HEAD(som, omi, omi_link);

                if (omh->som_length == 0) {

                        /* Load old fixed length optional metadata. */
                        DNPRINTF(SR_D_META, "%s: old optional metadata of type "
                            "%u\n", DEVNAME(sc), omh->som_type);

                        /* Validate checksum. */
                        sr_checksum(sc, (void *)omh, &checksum,
                            SR_OLD_META_OPT_SIZE - MD5_DIGEST_LENGTH);
                        if (bcmp(&checksum, (void *)omh + SR_OLD_META_OPT_MD5,
                            sizeof(checksum)))
                                panic("%s: invalid optional metadata checksum",
                                    DEVNAME(sc));

                        /* Determine correct length. */
                        switch (omh->som_type) {
                        case SR_OPT_CRYPTO:
                                omh->som_length = sizeof(struct sr_meta_crypto);
                                break;
                        case SR_OPT_BOOT:
                                omh->som_length = sizeof(struct sr_meta_boot);
                                break;
                        case SR_OPT_KEYDISK:
                                omh->som_length =
                                    sizeof(struct sr_meta_keydisk);
                                break;
                        default:
                                panic("unknown old optional metadata type %u",
                                    omh->som_type);
                        }

                        omi->omi_som = malloc(omh->som_length, M_DEVBUF,
                            M_WAITOK | M_ZERO);
                        memcpy((u_int8_t *)omi->omi_som + sizeof(*omi->omi_som),
                            (u_int8_t *)omh + SR_OLD_META_OPT_OFFSET,
                            omh->som_length - sizeof(*omi->omi_som));
                        omi->omi_som->som_type = omh->som_type;
                        omi->omi_som->som_length = omh->som_length;

                        omh = (struct sr_meta_opt_hdr *)((void *)omh +
                            SR_OLD_META_OPT_SIZE);
                } else {

                        /* Load variable length optional metadata. */
                        DNPRINTF(SR_D_META, "%s: optional metadata of type %u, "
                            "length %u\n", DEVNAME(sc), omh->som_type,
                            omh->som_length);
                        omi->omi_som = malloc(omh->som_length, M_DEVBUF,
                            M_WAITOK | M_ZERO);
                        memcpy(omi->omi_som, omh, omh->som_length);

                        /* Validate checksum. */
                        memcpy(&checksum, &omi->omi_som->som_checksum,
                            MD5_DIGEST_LENGTH);
                        bzero(&omi->omi_som->som_checksum, MD5_DIGEST_LENGTH);
                        sr_checksum(sc, omi->omi_som,
                            &omi->omi_som->som_checksum, omh->som_length);
                        if (bcmp(&checksum, &omi->omi_som->som_checksum,
                            sizeof(checksum)))
                                panic("%s: invalid optional metadata checksum",
                                    DEVNAME(sc));

                        omh = (struct sr_meta_opt_hdr *)((void *)omh +
                            omh->som_length);
                }
        }
}

int
sr_meta_validate(struct sr_discipline *sd, dev_t dev, struct sr_metadata *sm,
    void *fm)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_meta_driver   *s;
#ifdef SR_DEBUG
        struct sr_meta_chunk    *mc;
#endif
        u_int8_t                checksum[MD5_DIGEST_LENGTH];
        char                    devname[32];
        int                     rv = 1;

        DNPRINTF(SR_D_META, "%s: sr_meta_validate(%p)\n", DEVNAME(sc), sm);

        sr_meta_getdevname(sc, dev, devname, sizeof(devname));

        s = &smd[sd->sd_meta_type];
        if (sd->sd_meta_type != SR_META_F_NATIVE)
                if (s->smd_validate(sd, sm, fm)) {
                        sr_error(sc, "invalid foreign metadata");
                        goto done;
                }

        /*
         * at this point all foreign metadata has been translated to the native
         * format and will be treated just like the native format
         */

        if (sm->ssdi.ssd_magic != SR_MAGIC) {
                sr_error(sc, "not valid softraid metadata");
                goto done;
        }

        /* Verify metadata checksum. */
        sr_checksum(sc, sm, &checksum, sizeof(struct sr_meta_invariant));
        if (bcmp(&checksum, &sm->ssd_checksum, sizeof(checksum))) {
                sr_error(sc, "invalid metadata checksum");
                goto done;
        }

        /* Handle changes between versions. */
        if (sm->ssdi.ssd_version == 3) {

                /*
                 * Version 3 - update metadata version and fix up data blkno
                 * value since this did not exist in version 3.
                 */
                if (sm->ssd_data_blkno == 0)
                        sm->ssd_data_blkno = SR_META_V3_DATA_OFFSET;
                sm->ssdi.ssd_secsize = DEV_BSIZE;

        } else if (sm->ssdi.ssd_version == 4) {

                /*
                 * Version 4 - original metadata format did not store
                 * data blkno so fix this up if necessary.
                 */
                if (sm->ssd_data_blkno == 0)
                        sm->ssd_data_blkno = SR_DATA_OFFSET;
                sm->ssdi.ssd_secsize = DEV_BSIZE;

        } else if (sm->ssdi.ssd_version == 5) {

                /*
                 * Version 5 - variable length optional metadata. Migration
                 * from earlier fixed length optional metadata is handled
                 * in sr_meta_read().
                 */
                sm->ssdi.ssd_secsize = DEV_BSIZE;

        } else if (sm->ssdi.ssd_version == SR_META_VERSION) {

                /*
                 * Version 6 - store & report a sector size.
                 */

        } else {

                sr_error(sc, "cannot read metadata version %u on %s, "
                    "expected version %u or earlier",
                    sm->ssdi.ssd_version, devname, SR_META_VERSION);
                goto done;

        }

        /* Update version number and revision string. */
        sm->ssdi.ssd_version = SR_META_VERSION;
        snprintf(sm->ssdi.ssd_revision, sizeof(sm->ssdi.ssd_revision),
            "%03d", SR_META_VERSION);

#ifdef SR_DEBUG
        /* warn if disk changed order */
        mc = (struct sr_meta_chunk *)(sm + 1);
        if (strncmp(mc[sm->ssdi.ssd_chunk_id].scmi.scm_devname, devname,
            sizeof(mc[sm->ssdi.ssd_chunk_id].scmi.scm_devname)))
                DNPRINTF(SR_D_META, "%s: roaming device %s -> %s\n",
                    DEVNAME(sc), mc[sm->ssdi.ssd_chunk_id].scmi.scm_devname,
                    devname);
#endif

        /* we have meta data on disk */
        DNPRINTF(SR_D_META, "%s: sr_meta_validate valid metadata %s\n",
            DEVNAME(sc), devname);

        rv = 0;
done:
        return (rv);
}

int
sr_meta_native_bootprobe(struct sr_softc *sc, dev_t devno,
    struct sr_boot_chunk_head *bch)
{
        struct vnode            *vn;
        struct disklabel        *label = NULL;
        struct sr_metadata      *md = NULL;
        struct sr_discipline    *fake_sd = NULL;
        struct sr_boot_chunk    *bc;
        char                    devname[32];
        dev_t                   chrdev, rawdev;
        int                     error, i;
        int                     rv = SR_META_NOTCLAIMED;

        DNPRINTF(SR_D_META, "%s: sr_meta_native_bootprobe\n", DEVNAME(sc));

        /*
         * Use character raw device to avoid SCSI complaints about missing
         * media on removable media devices.
         */
        chrdev = blktochr(devno);
        rawdev = MAKEDISKDEV(major(chrdev), DISKUNIT(devno), RAW_PART);
        if (cdevvp(rawdev, &vn)) {
                sr_error(sc, "sr_meta_native_bootprobe: cannot allocate vnode");
                goto done;
        }

        /* open device */
        error = VOP_OPEN(vn, FREAD, NOCRED, curproc);
        if (error) {
                DNPRINTF(SR_D_META, "%s: sr_meta_native_bootprobe open "
                    "failed\n", DEVNAME(sc));
                vput(vn);
                goto done;
        }

        label = malloc(sizeof(*label), M_DEVBUF, M_WAITOK);

        /* get disklabel */
        error = VOP_IOCTL(vn, DIOCGDINFO, (caddr_t)label, FREAD, NOCRED,
            curproc);
        if (error) {
                DNPRINTF(SR_D_META, "%s: sr_meta_native_bootprobe ioctl "
                    "failed\n", DEVNAME(sc));
                VOP_CLOSE(vn, FREAD, NOCRED, curproc);
                vput(vn);
                goto done;
        }

        /* we are done, close device */
        error = VOP_CLOSE(vn, FREAD, NOCRED, curproc);
        if (error) {
                DNPRINTF(SR_D_META, "%s: sr_meta_native_bootprobe close "
                    "failed\n", DEVNAME(sc));
                vput(vn);
                goto done;
        }
        vput(vn);

        md = malloc(SR_META_SIZE * DEV_BSIZE, M_DEVBUF, M_ZERO | M_NOWAIT);
        if (md == NULL) {
                sr_error(sc, "not enough memory for metadata buffer");
                goto done;
        }

        /* create fake sd to use utility functions */
        fake_sd = malloc(sizeof(struct sr_discipline), M_DEVBUF,
            M_ZERO | M_NOWAIT);
        if (fake_sd == NULL) {
                sr_error(sc, "not enough memory for fake discipline");
                goto done;
        }
        fake_sd->sd_sc = sc;
        fake_sd->sd_meta_type = SR_META_F_NATIVE;

        for (i = 0; i < MAXPARTITIONS; i++) {
                if (label->d_partitions[i].p_fstype != FS_RAID)
                        continue;

                /* open partition */
                rawdev = MAKEDISKDEV(major(devno), DISKUNIT(devno), i);
                if (bdevvp(rawdev, &vn)) {
                        sr_error(sc, "sr_meta_native_bootprobe: cannot "
                            "allocate vnode for partition");
                        goto done;
                }
                error = VOP_OPEN(vn, FREAD, NOCRED, curproc);
                if (error) {
                        DNPRINTF(SR_D_META, "%s: sr_meta_native_bootprobe "
                            "open failed, partition %d\n",
                            DEVNAME(sc), i);
                        vput(vn);
                        continue;
                }

                if (sr_meta_native_read(fake_sd, rawdev, md, NULL)) {
                        sr_error(sc, "native bootprobe could not read native "
                            "metadata");
                        VOP_CLOSE(vn, FREAD, NOCRED, curproc);
                        vput(vn);
                        continue;
                }

                /* are we a softraid partition? */
                if (md->ssdi.ssd_magic != SR_MAGIC) {
                        VOP_CLOSE(vn, FREAD, NOCRED, curproc);
                        vput(vn);
                        continue;
                }

                sr_meta_getdevname(sc, rawdev, devname, sizeof(devname));
                if (sr_meta_validate(fake_sd, rawdev, md, NULL) == 0) {
                        /* XXX fix M_WAITOK, this is boot time */
                        bc = malloc(sizeof(struct sr_boot_chunk),
                            M_DEVBUF, M_WAITOK | M_ZERO);
                        bc->sbc_metadata = malloc(sizeof(struct sr_metadata),
                            M_DEVBUF, M_WAITOK | M_ZERO);
                        memcpy(bc->sbc_metadata, md, sizeof(struct sr_metadata));
                        bc->sbc_mm = rawdev;
                        SLIST_INSERT_HEAD(bch, bc, sbc_link);
                        rv = SR_META_CLAIMED;
                }

                /* we are done, close partition */
                VOP_CLOSE(vn, FREAD, NOCRED, curproc);
                vput(vn);
        }

done:
        free(label, M_DEVBUF, sizeof(*label));
        free(fake_sd, M_DEVBUF, sizeof(struct sr_discipline));
        free(md, M_DEVBUF, SR_META_SIZE * DEV_BSIZE);

        return (rv);
}

int
sr_boot_assembly(struct sr_softc *sc)
{
        struct sr_boot_volume_head bvh;
        struct sr_boot_chunk_head bch, kdh;
        struct sr_boot_volume   *bv, *bv1, *bv2;
        struct sr_boot_chunk    *bc, *bcnext, *bc1, *bc2;
        struct sr_disk_head     sdklist;
        struct sr_disk          *sdk;
        struct disk             *dk;
        struct bioc_createraid  bcr;
        struct sr_meta_chunk    *hm;
        struct sr_chunk_head    *cl;
        struct sr_chunk         *hotspare, *chunk, *last;
        u_int64_t               *ondisk = NULL;
        dev_t                   *devs = NULL;
        void                    *data;
        char                    devname[32];
        int                     rv = 0, i;

        DNPRINTF(SR_D_META, "%s: sr_boot_assembly\n", DEVNAME(sc));

        SLIST_INIT(&sdklist);
        SLIST_INIT(&bvh);
        SLIST_INIT(&bch);
        SLIST_INIT(&kdh);

        dk = TAILQ_FIRST(&disklist);
        while (dk != NULL) {

                /* See if this disk has been checked. */
                SLIST_FOREACH(sdk, &sdklist, sdk_link)
                        if (sdk->sdk_devno == dk->dk_devno)
                                break;

                if (sdk != NULL || dk->dk_devno == NODEV) {
                        dk = TAILQ_NEXT(dk, dk_link);
                        continue;
                }

                /* Add this disk to the list that we've checked. */
                sdk = malloc(sizeof(struct sr_disk), M_DEVBUF,
                    M_NOWAIT | M_ZERO);
                if (sdk == NULL)
                        goto unwind;
                sdk->sdk_devno = dk->dk_devno;
                SLIST_INSERT_HEAD(&sdklist, sdk, sdk_link);

                /* Only check sd(4) and wd(4) devices. */
                if (strncmp(dk->dk_name, "sd", 2) &&
                    strncmp(dk->dk_name, "wd", 2)) {
                        dk = TAILQ_NEXT(dk, dk_link);
                        continue;
                }

                /* native softraid uses partitions */
                rw_enter_write(&sc->sc_lock);
                bio_status_init(&sc->sc_status, &sc->sc_dev);
                sr_meta_native_bootprobe(sc, dk->dk_devno, &bch);
                rw_exit_write(&sc->sc_lock);

                /* probe non-native disks if native failed. */

                /* Restart scan since we may have slept. */
                dk = TAILQ_FIRST(&disklist);
        }

        /*
         * Create a list of volumes and associate chunks with each volume.
         */
        for (bc = SLIST_FIRST(&bch); bc != NULL; bc = bcnext) {

                bcnext = SLIST_NEXT(bc, sbc_link);
                SLIST_REMOVE(&bch, bc, sr_boot_chunk, sbc_link);
                bc->sbc_chunk_id = bc->sbc_metadata->ssdi.ssd_chunk_id;

                /* Handle key disks separately. */
                if (bc->sbc_metadata->ssdi.ssd_level == SR_KEYDISK_LEVEL) {
                        SLIST_INSERT_HEAD(&kdh, bc, sbc_link);
                        continue;
                }

                SLIST_FOREACH(bv, &bvh, sbv_link) {
                        if (bcmp(&bc->sbc_metadata->ssdi.ssd_uuid,
                            &bv->sbv_uuid,
                            sizeof(bc->sbc_metadata->ssdi.ssd_uuid)) == 0)
                                break;
                }

                if (bv == NULL) {
                        bv = malloc(sizeof(struct sr_boot_volume),
                            M_DEVBUF, M_NOWAIT | M_ZERO);
                        if (bv == NULL) {
                                printf("%s: failed to allocate boot volume\n",
                                    DEVNAME(sc));
                                goto unwind;
                        }

                        bv->sbv_level = bc->sbc_metadata->ssdi.ssd_level;
                        bv->sbv_volid = bc->sbc_metadata->ssdi.ssd_volid;
                        bv->sbv_chunk_no = bc->sbc_metadata->ssdi.ssd_chunk_no;
                        bv->sbv_flags = bc->sbc_metadata->ssdi.ssd_vol_flags;
                        memcpy(&bv->sbv_uuid, &bc->sbc_metadata->ssdi.ssd_uuid,
                            sizeof(bc->sbc_metadata->ssdi.ssd_uuid));
                        SLIST_INIT(&bv->sbv_chunks);

                        /* Maintain volume order. */
                        bv2 = NULL;
                        SLIST_FOREACH(bv1, &bvh, sbv_link) {
                                if (bv1->sbv_volid > bv->sbv_volid)
                                        break;
                                bv2 = bv1;
                        }
                        if (bv2 == NULL) {
                                DNPRINTF(SR_D_META, "%s: insert volume %u "
                                    "at head\n", DEVNAME(sc), bv->sbv_volid);
                                SLIST_INSERT_HEAD(&bvh, bv, sbv_link);
                        } else {
                                DNPRINTF(SR_D_META, "%s: insert volume %u "
                                    "after %u\n", DEVNAME(sc), bv->sbv_volid,
                                    bv2->sbv_volid);
                                SLIST_INSERT_AFTER(bv2, bv, sbv_link);
                        }
                }

                /* Maintain chunk order. */
                bc2 = NULL;
                SLIST_FOREACH(bc1, &bv->sbv_chunks, sbc_link) {
                        if (bc1->sbc_chunk_id > bc->sbc_chunk_id)
                                break;
                        bc2 = bc1;
                }
                if (bc2 == NULL) {
                        DNPRINTF(SR_D_META, "%s: volume %u insert chunk %u "
                            "at head\n", DEVNAME(sc), bv->sbv_volid,
                            bc->sbc_chunk_id);
                        SLIST_INSERT_HEAD(&bv->sbv_chunks, bc, sbc_link);
                } else {
                        DNPRINTF(SR_D_META, "%s: volume %u insert chunk %u "
                            "after %u\n", DEVNAME(sc), bv->sbv_volid,
                            bc->sbc_chunk_id, bc2->sbc_chunk_id);
                        SLIST_INSERT_AFTER(bc2, bc, sbc_link);
                }

                bv->sbv_chunks_found++;
        }

        /* Allocate memory for device and ondisk version arrays. */
        devs = mallocarray(BIOC_CRMAXLEN, sizeof(dev_t), M_DEVBUF,
            M_NOWAIT);
        if (devs == NULL) {
                printf("%s: failed to allocate device array\n", DEVNAME(sc));
                goto unwind;
        }
        ondisk = mallocarray(BIOC_CRMAXLEN, sizeof(u_int64_t), M_DEVBUF,
            M_NOWAIT);
        if (ondisk == NULL) {
                printf("%s: failed to allocate ondisk array\n", DEVNAME(sc));
                goto unwind;
        }

        /*
         * Assemble hotspare "volumes".
         */
        SLIST_FOREACH(bv, &bvh, sbv_link) {

                /* Check if this is a hotspare "volume". */
                if (bv->sbv_level != SR_HOTSPARE_LEVEL ||
                    bv->sbv_chunk_no != 1)
                        continue;

#ifdef SR_DEBUG
                DNPRINTF(SR_D_META, "%s: assembling hotspare volume ",
                    DEVNAME(sc));
                if (sr_debug & SR_D_META)
                        sr_uuid_print(&bv->sbv_uuid, 0);
                DNPRINTF(SR_D_META, " volid %u with %u chunks\n",
                    bv->sbv_volid, bv->sbv_chunk_no);
#endif

                /* Create hotspare chunk metadata. */
                hotspare = malloc(sizeof(struct sr_chunk), M_DEVBUF,
                    M_NOWAIT | M_ZERO);
                if (hotspare == NULL) {
                        printf("%s: failed to allocate hotspare\n",
                            DEVNAME(sc));
                        goto unwind;
                }

                bc = SLIST_FIRST(&bv->sbv_chunks);
                sr_meta_getdevname(sc, bc->sbc_mm, devname, sizeof(devname));
                hotspare->src_dev_mm = bc->sbc_mm;
                strlcpy(hotspare->src_devname, devname,
                    sizeof(hotspare->src_devname));
                hotspare->src_size = bc->sbc_metadata->ssdi.ssd_size;

                hm = &hotspare->src_meta;
                hm->scmi.scm_volid = SR_HOTSPARE_VOLID;
                hm->scmi.scm_chunk_id = 0;
                hm->scmi.scm_size = bc->sbc_metadata->ssdi.ssd_size;
                hm->scmi.scm_coerced_size = bc->sbc_metadata->ssdi.ssd_size;
                strlcpy(hm->scmi.scm_devname, devname,
                    sizeof(hm->scmi.scm_devname));
                memcpy(&hm->scmi.scm_uuid, &bc->sbc_metadata->ssdi.ssd_uuid,
                    sizeof(struct sr_uuid));

                sr_checksum(sc, hm, &hm->scm_checksum,
                    sizeof(struct sr_meta_chunk_invariant));

                hm->scm_status = BIOC_SDHOTSPARE;

                /* Add chunk to hotspare list. */
                rw_enter_write(&sc->sc_hs_lock);
                cl = &sc->sc_hotspare_list;
                if (SLIST_EMPTY(cl))
                        SLIST_INSERT_HEAD(cl, hotspare, src_link);
                else {
                        SLIST_FOREACH(chunk, cl, src_link)
                                last = chunk;
                        SLIST_INSERT_AFTER(last, hotspare, src_link);
                }
                sc->sc_hotspare_no++;
                rw_exit_write(&sc->sc_hs_lock);

        }

        /*
         * Assemble RAID volumes.
         */
        SLIST_FOREACH(bv, &bvh, sbv_link) {

                bzero(&bcr, sizeof(bcr));
                data = NULL;

                /* Check if this is a hotspare "volume". */
                if (bv->sbv_level == SR_HOTSPARE_LEVEL &&
                    bv->sbv_chunk_no == 1)
                        continue;

                /*
                 * Skip volumes that are marked as no auto assemble, unless
                 * this was the volume which we actually booted from.
                 */
                if (bcmp(&sr_bootuuid, &bv->sbv_uuid, sizeof(sr_bootuuid)) != 0)
                        if (bv->sbv_flags & BIOC_SCNOAUTOASSEMBLE)
                                continue;

#ifdef SR_DEBUG
                DNPRINTF(SR_D_META, "%s: assembling volume ", DEVNAME(sc));
                if (sr_debug & SR_D_META)
                        sr_uuid_print(&bv->sbv_uuid, 0);
                DNPRINTF(SR_D_META, " volid %u with %u chunks\n",
                    bv->sbv_volid, bv->sbv_chunk_no);
#endif

                /*
                 * If this is a crypto volume, try to find a matching
                 * key disk...
                 */
                bcr.bc_key_disk = NODEV;
                if (bv->sbv_level == 'C' || bv->sbv_level == 0x1C) {
                        SLIST_FOREACH(bc, &kdh, sbc_link) {
                                if (bcmp(&bc->sbc_metadata->ssdi.ssd_uuid,
                                    &bv->sbv_uuid,
                                    sizeof(bc->sbc_metadata->ssdi.ssd_uuid))
                                    == 0)
                                        bcr.bc_key_disk = bc->sbc_mm;
                        }
                }

                for (i = 0; i < BIOC_CRMAXLEN; i++) {
                        devs[i] = NODEV; /* mark device as illegal */
                        ondisk[i] = 0;
                }

                SLIST_FOREACH(bc, &bv->sbv_chunks, sbc_link) {
                        if (devs[bc->sbc_chunk_id] != NODEV) {
                                bv->sbv_chunks_found--;
                                sr_meta_getdevname(sc, bc->sbc_mm, devname,
                                    sizeof(devname));
                                printf("%s: found duplicate chunk %u for "
                                    "volume %u on device %s\n", DEVNAME(sc),
                                    bc->sbc_chunk_id, bv->sbv_volid, devname);
                        }

                        if (devs[bc->sbc_chunk_id] == NODEV ||
                            bc->sbc_metadata->ssd_ondisk >
                            ondisk[bc->sbc_chunk_id]) {
                                devs[bc->sbc_chunk_id] = bc->sbc_mm;
                                ondisk[bc->sbc_chunk_id] =
                                    bc->sbc_metadata->ssd_ondisk;
                                DNPRINTF(SR_D_META, "%s: using ondisk "
                                    "metadata version %llu for chunk %u\n",
                                    DEVNAME(sc), ondisk[bc->sbc_chunk_id],
                                    bc->sbc_chunk_id);
                        }
                }

                if (bv->sbv_chunk_no != bv->sbv_chunks_found) {
                        printf("%s: not all chunks were provided; "
                            "attempting to bring volume %d online\n",
                            DEVNAME(sc), bv->sbv_volid);
                }

                bcr.bc_level = bv->sbv_level;
                bcr.bc_dev_list_len = bv->sbv_chunk_no * sizeof(dev_t);
                bcr.bc_dev_list = devs;
                bcr.bc_flags = BIOC_SCDEVT |
                    (bv->sbv_flags & BIOC_SCNOAUTOASSEMBLE);

                if ((bv->sbv_level == 'C' || bv->sbv_level == 0x1C) &&
                    bcmp(&sr_bootuuid, &bv->sbv_uuid, sizeof(sr_bootuuid)) == 0)
                        data = sr_bootkey;

                rw_enter_write(&sc->sc_lock);
                bio_status_init(&sc->sc_status, &sc->sc_dev);
                sr_ioctl_createraid(sc, &bcr, 0, data);
                rw_exit_write(&sc->sc_lock);

                rv++;
        }

        /* done with metadata */
unwind:
        /* Free boot volumes and associated chunks. */
        for (bv1 = SLIST_FIRST(&bvh); bv1 != NULL; bv1 = bv2) {
                bv2 = SLIST_NEXT(bv1, sbv_link);
                for (bc1 = SLIST_FIRST(&bv1->sbv_chunks); bc1 != NULL;
                    bc1 = bc2) {
                        bc2 = SLIST_NEXT(bc1, sbc_link);
                        free(bc1->sbc_metadata, M_DEVBUF,
                            sizeof(*bc1->sbc_metadata));
                        free(bc1, M_DEVBUF, sizeof(*bc1));
                }
                free(bv1, M_DEVBUF, sizeof(*bv1));
        }
        /* Free keydisks chunks. */
        for (bc1 = SLIST_FIRST(&kdh); bc1 != NULL; bc1 = bc2) {
                bc2 = SLIST_NEXT(bc1, sbc_link);
                free(bc1->sbc_metadata, M_DEVBUF, sizeof(*bc1->sbc_metadata));
                free(bc1, M_DEVBUF, sizeof(*bc1));
        }
        /* Free unallocated chunks. */
        for (bc1 = SLIST_FIRST(&bch); bc1 != NULL; bc1 = bc2) {
                bc2 = SLIST_NEXT(bc1, sbc_link);
                free(bc1->sbc_metadata, M_DEVBUF, sizeof(*bc1->sbc_metadata));
                free(bc1, M_DEVBUF, sizeof(*bc1));
        }

        while (!SLIST_EMPTY(&sdklist)) {
                sdk = SLIST_FIRST(&sdklist);
                SLIST_REMOVE_HEAD(&sdklist, sdk_link);
                free(sdk, M_DEVBUF, sizeof(*sdk));
        }

        free(devs, M_DEVBUF, BIOC_CRMAXLEN * sizeof(dev_t));
        free(ondisk, M_DEVBUF, BIOC_CRMAXLEN * sizeof(u_int64_t));

        return (rv);
}

void
sr_map_root(void)
{
        struct sr_softc         *sc = softraid0;
        struct sr_discipline    *sd;
        struct sr_meta_opt_item *omi;
        struct sr_meta_boot     *sbm;
        u_char                  duid[8];
        int                     i;

        if (sc == NULL)
                return;

        DNPRINTF(SR_D_MISC, "%s: sr_map_root\n", DEVNAME(sc));

        bzero(duid, sizeof(duid));
        if (bcmp(rootduid, duid, sizeof(duid)) == 0) {
                DNPRINTF(SR_D_MISC, "%s: root duid is zero\n", DEVNAME(sc));
                return;
        }

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                SLIST_FOREACH(omi, &sd->sd_meta_opt, omi_link) {
                        if (omi->omi_som->som_type != SR_OPT_BOOT)
                                continue;
                        sbm = (struct sr_meta_boot *)omi->omi_som;
                        for (i = 0; i < SR_MAX_BOOT_DISKS; i++) {
                                if (bcmp(rootduid, sbm->sbm_boot_duid[i],
                                    sizeof(rootduid)) == 0) {
                                        memcpy(rootduid, sbm->sbm_root_duid,
                                            sizeof(rootduid));
                                        DNPRINTF(SR_D_MISC, "%s: root duid "
                                            "mapped to %s\n", DEVNAME(sc),
                                            duid_format(rootduid));
                                        return;
                                }
                        }
                }
        }
}

int
sr_meta_native_probe(struct sr_softc *sc, struct sr_chunk *ch_entry)
{
        struct disklabel        *label;
        char                    *devname;
        int                     error, part;
        u_int64_t               size;

        DNPRINTF(SR_D_META, "%s: sr_meta_native_probe(%s)\n",
           DEVNAME(sc), ch_entry->src_devname);

        devname = ch_entry->src_devname;
        part = DISKPART(ch_entry->src_dev_mm);

        label = malloc(sizeof(*label), M_DEVBUF, M_WAITOK);

        /* get disklabel */
        error = VOP_IOCTL(ch_entry->src_vn, DIOCGDINFO, (caddr_t)label, FREAD,
            NOCRED, curproc);
        if (error) {
                DNPRINTF(SR_D_META, "%s: %s can't obtain disklabel\n",
                    DEVNAME(sc), devname);
                goto unwind;
        }
        memcpy(ch_entry->src_duid, label->d_uid, sizeof(ch_entry->src_duid));

        /* make sure the partition is of the right type */
        if (label->d_partitions[part].p_fstype != FS_RAID) {
                DNPRINTF(SR_D_META,
                    "%s: %s partition not of type RAID (%d)\n", DEVNAME(sc),
                    devname,
                    label->d_partitions[part].p_fstype);
                goto unwind;
        }

        size = DL_SECTOBLK(label, DL_GETPSIZE(&label->d_partitions[part]));
        if (size <= SR_DATA_OFFSET) {
                DNPRINTF(SR_D_META, "%s: %s partition too small\n", DEVNAME(sc),
                    devname);
                goto unwind;
        }
        size -= SR_DATA_OFFSET;
        if (size > INT64_MAX) {
                DNPRINTF(SR_D_META, "%s: %s partition too large\n", DEVNAME(sc),
                    devname);
                goto unwind;
        }
        ch_entry->src_size = size;
        ch_entry->src_secsize = label->d_secsize;

        DNPRINTF(SR_D_META, "%s: probe found %s size %lld\n", DEVNAME(sc),
            devname, (long long)size);

        free(label, M_DEVBUF, sizeof(*label));
        return (SR_META_F_NATIVE);
unwind:
        DNPRINTF(SR_D_META, "%s: invalid device: %s\n", DEVNAME(sc),
            devname ? devname : "nodev");
        free(label, M_DEVBUF, sizeof(*label));
        return (SR_META_F_INVALID);
}

int
sr_meta_native_attach(struct sr_discipline *sd, int force)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk_head    *cl = &sd->sd_vol.sv_chunk_list;
        struct sr_metadata      *md = NULL;
        struct sr_chunk         *ch_entry, *ch_next;
        struct sr_uuid          uuid;
        u_int64_t               version = 0;
        int                     sr, not_sr, rv = 1, d, expected = -1, old_meta = 0;

        DNPRINTF(SR_D_META, "%s: sr_meta_native_attach\n", DEVNAME(sc));

        md = malloc(SR_META_SIZE * DEV_BSIZE, M_DEVBUF, M_ZERO | M_NOWAIT);
        if (md == NULL) {
                sr_error(sc, "not enough memory for metadata buffer");
                goto bad;
        }

        bzero(&uuid, sizeof uuid);

        sr = not_sr = d = 0;
        SLIST_FOREACH(ch_entry, cl, src_link) {
                if (ch_entry->src_dev_mm == NODEV)
                        continue;

                if (sr_meta_native_read(sd, ch_entry->src_dev_mm, md, NULL)) {
                        sr_error(sc, "could not read native metadata");
                        goto bad;
                }

                if (md->ssdi.ssd_magic == SR_MAGIC) {
                        sr++;
                        ch_entry->src_meta.scmi.scm_chunk_id =
                            md->ssdi.ssd_chunk_id;
                        if (d == 0) {
                                memcpy(&uuid, &md->ssdi.ssd_uuid, sizeof uuid);
                                expected = md->ssdi.ssd_chunk_no;
                                version = md->ssd_ondisk;
                                d++;
                                continue;
                        } else if (bcmp(&md->ssdi.ssd_uuid, &uuid,
                            sizeof uuid)) {
                                sr_error(sc, "not part of the same volume");
                                goto bad;
                        }
                        if (md->ssd_ondisk != version) {
                                old_meta++;
                                version = MAX(md->ssd_ondisk, version);
                        }
                } else
                        not_sr++;
        }

        if (sr && not_sr && !force) {
                sr_error(sc, "not all chunks are of the native metadata "
                    "format");
                goto bad;
        }

        /* mixed metadata versions; mark bad disks offline */
        if (old_meta) {
                d = 0;
                for (ch_entry = SLIST_FIRST(cl); ch_entry != NULL;
                    ch_entry = ch_next, d++) {
                        ch_next = SLIST_NEXT(ch_entry, src_link);

                        /* XXX do we want to read this again? */
                        if (ch_entry->src_dev_mm == NODEV)
                                panic("src_dev_mm == NODEV");
                        if (sr_meta_native_read(sd, ch_entry->src_dev_mm, md,
                            NULL))
                                sr_warn(sc, "could not read native metadata");
                        if (md->ssd_ondisk != version)
                                sd->sd_vol.sv_chunks[d]->src_meta.scm_status =
                                    BIOC_SDOFFLINE;
                }
        }

        if (expected != sr && !force && expected != -1) {
                DNPRINTF(SR_D_META, "%s: not all chunks were provided, trying "
                    "anyway\n", DEVNAME(sc));
        }

        rv = 0;
bad:
        free(md, M_DEVBUF, SR_META_SIZE * DEV_BSIZE);
        return (rv);
}

int
sr_meta_native_read(struct sr_discipline *sd, dev_t dev,
    struct sr_metadata *md, void *fm)
{
#ifdef SR_DEBUG
        struct sr_softc         *sc = sd->sd_sc;
#endif
        DNPRINTF(SR_D_META, "%s: sr_meta_native_read(0x%x, %p)\n",
            DEVNAME(sc), dev, md);

        return (sr_meta_rw(sd, dev, md, B_READ));
}

int
sr_meta_native_write(struct sr_discipline *sd, dev_t dev,
    struct sr_metadata *md, void *fm)
{
#ifdef SR_DEBUG
        struct sr_softc         *sc = sd->sd_sc;
#endif
        DNPRINTF(SR_D_META, "%s: sr_meta_native_write(0x%x, %p)\n",
            DEVNAME(sc), dev, md);

        return (sr_meta_rw(sd, dev, md, B_WRITE));
}

void
sr_hotplug_register(struct sr_discipline *sd, void *func)
{
        struct sr_hotplug_list  *mhe;

        DNPRINTF(SR_D_MISC, "%s: sr_hotplug_register: %p\n",
            DEVNAME(sd->sd_sc), func);

        /* make sure we aren't on the list yet */
        SLIST_FOREACH(mhe, &sr_hotplug_callbacks, shl_link)
                if (mhe->sh_hotplug == func)
                        return;

        mhe = malloc(sizeof(struct sr_hotplug_list), M_DEVBUF,
            M_WAITOK | M_ZERO);
        mhe->sh_hotplug = func;
        mhe->sh_sd = sd;
        SLIST_INSERT_HEAD(&sr_hotplug_callbacks, mhe, shl_link);
}

void
sr_hotplug_unregister(struct sr_discipline *sd, void *func)
{
        struct sr_hotplug_list  *mhe;

        DNPRINTF(SR_D_MISC, "%s: sr_hotplug_unregister: %s %p\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname, func);

        /* make sure we are on the list yet */
        SLIST_FOREACH(mhe, &sr_hotplug_callbacks, shl_link) {
                if (mhe->sh_hotplug == func)
                        break;
        }
        if (mhe != NULL) {
                SLIST_REMOVE(&sr_hotplug_callbacks, mhe,
                    sr_hotplug_list, shl_link);
                free(mhe, M_DEVBUF, sizeof(*mhe));
        }
}

void
sr_disk_attach(struct disk *diskp, int action)
{
        struct sr_hotplug_list  *mhe;

        SLIST_FOREACH(mhe, &sr_hotplug_callbacks, shl_link)
                if (mhe->sh_sd->sd_ready)
                        mhe->sh_hotplug(mhe->sh_sd, diskp, action);
}

int
sr_match(struct device *parent, void *match, void *aux)
{
        return (1);
}

void
sr_attach(struct device *parent, struct device *self, void *aux)
{
        struct sr_softc         *sc = (void *)self;
        struct scsibus_attach_args saa;

        DNPRINTF(SR_D_MISC, "\n%s: sr_attach", DEVNAME(sc));

        if (softraid0 == NULL)
                softraid0 = sc;

        rw_init(&sc->sc_lock, "sr_lock");
        rw_init(&sc->sc_hs_lock, "sr_hs_lock");

        SLIST_INIT(&sr_hotplug_callbacks);
        TAILQ_INIT(&sc->sc_dis_list);
        SLIST_INIT(&sc->sc_hotspare_list);

#if NBIO > 0
        if (bio_register(&sc->sc_dev, sr_bio_ioctl) != 0)
                printf("%s: controller registration failed", DEVNAME(sc));
#endif /* NBIO > 0 */

#ifndef SMALL_KERNEL
        strlcpy(sc->sc_sensordev.xname, DEVNAME(sc),
            sizeof(sc->sc_sensordev.xname));
        sensordev_install(&sc->sc_sensordev);
#endif /* SMALL_KERNEL */

        printf("\n");

        saa.saa_adapter_softc = sc;
        saa.saa_adapter = &sr_switch;
        saa.saa_adapter_target = SDEV_NO_ADAPTER_TARGET;
        saa.saa_adapter_buswidth = SR_MAX_LD;
        saa.saa_luns = 1;
        saa.saa_openings = 0;
        saa.saa_pool = NULL;
        saa.saa_quirks = saa.saa_flags = 0;
        saa.saa_wwpn = saa.saa_wwnn = 0;

        sc->sc_scsibus = (struct scsibus_softc *)config_found(&sc->sc_dev, &saa,
            scsiprint);

        softraid_disk_attach = sr_disk_attach;

        sr_boot_assembly(sc);

        explicit_bzero(sr_bootkey, sizeof(sr_bootkey));
}

int
sr_detach(struct device *self, int flags)
{
        struct sr_softc         *sc = (void *)self;
        int                     rv;

        DNPRINTF(SR_D_MISC, "%s: sr_detach\n", DEVNAME(sc));

        softraid_disk_attach = NULL;

        sr_shutdown(0);

#ifndef SMALL_KERNEL
        if (sc->sc_sensor_task != NULL)
                sensor_task_unregister(sc->sc_sensor_task);
        sensordev_deinstall(&sc->sc_sensordev);
#endif /* SMALL_KERNEL */

        if (sc->sc_scsibus != NULL) {
                rv = config_detach((struct device *)sc->sc_scsibus, flags);
                if (rv != 0)
                        return (rv);
                sc->sc_scsibus = NULL;
        }

        return (0);
}

void
sr_info(struct sr_softc *sc, const char *fmt, ...)
{
        va_list                 ap;

        rw_assert_wrlock(&sc->sc_lock);

        va_start(ap, fmt);
        bio_status(&sc->sc_status, 0, BIO_MSG_INFO, fmt, &ap);
        va_end(ap);
}

void
sr_warn(struct sr_softc *sc, const char *fmt, ...)
{
        va_list                 ap;

        rw_assert_wrlock(&sc->sc_lock);

        va_start(ap, fmt);
        bio_status(&sc->sc_status, 1, BIO_MSG_WARN, fmt, &ap);
        va_end(ap);
}

void
sr_error(struct sr_softc *sc, const char *fmt, ...)
{
        va_list                 ap;

        rw_assert_wrlock(&sc->sc_lock);

        va_start(ap, fmt);
        bio_status(&sc->sc_status, 1, BIO_MSG_ERROR, fmt, &ap);
        va_end(ap);
}

int
sr_ccb_alloc(struct sr_discipline *sd)
{
        struct sr_ccb           *ccb;
        int                     i;

        if (!sd)
                return (1);

        DNPRINTF(SR_D_CCB, "%s: sr_ccb_alloc\n", DEVNAME(sd->sd_sc));

        if (sd->sd_ccb)
                return (1);

        sd->sd_ccb = mallocarray(sd->sd_max_wu,
            sd->sd_max_ccb_per_wu * sizeof(struct sr_ccb),
            M_DEVBUF, M_WAITOK | M_ZERO);
        TAILQ_INIT(&sd->sd_ccb_freeq);
        for (i = 0; i < sd->sd_max_wu * sd->sd_max_ccb_per_wu; i++) {
                ccb = &sd->sd_ccb[i];
                ccb->ccb_dis = sd;
                sr_ccb_put(ccb);
        }

        DNPRINTF(SR_D_CCB, "%s: sr_ccb_alloc ccb: %d\n",
            DEVNAME(sd->sd_sc), sd->sd_max_wu * sd->sd_max_ccb_per_wu);

        return (0);
}

void
sr_ccb_free(struct sr_discipline *sd)
{
        struct sr_ccb           *ccb;

        if (!sd)
                return;

        DNPRINTF(SR_D_CCB, "%s: sr_ccb_free %p\n", DEVNAME(sd->sd_sc), sd);

        while ((ccb = TAILQ_FIRST(&sd->sd_ccb_freeq)) != NULL)
                TAILQ_REMOVE(&sd->sd_ccb_freeq, ccb, ccb_link);

        free(sd->sd_ccb, M_DEVBUF, sd->sd_max_wu * sd->sd_max_ccb_per_wu *
            sizeof(struct sr_ccb));
}

struct sr_ccb *
sr_ccb_get(struct sr_discipline *sd)
{
        struct sr_ccb           *ccb;
        int                     s;

        s = splbio();

        ccb = TAILQ_FIRST(&sd->sd_ccb_freeq);
        if (ccb) {
                TAILQ_REMOVE(&sd->sd_ccb_freeq, ccb, ccb_link);
                ccb->ccb_state = SR_CCB_INPROGRESS;
        }

        splx(s);

        DNPRINTF(SR_D_CCB, "%s: sr_ccb_get: %p\n", DEVNAME(sd->sd_sc),
            ccb);

        return (ccb);
}

void
sr_ccb_put(struct sr_ccb *ccb)
{
        struct sr_discipline    *sd = ccb->ccb_dis;
        int                     s;

        DNPRINTF(SR_D_CCB, "%s: sr_ccb_put: %p\n", DEVNAME(sd->sd_sc),
            ccb);

        s = splbio();

        ccb->ccb_wu = NULL;
        ccb->ccb_state = SR_CCB_FREE;
        ccb->ccb_target = -1;
        ccb->ccb_opaque = NULL;

        TAILQ_INSERT_TAIL(&sd->sd_ccb_freeq, ccb, ccb_link);

        splx(s);
}

struct sr_ccb *
sr_ccb_rw(struct sr_discipline *sd, int chunk, daddr_t blkno,
    long len, u_int8_t *data, int xsflags, int ccbflags)
{
        struct sr_chunk         *sc = sd->sd_vol.sv_chunks[chunk];
        struct sr_ccb           *ccb = NULL;
        int                     s;

        ccb = sr_ccb_get(sd);
        if (ccb == NULL)
                goto out;

        ccb->ccb_flags = ccbflags;
        ccb->ccb_target = chunk;

        ccb->ccb_buf.b_flags = B_PHYS | B_CALL;
        if (ISSET(xsflags, SCSI_DATA_IN))
                ccb->ccb_buf.b_flags |= B_READ;
        else
                ccb->ccb_buf.b_flags |= B_WRITE;

        ccb->ccb_buf.b_blkno = blkno + sd->sd_meta->ssd_data_blkno;
        ccb->ccb_buf.b_bcount = len;
        ccb->ccb_buf.b_bufsize = len;
        ccb->ccb_buf.b_resid = len;
        ccb->ccb_buf.b_data = data;
        ccb->ccb_buf.b_error = 0;
        ccb->ccb_buf.b_iodone = sd->sd_scsi_intr;
        ccb->ccb_buf.b_proc = curproc;
        ccb->ccb_buf.b_dev = sc->src_dev_mm;
        ccb->ccb_buf.b_vp = sc->src_vn;
        ccb->ccb_buf.b_bq = NULL;

        if (!ISSET(ccb->ccb_buf.b_flags, B_READ)) {
                s = splbio();
                ccb->ccb_buf.b_vp->v_numoutput++;
                splx(s);
        }

        DNPRINTF(SR_D_DIS, "%s: %s %s ccb "
            "b_bcount %ld b_blkno %lld b_flags 0x%0lx b_data %p\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname, sd->sd_name,
            ccb->ccb_buf.b_bcount, (long long)ccb->ccb_buf.b_blkno,
            ccb->ccb_buf.b_flags, ccb->ccb_buf.b_data);

out:
        return ccb;
}

void
sr_ccb_done(struct sr_ccb *ccb)
{
        struct sr_workunit      *wu = ccb->ccb_wu;
        struct sr_discipline    *sd = wu->swu_dis;
        struct sr_softc         *sc = sd->sd_sc;

        DNPRINTF(SR_D_INTR, "%s: %s %s ccb done b_bcount %ld b_resid %zu"
            " b_flags 0x%0lx block %lld target %d\n",
            DEVNAME(sc), sd->sd_meta->ssd_devname, sd->sd_name,
            ccb->ccb_buf.b_bcount, ccb->ccb_buf.b_resid, ccb->ccb_buf.b_flags,
            (long long)ccb->ccb_buf.b_blkno, ccb->ccb_target);

        splassert(IPL_BIO);

        if (ccb->ccb_target == -1)
                panic("%s: invalid target on wu: %p", DEVNAME(sc), wu);

        if (ccb->ccb_buf.b_flags & B_ERROR) {
                DNPRINTF(SR_D_INTR, "%s: i/o error on block %lld target %d\n",
                    DEVNAME(sc), (long long)ccb->ccb_buf.b_blkno,
                    ccb->ccb_target);
                if (ISSET(sd->sd_capabilities, SR_CAP_REDUNDANT))
                        sd->sd_set_chunk_state(sd, ccb->ccb_target,
                            BIOC_SDOFFLINE);
                else
                        printf("%s: %s: i/o error %d @ %s block %lld\n",
                            DEVNAME(sc), sd->sd_meta->ssd_devname,
                            ccb->ccb_buf.b_error, sd->sd_name,
                            (long long)ccb->ccb_buf.b_blkno);
                ccb->ccb_state = SR_CCB_FAILED;
                wu->swu_ios_failed++;
        } else {
                ccb->ccb_state = SR_CCB_OK;
                wu->swu_ios_succeeded++;
        }

        wu->swu_ios_complete++;
}

int
sr_wu_alloc(struct sr_discipline *sd)
{
        struct sr_workunit      *wu;
        int                     i, no_wu;

        DNPRINTF(SR_D_WU, "%s: sr_wu_alloc %p %d\n", DEVNAME(sd->sd_sc),
            sd, sd->sd_max_wu);

        no_wu = sd->sd_max_wu;
        sd->sd_wu_pending = no_wu;

        mtx_init(&sd->sd_wu_mtx, IPL_BIO);
        TAILQ_INIT(&sd->sd_wu);
        TAILQ_INIT(&sd->sd_wu_freeq);
        TAILQ_INIT(&sd->sd_wu_pendq);
        TAILQ_INIT(&sd->sd_wu_defq);

        for (i = 0; i < no_wu; i++) {
                wu = malloc(sd->sd_wu_size, M_DEVBUF, M_WAITOK | M_ZERO);
                TAILQ_INSERT_TAIL(&sd->sd_wu, wu, swu_next);
                TAILQ_INIT(&wu->swu_ccb);
                wu->swu_dis = sd;
                task_set(&wu->swu_task, sr_wu_done_callback, wu);
                sr_wu_put(sd, wu);
        }

        return (0);
}

void
sr_wu_free(struct sr_discipline *sd)
{
        struct sr_workunit      *wu;

        DNPRINTF(SR_D_WU, "%s: sr_wu_free %p\n", DEVNAME(sd->sd_sc), sd);

        while ((wu = TAILQ_FIRST(&sd->sd_wu_freeq)) != NULL)
                TAILQ_REMOVE(&sd->sd_wu_freeq, wu, swu_link);
        while ((wu = TAILQ_FIRST(&sd->sd_wu_pendq)) != NULL)
                TAILQ_REMOVE(&sd->sd_wu_pendq, wu, swu_link);
        while ((wu = TAILQ_FIRST(&sd->sd_wu_defq)) != NULL)
                TAILQ_REMOVE(&sd->sd_wu_defq, wu, swu_link);

        while ((wu = TAILQ_FIRST(&sd->sd_wu)) != NULL) {
                TAILQ_REMOVE(&sd->sd_wu, wu, swu_next);
                free(wu, M_DEVBUF, sd->sd_wu_size);
        }
}

void *
sr_wu_get(void *xsd)
{
        struct sr_discipline    *sd = (struct sr_discipline *)xsd;
        struct sr_workunit      *wu;

        mtx_enter(&sd->sd_wu_mtx);
        wu = TAILQ_FIRST(&sd->sd_wu_freeq);
        if (wu) {
                TAILQ_REMOVE(&sd->sd_wu_freeq, wu, swu_link);
                sd->sd_wu_pending++;
        }
        mtx_leave(&sd->sd_wu_mtx);

        DNPRINTF(SR_D_WU, "%s: sr_wu_get: %p\n", DEVNAME(sd->sd_sc), wu);

        return (wu);
}

void
sr_wu_put(void *xsd, void *xwu)
{
        struct sr_discipline    *sd = (struct sr_discipline *)xsd;
        struct sr_workunit      *wu = (struct sr_workunit *)xwu;

        DNPRINTF(SR_D_WU, "%s: sr_wu_put: %p\n", DEVNAME(sd->sd_sc), wu);

        sr_wu_release_ccbs(wu);
        sr_wu_init(sd, wu);

        mtx_enter(&sd->sd_wu_mtx);
        TAILQ_INSERT_TAIL(&sd->sd_wu_freeq, wu, swu_link);
        sd->sd_wu_pending--;
        mtx_leave(&sd->sd_wu_mtx);
}

void
sr_wu_init(struct sr_discipline *sd, struct sr_workunit *wu)
{
        int                     s;

        s = splbio();
        if (wu->swu_cb_active == 1)
                panic("%s: sr_wu_init got active wu", DEVNAME(sd->sd_sc));
        splx(s);

        wu->swu_xs = NULL;
        wu->swu_state = SR_WU_FREE;
        wu->swu_flags = 0;
        wu->swu_blk_start = 0;
        wu->swu_blk_end = 0;
        wu->swu_collider = NULL;
}

void
sr_wu_enqueue_ccb(struct sr_workunit *wu, struct sr_ccb *ccb)
{
        struct sr_discipline    *sd = wu->swu_dis;
        int                     s;

        s = splbio();
        if (wu->swu_cb_active == 1)
                panic("%s: sr_wu_enqueue_ccb got active wu",
                    DEVNAME(sd->sd_sc));
        ccb->ccb_wu = wu;
        wu->swu_io_count++;
        TAILQ_INSERT_TAIL(&wu->swu_ccb, ccb, ccb_link);
        splx(s);
}

void
sr_wu_release_ccbs(struct sr_workunit *wu)
{
        struct sr_ccb           *ccb;

        /* Return all ccbs that are associated with this workunit. */
        while ((ccb = TAILQ_FIRST(&wu->swu_ccb)) != NULL) {
                TAILQ_REMOVE(&wu->swu_ccb, ccb, ccb_link);
                sr_ccb_put(ccb);
        }

        wu->swu_io_count = 0;
        wu->swu_ios_complete = 0;
        wu->swu_ios_failed = 0;
        wu->swu_ios_succeeded = 0;
}

void
sr_wu_done(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;

        DNPRINTF(SR_D_INTR, "%s: sr_wu_done count %d completed %d failed %d\n",
            DEVNAME(sd->sd_sc), wu->swu_io_count, wu->swu_ios_complete,
            wu->swu_ios_failed);

        if (wu->swu_ios_complete < wu->swu_io_count)
                return;

        task_add(sd->sd_taskq, &wu->swu_task);
}

void
sr_wu_done_callback(void *xwu)
{
        struct sr_workunit      *wu = xwu;
        struct sr_discipline    *sd = wu->swu_dis;
        struct scsi_xfer        *xs = wu->swu_xs;
        struct sr_workunit      *wup;
        int                     s;

        /*
         * The SR_WUF_DISCIPLINE or SR_WUF_REBUILD flag must be set if
         * the work unit is not associated with a scsi_xfer.
         */
        KASSERT(xs != NULL ||
            (wu->swu_flags & (SR_WUF_DISCIPLINE|SR_WUF_REBUILD)));

        s = splbio();

        if (xs != NULL) {
                if (wu->swu_ios_failed)
                        xs->error = XS_DRIVER_STUFFUP;
                else
                        xs->error = XS_NOERROR;
        }

        if (sd->sd_scsi_wu_done) {
                if (sd->sd_scsi_wu_done(wu) == SR_WU_RESTART)
                        goto done;
        }

        /* Remove work unit from pending queue. */
        TAILQ_FOREACH(wup, &sd->sd_wu_pendq, swu_link)
                if (wup == wu)
                        break;
        if (wup == NULL)
                panic("%s: wu %p not on pending queue",
                    DEVNAME(sd->sd_sc), wu);
        TAILQ_REMOVE(&sd->sd_wu_pendq, wu, swu_link);

        if (wu->swu_collider) {
                if (wu->swu_ios_failed)
                        sr_raid_recreate_wu(wu->swu_collider);

                /* XXX Should the collider be failed if this xs failed? */
                sr_raid_startwu(wu->swu_collider);
        }

        /*
         * If a discipline provides its own sd_scsi_done function, then it
         * is responsible for calling sr_scsi_done() once I/O is complete.
         */
        if (wu->swu_flags & SR_WUF_REBUILD)
                wu->swu_flags |= SR_WUF_REBUILDIOCOMP;
        if (wu->swu_flags & SR_WUF_WAKEUP)
                wakeup(wu);
        if (sd->sd_scsi_done)
                sd->sd_scsi_done(wu);
        else if (wu->swu_flags & SR_WUF_DISCIPLINE)
                sr_scsi_wu_put(sd, wu);
        else if (!(wu->swu_flags & SR_WUF_REBUILD))
                sr_scsi_done(sd, xs);

done:
        splx(s);
}

struct sr_workunit *
sr_scsi_wu_get(struct sr_discipline *sd, int flags)
{
        return scsi_io_get(&sd->sd_iopool, flags);
}

void
sr_scsi_wu_put(struct sr_discipline *sd, struct sr_workunit *wu)
{
        scsi_io_put(&sd->sd_iopool, wu);

        if (sd->sd_sync && sd->sd_wu_pending == 0)
                wakeup(sd);
}

void
sr_scsi_done(struct sr_discipline *sd, struct scsi_xfer *xs)
{
        DNPRINTF(SR_D_DIS, "%s: sr_scsi_done: xs %p\n", DEVNAME(sd->sd_sc), xs);

        if (xs->error == XS_NOERROR)
                xs->resid = 0;

        scsi_done(xs);

        if (sd->sd_sync && sd->sd_wu_pending == 0)
                wakeup(sd);
}

void
sr_scsi_cmd(struct scsi_xfer *xs)
{
        struct scsi_link        *link = xs->sc_link;
        struct sr_softc         *sc = link->bus->sb_adapter_softc;
        struct sr_workunit      *wu = xs->io;
        struct sr_discipline    *sd;

        DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd target %d xs %p flags %#x\n",
            DEVNAME(sc), link->target, xs, xs->flags);

        sd = sc->sc_targets[link->target];
        if (sd == NULL)
                panic("%s: sr_scsi_cmd NULL discipline", DEVNAME(sc));

        if (sd->sd_deleted) {
                printf("%s: %s device is being deleted, failing io\n",
                    DEVNAME(sc), sd->sd_meta->ssd_devname);
                goto stuffup;
        }

        /* scsi layer *can* re-send wu without calling sr_wu_put(). */
        sr_wu_release_ccbs(wu);
        sr_wu_init(sd, wu);
        wu->swu_state = SR_WU_INPROGRESS;
        wu->swu_xs = xs;

        switch (xs->cmd.opcode) {
        case READ_COMMAND:
        case READ_10:
        case READ_16:
        case WRITE_COMMAND:
        case WRITE_10:
        case WRITE_16:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd: READ/WRITE %02x\n",
                    DEVNAME(sc), xs->cmd.opcode);
                if (sd->sd_scsi_rw(wu))
                        goto stuffup;
                break;

        case SYNCHRONIZE_CACHE:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd: SYNCHRONIZE_CACHE\n",
                    DEVNAME(sc));
                if (sd->sd_scsi_sync(wu))
                        goto stuffup;
                goto complete;

        case TEST_UNIT_READY:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd: TEST_UNIT_READY\n",
                    DEVNAME(sc));
                if (sd->sd_scsi_tur(wu))
                        goto stuffup;
                goto complete;

        case START_STOP:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd: START_STOP\n",
                    DEVNAME(sc));
                if (sd->sd_scsi_start_stop(wu))
                        goto stuffup;
                goto complete;

        case INQUIRY:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd: INQUIRY\n",
                    DEVNAME(sc));
                if (sd->sd_scsi_inquiry(wu))
                        goto stuffup;
                goto complete;

        case READ_CAPACITY:
        case READ_CAPACITY_16:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd READ CAPACITY 0x%02x\n",
                    DEVNAME(sc), xs->cmd.opcode);
                if (sd->sd_scsi_read_cap(wu))
                        goto stuffup;
                goto complete;

        case REQUEST_SENSE:
                DNPRINTF(SR_D_CMD, "%s: sr_scsi_cmd REQUEST SENSE\n",
                    DEVNAME(sc));
                if (sd->sd_scsi_req_sense(wu))
                        goto stuffup;
                goto complete;

        default:
                DNPRINTF(SR_D_CMD, "%s: unsupported scsi command %x\n",
                    DEVNAME(sc), xs->cmd.opcode);
                /* XXX might need to add generic function to handle others */
                goto stuffup;
        }

        return;
stuffup:
        if (sd->sd_scsi_sense.error_code) {
                xs->error = XS_SENSE;
                memcpy(&xs->sense, &sd->sd_scsi_sense, sizeof(xs->sense));
                bzero(&sd->sd_scsi_sense, sizeof(sd->sd_scsi_sense));
        } else {
                xs->error = XS_DRIVER_STUFFUP;
        }
complete:
        sr_scsi_done(sd, xs);
}

int
sr_scsi_probe(struct scsi_link *link)
{
        struct sr_softc         *sc = link->bus->sb_adapter_softc;
        struct sr_discipline    *sd;

        KASSERT(link->target < SR_MAX_LD && link->lun == 0);

        sd = sc->sc_targets[link->target];
        if (sd == NULL)
                return (ENODEV);

        link->pool = &sd->sd_iopool;
        if (sd->sd_openings)
                link->openings = sd->sd_openings(sd);
        else
                link->openings = sd->sd_max_wu;

        return (0);
}

int
sr_scsi_ioctl(struct scsi_link *link, u_long cmd, caddr_t addr, int flag)
{
        struct sr_softc         *sc = link->bus->sb_adapter_softc;
        struct sr_discipline    *sd;

        sd = sc->sc_targets[link->target];
        if (sd == NULL)
                return (ENODEV);

        DNPRINTF(SR_D_IOCTL, "%s: %s sr_scsi_ioctl cmd: %#lx\n",
            DEVNAME(sc), sd->sd_meta->ssd_devname, cmd);

        /* Pass bio ioctls through to the bio handler. */
        if (IOCGROUP(cmd) == 'B')
                return (sr_bio_handler(sc, sd, cmd, (struct bio *)addr));

        switch (cmd) {
        case DIOCGCACHE:
        case DIOCSCACHE:
                return (EOPNOTSUPP);
        default:
                return (ENOTTY);
        }
}

int
sr_bio_ioctl(struct device *dev, u_long cmd, caddr_t addr)
{
        struct sr_softc *sc = (struct sr_softc *) dev;
        DNPRINTF(SR_D_IOCTL, "%s: sr_bio_ioctl\n", DEVNAME(sc));

        return sr_bio_handler(sc, NULL, cmd, (struct bio *)addr);
}

int
sr_bio_handler(struct sr_softc *sc, struct sr_discipline *sd, u_long cmd,
    struct bio *bio)
{
        int                     rv = 0;

        DNPRINTF(SR_D_IOCTL, "%s: sr_bio_handler ", DEVNAME(sc));

        rw_enter_write(&sc->sc_lock);

        bio_status_init(&sc->sc_status, &sc->sc_dev);

        switch (cmd) {
        case BIOCINQ:
                DNPRINTF(SR_D_IOCTL, "inq\n");
                rv = sr_ioctl_inq(sc, (struct bioc_inq *)bio);
                break;

        case BIOCVOL:
                DNPRINTF(SR_D_IOCTL, "vol\n");
                rv = sr_ioctl_vol(sc, (struct bioc_vol *)bio);
                break;

        case BIOCDISK:
                DNPRINTF(SR_D_IOCTL, "disk\n");
                rv = sr_ioctl_disk(sc, (struct bioc_disk *)bio);
                break;

        case BIOCALARM:
                DNPRINTF(SR_D_IOCTL, "alarm\n");
                /*rv = sr_ioctl_alarm(sc, (struct bioc_alarm *)bio); */
                break;

        case BIOCBLINK:
                DNPRINTF(SR_D_IOCTL, "blink\n");
                /*rv = sr_ioctl_blink(sc, (struct bioc_blink *)bio); */
                break;

        case BIOCSETSTATE:
                DNPRINTF(SR_D_IOCTL, "setstate\n");
                rv = sr_ioctl_setstate(sc, (struct bioc_setstate *)bio);
                break;

        case BIOCCREATERAID:
                DNPRINTF(SR_D_IOCTL, "createraid\n");
                rv = sr_ioctl_createraid(sc, (struct bioc_createraid *)bio,
                    1, NULL);
                break;

        case BIOCDELETERAID:
                DNPRINTF(SR_D_IOCTL, "deleteraid\n");
                rv = sr_ioctl_deleteraid(sc, sd, (struct bioc_deleteraid *)bio);
                break;

        case BIOCDISCIPLINE:
                DNPRINTF(SR_D_IOCTL, "discipline\n");
                rv = sr_ioctl_discipline(sc, sd, (struct bioc_discipline *)bio);
                break;

        case BIOCINSTALLBOOT:
                DNPRINTF(SR_D_IOCTL, "installboot\n");
                rv = sr_ioctl_installboot(sc, sd,
                    (struct bioc_installboot *)bio);
                break;

        default:
                DNPRINTF(SR_D_IOCTL, "invalid ioctl\n");
                rv = ENOTTY;
        }

        sc->sc_status.bs_status = (rv ? BIO_STATUS_ERROR : BIO_STATUS_SUCCESS);

        if (sc->sc_status.bs_msg_count > 0)
                rv = 0;

        memcpy(&bio->bio_status, &sc->sc_status, sizeof(struct bio_status));

        rw_exit_write(&sc->sc_lock);

        return (rv);
}

int
sr_ioctl_inq(struct sr_softc *sc, struct bioc_inq *bi)
{
        struct sr_discipline    *sd;
        int                     vol = 0, disk = 0;

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                vol++;
                disk += sd->sd_meta->ssdi.ssd_chunk_no;
        }

        strlcpy(bi->bi_dev, sc->sc_dev.dv_xname, sizeof(bi->bi_dev));
        bi->bi_novol = vol + sc->sc_hotspare_no;
        bi->bi_nodisk = disk + sc->sc_hotspare_no;

        return (0);
}

int
sr_ioctl_vol(struct sr_softc *sc, struct bioc_vol *bv)
{
        int                     vol = -1, rv = EINVAL;
        struct sr_discipline    *sd;
        struct sr_chunk         *hotspare;

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                vol++;
                if (vol != bv->bv_volid)
                        continue;

                bv->bv_status = sd->sd_vol_status;
                bv->bv_size = sd->sd_meta->ssdi.ssd_size << DEV_BSHIFT;
                bv->bv_level = sd->sd_meta->ssdi.ssd_level;
                bv->bv_nodisk = sd->sd_meta->ssdi.ssd_chunk_no;

#ifdef CRYPTO
                if (sd->sd_meta->ssdi.ssd_level == 'C' &&
                    sd->mds.mdd_crypto.key_disk != NULL)
                        bv->bv_nodisk++;
                else if (sd->sd_meta->ssdi.ssd_level == 0x1C &&
                    sd->mds.mdd_raid1c.sr1c_crypto.key_disk != NULL)
                        bv->bv_nodisk++;
#endif
                if (bv->bv_status == BIOC_SVREBUILD)
                        bv->bv_percent = sr_rebuild_percent(sd);

                strlcpy(bv->bv_dev, sd->sd_meta->ssd_devname,
                    sizeof(bv->bv_dev));
                strlcpy(bv->bv_vendor, sd->sd_meta->ssdi.ssd_vendor,
                    sizeof(bv->bv_vendor));
                rv = 0;
                goto done;
        }

        /* Check hotspares list. */
        SLIST_FOREACH(hotspare, &sc->sc_hotspare_list, src_link) {
                vol++;
                if (vol != bv->bv_volid)
                        continue;

                bv->bv_status = BIOC_SVONLINE;
                bv->bv_size = hotspare->src_meta.scmi.scm_size << DEV_BSHIFT;
                bv->bv_level = -1;      /* Hotspare. */
                bv->bv_nodisk = 1;
                strlcpy(bv->bv_dev, hotspare->src_meta.scmi.scm_devname,
                    sizeof(bv->bv_dev));
                strlcpy(bv->bv_vendor, hotspare->src_meta.scmi.scm_devname,
                    sizeof(bv->bv_vendor));
                rv = 0;
                goto done;
        }

done:
        return (rv);
}

int
sr_ioctl_disk(struct sr_softc *sc, struct bioc_disk *bd)
{
        struct sr_discipline    *sd;
        struct sr_chunk         *src, *hotspare;
        int                     vol = -1, rv = EINVAL;

        if (bd->bd_diskid < 0)
                goto done;

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                vol++;
                if (vol != bd->bd_volid)
                        continue;

                if (bd->bd_diskid < sd->sd_meta->ssdi.ssd_chunk_no)
                        src = sd->sd_vol.sv_chunks[bd->bd_diskid];
#ifdef CRYPTO
                else if (bd->bd_diskid == sd->sd_meta->ssdi.ssd_chunk_no &&
                    sd->sd_meta->ssdi.ssd_level == 'C' &&
                    sd->mds.mdd_crypto.key_disk != NULL)
                        src = sd->mds.mdd_crypto.key_disk;
                else if (bd->bd_diskid == sd->sd_meta->ssdi.ssd_chunk_no &&
                    sd->sd_meta->ssdi.ssd_level == 0x1C &&
                    sd->mds.mdd_raid1c.sr1c_crypto.key_disk != NULL)
                        src = sd->mds.mdd_crypto.key_disk;
#endif
                else
                        break;

                bd->bd_status = src->src_meta.scm_status;
                bd->bd_size = src->src_meta.scmi.scm_size << DEV_BSHIFT;
                bd->bd_channel = vol;
                bd->bd_target = bd->bd_diskid;
                strlcpy(bd->bd_vendor, src->src_meta.scmi.scm_devname,
                    sizeof(bd->bd_vendor));
                rv = 0;
                goto done;
        }

        /* Check hotspares list. */
        SLIST_FOREACH(hotspare, &sc->sc_hotspare_list, src_link) {
                vol++;
                if (vol != bd->bd_volid)
                        continue;

                if (bd->bd_diskid != 0)
                        break;

                bd->bd_status = hotspare->src_meta.scm_status;
                bd->bd_size = hotspare->src_meta.scmi.scm_size << DEV_BSHIFT;
                bd->bd_channel = vol;
                bd->bd_target = bd->bd_diskid;
                strlcpy(bd->bd_vendor, hotspare->src_meta.scmi.scm_devname,
                    sizeof(bd->bd_vendor));
                rv = 0;
                goto done;
        }

done:
        return (rv);
}

int
sr_ioctl_setstate(struct sr_softc *sc, struct bioc_setstate *bs)
{
        int                     rv = EINVAL;
        int                     vol = -1, found, c;
        struct sr_discipline    *sd;
        struct sr_chunk         *ch_entry;
        struct sr_chunk_head    *cl;

        if (bs->bs_other_id_type == BIOC_SSOTHER_UNUSED)
                goto done;

        if (bs->bs_status == BIOC_SSHOTSPARE) {
                rv = sr_hotspare(sc, (dev_t)bs->bs_other_id);
                goto done;
        }

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                vol++;
                if (vol == bs->bs_volid)
                        break;
        }
        if (sd == NULL)
                goto done;

        switch (bs->bs_status) {
        case BIOC_SSOFFLINE:
                /* Take chunk offline */
                found = c = 0;
                cl = &sd->sd_vol.sv_chunk_list;
                SLIST_FOREACH(ch_entry, cl, src_link) {
                        if (ch_entry->src_dev_mm == bs->bs_other_id) {
                                found = 1;
                                break;
                        }
                        c++;
                }
                if (found == 0) {
                        sr_error(sc, "chunk not part of array");
                        goto done;
                }

                /* XXX: check current state first */
                sd->sd_set_chunk_state(sd, c, BIOC_SDOFFLINE);

                if (sr_meta_save(sd, SR_META_DIRTY)) {
                        sr_error(sc, "could not save metadata for %s",
                            sd->sd_meta->ssd_devname);
                        goto done;
                }
                rv = 0;
                break;

        case BIOC_SDSCRUB:
                break;

        case BIOC_SSREBUILD:
                rv = sr_rebuild_init(sd, (dev_t)bs->bs_other_id, 0);
                break;

        default:
                sr_error(sc, "unsupported state request %d", bs->bs_status);
        }

done:
        return (rv);
}

int
sr_chunk_in_use(struct sr_softc *sc, dev_t dev)
{
        struct sr_discipline    *sd;
        struct sr_chunk         *chunk;
        int                     i;

        DNPRINTF(SR_D_MISC, "%s: sr_chunk_in_use(%d)\n", DEVNAME(sc), dev);

        if (dev == NODEV)
                return BIOC_SDINVALID;

        /* See if chunk is already in use. */
        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                for (i = 0; i < sd->sd_meta->ssdi.ssd_chunk_no; i++) {
                        chunk = sd->sd_vol.sv_chunks[i];
                        if (chunk->src_dev_mm == dev)
                                return chunk->src_meta.scm_status;
                }
        }

        /* Check hotspares list. */
        SLIST_FOREACH(chunk, &sc->sc_hotspare_list, src_link)
                if (chunk->src_dev_mm == dev)
                        return chunk->src_meta.scm_status;

        return BIOC_SDINVALID;
}

int
sr_hotspare(struct sr_softc *sc, dev_t dev)
{
        struct sr_discipline    *sd = NULL;
        struct sr_metadata      *sm = NULL;
        struct sr_meta_chunk    *hm;
        struct sr_chunk_head    *cl;
        struct sr_chunk         *chunk, *last, *hotspare = NULL;
        struct sr_uuid          uuid;
        struct disklabel        *label = NULL;
        struct vnode            *vn;
        u_int64_t               size;
        char                    devname[32];
        int                     rv = EINVAL;
        int                     c, part, open = 0;

        /*
         * Add device to global hotspares list.
         */

        sr_meta_getdevname(sc, dev, devname, sizeof(devname));

        /* Make sure chunk is not already in use. */
        c = sr_chunk_in_use(sc, dev);
        if (c != BIOC_SDINVALID && c != BIOC_SDOFFLINE) {
                if (c == BIOC_SDHOTSPARE)
                        sr_error(sc, "%s is already a hotspare", devname);
                else
                        sr_error(sc, "%s is already in use", devname);
                goto done;
        }

        /* XXX - See if there is an existing degraded volume... */

        /* Open device. */
        if (bdevvp(dev, &vn)) {
                sr_error(sc, "sr_hotspare: cannot allocate vnode");
                goto done;
        }
        if (VOP_OPEN(vn, FREAD | FWRITE, NOCRED, curproc)) {
                DNPRINTF(SR_D_META,"%s: sr_hotspare cannot open %s\n",
                    DEVNAME(sc), devname);
                vput(vn);
                goto fail;
        }
        open = 1; /* close dev on error */

        label = malloc(sizeof(*label), M_DEVBUF, M_WAITOK);

        /* Get partition details. */
        part = DISKPART(dev);
        if (VOP_IOCTL(vn, DIOCGDINFO, (caddr_t)label, FREAD,
            NOCRED, curproc)) {
                DNPRINTF(SR_D_META, "%s: sr_hotspare ioctl failed\n",
                    DEVNAME(sc));
                goto fail;
        }
        if (label->d_partitions[part].p_fstype != FS_RAID) {
                sr_error(sc, "%s partition not of type RAID (%d)",
                    devname, label->d_partitions[part].p_fstype);
                goto fail;
        }

        /* Calculate partition size. */
        size = DL_SECTOBLK(label, DL_GETPSIZE(&label->d_partitions[part]));
        if (size <= SR_DATA_OFFSET) {
                DNPRINTF(SR_D_META, "%s: %s partition too small\n", DEVNAME(sc),
                    devname);
                goto fail;
        }
        size -= SR_DATA_OFFSET;
        if (size > INT64_MAX) {
                DNPRINTF(SR_D_META, "%s: %s partition too large\n", DEVNAME(sc),
                    devname);
                goto fail;
        }

        /*
         * Create and populate chunk metadata.
         */

        sr_uuid_generate(&uuid);
        hotspare = malloc(sizeof(struct sr_chunk), M_DEVBUF, M_WAITOK | M_ZERO);

        hotspare->src_dev_mm = dev;
        hotspare->src_vn = vn;
        strlcpy(hotspare->src_devname, devname, sizeof(hm->scmi.scm_devname));
        hotspare->src_size = size;

        hm = &hotspare->src_meta;
        hm->scmi.scm_volid = SR_HOTSPARE_VOLID;
        hm->scmi.scm_chunk_id = 0;
        hm->scmi.scm_size = size;
        hm->scmi.scm_coerced_size = size;
        strlcpy(hm->scmi.scm_devname, devname, sizeof(hm->scmi.scm_devname));
        memcpy(&hm->scmi.scm_uuid, &uuid, sizeof(struct sr_uuid));

        sr_checksum(sc, hm, &hm->scm_checksum,
            sizeof(struct sr_meta_chunk_invariant));

        hm->scm_status = BIOC_SDHOTSPARE;

        /*
         * Create and populate our own discipline and metadata.
         */

        sm = malloc(sizeof(struct sr_metadata), M_DEVBUF, M_WAITOK | M_ZERO);
        sm->ssdi.ssd_magic = SR_MAGIC;
        sm->ssdi.ssd_version = SR_META_VERSION;
        sm->ssd_ondisk = 0;
        sm->ssdi.ssd_vol_flags = 0;
        memcpy(&sm->ssdi.ssd_uuid, &uuid, sizeof(struct sr_uuid));
        sm->ssdi.ssd_chunk_no = 1;
        sm->ssdi.ssd_volid = SR_HOTSPARE_VOLID;
        sm->ssdi.ssd_level = SR_HOTSPARE_LEVEL;
        sm->ssdi.ssd_size = size;
        sm->ssdi.ssd_secsize = label->d_secsize;
        strlcpy(sm->ssdi.ssd_vendor, "OPENBSD", sizeof(sm->ssdi.ssd_vendor));
        snprintf(sm->ssdi.ssd_product, sizeof(sm->ssdi.ssd_product),
            "SR %s", "HOTSPARE");
        snprintf(sm->ssdi.ssd_revision, sizeof(sm->ssdi.ssd_revision),
            "%03d", SR_META_VERSION);

        sd = malloc(sizeof(struct sr_discipline), M_DEVBUF, M_WAITOK | M_ZERO);
        sd->sd_sc = sc;
        sd->sd_meta = sm;
        sd->sd_meta_type = SR_META_F_NATIVE;
        sd->sd_vol_status = BIOC_SVONLINE;
        strlcpy(sd->sd_name, "HOTSPARE", sizeof(sd->sd_name));
        SLIST_INIT(&sd->sd_meta_opt);

        /* Add chunk to volume. */
        sd->sd_vol.sv_chunks = malloc(sizeof(struct sr_chunk *), M_DEVBUF,
            M_WAITOK | M_ZERO);
        sd->sd_vol.sv_chunks[0] = hotspare;
        SLIST_INIT(&sd->sd_vol.sv_chunk_list);
        SLIST_INSERT_HEAD(&sd->sd_vol.sv_chunk_list, hotspare, src_link);

        /* Save metadata. */
        if (sr_meta_save(sd, SR_META_DIRTY)) {
                sr_error(sc, "could not save metadata to %s", devname);
                goto fail;
        }

        /*
         * Add chunk to hotspare list.
         */
        rw_enter_write(&sc->sc_hs_lock);
        cl = &sc->sc_hotspare_list;
        if (SLIST_EMPTY(cl))
                SLIST_INSERT_HEAD(cl, hotspare, src_link);
        else {
                SLIST_FOREACH(chunk, cl, src_link)
                        last = chunk;
                SLIST_INSERT_AFTER(last, hotspare, src_link);
        }
        sc->sc_hotspare_no++;
        rw_exit_write(&sc->sc_hs_lock);

        rv = 0;
        goto done;

fail:
        free(hotspare, M_DEVBUF, sizeof(*hotspare));

done:
        if (sd)
                free(sd->sd_vol.sv_chunks, M_DEVBUF,
                    sizeof(sd->sd_vol.sv_chunks));
        free(label, M_DEVBUF, sizeof(*label));
        free(sd, M_DEVBUF, sizeof(*sd));
        free(sm, M_DEVBUF, sizeof(*sm));
        if (open) {
                VOP_CLOSE(vn, FREAD | FWRITE, NOCRED, curproc);
                vput(vn);
        }

        return (rv);
}

void
sr_hotspare_rebuild_callback(void *xsd)
{
        struct sr_discipline *sd = xsd;
        sr_hotspare_rebuild(sd);
}

void
sr_hotspare_rebuild(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk_head    *cl;
        struct sr_chunk         *hotspare, *chunk = NULL;
        struct sr_workunit      *wu;
        struct sr_ccb           *ccb;
        int                     i, s, cid, busy;

        /*
         * Attempt to locate a hotspare and initiate rebuild.
         */

        /* Find first offline chunk. */
        for (cid = 0; cid < sd->sd_meta->ssdi.ssd_chunk_no; cid++) {
                if (sd->sd_vol.sv_chunks[cid]->src_meta.scm_status ==
                    BIOC_SDOFFLINE) {
                        chunk = sd->sd_vol.sv_chunks[cid];
                        break;
                }
        }
        if (chunk == NULL) {
                printf("%s: no offline chunk found on %s!\n",
                    DEVNAME(sc), sd->sd_meta->ssd_devname);
                return;
        }

        /* See if we have a suitable hotspare... */
        rw_enter_write(&sc->sc_hs_lock);
        cl = &sc->sc_hotspare_list;
        SLIST_FOREACH(hotspare, cl, src_link)
                if (hotspare->src_size >= chunk->src_size &&
                    hotspare->src_secsize <= sd->sd_meta->ssdi.ssd_secsize)
                        break;

        if (hotspare != NULL) {

                printf("%s: %s volume degraded, will attempt to "
                    "rebuild on hotspare %s\n", DEVNAME(sc),
                    sd->sd_meta->ssd_devname, hotspare->src_devname);

                /*
                 * Ensure that all pending I/O completes on the failed chunk
                 * before trying to initiate a rebuild.
                 */
                i = 0;
                do {
                        busy = 0;

                        s = splbio();
                        TAILQ_FOREACH(wu, &sd->sd_wu_pendq, swu_link) {
                                TAILQ_FOREACH(ccb, &wu->swu_ccb, ccb_link) {
                                        if (ccb->ccb_target == cid)
                                                busy = 1;
                                }
                        }
                        TAILQ_FOREACH(wu, &sd->sd_wu_defq, swu_link) {
                                TAILQ_FOREACH(ccb, &wu->swu_ccb, ccb_link) {
                                        if (ccb->ccb_target == cid)
                                                busy = 1;
                                }
                        }
                        splx(s);

                        if (busy) {
                                tsleep_nsec(sd, PRIBIO, "sr_hotspare",
                                    SEC_TO_NSEC(1));
                                i++;
                        }

                } while (busy && i < 120);

                DNPRINTF(SR_D_META, "%s: waited %i seconds for I/O to "
                    "complete on failed chunk %s\n", DEVNAME(sc),
                    i, chunk->src_devname);

                if (busy) {
                        printf("%s: pending I/O failed to complete on "
                            "failed chunk %s, hotspare rebuild aborted...\n",
                            DEVNAME(sc), chunk->src_devname);
                        goto done;
                }

                s = splbio();
                rw_enter_write(&sc->sc_lock);
                bio_status_init(&sc->sc_status, &sc->sc_dev);
                if (sr_rebuild_init(sd, hotspare->src_dev_mm, 1) == 0) {

                        /* Remove hotspare from available list. */
                        sc->sc_hotspare_no--;
                        SLIST_REMOVE(cl, hotspare, sr_chunk, src_link);
                        free(hotspare, M_DEVBUF, sizeof(*hotspare));

                }
                rw_exit_write(&sc->sc_lock);
                splx(s);
        }
done:
        rw_exit_write(&sc->sc_hs_lock);
}

int
sr_rebuild_init(struct sr_discipline *sd, dev_t dev, int hotspare)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk         *chunk = NULL;
        struct sr_meta_chunk    *meta;
        struct disklabel        *label = NULL;
        struct vnode            *vn;
        u_int64_t               size;
        int64_t                 csize;
        char                    devname[32];
        int                     rv = EINVAL, open = 0;
        int                     cid, i, part, status;

        /*
         * Attempt to initiate a rebuild onto the specified device.
         */

        if (!(sd->sd_capabilities & SR_CAP_REBUILD)) {
                sr_error(sc, "discipline does not support rebuild");
                goto done;
        }

        /* make sure volume is in the right state */
        if (sd->sd_vol_status == BIOC_SVREBUILD) {
                sr_error(sc, "rebuild already in progress");
                goto done;
        }
        if (sd->sd_vol_status != BIOC_SVDEGRADED) {
                sr_error(sc, "volume not degraded");
                goto done;
        }

        /* Find first offline chunk. */
        for (cid = 0; cid < sd->sd_meta->ssdi.ssd_chunk_no; cid++) {
                if (sd->sd_vol.sv_chunks[cid]->src_meta.scm_status ==
                    BIOC_SDOFFLINE) {
                        chunk = sd->sd_vol.sv_chunks[cid];
                        break;
                }
        }
        if (chunk == NULL) {
                sr_error(sc, "no offline chunks available to rebuild");
                goto done;
        }

        /* Get coerced size from another online chunk. */
        csize = 0;
        for (i = 0; i < sd->sd_meta->ssdi.ssd_chunk_no; i++) {
                if (sd->sd_vol.sv_chunks[i]->src_meta.scm_status ==
                    BIOC_SDONLINE) {
                        meta = &sd->sd_vol.sv_chunks[i]->src_meta;
                        csize = meta->scmi.scm_coerced_size;
                        break;
                }
        }
        if (csize == 0) {
                sr_error(sc, "no online chunks available for rebuild");
                goto done;
        }

        sr_meta_getdevname(sc, dev, devname, sizeof(devname));
        if (bdevvp(dev, &vn)) {
                printf("%s: sr_rebuild_init: can't allocate vnode\n",
                    DEVNAME(sc));
                goto done;
        }
        if (VOP_OPEN(vn, FREAD | FWRITE, NOCRED, curproc)) {
                DNPRINTF(SR_D_META,"%s: sr_ioctl_setstate can't "
                    "open %s\n", DEVNAME(sc), devname);
                vput(vn);
                goto done;
        }
        open = 1; /* close dev on error */

        label = malloc(sizeof(*label), M_DEVBUF, M_WAITOK);

        /* Get disklabel and check partition. */
        part = DISKPART(dev);
        if (VOP_IOCTL(vn, DIOCGDINFO, (caddr_t)label, FREAD,
            NOCRED, curproc)) {
                DNPRINTF(SR_D_META, "%s: sr_ioctl_setstate ioctl failed\n",
                    DEVNAME(sc));
                goto done;
        }
        if (label->d_partitions[part].p_fstype != FS_RAID) {
                sr_error(sc, "%s partition not of type RAID (%d)",
                    devname, label->d_partitions[part].p_fstype);
                goto done;
        }

        /* Is the partition large enough? */
        size = DL_SECTOBLK(label, DL_GETPSIZE(&label->d_partitions[part]));
        if (size <= sd->sd_meta->ssd_data_blkno) {
                sr_error(sc, "%s: %s partition too small", DEVNAME(sc),
                    devname);
                goto done;
        }
        size -= sd->sd_meta->ssd_data_blkno;
        if (size > INT64_MAX) {
                sr_error(sc, "%s: %s partition too large", DEVNAME(sc),
                    devname);
                goto done;
        }
        if (size < csize) {
                sr_error(sc, "%s partition too small, at least %lld bytes "
                    "required", devname, (long long)(csize << DEV_BSHIFT));
                goto done;
        } else if (size > csize)
                sr_warn(sc, "%s partition too large, wasting %lld bytes",
                    devname, (long long)((size - csize) << DEV_BSHIFT));
        if (label->d_secsize > sd->sd_meta->ssdi.ssd_secsize) {
                sr_error(sc, "%s sector size too large, <= %u bytes "
                    "required", devname, sd->sd_meta->ssdi.ssd_secsize);
                goto done;
        }

        /* Ensure that this chunk is not already in use. */
        status = sr_chunk_in_use(sc, dev);
        if (status != BIOC_SDINVALID && status != BIOC_SDOFFLINE &&
            !(hotspare && status == BIOC_SDHOTSPARE)) {
                sr_error(sc, "%s is already in use", devname);
                goto done;
        }

        /* Reset rebuild counter since we rebuilding onto a new chunk. */
        sd->sd_meta->ssd_rebuild = 0;

        open = 0; /* leave dev open from here on out */

        /* Fix up chunk. */
        memcpy(chunk->src_duid, label->d_uid, sizeof(chunk->src_duid));
        chunk->src_dev_mm = dev;
        chunk->src_vn = vn;

        /* Reconstruct metadata. */
        meta = &chunk->src_meta;
        meta->scmi.scm_volid = sd->sd_meta->ssdi.ssd_volid;
        meta->scmi.scm_chunk_id = cid;
        strlcpy(meta->scmi.scm_devname, devname,
            sizeof(meta->scmi.scm_devname));
        meta->scmi.scm_size = size;
        meta->scmi.scm_coerced_size = csize;
        memcpy(&meta->scmi.scm_uuid, &sd->sd_meta->ssdi.ssd_uuid,
            sizeof(meta->scmi.scm_uuid));
        sr_checksum(sc, meta, &meta->scm_checksum,
            sizeof(struct sr_meta_chunk_invariant));

        sd->sd_set_chunk_state(sd, cid, BIOC_SDREBUILD);

        if (sr_meta_save(sd, SR_META_DIRTY)) {
                sr_error(sc, "could not save metadata to %s", devname);
                open = 1;
                goto done;
        }

        sr_warn(sc, "rebuild of %s started on %s",
            sd->sd_meta->ssd_devname, devname);

        sd->sd_reb_abort = 0;
        kthread_create_deferred(sr_rebuild_start, sd);

        rv = 0;
done:
        free(label, M_DEVBUF, sizeof(*label));
        if (open) {
                VOP_CLOSE(vn, FREAD | FWRITE, NOCRED, curproc);
                vput(vn);
        }

        return (rv);
}

int
sr_rebuild_percent(struct sr_discipline *sd)
{
        daddr_t                 rb, sz;

        sz = sd->sd_meta->ssdi.ssd_size;
        rb = sd->sd_meta->ssd_rebuild;

        if (rb > 0)
                return (100 - ((sz * 100 - rb * 100) / sz) - 1);

        return (0);
}

void
sr_roam_chunks(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_chunk         *chunk;
        struct sr_meta_chunk    *meta;
        int                     roamed = 0;

        /* Have any chunks roamed? */
        SLIST_FOREACH(chunk, &sd->sd_vol.sv_chunk_list, src_link) {
                meta = &chunk->src_meta;
                if (strncmp(meta->scmi.scm_devname, chunk->src_devname,
                    sizeof(meta->scmi.scm_devname))) {

                        printf("%s: roaming device %s -> %s\n", DEVNAME(sc),
                            meta->scmi.scm_devname, chunk->src_devname);

                        strlcpy(meta->scmi.scm_devname, chunk->src_devname,
                            sizeof(meta->scmi.scm_devname));

                        roamed++;
                }
        }

        if (roamed)
                sr_meta_save(sd, SR_META_DIRTY);
}

int
sr_ioctl_createraid(struct sr_softc *sc, struct bioc_createraid *bc,
    int user, void *data)
{
        struct sr_meta_opt_item *omi;
        struct sr_chunk_head    *cl;
        struct sr_discipline    *sd = NULL;
        struct sr_chunk         *ch_entry;
        struct scsi_link        *link;
        struct device           *dev;
        char                    *uuid, devname[32];
        dev_t                   *dt = NULL;
        int                     i, no_chunk, rv = EINVAL, target, vol;
        int                     no_meta;

        DNPRINTF(SR_D_IOCTL, "%s: sr_ioctl_createraid(%d)\n",
            DEVNAME(sc), user);

        /* user input */
        if (bc->bc_dev_list_len > BIOC_CRMAXLEN)
                goto unwind;

        dt = malloc(bc->bc_dev_list_len, M_DEVBUF, M_WAITOK | M_ZERO);
        if (user) {
                if (copyin(bc->bc_dev_list, dt, bc->bc_dev_list_len) != 0)
                        goto unwind;
        } else
                memcpy(dt, bc->bc_dev_list, bc->bc_dev_list_len);

        /* Initialise discipline. */
        sd = malloc(sizeof(struct sr_discipline), M_DEVBUF, M_WAITOK | M_ZERO);
        sd->sd_sc = sc;
        SLIST_INIT(&sd->sd_meta_opt);
        sd->sd_taskq = taskq_create("srdis", 1, IPL_BIO, 0);
        if (sd->sd_taskq == NULL) {
                sr_error(sc, "could not create discipline taskq");
                goto unwind;
        }
        if (sr_discipline_init(sd, bc->bc_level)) {
                sr_error(sc, "could not initialize discipline");
                goto unwind;
        }

        no_chunk = bc->bc_dev_list_len / sizeof(dev_t);
        cl = &sd->sd_vol.sv_chunk_list;
        SLIST_INIT(cl);

        /* Ensure that chunks are not already in use. */
        for (i = 0; i < no_chunk; i++) {
                if (sr_chunk_in_use(sc, dt[i]) != BIOC_SDINVALID) {
                        sr_meta_getdevname(sc, dt[i], devname, sizeof(devname));
                        sr_error(sc, "chunk %s already in use", devname);
                        goto unwind;
                }
        }

        sd->sd_meta_type = sr_meta_probe(sd, dt, no_chunk);
        if (sd->sd_meta_type == SR_META_F_INVALID) {
                sr_error(sc, "invalid metadata format");
                goto unwind;
        }

        if (sr_meta_attach(sd, no_chunk, bc->bc_flags & BIOC_SCFORCE))
                goto unwind;

        /* force the raid volume by clearing metadata region */
        if (bc->bc_flags & BIOC_SCFORCE) {
                /* make sure disk isn't up and running */
                if (sr_meta_read(sd))
                        if (sr_already_assembled(sd)) {
                                uuid = sr_uuid_format(
                                    &sd->sd_meta->ssdi.ssd_uuid);
                                sr_error(sc, "disk %s is currently in use; "
                                    "cannot force create", uuid);
                                free(uuid, M_DEVBUF, 37);
                                goto unwind;
                        }

                if (sr_meta_clear(sd)) {
                        sr_error(sc, "failed to clear metadata");
                        goto unwind;
                }
        }

        no_meta = sr_meta_read(sd);
        if (no_meta == -1) {

                /* Corrupt metadata on one or more chunks. */
                sr_error(sc, "one of the chunks has corrupt metadata; "
                    "aborting assembly");
                goto unwind;

        } else if (no_meta == 0) {

                /* Initialise volume and chunk metadata. */
                sr_meta_init(sd, bc->bc_level, no_chunk);
                sd->sd_vol_status = BIOC_SVONLINE;
                sd->sd_meta_flags = bc->bc_flags & BIOC_SCNOAUTOASSEMBLE;
                if (sd->sd_create) {
                        if ((i = sd->sd_create(sd, bc, no_chunk,
                            sd->sd_vol.sv_chunk_minsz))) {
                                rv = i;
                                goto unwind;
                        }
                }
                sr_meta_init_complete(sd);

                DNPRINTF(SR_D_IOCTL,
                    "%s: sr_ioctl_createraid: vol_size: %lld\n",
                    DEVNAME(sc), sd->sd_meta->ssdi.ssd_size);

                /* Warn if we've wasted chunk space due to coercing. */
                if ((sd->sd_capabilities & SR_CAP_NON_COERCED) == 0 &&
                    sd->sd_vol.sv_chunk_minsz != sd->sd_vol.sv_chunk_maxsz)
                        sr_warn(sc, "chunk sizes are not equal; up to %llu "
                            "blocks wasted per chunk",
                            sd->sd_vol.sv_chunk_maxsz -
                            sd->sd_vol.sv_chunk_minsz);

        } else {

                /* Ensure we are assembling the correct # of chunks. */
                if (bc->bc_level == 0x1C &&
                    sd->sd_meta->ssdi.ssd_chunk_no > no_chunk) {
                        sr_warn(sc, "trying to bring up %s degraded",
                            sd->sd_meta->ssd_devname);
                } else if (sd->sd_meta->ssdi.ssd_chunk_no != no_chunk) {
                        sr_error(sc, "volume chunk count does not match metadata "
                            "chunk count");
                        goto unwind;
                }

                /* Ensure metadata level matches requested assembly level. */
                if (sd->sd_meta->ssdi.ssd_level != bc->bc_level) {
                        sr_error(sc, "volume level does not match metadata "
                            "level");
                        goto unwind;
                }

                if (sr_already_assembled(sd)) {
                        uuid = sr_uuid_format(&sd->sd_meta->ssdi.ssd_uuid);
                        sr_error(sc, "disk %s already assembled", uuid);
                        free(uuid, M_DEVBUF, 37);
                        goto unwind;
                }

                if (user == 0 && (sd->sd_meta_flags & BIOC_SCNOAUTOASSEMBLE)) {
                        DNPRINTF(SR_D_META, "%s: disk not auto assembled from "
                            "metadata\n", DEVNAME(sc));
                        goto unwind;
                }

                if (no_meta != no_chunk)
                        sr_warn(sc, "trying to bring up %s degraded",
                            sd->sd_meta->ssd_devname);

                if (sd->sd_meta->ssd_meta_flags & SR_META_DIRTY)
                        sr_warn(sc, "%s was not shutdown properly",
                            sd->sd_meta->ssd_devname);

                SLIST_FOREACH(omi, &sd->sd_meta_opt, omi_link)
                        if (sd->sd_meta_opt_handler == NULL ||
                            sd->sd_meta_opt_handler(sd, omi->omi_som) != 0)
                                sr_meta_opt_handler(sd, omi->omi_som);

                if (sd->sd_assemble) {
                        if ((i = sd->sd_assemble(sd, bc, no_chunk, data))) {
                                rv = i;
                                goto unwind;
                        }
                }

                DNPRINTF(SR_D_META, "%s: disk assembled from metadata\n",
                    DEVNAME(sc));

        }

        /* Metadata MUST be fully populated by this point. */
        TAILQ_INSERT_TAIL(&sc->sc_dis_list, sd, sd_link);

        /* Allocate all resources. */
        if ((rv = sd->sd_alloc_resources(sd)))
                goto unwind;

        /* Adjust flags if necessary. */
        if ((sd->sd_capabilities & SR_CAP_AUTO_ASSEMBLE) &&
            (bc->bc_flags & BIOC_SCNOAUTOASSEMBLE) !=
            (sd->sd_meta->ssdi.ssd_vol_flags & BIOC_SCNOAUTOASSEMBLE)) {
                sd->sd_meta->ssdi.ssd_vol_flags &= ~BIOC_SCNOAUTOASSEMBLE;
                sd->sd_meta->ssdi.ssd_vol_flags |=
                    bc->bc_flags & BIOC_SCNOAUTOASSEMBLE;
        }

        if (sd->sd_capabilities & SR_CAP_SYSTEM_DISK) {
                /* Initialise volume state. */
                sd->sd_set_vol_state(sd);
                if (sd->sd_vol_status == BIOC_SVOFFLINE) {
                        sr_error(sc, "%s is offline, will not be brought "
                            "online", sd->sd_meta->ssd_devname);
                        goto unwind;
                }

                /* Setup SCSI iopool. */
                scsi_iopool_init(&sd->sd_iopool, sd, sr_wu_get, sr_wu_put);

                /*
                 * All checks passed - return ENXIO if volume cannot be created.
                 */
                rv = ENXIO;

                /*
                 * Find a free target.
                 *
                 * XXX: We reserve sd_target == 0 to indicate the
                 * discipline is not linked into sc->sc_targets, so begin
                 * the search with target = 1.
                 */
                for (target = 1; target < SR_MAX_LD; target++)
                        if (sc->sc_targets[target] == NULL)
                                break;
                if (target == SR_MAX_LD) {
                        sr_error(sc, "no free target for %s",
                            sd->sd_meta->ssd_devname);
                        goto unwind;
                }

                /* Clear sense data. */
                bzero(&sd->sd_scsi_sense, sizeof(sd->sd_scsi_sense));

                /* Attach discipline and get midlayer to probe it. */
                sd->sd_target = target;
                sc->sc_targets[target] = sd;
                if (scsi_probe_lun(sc->sc_scsibus, target, 0) != 0) {
                        sr_error(sc, "scsi_probe_lun failed");
                        sc->sc_targets[target] = NULL;
                        sd->sd_target = 0;
                        goto unwind;
                }

                link = scsi_get_link(sc->sc_scsibus, target, 0);
                if (link == NULL)
                        goto unwind;

                dev = link->device_softc;
                DNPRINTF(SR_D_IOCTL, "%s: sr device added: %s at target %d\n",
                    DEVNAME(sc), dev->dv_xname, sd->sd_target);

                /* XXX - Count volumes, not targets. */
                for (i = 0, vol = -1; i <= sd->sd_target; i++)
                        if (sc->sc_targets[i])
                                vol++;

                rv = 0;

                if (sd->sd_meta->ssd_devname[0] != '\0' &&
                    strncmp(sd->sd_meta->ssd_devname, dev->dv_xname,
                    sizeof(dev->dv_xname)))
                        sr_warn(sc, "volume %s is roaming, it used to be %s, "
                            "updating metadata", dev->dv_xname,
                            sd->sd_meta->ssd_devname);

                /* Populate remaining volume metadata. */
                sd->sd_meta->ssdi.ssd_volid = vol;
                strlcpy(sd->sd_meta->ssd_devname, dev->dv_xname,
                    sizeof(sd->sd_meta->ssd_devname));

                sr_info(sc, "%s volume attached as %s",
                    sd->sd_name, sd->sd_meta->ssd_devname);

                /* Update device name on any roaming chunks. */
                sr_roam_chunks(sd);

#ifndef SMALL_KERNEL
                if (sr_sensors_create(sd))
                        sr_warn(sc, "unable to create sensor for %s",
                            dev->dv_xname);
#endif /* SMALL_KERNEL */
        } else {
                /* This volume does not attach as a system disk. */
                ch_entry = SLIST_FIRST(cl); /* XXX */
                strlcpy(sd->sd_meta->ssd_devname, ch_entry->src_devname,
                    sizeof(sd->sd_meta->ssd_devname));

                if (sd->sd_start_discipline(sd))
                        goto unwind;
        }

        /* Save current metadata to disk. */
        rv = sr_meta_save(sd, SR_META_DIRTY);

        if (sd->sd_vol_status == BIOC_SVREBUILD)
                kthread_create_deferred(sr_rebuild_start, sd);

        sd->sd_ready = 1;

        free(dt, M_DEVBUF, bc->bc_dev_list_len);

        return (rv);

unwind:
        free(dt, M_DEVBUF, bc->bc_dev_list_len);

        sr_discipline_shutdown(sd, 0, 0);

        if (rv == EAGAIN)
                rv = 0;

        return (rv);
}

int
sr_ioctl_deleteraid(struct sr_softc *sc, struct sr_discipline *sd,
    struct bioc_deleteraid *bd)
{
        int                     rv = 1;

        DNPRINTF(SR_D_IOCTL, "%s: sr_ioctl_deleteraid %s\n",
            DEVNAME(sc), bd->bd_dev);

        if (sd == NULL && (sd = sr_find_discipline(sc, bd->bd_dev)) == NULL) {
                sr_error(sc, "volume %s not found", bd->bd_dev);
                goto bad;
        }

        /*
         * XXX Better check for mounted file systems and refuse to detach any
         * volume that is actively in use.
         */
        if (bcmp(&sr_bootuuid, &sd->sd_meta->ssdi.ssd_uuid,
            sizeof(sr_bootuuid)) == 0) {
                sr_error(sc, "refusing to delete boot volume");
                goto bad;
        }

        sd->sd_deleted = 1;
        sd->sd_meta->ssdi.ssd_vol_flags = BIOC_SCNOAUTOASSEMBLE;
        sr_discipline_shutdown(sd, 1, 0);

        rv = 0;
bad:
        return (rv);
}

int
sr_ioctl_discipline(struct sr_softc *sc, struct sr_discipline *sd,
    struct bioc_discipline *bd)
{
        int                     rv = 1;

        /* Dispatch a discipline specific ioctl. */

        DNPRINTF(SR_D_IOCTL, "%s: sr_ioctl_discipline %s\n", DEVNAME(sc),
            bd->bd_dev);

        if (sd == NULL && (sd = sr_find_discipline(sc, bd->bd_dev)) == NULL) {
                sr_error(sc, "volume %s not found", bd->bd_dev);
                goto bad;
        }

        if (sd->sd_ioctl_handler)
                rv = sd->sd_ioctl_handler(sd, bd);

bad:
        return (rv);
}

int
sr_ioctl_installboot(struct sr_softc *sc, struct sr_discipline *sd,
    struct bioc_installboot *bb)
{
        void                    *bootblk = NULL, *bootldr = NULL;
        struct sr_chunk         *chunk;
        struct sr_meta_opt_item *omi;
        struct sr_meta_boot     *sbm;
        struct disk             *dk;
        u_int32_t               bbs = 0, bls = 0, secsize;
        u_char                  duid[8];
        int                     rv = EINVAL;
        int                     i;

        DNPRINTF(SR_D_IOCTL, "%s: sr_ioctl_installboot %s\n", DEVNAME(sc),
            bb->bb_dev);

        if (sd == NULL && (sd = sr_find_discipline(sc, bb->bb_dev)) == NULL) {
                sr_error(sc, "volume %s not found", bb->bb_dev);
                goto done;
        }

        TAILQ_FOREACH(dk, &disklist,  dk_link)
                if (!strncmp(dk->dk_name, bb->bb_dev, sizeof(bb->bb_dev)))
                        break;
        if (dk == NULL || dk->dk_label == NULL ||
            duid_iszero(dk->dk_label->d_uid)) {
                sr_error(sc, "failed to get DUID for softraid volume");
                goto done;
        }
        memcpy(duid, dk->dk_label->d_uid, sizeof(duid));

        /* Ensure that boot storage area is large enough. */
        if (sd->sd_meta->ssd_data_blkno < (SR_BOOT_OFFSET + SR_BOOT_SIZE)) {
                sr_error(sc, "insufficient boot storage");
                goto done;
        }

        if (bb->bb_bootblk_size > SR_BOOT_BLOCKS_SIZE * DEV_BSIZE) {
                sr_error(sc, "boot block too large (%d > %d)",
                    bb->bb_bootblk_size, SR_BOOT_BLOCKS_SIZE * DEV_BSIZE);
                goto done;
        }

        if (bb->bb_bootldr_size > SR_BOOT_LOADER_SIZE * DEV_BSIZE) {
                sr_error(sc, "boot loader too large (%d > %d)",
                    bb->bb_bootldr_size, SR_BOOT_LOADER_SIZE * DEV_BSIZE);
                goto done;
        }

        secsize = sd->sd_meta->ssdi.ssd_secsize;

        /* Copy in boot block. */
        bbs = howmany(bb->bb_bootblk_size, secsize) * secsize;
        bootblk = malloc(bbs, M_DEVBUF, M_WAITOK | M_ZERO);
        if (copyin(bb->bb_bootblk, bootblk, bb->bb_bootblk_size) != 0)
                goto done;

        /* Copy in boot loader. */
        bls = howmany(bb->bb_bootldr_size, secsize) * secsize;
        bootldr = malloc(bls, M_DEVBUF, M_WAITOK | M_ZERO);
        if (copyin(bb->bb_bootldr, bootldr, bb->bb_bootldr_size) != 0)
                goto done;

        /* Create or update optional meta for bootable volumes. */
        SLIST_FOREACH(omi, &sd->sd_meta_opt, omi_link)
                if (omi->omi_som->som_type == SR_OPT_BOOT)
                        break;
        if (omi == NULL) {
                omi = malloc(sizeof(struct sr_meta_opt_item), M_DEVBUF,
                    M_WAITOK | M_ZERO);
                omi->omi_som = malloc(sizeof(struct sr_meta_boot), M_DEVBUF,
                    M_WAITOK | M_ZERO);
                omi->omi_som->som_type = SR_OPT_BOOT;
                omi->omi_som->som_length = sizeof(struct sr_meta_boot);
                SLIST_INSERT_HEAD(&sd->sd_meta_opt, omi, omi_link);
                sd->sd_meta->ssdi.ssd_opt_no++;
        }
        sbm = (struct sr_meta_boot *)omi->omi_som;

        memcpy(sbm->sbm_root_duid, duid, sizeof(sbm->sbm_root_duid));
        bzero(&sbm->sbm_boot_duid, sizeof(sbm->sbm_boot_duid));
        sbm->sbm_bootblk_size = bbs;
        sbm->sbm_bootldr_size = bls;

        DNPRINTF(SR_D_IOCTL, "sr_ioctl_installboot: root duid is %s\n",
            duid_format(sbm->sbm_root_duid));

        /* Save boot block and boot loader to each chunk. */
        for (i = 0; i < sd->sd_meta->ssdi.ssd_chunk_no; i++) {

                chunk = sd->sd_vol.sv_chunks[i];
                if (chunk->src_meta.scm_status != BIOC_SDONLINE &&
                    chunk->src_meta.scm_status != BIOC_SDREBUILD)
                        continue;

                if (i < SR_MAX_BOOT_DISKS)
                        memcpy(&sbm->sbm_boot_duid[i], chunk->src_duid,
                            sizeof(sbm->sbm_boot_duid[i]));

                /* Save boot blocks. */
                DNPRINTF(SR_D_IOCTL,
                    "sr_ioctl_installboot: saving boot block to %s "
                    "(%u bytes)\n", chunk->src_devname, bbs);

                if (sr_rw(sc, chunk->src_dev_mm, bootblk, bbs,
                    SR_BOOT_BLOCKS_OFFSET, B_WRITE)) {
                        sr_error(sc, "failed to write boot block");
                        goto done;
                }

                /* Save boot loader.*/
                DNPRINTF(SR_D_IOCTL,
                    "sr_ioctl_installboot: saving boot loader to %s "
                    "(%u bytes)\n", chunk->src_devname, bls);

                if (sr_rw(sc, chunk->src_dev_mm, bootldr, bls,
                    SR_BOOT_LOADER_OFFSET, B_WRITE)) {
                        sr_error(sc, "failed to write boot loader");
                        goto done;
                }
        }

        /* XXX - Install boot block on disk - MD code. */

        /* Mark volume as bootable and save metadata. */
        sd->sd_meta->ssdi.ssd_vol_flags |= BIOC_SCBOOTABLE;
        if (sr_meta_save(sd, SR_META_DIRTY)) {
                sr_error(sc, "could not save metadata to %s", DEVNAME(sc));
                goto done;
        }

        rv = 0;

done:
        free(bootblk, M_DEVBUF, bbs);
        free(bootldr, M_DEVBUF, bls);

        return (rv);
}

void
sr_chunks_unwind(struct sr_softc *sc, struct sr_chunk_head *cl)
{
        struct sr_chunk         *ch_entry, *ch_next;

        DNPRINTF(SR_D_IOCTL, "%s: sr_chunks_unwind\n", DEVNAME(sc));

        if (!cl)
                return;

        for (ch_entry = SLIST_FIRST(cl); ch_entry != NULL; ch_entry = ch_next) {
                ch_next = SLIST_NEXT(ch_entry, src_link);

                DNPRINTF(SR_D_IOCTL, "%s: sr_chunks_unwind closing: %s\n",
                    DEVNAME(sc), ch_entry->src_devname);
                if (ch_entry->src_vn) {
                        /*
                         * XXX - explicitly lock the vnode until we can resolve
                         * the problem introduced by vnode aliasing... specfs
                         * has no locking, whereas ufs/ffs does!
                         */
                        vn_lock(ch_entry->src_vn, LK_EXCLUSIVE | LK_RETRY);
                        VOP_CLOSE(ch_entry->src_vn, FREAD | FWRITE, NOCRED,
                            curproc);
                        vput(ch_entry->src_vn);
                }
                free(ch_entry, M_DEVBUF, sizeof(*ch_entry));
        }
        SLIST_INIT(cl);
}

void
sr_discipline_free(struct sr_discipline *sd)
{
        struct sr_softc         *sc;
        struct sr_discipline    *sdtmp1;
        struct sr_meta_opt_head *som;
        struct sr_meta_opt_item *omi, *omi_next;

        if (!sd)
                return;

        sc = sd->sd_sc;

        DNPRINTF(SR_D_DIS, "%s: sr_discipline_free %s\n",
            DEVNAME(sc),
            sd->sd_meta ? sd->sd_meta->ssd_devname : "nodev");
        if (sd->sd_free_resources)
                sd->sd_free_resources(sd);
        free(sd->sd_vol.sv_chunks, M_DEVBUF, 0);
        free(sd->sd_meta, M_DEVBUF, SR_META_SIZE * DEV_BSIZE);
        free(sd->sd_meta_foreign, M_DEVBUF, smd[sd->sd_meta_type].smd_size);

        som = &sd->sd_meta_opt;
        for (omi = SLIST_FIRST(som); omi != NULL; omi = omi_next) {
                omi_next = SLIST_NEXT(omi, omi_link);
                free(omi->omi_som, M_DEVBUF, 0);
                free(omi, M_DEVBUF, sizeof(*omi));
        }

        if (sd->sd_target != 0) {
                KASSERT(sc->sc_targets[sd->sd_target] == sd);
                sc->sc_targets[sd->sd_target] = NULL;
        }

        TAILQ_FOREACH(sdtmp1, &sc->sc_dis_list, sd_link) {
                if (sdtmp1 == sd)
                        break;
        }
        if (sdtmp1 != NULL)
                TAILQ_REMOVE(&sc->sc_dis_list, sd, sd_link);

        explicit_bzero(sd, sizeof *sd);
        free(sd, M_DEVBUF, sizeof(*sd));
}

void
sr_discipline_shutdown(struct sr_discipline *sd, int meta_save, int dying)
{
        struct sr_softc         *sc;
        int                     ret, s;

        if (!sd)
                return;
        sc = sd->sd_sc;

        DNPRINTF(SR_D_DIS, "%s: sr_discipline_shutdown %s\n", DEVNAME(sc),
            sd->sd_meta ? sd->sd_meta->ssd_devname : "nodev");

        /* If rebuilding, abort rebuild and drain I/O. */
        if (sd->sd_reb_active) {
                sd->sd_reb_abort = 1;
                while (sd->sd_reb_active)
                        tsleep_nsec(sd, PWAIT, "sr_shutdown", MSEC_TO_NSEC(1));
        }

        if (meta_save)
                sr_meta_save(sd, 0);

        s = splbio();

        sd->sd_ready = 0;

        /* make sure there isn't a sync pending and yield */
        wakeup(sd);
        while (sd->sd_sync || sd->sd_must_flush) {
                ret = tsleep_nsec(&sd->sd_sync, MAXPRI, "sr_down",
                    SEC_TO_NSEC(60));
                if (ret == EWOULDBLOCK)
                        break;
        }
        if (dying == -1) {
                sd->sd_ready = 1;
                splx(s);
                return;
        }

#ifndef SMALL_KERNEL
        sr_sensors_delete(sd);
#endif /* SMALL_KERNEL */

        if (sd->sd_target != 0)
                scsi_detach_lun(sc->sc_scsibus, sd->sd_target, 0,
                    dying ? 0 : DETACH_FORCE);

        sr_chunks_unwind(sc, &sd->sd_vol.sv_chunk_list);

        if (sd->sd_taskq)
                taskq_destroy(sd->sd_taskq);

        sr_discipline_free(sd);

        splx(s);
}

int
sr_discipline_init(struct sr_discipline *sd, int level)
{
        int                     rv = 1;

        /* Initialise discipline function pointers with defaults. */
        sd->sd_alloc_resources = sr_alloc_resources;
        sd->sd_assemble = NULL;
        sd->sd_create = NULL;
        sd->sd_free_resources = sr_free_resources;
        sd->sd_ioctl_handler = NULL;
        sd->sd_openings = NULL;
        sd->sd_meta_opt_handler = NULL;
        sd->sd_rebuild = sr_rebuild;
        sd->sd_scsi_inquiry = sr_raid_inquiry;
        sd->sd_scsi_read_cap = sr_raid_read_cap;
        sd->sd_scsi_tur = sr_raid_tur;
        sd->sd_scsi_req_sense = sr_raid_request_sense;
        sd->sd_scsi_start_stop = sr_raid_start_stop;
        sd->sd_scsi_sync = sr_raid_sync;
        sd->sd_scsi_rw = NULL;
        sd->sd_scsi_intr = sr_raid_intr;
        sd->sd_scsi_wu_done = NULL;
        sd->sd_scsi_done = NULL;
        sd->sd_set_chunk_state = sr_set_chunk_state;
        sd->sd_set_vol_state = sr_set_vol_state;
        sd->sd_start_discipline = NULL;

        task_set(&sd->sd_meta_save_task, sr_meta_save_callback, sd);
        task_set(&sd->sd_hotspare_rebuild_task, sr_hotspare_rebuild_callback,
            sd);

        sd->sd_wu_size = sizeof(struct sr_workunit);
        switch (level) {
        case 0:
                sr_raid0_discipline_init(sd);
                break;
        case 1:
                sr_raid1_discipline_init(sd);
                break;
        case 5:
                sr_raid5_discipline_init(sd);
                break;
        case 6:
                sr_raid6_discipline_init(sd);
                break;
#ifdef CRYPTO
        case 'C':
                sr_crypto_discipline_init(sd);
                break;
        case 0x1C:
                sr_raid1c_discipline_init(sd);
                break;
#endif
        case 'c':
                sr_concat_discipline_init(sd);
                break;
        default:
                goto bad;
        }

        rv = 0;
bad:
        return (rv);
}

int
sr_raid_inquiry(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct scsi_xfer        *xs = wu->swu_xs;
        struct scsi_inquiry     *cdb = (struct scsi_inquiry *)&xs->cmd;
        struct scsi_inquiry_data inq;

        DNPRINTF(SR_D_DIS, "%s: sr_raid_inquiry\n", DEVNAME(sd->sd_sc));

        if (xs->cmdlen != sizeof(*cdb))
                return (EINVAL);

        if (ISSET(cdb->flags, SI_EVPD))
                return (EOPNOTSUPP);

        bzero(&inq, sizeof(inq));
        inq.device = T_DIRECT;
        inq.dev_qual2 = 0;
        inq.version = SCSI_REV_2;
        inq.response_format = SID_SCSI2_RESPONSE;
        inq.additional_length = SID_SCSI2_ALEN;
        inq.flags |= SID_CmdQue;
        strlcpy(inq.vendor, sd->sd_meta->ssdi.ssd_vendor,
            sizeof(inq.vendor));
        strlcpy(inq.product, sd->sd_meta->ssdi.ssd_product,
            sizeof(inq.product));
        strlcpy(inq.revision, sd->sd_meta->ssdi.ssd_revision,
            sizeof(inq.revision));
        scsi_copy_internal_data(xs, &inq, sizeof(inq));

        return (0);
}

int
sr_raid_read_cap(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct scsi_xfer        *xs = wu->swu_xs;
        struct scsi_read_cap_data rcd;
        struct scsi_read_cap_data_16 rcd16;
        u_int64_t               addr;
        int                     rv = 1;
        u_int32_t               secsize;

        DNPRINTF(SR_D_DIS, "%s: sr_raid_read_cap\n", DEVNAME(sd->sd_sc));

        secsize = sd->sd_meta->ssdi.ssd_secsize;

        addr = ((sd->sd_meta->ssdi.ssd_size * DEV_BSIZE) / secsize) - 1;
        if (xs->cmd.opcode == READ_CAPACITY) {
                bzero(&rcd, sizeof(rcd));
                if (addr > 0xffffffffllu)
                        _lto4b(0xffffffff, rcd.addr);
                else
                        _lto4b(addr, rcd.addr);
                _lto4b(secsize, rcd.length);
                scsi_copy_internal_data(xs, &rcd, sizeof(rcd));
                rv = 0;
        } else if (xs->cmd.opcode == READ_CAPACITY_16) {
                bzero(&rcd16, sizeof(rcd16));
                _lto8b(addr, rcd16.addr);
                _lto4b(secsize, rcd16.length);
                scsi_copy_internal_data(xs, &rcd16, sizeof(rcd16));
                rv = 0;
        }

        return (rv);
}

int
sr_raid_tur(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;

        DNPRINTF(SR_D_DIS, "%s: sr_raid_tur\n", DEVNAME(sd->sd_sc));

        if (sd->sd_vol_status == BIOC_SVOFFLINE) {
                sd->sd_scsi_sense.error_code = SSD_ERRCODE_CURRENT;
                sd->sd_scsi_sense.flags = SKEY_NOT_READY;
                sd->sd_scsi_sense.add_sense_code = 0x04;
                sd->sd_scsi_sense.add_sense_code_qual = 0x11;
                sd->sd_scsi_sense.extra_len = 4;
                return (1);
        } else if (sd->sd_vol_status == BIOC_SVINVALID) {
                sd->sd_scsi_sense.error_code = SSD_ERRCODE_CURRENT;
                sd->sd_scsi_sense.flags = SKEY_HARDWARE_ERROR;
                sd->sd_scsi_sense.add_sense_code = 0x05;
                sd->sd_scsi_sense.add_sense_code_qual = 0x00;
                sd->sd_scsi_sense.extra_len = 4;
                return (1);
        }

        return (0);
}

int
sr_raid_request_sense(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct scsi_xfer        *xs = wu->swu_xs;

        DNPRINTF(SR_D_DIS, "%s: sr_raid_request_sense\n",
            DEVNAME(sd->sd_sc));

        /* use latest sense data */
        memcpy(&xs->sense, &sd->sd_scsi_sense, sizeof(xs->sense));

        /* clear sense data */
        bzero(&sd->sd_scsi_sense, sizeof(sd->sd_scsi_sense));

        return (0);
}

int
sr_raid_start_stop(struct sr_workunit *wu)
{
        struct scsi_xfer        *xs = wu->swu_xs;
        struct scsi_start_stop  *ss = (struct scsi_start_stop *)&xs->cmd;

        DNPRINTF(SR_D_DIS, "%s: sr_raid_start_stop\n",
            DEVNAME(wu->swu_dis->sd_sc));

        if (!ss)
                return (1);

        /*
         * do nothing!
         * a softraid discipline should always reflect correct status
         */
        return (0);
}

int
sr_raid_sync(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        int                     s, ret, rv = 0, ios;

        DNPRINTF(SR_D_DIS, "%s: sr_raid_sync\n", DEVNAME(sd->sd_sc));

        /* when doing a fake sync don't count the wu */
        ios = (wu->swu_flags & SR_WUF_FAKE) ? 0 : 1;

        s = splbio();
        sd->sd_sync = 1;
        while (sd->sd_wu_pending > ios) {
                ret = tsleep_nsec(sd, PRIBIO, "sr_sync", SEC_TO_NSEC(15));
                if (ret == EWOULDBLOCK) {
                        DNPRINTF(SR_D_DIS, "%s: sr_raid_sync timeout\n",
                            DEVNAME(sd->sd_sc));
                        rv = 1;
                        break;
                }
        }
        sd->sd_sync = 0;
        splx(s);

        wakeup(&sd->sd_sync);

        return (rv);
}

void
sr_raid_intr(struct buf *bp)
{
        struct sr_ccb           *ccb = (struct sr_ccb *)bp;
        struct sr_workunit      *wu = ccb->ccb_wu;
#ifdef SR_DEBUG
        struct sr_discipline    *sd = wu->swu_dis;
        struct scsi_xfer        *xs = wu->swu_xs;
#endif
        int                     s;

        DNPRINTF(SR_D_INTR, "%s: %s %s intr bp %p xs %p\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname, sd->sd_name, bp, xs);

        s = splbio();
        sr_ccb_done(ccb);
        sr_wu_done(wu);
        splx(s);
}

void
sr_schedule_wu(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct sr_workunit      *wup;
        int                     s;

        DNPRINTF(SR_D_WU, "sr_schedule_wu: schedule wu %p state %i "
            "flags 0x%x\n", wu, wu->swu_state, wu->swu_flags);

        KASSERT(wu->swu_io_count > 0);

        s = splbio();

        /* Construct the work unit, do not schedule it. */
        if (wu->swu_state == SR_WU_CONSTRUCT)
                goto queued;

        /* Deferred work unit being reconstructed, do not start. */
        if (wu->swu_state == SR_WU_REQUEUE)
                goto queued;

        /* Current work unit failed, restart. */
        if (wu->swu_state == SR_WU_RESTART)
                goto start;

        if (wu->swu_state != SR_WU_INPROGRESS)
                panic("sr_schedule_wu: work unit not in progress (state %i)",
                    wu->swu_state);

        /* Walk queue backwards and fill in collider if we have one. */
        TAILQ_FOREACH_REVERSE(wup, &sd->sd_wu_pendq, sr_wu_list, swu_link) {
                if (wu->swu_blk_end < wup->swu_blk_start ||
                    wup->swu_blk_end < wu->swu_blk_start)
                        continue;

                /* Defer work unit due to LBA collision. */
                DNPRINTF(SR_D_WU, "sr_schedule_wu: deferring work unit %p\n",
                    wu);
                wu->swu_state = SR_WU_DEFERRED;
                while (wup->swu_collider)
                        wup = wup->swu_collider;
                wup->swu_collider = wu;
                TAILQ_INSERT_TAIL(&sd->sd_wu_defq, wu, swu_link);
                sd->sd_wu_collisions++;
                goto queued;
        }

start:
        sr_raid_startwu(wu);

queued:
        splx(s);
}

void
sr_raid_startwu(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct sr_ccb           *ccb;

        DNPRINTF(SR_D_WU, "sr_raid_startwu: start wu %p\n", wu);

        splassert(IPL_BIO);

        if (wu->swu_state == SR_WU_DEFERRED) {
                TAILQ_REMOVE(&sd->sd_wu_defq, wu, swu_link);
                wu->swu_state = SR_WU_INPROGRESS;
        }

        if (wu->swu_state != SR_WU_RESTART)
                TAILQ_INSERT_TAIL(&sd->sd_wu_pendq, wu, swu_link);

        /* Start all of the individual I/Os. */
        if (wu->swu_cb_active == 1)
                panic("%s: sr_startwu_callback", DEVNAME(sd->sd_sc));
        wu->swu_cb_active = 1;

        TAILQ_FOREACH(ccb, &wu->swu_ccb, ccb_link)
                VOP_STRATEGY(ccb->ccb_buf.b_vp, &ccb->ccb_buf);

        wu->swu_cb_active = 0;
}

void
sr_raid_recreate_wu(struct sr_workunit *wu)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct sr_workunit      *wup = wu;

        /*
         * Recreate a work unit by releasing the associated CCBs and reissuing
         * the SCSI I/O request. This process is then repeated for all of the
         * colliding work units.
         */
        do {
                sr_wu_release_ccbs(wup);

                wup->swu_state = SR_WU_REQUEUE;
                if (sd->sd_scsi_rw(wup))
                        panic("could not requeue I/O");

                wup = wup->swu_collider;
        } while (wup);
}

int
sr_alloc_resources(struct sr_discipline *sd)
{
        if (sr_wu_alloc(sd)) {
                sr_error(sd->sd_sc, "unable to allocate work units");
                return (ENOMEM);
        }
        if (sr_ccb_alloc(sd)) {
                sr_error(sd->sd_sc, "unable to allocate ccbs");
                return (ENOMEM);
        }

        return (0);
}

void
sr_free_resources(struct sr_discipline *sd)
{
        sr_wu_free(sd);
        sr_ccb_free(sd);
}

void
sr_set_chunk_state(struct sr_discipline *sd, int c, int new_state)
{
        int                     old_state, s;

        DNPRINTF(SR_D_STATE, "%s: %s: %s: sr_set_chunk_state %d -> %d\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname,
            sd->sd_vol.sv_chunks[c]->src_meta.scmi.scm_devname, c, new_state);

        /* ok to go to splbio since this only happens in error path */
        s = splbio();
        old_state = sd->sd_vol.sv_chunks[c]->src_meta.scm_status;

        /* multiple IOs to the same chunk that fail will come through here */
        if (old_state == new_state)
                goto done;

        switch (old_state) {
        case BIOC_SDONLINE:
                if (new_state == BIOC_SDOFFLINE)
                        break;
                else
                        goto die;
                break;

        case BIOC_SDOFFLINE:
                goto die;

        default:
die:
                splx(s); /* XXX */
                panic("%s: %s: %s: invalid chunk state transition %d -> %d",
                    DEVNAME(sd->sd_sc),
                    sd->sd_meta->ssd_devname,
                    sd->sd_vol.sv_chunks[c]->src_meta.scmi.scm_devname,
                    old_state, new_state);
                /* NOTREACHED */
        }

        sd->sd_vol.sv_chunks[c]->src_meta.scm_status = new_state;
        sd->sd_set_vol_state(sd);

        sd->sd_must_flush = 1;
        task_add(systq, &sd->sd_meta_save_task);
done:
        splx(s);
}

void
sr_set_vol_state(struct sr_discipline *sd)
{
        int                     states[SR_MAX_STATES];
        int                     new_state, i, nd;
        int                     old_state = sd->sd_vol_status;
        u_int32_t               s;

        DNPRINTF(SR_D_STATE, "%s: %s: sr_set_vol_state\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname);

        nd = sd->sd_meta->ssdi.ssd_chunk_no;

        for (i = 0; i < SR_MAX_STATES; i++)
                states[i] = 0;

        for (i = 0; i < nd; i++) {
                s = sd->sd_vol.sv_chunks[i]->src_meta.scm_status;
                if (s >= SR_MAX_STATES)
                        panic("%s: %s: %s: invalid chunk state",
                            DEVNAME(sd->sd_sc),
                            sd->sd_meta->ssd_devname,
                            sd->sd_vol.sv_chunks[i]->src_meta.scmi.scm_devname);
                states[s]++;
        }

        if (states[BIOC_SDONLINE] == nd)
                new_state = BIOC_SVONLINE;
        else
                new_state = BIOC_SVOFFLINE;

        DNPRINTF(SR_D_STATE, "%s: %s: sr_set_vol_state %d -> %d\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname,
            old_state, new_state);

        switch (old_state) {
        case BIOC_SVONLINE:
                if (new_state == BIOC_SVOFFLINE || new_state == BIOC_SVONLINE)
                        break;
                else
                        goto die;
                break;

        case BIOC_SVOFFLINE:
                /* XXX this might be a little too much */
                goto die;

        default:
die:
                panic("%s: %s: invalid volume state transition %d -> %d",
                    DEVNAME(sd->sd_sc),
                    sd->sd_meta->ssd_devname,
                    old_state, new_state);
                /* NOTREACHED */
        }

        sd->sd_vol_status = new_state;
}

void *
sr_block_get(struct sr_discipline *sd, long length)
{
        return dma_alloc(length, PR_NOWAIT | PR_ZERO);
}

void
sr_block_put(struct sr_discipline *sd, void *ptr, int length)
{
        dma_free(ptr, length);
}

void
sr_checksum_print(u_int8_t *md5)
{
        int                     i;

        for (i = 0; i < MD5_DIGEST_LENGTH; i++)
                printf("%02x", md5[i]);
}

void
sr_checksum(struct sr_softc *sc, void *src, void *md5, u_int32_t len)
{
        MD5_CTX                 ctx;

        DNPRINTF(SR_D_MISC, "%s: sr_checksum(%p %p %d)\n", DEVNAME(sc), src,
            md5, len);

        MD5Init(&ctx);
        MD5Update(&ctx, src, len);
        MD5Final(md5, &ctx);
}

void
sr_uuid_generate(struct sr_uuid *uuid)
{
        arc4random_buf(uuid->sui_id, sizeof(uuid->sui_id));
        /* UUID version 4: random */
        uuid->sui_id[6] &= 0x0f;
        uuid->sui_id[6] |= 0x40;
        /* RFC4122 variant */
        uuid->sui_id[8] &= 0x3f;
        uuid->sui_id[8] |= 0x80;
}

char *
sr_uuid_format(struct sr_uuid *uuid)
{
        char *uuidstr;

        uuidstr = malloc(37, M_DEVBUF, M_WAITOK);

        snprintf(uuidstr, 37,
            "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-"
            "%02x%02x%02x%02x%02x%02x",
            uuid->sui_id[0], uuid->sui_id[1],
            uuid->sui_id[2], uuid->sui_id[3],
            uuid->sui_id[4], uuid->sui_id[5],
            uuid->sui_id[6], uuid->sui_id[7],
            uuid->sui_id[8], uuid->sui_id[9],
            uuid->sui_id[10], uuid->sui_id[11],
            uuid->sui_id[12], uuid->sui_id[13],
            uuid->sui_id[14], uuid->sui_id[15]);

        return uuidstr;
}

void
sr_uuid_print(struct sr_uuid *uuid, int cr)
{
        char *uuidstr;

        uuidstr = sr_uuid_format(uuid);
        printf("%s%s", uuidstr, (cr ? "\n" : ""));
        free(uuidstr, M_DEVBUF, 37);
}

int
sr_already_assembled(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        struct sr_discipline    *sdtmp;

        TAILQ_FOREACH(sdtmp, &sc->sc_dis_list, sd_link) {
                if (!bcmp(&sd->sd_meta->ssdi.ssd_uuid,
                    &sdtmp->sd_meta->ssdi.ssd_uuid,
                    sizeof(sd->sd_meta->ssdi.ssd_uuid)))
                        return (1);
        }

        return (0);
}

int32_t
sr_validate_stripsize(u_int32_t b)
{
        int                     s = 0;

        if (b % DEV_BSIZE)
                return (-1);

        while ((b & 1) == 0) {
                b >>= 1;
                s++;
        }

        /* only multiple of twos */
        b >>= 1;
        if (b)
                return(-1);

        return (s);
}

void
sr_quiesce(void)
{
        struct sr_softc         *sc = softraid0;
        struct sr_discipline    *sd, *nsd;

        if (sc == NULL)
                return;

        /* Shutdown disciplines in reverse attach order. */
        TAILQ_FOREACH_REVERSE_SAFE(sd, &sc->sc_dis_list,
            sr_discipline_list, sd_link, nsd)
                sr_discipline_shutdown(sd, 1, -1);
}

void
sr_shutdown(int dying)
{
        struct sr_softc         *sc = softraid0;
        struct sr_discipline    *sd;

        if (sc == NULL)
                return;

        DNPRINTF(SR_D_MISC, "%s: sr_shutdown\n", DEVNAME(sc));

        /*
         * Since softraid is not under mainbus, we have to explicitly
         * notify its children that the power is going down, so they
         * can execute their shutdown hooks.
         */
        config_suspend((struct device *)sc, DVACT_POWERDOWN);

        /* Shutdown disciplines in reverse attach order. */
        while ((sd = TAILQ_LAST(&sc->sc_dis_list, sr_discipline_list)) != NULL)
                sr_discipline_shutdown(sd, 1, dying);
}

int
sr_validate_io(struct sr_workunit *wu, daddr_t *blkno, char *func)
{
        struct sr_discipline    *sd = wu->swu_dis;
        struct scsi_xfer        *xs = wu->swu_xs;
        int                     rv = 1;

        DNPRINTF(SR_D_DIS, "%s: %s 0x%02x\n", DEVNAME(sd->sd_sc), func,
            xs->cmd.opcode);

        if (sd->sd_meta->ssd_data_blkno == 0)
                panic("invalid data blkno");

        if (sd->sd_vol_status == BIOC_SVOFFLINE) {
                DNPRINTF(SR_D_DIS, "%s: %s device offline\n",
                    DEVNAME(sd->sd_sc), func);
                goto bad;
        }

        if (xs->datalen == 0) {
                printf("%s: %s: illegal block count for %s\n",
                    DEVNAME(sd->sd_sc), func, sd->sd_meta->ssd_devname);
                goto bad;
        }

        if (xs->cmdlen == 10)
                *blkno = _4btol(((struct scsi_rw_10 *)&xs->cmd)->addr);
        else if (xs->cmdlen == 16)
                *blkno = _8btol(((struct scsi_rw_16 *)&xs->cmd)->addr);
        else if (xs->cmdlen == 6)
                *blkno = _3btol(((struct scsi_rw *)&xs->cmd)->addr);
        else {
                printf("%s: %s: illegal cmdlen for %s\n",
                    DEVNAME(sd->sd_sc), func, sd->sd_meta->ssd_devname);
                goto bad;
        }

        *blkno *= (sd->sd_meta->ssdi.ssd_secsize / DEV_BSIZE);

        wu->swu_blk_start = *blkno;
        wu->swu_blk_end = *blkno + (xs->datalen >> DEV_BSHIFT) - 1;

        if (wu->swu_blk_end > sd->sd_meta->ssdi.ssd_size) {
                DNPRINTF(SR_D_DIS, "%s: %s out of bounds start: %lld "
                    "end: %lld length: %d\n",
                    DEVNAME(sd->sd_sc), func, (long long)wu->swu_blk_start,
                    (long long)wu->swu_blk_end, xs->datalen);

                sd->sd_scsi_sense.error_code = SSD_ERRCODE_CURRENT |
                    SSD_ERRCODE_VALID;
                sd->sd_scsi_sense.flags = SKEY_ILLEGAL_REQUEST;
                sd->sd_scsi_sense.add_sense_code = 0x21;
                sd->sd_scsi_sense.add_sense_code_qual = 0x00;
                sd->sd_scsi_sense.extra_len = 4;
                goto bad;
        }

        rv = 0;
bad:
        return (rv);
}

void
sr_rebuild_start(void *arg)
{
        struct sr_discipline    *sd = arg;
        struct sr_softc         *sc = sd->sd_sc;

        DNPRINTF(SR_D_REBUILD, "%s: %s starting rebuild thread\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname);

        if (kthread_create(sr_rebuild_thread, sd, &sd->sd_background_proc,
            DEVNAME(sc)) != 0)
                printf("%s: unable to start background operation\n",
                    DEVNAME(sc));
}

void
sr_rebuild_thread(void *arg)
{
        struct sr_discipline    *sd = arg;

        DNPRINTF(SR_D_REBUILD, "%s: %s rebuild thread started\n",
            DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname);

        sd->sd_reb_active = 1;
        sd->sd_rebuild(sd);
        sd->sd_reb_active = 0;

        kthread_exit(0);
}

void
sr_rebuild(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        u_int64_t               sz, whole_blk, partial_blk, blk, restart;
        daddr_t                 lba;
        struct sr_workunit      *wu_r, *wu_w;
        struct scsi_xfer        xs_r, xs_w;
        struct scsi_rw_16       *cr, *cw;
        int                     c, s, slept, percent = 0, old_percent = -1;
        u_int8_t                *buf;

        whole_blk = sd->sd_meta->ssdi.ssd_size / SR_REBUILD_IO_SIZE;
        partial_blk = sd->sd_meta->ssdi.ssd_size % SR_REBUILD_IO_SIZE;

        restart = sd->sd_meta->ssd_rebuild / SR_REBUILD_IO_SIZE;
        if (restart > whole_blk) {
                printf("%s: bogus rebuild restart offset, starting from 0\n",
                    DEVNAME(sc));
                restart = 0;
        }
        if (restart) {
                /*
                 * XXX there is a hole here; there is a possibility that we
                 * had a restart however the chunk that was supposed to
                 * be rebuilt is no longer valid; we can reach this situation
                 * when a rebuild is in progress and the box crashes and
                 * on reboot the rebuild chunk is different (like zero'd or
                 * replaced).  We need to check the uuid of the chunk that is
                 * being rebuilt to assert this.
                 */
                percent = sr_rebuild_percent(sd);
                printf("%s: resuming rebuild on %s at %d%%\n",
                    DEVNAME(sc), sd->sd_meta->ssd_devname, percent);
        }

        /* currently this is 64k therefore we can use dma_alloc */
        buf = dma_alloc(SR_REBUILD_IO_SIZE << DEV_BSHIFT, PR_WAITOK);
        for (blk = restart; blk <= whole_blk; blk++) {
                lba = blk * SR_REBUILD_IO_SIZE;
                sz = SR_REBUILD_IO_SIZE;
                if (blk == whole_blk) {
                        if (partial_blk == 0)
                                break;
                        sz = partial_blk;
                }

                /* get some wu */
                wu_r = sr_scsi_wu_get(sd, 0);
                wu_w = sr_scsi_wu_get(sd, 0);

                DNPRINTF(SR_D_REBUILD, "%s: %s rebuild wu_r %p, wu_w %p\n",
                    DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname, wu_r, wu_w);

                /* setup read io */
                bzero(&xs_r, sizeof xs_r);
                xs_r.error = XS_NOERROR;
                xs_r.flags = SCSI_DATA_IN;
                xs_r.datalen = sz << DEV_BSHIFT;
                xs_r.data = buf;
                xs_r.cmdlen = sizeof(*cr);
                cr = (struct scsi_rw_16 *)&xs_r.cmd;
                cr->opcode = READ_16;
                _lto4b(sz, cr->length);
                _lto8b(lba, cr->addr);
                wu_r->swu_state = SR_WU_CONSTRUCT;
                wu_r->swu_flags |= SR_WUF_REBUILD;
                wu_r->swu_xs = &xs_r;
                if (sd->sd_scsi_rw(wu_r)) {
                        printf("%s: could not create read io\n",
                            DEVNAME(sc));
                        goto fail;
                }

                /* setup write io */
                bzero(&xs_w, sizeof xs_w);
                xs_w.error = XS_NOERROR;
                xs_w.flags = SCSI_DATA_OUT;
                xs_w.datalen = sz << DEV_BSHIFT;
                xs_w.data = buf;
                xs_w.cmdlen = sizeof(*cw);
                cw = (struct scsi_rw_16 *)&xs_w.cmd;
                cw->opcode = WRITE_16;
                _lto4b(sz, cw->length);
                _lto8b(lba, cw->addr);
                wu_w->swu_state = SR_WU_CONSTRUCT;
                wu_w->swu_flags |= SR_WUF_REBUILD | SR_WUF_WAKEUP;
                wu_w->swu_xs = &xs_w;
                if (sd->sd_scsi_rw(wu_w)) {
                        printf("%s: could not create write io\n",
                            DEVNAME(sc));
                        goto fail;
                }

                /*
                 * collide with the read io so that we get automatically
                 * started when the read is done
                 */
                wu_w->swu_state = SR_WU_DEFERRED;
                wu_r->swu_collider = wu_w;
                s = splbio();
                TAILQ_INSERT_TAIL(&sd->sd_wu_defq, wu_w, swu_link);
                splx(s);

                DNPRINTF(SR_D_REBUILD, "%s: %s rebuild scheduling wu_r %p\n",
                    DEVNAME(sd->sd_sc), sd->sd_meta->ssd_devname, wu_r);

                wu_r->swu_state = SR_WU_INPROGRESS;
                sr_schedule_wu(wu_r);

                /* wait for write completion */
                slept = 0;
                while ((wu_w->swu_flags & SR_WUF_REBUILDIOCOMP) == 0) {
                        tsleep_nsec(wu_w, PRIBIO, "sr_rebuild", INFSLP);
                        slept = 1;
                }
                /* yield if we didn't sleep */
                if (slept == 0)
                        tsleep_nsec(sc, PWAIT, "sr_yield", MSEC_TO_NSEC(1));

                sr_scsi_wu_put(sd, wu_r);
                sr_scsi_wu_put(sd, wu_w);

                sd->sd_meta->ssd_rebuild = lba;

                /* XXX - this should be based on size, not percentage. */
                /* save metadata every percent */
                percent = sr_rebuild_percent(sd);
                if (percent != old_percent && blk != whole_blk) {
                        if (sr_meta_save(sd, SR_META_DIRTY))
                                printf("%s: could not save metadata to %s\n",
                                    DEVNAME(sc), sd->sd_meta->ssd_devname);
                        old_percent = percent;
                }

                if (sd->sd_reb_abort)
                        goto abort;
        }

        /* all done */
        sd->sd_meta->ssd_rebuild = 0;
        for (c = 0; c < sd->sd_meta->ssdi.ssd_chunk_no; c++) {
                if (sd->sd_vol.sv_chunks[c]->src_meta.scm_status ==
                    BIOC_SDREBUILD) {
                        sd->sd_set_chunk_state(sd, c, BIOC_SDONLINE);
                        break;
                }
        }

abort:
        if (sr_meta_save(sd, SR_META_DIRTY))
                printf("%s: could not save metadata to %s\n",
                    DEVNAME(sc), sd->sd_meta->ssd_devname);
fail:
        dma_free(buf, SR_REBUILD_IO_SIZE << DEV_BSHIFT);
}

struct sr_discipline *
sr_find_discipline(struct sr_softc *sc, const char *devname)
{
        struct sr_discipline    *sd;

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link)
                if (!strncmp(sd->sd_meta->ssd_devname, devname,
                    sizeof(sd->sd_meta->ssd_devname)))
                        break;
        return sd;
}

#ifndef SMALL_KERNEL
int
sr_sensors_create(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;
        int                     rv = 1;

        DNPRINTF(SR_D_STATE, "%s: %s: sr_sensors_create\n",
            DEVNAME(sc), sd->sd_meta->ssd_devname);

        sd->sd_vol.sv_sensor.type = SENSOR_DRIVE;
        sd->sd_vol.sv_sensor.status = SENSOR_S_UNKNOWN;
        strlcpy(sd->sd_vol.sv_sensor.desc, sd->sd_meta->ssd_devname,
            sizeof(sd->sd_vol.sv_sensor.desc));

        sensor_attach(&sc->sc_sensordev, &sd->sd_vol.sv_sensor);
        sd->sd_vol.sv_sensor_attached = 1;

        if (sc->sc_sensor_task == NULL) {
                sc->sc_sensor_task = sensor_task_register(sc,
                    sr_sensors_refresh, 10);
                if (sc->sc_sensor_task == NULL)
                        goto bad;
        }

        rv = 0;
bad:
        return (rv);
}

void
sr_sensors_delete(struct sr_discipline *sd)
{
        struct sr_softc         *sc = sd->sd_sc;

        DNPRINTF(SR_D_STATE, "%s: sr_sensors_delete\n", DEVNAME(sd->sd_sc));

        if (sd->sd_vol.sv_sensor_attached) {
                sensor_detach(&sd->sd_sc->sc_sensordev, &sd->sd_vol.sv_sensor);
                sd->sd_vol.sv_sensor_attached = 0;
        }

        /*
         * Unregister the refresh task if we detached our last sensor.
         */
        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link)
                if (sd->sd_vol.sv_sensor_attached)
                        return;
        if (sc->sc_sensor_task != NULL) {
                sensor_task_unregister(sc->sc_sensor_task);
                sc->sc_sensor_task = NULL;
        }
}

void
sr_sensors_refresh(void *arg)
{
        struct sr_softc         *sc = arg;
        struct sr_volume        *sv;
        struct sr_discipline    *sd;

        DNPRINTF(SR_D_STATE, "%s: sr_sensors_refresh\n", DEVNAME(sc));

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                sv = &sd->sd_vol;

                switch(sd->sd_vol_status) {
                case BIOC_SVOFFLINE:
                        sv->sv_sensor.value = SENSOR_DRIVE_FAIL;
                        sv->sv_sensor.status = SENSOR_S_CRIT;
                        break;

                case BIOC_SVDEGRADED:
                        sv->sv_sensor.value = SENSOR_DRIVE_PFAIL;
                        sv->sv_sensor.status = SENSOR_S_WARN;
                        break;

                case BIOC_SVREBUILD:
                        sv->sv_sensor.value = SENSOR_DRIVE_REBUILD;
                        sv->sv_sensor.status = SENSOR_S_WARN;
                        break;

                case BIOC_SVSCRUB:
                case BIOC_SVONLINE:
                        sv->sv_sensor.value = SENSOR_DRIVE_ONLINE;
                        sv->sv_sensor.status = SENSOR_S_OK;
                        break;

                default:
                        sv->sv_sensor.value = 0; /* unknown */
                        sv->sv_sensor.status = SENSOR_S_UNKNOWN;
                }
        }
}
#endif /* SMALL_KERNEL */

#ifdef SR_FANCY_STATS
void                            sr_print_stats(void);

void
sr_print_stats(void)
{
        struct sr_softc         *sc = softraid0;
        struct sr_discipline    *sd;

        if (sc == NULL) {
                printf("no softraid softc found\n");
                return;
        }

        TAILQ_FOREACH(sd, &sc->sc_dis_list, sd_link) {
                printf("%s: ios pending %d, collisions %llu\n",
                    sd->sd_meta->ssd_devname,
                    sd->sd_wu_pending,
                    sd->sd_wu_collisions);
        }
}
#endif /* SR_FANCY_STATS */

#ifdef SR_DEBUG
void
sr_meta_print(struct sr_metadata *m)
{
        int                     i;
        struct sr_meta_chunk    *mc;
        struct sr_meta_opt_hdr  *omh;

        if (!(sr_debug & SR_D_META))
                return;

        printf("\tssd_magic 0x%llx\n", m->ssdi.ssd_magic);
        printf("\tssd_version %d\n", m->ssdi.ssd_version);
        printf("\tssd_vol_flags 0x%x\n", m->ssdi.ssd_vol_flags);
        printf("\tssd_uuid ");
        sr_uuid_print(&m->ssdi.ssd_uuid, 1);
        printf("\tssd_chunk_no %d\n", m->ssdi.ssd_chunk_no);
        printf("\tssd_chunk_id %d\n", m->ssdi.ssd_chunk_id);
        printf("\tssd_opt_no %d\n", m->ssdi.ssd_opt_no);
        printf("\tssd_volid %d\n", m->ssdi.ssd_volid);
        printf("\tssd_level %d\n", m->ssdi.ssd_level);
        printf("\tssd_size %lld\n", m->ssdi.ssd_size);
        printf("\tssd_devname %s\n", m->ssd_devname);
        printf("\tssd_vendor %s\n", m->ssdi.ssd_vendor);
        printf("\tssd_product %s\n", m->ssdi.ssd_product);
        printf("\tssd_revision %s\n", m->ssdi.ssd_revision);
        printf("\tssd_strip_size %d\n", m->ssdi.ssd_strip_size);
        printf("\tssd_checksum ");
        sr_checksum_print(m->ssd_checksum);
        printf("\n");
        printf("\tssd_meta_flags 0x%x\n", m->ssd_meta_flags);
        printf("\tssd_ondisk %llu\n", m->ssd_ondisk);

        mc = (struct sr_meta_chunk *)(m + 1);
        for (i = 0; i < m->ssdi.ssd_chunk_no; i++, mc++) {
                printf("\t\tscm_volid %d\n", mc->scmi.scm_volid);
                printf("\t\tscm_chunk_id %d\n", mc->scmi.scm_chunk_id);
                printf("\t\tscm_devname %s\n", mc->scmi.scm_devname);
                printf("\t\tscm_size %lld\n", mc->scmi.scm_size);
                printf("\t\tscm_coerced_size %lld\n",mc->scmi.scm_coerced_size);
                printf("\t\tscm_uuid ");
                sr_uuid_print(&mc->scmi.scm_uuid, 1);
                printf("\t\tscm_checksum ");
                sr_checksum_print(mc->scm_checksum);
                printf("\n");
                printf("\t\tscm_status %d\n", mc->scm_status);
        }

        omh = (struct sr_meta_opt_hdr *)((u_int8_t *)(m + 1) +
            sizeof(struct sr_meta_chunk) * m->ssdi.ssd_chunk_no);
        for (i = 0; i < m->ssdi.ssd_opt_no; i++) {
                printf("\t\t\tsom_type %d\n", omh->som_type);
                printf("\t\t\tsom_checksum ");
                sr_checksum_print(omh->som_checksum);
                printf("\n");
                omh = (struct sr_meta_opt_hdr *)((void *)omh +
                    omh->som_length);
        }
}

void
sr_dump_block(void *blk, int len)
{
        uint8_t                 *b = blk;
        int                     i, j, c;

        for (i = 0; i < len; i += 16) {
                for (j = 0; j < 16; j++)
                        printf("%.2x ", b[i + j]);
                printf("  ");
                for (j = 0; j < 16; j++) {
                        c = b[i + j];
                        if (c < ' ' || c > 'z' || i + j > len)
                                c = '.';
                        printf("%c", c);
                }
                printf("\n");
        }
}

void
sr_dump_mem(u_int8_t *p, int len)
{
        int                     i;

        for (i = 0; i < len; i++)
                printf("%02x ", *p++);
        printf("\n");
}

#endif /* SR_DEBUG */

#ifdef HIBERNATE
/*
 * Side-effect free (no malloc, printf, pool, splx) softraid crypto writer.
 *
 * This function must perform the following:
 * 1. Determine the underlying device's own side-effect free I/O function
 *    (eg, ahci_hibernate_io, wd_hibernate_io, etc).
 * 2. Store enough information in the provided page argument for subsequent
 *    I/O calls (such as the crypto discipline structure for the keys, the
 *    offset of the softraid partition on the underlying disk, as well as
 *    the offset of the swap partition within the crypto volume.
 * 3. Encrypt the incoming data using the sr_discipline keys, then pass
 *    the request to the underlying device's own I/O function.
 */
int
sr_hibernate_io(dev_t dev, daddr_t blkno, vaddr_t addr, size_t size, int op, void *page)
{
        /* Struct for stashing data obtained on HIB_INIT.
         * XXX
         * We share the page with the underlying device's own
         * side-effect free I/O function, so we pad our data to
         * the end of the page. Presently this does not overlap
         * with the other side-effect free i/o functions
         * (ahci/wd/nvme/ufshci/sdmmc).
         */
        struct {
                char pad[3072];
                struct sr_discipline *srd;
                hibio_fn subfn;         /* underlying device i/o fn */
                dev_t subdev;           /* underlying device dev_t */
                daddr_t sr_swapoff;     /* ofs of swap part in sr volume */
                char buf[DEV_BSIZE];    /* encryption performed into this buf */
        } *my = page;
        extern struct cfdriver sd_cd;
        char errstr[128], *dl_ret;
        struct sr_chunk *schunk;
        struct sd_softc *sd;
        struct aes_xts_ctx ctx;
        struct sr_softc *sc;
        struct device *dv;
        daddr_t key_blkno;
        uint32_t sub_raidoff;  /* ofs of sr part in underlying dev */
        static struct disklabel dl;     /* XXX too big for kernel stack */
        struct partition *pp;
        size_t i, j;
        u_char iv[8];

        /*
         * In HIB_INIT, we are passed the swap partition size and offset
         * in 'size' and 'blkno' respectively. These are relative to the
         * start of the softraid partition, and we need to save these
         * for later translation to the underlying device's layout.
         */
        if (op == HIB_INIT) {
                dv = disk_lookup(&sd_cd, DISKUNIT(dev));
                sd = (struct sd_softc *)dv;
                sc = (struct sr_softc *)dv->dv_parent->dv_parent;

                /*
                 * Look up the sr discipline. This is used to determine
                 * if we are SR crypto and what the underlying device is.
                 */
                my->srd = sc->sc_targets[sd->sc_link->target];
                DNPRINTF(SR_D_MISC, "sr_hibernate_io: discipline is %s\n",
                        my->srd->sd_name);
                if (strncmp(my->srd->sd_name, "CRYPTO",
                    sizeof(my->srd->sd_name)))
                        return (ENOTSUP);

                /* Find the underlying device */
                schunk = my->srd->sd_vol.sv_chunks[0];
                my->subdev = schunk->src_dev_mm;

                /*
                 * Find the appropriate underlying device side effect free
                 * I/O function, based on the type of device it is.
                 */
                my->subfn = get_hibernate_io_function(my->subdev);
                if (!my->subfn)
                        return (ENODEV);

                /*
                 * Find blkno where this raid partition starts on
                 * the underlying disk.
                 */
                dl_ret = disk_readlabel(&dl, my->subdev, errstr,
                    sizeof(errstr));
                if (dl_ret) {
                        printf("Hibernate error reading disklabel: %s\n", dl_ret);
                        return (ENOTSUP);
                }

                pp = &dl.d_partitions[DISKPART(my->subdev)];
                if (pp->p_fstype != FS_RAID || DL_GETPSIZE(pp) == 0)
                        return (ENOTSUP);

                /* Find the blkno of the SR part in the underlying device */
                sub_raidoff = my->srd->sd_meta->ssd_data_blkno +
                    DL_SECTOBLK(&dl, DL_GETPOFFSET(pp));
                DNPRINTF(SR_D_MISC,"sr_hibernate_io: blk trans ofs: %d blks\n",
                    sub_raidoff);

                /* Save the blkno of the swap partition in the SR disk */
                my->sr_swapoff = blkno;

                /* Initialize the sub-device */
                return my->subfn(my->subdev, sub_raidoff + blkno,
                    addr, size, op, page);
        } else if (op == HIB_DONE)
                return my->subfn(my->subdev, blkno, addr, size, op, page);

        /* Hibernate only uses (and we only support) writes */
        if (op != HIB_W)
                return (ENOTSUP);

        /*
         * Blocks act as the IV for the encryption. These block numbers
         * are relative to the start of the sr partition, but the 'blkno'
         * passed above is relative to the start of the swap partition
         * inside the sr partition, so bias appropriately.
         */
        key_blkno = my->sr_swapoff + blkno;

        /* Process each disk block one at a time. */
        for (i = 0; i < size; i += DEV_BSIZE) {
                int res;

                bzero(&ctx, sizeof(ctx));

                /*
                 * Set encryption key (from the sr discipline stashed
                 * during HIB_INIT. This code is based on the softraid
                 * bootblock code.
                 */
                aes_xts_setkey(&ctx, my->srd->mds.mdd_crypto.scr_key[0], 64);
                /* We encrypt DEV_BSIZE bytes at a time in my->buf */
                memcpy(my->buf, ((char *)addr) + i, DEV_BSIZE);

                /* Block number is the IV */
                memcpy(&iv, &key_blkno, sizeof(key_blkno));
                aes_xts_reinit(&ctx, iv);

                /* Encrypt DEV_BSIZE bytes, AES_XTS_BLOCKSIZE bytes at a time */
                for (j = 0; j < DEV_BSIZE; j += AES_XTS_BLOCKSIZE)
                        aes_xts_encrypt(&ctx, my->buf + j);

                /*
                 * Write one block out from my->buf to the underlying device
                 * using its own side-effect free I/O function.
                 */
                res = my->subfn(my->subdev, blkno + (i / DEV_BSIZE),
                    (vaddr_t)(my->buf), DEV_BSIZE, op, page);
                if (res != 0)
                        return (res);
                key_blkno++;
        }
        return (0);
}
#endif /* HIBERNATE */