Remove bcopy(), bzero(), bcmp()

[mirror_zfs.git] / lib / libefi / rdwr_efi.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2012 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 2018 by Delphix. All rights reserved.
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <uuid/uuid.h>
#include <zlib.h>
#include <libintl.h>
#include <sys/types.h>
#include <sys/dkio.h>
#include <sys/vtoc.h>
#include <sys/mhd.h>
#include <sys/param.h>
#include <sys/dktp/fdisk.h>
#include <sys/efi_partition.h>
#include <sys/byteorder.h>
#include <sys/vdev_disk.h>
#include <linux/fs.h>
#include <linux/blkpg.h>

static struct uuid_to_ptag {
        struct uuid     uuid;
} conversion_array[] = {
        { EFI_UNUSED },
        { EFI_BOOT },
        { EFI_ROOT },
        { EFI_SWAP },
        { EFI_USR },
        { EFI_BACKUP },
        { EFI_UNUSED },         /* STAND is never used */
        { EFI_VAR },
        { EFI_HOME },
        { EFI_ALTSCTR },
        { EFI_UNUSED },         /* CACHE (cachefs) is never used */
        { EFI_RESERVED },
        { EFI_SYSTEM },
        { EFI_LEGACY_MBR },
        { EFI_SYMC_PUB },
        { EFI_SYMC_CDS },
        { EFI_MSFT_RESV },
        { EFI_DELL_BASIC },
        { EFI_DELL_RAID },
        { EFI_DELL_SWAP },
        { EFI_DELL_LVM },
        { EFI_DELL_RESV },
        { EFI_AAPL_HFS },
        { EFI_AAPL_UFS },
        { EFI_FREEBSD_BOOT },
        { EFI_FREEBSD_SWAP },
        { EFI_FREEBSD_UFS },
        { EFI_FREEBSD_VINUM },
        { EFI_FREEBSD_ZFS },
        { EFI_BIOS_BOOT },
        { EFI_INTC_RS },
        { EFI_SNE_BOOT },
        { EFI_LENOVO_BOOT },
        { EFI_MSFT_LDMM },
        { EFI_MSFT_LDMD },
        { EFI_MSFT_RE },
        { EFI_IBM_GPFS },
        { EFI_MSFT_STORAGESPACES },
        { EFI_HPQ_DATA },
        { EFI_HPQ_SVC },
        { EFI_RHT_DATA },
        { EFI_RHT_HOME },
        { EFI_RHT_SRV },
        { EFI_RHT_DMCRYPT },
        { EFI_RHT_LUKS },
        { EFI_FREEBSD_DISKLABEL },
        { EFI_AAPL_RAID },
        { EFI_AAPL_RAIDOFFLINE },
        { EFI_AAPL_BOOT },
        { EFI_AAPL_LABEL },
        { EFI_AAPL_TVRECOVERY },
        { EFI_AAPL_CORESTORAGE },
        { EFI_NETBSD_SWAP },
        { EFI_NETBSD_FFS },
        { EFI_NETBSD_LFS },
        { EFI_NETBSD_RAID },
        { EFI_NETBSD_CAT },
        { EFI_NETBSD_CRYPT },
        { EFI_GOOG_KERN },
        { EFI_GOOG_ROOT },
        { EFI_GOOG_RESV },
        { EFI_HAIKU_BFS },
        { EFI_MIDNIGHTBSD_BOOT },
        { EFI_MIDNIGHTBSD_DATA },
        { EFI_MIDNIGHTBSD_SWAP },
        { EFI_MIDNIGHTBSD_UFS },
        { EFI_MIDNIGHTBSD_VINUM },
        { EFI_MIDNIGHTBSD_ZFS },
        { EFI_CEPH_JOURNAL },
        { EFI_CEPH_DMCRYPTJOURNAL },
        { EFI_CEPH_OSD },
        { EFI_CEPH_DMCRYPTOSD },
        { EFI_CEPH_CREATE },
        { EFI_CEPH_DMCRYPTCREATE },
        { EFI_OPENBSD_DISKLABEL },
        { EFI_BBRY_QNX },
        { EFI_BELL_PLAN9 },
        { EFI_VMW_KCORE },
        { EFI_VMW_VMFS },
        { EFI_VMW_RESV },
        { EFI_RHT_ROOTX86 },
        { EFI_RHT_ROOTAMD64 },
        { EFI_RHT_ROOTARM },
        { EFI_RHT_ROOTARM64 },
        { EFI_ACRONIS_SECUREZONE },
        { EFI_ONIE_BOOT },
        { EFI_ONIE_CONFIG },
        { EFI_IBM_PPRPBOOT },
        { EFI_FREEDESKTOP_BOOT }
};

int efi_debug = 0;

static int efi_read(int, struct dk_gpt *);

/*
 * Return a 32-bit CRC of the contents of the buffer.  Pre-and-post
 * one's conditioning will be handled by crc32() internally.
 */
static uint32_t
efi_crc32(const unsigned char *buf, unsigned int size)
{
        uint32_t crc = crc32(0, Z_NULL, 0);

        crc = crc32(crc, buf, size);

        return (crc);
}

static int
read_disk_info(int fd, diskaddr_t *capacity, uint_t *lbsize)
{
        int sector_size;
        unsigned long long capacity_size;

        if (ioctl(fd, BLKSSZGET, &sector_size) < 0)
                return (-1);

        if (ioctl(fd, BLKGETSIZE64, &capacity_size) < 0)
                return (-1);

        *lbsize = (uint_t)sector_size;
        *capacity = (diskaddr_t)(capacity_size / sector_size);

        return (0);
}

/*
 * Return back the device name associated with the file descriptor. The
 * caller is responsible for freeing the memory associated with the
 * returned string.
 */
static char *
efi_get_devname(int fd)
{
        char path[32];

        /*
         * The libefi API only provides the open fd and not the file path.
         * To handle this realpath(3) is used to resolve the block device
         * name from /proc/self/fd/<fd>.
         */
        (void) snprintf(path, sizeof (path), "/proc/self/fd/%d", fd);
        return (realpath(path, NULL));
}

static int
efi_get_info(int fd, struct dk_cinfo *dki_info)
{
        char *dev_path;
        int rval = 0;

        memset(dki_info, 0, sizeof (*dki_info));

        /*
         * The simplest way to get the partition number under linux is
         * to parse it out of the /dev/<disk><partition> block device name.
         * The kernel creates this using the partition number when it
         * populates /dev/ so it may be trusted.  The tricky bit here is
         * that the naming convention is based on the block device type.
         * So we need to take this in to account when parsing out the
         * partition information.  Aside from the partition number we collect
         * some additional device info.
         */
        dev_path = efi_get_devname(fd);
        if (dev_path == NULL)
                goto error;

        if ((strncmp(dev_path, "/dev/sd", 7) == 0)) {
                strcpy(dki_info->dki_cname, "sd");
                dki_info->dki_ctype = DKC_SCSI_CCS;
                rval = sscanf(dev_path, "/dev/%[a-zA-Z]%hu",
                    dki_info->dki_dname,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/hd", 7) == 0)) {
                strcpy(dki_info->dki_cname, "hd");
                dki_info->dki_ctype = DKC_DIRECT;
                rval = sscanf(dev_path, "/dev/%[a-zA-Z]%hu",
                    dki_info->dki_dname,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/md", 7) == 0)) {
                strcpy(dki_info->dki_cname, "pseudo");
                dki_info->dki_ctype = DKC_MD;
                strcpy(dki_info->dki_dname, "md");
                rval = sscanf(dev_path, "/dev/md%[0-9]p%hu",
                    dki_info->dki_dname + 2,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/vd", 7) == 0)) {
                strcpy(dki_info->dki_cname, "vd");
                dki_info->dki_ctype = DKC_MD;
                rval = sscanf(dev_path, "/dev/%[a-zA-Z]%hu",
                    dki_info->dki_dname,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/xvd", 8) == 0)) {
                strcpy(dki_info->dki_cname, "xvd");
                dki_info->dki_ctype = DKC_MD;
                rval = sscanf(dev_path, "/dev/%[a-zA-Z]%hu",
                    dki_info->dki_dname,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/zd", 7) == 0)) {
                strcpy(dki_info->dki_cname, "zd");
                dki_info->dki_ctype = DKC_MD;
                strcpy(dki_info->dki_dname, "zd");
                rval = sscanf(dev_path, "/dev/zd%[0-9]p%hu",
                    dki_info->dki_dname + 2,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/dm-", 8) == 0)) {
                strcpy(dki_info->dki_cname, "pseudo");
                dki_info->dki_ctype = DKC_VBD;
                strcpy(dki_info->dki_dname, "dm-");
                rval = sscanf(dev_path, "/dev/dm-%[0-9]p%hu",
                    dki_info->dki_dname + 3,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/ram", 8) == 0)) {
                strcpy(dki_info->dki_cname, "pseudo");
                dki_info->dki_ctype = DKC_PCMCIA_MEM;
                strcpy(dki_info->dki_dname, "ram");
                rval = sscanf(dev_path, "/dev/ram%[0-9]p%hu",
                    dki_info->dki_dname + 3,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/loop", 9) == 0)) {
                strcpy(dki_info->dki_cname, "pseudo");
                dki_info->dki_ctype = DKC_VBD;
                strcpy(dki_info->dki_dname, "loop");
                rval = sscanf(dev_path, "/dev/loop%[0-9]p%hu",
                    dki_info->dki_dname + 4,
                    &dki_info->dki_partition);
        } else if ((strncmp(dev_path, "/dev/nvme", 9) == 0)) {
                strcpy(dki_info->dki_cname, "nvme");
                dki_info->dki_ctype = DKC_SCSI_CCS;
                strcpy(dki_info->dki_dname, "nvme");
                (void) sscanf(dev_path, "/dev/nvme%[0-9]",
                    dki_info->dki_dname + 4);
                size_t controller_length = strlen(
                    dki_info->dki_dname);
                strcpy(dki_info->dki_dname + controller_length,
                    "n");
                rval = sscanf(dev_path,
                    "/dev/nvme%*[0-9]n%[0-9]p%hu",
                    dki_info->dki_dname + controller_length + 1,
                    &dki_info->dki_partition);
        } else {
                strcpy(dki_info->dki_dname, "unknown");
                strcpy(dki_info->dki_cname, "unknown");
                dki_info->dki_ctype = DKC_UNKNOWN;
        }

        switch (rval) {
        case 0:
                errno = EINVAL;
                goto error;
        case 1:
                dki_info->dki_partition = 0;
        }

        free(dev_path);

        return (0);
error:
        if (efi_debug)
                (void) fprintf(stderr, "DKIOCINFO errno 0x%x\n", errno);

        switch (errno) {
        case EIO:
                return (VT_EIO);
        case EINVAL:
                return (VT_EINVAL);
        default:
                return (VT_ERROR);
        }
}

/*
 * the number of blocks the EFI label takes up (round up to nearest
 * block)
 */
#define NBLOCKS(p, l)   (1 + ((((p) * (int)sizeof (efi_gpe_t))  + \
                                ((l) - 1)) / (l)))
/* number of partitions -- limited by what we can malloc */
#define MAX_PARTS       ((4294967295UL - sizeof (struct dk_gpt)) / \
                            sizeof (struct dk_part))

int
efi_alloc_and_init(int fd, uint32_t nparts, struct dk_gpt **vtoc)
{
        diskaddr_t      capacity = 0;
        uint_t          lbsize = 0;
        uint_t          nblocks;
        size_t          length;
        struct dk_gpt   *vptr;
        struct uuid     uuid;
        struct dk_cinfo dki_info;

        if (read_disk_info(fd, &capacity, &lbsize) != 0)
                return (-1);

        if (efi_get_info(fd, &dki_info) != 0)
                return (-1);

        if (dki_info.dki_partition != 0)
                return (-1);

        if ((dki_info.dki_ctype == DKC_PCMCIA_MEM) ||
            (dki_info.dki_ctype == DKC_VBD) ||
            (dki_info.dki_ctype == DKC_UNKNOWN))
                return (-1);

        nblocks = NBLOCKS(nparts, lbsize);
        if ((nblocks * lbsize) < EFI_MIN_ARRAY_SIZE + lbsize) {
                /* 16K plus one block for the GPT */
                nblocks = EFI_MIN_ARRAY_SIZE / lbsize + 1;
        }

        if (nparts > MAX_PARTS) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                        "the maximum number of partitions supported is %lu\n",
                            MAX_PARTS);
                }
                return (-1);
        }

        length = sizeof (struct dk_gpt) +
            sizeof (struct dk_part) * (nparts - 1);

        vptr = calloc(1, length);
        if (vptr == NULL)
                return (-1);

        *vtoc = vptr;

        vptr->efi_version = EFI_VERSION_CURRENT;
        vptr->efi_lbasize = lbsize;
        vptr->efi_nparts = nparts;
        /*
         * add one block here for the PMBR; on disks with a 512 byte
         * block size and 128 or fewer partitions, efi_first_u_lba
         * should work out to "34"
         */
        vptr->efi_first_u_lba = nblocks + 1;
        vptr->efi_last_lba = capacity - 1;
        vptr->efi_altern_lba = capacity -1;
        vptr->efi_last_u_lba = vptr->efi_last_lba - nblocks;

        (void) uuid_generate((uchar_t *)&uuid);
        UUID_LE_CONVERT(vptr->efi_disk_uguid, uuid);
        return (0);
}

/*
 * Read EFI - return partition number upon success.
 */
int
efi_alloc_and_read(int fd, struct dk_gpt **vtoc)
{
        int                     rval;
        uint32_t                nparts;
        int                     length;
        struct dk_gpt           *vptr;

        /* figure out the number of entries that would fit into 16K */
        nparts = EFI_MIN_ARRAY_SIZE / sizeof (efi_gpe_t);
        length = (int) sizeof (struct dk_gpt) +
            (int) sizeof (struct dk_part) * (nparts - 1);
        vptr = calloc(1, length);

        if (vptr == NULL)
                return (VT_ERROR);

        vptr->efi_nparts = nparts;
        rval = efi_read(fd, vptr);

        if ((rval == VT_EINVAL) && vptr->efi_nparts > nparts) {
                void *tmp;
                length = (int) sizeof (struct dk_gpt) +
                    (int) sizeof (struct dk_part) * (vptr->efi_nparts - 1);
                nparts = vptr->efi_nparts;
                if ((tmp = realloc(vptr, length)) == NULL) {
                        /* cppcheck-suppress doubleFree */
                        free(vptr);
                        *vtoc = NULL;
                        return (VT_ERROR);
                } else {
                        vptr = tmp;
                        rval = efi_read(fd, vptr);
                }
        }

        if (rval < 0) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "read of EFI table failed, rval=%d\n", rval);
                }
                free(vptr);
                *vtoc = NULL;
        } else {
                *vtoc = vptr;
        }

        return (rval);
}

static int
efi_ioctl(int fd, int cmd, dk_efi_t *dk_ioc)
{
        void *data = dk_ioc->dki_data;
        int error;
        diskaddr_t capacity;
        uint_t lbsize;

        /*
         * When the IO is not being performed in kernel as an ioctl we need
         * to know the sector size so we can seek to the proper byte offset.
         */
        if (read_disk_info(fd, &capacity, &lbsize) == -1) {
                if (efi_debug)
                        fprintf(stderr, "unable to read disk info: %d", errno);

                errno = EIO;
                return (-1);
        }

        switch (cmd) {
        case DKIOCGETEFI:
                if (lbsize == 0) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCGETEFI assuming "
                                    "LBA %d bytes\n", DEV_BSIZE);

                        lbsize = DEV_BSIZE;
                }

                error = lseek(fd, dk_ioc->dki_lba * lbsize, SEEK_SET);
                if (error == -1) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCGETEFI lseek "
                                    "error: %d\n", errno);
                        return (error);
                }

                error = read(fd, data, dk_ioc->dki_length);
                if (error == -1) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCGETEFI read "
                                    "error: %d\n", errno);
                        return (error);
                }

                if (error != dk_ioc->dki_length) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCGETEFI short "
                                    "read of %d bytes\n", error);
                        errno = EIO;
                        return (-1);
                }
                error = 0;
                break;

        case DKIOCSETEFI:
                if (lbsize == 0) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCSETEFI unknown "
                                    "LBA size\n");
                        errno = EIO;
                        return (-1);
                }

                error = lseek(fd, dk_ioc->dki_lba * lbsize, SEEK_SET);
                if (error == -1) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCSETEFI lseek "
                                    "error: %d\n", errno);
                        return (error);
                }

                error = write(fd, data, dk_ioc->dki_length);
                if (error == -1) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCSETEFI write "
                                    "error: %d\n", errno);
                        return (error);
                }

                if (error != dk_ioc->dki_length) {
                        if (efi_debug)
                                (void) fprintf(stderr, "DKIOCSETEFI short "
                                    "write of %d bytes\n", error);
                        errno = EIO;
                        return (-1);
                }

                /* Sync the new EFI table to disk */
                error = fsync(fd);
                if (error == -1)
                        return (error);

                /* Ensure any local disk cache is also flushed */
                if (ioctl(fd, BLKFLSBUF, 0) == -1)
                        return (error);

                error = 0;
                break;

        default:
                if (efi_debug)
                        (void) fprintf(stderr, "unsupported ioctl()\n");

                errno = EIO;
                return (-1);
        }

        return (error);
}

int
efi_rescan(int fd)
{
        int retry = 10;
        int error;

        /* Notify the kernel a devices partition table has been updated */
        while ((error = ioctl(fd, BLKRRPART)) != 0) {
                if ((--retry == 0) || (errno != EBUSY)) {
                        (void) fprintf(stderr, "the kernel failed to rescan "
                            "the partition table: %d\n", errno);
                        return (-1);
                }
                usleep(50000);
        }

        return (0);
}

static int
check_label(int fd, dk_efi_t *dk_ioc)
{
        efi_gpt_t               *efi;
        uint_t                  crc;

        if (efi_ioctl(fd, DKIOCGETEFI, dk_ioc) == -1) {
                switch (errno) {
                case EIO:
                        return (VT_EIO);
                default:
                        return (VT_ERROR);
                }
        }
        efi = dk_ioc->dki_data;
        if (efi->efi_gpt_Signature != LE_64(EFI_SIGNATURE)) {
                if (efi_debug)
                        (void) fprintf(stderr,
                            "Bad EFI signature: 0x%llx != 0x%llx\n",
                            (long long)efi->efi_gpt_Signature,
                            (long long)LE_64(EFI_SIGNATURE));
                return (VT_EINVAL);
        }

        /*
         * check CRC of the header; the size of the header should
         * never be larger than one block
         */
        crc = efi->efi_gpt_HeaderCRC32;
        efi->efi_gpt_HeaderCRC32 = 0;
        len_t headerSize = (len_t)LE_32(efi->efi_gpt_HeaderSize);

        if (headerSize < EFI_MIN_LABEL_SIZE || headerSize > EFI_LABEL_SIZE) {
                if (efi_debug)
                        (void) fprintf(stderr,
                            "Invalid EFI HeaderSize %llu.  Assuming %d.\n",
                            headerSize, EFI_MIN_LABEL_SIZE);
        }

        if ((headerSize > dk_ioc->dki_length) ||
            crc != LE_32(efi_crc32((unsigned char *)efi, headerSize))) {
                if (efi_debug)
                        (void) fprintf(stderr,
                            "Bad EFI CRC: 0x%x != 0x%x\n",
                            crc, LE_32(efi_crc32((unsigned char *)efi,
                            headerSize)));
                return (VT_EINVAL);
        }

        return (0);
}

static int
efi_read(int fd, struct dk_gpt *vtoc)
{
        int                     i, j;
        int                     label_len;
        int                     rval = 0;
        int                     md_flag = 0;
        int                     vdc_flag = 0;
        diskaddr_t              capacity = 0;
        uint_t                  lbsize = 0;
        struct dk_minfo         disk_info;
        dk_efi_t                dk_ioc;
        efi_gpt_t               *efi;
        efi_gpe_t               *efi_parts;
        struct dk_cinfo         dki_info;
        uint32_t                user_length;
        boolean_t               legacy_label = B_FALSE;

        /*
         * get the partition number for this file descriptor.
         */
        if ((rval = efi_get_info(fd, &dki_info)) != 0)
                return (rval);

        if ((strncmp(dki_info.dki_cname, "pseudo", 7) == 0) &&
            (strncmp(dki_info.dki_dname, "md", 3) == 0)) {
                md_flag++;
        } else if ((strncmp(dki_info.dki_cname, "vdc", 4) == 0) &&
            (strncmp(dki_info.dki_dname, "vdc", 4) == 0)) {
                /*
                 * The controller and drive name "vdc" (virtual disk client)
                 * indicates a LDoms virtual disk.
                 */
                vdc_flag++;
        }

        /* get the LBA size */
        if (read_disk_info(fd, &capacity, &lbsize) == -1) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "unable to read disk info: %d",
                            errno);
                }
                return (VT_EINVAL);
        }

        disk_info.dki_lbsize = lbsize;
        disk_info.dki_capacity = capacity;

        if (disk_info.dki_lbsize == 0) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "efi_read: assuming LBA 512 bytes\n");
                }
                disk_info.dki_lbsize = DEV_BSIZE;
        }
        /*
         * Read the EFI GPT to figure out how many partitions we need
         * to deal with.
         */
        dk_ioc.dki_lba = 1;
        if (NBLOCKS(vtoc->efi_nparts, disk_info.dki_lbsize) < 34) {
                label_len = EFI_MIN_ARRAY_SIZE + disk_info.dki_lbsize;
        } else {
                label_len = vtoc->efi_nparts * (int) sizeof (efi_gpe_t) +
                    disk_info.dki_lbsize;
                if (label_len % disk_info.dki_lbsize) {
                        /* pad to physical sector size */
                        label_len += disk_info.dki_lbsize;
                        label_len &= ~(disk_info.dki_lbsize - 1);
                }
        }

        if (posix_memalign((void **)&dk_ioc.dki_data,
            disk_info.dki_lbsize, label_len))
                return (VT_ERROR);

        memset(dk_ioc.dki_data, 0, label_len);
        dk_ioc.dki_length = disk_info.dki_lbsize;
        user_length = vtoc->efi_nparts;
        efi = dk_ioc.dki_data;
        if (md_flag) {
                dk_ioc.dki_length = label_len;
                if (efi_ioctl(fd, DKIOCGETEFI, &dk_ioc) == -1) {
                        switch (errno) {
                        case EIO:
                                return (VT_EIO);
                        default:
                                return (VT_ERROR);
                        }
                }
        } else if ((rval = check_label(fd, &dk_ioc)) == VT_EINVAL) {
                /*
                 * No valid label here; try the alternate. Note that here
                 * we just read GPT header and save it into dk_ioc.data,
                 * Later, we will read GUID partition entry array if we
                 * can get valid GPT header.
                 */

                /*
                 * This is a workaround for legacy systems. In the past, the
                 * last sector of SCSI disk was invisible on x86 platform. At
                 * that time, backup label was saved on the next to the last
                 * sector. It is possible for users to move a disk from previous
                 * solaris system to present system. Here, we attempt to search
                 * legacy backup EFI label first.
                 */
                dk_ioc.dki_lba = disk_info.dki_capacity - 2;
                dk_ioc.dki_length = disk_info.dki_lbsize;
                rval = check_label(fd, &dk_ioc);
                if (rval == VT_EINVAL) {
                        /*
                         * we didn't find legacy backup EFI label, try to
                         * search backup EFI label in the last block.
                         */
                        dk_ioc.dki_lba = disk_info.dki_capacity - 1;
                        dk_ioc.dki_length = disk_info.dki_lbsize;
                        rval = check_label(fd, &dk_ioc);
                        if (rval == 0) {
                                legacy_label = B_TRUE;
                                if (efi_debug)
                                        (void) fprintf(stderr,
                                            "efi_read: primary label corrupt; "
                                            "using EFI backup label located on"
                                            " the last block\n");
                        }
                } else {
                        if ((efi_debug) && (rval == 0))
                                (void) fprintf(stderr, "efi_read: primary label"
                                    " corrupt; using legacy EFI backup label "
                                    " located on the next to last block\n");
                }

                if (rval == 0) {
                        dk_ioc.dki_lba = LE_64(efi->efi_gpt_PartitionEntryLBA);
                        vtoc->efi_flags |= EFI_GPT_PRIMARY_CORRUPT;
                        vtoc->efi_nparts =
                            LE_32(efi->efi_gpt_NumberOfPartitionEntries);
                        /*
                         * Partition tables are between backup GPT header
                         * table and ParitionEntryLBA (the starting LBA of
                         * the GUID partition entries array). Now that we
                         * already got valid GPT header and saved it in
                         * dk_ioc.dki_data, we try to get GUID partition
                         * entry array here.
                         */
                        /* LINTED */
                        dk_ioc.dki_data = (efi_gpt_t *)((char *)dk_ioc.dki_data
                            + disk_info.dki_lbsize);
                        if (legacy_label)
                                dk_ioc.dki_length = disk_info.dki_capacity - 1 -
                                    dk_ioc.dki_lba;
                        else
                                dk_ioc.dki_length = disk_info.dki_capacity - 2 -
                                    dk_ioc.dki_lba;
                        dk_ioc.dki_length *= disk_info.dki_lbsize;
                        if (dk_ioc.dki_length >
                            ((len_t)label_len - sizeof (*dk_ioc.dki_data))) {
                                rval = VT_EINVAL;
                        } else {
                                /*
                                 * read GUID partition entry array
                                 */
                                rval = efi_ioctl(fd, DKIOCGETEFI, &dk_ioc);
                        }
                }

        } else if (rval == 0) {

                dk_ioc.dki_lba = LE_64(efi->efi_gpt_PartitionEntryLBA);
                /* LINTED */
                dk_ioc.dki_data = (efi_gpt_t *)((char *)dk_ioc.dki_data
                    + disk_info.dki_lbsize);
                dk_ioc.dki_length = label_len - disk_info.dki_lbsize;
                rval = efi_ioctl(fd, DKIOCGETEFI, &dk_ioc);

        } else if (vdc_flag && rval == VT_ERROR && errno == EINVAL) {
                /*
                 * When the device is a LDoms virtual disk, the DKIOCGETEFI
                 * ioctl can fail with EINVAL if the virtual disk backend
                 * is a ZFS volume serviced by a domain running an old version
                 * of Solaris. This is because the DKIOCGETEFI ioctl was
                 * initially incorrectly implemented for a ZFS volume and it
                 * expected the GPT and GPE to be retrieved with a single ioctl.
                 * So we try to read the GPT and the GPE using that old style
                 * ioctl.
                 */
                dk_ioc.dki_lba = 1;
                dk_ioc.dki_length = label_len;
                rval = check_label(fd, &dk_ioc);
        }

        if (rval < 0) {
                free(efi);
                return (rval);
        }

        /* LINTED -- always longlong aligned */
        efi_parts = (efi_gpe_t *)(((char *)efi) + disk_info.dki_lbsize);

        /*
         * Assemble this into a "dk_gpt" struct for easier
         * digestibility by applications.
         */
        vtoc->efi_version = LE_32(efi->efi_gpt_Revision);
        vtoc->efi_nparts = LE_32(efi->efi_gpt_NumberOfPartitionEntries);
        vtoc->efi_part_size = LE_32(efi->efi_gpt_SizeOfPartitionEntry);
        vtoc->efi_lbasize = disk_info.dki_lbsize;
        vtoc->efi_last_lba = disk_info.dki_capacity - 1;
        vtoc->efi_first_u_lba = LE_64(efi->efi_gpt_FirstUsableLBA);
        vtoc->efi_last_u_lba = LE_64(efi->efi_gpt_LastUsableLBA);
        vtoc->efi_altern_lba = LE_64(efi->efi_gpt_AlternateLBA);
        UUID_LE_CONVERT(vtoc->efi_disk_uguid, efi->efi_gpt_DiskGUID);

        /*
         * If the array the user passed in is too small, set the length
         * to what it needs to be and return
         */
        if (user_length < vtoc->efi_nparts) {
                return (VT_EINVAL);
        }

        for (i = 0; i < vtoc->efi_nparts; i++) {

                UUID_LE_CONVERT(vtoc->efi_parts[i].p_guid,
                    efi_parts[i].efi_gpe_PartitionTypeGUID);

                for (j = 0;
                    j < sizeof (conversion_array)
                    / sizeof (struct uuid_to_ptag); j++) {

                        if (memcmp(&vtoc->efi_parts[i].p_guid,
                            &conversion_array[j].uuid,
                            sizeof (struct uuid)) == 0) {
                                vtoc->efi_parts[i].p_tag = j;
                                break;
                        }
                }
                if (vtoc->efi_parts[i].p_tag == V_UNASSIGNED)
                        continue;
                vtoc->efi_parts[i].p_flag =
                    LE_16(efi_parts[i].efi_gpe_Attributes.PartitionAttrs);
                vtoc->efi_parts[i].p_start =
                    LE_64(efi_parts[i].efi_gpe_StartingLBA);
                vtoc->efi_parts[i].p_size =
                    LE_64(efi_parts[i].efi_gpe_EndingLBA) -
                    vtoc->efi_parts[i].p_start + 1;
                for (j = 0; j < EFI_PART_NAME_LEN; j++) {
                        vtoc->efi_parts[i].p_name[j] =
                            (uchar_t)LE_16(
                            efi_parts[i].efi_gpe_PartitionName[j]);
                }

                UUID_LE_CONVERT(vtoc->efi_parts[i].p_uguid,
                    efi_parts[i].efi_gpe_UniquePartitionGUID);
        }
        free(efi);

        return (dki_info.dki_partition);
}

/* writes a "protective" MBR */
static int
write_pmbr(int fd, struct dk_gpt *vtoc)
{
        dk_efi_t        dk_ioc;
        struct mboot    mb;
        uchar_t         *cp;
        diskaddr_t      size_in_lba;
        uchar_t         *buf;
        int             len;

        len = (vtoc->efi_lbasize == 0) ? sizeof (mb) : vtoc->efi_lbasize;
        if (posix_memalign((void **)&buf, len, len))
                return (VT_ERROR);

        /*
         * Preserve any boot code and disk signature if the first block is
         * already an MBR.
         */
        memset(buf, 0, len);
        dk_ioc.dki_lba = 0;
        dk_ioc.dki_length = len;
        /* LINTED -- always longlong aligned */
        dk_ioc.dki_data = (efi_gpt_t *)buf;
        if (efi_ioctl(fd, DKIOCGETEFI, &dk_ioc) == -1) {
                memset(&mb, 0, sizeof (mb));
                mb.signature = LE_16(MBB_MAGIC);
        } else {
                (void) memcpy(&mb, buf, sizeof (mb));
                if (mb.signature != LE_16(MBB_MAGIC)) {
                        memset(&mb, 0, sizeof (mb));
                        mb.signature = LE_16(MBB_MAGIC);
                }
        }

        memset(&mb.parts, 0, sizeof (mb.parts));
        cp = (uchar_t *)&mb.parts[0];
        /* bootable or not */
        *cp++ = 0;
        /* beginning CHS; 0xffffff if not representable */
        *cp++ = 0xff;
        *cp++ = 0xff;
        *cp++ = 0xff;
        /* OS type */
        *cp++ = EFI_PMBR;
        /* ending CHS; 0xffffff if not representable */
        *cp++ = 0xff;
        *cp++ = 0xff;
        *cp++ = 0xff;
        /* starting LBA: 1 (little endian format) by EFI definition */
        *cp++ = 0x01;
        *cp++ = 0x00;
        *cp++ = 0x00;
        *cp++ = 0x00;
        /* ending LBA: last block on the disk (little endian format) */
        size_in_lba = vtoc->efi_last_lba;
        if (size_in_lba < 0xffffffff) {
                *cp++ = (size_in_lba & 0x000000ff);
                *cp++ = (size_in_lba & 0x0000ff00) >> 8;
                *cp++ = (size_in_lba & 0x00ff0000) >> 16;
                *cp++ = (size_in_lba & 0xff000000) >> 24;
        } else {
                *cp++ = 0xff;
                *cp++ = 0xff;
                *cp++ = 0xff;
                *cp++ = 0xff;
        }

        (void) memcpy(buf, &mb, sizeof (mb));
        /* LINTED -- always longlong aligned */
        dk_ioc.dki_data = (efi_gpt_t *)buf;
        dk_ioc.dki_lba = 0;
        dk_ioc.dki_length = len;
        if (efi_ioctl(fd, DKIOCSETEFI, &dk_ioc) == -1) {
                free(buf);
                switch (errno) {
                case EIO:
                        return (VT_EIO);
                case EINVAL:
                        return (VT_EINVAL);
                default:
                        return (VT_ERROR);
                }
        }
        free(buf);
        return (0);
}

/* make sure the user specified something reasonable */
static int
check_input(struct dk_gpt *vtoc)
{
        int                     resv_part = -1;
        int                     i, j;
        diskaddr_t              istart, jstart, isize, jsize, endsect;

        /*
         * Sanity-check the input (make sure no partitions overlap)
         */
        for (i = 0; i < vtoc->efi_nparts; i++) {
                /* It can't be unassigned and have an actual size */
                if ((vtoc->efi_parts[i].p_tag == V_UNASSIGNED) &&
                    (vtoc->efi_parts[i].p_size != 0)) {
                        if (efi_debug) {
                                (void) fprintf(stderr, "partition %d is "
                                    "\"unassigned\" but has a size of %llu",
                                    i, vtoc->efi_parts[i].p_size);
                        }
                        return (VT_EINVAL);
                }
                if (vtoc->efi_parts[i].p_tag == V_UNASSIGNED) {
                        if (uuid_is_null((uchar_t *)&vtoc->efi_parts[i].p_guid))
                                continue;
                        /* we have encountered an unknown uuid */
                        vtoc->efi_parts[i].p_tag = 0xff;
                }
                if (vtoc->efi_parts[i].p_tag == V_RESERVED) {
                        if (resv_part != -1) {
                                if (efi_debug) {
                                        (void) fprintf(stderr, "found "
                                            "duplicate reserved partition "
                                            "at %d\n", i);
                                }
                                return (VT_EINVAL);
                        }
                        resv_part = i;
                }
                if ((vtoc->efi_parts[i].p_start < vtoc->efi_first_u_lba) ||
                    (vtoc->efi_parts[i].p_start > vtoc->efi_last_u_lba)) {
                        if (efi_debug) {
                                (void) fprintf(stderr,
                                    "Partition %d starts at %llu.  ",
                                    i,
                                    vtoc->efi_parts[i].p_start);
                                (void) fprintf(stderr,
                                    "It must be between %llu and %llu.\n",
                                    vtoc->efi_first_u_lba,
                                    vtoc->efi_last_u_lba);
                        }
                        return (VT_EINVAL);
                }
                if ((vtoc->efi_parts[i].p_start +
                    vtoc->efi_parts[i].p_size <
                    vtoc->efi_first_u_lba) ||
                    (vtoc->efi_parts[i].p_start +
                    vtoc->efi_parts[i].p_size >
                    vtoc->efi_last_u_lba + 1)) {
                        if (efi_debug) {
                                (void) fprintf(stderr,
                                    "Partition %d ends at %llu.  ",
                                    i,
                                    vtoc->efi_parts[i].p_start +
                                    vtoc->efi_parts[i].p_size);
                                (void) fprintf(stderr,
                                    "It must be between %llu and %llu.\n",
                                    vtoc->efi_first_u_lba,
                                    vtoc->efi_last_u_lba);
                        }
                        return (VT_EINVAL);
                }

                for (j = 0; j < vtoc->efi_nparts; j++) {
                        isize = vtoc->efi_parts[i].p_size;
                        jsize = vtoc->efi_parts[j].p_size;
                        istart = vtoc->efi_parts[i].p_start;
                        jstart = vtoc->efi_parts[j].p_start;
                        if ((i != j) && (isize != 0) && (jsize != 0)) {
                                endsect = jstart + jsize -1;
                                if ((jstart <= istart) &&
                                    (istart <= endsect)) {
                                        if (efi_debug) {
                                                (void) fprintf(stderr,
                                                    "Partition %d overlaps "
                                                    "partition %d.", i, j);
                                        }
                                        return (VT_EINVAL);
                                }
                        }
                }
        }
        /* just a warning for now */
        if ((resv_part == -1) && efi_debug) {
                (void) fprintf(stderr,
                    "no reserved partition found\n");
        }
        return (0);
}

static int
call_blkpg_ioctl(int fd, int command, diskaddr_t start,
    diskaddr_t size, uint_t pno)
{
        struct blkpg_ioctl_arg ioctl_arg;
        struct blkpg_partition  linux_part;
        memset(&linux_part, 0, sizeof (linux_part));

        char *path = efi_get_devname(fd);
        if (path == NULL) {
                (void) fprintf(stderr, "failed to retrieve device name\n");
                return (VT_EINVAL);
        }

        linux_part.start = start;
        linux_part.length = size;
        linux_part.pno = pno;
        snprintf(linux_part.devname, BLKPG_DEVNAMELTH - 1, "%s%u", path, pno);
        linux_part.devname[BLKPG_DEVNAMELTH - 1] = '\0';
        free(path);

        ioctl_arg.op = command;
        ioctl_arg.flags = 0;
        ioctl_arg.datalen = sizeof (struct blkpg_partition);
        ioctl_arg.data = &linux_part;

        return (ioctl(fd, BLKPG, &ioctl_arg));
}

/*
 * add all the unallocated space to the current label
 */
int
efi_use_whole_disk(int fd)
{
        struct dk_gpt *efi_label = NULL;
        int rval;
        int i;
        uint_t resv_index = 0, data_index = 0;
        diskaddr_t resv_start = 0, data_start = 0;
        diskaddr_t data_size, limit, difference;
        boolean_t sync_needed = B_FALSE;
        uint_t nblocks;

        rval = efi_alloc_and_read(fd, &efi_label);
        if (rval < 0) {
                if (efi_label != NULL)
                        efi_free(efi_label);
                return (rval);
        }

        /*
         * Find the last physically non-zero partition.
         * This should be the reserved partition.
         */
        for (i = 0; i < efi_label->efi_nparts; i ++) {
                if (resv_start < efi_label->efi_parts[i].p_start) {
                        resv_start = efi_label->efi_parts[i].p_start;
                        resv_index = i;
                }
        }

        /*
         * Find the last physically non-zero partition before that.
         * This is the data partition.
         */
        for (i = 0; i < resv_index; i ++) {
                if (data_start < efi_label->efi_parts[i].p_start) {
                        data_start = efi_label->efi_parts[i].p_start;
                        data_index = i;
                }
        }
        data_size = efi_label->efi_parts[data_index].p_size;

        /*
         * See the "efi_alloc_and_init" function for more information
         * about where this "nblocks" value comes from.
         */
        nblocks = efi_label->efi_first_u_lba - 1;

        /*
         * Determine if the EFI label is out of sync. We check that:
         *
         * 1. the data partition ends at the limit we set, and
         * 2. the reserved partition starts at the limit we set.
         *
         * If either of these conditions is not met, then we need to
         * resync the EFI label.
         *
         * The limit is the last usable LBA, determined by the last LBA
         * and the first usable LBA fields on the EFI label of the disk
         * (see the lines directly above). Additionally, we factor in
         * EFI_MIN_RESV_SIZE (per its use in "zpool_label_disk") and
         * P2ALIGN it to ensure the partition boundaries are aligned
         * (for performance reasons). The alignment should match the
         * alignment used by the "zpool_label_disk" function.
         */
        limit = P2ALIGN(efi_label->efi_last_lba - nblocks - EFI_MIN_RESV_SIZE,
            PARTITION_END_ALIGNMENT);
        if (data_start + data_size != limit || resv_start != limit)
                sync_needed = B_TRUE;

        if (efi_debug && sync_needed)
                (void) fprintf(stderr, "efi_use_whole_disk: sync needed\n");

        /*
         * If alter_lba is 1, we are using the backup label.
         * Since we can locate the backup label by disk capacity,
         * there must be no unallocated space.
         */
        if ((efi_label->efi_altern_lba == 1) || (efi_label->efi_altern_lba
            >= efi_label->efi_last_lba && !sync_needed)) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "efi_use_whole_disk: requested space not found\n");
                }
                efi_free(efi_label);
                return (VT_ENOSPC);
        }

        /*
         * Verify that we've found the reserved partition by checking
         * that it looks the way it did when we created it in zpool_label_disk.
         * If we've found the incorrect partition, then we know that this
         * device was reformatted and no longer is solely used by ZFS.
         */
        if ((efi_label->efi_parts[resv_index].p_size != EFI_MIN_RESV_SIZE) ||
            (efi_label->efi_parts[resv_index].p_tag != V_RESERVED) ||
            (resv_index != 8)) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "efi_use_whole_disk: wholedisk not available\n");
                }
                efi_free(efi_label);
                return (VT_ENOSPC);
        }

        if (data_start + data_size != resv_start) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "efi_use_whole_disk: "
                            "data_start (%lli) + "
                            "data_size (%lli) != "
                            "resv_start (%lli)\n",
                            data_start, data_size, resv_start);
                }

                return (VT_EINVAL);
        }

        if (limit < resv_start) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "efi_use_whole_disk: "
                            "limit (%lli) < resv_start (%lli)\n",
                            limit, resv_start);
                }

                return (VT_EINVAL);
        }

        difference = limit - resv_start;

        if (efi_debug)
                (void) fprintf(stderr,
                    "efi_use_whole_disk: difference is %lli\n", difference);

        /*
         * Move the reserved partition. There is currently no data in
         * here except fabricated devids (which get generated via
         * efi_write()). So there is no need to copy data.
         */
        efi_label->efi_parts[data_index].p_size += difference;
        efi_label->efi_parts[resv_index].p_start += difference;
        efi_label->efi_last_u_lba = efi_label->efi_last_lba - nblocks;

        /*
         * Rescanning the partition table in the kernel can result
         * in the device links to be removed (see comment in vdev_disk_open).
         * If BLKPG_RESIZE_PARTITION is available, then we can resize
         * the partition table online and avoid having to remove the device
         * links used by the pool. This provides a very deterministic
         * approach to resizing devices and does not require any
         * loops waiting for devices to reappear.
         */
#ifdef BLKPG_RESIZE_PARTITION
        /*
         * Delete the reserved partition since we're about to expand
         * the data partition and it would overlap with the reserved
         * partition.
         * NOTE: The starting index for the ioctl is 1 while for the
         * EFI partitions it's 0. For that reason we have to add one
         * whenever we make an ioctl call.
         */
        rval = call_blkpg_ioctl(fd, BLKPG_DEL_PARTITION, 0, 0, resv_index + 1);
        if (rval != 0)
                goto out;

        /*
         * Expand the data partition
         */
        rval = call_blkpg_ioctl(fd, BLKPG_RESIZE_PARTITION,
            efi_label->efi_parts[data_index].p_start * efi_label->efi_lbasize,
            efi_label->efi_parts[data_index].p_size * efi_label->efi_lbasize,
            data_index + 1);
        if (rval != 0) {
                (void) fprintf(stderr, "Unable to resize data "
                    "partition:  %d\n", rval);
                /*
                 * Since we failed to resize, we need to reset the start
                 * of the reserve partition and re-create it.
                 */
                efi_label->efi_parts[resv_index].p_start -= difference;
        }

        /*
         * Re-add the reserved partition. If we've expanded the data partition
         * then we'll move the reserve partition to the end of the data
         * partition. Otherwise, we'll recreate the partition in its original
         * location. Note that we do this as best-effort and ignore any
         * errors that may arise here. This will ensure that we finish writing
         * the EFI label.
         */
        (void) call_blkpg_ioctl(fd, BLKPG_ADD_PARTITION,
            efi_label->efi_parts[resv_index].p_start * efi_label->efi_lbasize,
            efi_label->efi_parts[resv_index].p_size * efi_label->efi_lbasize,
            resv_index + 1);
#endif

        /*
         * We're now ready to write the EFI label.
         */
        if (rval == 0) {
                rval = efi_write(fd, efi_label);
                if (rval < 0 && efi_debug) {
                        (void) fprintf(stderr, "efi_use_whole_disk:fail "
                            "to write label, rval=%d\n", rval);
                }
        }

out:
        efi_free(efi_label);
        return (rval);
}

/*
 * write EFI label and backup label
 */
int
efi_write(int fd, struct dk_gpt *vtoc)
{
        dk_efi_t                dk_ioc;
        efi_gpt_t               *efi;
        efi_gpe_t               *efi_parts;
        int                     i, j;
        struct dk_cinfo         dki_info;
        int                     rval;
        int                     md_flag = 0;
        int                     nblocks;
        diskaddr_t              lba_backup_gpt_hdr;

        if ((rval = efi_get_info(fd, &dki_info)) != 0)
                return (rval);

        /* check if we are dealing with a metadevice */
        if ((strncmp(dki_info.dki_cname, "pseudo", 7) == 0) &&
            (strncmp(dki_info.dki_dname, "md", 3) == 0)) {
                md_flag = 1;
        }

        if (check_input(vtoc)) {
                /*
                 * not valid; if it's a metadevice just pass it down
                 * because SVM will do its own checking
                 */
                if (md_flag == 0) {
                        return (VT_EINVAL);
                }
        }

        dk_ioc.dki_lba = 1;
        if (NBLOCKS(vtoc->efi_nparts, vtoc->efi_lbasize) < 34) {
                dk_ioc.dki_length = EFI_MIN_ARRAY_SIZE + vtoc->efi_lbasize;
        } else {
                dk_ioc.dki_length = NBLOCKS(vtoc->efi_nparts,
                    vtoc->efi_lbasize) *
                    vtoc->efi_lbasize;
        }

        /*
         * the number of blocks occupied by GUID partition entry array
         */
        nblocks = dk_ioc.dki_length / vtoc->efi_lbasize - 1;

        /*
         * Backup GPT header is located on the block after GUID
         * partition entry array. Here, we calculate the address
         * for backup GPT header.
         */
        lba_backup_gpt_hdr = vtoc->efi_last_u_lba + 1 + nblocks;
        if (posix_memalign((void **)&dk_ioc.dki_data,
            vtoc->efi_lbasize, dk_ioc.dki_length))
                return (VT_ERROR);

        memset(dk_ioc.dki_data, 0, dk_ioc.dki_length);
        efi = dk_ioc.dki_data;

        /* stuff user's input into EFI struct */
        efi->efi_gpt_Signature = LE_64(EFI_SIGNATURE);
        efi->efi_gpt_Revision = LE_32(vtoc->efi_version); /* 0x02000100 */
        efi->efi_gpt_HeaderSize = LE_32(sizeof (struct efi_gpt) - LEN_EFI_PAD);
        efi->efi_gpt_Reserved1 = 0;
        efi->efi_gpt_MyLBA = LE_64(1ULL);
        efi->efi_gpt_AlternateLBA = LE_64(lba_backup_gpt_hdr);
        efi->efi_gpt_FirstUsableLBA = LE_64(vtoc->efi_first_u_lba);
        efi->efi_gpt_LastUsableLBA = LE_64(vtoc->efi_last_u_lba);
        efi->efi_gpt_PartitionEntryLBA = LE_64(2ULL);
        efi->efi_gpt_NumberOfPartitionEntries = LE_32(vtoc->efi_nparts);
        efi->efi_gpt_SizeOfPartitionEntry = LE_32(sizeof (struct efi_gpe));
        UUID_LE_CONVERT(efi->efi_gpt_DiskGUID, vtoc->efi_disk_uguid);

        /* LINTED -- always longlong aligned */
        efi_parts = (efi_gpe_t *)((char *)dk_ioc.dki_data + vtoc->efi_lbasize);

        for (i = 0; i < vtoc->efi_nparts; i++) {
                for (j = 0;
                    j < sizeof (conversion_array) /
                    sizeof (struct uuid_to_ptag); j++) {

                        if (vtoc->efi_parts[i].p_tag == j) {
                                UUID_LE_CONVERT(
                                    efi_parts[i].efi_gpe_PartitionTypeGUID,
                                    conversion_array[j].uuid);
                                break;
                        }
                }

                if (j == sizeof (conversion_array) /
                    sizeof (struct uuid_to_ptag)) {
                        /*
                         * If we didn't have a matching uuid match, bail here.
                         * Don't write a label with unknown uuid.
                         */
                        if (efi_debug) {
                                (void) fprintf(stderr,
                                    "Unknown uuid for p_tag %d\n",
                                    vtoc->efi_parts[i].p_tag);
                        }
                        return (VT_EINVAL);
                }

                /* Zero's should be written for empty partitions */
                if (vtoc->efi_parts[i].p_tag == V_UNASSIGNED)
                        continue;

                efi_parts[i].efi_gpe_StartingLBA =
                    LE_64(vtoc->efi_parts[i].p_start);
                efi_parts[i].efi_gpe_EndingLBA =
                    LE_64(vtoc->efi_parts[i].p_start +
                    vtoc->efi_parts[i].p_size - 1);
                efi_parts[i].efi_gpe_Attributes.PartitionAttrs =
                    LE_16(vtoc->efi_parts[i].p_flag);
                for (j = 0; j < EFI_PART_NAME_LEN; j++) {
                        efi_parts[i].efi_gpe_PartitionName[j] =
                            LE_16((ushort_t)vtoc->efi_parts[i].p_name[j]);
                }
                if ((vtoc->efi_parts[i].p_tag != V_UNASSIGNED) &&
                    uuid_is_null((uchar_t *)&vtoc->efi_parts[i].p_uguid)) {
                        (void) uuid_generate((uchar_t *)
                            &vtoc->efi_parts[i].p_uguid);
                }
                memcpy(&efi_parts[i].efi_gpe_UniquePartitionGUID,
                    &vtoc->efi_parts[i].p_uguid,
                    sizeof (uuid_t));
        }
        efi->efi_gpt_PartitionEntryArrayCRC32 =
            LE_32(efi_crc32((unsigned char *)efi_parts,
            vtoc->efi_nparts * (int)sizeof (struct efi_gpe)));
        efi->efi_gpt_HeaderCRC32 =
            LE_32(efi_crc32((unsigned char *)efi,
            LE_32(efi->efi_gpt_HeaderSize)));

        if (efi_ioctl(fd, DKIOCSETEFI, &dk_ioc) == -1) {
                free(dk_ioc.dki_data);
                switch (errno) {
                case EIO:
                        return (VT_EIO);
                case EINVAL:
                        return (VT_EINVAL);
                default:
                        return (VT_ERROR);
                }
        }
        /* if it's a metadevice we're done */
        if (md_flag) {
                free(dk_ioc.dki_data);
                return (0);
        }

        /* write backup partition array */
        dk_ioc.dki_lba = vtoc->efi_last_u_lba + 1;
        dk_ioc.dki_length -= vtoc->efi_lbasize;
        /* LINTED */
        dk_ioc.dki_data = (efi_gpt_t *)((char *)dk_ioc.dki_data +
            vtoc->efi_lbasize);

        if (efi_ioctl(fd, DKIOCSETEFI, &dk_ioc) == -1) {
                /*
                 * we wrote the primary label okay, so don't fail
                 */
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "write of backup partitions to block %llu "
                            "failed, errno %d\n",
                            vtoc->efi_last_u_lba + 1,
                            errno);
                }
        }
        /*
         * now swap MyLBA and AlternateLBA fields and write backup
         * partition table header
         */
        dk_ioc.dki_lba = lba_backup_gpt_hdr;
        dk_ioc.dki_length = vtoc->efi_lbasize;
        /* LINTED */
        dk_ioc.dki_data = (efi_gpt_t *)((char *)dk_ioc.dki_data -
            vtoc->efi_lbasize);
        efi->efi_gpt_AlternateLBA = LE_64(1ULL);
        efi->efi_gpt_MyLBA = LE_64(lba_backup_gpt_hdr);
        efi->efi_gpt_PartitionEntryLBA = LE_64(vtoc->efi_last_u_lba + 1);
        efi->efi_gpt_HeaderCRC32 = 0;
        efi->efi_gpt_HeaderCRC32 =
            LE_32(efi_crc32((unsigned char *)dk_ioc.dki_data,
            LE_32(efi->efi_gpt_HeaderSize)));

        if (efi_ioctl(fd, DKIOCSETEFI, &dk_ioc) == -1) {
                if (efi_debug) {
                        (void) fprintf(stderr,
                            "write of backup header to block %llu failed, "
                            "errno %d\n",
                            lba_backup_gpt_hdr,
                            errno);
                }
        }
        /* write the PMBR */
        (void) write_pmbr(fd, vtoc);
        free(dk_ioc.dki_data);

        return (0);
}

void
efi_free(struct dk_gpt *ptr)
{
        free(ptr);
}

void
efi_err_check(struct dk_gpt *vtoc)
{
        int                     resv_part = -1;
        int                     i, j;
        diskaddr_t              istart, jstart, isize, jsize, endsect;
        int                     overlap = 0;

        /*
         * make sure no partitions overlap
         */
        for (i = 0; i < vtoc->efi_nparts; i++) {
                /* It can't be unassigned and have an actual size */
                if ((vtoc->efi_parts[i].p_tag == V_UNASSIGNED) &&
                    (vtoc->efi_parts[i].p_size != 0)) {
                        (void) fprintf(stderr,
                            "partition %d is \"unassigned\" but has a size "
                            "of %llu\n", i, vtoc->efi_parts[i].p_size);
                }
                if (vtoc->efi_parts[i].p_tag == V_UNASSIGNED) {
                        continue;
                }
                if (vtoc->efi_parts[i].p_tag == V_RESERVED) {
                        if (resv_part != -1) {
                                (void) fprintf(stderr,
                                    "found duplicate reserved partition at "
                                    "%d\n", i);
                        }
                        resv_part = i;
                        if (vtoc->efi_parts[i].p_size != EFI_MIN_RESV_SIZE)
                                (void) fprintf(stderr,
                                    "Warning: reserved partition size must "
                                    "be %d sectors\n", EFI_MIN_RESV_SIZE);
                }
                if ((vtoc->efi_parts[i].p_start < vtoc->efi_first_u_lba) ||
                    (vtoc->efi_parts[i].p_start > vtoc->efi_last_u_lba)) {
                        (void) fprintf(stderr,
                            "Partition %d starts at %llu\n",
                            i,
                            vtoc->efi_parts[i].p_start);
                        (void) fprintf(stderr,
                            "It must be between %llu and %llu.\n",
                            vtoc->efi_first_u_lba,
                            vtoc->efi_last_u_lba);
                }
                if ((vtoc->efi_parts[i].p_start +
                    vtoc->efi_parts[i].p_size <
                    vtoc->efi_first_u_lba) ||
                    (vtoc->efi_parts[i].p_start +
                    vtoc->efi_parts[i].p_size >
                    vtoc->efi_last_u_lba + 1)) {
                        (void) fprintf(stderr,
                            "Partition %d ends at %llu\n",
                            i,
                            vtoc->efi_parts[i].p_start +
                            vtoc->efi_parts[i].p_size);
                        (void) fprintf(stderr,
                            "It must be between %llu and %llu.\n",
                            vtoc->efi_first_u_lba,
                            vtoc->efi_last_u_lba);
                }

                for (j = 0; j < vtoc->efi_nparts; j++) {
                        isize = vtoc->efi_parts[i].p_size;
                        jsize = vtoc->efi_parts[j].p_size;
                        istart = vtoc->efi_parts[i].p_start;
                        jstart = vtoc->efi_parts[j].p_start;
                        if ((i != j) && (isize != 0) && (jsize != 0)) {
                                endsect = jstart + jsize -1;
                                if ((jstart <= istart) &&
                                    (istart <= endsect)) {
                                        if (!overlap) {
                                        (void) fprintf(stderr,
                                            "label error: EFI Labels do not "
                                            "support overlapping partitions\n");
                                        }
                                        (void) fprintf(stderr,
                                            "Partition %d overlaps partition "
                                            "%d.\n", i, j);
                                        overlap = 1;
                                }
                        }
                }
        }
        /* make sure there is a reserved partition */
        if (resv_part == -1) {
                (void) fprintf(stderr,
                    "no reserved partition found\n");
        }
}