/*
 * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Matthew Dillon <dillon@backplane.com>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name of The DragonFly Project nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific, prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <sys/disklabel.h>
#include <sys/disklabel64.h>
#include <sys/diskslice.h>
#include <sys/disk.h>
#include <sys/kern_syscall.h>
#include <sys/buf2.h>

/*
 * Alignment against physical start (verses slice start).  We use a megabyte
 * here.  Why do we use a megabyte?  Because SSDs already use large 128K
 * blocks internally (for MLC) and who the hell knows in the future.
 *
 * This way if the sysop picks sane values for partition sizes everything
 * will be nicely aligned, particularly swap for e.g. swapcache, and
 * clustered operations against larger physical sector sizes for newer HDs,
 * and so forth.
 */
#define PALIGN_SIZE     (1024 * 1024)
#define PALIGN_MASK     (PALIGN_SIZE - 1)

/*
 * Retrieve the partition start and extent, in blocks.  Return 0 on success,
 * EINVAL on error.
 */
static int
l64_getpartbounds(struct diskslices *ssp, disklabel_t lp, u_int32_t part,
                  u_int64_t *start, u_int64_t *blocks)
{
        struct partition64 *pp;

        if (part >= lp.lab64->d_npartitions)
                return (EINVAL);

        pp = &lp.lab64->d_partitions[part];

        if ((pp->p_boffset & (ssp->dss_secsize - 1)) ||
            (pp->p_bsize & (ssp->dss_secsize - 1))) {
                return (EINVAL);
        }
        *start = pp->p_boffset / ssp->dss_secsize;
        *blocks = pp->p_bsize / ssp->dss_secsize;
        return(0);
}

/*
 * Get the filesystem type XXX - diskslices code needs to use uuids
 */
static void
l64_loadpartinfo(disklabel_t lp, u_int32_t part, struct partinfo *dpart)
{
        struct partition64 *pp;
        const size_t uuid_size = sizeof(struct uuid);

        if (part < lp.lab64->d_npartitions) {
                pp = &lp.lab64->d_partitions[part];
                dpart->fstype_uuid = pp->p_type_uuid;
                dpart->storage_uuid = pp->p_stor_uuid;
                dpart->fstype = pp->p_fstype;
        } else {
                bzero(&dpart->fstype_uuid, uuid_size);
                bzero(&dpart->storage_uuid, uuid_size);
                dpart->fstype = 0;
        }
}

/*
 * Get the number of partitions
 */
static u_int32_t
l64_getnumparts(disklabel_t lp)
{
        return(lp.lab64->d_npartitions);
}

static int
l64_getpackname(disklabel_t lp, char *buf, size_t bytes)
{
        size_t slen;

        if (lp.lab64->d_packname[0] == 0) {
                buf[0] = 0;
                return -1;
        }
        slen = strnlen(lp.lab64->d_packname, sizeof(lp.lab64->d_packname));
        if (slen >= bytes)
                slen = bytes - 1;
        bcopy(lp.lab64->d_packname, buf, slen);
        buf[slen] = 0;

        return 0;
}

static void
l64_freedisklabel(disklabel_t *lpp)
{
        kfree((*lpp).lab64, M_DEVBUF);
        (*lpp).lab64 = NULL;
}

/*
 * Attempt to read a disk label from a device.  64 bit disklabels are
 * sector-agnostic and begin at offset 0 on the device.
 *
 * Returns NULL on sucess, and an error string on failure.
 */
static const char *
l64_readdisklabel(cdev_t dev, struct diskslice *sp, disklabel_t *lpp,
                  struct disk_info *info)
{
        struct buf *bp;
        struct disklabel64 *dlp;
        const char *msg;
        uint32_t savecrc;
        size_t dlpcrcsize;
        size_t bpsize;
        int secsize;

        /*
         * XXX I/O size is subject to device DMA limitations
         */
        secsize = info->d_media_blksize;
        bpsize = roundup2(sizeof(*dlp), secsize);

        bp = getpbuf_mem(NULL);
        KKASSERT(bpsize <= bp->b_bufsize);
        bp->b_bio1.bio_offset = 0;
        bp->b_bio1.bio_done = biodone_sync;
        bp->b_bio1.bio_flags |= BIO_SYNC;
        bp->b_bcount = bpsize;
        bp->b_flags &= ~B_INVAL;
        bp->b_flags |= B_FAILONDIS;
        bp->b_cmd = BUF_CMD_READ;
        dev_dstrategy(dev, &bp->b_bio1);

        if (biowait(&bp->b_bio1, "labrd")) {
                msg = "I/O error";
        } else {
                dlp = (struct disklabel64 *)bp->b_data;
                dlpcrcsize = offsetof(struct disklabel64,
                                      d_partitions[dlp->d_npartitions]) -
                             offsetof(struct disklabel64, d_magic);
                savecrc = dlp->d_crc;
                dlp->d_crc = 0;
                if (dlp->d_magic != DISKMAGIC64) {
                        msg = "no disk label";
                } else if (dlp->d_npartitions > MAXPARTITIONS64) {
                        msg = "disklabel64 corrupted, too many partitions";
                } else if (savecrc != crc32(&dlp->d_magic, dlpcrcsize)) {
                        msg = "disklabel64 corrupted, bad CRC";
                } else {
                        dlp->d_crc = savecrc;
                        (*lpp).lab64 = kmalloc(sizeof(*dlp),
                                               M_DEVBUF, M_WAITOK|M_ZERO);
                        *(*lpp).lab64 = *dlp;
                        msg = NULL;
                }
        }
        bp->b_flags |= B_INVAL | B_AGE;
        relpbuf(bp, NULL);

        return (msg);
}

/*
 * If everything is good, copy olpx to nlpx.  Check to see if any
 * open partitions would change.
 */
static int
l64_setdisklabel(disklabel_t olpx, disklabel_t nlpx, struct diskslices *ssp,
                 struct diskslice *sp, u_int32_t *openmask)
{
        struct disklabel64 *olp, *nlp;
        struct partition64 *opp, *npp;
        uint32_t savecrc;
        uint64_t slicebsize;
        size_t nlpcrcsize;
        int i;

        olp = olpx.lab64;
        nlp = nlpx.lab64;

        slicebsize = (uint64_t)sp->ds_size * ssp->dss_secsize;

        if (nlp->d_magic != DISKMAGIC64)
                return (EINVAL);
        if (nlp->d_npartitions > MAXPARTITIONS64)
                return (EINVAL);
        savecrc = nlp->d_crc;
        nlp->d_crc = 0;
        nlpcrcsize = offsetof(struct disklabel64,
                              d_partitions[nlp->d_npartitions]) -
                     offsetof(struct disklabel64, d_magic);
        if (crc32(&nlp->d_magic, nlpcrcsize) != savecrc) {
                nlp->d_crc = savecrc;
                return (EINVAL);
        }
        nlp->d_crc = savecrc;

        /*
         * Check if open partitions have changed
         */
        i = 0;
        while (i < MAXPARTITIONS64) {
                if (openmask[i >> 5] == 0) {
                        i += 32;
                        continue;
                }
                if ((openmask[i >> 5] & (1 << (i & 31))) == 0) {
                        ++i;
                        continue;
                }
                if (nlp->d_npartitions <= i)
                        return (EBUSY);
                opp = &olp->d_partitions[i];
                npp = &nlp->d_partitions[i];
                if (npp->p_boffset != opp->p_boffset ||
                    npp->p_bsize < opp->p_bsize) {
                        return (EBUSY);
                }

                /*
                 * Do not allow p_type_uuid or p_stor_uuid to change if
                 * the partition is currently open.
                 */
                if (bcmp(&npp->p_type_uuid, &opp->p_type_uuid,
                     sizeof(npp->p_type_uuid)) != 0) {
                        return (EBUSY);
                }
                if (bcmp(&npp->p_stor_uuid, &opp->p_stor_uuid,
                     sizeof(npp->p_stor_uuid)) != 0) {
                        return (EBUSY);
                }
                ++i;
        }

        /*
         * Make sure the label and partition offsets and sizes are sane.
         */
        if (nlp->d_total_size > slicebsize)
                return (ENOSPC);
        if (nlp->d_total_size & (ssp->dss_secsize - 1))
                return (EINVAL);
        if (nlp->d_bbase & (ssp->dss_secsize - 1))
                return (EINVAL);
        if (nlp->d_pbase & (ssp->dss_secsize - 1))
                return (EINVAL);
        if (nlp->d_pstop & (ssp->dss_secsize - 1))
                return (EINVAL);
        if (nlp->d_abase & (ssp->dss_secsize - 1))
                return (EINVAL);

        for (i = 0; i < nlp->d_npartitions; ++i) {
                npp = &nlp->d_partitions[i];
                if (npp->p_bsize == 0) {
                        if (npp->p_boffset != 0)
                                return (EINVAL);
                        continue;
                }
                if (npp->p_boffset & (ssp->dss_secsize - 1))
                        return (EINVAL);
                if (npp->p_bsize & (ssp->dss_secsize - 1))
                        return (EINVAL);
                if (npp->p_boffset < nlp->d_pbase)
                        return (ENOSPC);
                if (npp->p_boffset + npp->p_bsize > nlp->d_total_size)
                        return (ENOSPC);
        }

        /*
         * Structurally we may add code to make modifications above in the
         * future, so regenerate the crc anyway.
         */
        nlp->d_crc = 0;
        nlp->d_crc = crc32(&nlp->d_magic, nlpcrcsize);
        *olp = *nlp;

        return (0);
}

/*
 * Write disk label back to device after modification.
 */
static int
l64_writedisklabel(cdev_t dev, struct diskslices *ssp,
                   struct diskslice *sp, disklabel_t lpx)
{
        struct disklabel64 *lp;
        struct disklabel64 *dlp;
        struct buf *bp;
        int error = 0;
        size_t bpsize;
        int secsize;

        lp = lpx.lab64;

        /*
         * XXX I/O size is subject to device DMA limitations
         */
        secsize = ssp->dss_secsize;
        bpsize = roundup2(sizeof(*lp), secsize);

        bp = getpbuf_mem(NULL);
        KKASSERT(bpsize <= bp->b_bufsize);
        bp->b_bio1.bio_offset = 0;
        bp->b_bio1.bio_done = biodone_sync;
        bp->b_bio1.bio_flags |= BIO_SYNC;
        bp->b_bcount = bpsize;
        bp->b_flags |= B_FAILONDIS;

        /*
         * Because our I/O is larger then the label, and because we do not
         * write the d_reserved0[] area, do a read-modify-write.
         */
        bp->b_flags &= ~B_INVAL;
        bp->b_cmd = BUF_CMD_READ;
        KKASSERT(dkpart(dev) == WHOLE_SLICE_PART);
        dev_dstrategy(dev, &bp->b_bio1);
        error = biowait(&bp->b_bio1, "labrd");
        if (error)
                goto done;

        dlp = (void *)bp->b_data;
        bcopy(&lp->d_magic, &dlp->d_magic,
              sizeof(*lp) - offsetof(struct disklabel64, d_magic));
        bp->b_cmd = BUF_CMD_WRITE;
        bp->b_bio1.bio_done = biodone_sync;
        bp->b_bio1.bio_flags |= BIO_SYNC;
        KKASSERT(dkpart(dev) == WHOLE_SLICE_PART);
        dev_dstrategy(dev, &bp->b_bio1);
        error = biowait(&bp->b_bio1, "labwr");
done:
        bp->b_flags |= B_INVAL | B_AGE;
        relpbuf(bp, NULL);

        return (error);
}

/*
 * Create a disklabel based on a disk_info structure for the purposes of
 * DSO_COMPATLABEL - cases where no real label exists on the storage medium.
 *
 * If a diskslice is passed, the label is truncated to the slice.
 *
 * NOTE!  This is not a legal label because d_bbase and d_pbase are both
 * set to 0.
 */
static disklabel_t
l64_clone_label(struct disk_info *info, struct diskslice *sp)
{
        struct disklabel64 *lp;
        disklabel_t res;
        uint32_t blksize = info->d_media_blksize;
        size_t lpcrcsize;

        lp = kmalloc(sizeof *lp, M_DEVBUF, M_WAITOK | M_ZERO);

        if (sp)
                lp->d_total_size = (uint64_t)sp->ds_size * blksize;
        else
                lp->d_total_size = info->d_media_blocks * blksize;

        lp->d_magic = DISKMAGIC64;
        lp->d_align = blksize;
        lp->d_npartitions = MAXPARTITIONS64;
        lp->d_pstop = lp->d_total_size;

        /*
         * Create a dummy 'c' part and a dummy 'a' part (if requested).
         * Note that the 'c' part is really a hack.  64 bit disklabels
         * do not use 'c' to mean the raw partition.
         */

        lp->d_partitions[2].p_boffset = 0;
        lp->d_partitions[2].p_bsize = lp->d_total_size;
        /* XXX SET FS TYPE */

        if (info->d_dsflags & DSO_COMPATPARTA) {
                lp->d_partitions[0].p_boffset = 0;
                lp->d_partitions[0].p_bsize = lp->d_total_size;
                /* XXX SET FS TYPE */
        }

        lpcrcsize = offsetof(struct disklabel64,
                             d_partitions[lp->d_npartitions]) -
                    offsetof(struct disklabel64, d_magic);

        lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
        res.lab64 = lp;
        return (res);
}

/*
 * Create a virgin disklabel64 suitable for writing to the media.
 *
 * disklabel64 always reserves 32KB for a boot area and leaves room
 * for up to RESPARTITIONS64 partitions.
 */
static void
l64_makevirginlabel(disklabel_t lpx, struct diskslices *ssp,
                    struct diskslice *sp, struct disk_info *info)
{
        struct disklabel64 *lp = lpx.lab64;
        struct partition64 *pp;
        uint32_t blksize;
        uint32_t ressize;
        uint64_t blkmask;       /* 64 bits so we can ~ */
        uint64_t doffset;
        size_t lpcrcsize;

        doffset = sp->ds_offset * info->d_media_blksize;

        /*
         * Setup the initial label.  Use of a block size of at least 4KB
         * for calculating the initial reserved areas to allow some degree
         * of portability between media with different sector sizes.
         *
         * Note that the modified blksize is stored in d_align as a hint
         * to the disklabeling program.
         */
        bzero(lp, sizeof(*lp));
        if ((blksize = info->d_media_blksize) < 4096)
                blksize = 4096;
        blkmask = blksize - 1;

        if (sp)
                lp->d_total_size = (uint64_t)sp->ds_size * ssp->dss_secsize;
        else
                lp->d_total_size = info->d_media_blocks * info->d_media_blksize;

        lp->d_magic = DISKMAGIC64;
        lp->d_align = blksize;
        lp->d_npartitions = MAXPARTITIONS64;
        kern_uuidgen(&lp->d_stor_uuid, 1);

        ressize = offsetof(struct disklabel64, d_partitions[RESPARTITIONS64]);
        ressize = (ressize + (uint32_t)blkmask) & ~blkmask;

        /* Reserve space for the stage2 boot code */
        lp->d_bbase = ressize;
        lp->d_pbase = lp->d_bbase + ((BOOT2SIZE64 + blkmask) & ~blkmask);

        /* Reserve space for the backup label at the slice end */
        lp->d_abase = lp->d_total_size - ressize;

        /*
         * NOTE: The pbase and pstop are calculated to align to PALIGN_SIZE
         *       and adjusted with the slice offset, so the partitions are
         *       aligned relative to the start of the physical disk.
         */
        lp->d_pbase = ((doffset + lp->d_pbase + PALIGN_MASK) &
                       ~(uint64_t)PALIGN_MASK) - doffset;
        lp->d_pstop = ((lp->d_abase - lp->d_pbase) &
                       ~(uint64_t)PALIGN_MASK) + lp->d_pbase;

        /*
         * All partitions are left empty unless DSO_COMPATPARTA is set
         */

        if (info->d_dsflags & DSO_COMPATPARTA) {
                pp = &lp->d_partitions[0];
                pp->p_boffset = lp->d_pbase;
                pp->p_bsize = lp->d_pstop - lp->d_pbase;
                /* XXX SET FS TYPE */
        }

        lpcrcsize = offsetof(struct disklabel64,
                             d_partitions[lp->d_npartitions]) -
                    offsetof(struct disklabel64, d_magic);
        lp->d_crc = crc32(&lp->d_magic, lpcrcsize);
}

/*
 * Set the number of blocks at the beginning of the slice which have
 * been reserved for label operations.  This area will be write-protected
 * when accessed via the slice.
 *
 * For now just protect the label area proper.  Do not protect the
 * boot area.  Note partitions in 64 bit disklabels do not overlap
 * the disklabel or boot area.
 */
static void
l64_adjust_label_reserved(struct diskslices *ssp, int slice,
                          struct diskslice *sp)
{
        struct disklabel64 *lp = sp->ds_label.lab64;

        sp->ds_reserved = lp->d_bbase / ssp->dss_secsize;
}

struct disklabel_ops disklabel64_ops = {
        .labelsize = sizeof(struct disklabel64),
        .op_readdisklabel = l64_readdisklabel,
        .op_setdisklabel = l64_setdisklabel,
        .op_writedisklabel = l64_writedisklabel,
        .op_clone_label = l64_clone_label,
        .op_adjust_label_reserved = l64_adjust_label_reserved,
        .op_getpartbounds = l64_getpartbounds,
        .op_loadpartinfo = l64_loadpartinfo,
        .op_getnumparts = l64_getnumparts,
        .op_getpackname = l64_getpackname,
        .op_makevirginlabel = l64_makevirginlabel,
        .op_freedisklabel = l64_freedisklabel
};