Archipelago » qemu

/*

 * Block driver for RAW files (posix)

 *

 * Copyright (c) 2006 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "qemu-common.h"

#include "qemu-timer.h"

#include "qemu-char.h"

#include "qemu-log.h"

#include "block_int.h"

#include "module.h"

#include "block/raw-posix-aio.h"

#ifdef CONFIG_COCOA

#include <paths.h>

#include <sys/param.h>

#include <IOKit/IOKitLib.h>

#include <IOKit/IOBSD.h>

#include <IOKit/storage/IOMediaBSDClient.h>

#include <IOKit/storage/IOMedia.h>

#include <IOKit/storage/IOCDMedia.h>

//#include <IOKit/storage/IOCDTypes.h>

#include <CoreFoundation/CoreFoundation.h>

#endif

#ifdef __sun__

#define _POSIX_PTHREAD_SEMANTICS 1

#include <signal.h>

#include <sys/dkio.h>

#endif

#ifdef __linux__

#include <sys/ioctl.h>

#include <sys/param.h>

#include <linux/cdrom.h>

#include <linux/fd.h>

#endif

#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

#include <signal.h>

#include <sys/disk.h>

#include <sys/cdio.h>

#endif

#ifdef __OpenBSD__

#include <sys/ioctl.h>

#include <sys/disklabel.h>

#include <sys/dkio.h>

#endif

#ifdef __DragonFly__

#include <sys/ioctl.h>

#include <sys/diskslice.h>

#endif

//#define DEBUG_FLOPPY

//#define DEBUG_BLOCK

#if defined(DEBUG_BLOCK)

#define DEBUG_BLOCK_PRINT(formatCstr, ...) do { if (qemu_log_enabled()) \

    { qemu_log(formatCstr, ## __VA_ARGS__); qemu_log_flush(); } } while (0)

#else

#define DEBUG_BLOCK_PRINT(formatCstr, ...)

#endif

/* OS X does not have O_DSYNC */

#ifndef O_DSYNC

#ifdef O_SYNC

#define O_DSYNC O_SYNC

#elif defined(O_FSYNC)

#define O_DSYNC O_FSYNC

#endif

#endif

/* Approximate O_DIRECT with O_DSYNC if O_DIRECT isn't available */

#ifndef O_DIRECT

#define O_DIRECT O_DSYNC

#endif

#define FTYPE_FILE   0

#define FTYPE_CD     1

#define FTYPE_FD     2

/* if the FD is not accessed during that time (in ns), we try to

   reopen it to see if the disk has been changed */

#define FD_OPEN_TIMEOUT (1000000000)

#define MAX_BLOCKSIZE        4096

typedef struct BDRVRawState {

    int fd;

    int type;

    int open_flags;

#if defined(__linux__)

    /* linux floppy specific */

    int64_t fd_open_time;

    int64_t fd_error_time;

    int fd_got_error;

    int fd_media_changed;

#endif

#ifdef CONFIG_LINUX_AIO

    int use_aio;

    void *aio_ctx;

#endif

    uint8_t *aligned_buf;

    unsigned aligned_buf_size;

} BDRVRawState;

static int fd_open(BlockDriverState *bs);

static int64_t raw_getlength(BlockDriverState *bs);

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)

static int cdrom_reopen(BlockDriverState *bs);

#endif

static int raw_open_common(BlockDriverState *bs, const char *filename,

                           int bdrv_flags, int open_flags)

{

    BDRVRawState *s = bs->opaque;

    int fd, ret;

    s->open_flags = open_flags | O_BINARY;

    s->open_flags &= ~O_ACCMODE;

    if (bdrv_flags & BDRV_O_RDWR) {

        s->open_flags |= O_RDWR;

    } else {

        s->open_flags |= O_RDONLY;

    }

    /* Use O_DSYNC for write-through caching, no flags for write-back caching,

     * and O_DIRECT for no caching. */

    if ((bdrv_flags & BDRV_O_NOCACHE))

        s->open_flags |= O_DIRECT;

    else if (!(bdrv_flags & BDRV_O_CACHE_WB))

        s->open_flags |= O_DSYNC;

    s->fd = -1;

    fd = qemu_open(filename, s->open_flags, 0644);

    if (fd < 0) {

        ret = -errno;

        if (ret == -EROFS)

            ret = -EACCES;

        return ret;

    }

    s->fd = fd;

    s->aligned_buf = NULL;

    if ((bdrv_flags & BDRV_O_NOCACHE)) {

        /*

         * Allocate a buffer for read/modify/write cycles.  Chose the size

         * pessimistically as we don't know the block size yet.

         */

        s->aligned_buf_size = 32 * MAX_BLOCKSIZE;

        s->aligned_buf = qemu_memalign(MAX_BLOCKSIZE, s->aligned_buf_size);

        if (s->aligned_buf == NULL) {

            goto out_close;

        }

    }

#ifdef CONFIG_LINUX_AIO

    if ((bdrv_flags & (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) ==

                      (BDRV_O_NOCACHE|BDRV_O_NATIVE_AIO)) {

        /* We're falling back to POSIX AIO in some cases */

        paio_init();

        s->aio_ctx = laio_init();

        if (!s->aio_ctx) {

            goto out_free_buf;

        }

        s->use_aio = 1;

    } else

#endif

    {

        if (paio_init() < 0) {

            goto out_free_buf;

        }

#ifdef CONFIG_LINUX_AIO

        s->use_aio = 0;

#endif

    }

    return 0;

out_free_buf:

    qemu_vfree(s->aligned_buf);

out_close:

    close(fd);

    return -errno;

}

static int raw_open(BlockDriverState *bs, const char *filename, int flags)

{

    BDRVRawState *s = bs->opaque;

    s->type = FTYPE_FILE;

    return raw_open_common(bs, filename, flags, 0);

}

/* XXX: use host sector size if necessary with:

#ifdef DIOCGSECTORSIZE

        {

            unsigned int sectorsize = 512;

            if (!ioctl(fd, DIOCGSECTORSIZE, &sectorsize) &&

                sectorsize > bufsize)

                bufsize = sectorsize;

        }

#endif

#ifdef CONFIG_COCOA

        uint32_t blockSize = 512;

        if ( !ioctl( fd, DKIOCGETBLOCKSIZE, &blockSize ) && blockSize > bufsize) {

            bufsize = blockSize;

        }

#endif

*/

/*

 * offset and count are in bytes, but must be multiples of 512 for files

 * opened with O_DIRECT. buf must be aligned to 512 bytes then.

 *

 * This function may be called without alignment if the caller ensures

 * that O_DIRECT is not in effect.

 */

static int raw_pread_aligned(BlockDriverState *bs, int64_t offset,

                     uint8_t *buf, int count)

{

    BDRVRawState *s = bs->opaque;

    int ret;

    ret = fd_open(bs);

    if (ret < 0)

        return ret;

    ret = pread(s->fd, buf, count, offset);

    if (ret == count)

        return ret;

    /* Allow reads beyond the end (needed for pwrite) */

    if ((ret == 0) && bs->growable) {

        int64_t size = raw_getlength(bs);

        if (offset >= size) {

            memset(buf, 0, count);

            return count;

        }

    }

    DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64

                      "] read failed %d : %d = %s\n",

                      s->fd, bs->filename, offset, buf, count,

                      bs->total_sectors, ret, errno, strerror(errno));

    /* Try harder for CDrom. */

    if (s->type != FTYPE_FILE) {

        ret = pread(s->fd, buf, count, offset);

        if (ret == count)

            return ret;

        ret = pread(s->fd, buf, count, offset);

        if (ret == count)

            return ret;

        DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64

                          "] retry read failed %d : %d = %s\n",

                          s->fd, bs->filename, offset, buf, count,

                          bs->total_sectors, ret, errno, strerror(errno));

    }

    return  (ret < 0) ? -errno : ret;

}

/*

 * offset and count are in bytes, but must be multiples of the sector size

 * for files opened with O_DIRECT. buf must be aligned to sector size bytes

 * then.

 *

 * This function may be called without alignment if the caller ensures

 * that O_DIRECT is not in effect.

 */

static int raw_pwrite_aligned(BlockDriverState *bs, int64_t offset,

                      const uint8_t *buf, int count)

{

    BDRVRawState *s = bs->opaque;

    int ret;

    ret = fd_open(bs);

    if (ret < 0)

        return -errno;

    ret = pwrite(s->fd, buf, count, offset);

    if (ret == count)

        return ret;

    DEBUG_BLOCK_PRINT("raw_pwrite(%d:%s, %" PRId64 ", %p, %d) [%" PRId64

                      "] write failed %d : %d = %s\n",

                      s->fd, bs->filename, offset, buf, count,

                      bs->total_sectors, ret, errno, strerror(errno));

    return  (ret < 0) ? -errno : ret;

}

/*

 * offset and count are in bytes and possibly not aligned. For files opened

 * with O_DIRECT, necessary alignments are ensured before calling

 * raw_pread_aligned to do the actual read.

 */

static int raw_pread(BlockDriverState *bs, int64_t offset,

                     uint8_t *buf, int count)

{

    BDRVRawState *s = bs->opaque;

    unsigned sector_mask = bs->buffer_alignment - 1;

    int size, ret, shift, sum;

    sum = 0;

    if (s->aligned_buf != NULL)  {

        if (offset & sector_mask) {

            /* align offset on a sector size bytes boundary */

            shift = offset & sector_mask;

            size = (shift + count + sector_mask) & ~sector_mask;

            if (size > s->aligned_buf_size)

                size = s->aligned_buf_size;

            ret = raw_pread_aligned(bs, offset - shift, s->aligned_buf, size);

            if (ret < 0)

                return ret;

            size = bs->buffer_alignment - shift;

            if (size > count)

                size = count;

            memcpy(buf, s->aligned_buf + shift, size);

            buf += size;

            offset += size;

            count -= size;

            sum += size;

            if (count == 0)

                return sum;

        }

        if (count & sector_mask || (uintptr_t) buf & sector_mask) {

            /* read on aligned buffer */

            while (count) {

                size = (count + sector_mask) & ~sector_mask;

                if (size > s->aligned_buf_size)

                    size = s->aligned_buf_size;

                ret = raw_pread_aligned(bs, offset, s->aligned_buf, size);

                if (ret < 0) {

                    return ret;

                } else if (ret == 0) {

                    fprintf(stderr, "raw_pread: read beyond end of file\n");

                    abort();

                }

                size = ret;

                if (size > count)

                    size = count;

                memcpy(buf, s->aligned_buf, size);

                buf += size;

                offset += size;

                count -= size;

                sum += size;

            }

            return sum;

        }

    }

    return raw_pread_aligned(bs, offset, buf, count) + sum;

}

static int raw_read(BlockDriverState *bs, int64_t sector_num,

                    uint8_t *buf, int nb_sectors)

{

    int ret;

    ret = raw_pread(bs, sector_num * BDRV_SECTOR_SIZE, buf,

                    nb_sectors * BDRV_SECTOR_SIZE);

    if (ret == (nb_sectors * BDRV_SECTOR_SIZE))

        ret = 0;

    return ret;

}

/*

 * offset and count are in bytes and possibly not aligned. For files opened

 * with O_DIRECT, necessary alignments are ensured before calling

 * raw_pwrite_aligned to do the actual write.

 */

static int raw_pwrite(BlockDriverState *bs, int64_t offset,

                      const uint8_t *buf, int count)

{

    BDRVRawState *s = bs->opaque;

    unsigned sector_mask = bs->buffer_alignment - 1;

    int size, ret, shift, sum;

    sum = 0;

    if (s->aligned_buf != NULL) {

        if (offset & sector_mask) {

            /* align offset on a sector size bytes boundary */

            shift = offset & sector_mask;

            ret = raw_pread_aligned(bs, offset - shift, s->aligned_buf,

                                    bs->buffer_alignment);

            if (ret < 0)

                return ret;

            size = bs->buffer_alignment - shift;

            if (size > count)

                size = count;

            memcpy(s->aligned_buf + shift, buf, size);

            ret = raw_pwrite_aligned(bs, offset - shift, s->aligned_buf,

                                     bs->buffer_alignment);

            if (ret < 0)

                return ret;

            buf += size;

            offset += size;

            count -= size;

            sum += size;

            if (count == 0)

                return sum;

        }

        if (count & sector_mask || (uintptr_t) buf & sector_mask) {

            while ((size = (count & ~sector_mask)) != 0) {

                if (size > s->aligned_buf_size)

                    size = s->aligned_buf_size;

                memcpy(s->aligned_buf, buf, size);

                ret = raw_pwrite_aligned(bs, offset, s->aligned_buf, size);

                if (ret < 0)

                    return ret;

                buf += ret;

                offset += ret;

                count -= ret;

                sum += ret;

            }

            /* here, count < 512 because (count & ~sector_mask) == 0 */

            if (count) {

                ret = raw_pread_aligned(bs, offset, s->aligned_buf,

                                     bs->buffer_alignment);

                if (ret < 0)

                    return ret;

                 memcpy(s->aligned_buf, buf, count);

                 ret = raw_pwrite_aligned(bs, offset, s->aligned_buf,

                                     bs->buffer_alignment);

                 if (ret < 0)

                     return ret;

                 if (count < ret)

                     ret = count;

                 sum += ret;

            }

            return sum;

        }

    }

    return raw_pwrite_aligned(bs, offset, buf, count) + sum;

}

static int raw_write(BlockDriverState *bs, int64_t sector_num,

                     const uint8_t *buf, int nb_sectors)

{

    int ret;

    ret = raw_pwrite(bs, sector_num * BDRV_SECTOR_SIZE, buf,

                     nb_sectors * BDRV_SECTOR_SIZE);

    if (ret == (nb_sectors * BDRV_SECTOR_SIZE))

        ret = 0;

    return ret;

}

/*

 * Check if all memory in this vector is sector aligned.

 */

static int qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)

{

    int i;

    for (i = 0; i < qiov->niov; i++) {

        if ((uintptr_t) qiov->iov[i].iov_base % bs->buffer_alignment) {

            return 0;

        }

    }

    return 1;

}

static BlockDriverAIOCB *raw_aio_submit(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque, int type)

{

    BDRVRawState *s = bs->opaque;

    if (fd_open(bs) < 0)

        return NULL;

    /*

     * If O_DIRECT is used the buffer needs to be aligned on a sector

     * boundary.  Check if this is the case or telll the low-level

     * driver that it needs to copy the buffer.

     */

    if (s->aligned_buf) {

        if (!qiov_is_aligned(bs, qiov)) {

            type |= QEMU_AIO_MISALIGNED;

#ifdef CONFIG_LINUX_AIO

        } else if (s->use_aio) {

            return laio_submit(bs, s->aio_ctx, s->fd, sector_num, qiov,

                               nb_sectors, cb, opaque, type);

#endif

        }

    }

    return paio_submit(bs, s->fd, sector_num, qiov, nb_sectors,

                       cb, opaque, type);

}

static BlockDriverAIOCB *raw_aio_readv(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque)

{

    return raw_aio_submit(bs, sector_num, qiov, nb_sectors,

                          cb, opaque, QEMU_AIO_READ);

}

static BlockDriverAIOCB *raw_aio_writev(BlockDriverState *bs,

        int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,

        BlockDriverCompletionFunc *cb, void *opaque)

{

    return raw_aio_submit(bs, sector_num, qiov, nb_sectors,

                          cb, opaque, QEMU_AIO_WRITE);

}

static BlockDriverAIOCB *raw_aio_flush(BlockDriverState *bs,

        BlockDriverCompletionFunc *cb, void *opaque)

{

    BDRVRawState *s = bs->opaque;

    if (fd_open(bs) < 0)

        return NULL;

    return paio_submit(bs, s->fd, 0, NULL, 0, cb, opaque, QEMU_AIO_FLUSH);

}

static void raw_close(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    if (s->fd >= 0) {

        close(s->fd);

        s->fd = -1;

        if (s->aligned_buf != NULL)

            qemu_vfree(s->aligned_buf);

    }

}

static int raw_truncate(BlockDriverState *bs, int64_t offset)

{

    BDRVRawState *s = bs->opaque;

    if (s->type != FTYPE_FILE)

        return -ENOTSUP;

    if (ftruncate(s->fd, offset) < 0)

        return -errno;

    return 0;

}

#ifdef __OpenBSD__

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int fd = s->fd;

    struct stat st;

    if (fstat(fd, &st))

        return -1;

    if (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) {

        struct disklabel dl;

        if (ioctl(fd, DIOCGDINFO, &dl))

            return -1;

        return (uint64_t)dl.d_secsize *

            dl.d_partitions[DISKPART(st.st_rdev)].p_size;

    } else

        return st.st_size;

}

#elif defined(__sun__)

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    struct dk_minfo minfo;

    int ret;

    ret = fd_open(bs);

    if (ret < 0) {

        return ret;

    }

    /*

     * Use the DKIOCGMEDIAINFO ioctl to read the size.

     */

    ret = ioctl(s->fd, DKIOCGMEDIAINFO, &minfo);

    if (ret != -1) {

        return minfo.dki_lbsize * minfo.dki_capacity;

    }

    /*

     * There are reports that lseek on some devices fails, but

     * irc discussion said that contingency on contingency was overkill.

     */

    return lseek(s->fd, 0, SEEK_END);

}

#elif defined(CONFIG_BSD)

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int fd = s->fd;

    int64_t size;

    struct stat sb;

#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

    int reopened = 0;

#endif

    int ret;

    ret = fd_open(bs);

    if (ret < 0)

        return ret;

#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)

again:

#endif

    if (!fstat(fd, &sb) && (S_IFCHR & sb.st_mode)) {

#ifdef DIOCGMEDIASIZE

        if (ioctl(fd, DIOCGMEDIASIZE, (off_t *)&size))

#elif defined(DIOCGPART)

        {

                struct partinfo pi;

                if (ioctl(fd, DIOCGPART, &pi) == 0)

                        size = pi.media_size;

                else

                        size = 0;

        }

        if (size == 0)

#endif

#ifdef CONFIG_COCOA

        size = LONG_LONG_MAX;

#else

        size = lseek(fd, 0LL, SEEK_END);

#endif

#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)

        switch(s->type) {

        case FTYPE_CD:

            /* XXX FreeBSD acd returns UINT_MAX sectors for an empty drive */

            if (size == 2048LL * (unsigned)-1)

                size = 0;

            /* XXX no disc?  maybe we need to reopen... */

            if (size <= 0 && !reopened && cdrom_reopen(bs) >= 0) {

                reopened = 1;

                goto again;

            }

        }

#endif

    } else {

        size = lseek(fd, 0, SEEK_END);

    }

    return size;

}

#else

static int64_t raw_getlength(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    int ret;

    ret = fd_open(bs);

    if (ret < 0) {

        return ret;

    }

    return lseek(s->fd, 0, SEEK_END);

}

#endif

static int raw_create(const char *filename, QEMUOptionParameter *options)

{

    int fd;

    int result = 0;

    int64_t total_size = 0;

    /* Read out options */

    while (options && options->name) {

        if (!strcmp(options->name, BLOCK_OPT_SIZE)) {

            total_size = options->value.n / BDRV_SECTOR_SIZE;

        }

        options++;

    }

    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,

              0644);

    if (fd < 0) {

        result = -errno;

    } else {

        if (ftruncate(fd, total_size * BDRV_SECTOR_SIZE) != 0) {

            result = -errno;

        }

        if (close(fd) != 0) {

            result = -errno;

        }

    }

    return result;

}

static int raw_flush(BlockDriverState *bs)

{

    BDRVRawState *s = bs->opaque;

    return qemu_fdatasync(s->fd);

}

static QEMUOptionParameter raw_create_options[] = {

    {

        .name = BLOCK_OPT_SIZE,

        .type = OPT_SIZE,

        .help = "Virtual disk size"

    },

    { NULL }

};

static BlockDriver bdrv_file = {

    .format_name = "file",

    .protocol_name = "file",

    .instance_size = sizeof(BDRVRawState),

    .bdrv_probe = NULL, /* no probe for protocols */

    .bdrv_file_open = raw_open,

    .bdrv_read = raw_read,

    .bdrv_write = raw_write,

    .bdrv_close = raw_close,

    .bdrv_create = raw_create,

    .bdrv_flush = raw_flush,

    .bdrv_aio_readv = raw_aio_readv,

    .bdrv_aio_writev = raw_aio_writev,

    .bdrv_aio_flush = raw_aio_flush,

    .bdrv_truncate = raw_truncate,

    .bdrv_getlength = raw_getlength,

    .create_options = raw_create_options,

};

/***********************************************/

/* host device */

#ifdef CONFIG_COCOA

static kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator );

static kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize );

kern_return_t FindEjectableCDMedia( io_iterator_t *mediaIterator )

{

    kern_return_t       kernResult;

    mach_port_t     masterPort;

    CFMutableDictionaryRef  classesToMatch;

    kernResult = IOMasterPort( MACH_PORT_NULL, &masterPort );

    if ( KERN_SUCCESS != kernResult ) {

        printf( "IOMasterPort returned %d\n", kernResult );

    }

    classesToMatch = IOServiceMatching( kIOCDMediaClass );

    if ( classesToMatch == NULL ) {

        printf( "IOServiceMatching returned a NULL dictionary.\n" );

    } else {

    CFDictionarySetValue( classesToMatch, CFSTR( kIOMediaEjectableKey ), kCFBooleanTrue );

    }

    kernResult = IOServiceGetMatchingServices( masterPort, classesToMatch, mediaIterator );

    if ( KERN_SUCCESS != kernResult )

    {

        printf( "IOServiceGetMatchingServices returned %d\n", kernResult );

    }

    return kernResult;

}

kern_return_t GetBSDPath( io_iterator_t mediaIterator, char *bsdPath, CFIndex maxPathSize )

{

    io_object_t     nextMedia;

    kern_return_t   kernResult = KERN_FAILURE;

    *bsdPath = '\0';

    nextMedia = IOIteratorNext( mediaIterator );

    if ( nextMedia )

    {

        CFTypeRef   bsdPathAsCFString;

    bsdPathAsCFString = IORegistryEntryCreateCFProperty( nextMedia, CFSTR( kIOBSDNameKey ), kCFAllocatorDefault, 0 );

        if ( bsdPathAsCFString ) {

            size_t devPathLength;

            strcpy( bsdPath, _PATH_DEV );

            strcat( bsdPath, "r" );

            devPathLength = strlen( bsdPath );

            if ( CFStringGetCString( bsdPathAsCFString, bsdPath + devPathLength, maxPathSize - devPathLength, kCFStringEncodingASCII ) ) {

                kernResult = KERN_SUCCESS;

            }

            CFRelease( bsdPathAsCFString );

        }

        IOObjectRelease( nextMedia );

    }

    return kernResult;

}

#endif

static int hdev_probe_device(const char *filename)

{

    struct stat st;

    /* allow a dedicated CD-ROM driver to match with a higher priority */

    if (strstart(filename, "/dev/cdrom", NULL))

        return 50;

    if (stat(filename, &st) >= 0 &&

            (S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode))) {

        return 100;

    }

    return 0;

}

static int hdev_open(BlockDriverState *bs, const char *filename, int flags)

{

    BDRVRawState *s = bs->opaque;

#ifdef CONFIG_COCOA

    if (strstart(filename, "/dev/cdrom", NULL)) {

        kern_return_t kernResult;

        io_iterator_t mediaIterator;

        char bsdPath[ MAXPATHLEN ];

        int fd;

        kernResult = FindEjectableCDMedia( &mediaIterator );

        kernResult = GetBSDPath( mediaIterator, bsdPath, sizeof( bsdPath ) );

        if ( bsdPath[ 0 ] != '\0' ) {

            strcat(bsdPath,"s0");

            /* some CDs don't have a partition 0 */

            fd = open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);

            if (fd < 0) {

                bsdPath[strlen(bsdPath)-1] = '1';

            } else {

                close(fd);

            }

            filename = bsdPath;

        }

        if ( mediaIterator )

            IOObjectRelease( mediaIterator );

    }

#endif

    s->type = FTYPE_FILE;

#if defined(__linux__)

    {

        char resolved_path[ MAXPATHLEN ], *temp;

        temp = realpath(filename, resolved_path);

        if (temp && strstart(temp, "/dev/sg", NULL)) {

            bs->sg = 1;

        }

    }

#endif

    return raw_open_common(bs, filename, flags, 0);

}

#if defined(__linux__)

/* Note: we do not have a reliable method to detect if the floppy is

   present. The current method is to try to open the floppy at every