qemu-img.c 35.7 KB
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/*
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 * QEMU disk image utility
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 *
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 * Copyright (c) 2003-2008 Fabrice Bellard
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 *
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 * 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.
 */
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#include "qemu-common.h"
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#include "qemu-option.h"
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#include "osdep.h"
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#include "block_int.h"
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#include <stdio.h>
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#ifdef _WIN32
#include <windows.h>
#endif

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typedef struct img_cmd_t {
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    const char *name;
    int (*handler)(int argc, char **argv);
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} img_cmd_t;
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/* Default to cache=writeback as data integrity is not important for qemu-tcg. */
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#define BDRV_O_FLAGS BDRV_O_CACHE_WB
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static void QEMU_NORETURN error(const char *fmt, ...)
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{
    va_list ap;
    va_start(ap, fmt);
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    fprintf(stderr, "qemu-img: ");
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    vfprintf(stderr, fmt, ap);
    fprintf(stderr, "\n");
    exit(1);
    va_end(ap);
}

static void format_print(void *opaque, const char *name)
{
    printf(" %s", name);
}

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/* Please keep in synch with qemu-img.texi */
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static void help(void)
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{
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    const char *help_msg =
           "qemu-img version " QEMU_VERSION ", Copyright (c) 2004-2008 Fabrice Bellard\n"
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           "usage: qemu-img command [command options]\n"
           "QEMU disk image utility\n"
           "\n"
           "Command syntax:\n"
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#define DEF(option, callback, arg_string)        \
           "  " arg_string "\n"
#include "qemu-img-cmds.h"
#undef DEF
#undef GEN_DOCS
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           "\n"
           "Command parameters:\n"
           "  'filename' is a disk image filename\n"
           "  'fmt' is the disk image format. It is guessed automatically in most cases\n"
           "  'size' is the disk image size in bytes. Optional suffixes\n"
           "    'k' or 'K' (kilobyte, 1024), 'M' (megabyte, 1024k), 'G' (gigabyte, 1024M)\n"
           "    and T (terabyte, 1024G) are supported. 'b' is ignored.\n"
           "  'output_filename' is the destination disk image filename\n"
           "  'output_fmt' is the destination format\n"
           "  'options' is a comma separated list of format specific options in a\n"
           "    name=value format. Use -o ? for an overview of the options supported by the\n"
           "    used format\n"
           "  '-c' indicates that target image must be compressed (qcow format only)\n"
           "  '-u' enables unsafe rebasing. It is assumed that old and new backing file\n"
           "       match exactly. The image doesn't need a working backing file before\n"
           "       rebasing in this case (useful for renaming the backing file)\n"
           "  '-h' with or without a command shows this help and lists the supported formats\n"
           "\n"
           "Parameters to snapshot subcommand:\n"
           "  'snapshot' is the name of the snapshot to create, apply or delete\n"
           "  '-a' applies a snapshot (revert disk to saved state)\n"
           "  '-c' creates a snapshot\n"
           "  '-d' deletes a snapshot\n"
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           "  '-l' lists all snapshots in the given image\n";

    printf("%s\nSupported formats:", help_msg);
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    bdrv_iterate_format(format_print, NULL);
    printf("\n");
    exit(1);
}

#if defined(WIN32)
/* XXX: put correct support for win32 */
static int read_password(char *buf, int buf_size)
{
    int c, i;
    printf("Password: ");
    fflush(stdout);
    i = 0;
    for(;;) {
        c = getchar();
        if (c == '\n')
            break;
        if (i < (buf_size - 1))
            buf[i++] = c;
    }
    buf[i] = '\0';
    return 0;
}

#else

#include <termios.h>

static struct termios oldtty;

static void term_exit(void)
{
    tcsetattr (0, TCSANOW, &oldtty);
}

static void term_init(void)
{
    struct termios tty;

    tcgetattr (0, &tty);
    oldtty = tty;

    tty.c_iflag &= ~(IGNBRK|BRKINT|PARMRK|ISTRIP
                          |INLCR|IGNCR|ICRNL|IXON);
    tty.c_oflag |= OPOST;
    tty.c_lflag &= ~(ECHO|ECHONL|ICANON|IEXTEN);
    tty.c_cflag &= ~(CSIZE|PARENB);
    tty.c_cflag |= CS8;
    tty.c_cc[VMIN] = 1;
    tty.c_cc[VTIME] = 0;
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    tcsetattr (0, TCSANOW, &tty);

    atexit(term_exit);
}

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static int read_password(char *buf, int buf_size)
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{
    uint8_t ch;
    int i, ret;

    printf("password: ");
    fflush(stdout);
    term_init();
    i = 0;
    for(;;) {
        ret = read(0, &ch, 1);
        if (ret == -1) {
            if (errno == EAGAIN || errno == EINTR) {
                continue;
            } else {
                ret = -1;
                break;
            }
        } else if (ret == 0) {
            ret = -1;
            break;
        } else {
            if (ch == '\r') {
                ret = 0;
                break;
            }
            if (i < (buf_size - 1))
                buf[i++] = ch;
        }
    }
    term_exit();
    buf[i] = '\0';
    printf("\n");
    return ret;
}
#endif

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static BlockDriverState *bdrv_new_open(const char *filename,
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                                       const char *fmt,
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                                       int flags)
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{
    BlockDriverState *bs;
    BlockDriver *drv;
    char password[256];

    bs = bdrv_new("");
    if (!bs)
        error("Not enough memory");
    if (fmt) {
        drv = bdrv_find_format(fmt);
        if (!drv)
            error("Unknown file format '%s'", fmt);
    } else {
        drv = NULL;
    }
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    if (bdrv_open(bs, filename, flags, drv) < 0) {
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        error("Could not open '%s'", filename);
    }
    if (bdrv_is_encrypted(bs)) {
        printf("Disk image '%s' is encrypted.\n", filename);
        if (read_password(password, sizeof(password)) < 0)
            error("No password given");
        if (bdrv_set_key(bs, password) < 0)
            error("invalid password");
    }
    return bs;
}

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static void add_old_style_options(const char *fmt, QEMUOptionParameter *list,
    int flags, const char *base_filename, const char *base_fmt)
{
    if (flags & BLOCK_FLAG_ENCRYPT) {
        if (set_option_parameter(list, BLOCK_OPT_ENCRYPT, "on")) {
            error("Encryption not supported for file format '%s'", fmt);
        }
    }
    if (flags & BLOCK_FLAG_COMPAT6) {
        if (set_option_parameter(list, BLOCK_OPT_COMPAT6, "on")) {
            error("VMDK version 6 not supported for file format '%s'", fmt);
        }
    }

    if (base_filename) {
        if (set_option_parameter(list, BLOCK_OPT_BACKING_FILE, base_filename)) {
            error("Backing file not supported for file format '%s'", fmt);
        }
    }
    if (base_fmt) {
        if (set_option_parameter(list, BLOCK_OPT_BACKING_FMT, base_fmt)) {
            error("Backing file format not supported for file format '%s'", fmt);
        }
    }
}

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static int img_create(int argc, char **argv)
{
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    int c, ret, flags;
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    const char *fmt = "raw";
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    const char *base_fmt = NULL;
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    const char *filename;
    const char *base_filename = NULL;
    BlockDriver *drv;
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    QEMUOptionParameter *param = NULL;
    char *options = NULL;
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    flags = 0;
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    for(;;) {
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        c = getopt(argc, argv, "F:b:f:he6o:");
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        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
            break;
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        case 'F':
            base_fmt = optarg;
            break;
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        case 'b':
            base_filename = optarg;
            break;
        case 'f':
            fmt = optarg;
            break;
        case 'e':
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            flags |= BLOCK_FLAG_ENCRYPT;
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            break;
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        case '6':
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            flags |= BLOCK_FLAG_COMPAT6;
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            break;
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        case 'o':
            options = optarg;
            break;
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        }
    }
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    /* Find driver and parse its options */
    drv = bdrv_find_format(fmt);
    if (!drv)
        error("Unknown file format '%s'", fmt);
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    if (options && !strcmp(options, "?")) {
        print_option_help(drv->create_options);
        return 0;
    }

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    /* Create parameter list with default values */
    param = parse_option_parameters("", drv->create_options, param);
    set_option_parameter_int(param, BLOCK_OPT_SIZE, -1);

    /* Parse -o options */
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    if (options) {
        param = parse_option_parameters(options, drv->create_options, param);
        if (param == NULL) {
            error("Invalid options for file format '%s'.", fmt);
        }
    }

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    /* Get the filename */
    if (optind >= argc)
        help();
    filename = argv[optind++];

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    /* Add size to parameters */
    if (optind < argc) {
        set_option_parameter(param, BLOCK_OPT_SIZE, argv[optind++]);
    }

    /* Add old-style options to parameters */
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    add_old_style_options(fmt, param, flags, base_filename, base_fmt);
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    // The size for the image must always be specified, with one exception:
    // If we are using a backing file, we can obtain the size from there
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    if (get_option_parameter(param, BLOCK_OPT_SIZE)->value.n == -1) {
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        QEMUOptionParameter *backing_file =
            get_option_parameter(param, BLOCK_OPT_BACKING_FILE);
        QEMUOptionParameter *backing_fmt =
            get_option_parameter(param, BLOCK_OPT_BACKING_FMT);

        if (backing_file && backing_file->value.s) {
            BlockDriverState *bs;
            uint64_t size;
            const char *fmt = NULL;
            char buf[32];

            if (backing_fmt && backing_fmt->value.s) {
                 if (bdrv_find_format(backing_fmt->value.s)) {
                     fmt = backing_fmt->value.s;
                } else {
                     error("Unknown backing file format '%s'",
                        backing_fmt->value.s);
                }
            }

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            bs = bdrv_new_open(backing_file->value.s, fmt, BDRV_O_FLAGS);
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            bdrv_get_geometry(bs, &size);
            size *= 512;
            bdrv_delete(bs);

            snprintf(buf, sizeof(buf), "%" PRId64, size);
            set_option_parameter(param, BLOCK_OPT_SIZE, buf);
        } else {
            error("Image creation needs a size parameter");
        }
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    }
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    printf("Formatting '%s', fmt=%s ", filename, fmt);
    print_option_parameters(param);
    puts("");

    ret = bdrv_create(drv, filename, param);
    free_option_parameters(param);

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    if (ret < 0) {
        if (ret == -ENOTSUP) {
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            error("Formatting or formatting option not supported for file format '%s'", fmt);
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        } else if (ret == -EFBIG) {
            error("The image size is too large for file format '%s'", fmt);
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        } else {
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            error("%s: error while creating %s: %s", filename, fmt, strerror(-ret));
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        }
    }
    return 0;
}

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static int img_check(int argc, char **argv)
{
    int c, ret;
    const char *filename, *fmt;
    BlockDriverState *bs;

    fmt = NULL;
    for(;;) {
        c = getopt(argc, argv, "f:h");
        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        }
    }
    if (optind >= argc)
        help();
    filename = argv[optind++];

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    bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS);
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    ret = bdrv_check(bs);
    switch(ret) {
    case 0:
        printf("No errors were found on the image.\n");
        break;
    case -ENOTSUP:
        error("This image format does not support checks");
        break;
    default:
        if (ret < 0) {
            error("An error occurred during the check");
        } else {
            printf("%d errors were found on the image.\n", ret);
        }
        break;
    }

    bdrv_delete(bs);
    return 0;
}

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static int img_commit(int argc, char **argv)
{
    int c, ret;
    const char *filename, *fmt;
    BlockDriverState *bs;

    fmt = NULL;
    for(;;) {
        c = getopt(argc, argv, "f:h");
        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        }
    }
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    if (optind >= argc)
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        help();
    filename = argv[optind++];

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    bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_RDWR);
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    ret = bdrv_commit(bs);
    switch(ret) {
    case 0:
        printf("Image committed.\n");
        break;
    case -ENOENT:
        error("No disk inserted");
        break;
    case -EACCES:
        error("Image is read-only");
        break;
    case -ENOTSUP:
        error("Image is already committed");
        break;
    default:
        error("Error while committing image");
        break;
    }

    bdrv_delete(bs);
    return 0;
}

static int is_not_zero(const uint8_t *sector, int len)
{
    int i;
    len >>= 2;
    for(i = 0;i < len; i++) {
        if (((uint32_t *)sector)[i] != 0)
            return 1;
    }
    return 0;
}

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/*
 * Returns true iff the first sector pointed to by 'buf' contains at least
 * a non-NUL byte.
 *
 * 'pnum' is set to the number of sectors (including and immediately following
 * the first one) that are known to be in the same allocated/unallocated state.
 */
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static int is_allocated_sectors(const uint8_t *buf, int n, int *pnum)
{
    int v, i;

    if (n <= 0) {
        *pnum = 0;
        return 0;
    }
    v = is_not_zero(buf, 512);
    for(i = 1; i < n; i++) {
        buf += 512;
        if (v != is_not_zero(buf, 512))
            break;
    }
    *pnum = i;
    return v;
}

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/*
 * Compares two buffers sector by sector. Returns 0 if the first sector of both
 * buffers matches, non-zero otherwise.
 *
 * pnum is set to the number of sectors (including and immediately following
 * the first one) that are known to have the same comparison result
 */
static int compare_sectors(const uint8_t *buf1, const uint8_t *buf2, int n,
    int *pnum)
{
    int res, i;

    if (n <= 0) {
        *pnum = 0;
        return 0;
    }

    res = !!memcmp(buf1, buf2, 512);
    for(i = 1; i < n; i++) {
        buf1 += 512;
        buf2 += 512;

        if (!!memcmp(buf1, buf2, 512) != res) {
            break;
        }
    }

    *pnum = i;
    return res;
}

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#define IO_BUF_SIZE (2 * 1024 * 1024)
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static int img_convert(int argc, char **argv)
{
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    int c, ret, n, n1, bs_n, bs_i, flags, cluster_size, cluster_sectors;
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    const char *fmt, *out_fmt, *out_baseimg, *out_filename;
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    BlockDriver *drv;
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    BlockDriverState **bs, *out_bs;
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    int64_t total_sectors, nb_sectors, sector_num, bs_offset;
    uint64_t bs_sectors;
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    uint8_t * buf;
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    const uint8_t *buf1;
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    BlockDriverInfo bdi;
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    QEMUOptionParameter *param = NULL;
    char *options = NULL;
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    fmt = NULL;
    out_fmt = "raw";
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    out_baseimg = NULL;
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    flags = 0;
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    for(;;) {
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        c = getopt(argc, argv, "f:O:B:hce6o:");
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        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        case 'O':
            out_fmt = optarg;
            break;
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        case 'B':
            out_baseimg = optarg;
            break;
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        case 'c':
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            flags |= BLOCK_FLAG_COMPRESS;
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            break;
        case 'e':
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            flags |= BLOCK_FLAG_ENCRYPT;
            break;
        case '6':
            flags |= BLOCK_FLAG_COMPAT6;
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            break;
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        case 'o':
            options = optarg;
            break;
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        }
    }
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    bs_n = argc - optind - 1;
    if (bs_n < 1) help();

    out_filename = argv[argc - 1];
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    if (bs_n > 1 && out_baseimg)
        error("-B makes no sense when concatenating multiple input images");
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    bs = calloc(bs_n, sizeof(BlockDriverState *));
    if (!bs)
        error("Out of memory");

    total_sectors = 0;
    for (bs_i = 0; bs_i < bs_n; bs_i++) {
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        bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt, BDRV_O_FLAGS);
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        if (!bs[bs_i])
            error("Could not open '%s'", argv[optind + bs_i]);
        bdrv_get_geometry(bs[bs_i], &bs_sectors);
        total_sectors += bs_sectors;
    }
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    /* Find driver and parse its options */
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    drv = bdrv_find_format(out_fmt);
    if (!drv)
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        error("Unknown file format '%s'", out_fmt);
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    if (options && !strcmp(options, "?")) {
        print_option_help(drv->create_options);
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        free(bs);
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        return 0;
    }

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    if (options) {
        param = parse_option_parameters(options, drv->create_options, param);
        if (param == NULL) {
            error("Invalid options for file format '%s'.", out_fmt);
        }
    } else {
        param = parse_option_parameters("", drv->create_options, param);
    }

    set_option_parameter_int(param, BLOCK_OPT_SIZE, total_sectors * 512);
    add_old_style_options(out_fmt, param, flags, out_baseimg, NULL);

    /* Check if compression is supported */
    if (flags & BLOCK_FLAG_COMPRESS) {
        QEMUOptionParameter *encryption =
            get_option_parameter(param, BLOCK_OPT_ENCRYPT);

        if (!drv->bdrv_write_compressed) {
            error("Compression not supported for this file format");
        }

        if (encryption && encryption->value.n) {
            error("Compression and encryption not supported at the same time");
        }
    }

    /* Create the new image */
    ret = bdrv_create(drv, out_filename, param);
    free_option_parameters(param);

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    if (ret < 0) {
        if (ret == -ENOTSUP) {
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            error("Formatting not supported for file format '%s'", out_fmt);
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        } else if (ret == -EFBIG) {
            error("The image size is too large for file format '%s'", out_fmt);
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        } else {
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            error("%s: error while converting %s: %s", out_filename, out_fmt, strerror(-ret));
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        }
    }
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    out_bs = bdrv_new_open(out_filename, out_fmt, BDRV_O_FLAGS | BDRV_O_RDWR);
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    bs_i = 0;
    bs_offset = 0;
    bdrv_get_geometry(bs[0], &bs_sectors);
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    buf = qemu_malloc(IO_BUF_SIZE);
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    if (flags & BLOCK_FLAG_COMPRESS) {
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        if (bdrv_get_info(out_bs, &bdi) < 0)
            error("could not get block driver info");
        cluster_size = bdi.cluster_size;
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        if (cluster_size <= 0 || cluster_size > IO_BUF_SIZE)
            error("invalid cluster size");
        cluster_sectors = cluster_size >> 9;
        sector_num = 0;
        for(;;) {
680 681 682 683
            int64_t bs_num;
            int remainder;
            uint8_t *buf2;

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            nb_sectors = total_sectors - sector_num;
            if (nb_sectors <= 0)
                break;
            if (nb_sectors >= cluster_sectors)
                n = cluster_sectors;
            else
                n = nb_sectors;
691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721

            bs_num = sector_num - bs_offset;
            assert (bs_num >= 0);
            remainder = n;
            buf2 = buf;
            while (remainder > 0) {
                int nlow;
                while (bs_num == bs_sectors) {
                    bs_i++;
                    assert (bs_i < bs_n);
                    bs_offset += bs_sectors;
                    bdrv_get_geometry(bs[bs_i], &bs_sectors);
                    bs_num = 0;
                    /* printf("changing part: sector_num=%lld, "
                       "bs_i=%d, bs_offset=%lld, bs_sectors=%lld\n",
                       sector_num, bs_i, bs_offset, bs_sectors); */
                }
                assert (bs_num < bs_sectors);

                nlow = (remainder > bs_sectors - bs_num) ? bs_sectors - bs_num : remainder;

                if (bdrv_read(bs[bs_i], bs_num, buf2, nlow) < 0) 
                    error("error while reading");

                buf2 += nlow * 512;
                bs_num += nlow;

                remainder -= nlow;
            }
            assert (remainder == 0);

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            if (n < cluster_sectors)
                memset(buf + n * 512, 0, cluster_size - n * 512);
            if (is_not_zero(buf, cluster_size)) {
725
                if (bdrv_write_compressed(out_bs, sector_num, buf,
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                                          cluster_sectors) != 0)
727 728
                    error("error while compressing sector %" PRId64,
                          sector_num);
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            }
            sector_num += n;
        }
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        /* signal EOF to align */
        bdrv_write_compressed(out_bs, 0, NULL, 0);
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    } else {
735
        sector_num = 0; // total number of sectors converted so far
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        for(;;) {
            nb_sectors = total_sectors - sector_num;
            if (nb_sectors <= 0)
                break;
            if (nb_sectors >= (IO_BUF_SIZE / 512))
                n = (IO_BUF_SIZE / 512);
            else
                n = nb_sectors;
744 745 746 747 748 749 750 751 752 753 754 755 756 757

            while (sector_num - bs_offset >= bs_sectors) {
                bs_i ++;
                assert (bs_i < bs_n);
                bs_offset += bs_sectors;
                bdrv_get_geometry(bs[bs_i], &bs_sectors);
                /* printf("changing part: sector_num=%lld, bs_i=%d, "
                  "bs_offset=%lld, bs_sectors=%lld\n",
                   sector_num, bs_i, bs_offset, bs_sectors); */
            }

            if (n > bs_offset + bs_sectors - sector_num)
                n = bs_offset + bs_sectors - sector_num;

758
            if (!drv->no_zero_init) {
759 760 761 762 763 764 765 766 767 768 769 770 771
                /* If the output image is being created as a copy on write image,
                   assume that sectors which are unallocated in the input image
                   are present in both the output's and input's base images (no
                   need to copy them). */
                if (out_baseimg) {
                    if (!bdrv_is_allocated(bs[bs_i], sector_num - bs_offset,
                                           n, &n1)) {
                        sector_num += n1;
                        continue;
                    }
                    /* The next 'n1' sectors are allocated in the input image. Copy
                       only those as they may be followed by unallocated sectors. */
                    n = n1;
772 773 774
                }
            } else {
                n1 = n;
775 776
            }

777
            if (bdrv_read(bs[bs_i], sector_num - bs_offset, buf, n) < 0) 
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                error("error while reading");
            /* NOTE: at the same time we convert, we do not write zero
               sectors to have a chance to compress the image. Ideally, we
               should add a specific call to have the info to go faster */
            buf1 = buf;
            while (n > 0) {
784 785
                /* If the output image is being created as a copy on write image,
                   copy all sectors even the ones containing only NUL bytes,
786 787 788 789 790
                   because they may differ from the sectors in the base image.

                   If the output is to a host device, we also write out
                   sectors that are entirely 0, since whatever data was
                   already there is garbage, not 0s. */
791
                if (drv->no_zero_init || out_baseimg ||
792
                    is_allocated_sectors(buf1, n, &n1)) {
793
                    if (bdrv_write(out_bs, sector_num, buf1, n1) < 0)
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                        error("error while writing");
                }
                sector_num += n1;
                n -= n1;
                buf1 += n1 * 512;
            }
        }
    }
802
    qemu_free(buf);
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    bdrv_delete(out_bs);
804 805 806
    for (bs_i = 0; bs_i < bs_n; bs_i++)
        bdrv_delete(bs[bs_i]);
    free(bs);
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    return 0;
}

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#ifdef _WIN32
static int64_t get_allocated_file_size(const char *filename)
{
813 814
    typedef DWORD (WINAPI * get_compressed_t)(const char *filename, DWORD *high);
    get_compressed_t get_compressed;
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    struct _stati64 st;
816 817 818 819 820 821 822 823 824 825

    /* WinNT support GetCompressedFileSize to determine allocate size */
    get_compressed = (get_compressed_t) GetProcAddress(GetModuleHandle("kernel32"), "GetCompressedFileSizeA");
    if (get_compressed) {
    	DWORD high, low;
    	low = get_compressed(filename, &high);
    	if (low != 0xFFFFFFFFlu || GetLastError() == NO_ERROR)
	    return (((int64_t) high) << 32) + low;
    }

826
    if (_stati64(filename, &st) < 0)
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        return -1;
    return st.st_size;
}
#else
static int64_t get_allocated_file_size(const char *filename)
{
    struct stat st;
834
    if (stat(filename, &st) < 0)
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        return -1;
    return (int64_t)st.st_blocks * 512;
}
#endif

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static void dump_snapshots(BlockDriverState *bs)
{
    QEMUSnapshotInfo *sn_tab, *sn;
    int nb_sns, i;
    char buf[256];

    nb_sns = bdrv_snapshot_list(bs, &sn_tab);
    if (nb_sns <= 0)
        return;
    printf("Snapshot list:\n");
    printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), NULL));
    for(i = 0; i < nb_sns; i++) {
        sn = &sn_tab[i];
        printf("%s\n", bdrv_snapshot_dump(buf, sizeof(buf), sn));
    }
    qemu_free(sn_tab);
}

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static int img_info(int argc, char **argv)
{
    int c;
    const char *filename, *fmt;
    BlockDriverState *bs;
    char fmt_name[128], size_buf[128], dsize_buf[128];
864 865
    uint64_t total_sectors;
    int64_t allocated_size;
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    char backing_filename[1024];
    char backing_filename2[1024];
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    BlockDriverInfo bdi;
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    fmt = NULL;
    for(;;) {
        c = getopt(argc, argv, "f:h");
        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
            break;
        case 'f':
            fmt = optarg;
            break;
        }
    }
884
    if (optind >= argc)
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        help();
    filename = argv[optind++];

888
    bs = bdrv_new_open(filename, fmt, BDRV_O_FLAGS | BDRV_O_NO_BACKING);
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    bdrv_get_format(bs, fmt_name, sizeof(fmt_name));
    bdrv_get_geometry(bs, &total_sectors);
    get_human_readable_size(size_buf, sizeof(size_buf), total_sectors * 512);
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    allocated_size = get_allocated_file_size(filename);
    if (allocated_size < 0)
894
        snprintf(dsize_buf, sizeof(dsize_buf), "unavailable");
895
    else
896
        get_human_readable_size(dsize_buf, sizeof(dsize_buf),
897
                                allocated_size);
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    printf("image: %s\n"
           "file format: %s\n"
900
           "virtual size: %s (%" PRId64 " bytes)\n"
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           "disk size: %s\n",
902
           filename, fmt_name, size_buf,
903
           (total_sectors * 512),
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           dsize_buf);
    if (bdrv_is_encrypted(bs))
        printf("encrypted: yes\n");
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    if (bdrv_get_info(bs, &bdi) >= 0) {
908
        if (bdi.cluster_size != 0)
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            printf("cluster_size: %d\n", bdi.cluster_size);
    }
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    bdrv_get_backing_filename(bs, backing_filename, sizeof(backing_filename));
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    if (backing_filename[0] != '\0') {
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        path_combine(backing_filename2, sizeof(backing_filename2),
                     filename, backing_filename);
915
        printf("backing file: %s (actual path: %s)\n",
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               backing_filename,
               backing_filename2);
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    }
    dump_snapshots(bs);
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    bdrv_delete(bs);
    return 0;
}

924 925 926 927 928
#define SNAPSHOT_LIST   1
#define SNAPSHOT_CREATE 2
#define SNAPSHOT_APPLY  3
#define SNAPSHOT_DELETE 4

929
static int img_snapshot(int argc, char **argv)
930 931 932 933
{
    BlockDriverState *bs;
    QEMUSnapshotInfo sn;
    char *filename, *snapshot_name = NULL;
934
    int c, ret, bdrv_oflags;
935 936 937
    int action = 0;
    qemu_timeval tv;

938
    bdrv_oflags = BDRV_O_RDWR;
939 940 941 942 943 944 945 946
    /* Parse commandline parameters */
    for(;;) {
        c = getopt(argc, argv, "la:c:d:h");
        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
947
            return 0;
948 949 950
        case 'l':
            if (action) {
                help();
951
                return 0;
952 953
            }
            action = SNAPSHOT_LIST;
954
            bdrv_oflags &= ~BDRV_O_RDWR; /* no need for RW */
955 956 957 958
            break;
        case 'a':
            if (action) {
                help();
959
                return 0;
960 961 962 963 964 965 966
            }
            action = SNAPSHOT_APPLY;
            snapshot_name = optarg;
            break;
        case 'c':
            if (action) {
                help();
967
                return 0;
968 969 970 971 972 973 974
            }
            action = SNAPSHOT_CREATE;
            snapshot_name = optarg;
            break;
        case 'd':
            if (action) {
                help();
975
                return 0;
976 977 978 979 980 981 982 983 984 985 986 987
            }
            action = SNAPSHOT_DELETE;
            snapshot_name = optarg;
            break;
        }
    }

    if (optind >= argc)
        help();
    filename = argv[optind++];

    /* Open the image */
988
    bs = bdrv_new_open(filename, NULL, bdrv_oflags);
989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026

    /* Perform the requested action */
    switch(action) {
    case SNAPSHOT_LIST:
        dump_snapshots(bs);
        break;

    case SNAPSHOT_CREATE:
        memset(&sn, 0, sizeof(sn));
        pstrcpy(sn.name, sizeof(sn.name), snapshot_name);

        qemu_gettimeofday(&tv);
        sn.date_sec = tv.tv_sec;
        sn.date_nsec = tv.tv_usec * 1000;

        ret = bdrv_snapshot_create(bs, &sn);
        if (ret)
            error("Could not create snapshot '%s': %d (%s)",
                snapshot_name, ret, strerror(-ret));
        break;

    case SNAPSHOT_APPLY:
        ret = bdrv_snapshot_goto(bs, snapshot_name);
        if (ret)
            error("Could not apply snapshot '%s': %d (%s)",
                snapshot_name, ret, strerror(-ret));
        break;

    case SNAPSHOT_DELETE:
        ret = bdrv_snapshot_delete(bs, snapshot_name);
        if (ret)
            error("Could not delete snapshot '%s': %d (%s)",
                snapshot_name, ret, strerror(-ret));
        break;
    }

    /* Cleanup */
    bdrv_delete(bs);
1027 1028

    return 0;
1029 1030
}

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static int img_rebase(int argc, char **argv)
{
    BlockDriverState *bs, *bs_old_backing, *bs_new_backing;
1034
    BlockDriver *old_backing_drv, *new_backing_drv;
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    char *filename;
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    const char *fmt, *out_basefmt, *out_baseimg;
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    int c, flags, ret;
    int unsafe = 0;

    /* Parse commandline parameters */
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    fmt = NULL;
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1042 1043 1044 1045
    out_baseimg = NULL;
    out_basefmt = NULL;

    for(;;) {
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1046
        c = getopt(argc, argv, "uhf:F:b:");
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1047 1048 1049 1050 1051 1052
        if (c == -1)
            break;
        switch(c) {
        case 'h':
            help();
            return 0;
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        case 'f':
            fmt = optarg;
            break;
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1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077
        case 'F':
            out_basefmt = optarg;
            break;
        case 'b':
            out_baseimg = optarg;
            break;
        case 'u':
            unsafe = 1;
            break;
        }
    }

    if ((optind >= argc) || !out_baseimg)
        help();
    filename = argv[optind++];

    /*
     * Open the images.
     *
     * Ignore the old backing file for unsafe rebase in case we want to correct
     * the reference to a renamed or moved backing file.
     */
1078
    flags = BDRV_O_FLAGS | BDRV_O_RDWR | (unsafe ? BDRV_O_NO_BACKING : 0);
1079
    bs = bdrv_new_open(filename, fmt, flags);
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    /* Find the right drivers for the backing files */
    old_backing_drv = NULL;
    new_backing_drv = NULL;

    if (!unsafe && bs->backing_format[0] != '\0') {
        old_backing_drv = bdrv_find_format(bs->backing_format);
        if (old_backing_drv == NULL) {
            error("Invalid format name: '%s'", bs->backing_format);
        }
    }

    if (out_basefmt != NULL) {
        new_backing_drv = bdrv_find_format(out_basefmt);
        if (new_backing_drv == NULL) {
            error("Invalid format name: '%s'", out_basefmt);
        }
    }

    /* For safe rebasing we need to compare old and new backing file */
    if (unsafe) {
        /* Make the compiler happy */
        bs_old_backing = NULL;
        bs_new_backing = NULL;
    } else {
        char backing_name[1024];

        bs_old_backing = bdrv_new("old_backing");
        bdrv_get_backing_filename(bs, backing_name, sizeof(backing_name));
1109
        if (bdrv_open(bs_old_backing, backing_name, BDRV_O_FLAGS,
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            old_backing_drv))
        {
            error("Could not open old backing file '%s'", backing_name);
            return -1;
        }

        bs_new_backing = bdrv_new("new_backing");
1117
        if (bdrv_open(bs_new_backing, out_baseimg, BDRV_O_FLAGS | BDRV_O_RDWR,
K
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1118 1119
            new_backing_drv))
        {
K
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1120
            error("Could not open new backing file '%s'", out_baseimg);
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1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137
            return -1;
        }
    }

    /*
     * Check each unallocated cluster in the COW file. If it is unallocated,
     * accesses go to the backing file. We must therefore compare this cluster
     * in the old and new backing file, and if they differ we need to copy it
     * from the old backing file into the COW file.
     *
     * If qemu-img crashes during this step, no harm is done. The content of
     * the image is the same as the original one at any time.
     */
    if (!unsafe) {
        uint64_t num_sectors;
        uint64_t sector;
        int n, n1;
1138 1139 1140 1141 1142
        uint8_t * buf_old;
        uint8_t * buf_new;

        buf_old = qemu_malloc(IO_BUF_SIZE);
        buf_new = qemu_malloc(IO_BUF_SIZE);
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1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175

        bdrv_get_geometry(bs, &num_sectors);

        for (sector = 0; sector < num_sectors; sector += n) {

            /* How many sectors can we handle with the next read? */
            if (sector + (IO_BUF_SIZE / 512) <= num_sectors) {
                n = (IO_BUF_SIZE / 512);
            } else {
                n = num_sectors - sector;
            }

            /* If the cluster is allocated, we don't need to take action */
            if (bdrv_is_allocated(bs, sector, n, &n1)) {
                n = n1;
                continue;
            }

            /* Read old and new backing file */
            if (bdrv_read(bs_old_backing, sector, buf_old, n) < 0) {
                error("error while reading from old backing file");
            }
            if (bdrv_read(bs_new_backing, sector, buf_new, n) < 0) {
                error("error while reading from new backing file");
            }

            /* If they differ, we need to write to the COW file */
            uint64_t written = 0;

            while (written < n) {
                int pnum;

                if (compare_sectors(buf_old + written * 512,
1176
                    buf_new + written * 512, n - written, &pnum))
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                {
                    ret = bdrv_write(bs, sector + written,
                        buf_old + written * 512, pnum);
                    if (ret < 0) {
                        error("Error while writing to COW image: %s",
                            strerror(-ret));
                    }
                }

                written += pnum;
            }
        }
1189 1190 1191

        qemu_free(buf_old);
        qemu_free(buf_new);
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    }

    /*
     * Change the backing file. All clusters that are different from the old
     * backing file are overwritten in the COW file now, so the visible content
     * doesn't change when we switch the backing file.
     */
    ret = bdrv_change_backing_file(bs, out_baseimg, out_basefmt);
    if (ret == -ENOSPC) {
        error("Could not change the backing file to '%s': No space left in "
            "the file header", out_baseimg);
    } else if (ret < 0) {
        error("Could not change the backing file to '%s': %s",
            out_baseimg, strerror(-ret));
    }

    /*
     * TODO At this point it is possible to check if any clusters that are
     * allocated in the COW file are the same in the backing file. If so, they
     * could be dropped from the COW file. Don't do this before switching the
     * backing file, in case of a crash this would lead to corruption.
     */

    /* Cleanup */
    if (!unsafe) {
        bdrv_delete(bs_old_backing);
        bdrv_delete(bs_new_backing);
    }

    bdrv_delete(bs);

    return 0;
}

A
Anthony Liguori 已提交
1226
static const img_cmd_t img_cmds[] = {
1227 1228 1229 1230 1231 1232 1233 1234
#define DEF(option, callback, arg_string)        \
    { option, callback },
#include "qemu-img-cmds.h"
#undef DEF
#undef GEN_DOCS
    { NULL, NULL, },
};

B
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int main(int argc, char **argv)
{
A
Anthony Liguori 已提交
1237
    const img_cmd_t *cmd;
1238
    const char *cmdname;
B
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    bdrv_init();
    if (argc < 2)
        help();
1243
    cmdname = argv[1];
1244
    argc--; argv++;
1245 1246 1247 1248 1249 1250

    /* find the command */
    for(cmd = img_cmds; cmd->name != NULL; cmd++) {
        if (!strcmp(cmdname, cmd->name)) {
            return cmd->handler(argc, argv);
        }
B
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    }
1252 1253 1254

    /* not found */
    help();
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    return 0;
}