Commit 86ce1f6e authored by Reda Sallahi's avatar Reda Sallahi Committed by Max Reitz
Browse files

qemu-img: add the 'dd' subcommand 



This patch adds a basic dd subcommand analogous to dd(1) to qemu-img.

For the start, this implements the bs, if, of and count options and requires
both if and of to be specified (no stdin/stdout if not specified) and doesn't
support tty, pipes, etc.

The image format must be specified with -O for the output if the raw format
is not the intended one.

Two tests are added to test qemu-img dd.

Signed-off-by: default avatarReda Sallahi <fullmanet@gmail.com>
Message-id: 20160810024312.14544-1-fullmanet@gmail.com
Reviewed-by: default avatarStefan Hajnoczi <stefanha@redhat.com>
[mreitz: Moved test 158 to 170]
Signed-off-by: default avatarMax Reitz <mreitz@redhat.com>
parent a008535b

qemu-img-cmds.hx

+6 −0
Original line number Diff line number Diff line
@@ -45,6 +45,12 @@ STEXI 
@item convert [--object @var{objectdef}] [--image-opts] [-c] [-p] [-q] [-n] [-f @var{fmt}] [-t @var{cache}] [-T @var{src_cache}] [-O @var{output_fmt}] [-o @var{options}] [-s @var{snapshot_id_or_name}] [-l @var{snapshot_param}] [-S @var{sparse_size}] @var{filename} [@var{filename2} [...]] @var{output_filename}

ETEXI



DEF("dd", img_dd,

    "dd [--image-opts] [-f fmt] [-O output_fmt] [bs=block_size] [count=blocks] if=input of=output")

STEXI

@item dd [--image-opts] [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] if=@var{input} of=@var{output}

ETEXI



DEF("info", img_info,

    "info [--object objectdef] [--image-opts] [-f fmt] [--output=ofmt] [--backing-chain] filename")

STEXI

qemu-img.c

+302 −1
Original line number Diff line number Diff line
@@ -166,7 +166,14 @@ static void QEMU_NORETURN help(void) 
           "Parameters to compare subcommand:\n"

           "  '-f' first image format\n"

           "  '-F' second image format\n"

           "  '-s' run in Strict mode - fail on different image size or sector allocation\n";

           "  '-s' run in Strict mode - fail on different image size or sector allocation\n"

           "\n"

           "Parameters to dd subcommand:\n"

           "  'bs=BYTES' read and write up to BYTES bytes at a time "

           "(default: 512)\n"

           "  'count=N' copy only N input blocks\n"

           "  'if=FILE' read from FILE\n"

           "  'of=FILE' write to FILE\n";



    printf("%s\nSupported formats:", help_msg);

    bdrv_iterate_format(format_print, NULL);
@@ -3796,6 +3803,300 @@ out: 
    return 0;

}



#define C_BS      01

#define C_COUNT   02

#define C_IF      04

#define C_OF      010



struct DdInfo {

    unsigned int flags;

    int64_t count;

};



struct DdIo {

    int bsz;    /* Block size */

    char *filename;

    uint8_t *buf;

};



struct DdOpts {

    const char *name;

    int (*f)(const char *, struct DdIo *, struct DdIo *, struct DdInfo *);

    unsigned int flag;

};



static int img_dd_bs(const char *arg,

                     struct DdIo *in, struct DdIo *out,

                     struct DdInfo *dd)

{

    char *end;

    int64_t res;



    res = qemu_strtosz_suffix(arg, &end, QEMU_STRTOSZ_DEFSUFFIX_B);



    if (res <= 0 || res > INT_MAX || *end) {

        error_report("invalid number: '%s'", arg);

        return 1;

    }

    in->bsz = out->bsz = res;



    return 0;

}



static int img_dd_count(const char *arg,

                        struct DdIo *in, struct DdIo *out,

                        struct DdInfo *dd)

{

    char *end;



    dd->count = qemu_strtosz_suffix(arg, &end, QEMU_STRTOSZ_DEFSUFFIX_B);



    if (dd->count < 0 || *end) {

        error_report("invalid number: '%s'", arg);

        return 1;

    }



    return 0;

}



static int img_dd_if(const char *arg,

                     struct DdIo *in, struct DdIo *out,

                     struct DdInfo *dd)

{

    in->filename = g_strdup(arg);



    return 0;

}



static int img_dd_of(const char *arg,

                     struct DdIo *in, struct DdIo *out,

                     struct DdInfo *dd)

{

    out->filename = g_strdup(arg);



    return 0;

}



static int img_dd(int argc, char **argv)

{

    int ret = 0;

    char *arg = NULL;

    char *tmp;

    BlockDriver *drv = NULL, *proto_drv = NULL;

    BlockBackend *blk1 = NULL, *blk2 = NULL;

    QemuOpts *opts = NULL;

    QemuOptsList *create_opts = NULL;

    Error *local_err = NULL;

    bool image_opts = false;

    int c, i;

    const char *out_fmt = "raw";

    const char *fmt = NULL;

    int64_t size = 0;

    int64_t block_count = 0, out_pos, in_pos;

    struct DdInfo dd = {

        .flags = 0,

        .count = 0,

    };

    struct DdIo in = {

        .bsz = 512, /* Block size is by default 512 bytes */

        .filename = NULL,

        .buf = NULL

    };

    struct DdIo out = {

        .bsz = 512,

        .filename = NULL,

        .buf = NULL

    };



    const struct DdOpts options[] = {

        { "bs", img_dd_bs, C_BS },

        { "count", img_dd_count, C_COUNT },

        { "if", img_dd_if, C_IF },

        { "of", img_dd_of, C_OF },

        { NULL, NULL, 0 }

    };

    const struct option long_options[] = {

        { "help", no_argument, 0, 'h'},

        { "image-opts", no_argument, 0, OPTION_IMAGE_OPTS},

        { 0, 0, 0, 0 }

    };



    while ((c = getopt_long(argc, argv, "hf:O:", long_options, NULL))) {

        if (c == EOF) {

            break;

        }

        switch (c) {

        case 'O':

            out_fmt = optarg;

            break;

        case 'f':

            fmt = optarg;

            break;

        case '?':

            error_report("Try 'qemu-img --help' for more information.");

            ret = -1;

            goto out;

        case 'h':

            help();

            break;

        case OPTION_IMAGE_OPTS:

            image_opts = true;

            break;

        }

    }



    for (i = optind; i < argc; i++) {

        int j;

        arg = g_strdup(argv[i]);



        tmp = strchr(arg, '=');

        if (tmp == NULL) {

            error_report("unrecognized operand %s", arg);

            ret = -1;

            goto out;

        }



        *tmp++ = '\0';



        for (j = 0; options[j].name != NULL; j++) {

            if (!strcmp(arg, options[j].name)) {

                break;

            }

        }

        if (options[j].name == NULL) {

            error_report("unrecognized operand %s", arg);

            ret = -1;

            goto out;

        }



        if (options[j].f(tmp, &in, &out, &dd) != 0) {

            ret = -1;

            goto out;

        }

        dd.flags |= options[j].flag;

        g_free(arg);

        arg = NULL;

    }



    if (!(dd.flags & C_IF && dd.flags & C_OF)) {

        error_report("Must specify both input and output files");

        ret = -1;

        goto out;

    }

    blk1 = img_open(image_opts, in.filename, fmt, 0, false, false);



    if (!blk1) {

        ret = -1;

        goto out;

    }



    drv = bdrv_find_format(out_fmt);

    if (!drv) {

        error_report("Unknown file format");

        ret = -1;

        goto out;

    }

    proto_drv = bdrv_find_protocol(out.filename, true, &local_err);



    if (!proto_drv) {

        error_report_err(local_err);

        ret = -1;

        goto out;

    }

    if (!drv->create_opts) {

        error_report("Format driver '%s' does not support image creation",

                     drv->format_name);

        ret = -1;

        goto out;

    }

    if (!proto_drv->create_opts) {

        error_report("Protocol driver '%s' does not support image creation",

                     proto_drv->format_name);

        ret = -1;

        goto out;

    }

    create_opts = qemu_opts_append(create_opts, drv->create_opts);

    create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);



    opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);



    size = blk_getlength(blk1);

    if (size < 0) {

        error_report("Failed to get size for '%s'", in.filename);

        ret = -1;

        goto out;

    }



    if (dd.flags & C_COUNT && dd.count <= INT64_MAX / in.bsz &&

        dd.count * in.bsz < size) {

        size = dd.count * in.bsz;

    }



    qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &error_abort);



    ret = bdrv_create(drv, out.filename, opts, &local_err);

    if (ret < 0) {

        error_reportf_err(local_err,

                          "%s: error while creating output image: ",

                          out.filename);

        ret = -1;

        goto out;

    }



    blk2 = img_open(image_opts, out.filename, out_fmt, BDRV_O_RDWR,

                    false, false);



    if (!blk2) {

        ret = -1;

        goto out;

    }



    in.buf = g_new(uint8_t, in.bsz);



    for (in_pos = 0, out_pos = 0; in_pos < size; block_count++) {

        int in_ret, out_ret;



        if (in_pos + in.bsz > size) {

            in_ret = blk_pread(blk1, in_pos, in.buf, size - in_pos);

        } else {

            in_ret = blk_pread(blk1, in_pos, in.buf, in.bsz);

        }

        if (in_ret < 0) {

            error_report("error while reading from input image file: %s",

                         strerror(-in_ret));

            ret = -1;

            goto out;

        }

        in_pos += in_ret;



        out_ret = blk_pwrite(blk2, out_pos, in.buf, in_ret, 0);



        if (out_ret < 0) {

            error_report("error while writing to output image file: %s",

                         strerror(-out_ret));

            ret = -1;

            goto out;

        }

        out_pos += out_ret;

    }



out:

    g_free(arg);

    qemu_opts_del(opts);

    qemu_opts_free(create_opts);

    blk_unref(blk1);

    blk_unref(blk2);

    g_free(in.filename);

    g_free(out.filename);

    g_free(in.buf);

    g_free(out.buf);



    if (ret) {

        return 1;

    }

    return 0;

}





static const img_cmd_t img_cmds[] = {

#define DEF(option, callback, arg_string)        \

qemu-img.texi

+25 −0
Original line number Diff line number Diff line
@@ -139,6 +139,20 @@ Parameters to convert subcommand: 
Skip the creation of the target volume

@end table



Parameters to dd subcommand:



@table @option



@item bs=@var{block_size}

defines the block size

@item count=@var{blocks}

sets the number of input blocks to copy

@item if=@var{input}

sets the input file

@item of=@var{output}

sets the output file

@end table



Command description:



@table @option
@@ -310,6 +324,17 @@ skipped. This is useful for formats such as @code{rbd} if the target 
volume has already been created with site specific options that cannot

be supplied through qemu-img.



@item dd [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] [count=@var{blocks}] if=@var{input} of=@var{output}



Dd copies from @var{input} file to @var{output} file converting it from

@var{fmt} format to @var{output_fmt} format.



The data is by default read and written using blocks of 512 bytes but can be

modified by specifying @var{block_size}. If count=@var{blocks} is specified

dd will stop reading input after reading @var{blocks} input blocks.



The size syntax is similar to dd(1)'s size syntax.



@item info [-f @var{fmt}] [--output=@var{ofmt}] [--backing-chain] @var{filename}



Give information about the disk image @var{filename}. Use it in

tests/qemu-iotests/159

0 → 100755
+70 −0
Original line number Diff line number Diff line 
#! /bin/bash

#

# qemu-img dd test with different block sizes

#

# Copyright (C) 2016 Reda Sallahi

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

#



owner=fullmanet@gmail.com



seq="$(basename $0)"

echo "QA output created by $seq"



here="$PWD"

status=1



_cleanup()

{

    _cleanup_test_img

    rm -f "$TEST_IMG.out"

}

trap "_cleanup; exit \$status" 0 1 2 3 15



. ./common.rc

. ./common.filter

. ./common.pattern



_supported_fmt generic

_supported_proto file

_supported_os Linux



TEST_SIZES="5 512 1024 1999 1K 64K 1M"



for bs in $TEST_SIZES; do

    echo

    echo "== Creating image =="



    size=1M

    _make_test_img $size

    _check_test_img

    $QEMU_IO -c "write -P 0xa 0 $size" "$TEST_IMG" | _filter_qemu_io



    echo

    echo "== Converting the image with dd with a block size of $bs =="



    $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" bs=$bs -O "$IMGFMT"

    TEST_IMG="$TEST_IMG.out" _check_test_img



    echo

    echo "== Compare the images with qemu-img compare =="



    $QEMU_IMG compare "$TEST_IMG" "$TEST_IMG.out"

done



echo

echo "*** done"

rm -f "$seq.full"

status=0

tests/qemu-iotests/159.out

0 → 100644
+87 −0
Original line number Diff line number Diff line 
QA output created by 159



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 5 ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 512 ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 1024 ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 1999 ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 1K ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 64K ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



== Creating image ==

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576

No errors were found on the image.

wrote 1048576/1048576 bytes at offset 0

1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)



== Converting the image with dd with a block size of 1M ==

No errors were found on the image.



== Compare the images with qemu-img compare ==

Images are identical.



*** done