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: Reda Sallahi <fullmanet@gmail.com>
Message-id: 20160810024312.14544-1-fullmanet@gmail.com
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[mreitz: Moved test 158 to 170]
Signed-off-by: Max Reitz <mreitz@redhat.com>
diff --git a/qemu-img.c b/qemu-img.c
index ea52486..5bdac8d 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -166,7 +166,14 @@
"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 @@
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) \
