The -n arg to the convert command allows use of a pre-existing image,
rather than creating a new image. This adds a -n arg to the dd command
to get feature parity.
Signed-off-by: Daniel P. Berrange <berra...@redhat.com>
---
qemu-img-cmds.hx | 4 +--
qemu-img.c | 79 ++++++++++++++++++++++++++++++++++++--------------------
qemu-img.texi | 7 ++++-
3 files changed, 59 insertions(+), 31 deletions(-)
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index f054599..6732713 100644
--- a/qemu-img-cmds.hx
+++ b/qemu-img-cmds.hx
@@ -46,9 +46,9 @@ STEXI
ETEXI
DEF("dd", img_dd,
- "dd [--image-opts] [-f fmt] [-O output_fmt] [bs=block_size] [count=blocks]
[skip=blocks] if=input of=output")
+ "dd [--image-opts] [-n] [-f fmt] [-O output_fmt] [bs=block_size]
[count=blocks] [skip=blocks] if=input of=output")
STEXI
-@item dd [--image-opts] [-f @var{fmt}] [-O @var{output_fmt}]
[bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] if=@var{input}
of=@var{output}
+@item dd [--image-opts] [-n] [-f @var{fmt}] [-O @var{output_fmt}]
[bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] if=@var{input}
of=@var{output}
ETEXI
DEF("info", img_info,
diff --git a/qemu-img.c b/qemu-img.c
index 629f9e9..4d8d041 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3917,10 +3917,10 @@ static int img_dd(int argc, char **argv)
QemuOptsList *create_opts = NULL;
Error *local_err = NULL;
bool image_opts = false;
- int c, i;
+ int c, i, skip_create = 0;
const char *out_fmt = "raw";
const char *fmt = NULL;
- int64_t size = 0;
+ int64_t size = 0, out_size;
int64_t block_count = 0, out_pos, in_pos;
struct DdInfo dd = {
.flags = 0,
@@ -3954,7 +3954,7 @@ static int img_dd(int argc, char **argv)
{ 0, 0, 0, 0 }
};
- while ((c = getopt_long(argc, argv, "hf:O:", long_options, NULL))) {
+ while ((c = getopt_long(argc, argv, "hnf:O:", long_options, NULL))) {
if (c == EOF) {
break;
}
@@ -3965,6 +3965,9 @@ static int img_dd(int argc, char **argv)
case 'f':
fmt = optarg;
break;
+ case 'n':
+ skip_create = 1;
+ break;
case '?':
error_report("Try 'qemu-img --help' for more information.");
ret = -1;
@@ -4051,22 +4054,25 @@ static int img_dd(int argc, char **argv)
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);
+ if (!skip_create) {
+ 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) {
@@ -4083,19 +4089,22 @@ static int img_dd(int argc, char **argv)
/* Overflow means the specified offset is beyond input image's size */
if (dd.flags & C_SKIP && (in.offset > INT64_MAX / in.bsz ||
size < in.bsz * in.offset)) {
- qemu_opt_set_number(opts, BLOCK_OPT_SIZE, 0, &error_abort);
+ out_size = 0;
} else {
- qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
- size - in.bsz * in.offset, &error_abort);
+ out_size = size - in.bsz * in.offset;
}
- 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;
+ if (!skip_create) {
+ qemu_opt_set_number(opts, BLOCK_OPT_SIZE, out_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;
+ }
}
/* TODO, we can't honour --image-opts for the target,
@@ -4111,6 +4120,20 @@ static int img_dd(int argc, char **argv)
goto out;
}
+ if (skip_create) {
+ int64_t existing_size = blk_getlength(blk2);
+ if (existing_size < 0) {
+ error_report("unable to get output image length: %s",
+ strerror(-existing_size));
+ ret = -1;
+ goto out;
+ } else if (existing_size < out_size) {
+ error_report("output file is smaller than input data length");
+ ret = -1;
+ goto out;
+ }
+ }
+
if (dd.flags & C_SKIP && (in.offset > INT64_MAX / in.bsz ||
size < in.offset * in.bsz)) {
/* We give a warning if the skip option is bigger than the input
diff --git a/qemu-img.texi b/qemu-img.texi
index 174aae3..b952d6a 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -326,7 +326,7 @@ 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}] [skip=@var{blocks}] if=@var{input} of=@var{output}
+@item dd [-n] [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}]
[count=@var{blocks}] [skip=@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.
@@ -337,6 +337,11 @@ dd will stop reading input after reading @var{blocks}
input blocks.
The size syntax is similar to dd(1)'s size syntax.
+If the @code{-n} option is specified, the target volume creation will be
+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 info [-f @var{fmt}] [--output=@var{ofmt}] [--backing-chain]
@var{filename}
Give information about the disk image @var{filename}. Use it in
--
2.9.3
