dd was creating an output image regardless of whether there was one already
created. With this patch we try to open first the output image and resize it
if necessary.
Signed-off-by: Reda Sallahi <fullma...@gmail.com>
---
Depends on:
[PATCH v2] qemu-img: add conv=notrunc option to dd
qemu-img.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 76 insertions(+), 15 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index 7c546c1..dfa0e63 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -3919,6 +3919,8 @@ static int img_dd(int argc, char **argv)
char *tmp;
BlockDriver *drv = NULL, *proto_drv = NULL;
BlockBackend *blk1 = NULL, *blk2 = NULL;
+ BlockDriverState *bs = NULL;
+ QDict *qoptions = NULL;
QemuOpts *opts = NULL;
QemuOptsList *create_opts = NULL;
Error *local_err = NULL;
@@ -4080,22 +4082,60 @@ static int img_dd(int argc, char **argv)
size = dd.count * in.bsz;
}
- /* 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);
- } else {
- qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
- size - in.bsz * in.offset, &error_abort);
- }
+ qoptions = qdict_new();
+ qdict_put(qoptions, "driver", qstring_from_str(out_fmt));
- 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;
+ bs = bdrv_open(out.filename, NULL, qoptions, BDRV_O_RDWR, &local_err);
+
+ if (!bs) {
+ 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);
+
+ /* Overflow means the specified offset is beyond input image's size */
+ if (dd.flags & C_SKIP && (in.offset > INT64_MAX / in.bsz ||
+ size < in.offset * in.bsz)) {
+ qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
+ 0, &error_abort);
+ } else {
+ qemu_opt_set_number(opts, BLOCK_OPT_SIZE,
+ size - in.offset * in.bsz, &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,
@@ -4117,6 +4157,26 @@ static int img_dd(int argc, char **argv)
in_pos = in.offset * in.bsz;
}
+ if (bs) {
+ int64_t blk2sz = blk_getlength(blk2);
+ if (blk2sz < 0) {
+ error_report("Failed to get size for '%s'", in.filename);
+ ret = -1;
+ goto out;
+ }
+
+ if (!(dd.conv & C_NOTRUNC)) {
+ blk_truncate(blk2, 0);
+ }
+ if (!(dd.flags & C_SKIP) || (in.offset <= INT64_MAX / in.bsz &&
+ size >= in.offset * in.bsz)) {
+ if (!(dd.conv & C_NOTRUNC) ||
+ blk2sz < size - in.offset * in.bsz) {
+ blk_truncate(blk2, size - in.offset * in.bsz);
+ }
+ }
+ }
+
in.buf = g_new(uint8_t, in.bsz);
for (out_pos = 0; in_pos < size; block_count++) {
@@ -4152,6 +4212,7 @@ out:
qemu_opts_free(create_opts);
blk_unref(blk1);
blk_unref(blk2);
+ bdrv_unref(bs);
g_free(in.filename);
g_free(out.filename);
g_free(in.buf);
--
2.9.2
