From: Wolfgang Bumiller <w.bumil...@proxmox.com>
for writing small images from stdin to bigger ones
In order to distinguish between an actually unexpected and
an expected end of input.
Signed-off-by: Wolfgang Bumiller <w.bumil...@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lampre...@proxmox.com>
---
qemu-img.c | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/qemu-img.c b/qemu-img.c
index d2516968c6..8da1ea3951 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -4406,11 +4406,13 @@ out:
#define C_OF 010
#define C_SKIP 020
#define C_OSIZE 040
+#define C_ISIZE 0100
struct DdInfo {
unsigned int flags;
int64_t count;
int64_t osize;
+ int64_t isize;
};
struct DdIo {
@@ -4503,6 +4505,20 @@ static int img_dd_osize(const char *arg,
return 0;
}
+static int img_dd_isize(const char *arg,
+ struct DdIo *in, struct DdIo *out,
+ struct DdInfo *dd)
+{
+ dd->isize = cvtnum(arg);
+
+ if (dd->isize < 0) {
+ error_report("invalid number: '%s'", arg);
+ return 1;
+ }
+
+ return 0;
+}
+
static int img_dd(int argc, char **argv)
{
int ret = 0;
@@ -4517,12 +4533,14 @@ static int img_dd(int argc, char **argv)
int c, i;
const char *out_fmt = "raw";
const char *fmt = NULL;
- int64_t size = 0;
+ int64_t size = 0, readsize = 0;
int64_t block_count = 0, out_pos, in_pos;
bool force_share = false;
struct DdInfo dd = {
.flags = 0,
.count = 0,
+ .osize = 0,
+ .isize = -1,
};
struct DdIo in = {
.bsz = 512, /* Block size is by default 512 bytes */
@@ -4544,6 +4562,7 @@ static int img_dd(int argc, char **argv)
{ "of", img_dd_of, C_OF },
{ "skip", img_dd_skip, C_SKIP },
{ "osize", img_dd_osize, C_OSIZE },
+ { "isize", img_dd_isize, C_ISIZE },
{ NULL, NULL, 0 }
};
const struct option long_options[] = {
@@ -4750,14 +4769,18 @@ static int img_dd(int argc, char **argv)
in.buf = g_new(uint8_t, in.bsz);
- for (out_pos = 0; in_pos < size; block_count++) {
+ readsize = (dd.isize > 0) ? dd.isize : size;
+ for (out_pos = 0; in_pos < readsize; block_count++) {
int in_ret, out_ret;
- size_t in_bsz = in_pos + in.bsz > size ? size - in_pos : in.bsz;
+ size_t in_bsz = in_pos + in.bsz > readsize ? readsize - in_pos :
in.bsz;
if (blk1) {
in_ret = blk_pread(blk1, in_pos, in.buf, in_bsz);
} else {
in_ret = read(STDIN_FILENO, in.buf, in_bsz);
if (in_ret == 0) {
+ if (dd.isize == 0) {
+ goto out;
+ }
/* early EOF is considered an error */
error_report("Input ended unexpectedly");
ret = -1;
--
2.20.1
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