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[Qemu-devel] [PULL v2 2/8] qemu-img: add skip option to dd
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PULL v2 2/8] qemu-img: add skip option to dd |
Date: |
Sun, 18 Sep 2016 00:05:59 +0200 |
From: Reda Sallahi <address@hidden>
This adds the skip option which allows qemu-img dd to skip a number of blocks
before copying the input.
A test case was added to test the skip option.
Signed-off-by: Reda Sallahi <address@hidden>
Message-id: address@hidden
Signed-off-by: Max Reitz <address@hidden>
---
qemu-img-cmds.hx | 4 +--
qemu-img.c | 50 ++++++++++++++++++++++++++++----
qemu-img.texi | 4 ++-
tests/qemu-iotests/160 | 72 ++++++++++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/160.out | 51 ++++++++++++++++++++++++++++++++
tests/qemu-iotests/group | 1 +
6 files changed, 174 insertions(+), 8 deletions(-)
create mode 100755 tests/qemu-iotests/160
create mode 100644 tests/qemu-iotests/160.out
diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
index 03bdd7a..f054599 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]
if=input of=output")
+ "dd [--image-opts] [-f fmt] [-O output_fmt] [bs=block_size] [count=blocks]
[skip=blocks] if=input of=output")
STEXI
address@hidden dd [--image-opts] [-f @var{fmt}] [-O @var{output_fmt}]
address@hidden address@hidden address@hidden address@hidden
address@hidden dd [--image-opts] [-f @var{fmt}] [-O @var{output_fmt}]
address@hidden address@hidden address@hidden address@hidden address@hidden
ETEXI
DEF("info", img_info,
diff --git a/qemu-img.c b/qemu-img.c
index 5bdac8d..ceffefe 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -173,7 +173,8 @@ static void QEMU_NORETURN help(void)
"(default: 512)\n"
" 'count=N' copy only N input blocks\n"
" 'if=FILE' read from FILE\n"
- " 'of=FILE' write to FILE\n";
+ " 'of=FILE' write to FILE\n"
+ " 'skip=N' skip N bs-sized blocks at the start of input\n";
printf("%s\nSupported formats:", help_msg);
bdrv_iterate_format(format_print, NULL);
@@ -3807,6 +3808,7 @@ out:
#define C_COUNT 02
#define C_IF 04
#define C_OF 010
+#define C_SKIP 020
struct DdInfo {
unsigned int flags;
@@ -3817,6 +3819,7 @@ struct DdIo {
int bsz; /* Block size */
char *filename;
uint8_t *buf;
+ int64_t offset;
};
struct DdOpts {
@@ -3877,6 +3880,22 @@ static int img_dd_of(const char *arg,
return 0;
}
+static int img_dd_skip(const char *arg,
+ struct DdIo *in, struct DdIo *out,
+ struct DdInfo *dd)
+{
+ char *end;
+
+ in->offset = qemu_strtosz_suffix(arg, &end, QEMU_STRTOSZ_DEFSUFFIX_B);
+
+ if (in->offset < 0 || *end) {
+ error_report("invalid number: '%s'", arg);
+ return 1;
+ }
+
+ return 0;
+}
+
static int img_dd(int argc, char **argv)
{
int ret = 0;
@@ -3900,12 +3919,14 @@ static int img_dd(int argc, char **argv)
struct DdIo in = {
.bsz = 512, /* Block size is by default 512 bytes */
.filename = NULL,
- .buf = NULL
+ .buf = NULL,
+ .offset = 0
};
struct DdIo out = {
.bsz = 512,
.filename = NULL,
- .buf = NULL
+ .buf = NULL,
+ .offset = 0
};
const struct DdOpts options[] = {
@@ -3913,6 +3934,7 @@ static int img_dd(int argc, char **argv)
{ "count", img_dd_count, C_COUNT },
{ "if", img_dd_if, C_IF },
{ "of", img_dd_of, C_OF },
+ { "skip", img_dd_skip, C_SKIP },
{ NULL, NULL, 0 }
};
const struct option long_options[] = {
@@ -4032,7 +4054,14 @@ static int img_dd(int argc, char **argv)
size = dd.count * in.bsz;
}
- qemu_opt_set_number(opts, BLOCK_OPT_SIZE, size, &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.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);
+ }
ret = bdrv_create(drv, out.filename, opts, &local_err);
if (ret < 0) {
@@ -4051,9 +4080,20 @@ static int img_dd(int argc, char **argv)
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
+ * size and create an empty output disk image (i.e. like dd(1)).
+ */
+ error_report("%s: cannot skip to specified offset", in.filename);
+ in_pos = size;
+ } else {
+ in_pos = in.offset * in.bsz;
+ }
+
in.buf = g_new(uint8_t, in.bsz);
- for (in_pos = 0, out_pos = 0; in_pos < size; block_count++) {
+ for (out_pos = 0; in_pos < size; block_count++) {
int in_ret, out_ret;
if (in_pos + in.bsz > size) {
diff --git a/qemu-img.texi b/qemu-img.texi
index 880293a..174aae3 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -151,6 +151,8 @@ sets the number of input blocks to copy
sets the input file
@item address@hidden
sets the output file
address@hidden address@hidden
+sets the number of input blocks to skip
@end table
Command description:
@@ -324,7 +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.
address@hidden dd [-f @var{fmt}] [-O @var{output_fmt}] address@hidden
address@hidden address@hidden address@hidden
address@hidden dd [-f @var{fmt}] [-O @var{output_fmt}] address@hidden
address@hidden address@hidden address@hidden address@hidden
Dd copies from @var{input} file to @var{output} file converting it from
@var{fmt} format to @var{output_fmt} format.
diff --git a/tests/qemu-iotests/160 b/tests/qemu-iotests/160
new file mode 100755
index 0000000..5c910e5
--- /dev/null
+++ b/tests/qemu-iotests/160
@@ -0,0 +1,72 @@
+#! /bin/bash
+#
+# qemu-img dd test for the skip option
+#
+# 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/>.
+#
+
address@hidden
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+here="$PWD"
+status=1
+
+_cleanup()
+{
+ _cleanup_test_img
+ rm -f "$TEST_IMG.out" "$TEST_IMG.out.dd"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+. ./common.rc
+. ./common.filter
+. ./common.pattern
+
+_supported_fmt raw
+_supported_proto file
+_supported_os Linux
+
+TEST_SKIP_BLOCKS="1 2 30 30K"
+
+for skip in $TEST_SKIP_BLOCKS; do
+ echo
+ echo "== Creating image =="
+
+ size=1M
+ _make_test_img $size
+ _check_test_img
+ $QEMU_IO -c "write -P 0xa 24 512k" "$TEST_IMG" | _filter_qemu_io
+
+ echo
+ echo "== Converting the image with dd with skip=$skip =="
+
+ $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" skip="$skip" -O "$IMGFMT" \
+ 2> /dev/null
+ TEST_IMG="$TEST_IMG.out" _check_test_img
+ dd if="$TEST_IMG" of="$TEST_IMG.out.dd" skip="$skip" status=none
+
+ echo
+ echo "== Compare the images with qemu-img compare =="
+
+ $QEMU_IMG compare "$TEST_IMG.out.dd" "$TEST_IMG.out"
+done
+
+echo
+echo "*** done"
+rm -f "$seq.full"
+status=0
diff --git a/tests/qemu-iotests/160.out b/tests/qemu-iotests/160.out
new file mode 100644
index 0000000..9cedc80
--- /dev/null
+++ b/tests/qemu-iotests/160.out
@@ -0,0 +1,51 @@
+QA output created by 160
+
+== Creating image ==
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
+No errors were found on the image.
+wrote 524288/524288 bytes at offset 24
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== Converting the image with dd with skip=1 ==
+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 524288/524288 bytes at offset 24
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== Converting the image with dd with skip=2 ==
+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 524288/524288 bytes at offset 24
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== Converting the image with dd with skip=30 ==
+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 524288/524288 bytes at offset 24
+512 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== Converting the image with dd with skip=30K ==
+No errors were found on the image.
+
+== Compare the images with qemu-img compare ==
+Images are identical.
+
+*** done
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index c46beb1..a57fc92 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -158,5 +158,6 @@
156 rw auto quick
157 auto
159 rw auto quick
+160 rw auto quick
162 auto quick
170 rw auto quick
--
2.9.3
- [Qemu-devel] [PULL v2 0/8] Block layer patches, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 1/8] qemu-img: add the 'dd' subcommand, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 3/8] blockdev: prepare iSCSI block driver for dynamic loading, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 4/8] blockdev: Add dynamic generation of module_block.h, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 2/8] qemu-img: add skip option to dd,
Max Reitz <=
- [Qemu-devel] [PULL v2 5/8] blockdev: Add dynamic module loading for block drivers, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 6/8] blockdev: Modularize nfs block driver, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 7/8] commit: get the overlay node before manipulating the backing chain, Max Reitz, 2016/09/17
- [Qemu-devel] [PULL v2 8/8] iotest 055: refactor and speed up, Max Reitz, 2016/09/17
- Re: [Qemu-devel] [PULL v2 0/8] Block layer patches, Peter Maydell, 2016/09/19