On Thu, 08/11 05:07, Reda Sallahi wrote: > This adds the conv=notrunc option to dd which tells dd to not truncate the > output. > > For the time being we make it mandatory to specify conv=notrunc. > > Signed-off-by: Reda Sallahi <fullma...@gmail.com> > --- > qemu-img-cmds.hx | 4 ++-- > qemu-img.c | 31 ++++++++++++++++++++++++++++--- > qemu-img.texi | 15 +++++++++------ > tests/qemu-iotests/158 | 2 +- > tests/qemu-iotests/159 | 3 ++- > tests/qemu-iotests/160 | 7 ++++--- > 6 files changed, 46 insertions(+), 16 deletions(-) > > diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx > index f054599..18685ac 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] [-f fmt] [-O output_fmt] [bs=block_size] > [count=blocks] [skip=blocks] [conv=notrunc] 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] [-f @var{fmt}] [-O @var{output_fmt}] > [bs=@var{block_size}] [count=@var{blocks}] [skip=@var{blocks}] [conv=notrunc] > if=@var{input} of=@var{output} > ETEXI > > DEF("info", img_info, > diff --git a/qemu-img.c b/qemu-img.c > index 3adec86..16b56b8 100644 > --- a/qemu-img.c > +++ b/qemu-img.c > @@ -174,7 +174,8 @@ static void QEMU_NORETURN help(void) > " 'count=N' copy only N input blocks\n" > " 'if=FILE' read from FILE\n" > " 'of=FILE' write to FILE\n" > - " 'skip=N' skip N bs-sized blocks at the start of input\n"; > + " 'skip=N' skip N bs-sized blocks at the start of input\n" > + " 'conv=notrunc' do not truncate the output file\n"; > > printf("%s\nSupported formats:", help_msg); > bdrv_iterate_format(format_print, NULL); > @@ -3807,10 +3808,12 @@ out: > #define C_IF 04 > #define C_OF 010 > #define C_SKIP 020 > +#define C_CONV 040 > > struct DdInfo { > unsigned int flags; > int64_t count; > + unsigned int conv; > }; > > struct DdIo { > @@ -3894,6 +3897,21 @@ static int img_dd_skip(const char *arg, > return 0; > } > > +#define C_NOTRUNC 01 > + > +static int img_dd_conv(const char *arg, > + struct DdIo *in, struct DdIo *out, > + struct DdInfo *dd) > +{ > + if (!strcmp(arg, "notrunc")) { > + dd->conv |= C_NOTRUNC; > + return 0; > + } else { > + error_report("invalid conversion: '%s'", arg); > + return 1; > + } > +} > + > static int img_dd(int argc, char **argv) > { > int ret = 0; > @@ -3909,10 +3927,11 @@ static int img_dd(int argc, char **argv) > const char *out_fmt = "raw"; > const char *fmt = NULL; > int64_t size = 0; > - int64_t block_count = 0, out_pos, in_pos; > + int64_t out_pos, in_pos;
This change is not related to this patch. It should probably done by another patch, or removed. > struct DdInfo dd = { > .flags = 0, > .count = 0, > + .conv = 0 > }; > struct DdIo in = { > .bsz = 512, /* Block size is by default 512 bytes */ > @@ -3933,6 +3952,7 @@ static int img_dd(int argc, char **argv) > { "if", img_dd_if, C_IF }, > { "of", img_dd_of, C_OF }, > { "skip", img_dd_skip, C_SKIP }, > + { "conv", img_dd_conv, C_CONV }, > { NULL, NULL, 0 } > }; > const struct option long_options[] = { > @@ -3997,6 +4017,11 @@ static int img_dd(int argc, char **argv) > g_free(arg); > arg = NULL; > } > + if (!(dd.conv & C_NOTRUNC)) { > + error_report("conv=notrunc not specified"); A comment and/or a more detailed error message explaining the situation why we do this now would be necessary, so that in the future we'll remember to do the right thing once it's decided. > + ret = -1; > + goto out; > + } > > if (!(dd.flags & C_IF && dd.flags & C_OF)) { > error_report("Must specify both input and output files"); > @@ -4091,7 +4116,7 @@ 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++) { > + for (out_pos = 0; in_pos < size; ) { > int in_ret, out_ret; > > if (in_pos + in.bsz > size) { > diff --git a/qemu-img.texi b/qemu-img.texi > index 174aae3..891af14 100644 > --- a/qemu-img.texi > +++ b/qemu-img.texi > @@ -144,15 +144,18 @@ Parameters to dd subcommand: > @table @option > > @item bs=@var{block_size} > -defines the block size > +Defines the block size. > @item count=@var{blocks} > -sets the number of input blocks to copy > +Sets the number of input blocks to copy. > @item if=@var{input} > -sets the input file > +Sets the input file. > @item of=@var{output} > -sets the output file > +Sets the output file. dd truncates the output file to zero if 'conv=notrunc' > +is not specified. > @item skip=@var{blocks} > -sets the number of input blocks to skip > +Sets the number of input blocks to skip. > +@item conv=notrunc > +Makes dd not truncate output file to zero. Capitalizing other sentences should go as a sepearte patch. > @end table > > Command description: > @@ -326,7 +329,7 @@ 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 [-f @var{fmt}] [-O @var{output_fmt}] [bs=@var{block_size}] > [count=@var{blocks}] [skip=@var{blocks}] [conv=notrunc] 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. > diff --git a/tests/qemu-iotests/158 b/tests/qemu-iotests/158 > index 5b335db..63e2a10 100755 > --- a/tests/qemu-iotests/158 > +++ b/tests/qemu-iotests/158 > @@ -53,7 +53,7 @@ $QEMU_IO -c "write -P 0xa 0 $size" "$TEST_IMG" | > _filter_qemu_io > echo > echo "== Converting the image with dd ==" > > -$QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" -O "$IMGFMT" > +$QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" conv=notrunc -O "$IMGFMT" > TEST_IMG="$TEST_IMG.out" _check_test_img > > echo > diff --git a/tests/qemu-iotests/159 b/tests/qemu-iotests/159 > index 825f05f..d68a19f 100755 > --- a/tests/qemu-iotests/159 > +++ b/tests/qemu-iotests/159 > @@ -55,7 +55,8 @@ for bs in $TEST_SIZES; do > echo > echo "== Converting the image with dd with a block size of $bs ==" > > - $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" bs=$bs -O "$IMGFMT" > + $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" bs=$bs conv=notrunc \ > + -O "$IMGFMT" > TEST_IMG="$TEST_IMG.out" _check_test_img > > echo > diff --git a/tests/qemu-iotests/160 b/tests/qemu-iotests/160 > index 5c910e5..53b3c30 100755 > --- a/tests/qemu-iotests/160 > +++ b/tests/qemu-iotests/160 > @@ -55,10 +55,11 @@ for skip in $TEST_SKIP_BLOCKS; do > echo > echo "== Converting the image with dd with skip=$skip ==" > > - $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" skip="$skip" -O "$IMGFMT" > \ > - 2> /dev/null > + $QEMU_IMG dd if="$TEST_IMG" of="$TEST_IMG.out" skip="$skip" conv=notrunc > \ > + -O "$IMGFMT" 2> /dev/null > TEST_IMG="$TEST_IMG.out" _check_test_img > - dd if="$TEST_IMG" of="$TEST_IMG.out.dd" skip="$skip" status=none > + dd if="$TEST_IMG" of="$TEST_IMG.out.dd" skip="$skip" conv=notrunc \ > + status=none > > echo > echo "== Compare the images with qemu-img compare ==" > -- > 2.9.2 > Apart from above, the conv=notrunc code looks good to me. Thanks! Fam