From: Wolfgang Bumiller <[email protected]> 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 <[email protected]> Signed-off-by: Thomas Lamprecht <[email protected]> [FE: override size earlier use flag to detect parameter add documenation] Signed-off-by: Fabian Ebner <[email protected]> --- docs/tools/qemu-img.rst | 10 ++++++++-- qemu-img-cmds.hx | 4 ++-- qemu-img.c | 24 +++++++++++++++++++++++- 3 files changed, 33 insertions(+), 5 deletions(-) diff --git a/docs/tools/qemu-img.rst b/docs/tools/qemu-img.rst index 775eaf3097..43328fe108 100644 --- a/docs/tools/qemu-img.rst +++ b/docs/tools/qemu-img.rst @@ -230,6 +230,10 @@ Parameters to dd subcommand: Sets the number of input blocks to skip +.. option:: isize=INPUT_SIZE + + Treat the input image or stream as if it had this size + .. option:: osize=OUTPUT_SIZE Sets the output image's size @@ -492,7 +496,7 @@ Command description: it doesn't need to be specified separately in this case. -.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [osize=OUTPUT_SIZE] [if=INPUT] [of=OUTPUT] +.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [isize=INPUT_SIZE] [osize=OUTPUT_SIZE] [if=INPUT] [of=OUTPUT] dd copies from *INPUT* file (default: STDIN) to *OUTPUT* file (default: STDOUT) converting it from *FMT* format to *OUTPUT_FMT* format. @@ -504,7 +508,9 @@ Command description: The size syntax is similar to :manpage:`dd(1)`'s size syntax. The output image will be created with size *OUTPUT_SIZE* and at most this many - bytes will be copied. + bytes will be copied. When *INPUT_SIZE* is positive, it overrides the input + image's size for the copy operation. When *INPUT_SIZE* is zero and reading + from STDIN, do not treat premature end of the input stream as an error. .. option:: info [--object OBJECTDEF] [--image-opts] [-f FMT] [--output=OFMT] [--backing-chain] [-U] FILENAME diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx index e4935365c9..50993e6c47 100644 --- a/qemu-img-cmds.hx +++ b/qemu-img-cmds.hx @@ -58,9 +58,9 @@ SRST ERST DEF("dd", img_dd, - "dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [bs=block_size] [count=blocks] [skip=blocks] [osize=output_size] [if=input] [of=output]") + "dd [--image-opts] [-U] [-f fmt] [-O output_fmt] [bs=block_size] [count=blocks] [skip=blocks] [isize=input_size] [osize=output_size] [if=input] [of=output]") SRST -.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [osize=OUTPUT_SIZE] [if=INPUT] [of=OUTPUT] +.. option:: dd [--image-opts] [-U] [-f FMT] [-O OUTPUT_FMT] [bs=BLOCK_SIZE] [count=BLOCKS] [skip=BLOCKS] [isize=INPUT_SIZE] [osize=OUTPUT_SIZE] [if=INPUT] [of=OUTPUT] ERST DEF("info", img_info, diff --git a/qemu-img.c b/qemu-img.c index ea488fd190..630928773d 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -4820,11 +4820,13 @@ static int img_bitmap(int argc, char **argv) #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 { @@ -4913,6 +4915,19 @@ 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("isize", arg); + + if (dd->isize < 0) { + return 1; + } + + return 0; +} + static int img_dd(int argc, char **argv) { int ret = 0; @@ -4934,6 +4949,7 @@ static int img_dd(int argc, char **argv) .flags = 0, .count = 0, .osize = 0, + .isize = 0, }; struct DdIo in = { .bsz = 512, /* Block size is by default 512 bytes */ @@ -4955,6 +4971,7 @@ 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[] = { @@ -5061,7 +5078,9 @@ static int img_dd(int argc, char **argv) } } - if (dd.flags & C_IF) { + if (dd.flags & C_ISIZE && dd.isize > 0) { + size = dd.isize; + } else if (dd.flags & C_IF) { size = blk_getlength(blk1); if (size < 0) { error_report("Failed to get size for '%s'", in.filename); @@ -5174,6 +5193,9 @@ static int img_dd(int argc, char **argv) } else { in_ret = read(STDIN_FILENO, in.buf, in_bsz); if (in_ret == 0) { + if (dd.flags & C_ISIZE && dd.isize == 0) { + goto out; + } /* early EOF is considered an error */ error_report("Input ended unexpectedly"); ret = -1; -- 2.30.2
