On 12/27/19 5:43 AM, Andrey Shinkevich wrote:
Let QEMU-IMG CHECK command show QCOW2 structure to inform a user about
metadata allocations on disk. Introduce '-M'('--dump-meta') key option.
Suggested-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
---
+++ b/qemu-img.c
@@ -173,6 +173,7 @@ static void QEMU_NORETURN help(void)
" '-r leaks' repairs only cluster leaks, whereas '-r all' fixes
all\n"
" kinds of errors, with a higher risk of choosing the wrong fix
or\n"
" hiding corruption that has already occurred.\n"
+ " '-M' Dump QCOW2 metadata to stdout in JSON format.\n"
Should QCOW2 be all caps?
}
@@ -701,9 +710,10 @@ static int img_check(int argc, char **argv)
{"object", required_argument, 0, OPTION_OBJECT},
{"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
{"force-share", no_argument, 0, 'U'},
+ {"dump-meta", no_argument, 0, 'M'},
{0, 0, 0, 0}
};
- c = getopt_long(argc, argv, ":hf:r:T:qU",
+ c = getopt_long(argc, argv, ":hf:r:T:qU:M",
We are already inconsistent, but I tend to add options in alphabetical
order, both here...
long_options, &option_index);
if (c == -1) {
break;
@@ -745,6 +755,9 @@ static int img_check(int argc, char **argv)
case 'U':
force_share = true;
break;
+ case 'M':
...and here, as it is then easier to find a given option for later editing.
+ fix |= BDRV_DUMP_META;
+ break;
case OPTION_OBJECT: {
QemuOpts *opts;
opts = qemu_opts_parse_noisily(&qemu_object_opts,
@@ -772,6 +785,11 @@ static int img_check(int argc, char **argv)
return 1;
}
+ if ((fix & BDRV_DUMP_META) && output_format != OFORMAT_JSON) {
+ error_report("Metadata output in JSON format only");
+ return 1;
Why this restriction?
+ }
+
if (qemu_opts_foreach(&qemu_object_opts,
user_creatable_add_opts_foreach,
qemu_img_object_print_help, &error_fatal)) {
@@ -792,6 +810,15 @@ static int img_check(int argc, char **argv)
bs = blk_bs(blk);
check = g_new0(ImageCheck, 1);
+
+ if (fix & BDRV_DUMP_META) {
+ if (strcmp(bs->drv->format_name, "qcow2")) {
+ error_report("Metadata output supported for QCOW2 format only");
+ ret = -ENOTSUP;
This one makes sense, I guess - we may relax it in later versions if
more file formats gain the ability to dump extra metadata.
+++ b/qemu-img.texi
@@ -230,7 +230,7 @@ specified as well.
For write tests, by default a buffer filled with zeros is written. This can be
overridden with a pattern byte specified by @var{pattern}.
-@item check [--object @var{objectdef}] [--image-opts] [-q] [-f @var{fmt}] [--output=@var{ofmt}] [-r [leaks | all]] [-T @var{src_cache}] [-U] @var{filename}
+@item check [--object @var{objectdef}] [--image-opts] [-M] [-q] [-f @var{fmt}]
[--output=@var{ofmt}] [-r [leaks | all]] [-T @var{src_cache}] [-U]
@var{filename}
This mentions that -M is valid, but has no further documentation on what
-M means. Without that, it's anyone's guess.
Perform a consistency check on the disk image @var{filename}. The command can
output in the format @var{ofmt} which is either @code{human} or @code{json}.
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
