Am 30.07.2013 um 17:22 hat Paolo Bonzini geschrieben:
> Il 30/07/2013 17:13, Kevin Wolf ha scritto:
> > Am 25.07.2013 um 16:23 hat Paolo Bonzini geschrieben:
> >> This command dumps the metadata of an entire chain, in either tabular or
> >> JSON
> >> format.
> >>
> >> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> >
> > Hm, we have a 'map' command in qemu-io, which isn't exactly the same,
> > but then not much different either.
> >
> > Depending on the use cases, should we move this to qemu-io, should we
> > remove the old function from qemu-io, or should we really keep both?
>
> I would remove the one in qemu-io (but I haven't checked if qemu-iotests
> uses it).
>
> >> diff --git a/qemu-img.c b/qemu-img.c
> >> index c5c8ebc..b28d388 100644
> >> --- a/qemu-img.c
> >> +++ b/qemu-img.c
> >> @@ -1768,6 +1768,192 @@ static int img_info(int argc, char **argv)
> >> return 0;
> >> }
> >>
> >> +
> >> +typedef struct MapEntry {
> >> + int flags;
> >> + int depth;
> >> + int64_t start;
> >> + int64_t length;
> >> + int64_t offset;
> >> +} MapEntry;
> >> +
> >> +static void dump_map_entry(OutputFormat output_format, MapEntry *e,
> >> + MapEntry *next)
> >> +{
> >> + switch (output_format) {
> >> + case OFORMAT_HUMAN:
> >> + if ((e->flags & BDRV_BLOCK_DATA) &&
> >> + !(e->flags & BDRV_BLOCK_OFFSET_VALID)) {
> >> + error_report("File contains external, encrypted or compressed
> >> clusters.");
> >> + exit(1);
> >> + }
> >> + if ((e->flags & (BDRV_BLOCK_DATA|BDRV_BLOCK_ZERO)) ==
> >> BDRV_BLOCK_DATA) {
> >> + printf("%"PRId64" %"PRId64" %d %"PRId64"\n",
> >> + e->start, e->length, e->depth, e->offset);
> >
> > Is this really human-readable output?
>
> I will change it to use tabs and add a heading line.
The documentation patch contains a line like this:
0 131072 2 327680
A heading line and tabs (or even better, fixed printf column widths)
sounds good, but I think if it's really only for human users and not for
shell scripts, we can further improve the output:
Offset Length Mapped to File
0 + 128k -> 320k /tmp/backing.qcow2
128k + 256k -> 2M /tmp/overlay.qcow2
We could add another exact, more technical format like this, which could
leave out things like + and -> so that it is easier to parse from shell
scripts, too:
Offset Length Mapped to Depth File
0 0x20000 0x50000 1 /tmp/backing.qcow2
0x20000 0x40000 0x200000 0 /tmp/overlay.qcow2
What do you think?
Kevin
