qemu-img.texi: Describe human-readable info output

@code{json}.  The JSON output is an object of QAPI type @code{ImageInfo}; with

@code{--backing-chain}, it is an array of @code{ImageInfo} objects.

@code{--output=human} reports the following information (for every image in the

chain):

@table @var

@item image

The image file name

@item file format

The image format

@item virtual size

The size of the guest disk

@item disk size

How much space the image file occupies on the host file system (may be shown as

0 if this information is unavailable, e.g. because there is no file system)

@item cluster_size

Cluster size of the image format, if applicable

@item encrypted

Whether the image is encrypted (only present if so)

@item cleanly shut down

This is shown as @code{no} if the image is dirty and will have to be

auto-repaired the next time it is opened in qemu.

@item backing file

The backing file name, if present

@item backing file format

The format of the backing file, if the image enforces it

@item Snapshot list

A list of all internal snapshots

@item Format specific information

Further information whose structure depends on the image format.  This section

is a textual representation of the respective @code{ImageInfoSpecific*} QAPI

object (e.g. @code{ImageInfoSpecificQCow2} for qcow2 images).

@end table

@item map [--object @var{objectdef}] [--image-opts] [-f @var{fmt}] [--output=@var{ofmt}] [-U] @var{filename}

Dump the metadata of image @var{filename} and its backing file chain.