[0/2] Dump QCOW2 metadata

Message

Andrey Shinkevich Dec. 27, 2019, 11:43 a.m. UTC

The information about QCOW2 metadata allocations in an image ELF-file is
helpful for finding issues with the image data integrity.

Snapshots dump example:

$ sudo ./qemu-img check /.../.../harddisk.hdd -M --output=json
{
    "image-end-offset": 24820842496,
    "total-clusters": 153600,
    "check-errors": 0,
    "viscera": {
        "refcount-table": {
            "location": {
                "offset": 3845128192,
                "size": 1048576
            }
        },
        "active-l1": {
            "name": "L1 active table",
            "location": {
                "offset": 4194304,
                "size": 16
            },
            "l2-list": [
                {
                    "offset": 619708416,
                    "size": 1048576
                },
                {
                    "offset": 1156579328,
                    "size": 1048576
                }
            ]
        },
        "qcow2-header": {
            "location": {
                "offset": 0,
                "size": 1048576
            },
            "version": 3
        },
        "snapshot-table": {
            "location": {
                "offset": 648019968,
                "size": 191
            },
            "l1-list": [
                {
                    "name": "{3036f6c5-3a1f-44cb-af1f-653cc87fba04}",
                    "location": {
                        "offset": 14680064,
                        "size": 16
                    },
                    "l2-list": [
                        {
                            "offset": 3957325824,
                            "size": 1048576
                        },
                        {
                            "offset": 7025459200,
                            "size": 1048576
                        }
                    ]
                },
                {
                    "name": "{0aa1a7d6-16ee-4b44-a515-b5ecc571c959}",
                    "location": {
                        "offset": 638582784,
                        "size": 16
                    },
                    "l2-list": [
                        {
                            "offset": 3957325824,
                            "size": 1048576
                        },
                        {
                            "offset": 7025459200,
                            "size": 1048576
                        }
                    ]
                }
            ]
        }
    },
    "allocated-clusters": 22485,
    "filename": "/.../.../harddisk.hdd",
    "format": "qcow2",
    "fragmented-clusters": 3549
}

Bitmaps dump example:

$ ./qemu-img check /home/disk -M --output=json
{
    "image-end-offset": 1441792,
    "total-clusters": 16,
    "check-errors": 0,
    "viscera": {
        "refcount-table": {
            "location": {
                "offset": 65536,
                "size": 65536
            }
        },
        "active-l1": {
            "name": "L1 active table",
            "location": {
                "offset": 196608,
                "size": 8
            },
            "l2-list": [
                {
                    "offset": 262144,
                    "size": 65536
                }
            ]
        },
        "bitmaps": {
            "bitmap-dir": {
                "location": {
                    "offset": 1048576,
                    "size": 64
                },
                "dir-entries": [
                    {
                        "bitmap-table": {
                            "location": {
                                "offset": 589824,
                                "size": 8
                            },
                            "table-entries": [
                                {
                                    "type": "all-zeros"
                                }
                            ]
                        },
                        "bitmap-name": "bitmap-1"
                    },
                    {
                        "bitmap-table": {
                            "location": {
                                "offset": 983040,
                                "size": 8
                            },
                            "table-entries": [
                                {
                                    "cluster": {
                                        "offset": 655360,
                                        "size": 65536
                                    },
                                    "type": "serialized"
                                }
                            ]
                        },
                        "bitmap-name": "bitmap-2"
                    }
                ]
            },
            "nb-bitmaps": 2
        },
        "qcow2-header": {
            "location": {
                "offset": 0,
                "size": 65536
            },
            "version": 3
        }
    },
    "allocated-clusters": 12,
    "filename": "/home/disk",
    "format": "qcow2",
    "fragmented-clusters": 2
}

Andrey Shinkevich (2):
  qcow2: introduce Qcow2Metadata structure
  qcow2: dump QCOW2 metadata

 block/qcow2-bitmap.c   |  53 ++++++++++++-
 block/qcow2-refcount.c |  84 ++++++++++++++++----
 block/qcow2.c          |  30 +++++++
 block/qcow2.h          |   6 +-
 include/block/block.h  |   3 +-
 qapi/block-core.json   | 208 ++++++++++++++++++++++++++++++++++++++++++++++++-
 qemu-img.c             |  29 ++++++-
 qemu-img.texi          |   2 +-
 8 files changed, 390 insertions(+), 25 deletions(-)