Bug 1666884

For incremental_live_backup, test on qemu-kvm-rhev-2.12.0-23.el7.x86_64, only in this 
testing scenarios, we can hit this issue.

 1.Start guest with a qcow2 image.
    -object iothread,id=iothread0 \
    -blockdev driver=file,node-name=file_base,filename=/home/kvm_autotest_root/images/rhel77-64-virtio.qcow2,auto-read-only=on \
    -blockdev driver=qcow2,file=file_base,node-name=drive_image1,auto-read-only=on \
    -device virtio-blk-pci,id=image1,drive=drive_image1,bus=pci.0,iothread=iothread0 \
 
 2.Create a persistent bitmap.
     { "execute": "block-dirty-bitmap-add", "arguments": {"node": "drive_image1", "name": "bitmap0","persistent":true}}

 3.Shutdown vm.
   (qemu)quit
 
 4.Re-start it with the qcow2 image.
    -object iothread,id=iothread0 \
    -blockdev driver=file,node-name=file_base,filename=/home/kvm_autotest_root/images/rhel77-64-virtio.qcow2,auto-read-only=on \
    -blockdev driver=qcow2,file=file_base,node-name=drive_image1,auto-read-only=on \
    -device virtio-blk-pci,id=image1,drive=drive_image1,bus=pci.0,iothread=iothread0 \

 5.Do block resize
    { "execute": "block_resize", "arguments": { "node-name":"drive_image1", "size":32212254720}}

Test Result:
 Block_resize in step5 failed with error info:
   {"error": {"class": "GenericError", "desc": "Can't resize an image which has bitmaps"}}


 When we do block_resize after step2, don't hit this issue.

Preliminary fixes for this have been posted upstream, setting to assigned.

Ref: https://lists.gnu.org/archive/html/qemu-devel/2019-03/msg01319.html

Reproduce this bug offline as below.

Tested with:
qemu-kvm-rhev-2.12.0-25.el7
kernel-3.10.0-1014.el7


Steps:
1. Boot a guest with a data disk of qcow2 format.
# /usr/libexec/qemu-kvm \
        ......
        -device virtio-blk-pci,id=virtio_blk_pci1,drive=my_file1,bus=pcie.0,addr=06 \
        -blockdev driver=qcow2,cache.direct=off,cache.no-flush=on,node-name=my_file1,file.driver=file,file.filename=data.qcow2 \
        ......
2. Check blocks info with HMP
(qemu) info block
my_file: sn.qcow2 (qcow2)
    Attached to:      /machine/peripheral/virtio_blk_pci0/virtio-backend
    Cache mode:       writethrough, ignore flushes
    Backing file:     json:{"driver": "raw", "file": {"pool": "rbd", "image": "new_base.img", "driver": "rbd"}} (chain depth: 1)

my_file1: data.qcow2 (qcow2)
    Attached to:      /machine/peripheral/virtio_blk_pci1/virtio-backend
    Cache mode:       writethrough, ignore flushes
(qemu) 

3. Create a persistent bitmap by QMP
{"QMP": {"version": {"qemu": {"micro": 0, "minor": 12, "major": 2}, "package": "qemu-kvm-rhev-2.12.0-25.el7"}, "capabilities": []}}

{"execute": "qmp_capabilities"}
{"return": {}}

{ "execute": "block-dirty-bitmap-add", "arguments": {"node": "my_file1", "name": "bitmap0","persistent":true}}
{"return": {}}

4. Shutdown the guest

5. Resize the data disk
# qemu-img resize data.qcow2 +1G
qemu-img: Can't resize an image which has bitmaps

Fix included in qemu-kvm-rhev-2.12.0-27.el7

Verified in qemu-kvm-rhev-2.12.0-27.el7, it has been fixed. Will set bug's status to "Verified" after "ON_QA".

Test steps:
 1.Start guest with qemu cmds:
    /usr/libexec/qemu-kvm \
    -name 'avocado-vt-vm1' \
    -machine pc  \
    -nodefaults \
    -device VGA,bus=pci.0,addr=0x2  \
    -chardev socket,id=qmp_id_qmpmonitor1,path=/var/tmp/monitor-qmpmonitor1-20190412-011839-sZJY2UtD,server,nowait \
    -mon chardev=qmp_id_qmpmonitor1,mode=control  \
    -chardev socket,id=qmp_id_catch_monitor,path=/var/tmp/monitor-catch_monitor-20190412-011839-sZJY2UtD,server,nowait \
    -mon chardev=qmp_id_catch_monitor,mode=control \
    -device pvpanic,ioport=0x505,id=idbSDNv4  \
    -chardev socket,id=serial_id_serial0,path=/var/tmp/serial-serial0-20190412-011839-sZJY2UtD,server,nowait \
    -device isa-serial,chardev=serial_id_serial0  \
    -chardev socket,id=seabioslog_id_20190412-011839-sZJY2UtD,path=/var/tmp/seabios-20190412-011839-sZJY2UtD,server,nowait \
    -device isa-debugcon,chardev=seabioslog_id_20190412-011839-sZJY2UtD,iobase=0x402 \
    -device nec-usb-xhci,id=usb1,bus=pci.0,addr=0x3 \
    -object iothread,id=iothread0 \
    -device virtio-scsi-pci,id=virtio_scsi_pci0,bus=pci.0,addr=0x4,iothread=iothread0 \
    -blockdev driver=file,node-name=file_node,filename=/home/kvm_autotest_root/images/rhel77-64-virtio-scsi.qcow2 \
    -blockdev driver=qcow2,node-name=drive_image1,file=file_node \
    -device scsi-hd,id=image1,drive=drive_image1 \
    -device virtio-net-pci,mac=9a:dc:dd:de:df:e0,id=idb7yKIW,vectors=4,netdev=idpOQ1y9,bus=pci.0,addr=0x5  \
    -netdev tap,id=idpOQ1y9,vhost=on \
    -m 30720  \
    -smp 16,maxcpus=16,cores=8,threads=1,sockets=2  \
    -cpu 'IvyBridge',+kvm_pv_unhalt \
    -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1  \
    -vnc :0  \
    -rtc base=utc,clock=host,driftfix=slew  \
    -boot menu=off,strict=off,order=cdn,once=c \
    -enable-kvm \
    -monitor stdio \
    -qmp tcp:0:3000,server,nowait \

  2.Add a persistent bitmap
    { "execute": "block-dirty-bitmap-add", "arguments": {"node": "drive_image1", "name": "bitmap1","persistent":true,"disabled":true,"granularity":4096}}

  3.Resize disk size to 30G
    { "execute": "block_resize", "arguments": { "node-name":"drive_image1", "size":32212254720}}
  
  4.Check image info.
    # qemu-img info rhel77-64-virtio-scsi.qcow2 -U
image: rhel77-64-virtio-scsi.qcow2
file format: qcow2
virtual size: 30G (32212254720 bytes)
disk size: 4.3G
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false
  
  5.Shutdown vm, resize disk size to 31G
     qemu-img resize /home/kvm_autotest_root/images/rhel77-64-virtio-scsi.qcow2 +1G
 
  6.Check image info:
     # qemu-img info rhel77-64-virtio-scsi.qcow2
image: rhel77-64-virtio-scsi.qcow2
file format: qcow2
virtual size: 31G (33285996544 bytes)
disk size: 4.3G
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    bitmaps:
        [0]:
            flags:
            name: bitmap1
            granularity: 4096
    refcount bits: 16
    corrupt: false

  7.Re-start vm, shrink its size to 30G
     { "execute": "block_resize", "arguments": { "node-name":"drive_image1", "size":32212254720}}
  
  8.Check image info:
     qemu-img info rhel77-64-virtio-scsi.qcow2 -U
image: rhel77-64-virtio-scsi.qcow2
file format: qcow2
virtual size: 30G (32212254720 bytes)
disk size: 4.3G
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    bitmaps:
        [0]:
            flags:
                [0]: in-use
            name: bitmap1
            granularity: 4096
    refcount bits: 16
    corrupt: false

  9.Shutdown vm, shrink its size to 29G.
    qemu-img resize --shrink /home/kvm_autotest_root/images/rhel77-64-virtio-scsi.qcow2 -1G

  10.Check image info:
     qemu-img info rhel77-64-virtio-scsi.qcow2
image: rhel77-64-virtio-scsi.qcow2
file format: qcow2
virtual size: 29G (31138512896 bytes)
disk size: 4.3G
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    bitmaps:
        [0]:
            flags:
            name: bitmap1
            granularity: 4096
    refcount bits: 16
    corrupt: false

 11.Re-start vm, then remove bitmap and resize image size to 30G:
     { 'execute': 'block-dirty-bitmap-remove', 'arguments': {'node':'drive_image1', 'name':'bitmap1'}}
     { "execute": "block_resize", "arguments": { "node-name":"drive_image1", "size":32212254720}}

 12.Check image info:
     qemu-img info rhel77-64-virtio-scsi.qcow2 -U
image: rhel77-64-virtio-scsi.qcow2
file format: qcow2
virtual size: 30G (32212254720 bytes)
disk size: 4.3G
cluster_size: 65536
Format specific information:
    compat: 1.1
    lazy refcounts: false
    refcount bits: 16
    corrupt: false

As comment 7, set bug's status to "Verified".

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2019:2553