Description of problem:
Create a new file using "dd" command in guest which use qcow2 image, when "dd" command finish, immediately type "quit" on qemu console to end the guest, boot guest with the image again, the file "dd" created does not exist.

Version-Release number of selected component (if applicable):
host info:
#uname -r
2.6.32-113.el6.x86_64
#rpm -q qemu-kvm
qemu-kvm-0.12.1.2-2.145.el6.x86_64
guest info:
2.6.18-238.el5

How reproducible:
100% if quit quickly enough

Steps to Reproduce:
1. create a qcow2 image: qemu-img create -f qcow2 rhel5.6_64_qcow2_base 20G
2. boot guest: /usr/libexec/qemu-kvm -M rhel6.1.0 -enable-kvm -m 2G -smp 2 -name RHEL-Server-5.6-64-base -uuid `uuidgen` -rtc base=utc -boot order=cd -drive file=./rhel5.6_64_qcow2_base,if=none,id=drive-virtio-disk0,format=qcow2,cache=none,werror=stop,rerror=stop -device virtio-blk-pci,drive=drive-virtio-disk0,id=virtio-disk0 -netdev tap,script=/etc/qemu-ifup,id=hostnet0 -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:7b:a2:fa -usb -device usb-tablet,id=input0 -vnc :10 -monitor stdio
3. after guest boot, on qemu console, type "quit" ahead, but don't press ENTER: ((qemu)) quit
4. in the guest, use "dd" create a new file: dd if=/dev/zero of=./base bs=1M count=1024
5. wait for dd finish, when you see the output of dd, switch your window to qemu console press ENTER immediately, this can be easily accomplished within 1 second.

  
Actual results:
boot guest with the image again, the file "base" does not exist.

Expected results:
boot guest with the image again, the file "base" should exist.

Additional info: