device: 0.874
performance: 0.866
graphic: 0.850
network: 0.745
semantic: 0.741
other: 0.694
permissions: 0.675
PID: 0.674
vnc: 0.656
debug: 0.632
boot: 0.626
socket: 0.433
KVM: 0.326
files: 0.151

there is no 'write' lock checked when exec `qemu-img check lvqcow2`
Description of problem:
There is a difference between a qcow2 file image and a lvqcow2 img.

'write' lock will be checked when using a normal qcow2-format image (/path/to/img/test.qcow2) to avoid some risky operations. However, when I create a qcow2 img on a lv, there is not any write lock checked when I perform `qemu-img check` on this lvqcow2 even though it was attached to a vm.
Steps to reproduce:
1. create a lvqcow2: `qemu-img create -f qcow2 /path/to/lv  xxG`
2. create a vm using this lvqcow2
3. exec `qemu-img check` on this lvqcow2, there is no any perm (such as 'write' lock) check and notifaction even though this lvqcow2 is using in qemu vm.
Additional information: