device: 0.799
graphic: 0.686
other: 0.638
performance: 0.605
network: 0.457
permissions: 0.452
debug: 0.440
semantic: 0.423
boot: 0.354
socket: 0.275
vnc: 0.219
PID: 0.212
files: 0.066
KVM: 0.044

qemu-img info foo.qcow2 tries to get write lock
Description of problem:
When trying to run qemu-img info on an image which is used by QEMU qemu-img tries to acquire a write lock. Ideally this would not attempt to acquire a write lock and let qemu-img info succeed.
```
[jelle@t14s][/tmp]%qemu-img info /var/tmp/cockpit-qr_j3e_m.qcow2
qemu-img: Could not open '/var/tmp/cockpit-qr_j3e_m.qcow2': Failed to get shared "write" lock
Is another process using the image [/var/tmp/cockpit-qr_j3e_m.qcow2]?
```
Steps to reproduce:
1. Run qemu-img on an image used by a QEMU process.