This bug has been copied from bug #1554650 and has been proposed to be backported to 7.5 z-stream (EUS).
Fix included in qemu-kvm-ma-2.10.0-21.el7_5.2
This bug can be reproduced with qemu-img-ma-2.10.0-20.el7 Reproduce Steps: 1. Create a qcow2 image - base.qcow2 # qemu-img create -f qcow2 base.qcow2 22G 2. Create a child of the base image: # qemu-img create -f qcow2 -b base.qcow2 child1.img 22G 3. Run a qemu process that uses child1 image 4. Create another child of the base image: # qemu-img create -f qcow2 -b base.qcow2 child2.img 22G 5. Create a child of child2 image: # qemu-img create -f qcow2 -b child2.img child2_2.img 22G 6. Commit child2_2 into child2 # qemu-img commit -p -t none -b child2.img child2_2.img (0.00/100%) qemu-img: Failed to get "write" lock Is another process using the image? Actual Results: Step #6 fails #### And this bug is verified against qemu-kvm-ma-2.10.0-21.el7_5.2 Host kernel: 3.10.0-862.el7.ppc64le (Power8) Verify Steps: the same as Reproduce Steps Actual Results: Step #6 succeeds, output is like following: # qemu-img commit -p -t none -b child2.img child2_2.img (100.00/100%) Image committed. Besides, I also ran the following two tests to verify this bug: 1. All the cases in https://bugzilla.redhat.com/show_bug.cgi?id=1554946#c8 , and all passed 2. qemu-img related cases from polarion, NO failed cases found Based on this, set this bug as 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/RHBA-2018:1368