Comment 0 for bug 1603902

When i try to convert raw image to qcow2 format with command:

qemu-img convert -O qcow2 base-image.img base-image.qcow2

i have several problems:

1. qemu-img process never stops by itself and i can not kill it with kill -9
2. qemu-img process utilizes 100% of one cpu core

Additional information:

1. I use supermicro server with 28 cpu cores and host Ubuntu Server 16.04
2. Filesystem is ext4
3. Original VM raw image (with installed guest Ubuntu Server 16.04) works without any problem. When i am trying to convert formats this VM is powered off.

4. uname -r
    4.4.0-28-generic

    dpkg -s qemu-kvm | grep Version
    Version: 1:2.5+dfsg-5ubuntu10.2

    dpkg -s qemu-utils | grep Version
    Version: 1:2.5+dfsg-5ubuntu10.2

    strace qemu-img convert -O qcow2 base-image.img base-image.qcow2
    ...
    lseek(10, 1361051648, SEEK_DATA) = 1386217472
    lseek(10, 1386217472, SEEK_DATA) = 1386217472
    lseek(10, 1386217472, SEEK_HOLE) = 1403359232
    lseek(10, 1403359232, SEEK_DATA) = 1403387904
    lseek(10, 1403387904, SEEK_DATA) = 1403387904
    lseek(10, 1403387904, SEEK_HOLE) = 1419091968
    lseek(10, 1419091968, SEEK_DATA

What can cause such strange behavior, and how can i convert raw image to qcow2 format?

UPDATED: I have installed 4.6.0 linux kernel, and everything works fine right now. But the question still exists: is there any other way to fix this bug for qemu-img and Ubuntu 16.04?