Comment 9 for bug 1505948

Duplicating my post to the fuse developer mailing list here:

Hi all,

the kernel crash can be triggered if async direct IO is used which comes with Fuse 3.0_pre0 (i.e. current head). My workload was to install CentOS7 on a newly created qcow2 disk. The kernel (Fedora 21; 4.1.8-100.fc21.x86_64) crashed in 2/2 runs using qemu/kvm atop of ntfs-3g built against fuse3:

1) Build fuse3 from current head
2) Build ntfs-3g against fuse3 (feel free to use the attached patch. It assumes that pkg-config is able to find fuse3, so install fuse3.pc in a PKG_CONFIG_PATH)
3) ntfs-3g: ./configure --with-fuse=external; make
4) "src/lowntfs-3g --version" should now print 'lowntfs-3g 2015.3.14 external FUSE 30'

5) create and mount an NTFS volume
6) create a VM disk: qemu-img create -f qcow2 disk.qcow2 20G
7) make sure that the VM actually uses async direct io (cache='none' io='native')

In my case the kernel crashed around 12 minutes after the VM was started.

Regards,
Robert