sorry, if it was not as clear as it should be... the assignment you describe is done until old_allocs is NULL (well the asm-test checks against zero, I've not looked at the macrodef of QLIST_FOREACH), but in this special case old_allocs points to address "foobar" *and* old_allocs->next_in_flight.le_next points to same address "foobar", too, so it will never become NULL and will endless loop...
gdb shows this: 777 QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { 779 uint64_t end_offset = offset + nb_clusters * s->cluster_size; 780 uint64_t old_offset = old_alloc->offset; 779 uint64_t end_offset = offset + nb_clusters * s->cluster_size; 784 if (end_offset < old_offset || offset > old_end_offset) { 782 old_alloc->nb_clusters * s->cluster_size; 781 uint64_t old_end_offset = old_alloc->offset + 784 if (end_offset < old_offset || offset > old_end_offset) { 777 QLIST_FOREACH(old_alloc, &s->cluster_allocs, next_in_flight) { (gdb) print old_alloc $1 = (QCowL2Meta *) 0x34cb7a0 (gdb) print old_alloc->next_in_flight.le_next $2 = (struct QCowL2Meta *) 0x34cb7a0 I've not analyzed, what is done within the loop, but there should be a point of another break-possibility. I've only understood, that there's something done to expand the allocation of the qcow2-file, because of some needs within the guest. because I don't know, how I created that certain disk, I've just started another VM with a newly created disk. this is done via the virt-manager-interface of libvirt. if this tool simply calls qemu-img or may make some api-calls by it's own - I don't know, but if it's as important I'll strace it. the disk has a maximum of 32768MB with 0 pre-allocated. qemu-img info say at the current loop (tried to install the soft again): file format: qcow2 virtual size: 32G (34359738368 bytes) disk size: 76M cluster_size: 65536 if you want more output out of gdb, tell me. the VM currently hangs and now gdb waits for commands... -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/917824 Title: qemu loops/hangs on extending qcow2-diskspace To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/917824/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs