Comment 1 for bug 917824

Thanks for reporting this bug and doing the analysis.

Despite your pinpointing, I'm afraid I don't quite understand where you are saying the problem is. I'm sorry, please bear with me. The QLIST_FOREACH variables are (var, head, field), so we start with &s->cluster_allocs as head, assign 'old_alloc' to s->cluster_allocs.lh_first to begin, use that in the loop, and then on each iteration we set old_allocs = old_allocs->next_in_flight.le_next. What are you saying we should be using instead?

can you tell me exactly how to reproduce this, with a precise 'qemu-img create' command, precise kvm command, and how big the qcow2 image is when it hangs? Given how reproducible it is for you, I"m surprised I haven't run into it, so I imagine you must be using different options than I usually do. I'll try to reproduce with your exact options, so that I can try on the upstream qemu version to see if this has been fixed upstream.

Thanks again.