Comment 2 for bug 1805256

ext4 filesystem, SATA drive:

(gdb) thread apply all bt

Thread 3 (Thread 0xffff9bffc9a0 (LWP 9015)):
#0 0x0000ffffaaa462cc in __GI___sigtimedwait (set=<optimized out>,
    set@entry=0xaaaae725c070, info=info@entry=0xffff9bffbf18,
    timeout=0x3ff0000000000001, timeout@entry=0x0)
    at ../sysdeps/unix/sysv/linux/sigtimedwait.c:42
#1 0x0000ffffaab7dfac in __sigwait (set=set@entry=0xaaaae725c070,
    sig=sig@entry=0xffff9bffbff4) at ../sysdeps/unix/sysv/linux/sigwait.c:28
#2 0x0000aaaad998a628 in sigwait_compat (opaque=0xaaaae725c070)
    at util/compatfd.c:36
#3 0x0000aaaad998bce0 in qemu_thread_start (args=<optimized out>)
    at util/qemu-thread-posix.c:498
#4 0x0000ffffaab73088 in start_thread (arg=0xffffc528531f)
    at pthread_create.c:463
#5 0x0000ffffaaae34ec in thread_start ()
    at ../sysdeps/unix/sysv/linux/aarch64/clone.S:78

Thread 2 (Thread 0xffffa0e779a0 (LWP 9014)):
#0 syscall () at ../sysdeps/unix/sysv/linux/aarch64/syscall.S:38
#1 0x0000aaaad998c9e8 in qemu_futex_wait (val=<optimized out>, f=<optimized out>)
    at /home/ubuntu/qemu/include/qemu/futex.h:29
#2 qemu_event_wait (ev=ev@entry=0xaaaad9a091c0 <rcu_call_ready_event>)
    at util/qemu-thread-posix.c:442
#3 0x0000aaaad99a6834 in call_rcu_thread (opaque=<optimized out>)
    at util/rcu.c:261
#4 0x0000aaaad998bce0 in qemu_thread_start (args=<optimized out>)
    at util/qemu-thread-posix.c:498
#5 0x0000ffffaab73088 in start_thread (arg=0xffffc528542f)
    at pthread_create.c:463
#6 0x0000ffffaaae34ec in thread_start ()
    at ../sysdeps/unix/sysv/linux/aarch64/clone.S:78

Thread 1 (Thread 0xffffa0fa8010 (LWP 9013)):
#0 0x0000ffffaaada154 in __GI_ppoll (fds=0xaaaae7291dc0, nfds=187650771816320,
    timeout=<optimized out>, timeout@entry=0x0, sigmask=0xffffc52852e0)
    at ../sysdeps/unix/sysv/linux/ppoll.c:39
#1 0x0000aaaad9987f00 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>,
    __fds=<optimized out>) at /usr/include/aarch64-linux-gnu/bits/poll2.h:77
#2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>,
    timeout=timeout@entry=-1) at util/qemu-timer.c:322
#3 0x0000aaaad9988f80 in os_host_main_loop_wait (timeout=-1)
    at util/main-loop.c:233
#4 main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:497
#5 0x0000aaaad98b7a30 in convert_do_copy (s=0xffffc52854e8) at qemu-img.c:1980
#6 img_convert (argc=<optimized out>, argv=<optimized out>) at qemu-img.c:2456
#7 0x0000aaaad98b033c in main (argc=7, argv=<optimized out>) at qemu-img.c:4975