But I need to mention that it takes some time to reproduce this. This time I run/aborted about 500 backup jobs until it triggers.
> > I *think* the second patch also fixes the hangs on backup abort that I and > > Dietmar noticed in v1, but I'm not sure, they we're somewhat intermittent > > before too. > > No, I still get this freeze: > > 0 0x00007f0aa4866916 in __GI_ppoll (fds=0x7f0a12935c40, nfds=2, > timeout=<optimized out>, timeout@entry=0x0, sigmask=sigmask@entry=0x0) > at ../sysdeps/unix/sysv/linux/ppoll.c:39 > #1 0x000055d3a6c91d29 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized > out>, __fds=<optimized out>) > at /usr/include/x86_64-linux-gnu/bits/poll2.h:77 > #2 0x000055d3a6c91d29 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized > out>, timeout=timeout@entry=-1) at util/qemu-timer.c:335 > #3 0x000055d3a6c94511 in fdmon_poll_wait (ctx=0x7f0a97505e80, > ready_list=0x7fff67e5c358, timeout=-1) at util/fdmon-poll.c:79 > #4 0x000055d3a6c93af7 in aio_poll (ctx=0x7f0a97505e80, > blocking=blocking@entry=true) at util/aio-posix.c:589 > #5 0x000055d3a6bf4cd3 in bdrv_do_drained_begin > (poll=<optimized out>, ignore_bds_parents=false, parent=0x0, > recursive=false, bs=0x7f0a9754c280) at block/io.c:429 > #6 0x000055d3a6bf4cd3 in bdrv_do_drained_begin > (bs=0x7f0a9754c280, recursive=<optimized out>, parent=0x0, > ignore_bds_parents=<optimized out>, poll=<optimized out>) at block/io.c:395 > #7 0x000055d3a6be5c87 in blk_drain (blk=0x7f0a97abcc00) at > block/block-backend.c:1617 > #8 0x000055d3a6be686d in blk_unref (blk=0x7f0a97abcc00) at > block/block-backend.c:473 > #9 0x000055d3a6b9e835 in block_job_free (job=0x7f0a15f44e00) at blockjob.c:89 > #10 0x000055d3a6b9fe29 in job_unref (job=0x7f0a15f44e00) at job.c:376 > #11 0x000055d3a6b9fe29 in job_unref (job=0x7f0a15f44e00) at job.c:368 > #12 0x000055d3a6ba07aa in job_finish_sync (job=job@entry=0x7f0a15f44e00, > finish=finish@entry= > 0x55d3a6ba0cd0 <job_cancel_err>, errp=errp@entry=0x0) at job.c:1004 > #13 0x000055d3a6ba0cee in job_cancel_sync (job=job@entry=0x7f0a15f44e00) at > job.c:947