Am 21.11.2017 um 18:03 hat Jeff Cody geschrieben: > When block_job_sleep_ns() is called, the co-routine is scheduled for > future execution. If we allow the job to be re-entered prior to the > scheduled time, we present a race condition in which a coroutine can be > entered recursively, or even entered after the coroutine is deleted. > > The job->busy flag is used by blockjobs when a coroutine is busy > executing. The function 'block_job_enter()' obeys the busy flag, > and will not enter a coroutine if set. If we sleep a job, we need to > leave the busy flag set, so that subsequent calls to block_job_enter() > are prevented. > > This changes the prior behavior of block_job_cancel() being able to > immediately wake up and cancel a job; in practice, this should not be an > issue, as the coroutine sleep times are generally very small, and the > cancel will occur the next time the coroutine wakes up. > > This fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1508708 > > Signed-off-by: Jeff Cody <jc...@redhat.com> > Reviewed-by: Stefan Hajnoczi <stefa...@redhat.com>
git bisect says that this is the commit where qemu-iotests started to break, e.g. case 020: --- /home/kwolf/source/qemu/tests/qemu-iotests/020.out 2017-11-20 10:43:53.157894898 +0100 +++ /home/kwolf/source/qemu/tests/qemu-iotests/020.out.bad 2017-11-22 11:22:48.781344756 +0100 @@ -537,7 +537,8 @@ wrote 65536/65536 bytes at offset 4295098368 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) No errors were found on the image. -Image committed. +qemu-img: block/block-backend.c:2086: blk_root_drained_end: Assertion `blk->quiesce_counter' failed. +./common.rc: line 61: 17396 Aborted (core dumped) ( exec "$QEMU_IMG_PROG" $QEMU_IMG_OPTIONS "$@" ) Reading from the backing file
