Hi, We sometimes have a problem with jobs remaining on STANDBY after a drain (for a short duration), so if the user immediately issues a block-job-complete, that will fail.
(See also https://lists.nongnu.org/archive/html/qemu-block/2021-04/msg00215.html, which this series is an alternative for.) Looking at the only implementation of .complete(), which is mirror_complete(), it looks like there is basically nothing that would prevent it from being run while mirror is paused. Really only the job_enter() at the end, which we should not and need not do when the job is paused. So make that conditional (patch 2), clean up the function on the way (patch 1, which moves one of its blocks to mirror_exit_common()), and then we can allow job_complete() on jobs that are on standby (patch 3). Patch 4 is basically the same test as in https://lists.nongnu.org/archive/html/qemu-block/2021-04/msg00214.html, except some comments are different and, well, job_complete() just works on STANDBY jobs. Patch 5 is an iotest that may or may not show the problem for you. I’ve tuned the numbers so that on my machine, it fails about 50/50 without this series (i.e., the job is still on STANDBY and job_complete() refuses to do anything). I’m not sure we want that iotest, because it does quite a bit of I/O and it’s unreliable, and I don’t think there’s anything I can do to make it reliable. Max Reitz (5): mirror: Move open_backing_file to exit_common mirror: Do not enter a paused job on completion job: Allow complete for jobs on standby test-blockjob: Test job_wait_unpaused() iotests: Test completion immediately after drain block/mirror.c | 28 ++-- job.c | 4 +- tests/unit/test-blockjob.c | 121 ++++++++++++++++++ .../tests/mirror-complete-after-drain | 89 +++++++++++++ .../tests/mirror-complete-after-drain.out | 14 ++ 5 files changed, 239 insertions(+), 17 deletions(-) create mode 100755 tests/qemu-iotests/tests/mirror-complete-after-drain create mode 100644 tests/qemu-iotests/tests/mirror-complete-after-drain.out -- 2.29.2