For reference, see the QMP docs [0][1]. [0]: https://qemu.readthedocs.io/en/master/interop/qemu-qmp-ref.html#command-QMP-block-core.block-commit [1]: https://qemu.readthedocs.io/en/master/interop/qemu-qmp-ref.html#command-QMP-job.job-complete
Signed-off-by: Fiona Ebner <[email protected]> --- src/PVE/QemuServer/Blockdev.pm | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/src/PVE/QemuServer/Blockdev.pm b/src/PVE/QemuServer/Blockdev.pm index af7e769b..8eb01b45 100644 --- a/src/PVE/QemuServer/Blockdev.pm +++ b/src/PVE/QemuServer/Blockdev.pm @@ -1074,7 +1074,15 @@ sub blockdev_commit { mon_cmd($vmid, "block-commit", %$opts); $jobs->{$job_id} = {}; - # if we commit the current, the blockjob need to be in 'complete' mode + # If the 'current' state is committed to its backing snapshot, the job will not complete + # automatically, because there is a writer, i.e. the guest. It is necessary to use the + # 'complete' completion mode, so that the 'current' block node is replaced with the backing + # node upon completion. Like that, IO after the commit operation will already land in the + # backing node, which will be renamed since it will be the new top of the chain (done by the + # caller). + # + # For other snapshots in the chain, it can be assumed that they have no writer, so + # 'block-commit' will complete automatically. my $complete = $src_snap && $src_snap ne 'current' ? 'auto' : 'complete'; eval { -- 2.47.3
