qemu/docs/interop
Kashyap Chamarthy c117bb14ff QAPI & interop: Clarify events emitted by 'block-job-cancel'
When you cancel an in-progress 'mirror' job (or "active `block-commit`")
with QMP `block-job-cancel`, it emits the event: BLOCK_JOB_CANCELLED.
However, when `block-job-cancel` is issued *after* `drive-mirror` has
indicated (via the event BLOCK_JOB_READY) that the source and
destination have reached synchronization:

    [...] # Snip `drive-mirror` invocation & outputs
    {
      "execute":"block-job-cancel",
      "arguments":{
        "device":"virtio0"
      }
    }

    {"return": {}}

It (`block-job-cancel`) will counterintuitively emit the event
'BLOCK_JOB_COMPLETED':

    {
      "timestamp":{
        "seconds":1510678024,
        "microseconds":526240
      },
      "event":"BLOCK_JOB_COMPLETED",
      "data":{
        "device":"virtio0",
        "len":41126400,
        "offset":41126400,
        "speed":0,
        "type":"mirror"
      }
    }

But this is expected behaviour, where the _COMPLETED event indicates
that synchronization has successfully ended (and the destination now has
a point-in-time copy, which is at the time of cancel).

So add a small note to this effect in 'block-core.json'.  While at it,
also update the "Live disk synchronization -- drive-mirror and
blockdev-mirror" section in 'live-block-operations.rst'.

(Thanks: Max Reitz for reminding me of this caveat on IRC.)

Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-11-27 14:59:35 +01:00
..
bitmaps.rst bitmaps.md: Convert to rST; move it into 'interop' dir 2017-07-18 00:11:01 -04:00
live-block-operations.rst QAPI & interop: Clarify events emitted by 'block-job-cancel' 2017-11-27 14:59:35 +01:00
parallels.txt docs: create interop/ subdirectory 2017-06-15 11:18:39 +02:00
pr-helper.rst scsi: build qemu-pr-helper 2017-09-22 21:07:24 +02:00
qcow2.txt specs/qcow2: do not use wording 'bitmap header' 2017-07-11 17:44:57 +02:00
qed_spec.txt docs: create interop/ subdirectory 2017-06-15 11:18:39 +02:00
qemu-ga-ref.texi docs: create interop/ subdirectory 2017-06-15 11:18:39 +02:00
qemu-qmp-ref.texi docs: create interop/ subdirectory 2017-06-15 11:18:39 +02:00
qmp-intro.txt Use HTTPS for qemu.org and other domains 2017-11-21 13:34:13 +00:00
qmp-spec.txt docs: create interop/ subdirectory 2017-06-15 11:18:39 +02:00
vhost-user.txt vhost-user: fix legacy cross-endian configurations 2017-08-02 00:13:25 +03:00
vnc-ledstate-Pseudo-encoding.txt docs: create interop/ subdirectory 2017-06-15 11:18:39 +02:00