blockjob: drop BlockJob.blk field

It's unused now (except for permission handling)[*]. The only reasonable
user of it was block-stream job, recently updated to use own blk. And
other block jobs prefer to use own source node related objects.

So, the arguments of dropping the field are:

 - block jobs prefer not to use it
 - block jobs usually has more then one node to operate on, and better
   to operate symmetrically (for example has both source and target
   blk's in specific block-job state structure)

*: BlockJob.blk is used to keep some permissions. We simply move
permissions to block-job child created in block_job_create() together
with blk.

In mirror, we just should not care anymore about restoring state of
blk. Most probably this code could be dropped long ago, after dropping
bs->job pointer. Now it finally goes away together with BlockJob.blk
itself.

iotest 141 output is updated, as "bdrv_has_blk(bs)" check in
qmp_blockdev_del() doesn't fail (we don't have blk now). Still, new
error message looks even better.

In iotest 283 we need to add a job id, otherwise "Invalid job ID"
happens now earlier than permission check (as permissions moved from
blk to block-job node).

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Nikita Lapshin <nikita.lapshin@virtuozzo.com>

3 files changed, 4 insertions, 3 deletions

diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out
index c4c15fb275..63203d9944 100644
--- a/tests/qemu-iotests/141.out
+++ b/tests/qemu-iotests/141.out
@@ -132,7 +132,7 @@ wrote 1048576/1048576 bytes at offset 0
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
 {'execute': 'blockdev-del',
           'arguments': {'node-name': 'drv0'}}
-{"error": {"class": "GenericError", "desc": "Node drv0 is in use"}}
+{"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: commit"}}
 {'execute': 'block-job-cancel',
           'arguments': {'device': 'job0'}}
 {"return": {}}
diff --git a/tests/qemu-iotests/283 b/tests/qemu-iotests/283
index a09e0183ae..5defe48e97 100755
--- a/tests/qemu-iotests/283
+++ b/tests/qemu-iotests/283
@@ -93,7 +93,8 @@ vm.qmp_log('blockdev-add', **{
     'take-child-perms': ['write']
 })
 
-vm.qmp_log('blockdev-backup', sync='full', device='source', target='target')
+vm.qmp_log('blockdev-backup', sync='full', device='source', target='target',
+           job_id="backup0")
 
 vm.shutdown()
 
diff --git a/tests/qemu-iotests/283.out b/tests/qemu-iotests/283.out
index 5bb75952ef..5e4f456db5 100644
--- a/tests/qemu-iotests/283.out
+++ b/tests/qemu-iotests/283.out
@@ -4,7 +4,7 @@
 {"return": {}}
 {"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}}
 {"return": {}}
-{"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}}
+{"execute": "blockdev-backup", "arguments": {"device": "source", "job-id": "backup0", "sync": "full", "target": "target"}}
 {"error": {"class": "GenericError", "desc": "Permission conflict on node 'base': permissions 'write' are both required by node 'other' (uses node 'base' as 'image' child) and unshared by node 'source' (uses node 'base' as 'image' child)."}}
 
 === copy-before-write filter should be gone after job-finalize ===