blockjob: Add "ready" field

When a block job signals readiness, this is currently reported only
through QMP. If qemu wants to use block jobs for internal tasks, there
needs to be another way to correctly detect when a block job may be
completed.

For this reason, introduce a bool "ready" which is set when the block
job may be completed.
Signed-off-by: NMax Reitz <mreitz@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Message-id: 1414159063-25977-6-git-send-email-mreitz@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

blockjob.c

@@ -261,6 +261,7 @@ BlockJobInfo *block_job_query(BlockJob *job)
     info->offset    = job->offset;
     info->speed     = job->speed;
     info->io_status = job->iostatus;
+    info->ready     = job->ready;
     return info;
 }
 
@@ -296,6 +297,8 @@ void block_job_event_completed(BlockJob *job, const char *msg)
 
 void block_job_event_ready(BlockJob *job)
 {
+    job->ready = true;
+
     qapi_event_send_block_job_ready(job->driver->job_type,
                                     bdrv_get_device_name(job->bs),
                                     job->len,

include/block/blockjob.h

@@ -91,6 +91,11 @@ struct BlockJob {
      */
     bool busy;
 
+    /**
+     * Set to true when the job is ready to be completed.
+     */
+    bool ready;
+
     /** Status that is published by the query-block-jobs QMP API */
     BlockDeviceIoStatus iostatus;
 

qapi/block-core.json

@@ -514,12 +514,14 @@
 #
 # @io-status: the status of the job (since 1.3)
 #
+# @ready: true if the job may be completed (since 2.2)
+#
 # Since: 1.1
 ##
 { 'type': 'BlockJobInfo',
   'data': {'type': 'str', 'device': 'str', 'len': 'int',
            'offset': 'int', 'busy': 'bool', 'paused': 'bool', 'speed': 'int',
-           'io-status': 'BlockDeviceIoStatus'} }
+           'io-status': 'BlockDeviceIoStatus', 'ready': 'bool'} }
 
 ##
 # @query-block-jobs: