job: Add reference counting

This moves reference counting from BlockJob to Job.

In order to keep calling the BlockJob cleanup code when the job is
deleted via job_unref(), introduce a new JobDriver.free callback. Every
block job must use block_job_free() for this callback, this is asserted
in block_job_create().

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/block/blockjob_int.h b/include/block/blockjob_int.h
index 1e62d6dd30..6f0fe3c48d 100644
--- a/include/block/blockjob_int.h
+++ b/include/block/blockjob_int.h
@@ -144,6 +144,13 @@ void *block_job_create(const char *job_id, const BlockJobDriver *driver,
                        BlockCompletionFunc *cb, void *opaque, Error **errp);
 
 /**
+ * block_job_free:
+ * Callback to be used for JobDriver.free in all block jobs. Frees block job
+ * specific resources in @job.
+ */
+void block_job_free(Job *job);
+
+/**
  * block_job_sleep_ns:
  * @job: The job that calls the function.
  * @ns: How many nanoseconds to stop for.