All block jobs are using block_job_defer_to_main_loop as the final
step just before the coroutine terminates. At this point,
block_job_enter should do nothing, but currently it restarts
the freed coroutine.
Now, the job->co states should probably be changed to an enum
(e.g. BEFORE_START, STARTED, YIELDED, COMPLETED) subsuming
block_job_started, job->deferred_to_main_loop and job->busy.
For now, this patch eliminates the problematic reenter by
removing the reset of job->deferred_to_main_loop (which served
no purpose, as far as I could see) and checking the flag in
block_job_enter.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id:
20170508141310.8674-12-pbonzini@redhat.com
Signed-off-by: Jeff Cody <jcody@redhat.com>
void block_job_enter(BlockJob *job)
{
- if (job->co && !job->busy) {
+ if (!block_job_started(job)) {
+ return;
+ }
+ if (job->deferred_to_main_loop) {
+ return;
+ }
+
+ if (!job->busy) {
bdrv_coroutine_enter(blk_bs(job->blk), job->co);
}
}
aio_context_acquire(aio_context);
}
- data->job->deferred_to_main_loop = false;
data->fn(data->job, data->opaque);
if (aio_context != data->aio_context) {
* @fn: The function to run in the main loop
* @opaque: The opaque value that is passed to @fn
*
- * Execute a given function in the main loop with the BlockDriverState
+ * This function must be called by the main job coroutine just before it
+ * returns. @fn is executed in the main loop with the BlockDriverState
* AioContext acquired. Block jobs must call bdrv_unref(), bdrv_close(), and
* anything that uses bdrv_drain_all() in the main loop.
*