commit: Fix completion with extra reference

commit_complete() can't assume that after its block_job_completed() the
job is actually immediately freed; someone else may still be holding
references. In this case, the op blockers on the intermediate nodes make
the graph reconfiguration in the completion code fail.

Call block_job_remove_all_bdrv() manually so that we know for sure that
any blockers on intermediate nodes are given up.

Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2017-06-09 13:29:36 +02:00
parent 931892e8a6
commit 4f78a16fee

View File

@ -119,6 +119,13 @@ static void commit_complete(BlockJob *job, void *opaque)
}
g_free(s->backing_file_str);
blk_unref(s->top);
/* If there is more than one reference to the job (e.g. if called from
* block_job_finish_sync()), block_job_completed() won't free it and
* therefore the blockers on the intermediate nodes remain. This would
* cause bdrv_set_backing_hd() to fail. */
block_job_remove_all_bdrv(job);
block_job_completed(&s->common, ret);
g_free(data);