From 4f78a16fee462471416dc49b409d57b2071cf3d9 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Fri, 9 Jun 2017 13:29:36 +0200 Subject: [PATCH] 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 Reviewed-by: Eric Blake Reviewed-by: Max Reitz --- block/commit.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/commit.c b/block/commit.c index af6fa68cf3..8c09c3dbcd 100644 --- a/block/commit.c +++ b/block/commit.c @@ -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); -- 2.11.4.GIT