When starting an active commit job, other callbacks can run before mirror_start_job() calls bdrv_ref() where needed and cause the nodes to go away. Add another pair of bdrv_ref/unref() around it to protect against this case.
Signed-off-by: Kevin Wolf <kw...@redhat.com> --- block/mirror.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/block/mirror.c b/block/mirror.c index 56d9ef7474..c8657991cf 100644 --- a/block/mirror.c +++ b/block/mirror.c @@ -1697,7 +1697,14 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, orig_base_flags = bdrv_get_flags(base); + /* bdrv_reopen() drains, which might make the BDSes go away before a + * reference is taken in mirror_start_job(). */ + bdrv_ref(bs); + bdrv_ref(base); + if (bdrv_reopen(base, bs->open_flags, errp)) { + bdrv_unref(bs); + bdrv_unref(base); return; } @@ -1707,6 +1714,10 @@ void commit_active_start(const char *job_id, BlockDriverState *bs, &commit_active_job_driver, false, base, auto_complete, filter_node_name, false, MIRROR_COPY_MODE_BACKGROUND, &local_err); + + bdrv_unref(bs); + bdrv_unref(base); + if (local_err) { error_propagate(errp, local_err); goto error_restore_flags; -- 2.13.6