On Mon, 3 May 2021 at 10:55, Max Reitz <mreitz@redhat.com> wrote:
In the bdrv_snapshot_goto() fallback code, we work with a pointer to
either bs->file or bs->backing. We close that child, close the node
(with .bdrv_close()), apply the snapshot on the child node, and then
re-open the node (with .bdrv_open()).
In order for .bdrv_open() to attach the same child node that we had
before, we pass "file={child-node}" or "backing={child-node}" to it.
Therefore, when .bdrv_open() has returned success, we can assume that
bs->file or bs->backing (respectively) points to our original child
again. This is verified by an assertion.
All of this is not immediately clear from a quick glance at the code,
so add a comment to the assertion what it is for, and why it is valid.
It certainly confused Coverity.
Reported-by: Coverity (CID 1452774)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Did this patch get lost? I was just going through outstanding
coverity issues and noticed it was posted a month ago and not
in master...