QEMU’s always been confused over what a snapshot is: Is it the overlay? Is it the backing image?
Confusion is rarely a good thing. I can’t think of any objective reason why the overlay would be a snapshot. A snapshot is something that does not change over time; the overlay does. (I suppose historically the reason is that “Taking an overlay” makes no sense, so the operations are called “Taking a snapshot”. Somehow, this meaning carried over to the new file that is created during that operation; if “Creating a snapshot” creates a file, that file must be the snapshot, right? Well, no, it isn’t.) Let’s fix this as best as we can. Better Nate than lever. v2: - Don’t break the iotests for a change (kept Eric’s R-b, because it felt like the right thing to do) git backport-diff against v1: Key: [----] : patches are identical [####] : number of functional differences between upstream/downstream patch [down] : patch is downstream-only The flags [FC] indicate (F)unctional and (C)ontextual differences, respectively 001/2:[----] [--] 'qapi/block-core: Overlays are not snapshots' 002/2:[0010] [FC] 'blockdev: Overlays are not snapshots' Max Reitz (2): qapi/block-core: Overlays are not snapshots blockdev: Overlays are not snapshots qapi/block-core.json | 20 ++++++++++---------- blockdev.c | 10 +++++----- tests/qemu-iotests/085.out | 10 +++++----- 3 files changed, 20 insertions(+), 20 deletions(-) -- 2.21.0