Re: [PATCH 3/3] rbd: do not treat standalone as flatten

[Josh Durgin <josh.durgin@inktank.com>]

On 01/20/2015 04:41 AM, Ilya Dryomov wrote:
> If the clone is resized down to 0, it becomes standalone.  If such
> resize is carried over while an image is mapped we would detect this
> and call rbd_dev_parent_put() which means "let go of all parent state,
> including the spec(s) of parent images(s)".  This leads to a mismatch
> between "rbd info" and sysfs parent fields, so a fix is in order.
>
>      # rbd create --image-format 2 --size 1 foo
>      # rbd snap create foo@snap
>      # rbd snap protect foo@snap
>      # rbd clone foo@snap bar
>      # DEV=$(rbd map bar)
>      # rbd resize --allow-shrink --size 0 bar
>      # rbd resize --size 1 bar
>      # rbd info bar | grep parent
>              parent: rbd/foo@snap
>
> Before:
>
>      # cat /sys/bus/rbd/devices/0/parent
>      (no parent image)
>
> After:
>
>      # cat /sys/bus/rbd/devices/0/parent
>      pool_id 0
>      pool_name rbd
>      image_id 10056b8b4567
>      image_name foo
>      snap_id 2
>      snap_name snap
>      overlap 0
>
> Signed-off-by: Ilya Dryomov <idryomov@redhat.com>

Reviewed-by: Josh Durgin <jdurgin@redhat.com>