Really fixing 2 things:
1. Panic when any error is detected while walking the btrfs graph dir on
removal due to no error check.
2. Nested subvolumes weren't actually being removed due to passing in
the wrong path
On point 2, for a path detected as a nested subvolume, we were calling
`subvolDelete("/path/to/subvol", "subvol")`, where the last part of the
path was duplicated due to a logic error, and as such actually causing
point #1 since `subvolDelete` joins the two arguemtns, and
`/path/to/subvol/subvol` (the joined version) doesn't exist.
Also adds a test for nested subvol delete.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This adds daemon/graphdriver/graphtest/graphtest which has a few
generic tests for all graph drivers, and then uses these
from the btrs, devicemapper and vfs backends.
I've not yet added the aufs backend, because i can't test that here
atm. It should work though.
Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
