Re: [PATCH] iotests: Skip read-only cases in 118 when run as root

[Kevin Wolf <kwolf@redhat.com>]

Am 18.10.2019 um 14:59 hat Philippe Mathieu-Daudé geschrieben:
> Hi Kevin,
> 
> On 10/18/19 1:51 PM, Kevin Wolf wrote:
> > Some tests in 118 use chmod to remove write permissions from the file
> > and assume that the image can indeed not be opened read-write
> > afterwards. This doesn't work when the test is run as root, because root
> > can still open the file as writable even when the permission bit isn't
> > set.
> > 
> > Introduce a @skip_if_root decorator and use it in 118 to skip the tests
> > in question when the script is run as root.
> > 
> > Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> > ---
> >   tests/qemu-iotests/118        |  3 +++
> >   tests/qemu-iotests/iotests.py | 10 ++++++++++
> >   2 files changed, 13 insertions(+)
> > 
> > diff --git a/tests/qemu-iotests/118 b/tests/qemu-iotests/118
> > index ea0b326ae0..9eff46d189 100755
> > --- a/tests/qemu-iotests/118
> > +++ b/tests/qemu-iotests/118
> > @@ -446,6 +446,7 @@ class TestChangeReadOnly(ChangeBaseClass):
> >           self.assert_qmp(result, 'return[0]/inserted/ro', True)
> >           self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
> > +    @iotests.skip_if_root
> 
> Why not have case_notrun() return 'reason' and use:
> 
> @unittest.skipIf(os.getuid() == 0, case_notrun("cannot be run as root"))

Because we can't skip test cases using unittest functionality, it
results in different output (the test is marked as 's' instead of '.'
and a message '(skipped=n)' is added), which means failure for
qemu-iotests.

Apart from that, it would duplicate the logic and the error message in
every place, which wouldn't be very nice anyway. With the necessary
iotests.case_notrun() the line becomes > 80 characters, too.

> >       def test_rw_ro_retain(self):
> >           os.chmod(new_img, 0o444)
> >           self.vm.add_drive(old_img, 'media=disk', 'none')
> > @@ -530,6 +531,7 @@ class TestChangeReadOnly(ChangeBaseClass):
> >           self.assert_qmp(result, 'return[0]/inserted/ro', True)
> >           self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
> > +    @iotests.skip_if_root
> >       def test_make_ro_rw(self):
> >           os.chmod(new_img, 0o444)
> >           self.vm.add_drive(old_img, 'media=disk', 'none')
> > @@ -571,6 +573,7 @@ class TestChangeReadOnly(ChangeBaseClass):
> >           self.assert_qmp(result, 'return[0]/inserted/ro', True)
> >           self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
> > +    @iotests.skip_if_root
> >       def test_make_ro_rw_by_retain(self):
> >           os.chmod(new_img, 0o444)
> >           self.vm.add_drive(old_img, 'media=disk', 'none')
> > diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
> > index 3a8f378f90..9c66db613e 100644
> > --- a/tests/qemu-iotests/iotests.py
> > +++ b/tests/qemu-iotests/iotests.py
> > @@ -920,6 +920,16 @@ def skip_if_unsupported(required_formats=[], read_only=False):
> >           return func_wrapper
> >       return skip_test_decorator
> > +def skip_if_root(func):
> 
> skip_if_user_is_root() is slightly less confuse.

Ok, I can make this change.

Kevin