On Tue, Jul 7, 2015 at 9:35 AM, Ludovic Courtès <l...@gnu.org> wrote:
> David Thompson <dthomps...@worcester.edu> skribis:
>
>> From: David Thompson <da...@gnu.org>
>>
>> * guix/build/syscalls.scm (pivot-root): New procedure.
>> * tests/syscalls.scm: Test it.
>
> [...]
>
>> +(test-assert "pivot-root"
>> + (match (pipe)
>> + ((in . out)
>> + (match (clone (logior CLONE_NEWUSER CLONE_NEWNS))
>> + (0
>> + (close in)
>> + (call-with-temporary-directory
>> + (lambda (root)
>> + (let ((put-old (string-append root "/real-root")))
>> + (mount "none" root "tmpfs")
>> + (mkdir put-old)
>> + (call-with-output-file (string-append root "/test")
>> + (lambda (port)
>> + (display "testing\n" port)))
>> + (pivot-root root put-old)
>> + ;; The test file should now be located inside the root
>> directory.
>> + (write (file-exists "/test") out)
>> + (close out))))
>> + (primitive-exit 0))
>> + (pid
>> + (close out)
>> + (read in))))))
>
> Shouldn’t it be:
>
> (file-exists? (string-append put-old "/test"))
No, because put-old contains the current system root directory. I
wanted to test that the file I made in the temporary directory is now
located in the new root file system. I hope this makes sense.
> To be on the safe side, the last line should probably be:
>
> (eq? #t (read in))
>
> Otherwise a return value of *unspecified* works as well.
Good call. I had a typo ('file-exists' instead of 'file-exists?')
that was making this test pass when it should've failed. That's bad
"test driven development" on my part. ;)
> Also, ‘waidpid’:
>
> (pid
> (close out)
> (let ((result (read in)))
> (close in)
> (and (zero? (status:exit-val (waitpid pid)))
> (eq? #t result))))
>
> OK with these changes.
Fixed and pushed. Thanks!
- Dave
