[systemd-devel] [PATCH] tmpfiles: don't create subvolumes in chroot

["Jóhann B. Guðmundsson"]

On 04/01/2015 01:04 PM, Lennart Poettering wrote:
> On Wed, 01.04.15 12:40, Jóhann B. Guðmundsson (johannbg at gmail.com) wrote:
>
>>> diff --git a/src/tmpfiles/tmpfiles.c b/src/tmpfiles/tmpfiles.c
>>> index 494fd1a..9280fd7 100644
>>> --- a/src/tmpfiles/tmpfiles.c
>>> +++ b/src/tmpfiles/tmpfiles.c
>>> @@ -1099,9 +1099,15 @@ static int create_item(Item *i) {
>>>                   break;
>>> +        case CREATE_SUBVOLUME:
>>> +
>>> +                /* Don't create subvolumes in chrooted environments. */
>>> +                if (running_in_chroot())
>>> +                        break;
>>> +                /* FALLTHROUGH */
>>> +
>>>           case CREATE_DIRECTORY:
>>>           case TRUNCATE_DIRECTORY:
>>> -        case CREATE_SUBVOLUME:
>>>                   RUN_WITH_UMASK(0000)
>>>                           mkdir_parents_label(i->path, 0755);
>>
>> This breakage is not limited to chroot, subvolumes should not be created et
>> all.
> Why not?

Because you break factory,stateless,reproducible,verifiable, mock and 
variety of servers setups with enterprise storage of any kind that uses 
btrfs ( and whatever else 'v' switch might support in the future ).
( Prime example that covers a lot of usecase where this breaks on btrfs 
/var/lib/machines )

Let's leave it up to vendor and downstream distributions to make an 
enlighten choice of turning the 'v' feature on after careful 
consideration and creating relevant documentation instead of breaking 
for them and have every distributions patching this "feature" out for 
example because they suddenly found themselves in a pile of bug reports 
because users could not delete those directories in the traditional 
manner they had expected ( rm ) but had to magically discover they will 
have to use the relevant subvolume removal command for the file system 
in question on those directories that it had been enabled on .

Bottom line upstream default should always be 'd' as in create a 
directory if it does not exist yet, never v as in create a subvolume if 
the path does not exist yet and the file system supports it.

JBG