[systemd-devel] [PATCH ] Adding /etc/fstab.d/*.fstab support

[Masatake YAMATO]

On Fri, 20 Jan 2012 14:46:21 +0100, Kay Sievers <kay.sievers at vrfy.org> wrote
> On Fri, Jan 20, 2012 at 14:36, Masatake YAMATO <yamato at redhat.com> wrote:
>>> On Fri, Jan 20, 2012 at 07:52, Masatake YAMATO <yamato at redhat.com> wrote:
>>>> mount command in the latest version of util-linux(2.21-rc1[1])
>>>> supports /etc/fstab.d; mount command reads /etc/fstab.d/*.fstab
>>>> files as if they are written in /etc/fstab.
>>>>
>>>> The benefits of .d mechanism are explained in [2][3].
>>>>
>>>> With this patch, systemd can handle /etc/fstab.d/*.fstab.
>>>
>>> That's an absolute mis-feature, that needs to be removed. I'm all
>>> against supporting that, it breaks tons of stuff, and must not happen.
> 
>> Could you tell me more?
>> I'd like to know typical problem.
> 
> This breaks a glibc feature, and common expectations. Random tools
> that expect to find all 'system volumes' by parsing /etc/fstab. We
> should not change that. /etc/fstab is not a service config file which
> can be just split up, it's an ABI and used by lots of tools.
> 
> It's just naive to believe we can patch all the tools, and we can not
> argue that /etc/fstab is anything like broken today, like we could
> justify getting rid of /etc/mtab. The gain of feature vs. the amount
> of breakage will not justify such a change.
> 
> If we go for advanced storage handling, we might need to invent
> something that can carry real metadata and assembly instructions, and
> this might need to live in their own files, sure. But that's a
> different issue, and would all be fine. But please leave fstab alone,
> we don't want to deal with changing that.
> 
> Kay

Thank you for explanation.

systemd.mount(5) says:

    FSTAB
	   Mount units may either be configured via unit files, or via
	   /etc/fstab (see fstab(5) for details).

systemd, which handles unit files for mount, already breaks the expectation of the 
random tools, doesn't it? The random tools don't know the unit files. 

Am I missing something?

Masatake YAMATO