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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Thu, 18 Oct 2018 09:42:17 +0200
Message-ID: <CAJfpegseDedv47mSWE=Noue+Y2e6xBDPe2WVb+tU=Y-Cq-zcyw@mail.gmail.com>
Subject: Re: statx(2) API and documentation
To:     Florian Weimer <fw@deneb.enyo.de>
Cc:     Andreas Dilger <adilger@dilger.ca>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        David Howells <dhowells@redhat.com>,
        Linux FS-devel Mailing List <linux-fsdevel@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux API <linux-api@vger.kernel.org>
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On Thu, Oct 18, 2018 at 9:39 AM, Florian Weimer <fw@deneb.enyo.de> wrote:
> * Miklos Szeredi:
>
>> On Thu, Oct 18, 2018 at 12:22 AM, Florian Weimer <fw@deneb.enyo.de> wrote:
>>> * Andreas Dilger:
>>>
>>>>> So what's the point exactly?
>>>>
>>>> Ah, I see your point...  STATX_ALL seems to be mostly useful for the kernel
>>>> to mask off flags that it doesn't currently understand.  It doesn't make
>>>> much sense for applications to specify STATX_ALL, since they don't have any
>>>> way to know what each flag means unless they are hard-coded to check each of
>>>> the STATX_* flags individually.  They should build up a mask of STATX_* flags
>>>> based on what they care about (e.g. "find" should only request attributes
>>>> based on the command-line options given).
>>>
>>> Could you remove it from the UAPI header?  I didn't want to put it
>>> into the glibc header, but was overruled.
>>
>> To summarize Linus' rule of backward incompatibility: you can do it as
>> long as nobody notices.  So yeah, we could try removing STATX_ALL from
>> the uapi header, but we'd have to put it back in, once somebody
>> complains.
>
> I don't recall a rule about backwards-incompatible API changes.  This
> wouldn't impact ABI at all.

Right, API rules maybe are softer.   I'll do some patches...

Thanks,
Miklos