Re: statx(2) API and documentation

[Florian Weimer <fw@deneb.enyo.de>]

* 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.