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From:   Miklos Szeredi <miklos@szeredi.hu>
Date:   Thu, 18 Oct 2018 09:37:44 +0200
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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 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.

Thanks,
Miklos