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Date: Tue, 7 Mar 2017 10:44:35 -0800
From: "Darrick J. Wong" <darrick.wong@oracle.com>
To: David Howells <dhowells@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>, mtk.manpages@gmail.com,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        xfs <linux-xfs@vger.kernel.org>
Subject: Re: statx manpage
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On Tue, Mar 07, 2017 at 06:39:42PM +0000, David Howells wrote:
> Darrick J. Wong <darrick.wong@oracle.com> wrote:
> 
> > Is (flags & AT_EMPTY_PATH) is the same as (pathname == NULL)?
> 
> I'm not sure.  I was wondering about that whilst writing this.  The text
> describing the option is copied from the stat(2) manpage.  It specified an
> empty path (presumably "") rather than NULL.  I'm also not sure whether it has
> other ramifications.

<nod>

> > > .I Note:
> > > For performance and simplicity reasons, different fields in the
> > > .I statx
> > > structure may contain state information from different moments
> > > during the execution of the system call.
> > 
> > Hm.  Judging from the ext4 patch you proposed, I gather this is
> > expected, at least in the btime case.

Ugh, I put that in the wrong part -- this was supposed to be a comment
about the part where the manpage states that filesystems can return more
than userspace asked for.  My eyes are bad at reading manpage source. :/

(Sorry for the noise.)

--D

> This is copied from the stat(2) manpage.  The comment in the source there says
> it's because there's no locking in the getattr path against the setattr path.
> 
> David