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From:   "NeilBrown" <neilb@suse.de>
To:     "Christian Brauner" <brauner@kernel.org>
Cc:     "Jeff Layton" <jlayton@kernel.org>,
        "Alexander Viro" <viro@zeniv.linux.org.uk>,
        "Chuck Lever" <chuck.lever@oracle.com>,
        "Olga Kornievskaia" <kolga@netapp.com>,
        "Dai Ngo" <Dai.Ngo@oracle.com>, "Tom Talpey" <tom@talpey.com>,
        "Chandan Babu R" <chandan.babu@oracle.com>,
        "Darrick J. Wong" <djwong@kernel.org>,
        "Dave Chinner" <david@fromorbit.com>, "Jan Kara" <jack@suse.cz>,
        "Linus Torvalds" <torvalds@linux-foundation.org>,
        "Kent Overstreet" <kent.overstreet@linux.dev>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org
Subject: Re: [PATCH v8 0/5] fs: multigrain timestamps for XFS's change_cookie
In-reply-to: <20230924-mitfeiern-vorladung-13092c2af585@brauner>
References: <20230922-ctime-v8-0-45f0c236ede1@kernel.org>,
 <20230924-mitfeiern-vorladung-13092c2af585@brauner>
Date:   Mon, 25 Sep 2023 08:44:47 +1000
Message-id: <169559548777.19404.13247796879745924682@noble.neil.brown.name>
Precedence: bulk

On Sun, 24 Sep 2023, Christian Brauner wrote:
> > My initial goal was to implement multigrain timestamps on most major
> > filesystems, so we could present them to userland, and use them for
> > NFSv3, etc.
> 
> If there's no clear users and workloads depending on this other than for
> the sake of NFS then we shouldn't expose this to userspace. We've tried
> this and I'm not convinced we're getting anything other than regressions
> out of it. Keep it internal and confined to the filesystem that actually
> needs this.
> 

Some NFS servers run in userspace, and they would a "clear user" of this
functionality.

NeilBrown