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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed, 12 Aug 2020 12:50:28 -0700
Message-ID: <CAHk-=wgz5H-xYG4bOrHaEtY7rvFA1_6+mTSpjrgK8OsNbfF+Pw@mail.gmail.com>
Subject: Re: file metadata via fs API
To:     Steven Whitehouse <swhiteho@redhat.com>
Cc:     David Howells <dhowells@redhat.com>,
        Miklos Szeredi <miklos@szeredi.hu>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Al Viro <viro@zeniv.linux.org.uk>, Karel Zak <kzak@redhat.com>,
        Jeff Layton <jlayton@redhat.com>,
        Miklos Szeredi <mszeredi@redhat.com>,
        Nicolas Dichtel <nicolas.dichtel@6wind.com>,
        Christian Brauner <christian@brauner.io>,
        Lennart Poettering <lennart@poettering.net>,
        Linux API <linux-api@vger.kernel.org>,
        Ian Kent <raven@themaw.net>,
        LSM <linux-security-module@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, Aug 12, 2020 at 12:34 PM Steven Whitehouse <swhiteho@redhat.com> wrote:
>
> The point of this is to give us the ability to monitor mounts from
> userspace.

We haven't had that before, I don't see why it's suddenly such a big deal.

The notification side I understand. Polling /proc files is not the answer.

But the whole "let's design this crazy subsystem for it" seems way
overkill. I don't see anybody caring that deeply.

It really smells like "do it because we can, not because we must".

Who the hell cares about monitoring mounts at a kHz frequencies? If
this is for MIS use, you want a nice GUI and not wasting CPU time
polling.

I'm starting to ignore the pull requests from David Howells, because
by now they have had the same pattern for a couple of years now:
esoteric new interfaces that seem overdesigned for corner-cases that
I'm not seeing people clamoring for.

I need (a) proof this is actualyl something real users care about and
(b) way more open discussion and implementation from multiple parties.

Because right now it looks like a small in-cabal of a couple of people
who have wild ideas but I'm not seeing the wider use of it.

Convince me otherwise. AGAIN. This is the exact same issue I had with
the notification queues that I really wanted actual use-cases for, and
feedback from actual outside users.

I really think this is engineering for its own sake, rather than
responding to actual user concerns.

               Linus