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[209.85.167.49]) by smtp.gmail.com with ESMTPSA id h22-v6sm845265ljg.24.2019.01.15.20.55.07 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 15 Jan 2019 20:55:07 -0800 (PST) Received: by mail-lf1-f49.google.com with SMTP id n18so3844393lfh.6 for ; Tue, 15 Jan 2019 20:55:07 -0800 (PST) X-Received: by 2002:a19:c014:: with SMTP id q20mr5021271lff.16.1547614506503; Tue, 15 Jan 2019 20:55:06 -0800 (PST) MIME-Version: 1.0 References: <20190110070355.GJ27534@dastard> <20190110122442.GA21216@nautica> <20190111020340.GM27534@dastard> <20190111040434.GN27534@dastard> <20190111073606.GP27534@dastard> <20190115234510.GA6173@dastard> In-Reply-To: <20190115234510.GA6173@dastard> From: Linus Torvalds Date: Wed, 16 Jan 2019 16:54:49 +1200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] mm/mincore: allow for making sys_mincore() privileged To: Dave Chinner Cc: Dominique Martinet , Jiri Kosina , Matthew Wilcox , Jann Horn , Andrew Morton , Greg KH , Peter Zijlstra , Michal Hocko , Linux-MM , kernel list , Linux API Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 16, 2019 at 11:45 AM Dave Chinner wrote: > > I'm assuming that you can invalidate the page cache reliably by a > means that does not repeated require probing to detect invalidation > has occurred. I've mentioned one method in this discussion > already... Yes. And it was made clear to you that it was a bug in xfs dio and what the right thing to do was. And you ignored that, and claimed it was a feature. Why do you then bother arguing this thing? We absolutely agree that xfs has an information leak. If you don't care, just _say_ so. Don't try to argue against other people who are trying to fix things. We can easily just say "ok, xfs people don't care", and ignore the xfs invalidation issue. That's fine. But don't try to make it a big deal for other filesystems that _don't_ have the bug. I even pointed out how ext4 does the page cache flushing correcrly. You pooh-poohed it. You can't have it both ways. Either you care or you don't. If you don't care (and so far everything you said seems to imply you don't), then why are you even discussing this? Just admit you don't care, and we're done. Linus