From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp.codeaurora.org by pdx-caf-mail.web.codeaurora.org (Dovecot) with LMTP id 2EvRM3KtHFuzEgAAmS7hNA ; Sun, 10 Jun 2018 04:58:07 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 2E054607BB; Sun, 10 Jun 2018 04:58:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on pdx-caf-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=unavailable autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by smtp.codeaurora.org (Postfix) with ESMTP id B0294601C3; Sun, 10 Jun 2018 04:58:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org B0294601C3 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=ZenIV.linux.org.uk Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753678AbeFJE6E (ORCPT + 25 others); Sun, 10 Jun 2018 00:58:04 -0400 Received: from zeniv.linux.org.uk ([195.92.253.2]:53784 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753459AbeFJE6C (ORCPT ); Sun, 10 Jun 2018 00:58:02 -0400 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.87 #1 (Red Hat Linux)) id 1fRsPY-0002ql-IZ; Sun, 10 Jun 2018 04:57:17 +0000 Date: Sun, 10 Jun 2018 05:57:04 +0100 From: Al Viro To: Christoph Hellwig Cc: Miklos Szeredi , linux-unionfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 07/39] vfs: export vfs_ioctl() to modules Message-ID: <20180610045657.GM30522@ZenIV.linux.org.uk> References: <20180529144339.16538-1-mszeredi@redhat.com> <20180529144339.16538-8-mszeredi@redhat.com> <20180604084904.GF11333@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180604084904.GF11333@infradead.org> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 04, 2018 at 01:49:04AM -0700, Christoph Hellwig wrote: > On Tue, May 29, 2018 at 04:43:07PM +0200, Miklos Szeredi wrote: > > This is needed by the stacked ioctl implementation in overlayfs. > > EXPORT_SYMBOL_GPL for exporting random internals, please. Same > for any following patches. *blink* Christoph, get real and RTFS - vfs_ioctl() simply calls ->unlocked_ioctl(); all there is to it. This isn't even a case of "using that function establishes that the caller is a derived work" - *anyone* who can see definition of file_operations can bloody well open-code it. There isn't anything establishing derivation here. Hell, it could've been a static inline in include/linux/fs.h and it would neither differ from many other inlines in there nor need an export at all. This is really getting close to lxo-worthy levels of bogosity... More interesting question is why do we want to pass those ioctls to layers in the first place, especially if it's something with different availability (or, worse yet, argument layouts) before and after copyup.