From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21B80C476E8 for ; Thu, 12 Jul 2018 17:15:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D88AB20842 for ; Thu, 12 Jul 2018 17:15:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D88AB20842 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732514AbeGLRZg (ORCPT ); Thu, 12 Jul 2018 13:25:36 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:35302 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727092AbeGLRZg (ORCPT ); Thu, 12 Jul 2018 13:25:36 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id D44D8D85; Thu, 12 Jul 2018 17:15:07 +0000 (UTC) Date: Thu, 12 Jul 2018 19:15:05 +0200 From: Greg KH To: David Howells Cc: viro@zeniv.linux.org.uk, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 24/32] vfs: syscall: Add fsopen() to prepare for superblock creation [ver #9] Message-ID: <20180712171505.GA23780@kroah.com> References: <153126248868.14533.9751473662727327569.stgit@warthog.procyon.org.uk> <153126264966.14533.3388004240803696769.stgit@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <153126264966.14533.3388004240803696769.stgit@warthog.procyon.org.uk> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 10, 2018 at 11:44:09PM +0100, David Howells wrote: > Provide an fsopen() system call that starts the process of preparing to > create a superblock that will then be mountable, using an fd as a context > handle. fsopen() is given the name of the filesystem that will be used: > > int mfd = fsopen(const char *fsname, unsigned int flags); > > where flags can be 0 or FSOPEN_CLOEXEC. > > For example: > > sfd = fsopen("ext4", FSOPEN_CLOEXEC); > write(sfd, "s /dev/sdb1"); // note I'm ignoring write's length arg > write(sfd, "o noatime"); > write(sfd, "o acl"); > write(sfd, "o user_attr"); > write(sfd, "o iversion"); > write(sfd, "o "); > write(sfd, "r /my/container"); // root inside the fs > write(sfd, "x create"); // create the superblock Ugh, creating configfs again in a syscall form? I know people love file descriptors, but can't you do this with a configfs entry instead if you really want to do this type of thing from userspace in this type of "style"? Why reinvent the wheel again? thanks, greg k-h