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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 A07C9C433E0 for ; Tue, 9 Feb 2021 14:37:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 63D9D64E6C for ; Tue, 9 Feb 2021 14:37:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231996AbhBIOhl convert rfc822-to-8bit (ORCPT ); Tue, 9 Feb 2021 09:37:41 -0500 Received: from lithops.sigma-star.at ([195.201.40.130]:41548 "EHLO lithops.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232155AbhBIOgm (ORCPT ); Tue, 9 Feb 2021 09:36:42 -0500 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 6B886608A38A; Tue, 9 Feb 2021 15:35:58 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 8Vwy9HmKlMkY; Tue, 9 Feb 2021 15:35:58 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 0B252605B49C; Tue, 9 Feb 2021 15:35:58 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id BlL2HfhYicrX; Tue, 9 Feb 2021 15:35:57 +0100 (CET) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id D535B608A38A; Tue, 9 Feb 2021 15:35:57 +0100 (CET) Date: Tue, 9 Feb 2021 15:35:57 +0100 (CET) From: Richard Weinberger To: Miklos Szeredi Cc: Miquel Raynal , Vignesh Raghavendra , Boris Brezillon , Ron Minnich , sven@narfation.org, linux-kernel , linux-mtd , fuse-devel Message-ID: <563952295.378372.1612881357746.JavaMail.zimbra@nod.at> In-Reply-To: References: <20210124232007.21639-1-richard@nod.at> Subject: Re: [PATCH 0/8] MUSE: Userspace backed MTD v3 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF78 (Linux)/8.8.12_GA_3809) Thread-Topic: MUSE: Userspace backed MTD v3 Thread-Index: NVDMpjLzrmLV3u3YwGU4qvbOOzku6A== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Miklos, ----- Ursprüngliche Mail ----- >> The core goal of MUSE is having the complexity on the userspace side and >> only a small MTD driver in kernelspace. >> While playing with different approaches I realized that FUSE offers everything >> we need. So MUSE is a little like CUSE except that it does not implement a >> bare character device but an MTD. > > Looks fine. I'm glad to hear that! > I do wonder if MUSE should go to drivers/mtd/ instead. Long term > goal would be move CUSE to drivers/char and move the transport part of > fuse into net/fuse leaving only the actual filesystems (fuse and > virtiofs) under fs/. > > But for now just moving the minimal interface needed for MUSE into a > separate header () would work, I guess. > > Do you think that would make sense? Yes, I'm all for having MUSE in drivers/mtd/. I placed MUSE initially in fs/fuse/ because CUSE was already there and muse.c includes fuse_i.h. So tried to be as little invasive as possible. >> >> Notes: >> ------ >> >> - OOB support is currently limited. Currently MUSE has no support for processing >> in- and out-band in the same MTD operation. It is good enough to make JFFS2 >> happy. This limitation is because FUSE has no support more than one variable >> length buffer in a FUSE request. >> At least I didn’t find a good way to pass more than one buffer to a request. >> Maybe FUSE folks can correct me. :-) > > If you look at fuse_do_ioctl() it does variable length input and > output at the same time. I guess you need something similar to that. I'll dig into this! Thanks, //richard