From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f175.google.com (mail-yw1-f175.google.com [209.85.128.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6FAD12568 for ; Sun, 10 Sep 2023 17:26:44 +0000 (UTC) Received: by mail-yw1-f175.google.com with SMTP id 00721157ae682-59b50b4556eso26060937b3.1 for ; Sun, 10 Sep 2023 10:26:44 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694366803; x=1694971603; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=+d/Au1fHXa75PgVco+gMMH+imp/hCis9khLj99DfGd4=; b=Yin+UjRGeE64WK1Gzfy3bGFx7v/it3iBvxmsmSMtEiV5Flkqh8g9jvAXXyophGN/2u TZIuJezyPo7/tYVrumZvtuy5dDvMSJ4xHWXuIdv39oopEgLLU7VbKsFXzIJ2T0O8chax iEux9Ux8+SMePqQ9EEUZEYNK/oCpTjAkmmQW/9pGpzwvSas6tsJoCcz0tYMU+Rn+hwUY +NYlXNUtR/V5p8CfgbPAdLCQ+0uVYmArW/8W57XJ5V3BaJds+/Ygc3tQH/E+Sie4CVjv U8exo6pLbt3FdyZeHFNOlBkAvNZTm9SZhRz8/uVFXwIke6T6UNkTRlWtqRT5T0W4/xzV atng== X-Gm-Message-State: AOJu0YxKlugKie/mzllewSHIaoklKchCxHI8EZclifeu3OqZAKqI0IJw f4xtJ3yjmuExO7vwvVJMMppqz+Ng8h1VGA== X-Google-Smtp-Source: AGHT+IEnx3pmJerKv1n+/iwE/r7aOzra9L9o2x2FS8xHE79jki1u3ShOqfKpHt2anb8lElHwUcZ2eg== X-Received: by 2002:a0d:e248:0:b0:591:4f2b:7eea with SMTP id l69-20020a0de248000000b005914f2b7eeamr7917914ywe.18.1694366803165; Sun, 10 Sep 2023 10:26:43 -0700 (PDT) Received: from mail-yb1-f174.google.com (mail-yb1-f174.google.com. [209.85.219.174]) by smtp.gmail.com with ESMTPSA id v8-20020a814808000000b005845e6f9b50sm1510424ywa.113.2023.09.10.10.26.42 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 10 Sep 2023 10:26:42 -0700 (PDT) Received: by mail-yb1-f174.google.com with SMTP id 3f1490d57ef6-d7b8d2631fdso3467361276.3 for ; Sun, 10 Sep 2023 10:26:42 -0700 (PDT) X-Received: by 2002:a25:2488:0:b0:d74:6c9f:e734 with SMTP id k130-20020a252488000000b00d746c9fe734mr7321441ybk.47.1694366801859; Sun, 10 Sep 2023 10:26:41 -0700 (PDT) Precedence: bulk X-Mailing-List: ksummit@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <8dd2f626f16b0fc863d6a71561196950da7e893f.camel@HansenPartnership.com> <20230909224230.3hm4rqln33qspmma@moria.home.lan> <20230910163533.ysbcztauujywrbk4@moria.home.lan> In-Reply-To: <20230910163533.ysbcztauujywrbk4@moria.home.lan> From: Geert Uytterhoeven Date: Sun, 10 Sep 2023 19:26:26 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [MAINTAINERS/KERNEL SUMMIT] Trust and maintenance of file systems To: Kent Overstreet Cc: James Bottomley , Matthew Wilcox , Dave Chinner , Christoph Hellwig , ksummit@lists.linux.dev, linux-fsdevel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sun, Sep 10, 2023 at 6:35=E2=80=AFPM Kent Overstreet wrote: > On Sun, Sep 10, 2023 at 10:19:30AM +0200, Geert Uytterhoeven wrote: > > On Sun, Sep 10, 2023 at 12:42=E2=80=AFAM Kent Overstreet > > wrote: > > > On Sat, Sep 09, 2023 at 08:50:39AM -0400, James Bottomley wrote: > > > > So why can't we figure out that easier way? What's wrong with tryin= g to > > > > figure out if we can do some sort of helper or library set that ass= ists > > > > supporting and porting older filesystems. If we can do that it will= not > > > > only make the job of an old fs maintainer a lot easier, but it migh= t > > > > just provide the stepping stones we need to encourage more people c= limb > > > > up into the modern VFS world. > > > > > > What if we could run our existing filesystem code in userspace? > > > > > > bcachefs has a shim layer (like xfs, but more extensive) to run nearl= y > > > the entire filesystem - about 90% by loc - in userspace. > > > > > > Right now this is used for e.g. userspace fsck, but one of my goals i= s > > > to have the entire filesystem available as a FUSE filesystem. I'd bee= n > > > planning on doing the fuse port as a straight fuse implementation, bu= t > > > OTOH if we attempted a sh vfs iops/aops/etc. -> fuse shim, then we wo= uld > > > have pretty much everything we need to run any existing fs (e.g. > > > reiserfs) as a fuse filesystem. > > > > > > It'd be a nontrivial project with some open questions (e.g. do we hav= e > > > to lift all of bufferheads to userspace?) but it seems worth > > > investigating. > > > > 1. https://xkcd.com/1200/ (not an exact match, but you should get the= idea), > > 2. Once a file system is removed from the kernel, would the user spac= e > > implementation be maintained better? > > This would be for the filesystems that aren't getting maintained and > tested, to eliminate accidental breakage from in-kernel refactoring and > changing of APIs. > > Getting that code out of the kernel would also greatly help with > security concerns. OK, xkcd 1200 it is... Gr{oetje,eeting}s, Geert --=20 Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k= .org In personal conversations with technical people, I call myself a hacker. Bu= t when I'm talking to journalists I just say "programmer" or something like t= hat. -- Linus Torvalds