From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) (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 9A4AE3C3BF1 for ; Mon, 13 Apr 2026 12:24:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.51 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776083057; cv=none; b=G0JWqvTpLxKQRPm0gVIPQ9ZomUjpnIX8VyR+gT5EWS+vF+U27v8pnKjESVgvzY+l9hpTc/fTefFZwxv3A4bY1UEUX7qH6lD/LMO1VtxnSHCzkcK4jFtt29GktNFnDLI+iBlt8ynS2zFCSYWTUh6CXab+BzYJFfc/x8q98JFaMWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776083057; c=relaxed/simple; bh=W6Yg4ksBDc415XgtlNd66ie2t44DTmR6Gl2MEOmu/4c=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=Lrj3G3TliQ5mCurqa8XuXpDlDzaauYa2sWGnJfX5fqf9qtR5XsCAM4mTPHMshsKDhdvpVbXVcwkXUY5mnqLd1WrB/STMzq3fmEkKekNP1Gmjn2wEpNLmWVVx2EiToTxfOf31BJLVnMxfwvEXD3Q3/ozZs+YsjPy4go7HnvLqROY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=hackers.camp; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.221.51 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=hackers.camp Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wr1-f51.google.com with SMTP id ffacd0b85a97d-43d7b879691so64758f8f.1 for ; Mon, 13 Apr 2026 05:24:15 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776083054; x=1776687854; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=n+Lahrzrgk6CwlPElUw4Plq1IP8p7iTjH1OLtfPx/+c=; b=fL8CA3Vf9++cw4oippgpF1VjFTj+4Qa0mI0AMP/YlMPhtAp0Ih/bNooda/CV0+Gvbe z958NidH34PlXd5c7wr7wuIc/yBlyDmVKIzj2Ufrkbk6tnV360+kKnAz3R4wAqyLRlae 0ZwnUcqj/LzOk/SqOnct5/KuXmY4cGPuTz+CgWseLf6McyXoiyOTCi8Qk4yTxhGPOmx3 U+JzYHzbUgPDWJl8gYckorYDccNVSu6C5DNhNEYXuTzlVl1HfO4uNdi934e5GXfFsD+Y 80xGPR1gcRouPNw1gM48slduVO842i7VaGqjKMkusukLvwE1vlU53bD/oua6Cqb4VcJC dmbg== X-Gm-Message-State: AOJu0Yw1IKGUWtHuurZ2VVeyiikgEGpc0BZpFWSXq1YMe9VIkmjuVSDU 0i25+97Nvogl3ZVXGVQQ2FD0+UgUn05sxpZivrYLDrvPucL6V+ZydOHohZAY8FIEToA= X-Gm-Gg: AeBDiesgjhFSwJGt+AcIOjQVQ9VOTShhmioT1/Zyn5EQM3Bpk49VlEL0jxa3hwXiAH3 WQcVd2nBzqmgInsyYxt8uUC9+3gI8NJnPPhH2GZKHvvW9bTLq+gZm7YEBpJOdt/p+DL21T66klg iQh0auk3OuH0Fc8f1lQEB8gZTTEFkUi0JIIO5doWFdHe2OALJvv87QgpE+KKc1jsQG7RJldSVlo qV0aQ59irt4Ex1qDVgn9gsdsJOktDVZ/VW22OFL7XRtz9b6qN90l9XZ0FV5udbMSGh9sC8v+lEk zefujNkzw0t9wp2Z1ja1Gevagm6ob6IMr84HgiBrTQEg0nucf+Ul1IbffItFihHdM1U2ZzkTeUZ bj7ZqQE7Is86owl2DcN/ZosxQBYrjG1vT3OMgX3T1iddKr5d58DmcR783tutZgvIzKb+n9ObsfQ Zjybue8OUpCU6hVezKhJhXRYtOjmvwKvCNy5oWNutg6ilhGA031JgqgibeKmtC1SUpRw== X-Received: by 2002:a05:600c:630d:b0:488:a87e:dad8 with SMTP id 5b1f17b1804b1-488d6abed83mr95011265e9.8.1776083053453; Mon, 13 Apr 2026 05:24:13 -0700 (PDT) Received: from spartian-1.home ([2a01:cb1c:784:2f00:708:2805:7128:7a75]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488d532ed4dsm278260915e9.4.2026.04.13.05.24.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 13 Apr 2026 05:24:13 -0700 (PDT) From: Aurelien DESBRIERES To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, aurelien@hackers.camp Subject: [RFC PATCH 0/10] ftrfs: Fault-Tolerant Radiation-Robust Filesystem Date: Mon, 13 Apr 2026 16:23:46 +0200 Message-ID: <20260413142357.515792-1-aurelien@hackers.camp> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Aurélien DESBRIERES This RFC introduces FTRFS, a new Linux filesystem designed for dependable storage in radiation-intensive environments, targeting embedded Linux systems operating in space or other harsh conditions. FTRFS was originally described in: Fuchs, C.M., Langer, M., Trinitis, C. (2015). FTRFS: A Fault-Tolerant Radiation-Robust Filesystem for Space Use. ARCS 2015, LNCS vol 9017, Springer. https://doi.org/10.1007/978-3-319-16086-3_8 This implementation is an independent open-source realization of the concepts described in that paper, developed for the Linux kernel. == Design == FTRFS provides three layers of data integrity: - CRC32 per block and per inode (hardware-accelerated via crc32_le) - Reed-Solomon FEC (encoder implemented, decoder planned) - EDAC-compatible error tracking On-disk layout: Block 0 : superblock (magic 0x46545246, CRC32-protected) Block 1..N : inode table (128 bytes/inode, CRC32 per inode) Block N+1..end : data blocks (CRC32 + RS FEC per block) Inodes use direct addressing (12 direct block pointers) plus single and double indirection. Directory entries are fixed-size (268 bytes) stored in direct blocks. == Current Status == - Superblock: mount/umount, CRC32 validation [done] - Inodes: read with CRC32 verification [done] - Directories: readdir, lookup [done] - Files: read via generic page cache helpers [done] - Allocator: in-memory bitmap for blocks and inodes [done] - Write path: create, mkdir, unlink, rmdir, link [done] - Reed-Solomon: encoder done, decoder planned [partial] - xattrs / SELinux [planned] - fsck.ftrfs [planned] - Indirect block support for large files [planned] == Validation == FTRFS has been validated on arm64 (cortex-a57) running Linux 7.0-rc7, built with Yocto Styhead (5.1), deployed as a data partition in a 3-node Slurm HPC cluster on KVM/QEMU: insmod ftrfs.ko -> module loaded mount -t ftrfs /dev/vdb /mnt -> success ls /mnt -> returns empty directory correctly Compile-tested on x86_64 with Linux 7.0 (this series). checkpatch.pl: 0 errors on all patches. == Feedback Requested == This is an RFC. Feedback is welcome on: 1. On-disk format: is the superblock/inode layout reasonable? 2. Directory entry design: fixed 268-byte entries vs. variable length 3. Reed-Solomon: use lib/reed_solomon or keep custom GF(2^8) tables? 4. Allocator: in-memory bitmap vs. dedicated on-disk bitmap block 5. Any VFS API misuse or missing locking The code is also available at: https://github.com/roastercode/FTRFS Aurélien DESBRIERES (10): ftrfs: add on-disk format and in-memory data structures ftrfs: add superblock operations ftrfs: add inode operations ftrfs: add directory operations ftrfs: add file operations ftrfs: add block and inode allocator ftrfs: add filename and directory entry operations ftrfs: add CRC32 checksumming and Reed-Solomon FEC skeleton ftrfs: add Kconfig, Makefile and fs/ tree integration MAINTAINERS: add entry for FTRFS filesystem MAINTAINERS | 6 + fs/Kconfig | 1 + fs/Makefile | 1 + fs/ftrfs/Kconfig | 49 +++ fs/ftrfs/Makefile | 16 + fs/ftrfs/alloc.c | 251 +++++++++++++++ fs/ftrfs/dir.c | 132 ++++++++ fs/ftrfs/edac.c | 84 +++++ fs/ftrfs/file.c | 25 ++ fs/ftrfs/ftrfs.h | 168 ++++++++++ fs/ftrfs/inode.c | 103 +++++++ fs/ftrfs/namei.c | 428 +++++++++++++++++++++++++++ fs/ftrfs/super.c | 274 ++++++++++++++++ 13 files changed, 1538 insertions(+) Signed-off-by: Aurélien DESBRIERES