From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f42.google.com (mail-wr1-f42.google.com [209.85.221.42]) (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 85CF53E6393 for ; Tue, 14 Apr 2026 12:07:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.42 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776168461; cv=none; b=AiBA26lPUlZGVol6Ax4Eu26JxKNbGhyqyOscWdoL35c5chcEvcm33q84/YTE1IVc+95MjeYu1rMEyDD6jSf5BZAm7Q7nvxY/ro5wJKX13R6C01fGNk89rcVkIYafUsERbIjnqw5aYqI5JRhXAcrz1dUwY/Pq8yITAmL0O0L7rCs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776168461; c=relaxed/simple; bh=UaebnlNS68Z+R0VpuogugIfCBIL96+3eUIbIHkfdW5Y=; h=From:To:Cc:Subject:In-Reply-To:References:Content-Type:Date: Message-Id; b=kRJGFPRaQkged3bLcZ7TcQ+iWcciPHWgBQC+denT0rwCS1MLV4uS0OSFoR5Eoe8YaQn0hmpqf7c3j5Z5/75GweUxXtmgVitWwv1sRu9i6LfZY+AqmJpAIgIioYqkEfG2fs4vQqpnnspreCcWkJAPOK6B1Ou4fyg3Mp6nDlazhtk= 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=209.85.221.42 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-f42.google.com with SMTP id ffacd0b85a97d-43d7dab87e1so98101f8f.3 for ; Tue, 14 Apr 2026 05:07:40 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776168459; x=1776773259; h=message-id:date:references:in-reply-to:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=UaebnlNS68Z+R0VpuogugIfCBIL96+3eUIbIHkfdW5Y=; b=qrLTS68VJhQEbJSLcqfffIe7ySNbk0n2crQ3NrBh6ssi+7JhYJzlAcy/cYdq3WO4zE lI51sIn84GHgMFZjlVcHMtDcTvPhE2ZoAPc+ikPYrAJJhZQ7nu41FbpAfW4l1CzoXOhN 0f57W6xENaXCpn06tEHaBQuBZjtsDLaP40MdOKDzjAWp8gRqza/5Ldv18wIGUSog7sfc 7moqJ98PYe2tkrzTqLR6jeQG3Jcd0bwoA5lhomU104Dgm9+cMOjl5rSYH1SqQ4H6ls8F M+sITp866/M8zDsvjIbKRE00+VLA0dJV9bnF16l0dnx8amUC5lwDSBPa7LRHrglNhhBH /22w== X-Forwarded-Encrypted: i=1; AFNElJ/1ROvjxHCYFioKpb2P/aYnnuOUcx+Z4gW8IT9d39MYG9AQdPAYWtdRHywAGtc9SLt/uzvDFlSSp5lEAKs=@vger.kernel.org X-Gm-Message-State: AOJu0YwRe1e08uBtRrNob/rZLpGezKBubknW9ZGBvBRJzIj/sP7vMV6L TapwDY9jCsSdyOwDUyWv5Rw1Z8A8Na7RLq6SDY5yus5Sa2Ql2lGYwdMhqkhgDLZx X-Gm-Gg: AeBDietulgJLonL2uITFZRvMwfDiUHxn5MMmK1uB1KEltGs8vPhHhfptE3+pkocCI4D hKf3E2I+herOLR7dQ9gwJoG8dAMR/EuB2pSeT9wW3PqtwLzCnBQo10N/CU2CEGY703aIaY19+vX VS9enO3Gyf9erYO1VkDz8OiIsHYzjoHPudK2L2x5R44Lguv9p2lMgSutdGvHMAjUQAwT6oLHpiN rGOr6qN8/CZnKC3h4Wm1D5t//279u8Fv+d5Y92pmUY4ittDCYQPBhKUTRM9CqmBWWoBp4RxUfoO JXe104R2YvpHmYzzEMOkS/dHJhm5mzcl+LnxUPxApI1KaEgaobChvxIYjXW4WtZLzfFoA8RS71v AXmNMPa8lBdRofT9SBfyo+SJHLFSndMoqaM2yTewCoWD8C2/7w5cO921cjOaIHybmqsqjFsDfP6 sUBd/iI39DzzwsfSHp9wxdS6tpp1hFWWnBP5hIhsZwr85v6fVLdeAvyZlEVCaBRkO8knaG5u6/d +J5aseSsN2FhgmbATPp4jZfB3c= X-Received: by 2002:a05:600c:46d3:b0:488:78f0:5ba with SMTP id 5b1f17b1804b1-488d6890f22mr141956715e9.7.1776168458623; Tue, 14 Apr 2026 05:07:38 -0700 (PDT) Received: from hackers.camp ([2a01:cb1c:784:2f00:708:2805:7128:7a75]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-488ede24eb0sm49753965e9.8.2026.04.14.05.07.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Apr 2026 05:07:38 -0700 (PDT) Received: (nullmailer pid 8855 invoked by uid 1000); Tue, 14 Apr 2026 13:31:27 -0000 From: Aurelien DESBRIERES To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org Subject: Re: [RFC PATCH 0/10] ftrfs: Fault-Tolerant Radiation-Robust Filesystem In-Reply-To: References: <20260413142357.515792-1-aurelien@hackers.camp> Content-Type: text/plain; charset=UTF-8 Date: Tue, 14 Apr 2026 15:31:27 +0200 Message-Id: <1776173487.564511.8854.nullmailer@me> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: On Mon, Apr 13, 2026 at 04:06:07PM +0100, Matthew Wilcox wrote: > Might be nice to link to a non-paywalled copy of that paper, eg: > https://www.cfuchs.net/chris/publication-list/ARCS2015/FTRFS.pdf Done in v2 and v3 cover letters. > Can I ask why? Is the original code not available or too ugly? The original FTRFS from the ARCS 2015 paper was a research prototype targeting a custom RTOS (not Linux). There is no upstream Linux implementation. This series is an independent open-source realization of the published design for the mainline Linux kernel. > This is very old-school. That may be appropriate for the intended > use-case, but it ignores about five decades of filesystem research. Intentional. The design constraints are auditability (DO-178C, ECSS-E-ST-40C, IEC 61508) and minimal code size (target < 5000 lines). Five decades of filesystem research produced ext4 (~100k lines) and btrfs (~200k lines), neither of which is certifiable under these frameworks. The old-school approach is a feature, not a limitation. The iomap IO path was adopted in v3 as you requested, replacing the buffer_head based read/write. buffer_head is retained for metadata IO (inode table, directory blocks) pending further review. Aurelien DESBRIERES