From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 28E9D1CF8B; Mon, 13 Apr 2026 15:06:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776092775; cv=none; b=XQYW+T9KXRvstW/uot29ktlcj9dCB4il1sMaakToUuXS/fbA19z/qbWFnxRxuBKJMK91+E5Zkt1yd8ZKDfQfYabxoGKnA6Id0A5436A6dCDhB7PwObb+h602f8DEnOAxznHstXcoYUMHDBA6W23M+Ijr4hnbBvbMFqidIjRaqZY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776092775; c=relaxed/simple; bh=+g6LH2zhk/nYRTREJBiSimauDhpBSVZSIdQg4ygSs00=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Hm1JCnbCi0ioH4uvQ5Q9sCro6U8Sf7wSZqMij63GWLxVaE12mtmJRcwI5pHi5K2WuS4x8RUQHobD5ttenvfuT0cCCf3FIpjrkatrNtKtVeeel6J7liH3526ucfSfjVN7GH/5YYCe2t8cOHqs50G8lyeo1jQhuRlLzN1kA7FxTjI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=DEzP2hQt; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="DEzP2hQt" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=2owUYSzBAwJcZlAorCO0uN1WFwAEJ0DzTHeENfLCTSw=; b=DEzP2hQt4mG5E7xJ5+8knXvd0V 5gnOVAbva0JZxGIcJ7rwbYnjBmpkzNtDvZXCe0QW3DETeE0stgLyj4Tz9FUeN34N+L0hr4Fprdm4Q Jfz4BOScIa5zhBy0rdyA7zw9y//DZe2KukwILwVLBWtnx1XMPi71u8DFiVzyRxjy66sWSn42eRrww TXj0lmnPHAbLegX1E29Mkg9DRXwg483v0vqoBuH2mdaw+IQElbl7rOki7OtC5UugyZU/te46oQblT VgD+qMaJxA3xb9Niti+ZMQcA1UkF3po0ze3t7JQWtFMDfWWjZFm9Y4Ay0dm9bcIREX3kOP6pzrPtY 7zIGi2pQ==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1wCIrX-0000000E3Nl-415E; Mon, 13 Apr 2026 15:06:07 +0000 Date: Mon, 13 Apr 2026 16:06:07 +0100 From: Matthew Wilcox To: Aurelien DESBRIERES 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 Message-ID: References: <20260413142357.515792-1-aurelien@hackers.camp> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260413142357.515792-1-aurelien@hackers.camp> On Mon, Apr 13, 2026 at 04:23:46PM +0200, Aurelien DESBRIERES wrote: > 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 Might be nice to link to a non-paywalled copy of that paper, eg: https://www.cfuchs.net/chris/publication-list/ARCS2015/FTRFS.pdf > This implementation is an independent open-source realization of the > concepts described in that paper, developed for the Linux kernel. Can I ask why? Is the original code not available or too ugly? > 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. This is very old-school. That may be appropriate for the intended use-case, but it ignores about five decades of filesystem research.