From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3346117A2EA; Tue, 14 Apr 2026 17:34:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776188066; cv=none; b=qNZO2x+RTna4VIBa84Ljk/mqkrsk04KcTB/888mY/gddzQapNJeKSQHiEiZTdPJK7Hsvn0DARL3cGKiXrkznlAJy78HhxyCbIPc0iLQIusYcXaXEruxjNJn2axGviJi8NAehKD31vJ+Eypv3uNz/jCPLA1tmmnENkAtcTMPU3Sc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776188066; c=relaxed/simple; bh=RZIJkrt4uTkUK0CCrjlOPMYTyc5t7ImaWmtrc8Kh5vM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FTVwKjLPJCplUgSKPwvu88r3QRdaEjXsLXb0lSAK+J03x+NDwkgXWp5FGGCPy2uY0gOMeln7Al8Xe1wory3lRYQK4fNcVj2Qytvkev9fBOd9Ix5X9jse+0IZOwSpr25yYs6D1wi6vMPp9FTiiqqdFnt41qAMA6imMzTHU0e4Iuk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=t3A9UrTW; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="t3A9UrTW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D494C19425; Tue, 14 Apr 2026 17:34:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776188065; bh=RZIJkrt4uTkUK0CCrjlOPMYTyc5t7ImaWmtrc8Kh5vM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=t3A9UrTW5Hyp0LuXchy7Wo4I7zbQ1aSQHmu1lMSW6a5HZyiNB7iQcO0dL0wU28VKV MK/4VmMQi6nXHhYg0k0l1QBsuiz/V1Y0mXn3S6ybt70aCfLaFwNPVAkhGSQYxwk2b1 RzragL4ak6K5lbfALOMXHNXkf7JX0vDt5/+tvooWm66PIMKaxEjkmnHG9Jei9p5+y1 9/VMLbqpegmmDddKQbWAVruAqyaBKnc642/67hoZtR6U6b5i+2mnXLy37IfKGSNTmL 1B0hLdvgUcDGT/eddkZ6U95TULcFDMRgTFxG8gikHW7YzwPVroGdUYY8hLaiLWYzk5 7IMk8AZBpt/Lg== Date: Tue, 14 Apr 2026 10:34:23 -0700 From: Eric Biggers To: Aurelien DESBRIERES Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, djwong@kernel.org, adilger@dilger.ca, pfalcato@suse.de Subject: Re: [PATCH v2 08/11] ftrfs: add CRC32 checksumming and Reed-Solomon FEC skeleton Message-ID: <20260414173423.GA24456@quark> References: <20260413230601.525400-1-aurelien@hackers.camp> <20260413230601.525400-9-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: <20260413230601.525400-9-aurelien@hackers.camp> On Tue, Apr 14, 2026 at 01:05:49AM +0200, Aurelien DESBRIERES wrote: > Implement data integrity layer: > > - ftrfs_crc32(): CRC32 wrapper via kernel crc32_le(), used for > per-inode and per-superblock checksums > - init_gf_tables(): initialize GF(2^8) Galois Field lookup tables > (primitive polynomial 0x1d) for Reed-Solomon arithmetic > - gf_mul(): GF(2^8) multiplication via log/exp tables > - ftrfs_rs_encode(): systematic Reed-Solomon encoder over > FTRFS_SUBBLOCK_DATA bytes with FTRFS_RS_PARITY check symbols > > The RS encoder operates on sub-blocks within each 4096-byte data > block. Decoding (error correction) is not yet implemented. > > Signed-off-by: Aurelien DESBRIERES Is there a reason why the kernel's existing Reed-Solomon encoding/decoding library isn't being used? - Eric