From: Aurelien DESBRIERES <aurelien@hackers.camp>
To: ebiggers@kernel.org
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,
Aurelien DESBRIERES <aurelien@hackers.camp>
Subject: Re: [PATCH v2 08/11] ftrfs: add CRC32 checksumming and Reed-Solomon FEC skeleton
Date: Sat, 18 Apr 2026 10:16:26 +0200 [thread overview]
Message-ID: <20260418081625.2265166-2-aurelien@hackers.camp> (raw)
In-Reply-To: <20260414173423.GA24456@quark>
On Tue, Apr 14, 2026 at 10:34:23AM -0700, Eric Biggers wrote:
> Is there a reason why the kernel's existing Reed-Solomon
> encoding/decoding library isn't being used?
No good reason. v2 had a custom GF(2^8) implementation - rolling our
own RS arithmetic when lib/reed_solomon exists is not justifiable.
v3 (<20260414120726.5713-1-aurelien@hackers.camp>) replaces the custom
code entirely. The codec is initialized at module load via:
init_rs(8, 0x187, 0, 1, 16)
encode_rs8/decode_rs8 are used for all RS operations. The custom
GF tables and encoder are gone.
The v2 custom encoder was also incorrect - it did not produce codewords
compatible with lib/reed_solomon. This would have caused silent
corruption on RS-protected blocks written by mkfs and read by the
kernel. Fixed in v3 and validated: mkfs parity matches lib/reed_solomon
byte-for-byte on arm64 kernel 7.0.
Aurelien DESBRIERES <aurelien@hackers.camp>
next prev parent reply other threads:[~2026-04-18 6:16 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-13 23:05 [PATCH v2 00/11] ftrfs: Fault-Tolerant Radiation-Robust Filesystem Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 01/11] ftrfs: add on-disk format and in-memory data structures Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 02/11] ftrfs: add superblock operations Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 03/11] ftrfs: add inode operations Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 04/11] ftrfs: add directory operations Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 05/11] ftrfs: add file operations Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 06/11] ftrfs: add block and inode allocator Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 07/11] ftrfs: add filename and directory entry operations Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 08/11] ftrfs: add CRC32 checksumming and Reed-Solomon FEC skeleton Aurelien DESBRIERES
2026-04-14 17:34 ` Eric Biggers
2026-04-18 8:16 ` Aurelien DESBRIERES [this message]
2026-04-13 23:05 ` [PATCH v2 09/11] ftrfs: add Kconfig, Makefile and fs/ tree integration Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 10/11] MAINTAINERS: add entry for FTRFS filesystem Aurelien DESBRIERES
2026-04-13 23:05 ` [PATCH v2 11/11] ftrfs: v2 fixes — write path, inode lifecycle, on-disk format Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 00/12] ftrfs: Fault-Tolerant Radiation-Robust Filesystem Aurelien DESBRIERES
2026-04-14 10:22 ` Pedro Falcato
2026-04-14 11:05 ` Joshua Peisach
2026-04-14 11:28 ` Pedro Falcato
2026-04-14 13:46 ` Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 01/12] ftrfs: add on-disk format and in-memory data structures Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 02/12] ftrfs: add superblock operations Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 03/12] ftrfs: add inode operations Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 04/12] ftrfs: add directory operations Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 05/12] ftrfs: add file operations Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 06/12] ftrfs: add block and inode allocator Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 07/12] ftrfs: add filename and directory entry operations Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 08/12] ftrfs: add CRC32 checksumming and Reed-Solomon FEC skeleton Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 09/12] ftrfs: add Kconfig, Makefile and fs/ tree integration Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 10/12] MAINTAINERS: add entry for FTRFS filesystem Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 11/12] ftrfs: v2 fixes — write path, inode lifecycle, on-disk format Aurelien DESBRIERES
2026-04-14 12:07 ` [PATCH v3 12/12] ftrfs: v3 — iomap IO path, rename, RS decoder, Radiation Event Journal Aurelien DESBRIERES
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