linux-kernel - Re: [PATCH 00/11] ntfsplus: ntfs filesystem remake

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251022063056.GR13776@twin.jikos.cz>
Date: Wed, 22 Oct 2025 08:30:56 +0200
From: David Sterba <dsterba@...e.cz>
To: Namjae Jeon <linkinjeon@...nel.org>
Cc: viro@...iv.linux.org.uk, brauner@...nel.org, hch@...radead.org,
	hch@....de, tytso@....edu, willy@...radead.org, jack@...e.cz,
	djwong@...nel.org, josef@...icpanda.com, sandeen@...deen.net,
	rgoldwyn@...e.com, xiang@...nel.org, dsterba@...e.com,
	pali@...nel.org, ebiggers@...nel.org, neil@...wn.name,
	amir73il@...il.com, linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org, iamjoonsoo.kim@....com,
	cheol.lee@....com, jay.sim@....com, gunho.lee@....com
Subject: Re: [PATCH 00/11] ntfsplus: ntfs filesystem remake

On Mon, Oct 20, 2025 at 11:07:38AM +0900, Namjae Jeon wrote:
> The feature comparison summary
> ==============================
> 
> Feature                               ntfsplus   ntfs3
> ===================================   ========   ===========
> Write support                         Yes        Yes
> iomap support                         Yes        No
> No buffer head                        Yes        No
> Public utilities(mkfs, fsck, etc.)    Yes        No
> xfstests passed                       287        218
> Idmapped mount                        Yes        No
> Delayed allocation                    Yes        No
> Bonnie++                              Pass       Fail
> Journaling                            Planned    Inoperative
> ===================================   ========   ===========

Having two implementations of the same is problematic but I think what
votes for ntfs+ is that it's using the current internal interfaces like
iomap and no buffer heads. I'm not familiar with recent ntfs3
development but it would be good to know if the API conversions are
planned at all.

There are many filesystems using the old interfaces and I think most of
them will stay like that. The config options BUFFER_HEAD and FS_IOMAP
make the distinction what people care about most. In case of ntfs it's
clearly for interoperability.

As a user I'd be interested in feature parity with ntfs3, eg. I don't
see the label ioctls supported but it's a minor thing. Ideally there's
one full featured implementation but I take it that it may not be
feasible to update ntfs3 so it's equivalent to ntfs+. As this is not a
native linux filesystem swapping the implementation can be fairly
transparent, depending only on the config options. The drawback is
losing the history of fixed bugs that may show up again.

We could do the same as when ntfs3 appeared, but back then it had
arguably better position as it brought full write support. Right now I
understand it more of as maintenance problem.