Re: [PATCH] bfs: remove the filesystem

Hello!

On Fri 04-09-26 09:51:10, Tigran Aivazian wrote:

On Fri, 4 Sept 2026 at 09:30, Ethan Nelson-Moore [off-list ref] wrote:

quoted

BFS (not to be confused with BeFS, the BeOS filesystem) is the
filesystem UnixWare uses for its boot partition. It has extremely
limited functionality, only supporting contiguous files and no
subdirectories. Even though the bfs driver is very small and is
unlikely to cause future maintenance problems, given that the only type
of data stored on such a partition is likely to be kernels and
bootloader settings, there is very little reason anyone would want to
access it from Linux. Other old Unix filesystems (efs, freevxfs) have
been removed recently, and bfs is highly unlikely to have any users, so
remove it as well. Retain the UAPI header to be safe.

You are right that probably no one would want to use BFS for storing the
actual data today. But some things have didactical value, rather than
mere pragmatic usage. It is the didactic value of MINIX (and its
limitations wrt making use of the wonderful capabilities of i386) that
has originally triggered the creation of Linux. But back to BFS: it is
actually used in Steve Pate's book "Linux Filesystems" (2024, unfinished
yet), which is a sequel to his excellent classic "UNIX Filesystems"
(2003), as an illustration of a particularly simple filesystem
implementation.

So I agree BFS is simple. In fact so simple that I was confused by how it
can get away with not implementing certain bits when having to modify it
couple months ago when doing some fs-wide fixes :). Regarding didactical
value, we currently also have minix and ext2 implementations more or less
for educational purposes so frankly, I don't think we need a third one.

								Honza
-- 
Jan Kara [off-list ref]
SUSE Labs, CR