Microsoft effectively open-sourced exFAT in 201 9. More
precisely, it made public the filesystem’s specifications
and offered free licensing to any member of the Open
Invention Network (OIN), the holders of a defensive
patent pool to which Microsoft and others have
contributed their IP. It left the actual work of writing a
driver to the community, and this, thanks to Samsung,
was added to Kernel 5.7.
Again, there was previously an exFAT kernel driver
which first appeared in version 5.4. This was based on
an old driver for one of Samsung’s Android tablets, the
code accidentally ended up on GitHub in 2013 and was
later open-sourced by Samsung. That code ended up in
the Kernel’s Staging tree where it was improved, before
being replaced by Samsung’s newer code drop.
Network filesystems have been improved by
Samsung too. Kernel 5 .1 5 includes a new driver,
KSMBD, for serving shares over the latest version of
Windows’ Server Message Block (SMB3) protocol. This
should make for faster transfers in the immediate term,
but long term, the goal is to have a leaner project that’s
easy to add new features to as the protocol evolves.
This is in contrast to the userspace Samba, a massive
project that deals not just with serving files over SMB,
but also client tools, authentication, Active Directory,
and much more. So KSMBD is designed to work in
harmony with Samba, rather than replace it.
High on KSMBD’s list of things to do is to implement
RDMA (Remote Direct Memory Access) support, also
known as SMB Direct, which enables file transfers to
skip protocol overheads, which is currently a bottleneck
for both mobile and embedded systems.
Samba is vital for anyone who wants to use a Linux
machine on a Windows network and for the most part
it works out of the box. There are some edge cases
though. For some reason, plenty of people have run
into the issue of old ‘LANman’ password authentication
no longer being supported, so out of the box, it’s not
possible to connect to SMB shares on Windows XP (or
older) machines.
These machines also, by default, use an older
version of the protocol, and to make Samba play along
the generally accepted solution is to add the following
lines to /etc/samba/smb.conf:
server min protocol = NT 1
lanman auth = yes
ntlm auth =yes
This, of course, weakens security, but
if you’re still using Windows XP on your
network server, you probably have no
business being concerned about security.
There is a registry hack to force NTLMv2
authentication described at https://kb.iu.
edu/d/atcm, which will afford you the
luxury of setting lanman auth = ntlmv 2 -
only instead of the final line above. But
SMBv1 as a protocol is vulnerable to
the WannaCry-type exploits, so you
probably should steer clear.
With that nod to old frictions, we
conclude our foray into the brave
new world of Linux on Windows
and Windows loving Linux.PARAGON NTFS 3 DRIVER
After years of having to make do with
the NTFS-3g FUSE (Filesystem in
USErspace) driver to read and write
to Windows NTFS volumes in Linux, a
driver is finally coming to the kernel.
Actually, there has been a kernel
driver for a long time (since 2001 in
fact), but it only ever provided read-
only support and was overlooked by
most people.
NTFS-3g was a valuable crutch
for people who worked on dual-bootsystems but compared to native
NTFS its performance was weak.
On older systems, in particular, it
would consume a lot of CPU cycles for
the underwhelming rate at which it
wrote bits.
The new kernel driver, dubbed
NTFS3, comes from Paragon Software,
a commercial provider of cross
filesystem, partitioning, and network
management tools. NTFS has been
around since 1993 and is of muchless commercial interest than it once
was. Microsoft has superseded it in
new versions of Windows, so Paragon
chose to open source it last year.
This was a rocky road: Paragon’s
first attempt to dump 27k lines of
spaghetti code to the Kernel was
met with a swift refusal. However,
22 tries and some community advice
later, the code has finally landed in
Kernel 5.15, which will be released by
the time you read this.Windows Disk Management tool begrudgingly accepts our
Linux partition is there, but offers no info