No, Windows has deny-mode locking at open time, but the kernel's
mandatory locks are enforced during read/write (which is why they are
such a pain). Samba will not miss these at all.

If we want something to provide windows-like semantics, we'd probably
want to start with something like Pavel Shilovsky's O_DENY_* patches.

-- Jeff

On Fri, 2021-08-20 at 12:17 -0700, H. Peter Anvin wrote:

I thought the main user was Samba and/or otherwise providing file service for M$ systems?

On August 20, 2021 9:30:31 AM PDT, Kees Cook [off-list ref] wrote:

quoted

On Thu, Aug 19, 2021 at 12:15:08PM -0700, Linus Torvalds wrote:

quoted

On Thu, Aug 19, 2021 at 11:39 AM Jeff Layton [off-list ref] wrote:

quoted

I'm all for ripping it out too. It's an insane interface anyway.

I've not heard a single complaint about this being turned off in
fedora/rhel or any other distro that has this disabled.

I'd love to remove it, we could absolutely test it. The fact that
several major distros have it disabled makes me think it's fine.

FWIW, it is now disabled in Ubuntu too:

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/impish/commit/?h=master-next&id=f3aac5e47789cbeb3177a14d3d2a06575249e14b

quoted

But as always, it would be good to check Android.

It looks like it's enabled (checking the Pixel 4 kernel image), but it's
not specifically mentioned in any of the build configs that are used to
construct the image, so I think this is just catching the "default y". I
expect it'd be fine to turn this off.

I will ask around to see if it's actually used.

-- 
Jeff Layton [off-list ref]