Re: [PATCH v2] 9pfs: Add FreeBSD support

[Christian Schoenebeck <qemu_oss@crudebyte.com>]

On Wednesday, August 27, 2025 4:29:37 PM CEST Mark Johnston wrote:
> On Tue, Aug 26, 2025 at 02:34:45PM +0200, Christian Schoenebeck wrote:
[...]
> I folded your suggestion in with a couple of minor tweaks:
> 
> commit 61de78986912b03f08354a177caf603857b531b5
> Author: Mark Johnston <markj@FreeBSD.org>
> Date:   Wed Jul 16 20:32:05 2025 +0000
> 
>     9pfs: Add FreeBSD support
> 
>     This is largely derived from existing Darwin support.  FreeBSD
>     apparently has better support for *at() system calls so doesn't require
>     workarounds for a missing mknodat().  The implementation has a couple of
> warts however:
>     - The extattr(2) system calls don't support anything akin to
>       XATTR_CREATE or XATTR_REPLACE, so a racy workaround is implemented.
>     - Attribute names cannot begin with "user." or "system." on ZFS.
>       However FreeBSD's extattr(2) system calls support two dedicated
>       namespaces for these two.  So "user." or "system." prefixes are
>       trimmed off from attribute names and instead EXTATTR_NAMESPACE_USER or
> EXTATTR_NAMESPACE_SYSTEM are picked and passed to extattr system calls
> accordingly.
> 
>     The 9pfs tests were verified to pass on the UFS, ZFS and tmpfs
>     filesystems.
> 
>     Signed-off-by: Mark Johnston <markj@FreeBSD.org>

LGTM, thanks!

/Christian