Re: [PATCH] 9pfs: Add FreeBSD support

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Jul 29, 2025 at 06:09:35PM +0200, Christian Schoenebeck wrote:
> On Wednesday, July 23, 2025 5:55:58 PM CEST Mark Johnston wrote:
> > 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." on ZFS, so the prefix is
> >   trimmed off.  FreeBSD's extattr system calls sport an extra
> >   "namespace" identifier, and attributes created by the 9pfs backend
> >   live in the universal user namespace, so this seems innocent enough.
> > 
> > The 9pfs tests were verified to pass on the UFS, ZFS and tmpfs
> > filesystems.
> > 
> > Signed-off-by: Mark Johnston <markj@FreeBSD.org>
> 
> Hi Mark,
> 
> first off, the problem is I currently don't have a FreeBSD host to test and
> won't have the time in near future neither.
> 
> So what was your general intention regarding this patch, fire and forget, or
> would you be around for issues/patches regarding 9pfs FreeBSD support?
> 
> > ---
> >  fsdev/file-op-9p.h        |   6 +-
> >  fsdev/meson.build         |   2 +-
> >  hw/9pfs/9p-synth.c        |   2 +-
> >  hw/9pfs/9p-util-freebsd.c | 124 ++++++++++++++++++++++++++++++++++++++
> >  hw/9pfs/9p-util.h         |  19 ++++--
> >  hw/9pfs/9p.c              |  16 ++++-
> >  hw/9pfs/meson.build       |   2 +
> >  include/qemu/xattr.h      |   6 +-
> >  meson.build               |   8 +--
> >  9 files changed, 170 insertions(+), 15 deletions(-)
> >  create mode 100644 hw/9pfs/9p-util-freebsd.c

> > diff --git a/hw/9pfs/9p-util-freebsd.c b/hw/9pfs/9p-util-freebsd.c
> > new file mode 100644
> > index 0000000000..e649f79d4b
> > --- /dev/null
> > +++ b/hw/9pfs/9p-util-freebsd.c
> > @@ -0,0 +1,124 @@
> > +/*
> > + * 9p utilities (FreeBSD Implementation)
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> > + * See the COPYING file in the top-level directory.
> > + */
> 
> I think for new source files in QEMU the policy is to use
> SPDX-License-Identifier: ... now?

Yes, checkpatch.pl should complain both about the missing SPDX tag
and about this license blurb which would be redundant if SPDX were
present.


With regards,
Daniel
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