Re: git: a6d57f312f18 - main - nfsd: Fix handling of hidden/system during Open/Create

On Fri, Jan 09, 2026 at 03:04:33PM -0800, Rick Macklem wrote:
> On Fri, Jan 9, 2026 at 11:56 AM Benjamin Kaduk <bjkfbsd@gmail.com> wrote:
> >
> > On Thu, Jan 8, 2026 at 4:33 PM Rick Macklem <rmacklem@freebsd.org> wrote:
> >>
> >> The branch main has been updated by rmacklem:
> >>
> >> URL: https://cgit.FreeBSD.org/src/commit/?id=a6d57f312f18bbeeda8a34e99d0a662b0db9a190
> >>
> >> commit a6d57f312f18bbeeda8a34e99d0a662b0db9a190
> >> Author:     Rick Macklem <rmacklem@FreeBSD.org>
> >> AuthorDate: 2026-01-08 16:27:32 +0000
> >> Commit:     Rick Macklem <rmacklem@FreeBSD.org>
> >> CommitDate: 2026-01-08 16:27:32 +0000
> >>
> >>     nfsd: Fix handling of hidden/system during Open/Create
> >>
> >>     When an NFSv4.n client specifies settings for the archive,
> >>     hidden and/or system attributes during a Open/Create, the
> >>     Open/Create fails for ZFS.  This is caused by ZFS doing
> >>     a secpolicy_xvattr() call, which fails for non-root.
> >>     If this check is bypassed, ZFS panics.
> >>
> >>     This patch resolves the problem by disabling va_flags
> >>     for the VOP_CREATE() call in the NFSv4.n server and
> >>     then setting the flags with a subsequent VOP_SETATTR().
> >>
> >
> > The diff doesn't really include enough context to tell -- does this introduce a race window where a file that's supposed to be hidden and/or system is visible without that attribute from a different process?
> I believe that the answer is no.
> 
> VOP_CREATE() returns the new file's vnode exclusively locked
> and the update via VOP_SETATTR() happens before the vnode
> lock is released.

I expected/hoped that that was the case, but just couldn't tell from the
diff itself.

Thanks!

-Ben