[PATCH 31/39] convert selinuxfs

[Al Viro]

On Sun, Sep 21, 2025 at 04:44:28PM -0400, Paul Moore wrote:
> > +       dput(dentry);
> > +       return dentry;  // borrowed
> >  }
> 
> Prefer C style comments on their own line:
> 
>   dput(dentry);
>   /* borrowed dentry */
>   return dentry;

Umm...  IMO that's more of an annotation along the lines of "fallthru"...

> > @@ -2079,15 +2088,14 @@ static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
> >                 goto err;
> >         }
> >
> > -       fsi->policycap_dir = sel_make_dir(sb->s_root, POLICYCAP_DIR_NAME,
> > +       dentry = sel_make_dir(sb->s_root, POLICYCAP_DIR_NAME,
> >                                           &fsi->last_ino);
> 
> I'd probably keep fsi->policycap_dir in this patch simply to limit the
> scope of this patch to just the DCACHE_PERSISTENT related changes, but
> I'm not going to make a big fuss about that.

Not hard to split that way.  Will do...


BTW, an unrelated question: does userland care about selinuxfs /null being
called that (and being on selinuxfs, for that matter)?  Same for the
apparmor's securityfs /apparmor/.null...

If nobody cares, I would rather add an internal-only filesystem with
root being a character device (1,3) and whatever markings selinux et.al.
need for it.  With open_devnull(creds) provided for selinux,
apparmor and whoever else wants to play with neutering descriptors
on exec...