Making Linux stat() less evil

[Roman Divacky]

On Thu, Feb 19, 2009 at 09:56:45PM +0100, Ed Schouten wrote:
> Hi folks,
> 
> I may have mentioned this earlier, but our Linuxolator's stat()
> implementation calls kern_openat(), followed by an
> translate_fd_major_minor() to perform a device major/minor number
> lookup. This is very evil, because it causes random chardevs to be
> opened when you run ls -l /dev.
> 
> I propose the following patch:
> 
> 	http://80386.nl/pub/linux-stat.diff
> 
> I've copied kern_stat() into the Linuxolator. Not the ideal solution,
> but it's better than what we have right now. Comments?

why cant you use kern_statat() and perform this after it returns?

+		if (S_ISCHR(sb.st_mode) && nd.ni_vp->v_un.vu_cdev != NULL &&
+		    linux_driver_get_major_minor(
+		        nd.ni_vp->v_un.vu_cdev->si_name, &major, &minor) == 0) {
+			sb.st_rdev = (major << 8 | minor);
+		}