Description of problem:
When create device file via mknod with invalid mode, it just succeeds but not reports any error. This is quite like the situation in BZ #582901.

Version-Release number of selected component (if applicable):
libguestfs-1.0.85-1.fc12.3.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. ><fs> mknod-b 066666  8 1 /sd
mknod_b 28086 8 1 "/sd"
send_to_daemon: 0x25eb050 g->state = 3, n = 48
recv_from_daemon: 0x25eb050 g->state = 3, size_rtn = 0x7fffdb87b84c, buf_rtn = 0x7fffdb87b840
proc 135 (mknod_b) took 0.03 seconds

2. ><fs> ll /sd
ll "/sd"
send_to_daemon: 0x25eb050 g->state = 3, n = 36
recv_from_daemon: 0x25eb050 g->state = 3, size_rtn = 0x7fffdb87b86c, buf_rtn = 0x7fffdb87b860
ls -la /sysroot/sd
proc 5 (ll) took 0.00 seconds
brwSr-Sr-- 1 root root 8, 1 Apr 16 07:45 /sysroot/sd

3.
  
Actual results:


Expected results:
When you use a invalid mode, mknod should exit and report error.

Additional info: