# pgrep codesys                           
793
# strace -f -p 793 -e mount,umount       
Process 793 attached with 13 threads
[pid   826] mount("", "/media/usb0", 0xb6d10694, MS_REMOUNT|MS_BIND, "") = 0
[pid   826] mount("", "/media/usb0", 0xb6d10694, MS_REMOUNT|MS_BIND, "") = 0
[pid   826] umount("/media/usb0", MNT_DETACH) = 0
[pid   826] mount("", "/media/usb0", 0xb6d10694, MS_REMOUNT|MS_BIND, "") = -1 EINVAL (Invalid argument)