Posts by pedward

  • Bug in busybox implementation of CIFS mount

    I know this issue has been beaten to death, but I have done a couple hours of debugging and I know what's going on.

    Working on Libreelec rPi2 8.2.2 and LibreELEC (community): devel-20171004193021-r26173-gd404dbb (TinkerBoard.arm) trying to execute this:

    Code
    mount -t cifs -oguest //192.168.1.1/ROMS /storage/emulators/roms

    I keep getting Invalid arguments

    I ran strace on Libreelec and my desktop (Fedora 27) machine, comparing the syscalls:

    Libreelec:

    Code
    mount("//192.168.1.1/ROMS", "/storage/emulators/roms/", "cifs", MS_SILENT, "guest,unc=\\\\192.168.1.1\\ROMS,ip=192.168.1.1") = -1 EINVAL (Invalid argument)

    Fedora:

    Code
    mount("//192.168.1.1/ROMS", ".", "cifs", 0, "ip=192.168.1.1,unc=\\\\192.168.1.1\\ROMS,user=,pass=") = 0

    Those 2 syscalls are the result of exactly the same command (with mount directory changed).

    The difference is that the Fedora command is invoked by mount.cifs, in the cifs-tools package, whereas the Libreelec is busybox.

    To make busybox mount using guest mounts correctly, you must use the following syntax:

    Code
    mount -t cifs -ouser=,pass= //192.168.1.1/ROMS /storage/emulators/roms

    Consequently, in the systemd.mount file, you MUST use this syntax for guest mounts:

    Code
    Options=user=,pass=

    The systemd.mount method above is a workaround, the proper behavior should be to issue user= and pass= when using guest. If you pull in the cifs-tools package, it will solve this problem for you.

    --Perry Harrington