Comment # 3 on bug 1069731 from Aurelien Aptel

[pid 18153] mount("//192.168.33.100/DATEN/Musik", ".", "cifs", 0,
"ip=192.168.33.100,unc=\\\\192.168."...) = -1 EINVAL (Invalid argument)

The string is truncated unfortunately. We need a more verbose output anyway.

    # make the kernel as verbose as possible
    echo 'module cifs +p' > /sys/kernel/debug/dynamic_debug/control
    echo 'file fs/cifs/* +p' > /sys/kernel/debug/dynamic_debug/control
    echo 1 > /proc/fs/cifs/cifsFYI
    echo 1 > /sys/module/dns_resolver/parameters/debug

    # get kernel output + network trace
    dmesg --clear
    tcpdump -w trace.pcap & pid=$!
    sleep 3
    mount.cifs -vvv ....(your mount options here)
    sleep 3
    kill $pid
    dmesg > trace.log

This script should produce a kernel console output trace.log and a network
capture trace.pcap.

(You can reverse the verbosity levels by re-running the echo commands and
changing the + into - and 1 into 0)