modules.d/95nbd/parse-nbdroot.sh

   1 #!/bin/sh
   2 # -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
   3 # ex: ts=8 sw=4 sts=4 et filetype=sh
   4 #
   5 # Preferred format:
   6 #       root=nbd:srv:port[:fstype[:rootflags[:nbdopts]]]
   7 #       [root=*] netroot=nbd:srv:port[:fstype[:rootflags[:nbdopts]]]
   8 #
   9 # nbdopts is a comma separated list of options to give to nbd-client
  10 #
  11 # root= takes precedence over netroot= if root=nbd[...]
  12 #
  13
  14 # Sadly there's no easy way to split ':' separated lines into variables
  15 netroot_to_var() {
  16     local v=${1}:
  17     set --
  18     while [ -n "$v" ]; do
  19         set -- "$@" "${v%%:*}"
  20         v=${v#*:}
  21     done
  22
  23     unset server port
  24     server=$2; port=$3;
  25 }
  26
  27 # This script is sourced, so root should be set. But let's be paranoid
  28 [ -z "$root" ] && root=$(getarg root=)
  29 [ -z "$netroot" ] && netroot=$(getarg netroot=)
  30
  31 # Root takes precedence over netroot
  32 if [ "${root%%:*}" = "nbd" ] ; then
  33
  34     # Don't continue if root is ok
  35     [ -n "$rootok" ] && return
  36
  37     if [ -n "$netroot" ] ; then
  38         warn "root takes precedence over netroot. Ignoring netroot"
  39
  40     fi
  41     netroot=$root
  42     unset root
  43 fi
  44
  45 # If it's not nbd we don't continue
  46 [ "${netroot%%:*}" = "nbd" ] || return
  47
  48 # Check required arguments
  49 netroot_to_var $netroot
  50 [ -z "$server" ] && die "Argument server for nbdroot is missing"
  51 [ -z "$port" ] && die "Argument port for nbdroot is missing"
  52
  53 # NBD actually supported?
  54 incol2 /proc/devices nbd || modprobe nbd || die "nbdroot requested but kernel/initrd does not support nbd"
  55
  56 # Done, all good!
  57 rootok=1
  58
  59 # Shut up init error check
  60 if [ -z "$root" ]; then
  61     root=block:/dev/root
  62     wait_for_dev /dev/root
  63 fi
  64