modules.d/95nbd/nbdroot

   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 type getarg >/dev/null 2>&1 || . /lib/dracut-lib.sh
   6
   7 PATH=/usr/sbin:/usr/bin:/sbin:/bin
   8
   9 # Huh? Empty $1?
  10 [ -z "$1" ] && exit 1
  11
  12 # Huh? Empty $2?
  13 [ -z "$2" ] && exit 1
  14
  15 # Huh? Empty $3?
  16 [ -z "$3" ] && exit 1
  17
  18 # root is in the form root=nbd:srv:port[:fstype[:rootflags[:nbdopts]]]
  19 netif="$1"
  20 root="$2"
  21 NEWROOT="$3"
  22
  23 # If it's not nbd we don't continue
  24 [ "${root%%:*}" = "nbd" ] || return
  25
  26 root=${root#nbd:}
  27 nbdserver=${root%%:*}; root=${root#*:}
  28 nbdport=${root%%:*}; root=${root#*:}
  29 nbdfstype=${root%%:*}; root=${root#*:}
  30 nbdflags=${root%%:*}
  31 nbdopts=${root#*:}
  32
  33 if [ "$nbdopts" = "$nbdflags" ]; then
  34     unset nbdopts
  35 fi
  36 if [ "$nbdflags" = "$nbdfstype" ]; then
  37     unset nbdflags
  38 fi
  39 if [ "$nbdfstype" = "$nbdport" ]; then
  40     unset nbdfstype
  41 fi
  42 if [ -z "$nbdfstype" ]; then
  43     nbdfstype=auto
  44 fi
  45
  46 # look through the NBD options and pull out the ones that need to
  47 # go before the host etc. Append a ',' so we know we terminate the loop
  48 nbdopts=${nbdopts},
  49 while [ -n "$nbdopts" ]; do
  50     f=${nbdopts%%,*}
  51     nbdopts=${nbdopts#*,}
  52     if [ -z "$f" ]; then
  53         break
  54     fi
  55     if [ -z "${f%bs=*}" -o -z "${f%timeout=*}" ]; then
  56         preopts="$preopts $f"
  57         continue
  58     fi
  59     opts="$opts $f"
  60 done
  61
  62 # look through the flags and see if any are overridden by the command line
  63 nbdflags=${nbdflags},
  64 while [ -n "$nbdflags" ]; do
  65     f=${nbdflags%%,*}
  66     nbdflags=${nbdflags#*,}
  67     if [ -z "$f" ]; then
  68         break
  69     fi
  70     if [ "$f" = "ro" -o "$f" = "rw" ]; then
  71         nbdrw=$f
  72         continue
  73     fi
  74     fsopts=${fsopts+$fsopts,}$f
  75 done
  76
  77 getarg ro && nbdrw=ro
  78 getarg rw && nbdrw=rw
  79 fsopts=${fsopts+$fsopts,}${nbdrw}
  80
  81 # XXX better way to wait for the device to be made?
  82 i=0
  83 while [ ! -b /dev/nbd0 ]; do
  84     [ $i -ge 20 ] && exit 1
  85     if [ $UDEVVERSION -ge 143 ]; then
  86         udevadm settle --exit-if-exists=/dev/nbd0
  87     else
  88         sleep 0.1
  89     fi
  90     i=$(( $i + 1))
  91 done
  92
  93 nbd-client $preopts "$nbdserver" "$nbdport" /dev/nbd0 $opts || exit 1
  94
  95 # If we didn't get a root= on the command line, then we need to
  96 # add the udev rules for mounting the nbd0 device
  97 root=$(getarg root=)
  98 if [ -z "$root" ] || strstr "$root" "nbd:" || strstr "$root" "dhcp"; then
  99     echo '[ -e /dev/root ] || { info=$(udevadm info --query=env --name=/dev/nbd0); [ -z "${info%%*ID_FS_TYPE*}" ] && { ln -s /dev/nbd0 /dev/root 2>/dev/null; :; };} && rm $job;' \
 100         > $hookdir/initqueue/settled/nbd.sh
 101
 102     printf '/bin/mount -t %s -o %s %s %s\n' \
 103         "$nbdfstype" "$fsopts" /dev/nbd0 "$NEWROOT" \
 104         > $hookdir/mount/01-$$-nbd.sh
 105 fi
 106
 107 # NBD doesn't emit uevents when it gets connected, so kick it
 108 echo change > /sys/block/nbd0/uevent
 109 udevadm settle
 110 need_shutdown
 111 exit 0