mod-multipath.sh

   1 #!/bin/sh
   2 #
   3 # geninitrd mod: dm-multipath
   4
   5 # if we should init dm-multipath at boot
   6 have_multipath=no
   7
   8 if [ -x /sbin/multipath ]; then
   9         USE_MULTIPATH=yes
  10 else
  11         USE_MULTIPATH=no
  12 fi
  13
  14 # dm-multipath wwid which is used for rootfs
  15 MPATH_WWID=
  16
  17 # return true if node is multipath controlled
  18 # @param        string $node device node to be examined
  19 # @access       public
  20 is_multipath() {
  21         local devpath="$1"
  22
  23         # multipath disabled
  24         if ! is_yes "$USE_MULTIPATH"; then
  25                 return 1
  26         fi
  27
  28         # multipath nodes are under device mapper
  29         if [[ "$devpath" != /dev/mapper/* ]]; then
  30                 return 1
  31         fi
  32
  33         DM_NAME=
  34         eval $(dm_export "$devpath")
  35         if [ -z "$DM_NAME" ]; then
  36                 die "dm_export failed unexpectedly"
  37         fi
  38
  39         local MPATH_WWID=${DM_UUID##*-}
  40         local info=$(multipath -l $MPATH_WWID)
  41         if [ -z "$info" ]; then
  42                 return 1
  43         fi
  44
  45         return 0
  46 }
  47
  48 # find modules for $devpath
  49 # @param        $devpath        device to be examined
  50 # @access       public
  51 # find dm-multipath modules for $devpath
  52 # returns false if $devpath is not dm-multipath
  53 find_modules_multipath() {
  54         local devpath="$1"
  55
  56         DM_NAME=
  57         eval $(dm_export "$devpath")
  58         if [ -z "$DM_NAME" ]; then
  59                 die "dm_export failed unexpectedly"
  60         fi
  61
  62         # Partition:
  63         #  DM_NAME=LUN-28p1
  64         #  DM_UUID=part1-mpath-36006016002c11800a0aa05fbfae0db11
  65         # Disk:
  66         #  DM_NAME=LUN-28
  67         #  DM_UUID=mpath-36006016002c11800a0aa05fbfae0db11
  68         MPATH_WWID=${DM_UUID##*-}
  69
  70         local info=$(multipath -l $MPATH_WWID)
  71         if [ -z "$info" ]; then
  72                 return 1
  73         fi
  74
  75         debug "Finding modules for dm-multipath (WWID=$MPATH_WWID)"
  76         have_multipath=yes
  77         local dev phydevs=$(echo "$info" | awk '$2 ~ /^[0-9]+:[0-9]+:[0-9]+:[0-9]+$/{printf("/dev/%s\n", $3)}')
  78         for dev in $phydevs; do
  79                 find_modules_for_devpath $dev
  80                 lvm_ignore_devices="$lvm_ignore_devices $dev"
  81         done
  82
  83         local hw hwhandlers=$(echo "$info" | awk '/hwhandler=1/{sub(/.*hwhandler=1 /, ""); sub(/\]$/, ""); print}')
  84         for hw in $hwhandlers; do
  85                 findmodule "dm-$hw"
  86         done
  87
  88         local target targets=$(echo "$info" | awk '/prio=/{print $2}' | sort -u)
  89         for target in $targets; do
  90                 findmodule "dm-$target"
  91         done
  92
  93         findmodule "dm-mod"
  94         return 0
  95 }
  96
  97 # generate initrd fragment
  98 # @access       public
  99 initrd_gen_multipath() {
 100         inst_d /sbin /lib/udev /etc/multipath
 101         inst_exec /sbin/kpartx /sbin
 102         inst_exec /sbin/multipath /sbin
 103
 104         # for udev callouts
 105         inst_exec /sbin/scsi_id /lib/udev
 106         inst_exec /sbin/mpath* /sbin
 107         egrep -v '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 108
 109         if [ -f /etc/multipath/bindings ]; then
 110                 egrep -v '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 111         else
 112                 touch $DESTDIR/etc/multipath/bindings
 113         fi
 114
 115         mount_dev
 116         initrd_gen_devices
 117
 118         mount_sys
 119         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 120         add_linuxrc <<-'EOF'
 121                 # parse mpath_wwid= from kernel commandline
 122                 for arg in $CMDLINE; do
 123                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 124                                 MPATH_WWID=${arg##mpath_wwid=}
 125                                 if [ "$MPATH_WWID" = "*" ]; then
 126                                         # '*' would mean activate all WWID-s
 127                                         MPATH_WWID=
 128                                         echo "multipath: Activating all WWID-s"
 129                                 else
 130                                         echo "multipath: Activating WWID=$WWID"
 131                                 fi
 132                         fi
 133                 done
 134
 135                 debugshell
 136                 /sbin/multipath -v 0 $MPATH_WWID
 137
 138                 for a in /dev/mapper/*; do
 139                         [ $a = /dev/mapper/control ] && continue
 140                         /sbin/kpartx -a -p p $a
 141                 done
 142                 debugshell
 143         EOF
 144 }
 145
 146
 147 # PRIVATE METHODS
 148 # export info from dmsetup
 149 # param can be:
 150 # - MAJOR:MINOR
 151 # - /dev/dm-MINOR
 152 # - /dev/mapper/DM_NAME
 153 dm_export() {
 154         local arg="$1"
 155
 156         case "$arg" in
 157         *:*)
 158                 local maj=${arg%:*} min=${arg#*:}
 159                 dmsetup -j $maj -m $min export
 160                 ;;
 161         /dev/dm-*)
 162                 local min=${arg#*dm-}
 163                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 164                 dm_export $maj:$min
 165                 ;;
 166         /dev/mapper/*)
 167                 local dm_name=${arg#/dev/mapper/}
 168                 dmsetup export $dm_name
 169                 ;;
 170         *)
 171                 die "dm_export: unexpected $arg"
 172                 ;;
 173         esac
 174 }
 175