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 # dm-multipath wwid which is used for rootfs
   9 MPATH_WWID=
  10
  11 # setup geninitrd module
  12 # @access       public
  13 setup_mod_multipath() {
  14         if [ -x /sbin/multipath ]; then
  15                 USE_MULTIPATH=yes
  16         else
  17                 USE_MULTIPATH=no
  18         fi
  19 }
  20
  21 # return true if node is multipath controlled
  22 # @param        string $node device node to be examined
  23 # @access       public
  24 is_multipath() {
  25         local devpath="$1"
  26
  27         # multipath disabled
  28         if ! is_yes "$USE_MULTIPATH"; then
  29                 return 1
  30         fi
  31
  32         # multipath nodes are under device mapper
  33         if [[ "$devpath" != /dev/mapper/* ]]; then
  34                 return 1
  35         fi
  36
  37         DM_NAME=
  38         eval $(dm_export "$devpath")
  39         if [ -z "$DM_NAME" ]; then
  40                 die "dm_export failed unexpectedly"
  41         fi
  42
  43         local MPATH_WWID=${DM_UUID##*-}
  44         local info=$(multipath -l $MPATH_WWID)
  45         if [ -z "$info" ]; then
  46                 return 1
  47         fi
  48
  49         return 0
  50 }
  51
  52 # find modules for $devpath
  53 # @param        $devpath        device to be examined
  54 # @access       public
  55 # find dm-multipath modules for $devpath
  56 # returns false if $devpath is not dm-multipath
  57 find_modules_multipath() {
  58         local devpath="$1"
  59
  60         DM_NAME=
  61         eval $(dm_export "$devpath")
  62         if [ -z "$DM_NAME" ]; then
  63                 die "dm_export failed unexpectedly"
  64         fi
  65
  66         # Partition:
  67         #  DM_NAME=LUN-28p1
  68         #  DM_UUID=part1-mpath-36006016002c11800a0aa05fbfae0db11
  69         # Disk:
  70         #  DM_NAME=LUN-28
  71         #  DM_UUID=mpath-36006016002c11800a0aa05fbfae0db11
  72         MPATH_WWID=${DM_UUID##*-}
  73
  74         local info=$(multipath -l $MPATH_WWID)
  75         if [ -z "$info" ]; then
  76                 return 1
  77         fi
  78
  79         debug "Finding modules for dm-multipath (WWID=$MPATH_WWID)"
  80         have_multipath=yes
  81         local dev phydevs=$(echo "$info" | awk '$2 ~ /^[0-9]+:[0-9]+:[0-9]+:[0-9]+$/{printf("/dev/%s\n", $3)}')
  82         for dev in $phydevs; do
  83                 find_modules_for_devpath $dev
  84                 lvm_ignore_devices="$lvm_ignore_devices $dev"
  85         done
  86
  87         local hw hwhandlers=$(echo "$info" | awk '/hwhandler=1/{sub(/.*hwhandler=1 /, ""); sub(/\]$/, ""); print}')
  88         for hw in $hwhandlers; do
  89                 find_module "dm-$hw"
  90         done
  91
  92         local target targets=$(echo "$info" | awk '/prio=/{print $2}' | sort -u)
  93         for target in $targets; do
  94                 find_module "dm-$target"
  95         done
  96
  97         find_module "dm-mod"
  98         return 0
  99 }
 100
 101 # generate initrd fragment
 102 # @access       public
 103 initrd_gen_multipath() {
 104         inst_d /sbin /lib/udev /etc/multipath
 105         inst_exec /sbin/kpartx /sbin
 106         inst_exec /sbin/multipath /sbin
 107
 108         # for udev callouts
 109         inst_exec /sbin/scsi_id /lib/udev
 110         inst_exec /sbin/mpath* /sbin
 111         egrep -v '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 112
 113         if [ -f /etc/multipath/bindings ]; then
 114                 egrep -v '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 115         else
 116                 touch $DESTDIR/etc/multipath/bindings
 117         fi
 118
 119         mount_dev
 120         initrd_gen_devices
 121
 122         mount_sys
 123         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 124         add_linuxrc <<-'EOF'
 125                 # parse mpath_wwid= from kernel commandline
 126                 for arg in $CMDLINE; do
 127                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 128                                 MPATH_WWID=${arg##mpath_wwid=}
 129                                 if [ "$MPATH_WWID" = "*" ]; then
 130                                         # '*' would mean activate all WWID-s
 131                                         MPATH_WWID=
 132                                         echo "multipath: Activating all WWID-s"
 133                                 else
 134                                         echo "multipath: Activating WWID=$WWID"
 135                                 fi
 136                         fi
 137                 done
 138
 139                 debugshell
 140                 /sbin/multipath -v 0 $MPATH_WWID
 141
 142                 for a in /dev/mapper/*; do
 143                         [ $a = /dev/mapper/control ] && continue
 144                         /sbin/kpartx -a -p p $a
 145                 done
 146                 debugshell
 147         EOF
 148 }
 149
 150
 151 # PRIVATE METHODS
 152 # export info from dmsetup
 153 # param can be:
 154 # - MAJOR:MINOR
 155 # - /dev/dm-MINOR
 156 # - /dev/mapper/DM_NAME
 157 dm_export() {
 158         local arg="$1"
 159
 160         case "$arg" in
 161         *:*)
 162                 local maj=${arg%:*} min=${arg#*:}
 163                 dmsetup -j $maj -m $min export
 164                 ;;
 165         /dev/dm-*)
 166                 local min=${arg#*dm-}
 167                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 168                 dm_export $maj:$min
 169                 ;;
 170         /dev/mapper/*)
 171                 local dm_name=${arg#/dev/mapper/}
 172                 dmsetup export $dm_name
 173                 ;;
 174         *)
 175                 die "dm_export: unexpected $arg"
 176                 ;;
 177         esac
 178 }
 179