mod-multipath.sh

   1 #!/bin/sh
   2 #
   3 # geninitrd mod: dm-multipath
   4 USE_MULTIPATH=${USE_MULTIPATH:-yes}
   5
   6 # if we should init dm-multipath at boot
   7 have_multipath=no
   8
   9 # dm-multipath wwid which is used for rootfs
  10 MPATH_WWID=
  11
  12 # setup geninitrd module
  13 # @access       public
  14 setup_mod_multipath() {
  15         if [ ! -x /sbin/multipath ]; then
  16                 USE_MULTIPATH=no
  17         fi
  18 }
  19
  20 # return true if node is multipath controlled
  21 # @param        string $node device node to be examined
  22 # @access       public
  23 is_multipath() {
  24         local devpath="$1"
  25
  26         # multipath disabled
  27         if is_no "$USE_MULTIPATH"; then
  28                 return 1
  29         fi
  30
  31         # multipath nodes are under device mapper
  32         if [[ "$devpath" != /dev/mapper/* ]]; then
  33                 return 1
  34         fi
  35
  36         DM_NAME=
  37         eval $(dm_export "$devpath")
  38         if [ -z "$DM_NAME" ]; then
  39                 die "Couldn't extract DM_NAME from $devpath"
  40         fi
  41
  42         local MPATH_WWID=${DM_UUID##*-}
  43
  44         # just check if it is valid.
  45         local info=$(multipath -l $MPATH_WWID)
  46         if [ -z "$info" ]; then
  47                 return 1
  48         fi
  49
  50         return 0
  51 }
  52
  53 # find modules for $devpath
  54 # @param        $devpath        device to be examined
  55 # @access       public
  56 # find dm-multipath modules for $devpath
  57 # returns false if $devpath is not dm-multipath
  58 find_modules_multipath() {
  59         local devpath="$1"
  60
  61         DM_NAME=
  62         eval $(dm_export "$devpath")
  63         if [ -z "$DM_NAME" ]; then
  64                 die "Couldn't extract DM_NAME from $devpath"
  65         fi
  66
  67         # Partition:
  68         #  DM_NAME=LUN-28p1
  69         #  DM_UUID=part1-mpath-36006016002c11800a0aa05fbfae0db11
  70         # Disk:
  71         #  DM_NAME=LUN-28
  72         #  DM_UUID=mpath-36006016002c11800a0aa05fbfae0db11
  73         MPATH_WWID=${DM_UUID##*-}
  74
  75         local info=$(multipath -l $MPATH_WWID)
  76         if [ -z "$info" ]; then
  77                 return 1
  78         fi
  79
  80         debug "Finding modules for dm-multipath (WWID=$MPATH_WWID)"
  81         have_multipath=yes
  82
  83         local p list
  84         list=$(mp_parse_devs "$info")
  85         for p in $list; do
  86                 find_modules_for_devpath $p
  87                 lvm_ignore_devices="$lvm_ignore_devices $p"
  88         done
  89
  90         list=$(mp_parse_hwhandler "$info")
  91         for p in $list; do
  92                 find_module "$p"
  93         done
  94
  95         list=$(mp_parse_policy "$info")
  96         for p in $list; do
  97                 find_module "dm-$p"
  98         done
  99
 100         find_module "dm-mod"
 101         return 0
 102 }
 103
 104 # generate initrd fragment
 105 # @access       public
 106 initrd_gen_multipath() {
 107         inst_d /sbin /lib/udev /etc/multipath
 108         inst_exec /sbin/kpartx /sbin
 109         inst_exec /sbin/multipath /sbin
 110
 111         # for udev callouts
 112         local scsi_id=$(find_tool /$_lib/udev/scsi_id /lib/udev/scsi_id /sbin/scsi_id)
 113         inst_exec $scsi_id /lib/udev
 114
 115         if [ -d /$_lib/multipath ]; then
 116                 inst_d /$_lib/multipath
 117                 inst_exec /$_lib/multipath/* /$_lib/multipath
 118         else
 119                 inst_exec /sbin/mpath* /sbin
 120         fi
 121
 122         egrep -v '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 123
 124         if [ -f /etc/multipath/bindings ]; then
 125                 egrep -v '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 126         else
 127                 touch $DESTDIR/etc/multipath/bindings
 128         fi
 129
 130         mount_dev
 131         initrd_gen_devices
 132
 133         mount_sys
 134         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 135         add_linuxrc <<-'EOF'
 136                 # parse mpath_wwid= from kernel commandline
 137                 for arg in $CMDLINE; do
 138                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 139                                 MPATH_WWID=${arg##mpath_wwid=}
 140                                 if [ "$MPATH_WWID" = "*" ]; then
 141                                         # '*' would mean activate all WWID-s
 142                                         MPATH_WWID=
 143                                         echo "multipath: Activating all WWID-s"
 144                                 else
 145                                         echo "multipath: Activating WWID=$WWID"
 146                                 fi
 147                         fi
 148                 done
 149
 150                 debugshell
 151                 /sbin/multipath -v 0 $MPATH_WWID
 152
 153                 for a in /dev/mapper/*; do
 154                         [ $a = /dev/mapper/control ] && continue
 155                         /sbin/kpartx -a -p p $a
 156                 done
 157                 debugshell
 158         EOF
 159 }
 160
 161
 162 # PRIVATE METHODS
 163 # export info from dmsetup
 164 # param can be:
 165 # - MAJOR:MINOR
 166 # - /dev/dm-MINOR
 167 # - /dev/mapper/DM_NAME
 168 dm_export() {
 169         local arg="$1"
 170
 171         case "$arg" in
 172         *:*)
 173                 local maj=${arg%:*} min=${arg#*:}
 174                 dmsetup -j $maj -m $min export
 175                 ;;
 176         /dev/dm-*)
 177                 local min=${arg#*dm-}
 178                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 179                 dm_export $maj:$min
 180                 ;;
 181         /dev/mapper/*)
 182                 local dm_name=${arg#/dev/mapper/}
 183                 dmsetup export $dm_name
 184                 ;;
 185         *)
 186                 die "dm_export: unexpected $arg"
 187                 ;;
 188         esac
 189 }
 190
 191 # parse blockdevices behind multipath device
 192 # takes 'multipath -l' output as input
 193 mp_parse_devs() {
 194         local info="$1"
 195
 196         # parse "0:0:1:0 sdf" -> /dev/sdf
 197         #
 198         # multipath-tools-0.4.8-0.12.amd64
 199         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 200         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 201         # \_ round-robin 0 [prio=0][active]
 202         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 203         # \_ round-robin 0 [prio=0][enabled]
 204         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 205         #
 206         # multipath-tools-0.4.8-9.x86_64
 207         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 208         # size=7.0G features='0' hwhandler='0' wp=rw
 209         # |-+- policy='round-robin 0' prio=-1 status=enabled
 210         # | `- #:#:#:# sde 8:64 failed undef running
 211         # `-+- policy='round-robin 0' prio=-1 status=active
 212         #   `- #:#:#:# sdb 8:16 active undef running
 213
 214         echo "$info" | awk '{
 215                 if (match($0, /[#0-9]+:[#0-9]+:[#0-9]+:[#0-9]+ [^ ]+ [0-9]+:[0-9]/)) {
 216                         # take whole matched part into "l" variable
 217                         l = substr($0, RSTART, RLENGTH);
 218                         split(l, a, " ");
 219                         printf("/dev/%s\n", a[2])
 220                 }
 221         }'
 222 }
 223
 224 # parse policy output for each device
 225 # takes 'multipath -l' output as input
 226 mp_parse_policy() {
 227         local info="$1"
 228
 229         # multipath-tools-0.4.8-0.12.amd64
 230         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 231         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 232         # \_ round-robin 0 [prio=0][active]
 233         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 234         # \_ round-robin 0 [prio=0][enabled]
 235         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 236         #
 237         # multipath-tools-0.4.8-9.x86_64
 238         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 239         # size=7.0G features='0' hwhandler='0' wp=rw
 240         # |-+- policy='round-robin 0' prio=-1 status=enabled
 241         # | `- #:#:#:# sde 8:64 failed undef running
 242         # `-+- policy='round-robin 0' prio=-1 status=active
 243         #   `- #:#:#:# sdb 8:16 active undef running
 244
 245         echo "$info" | awk '
 246                 # multipath-tools-0.4.8-0.12.amd64
 247                 /\[prio=/{
 248                         print $2
 249                 }
 250                 # multipath-tools-0.4.8-9.x86_64
 251                 /policy=/{
 252                         if (match($0, /policy=[^ ]+/)) {
 253                                 # take whole matched part into "l" variable
 254                                 l = substr($0, RSTART, RLENGTH);
 255                                 # remove policy= and single quote,
 256                                 # which we can not use in this awk inline script, therefore the %c hack
 257                                 sub(sprintf("^policy=%c?", 39), "", l);
 258                                 print l
 259                         }
 260                 }
 261         ' | sort -u
 262 }
 263
 264 # parse hwhandler from multipath output
 265 # takes 'multipath -l' output as input
 266 mp_parse_hwhandler() {
 267         local info="$1"
 268
 269         # TODO: actually the dm-emc vs scsi-dh-emc is dependant on kernel version
 270         # not version of the tools installed
 271
 272         # multipath-tools-0.4.8-0.12.amd64
 273         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 274         #
 275         # multipath-tools-0.4.8-11.x86_64
 276         # size=7.0G features='0' hwhandler='0' wp=rw
 277         # size=2.0G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
 278         echo "$info" | sed -ne "
 279                 # multipath-tools-0.4.8-0.12.amd64
 280                 /\[hwhandler=1/{
 281                         s,^.*\[hwhandler=1 \([^]]*\)\].*$,dm-\1,
 282                         p
 283                 }
 284                 # multipath-tools-0.4.8-11.x86_64
 285                 /hwhandler='1/{
 286                         s,^.*hwhandler='1 \([^']*\)'.*$,scsi-dh-\1,
 287                         p
 288                 }
 289         " | sort -u
 290 }