mod-multipath.sh

   1 #!/bin/sh
   2 # geninitrd mod: dm-multipath
   3 USE_MULTIPATH=${USE_MULTIPATH:-yes}
   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=no
  16         fi
  17 }
  18
  19 # return true if node is multipath controlled
  20 # @param        string $node device node to be examined
  21 # @access       public
  22 is_multipath() {
  23         local devpath="$1"
  24
  25         # multipath disabled
  26         if is_no "$USE_MULTIPATH"; then
  27                 return 1
  28         fi
  29
  30         # multipath nodes are under device mapper
  31         if [[ "$devpath" != /dev/mapper/* ]]; then
  32                 return 1
  33         fi
  34
  35         DM_NAME=
  36         eval $(dm_export "$devpath")
  37         if [ -z "$DM_NAME" ]; then
  38                 die "Couldn't extract DM_NAME from $devpath"
  39         fi
  40
  41         local MPATH_WWID=${DM_UUID##*-}
  42
  43         # just check if it is valid.
  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 "Couldn't extract DM_NAME from $devpath"
  64         fi
  65
  66         # Partition:
  67         #  DM_NAME=LUN-28p1
  68         #  DM_UUID=part1-mpath-36006016002c11800a0aa05fbfae0db11
  69         # Disk:
  70         #  DM_NAME=LUN-28
  71         #  DM_UUID=mpath-36006016002c11800a0aa05fbfae0db11
  72         MPATH_WWID=${DM_UUID##*-}
  73
  74         local info=$(multipath -l $MPATH_WWID)
  75         if [ -z "$info" ]; then
  76                 return 1
  77         fi
  78
  79         verbose "Finding modules for dm-multipath (WWID=$MPATH_WWID)"
  80         have_multipath=yes
  81
  82         local p list
  83         list=$(mp_parse_devs "$info")
  84         for p in $list; do
  85                 find_modules_for_devpath $p
  86                 lvm_ignore_devices="$lvm_ignore_devices $p"
  87         done
  88
  89         list=$(mp_parse_hwhandler "$info")
  90         for p in $list; do
  91                 find_module "$p"
  92         done
  93
  94         list=$(mp_parse_policy "$info")
  95         for p in $list; do
  96                 find_module "dm-$p"
  97         done
  98
  99         find_module "dm-mod"
 100         return 0
 101 }
 102
 103 # generate initrd fragment
 104 # @access       public
 105 initrd_gen_multipath() {
 106         if ! is_yes "$have_multipath"; then
 107                 return
 108         fi
 109
 110         inst_d /sbin /lib/udev /etc/multipath
 111         inst_exec /sbin/kpartx /sbin
 112         inst_exec /sbin/multipath /sbin
 113
 114         # for udev callouts
 115         local scsi_id=$(find_tool $(get_libdir /LIBDIR/udev/scsi_id) /lib/udev/scsi_id /sbin/scsi_id)
 116         inst_exec $scsi_id /lib/udev
 117
 118         local installed=0
 119         for _lib in $(get_libdir LIBDIR); do
 120                 if [ -d /$_lib/multipath ]; then
 121                         inst_d /$_lib/multipath
 122                         inst_exec /$_lib/multipath/* /$_lib/multipath
 123                         installed=1
 124                         break
 125                 fi
 126         done
 127         if [ "$installed" -eq 0 ]; then
 128                 inst_exec /sbin/mpath* /sbin
 129         fi
 130
 131         grep -Ev '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 132
 133         if [ -f /etc/multipath/bindings ]; then
 134                 grep -Ev '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 135         else
 136                 touch $DESTDIR/etc/multipath/bindings
 137         fi
 138
 139         mount_dev
 140         initrd_gen_devices
 141
 142         mount_sys
 143         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 144         add_linuxrc <<-'EOF'
 145                 # parse mpath_wwid= from kernel commandline
 146                 for arg in $CMDLINE; do
 147                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 148                                 MPATH_WWID=${arg##mpath_wwid=}
 149                                 if [ "$MPATH_WWID" = "*" ]; then
 150                                         # '*' would mean activate all WWID-s
 151                                         MPATH_WWID=
 152                                         echo "multipath: Activating all WWID-s"
 153                                 else
 154                                         echo "multipath: Activating WWID=$WWID"
 155                                 fi
 156                         fi
 157                 done
 158
 159                 debugshell
 160                 /sbin/multipath -v 0 $MPATH_WWID
 161
 162                 for a in /dev/mapper/*; do
 163                         [ $a = /dev/mapper/control ] && continue
 164                         /sbin/kpartx -a -p p $a
 165                 done
 166                 debugshell
 167         EOF
 168 }
 169
 170
 171 # PRIVATE METHODS
 172 # export info from dmsetup
 173 # param can be:
 174 # - MAJOR:MINOR
 175 # - /dev/dm-MINOR
 176 # - /dev/mapper/DM_NAME
 177 dm_export() {
 178         local arg="$1"
 179
 180         case "$arg" in
 181         *:*)
 182                 local maj=${arg%:*} min=${arg#*:}
 183                 dmsetup -j $maj -m $min export
 184                 ;;
 185         /dev/dm-*)
 186                 local min=${arg#*dm-}
 187                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 188                 dm_export $maj:$min
 189                 ;;
 190         /dev/mapper/*)
 191                 local dm_name=${arg#/dev/mapper/}
 192                 dmsetup export $dm_name
 193                 ;;
 194         *)
 195                 die "dm_export: unexpected $arg"
 196                 ;;
 197         esac
 198 }
 199
 200 # parse blockdevices behind multipath device
 201 # takes 'multipath -l' output as input
 202 mp_parse_devs() {
 203         local info="$1"
 204
 205         # parse "0:0:1:0 sdf" -> /dev/sdf
 206         #
 207         # multipath-tools-0.4.8-0.12.amd64
 208         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 209         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 210         # \_ round-robin 0 [prio=0][active]
 211         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 212         # \_ round-robin 0 [prio=0][enabled]
 213         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 214         #
 215         # multipath-tools-0.4.8-9.x86_64
 216         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 217         # size=7.0G features='0' hwhandler='0' wp=rw
 218         # |-+- policy='round-robin 0' prio=-1 status=enabled
 219         # | `- #:#:#:# sde 8:64 failed undef running
 220         # `-+- policy='round-robin 0' prio=-1 status=active
 221         #   `- #:#:#:# sdb 8:16 active undef running
 222
 223         echo "$info" | awk '{
 224                 if (match($0, /[#0-9]+:[#0-9]+:[#0-9]+:[#0-9]+ [^ ]+ [0-9]+:[0-9]/)) {
 225                         # take whole matched part into "l" variable
 226                         l = substr($0, RSTART, RLENGTH);
 227                         split(l, a, " ");
 228                         printf("/dev/%s\n", a[2])
 229                 }
 230         }'
 231 }
 232
 233 # parse policy output for each device
 234 # takes 'multipath -l' output as input
 235 mp_parse_policy() {
 236         local info="$1"
 237
 238         # multipath-tools-0.4.8-0.12.amd64
 239         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 240         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 241         # \_ round-robin 0 [prio=0][active]
 242         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 243         # \_ round-robin 0 [prio=0][enabled]
 244         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 245         #
 246         # multipath-tools-0.4.8-9.x86_64
 247         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 248         # size=7.0G features='0' hwhandler='0' wp=rw
 249         # |-+- policy='round-robin 0' prio=-1 status=enabled
 250         # | `- #:#:#:# sde 8:64 failed undef running
 251         # `-+- policy='round-robin 0' prio=-1 status=active
 252         #   `- #:#:#:# sdb 8:16 active undef running
 253
 254         echo "$info" | awk '
 255                 # multipath-tools-0.4.8-0.12.amd64
 256                 /\[prio=/{
 257                         print $2
 258                 }
 259                 # multipath-tools-0.4.8-9.x86_64
 260                 /policy=/{
 261                         if (match($0, /policy=[^ ]+/)) {
 262                                 # take whole matched part into "l" variable
 263                                 l = substr($0, RSTART, RLENGTH);
 264                                 # remove policy= and single quote,
 265                                 # which we can not use in this awk inline script, therefore the %c hack
 266                                 sub(sprintf("^policy=%c?", 39), "", l);
 267                                 print l
 268                         }
 269                 }
 270         ' | sort -u
 271 }
 272
 273 # parse hwhandler from multipath output
 274 # takes 'multipath -l' output as input
 275 mp_parse_hwhandler() {
 276         local info="$1"
 277
 278         # TODO: actually the dm-emc vs scsi-dh-emc is dependant on kernel version
 279         # not version of the tools installed
 280
 281         # multipath-tools-0.4.8-0.12.amd64
 282         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 283         #
 284         # multipath-tools-0.4.8-11.x86_64
 285         # size=7.0G features='0' hwhandler='0' wp=rw
 286         # size=2.0G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
 287         echo "$info" | sed -ne "
 288                 # multipath-tools-0.4.8-0.12.amd64
 289                 /\[hwhandler=1/{
 290                         s,^.*\[hwhandler=1 \([^]]*\)\].*$,dm-\1,
 291                         p
 292                 }
 293                 # multipath-tools-0.4.8-11.x86_64
 294                 /hwhandler='1/{
 295                         s,^.*hwhandler='1 \([^']*\)'.*$,scsi-dh-\1,
 296                         p
 297                 }
 298         " | sort -u
 299 }