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         if ! is_yes "$have_multipath"; then
 108                 return
 109         fi
 110
 111         inst_d /sbin /lib/udev /etc/multipath
 112         inst_exec /sbin/kpartx /sbin
 113         inst_exec /sbin/multipath /sbin
 114
 115         # for udev callouts
 116         local scsi_id=$(find_tool /$_lib/udev/scsi_id /lib/udev/scsi_id /sbin/scsi_id)
 117         inst_exec $scsi_id /lib/udev
 118
 119         if [ -d /$_lib/multipath ]; then
 120                 inst_d /$_lib/multipath
 121                 inst_exec /$_lib/multipath/* /$_lib/multipath
 122         else
 123                 inst_exec /sbin/mpath* /sbin
 124         fi
 125
 126         egrep -v '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 127
 128         if [ -f /etc/multipath/bindings ]; then
 129                 egrep -v '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 130         else
 131                 touch $DESTDIR/etc/multipath/bindings
 132         fi
 133
 134         mount_dev
 135         initrd_gen_devices
 136
 137         mount_sys
 138         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 139         add_linuxrc <<-'EOF'
 140                 # parse mpath_wwid= from kernel commandline
 141                 for arg in $CMDLINE; do
 142                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 143                                 MPATH_WWID=${arg##mpath_wwid=}
 144                                 if [ "$MPATH_WWID" = "*" ]; then
 145                                         # '*' would mean activate all WWID-s
 146                                         MPATH_WWID=
 147                                         echo "multipath: Activating all WWID-s"
 148                                 else
 149                                         echo "multipath: Activating WWID=$WWID"
 150                                 fi
 151                         fi
 152                 done
 153
 154                 debugshell
 155                 /sbin/multipath -v 0 $MPATH_WWID
 156
 157                 for a in /dev/mapper/*; do
 158                         [ $a = /dev/mapper/control ] && continue
 159                         /sbin/kpartx -a -p p $a
 160                 done
 161                 debugshell
 162         EOF
 163 }
 164
 165
 166 # PRIVATE METHODS
 167 # export info from dmsetup
 168 # param can be:
 169 # - MAJOR:MINOR
 170 # - /dev/dm-MINOR
 171 # - /dev/mapper/DM_NAME
 172 dm_export() {
 173         local arg="$1"
 174
 175         case "$arg" in
 176         *:*)
 177                 local maj=${arg%:*} min=${arg#*:}
 178                 dmsetup -j $maj -m $min export
 179                 ;;
 180         /dev/dm-*)
 181                 local min=${arg#*dm-}
 182                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 183                 dm_export $maj:$min
 184                 ;;
 185         /dev/mapper/*)
 186                 local dm_name=${arg#/dev/mapper/}
 187                 dmsetup export $dm_name
 188                 ;;
 189         *)
 190                 die "dm_export: unexpected $arg"
 191                 ;;
 192         esac
 193 }
 194
 195 # parse blockdevices behind multipath device
 196 # takes 'multipath -l' output as input
 197 mp_parse_devs() {
 198         local info="$1"
 199
 200         # parse "0:0:1:0 sdf" -> /dev/sdf
 201         #
 202         # multipath-tools-0.4.8-0.12.amd64
 203         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 204         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 205         # \_ round-robin 0 [prio=0][active]
 206         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 207         # \_ round-robin 0 [prio=0][enabled]
 208         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 209         #
 210         # multipath-tools-0.4.8-9.x86_64
 211         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 212         # size=7.0G features='0' hwhandler='0' wp=rw
 213         # |-+- policy='round-robin 0' prio=-1 status=enabled
 214         # | `- #:#:#:# sde 8:64 failed undef running
 215         # `-+- policy='round-robin 0' prio=-1 status=active
 216         #   `- #:#:#:# sdb 8:16 active undef running
 217
 218         echo "$info" | awk '{
 219                 if (match($0, /[#0-9]+:[#0-9]+:[#0-9]+:[#0-9]+ [^ ]+ [0-9]+:[0-9]/)) {
 220                         # take whole matched part into "l" variable
 221                         l = substr($0, RSTART, RLENGTH);
 222                         split(l, a, " ");
 223                         printf("/dev/%s\n", a[2])
 224                 }
 225         }'
 226 }
 227
 228 # parse policy output for each device
 229 # takes 'multipath -l' output as input
 230 mp_parse_policy() {
 231         local info="$1"
 232
 233         # multipath-tools-0.4.8-0.12.amd64
 234         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 235         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 236         # \_ round-robin 0 [prio=0][active]
 237         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 238         # \_ round-robin 0 [prio=0][enabled]
 239         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 240         #
 241         # multipath-tools-0.4.8-9.x86_64
 242         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 243         # size=7.0G features='0' hwhandler='0' wp=rw
 244         # |-+- policy='round-robin 0' prio=-1 status=enabled
 245         # | `- #:#:#:# sde 8:64 failed undef running
 246         # `-+- policy='round-robin 0' prio=-1 status=active
 247         #   `- #:#:#:# sdb 8:16 active undef running
 248
 249         echo "$info" | awk '
 250                 # multipath-tools-0.4.8-0.12.amd64
 251                 /\[prio=/{
 252                         print $2
 253                 }
 254                 # multipath-tools-0.4.8-9.x86_64
 255                 /policy=/{
 256                         if (match($0, /policy=[^ ]+/)) {
 257                                 # take whole matched part into "l" variable
 258                                 l = substr($0, RSTART, RLENGTH);
 259                                 # remove policy= and single quote,
 260                                 # which we can not use in this awk inline script, therefore the %c hack
 261                                 sub(sprintf("^policy=%c?", 39), "", l);
 262                                 print l
 263                         }
 264                 }
 265         ' | sort -u
 266 }
 267
 268 # parse hwhandler from multipath output
 269 # takes 'multipath -l' output as input
 270 mp_parse_hwhandler() {
 271         local info="$1"
 272
 273         # TODO: actually the dm-emc vs scsi-dh-emc is dependant on kernel version
 274         # not version of the tools installed
 275
 276         # multipath-tools-0.4.8-0.12.amd64
 277         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 278         #
 279         # multipath-tools-0.4.8-11.x86_64
 280         # size=7.0G features='0' hwhandler='0' wp=rw
 281         # size=2.0G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
 282         echo "$info" | sed -ne "
 283                 # multipath-tools-0.4.8-0.12.amd64
 284                 /\[hwhandler=1/{
 285                         s,^.*\[hwhandler=1 \([^]]*\)\].*$,dm-\1,
 286                         p
 287                 }
 288                 # multipath-tools-0.4.8-11.x86_64
 289                 /hwhandler='1/{
 290                         s,^.*hwhandler='1 \([^']*\)'.*$,scsi-dh-\1,
 291                         p
 292                 }
 293         " | sort -u
 294 }