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 $p"
  88         done
  89
  90         # TODO: handle newer multipath-tools:
  91         # size=7.0G features='0' hwhandler='0' wp=rw
  92         list=$(echo "$info" | awk '/hwhandler=1/{sub(/.*hwhandler=1 /, ""); sub(/\]$/, ""); print}')
  93         for p in $list; do
  94                 find_module "dm-$p"
  95         done
  96
  97         list=$(mp_parse_policy "$info")
  98         for p in $list; do
  99                 find_module "dm-$p"
 100         done
 101
 102         find_module "dm-mod"
 103         return 0
 104 }
 105
 106 # generate initrd fragment
 107 # @access       public
 108 initrd_gen_multipath() {
 109         inst_d /sbin /lib/udev /etc/multipath
 110         inst_exec /sbin/kpartx /sbin
 111         inst_exec /sbin/multipath /sbin
 112
 113         # for udev callouts
 114         local scsi_id=$(find_tool /lib/udev/scsi_id /sbin/scsi_id)
 115         inst_exec $scsi_id /lib/udev
 116
 117         if [ -d /lib/multipath ]; then
 118                 inst_d /lib/multipath
 119                 inst_exec /lib/multipath/* /lib/multipath
 120         else
 121                 inst_exec /sbin/mpath* /sbin
 122         fi
 123
 124         egrep -v '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 125
 126         if [ -f /etc/multipath/bindings ]; then
 127                 egrep -v '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 128         else
 129                 touch $DESTDIR/etc/multipath/bindings
 130         fi
 131
 132         mount_dev
 133         initrd_gen_devices
 134
 135         mount_sys
 136         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 137         add_linuxrc <<-'EOF'
 138                 # parse mpath_wwid= from kernel commandline
 139                 for arg in $CMDLINE; do
 140                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 141                                 MPATH_WWID=${arg##mpath_wwid=}
 142                                 if [ "$MPATH_WWID" = "*" ]; then
 143                                         # '*' would mean activate all WWID-s
 144                                         MPATH_WWID=
 145                                         echo "multipath: Activating all WWID-s"
 146                                 else
 147                                         echo "multipath: Activating WWID=$WWID"
 148                                 fi
 149                         fi
 150                 done
 151
 152                 debugshell
 153                 /sbin/multipath -v 0 $MPATH_WWID
 154
 155                 for a in /dev/mapper/*; do
 156                         [ $a = /dev/mapper/control ] && continue
 157                         /sbin/kpartx -a -p p $a
 158                 done
 159                 debugshell
 160         EOF
 161 }
 162
 163
 164 # PRIVATE METHODS
 165 # export info from dmsetup
 166 # param can be:
 167 # - MAJOR:MINOR
 168 # - /dev/dm-MINOR
 169 # - /dev/mapper/DM_NAME
 170 dm_export() {
 171         local arg="$1"
 172
 173         case "$arg" in
 174         *:*)
 175                 local maj=${arg%:*} min=${arg#*:}
 176                 dmsetup -j $maj -m $min export
 177                 ;;
 178         /dev/dm-*)
 179                 local min=${arg#*dm-}
 180                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 181                 dm_export $maj:$min
 182                 ;;
 183         /dev/mapper/*)
 184                 local dm_name=${arg#/dev/mapper/}
 185                 dmsetup export $dm_name
 186                 ;;
 187         *)
 188                 die "dm_export: unexpected $arg"
 189                 ;;
 190         esac
 191 }
 192
 193 # parse blockdevices behind multipath device
 194 # takes 'multipath -l' output as input
 195 mp_parse_devs() {
 196         local info="$1"
 197
 198         # parse "0:0:1:0 sdf" -> /dev/sdf
 199         #
 200         # multipath-tools-0.4.8-0.12.amd64
 201         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 202         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 203         # \_ round-robin 0 [prio=0][active]
 204         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 205         # \_ round-robin 0 [prio=0][enabled]
 206         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 207         #
 208         # multipath-tools-0.4.8-9.x86_64
 209         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 210         # size=7.0G features='0' hwhandler='0' wp=rw
 211         # |-+- policy='round-robin 0' prio=-1 status=enabled
 212         # | `- #:#:#:# sde 8:64 failed undef running
 213         # `-+- policy='round-robin 0' prio=-1 status=active
 214         #   `- #:#:#:# sdb 8:16 active undef running
 215
 216         echo "$info" | awk '{
 217                 if (match($0, /[#0-9]+:[#0-9]+:[#0-9]+:[#0-9]+ [^ ]+ [0-9]+:[0-9]/)) {
 218                         # take whole matched part into "l" variable
 219                         l = substr($0, RSTART, RLENGTH);
 220                         split(l, a, " ");
 221                         printf("/dev/%s\n", a[2])
 222                 }
 223         }'
 224 }
 225
 226 # parse policy output for each device
 227 # takes 'multipath -l' output as input
 228 mp_parse_policy() {
 229         local info="$1"
 230
 231         # multipath-tools-0.4.8-0.12.amd64
 232         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 233         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 234         # \_ round-robin 0 [prio=0][active]
 235         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 236         # \_ round-robin 0 [prio=0][enabled]
 237         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 238         #
 239         # multipath-tools-0.4.8-9.x86_64
 240         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 241         # size=7.0G features='0' hwhandler='0' wp=rw
 242         # |-+- policy='round-robin 0' prio=-1 status=enabled
 243         # | `- #:#:#:# sde 8:64 failed undef running
 244         # `-+- policy='round-robin 0' prio=-1 status=active
 245         #   `- #:#:#:# sdb 8:16 active undef running
 246
 247         echo "$info" | awk '
 248                 # multipath-tools-0.4.8-0.12.amd64
 249                 /\[prio=/{
 250                         print $2
 251                 }
 252                 # multipath-tools-0.4.8-9.x86_64
 253                 /policy=/{
 254                         if (match($0, /policy=[^ ]+/)) {
 255                                 # take whole matched part into "l" variable
 256                                 l = substr($0, RSTART, RLENGTH);
 257                                 # remove policy= and single quote,
 258                                 # which we can not use in this awk inline script, therefore the %c hack
 259                                 sub(sprintf("^policy=%c?", 39), "", l);
 260                                 print l
 261                         }
 262                 }
 263         ' | sort -u
 264 }