mod-multipath.sh

   1 #!/bin/sh
   2 MULTIPATH_RCSID='$Revision$ $Date::                            $'
   3
   4 # geninitrd mod: dm-multipath
   5 USE_MULTIPATH=${USE_MULTIPATH:-yes}
   6
   7 # if we should init dm-multipath at boot
   8 have_multipath=no
   9
  10 # dm-multipath wwid which is used for rootfs
  11 MPATH_WWID=
  12
  13 # setup geninitrd module
  14 # @access       public
  15 setup_mod_multipath() {
  16         if [ ! -x /sbin/multipath ]; then
  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="$1"
  26
  27         # multipath disabled
  28         if is_no "$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 "Couldn't extract DM_NAME from $devpath"
  41         fi
  42
  43         local MPATH_WWID=${DM_UUID##*-}
  44
  45         # just check if it is valid.
  46         local info=$(multipath -l $MPATH_WWID)
  47         if [ -z "$info" ]; then
  48                 return 1
  49         fi
  50
  51         return 0
  52 }
  53
  54 # find modules for $devpath
  55 # @param        $devpath        device to be examined
  56 # @access       public
  57 # find dm-multipath modules for $devpath
  58 # returns false if $devpath is not dm-multipath
  59 find_modules_multipath() {
  60         local devpath="$1"
  61
  62         DM_NAME=
  63         eval $(dm_export "$devpath")
  64         if [ -z "$DM_NAME" ]; then
  65                 die "Couldn't extract DM_NAME from $devpath"
  66         fi
  67
  68         # Partition:
  69         #  DM_NAME=LUN-28p1
  70         #  DM_UUID=part1-mpath-36006016002c11800a0aa05fbfae0db11
  71         # Disk:
  72         #  DM_NAME=LUN-28
  73         #  DM_UUID=mpath-36006016002c11800a0aa05fbfae0db11
  74         MPATH_WWID=${DM_UUID##*-}
  75
  76         local info=$(multipath -l $MPATH_WWID)
  77         if [ -z "$info" ]; then
  78                 return 1
  79         fi
  80
  81         verbose "Finding modules for dm-multipath (WWID=$MPATH_WWID)"
  82         have_multipath=yes
  83
  84         local p list
  85         list=$(mp_parse_devs "$info")
  86         for p in $list; do
  87                 find_modules_for_devpath $p
  88                 lvm_ignore_devices="$lvm_ignore_devices $p"
  89         done
  90
  91         list=$(mp_parse_hwhandler "$info")
  92         for p in $list; do
  93                 find_module "$p"
  94         done
  95
  96         list=$(mp_parse_policy "$info")
  97         for p in $list; do
  98                 find_module "dm-$p"
  99         done
 100
 101         find_module "dm-mod"
 102         return 0
 103 }
 104
 105 # generate initrd fragment
 106 # @access       public
 107 initrd_gen_multipath() {
 108         if ! is_yes "$have_multipath"; then
 109                 return
 110         fi
 111
 112         inst_d /sbin /lib/udev /etc/multipath
 113         inst_exec /sbin/kpartx /sbin
 114         inst_exec /sbin/multipath /sbin
 115
 116         # for udev callouts
 117         local scsi_id=$(find_tool /$_lib/udev/scsi_id /lib/udev/scsi_id /sbin/scsi_id)
 118         inst_exec $scsi_id /lib/udev
 119
 120         if [ -d /$_lib/multipath ]; then
 121                 inst_d /$_lib/multipath
 122                 inst_exec /$_lib/multipath/* /$_lib/multipath
 123         else
 124                 inst_exec /sbin/mpath* /sbin
 125         fi
 126
 127         grep -Ev '^([   ]*$|#)' /etc/multipath.conf > $DESTDIR/etc/multipath.conf
 128
 129         if [ -f /etc/multipath/bindings ]; then
 130                 grep -Ev '^([   ]*$|#)' /etc/multipath/bindings > $DESTDIR/etc/multipath/bindings
 131         else
 132                 touch $DESTDIR/etc/multipath/bindings
 133         fi
 134
 135         mount_dev
 136         initrd_gen_devices
 137
 138         mount_sys
 139         echo "export MPATH_WWID=$MPATH_WWID" | add_linuxrc
 140         add_linuxrc <<-'EOF'
 141                 # parse mpath_wwid= from kernel commandline
 142                 for arg in $CMDLINE; do
 143                         if [ "${arg##mpath_wwid=}" != "${arg}" ]; then
 144                                 MPATH_WWID=${arg##mpath_wwid=}
 145                                 if [ "$MPATH_WWID" = "*" ]; then
 146                                         # '*' would mean activate all WWID-s
 147                                         MPATH_WWID=
 148                                         echo "multipath: Activating all WWID-s"
 149                                 else
 150                                         echo "multipath: Activating WWID=$WWID"
 151                                 fi
 152                         fi
 153                 done
 154
 155                 debugshell
 156                 /sbin/multipath -v 0 $MPATH_WWID
 157
 158                 for a in /dev/mapper/*; do
 159                         [ $a = /dev/mapper/control ] && continue
 160                         /sbin/kpartx -a -p p $a
 161                 done
 162                 debugshell
 163         EOF
 164 }
 165
 166
 167 # PRIVATE METHODS
 168 # export info from dmsetup
 169 # param can be:
 170 # - MAJOR:MINOR
 171 # - /dev/dm-MINOR
 172 # - /dev/mapper/DM_NAME
 173 dm_export() {
 174         local arg="$1"
 175
 176         case "$arg" in
 177         *:*)
 178                 local maj=${arg%:*} min=${arg#*:}
 179                 dmsetup -j $maj -m $min export
 180                 ;;
 181         /dev/dm-*)
 182                 local min=${arg#*dm-}
 183                 local maj=$(awk '$2 == "device-mapper" {print $1}' /proc/devices)
 184                 dm_export $maj:$min
 185                 ;;
 186         /dev/mapper/*)
 187                 local dm_name=${arg#/dev/mapper/}
 188                 dmsetup export $dm_name
 189                 ;;
 190         *)
 191                 die "dm_export: unexpected $arg"
 192                 ;;
 193         esac
 194 }
 195
 196 # parse blockdevices behind multipath device
 197 # takes 'multipath -l' output as input
 198 mp_parse_devs() {
 199         local info="$1"
 200
 201         # parse "0:0:1:0 sdf" -> /dev/sdf
 202         #
 203         # multipath-tools-0.4.8-0.12.amd64
 204         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 205         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 206         # \_ round-robin 0 [prio=0][active]
 207         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 208         # \_ round-robin 0 [prio=0][enabled]
 209         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 210         #
 211         # multipath-tools-0.4.8-9.x86_64
 212         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 213         # size=7.0G features='0' hwhandler='0' wp=rw
 214         # |-+- policy='round-robin 0' prio=-1 status=enabled
 215         # | `- #:#:#:# sde 8:64 failed undef running
 216         # `-+- policy='round-robin 0' prio=-1 status=active
 217         #   `- #:#:#:# sdb 8:16 active undef running
 218
 219         echo "$info" | awk '{
 220                 if (match($0, /[#0-9]+:[#0-9]+:[#0-9]+:[#0-9]+ [^ ]+ [0-9]+:[0-9]/)) {
 221                         # take whole matched part into "l" variable
 222                         l = substr($0, RSTART, RLENGTH);
 223                         split(l, a, " ");
 224                         printf("/dev/%s\n", a[2])
 225                 }
 226         }'
 227 }
 228
 229 # parse policy output for each device
 230 # takes 'multipath -l' output as input
 231 mp_parse_policy() {
 232         local info="$1"
 233
 234         # multipath-tools-0.4.8-0.12.amd64
 235         # LUN-02 (36006016002c11800ce520d27c6ebda11) dm-0 DGC     ,RAID 10
 236         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 237         # \_ round-robin 0 [prio=0][active]
 238         #  \_ 0:0:0:0 sda 8:0   [active][undef]
 239         # \_ round-robin 0 [prio=0][enabled]
 240         #  \_ 0:0:1:0 sdf 8:80  [active][undef]
 241         #
 242         # multipath-tools-0.4.8-9.x86_64
 243         # LUN-14 (36006016002c118006f4f8bccc7fada11) dm-3 ,
 244         # size=7.0G features='0' hwhandler='0' wp=rw
 245         # |-+- policy='round-robin 0' prio=-1 status=enabled
 246         # | `- #:#:#:# sde 8:64 failed undef running
 247         # `-+- policy='round-robin 0' prio=-1 status=active
 248         #   `- #:#:#:# sdb 8:16 active undef running
 249
 250         echo "$info" | awk '
 251                 # multipath-tools-0.4.8-0.12.amd64
 252                 /\[prio=/{
 253                         print $2
 254                 }
 255                 # multipath-tools-0.4.8-9.x86_64
 256                 /policy=/{
 257                         if (match($0, /policy=[^ ]+/)) {
 258                                 # take whole matched part into "l" variable
 259                                 l = substr($0, RSTART, RLENGTH);
 260                                 # remove policy= and single quote,
 261                                 # which we can not use in this awk inline script, therefore the %c hack
 262                                 sub(sprintf("^policy=%c?", 39), "", l);
 263                                 print l
 264                         }
 265                 }
 266         ' | sort -u
 267 }
 268
 269 # parse hwhandler from multipath output
 270 # takes 'multipath -l' output as input
 271 mp_parse_hwhandler() {
 272         local info="$1"
 273
 274         # TODO: actually the dm-emc vs scsi-dh-emc is dependant on kernel version
 275         # not version of the tools installed
 276
 277         # multipath-tools-0.4.8-0.12.amd64
 278         # [size=12G][features=1 queue_if_no_path][hwhandler=1 emc]
 279         #
 280         # multipath-tools-0.4.8-11.x86_64
 281         # size=7.0G features='0' hwhandler='0' wp=rw
 282         # size=2.0G features='1 queue_if_no_path' hwhandler='1 emc' wp=rw
 283         echo "$info" | sed -ne "
 284                 # multipath-tools-0.4.8-0.12.amd64
 285                 /\[hwhandler=1/{
 286                         s,^.*\[hwhandler=1 \([^]]*\)\].*$,dm-\1,
 287                         p
 288                 }
 289                 # multipath-tools-0.4.8-11.x86_64
 290                 /hwhandler='1/{
 291                         s,^.*hwhandler='1 \([^']*\)'.*$,scsi-dh-\1,
 292                         p
 293                 }
 294         " | sort -u
 295 }