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