functions

   1 #!/bin/sh
   2 #
   3 # geninitrd functions
   4
   5 # Find root device from fstab.
   6 #
   7 # @param        string  $fstab location of /etc/fstab
   8 # @return       false on failure
   9 #
  10 # Sets global variables:
  11 # - $rootdev
  12 # - $rootdev_add
  13 # - $rootFS
  14 #
  15 find_root() {
  16         local fstab="$1"
  17         local function="${PROGRAM:+$PROGRAM: }find_root"
  18         local rootopt
  19
  20         eval $(awk '!/^[\t ]*#/ && $2 == "/" {printf("rootdev=\"%s\"\nrootFs=\"%s\"\nrootopt=\"%s\"\n", $1, $3, $4)}' $fstab)
  21         if [ -z "$rootdev" ]; then
  22                 echo >&2 "$function: can't find fstab entry for root mountpoint"
  23                 return 1
  24         fi
  25
  26         # additional devices needed (xfs logdev)
  27         rootdev_add=$(echo "$rootopt" | awk -F',' '{ for (i=1; i<=NF; i++) { if ($i ~ /^logdev=/) { gsub(/^logdev=/, NIL, $i); print $i; } } }')
  28
  29         case $rootdev in
  30         LABEL=*)
  31                 if [ ! -x /sbin/blkid ]; then
  32                         echo >&2 "$function: /sbin/blkid is missing"
  33                         return 2
  34                 fi
  35
  36                 local label=${rootdev#"LABEL="}
  37                 local dev=$(/sbin/blkid -l -t LABEL="$label" -o device)
  38                 if [ "$dev" ]; then
  39                         if [ ! -r "$dev" ]; then
  40                                 echo >&2 "$function: blkid returned device $dev which doesn't exist"
  41                                 return 2
  42                         fi
  43                         rootdev=$dev
  44                 fi
  45                 ;;
  46
  47         UUID=*)
  48                 if [ ! -x /sbin/blkid ]; then
  49                         echo >&2 "$function: /sbin/blkid is missing"
  50                         return 2
  51                 fi
  52
  53                 local uuid=${rootdev#"UUID="}
  54                 local dev=$(/sbin/blkid -l -t UUID="$uuid" -o device)
  55
  56                 if [ "$dev" ]; then
  57                         if [ ! -r "$dev" ]; then
  58                                 echo >&2 "$function: blkid returned device $dev which doesn't exist"
  59                                 return 2
  60                         fi
  61                         rootdev=$dev
  62                 fi
  63                 ;;
  64         esac
  65
  66         case $rootdev in
  67         /dev/dm-*)
  68                 local node
  69                 node=$(dm_node "$rootdev") || return 1
  70                 if [ "$node" ]; then
  71                         rootdev="$node"
  72                 fi
  73                 ;;
  74         esac
  75
  76         case $rootdev in
  77         /dev/mapper/*)
  78                 local dm_subsystem=$(dm_subsystem "$rootdev")
  79                 case $dm_subsystem in
  80                 LVM)
  81                         local node
  82                         node=$(dm_lvm2_name "$rootdev") || return 1
  83                         if [ "$node" ]; then
  84                                 rootdev="$node"
  85                         fi
  86                         return 0
  87                         ;;
  88                 CRYPT)
  89                         return 0
  90                         ;;
  91                 esac
  92         esac
  93
  94         if [ "$rootFs" = "nfs" ]; then
  95                 rootdev="/dev/nfs"
  96                 return 0
  97         fi
  98
  99         if [ ! -r "$rootdev" ]; then
 100                 echo >&2 "$function: rootfs device file $rootdev doesn't exist"
 101                 return 1
 102         fi
 103
 104         return 0
 105 }
 106
 107 # resolve /dev/dm-0 to lvm2 node
 108 # which they got from blkid program fs was specifed as UUID= in fstab
 109 dm_lvm2_name() {
 110         local node="$1"
 111         local dm_minor stat
 112
 113         if [ ! -b "$node" ]; then
 114                 echo >&2 "dm_lvm2_name: $node is not a block device"
 115                 return 1
 116         fi
 117
 118         case $node in
 119         /dev/dm-*)
 120                 dm_minor=${node#/dev/dm-}
 121                 ;;
 122         /dev/mapper/*)
 123                 stat=$(stat -L --format=%T "$node") || die "stat failed: $node"
 124                 dm_minor=$((0x$stat))
 125         ;;
 126         esac
 127
 128         local lvm_path=$(/sbin/lvdisplay -c 2>/dev/null | awk -F: -vn=$dm_minor '{node=$1; major=$12; minor=$13; if (n == minor) print node}' | xargs)
 129         if [ -z "$lvm_path" ]; then
 130                 # XXX: this could happen also for non-lvm nodes?
 131                 cat >&2 <<-EOF
 132                 LVM doesn't recognize device-mapper node with minor $dm_minor
 133
 134                 In case your Physical Volumes are device mapper nodes, you should add to lvm.conf:
 135                     types = [ "device-mapper", 254 ]
 136
 137                 In case the LVM nodes are not present yet, it could be fixed by running:
 138                 # vgscan --mknodes
 139                 EOF
 140                 return 2
 141         fi
 142         if [ ! -r "$lvm_path" ]; then
 143                 echo >&2 "lvdisplay returned $lvm_path which doesn't exist in filesystem; try running 'vgscan --mknodes'."
 144                 return 2
 145         fi
 146         echo $lvm_path
 147 }
 148
 149 # resolve /dev/dm-0, /dev/mapper/name
 150 # @return       DM name
 151 dm_name() {
 152         local node="$1"
 153         dmsetup info -c --noheadings -o name $node
 154 }
 155
 156 # get subsystem name for DM node
 157 # node can be /dev/dm-0, /dev/mapper/name
 158 # @return       subsystem name
 159 dm_subsystem() {
 160         local node="$1"
 161         dmsetup info -c --noheadings -o subsystem $node
 162 }
 163
 164 # resolve any dm node to it's full path in /dev/mapper
 165 dm_node() {
 166         local node="$1"
 167         printf "/dev/mapper/%s" $(dm_name "$node")
 168 }