scripts/blktap

   1 #!/bin/bash
   2
   3 # Copyright (c) 2005, XenSource Ltd.
   4
   5 dir=$(dirname "$0")
   6 . "$dir/xen-hotplug-common.sh"
   7 . "$dir/block-common.sh"
   8
   9 findCommand "$@"
  10
  11 ##
  12 # check_blktap_sharing file mode
  13 #
  14 # Perform the sharing check for the given blktap and mode.
  15 #
  16 check_blktap_sharing()
  17 {
  18     local file="$1"
  19     local mode="$2"
  20
  21     local base_path="$XENBUS_BASE_PATH/$XENBUS_TYPE"
  22     for dom in $(xenstore-list "$base_path")
  23     do
  24         for dev in $(xenstore-list "$base_path/$dom")
  25         do
  26             params=$(xenstore_read "$base_path/$dom/$dev/params" | cut -d: -f2)
  27             if [ "$file" = "$params" ]
  28             then
  29
  30                 if [ "$mode" = 'w' ]
  31                 then
  32                     if ! same_vm "$dom"
  33                     then
  34                         echo 'guest'
  35                         return
  36                     fi
  37                 else
  38                     local m=$(xenstore_read "$base_path/$dom/$dev/mode")
  39                     m=$(canonicalise_mode "$m")
  40
  41                     if [ "$m" = 'w' ]
  42                     then
  43                         if ! same_vm "$dom"
  44                         then
  45                             echo 'guest'
  46                             return
  47                         fi
  48                     fi
  49                 fi
  50             fi
  51         done
  52     done
  53
  54     echo 'ok'
  55 }
  56
  57
  58 t=$(xenstore_read_default "$XENBUS_PATH/type" 'MISSING')
  59 if [ -n "$t" ]
  60 then
  61     p=$(xenstore_read "$XENBUS_PATH/params")
  62     # if we have a ':', chew from head including :
  63     if echo $p | grep -q \:
  64     then
  65         p=${p#*:}
  66     fi
  67 fi
  68 # some versions of readlink cannot be passed a regular file
  69 if [ -L "$p" ]; then
  70     file=$(readlink -f "$p") || fatal "$p link does not exist."
  71 else
  72     file="$p"
  73 fi
  74
  75 if [ "$command" = 'add' ]
  76 then
  77     [ -e "$file" ] || { fatal $file does not exist; }
  78
  79     FRONTEND_ID=$(xenstore_read "$XENBUS_PATH/frontend-id")
  80     FRONTEND_UUID=$(xenstore_read "/local/domain/$FRONTEND_ID/vm")
  81     mode=$(xenstore_read "$XENBUS_PATH/mode")
  82     mode=$(canonicalise_mode "$mode")
  83
  84     if [ "$mode" != '!' ]
  85     then
  86         result=$(check_blktap_sharing "$file" "$mode")
  87         [ "$result" = 'ok' ] || ebusy "$file already in use by other domain"
  88     fi
  89
  90     success
  91 fi
  92
  93 exit 0