functions.initrd

   1 # Functions used from inside of initrd.
   2
   3
   4 # Wait for specific /dev files to appear but only one
   5 # time regardless how often this function is called
   6 # in one initrd run. Needs writable /tmp.
   7 wait_for_files() {
   8         local i=0 timeout=30 all_found not_found wff_dir fpath file
   9         while getopts t: opt "$@"; do
  10                 case "$opt" in
  11                         t)
  12                                 timeout="${OPTARG}"
  13                                 break
  14                                 ;;
  15                         *)
  16                                 echo "$0: wait_for_files: unknown option" >&2
  17                                 return 1
  18                                 ;;
  19                 esac
  20         done
  21         shift $((OPTIND - 1))
  22
  23         wff_dir="/tmp/wait_for_files"
  24
  25         [ ! -d "$wff_dir" ] && mkdir "$wff_dir"
  26
  27         echo "Waiting for files ($@) with ${timeout}s timeout"
  28         i=0
  29         timeout=$((timeout * 4))
  30         while [ $i -lt $timeout ]; do
  31                 all_found=1
  32                 for file in $@; do
  33                         fpath="$wff_dir/${file}"
  34                         [ -e "$fpath" -o -e "$file" ] && continue
  35                         all_found=0
  36                 done
  37                 if [ $all_found -eq 1 ]; then
  38                         return 0
  39                 fi
  40                 usleep 250000
  41                 i=$((i + 1 ))
  42         done
  43         not_found=""
  44         # mark files that we have waited for
  45         for file in $@; do
  46                 fpath="$wff_dir/${file}"
  47                 [ ! -e "$fpath" ] && mkdir -p "$fpath"
  48                 [ ! -e "$file" ] && not_found="$not_found $file"
  49         done
  50         echo "Waiting for files ($@) finished. Missing files: $not_found"
  51
  52         return 0
  53 }