contrib/populate-extfs.sh

   1 #!/bin/sh
   2 #
   3 # This script uses debugfs command to populate the ext2/3/4 filesystem
   4 # from a given directory.
   5 #
   6
   7 do_usage () {
   8         cat << _EOF
   9 Usage: populate-extfs.sh <source> <device>
  10 Create an ext2/ext3/ext4 filesystem from a directory or file
  11
  12   source: The source directory or file
  13   device: The target device
  14
  15 _EOF
  16         exit 1
  17 }
  18
  19 [ $# -ne 2 ] && do_usage
  20
  21 SRCDIR=${1%%/}
  22 DEVICE=$2
  23
  24 # Find where is the debugfs command if not found in the env.
  25 if [ -z "$DEBUGFS" ]; then
  26         CONTRIB_DIR=$(dirname $(readlink -f $0))
  27         DEBUGFS="$CONTRIB_DIR/../debugfs/debugfs"
  28 fi
  29
  30 {
  31         CWD="/"
  32         find $SRCDIR | while read FILE; do
  33                 TGT="${FILE##*/}"
  34                 DIR="${FILE#$SRCDIR}"
  35                 DIR="${DIR%$TGT}"
  36
  37                 # Skip the root dir
  38                 [ ! -z "$DIR" ] || continue
  39                 [ ! -z "$TGT" ] || continue
  40
  41                 if [ "$DIR" != "$CWD" ]; then
  42                         echo "cd $DIR"
  43                         CWD="$DIR"
  44                 fi
  45
  46                 # Only stat once since stat is a time consuming command
  47                 STAT=$(stat -c "TYPE=\"%F\";DEVNO=\"0x%t 0x%T\";MODE=\"%f\";U=\"%u\";G=\"%g\"" $FILE)
  48                 eval $STAT
  49
  50                 case $TYPE in
  51                 "directory")
  52                         echo "mkdir $TGT"
  53                         ;;
  54                 "regular file" | "regular empty file")
  55                         echo "write $FILE $TGT"
  56                         ;;
  57                 "symbolic link")
  58                         LINK_TGT=$(readlink $FILE)
  59                         echo "symlink $TGT $LINK_TGT"
  60                         ;;
  61                 "block special file")
  62                         echo "mknod $TGT b $DEVNO"
  63                         ;;
  64                 "character special file")
  65                         echo "mknod $TGT c $DEVNO"
  66                         ;;
  67                 "fifo")
  68                         echo "mknod $TGT p"
  69                         ;;
  70                 *)
  71                         echo "Unknown/unhandled file type '$TYPE' file: $FILE" 1>&2
  72                         ;;
  73                 esac
  74
  75                 # Set the file mode
  76                 echo "sif $TGT mode 0x$MODE"
  77
  78                 # Set uid and gid
  79                 echo "sif $TGT uid $U"
  80                 echo "sif $TGT gid $G"
  81         done
  82
  83         # Handle the hard links.
  84         # Save the hard links to a file, use the inode number as the filename, for example:
  85         # If a and b's inode number is 6775928, save a and b to /tmp/tmp.VrCwHh5gdt/6775928.
  86         INODE_DIR=`mktemp -d` || exit 1
  87         for i in `find $SRCDIR -type f -links +1 -printf 'INODE=%i###FN=%p\n'`; do
  88                 eval `echo $i | sed 's$###$ $'`
  89                 echo ${FN#$SRCDIR} >>$INODE_DIR/$INODE
  90         done
  91         # Use the debugfs' ln and "sif links_count" to handle them.
  92         for i in `ls $INODE_DIR`; do
  93                 # The link source
  94                 SRC=`head -1 $INODE_DIR/$i`
  95                 # Remove the files and link them again except the first one
  96                 for TGT in `sed -n -e '1!p' $INODE_DIR/$i`; do
  97                         echo "rm $TGT"
  98                         echo "ln $SRC $TGT"
  99                 done
 100                 LN_CNT=`cat $INODE_DIR/$i | wc -l`
 101                 # Set the links count
 102                 echo "sif $SRC links_count $LN_CNT"
 103         done
 104         rm -fr $INODE_DIR
 105 } | $DEBUGFS -w -f - $DEVICE