contrib/populate-extfs.sh: use debugfs to populate extX fs

This script uses debugfs command to populate the ext2/3/4 filesystem
from a given directory, it is a little similar to genext2fs, but this
one fully supports ext3 and ext4.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/contrib/populate-extfs.sh b/contrib/populate-extfs.sh
new file mode 100755 (executable)
index 0000000..b1d3d1f
--- /dev/null
+++ b/contrib/populate-extfs.sh
@@ -0,0 +1,105 @@
+#!/bin/sh
+#
+# This script uses debugfs command to populate the ext2/3/4 filesystem
+# from a given directory.
+#
+
+do_usage () {
+       cat << _EOF
+Usage: populate-extfs.sh <source> <device>
+Create an ext2/ext3/ext4 filesystem from a directory or file
+
+  source: The source directory or file
+  device: The target device
+
+_EOF
+       exit 1
+}
+
+[ $# -ne 2 ] && do_usage
+
+SRCDIR=${1%%/}
+DEVICE=$2
+
+# Find where is the debugfs command if not found in the env.
+if [ -z "$DEBUGFS" ]; then
+       CONTRIB_DIR=$(dirname $(readlink -f $0))
+       DEBUGFS="$CONTRIB_DIR/../debugfs/debugfs"
+fi
+
+{
+       CWD="/"
+       find $SRCDIR | while read FILE; do
+                TGT="${FILE##*/}"
+                DIR="${FILE#$SRCDIR}"
+                DIR="${DIR%$TGT}"
+
+               # Skip the root dir
+               [ ! -z "$DIR" ] || continue
+               [ ! -z "$TGT" ] || continue
+
+               if [ "$DIR" != "$CWD" ]; then
+                       echo "cd $DIR"
+                       CWD="$DIR"
+               fi
+
+               # Only stat once since stat is a time consuming command
+               STAT=$(stat -c "TYPE=\"%F\";DEVNO=\"0x%t 0x%T\";MODE=\"%f\";U=\"%u\";G=\"%g\"" $FILE)
+               eval $STAT
+
+               case $TYPE in
+               "directory")
+                       echo "mkdir $TGT"
+                       ;;
+               "regular file" | "regular empty file")
+                       echo "write $FILE $TGT"
+                       ;;
+               "symbolic link")
+                       LINK_TGT=$(readlink $FILE)
+                       echo "symlink $TGT $LINK_TGT"
+                       ;;
+               "block special file")
+                       echo "mknod $TGT b $DEVNO"
+                       ;;
+               "character special file")
+                       echo "mknod $TGT c $DEVNO"
+                       ;;
+               "fifo")
+                       echo "mknod $TGT p"
+                       ;;
+               *)
+                       echo "Unknown/unhandled file type '$TYPE' file: $FILE" 1>&2
+                       ;;
+               esac
+
+               # Set the file mode
+               echo "sif $TGT mode 0x$MODE"
+
+               # Set uid and gid
+               echo "sif $TGT uid $U"
+               echo "sif $TGT gid $G"
+       done
+
+       # Handle the hard links.
+       # Save the hard links to a file, use the inode number as the filename, for example:
+       # If a and b's inode number is 6775928, save a and b to /tmp/tmp.VrCwHh5gdt/6775928.
+       INODE_DIR=`mktemp -d` || exit 1
+       for i in `find $SRCDIR -type f -links +1 -printf 'INODE=%i###FN=%p\n'`; do
+               eval `echo $i | sed 's$###$ $'`
+               echo ${FN#$SRCDIR} >>$INODE_DIR/$INODE
+       done
+       # Use the debugfs' ln and "sif links_count" to handle them.
+       for i in `ls $INODE_DIR`; do
+               # The link source
+               SRC=`head -1 $INODE_DIR/$i`
+               # Remove the files and link them again except the first one
+               for TGT in `sed -n -e '1!p' $INODE_DIR/$i`; do
+                       echo "rm $TGT"
+                       echo "ln $SRC $TGT"
+               done
+               LN_CNT=`cat $INODE_DIR/$i | wc -l`
+               # Set the links count
+               echo "sif $SRC links_count $LN_CNT"
+       done
+       rm -fr $INODE_DIR
+} | $DEBUGFS -w -f - $DEVICE