#!/bin/bash

# Create the block device nodes for a mass-storage device and its
# partitions.  The argument to this script is the canonical name of
# the device without the /dev prefix, like "hda" or "i2o/sda".

die () {
    echo "$@"
    exit 2
}

sys_block=/sys/block

[ -d $sys_block ] \
    || die "$sys_block not found!"

# Argument is a directory like /sys/block/hda, /sys/block/sda/sda1,
# /sys/block/i2o!hda, or /sys/block/i2o!hda/i2o!hda2.
make_block_device () {
    local path="$1"

    # Everything after the last /
    local name=${path##*/}
    local dev_file="/dev/$name"
    # Replace ! with /
    dev_file=${dev_file//\!/\/}
    echo "Making device $dev_file"
    [ -f "$path/dev" ] \
        || die "$0: Internal error: $path/dev not found"

    # Everything up to the last /
    local dev_dir=${dev_file%/*}
    mkdir -p "$dev_dir"
    [ -d "$dev_dir" ] \
        || die "$0: Unable to mkdir $dev_dir"

    local major_minor="`cat $path/dev`"
    local temp="$dev_file.$$.tmp"
    mknod "$temp" b ${major_minor%:*} ${major_minor#*:} \
        || die "mknod failed"
    mv -f "$temp" "$dev_file" \
        || die "rename $temp to $fullname failed"
}

# Replace / with !
dev="${1//\//!}"

[ -n "$dev" ] \
    || die "$0: I need an argument"

# Force "foo*" to expand to nothing if no matches found
shopt -s nullglob

# Exit silently if device does not exist
[ -d "$sys_block/$dev" ] \
    || exit 1

make_block_device "$sys_block/$dev"

# Devices like /dev/sda have partition names like /dev/sda1, while
# devices like /dev/rd/c0d0 have partition names like /dev/rd/c0d0p1.
# That is, we must append "pX" if the last character is a digit.  See
# disk_name() in linux/fs/partitions/check.c.
[[ $dev = *[0-9] ]] \
    && p=p

for devX in "$sys_block/$dev/$dev"$p[1-9]* ; do
    make_block_device "$devX"
done

exit 0