#!/bin/bash

############################################################################
#
# Script for converting the SCST source tree as it exists in the Subversion
# repository to a Linux kernel patch.
#
# Copyright (C) 2008 Bart Van Assche <bart.vanassche@gmail.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation, version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
############################################################################

########################
# Function definitions #
########################

function usage {
  echo "Usage: $0 [-m] [-q] <kernel version>."
}

# Convert an existing patch.
# $1: path of patch to be added.
# $2: path in kernel tree of file to be patched.
function add_patch {
  if [ ! -e "$1" ]; then
    echo "Error: could not find $1." >&2
    exit 1
  fi

  sed -e "s:^--- [^ ]*:--- orig/linux-${kernel_version}/$2:" \
      -e "s:^+++ [^ ]*:+++ linux-${kernel_version}/$2:"      \
      < "$1"
}

# Generate a patch for a file to be added to the kernel source tree, and strip
# trailing whitespace from C source files while converting the file to patch
# format.
# $1: path of file to be added.
# $2: path in kernel tree where file should be added.
function add_file {
  local a b

  if [ ! -e "$1" ]; then
    echo "Error: could not find $1." >&2
    exit 1
  fi

  # Only include files that were not generated by the build process
  # -- skip *.mod.c.
  if [ "$1" = "${1%.mod.c}" -a "$1" ]; then
    cat <<EOF
diff -uprN orig/linux-${kernel_version}/$2 linux-${kernel_version}/$2
--- orig/linux-${kernel_version}/$2
+++ linux-${kernel_version}/$2
@@ -0,0 +1,$(wc -l "$1" | { read a b; echo $a; }) @@
EOF
    if [ "${2%.[ch]}" != "$2" ]; then
      sed -e 's/^ \([^ ]*:\)$/\1/' -e 's/^/+/' < "$1"
    else
      sed -e 's/^/+/' < "$1"
    fi
  fi
}


#########################
# Argument verification #
#########################

mpt_scst="false"
qla2x00t="false"

if [ ! -e scst -o ! -e iscsi-scst -o ! -e srpt ]; then
  echo "Please run this script from inside the SCST subversion source tree."
  exit 1
fi

set -- $(/usr/bin/getopt mq "$@")
while [ "$1" != "${1#-}" ]
do
  case "$1" in
    '-m') mpt_scst="true"; shift;;
    '-q') qla2x00t="true"; shift;;
    '--') shift;;
    *)    usage; exit 1;;
  esac
done

if [ $# != 1 ]; then
  usage
  exit 1
fi


####################
# Patch Generation #
####################

kernel_version="$1"
kpatch=(                                                                \
  "scst/kernel/scst_exec_req_fifo-${kernel_version}.patch"              \
  "iscsi-scst/kernel/patches/put_page_callback-${kernel_version}.patch" \
)

for p in "${kpatch[@]}"
do
  if [ ! -e "$p" ]; then
    echo "Error: kernel version ${kernel_version} is not supported by SCST."
    echo "(could not find file $p)."
    exit 1
  fi >&2
done


# Redirect the output of all subsequent commands to the specialize-patch script

trap "rm -f ${fifo}" EXIT
fifo=/tmp/generate-kernel-patch-fifo.$$
rm -f "${fifo}"
mkfifo "${fifo}"
"$(dirname $0)/specialize-patch" -v kernel_version="${kernel_version}" \
  < "${fifo}" &
exec >"${fifo}"

# General kernel patches.

cat "${kpatch[@]}"


# Directory include/scst/

# Make sure the file iscsi-scst/iscsi_scst_itf_ver.h is up to date.
make -s -C iscsi-scst include/iscsi_scst_itf_ver.h

for f in scst/include/*h
do
  add_file "${f}" "include/scst/${f#scst/include/}"
done

for f in iscsi-scst/include/*h
do
  add_file "${f}" "include/scst/${f#iscsi-scst/include/}"
done


# Directory drivers/

add_patch "scst/kernel/in-tree/Kconfig.drivers.Linux-${kernel_version}.patch" \
          "drivers/Kconfig"

add_patch "scst/kernel/in-tree/Makefile.drivers.Linux-${kernel_version}.patch"\
          "drivers/Makefile"


# Directory drivers/scst/

add_file "scst/kernel/in-tree/Kconfig.scst"  "drivers/scst/Kconfig"

add_file "scst/kernel/in-tree/Makefile.scst" "drivers/scst/Makefile"

add_file "scst/README"                       "Documentation/scst/README.scst"

for f in scst/src/*.[ch]
do
  add_file "${f}" "drivers/scst/${f#scst/src/}"
done


# Directory drivers/scst/dev_handlers/

add_file "scst/kernel/in-tree/Makefile.dev_handlers" \
         "drivers/scst/dev_handlers/Makefile"

for f in scst/src/dev_handlers/*.[ch]
do
  add_file "${f}" "drivers/scst/dev_handlers/${f#scst/src/dev_handlers/}"
done


# Directory drivers/scst/iscsi-scst/

add_file "iscsi-scst/kernel/Makefile.in-kernel" \
         "drivers/scst/iscsi-scst/Makefile"

add_file "iscsi-scst/kernel/Kconfig"  "drivers/scst/iscsi-scst/Kconfig"

add_file "iscsi-scst/README"          "Documentation/scst/README.iscsi"

for f in iscsi-scst/kernel/*.[ch]
do
  add_file "${f}" "drivers/scst/iscsi-scst/${f#iscsi-scst/kernel/}"
done


# Directory drivers/scst/qla2x00-target/

if [ "${qla2x00t}" = "true" ]; then

  #add_file "qla2x00t/qla2x00-target/Makefile.in-kernel" \
  #         "drivers/scst/qla2x00-target/Makefile"

  #add_file "qla2x00t/qla2x00-target/Kconfig" \
  #         "drivers/scst/qla2x00-target/Kconfig"

  add_file "qla2x00t/qla2x_tgt_def.h" \
           "drivers/scst/qla2x00-target/qla2x_tgt_def.h"

  add_file "qla2x00t/qla2x00-target/README" \
           "Documentation/scst/README.qla2x00t"

  for f in qla2x00t/qla2x00-target/*.[ch]
  do
    add_file "${f}" "drivers/scst/qla2x00-target/${f#qla2x00t/qla2x00-target/}"
  done

fi


# Directory drivers/infiniband/ulp/srpt/

add_patch "srpt/src/Kconfig.infiniband.Linux-${kernel_version}.patch" \
          "drivers/infiniband/Kconfig"

add_patch "srpt/src/Makefile.infiniband.Linux-${kernel_version}.patch" \
          "drivers/infiniband/Makefile"

add_file  "srpt/src/Kconfig"            "drivers/infiniband/ulp/srpt/Kconfig"

add_file  "srpt/src/Makefile.in_kernel" "drivers/infiniband/ulp/srpt/Makefile"

add_file  "srpt/README"                 "Documentation/scst/README.srpt"

for f in srpt/src/*.[ch]
do
  add_file "${f}" "drivers/infiniband/ulp/srpt/${f#srpt/src/}"
done


# Directory drivers/message/fusion/mpt_scst

if [ "$mpt_scst" = "true" ]; then

  add_patch "mpt/in-tree/Kconfig-2.6.24.diff" "drivers/message/fusion/Kconfig"

  add_patch "mpt/in-tree/Makefile.diff"       "drivers/message/fusion/Makefile"

  add_file  "mpt/Makefile" "drivers/message/fusion/mpt_scst/Makefile"

  add_file  "mpt/Kconfig"  "drivers/message/fusion/mpt_scst/Kconfig"

  for f in mpt/*.[ch]
  do
    add_file "${f}" "drivers/message/fusion/mpt_scst/${f#mpt/}"
  done

fi