#!/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 #
########################

# 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."
    exit 1
  fi

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

# Generate a patch for a file to be added to the kernel source tree.
# $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."
    exit 1
  fi

  cat <<EOF
diff -uprN orig/$2 $2
--- orig/$2
+++ $2
@@ -0,0 +1,$(wc -l "$1" | { read a b; echo $a; }) @@
EOF
  sed "s/^/+/" <"$1"
}


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

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

if [ $# != 1 ]; then
  echo "Usage: $0 <kernel version>."
  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
done


# Kernel patches for other directories than drivers/scsi/scsi_tgt/.

for p in "${kpatch[@]}"
do
  cat "$p"
  echo ''
  echo ''
done

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

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


# Directory include/scsi_tgt/

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


# Directory drivers/scsi/scsi_tgt/

add_file "scst/kernel/in-tree/Kconfig.scsi_tgt" \
         "drivers/scsi/scsi_tgt/Kconfig"
add_file "scst/kernel/in-tree/Makefile.scsi_tgt" \
         "drivers/scsi/scsi_tgt/Makefile"


for f in scst/src/*[ch]
do
  add_file ${f} linux-${kernel_version}/drivers/scsi/scsi_tgt/${f#scst/src/}
  echo ''
  echo ''
done


# Directory drivers/scsi/scsi_tgt/dev_handlers/

add_file "scst/kernel/in-tree/Makefile.dev_handlers" \
         "linux-${kernel_version}/drivers/scsi/scsi_tgt/dev_handlers/Makefile"

for f in scst/src/dev_handlers/*.[ch]
do
  add_file ${f} linux-${kernel_version}/drivers/scsi/scsi_tgt/dev_handlers/${f#scst/src/dev_handlers/}
  echo ''
  echo ''
done


# Directory drivers/infiniband/ulp/srpt/

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

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

for f in srpt/src/*[ch]
do
  add_file ${f} linux-${kernel_version}/drivers/infiniband/ulp/srpt/${f#srpt/src/}
  echo ''
  echo ''
done