[PATCH] kbuild: rebuild initramfs if included files changes

[Sam Ravnborg <sam@ravnborg.org>]

This fix has been implemented in preparation for the upcoming klibc
merge in -mm. But as it fixes a real (but rare I hope) bug in vanilla
kernel it will be added to my pending 2.6.17 kbuild queue.

I've done quite some changes to the gen_initramfs script and
being shell programming newbie review by more experienced shell
hackers would be appreciated.

I did a git mv scripts/gen_initramfs_list.sh usr/gen_initramfs.sh
But the changes was so many that git does not see the rename.
Due to the rename the diffstat shows a bit mroe changes than reality.

	Sam

 b/usr/Makefile                |   82 ++++--------
 b/usr/gen_initramfs.sh        |  285 ++++++++++++++++++++++++++++++++++++++++++
 scripts/gen_initramfs_list.sh |  203 -----------------------------
 3 files changed, 313 insertions(+), 257 deletions(-)

diff-tree 73ef2e1760bb20a1190b25a2d559789b513bd3c2 (from d9df92e22aca939857c5bc9ecb130ef22307ccc1)
Author: Sam Ravnborg <sam@mars.ravnborg.org>
Date:   Sun Apr 9 22:48:16 2006 +0200

    kbuild: rebuild initramfs if included files changes

    initramfs.cpio.gz being build in usr/ and included in the
    kernel was not rebuild when the included files changed.

    To fix this the following was done:
    - moved gen_init_ramfs_list.sh to usr/gen_initramfs.sh
    - let gen_initramfs.sh generate a list of files and directories included
      in the initramfs
    - gen_initramfs generate the gzipped cpio archive so we could simplify
      the kbuild file (Makefile)
    - utilising the kbuild infrastructure so when uid/gid root mapping changes
      the initramfs will be rebuild

    With this change we have a much more robust initramfs generation.

    Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

diff --git a/usr/Makefile b/usr/Makefile
index e2129cb..ed18668 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -1,65 +1,39 @@
+#
+# kbuild file for usr/ - including initramfs image
+#
 
+# Generate builtin.o based on initramfs_data.o
 obj-y := initramfs_data.o
 
-hostprogs-y  := gen_init_cpio
-
-clean-files := initramfs_data.cpio.gz initramfs_list
-
 # initramfs_data.o contains the initramfs_data.cpio.gz image.
 # The image is included using .incbin, a dependency which is not
 # tracked automatically.
 $(obj)/initramfs_data.o: $(obj)/initramfs_data.cpio.gz FORCE
-
-ifdef CONFIG_INITRAMFS_ROOT_UID
-gen_initramfs_args += -u $(CONFIG_INITRAMFS_ROOT_UID)
-endif
-
-ifdef CONFIG_INITRAMFS_ROOT_GID
-gen_initramfs_args += -g $(CONFIG_INITRAMFS_ROOT_GID)
-endif
-
-# The $(shell echo $(CONFIG_INITRAMFS_SOURCE)) is to remove the
-# gratuitous begin and end quotes from the Kconfig string type.
-# Internal, escaped quotes in the Kconfig string will loose the
-# escape and become active quotes.
-quotefixed_initramfs_source := $(shell echo $(CONFIG_INITRAMFS_SOURCE))
-
-filechk_initramfs_list = $(CONFIG_SHELL) \
- $(srctree)/scripts/gen_initramfs_list.sh $(gen_initramfs_args) $(quotefixed_initramfs_source)
-
-$(obj)/initramfs_list: $(obj)/Makefile FORCE
-	$(call filechk,initramfs_list)
-
-quiet_cmd_cpio = CPIO    $@
-      cmd_cpio = ./$< $(obj)/initramfs_list > $@
 
+#####
+# Generate the initramfs cpio archive
+# Following steps are executed:
+# Create list of files to be included in archive (ramfs-filelist)
+# If any of the files are newer than target generate new cpio archive
 
-# Check if the INITRAMFS_SOURCE is a cpio archive
-ifneq (,$(findstring .cpio,$(quotefixed_initramfs_source)))
-
-# INITRAMFS_SOURCE has a cpio archive - verify that it's a single file
-ifneq (1,$(words $(quotefixed_initramfs_source)))
-$(error Only a single file may be specified in CONFIG_INITRAMFS_SOURCE (="$(quotefixed_initramfs_source)") when a cpio archive is directly specified.)
-endif
-# Now use the cpio archive directly
-initramfs_data_cpio = $(quotefixed_initramfs_source)
-targets += $(quotefixed_initramfs_source)
-
-else
-
-# INITRAMFS_SOURCE is not a cpio archive - create one
-$(obj)/initramfs_data.cpio: $(obj)/gen_init_cpio \
-                            $(initramfs-y) $(obj)/initramfs_list FORCE
-	$(call if_changed,cpio)
-
-targets += initramfs_data.cpio
-initramfs_data_cpio = $(obj)/initramfs_data.cpio
-
-endif
-
-
-$(obj)/initramfs_data.cpio.gz: $(initramfs_data_cpio) FORCE
-	$(call if_changed,gzip)
+# Create cpio archive from filelist
+hostprogs-y  := gen_init_cpio
 
-targets += initramfs_data.cpio.gz
+# Files included in cpio archive (cpio archive is updated if
+# any included files are newer than the cpio archive)
+initramfs     := $(CONFIG_SHELL) $(srctree)/$(src)/gen_initramfs.sh
+ramfs-input    = $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
+                      $(CONFIG_INITRAMFS_SOURCE),-d)
+ramfs-filelist = $(shell $(initramfs) -l $(ramfs-input))
+
+quiet_cmd_initfs = GEN     $@
+      cmd_initfs = \
+	$(initramfs) -o $@ \
+	$(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
+	$(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
+	$(ramfs-input)
+
+targets := initramfs_data.cpio.gz
+$(obj)/initramfs_data.cpio.gz: $(ramfs-filelist) $(obj)/gen_init_cpio FORCE
+	$(call if_changed,initfs)
 
diff --git a/usr/gen_initramfs.sh b/usr/gen_initramfs.sh
new file mode 100755
index 0000000..7749615
--- /dev/null
+++ b/usr/gen_initramfs.sh
@@ -0,0 +1,285 @@
+#!/bin/bash
+# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
+# Copyright (c) 2006           Sam Ravnborg <sam@ravnborg.org>
+#
+# Released under the terms of the GNU GPL
+#
+# Generate a cpio packed initramfs. It uses gen_init_cpio to generate
+# the cpio archive, and gzip to pack it.
+# The script may also be sued to generate the inputfile used for gen_init_cpio
+# This script assumes that gen_init_cpio is located in same directory
+# as the script
+
+# error out on errors
+set -e
+
+usage() {
+cat << EOF
+Usage:
+$0 -l {-d | <cpio_source>} ...
+$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
+	-l             List all files/dirs that will be added to initramfs
+	-o <file>      Create gzipped initramfs file named <file> using
+	               gen_init_cpio and gzip
+	-u <uid>       User ID to map to user ID 0 (root).
+	               <uid> is only meaningful if <cpio_source>
+	               is a directory.
+	-g <gid>       Group ID to map to group ID 0 (root).
+	               <gid> is only meaningful if <cpio_source>
+	               is a directory.
+	<cpio_source>  File list or directory for cpio archive.
+	               If <cpio_source> is a .cpio file it will be used
+		       as direct input to initramfs.
+	-d             Output the default cpio list.
+
+All options except -o and -l may be repeated and are interpreted
+sequentially and immediately.  -u and -g states are preserved across
+<cpio_source> options so an explicit "-u 0 -g 0" is required
+to reset the root/group mapping.
+EOF
+}
+
+list_default_initramfs() {
+	# echo usr/kinit/kinit
+	:
+}
+
+default_initramfs() {
+	cat <<-EOF >> ${output}
+		# This is a very simple, default initramfs
+
+		dir /dev 0755 0 0
+		nod /dev/console 0600 0 0 c 5 1
+		dir /root 0700 0 0
+		# file /kinit usr/kinit/kinit 0755 0 0
+		# slink /init kinit 0755 0 0
+	EOF
+}
+
+filetype() {
+	local argv1="$1"
+
+	# symlink test must come before file test
+	if [ -L "${argv1}" ]; then
+		echo "slink"
+	elif [ -f "${argv1}" ]; then
+		echo "file"
+	elif [ -d "${argv1}" ]; then
+		echo "dir"
+	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
+		echo "nod"
+	elif [ -p "${argv1}" ]; then
+		echo "pipe"
+	elif [ -S "${argv1}" ]; then
+		echo "sock"
+	else
+		echo "invalid"
+	fi
+	return 0
+}
+
+list_print_mtime() {
+	:
+}
+
+print_mtime() {
+	local my_mtime="0"
+
+	if [ -e "$1" ]; then
+		my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
+	fi
+
+	echo "# Last modified: ${my_mtime}" >> ${output}
+	echo "" >> ${output}
+}
+
+list_parse() {
+	echo "$1"
+}
+
+# for each file print a line in following format
+# <filetype> <name> <path to file> <octal mode> <uid> <gid>
+# for links, devices etc the format differs. See gen_init_cpio for details
+parse() {
+	local location="$1"
+	local name="${location/${srcdir}//}"
+	# change '//' into '/'
+	name="${name//\/\///}"
+	local mode="$2"
+	local uid="$3"
+	local gid="$4"
+	local ftype=$(filetype "${location}")
+	# remap uid/gid to 0 if necessary
+	[ "$uid" -eq "$root_uid" ] && uid=0
+	[ "$gid" -eq "$root_gid" ] && gid=0
+	local str="${mode} ${uid} ${gid}"
+
+	[ "${ftype}" == "invalid" ] && return 0
+	[ "${location}" == "${srcdir}" ] && return 0
+
+	case "${ftype}" in
+		"file")
+			str="${ftype} ${name} ${location} ${str}"
+			;;
+		"nod")
+			local dev_type=
+			local maj=$(LC_ALL=C ls -l "${location}" | \
+					gawk '{sub(/,/, "", $5); print $5}')
+			local min=$(LC_ALL=C ls -l "${location}" | \
+					gawk '{print $6}')
+
+			if [ -b "${location}" ]; then
+				dev_type="b"
+			else
+				dev_type="c"
+			fi
+			str="${ftype} ${name} ${str} ${dev_type} ${maj} ${min}"
+			;;
+		"slink")
+			local target=$(LC_ALL=C ls -l "${location}" | \
+					gawk '{print $11}')
+			str="${ftype} ${name} ${target} ${str}"
+			;;
+		*)
+			str="${ftype} ${name} ${str}"
+			;;
+	esac
+
+	echo "${str}" >> ${output}
+
+	return 0
+}
+
+unknown_option() {
+	printf "ERROR: unknown option \"$arg\"\n" >&2
+	printf "If the filename validly begins with '-', " >&2
+	printf "then it must be prefixed\n" >&2
+	printf "by './' so that it won't be interpreted as an option." >&2
+	printf "\n" >&2
+	usage >&2
+	exit 1
+}
+
+list_header() {
+	:
+}
+
+header() {
+	printf "\n#####################\n# $1\n" >> ${output}
+}
+
+# process one directory (incl sub-directories)
+dir_filelist() {
+	${file_list}header "$1"
+
+	srcdir=$(echo "$1" | sed -e 's://*:/:g')
+	dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" 2>/dev/null)
+
+	# If $dirlist is only one line, then the directory is empty
+	if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
+		${file_list}print_mtime "$1"
+
+		echo "${dirlist}" | \
+		while read x; do
+			${file_list}parse ${x}
+		done
+	fi
+}
+
+# if only one file is specified and it is .cpio file then use it direct as fs
+# if a directory is specified then add all files in given direcotry to fs
+# if a regular file is specified assume it is in gen_initramfs format
+input_file() {
+	source="$1"
+	if [ -f "$1" ]; then
+		is_cpio="$(echo "$1" | sed 's/^.*\.cpio/cpio/')"
+		if [ $2 -eq 0 -a ${is_cpio} == "cpio" ]; then
+			cpio_file=$1
+			[ ! -z ${list_file} ] && echo "$1"
+			return 0
+		fi
+		if [ -z ${file_list} ]; then
+			header "$1"
+			print_mtime "$1" >> ${output}
+			cat "$1"         >> ${output}
+		else
+			grep ^file "$1" | cut -d ' ' -f 3
+		fi
+	elif [ -d "$1" ]; then
+		dir_filelist "$1"
+	else
+		echo "  ${prog}: Cannot open '$1'" >&2
+		exit 1
+	fi
+}
+
+prog=$0
+root_uid=0
+root_gid=0
+file_list=
+cpio_file=
+cpio_list=
+output="/dev/stdout"
+output_file=""
+
+arg="$1"
+case "$arg" in
+	"-l")	# list contained files only
+		file_list="list_"
+		shift
+		;;
+	"-o")	# generate gzipped cpio image named $1
+		shift
+		output_file="$1"
+		cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
+		output=${cpio_list}
+		shift
+		;;
+esac
+while [ $# -gt 0 ]; do
+	arg="$1"
+	shift
+	case "$arg" in
+		"-u")	# map $1 to uid=0 (root)
+			root_uid="$1"
+			shift
+			;;
+		"-g")	# map $1 to gid=0 (root)
+			root_gid="$1"
+			shift
+			;;
+		"-d")	# display default initramfs list
+			default_list="$arg"
+			${file_list}default_initramfs
+			;;
+		"-h")
+			usage
+			exit 0
+			;;
+		*)
+			case "$arg" in
+				"-"*)
+					unknown_option
+					;;
+				*)	# input file/dir - process it
+					input_file "$arg" "$#"
+					;;
+			esac
+			;;
+	esac
+done
+
+# If output_file is set we will generate cpio archive and gzip it
+# we are carefull to delete tmp files
+if [ ! -z ${output_file} ]; then
+	if [ -z ${cpio_file} ]; then
+		cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
+		$(dirname ${prog})/gen_init_cpio ${cpio_list} > ${cpio_tfile}
+	else
+		cpio_tfile=${cpio_file}
+	fi
+	rm ${cpio_list}
+	cat ${cpio_tfile} | gzip -f -9 - > ${output_file}
+	[ -z ${cpio_file} ] && rm ${cpio_tfile}
+fi
+exit 0
diff --git a/scripts/gen_initramfs_list.sh b/scripts/gen_initramfs_list.sh
deleted file mode 100644
index 6d41116..0000000
--- a/scripts/gen_initramfs_list.sh
+++ /dev/null
@@ -1,203 +0,0 @@
-#!/bin/bash
-# Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
-# Released under the terms of the GNU GPL
-#
-# Generate a newline separated list of entries from the file/directory
-# supplied as an argument.
-#
-# If a file/directory is not supplied then generate a small dummy file.
-#
-# The output is suitable for gen_init_cpio built from usr/gen_init_cpio.c.
-#
-
-default_initramfs() {
-	cat <<-EOF
-		# This is a very simple, default initramfs
-
-		dir /dev 0755 0 0
-		nod /dev/console 0600 0 0 c 5 1
-		dir /root 0700 0 0
-	EOF
-}
-
-filetype() {
-	local argv1="$1"
-
-	# symlink test must come before file test
-	if [ -L "${argv1}" ]; then
-		echo "slink"
-	elif [ -f "${argv1}" ]; then
-		echo "file"
-	elif [ -d "${argv1}" ]; then
-		echo "dir"
-	elif [ -b "${argv1}" -o -c "${argv1}" ]; then
-		echo "nod"
-	elif [ -p "${argv1}" ]; then
-		echo "pipe"
-	elif [ -S "${argv1}" ]; then
-		echo "sock"
-	else
-		echo "invalid"
-	fi
-	return 0
-}
-
-print_mtime() {
-	local argv1="$1"
-	local my_mtime="0"
-
-	if [ -e "${argv1}" ]; then
-		my_mtime=$(find "${argv1}" -printf "%T@\n" | sort -r | head -n 1)
-	fi
-	
-	echo "# Last modified: ${my_mtime}"
-	echo
-}
-
-parse() {
-	local location="$1"
-	local name="${location/${srcdir}//}"
-	# change '//' into '/'
-	name="${name//\/\///}"
-	local mode="$2"
-	local uid="$3"
-	local gid="$4"
-	local ftype=$(filetype "${location}")
-	# remap uid/gid to 0 if necessary
-	[ "$uid" -eq "$root_uid" ] && uid=0
-	[ "$gid" -eq "$root_gid" ] && gid=0
-	local str="${mode} ${uid} ${gid}"
-
-	[ "${ftype}" == "invalid" ] && return 0
-	[ "${location}" == "${srcdir}" ] && return 0
-
-	case "${ftype}" in
-		"file")
-			str="${ftype} ${name} ${location} ${str}"
-			;;
-		"nod")
-			local dev_type=
-			local maj=$(LC_ALL=C ls -l "${location}" | \
-					gawk '{sub(/,/, "", $5); print $5}')
-			local min=$(LC_ALL=C ls -l "${location}" | \
-					gawk '{print $6}')
-
-			if [ -b "${location}" ]; then
-				dev_type="b"
-			else
-				dev_type="c"
-			fi
-			str="${ftype} ${name} ${str} ${dev_type} ${maj} ${min}"
-			;;
-		"slink")
-			local target=$(LC_ALL=C ls -l "${location}" | \
-					gawk '{print $11}')
-			str="${ftype} ${name} ${target} ${str}"
-			;;
-		*)
-			str="${ftype} ${name} ${str}"
-			;;
-	esac
-
-	echo "${str}"
-
-	return 0
-}
-
-usage() {
-	printf    "Usage:\n"
-	printf    "$0 [ [-u <root_uid>] [-g <root_gid>] [-d | <cpio_source>] ] . . .\n"
-	printf    "\n"
-	printf -- "-u <root_uid>  User ID to map to user ID 0 (root).\n"
-	printf    "               <root_uid> is only meaningful if <cpio_source>\n"
-	printf    "               is a directory.\n"
-	printf -- "-g <root_gid>  Group ID to map to group ID 0 (root).\n"
-	printf    "               <root_gid> is only meaningful if <cpio_source>\n"
-	printf    "               is a directory.\n"
-	printf    "<cpio_source>  File list or directory for cpio archive.\n"
-	printf    "               If <cpio_source> is not provided then a\n"
-	printf    "               a default list will be output.\n"
-	printf -- "-d             Output the default cpio list.  If no <cpio_source>\n"
-	printf    "               is given then the default cpio list will be output.\n"
-	printf    "\n"
-	printf    "All options may be repeated and are interpreted sequentially\n"
-	printf    "and immediately.  -u and -g states are preserved across\n"
-	printf    "<cpio_source> options so an explicit \"-u 0 -g 0\" is required\n"
-	printf    "to reset the root/group mapping.\n"
-}
-
-build_list() {
-	printf "\n#####################\n# $cpio_source\n"
-
-	if [ -f "$cpio_source" ]; then
-		print_mtime "$cpio_source"
-		cat "$cpio_source"
-	elif [ -d "$cpio_source" ]; then
-		srcdir=$(echo "$cpio_source" | sed -e 's://*:/:g')
-		dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n" 2>/dev/null)
-
-		# If $dirlist is only one line, then the directory is empty
-		if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
-			print_mtime "$cpio_source"
-		
-			echo "${dirlist}" | \
-			while read x; do
-				parse ${x}
-			done
-		else
-			# Failsafe in case directory is empty
-			default_initramfs
-		fi
-	else
-		echo "  $0: Cannot open '$cpio_source'" >&2
-		exit 1
-	fi
-}
-
-
-root_uid=0
-root_gid=0
-
-while [ $# -gt 0 ]; do
-	arg="$1"
-	shift
-	case "$arg" in
-		"-u")
-			root_uid="$1"
-			shift
-			;;
-		"-g")
-			root_gid="$1"
-			shift
-			;;
-		"-d")
-			default_list="$arg"
-			default_initramfs
-			;;
-		"-h")
-			usage
-			exit 0
-			;;
-		*)
-			case "$arg" in
-				"-"*)
-					printf "ERROR: unknown option \"$arg\"\n" >&2
-					printf "If the filename validly begins with '-', then it must be prefixed\n" >&2
-					printf "by './' so that it won't be interpreted as an option." >&2
-					printf "\n" >&2
-					usage >&2
-					exit 1
-					;;
-				*)
-					cpio_source="$arg"
-					build_list
-					;;
-			esac
-			;;
-	esac
-done
-
-# spit out the default cpio list if a source hasn't been specified
-[ -z "$cpio_source" -a -z "$default_list" ] && default_initramfs
-
-exit 0