[PATCH] kbuild: rebuild initramfs if included files changes

From: Sam Ravnborg
Date: Sun Apr 09 2006 - 17:06:48 EST


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@xxxxxxxxxxxxxxxxx>
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@xxxxxxxxxxxx>

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@xxxxxxxxxxxxxxxx>
+# Copyright (c) 2006 Sam Ravnborg <sam@xxxxxxxxxxxx>
+#
+# 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@xxxxxxxxxxxxxxxx>
-# 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

-
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