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SubjectRe: [klibc] [PATCH] kbuild: rebuild initramfs if included files changes
On Tue, Apr 11, 2006 at 12:32:09AM +0200, Sam Ravnborg wrote:
> On Sun, Apr 09, 2006 at 10:59:20PM +0200, Sam Ravnborg wrote:
> > 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.
>
> This patch turned out to be bogus.
> I have something new in the works - will be finished tomorrow.
And here it goes.

scripts/gen_initramfs_list.sh | 225 ++++++++++++++++++++++++++++--------------
usr/Makefile | 91 ++++++----------
2 files changed, 189 insertions(+), 127 deletions(-)
diff-tree d39a206bc35d46a3b2eb98cd4f34e340d5e56a50 (from d9df92e22aca939857c5bc9ecb130ef22307ccc1)
Author: Sam Ravnborg <sam@mars.ravnborg.org>
Date: Tue Apr 11 13:24:32 2006 +0200
kbuild: rebuild initramfs if content of initramfs 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:
- 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/scripts/gen_initramfs_list.sh b/scripts/gen_initramfs_list.sh
index 6d41116..56b3bed 100644
--- a/scripts/gen_initramfs_list.sh
+++ b/scripts/gen_initramfs_list.sh
@@ -1,22 +1,55 @@
#!/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.
+# Copyright (c) 2006 Sam Ravnborg <sam@ravnborg.org>
#
-# The output is suitable for gen_init_cpio built from usr/gen_init_cpio.c.
+# 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 used to generate the inputfile used for gen_init_cpio
+# This script assumes that gen_init_cpio is located in usr/ directory
+
+# error out on errors
+set -e
+
+usage() {
+cat << EOF
+Usage:
+$0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
+ -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
+ 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
}

@@ -40,20 +73,30 @@ filetype() {
echo "invalid"
fi
return 0
+}
+
+list_print_mtime() {
+ :
}

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)
+ if [ -e "$1" ]; then
+ my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
fi
-
- echo "# Last modified: ${my_mtime}"
- echo
+
+ 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}//}"
@@ -99,80 +142,112 @@ parse() {
;;
esac

- echo "${str}"
+ echo "${str}" >> ${output}

return 0
}

-usage() {
- printf "Usage:\n"
- printf "$0 [ [-u <root_uid>] [-g <root_gid>] [-d | <cpio_source>] ] . . .\n"
- printf "\n"
- printf -- "-u <root_uid> User ID to map to user ID 0 (root).\n"
- printf " <root_uid> is only meaningful if <cpio_source>\n"
- printf " is a directory.\n"
- printf -- "-g <root_gid> Group ID to map to group ID 0 (root).\n"
- printf " <root_gid> is only meaningful if <cpio_source>\n"
- printf " is a directory.\n"
- printf "<cpio_source> File list or directory for cpio archive.\n"
- printf " If <cpio_source> is not provided then a\n"
- printf " a default list will be output.\n"
- printf -- "-d Output the default cpio list. If no <cpio_source>\n"
- printf " is given then the default cpio list will be output.\n"
- printf "\n"
- printf "All options may be repeated and are interpreted sequentially\n"
- printf "and immediately. -u and -g states are preserved across\n"
- printf "<cpio_source> options so an explicit \"-u 0 -g 0\" is required\n"
- printf "to reset the root/group mapping.\n"
+unknown_option() {
+ printf "ERROR: unknown option \"$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() {
+ echo "deps_initramfs := \\"
+}
+
+header() {
+ printf "\n#####################\n# $1\n" >> ${output}
+}
+
+# process one directory (incl sub-directories)
+dir_filelist() {
+ ${dep_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
+ ${dep_list}print_mtime "$1"
+
+ echo "${dirlist}" | \
+ while read x; do
+ ${dep_list}parse ${x}
+ done
+ fi
}

-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
+# 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
+ ${dep_list}header "$1"
+ is_cpio="$(echo "$1" | sed 's/^.*\.cpio/cpio/')"
+ if [ $2 -eq 0 -a ${is_cpio} == "cpio" ]; then
+ cpio_file=$1
+ [ ! -z ${dep_list} ] && echo "$1"
+ return 0
+ fi
+ if [ -z ${dep_list} ]; then
+ print_mtime "$1" >> ${output}
+ cat "$1" >> ${output}
else
- # Failsafe in case directory is empty
- default_initramfs
+ grep ^file "$1" | cut -d ' ' -f 3
fi
+ elif [ -d "$1" ]; then
+ dir_filelist "$1"
else
- echo " $0: Cannot open '$cpio_source'" >&2
+ echo " ${prog}: Cannot open '$1'" >&2
exit 1
fi
}

-
+prog=$0
root_uid=0
root_gid=0
+dep_list=
+cpio_file=
+cpio_list=
+output="/dev/stdout"
+output_file=""

+arg="$1"
+case "$arg" in
+ "-l") # files included in initramfs - used by kbuild
+ dep_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")
+ "-u") # map $1 to uid=0 (root)
root_uid="$1"
shift
;;
- "-g")
+ "-g") # map $1 to gid=0 (root)
root_gid="$1"
shift
;;
- "-d")
+ "-d") # display default initramfs list
default_list="$arg"
- default_initramfs
+ ${dep_list}default_initramfs
;;
"-h")
usage
@@ -181,23 +256,27 @@ while [ $# -gt 0 ]; do
*)
case "$arg" in
"-"*)
- printf "ERROR: unknown option \"$arg\"\n" >&2
- printf "If the filename validly begins with '-', then it must be prefixed\n" >&2
- printf "by './' so that it won't be interpreted as an option." >&2
- printf "\n" >&2
- usage >&2
- exit 1
+ unknown_option
;;
- *)
- cpio_source="$arg"
- build_list
+ *) # input file/dir - process it
+ input_file "$arg" "$#"
;;
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

+# 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)"
+ usr/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/usr/Makefile b/usr/Makefile
index e2129cb..19d74e6 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -1,65 +1,48 @@
+#
+# kbuild file for usr/ - including initramfs image
+#

-obj-y := initramfs_data.o
-
-hostprogs-y := gen_init_cpio
+klibcdirs:;

-clean-files := initramfs_data.cpio.gz initramfs_list
+# Generate builtin.o based on initramfs_data.o
+obj-y := initramfs_data.o

# 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 > $@
-
-
-# Check if the INITRAMFS_SOURCE is a cpio archive
-ifneq (,$(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
-
+#####
+# Generate the initramfs cpio archive
+
+hostprogs-y := gen_init_cpio
+initramfs := $(CONFIG_SHELL) $(srctree)/scripts/gen_initramfs_list.sh
+ramfs-input := $(if $(filter-out "",$(CONFIG_INITRAMFS_SOURCE)), \
+ $(CONFIG_INITRAMFS_SOURCE),-d)
+ramfs-args := \
+ $(if $(CONFIG_INITRAMFS_ROOT_UID), -u $(CONFIG_INITRAMFS_ROOT_UID)) \
+ $(if $(CONFIG_INITRAMFS_ROOT_GID), -g $(CONFIG_INITRAMFS_ROOT_GID)) \
+ $(ramfs-input)
+
+# .initramfs_data.cpio.gz.d is used to identify all files included
+# in initramfs and to detect if any files are added/removed.
+# Removed files are identified by directory timestamp being updated
+# The dependency list is generated by gen_initramfs.sh -l
+ifneq ($(wildcard $(obj)/.initramfs_data.cpio.gz.d),)
+ include $(obj)/.initramfs_data.cpio.gz.d
endif
-
-
-$(obj)/initramfs_data.cpio.gz: $(initramfs_data_cpio) FORCE
- $(call if_changed,gzip)

-targets += initramfs_data.cpio.gz
+quiet_cmd_initfs = GEN $@
+ cmd_initfs = $(initramfs) -o $@ $(ramfs-args) $(ramfs-input)
+
+targets := initramfs_data.cpio.gz
+$(deps_initramfs): klibcdirs
+# We rebuild initramfs_data.cpio.gz if:
+# 1) Any included file is newer then initramfs_data.cpio.gz
+# 2) There are changes in which files are included (added or deleted)
+# 3) If gen_init_cpio are newer than initramfs_data.cpio.gz
+# 4) arguments to gen_initramfs.sh changes
+$(obj)/initramfs_data.cpio.gz: $(obj)/gen_init_cpio $(deps_initramfs) klibcdirs
+ $(Q)$(initramfs) -l $(ramfs-input) > $(obj)/.initramfs_data.cpio.gz.d
+ $(call if_changed,initfs)

-
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