[PATCH 0/6] Readonly rootfs support

[PATCH 0/6] Readonly rootfs support

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

Use union mount to support read-only rootfs.

The following changes since commit b2869b6810728a5f003ddad335fd7f6512181a57:

  ref-manual: Added a general reference and link to kernel-dev (2013-01-27 13:56:06 +0000)

are available in the git repository at:

  git://git.pokylinux.org/poky-contrib ChenQi/readonly-rootfs-unionfs
  http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=ChenQi/readonly-rootfs-unionfs

Chen Qi (6):
  sysvinit: add ROOTFS_READ_ONLY variable to rcS-default
  image.bbclass: add a hook funtion to support readonly rootfs
  core-image.bbclass: support read-only rootfs
  populate-volatile.sh: improve this script
  initscripts: let populate-volatile.sh create the /tmp link
  initscripts: add read-only-rootfs-hook.sh script

 meta/classes/core-image.bbclass                    |    4 +
 meta/classes/image.bbclass                         |   18 ++
 .../initscripts/initscripts-1.0/bootmisc.sh        |    9 +-
 .../initscripts-1.0/populate-volatile.sh           |  287 ++++++++++----------
 .../initscripts-1.0/read-only-rootfs-hook.sh       |   19 ++
 .../initscripts/initscripts-1.0/volatiles          |    1 +
 meta/recipes-core/initscripts/initscripts_1.0.bb   |    3 +
 meta/recipes-core/sysvinit/sysvinit/rcS-default    |    4 +
 meta/recipes-core/sysvinit/sysvinit_2.88dsf.bb     |    2 +-
 9 files changed, 194 insertions(+), 153 deletions(-)
 create mode 100644 meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh

-- 
1.7.9.5

[PATCH 1/6] sysvinit: add ROOTFS_READ_ONLY variable to rcS-default

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

This variable indicates whether the rootfs is intended to be read-only
or not. Changing this value from 'no' to 'yes' on a currently running
system with read-write rootfs and rebooting will give the user a working
system with read-only rootfs.

However, it is not suggested to change its value. Normally, if a read-only
rootfs is required, we should build an image with 'read-only-rootfs' image
feature.

[YOCTO #3406]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/recipes-core/sysvinit/sysvinit/rcS-default |    4 ++++
 meta/recipes-core/sysvinit/sysvinit_2.88dsf.bb  |    2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/meta/recipes-core/sysvinit/sysvinit/rcS-default b/meta/recipes-core/sysvinit/sysvinit/rcS-default
index 3c9dea9..709cdf6 100644
--- a/meta/recipes-core/sysvinit/sysvinit/rcS-default
+++ b/meta/recipes-core/sysvinit/sysvinit/rcS-default
@@ -23,3 +23,7 @@ FSCKFIX=yes
 #TICKADJ=10000
 # Enable caching in populate-volatile.sh
 VOLATILE_ENABLE_CACHE=yes
+# Indicate whether the rootfs is intended to be read-only or not.
+# Setting ROOTFS_READ_ONLY to yes and rebooting will give you a read-only rootfs.
+# Normally you should not change this value.
+ROOTFS_READ_ONLY=no
diff --git a/meta/recipes-core/sysvinit/sysvinit_2.88dsf.bb b/meta/recipes-core/sysvinit/sysvinit_2.88dsf.bb
index de073b8..bf6a29b 100644
--- a/meta/recipes-core/sysvinit/sysvinit_2.88dsf.bb
+++ b/meta/recipes-core/sysvinit/sysvinit_2.88dsf.bb
@@ -5,7 +5,7 @@ SECTION = "base"
 LICENSE = "GPLv2+"
 LIC_FILES_CHKSUM = "file://COPYING;md5=751419260aa954499f7abaabaa882bbe \
                     file://COPYRIGHT;endline=15;md5=349c872e0066155e1818b786938876a4"
-PR = "r9"
+PR = "r10"
 
 RDEPENDS_${PN} = "${PN}-inittab"
 
-- 
1.7.9.5

[PATCH 2/6] image.bbclass: add a hook funtion to support readonly rootfs

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

read_only_rootfs_hook: this funtion is invoked only if 'read-only-rootfs'
is in IMAGE_FEATURES. It tweaks some basic files and makes populate-
volatile.sh script run at rootfs time.

For now, it has real effect only if the init system is sysvinit.

[YOCTO #3406]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/classes/image.bbclass |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 9b4dec8..9c51bf6 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -201,6 +201,24 @@ run_intercept_scriptlets () {
 	fi
 }
 
+# A hook function to support read-only-rootfs IMAGE_FEATURES
+# Currently, it only supports sysvinit system.
+read_only_rootfs_hook () {
+	if ${@base_contains("DISTRO_FEATURES", "sysvinit", "true", "false", d)}; then
+	        # Tweak the mount option in fstab
+		sed -i '/rootfs/ s/defaults/ro/' ${IMAGE_ROOTFS}/etc/fstab
+	        # Change the value of ROOTFS_READ_ONLY in /etc/default/rcS to yes
+		if [ -e ${IMAGE_ROOTFS}/etc/default/rcS ]; then
+			sed -i 's/ROOTFS_READ_ONLY=no/ROOTFS_READ_ONLY=yes/' ${IMAGE_ROOTFS}/etc/default/rcS
+		fi
+	        # Run populate-volatile.sh at rootfs time to set up basic files
+	        # and directories to support read-only rootfs.
+		if [ -e ${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh ]; then
+			${IMAGE_ROOTFS}/etc/init.d/populate-volatile.sh
+		fi
+	fi
+}
+
 fakeroot do_rootfs () {
 	#set -x
 	# When use the rpm incremental image generation, don't remove the rootfs
-- 
1.7.9.5

[PATCH 3/6] core-image.bbclass: support read-only rootfs

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

The hook function is appended to ROOTFS_POSTPROCESS_COMMAND
properly to support the 'read-only-rootfs' image feature.

[YOCTO #3406]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/classes/core-image.bbclass |    4 ++++
 1 file changed, 4 insertions(+)

diff --git a/meta/classes/core-image.bbclass b/meta/classes/core-image.bbclass
index 657d5f2..4c70d32 100644
--- a/meta/classes/core-image.bbclass
+++ b/meta/classes/core-image.bbclass
@@ -29,6 +29,7 @@ LIC_FILES_CHKSUM = "file://${COREBASE}/LICENSE;md5=3f40d7994397109285ec7b81fdeb3
 # - dev-pkgs            - development packages (headers, etc.) for all installed packages in the rootfs
 # - dbg-pkgs            - debug symbol packages for all installed packages in the rootfs
 # - doc-pkgs            - documentation packages for all installed packages in the rootfs
+# - read-only-rootfs    - tweaks an image to support read-only rootfs
 #
 PACKAGE_GROUP_x11 = "packagegroup-core-x11"
 PACKAGE_GROUP_x11-base = "packagegroup-core-x11-base"
@@ -80,3 +81,6 @@ ROOTFS_POSTPROCESS_COMMAND += "rootfs_update_timestamp ; "
 
 # Zap the root password if debug-tweaks feature is not enabled
 ROOTFS_POSTPROCESS_COMMAND += '${@base_contains("IMAGE_FEATURES", "debug-tweaks", "", "zap_root_password ; ",d)}'
+
+# Tweak the mount options for rootfs in /etc/fstab if read-only-rootfs is enabled
+ROOTFS_POSTPROCESS_COMMAND += '${@base_contains("IMAGE_FEATURES", "read-only-rootfs", "read_only_rootfs_hook; ", "",d)}'
-- 
1.7.9.5

[PATCH 4/6] populate-volatile.sh: improve this script

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

Here's a list of improvements:
1) Make it run correctly at rootfs time.
2) Handle link config items more reasonably.
3) Support read-only rootfs.
4) Avoid data loss when removing directories.

[YOCTO #3406]
[YOCTO #3404]
[YOCTO #3181]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 .../initscripts-1.0/populate-volatile.sh           |  287 ++++++++++----------
 1 file changed, 143 insertions(+), 144 deletions(-)

diff --git a/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh b/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh
index d2175d7..61ef6c9 100755
--- a/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh
+++ b/meta/recipes-core/initscripts/initscripts-1.0/populate-volatile.sh
@@ -8,192 +8,191 @@
 # Short-Description:  Populate the volatile filesystem
 ### END INIT INFO
 
-. /etc/default/rcS
-
-CFGDIR="/etc/default/volatiles"
-TMPROOT="/var/tmp"
+# Get ROOT_DIR
+DIRNAME=`dirname $0`
+ROOT_DIR=`echo $DIRNAME | sed -ne 's:etc/.*::p'`
+
+. ${ROOT_DIR}/etc/default/rcS
+# When running populat-volatile.sh at rootfs time, disable cache.
+[ "$ROOT_DIR" != "/" ] && VOLATILE_ENABLE_CACHE=no
+# If rootfs is read-only, disable cache.
+[ "$ROOTFS_READ_ONLY" = "yes" ] && VOLATILE_ENABLE_CACHE=no
+# All above statements will be moved to a central place, say var.sh which
+# encapsulates '. /etc/default/rcS'.
+
+CFGDIR="${ROOT_DIR}/etc/default/volatiles"
+TMPROOT="${ROOT_DIR}/var/volatile/tmp"
 COREDEF="00_core"
+READONLY_MATCH="readonly-"
 
-[ "${VERBOSE}" != "no" ] && echo "Populating volatile Filesystems."
+[ "${VERBOSE}" != "no" ] && echo "Setting up basic files related to volatile storage under ${ROOT_DIR}."
 
 create_file() {
-	EXEC=" 
-	touch \"$1\"; 
-	chown ${TUSER}.${TGROUP} $1 || echo \"Failed to set owner -${TUSER}- for -$1-.\" >/dev/tty0 2>&1; 
-	chmod ${TMODE} $1 || echo \"Failed to set mode -${TMODE}- for -$1-.\" >/dev/tty0 2>&1 " 
+	EXEC="
+	touch \"$1\";
+	chown ${TUSER}.${TGROUP} $1 || echo \"Failed to set owner -${TUSER}- for -$1-.\" > /dev/null 2>&1;
+	chmod ${TMODE} $1 || echo \"Failed to set mode -${TMODE}- for -$1-.\" > /dev/null 2>&1 "
 
 	test "$VOLATILE_ENABLE_CACHE" = yes && echo "$EXEC" >> /etc/volatile.cache.build
 
 	[ -e "$1" ] && {
-	  [ "${VERBOSE}" != "no" ] && echo "Target already exists. Skipping."
+		[ "${VERBOSE}" != "no" ] && echo "Target $1 already exists. Skipping."
 	} || {
-	  eval $EXEC &
+		if [ "$ROOT_DIR" = "/" ]; then
+			eval $EXEC
+		else
+			# Some operations at rootfs time may fail and should fail,
+		        # but these failures should not be logged.
+			eval $EXEC > /dev/null 2>&1
+		fi
 	}
 }
 
 mk_dir() {
-	EXEC=" 
-	mkdir -p \"$1\"; 
-	chown ${TUSER}.${TGROUP} $1 || echo \"Failed to set owner -${TUSER}- for -$1-.\" >/dev/tty0 2>&1; 
-	chmod ${TMODE} $1 || echo \"Failed to set mode -${TMODE}- for -$1-.\" >/dev/tty0 2>&1 "
+	EXEC="
+	mkdir -p \"$1\";
+	chown ${TUSER}.${TGROUP} $1 || echo \"Failed to set owner -${TUSER}- for -$1-.\" 2>&1; 
+	chmod ${TMODE} $1 || echo \"Failed to set mode -${TMODE}- for -$1-.\" 2>&1 "
 
 	test "$VOLATILE_ENABLE_CACHE" = yes && echo "$EXEC" >> /etc/volatile.cache.build
-	
 	[ -e "$1" ] && {
-	  [ "${VERBOSE}" != "no" ] && echo "Target already exists. Skipping."
+		[ "${VERBOSE}" != "no" ] && echo "Target ${1} already exists. Skipping."
 	} || {
-	  eval $EXEC
+		if [ "$ROOT_DIR" = "/" ]; then
+			eval $EXEC
+		else
+			# Some operations at rootfs time may fail and should fail,
+                        # but these failures should not be logged.
+			eval $EXEC > /dev/null 2>&1
+		fi
 	}
 }
 
 link_file() {
-	EXEC="test -e \"$2\" -o -L $2 || ln -s \"$1\" \"$2\" >/dev/tty0 2>&1" 
-
-	test "$VOLATILE_ENABLE_CACHE" = yes && echo "	$EXEC" >> /etc/volatile.cache.build
-	
-	[ -e "$2" ] && {
-	  echo "Cannot create link over existing -${TNAME}-." >&2
-	} || {
-	  eval $EXEC &
-	}
+	EXEC="
+	if [ -L \"$2\" ]; then
+		[ \"$(readlink -f \"$2\")\" != \"$(readlink -f \"$1\")\" ] && { rm -f \"$2\"; ln -sf \"$1\" \"$2\"; };
+	elif [ -d \"$2\" ]; then
+		for f in $2/* $2/.[^.]*; do [ -e $f ] && cp -rf $f $1; done;
+		rm -rf \"$2\";
+		ln -sf \"$1\" \"$2\";
+	else
+		ln -sf \"$1\" \"$2\";
+	fi
+        "
+        test "$VOLATILE_ENABLE_CACHE" = yes && echo "   $EXEC" >> /etc/volatile.cache.build
+	if [ "$ROOT_DIR" = "/" ]; then
+		eval $EXEC
+	else
+		# Some operations at rootfs time may fail and should fail,
+                # but these failures should not be logged
+		eval $EXEC > /dev/null 2>&1
+	fi
 }
 
 check_requirements() {
+	cleanup() {
+		rm "${TMP_INTERMED}"
+		rm "${TMP_DEFINED}"
+		rm "${TMP_COMBINED}"
+	}
+	
+	CFGFILE="$1"
+	[ `basename "${CFGFILE}"` = "${COREDEF}" ] && return 0
+	# read-only-rootfs specific conf files should only be applied when rootfs is read-only
+	case `basename "${CFGFILE}"` in
+		${READONLY_MATCH}*)
+		[ "$ROOTFS_READ_ONLY" = "yes" ] && return 0 || return 1
+		;;
+		*)
+		;;
+	esac
 
-  cleanup() {
-    rm "${TMP_INTERMED}"
-    rm "${TMP_DEFINED}"
-    rm "${TMP_COMBINED}"
-    }
-    
-  CFGFILE="$1"
-
-  [ `basename "${CFGFILE}"` = "${COREDEF}" ] && return 0
-
-  TMP_INTERMED="${TMPROOT}/tmp.$$"
-  TMP_DEFINED="${TMPROOT}/tmpdefined.$$"
-  TMP_COMBINED="${TMPROOT}/tmpcombined.$$"
-
-
-  cat /etc/passwd | sed 's@\(^:\)*:.*@\1@' | sort | uniq > "${TMP_DEFINED}"
-  cat ${CFGFILE} | grep -v "^#" | cut -d " " -f 2 > "${TMP_INTERMED}"
-  cat "${TMP_DEFINED}" "${TMP_INTERMED}" | sort | uniq > "${TMP_COMBINED}"
-
-  NR_DEFINED_USERS="`cat "${TMP_DEFINED}" | wc -l`"
-  NR_COMBINED_USERS="`cat "${TMP_COMBINED}" | wc -l`"
-
-  [ "${NR_DEFINED_USERS}" -ne "${NR_COMBINED_USERS}" ] && {
-    echo "Undefined users:"
-    diff "${TMP_DEFINED}" "${TMP_COMBINED}" | grep "^>"
-    cleanup
-    return 1
-    }
-
+	TMP_INTERMED="${TMPROOT}/tmp.$$"
+	TMP_DEFINED="${TMPROOT}/tmpdefined.$$"
+	TMP_COMBINED="${TMPROOT}/tmpcombined.$$"
+
+	cat ${ROOT_DIR}/etc/passwd | sed 's@\(^:\)*:.*@\1@' | sort | uniq > "${TMP_DEFINED}"
+	cat ${CFGFILE} | grep -v "^#" | cut -d " " -f 2 > "${TMP_INTERMED}"
+	cat "${TMP_DEFINED}" "${TMP_INTERMED}" | sort | uniq > "${TMP_COMBINED}"
+	NR_DEFINED_USERS="`cat "${TMP_DEFINED}" | wc -l`"
+	NR_COMBINED_USERS="`cat "${TMP_COMBINED}" | wc -l`"
+
+	[ "${NR_DEFINED_USERS}" -ne "${NR_COMBINED_USERS}" ] && {
+		echo "Undefined users:"
+		diff "${TMP_DEFINED}" "${TMP_COMBINED}" | grep "^>"
+		cleanup
+		return 1
+	}
 
-  cat /etc/group | sed 's@\(^:\)*:.*@\1@' | sort | uniq > "${TMP_DEFINED}"
-  cat ${CFGFILE} | grep -v "^#" | cut -d " " -f 3 > "${TMP_INTERMED}"
-  cat "${TMP_DEFINED}" "${TMP_INTERMED}" | sort | uniq > "${TMP_COMBINED}"
 
-  NR_DEFINED_GROUPS="`cat "${TMP_DEFINED}" | wc -l`"
-  NR_COMBINED_GROUPS="`cat "${TMP_COMBINED}" | wc -l`"
+	cat ${ROOT_DIR}/etc/group | sed 's@\(^:\)*:.*@\1@' | sort | uniq > "${TMP_DEFINED}"
+	cat ${CFGFILE} | grep -v "^#" | cut -d " " -f 3 > "${TMP_INTERMED}"
+	cat "${TMP_DEFINED}" "${TMP_INTERMED}" | sort | uniq > "${TMP_COMBINED}"
 
-  [ "${NR_DEFINED_GROUPS}" -ne "${NR_COMBINED_GROUPS}" ] && {
-    echo "Undefined groups:"
-    diff "${TMP_DEFINED}" "${TMP_COMBINED}" | grep "^>"
-    cleanup
-    return 1
-    }
+	NR_DEFINED_GROUPS="`cat "${TMP_DEFINED}" | wc -l`"
+	NR_COMBINED_GROUPS="`cat "${TMP_COMBINED}" | wc -l`"
 
-  # Add checks for required directories here
+	[ "${NR_DEFINED_GROUPS}" -ne "${NR_COMBINED_GROUPS}" ] && {
+		echo "Undefined groups:"
+		diff "${TMP_DEFINED}" "${TMP_COMBINED}" | grep "^>"
+		cleanup
+		return 1
+	}
 
-  cleanup
-  return 0
-  }
+	cleanup
+	return 0
+}
 
 apply_cfgfile() {
+	CFGFILE="$1"
+	[ ${VERBOSE} != "no" ] && echo "Applying config file: $CFGFILE"
+	
+	check_requirements "${CFGFILE}" || {
+		echo "Skipping ${CFGFILE}"
+		return 1
+	}
 
-  CFGFILE="$1"
-
-  check_requirements "${CFGFILE}" || {
-    echo "Skipping ${CFGFILE}"
-    return 1
-    }
-
-  cat ${CFGFILE} | grep -v "^#" | \
-  while read LINE; do
-
-    eval `echo "$LINE" | sed -n "s/\(.*\)\ \(.*\) \(.*\)\ \(.*\)\ \(.*\)\ \(.*\)/TTYPE=\1 ; TUSER=\2; TGROUP=\3; TMODE=\4; TNAME=\5 TLTARGET=\6/p"`
-
-    [ "${VERBOSE}" != "no" ] && echo "Checking for -${TNAME}-."
-
-
-    [ "${TTYPE}" = "l" ] && {
-      TSOURCE="$TLTARGET"
-      [ -L "${TNAME}" ] || {
-        [ "${VERBOSE}" != "no" ] && echo "Creating link -${TNAME}- pointing to -${TSOURCE}-."
-        link_file "${TSOURCE}" "${TNAME}" &
-        }
-      continue
-      }
-
-    [ -L "${TNAME}" ] && {
-      [ "${VERBOSE}" != "no" ] && echo "Found link."
-      NEWNAME=`ls -l "${TNAME}" | sed -e 's/^.*-> \(.*\)$/\1/'`
-      echo ${NEWNAME} | grep -v "^/" >/dev/null && {
-        TNAME="`echo ${TNAME} | sed -e 's@\(.*\)/.*@\1@'`/${NEWNAME}"
-        [ "${VERBOSE}" != "no" ] && echo "Converted relative linktarget to absolute path -${TNAME}-."
-        } || {
-        TNAME="${NEWNAME}"
-        [ "${VERBOSE}" != "no" ] && echo "Using absolute link target -${TNAME}-."
-        }
-      }
-
-    case "${TTYPE}" in
-      "f")  [ "${VERBOSE}" != "no" ] && echo "Creating file -${TNAME}-."
-            create_file "${TNAME}" &
-	    ;;
-      "d")  [ "${VERBOSE}" != "no" ] && echo "Creating directory -${TNAME}-."
-            mk_dir "${TNAME}"
-	    # Add check to see if there's an entry in fstab to mount.
-	    ;;
-      *)    [ "${VERBOSE}" != "no" ] && echo "Invalid type -${TTYPE}-."
-            continue
-	    ;;
-    esac
-
-
-    done
-
-  return 0
-
-  }
-
-clearcache=0
-exec 9</proc/cmdline
-while read line <&9
-do
-	case "$line" in
-		*clearcache*)  clearcache=1
-			       ;;
-		*)	       continue
-			       ;;
-	esac
-done
-exec 9>&-
+	cat ${CFGFILE} | grep -v "^#" | sed -e '/^$/ d' | \
+		while read LINE; do
+		eval `echo "$LINE" | sed -n "s/\(.*\)\ \(.*\) \(.*\)\ \(.*\)\ \(.*\)\ \(.*\)/TTYPE=\1 ; TUSER=\2; TGROUP=\3; TMODE=\4; TNAME=\5 TLTARGET=\6/p"`
+		TNAME=${ROOT_DIR}/${TNAME}
+		[ "${VERBOSE}" != "no" ] && echo "Checking for -${TNAME}-."
+
+		[ "${TTYPE}" = "l" ] && {
+			TSOURCE="$TLTARGET"
+			[ "${VERBOSE}" != "no" ] && echo "Creating link -${TNAME}- pointing to -${TSOURCE}-."
+			link_file "${TSOURCE}" "${TNAME}"
+			continue
+		}
+		case "${TTYPE}" in
+			"f")  [ "${VERBOSE}" != "no" ] && echo "Creating file -${TNAME}-."
+				create_file "${TNAME}"
+				;;
+			"d")  [ "${VERBOSE}" != "no" ] && echo "Creating directory -${TNAME}-."
+				mk_dir "${TNAME}"
+				;;
+			*)    [ "${VERBOSE}" != "no" ] && echo "Invalid type -${TTYPE}-."
+				continue
+				;;
+		esac
+	done
+	return 0
+}
 
-if test -e /etc/volatile.cache -a "$VOLATILE_ENABLE_CACHE" = "yes" -a "x$1" != "xupdate" -a "x$clearcache" = "x0"
+if test -e ${ROOT_DIR}/etc/volatile.cache -a $VOLATILE_ENABLE_CACHE = yes -a x$1 != xupdate
 then
-	sh /etc/volatile.cache
+	sh ${ROOT_DIR}/etc/volatile.cache
 else	
-	rm -f /etc/volatile.cache /etc/volatile.cache.build
+	rm -f ${ROOT_DRI}/etc/volatile.cache ${ROOT_DIR}/etc/volatile.cache.build
 	for file in `ls -1 "${CFGDIR}" | sort`; do
 		apply_cfgfile "${CFGDIR}/${file}"
 	done
 
-	[ -e /etc/volatile.cache.build ] && sync && mv /etc/volatile.cache.build /etc/volatile.cache
+	[ -e ${ROOT_DIR}/etc/volatile.cache.build ] && sync && mv ${ROOT_DIR}/etc/volatile.cache.build ${ROOT_DIR}/etc/volatile.cache
 fi
 
-if test -f /etc/ld.so.cache -a ! -f /var/run/ld.so.cache
+if [ "${ROOT_DIR}" = "/" ] && [ -f /etc/ld.so.cache ] && [ ! -f /var/run/ld.so.cache ]
 then
 	ln -s /etc/ld.so.cache /var/run/ld.so.cache
 fi
-- 
1.7.9.5

[PATCH 5/6] initscripts: let populate-volatile.sh create the /tmp link

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

Previously, the /tmp link (/tmp -> /var/tmp) was created by the
bootmisc.sh script. So in case of a read-only rootfs, this symlink
would not be created correctly.

The populate-volatile.sh script is intended to handle all directories
and files related to volatile storage, so we should let it create
the /tmp link.

In addition, because of the improments of populate-volatile.sh, the data
loss problem of bug#3404 is also resolved by this patch.

[YOCTO #3406]
[YOCTO #3404]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 .../initscripts/initscripts-1.0/bootmisc.sh        |    9 +--------
 .../initscripts/initscripts-1.0/volatiles          |    1 +
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/meta/recipes-core/initscripts/initscripts-1.0/bootmisc.sh b/meta/recipes-core/initscripts/initscripts-1.0/bootmisc.sh
index 4f76cb4..3b5a47f 100755
--- a/meta/recipes-core/initscripts/initscripts-1.0/bootmisc.sh
+++ b/meta/recipes-core/initscripts/initscripts-1.0/bootmisc.sh
@@ -54,14 +54,7 @@ fi
 
 #
 # This is as good a place as any for a sanity check
-# /tmp should be a symlink to /var/tmp to cut down on the number
-# of mounted ramdisks.
-if test ! -L /tmp && test -d /var/tmp
-then
-	rm -rf /tmp
-	ln -sf /var/tmp /tmp
-fi
-
+#
 # Set the system clock from hardware clock
 # If the timestamp is more recent than the current time,
 # use the timestamp instead.
diff --git a/meta/recipes-core/initscripts/initscripts-1.0/volatiles b/meta/recipes-core/initscripts/initscripts-1.0/volatiles
index e0741aa..f7e2ef7 100644
--- a/meta/recipes-core/initscripts/initscripts-1.0/volatiles
+++ b/meta/recipes-core/initscripts/initscripts-1.0/volatiles
@@ -31,6 +31,7 @@ l root root 1777 /var/lock /var/volatile/lock
 l root root 0755 /var/log /var/volatile/log
 l root root 0755 /var/run /var/volatile/run
 l root root 1777 /var/tmp /var/volatile/tmp
+l root root 1777 /tmp /var/tmp
 d root root 0755 /var/lock/subsys none
 f root root 0664 /var/log/wtmp none
 f root root 0664 /var/run/utmp none
-- 
1.7.9.5

[PATCH 6/6] initscripts: add read-only-rootfs-hook.sh script

[Qi.Chen]

From: Chen Qi <Qi.Chen@windriver.com>

Add read-only-rootfs-hook.sh script to support a read-only rootfs.
This script makes a union mount of /var/lib and /var/volatile/lib,
making /var/lib directory writable.

[YOCTO #3406]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 .../initscripts-1.0/read-only-rootfs-hook.sh       |   19 +++++++++++++++++++
 meta/recipes-core/initscripts/initscripts_1.0.bb   |    3 +++
 2 files changed, 22 insertions(+)
 create mode 100644 meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh

diff --git a/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh b/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh
new file mode 100644
index 0000000..3a295ee
--- /dev/null
+++ b/meta/recipes-core/initscripts/initscripts-1.0/read-only-rootfs-hook.sh
@@ -0,0 +1,19 @@
+#!/bin/sh
+
+. /etc/default/rcS
+
+[ "$ROOTFS_READ_ONLY" = "no" ] && exit 0
+
+# Make sure unionfs is in /proc/filesystems
+if ! grep -q unionfs /proc/filesystems; then
+    echo "ERROR: unionfs not supported by kernel!"
+    exit 1
+fi
+
+mkdir -p /var/volatile/lib
+mount -t unionfs -o dirs=/var/volatile/lib:/var/lib=ro none /var/lib
+
+if [ $? != 0 ]; then
+    echo "ERROR: Union mount failed!"
+    exit 1
+fi
diff --git a/meta/recipes-core/initscripts/initscripts_1.0.bb b/meta/recipes-core/initscripts/initscripts_1.0.bb
index 6e15f88..a8b093b 100644
--- a/meta/recipes-core/initscripts/initscripts_1.0.bb
+++ b/meta/recipes-core/initscripts/initscripts_1.0.bb
@@ -28,6 +28,7 @@ SRC_URI = "file://functions \
            file://sysfs.sh \
            file://device_table.txt \
            file://populate-volatile.sh \
+           file://read-only-rootfs-hook.sh \
            file://volatiles \
            file://save-rtc.sh \
            file://GPLv2.patch"
@@ -82,6 +83,7 @@ do_install () {
 	install -m 0755    ${WORKDIR}/devpts		${D}${sysconfdir}/default
 	install -m 0755    ${WORKDIR}/sysfs.sh		${D}${sysconfdir}/init.d
 	install -m 0755    ${WORKDIR}/populate-volatile.sh ${D}${sysconfdir}/init.d
+	install -m 0755    ${WORKDIR}/read-only-rootfs-hook.sh ${D}${sysconfdir}/init.d
 	install -m 0755    ${WORKDIR}/save-rtc.sh	${D}${sysconfdir}/init.d
 	install -m 0644    ${WORKDIR}/volatiles		${D}${sysconfdir}/default/volatiles/00_core
 	if [ "${TARGET_ARCH}" = "arm" ]; then
@@ -124,6 +126,7 @@ do_install () {
 	ln -sf		../init.d/sysfs.sh	${D}${sysconfdir}/rcS.d/S02sysfs.sh
 	# udev will run at S03 if installed
 	ln -sf		../init.d/populate-volatile.sh	${D}${sysconfdir}/rcS.d/S37populate-volatile.sh
+	ln -sf		../init.d/read-only-rootfs-hook.sh  ${D}${sysconfdir}/rcS.d/S41read-only-rootfs-hook.sh
 	ln -sf		../init.d/devpts.sh	${D}${sysconfdir}/rcS.d/S38devpts.sh
 	if [ "${TARGET_ARCH}" = "arm" ]; then
 		ln -sf	../init.d/alignment.sh	${D}${sysconfdir}/rcS.d/S06alignment.sh
-- 
1.7.9.5

Re: [PATCH 4/6] populate-volatile.sh: improve this script

[Richard Purdie]

On Mon, 2013-01-28 at 17:05 +0800, Qi.Chen@windriver.com wrote:
> From: Chen Qi <Qi.Chen@windriver.com>
> 
> Here's a list of improvements:
> 1) Make it run correctly at rootfs time.
> 2) Handle link config items more reasonably.
> 3) Support read-only rootfs.
> 4) Avoid data loss when removing directories.
> 
> [YOCTO #3406]
> [YOCTO #3404]
> [YOCTO #3181]
> 
> Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
> ---
>  .../initscripts-1.0/populate-volatile.sh           |  287 ++++++++++----------
>  1 file changed, 143 insertions(+), 144 deletions(-)

I'm getting a little annoyed with this patch. Saul keeps sending it to
me, I keep seeing it and rejecting it.

I will not take code changes mixed in with whitespace reformatting. I've
said this once already.

This series should have a patch like:

http://git.openembedded.org/openembedded-core/commit/?h=master-next&id=35f3369e5e6365aa06914862ef8a55e21f2fb73b

and then a follow up like:

http://git.openembedded.org/openembedded-core/commit/?h=master-next&id=ca8ca587643caa81a6c6530dfead0db6fa8c27b6

which has the actual code changes in it. I did this just so I could see
what the patch was doing.

Next problem is that there are too many different code changes in this
to figure out what is going on and properly review it. It needs to be
split up further into logical changes with a clear explanation of what
is happening. Why was the cacheclear mechanism removed? Why isn't the
background parallelisation important (I know why when I think about it
but the commit message says nothing about it)?

There is also a typo of ROOT_DRI in there.

I will merge the whitespace change, just so I don't have to see it
again. Please split up the rest of the changes into a logical set and
resubmit. meld is a good tool for work like that.

Cheers,

Richard

Re: [PATCH 4/6] populate-volatile.sh: improve this script

[ChenQi]

On 02/06/2013 10:40 PM, Richard Purdie wrote:
> On Mon, 2013-01-28 at 17:05 +0800, Qi.Chen@windriver.com wrote:
>> From: Chen Qi <Qi.Chen@windriver.com>
>>
>> Here's a list of improvements:
>> 1) Make it run correctly at rootfs time.
>> 2) Handle link config items more reasonably.
>> 3) Support read-only rootfs.
>> 4) Avoid data loss when removing directories.
>>
>> [YOCTO #3406]
>> [YOCTO #3404]
>> [YOCTO #3181]
>>
>> Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
>> ---
>>   .../initscripts-1.0/populate-volatile.sh           |  287 ++++++++++----------
>>   1 file changed, 143 insertions(+), 144 deletions(-)
> I'm getting a little annoyed with this patch. Saul keeps sending it to
> me, I keep seeing it and rejecting it.
>
> I will not take code changes mixed in with whitespace reformatting. I've
> said this once already.
>
> This series should have a patch like:
>
> http://git.openembedded.org/openembedded-core/commit/?h=master-next&id=35f3369e5e6365aa06914862ef8a55e21f2fb73b
>
> and then a follow up like:
>
> http://git.openembedded.org/openembedded-core/commit/?h=master-next&id=ca8ca587643caa81a6c6530dfead0db6fa8c27b6
>
> which has the actual code changes in it. I did this just so I could see
> what the patch was doing.
>
> Next problem is that there are too many different code changes in this
> to figure out what is going on and properly review it. It needs to be
> split up further into logical changes with a clear explanation of what
> is happening. Why was the cacheclear mechanism removed? Why isn't the
> background parallelisation important (I know why when I think about it
> but the commit message says nothing about it)?
>
> There is also a typo of ROOT_DRI in there.
>
> I will merge the whitespace change, just so I don't have to see it
> again. Please split up the rest of the changes into a logical set and
> resubmit. meld is a good tool for work like that.

Thanks for your advices.
I'll rework on this patch and resubmit it.

Thanks,
Chen Qi

> Cheers,
>
> Richard
>
>
>
>