[PATCH 0/2] live image: try to make a valid union mount

[PATCH 0/2] live image: try to make a valid union mount

[Qi.Chen]

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

This patchset cleans up the unionfs related code and tries to make a union mount
with aufs or overlayfs.

The following changes since commit 042203531b10b37ac9a8201b376f5dec403e51d8:

  sanity.bbclass: Fix COREBASE sanity tests (2013-06-27 12:48:56 +0100)

are available in the git repository at:

  git://git.pokylinux.org/poky-contrib ChenQi/live-image-union-mount
  http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=ChenQi/live-image-union-mount

Chen Qi (2):
  initrdscripts: unionfs cleanup
  init-live.sh: try to make a union mount when possible

 meta/recipes-core/initrdscripts/files/init-live.sh |   71 ++++++++++++++------
 .../initrdscripts/initramfs-live-boot_1.0.bb       |    7 --
 2 files changed, 52 insertions(+), 26 deletions(-)

-- 
1.7.9.5

[PATCH 1/2] initrdscripts: unionfs cleanup

[Qi.Chen]

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

The unionfs has been disabled for more than a year and it's not going
to be used any more.

This patch cleans up the unionfs related code.

[YOCTO #4761]
[YOCTO #1487]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/recipes-core/initrdscripts/files/init-live.sh |   22 +++-----------------
 .../initrdscripts/initramfs-live-boot_1.0.bb       |    7 -------
 2 files changed, 3 insertions(+), 26 deletions(-)

diff --git a/meta/recipes-core/initrdscripts/files/init-live.sh b/meta/recipes-core/initrdscripts/files/init-live.sh
index 804e16e..00c2558 100644
--- a/meta/recipes-core/initrdscripts/files/init-live.sh
+++ b/meta/recipes-core/initrdscripts/files/init-live.sh
@@ -7,7 +7,6 @@ ROOT_IMAGE="rootfs.img"
 MOUNT="/bin/mount"
 UMOUNT="/bin/umount"
 ISOLINUX=""
-UNIONFS="no"
 
 # Copied from initramfs-framework. The core of this script probably should be
 # turned into initramfs-framework modules to reduce duplication.
@@ -140,25 +139,10 @@ case $label in
     boot)
 	mkdir $ROOT_MOUNT
 	mknod /dev/loop0 b 7 0 2>/dev/null
-
-	
-	if [ "$UNIONFS" = "yes" ]; then
-	    mkdir /rootfs-tmp
-
-	    if ! $MOUNT -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE /rootfs-tmp ; then
-		fatal "Could not mount rootfs image"
-	    else
-		mkdir /cow
-		mount -t tmpfs -o rw,noatime,mode=755 tmpfs /cow
-		mount -t unionfs -o dirs=/cow:/rootfs-tmp=ro unionfs $ROOT_MOUNT
-		boot_live_root
-	    fi
+	if ! $MOUNT -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then
+	    fatal "Could not mount rootfs image"
 	else
-	    if ! $MOUNT -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then
-		fatal "Could not mount rootfs image"
-	    else
-		boot_live_root
-	    fi
+	    boot_live_root
 	fi
 	;;
     install|install-efi)
diff --git a/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb b/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb
index 0cbfe02..8626bb5 100644
--- a/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb
+++ b/meta/recipes-core/initrdscripts/initramfs-live-boot_1.0.bb
@@ -7,13 +7,6 @@ SRC_URI = "file://init-live.sh"
 
 PR = "r11"
 
-do_compile() {
-	#if grep -q "CONFIG_UNION_FS=y" ${STAGING_KERNEL_DIR}/.config; then
-	#	sed -i 's/UNIONFS="no"/UNIONFS="yes"/g' ${WORKDIR}/init-live.sh
-	#fi
-	:
-}
- 
 do_install() {
         install -m 0755 ${WORKDIR}/init-live.sh ${D}/init
 }
-- 
1.7.9.5

[PATCH 2/2] init-live.sh: try to make a union mount when possible

[Qi.Chen]

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

This patch tries to make a union mount in live image. For example,
if aufs is enabled with the aufs-enable.scc configuration fragment,
the init-live.sh script will use aufs to make a union mount.

Although overlayfs is not supported by Yocto kernel yet, this patch
still takes it into consideration with the expect that the related
code should at least serve as a placeholder.

[YOCTO #1487]
[YOCTO #4761]

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
---
 meta/recipes-core/initrdscripts/files/init-live.sh |   63 +++++++++++++++++---
 1 file changed, 56 insertions(+), 7 deletions(-)

diff --git a/meta/recipes-core/initrdscripts/files/init-live.sh b/meta/recipes-core/initrdscripts/files/init-live.sh
index 00c2558..9804504 100644
--- a/meta/recipes-core/initrdscripts/files/init-live.sh
+++ b/meta/recipes-core/initrdscripts/files/init-live.sh
@@ -135,15 +135,64 @@ do
   sleep 1
 done
 
+# Try to make a union mount of the root image.
+# If no unification filesystem is available, mount the image read-only.
+mount_and_boot() {
+    mkdir $ROOT_MOUNT
+    mknod /dev/loop0 b 7 0 2>/dev/null
+
+    # determine which unification filesystem to use
+    union_fs_type=""
+    if grep -q -w "overlayfs" /proc/filesystems; then
+	union_fs_type="overlayfs"
+    elif grep -q -w "aufs" /proc/filesystems; then
+	union_fs_type="aufs"
+    else
+	union_fs_type=""
+    fi
+
+    # make a union mount if possible
+    case $union_fs_type in
+	"overlayfs")
+	    mkdir -p /rootfs.ro /rootfs.rw
+	    if ! mount -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE /rootfs.ro; then
+		rm -rf /rootfs.ro /rootfs.rw
+		fatal "Could not mount rootfs image"
+	    else
+		mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw
+		mount -t overlayfs -o "lowerdir=/rootfs.ro,upperdir=/rootfs.rw" overlayfs $ROOT_MOUNT
+		mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw
+		mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro
+		mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw
+	    fi
+	    ;;
+	"aufs")
+	    mkdir -p /rootfs.ro /rootfs.rw
+	    if ! mount -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE /rootfs.ro; then
+		rm -rf /rootfs.ro /rootfs.rw
+		fatal "Could not mount rootfs image"
+	    else
+		mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw
+		mount -t aufs -o "dirs=/rootfs.rw=rw:/rootfs.ro=ro" aufs $ROOT_MOUNT
+		mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw
+		mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro
+		mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw
+	    fi
+	    ;;
+	"")
+	    if ! mount -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then
+		fatal "Could not mount rootfs image"
+	    fi
+	    ;;
+    esac
+
+    # boot the image
+    boot_live_root
+}
+
 case $label in
     boot)
-	mkdir $ROOT_MOUNT
-	mknod /dev/loop0 b 7 0 2>/dev/null
-	if ! $MOUNT -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then
-	    fatal "Could not mount rootfs image"
-	else
-	    boot_live_root
-	fi
+	mount_and_boot
 	;;
     install|install-efi)
 	if [ -f /media/$i/$ISOLINUX/$ROOT_IMAGE ] ; then
-- 
1.7.9.5