[build] RFS split improvements

* add more files to RFS_DEB_FILES
* improved umount in build_debian.sh (taken from #16672)
* explicit RFS_SPLIT_LAST_STAGE=n when building the first stage

Signed-off-by: Yakiv Huryk <[email protected]>

Author: Yakiv-Huryk

Makefile.cache

@@ -359,8 +359,10 @@ endef
 
 RFS_DEP_FILES := $(wildcard \
 	$(addprefix scripts/, build_debian_base_system.sh prepare_debian_image_buildinfo.sh build_mirror_config.sh) \
-	$(wildcard files/initramfs-tools/*) \
+	$(shell git ls-files files/initramfs-tools) \
 	$(shell git ls-files files/image_config) \
+	$(shell git ls-files files/apparmor) \
+	$(shell git ls-files files/apt) \
 	$(wildcard files/sshd/*) \
 	$(wildcard files/dhcp/*) \
 	src/sonic-build-hooks/buildinfo/trusted.gpg.d \

build_debian.sh

@@ -612,8 +612,7 @@ if [[ $RFS_SPLIT_FIRST_STAGE == y ]]; then
     ## Kill the processes
     sudo LANG=C chroot $FILESYSTEM_ROOT fuser -km /proc || true
     ## Wait fuser fully kill the processes
-    sleep 15
-    sudo LANG=C chroot $FILESYSTEM_ROOT umount /proc
+    sudo timeout 15s bash -c 'until LANG=C chroot $0 umount /proc; do sleep 1; done' $FILESYSTEM_ROOT || true
 
     sudo rm -f $TARGET_PATH/$RFS_SQUASHFS_NAME
     sudo mksquashfs $FILESYSTEM_ROOT $TARGET_PATH/$RFS_SQUASHFS_NAME -Xcompression-level 1

slave.mk

@@ -1264,6 +1264,7 @@ $(addprefix $(TARGET_PATH)/, $(SONIC_RFS_TARGETS)) : $(TARGET_PATH)/% : \
 		export sonicadmin_user="$(USERNAME)"
 		export sonic_asic_platform="$(patsubst %-$(CONFIGURED_ARCH),%,$(CONFIGURED_PLATFORM))"
 		export RFS_SPLIT_FIRST_STAGE=y
+		export RFS_SPLIT_LAST_STAGE=n
 
 		j2 -f env files/initramfs-tools/union-mount.j2 onie-image.conf > files/initramfs-tools/union-mount
 		j2 -f env files/initramfs-tools/arista-convertfs.j2 onie-image.conf > files/initramfs-tools/arista-convertfs