[openwrt/openwrt] kernel: rework Initramfs compile cpio handling

[LEDE Commits]

ansuel pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/bfb2e099e41172d4cf8884a97058ff6d495b9976

commit bfb2e099e41172d4cf8884a97058ff6d495b9976
Author: Christian Marangi <ansuelsmth at gmail.com>
AuthorDate: Thu Sep 19 01:01:27 2024 +0200

    kernel: rework Initramfs compile cpio handling
    
    Now that we copy and then delete the Per-Device rootfs linux directory,
    it's not valid anymore placing the generated cpio there as artifacts
    or subsequent commands need the generated cpio.
    
    To handle this, rework Initramfs compile cpio handling by placing them in
    the KERNEL_BUILD_DIR but add to the name the rootfs HASH ID.
    
    To also prevent race condition, generate and access these file under a
    lock to prevent fit command to reference a cpio while a parallel
    execution is genereting it.
    
    Fixes: 52cc9d82f113 ("kernel: rework Initramfs locking logic")
    Signed-off-by: Christian Marangi <ansuelsmth at gmail.com>
---
 include/image-commands.mk  |  6 +++---
 include/kernel-defaults.mk | 40 +++++++++++++++++++++-------------------
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/include/image-commands.mk b/include/image-commands.mk
index cb899a2f30..d2974f4e01 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -373,7 +373,7 @@ define Build/initrd_compression
 endef
 
 define Build/fit
-	$(TOPDIR)/scripts/mkits.sh \
+	$(call locked,$(TOPDIR)/scripts/mkits.sh \
 		-D $(DEVICE_NAME) -o $@.its -k $@ \
 		-C $(word 1,$(1)) \
 		$(if $(word 2,$(1)),\
@@ -383,14 +383,14 @@ define Build/fit
 		$(if $(findstring with-rootfs,$(word 3,$(1))),-r $(IMAGE_ROOTFS)) \
 		$(if $(findstring with-initrd,$(word 3,$(1))), \
 			$(if $(CONFIG_TARGET_ROOTFS_INITRAMFS_SEPARATE), \
-				-i $(if $(TARGET_PER_DEVICE_ROOTFS),$(LINUX_DIR).$(ROOTFS_ID/$(DEVICE_NAME)),$(KERNEL_BUILD_DIR))/initrd.cpio$(strip $(call Build/initrd_compression)))) \
+				-i $(KERNEL_BUILD_DIR)/initrd$(if $(TARGET_PER_DEVICE_ROOTFS),.$(ROOTFS_ID/$(DEVICE_NAME))).cpio$(strip $(call Build/initrd_compression)))) \
 		-a $(KERNEL_LOADADDR) -e $(if $(KERNEL_ENTRY),$(KERNEL_ENTRY),$(KERNEL_LOADADDR)) \
 		$(if $(DEVICE_FDT_NUM),-n $(DEVICE_FDT_NUM)) \
 		$(if $(DEVICE_DTS_DELIMITER),-l $(DEVICE_DTS_DELIMITER)) \
 		$(if $(DEVICE_DTS_LOADADDR),-s $(DEVICE_DTS_LOADADDR)) \
 		$(if $(DEVICE_DTS_OVERLAY),$(foreach dtso,$(DEVICE_DTS_OVERLAY), -O $(dtso):$(KERNEL_BUILD_DIR)/image-$(dtso).dtbo)) \
 		-c $(if $(DEVICE_DTS_CONFIG),$(DEVICE_DTS_CONFIG),"config-1") \
-		-A $(LINUX_KARCH) -v $(LINUX_VERSION)
+		-A $(LINUX_KARCH) -v $(LINUX_VERSION), gen-cpio$(if $(TARGET_PER_DEVICE_ROOTFS),.$(ROOTFS_ID/$(DEVICE_NAME))))
 	PATH=$(LINUX_DIR)/scripts/dtc:$(PATH) mkimage $(if $(findstring external,$(word 3,$(1))),\
 		-E -B 0x1000 $(if $(findstring static,$(word 3,$(1))),-p 0x1000)) -f $@.its $@.new
 	@mv $@.new $@
diff --git a/include/kernel-defaults.mk b/include/kernel-defaults.mk
index 64b8a3775e..f94ed33230 100644
--- a/include/kernel-defaults.mk
+++ b/include/kernel-defaults.mk
@@ -191,25 +191,27 @@ define Kernel/CompileImage/Initramfs
 		$(CP) $(GENERIC_PLATFORM_DIR)/other-files/init $(if $(1),$(1),$(TARGET_DIR))/init; \
 		$(if $(SOURCE_DATE_EPOCH),touch -hcd "@$(SOURCE_DATE_EPOCH)" $(if $(1),$(1),$(TARGET_DIR)) $(if $(1),$(1),$(TARGET_DIR))/init;) \
 		$(if $(CONFIG_TARGET_ROOTFS_INITRAMFS_SEPARATE), \
-			$(if $(call qstrip,$(CONFIG_EXTERNAL_CPIO)), \
-				$(CP) $(CONFIG_EXTERNAL_CPIO) $(KERNEL_BUILD_DIR)/initrd.cpio;,\
-				( cd $(if $(1),$(1),$(TARGET_DIR)); find . | LC_ALL=C sort | $(STAGING_DIR_HOST)/bin/cpio --reproducible -o -H newc -R 0:0 > $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio );) \
-			$(if $(SOURCE_DATE_EPOCH), \
-				touch -hcd "@$(SOURCE_DATE_EPOCH)" $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_BZIP2), \
-				$(STAGING_DIR_HOST)/bin/bzip2 -9 -c < $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio > $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio.bzip2;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_GZIP), \
-				$(STAGING_DIR_HOST)/bin/libdeflate-gzip -n -f -S .gzip -12 $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZ4), \
-				$(STAGING_DIR_HOST)/bin/lz4c -l -c1 -fz --favor-decSpeed $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZMA), \
-				$(STAGING_DIR_HOST)/bin/lzma e -lc1 -lp2 -pb2 $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio.lzma;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZO), \
-				$(STAGING_DIR_HOST)/bin/lzop -9 -f $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_XZ), \
-				$(STAGING_DIR_HOST)/bin/xz -T$(if $(filter 1,$(NPROC)),2,0) -9 -fz --check=crc32 $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
-			$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_ZSTD), \
-				$(STAGING_DIR_HOST)/bin/zstd -T0 -f -o $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio.zstd $(if $(2),$(LINUX_DIR)$(2),$(KERNEL_BUILD_DIR))/initrd.cpio;) \
+			$(call locked,{ \
+				$(if $(call qstrip,$(CONFIG_EXTERNAL_CPIO)), \
+					$(CP) $(CONFIG_EXTERNAL_CPIO) $(KERNEL_BUILD_DIR)/initrd$(2).cpio;,\
+					( cd $(if $(1),$(1),$(TARGET_DIR)); find . | LC_ALL=C sort | $(STAGING_DIR_HOST)/bin/cpio --reproducible -o -H newc -R 0:0 > $(KERNEL_BUILD_DIR)/initrd$(2).cpio );) \
+				$(if $(SOURCE_DATE_EPOCH), \
+					touch -hcd "@$(SOURCE_DATE_EPOCH)" $(KERNEL_BUILD_DIR)/initrd$(2).cpio;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_BZIP2), \
+					$(STAGING_DIR_HOST)/bin/bzip2 -9 -c < $(KERNEL_BUILD_DIR)/initrd$(2).cpio > $(KERNEL_BUILD_DIR)/initrd$(2).cpio.bzip2;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_GZIP), \
+					$(STAGING_DIR_HOST)/bin/libdeflate-gzip -n -f -S .gzip -12 $(KERNEL_BUILD_DIR)/initrd$(2).cpio;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZ4), \
+					$(STAGING_DIR_HOST)/bin/lz4c -l -c1 -fz --favor-decSpeed $(KERNEL_BUILD_DIR)/initrd$(2).cpio;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZMA), \
+					$(STAGING_DIR_HOST)/bin/lzma e -lc1 -lp2 -pb2 $(KERNEL_BUILD_DIR)/initrd$(2).cpio $(KERNEL_BUILD_DIR)/initrd$(2).cpio.lzma;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_LZO), \
+					$(STAGING_DIR_HOST)/bin/lzop -9 -f $(KERNEL_BUILD_DIR)/initrd$(2).cpio;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_XZ), \
+					$(STAGING_DIR_HOST)/bin/xz -T$(if $(filter 1,$(NPROC)),2,0) -9 -fz --check=crc32 $(KERNEL_BUILD_DIR)/initrd$(2).cpio;) \
+				$(if $(CONFIG_TARGET_INITRAMFS_COMPRESSION_ZSTD), \
+					$(STAGING_DIR_HOST)/bin/zstd -T0 -f -o $(KERNEL_BUILD_DIR)/initrd$(2).cpio.zstd $(KERNEL_BUILD_DIR)/initrd$(2).cpio;) \
+			}, gen-cpio$(2)); \
 			$(if $(2),,$(KERNEL_MAKE) $(KERNEL_MAKEOPTS_IMAGE) $(if $(KERNELNAME),$(KERNELNAME),all);),\
 			$(KERNEL_MAKE) $(if $(2),-C $(LINUX_DIR)$(2)) $(KERNEL_MAKEOPTS_IMAGE) $(if $(KERNELNAME),$(KERNELNAME),all);) \
 		$(call Kernel/CopyImage,-initramfs,$(2)); \