build: fix restoring /etc/opkg with PER_DEVICE_ROOTFS

When generating per-device rootfs directories, the ./etc/opkg/ directory
is moved away prior to calling opkg install, opkg remove and rootfs_prepare.
After the opkg invocations and the rootfs_prepare macro call, the saved opkg
config directory is supposed to be moved back to its previous ./etc/opkg
location.

The mv command however can fail to properly restore the directory under
certain circumstances, e.g. when the prior opkg or files/ overlay copy
operations caused a new ./etc/opkg/ directory to be created.

In this case, the backed up directory (named target-dir-$hash.opkg) will be
moved into the preexisting ./etc/opkg/ directory instead, causing the opkg
configuration to be located in a wrong path on the final rootfs, e.g. in
/etc/opkg/target-dir-$hash.opkg/distfeeds.conf instead of
/etc/opkg/distfeeds.conf.

Solve this problem by replacing the naive "mv" command with a recursive
"cp -T" invocation which causes the backed up directory tree to get merged
with the destination directory in case it already exists.

Also perform the rootfs_prepare macro call after restoring the opkg
configuration, to allow users to override it again by using the files/
overlay mechanism.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>
(cherry picked from commit ab1785b1b2559c9f2d09d4d3ce43e11f4b828616)

diff --git a/include/image.mk b/include/image.mk
index 84b46f256cf5ac92b8c92fca2983402794468008..8846353390b8d9b96f0261c739e981cee4065278 100644 (file)
--- a/include/image.mk
+++ b/include/image.mk
@@ -302,9 +302,9 @@ target-dir-%: FORCE
                $(opkg_target) update && \
                $(opkg_target) install \
                        $(call opkg_package_files,$(mkfs_packages_add)))
+       -$(CP) -T $(mkfs_cur_target_dir).opkg/ $(mkfs_cur_target_dir)/etc/opkg/
+       rm -rf $(mkfs_cur_target_dir).opkg $(mkfs_cur_target_dir).conf
        $(call prepare_rootfs,$(mkfs_cur_target_dir))
-       -mv $(mkfs_cur_target_dir).opkg $(mkfs_cur_target_dir)/etc/opkg
-       rm -f $(mkfs_cur_target_dir).conf
 
 $(KDIR)/root.%: kernel_prepare
        $(call Image/mkfs/$(word 1,$(target_params)),$(target_params))