From: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Date: Fri, 24 Apr 2020 14:04:14 +0000 (+0300)
Subject: base-files: prevent issues w/ overlay on powerloss after sysupgrade
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=880c1f0336616b0b5692ff284f83923011c548f2;p=openwrt%2Fstaging%2Fblocktrron.git

base-files: prevent issues w/ overlay on powerloss after sysupgrade

Due to filesystem write caching the old configuration data could stay
out of flash for a long time during a first boot after the sysupgrade.
Power loss during this period could damage the overlay data and even
make device inaccessable via the network.

Fix this by syncing data to a flash as soon as the previous
configuration will be unpacked after the sysupgrade. Also sync the FS
state after the sysupgrade.tgz archive removing to prevent duplicative
extraction of a previous configuration.

Tested with AMD Geode based board.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
---

diff --git a/package/base-files/files/etc/init.d/done b/package/base-files/files/etc/init.d/done
index 374353a23c..32d6118df7 100755
--- a/package/base-files/files/etc/init.d/done
+++ b/package/base-files/files/etc/init.d/done
@@ -4,7 +4,7 @@
 START=95
 boot() {
 	mount_root done
-	rm -f /sysupgrade.tgz
+	rm -f /sysupgrade.tgz && sync
 
 	# process user commands
 	[ -f /etc/rc.local ] && {
diff --git a/package/base-files/files/lib/preinit/80_mount_root b/package/base-files/files/lib/preinit/80_mount_root
index f3fe788e19..265a3f18df 100644
--- a/package/base-files/files/lib/preinit/80_mount_root
+++ b/package/base-files/files/lib/preinit/80_mount_root
@@ -9,6 +9,8 @@ do_mount_root() {
 		echo "- config restore -"
 		cd /
 		tar xzf /sysupgrade.tgz
+		# Prevent configuration corruption on a power loss
+		sync
 	}
 }