WNR2200 with extroot reboots then opening LUCI

[SimplyKot]

Describe the bug

WNR2200 with extroot reboots then opening LUCI

OpenWrt version

r20134-5f15225c1e

OpenWrt target/subtarget

ath79/generic

Device

Netgear WNR2200 (16M

Image kind

Official downloaded image

Steps to reproduce

Add USB drive support ([(https://openwrt.org/docs/guide-user/storage/usb-drives)]):

opkg update
opkg install kmod-usb-storage
opkg install kmod-usb-storage-uas

opkg install usbutils
lsusb -t

root@OpenWrt:~# lsusb -t
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-platform/1p, 480M
|__ Port 1: Dev 2, If 0, Class=, Driver=uas, 480M

opkg install block-mount
block info | grep "/dev/sd"

/dev/sda1: UUID="f5383639-7a98-43cd-8a0a-29174983c7bb" LABEL="extroot" VERSION="1.0" TYPE="ext4"
/dev/sda2: UUID="c8ff74ed-5e68-d901-40a7-74ed5e68d901" LABEL="data" VERSION="1.0" TYPE="ext4"
/dev/sda3: VERSION="1" TYPE="swap"

opkg install e2fsprogs
opkg install kmod-fs-ext4

Configure extroot (https://openwrt.org/docs/guide-user/additional-software/extroot_configuration):

DEVICE="$(sed -n -e "/\s\/overlay\s.*$/s///p" /etc/mtab)"
uci -q delete fstab.rwm
uci set fstab.rwm="mount"
uci set fstab.rwm.device="${DEVICE}"
uci set fstab.rwm.target="/rwm"
uci commit fstab

DEVICE="/dev/sda1"
mkfs.ext4 -L extroot ${DEVICE}

eval $(block info ${DEVICE} | grep -o -e "UUID=\S*")
uci -q delete fstab.overlay
uci set fstab.overlay="mount"
uci set fstab.overlay.uuid="${UUID}"
uci set fstab.overlay.target="/overlay"
uci commit fstab

mount ${DEVICE} /mnt
tar -C /overlay -cvf - . | tar -C /mnt -xf -
reboot

Then edit /etc/rc.local :

# Put your custom commands here that should be executed once
# the system init finished. By default this file does nothing.

export PREINIT=1
mount_root

exit 0

At this point extroot is working:

root@OpenWrt:~# df -h /overlay /
Filesystem Size Used Available Use% Mounted on
/dev/sda1 1.9G 2.7M 1.8G 0% /overlay
overlayfs:/overlay 1.9G 2.7M 1.8G 0% /

root@OpenWrt:~# grep -e /overlay /etc/mtab
/dev/mtdblock5 /rom/overlay jffs2 rw,noatime 0 0
overlayfs:/overlay /rom overlay rw,noatime,lowerdir=/,upperdir=/overlay/upper,workdir=/overlay/work 0 0
/dev/sda1 /overlay ext4 rw,relatime,stripe=8191 0 0
overlayfs:/overlay / overlay rw,noatime,lowerdir=/,upperdir=/overlay/upper,workdir=/overlay/work 0 0

Actual behaviour

Router reboots the accessing web interface

Expected behaviour

LUCI interface successfully opened in browser.

Additional info

No response

Diffconfig

No response

Terms

• I am reporting an issue for OpenWrt, not an unsupported fork.

[brada4]

try to catch logread -f in shell session while triggering reboot.

[SimplyKot]

try to catch logread -f in shell session while triggering reboot.

This is what I tried first: it's empty

[brada4]

The anomalous occurrence is high 'sys' CPU usage and procd CPU usage spike.
For me procd uses nothing and sys CPU does not spike above 1-2%% outside heavy traffic.
You can try UDP syslog during crash (Free Kiwi Syslog Server if you are in Windows worlds)
Does the crash also occur on snapshot (backup config, update to latest snapshot, install luci-mod-admin-full, check for crash, roll back to v22 resetting config and reloading config backup)

[SimplyKot]

First, /usr/bin/lua causes CPU load and only then /sbin/procd.

[SimplyKot]

By the way OpenWrt 21.02.7, r16847-f8282da11e works fine!

[brada4]

Lua starts, that is expected(you see incrementing PID in busybox top already.
But procd is too high if it crashes linux reboots.Not sure though with logs silent.

[SimplyKot]

You can try UDP syslog during crash

Still empty logs

[brada4]

I can only speculate without proof that procd crashes after eating cpu, its the thing restarting services, and services (or their scripts) connect and tell it they are up.