FS#4048 - sysupgrade with "-k"

[openwrt-bot]

Aikhjarto:

When using sysupgrade with "-k" to include a list of installed packages in the backup, a mounting error is both logged to console and to log.

======How to reproduce:======
Do backup with "-k"

root@router:~# /sbin/sysupgrade -k -b /mnt/sda1/backup.tar.gz
mount: mounting overlay on /etc/backup failed: Invalid argument
Cannot mount '/etc/backup' as tmpfs to avoid touching disk while saving the list of installed packages.
Tue Sep 21 16:12:05 CEST 2021 upgrade: Saving config files...

It does not matter where to backup,the same errors show up when using sysupgrade -k -b - >/dev/null to backup to stdout.

Show kernel error from log:

root@router:~# logread | grep kern.err
TueSep 21 16:12:05 2021 kern.err kernel: [539662.073867] overlayfs: maximum fs stacking depth exceeded


======System======
Hardware:
TP-Link Archer C7

OpenWrt version:

root@router:~# cat /etc/os-release
NAME="OpenWrt"
VERSION="21.02.0"
ID="openwrt"
ID_LIKE="lede openwrt"
PRETTY_NAME="OpenWrt 21.02.0"
VERSION_ID="21.02.0"
HOME_URL="https://openwrt.org/"
BUG_URL="https://bugs.openwrt.org/"
SUPPORT_URL="https://forum.openwrt.org/"
BUILD_ID="r16279-5cc0535800"
OPENWRT_BOARD="ath79/generic"
OPENWRT_ARCH="mips_24kc"
OPENWRT_TAINTS=""
OPENWRT_DEVICE_MANUFACTURER="OpenWrt"
OPENWRT_DEVICE_MANUFACTURER_URL="https://openwrt.org/"
OPENWRT_DEVICE_PRODUCT="Generic"
OPENWRT_DEVICE_REVISION="v0"
OPENWRT_RELEASE="OpenWrt 21.02.0 r16279-5cc0535800"


[openwrt-bot]

Aikhjarto:

Apparently, when sysupgrade is interrupted, it does not clean up after itself, leaving /tmp/sysupgrade.XXXXXX folders and possibly (if called with "-k") a mount on /etc/backup behind.

Last line of the output of mount after interrupting "sysupgrade -k".

overlay on /etc/backup type overlay (rw,relatime,lowerdir=/etc/backup,upperdir=/tmp/sysupgrade.jlomom/upper,workdir=/tmp/sysupgrade.jlomom/work)


The next call to "sysupgrade -k" generates the mount-errors since /etc/backup is then already mounted, but with the wrong folder.