How to repair f2fs filesystem in extroot configuration

Hi.
Several years ago I configured extFS by “**Extroot configuration” manual.
Today, after hard reboot my router (tplink-WDR4300), I lost /etc/config/sshtunnel file.

root@OpenWrt:/etc/config# ls -l sshtunnel
ls: sshtunnel: Invalid argument
root@OpenWrt:/etc/config# ls -l
ls: ./sshtunnel: Invalid argument
-rw-------    1 root     root          1008 Jul 15  2024 dhcp
-rw-------    1 root     root           134 Jul 15  2024 dropbear
-rw-r--r--    1 root     root           475 Aug 15  2025 firewall
-rw-r--r--    1 root     root           439 Sep 11  2024 fstab
-rw-r--r--    1 root     root           968 Jul 15  2024 luci
-rw-------    1 root     root           965 Sep 11  2024 network
-rw-------    1 root     root           167 Jul 15  2024 rpcd
-rw-------    1 root     root           357 Jul 15  2024 system
-rw-r--r--    1 root     root             0 Jul 15  2024 ubootenv
-rw-r--r--    1 root     root           788 Jul 15  2024 ucitrack
-rw-------    1 root     root           783 Jul 15  2024 uhttpd
-rw-r--r--    1 root     root           747 Apr 24 09:27 wireless
root@OpenWrt:/etc/config# touch sshtunnel
touch: sshtunnel: Invalid argument
root@OpenWrt:/etc/config# ls -l sshtunnel
ls: sshtunnel: Invalid argument

root@OpenWrt:/etc/config# lsblk
NAME      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
sda         8:0    1  1.9G  0 disk
└─sda1      8:1    1  1.9G  0 part /tmp/extroot/overlay
/overlay
mtdblock0  31:0    0  128K  1 disk
mtdblock1  31:1    0  7.8M  0 disk
mtdblock2  31:2    0  2.2M  1 disk
mtdblock3  31:3    0  5.6M  1 disk /rom
mtdblock4  31:4    0    2M  0 disk /rwm
mtdblock5  31:5    0   64K  1 disk

How to repair f2fs filesystem, to findout /etc/config/sshtunnel or recreate it?

root@OpenWrt:/etc/config# dmesg | tail -20
[   64.222443] br-lan: port 2(phy1-ap0) entered blocking state
[   64.228254] br-lan: port 2(phy1-ap0) entered disabled state
[   64.234293] device phy1-ap0 entered promiscuous mode
[   64.779540] IPv6: ADDRCONF(NETDEV_CHANGE): phy1-ap0: link becomes ready
[   64.786538] br-lan: port 2(phy1-ap0) entered blocking state
[   64.792210] br-lan: port 2(phy1-ap0) entered forwarding state
[   66.750092] br-lan: port 3(phy0-ap0) entered blocking state
[   66.755871] br-lan: port 3(phy0-ap0) entered disabled state
[   66.762379] device phy0-ap0 entered promiscuous mode
[   67.423952] IPv6: ADDRCONF(NETDEV_CHANGE): phy0-ap0: link becomes ready
[   67.431024] br-lan: port 3(phy0-ap0) entered blocking state
[   67.436789] br-lan: port 3(phy0-ap0) entered forwarding state
[   74.501219] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[   79.958710] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[  789.849497] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[  789.865203] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[  790.231201] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[ 1205.872220] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[ 1213.557336] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]
[ 1216.435453] F2FS-fs (sda1): inconsistent node block, nid:77, node_footer[nid:943,ino:943,ofs:0,cpver:7001075660830728450,blkaddr:11194]