Any of these problems can be solved by following the given procedure
It is always good to copy db folder before doing any disk error fixing.
First boot using Clonezilla bootable usb drive and login to the command shell (Ctrl+Alt+F1).
1. Solving bad sector error
sudo -s fsck.ext4 -y /dev/sda or fsck.ext4 -y /dev/mmcblk0
2. Fill disk with zeros to reset all data from disk
sudo -s dd if=/dev/zero of=/dev/mmcblk0 or dd if=/dev/zero of=/dev/sda
3. Fix corrupted superblock:
sudo -s fsck.ext4 /dev/mmcblk0p1 or fsck.ext4 /dev/sda
4. Fix mmc failure during booting. This has to be done from Saleculator command shell.
echo "options sdhci debug_quirks=0x40" >> /etc/modprobe.d/sdhci-pci.conf reboot