How to properly mount img image in linux?

Question

linux

I'm trying to do everything according to the manual.
https://xakep.ru/2012/10/22/android-tablet-linux-i...
Create a block loopback device, connect a disk image to it and mount it:
# mknod /dev/block/loop255 b 7 255
# mount -o remount,rw /
# mkdir /mnt/ubuntu
# mount -o loop,noatime -t ext2 \
/sdcard/ubuntu.img /mnt/ubuntu
connected to the tablet via adb shell, after the fourth command (# mount -o loop,noatime -t ext2 \
/sdcard/ubuntu.img /mnt/ubuntu) gives the following "open backing file failed: No such file or directory" help me figure out how to fix this shortcoming.

Answer 1

The answer to the question from the subject of the message - "How to properly mount a disk image in Linux?"
Install kpartx:
Mount:
Unmount:
kpartx -dv /path/to/the/image.img