In journal filesystem(for example ext4, XFS, ZFS, JFS, btrfs), there are file access permission rules.
Hence if I mount a HDD which include a unix OS on it, when I access the file on this disk without root priority, it will be failed to read or write it. However if the current username and password are same as the owner of this file on this disk.
What will happen?
If the access still remain failure, what information is involved in identifying this two different user with same username and password?