Like the title say I have some ext4 that mounts well without umask but are innacessible because of permissions, but leads to error wrong fs type when mounted with umask=0
I'm on a live USB. So fstab is basically tmpfs, and I can't reboot for any changes to take effect (ro filesystem)
Not all mount options are available for all filesystem types.
In particular, there is no umask= mount option for ext4 or for any fully supported Unix-style filesystems really, because for those filesystem types, the chown, chgrp and chmod commands will work as designed.
If you need to access something that is not allowed for you according to the filesystem's ownership/permission information, then you must be root to do so.
