

oh, that’s right, sorry. it must have changed in recent years.
so I haven’t either found a definitive answer to whether it is a default mount option, but the closest I found is almost it: man mount
says to look in man ext4
, and there itsays the defaults are determined by the filesystem superblock.
the superblock’s settings can be viewed with tune2fs -l /dev/your_blockdev
, and according to the “default mount options” line I indeed have acl enabled by default on all my ext4 filesystems.
so in the end, the default is determined by the tool that makes the filesystem. mkfs.ext4
reads them from /etc/mke2fs.conf
if not overridden with an argument. on my system tue acl option is right there in this file.
and that also means that this depends not on your current system, but on the system where the filesystem was created.
I don’t understand their aversion with JSON, but holy shit all the rest is miserable