I know that a lot of deleted files can theoretically be recovered, which suggests that deleting doesn't actually remove the information. So how do the various extN (e.g. ext4) filesystems delete files? Do they just mark the space as free?
How does ext[n] delete files?
filesystems;data recovery;deleted files
Do they just mark the space as free?Yes.Removing the file would take extra work and is in most cases unnecessary.