NotesHierarchical Directories
The file system is the array of files. To humans, it is much easier to have something that is named.
Each directory has . (current working directory) and .. (parent directory)
By convention, the root directory is usually the first inode in the array
- the
..directory to the root is itself
Hard Links
This is possible because the name space is decoupled from the flat file system, files also have reference counts.
We can’t have hard links to directories because that would require a cyclic graph (we would need to have a reference to parent because then .. could mean multiple things).
If we had a cycle, we could have floating islands that are no longer accessible which would need to be garbage collected, which would then be very slow on a large file system.
Symbolic Links
Doesn’t change reference count