The journalling layer uses typedefs to 'hide' the concrete definitions
of the structures used. As a client of the JBD layer you can
just rely on the using the pointer as a magic cookie of some sort.
Obviously the hiding is not enforced as this is 'C'.
- typedef handle_t —
The handle_t type represents a single atomic update being performed by some process.
- typedef journal_t —
The journal_t maintains all of the journaling state information for a single filesystem.
- struct handle_s —
this is the concrete type associated with handle_t.
- struct journal_s —
this is the concrete type associated with journal_t.