Systems and methods for extent reference count updates are presented. In one embodiment; a reference count update method includes: receiving an indication of new reference association with an extent of a shared storage component; generating reference count update log information for a reference count update log to indicate the new reference association with an extent of a shared storage component, wherein the altering occurs inline; forwarding a successful data update indicator to initiator of activity triggering the new reference association with the extent of the shared storage component; and updating a reference count table in accordance with the information in the reference count update log, wherein the updating is included in a background process.