(a) All legal service liability actions against a legal service provider must be commenced within two years after the act or omission or failure giving rise to the claim, and not afterwards; provided, that if the cause of action is not discovered and could not reasonably have been discovered within such period, then the action may be commenced within six months from the date of such discovery or the date of discovery of facts which would reasonably lead to such discovery, whichever is earlier; provided, further, that in no event may the action be commenced more than four years after such act or omission or failure; except, that an act or omission or failure giving rise to a claim which occurred before August 1, 1987, shall not in any event be barred until the expiration of one year from such date.
(b) Subsection (a) of this section shall be subject to all existing provisions of law relating to the computation of statutory periods of limitations for the commencement of actions, namely, Sections 6-2-1, 6-2-2, 6-2-3, 6-2-5, 6-2-6, 6-2-8, 6-2-9, 6-2-10, 6-2-13, 6-2-15, 6-2-16, 6-2-17, 6-2-30, and 6-2-39; provided, that notwithstanding any provisions of such sections, no action shall be commenced more than four years after the act, omission, or failure complained of; except, that in the case of a minor under four years of age, such minor shall have until his or her eighth birthday to commence such action.