Count removal only after every source drive confirms version absence, including free records and concurrently deleted parents. Retire successful candidates independently with the existing source, destination and tier ownership checks. Reject ambiguous raw reads, verify remaining metadata directly, and propagate cancellation.
Signed-off-by: Feng Ruohang <rh@vonng.com>
(cherry picked from commit b1a97c7e6cc7ab5f44110b5b8258afb60a50053e)
Feng Ruohang