Revert "Stop readahead thread if the file isn’t opened try #2"

This reverts commit 8ca6129054eff2932b2ed96468d1b096c0145c38.
Revert "Abort early when trying to open a 0 bytes file size if it’s not being written to"

This reverts commit 6c24a54d85c4def769fb9bbe7a59b3ff71663dc1.