We can determine if what we read from the disk is a valid block or not by checking if the checksum we wrote to the disk matches the block checksum contained in the header file.

This is complicated somewhat by the presence of the flag WT_BLOCK_COMPRESS_SKIP , therefore we should only do this ticket after completing the work to deprecate other block checksum methods.

Those largely are define here:

https://github.com/wiredtiger/wiredtiger/blob/a1ddb57707206a466d26de0b062cd185bdf390c9/src/btree/bt_handle.c#L532