ce9adaa5a7
Before, metadata checksumming was done by the callers of read_tree_block, which would set EXTENT_CSUM bits in the extent tree to show that a given range of pages was already checksummed and didn't need to be verified again. But, those bits could go away via try_to_releasepage, and the end result was bogus checksum failures on pages that never left the cache. The new code validates checksums when the page is read. It is a little tricky because metadata blocks can span pages and a single read may end up going via multiple bios. Signed-off-by: Chris Mason <chris.mason@oracle.com>