btrfs scrub: don't coalesce pages that are logically discontiguous

scrub_page collects several pages into one bio as long as they are physically
contiguous. As we only save one logical address for the whole bio, don't
collect pages that are physically contiguous but logically discontiguous.
Signed-off-by: Arne Jansen <sensille@gmx.net>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/scrub.c

@@ -631,7 +631,8 @@ static int scrub_page(struct scrub_dev *sdev, u64 logical, u64 len,
 	if (sbio->count == 0) {
 		sbio->physical = physical;
 		sbio->logical = logical;
-	} else if (sbio->physical + sbio->count * PAGE_SIZE != physical) {
+	} else if (sbio->physical + sbio->count * PAGE_SIZE != physical ||
+		   sbio->logical + sbio->count * PAGE_SIZE != logical) {
 		scrub_submit(sdev);
 		goto again;
 	}