// When writing, we need to block session renewal
// until we're finished, in order to guarantee the
// effect of the write is visible in future responses.
- // But if we're not writing, we can release the lcok
+ // But if we're not writing, we can release the lock
// early. This enables us to keep renewing sessions
// and processing more requests even if a slow client
// takes a long time to download a large file.