On Tue, Jul 05, 2022 at 09:47:25AM -0400, Josef Bacik wrote: > This appears to be just a confusion about what we think NOWAIT should mean. > Looking at the btrfs code it seems like Goldwyn took it as literally as possible > so we wouldn't do any NOWAIT IO's unless it was into a NOCOW area, meaning we > literally wouldn't do anything other than wrap the bio up and fire it off. It means don't do anything that would block. And I suspect in btrfs the above is about as much as you can do without blocking.