Re: [PATCH v7 15/15] xfs: Add async buffered write support

Christoph Hellwig
2022-07-05T16:11:42Z

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.