On Thu, Aug 15, 2019 at 02:04:02PM -0700, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@xxxxxx>
>
> generic_write_checks() may modify iov_iter_count(), so we must get the
> count after the call, not before. Using the wrong one has a couple of
> consequences:
>
> 1. We check a longer range in check_can_nocow() for nowait than we're
> actually writing.
> 2. We create extra hole extent maps in btrfs_cont_expand(). As far as I
> can tell, this is harmless, but I might be missing something.
>
> These issues are pretty minor, but let's fix it before something more
> important trips on it.
>
> Fixes: edf064e7c6fe ("btrfs: nowait aio support")
> Signed-off-by: Omar Sandoval <osandov@xxxxxx>
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Thanks,
Josef
