On 8/16/19 4:55 AM, Kevin Wolf wrote:
> If QEMU_AIO_NO_FALLBACK is given, we always return failure and don't
> even try to use the BLKZEROOUT ioctl. In this failure case, we shouldn't
> disable has_write_zeroes because we didn't learn anything about the
> ioctl. The next request might not set QEMU_AIO_NO_FALLBACK and we can
> still use the ioctl then.
> 
> Reported-by: Eric Blake <eblake@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block/file-posix.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 

Reviewed-by: Eric Blake <eblake@redhat.com>
Fixes: 738301e1175

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org