[Virtio-fs] [PATCH 1/2] fuse: disable atomic_o_trunc if no_open is enabled

[Miklos Szeredi]

On Thu, 12 Aug 2021 at 07:46, Jeffle Xu <jefflexu at linux.alibaba.com> wrote:
>
> From: Liu Bo <bo.liu at linux.alibaba.com>
>
> When 'no_open' is used by virtiofsd, guest kernel won't send OPEN request
> any more.  However, with atomic_o_trunc, SETATTR request is also omitted in
> OPEN(O_TRUNC) so that the backend file is not truncated.  With a following
> GETATTR, inode size on guest side is updated to be same with that on host
> side, the end result is that O_TRUNC semantic is broken.
>
> This disables atomic_o_trunc as well if with no_open.

I don't quite get it why one would want to enable atomic_o_trunc with
no_open in the first place?

Thanks,
Miklos