[RFC PATCH 17/17] netfs: Combine prepare and issue ops and grab the buffers on request

[Paulo Alcantara]

ChenXiaoSong <chenxiaosong at chenxiaosong.com> writes:

> --- a/fs/netfs/direct_write.c
> +++ b/fs/netfs/direct_write.c
> @@ -161,8 +161,8 @@ static int netfs_unbuffered_write(struct 
> netfs_io_request *wreq)
>                                          break;
>                                  }
>                                  netfs_put_subrequest(subreq, 
> netfs_sreq_trace_put_failed);
> -                               subreq = NULL;
>                                  ret = subreq->error;
> +                               subreq = NULL;
>                                  goto failed;

Thanks for the review.  The above is still broken as it wolud cause an
UAF on @subreq as we're putting it with netfs_put_subrequest() and then
dereferencing it afterwards.

Besides, we could also get rid of 'subreq = NULL' as it is currently a
no-op -- including in other places.

Let's wait for next patchset from Dave, though.