Re: [Qemu-devel] [PATCH 2/2] block/nfs: refuse readahead if cache.direct is on

[Jeff Cody <jcody@redhat.com>]

On Tue, May 17, 2016 at 04:11:55PM +0200, Peter Lieven wrote:
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block/nfs.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/block/nfs.c b/block/nfs.c
> index 975510f..8b73a35 100644
> --- a/block/nfs.c
> +++ b/block/nfs.c
> @@ -331,6 +331,11 @@ static int64_t nfs_client_open(NFSClient *client, const char *filename,
>              nfs_set_tcp_syncnt(client->context, val);
>  #ifdef LIBNFS_FEATURE_READAHEAD
>          } else if (!strcmp(qp->p[i].name, "readahead")) {
> +            if (open_flags & BDRV_O_NOCACHE) {
> +                error_setg(errp, "Cannot enable NFS readahead "
> +                                 "if cache.direct = on");
> +                goto fail;
> +            }
>              if (val > QEMU_NFS_MAX_READAHEAD_SIZE) {
>                  error_report("NFS Warning: Truncating NFS readahead"
>                               " size to %d", QEMU_NFS_MAX_READAHEAD_SIZE);
> -- 
> 1.9.1
>

Do we to check for cache mode changes now in nfs_reopen_prepare()?