* Michael S. Tsirkin (mst@xxxxxxxxxx) wrote:
> virtio fs tunnels fuse over a virtio channel. One issue is two sides
> might be speaking different endian-ness. To detects this,
> host side looks at the opcode value in the FUSE_INIT command.
> Works fine at the moment but might fail if a future version
> of fuse will use such an opcode for initialization.
> Let's reserve this opcode so we remember and don't do this.
I think in theory that works even for normal fuse.
> Same for CUSE_INIT.
>
> Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
> ---
> include/uapi/linux/fuse.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/include/uapi/linux/fuse.h b/include/uapi/linux/fuse.h
> index 2971d29a42e4..f042e63f4aa0 100644
> --- a/include/uapi/linux/fuse.h
> +++ b/include/uapi/linux/fuse.h
> @@ -425,6 +425,10 @@ enum fuse_opcode {
>
> /* CUSE specific operations */
> CUSE_INIT = 4096,
> +
> + /* Reserved opcodes: helpful to detect structure endian-ness */
> + FUSE_INIT_BSWAP_RESERVED = 26 << 24,
FUSE_INIT << 24 probably works?
> + CUSE_INIT_BSWAP_RESERVED = 16 << 16,
Dave
> };
>
> enum fuse_notify_code {
> --
> MST
--
Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK
