From: "Michael S. Tsirkin" <mst@redhat.com>
Date: Wed, 4 Sep 2019 08:36:33 -0400
Subject: fuse: reserve byteswapped init opcodes
Git-commit: 501ae8ecae2ba5122774dee4445003505a7fd01b
Patch-mainline: v5.4-rc1
References: jsc#SLE-13782
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.
Same for CUSE_INIT.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Luis Henriques <lhenriques@suse.com>
---
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..df2e12fb3381 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 */
+ CUSE_INIT_BSWAP_RESERVED = 1048576, /* CUSE_INIT << 8 */
+ FUSE_INIT_BSWAP_RESERVED = 436207616, /* FUSE_INIT << 24 */
};
enum fuse_notify_code {