fuse: fix ioctl ABI

In kernel ABI version 7.16 and later FUSE_IOCTL_RETRY reply from a
unrestricted IOCTL request shall return with an array of 'struct
fuse_ioctl_iovec' instead of 'struct iovec'.  This fixes the ABI
ambiguity of 32bit vs. 64bit.

Reported-by: "ccmail111" <ccmail111@yahoo.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: Tejun Heo <tj@kernel.org>
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index cf11881..d464de5 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -44,6 +44,9 @@
  *
  * 7.16
  *  - add BATCH_FORGET request
+ *  - FUSE_IOCTL_UNRESTRICTED shall now return with array of 'struct
+ *    fuse_ioctl_iovec' instead of ambiguous 'struct iovec'
+ *  - add FUSE_IOCTL_32BIT flag
  */
 
 #ifndef _LINUX_FUSE_H
@@ -203,12 +206,14 @@
  * FUSE_IOCTL_COMPAT: 32bit compat ioctl on 64bit machine
  * FUSE_IOCTL_UNRESTRICTED: not restricted to well-formed ioctls, retry allowed
  * FUSE_IOCTL_RETRY: retry with new iovecs
+ * FUSE_IOCTL_32BIT: 32bit ioctl
  *
  * FUSE_IOCTL_MAX_IOV: maximum of in_iovecs + out_iovecs
  */
 #define FUSE_IOCTL_COMPAT	(1 << 0)
 #define FUSE_IOCTL_UNRESTRICTED	(1 << 1)
 #define FUSE_IOCTL_RETRY	(1 << 2)
+#define FUSE_IOCTL_32BIT	(1 << 3)
 
 #define FUSE_IOCTL_MAX_IOV	256
 
@@ -524,6 +529,11 @@
 	__u32	out_size;
 };
 
+struct fuse_ioctl_iovec {
+	__u64	base;
+	__u64	len;
+};
+
 struct fuse_ioctl_out {
 	__s32	result;
 	__u32	flags;