nfs: use btrfs ioctl defintions for clone

The NFS CLONE_RANGE defintion was wrong and thus never worked.  Fix this
by simply using the btrfs ioctl defintion.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/nfs4file.c

@@ -7,6 +7,7 @@
 #include <linux/file.h>
 #include <linux/falloc.h>
 #include <linux/nfs_fs.h>
+#include <uapi/linux/btrfs.h>	/* BTRFS_IOC_CLONE/BTRFS_IOC_CLONE_RANGE */
 #include "delegation.h"
 #include "internal.h"
 #include "iostat.h"
@@ -300,12 +301,13 @@ nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
 
 static long nfs42_ioctl_clone_range(struct file *dst_file, void __user *argp)
 {
-	struct nfs_ioctl_clone_range_args args;
+	struct btrfs_ioctl_clone_range_args args;
 
 	if (copy_from_user(&args, argp, sizeof(args)))
 		return -EFAULT;
 
-	return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_off, args.dst_off, args.count);
+	return nfs42_ioctl_clone(dst_file, args.src_fd, args.src_offset,
+				 args.dest_offset, args.src_length);
 }
 #else
 static long nfs42_ioctl_clone(struct file *dst_file, unsigned long srcfd,
@@ -325,9 +327,9 @@ long nfs4_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	void __user *argp = (void __user *)arg;
 
 	switch (cmd) {
-	case NFS_IOC_CLONE:
+	case BTRFS_IOC_CLONE:
 		return nfs42_ioctl_clone(file, arg, 0, 0, 0);
-	case NFS_IOC_CLONE_RANGE:
+	case BTRFS_IOC_CLONE_RANGE:
 		return nfs42_ioctl_clone_range(file, argp);
 	}
 

include/uapi/linux/nfs.h

@@ -33,17 +33,6 @@
 
 #define NFS_PIPE_DIRNAME "nfs"
 
-/* NFS ioctls */
-/* Let's follow btrfs lead on CLONE to avoid messing userspace */
-#define NFS_IOC_CLONE		_IOW(0x94, 9, int)
-#define NFS_IOC_CLONE_RANGE	_IOW(0x94, 13, int)
-
-struct nfs_ioctl_clone_range_args {
-	__s64 src_fd;
-	__u64 src_off, count;
-	__u64 dst_off;
-};
-
 /*
  * NFS stats. The good thing with these values is that NFSv3 errors are
  * a superset of NFSv2 errors (with the exception of NFSERR_WFLUSH which