NFSv4.2 fix unnecessary retry in nfs4_copy_file_range

commit 45ac486ecf2dc998e25cf32f0cabf2deaad875be upstream.

Currently nfs42_proc_copy_file_range() can not return EAGAIN.

Fixes: e4648aa4 ("NFS recover from destination server reboot for copies")
Signed-off-by: NOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Acked-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: NCaspar Zhang <caspar@linux.alibaba.com>

fs/nfs/nfs4file.c

@@ -133,15 +133,9 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
 				    struct file *file_out, loff_t pos_out,
 				    size_t count, unsigned int flags)
 {
-	ssize_t ret;
-
 	if (file_inode(file_in) == file_inode(file_out))
 		return -EINVAL;
-retry:
-	ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
-	if (ret == -EAGAIN)
-		goto retry;
-	return ret;
+	return nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
 }
 
 static loff_t nfs4_file_llseek(struct file *filep, loff_t offset, int whence)