fuse: implement nonseekable open

Let the client request nonseekable open using FOPEN_NONSEEKABLE and
call nonseekable_open() on the file if requested.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 98079aa..34930a9 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -101,6 +101,8 @@
 		file->f_op = &fuse_direct_io_file_operations;
 	if (!(outarg->open_flags & FOPEN_KEEP_CACHE))
 		invalidate_inode_pages2(inode->i_mapping);
+	if (outarg->open_flags & FOPEN_NONSEEKABLE)
+		nonseekable_open(inode, file);
 	ff->fh = outarg->fh;
 	file->private_data = fuse_file_get(ff);
 }