convenience helper: get_tree_single()

counterpart of mount_single(); switch fusectl to it
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/fuse/control.c

@@ -346,7 +346,7 @@ static int fuse_ctl_fill_super(struct super_block *sb, struct fs_context *fctx)
 
 static int fuse_ctl_get_tree(struct fs_context *fc)
 {
-	return vfs_get_super(fc, vfs_get_single_super, fuse_ctl_fill_super);
+	return get_tree_single(fc, fuse_ctl_fill_super);
 }
 
 static const struct fs_context_operations fuse_ctl_context_ops = {

fs/super.c

@@ -1206,6 +1206,14 @@ int get_tree_nodev(struct fs_context *fc,
 }
 EXPORT_SYMBOL(get_tree_nodev);
 
+int get_tree_single(struct fs_context *fc,
+		  int (*fill_super)(struct super_block *sb,
+				    struct fs_context *fc))
+{
+	return vfs_get_super(fc, vfs_get_single_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_single);
+
 #ifdef CONFIG_BLOCK
 static int set_bdev_super(struct super_block *s, void *data)
 {

include/linux/fs_context.h

@@ -154,6 +154,9 @@ extern int vfs_get_super(struct fs_context *fc,
 extern int get_tree_nodev(struct fs_context *fc,
 			 int (*fill_super)(struct super_block *sb,
 					   struct fs_context *fc));
+extern int get_tree_single(struct fs_context *fc,
+			 int (*fill_super)(struct super_block *sb,
+					   struct fs_context *fc));
 
 extern const struct file_operations fscontext_fops;