convenience helper get_tree_nodev()

counterpart of mount_nodev().  Switch hugetlb and pseudo to it.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hugetlbfs/inode.c

@@ -1299,7 +1299,7 @@ static int hugetlbfs_get_tree(struct fs_context *fc)
 	int err = hugetlbfs_validate(fc);
 	if (err)
 		return err;
-	return vfs_get_super(fc, vfs_get_independent_super, hugetlbfs_fill_super);
+	return get_tree_nodev(fc, hugetlbfs_fill_super);
 }
 
 static void hugetlbfs_fs_context_free(struct fs_context *fc)

fs/libfs.c

@@ -270,7 +270,7 @@ static int pseudo_fs_fill_super(struct super_block *s, struct fs_context *fc)
 
 static int pseudo_fs_get_tree(struct fs_context *fc)
 {
-	return vfs_get_super(fc, vfs_get_independent_super, pseudo_fs_fill_super);
+	return get_tree_nodev(fc, pseudo_fs_fill_super);
 }
 
 static void pseudo_fs_free(struct fs_context *fc)

fs/super.c

@@ -1198,6 +1198,14 @@ int vfs_get_super(struct fs_context *fc,
 }
 EXPORT_SYMBOL(vfs_get_super);
 
+int get_tree_nodev(struct fs_context *fc,
+		  int (*fill_super)(struct super_block *sb,
+				    struct fs_context *fc))
+{
+	return vfs_get_super(fc, vfs_get_independent_super, fill_super);
+}
+EXPORT_SYMBOL(get_tree_nodev);
+
 #ifdef CONFIG_BLOCK
 static int set_bdev_super(struct super_block *s, void *data)
 {

include/linux/fs_context.h

@@ -151,6 +151,9 @@ extern int vfs_get_super(struct fs_context *fc,
 			 enum vfs_get_super_keying keying,
 			 int (*fill_super)(struct super_block *sb,
 					   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 const struct file_operations fscontext_fops;