page_actor.h

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2#ifndef PAGE_ACTOR_H
 3#define PAGE_ACTOR_H
 4/*
 5 * Copyright (c) 2013
 6 * Phillip Lougher <phillip@squashfs.org.uk>
 7 */
 8
 9struct squashfs_page_actor {
10	union {
11		void		**buffer;
12		struct page	**page;
13	};
14	void	*pageaddr;
15	void	*tmp_buffer;
16	void    *(*squashfs_first_page)(struct squashfs_page_actor *);
17	void    *(*squashfs_next_page)(struct squashfs_page_actor *);
18	void    (*squashfs_finish_page)(struct squashfs_page_actor *);
19	struct page *last_page;
20	int	pages;
21	int	length;
22	int	next_page;
23	int	alloc_buffer;
24	int	returned_pages;
25	pgoff_t	next_index;
26};
27
28extern struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
29				int pages, int length);
30extern struct squashfs_page_actor *squashfs_page_actor_init_special(
31				struct squashfs_sb_info *msblk,
32				struct page **page, int pages, int length,
33				loff_t start_index);
34static inline struct page *squashfs_page_actor_free(struct squashfs_page_actor *actor)
35{
36	struct page *last_page = actor->next_page == actor->pages ? actor->last_page : ERR_PTR(-EIO);
37
38	kfree(actor->tmp_buffer);
39	kfree(actor);
40
41	return last_page;
42}
43static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
44{
45	return actor->squashfs_first_page(actor);
46}
47static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
48{
49	return actor->squashfs_next_page(actor);
50}
51static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
52{
53	actor->squashfs_finish_page(actor);
54}
55static inline void squashfs_actor_nobuff(struct squashfs_page_actor *actor)
56{
57	actor->alloc_buffer = 0;
58}
59#endif