xref: /linux/fs/squashfs/page_actor.h (revision 55d0969c451159cff86949b38c39171cab962069)
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 
9 struct 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 
28 extern struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
29 				int pages, int length);
30 extern 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);
34 static 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 }
43 static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
44 {
45 	return actor->squashfs_first_page(actor);
46 }
47 static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
48 {
49 	return actor->squashfs_next_page(actor);
50 }
51 static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
52 {
53 	actor->squashfs_finish_page(actor);
54 }
55 static inline void squashfs_actor_nobuff(struct squashfs_page_actor *actor)
56 {
57 	actor->alloc_buffer = 0;
58 }
59 #endif
60