fs/squashfs/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
   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