kernel-ark/fs/squashfs/page_actor.h

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#ifndef PAGE_ACTOR_H
#define PAGE_ACTOR_H
/*
* Copyright (c) 2013
* Phillip Lougher <phillip@squashfs.org.uk>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*/
#ifndef CONFIG_SQUASHFS_FILE_DIRECT
struct squashfs_page_actor {
void **page;
int pages;
int length;
int next_page;
};
static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
int pages, int length)
{
struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
if (actor == NULL)
return NULL;
actor->length = length ? : pages * PAGE_CACHE_SIZE;
actor->page = page;
actor->pages = pages;
actor->next_page = 0;
return actor;
}
static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
actor->next_page = 1;
return actor->page[0];
}
static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
return actor->next_page == actor->pages ? NULL :
actor->page[actor->next_page++];
}
static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
/* empty */
}
#else
struct squashfs_page_actor {
union {
void **buffer;
struct page **page;
};
void *pageaddr;
void *(*squashfs_first_page)(struct squashfs_page_actor *);
void *(*squashfs_next_page)(struct squashfs_page_actor *);
void (*squashfs_finish_page)(struct squashfs_page_actor *);
int pages;
int length;
int next_page;
};
extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int);
extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page
**, int, int);
static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
{
return actor->squashfs_first_page(actor);
}
static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
{
return actor->squashfs_next_page(actor);
}
static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
{
actor->squashfs_finish_page(actor);
}
#endif
#endif