66 lines
1.9 KiB
C
66 lines
1.9 KiB
C
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#ifndef PAGE_ACTOR_H
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#define PAGE_ACTOR_H
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/*
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* Copyright (c) 2013
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* Phillip Lougher <phillip@squashfs.org.uk>
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level squashfsory.
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*/
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struct squashfs_page_actor {
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struct page **page;
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void *pageaddr;
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int pages;
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int length;
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int next_page;
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void (*release_pages)(struct page **, int, int);
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};
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extern struct squashfs_page_actor *squashfs_page_actor_init(struct page **,
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int, int, void (*)(struct page **, int, int));
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extern void squashfs_page_actor_free(struct squashfs_page_actor *, int);
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extern void squashfs_actor_to_buf(struct squashfs_page_actor *, void *, int);
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extern void squashfs_buf_to_actor(void *, struct squashfs_page_actor *, int);
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extern void squashfs_bh_to_actor(struct buffer_head **, int,
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struct squashfs_page_actor *, int, int, int);
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extern void squashfs_bh_to_buf(struct buffer_head **, int, void *, int, int,
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int);
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/*
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* Calling code should avoid sleeping between calls to squashfs_first_page()
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* and squashfs_finish_page().
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*/
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static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
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{
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actor->next_page = 1;
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return actor->pageaddr = actor->page[0] ? kmap_atomic(actor->page[0])
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: NULL;
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}
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static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
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{
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if (!IS_ERR_OR_NULL(actor->pageaddr))
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kunmap_atomic(actor->pageaddr);
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if (actor->next_page == actor->pages)
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return actor->pageaddr = ERR_PTR(-ENODATA);
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actor->pageaddr = actor->page[actor->next_page] ?
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kmap_atomic(actor->page[actor->next_page]) : NULL;
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++actor->next_page;
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return actor->pageaddr;
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}
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static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
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{
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if (!IS_ERR_OR_NULL(actor->pageaddr))
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kunmap_atomic(actor->pageaddr);
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}
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extern struct page **alloc_page_array(int, int);
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extern void free_page_array(struct page **, int);
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#endif
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