include/linux/pagevec.h

   1 /*
   2  * include/linux/pagevec.h
   3  *
   4  * In many places it is efficient to batch an operation up against multiple
   5  * pages.  A pagevec is a multipage container which is used for that.
   6  */
   7
   8 #ifndef _LINUX_PAGEVEC_H
   9 #define _LINUX_PAGEVEC_H
  10
  11 /* 14 pointers + two long's align the pagevec structure to a power of two */
  12 #define PAGEVEC_SIZE    14
  13
  14 struct page;
  15 struct address_space;
  16
  17 struct pagevec {
  18         unsigned long nr;
  19         unsigned long cold;
  20         struct page *pages[PAGEVEC_SIZE];
  21 };
  22
  23 void __pagevec_release(struct pagevec *pvec);
  24 void __pagevec_lru_add(struct pagevec *pvec);
  25 unsigned pagevec_lookup_entries(struct pagevec *pvec,
  26                                 struct address_space *mapping,
  27                                 pgoff_t start, unsigned nr_entries,
  28                                 pgoff_t *indices);
  29 void pagevec_remove_exceptionals(struct pagevec *pvec);
  30 unsigned pagevec_lookup_range(struct pagevec *pvec,
  31                               struct address_space *mapping,
  32                               pgoff_t *start, pgoff_t end);
  33 static inline unsigned pagevec_lookup(struct pagevec *pvec,
  34                                       struct address_space *mapping,
  35                                       pgoff_t *start)
  36 {
  37         return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1);
  38 }
  39
  40 unsigned pagevec_lookup_tag(struct pagevec *pvec,
  41                 struct address_space *mapping, pgoff_t *index, int tag,
  42                 unsigned nr_pages);
  43
  44 static inline void pagevec_init(struct pagevec *pvec, int cold)
  45 {
  46         pvec->nr = 0;
  47         pvec->cold = cold;
  48 }
  49
  50 static inline void pagevec_reinit(struct pagevec *pvec)
  51 {
  52         pvec->nr = 0;
  53 }
  54
  55 static inline unsigned pagevec_count(struct pagevec *pvec)
  56 {
  57         return pvec->nr;
  58 }
  59
  60 static inline unsigned pagevec_space(struct pagevec *pvec)
  61 {
  62         return PAGEVEC_SIZE - pvec->nr;
  63 }
  64
  65 /*
  66  * Add a page to a pagevec.  Returns the number of slots still available.
  67  */
  68 static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  69 {
  70         pvec->pages[pvec->nr++] = page;
  71         return pagevec_space(pvec);
  72 }
  73
  74 static inline void pagevec_release(struct pagevec *pvec)
  75 {
  76         if (pagevec_count(pvec))
  77                 __pagevec_release(pvec);
  78 }
  79
  80 #endif /* _LINUX_PAGEVEC_H */