LXR linux/include/linux/pagevec.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * include/linux/pagevec.h
   4 *
   5 * In many places it is efficient to batch an operation up against multiple
   6 * pages.  A pagevec is a multipage container which is used for that.
   7 */
   8
   9#ifndef _LINUX_PAGEVEC_H
  10#define _LINUX_PAGEVEC_H
  11
  12/* 15 pointers + header align the pagevec structure to a power of two */
  13#define PAGEVEC_SIZE    15
  14
  15struct page;
  16struct address_space;
  17
  18struct pagevec {
  19        unsigned char nr;
  20        bool percpu_pvec_drained;
  21        struct page *pages[PAGEVEC_SIZE];
  22};
  23
  24void __pagevec_release(struct pagevec *pvec);
  25void __pagevec_lru_add(struct pagevec *pvec);
  26unsigned pagevec_lookup_entries(struct pagevec *pvec,
  27                                struct address_space *mapping,
  28                                pgoff_t start, unsigned nr_entries,
  29                                pgoff_t *indices);
  30void pagevec_remove_exceptionals(struct pagevec *pvec);
  31unsigned pagevec_lookup_range(struct pagevec *pvec,
  32                              struct address_space *mapping,
  33                              pgoff_t *start, pgoff_t end);
  34static inline unsigned pagevec_lookup(struct pagevec *pvec,
  35                                      struct address_space *mapping,
  36                                      pgoff_t *start)
  37{
  38        return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1);
  39}
  40
  41unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
  42                struct address_space *mapping, pgoff_t *index, pgoff_t end,
  43                int tag);
  44unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec,
  45                struct address_space *mapping, pgoff_t *index, pgoff_t end,
  46                int tag, unsigned max_pages);
  47static inline unsigned pagevec_lookup_tag(struct pagevec *pvec,
  48                struct address_space *mapping, pgoff_t *index, int tag)
  49{
  50        return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag);
  51}
  52
  53static inline void pagevec_init(struct pagevec *pvec)
  54{
  55        pvec->nr = 0;
  56        pvec->percpu_pvec_drained = false;
  57}
  58
  59static inline void pagevec_reinit(struct pagevec *pvec)
  60{
  61        pvec->nr = 0;
  62}
  63
  64static inline unsigned pagevec_count(struct pagevec *pvec)
  65{
  66        return pvec->nr;
  67}
  68
  69static inline unsigned pagevec_space(struct pagevec *pvec)
  70{
  71        return PAGEVEC_SIZE - pvec->nr;
  72}
  73
  74/*
  75 * Add a page to a pagevec.  Returns the number of slots still available.
  76 */
  77static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
  78{
  79        pvec->pages[pvec->nr++] = page;
  80        return pagevec_space(pvec);
  81}
  82
  83static inline void pagevec_release(struct pagevec *pvec)
  84{
  85        if (pagevec_count(pvec))
  86                __pagevec_release(pvec);
  87}
  88
  89#endif /* _LINUX_PAGEVEC_H */
  90