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- /* SPDX-License-Identifier: GPL-2.0 */
- /*
- * include/linux/pagevec.h
- *
- * In many places it is efficient to batch an operation up against multiple
- * pages. A pagevec is a multipage container which is used for that.
- */
- #ifndef _LINUX_PAGEVEC_H
- #define _LINUX_PAGEVEC_H
- #include <linux/xarray.h>
- /* 15 pointers + header align the pagevec structure to a power of two */
- #define PAGEVEC_SIZE 15
- struct page;
- struct folio;
- struct address_space;
- /* Layout must match folio_batch */
- struct pagevec {
- unsigned char nr;
- bool percpu_pvec_drained;
- struct page *pages[PAGEVEC_SIZE];
- };
- void __pagevec_release(struct pagevec *pvec);
- unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
- struct address_space *mapping, pgoff_t *index, pgoff_t end,
- xa_mark_t tag);
- static inline unsigned pagevec_lookup_tag(struct pagevec *pvec,
- struct address_space *mapping, pgoff_t *index, xa_mark_t tag)
- {
- return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag);
- }
- static inline void pagevec_init(struct pagevec *pvec)
- {
- pvec->nr = 0;
- pvec->percpu_pvec_drained = false;
- }
- static inline void pagevec_reinit(struct pagevec *pvec)
- {
- pvec->nr = 0;
- }
- static inline unsigned pagevec_count(struct pagevec *pvec)
- {
- return pvec->nr;
- }
- static inline unsigned pagevec_space(struct pagevec *pvec)
- {
- return PAGEVEC_SIZE - pvec->nr;
- }
- /*
- * Add a page to a pagevec. Returns the number of slots still available.
- */
- static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
- {
- pvec->pages[pvec->nr++] = page;
- return pagevec_space(pvec);
- }
- static inline void pagevec_release(struct pagevec *pvec)
- {
- if (pagevec_count(pvec))
- __pagevec_release(pvec);
- }
- /**
- * struct folio_batch - A collection of folios.
- *
- * The folio_batch is used to amortise the cost of retrieving and
- * operating on a set of folios. The order of folios in the batch may be
- * significant (eg delete_from_page_cache_batch()). Some users of the
- * folio_batch store "exceptional" entries in it which can be removed
- * by calling folio_batch_remove_exceptionals().
- */
- struct folio_batch {
- unsigned char nr;
- bool percpu_pvec_drained;
- struct folio *folios[PAGEVEC_SIZE];
- };
- /* Layout must match pagevec */
- static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch));
- static_assert(offsetof(struct pagevec, pages) ==
- offsetof(struct folio_batch, folios));
- /**
- * folio_batch_init() - Initialise a batch of folios
- * @fbatch: The folio batch.
- *
- * A freshly initialised folio_batch contains zero folios.
- */
- static inline void folio_batch_init(struct folio_batch *fbatch)
- {
- fbatch->nr = 0;
- fbatch->percpu_pvec_drained = false;
- }
- static inline unsigned int folio_batch_count(struct folio_batch *fbatch)
- {
- return fbatch->nr;
- }
- static inline unsigned int fbatch_space(struct folio_batch *fbatch)
- {
- return PAGEVEC_SIZE - fbatch->nr;
- }
- /**
- * folio_batch_add() - Add a folio to a batch.
- * @fbatch: The folio batch.
- * @folio: The folio to add.
- *
- * The folio is added to the end of the batch.
- * The batch must have previously been initialised using folio_batch_init().
- *
- * Return: The number of slots still available.
- */
- static inline unsigned folio_batch_add(struct folio_batch *fbatch,
- struct folio *folio)
- {
- fbatch->folios[fbatch->nr++] = folio;
- return fbatch_space(fbatch);
- }
- static inline void folio_batch_release(struct folio_batch *fbatch)
- {
- pagevec_release((struct pagevec *)fbatch);
- }
- void folio_batch_remove_exceptionals(struct folio_batch *fbatch);
- #endif /* _LINUX_PAGEVEC_H */
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