v4.19.13 snapshot.
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
new file mode 100644
index 0000000..6dc456a
--- /dev/null
+++ b/include/linux/pagevec.h
@@ -0,0 +1,89 @@
+/* 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
+
+/* 15 pointers + header align the pagevec structure to a power of two */
+#define PAGEVEC_SIZE 15
+
+struct page;
+struct address_space;
+
+struct pagevec {
+ unsigned char nr;
+ bool percpu_pvec_drained;
+ struct page *pages[PAGEVEC_SIZE];
+};
+
+void __pagevec_release(struct pagevec *pvec);
+void __pagevec_lru_add(struct pagevec *pvec);
+unsigned pagevec_lookup_entries(struct pagevec *pvec,
+ struct address_space *mapping,
+ pgoff_t start, unsigned nr_entries,
+ pgoff_t *indices);
+void pagevec_remove_exceptionals(struct pagevec *pvec);
+unsigned pagevec_lookup_range(struct pagevec *pvec,
+ struct address_space *mapping,
+ pgoff_t *start, pgoff_t end);
+static inline unsigned pagevec_lookup(struct pagevec *pvec,
+ struct address_space *mapping,
+ pgoff_t *start)
+{
+ return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1);
+}
+
+unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
+ struct address_space *mapping, pgoff_t *index, pgoff_t end,
+ int tag);
+unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec,
+ struct address_space *mapping, pgoff_t *index, pgoff_t end,
+ int tag, unsigned max_pages);
+static inline unsigned pagevec_lookup_tag(struct pagevec *pvec,
+ struct address_space *mapping, pgoff_t *index, int 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);
+}
+
+#endif /* _LINUX_PAGEVEC_H */