Merge tag 'folio-5.17a' of git://git.infradead.org/users/willy/pagecache

Pull more folio updates from Matthew Wilcox:
 "Three small folio patches.

  One bug fix, one patch pulled forward from the patches destined for
  5.18 and then a patch to make use of that functionality"

* tag 'folio-5.17a' of git://git.infradead.org/users/willy/pagecache:
  filemap: Use folio_put_refs() in filemap_free_folio()
  mm: Add folio_put_refs()
  pagevec: Initialise folio_batch->percpu_pvec_drained

2 files changed, 21 insertions, 0 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index aa47705191bc..e1a84b1e6787 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1199,6 +1199,26 @@ static inline void folio_put(struct folio *folio)
 		__put_page(&folio->page);
 }
 
+/**
+ * folio_put_refs - Reduce the reference count on a folio.
+ * @folio: The folio.
+ * @refs: The amount to subtract from the folio's reference count.
+ *
+ * If the folio's reference count reaches zero, the memory will be
+ * released back to the page allocator and may be used by another
+ * allocation immediately.  Do not access the memory or the struct folio
+ * after calling folio_put_refs() unless you can be sure that these weren't
+ * the last references.
+ *
+ * Context: May be called in process or interrupt context, but not in NMI
+ * context.  May be called while holding a spinlock.
+ */
+static inline void folio_put_refs(struct folio *folio, int refs)
+{
+	if (folio_ref_sub_and_test(folio, refs))
+		__put_page(&folio->page);
+}
+
 static inline void put_page(struct page *page)
 {
 	struct folio *folio = page_folio(page);
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
index dda8d5868c81..67b1246f136b 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -111,6 +111,7 @@ static_assert(offsetof(struct pagevec, pages) ==
 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)