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
diff --git a/include/linux/mm.h b/include/linux/mm.h
index aa47705..e1a84b1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1199,6 +1199,26 @@
__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 dda8d58..67b1246 100644
--- a/include/linux/pagevec.h
+++ b/include/linux/pagevec.h
@@ -111,6 +111,7 @@
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)
diff --git a/mm/filemap.c b/mm/filemap.c
index 2fd9b2f..afc8f5c 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -231,17 +231,15 @@
void filemap_free_folio(struct address_space *mapping, struct folio *folio)
{
void (*freepage)(struct page *);
+ int refs = 1;
freepage = mapping->a_ops->freepage;
if (freepage)
freepage(&folio->page);
- if (folio_test_large(folio) && !folio_test_hugetlb(folio)) {
- folio_ref_sub(folio, folio_nr_pages(folio));
- VM_BUG_ON_FOLIO(folio_ref_count(folio) <= 0, folio);
- } else {
- folio_put(folio);
- }
+ if (folio_test_large(folio) && !folio_test_hugetlb(folio))
+ refs = folio_nr_pages(folio);
+ folio_put_refs(folio, refs);
}
/**
