mm/rmap: Turn page_lock_anon_vma_read() into folio_lock_anon_vma_read()
Add back page_lock_anon_vma_read() as a wrapper. This saves a few calls
to compound_head(). If any callers were passing a tail page before,
this would have failed to lock the anon VMA as page->mapping is not
valid for tail pages.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
diff --git a/mm/rmap.c b/mm/rmap.c
index c74de8a..64655d3 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -526,28 +526,28 @@ struct anon_vma *page_get_anon_vma(struct page *page)
* atomic op -- the trylock. If we fail the trylock, we fall back to getting a
* reference like with page_get_anon_vma() and then block on the mutex.
*/
-struct anon_vma *page_lock_anon_vma_read(struct page *page)
+struct anon_vma *folio_lock_anon_vma_read(struct folio *folio)
{
struct anon_vma *anon_vma = NULL;
struct anon_vma *root_anon_vma;
unsigned long anon_mapping;
rcu_read_lock();
- anon_mapping = (unsigned long)READ_ONCE(page->mapping);
+ anon_mapping = (unsigned long)READ_ONCE(folio->mapping);
if ((anon_mapping & PAGE_MAPPING_FLAGS) != PAGE_MAPPING_ANON)
goto out;
- if (!page_mapped(page))
+ if (!folio_mapped(folio))
goto out;
anon_vma = (struct anon_vma *) (anon_mapping - PAGE_MAPPING_ANON);
root_anon_vma = READ_ONCE(anon_vma->root);
if (down_read_trylock(&root_anon_vma->rwsem)) {
/*
- * If the page is still mapped, then this anon_vma is still
+ * If the folio is still mapped, then this anon_vma is still
* its anon_vma, and holding the mutex ensures that it will
* not go away, see anon_vma_free().
*/
- if (!page_mapped(page)) {
+ if (!folio_mapped(folio)) {
up_read(&root_anon_vma->rwsem);
anon_vma = NULL;
}
@@ -560,7 +560,7 @@ struct anon_vma *page_lock_anon_vma_read(struct page *page)
goto out;
}
- if (!page_mapped(page)) {
+ if (!folio_mapped(folio)) {
rcu_read_unlock();
put_anon_vma(anon_vma);
return NULL;
