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/include/linux/rmap.h b/include/linux/rmap.h
index 21af80d5b711bc06542dfda008e5853509dc31dc..be020d38b0a5c4b4083aa070c98e8f2bf9737491 100644 (file)
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -267,6 +267,7 @@ void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked);
  * Called by memory-failure.c to kill processes.
  */
 struct anon_vma *page_lock_anon_vma_read(struct page *page);
+struct anon_vma *folio_lock_anon_vma_read(struct folio *folio);
 void page_unlock_anon_vma_read(struct anon_vma *anon_vma);
 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
 

diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 46fa179e32fb262306e459dae71ed92bd59d250e..968ad97bbffa9d093647f8743e20f7cdc9c91bf7 100644 (file)
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -164,3 +164,10 @@ void putback_lru_page(struct page *page)
 {
        folio_putback_lru(page_folio(page));
 }
+
+#ifdef CONFIG_MMU
+struct anon_vma *page_lock_anon_vma_read(struct page *page)
+{
+       return folio_lock_anon_vma_read(page_folio(page));
+}
+#endif

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 258913d5e036b7c3173fa4c1156c1b2294edd681..aa8236848949f5fe337dc7762253e27c1808a8cc 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -487,12 +487,13 @@ static struct task_struct *task_early_kill(struct task_struct *tsk,
 static void collect_procs_anon(struct page *page, struct list_head *to_kill,
                                int force_early)
 {
+       struct folio *folio = page_folio(page);
        struct vm_area_struct *vma;
        struct task_struct *tsk;
        struct anon_vma *av;
        pgoff_t pgoff;
 
-       av = page_lock_anon_vma_read(page);
+       av = folio_lock_anon_vma_read(folio);
        if (av == NULL) /* Not actually mapped anymore */
                return;
 

diff --git a/mm/rmap.c b/mm/rmap.c
index c74de8af7eecb65eab8752355467d46949edf5db..64655d345234184c8f45f21d49622f630b45a013 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -526,28 +526,28 @@ out:
  * 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;