[PATCH v3 03/11] mm: Return the address from page_mapped_in_vma()

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

The only user of this function calls page_address_in_vma() immediately
after page_mapped_in_vma() calculates it and uses it to return true/false.
Return the address instead, allowing memory-failure to skip the call
to page_address_in_vma().

Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Jane Chu <jane.chu@oracle.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/rmap.h |  2 +-
 mm/memory-failure.c  | 22 +++++++++++++---------
 mm/page_vma_mapped.c | 16 +++++++++-------
 3 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 0f906dc6d280..7229b9baf20d 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -730,7 +730,7 @@ int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff,
 
 void remove_migration_ptes(struct folio *src, struct folio *dst, bool locked);
 
-int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
+unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
 
 /*
  * rmap_walk_control: To control rmap traversing for specific needs
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index aec407788df1..0ad6b8936512 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -467,10 +467,11 @@ static void __add_to_kill(struct task_struct *tsk, struct page *p,
 }
 
 static void add_to_kill_anon_file(struct task_struct *tsk, struct page *p,
-				  struct vm_area_struct *vma,
-				  struct list_head *to_kill)
+		struct vm_area_struct *vma, struct list_head *to_kill,
+		unsigned long addr)
 {
-	unsigned long addr = page_address_in_vma(p, vma);
+	if (addr == -EFAULT)
+		return;
 	__add_to_kill(tsk, p, vma, to_kill, addr);
 }
 
@@ -595,7 +596,6 @@ struct task_struct *task_early_kill(struct task_struct *tsk, int force_early)
 static void collect_procs_anon(struct folio *folio, struct page *page,
 		struct list_head *to_kill, int force_early)
 {
-	struct vm_area_struct *vma;
 	struct task_struct *tsk;
 	struct anon_vma *av;
 	pgoff_t pgoff;
@@ -607,8 +607,10 @@ static void collect_procs_anon(struct folio *folio, struct page *page,
 	pgoff = page_to_pgoff(page);
 	rcu_read_lock();
 	for_each_process(tsk) {
+		struct vm_area_struct *vma;
 		struct anon_vma_chain *vmac;
 		struct task_struct *t = task_early_kill(tsk, force_early);
+		unsigned long addr;
 
 		if (!t)
 			continue;
@@ -617,9 +619,8 @@ static void collect_procs_anon(struct folio *folio, struct page *page,
 			vma = vmac->vma;
 			if (vma->vm_mm != t->mm)
 				continue;
-			if (!page_mapped_in_vma(page, vma))
-				continue;
-			add_to_kill_anon_file(t, page, vma, to_kill);
+			addr = page_mapped_in_vma(page, vma);
+			add_to_kill_anon_file(t, page, vma, to_kill, addr);
 		}
 	}
 	rcu_read_unlock();
@@ -642,6 +643,7 @@ static void collect_procs_file(struct folio *folio, struct page *page,
 	pgoff = page_to_pgoff(page);
 	for_each_process(tsk) {
 		struct task_struct *t = task_early_kill(tsk, force_early);
+		unsigned long addr;
 
 		if (!t)
 			continue;
@@ -654,8 +656,10 @@ static void collect_procs_file(struct folio *folio, struct page *page,
 			 * Assume applications who requested early kill want
 			 * to be informed of all such data corruptions.
 			 */
-			if (vma->vm_mm == t->mm)
-				add_to_kill_anon_file(t, page, vma, to_kill);
+			if (vma->vm_mm != t->mm)
+				continue;
+			addr = page_address_in_vma(page, vma);
+			add_to_kill_anon_file(t, page, vma, to_kill, addr);
 		}
 	}
 	rcu_read_unlock();
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 53b8868ede61..c202eab84936 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -319,11 +319,12 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw)
  * @page: the page to test
  * @vma: the VMA to test
  *
- * Returns 1 if the page is mapped into the page tables of the VMA, 0
- * if the page is not mapped into the page tables of this VMA.  Only
- * valid for normal file or anonymous VMAs.
+ * Return: The address the page is mapped at if the page is in the range
+ * covered by the VMA and present in the page table.  If the page is
+ * outside the VMA or not present, returns -EFAULT.
+ * Only valid for normal file or anonymous VMAs.
  */
-int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
+unsigned long page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
 {
 	struct folio *folio = page_folio(page);
 	pgoff_t pgoff = folio->index + folio_page_idx(folio, page);
@@ -336,9 +337,10 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
 
 	pvmw.address = vma_address(vma, pgoff, 1);
 	if (pvmw.address == -EFAULT)
-		return 0;
+		goto out;
 	if (!page_vma_mapped_walk(&pvmw))
-		return 0;
+		return -EFAULT;
 	page_vma_mapped_walk_done(&pvmw);
-	return 1;
+out:
+	return pvmw.address;
 }
-- 
2.43.0