Merge tag 'hole_punch_for_v5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel...

[linux-2.6-microblaze.git] / mm / rmap.c

diff --git a/mm/rmap.c b/mm/rmap.c
index 86471aa..2d29a57 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1441,21 +1441,20 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                /*
                 * If the page is mlock()d, we cannot swap it out.
                 */
-               if (!(flags & TTU_IGNORE_MLOCK)) {
-                       if (vma->vm_flags & VM_LOCKED) {
-                               /* PTE-mapped THP are never marked as mlocked */
-                               if (!PageTransCompound(page) ||
-                                   (PageHead(page) && !PageDoubleMap(page))) {
-                                       /*
-                                        * Holding pte lock, we do *not* need
-                                        * mmap_lock here
-                                        */
-                                       mlock_vma_page(page);
-                               }
-                               ret = false;
-                               page_vma_mapped_walk_done(&pvmw);
-                               break;
-                       }
+               if (!(flags & TTU_IGNORE_MLOCK) &&
+                   (vma->vm_flags & VM_LOCKED)) {
+                       /*
+                        * PTE-mapped THP are never marked as mlocked: so do
+                        * not set it on a DoubleMap THP, nor on an Anon THP
+                        * (which may still be PTE-mapped after DoubleMap was
+                        * cleared).  But stop unmapping even in those cases.
+                        */
+                       if (!PageTransCompound(page) || (PageHead(page) &&
+                            !PageDoubleMap(page) && !PageAnon(page)))
+                               mlock_vma_page(page);
+                       page_vma_mapped_walk_done(&pvmw);
+                       ret = false;
+                       break;
                }
 
                /* Unexpected PMD-mapped THP? */
@@ -1987,8 +1986,10 @@ static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
                 */
                if (vma->vm_flags & VM_LOCKED) {
                        /*
-                        * PTE-mapped THP are never marked as mlocked, but
-                        * this function is never called when PageDoubleMap().
+                        * PTE-mapped THP are never marked as mlocked; but
+                        * this function is never called on a DoubleMap THP,
+                        * nor on an Anon THP (which may still be PTE-mapped
+                        * after DoubleMap was cleared).
                         */
                        mlock_vma_page(page);
                        /*
@@ -2023,6 +2024,10 @@ void page_mlock(struct page *page)
        VM_BUG_ON_PAGE(!PageLocked(page) || PageLRU(page), page);
        VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page);
 
+       /* Anon THP are only marked as mlocked when singly mapped */
+       if (PageTransCompound(page) && PageAnon(page))
+               return;
+
        rmap_walk(page, &rwc);
 }