1 files changed, 23 insertions, 16 deletions

diff --git a/mm/memory.c b/mm/memory.c
index ca920d1fd314..54f3a9b00956 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -235,6 +235,9 @@ void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned long
 
 static void tlb_flush_mmu_tlbonly(struct mmu_gather *tlb)
 {
+        if (!tlb->end)
+                return;
+
         tlb_flush(tlb);
         mmu_notifier_invalidate_range(tlb->mm, tlb->start, tlb->end);
 #ifdef CONFIG_HAVE_RCU_TABLE_FREE
@@ -247,7 +250,7 @@ static void tlb_flush_mmu_free(struct mmu_gather *tlb)
 {
         struct mmu_gather_batch *batch;
 
-        for (batch = &tlb->local; batch; batch = batch->next) {
+        for (batch = &tlb->local; batch && batch->nr; batch = batch->next) {
                 free_pages_and_swap_cache(batch->pages, batch->nr);
                 batch->nr = 0;
         }
@@ -256,9 +259,6 @@ static void tlb_flush_mmu_free(struct mmu_gather *tlb)
 
 void tlb_flush_mmu(struct mmu_gather *tlb)
 {
-        if (!tlb->end)
-                return;
-
         tlb_flush_mmu_tlbonly(tlb);
         tlb_flush_mmu_free(tlb);
 }
@@ -2137,17 +2137,24 @@ reuse:
                 if (!dirty_page)
                         return ret;
 
-                /*
-                 * Yes, Virginia, this is actually required to prevent a race
-                 * with clear_page_dirty_for_io() from clearing the page dirty
-                 * bit after it clear all dirty ptes, but before a racing
-                 * do_wp_page installs a dirty pte.
-                 *
-                 * do_shared_fault is protected similarly.
-                 */
                 if (!page_mkwrite) {
-                        wait_on_page_locked(dirty_page);
-                        set_page_dirty_balance(dirty_page);
+                        struct address_space *mapping;
+                        int dirtied;
+
+                        lock_page(dirty_page);
+                        dirtied = set_page_dirty(dirty_page);
+                        VM_BUG_ON_PAGE(PageAnon(dirty_page), dirty_page);
+                        mapping = dirty_page->mapping;
+                        unlock_page(dirty_page);
+
+                        if (dirtied && mapping) {
+                                /*
+                                 * Some device drivers do not set page.mapping
+                                 * but still dirty their pages
+                                 */
+                                balance_dirty_pages_ratelimited(mapping);
+                        }
+
                         /* file_update_time outside page_lock */
                         if (vma->vm_file)
                                 file_update_time(vma->vm_file);
@@ -2593,7 +2600,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
                 if (prev && prev->vm_end == address)
                         return prev->vm_flags & VM_GROWSDOWN ? 0 : -ENOMEM;
 
-                expand_downwards(vma, address - PAGE_SIZE);
+                return expand_downwards(vma, address - PAGE_SIZE);
         }
         if ((vma->vm_flags & VM_GROWSUP) && address + PAGE_SIZE == vma->vm_end) {
                 struct vm_area_struct *next = vma->vm_next;
@@ -2602,7 +2609,7 @@ static inline int check_stack_guard_page(struct vm_area_struct *vma, unsigned lo
                 if (next && next->vm_start == address + PAGE_SIZE)
                         return next->vm_flags & VM_GROWSUP ? 0 : -ENOMEM;
 
-                expand_upwards(vma, address + PAGE_SIZE);
+                return expand_upwards(vma, address + PAGE_SIZE);
         }
         return 0;
 }