[PATCH] make_coherent pgoff

Patch from Hugh Dickins

In wandering through the Linus 2.6 tree preparing for changeover of
i_mmap and i_mmap_shared to Rajesh's prio tree for object-based rmap...
I noticed that pgoff in make_coherent doesn't add up (plus, I think
we need to mask out the word "don't" in the comment further down).
2.4.25 looks equally wrong.

arch/arm/mm/fault-armv.c

@@ -226,9 +226,11 @@ make_coherent(struct vm_area_struct *vma, unsigned long addr, struct page *page,
 {
 	struct list_head *l;
 	struct mm_struct *mm = vma->vm_mm;
-	unsigned long pgoff = (addr - vma->vm_start) >> PAGE_SHIFT;
+	unsigned long pgoff;
 	int aliases = 0;
 
+	pgoff = vma->vm_pgoff + ((addr - vma->vm_start) >> PAGE_SHIFT);
+
 	/*
 	 * If we have any shared mappings that are in the same mm
 	 * space, then we need to handle them specially to maintain
@@ -242,7 +244,7 @@ make_coherent(struct vm_area_struct *vma, unsigned long addr, struct page *page,
 
 		/*
 		 * If this VMA is not in our MM, we can ignore it.
-		 * Note that we intentionally don't mask out the VMA
+		 * Note that we intentionally mask out the VMA
 		 * that we are fixing up.
 		 */
 		if (mpnt->vm_mm != mm || mpnt == vma)