mm: nommu: don't scan the vma list when deleting
Since commit 297c5eee3724 ("mm: make the vma list be doubly linked") made
it a doubly linked list, we don't need to scan the list when deleting
@vma.
And the original code didn't update the prev pointer. Fix it too.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/nommu.c b/mm/nommu.c
index 0b16cb4..2454d39 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -746,7 +746,6 @@
*/
static void delete_vma_from_mm(struct vm_area_struct *vma)
{
- struct vm_area_struct **pp;
struct address_space *mapping;
struct mm_struct *mm = vma->vm_mm;
@@ -769,12 +768,14 @@
/* remove from the MM's tree and list */
rb_erase(&vma->vm_rb, &mm->mm_rb);
- for (pp = &mm->mmap; *pp; pp = &(*pp)->vm_next) {
- if (*pp == vma) {
- *pp = vma->vm_next;
- break;
- }
- }
+
+ if (vma->vm_prev)
+ vma->vm_prev->vm_next = vma->vm_next;
+ else
+ mm->mmap = vma->vm_next;
+
+ if (vma->vm_next)
+ vma->vm_next->vm_prev = vma->vm_prev;
vma->vm_mm = NULL;
}