This is a note to let you know that I've just added the patch titled

    revert "mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy 
linkages"

to the 3.4-stable tree which can be found at:
    
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     
revert-mm-mempolicy-let-vma_merge-and-vma_split-handle-vma-vm_policy-linkages.patch
and it can be found in the queue-3.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 8d34694c1abf29df1f3c7317936b7e3e2e308d9b Mon Sep 17 00:00:00 2001
From: KOSAKI Motohiro <kosaki.motoh...@gmail.com>
Date: Mon, 8 Oct 2012 16:29:14 -0700
Subject: revert "mm: mempolicy: Let vma_merge and vma_split handle 
vma->vm_policy linkages"

From: KOSAKI Motohiro <kosaki.motoh...@gmail.com>

commit 8d34694c1abf29df1f3c7317936b7e3e2e308d9b upstream.

Commit 05f144a0d5c2 ("mm: mempolicy: Let vma_merge and vma_split handle
vma->vm_policy linkages") removed vma->vm_policy updates code but it is
the purpose of mbind_range().  Now, mbind_range() is virtually a no-op
and while it does not allow memory corruption it is not the right fix.
This patch is a revert.

[mgor...@suse.de: Edited changelog]
Signed-off-by: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mgor...@suse.de>
Cc: Christoph Lameter <c...@linux.com>
Cc: Josh Boyer <jwbo...@gmail.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 mm/mempolicy.c |   41 ++++++++++++++++++++++++-----------------
 1 file changed, 24 insertions(+), 17 deletions(-)

--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -607,6 +607,27 @@ check_range(struct mm_struct *mm, unsign
        return first;
 }
 
+/* Apply policy to a single VMA */
+static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
+{
+       int err = 0;
+       struct mempolicy *old = vma->vm_policy;
+
+       pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
+                vma->vm_start, vma->vm_end, vma->vm_pgoff,
+                vma->vm_ops, vma->vm_file,
+                vma->vm_ops ? vma->vm_ops->set_policy : NULL);
+
+       if (vma->vm_ops && vma->vm_ops->set_policy)
+               err = vma->vm_ops->set_policy(vma, new);
+       if (!err) {
+               mpol_get(new);
+               vma->vm_policy = new;
+               mpol_put(old);
+       }
+       return err;
+}
+
 /* Step 2: apply policy to a range and do splits. */
 static int mbind_range(struct mm_struct *mm, unsigned long start,
                       unsigned long end, struct mempolicy *new_pol)
@@ -655,23 +676,9 @@ static int mbind_range(struct mm_struct
                        if (err)
                                goto out;
                }
-
-               /*
-                * Apply policy to a single VMA. The reference counting of
-                * policy for vma_policy linkages has already been handled by
-                * vma_merge and split_vma as necessary. If this is a shared
-                * policy then ->set_policy will increment the reference count
-                * for an sp node.
-                */
-               pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
-                       vma->vm_start, vma->vm_end, vma->vm_pgoff,
-                       vma->vm_ops, vma->vm_file,
-                       vma->vm_ops ? vma->vm_ops->set_policy : NULL);
-               if (vma->vm_ops && vma->vm_ops->set_policy) {
-                       err = vma->vm_ops->set_policy(vma, new_pol);
-                       if (err)
-                               goto out;
-               }
+               err = policy_vma(vma, new_pol);
+               if (err)
+                       goto out;
        }
 
  out:


Patches currently in stable-queue which might be from kosaki.motoh...@gmail.com 
are

queue-3.4/revert-mm-mempolicy-let-vma_merge-and-vma_split-handle-vma-vm_policy-linkages.patch
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