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

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Commit 05f144a0d5 ("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.

[mgorman@suse.de: Edited changelog]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
KOSAKI Motohiro 2012-10-08 16:29:14 -07:00 committed by Linus Torvalds
parent 1fb3f8ca0e
commit 8d34694c1a
1 changed files with 24 additions and 17 deletions
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37
mm/mempolicy.c
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@ -607,6 +607,27 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
return first; 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. */ /* Step 2: apply policy to a range and do splits. */
static int mbind_range(struct mm_struct *mm, unsigned long start, static int mbind_range(struct mm_struct *mm, unsigned long start,
unsigned long end, struct mempolicy *new_pol) unsigned long end, struct mempolicy *new_pol)
@ -655,24 +676,10 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
if (err) if (err)
goto out; goto out;
} }
err = policy_vma(vma, new_pol);
/*
* 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) if (err)
goto out; goto out;
} }
}
out: out:
return err; return err;