[114/289] mm/hugetlb.c: add missing spin_lock() to hugetlb_cow()

Greg KH
2010-12-08T01:39:11Z

From: Dean Nelson <dnelson@redhat.com>

commit 44e2aa937e698ea95dd86b2a4fabd734ef2c76db upstream.

Add missing spin_lock() of the page_table_lock before an error return in
hugetlb_cow(). Callers of hugtelb_cow() expect it to be held upon return.

Signed-off-by: Dean Nelson <dnelson@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
mm/hugetlb.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2380,8 +2380,11 @@ retry_avoidcopy:
* When the original hugepage is shared one, it does not have
* anon_vma prepared.
*/
- if (unlikely(anon_vma_prepare(vma)))
+ if (unlikely(anon_vma_prepare(vma))) {
+ /* Caller expects lock to be held */
+ spin_lock(&mm->page_table_lock);
return VM_FAULT_OOM;
+ }

copy_huge_page(new_page, old_page, address, vma);
__SetPageUptodate(new_page);