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

[Greg KH]

2.6.36-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Dean Nelson <dnelson@xxxxxxxxxx>

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@xxxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 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);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/