cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags

[pandora-kernel.git] / mm / memory-failure.c

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index a013bc9..44c6bd2 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1172,6 +1172,16 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 
        lock_page(hpage);
 
+       /*
+        * The page could have changed compound pages during the locking.
+        * If this happens just bail out.
+        */
+       if (compound_head(p) != hpage) {
+               action_result(pfn, "different compound page after locking", IGNORED);
+               res = -EBUSY;
+               goto out;
+       }
+
        /*
         * We use page flags to determine what action should be taken, but
         * the flags can be modified by the error containment action.  One