1 files changed, 13 insertions, 4 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 89e6286a7f57..20e04c64468d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -296,8 +296,10 @@ static int gather_surplus_pages(int delta)
         int needed, allocated;
 
         needed = (resv_huge_pages + delta) - free_huge_pages;
-        if (needed <= 0)
+        if (needed <= 0) {
+                resv_huge_pages += delta;
                 return 0;
+        }
 
         allocated = 0;
         INIT_LIST_HEAD(&surplus_list);
@@ -335,9 +337,12 @@ retry:
          * The surplus_list now contains _at_least_ the number of extra pages
          * needed to accomodate the reservation.  Add the appropriate number
          * of pages to the hugetlb pool and free the extras back to the buddy
-         * allocator.
+         * allocator.  Commit the entire reservation here to prevent another
+         * process from stealing the pages as they are added to the pool but
+         * before they are reserved.
          */
         needed += allocated;
+        resv_huge_pages += delta;
         ret = 0;
 free:
         list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
@@ -371,6 +376,9 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages)
         struct page *page;
         unsigned long nr_pages;
 
+        /* Uncommit the reservation */
+        resv_huge_pages -= unused_resv_pages;
+
         nr_pages = min(unused_resv_pages, surplus_huge_pages);
 
         while (nr_pages) {
@@ -1205,12 +1213,13 @@ static int hugetlb_acct_memory(long delta)
                 if (gather_surplus_pages(delta) < 0)
                         goto out;
 
-                if (delta > cpuset_mems_nr(free_huge_pages_node))
+                if (delta > cpuset_mems_nr(free_huge_pages_node)) {
+                        return_unused_surplus_pages(delta);
                         goto out;
+                }
         }
 
         ret = 0;
-        resv_huge_pages += delta;
         if (delta < 0)
                 return_unused_surplus_pages((unsigned long) -delta);