1 files changed, 8 insertions, 4 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index cfffe5098d53..0095533cdde9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -822,6 +822,8 @@ shrink_zone(struct zone *zone, struct scan_control *sc)
         unsigned long nr_active;
         unsigned long nr_inactive;
 
+        atomic_inc(&zone->reclaim_in_progress);
+
         /*
          * Add one to `nr_to_scan' just to make sure that the kernel will
          * slowly sift through the active list.
@@ -861,6 +863,8 @@ shrink_zone(struct zone *zone, struct scan_control *sc)
         }
 
         throttle_vm_writeout();
+
+        atomic_dec(&zone->reclaim_in_progress);
 }
 
 /*
@@ -900,9 +904,7 @@ shrink_caches(struct zone **zones, struct scan_control *sc)
                 if (zone->all_unreclaimable && sc->priority != DEF_PRIORITY)
                         continue;       /* Let kswapd poll it */
 
-                atomic_inc(&zone->reclaim_in_progress);
                 shrink_zone(zone, sc);
-                atomic_dec(&zone->reclaim_in_progress);
         }
 }
  
@@ -1358,14 +1360,13 @@ int zone_reclaim(struct zone *zone, unsigned int gfp_mask, unsigned int order)
                 sc.swap_cluster_max = SWAP_CLUSTER_MAX;
 
         /* Don't reclaim the zone if there are other reclaimers active */
-        if (!atomic_inc_and_test(&zone->reclaim_in_progress))
+        if (atomic_read(&zone->reclaim_in_progress) > 0)
                 goto out;
 
         shrink_zone(zone, &sc);
         total_reclaimed = sc.nr_reclaimed;
 
  out:
-        atomic_dec(&zone->reclaim_in_progress);
         return total_reclaimed;
 }
 
@@ -1375,6 +1376,9 @@ asmlinkage long sys_set_zone_reclaim(unsigned int node, unsigned int zone,
         struct zone *z;
         int i;
 
+        if (!capable(CAP_SYS_ADMIN))
+                return -EACCES;
+
         if (node >= MAX_NUMNODES || !node_online(node))
                 return -EINVAL;