1 files changed, 31 insertions, 20 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index cfffe5098d53..135bf8ca96ee 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -70,7 +70,7 @@ struct scan_control {
 	unsigned int priority;
 
 	/* This context's GFP mask */
-	unsigned int gfp_mask;
+	gfp_t gfp_mask;
 
 	int may_writepage;
 
@@ -186,7 +186,7 @@ EXPORT_SYMBOL(remove_shrinker);
  *
  * Returns the number of slab objects which we shrunk.
  */
-static int shrink_slab(unsigned long scanned, unsigned int gfp_mask,
+static int shrink_slab(unsigned long scanned, gfp_t gfp_mask,
 			unsigned long lru_pages)
 {
 	struct shrinker *shrinker;
@@ -417,7 +417,9 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc)
 		 * Anonymous process memory has backing store?
 		 * Try to allocate it some swap space here.
 		 */
-		if (PageAnon(page) && !PageSwapCache(page) && sc->may_swap) {
+		if (PageAnon(page) && !PageSwapCache(page)) {
+			if (!sc->may_swap)
+				goto keep_locked;
 			if (!add_to_swap(page))
 				goto activate_locked;
 		}
@@ -511,14 +513,15 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc)
 		 * PageDirty _after_ making sure that the page is freeable and
 		 * not in use by anybody. 	(pagecache + us == 2)
 		 */
-		if (page_count(page) != 2 || PageDirty(page)) {
-			write_unlock_irq(&mapping->tree_lock);
-			goto keep_locked;
-		}
+		if (unlikely(page_count(page) != 2))
+			goto cannot_free;
+		smp_rmb();
+		if (unlikely(PageDirty(page)))
+			goto cannot_free;
 
 #ifdef CONFIG_SWAP
 		if (PageSwapCache(page)) {
-			swp_entry_t swap = { .val = page->private };
+			swp_entry_t swap = { .val = page_private(page) };
 			__delete_from_swap_cache(page);
 			write_unlock_irq(&mapping->tree_lock);
 			swap_free(swap);
@@ -538,6 +541,10 @@ free_it:
 			__pagevec_release_nonlru(&freed_pvec);
 		continue;
 
+cannot_free:
+		write_unlock_irq(&mapping->tree_lock);
+		goto keep_locked;
+
 activate_locked:
 		SetPageActive(page);
 		pgactivate++;
@@ -822,6 +829,8 @@ 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 +870,8 @@ shrink_zone(struct zone *zone, struct scan_control *sc)
 	}
 
 	throttle_vm_writeout();
+
+	atomic_dec(&zone->reclaim_in_progress);
 }
 
 /*
@@ -890,7 +901,7 @@ shrink_caches(struct zone **zones, struct scan_control *sc)
 		if (zone->present_pages == 0)
 			continue;
 
-		if (!cpuset_zone_allowed(zone))
+		if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))
 			continue;
 
 		zone->temp_priority = sc->priority;
@@ -900,9 +911,7 @@ 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);
 	}
 }
  
@@ -919,7 +928,7 @@ shrink_caches(struct zone **zones, struct scan_control *sc)
  * holds filesystem locks which prevent writeout this might not work, and the
  * allocation attempt will fail.
  */
-int try_to_free_pages(struct zone **zones, unsigned int gfp_mask)
+int try_to_free_pages(struct zone **zones, gfp_t gfp_mask)
 {
 	int priority;
 	int ret = 0;
@@ -938,7 +947,7 @@ int try_to_free_pages(struct zone **zones, unsigned int gfp_mask)
 	for (i = 0; zones[i] != NULL; i++) {
 		struct zone *zone = zones[i];
 
-		if (!cpuset_zone_allowed(zone))
+		if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))
 			continue;
 
 		zone->temp_priority = DEF_PRIORITY;
@@ -984,7 +993,7 @@ out:
 	for (i = 0; zones[i] != 0; i++) {
 		struct zone *zone = zones[i];
 
-		if (!cpuset_zone_allowed(zone))
+		if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))
 			continue;
 
 		zone->prev_priority = zone->temp_priority;
@@ -1254,11 +1263,11 @@ void wakeup_kswapd(struct zone *zone, int order)
 		return;
 	if (pgdat->kswapd_max_order < order)
 		pgdat->kswapd_max_order = order;
-	if (!cpuset_zone_allowed(zone))
+	if (!cpuset_zone_allowed(zone, __GFP_HARDWALL))
 		return;
-	if (!waitqueue_active(&zone->zone_pgdat->kswapd_wait))
+	if (!waitqueue_active(&pgdat->kswapd_wait))
 		return;
-	wake_up_interruptible(&zone->zone_pgdat->kswapd_wait);
+	wake_up_interruptible(&pgdat->kswapd_wait);
 }
 
 #ifdef CONFIG_PM
@@ -1331,7 +1340,7 @@ module_init(kswapd_init)
 /*
  * Try to free up some pages from this zone through reclaim.
  */
-int zone_reclaim(struct zone *zone, unsigned int gfp_mask, unsigned int order)
+int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 {
 	struct scan_control sc;
 	int nr_pages = 1 << order;
@@ -1358,14 +1367,13 @@ 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 +1383,9 @@ 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;