mm/mempolicy: return NULL if node is NUMA_NO_NODE in get_task_policy

If node == NUMA_NO_NODE, pol is NULL, we should return NULL instead of
do "if (!pol->mode)" check.

[akpm@linux-foundation.org: reorganise code]
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 7 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 6b1d426731ae..27022ca890f8 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -123,16 +123,19 @@ static struct mempolicy preferred_node_policy[MAX_NUMNODES];
 static struct mempolicy *get_task_policy(struct task_struct *p)
 {
         struct mempolicy *pol = p->mempolicy;
-        int node;
 
         if (!pol) {
-                node = numa_node_id();
-                if (node != NUMA_NO_NODE)
-                        pol = &preferred_node_policy[node];
+                int node = numa_node_id();
 
-                /* preferred_node_policy is not initialised early in boot */
-                if (!pol->mode)
-                        pol = NULL;
+                if (node != NUMA_NO_NODE) {
+                        pol = &preferred_node_policy[node];
+                        /*
+                         * preferred_node_policy is not initialised early in
+                         * boot
+                         */
+                        if (!pol->mode)
+                                pol = NULL;
+                }
         }
 
         return pol;