1 files changed, 12 insertions, 17 deletions

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 1efe4ecc02b1..e77c29f4c243 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -73,19 +73,19 @@ list_lru_walk_node(struct list_lru *lru, int nid, list_lru_walk_cb isolate,
         struct list_lru_node    *nlru = &lru->node[nid];
         struct list_head *item, *n;
         unsigned long isolated = 0;
-        /*
-         * If we don't keep state of at which pass we are, we can loop at
-         * LRU_RETRY, since we have no guarantees that the caller will be able
-         * to do something other than retry on the next pass. We handle this by
-         * allowing at most one retry per object. This should not be altered
-         * by any condition other than LRU_RETRY.
-         */
-        bool first_pass = true;
 
         spin_lock(&nlru->lock);
 restart:
         list_for_each_safe(item, n, &nlru->list) {
                 enum lru_status ret;
+
+                /*
+                 * decrement nr_to_walk first so that we don't livelock if we
+                 * get stuck on large numbesr of LRU_RETRY items
+                 */
+                if (--(*nr_to_walk) == 0)
+                        break;
+
                 ret = isolate(item, &nlru->lock, cb_arg);
                 switch (ret) {
                 case LRU_REMOVED:
@@ -100,19 +100,14 @@ restart:
                 case LRU_SKIP:
                         break;
                 case LRU_RETRY:
-                        if (!first_pass) {
-                                first_pass = true;
-                                break;
-                        }
-                        first_pass = false;
+                        /*
+                         * The lru lock has been dropped, our list traversal is
+                         * now invalid and so we have to restart from scratch.
+                         */
                         goto restart;
                 default:
                         BUG();
                 }
-
-                if ((*nr_to_walk)-- == 0)
-                        break;
-
         }
 
         spin_unlock(&nlru->lock);