1 files changed, 29 insertions, 11 deletions

diff --git a/net/sunrpc/cache.c b/net/sunrpc/cache.c
index 3b3f14fc02c5..8e964ae8d7b5 100644
--- a/net/sunrpc/cache.c
+++ b/net/sunrpc/cache.c
@@ -1036,23 +1036,32 @@ static int cache_release(struct inode *inode, struct file *filp,
 
 static void cache_dequeue(struct cache_detail *detail, struct cache_head *ch)
 {
-        struct cache_queue *cq;
+        struct cache_queue *cq, *tmp;
+        struct cache_request *cr;
+        struct list_head dequeued;
+
+        INIT_LIST_HEAD(&dequeued);
         spin_lock(&queue_lock);
-        list_for_each_entry(cq, &detail->queue, list)
+        list_for_each_entry_safe(cq, tmp, &detail->queue, list)
                 if (!cq->reader) {
-                        struct cache_request *cr = container_of(cq, struct cache_request, q);
+                        cr = container_of(cq, struct cache_request, q);
                         if (cr->item != ch)
                                 continue;
+                        if (test_bit(CACHE_PENDING, &ch->flags))
+                                /* Lost a race and it is pending again */
+                                break;
                         if (cr->readers != 0)
                                 continue;
-                        list_del(&cr->q.list);
-                        spin_unlock(&queue_lock);
-                        cache_put(cr->item, detail);
-                        kfree(cr->buf);
-                        kfree(cr);
-                        return;
+                        list_move(&cr->q.list, &dequeued);
                 }
         spin_unlock(&queue_lock);
+        while (!list_empty(&dequeued)) {
+                cr = list_entry(dequeued.next, struct cache_request, q.list);
+                list_del(&cr->q.list);
+                cache_put(cr->item, detail);
+                kfree(cr->buf);
+                kfree(cr);
+        }
 }
 
 /*
@@ -1166,6 +1175,7 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
 
         char *buf;
         struct cache_request *crq;
+        int ret = 0;
 
         if (!detail->cache_request)
                 return -EINVAL;
@@ -1191,10 +1201,18 @@ int sunrpc_cache_pipe_upcall(struct cache_detail *detail, struct cache_head *h)
         crq->len = 0;
         crq->readers = 0;
         spin_lock(&queue_lock);
-        list_add_tail(&crq->q.list, &detail->queue);
+        if (test_bit(CACHE_PENDING, &h->flags))
+                list_add_tail(&crq->q.list, &detail->queue);
+        else
+                /* Lost a race, no longer PENDING, so don't enqueue */
+                ret = -EAGAIN;
         spin_unlock(&queue_lock);
         wake_up(&queue_wait);
-        return 0;
+        if (ret == -EAGAIN) {
+                kfree(buf);
+                kfree(crq);
+        }
+        return ret;
 }
 EXPORT_SYMBOL_GPL(sunrpc_cache_pipe_upcall);