drm/i915: Fix refleak during eviction.

Now that we hold onto a reference whilst evicting objects, we need to
be sure that we drop all the references taken -- even on the error
paths.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 20 insertions, 25 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_evict.c b/drivers/gpu/drm/i915/i915_gem_evict.c
index e85246ef691c..5c428fa3e0b3 100644
--- a/drivers/gpu/drm/i915/i915_gem_evict.c
+++ b/drivers/gpu/drm/i915/i915_gem_evict.c
@@ -93,7 +93,7 @@ i915_gem_evict_something(struct drm_device *dev, int min_size, unsigned alignmen
 {
         drm_i915_private_t *dev_priv = dev->dev_private;
         struct list_head eviction_list, unwind_list;
-        struct drm_i915_gem_object *obj_priv, *tmp_obj_priv;
+        struct drm_i915_gem_object *obj_priv;
         struct list_head *render_iter, *bsd_iter;
         int ret = 0;
 
@@ -175,39 +175,34 @@ i915_gem_evict_something(struct drm_device *dev, int min_size, unsigned alignmen
         return -ENOSPC;
 
 found:
+        /* drm_mm doesn't allow any other other operations while
+         * scanning, therefore store to be evicted objects on a
+         * temporary list. */
         INIT_LIST_HEAD(&eviction_list);
-        list_for_each_entry_safe(obj_priv, tmp_obj_priv,
-                                 &unwind_list, evict_list) {
+        while (!list_empty(&unwind_list)) {
+                obj_priv = list_first_entry(&unwind_list,
+                                            struct drm_i915_gem_object,
+                                            evict_list);
                 if (drm_mm_scan_remove_block(obj_priv->gtt_space)) {
-                        /* drm_mm doesn't allow any other other operations while
-                         * scanning, therefore store to be evicted objects on a
-                         * temporary list. */
                         list_move(&obj_priv->evict_list, &eviction_list);
-                } else
-                        drm_gem_object_unreference(&obj_priv->base);
+                        continue;
+                }
+                list_del(&obj_priv->evict_list);
+                drm_gem_object_unreference(&obj_priv->base);
         }
 
         /* Unbinding will emit any required flushes */
-        list_for_each_entry_safe(obj_priv, tmp_obj_priv,
-                                 &eviction_list, evict_list) {
-#if WATCH_LRU
-                DRM_INFO("%s: evicting %p\n", __func__, &obj_priv->base);
-#endif
-                ret = i915_gem_object_unbind(&obj_priv->base);
-                if (ret)
-                        return ret;
-
+        while (!list_empty(&eviction_list)) {
+                obj_priv = list_first_entry(&eviction_list,
+                                            struct drm_i915_gem_object,
+                                            evict_list);
+                if (ret == 0)
+                        ret = i915_gem_object_unbind(&obj_priv->base);
+                list_del(&obj_priv->evict_list);
                 drm_gem_object_unreference(&obj_priv->base);
         }
 
-        /* The just created free hole should be on the top of the free stack
-         * maintained by drm_mm, so this BUG_ON actually executes in O(1).
-         * Furthermore all accessed data has just recently been used, so it
-         * should be really fast, too. */
-        BUG_ON(!drm_mm_search_free(&dev_priv->mm.gtt_space, min_size,
-                                   alignment, 0));
-
-        return 0;
+        return ret;
 }
 
 int