block, bfq: fix queue removal from weights tree

[thirdparty/kernel/stable.git] / block / bfq-iosched.c

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 12228af161982f5b32d7148d3b6ab9f5c1078d7e..bf585ad29bb5102bd01abd14ba4b512707dd9cab 100644 (file)
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -754,6 +754,7 @@ void bfq_weights_tree_add(struct bfq_data *bfqd, struct bfq_queue *bfqq,
 
 inc_counter:
        bfqq->weight_counter->num_active++;
+       bfqq->ref++;
 }
 
 /*
@@ -778,6 +779,7 @@ void __bfq_weights_tree_remove(struct bfq_data *bfqd,
 
 reset_entity_pointer:
        bfqq->weight_counter = NULL;
+       bfq_put_queue(bfqq);
 }
 
 /*
@@ -789,9 +791,6 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd,
 {
        struct bfq_entity *entity = bfqq->entity.parent;
 
-       __bfq_weights_tree_remove(bfqd, bfqq,
-                                 &bfqd->queue_weights_tree);
-
        for_each_entity(entity) {
                struct bfq_sched_data *sd = entity->my_sched_data;
 
@@ -825,6 +824,15 @@ void bfq_weights_tree_remove(struct bfq_data *bfqd,
                        bfqd->num_groups_with_pending_reqs--;
                }
        }
+
+       /*
+        * Next function is invoked last, because it causes bfqq to be
+        * freed if the following holds: bfqq is not in service and
+        * has no dispatched request. DO NOT use bfqq after the next
+        * function invocation.
+        */
+       __bfq_weights_tree_remove(bfqd, bfqq,
+                                 &bfqd->queue_weights_tree);
 }
 
 /*
@@ -1020,7 +1028,8 @@ bfq_bfqq_resume_state(struct bfq_queue *bfqq, struct bfq_data *bfqd,
 
 static int bfqq_process_refs(struct bfq_queue *bfqq)
 {
-       return bfqq->ref - bfqq->allocated - bfqq->entity.on_st;
+       return bfqq->ref - bfqq->allocated - bfqq->entity.on_st -
+               (bfqq->weight_counter != NULL);
 }
 
 /* Empty burst list and add just bfqq (see comments on bfq_handle_burst) */