libceph: kfree() in put_osd() shouldn't depend on authorizer

[linux-beck.git] / block / blk-mq.c

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2f95747c287eac350b45cc272fcd3d6e9c43ee09..2390c5541e71fb09c3353004224d76b4c81bddc8 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1641,10 +1641,8 @@ static void blk_mq_free_hw_queues(struct request_queue *q,
        struct blk_mq_hw_ctx *hctx;
        unsigned int i;
 
-       queue_for_each_hw_ctx(q, hctx, i) {
+       queue_for_each_hw_ctx(q, hctx, i)
                free_cpumask_var(hctx->cpumask);
-               kfree(hctx);
-       }
 }
 
 static int blk_mq_init_hctx(struct request_queue *q,
@@ -1869,6 +1867,27 @@ static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
        mutex_unlock(&set->tag_list_lock);
 }
 
+/*
+ * It is the actual release handler for mq, but we do it from
+ * request queue's release handler for avoiding use-after-free
+ * and headache because q->mq_kobj shouldn't have been introduced,
+ * but we can't group ctx/kctx kobj without it.
+ */
+void blk_mq_release(struct request_queue *q)
+{
+       struct blk_mq_hw_ctx *hctx;
+       unsigned int i;
+
+       /* hctx kobj stays in hctx */
+       queue_for_each_hw_ctx(q, hctx, i)
+               kfree(hctx);
+
+       kfree(q->queue_hw_ctx);
+
+       /* ctx kobj stays in queue_ctx */
+       free_percpu(q->queue_ctx);
+}
+
 struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 {
        struct blk_mq_hw_ctx **hctxs;
@@ -2002,12 +2021,8 @@ void blk_mq_free_queue(struct request_queue *q)
 
        percpu_ref_exit(&q->mq_usage_counter);
 
-       free_percpu(q->queue_ctx);
-       kfree(q->queue_hw_ctx);
        kfree(q->mq_map);
 
-       q->queue_ctx = NULL;
-       q->queue_hw_ctx = NULL;
        q->mq_map = NULL;
 
        mutex_lock(&all_q_mutex);