net: igb: convert to timecounter adjtime.

[cascardo/linux.git] / block / blk-sysfs.c

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 17f5c84..935ea2a 100644 (file)
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -492,17 +492,15 @@ static void blk_free_queue_rcu(struct rcu_head *rcu_head)
  *     Currently, its primary task it to free all the &struct request
  *     structures that were allocated to the queue and the queue itself.
  *
- * Caveat:
- *     Hopefully the low level driver will have finished any
- *     outstanding requests first...
+ * Note:
+ *     The low level driver must have finished any outstanding requests first
+ *     via blk_cleanup_queue().
  **/
 static void blk_release_queue(struct kobject *kobj)
 {
        struct request_queue *q =
                container_of(kobj, struct request_queue, kobj);
 
-       blk_sync_queue(q);
-
        blkcg_exit_queue(q);
 
        if (q->elevator) {
@@ -517,10 +515,8 @@ static void blk_release_queue(struct kobject *kobj)
        if (q->queue_tags)
                __blk_queue_free_tags(q);
 
-       if (q->mq_ops)
-               blk_mq_free_queue(q);
-
-       kfree(q->flush_rq);
+       if (!q->mq_ops)
+               blk_free_flush_queue(q->fq);
 
        blk_trace_shutdown(q);
 
@@ -551,12 +547,19 @@ int blk_register_queue(struct gendisk *disk)
                return -ENXIO;
 
        /*
-        * Initialization must be complete by now.  Finish the initial
-        * bypass from queue allocation.
+        * SCSI probing may synchronously create and destroy a lot of
+        * request_queues for non-existent devices.  Shutting down a fully
+        * functional queue takes measureable wallclock time as RCU grace
+        * periods are involved.  To avoid excessive latency in these
+        * cases, a request_queue starts out in a degraded mode which is
+        * faster to shut down and is made fully functional here as
+        * request_queues for non-existent devices never get registered.
         */
        if (!blk_queue_init_done(q)) {
                queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
                blk_queue_bypass_end(q);
+               if (q->mq_ops)
+                       blk_mq_finish_init(q);
        }
 
        ret = blk_trace_init_sysfs(dev);