Mark queue init done when everything is done well in blk_register_queue(),
so that wbt_enable_default() can be run quickly without any RCU period
involved since adding rq qos requires to freeze queue.
Also no any side effect by delaying to mark queue init done.
Reported-by: Yi Zhang <yi.zhang@xxxxxxxxxx>
Cc: Bart Van Assche <bvanassche@xxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-sysfs.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index f89e2fc3963b..370d83c18057 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -866,20 +866,6 @@ int blk_register_queue(struct gendisk *disk)
"%s is registering an already registered queue\n",
kobject_name(&dev->kobj));
- /*
- * 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)) {
- blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
- percpu_ref_switch_to_percpu(&q->q_usage_counter);
- }
-
blk_queue_update_readahead(q);
ret = blk_trace_init_sysfs(dev);
@@ -938,6 +924,21 @@ int blk_register_queue(struct gendisk *disk)
ret = 0;
unlock:
mutex_unlock(&q->sysfs_dir_lock);
+
+ /*
+ * 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)) {
+ blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
+ percpu_ref_switch_to_percpu(&q->q_usage_counter);
+ }
+
return ret;
}
EXPORT_SYMBOL_GPL(blk_register_queue);
--
2.31.1
