Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[sfrench/cifs-2.6.git] / block / elevator.c

diff --git a/block/elevator.c b/block/elevator.c
index 7bda083d59684177bb66eec2e221177417c893ac..e87e9b43aba09ac2989d4350e225422892ab6944 100644 (file)
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -869,6 +869,8 @@ int elv_register_queue(struct request_queue *q)
        struct elevator_queue *e = q->elevator;
        int error;
 
+       lockdep_assert_held(&q->sysfs_lock);
+
        error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
        if (!error) {
                struct elv_fs_entry *attr = e->type->elevator_attrs;
@@ -886,10 +888,11 @@ int elv_register_queue(struct request_queue *q)
        }
        return error;
 }
-EXPORT_SYMBOL(elv_register_queue);
 
 void elv_unregister_queue(struct request_queue *q)
 {
+       lockdep_assert_held(&q->sysfs_lock);
+
        if (q) {
                struct elevator_queue *e = q->elevator;
 
@@ -900,7 +903,6 @@ void elv_unregister_queue(struct request_queue *q)
                wbt_enable_default(q);
        }
 }
-EXPORT_SYMBOL(elv_unregister_queue);
 
 int elv_register(struct elevator_type *e)
 {
@@ -967,7 +969,10 @@ static int elevator_switch_mq(struct request_queue *q,
 {
        int ret;
 
+       lockdep_assert_held(&q->sysfs_lock);
+
        blk_mq_freeze_queue(q);
+       blk_mq_quiesce_queue(q);
 
        if (q->elevator) {
                if (q->elevator->registered)
@@ -994,6 +999,7 @@ static int elevator_switch_mq(struct request_queue *q,
                blk_add_trace_msg(q, "elv switch: none");
 
 out:
+       blk_mq_unquiesce_queue(q);
        blk_mq_unfreeze_queue(q);
        return ret;
 }
@@ -1010,6 +1016,8 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
        bool old_registered = false;
        int err;
 
+       lockdep_assert_held(&q->sysfs_lock);
+
        if (q->mq_ops)
                return elevator_switch_mq(q, new_e);