Pull block fixes from Jens Axboe:
"A few fixes/changes to round off this merge window. This contains:
- Small series making some functional tweaks to blk-iocost (Tejun)
- Elevator switch locking fix (Ming)
- Kill redundant call in blk-wbt (Yufen)
- Fix flush timeout handling (Yufen)"
* tag 'for-linus-2019-09-27' of git://git.kernel.dk/linux-block:
block: fix null pointer dereference in blk_mq_rq_timed_out()
rq-qos: get rid of redundant wbt_update_limits()
iocost: bump up default latency targets for hard disks
iocost: improve nr_lagging handling
iocost: better trace vrate changes
block: don't release queue's sysfs lock during switching elevator
blk-mq: move lockdep_assert_held() into elevator_exit