Hello Jens,
This patchset cleans up elevator change code, and unifying it via single
helper, meantime moves kobject_add/del & debugfs register/unregister out of
queue freezing & elevator_lock. This way fixes many lockdep warnings
reported recently, especially since fs_reclaim is connected with freeze lock
manually by commit ffa1e7ada456 ("block: Make request_queue lockdep splats
show up earlier").
Thanks,
Ming
V3:
- replace srcu with rw_sem for avoiding race between add/del disk &
elevator switch and updating nr_hw_queues (Nilay Shoff)
- add elv_update_nr_hw_queues() for elevator reattachment in case of
updating nr_hw_queues, meantime keep elv_change_ctx as local structure
(Christoph)
- replace ->elevator_lock with disk->rqos_state_mutex for covering wbt
state change
- add new patch "block: use q->elevator with ->elevator_lock held in elv_iosched_show()"
- small cleanup & commit log improvement
V2:
- retry add/del disk when blk_mq_update_nr_hw_queues() is in-progress
- swap blk_mq_add_queue_tag_set() with blk_mq_map_swqueue() in
blk_mq_init_allocated_queue() (Nilay Shroff)
- move ELEVATOR_FLAG_DISABLE_WBT to request queue's flags (Nilay Shoff)
- fix race because of delaying elevator unregister
- define flags of `elv_change_ctx` as `bool` (Christoph)
- improve comment and commit log (Christoph)
Ming Lei (20):
block: move blk_mq_add_queue_tag_set() after blk_mq_map_swqueue()
block: move ELEVATOR_FLAG_DISABLE_WBT a request queue flag
block: don't call freeze queue in elevator_switch() and
elevator_disable()
block: use q->elevator with ->elevator_lock held in elv_iosched_show()
block: add two helpers for registering/un-registering sched debugfs
block: move sched debugfs register into elvevator_register_queue
block: prevent adding/deleting disk during updating nr_hw_queues
block: don't allow to switch elevator if updating nr_hw_queues is
in-progress
block: simplify elevator reattachment for updating nr_hw_queues
block: move blk_unregister_queue() & device_del() after freeze wait
block: move queue freezing & elevator_lock into elevator_change()
block: add `struct elv_change_ctx` for unifying elevator change
block: unifying elevator change
block: pass elevator_queue to elv_register_queue & unregister_queue
block: fail to show/store elevator sysfs attribute if elevator is
dying
block: move elv_register[unregister]_queue out of elevator_lock
block: move debugfs/sysfs register out of freezing queue
block: remove several ->elevator_lock
block: move hctx cpuhp add/del out of queue freezing
block: move wbt_enable_default() out of queue freezing from sched
->exit()
block/bfq-iosched.c | 6 +-
block/blk-mq-debugfs.c | 12 +-
block/blk-mq-sched.c | 41 +++---
block/blk-mq.c | 132 +++---------------
block/blk-sysfs.c | 24 ++--
block/blk-wbt.c | 13 +-
block/blk.h | 8 +-
block/elevator.c | 302 ++++++++++++++++++++++++++++-------------
block/elevator.h | 6 +-
block/genhd.c | 129 +++++++++++-------
include/linux/blk-mq.h | 3 +
include/linux/blkdev.h | 5 +
12 files changed, 365 insertions(+), 316 deletions(-)
--
2.47.0
