From 7e5a8794492e43e9eebb68a98a23be055888ccd0 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 14 Dec 2011 00:33:42 +0100 Subject: block, cfq: move io_cq exit/release to blk-ioc.c With kmem_cache managed by blk-ioc, io_cq exit/release can be moved to blk-ioc too. The odd ->io_cq->exit/release() callbacks are replaced with elevator_ops->elevator_exit_icq_fn() with unlinking from both ioc and q, and freeing automatically handled by blk-ioc. The elevator operation only need to perform exit operation specific to the elevator - in cfq's case, exiting the cfqq's. Also, clearing of io_cq's on q detach is moved to block core and automatically performed on elevator switch and q release. Because the q io_cq points to might be freed before RCU callback for the io_cq runs, blk-ioc code should remember to which cache the io_cq needs to be freed when the io_cq is released. New field io_cq->__rcu_icq_cache is added for this purpose. As both the new field and rcu_head are used only after io_cq is released and the q/ioc_node fields aren't, they are put into unions. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- block/elevator.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'block/elevator.c') diff --git a/block/elevator.c b/block/elevator.c index cca049fb45c8..91e18f8af9be 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -979,8 +979,9 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) goto fail_register; } - /* done, replace the old one with new one and turn off BYPASS */ + /* done, clear io_cq's, switch elevators and turn off BYPASS */ spin_lock_irq(q->queue_lock); + ioc_clear_queue(q); old_elevator = q->elevator; q->elevator = e; spin_unlock_irq(q->queue_lock); -- cgit v1.2.3-59-g8ed1b