Commit c45e6a03 authored by Jens Axboe's avatar Jens Axboe
Browse files

blk-wbt: fix has-sleeper queueing check 



We need to do this inside the loop as well, or we can allow new
IO to supersede previous IO.

Tested-by: default avatarAnchal Agarwal <anchalag@amazon.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent b7882093

block/blk-wbt.c

+5 −3
Original line number Diff line number Diff line
@@ -492,16 +492,17 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct, 
{

	struct rq_wait *rqw = get_rq_wait(rwb, wb_acct);

	DECLARE_WAITQUEUE(wait, current);

	bool has_sleeper;



	if (!wq_has_sleeper(&rqw->wait) &&

	    rq_wait_inc_below(rqw, get_limit(rwb, rw)))

	has_sleeper = wq_has_sleeper(&rqw->wait);

	if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw)))

		return;



	add_wait_queue_exclusive(&rqw->wait, &wait);

	do {

		set_current_state(TASK_UNINTERRUPTIBLE);



		if (rq_wait_inc_below(rqw, get_limit(rwb, rw)))

		if (!has_sleeper && rq_wait_inc_below(rqw, get_limit(rwb, rw)))

			break;



		if (lock) {
@@ -510,6 +511,7 @@ static void __wbt_wait(struct rq_wb *rwb, enum wbt_flags wb_acct, 
			spin_lock_irq(lock);

		} else

			io_schedule();

		has_sleeper = false;

	} while (1);



	__set_current_state(TASK_RUNNING);