Commit a2fa8a19 authored Oct 10, 2018 by Maciej S. Szmigiero Committed by Jens Axboe Oct 11, 2018

cfq: clear queue pointers from cfqg after unpinning them in cfq_pd_offline



BFQ is already doing a similar thing in its .pd_offline_fn() method
implementation.

While it seems that after commit 4c699480
("blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()")
was reverted leaving these pointers intact no longer causes crashes
clearing them is still a sensible thing to do to make the code more robust.

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 4822e902

block/cfq-iosched.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -1644,14 +1644,20 @@ static void cfq_pd_offline(struct blkg_policy_data *pd)
		int i;

		for (i = 0; i < IOPRIO_BE_NR; i++) {
		if (cfqg->async_cfqq[0][i])
		if (cfqg->async_cfqq[0][i]) {
		cfq_put_queue(cfqg->async_cfqq[0][i]);
		if (cfqg->async_cfqq[1][i])
		cfqg->async_cfqq[0][i] = NULL;
		}
		if (cfqg->async_cfqq[1][i]) {
		cfq_put_queue(cfqg->async_cfqq[1][i]);
		cfqg->async_cfqq[1][i] = NULL;
		}
		}

		if (cfqg->async_idle_cfqq)
		if (cfqg->async_idle_cfqq) {
		cfq_put_queue(cfqg->async_idle_cfqq);
		cfqg->async_idle_cfqq = NULL;
		}

		/*
		* @blkg is going offline and will be ignored by