From a2fa8a19b75b5a649db2a6bec892ff5e03a23e76 Mon Sep 17 00:00:00 2001 From: "Maciej S. Szmigiero" Date: Wed, 10 Oct 2018 23:16:50 +0200 Subject: [PATCH] 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 4c6994806f70 ("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 Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index d219e9a1af65..6a3d87dd3c1a 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -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 -- 2.39.5