Commit a322baad authored Jul 07, 2015 by Arianna Avanzini Committed by Jens Axboe Jul 07, 2015

block/blk-cgroup.c: free per-blkcg data when freeing the blkcg



Currently, per-blkcg data is freed each time a policy is deactivated,
that is also upon scheduler switch. However, when switching from a
scheduler implementing a policy which requires per-blkcg data to
another one, that same policy might be active on other devices, and
therefore those same per-blkcg data could be still in use.
This commit lets per-blkcg data be freed when the blkcg is freed
instead of on policy deactivation.

Signed-off-by: Arianna Avanzini <avanzini.arianna@gmail.com>
Reported-and-tested-by: Michael Kaminsky <kaminsky@cs.cmu.edu>
Fixes: e48453c3 ("block, cgroup: implement policy-specific per-blkcg data")
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 0762b23d

block/blk-cgroup.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -822,9 +822,14 @@ static void blkcg_css_free(struct cgroup_subsys_state *css)
		{
		struct blkcg *blkcg = css_to_blkcg(css);

		if (blkcg != &blkcg_root)
		if (blkcg != &blkcg_root) {
		int i;

		for (i = 0; i < BLKCG_MAX_POLS; i++)
		kfree(blkcg->pd[i]);
		kfree(blkcg);
		}
		}

		static struct cgroup_subsys_state *
		blkcg_css_alloc(struct cgroup_subsys_state *parent_css)
		@@ -1162,8 +1167,6 @@ void blkcg_deactivate_policy(struct request_queue *q,

		kfree(blkg->pd[pol->plid]);
		blkg->pd[pol->plid] = NULL;
		kfree(blkg->blkcg->pd[pol->plid]);
		blkg->blkcg->pd[pol->plid] = NULL;

		spin_unlock(&blkg->blkcg->lock);
		}