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>
This commit is contained in:
Arianna Avanzini 2015-07-07 03:08:15 +02:00 committed by Jens Axboe
parent 0762b23d23
commit a322baad10

View File

@ -822,8 +822,13 @@ 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 *
@ -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);
}