policy_list walks are protected with blkcg->lock everywhere else in the code. In destroy(), they are not. Because destroy is usually protected with the cgroup_mutex(), this is usually not a problem. But it would be a lot better not to assume this.
Signed-off-by: Glauber Costa <[email protected]> --- block/blk-cgroup.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 126c341..35fd701 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -1557,10 +1557,12 @@ static void blkiocg_destroy(struct cgroup *cgroup) spin_unlock(&blkio_list_lock); } while (1); + spin_lock_irqsave(&blkcg->lock, flags); list_for_each_entry_safe(pn, pntmp, &blkcg->policy_list, node) { blkio_policy_delete_node(pn); kfree(pn); } + spin_unlock_irqrestore(&blkcg->lock, flags); free_css_id(&blkio_subsys, &blkcg->css); rcu_read_unlock(); -- 1.7.7.6 _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
