diff options
| -rw-r--r-- | block/blk-cgroup.c | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index f9797b244eb3..87ea95d1f533 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -504,8 +504,9 @@ static const char *blkg_dev_name(struct blkcg_gq *blkg) * * This function invokes @prfill on each blkg of @blkcg if pd for the * policy specified by @pol exists. @prfill is invoked with @sf, the - * policy data and @data. If @show_total is %true, the sum of the return - * values from @prfill is printed with "Total" label at the end. + * policy data and @data and the matching queue lock held. If @show_total + * is %true, the sum of the return values from @prfill is printed with + * "Total" label at the end. * * This is to be used to construct print functions for * cftype->read_seq_string method. @@ -520,11 +521,14 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg, struct hlist_node *n; u64 total = 0; - spin_lock_irq(&blkcg->lock); - hlist_for_each_entry(blkg, n, &blkcg->blkg_list, blkcg_node) + rcu_read_lock(); + hlist_for_each_entry_rcu(blkg, n, &blkcg->blkg_list, blkcg_node) { + spin_lock_irq(blkg->q->queue_lock); if (blkcg_policy_enabled(blkg->q, pol)) total += prfill(sf, blkg->pd[pol->plid], data); - spin_unlock_irq(&blkcg->lock); + spin_unlock_irq(blkg->q->queue_lock); + } + rcu_read_unlock(); if (show_total) seq_printf(sf, "Total %llu\n", (unsigned long long)total); |