From: Yu Kuai <[email protected]> blkg creation is now serialized by q->blkcg_mutex and no longer runs under q->queue_lock. The radix tree is initialized with GFP_NOWAIT, so radix_tree_insert() cannot sleep while blkcg->lock is held and the old preload dance is no longer needed.
Remove the preload calls and the associated unwind path. Signed-off-by: Yu Kuai <[email protected]> --- block/blk-cgroup.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c index 71313bb3c4f3..b99ab8d67798 100644 --- a/block/blk-cgroup.c +++ b/block/blk-cgroup.c @@ -420,7 +420,6 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk, pol->pd_init_fn(blkg->pd[i]); } - /* insert */ spin_lock_irq(&blkcg->lock); ret = radix_tree_insert(&blkcg->blkg_tree, disk->queue->id, blkg); if (likely(!ret)) { @@ -875,16 +874,10 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, goto fail_unlock; } - if (radix_tree_preload(GFP_KERNEL)) { - blkg_free(new_blkg); - ret = -ENOMEM; - goto fail_unlock; - } - if (!blkcg_policy_enabled(q, pol)) { blkg_free(new_blkg); ret = -EOPNOTSUPP; - goto fail_preloaded; + goto fail_unlock; } rcu_read_lock(); @@ -896,12 +889,10 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, blkg = blkg_create(pos, disk, new_blkg); if (IS_ERR(blkg)) { ret = PTR_ERR(blkg); - goto fail_preloaded; + goto fail_unlock; } } - radix_tree_preload_end(); - if (pos == blkcg) goto success; } @@ -909,8 +900,6 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol, ctx->blkg = blkg; return 0; -fail_preloaded: - radix_tree_preload_end(); fail_unlock: mutex_unlock(&q->blkcg_mutex); /* @@ -1448,7 +1437,6 @@ int blkcg_init_disk(struct gendisk *disk) { struct request_queue *q = disk->queue; struct blkcg_gq *new_blkg, *blkg; - bool preloaded; /* * If the queue is shared across disk rebind (e.g., SCSI), the @@ -1466,8 +1454,6 @@ int blkcg_init_disk(struct gendisk *disk) if (!new_blkg) return -ENOMEM; - preloaded = !radix_tree_preload(GFP_KERNEL); - /* Make sure the root blkg exists. */ mutex_lock(&q->blkcg_mutex); blkg = blkg_create(&blkcg_root, disk, new_blkg); @@ -1475,16 +1461,12 @@ int blkcg_init_disk(struct gendisk *disk) goto err_unlock; q->root_blkg = blkg; - if (preloaded) - radix_tree_preload_end(); mutex_unlock(&q->blkcg_mutex); return 0; err_unlock: mutex_unlock(&q->blkcg_mutex); - if (preloaded) - radix_tree_preload_end(); return PTR_ERR(blkg); } -- 2.51.0
