From: Yu Kuai <yukuai3@huawei.com>

Now that blkcg_mutex is used to protect blkgs, memory allocation no
longer need to be non-blocking, this is not needed.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 block/blk-cgroup.c | 20 ++------------------
 1 file changed, 2 insertions(+), 18 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b8bb2f3506aa..030499d70543 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -894,16 +894,10 @@ 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;
 		}
 
 		blkg = blkg_lookup(pos, q);
@@ -913,12 +907,10 @@ 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;
 	}
@@ -926,8 +918,6 @@ 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);
 	/*
@@ -1480,14 +1470,12 @@ int blkcg_init_disk(struct gendisk *disk)
 {
 	struct request_queue *q = disk->queue;
 	struct blkcg_gq *new_blkg, *blkg;
-	bool preloaded;
 
 	new_blkg = blkg_alloc(&blkcg_root, disk, GFP_KERNEL);
 	if (!new_blkg)
 		return -ENOMEM;
 
 	mutex_lock(&q->blkcg_mutex);
-	preloaded = !radix_tree_preload(GFP_NOIO);
 
 	/* Make sure the root blkg exists. */
 	blkg = blkg_create(&blkcg_root, disk, new_blkg);
@@ -1495,16 +1483,12 @@ 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