From 754edc4c9c69831166dbdeb00439c8bd1a614edf Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Wed, 28 Aug 2019 15:05:52 -0700
Subject: [PATCH] blkcg: make ->cpd_init_fn() optional

commit 86a5bba5c252e90d264c7460e29a0b9e633777e7 upstream.

For policies which can do enough initialization from ->cpd_alloc_fn(),
make ->cpd_init_fn() optional.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
---
 block/blk-cgroup.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 94b15808cf71..378d2f6112c6 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1544,7 +1544,8 @@ int blkcg_policy_register(struct blkcg_policy *pol)
 			blkcg->cpd[pol->plid] = cpd;
 			cpd->blkcg = blkcg;
 			cpd->plid = pol->plid;
-			pol->cpd_init_fn(cpd);
+			if (pol->cpd_init_fn)
+				pol->cpd_init_fn(cpd);
 		}
 	}
 
-- 
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