blkcg: make ->cpd_init_fn() optional

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>

1 files changed, 2 insertions, 1 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 6a82ca3fb5cf..78ccbdcfe723 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1475,7 +1475,8 @@ 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);
                 }
         }