[PATCH 01/11] blkcg: fix blkg_alloc() failure path

[Tejun Heo]

When policy data allocation fails in the middle, blkg_alloc() invokes
blkg_free() to destroy the half constructed blkg.  This ends up
calling pd_exit_fn() on policy datas which didn't go through
pd_init_fn().  Fix it by making blkg_alloc() call pd_init_fn()
immediately after each policy data allocation.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
---
 block/blk-cgroup.c |    6 +-----
 1 files changed, 1 insertions(+), 5 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 02cf633..4ab7420 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -125,12 +125,8 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q)
 
 		blkg->pd[i] = pd;
 		pd->blkg = blkg;
-	}
-
-	/* invoke per-policy init */
-	for (i = 0; i < BLKCG_MAX_POLS; i++) {
-		struct blkcg_policy *pol = blkcg_policy[i];
 
+		/* invoke per-policy init */
 		if (blkcg_policy_enabled(blkg->q, pol))
 			pol->pd_init_fn(blkg);
 	}
-- 
1.7.7.3

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