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

Tejun Heo
2012-04-26T22:03:08Z

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@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
---
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