[PATCH 5.15 593/731] blk-iocost: simplify ioc_name

Greg Kroah-Hartman
2022-12-28T15:45:47Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit 9df3e65139b923dfe98f76b7057882c7afb2d3e4 ]

Just directly dereference the disk name instead of going through multiple
hoops to find the same value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220921180501.1539876-10-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: d36a9ea5e776 ("block: fix use-after-free of q->q_usage_counter")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/blk-iocost.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 069193dee95b..f5b501888ba4 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -665,17 +665,13 @@ static struct ioc *q_to_ioc(struct request_queue *q)
return rqos_to_ioc(rq_qos_id(q, RQ_QOS_COST));
}

-static const char *q_name(struct request_queue *q)
-{
- if (blk_queue_registered(q))
- return kobject_name(q->kobj.parent);
- else
- return "<unknown>";
-}
-
static const char __maybe_unused *ioc_name(struct ioc *ioc)
{
- return q_name(ioc->rqos.q);
+ struct gendisk *disk = ioc->rqos.q->disk;
+
+ if (!disk)
+ return "<unknown>";
+ return disk->disk_name;
}

static struct ioc_gq *pd_to_iocg(struct blkg_policy_data *pd)
--
2.35.1