This is a note to let you know that I've just added the patch titled blk-iocost: simplify ioc_name to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: blk-iocost-simplify-ioc_name.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 544655d1492227d5b309feb166eaf7999f2058ee Author: Christoph Hellwig <hch@xxxxxx> Date: Wed Sep 21 20:04:53 2022 +0200 blk-iocost: simplify ioc_name [ 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@xxxxxx> Reviewed-by: Andreas Herrmann <aherrmann@xxxxxxx> Acked-by: Tejun Heo <tj@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220921180501.1539876-10-hch@xxxxxx Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> Stable-dep-of: d36a9ea5e776 ("block: fix use-after-free of q->q_usage_counter") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> 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)