On Mon, Jun 16, 2025 at 11:02:25PM +0530, Nilay Shroff wrote:
> In preparation for allocating sched_tags before freezing the request
> queue and acquiring ->elevator_lock, move the elevator queue allocation
> logic from the elevator ops ->init_sched callback into blk_mq_init_sched.
>
> This refactoring provides a centralized location for elevator queue
> initialization, which makes it easier to store pre-allocated sched_tags
> in the struct elevator_queue during later changes.
>
> Signed-off-by: Nilay Shroff <nilay@xxxxxxxxxxxxx>
> ---
> block/bfq-iosched.c | 13 +++----------
> block/blk-mq-sched.c | 7 ++++++-
> block/elevator.h | 2 +-
> block/kyber-iosched.c | 11 ++---------
> block/mq-deadline.c | 14 ++------------
> 5 files changed, 14 insertions(+), 33 deletions(-)
>
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 0cb1e9873aab..fd26dc1901b0 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -7232,22 +7232,16 @@ static void bfq_init_root_group(struct bfq_group *root_group,
> root_group->sched_data.bfq_class_idle_last_service = jiffies;
> }
>
> -static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
> +static int bfq_init_queue(struct request_queue *q, struct elevator_queue *eq)
> {
> struct bfq_data *bfqd;
> - struct elevator_queue *eq;
> unsigned int i;
> struct blk_independent_access_ranges *ia_ranges = q->disk->ia_ranges;
>
> - eq = elevator_alloc(q, e);
> - if (!eq)
> - return -ENOMEM;
> -
> bfqd = kzalloc_node(sizeof(*bfqd), GFP_KERNEL, q->node);
> - if (!bfqd) {
> - kobject_put(&eq->kobj);
> + if (!bfqd)
> return -ENOMEM;
> - }
> +
> eq->elevator_data = bfqd;
>
> spin_lock_irq(&q->queue_lock);
> @@ -7405,7 +7399,6 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
>
> out_free:
> kfree(bfqd);
> - kobject_put(&eq->kobj);
> return -ENOMEM;
> }
>
> diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
> index 55a0fd105147..d914eb9d61a6 100644
> --- a/block/blk-mq-sched.c
> +++ b/block/blk-mq-sched.c
> @@ -475,6 +475,10 @@ int blk_mq_init_sched(struct request_queue *q, struct elevator_type *e)
> q->nr_requests = 2 * min_t(unsigned int, q->tag_set->queue_depth,
> BLKDEV_DEFAULT_RQ);
>
> + eq = elevator_alloc(q, e);
> + if (!eq)
> + return -ENOMEM;
> +
> if (blk_mq_is_shared_tags(flags)) {
> ret = blk_mq_init_sched_shared_tags(q);
> if (ret)
The above failure needs to be handled by kobject_put(&eq->kobj).
Otherwise, feel free to add:
Reviewed-by: Ming Lei <ming.lei@xxxxxxxxxx>
Thanks,
Ming
