[PATCH] nvme-core: do not pass empty queue_limits to blk_mq_alloc_queue()

[PATCH] nvme-core: do not pass empty queue_limits to blk_mq_alloc_queue()

[Maurizio Lombardi]

In nvme_alloc_admin_tag_set(), an empty queue_limits struct is
currently allocated on the stack and passed by reference to
blk_mq_alloc_queue().

This is redundant because blk_mq_alloc_queue() already handles
a NULL limits pointer by internally substituting it with a default
empty queue_limits struct.
Remove the unnecessary local variable and pass a NULL value.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
---
 drivers/nvme/host/core.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 19b67cf5d550..8798a51f735c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4845,7 +4845,6 @@ EXPORT_SYMBOL_GPL(nvme_complete_async_event);
 int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
 		const struct blk_mq_ops *ops, unsigned int cmd_size)
 {
-	struct queue_limits lim = {};
 	int ret;
 
 	memset(set, 0, sizeof(*set));
@@ -4865,7 +4864,7 @@ int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
 	if (ret)
 		return ret;
 
-	ctrl->admin_q = blk_mq_alloc_queue(set, &lim, NULL);
+	ctrl->admin_q = blk_mq_alloc_queue(set, NULL, NULL);
 	if (IS_ERR(ctrl->admin_q)) {
 		ret = PTR_ERR(ctrl->admin_q);
 		goto out_free_tagset;
-- 
2.53.0

Re: [PATCH] nvme-core: do not pass empty queue_limits to blk_mq_alloc_queue()

[Kanchan Joshi]

Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>

Re: [PATCH] nvme-core: do not pass empty queue_limits to blk_mq_alloc_queue()

[Maurizio Lombardi]

Keith? Can you review this?

Thanks,
Maurizio

On Fri Feb 20, 2026 at 2:30 PM CET, Maurizio Lombardi wrote:
> In nvme_alloc_admin_tag_set(), an empty queue_limits struct is
> currently allocated on the stack and passed by reference to
> blk_mq_alloc_queue().
>
> This is redundant because blk_mq_alloc_queue() already handles
> a NULL limits pointer by internally substituting it with a default
> empty queue_limits struct.
> Remove the unnecessary local variable and pass a NULL value.
>
> Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
> ---
>  drivers/nvme/host/core.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 19b67cf5d550..8798a51f735c 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -4845,7 +4845,6 @@ EXPORT_SYMBOL_GPL(nvme_complete_async_event);
>  int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
>  		const struct blk_mq_ops *ops, unsigned int cmd_size)
>  {
> -	struct queue_limits lim = {};
>  	int ret;
>  
>  	memset(set, 0, sizeof(*set));
> @@ -4865,7 +4864,7 @@ int nvme_alloc_admin_tag_set(struct nvme_ctrl *ctrl, struct blk_mq_tag_set *set,
>  	if (ret)
>  		return ret;
>  
> -	ctrl->admin_q = blk_mq_alloc_queue(set, &lim, NULL);
> +	ctrl->admin_q = blk_mq_alloc_queue(set, NULL, NULL);
>  	if (IS_ERR(ctrl->admin_q)) {
>  		ret = PTR_ERR(ctrl->admin_q);
>  		goto out_free_tagset;

Re: [PATCH] nvme-core: do not pass empty queue_limits to blk_mq_alloc_queue()

[Keith Busch]

On Fri, Feb 20, 2026 at 02:30:16PM +0100, Maurizio Lombardi wrote:
> In nvme_alloc_admin_tag_set(), an empty queue_limits struct is
> currently allocated on the stack and passed by reference to
> blk_mq_alloc_queue().

Thanks, applied.