[PATCH AUTOSEL 6.18-6.1] nvme-core: align fabrics_q teardown with admin_q in nvme_free_ctrl

[Sasha Levin]

From: Maurizio Lombardi <mlombard@xxxxxxxxxx>

[ Upstream commit f702badaf7d31dc3dea6c66da92b5f35fadd89dc ]

Currently, the final reference for the fabrics admin queue (fabrics_q)
is dropped inside nvme_remove_admin_tag_set(). However, the primary admin
queue (admin_q) defers dropping its final reference until
nvme_free_ctrl().

Move the blk_put_queue() call for fabrics_q from
nvme_remove_admin_tag_set() to nvme_free_ctrl(). This aligns the
lifecycle management of both admin queues, ensuring they are freed
symmetrically when the controller is finally torn down.

Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxxxx>
Reviewed-by: Sagi Grimberg <sagi@xxxxxxxxxxx>
Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>
Signed-off-by: Maurizio Lombardi <mlombard@xxxxxxxxxx>
Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---

LLM Generated explanations, may be completely bogus:

The background git searches finished: all three lookups (`git log
--grep='align fabrics_q'` and `--grep='fabrics_q teardown'` on HEAD and
`stable/linux-6.18.y`) returned no matches. That confirms the fabrics_q
alignment fix is not in this `6.18.44` tree yet, which matches the
earlier analysis — the asymmetry from `03b3bcd319b3a` is still present,
and the backport recommendation remains **YES**.

 drivers/nvme/host/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 24a5ca35aeb25..8feb774616029 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4908,10 +4908,8 @@ void nvme_remove_admin_tag_set(struct nvme_ctrl *ctrl)
 	 */
 	nvme_stop_keep_alive(ctrl);
 	blk_mq_destroy_queue(ctrl->admin_q);
-	if (ctrl->ops->flags & NVME_F_FABRICS) {
+	if (ctrl->fabrics_q)
 		blk_mq_destroy_queue(ctrl->fabrics_q);
-		blk_put_queue(ctrl->fabrics_q);
-	}
 	blk_mq_free_tag_set(ctrl->admin_tagset);
 }
 EXPORT_SYMBOL_GPL(nvme_remove_admin_tag_set);
@@ -5053,6 +5051,8 @@ static void nvme_free_ctrl(struct device *dev)
 
 	if (ctrl->admin_q)
 		blk_put_queue(ctrl->admin_q);
+	if (ctrl->fabrics_q)
+		blk_put_queue(ctrl->fabrics_q);
 	if (!subsys || ctrl->instance != subsys->instance)
 		ida_free(&nvme_instance_ida, ctrl->instance);
 	nvme_free_cels(ctrl);
-- 
2.53.0