[PATCH v8 1/2] nvme: add per-queue sysfs directories

[Hannes Reinecke]

On 11/7/26 10:53 AM, Saravanan D wrote:
> Per I/O queue transport state, such as the nvme-tcp io_cpu, has
> nowhere to live in sysfs, since the core has no directory for
> individual queues.
> 
> Add helpers that create the controller's queues directory and add or
> remove one directory per queue
> 
>    /sys/class/nvme/nvmeX/queues/<qid>/
> 
> carrying the attributes a transport sets in the new queue_attr_groups
> member of struct nvme_ctrl_ops. For such transports nvme_add_ctrl()
> creates the queues directory. It holds a reference on the controller
> device, so nvme_uninit_ctrl() deletes it before deleting the device,
> after the transport has removed the queue directories.
> 
> The transport adds a queue's directory when it sets the queue up and
> removes it when it frees the queue, so the directories follow the
> queues across reconnects and changes in the queue count. The core
> allocates each queue directory and its release frees only that
> allocation. Removal waits for running attribute callbacks, so the
> transport may tear the queue down once it returns.
> 
> Suggested-by: Sagi Grimberg <sagi at grimberg.me>
> Link: https://lore.kernel.org/linux-nvme/13c160d0-0657-47ce-9a16-58d348267ab0@grimberg.me/
> Assisted-by: Claude:claude-opus-5-5 [Claude Code]
> Signed-off-by: Saravanan D <saravanand at crusoe.ai>
> ---
>   drivers/nvme/host/core.c  | 12 ++++++
>   drivers/nvme/host/nvme.h  | 25 +++++++++++
>   drivers/nvme/host/sysfs.c | 90 +++++++++++++++++++++++++++++++++++++++
>   3 files changed, 127 insertions(+)
> 
Reviewed-by: Hannes Reinecke <hare at kernel.org>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare at suse.de                                +49 911 74053 688
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