Re: [PATCH V5 3/7] nvme: add sysfs attribute to change admin timeout per nvme controller

[Mohamed Khalfella <mkhalfella@purestorage.com>]

On Thu 2026-05-14 10:32:51 +0200, Maurizio Lombardi wrote:
> Currently, there is no method to adjust the timeout values on a
> per-controller basis with nvme admin queues.
> Add an admin_timeout attribute to nvme so that different nvme controllers
> which may have different timeout requirements can have custom admin
> timeouts set.
> 
> The admin timeout is also applied to the fabrics queue (fabrics_q).
> The fabrics queue is utilized for fabric-specific administrative and
> control operations, such as Connect and Property Get/Set commands.
> 
> Reviewed-by: Daniel Wagner <dwagner@suse.de>
> Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
> Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>

Reviewed-by: Mohamed Khalfella <mkhalfella@purestorage.com>

> ---
>  drivers/nvme/host/core.c  |  1 +
>  drivers/nvme/host/nvme.h  |  1 +
>  drivers/nvme/host/pci.c   |  2 +-
>  drivers/nvme/host/sysfs.c | 41 +++++++++++++++++++++++++++++++++++++++
>  4 files changed, 44 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 84f295e3bf08..fe6dcd19cecb 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -5144,6 +5144,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
>  	memset(&ctrl->ka_cmd, 0, sizeof(ctrl->ka_cmd));
>  	ctrl->ka_cmd.common.opcode = nvme_admin_keep_alive;
>  	ctrl->ka_last_check_time = jiffies;
> +	ctrl->admin_timeout = NVME_ADMIN_TIMEOUT;
>  
>  	BUILD_BUG_ON(NVME_DSM_MAX_RANGES * sizeof(struct nvme_dsm_range) >
>  			PAGE_SIZE);

nvme_alloc_admin_tag_set() uses NVME_ADMIN_TIMEOUT. Do we want to
replace that with ctrl->admin_timeout?

> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 6f9ecb4948f4..7923533cce00 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -370,6 +370,7 @@ struct nvme_ctrl {
>  	u16 mtfa;
>  	u32 ctrl_config;
>  	u32 queue_count;
> +	u32 admin_timeout;
>  
>  	u64 cap;
>  	u32 max_hw_sectors;
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 8dc353451b21..80d2e517aac3 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -3096,7 +3096,7 @@ static bool __nvme_delete_io_queues(struct nvme_dev *dev, u8 opcode)
>  	unsigned long timeout;
>  
>   retry:
> -	timeout = NVME_ADMIN_TIMEOUT;
> +	timeout = dev->ctrl.admin_timeout;
>  	while (nr_queues > 0) {
>  		if (nvme_delete_queue(&dev->queues[nr_queues], opcode))
>  			break;
> diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
> index e59758616f27..3b39b64cd9da 100644
> --- a/drivers/nvme/host/sysfs.c
> +++ b/drivers/nvme/host/sysfs.c
> @@ -623,6 +623,46 @@ static ssize_t quirks_show(struct device *dev, struct device_attribute *attr,
>  }
>  static DEVICE_ATTR_RO(quirks);
>  
> +static ssize_t nvme_admin_timeout_show(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +
> +	return sysfs_emit(buf, "%u\n",
> +				jiffies_to_msecs(ctrl->admin_timeout));
> +}
> +
> +static ssize_t nvme_admin_timeout_store(struct device *dev,
> +		struct device_attribute *attr,
> +		const char *buf, size_t count)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +	u32 timeout;
> +	int err;
> +
> +	/*
> +	 * Wait until the controller reaches the LIVE state to be sure that
> +	 * admin_q and fabrics_q are properly initialized.
> +	 */
> +	if (!test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags))
> +		return -EBUSY;
> +
> +	err = kstrtou32(buf, 10, &timeout);
> +	if (err || !timeout)
> +		return -EINVAL;
> +
> +	ctrl->admin_timeout = msecs_to_jiffies(timeout);
> +
> +	blk_queue_rq_timeout(ctrl->admin_q, ctrl->admin_timeout);
> +	if (ctrl->fabrics_q)
> +		blk_queue_rq_timeout(ctrl->fabrics_q, ctrl->admin_timeout);
> +
> +	return count;
> +}
> +
> +static DEVICE_ATTR(admin_timeout, S_IRUGO | S_IWUSR,
> +	nvme_admin_timeout_show, nvme_admin_timeout_store);
> +
>  #ifdef CONFIG_NVME_HOST_AUTH
>  static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
>  		struct device_attribute *attr, char *buf)
> @@ -765,6 +805,7 @@ static struct attribute *nvme_dev_attrs[] = {
>  	&dev_attr_cntrltype.attr,
>  	&dev_attr_dctype.attr,
>  	&dev_attr_quirks.attr,
> +	&dev_attr_admin_timeout.attr,
>  #ifdef CONFIG_NVME_HOST_AUTH
>  	&dev_attr_dhchap_secret.attr,
>  	&dev_attr_dhchap_ctrl_secret.attr,
> -- 
> 2.54.0
>