Re: [PATCH] nvme: implement ->get_unique_id

[Chuck Lever <chuck.lever@oracle.com>]

On Fri, Jul 05, 2024 at 06:46:26PM +0200, Christoph Hellwig wrote:
> Implement the get_unique_id method to allow pNFS SCSI layout access to
> NVMe namespaces.
> 
> This is the server side implementation of RFC 9561 "Using the Parallel
> NFS (pNFS) SCSI Layout to Access Non-Volatile Memory Express (NVMe)
> Storage Devices".
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/nvme/host/core.c      | 27 +++++++++++++++++++++++++++
>  drivers/nvme/host/multipath.c | 16 ++++++++++++++++
>  drivers/nvme/host/nvme.h      |  3 +++
>  3 files changed, 46 insertions(+)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 782090ce0bc10d..96e0879013b79d 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2230,6 +2230,32 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
>  	return ret;
>  }
>  
> +int nvme_ns_get_unique_id(struct nvme_ns *ns, u8 id[16],
> +		enum blk_unique_id type)
> +{
> +	struct nvme_ns_ids *ids = &ns->head->ids;
> +
> +	if (type != BLK_UID_EUI64)
> +		return -EINVAL;
> +
> +	if (memchr_inv(ids->nguid, 0, sizeof(ids->nguid))) {
> +		memcpy(id, &ids->nguid, sizeof(ids->nguid));
> +		return sizeof(ids->nguid);
> +	}
> +	if (memchr_inv(ids->eui64, 0, sizeof(ids->eui64))) {
> +		memcpy(id, &ids->eui64, sizeof(ids->eui64));
> +		return sizeof(ids->eui64);
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int nvme_get_unique_id(struct gendisk *disk, u8 id[16],
> +		enum blk_unique_id type)
> +{
> +	return nvme_ns_get_unique_id(disk->private_data, id, type);
> +}
> +
>  #ifdef CONFIG_BLK_SED_OPAL
>  static int nvme_sec_submit(void *data, u16 spsp, u8 secp, void *buffer, size_t len,
>  		bool send)
> @@ -2285,6 +2311,7 @@ const struct block_device_operations nvme_bdev_ops = {
>  	.open		= nvme_open,
>  	.release	= nvme_release,
>  	.getgeo		= nvme_getgeo,
> +	.get_unique_id	= nvme_get_unique_id,
>  	.report_zones	= nvme_report_zones,
>  	.pr_ops		= &nvme_pr_ops,
>  };
> diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
> index d8b6b4648eaff9..1aed93d792b610 100644
> --- a/drivers/nvme/host/multipath.c
> +++ b/drivers/nvme/host/multipath.c
> @@ -427,6 +427,21 @@ static void nvme_ns_head_release(struct gendisk *disk)
>  	nvme_put_ns_head(disk->private_data);
>  }
>  
> +static int nvme_ns_head_get_unique_id(struct gendisk *disk, u8 id[16],
> +		enum blk_unique_id type)
> +{
> +	struct nvme_ns_head *head = disk->private_data;
> +	struct nvme_ns *ns;
> +	int srcu_idx, ret = -EWOULDBLOCK;
> +
> +	srcu_idx = srcu_read_lock(&head->srcu);
> +	ns = nvme_find_path(head);
> +	if (ns)
> +		ret = nvme_ns_get_unique_id(ns, id, type);
> +	srcu_read_unlock(&head->srcu, srcu_idx);
> +	return ret;
> +}
> +
>  #ifdef CONFIG_BLK_DEV_ZONED
>  static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector,
>  		unsigned int nr_zones, report_zones_cb cb, void *data)
> @@ -454,6 +469,7 @@ const struct block_device_operations nvme_ns_head_ops = {
>  	.ioctl		= nvme_ns_head_ioctl,
>  	.compat_ioctl	= blkdev_compat_ptr_ioctl,
>  	.getgeo		= nvme_getgeo,
> +	.get_unique_id	= nvme_ns_head_get_unique_id,
>  	.report_zones	= nvme_ns_head_report_zones,
>  	.pr_ops		= &nvme_pr_ops,
>  };
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index f3a41133ac3f97..1907fbc3f5dbb3 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -1062,6 +1062,9 @@ static inline bool nvme_disk_is_ns_head(struct gendisk *disk)
>  }
>  #endif /* CONFIG_NVME_MULTIPATH */
>  
> +int nvme_ns_get_unique_id(struct nvme_ns *ns, u8 id[16],
> +		enum blk_unique_id type);
> +
>  struct nvme_zone_info {
>  	u64 zone_size;
>  	unsigned int max_open_zones;
> -- 
> 2.43.0
> 
> 

I am happy to see this. Fwiw:

Acked-by: Chuck Lever <chuck.lever@oracle.com>

I will connect with you offline to advise me on setting up a test
harness similar to what I have with iSCSI.


-- 
Chuck Lever