[PATCH 3/5] nvme: refactor namespace probing

Joel Granados j.granados at samsung.com
Wed Jul 20 01:19:12 PDT 2022


On Mon, Jul 18, 2022 at 07:25:01AM +0200, Christoph Hellwig wrote:
> Change nvme_ns_scan to gather all information needed for generic
> namespace setup into a nvme_ns_info structure.  This structure is filled
> from the Command Set Idependent Identify Namespace data structure if
> it is available or else the legacy Identify namespace structure.
> 
> With that everything related to the NVM command set (and the ZNS command
> set derived from it) can be encapsulated in the nvme_update_ns_info_block
> function while keeping the rest of the namespace probing generic.
> 
> The downside is that we now always issue two Identify Namespace calls for
> each probed namespace instead of usually just a single one previously.
> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Javier González <javier.gonz at samsung.com>
> ---
>  drivers/nvme/host/core.c | 231 +++++++++++++++++++++------------------
>  1 file changed, 126 insertions(+), 105 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 4769c49141913..659068f90165c 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -31,6 +31,14 @@
>  
>  #define NVME_MINORS		(1U << MINORBITS)
>  
> +struct nvme_ns_info {
> +	struct nvme_ns_ids ids;
> +	u32 nsid;
> +	__le32 anagrpid;
> +	bool is_shared;
> +	bool is_ready;
> +};
Nitpick after looking at this for the second time:
Should we use tabs instead of spaces to increase readability here?

> +
>  unsigned int admin_timeout = 60;
>  module_param(admin_timeout, uint, 0644);
>  MODULE_PARM_DESC(admin_timeout, "timeout in seconds for admin commands");
> @@ -1342,8 +1350,8 @@ static int nvme_process_ns_desc(struct nvme_ctrl *ctrl, struct nvme_ns_ids *ids,
>  	}
>  }
>  
> -static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
> -		struct nvme_ns_ids *ids)
> +static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl,
> +		struct nvme_ns_info *info)
>  {
>  	struct nvme_command c = { };
>  	bool csi_seen = false;
> @@ -1356,7 +1364,7 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>  		return 0;
>  
>  	c.identify.opcode = nvme_admin_identify;
> -	c.identify.nsid = cpu_to_le32(nsid);
> +	c.identify.nsid = cpu_to_le32(info->nsid);
>  	c.identify.cns = NVME_ID_CNS_NS_DESC_LIST;
>  
>  	data = kzalloc(NVME_IDENTIFY_DATA_SIZE, GFP_KERNEL);
> @@ -1368,7 +1376,7 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>  	if (status) {
>  		dev_warn(ctrl->device,
>  			"Identify Descriptors failed (nsid=%u, status=0x%x)\n",
> -			nsid, status);
> +			info->nsid, status);
>  		goto free_data;
>  	}
>  
> @@ -1378,7 +1386,7 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>  		if (cur->nidl == 0)
>  			break;
>  
> -		len = nvme_process_ns_desc(ctrl, ids, cur, &csi_seen);
> +		len = nvme_process_ns_desc(ctrl, &info->ids, cur, &csi_seen);
>  		if (len < 0)
>  			break;
>  
> @@ -1387,7 +1395,7 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>  
>  	if (nvme_multi_css(ctrl) && !csi_seen) {
>  		dev_warn(ctrl->device, "Command set not reported for nsid:%d\n",
> -			 nsid);
> +			 info->nsid);
>  		status = -EINVAL;
>  	}
>  
> @@ -1397,7 +1405,7 @@ static int nvme_identify_ns_descs(struct nvme_ctrl *ctrl, unsigned nsid,
>  }
>  
>  static int nvme_identify_ns(struct nvme_ctrl *ctrl, unsigned nsid,
> -			struct nvme_ns_ids *ids, struct nvme_id_ns **id)
> +			struct nvme_id_ns **id)
>  {
>  	struct nvme_command c = { };
>  	int error;
> @@ -1420,51 +1428,64 @@ static int nvme_identify_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>  	error = NVME_SC_INVALID_NS | NVME_SC_DNR;
>  	if ((*id)->ncap == 0) /* namespace not allocated or attached */
>  		goto out_free_id;
> +	return 0;
>  
> +out_free_id:
> +	kfree(*id);
> +	return error;
> +}
>  
> +static int nvme_ns_info_from_identify(struct nvme_ctrl *ctrl,
> +		struct nvme_ns_info *info)
> +{
> +	struct nvme_ns_ids *ids = &info->ids;
> +	struct nvme_id_ns *id;
> +	int ret;
> +
> +	ret = nvme_identify_ns(ctrl, info->nsid, &id);
> +	if (ret)
> +		return ret;
> +	info->anagrpid = id->anagrpid;
> +	info->is_shared = id->nmic & NVME_NS_NMIC_SHARED;
> +	info->is_ready = true;
>  	if (ctrl->quirks & NVME_QUIRK_BOGUS_NID) {
>  		dev_info(ctrl->device,
>  			 "Ignoring bogus Namespace Identifiers\n");
>  	} else {
>  		if (ctrl->vs >= NVME_VS(1, 1, 0) &&
>  		    !memchr_inv(ids->eui64, 0, sizeof(ids->eui64)))
> -			memcpy(ids->eui64, (*id)->eui64, sizeof(ids->eui64));
> +			memcpy(ids->eui64, id->eui64, sizeof(ids->eui64));
>  		if (ctrl->vs >= NVME_VS(1, 2, 0) &&
>  		    !memchr_inv(ids->nguid, 0, sizeof(ids->nguid)))
> -			memcpy(ids->nguid, (*id)->nguid, sizeof(ids->nguid));
> +			memcpy(ids->nguid, id->nguid, sizeof(ids->nguid));
>  	}
> -
> +	kfree(id);
>  	return 0;
> -
> -out_free_id:
> -	kfree(*id);
> -	return error;
>  }
>  
> -static int nvme_identify_ns_cs_indep(struct nvme_ctrl *ctrl, unsigned nsid,
> -			struct nvme_id_ns_cs_indep **id)
> +static int nvme_ns_info_from_id_cs_indep(struct nvme_ctrl *ctrl,
> +		struct nvme_ns_info *info)
>  {
> +	struct nvme_id_ns_cs_indep *id;
>  	struct nvme_command c = {
>  		.identify.opcode	= nvme_admin_identify,
> -		.identify.nsid		= cpu_to_le32(nsid),
> +		.identify.nsid		= cpu_to_le32(info->nsid),
>  		.identify.cns		= NVME_ID_CNS_NS_CS_INDEP,
>  	};
>  	int ret;
>  
> -	*id = kmalloc(sizeof(**id), GFP_KERNEL);
> -	if (!*id)
> +	id = kmalloc(sizeof(*id), GFP_KERNEL);
> +	if (!id)
>  		return -ENOMEM;
>  
> -	ret = nvme_submit_sync_cmd(ctrl->admin_q, &c, *id, sizeof(**id));
> -	if (ret) {
> -		dev_warn(ctrl->device,
> -			 "Identify namespace (CS independent) failed (%d)\n",
> -			 ret);
> -		kfree(*id);
> -		return ret;
> +	ret = nvme_submit_sync_cmd(ctrl->admin_q, &c, id, sizeof(*id));
> +	if (!ret) {
> +		info->anagrpid = id->anagrpid;
> +		info->is_shared = id->nmic & NVME_NS_NMIC_SHARED;
> +		info->is_ready = id->nstat & NVME_NSTAT_NRDY;
>  	}
> -
> -	return 0;
> +	kfree(id);
> +	return ret;
>  }
>  
>  static int nvme_features(struct nvme_ctrl *dev, u8 op, unsigned int fid,
> @@ -1925,12 +1946,19 @@ static void nvme_set_chunk_sectors(struct nvme_ns *ns, struct nvme_id_ns *id)
>  	blk_queue_chunk_sectors(ns->queue, iob);
>  }
>  
> -static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
> +static int nvme_update_ns_info_block(struct nvme_ns *ns,
> +		struct nvme_ns_info *info)
>  {
> -	unsigned lbaf = nvme_lbaf_index(id->flbas);
> +	struct nvme_id_ns *id;
> +	unsigned lbaf;
Checkpatch.pl has a warning here for use of 'unsigned int' instead of
just 'unsigned'

>  	int ret;
>  
> +	ret = nvme_identify_ns(ns->ctrl, info->nsid, &id);
> +	if (ret)
> +		return ret;
> +
>  	blk_mq_freeze_queue(ns->disk->queue);
> +	lbaf = nvme_lbaf_index(id->flbas);
>  	ns->lba_shift = id->lbaf[lbaf].ds;
>  	nvme_set_queue_limits(ns->ctrl, ns->queue);
>  
> @@ -1967,6 +1995,7 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
>  		disk_update_readahead(ns->head->disk);
>  		blk_mq_unfreeze_queue(ns->head->disk->queue);
>  	}
> +	kfree(id);
>  	return 0;
>  
>  out_unfreeze:
> @@ -1980,9 +2009,30 @@ static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_id_ns *id)
>  		ret = 0;
>  	}
>  	blk_mq_unfreeze_queue(ns->disk->queue);
> +	kfree(id);
>  	return ret;
>  }
>  
> +static int nvme_update_ns_info(struct nvme_ns *ns, struct nvme_ns_info *info)
> +{
> +	switch (info->ids.csi) {
> +	case NVME_CSI_ZNS:
> +		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
> +			dev_warn(ns->ctrl->device,
> +	"nsid %u not supported without CONFIG_BLK_DEV_ZONED\n",
> +				info->nsid);
> +			return -ENODEV;
> +		}
> +		return nvme_update_ns_info_block(ns, info);
> +	case NVME_CSI_NVM:
> +		return nvme_update_ns_info_block(ns, info);
> +	default:
> +		dev_warn(ns->ctrl->device, "unknown csi %u for nsid %u\n",
> +			info->ids.csi, info->nsid);
> +		return -ENODEV;
> +	}
> +}
> +
>  static char nvme_pr_type(enum pr_type type)
>  {
>  	switch (type) {
> @@ -3911,7 +3961,7 @@ static int nvme_add_ns_cdev(struct nvme_ns *ns)
>  }
>  
>  static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
> -		unsigned nsid, struct nvme_ns_ids *ids)
> +		struct nvme_ns_info *info)
>  {
>  	struct nvme_ns_head *head;
>  	size_t size = sizeof(*head);
> @@ -3933,8 +3983,9 @@ static struct nvme_ns_head *nvme_alloc_ns_head(struct nvme_ctrl *ctrl,
>  	if (ret)
>  		goto out_ida_remove;
>  	head->subsys = ctrl->subsys;
> -	head->ns_id = nsid;
> -	head->ids = *ids;
> +	head->ns_id = info->nsid;
> +	head->ids = info->ids;
> +	head->shared = info->is_shared;
>  	kref_init(&head->ref);
>  
>  	if (head->ids.csi) {
> @@ -3991,55 +4042,54 @@ static int nvme_global_check_duplicate_ids(struct nvme_subsystem *this,
>  	return ret;
>  }
>  
> -static int nvme_init_ns_head(struct nvme_ns *ns, unsigned nsid,
> -		struct nvme_ns_ids *ids, bool is_shared)
> +static int nvme_init_ns_head(struct nvme_ns *ns, struct nvme_ns_info *info)
>  {
>  	struct nvme_ctrl *ctrl = ns->ctrl;
>  	struct nvme_ns_head *head = NULL;
>  	int ret;
>  
> -	ret = nvme_global_check_duplicate_ids(ctrl->subsys, ids);
> +	ret = nvme_global_check_duplicate_ids(ctrl->subsys, &info->ids);
>  	if (ret) {
>  		dev_err(ctrl->device,
> -			"globally duplicate IDs for nsid %d\n", nsid);
> +			"globally duplicate IDs for nsid %d\n", info->nsid);
>  		nvme_print_device_info(ctrl);
>  		return ret;
>  	}
>  
>  	mutex_lock(&ctrl->subsys->lock);
> -	head = nvme_find_ns_head(ctrl, nsid);
> +	head = nvme_find_ns_head(ctrl, info->nsid);
>  	if (!head) {
> -		ret = nvme_subsys_check_duplicate_ids(ctrl->subsys, ids);
> +		ret = nvme_subsys_check_duplicate_ids(ctrl->subsys, &info->ids);
>  		if (ret) {
>  			dev_err(ctrl->device,
>  				"duplicate IDs in subsystem for nsid %d\n",
> -				nsid);
> +				info->nsid);
>  			goto out_unlock;
>  		}
> -		head = nvme_alloc_ns_head(ctrl, nsid, ids);
> +		head = nvme_alloc_ns_head(ctrl, info);
>  		if (IS_ERR(head)) {
>  			ret = PTR_ERR(head);
>  			goto out_unlock;
>  		}
> -		head->shared = is_shared;
>  	} else {
>  		ret = -EINVAL;
> -		if (!is_shared || !head->shared) {
> +		if (!info->is_shared || !head->shared) {
>  			dev_err(ctrl->device,
> -				"Duplicate unshared namespace %d\n", nsid);
> +				"Duplicate unshared namespace %d\n",
> +				info->nsid);
>  			goto out_put_ns_head;
>  		}
> -		if (!nvme_ns_ids_equal(&head->ids, ids)) {
> +		if (!nvme_ns_ids_equal(&head->ids, &info->ids)) {
>  			dev_err(ctrl->device,
>  				"IDs don't match for shared namespace %d\n",
> -					nsid);
> +					info->nsid);
>  			goto out_put_ns_head;
>  		}
>  
>  		if (!multipath && !list_empty(&head->list)) {
>  			dev_warn(ctrl->device,
>  				"Found shared namespace %d, but multipathing not supported.\n",
> -				nsid);
> +				info->nsid);
>  			dev_warn_once(ctrl->device,
>  				"Support for shared namespaces without CONFIG_NVME_MULTIPATH is deprecated and will be removed in Linux 6.0\n.");
>  		}
> @@ -4093,20 +4143,15 @@ static void nvme_ns_add_to_ctrl_list(struct nvme_ns *ns)
>  	list_add(&ns->list, &ns->ctrl->namespaces);
>  }
>  
> -static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
> -		struct nvme_ns_ids *ids)
> +static void nvme_alloc_ns(struct nvme_ctrl *ctrl, struct nvme_ns_info *info)
>  {
>  	struct nvme_ns *ns;
>  	struct gendisk *disk;
> -	struct nvme_id_ns *id;
>  	int node = ctrl->numa_node;
>  
> -	if (nvme_identify_ns(ctrl, nsid, ids, &id))
> -		return;
> -
>  	ns = kzalloc_node(sizeof(*ns), GFP_KERNEL, node);
>  	if (!ns)
> -		goto out_free_id;
> +		return;
>  
>  	disk = blk_mq_alloc_disk(ctrl->tagset, ns);
>  	if (IS_ERR(disk))
> @@ -4127,7 +4172,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>  	ns->ctrl = ctrl;
>  	kref_init(&ns->kref);
>  
> -	if (nvme_init_ns_head(ns, nsid, ids, id->nmic & NVME_NS_NMIC_SHARED))
> +	if (nvme_init_ns_head(ns, info))
>  		goto out_cleanup_disk;
>  
>  	/*
> @@ -4153,7 +4198,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>  			ns->head->instance);
>  	}
>  
> -	if (nvme_update_ns_info(ns, id))
> +	if (nvme_update_ns_info(ns, info))
>  		goto out_unlink_ns;
>  
>  	down_write(&ctrl->namespaces_rwsem);
> @@ -4167,9 +4212,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>  	if (!nvme_ns_head_multipath(ns->head))
>  		nvme_add_ns_cdev(ns);
>  
> -	nvme_mpath_add_disk(ns, id->anagrpid);
> +	nvme_mpath_add_disk(ns, info->anagrpid);
>  	nvme_fault_inject_init(&ns->fault_inject, ns->disk->disk_name);
> -	kfree(id);
>  
>  	return;
>  
> @@ -4189,8 +4233,6 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
>  	blk_cleanup_disk(disk);
>   out_free_ns:
>  	kfree(ns);
> - out_free_id:
> -	kfree(id);
>  }
>  
>  static void nvme_ns_remove(struct nvme_ns *ns)
> @@ -4249,29 +4291,21 @@ static void nvme_ns_remove_by_nsid(struct nvme_ctrl *ctrl, u32 nsid)
>  	}
>  }
>  
> -static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
> +static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_info *info)
>  {
> -	struct nvme_id_ns *id;
>  	int ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
>  
>  	if (test_bit(NVME_NS_DEAD, &ns->flags))
>  		goto out;
>  
> -	ret = nvme_identify_ns(ns->ctrl, ns->head->ns_id, ids, &id);
> -	if (ret)
> -		goto out;
> -
>  	ret = NVME_SC_INVALID_NS | NVME_SC_DNR;
> -	if (!nvme_ns_ids_equal(&ns->head->ids, ids)) {
> +	if (!nvme_ns_ids_equal(&ns->head->ids, &info->ids)) {
>  		dev_err(ns->ctrl->device,
>  			"identifiers changed for nsid %d\n", ns->head->ns_id);
> -		goto out_free_id;
> +		goto out;
>  	}
>  
> -	ret = nvme_update_ns_info(ns, id);
> -
> -out_free_id:
> -	kfree(id);
> +	ret = nvme_update_ns_info(ns, info);
>  out:
>  	/*
>  	 * Only remove the namespace if we got a fatal error back from the
> @@ -4285,57 +4319,44 @@ static void nvme_validate_ns(struct nvme_ns *ns, struct nvme_ns_ids *ids)
>  
>  static void nvme_scan_ns(struct nvme_ctrl *ctrl, unsigned nsid)
>  {
> -	struct nvme_ns_ids ids = { };
> -	struct nvme_id_ns_cs_indep *id;
> +	struct nvme_ns_info info = { .nsid = nsid };
>  	struct nvme_ns *ns;
> -	bool ready = true;
>  
> -	if (nvme_identify_ns_descs(ctrl, nsid, &ids))
> +	if (nvme_identify_ns_descs(ctrl, &info))
>  		return;
>  
> -	if (ids.csi != NVME_CSI_NVM && !nvme_multi_css(ctrl)) {
> +	if (info.ids.csi != NVME_CSI_NVM && !nvme_multi_css(ctrl)) {
>  		dev_warn(ctrl->device,
>  			"command set not reported for nsid: %d\n", nsid);
>  		return;
>  	}
>  
>  	/*
> -	 * Check if the namespace is ready.  If not ignore it, we will get an
> -	 * AEN once it becomes ready and restart the scan.
> +	 * If available try to use the Command Set Idependent Identify Namespace
> +	 * data structure to find all the generic information that is needed to
> +	 * set up a namespace.  If not fall back to the legacy version.
>  	 */
> -	if ((ctrl->cap & NVME_CAP_CRMS_CRIMS) &&
> -	    !nvme_identify_ns_cs_indep(ctrl, nsid, &id)) {
> -		ready = id->nstat & NVME_NSTAT_NRDY;
> -		kfree(id);
> +	if (ctrl->cap & NVME_CAP_CRMS_CRIMS) {
> +		if (nvme_ns_info_from_id_cs_indep(ctrl, &info))
> +			return;
> +	} else {
> +		if (nvme_ns_info_from_identify(ctrl, &info))
> +			return;
>  	}
>  
> -	if (!ready)
> +	/*
> +	 * Ignore the namespace if it is not ready. We will get an AEN once it
> +	 * becomes ready and restart the scan.
> +	 */
> +	if (!info.is_ready)
>  		return;
>  
>  	ns = nvme_find_get_ns(ctrl, nsid);
>  	if (ns) {
> -		nvme_validate_ns(ns, &ids);
> +		nvme_validate_ns(ns, &info);
>  		nvme_put_ns(ns);
> -		return;
> -	}
> -
> -	switch (ids.csi) {
> -	case NVME_CSI_NVM:
> -		nvme_alloc_ns(ctrl, nsid, &ids);
> -		break;
> -	case NVME_CSI_ZNS:
> -		if (!IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
> -			dev_warn(ctrl->device,
> -				"nsid %u not supported without CONFIG_BLK_DEV_ZONED\n",
> -				nsid);
> -			break;
> -		}
> -		nvme_alloc_ns(ctrl, nsid, &ids);
> -		break;
> -	default:
> -		dev_warn(ctrl->device, "unknown csi %u for nsid %u\n",
> -			ids.csi, nsid);
> -		break;
> +	} else {
> +		nvme_alloc_ns(ctrl, &info);
>  	}
>  }
>  
> -- 
> 2.30.2
> 
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