[PATCHv2 0/2] NVMe namespace identification

[PATCHv2 0/2] NVMe namespace identification

[Keith Busch]

Here's version 2 exposing unique namespace identification to sysfs.

This is simpler thanks to feedback from Willy, Christoph, and Dan.

There are two identification attributes displayed in ASCII instead of
binary. Each method has its own file so parsers will know the format.

The first patch in the series adds a new print format since EUI-64
didn't have a specifier. It's essentially an extented MAC identifier,
so appending a specifier for the longer format to that.

I don't know who owns lib/vsprintf, so copying Greg & LKML.

Keith Busch (2):
  Print: Add print format for 8-byte EUI-64 type
  NVMe: Expose namespace identity attribute to sysfs

 Documentation/printk-formats.txt | 13 +++++++--
 drivers/nvme/host/core.c         | 60 ++++++++++++++++++++++++++++++++++++++--
 drivers/nvme/host/nvme.h         |  3 ++
 lib/vsprintf.c                   | 17 ++++++++----
 4 files changed, 83 insertions(+), 10 deletions(-)

-- 
2.6.2.307.g37023ba

[PATCHv2 1/2] Print: Add print format for 8-byte EUI-64 type

[Keith Busch]

MAC addresses may be formed using rules based on EUI-64, which is 2 bytes
longer than a typical 6-byte MAC. This patch adds a long specifier to
the %pM format to support the extended unique identifier.

Signed-off-by: Keith Busch <keith.busch@intel.com>
---
 Documentation/printk-formats.txt | 13 ++++++++++---
 lib/vsprintf.c                   | 17 ++++++++++++-----
 2 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
index b784c27..e2fe4ed 100644
--- a/Documentation/printk-formats.txt
+++ b/Documentation/printk-formats.txt
@@ -136,14 +136,21 @@ Raw buffer as a hex string:
 MAC/FDDI addresses:
 
 	%pM	00:01:02:03:04:05
+	%pMl	00:01:02:03:04:05:06:07
 	%pMR	05:04:03:02:01:00
+	%pMRl	07:06:05:04:03:02:01:00
 	%pMF	00-01-02-03-04-05
+	%pMFl	00-01-02-03-04-05-06-07
 	%pm	000102030405
+	%pml	0001020304050607
 	%pmR	050403020100
+	%pmRl	0706050403020100
 
-	For printing 6-byte MAC/FDDI addresses in hex notation. The 'M' and 'm'
-	specifiers result in a printed address with ('M') or without ('m') byte
-	separators. The default byte separator is the colon (':').
+	For printing 6 or 8-byte MAC/FDDI addresses in hex notation. The
+	'M' and 'm' specifiers result in a printed address with ('M')
+	or without ('m') byte separators. The default byte separator is
+	the colon (':'). Append 'l' to specify an 8-byte in accordance
+	with EUI-64 format.
 
 	Where FDDI addresses are concerned the 'F' specifier can be used after
 	the 'M' specifier to use dash ('-') separators instead of the default
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index f9cee8e..a2d20b7 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -889,9 +889,9 @@ static noinline_for_stack
 char *mac_address_string(char *buf, char *end, u8 *addr,
 			 struct printf_spec spec, const char *fmt)
 {
-	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx")];
+	char mac_addr[sizeof("xx:xx:xx:xx:xx:xx:xx:xx")];
 	char *p = mac_addr;
-	int i;
+	int i, bytes = 6;
 	char separator;
 	bool reversed = false;
 
@@ -908,14 +908,21 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
 		separator = ':';
 		break;
 	}
+	switch (fmt[2]) {
+	case 'l':
+		bytes = 8;
+		break;
+	default:
+		break;
+	}
 
-	for (i = 0; i < 6; i++) {
+	for (i = 0; i < bytes; i++) {
 		if (reversed)
-			p = hex_byte_pack(p, addr[5 - i]);
+			p = hex_byte_pack(p, addr[(bytes - 1) - i]);
 		else
 			p = hex_byte_pack(p, addr[i]);
 
-		if (fmt[0] == 'M' && i != 5)
+		if (fmt[0] == 'M' && i != (bytes - 1))
 			*p++ = separator;
 	}
 	*p = '\0';
-- 
2.6.2.307.g37023ba

[PATCHv2 2/2] NVMe: Expose namespace identity attribute to sysfs

[Keith Busch]

Adds EUI-64 and NGUID attributes to sysfs under the gendisk kobject
path. The files' visibility depends on the namespace capabilities. User
space needs to check the existence of both files to determine how to
identify the namespace.

NGUID format: 00000000-0000-0000-0000-000000000000
EUI64 format: 00-00-00-00-00-00-00-00

Signed-off-by: Keith Busch <keith.busch@intel.com>
---
 drivers/nvme/host/core.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++--
 drivers/nvme/host/nvme.h |  3 +++
 2 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index cd2a64f..bc85318 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -574,6 +574,11 @@ static int nvme_revalidate_disk(struct gendisk *disk)
 		ns->type = NVME_NS_LIGHTNVM;
 	}
 
+	if (ns->ctrl->vs >= NVME_VS(1, 1))
+		memcpy(ns->eui, id->eui64, sizeof(ns->eui));
+	if (ns->ctrl->vs >= NVME_VS(1, 2))
+		memcpy(ns->uuid, id->nguid, sizeof(ns->uuid));
+
 	old_ms = ns->ms;
 	lbaf = id->flbas & NVME_NS_FLBAS_LBA_MASK;
 	ns->lba_shift = id->lbaf[lbaf].ds;
@@ -994,6 +999,50 @@ static const struct attribute_group *nvme_dev_attr_groups[] = {
 	NULL
 };
 
+static ssize_t uuid_show(struct device *dev, struct device_attribute *attr,
+								char *buf)
+{
+	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	return sprintf(buf, "%pU\n", ns->uuid);
+}
+static DEVICE_ATTR(uuid, S_IRUGO, uuid_show, NULL);
+
+static ssize_t eui_show(struct device *dev, struct device_attribute *attr,
+								char *buf)
+{
+	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+	return sprintf(buf, "%pMFl\n", ns->eui);
+}
+static DEVICE_ATTR(eui, S_IRUGO, eui_show, NULL);
+
+static struct attribute *nvme_ns_attrs[] = {
+	&dev_attr_uuid.attr,
+	&dev_attr_eui.attr,
+	NULL,
+};
+
+static umode_t nvme_attrs_are_visible(struct kobject *kobj,
+		struct attribute *a, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct nvme_ns *ns = dev_to_disk(dev)->private_data;
+
+	if (a == &dev_attr_uuid.attr) {
+		if (!memchr_inv(ns->uuid, 0, sizeof(ns->uuid)))
+			return 0;
+	}
+	if (a == &dev_attr_eui.attr) {
+		if (!memchr_inv(ns->eui, 0, sizeof(ns->eui)))
+			return 0;
+	}
+	return a->mode;
+}
+
+static const struct attribute_group nvme_ns_attr_group = {
+	.attrs		= nvme_ns_attrs,
+	.is_visible	= nvme_attrs_are_visible,
+};
+
 static int ns_cmp(void *priv, struct list_head *a, struct list_head *b)
 {
 	struct nvme_ns *nsa = container_of(a, struct nvme_ns, list);
@@ -1068,9 +1117,14 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 
 	list_add_tail(&ns->list, &ctrl->namespaces);
 	kref_get(&ctrl->kref);
-	if (ns->type != NVME_NS_LIGHTNVM)
-		add_disk(ns->disk);
+	if (ns->type == NVME_NS_LIGHTNVM)
+		return;
 
+	add_disk(ns->disk);
+	if (sysfs_create_group(&disk_to_dev(ns->disk)->kobj,
+					&nvme_ns_attr_group))
+		pr_warn("%s: failed to create sysfs group for identification\n",
+			ns->disk->disk_name);
 	return;
  out_free_disk:
 	kfree(disk);
@@ -1090,6 +1144,8 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 	if (ns->disk->flags & GENHD_FL_UP) {
 		if (blk_get_integrity(ns->disk))
 			blk_integrity_unregister(ns->disk);
+		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
+					&nvme_ns_attr_group);
 		del_gendisk(ns->disk);
 	}
 	if (kill || !blk_queue_dying(ns->queue)) {
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index b041762..d88cf45 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -102,6 +102,9 @@ struct nvme_ns {
 	struct gendisk *disk;
 	struct kref kref;
 
+	u8 eui[8];
+	u8 uuid[16];
+
 	unsigned ns_id;
 	int lba_shift;
 	u16 ms;
-- 
2.6.2.307.g37023ba

Re: [PATCHv2 1/2] Print: Add print format for 8-byte EUI-64 type

[Joe Perches]

On Wed, 2015-12-09 at 11:42 -0700, Keith Busch wrote:
> MAC addresses may be formed using rules based on EUI-64, which is 2 bytes
> longer than a typical 6-byte MAC. This patch adds a long specifier to
> the %pM format to support the extended unique identifier.
[]
> diff --git a/Documentation/printk-formats.txt b/Documentation/printk-formats.txt
[]
> @@ -136,14 +136,21 @@ Raw buffer as a hex string:
>  MAC/FDDI addresses:
>  
>  	%pM	00:01:02:03:04:05
> +	%pMl	00:01:02:03:04:05:06:07
>  	%pMR	05:04:03:02:01:00
> +	%pMRl	07:06:05:04:03:02:01:00
>  	%pMF	00-01-02-03-04-05
> +	%pMFl	00-01-02-03-04-05-06-07
>  	%pm	000102030405
> +	%pml	0001020304050607
>  	%pmR	050403020100
> +	%pmRl	0706050403020100
[]
> diff --git a/lib/vsprintf.c b/lib/vsprintf.c
[]
> @@ -908,14 +908,21 @@ char *mac_address_string(char *buf, char *end, u8 *addr,
>  		separator = ':';
>  		break;
>  	}
> +	switch (fmt[2]) {
> +	case 'l':
> +		bytes = 8;
> +		break;
> +	default:
> +		break;
> +	}

This doesn't work for formats without pmR or pmF.
like "%pml" or "%pMl" as fmt[2] can be anything.