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NVMe namespace identification

PATCH In review Keith Busch 2 participants 4 messages Dec 9, 2015

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#0 lore raw

v2 cover NVMe namespace identification

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(-)
Signature · 1 line
2.6.2.307.g37023ba
#1 lore raw

PATCH v2 1/2 Print: Add print format for 8-byte EUI-64 type

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 at intel.com>
---
 Documentation/printk-formats.txt | 13 ++++++++++---
 lib/vsprintf.c                   | 17 ++++++++++++-----
 2 files changed, 22 insertions(+), 8 deletions(-)
Documentation/printk-formats.txt +10 -3
index b784c27..e2fe4ed 100644
@@ -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
lib/vsprintf.c +12 -5
index f9cee8e..a2d20b7 100644
@@ -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';
Signature · 1 line
2.6.2.307.g37023ba
#2 lore raw

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

Quoted 3 lines · 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.

[]

Documentation/printk-formats.txt

Quoted 1 line
Documentation/printk-formats.txt +0 -0

[]

Documentation/printk-formats.txt Raw buffer as a hex string: · line 147

Quoted 13 lines
Documentation/printk-formats.txt +0 -0
@@ -136,14 +136,21 @@ Raw buffer as a hex string:

?MAC/FDDI addresses:
?
? %pM 00:01:02:03:04:05

Documentation/printk-formats.txt +1 -0
+	%pMl	00:01:02:03:04:05:06:07

? %pMR 05:04:03:02:01:00

Documentation/printk-formats.txt +1 -0
+	%pMRl	07:06:05:04:03:02:01:00

? %pMF 00-01-02-03-04-05

Documentation/printk-formats.txt +1 -0
+	%pMFl	00-01-02-03-04-05-06-07

? %pm 000102030405

Documentation/printk-formats.txt +1 -0
+	%pml	0001020304050607

? %pmR 050403020100

Documentation/printk-formats.txt +1 -0
+	%pmRl	0706050403020100

[]

lib/vsprintf.c

Quoted 1 line
lib/vsprintf.c +0 -0

[]

lib/vsprintf.c char *mac_address_string(char *buf, char *end, u8 *addr, · line 917

Quoted 11 lines
lib/vsprintf.c +7 -0
@@ -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.

#3 lore raw

PATCH v2 2/2 NVMe: Expose namespace identity attribute to sysfs

In reply to 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 at intel.com>
---
 drivers/nvme/host/core.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++--
 drivers/nvme/host/nvme.h |  3 +++
 2 files changed, 61 insertions(+), 2 deletions(-)
drivers/nvme/host/core.c +58 -2
index cd2a64f..bc85318 100644
@@ -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)) {
drivers/nvme/host/nvme.h +3 -0
index b041762..d88cf45 100644
@@ -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;
Signature · 1 line
2.6.2.307.g37023ba