[PATCHv2] Fill NVMe specific path info

[keith.busch@intel.com (Keith Busch)]

Signed-off-by: Keith Busch <keith.busch at intel.com>
---
v1->v2:
  Removed explicitly setting the wwid path information. We get that with
  through exported udev attributes.

  Added default retain_hwhandler to off for NVME devices. This has the
  kernel not call into scsi specific APIs that don't exist for NVMe.

 libmultipath/discovery.c | 35 +++++++++++++++++++++++++++++++++++
 libmultipath/hwtable.c   | 10 ++++++++++
 libmultipath/structs.h   |  1 +
 3 files changed, 46 insertions(+)

diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index d1aec31..39dd92a 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -1187,6 +1187,36 @@ scsi_sysfs_pathinfo (struct path * pp, vector hwtable)
 }
 
 static int
+nvme_sysfs_pathinfo (struct path * pp, vector hwtable)
+{
+	struct udev_device *parent, *nvme = NULL;
+
+	parent = pp->udev;
+	while (parent) {
+		const char *subsys = udev_device_get_subsystem(parent);
+
+		if (subsys && !strncmp(subsys, "nvme", 4)) {
+			nvme = parent;
+			break;
+		}
+		parent = udev_device_get_parent(parent);
+	}
+	if (!nvme)
+		return 1;
+
+	snprintf(pp->vendor_id, SCSI_VENDOR_SIZE, "NVME");
+	snprintf(pp->product_id, SCSI_PRODUCT_SIZE, "%s", udev_device_get_sysattr_value(nvme, "model"));
+	snprintf(pp->serial, SERIAL_SIZE, "%s", udev_device_get_sysattr_value(nvme, "serial"));
+	snprintf(pp->rev, SCSI_REV_SIZE, "%s", udev_device_get_sysattr_value(nvme, "firmware_rev"));
+
+	condlog(3, "%s: vendor:%s product:%s serial:%s rev:%s", pp->dev,
+		pp->vendor_id, pp->product_id, pp->serial, pp->rev);
+	pp->hwe = find_hwe(hwtable, pp->vendor_id, pp->product_id, NULL);
+
+	return 0;
+}
+
+static int
 rbd_sysfs_pathinfo (struct path * pp, vector hwtable)
 {
 	sprintf(pp->vendor_id, "Ceph");
@@ -1405,6 +1435,8 @@ sysfs_pathinfo(struct path * pp, vector hwtable)
 		pp->bus = SYSFS_BUS_SCSI;
 	if (!strncmp(pp->dev,"rbd", 3))
 		pp->bus = SYSFS_BUS_RBD;
+	if (!strncmp(pp->dev,"nvme", 4))
+		pp->bus = SYSFS_BUS_NVME;
 
 	if (pp->bus == SYSFS_BUS_UNDEF)
 		return 0;
@@ -1420,6 +1452,9 @@ sysfs_pathinfo(struct path * pp, vector hwtable)
 	} else if (pp->bus == SYSFS_BUS_RBD) {
 		if (rbd_sysfs_pathinfo(pp, hwtable))
 			return 1;
+	} else if (pp->bus == SYSFS_BUS_NVME) {
+		if (nvme_sysfs_pathinfo(pp, hwtable))
+			return 1;
 	}
 	return 0;
 }
diff --git a/libmultipath/hwtable.c b/libmultipath/hwtable.c
index f5a5f7b..8409261 100644
--- a/libmultipath/hwtable.c
+++ b/libmultipath/hwtable.c
@@ -1073,6 +1073,16 @@ static struct hwentry default_hw[] = {
 		.prio_name     = PRIO_ALUA,
 		.no_path_retry = 30,
 	},
+	/*
+	 * Generic NVMe devices
+	 */
+	{
+		.vendor	       = "NVME",
+		.product       = ".*",
+		.uid_attribute = "ID_WWN",
+		.checker_name  = DIRECTIO,
+		.retain_hwhandler = RETAIN_HWHANDLER_OFF,
+	},
 #if 0
 	/*
 	 * Copy this TEMPLATE to add new hardware.
diff --git a/libmultipath/structs.h b/libmultipath/structs.h
index 6edd927..dfd65ae 100644
--- a/libmultipath/structs.h
+++ b/libmultipath/structs.h
@@ -53,6 +53,7 @@ enum sysfs_buses {
 	SYSFS_BUS_CCW,
 	SYSFS_BUS_CCISS,
 	SYSFS_BUS_RBD,
+	SYSFS_BUS_NVME,
 };
 
 enum pathstates {
-- 
2.5.5