From 05004e584a76645dcbcaaa4d5c2d3d3255900770 Mon Sep 17 00:00:00 2001

From: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>

Date: Tue, 23 Feb 2016 15:02:02 -0300

Subject: [PATCH] udev: path-id: fibre channel NPIV - use fc_vport's port_name

With the Fibre Channel NPIV (N_Port ID Virtualization) feature,

a single physical N_Port (e.g., PCI address) can have multiple

N_Port IDs (e.g., different fc_host nodes) - which can connect

to the same target LUN (e.g., fc_remote_port's port_name and

LUN number).

Thus, in order to be unique, the device persistent path should

include the fc_vport's port_name (only if the fc_vport is used),

in addition to the already in use PCI address, fc_remote_port's

port_name and LUN number.

The patch merges the 2 proposals submitted upstream, addressing

some problems with both:

- #2500 (don't replace the fc_rport's port_name with fc_vport's)

- #2665 (don't add a fc_host/fc_vport's port_name if not needed)

Links

- https://github.com/systemd/systemd/pull/2500/

- https://github.com/systemd/systemd/pull/2665/

Built, checked, tested on RHEL Server 7.1 with no regressions.

With the patch, /dev/disk/by-path symlinks are created correctly,

and are unique, backward-compatible with the physical port case:

- physical port (no vport field)

- virtual ports (w/ vport field)

    # ls -l /dev/disk/by-path | grep 0001:09:00.0

    <...> pci-0001:09:00.0-fc-0x500507680b2255fe-lun-0 -> ../../sdh

    <...> pci-0001:09:00.0-fc-0x500507680b2255ff-lun-0 -> ../../sdi

    <...> pci-0001:09:00.0-vport-0x5001a4aaf00a6785-fc-0x500507680b2255fe-lun-0 -> ../../sde

    <...> pci-0001:09:00.0-vport-0x5001a4aaf00a6785-fc-0x500507680b2255ff-lun-0 -> ../../sdd

    <...> pci-0001:09:00.0-vport-0x5001a4ad99d8c2de-fc-0x500507680b2255fe-lun-0 -> ../../sdc

    <...> pci-0001:09:00.0-vport-0x5001a4ad99d8c2de-fc-0x500507680b2255ff-lun-0 -> ../../sdb

Accordingly w/ sysfs:

    # ls -ld /sys/block/sd* | grep host1

    <...> /sys/block/sdb -> ../devices/pci0001:00/<...>/0001:09:00.0/host1/vport-1:0-0/host3/rport-3:0-1/target3:0:0/3:0:0:0/block/sdb

    <...> /sys/block/sdc -> ../devices/pci0001:00/<...>/0001:09:00.0/host1/vport-1:0-0/host3/rport-3:0-2/target3:0:1/3:0:1:0/block/sdc

    <...> /sys/block/sdd -> ../devices/pci0001:00/<...>/0001:09:00.0/host1/vport-1:0-2/host5/rport-5:0-1/target5:0:0/5:0:0:0/block/sdd

    <...> /sys/block/sde -> ../devices/pci0001:00/<...>/0001:09:00.0/host1/vport-1:0-2/host5/rport-5:0-2/target5:0:1/5:0:1:0/block/sde

    <...> /sys/block/sdh -> ../devices/pci0001:00/<...>/0001:09:00.0/host1/rport-1:0-3/target1:0:0/1:0:0:0/block/sdh

    <...> /sys/block/sdi -> ../devices/pci0001:00/<...>/0001:09:00.0/host1/rport-1:0-4/target1:0:1/1:0:1:0/block/sdi

The symlinks still include the fc_remote_port's (target) port_name:

    # grep . /sys/class/fc_remote_ports/rport-{3:0-{1,2},5:0-{1,2},1:0-{3,4}}/port_name

    /sys/class/fc_remote_ports/rport-3:0-1/port_name:0x500507680b2255ff

    /sys/class/fc_remote_ports/rport-3:0-2/port_name:0x500507680b2255fe

    /sys/class/fc_remote_ports/rport-5:0-1/port_name:0x500507680b2255ff

    /sys/class/fc_remote_ports/rport-5:0-2/port_name:0x500507680b2255fe

    /sys/class/fc_remote_ports/rport-1:0-3/port_name:0x500507680b2255fe

    /sys/class/fc_remote_ports/rport-1:0-4/port_name:0x500507680b2255ff

And now include the fc_vport's (virtual host) port_name *if* it's from a fc_vport:

    # grep . /sys/class/fc_host/host1/port_name /sys/class/fc_vports/vport-1:0-{0,2}/port_name

    /sys/class/fc_host/host1/port_name:0x10000090fa8f0ebc

    /sys/class/fc_vports/vport-1:0-0/port_name:0x5001a4ad99d8c2de

    /sys/class/fc_vports/vport-1:0-2/port_name:0x5001a4aaf00a6785

Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>

Reported-by: Srikanth B. Aithal <bssrikanth@in.ibm.com>

Cherry-picked from: 6a3d3f9e5970cf982ac37c65d0b856146b675a12

Resolves: #1266934

---

 src/udev/udev-builtin-path_id.c | 30 ++++++++++++++++++++++++++++++

 1 file changed, 30 insertions(+)

diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c

index 9ca6084..3b72922 100644

--- a/src/udev/udev-builtin-path_id.c

+++ b/src/udev/udev-builtin-path_id.c

@@ -92,7 +92,11 @@ static struct udev_device *skip_subsystem(struct udev_device *dev, const char *s

 static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent, char **path) {

         struct udev *udev  = udev_device_get_udev(parent);

         struct udev_device *targetdev;

+        struct udev_device *rportdev;

+        struct udev_device *hostdev;

+        struct udev_device *vportdev;

         struct udev_device *fcdev = NULL;

+        struct udev_device *fc_vportdev = NULL;

         const char *port;

         char *lun = NULL;

@@ -113,6 +117,32 @@ static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent,

         path_prepend(path, "fc-%s-%s", port, lun);

         if (lun)

                 free(lun);

+

+        /* NPIV */

+        rportdev = udev_device_get_parent(targetdev);

+        if (rportdev == NULL)

+                goto out;

+

+        hostdev = udev_device_get_parent(rportdev);

+        if (hostdev == NULL)

+                goto out;

+

+        vportdev = udev_device_get_parent(hostdev);

+        if (vportdev == NULL)

+                goto out;

+

+        fc_vportdev = udev_device_new_from_subsystem_sysname(udev, "fc_vports", udev_device_get_sysname(vportdev));

+        if (fc_vportdev == NULL)

+                goto out;

+

+        port = udev_device_get_sysattr_value(fc_vportdev, "port_name");

+        if (port == NULL)

+                goto out_npiv;

+

+        path_prepend(path, "vport-%s", port);

+

+out_npiv:

+        udev_device_unref(fc_vportdev);

 out:

         udev_device_unref(fcdev);

         return parent;