From 63da3cb8a40500c889c8faa4326f81d16997a3c8 Mon Sep 17 00:00:00 2001

From: Tomas Bzatek <tbzatek@redhat.com>

Date: Mon, 27 Nov 2023 18:55:55 +0100

Subject: [PATCH] nvme: Retrieve HostNQN from a first active fabrics connection

When no /etc/hostnqn exists, look for any active NVMe over Fabrics

connections and take the values from a first one, rather than

generating new ones.

---

 blivet/nvme.py | 21 +++++++++++++++++++++

 1 file changed, 21 insertions(+)

diff --git a/blivet/nvme.py b/blivet/nvme.py

index 5ac41cffa..2e4686e68 100644

--- a/blivet/nvme.py

+++ b/blivet/nvme.py

@@ -18,6 +18,7 @@

 #

 import os

+import glob

 from . import errors

@@ -54,6 +55,22 @@ def __call__(self):

     def __deepcopy__(self, memo_dict):  # pylint: disable=unused-argument

         return self

+    def _retrieve_fabrics_hostnqn(self):

+        for d in glob.glob('/sys/class/nvme-fabrics/ctl/nvme*/'):

+            try:

+                # invalidate old values

+                self._hostnqn = None

+                self._hostid = None

+                # read from sysfs

+                with open(os.path.join(d, 'hostnqn')) as f:

+                    self._hostnqn = f.readline().strip()

+                with open(os.path.join(d, 'hostid')) as f:

+                    self._hostid = f.readline().strip()

+                if self._hostnqn:

+                    break

+            except Exception:  # pylint: disable=broad-except

+                pass

+

     def startup(self):

         if self.started:

             return

@@ -61,6 +78,10 @@ def startup(self):

         self._hostnqn = blockdev.nvme_get_host_nqn()

         self._hostid = blockdev.nvme_get_host_id()

         if not self._hostnqn:

+            # see if there are any active fabrics connections and take their values over

+            self._retrieve_fabrics_hostnqn()

+        if not self._hostnqn:

+            # generate new values

             self._hostnqn = blockdev.nvme_generate_host_nqn()

         if not self._hostnqn:

             raise errors.NVMeError("Failed to generate HostNQN")