nodedev: Fabric name must not be required for fc_host capability

fabric_name is one of many fc_host attributes in Linux that is optional
and left to the low-level driver to decide if it is implemented.
The zfcp device driver does not provide a fabric name for an fcp host.

This patch removes the requirement for a fabric name by making it optional.
Signed-off-by: NBoris Fiuczynski <fiuczy@linux.vnet.ibm.com>

docs/formatnode.html.in

@@ -254,7 +254,7 @@
                 number of vport in use. <code>max_vports</code> shows the
                 maximum vports the HBA supports. "fc_host" implies following
                 sub-elements: <code>wwnn</code>, <code>wwpn</code>, and
-                <code>fabric_wwn</code>.
+                optionally <code>fabric_wwn</code>.
               </dd>
             </dl>
           </dd>

docs/news.xml

@@ -18,7 +18,18 @@
       <change/>
     </section>
     <section title="Bug fixes">
-      <change/>
+      <change>
+        <summary>
+          nodedev: Fabric name must not be required for fc_host capability
+        </summary>
+        <description>
+          fabric_name is one of many fc_host attributes in Linux that is
+          optional and left to the low-level driver to decide if it is
+          implemented. For example the zfcp device driver does not provide a
+          fabric name for an fcp host. The requirement for the existence of
+          a fabric name has been removed by making it optional.
+        </description>
+      </change>
     </section>
   </release>
   <release version="v3.0.0" date="2017-01-17">

docs/schemas/nodedev.rng

@@ -367,9 +367,11 @@
       <ref name='wwn'/>
     </element>
 
-    <element name='fabric_wwn'>
-      <ref name='wwn'/>
-    </element>
+    <optional>
+      <element name='fabric_wwn'>
+        <ref name='wwn'/>
+      </element>
+    </optional>
   </define>
 
   <define name='capsvports'>

src/node_device/node_device_linux_sysfs.c

@@ -72,13 +72,10 @@ nodeDeviceSysfsGetSCSIHostCaps(virNodeDevCapDataPtr d)
         VIR_FREE(d->scsi_host.wwnn);
         VIR_STEAL_PTR(d->scsi_host.wwnn, tmp);
 
-        if (!(tmp = virReadFCHost(NULL, d->scsi_host.host, "fabric_name"))) {
-            VIR_WARN("Failed to read fabric WWN for host%d",
-                     d->scsi_host.host);
-            goto cleanup;
+        if ((tmp = virReadFCHost(NULL, d->scsi_host.host, "fabric_name"))) {
+            VIR_FREE(d->scsi_host.fabric_wwn);
+            VIR_STEAL_PTR(d->scsi_host.fabric_wwn, tmp);
         }
-        VIR_FREE(d->scsi_host.fabric_wwn);
-        VIR_STEAL_PTR(d->scsi_host.fabric_wwn, tmp);
     }
 
     if (virIsCapableVport(NULL, d->scsi_host.host)) {

tests/fchostdata/fc_host/host6/node_name

+0x2002001b32a9da4e

tests/fchostdata/fc_host/host6/port_name

+0x2102001b32a9da4e

tests/fchostdata/fc_host/host6/port_state

+Online

tests/fchosttest.c

@@ -29,13 +29,16 @@ static char *fchost_prefix;
 
 #define TEST_FC_HOST_PREFIX fchost_prefix
 #define TEST_FC_HOST_NUM 5
+#define TEST_FC_HOST_NUM_NO_FAB 6
 
 /* Test virIsCapableFCHost */
 static int
 test1(const void *data ATTRIBUTE_UNUSED)
 {
     if (virIsCapableFCHost(TEST_FC_HOST_PREFIX,
-                           TEST_FC_HOST_NUM))
+                           TEST_FC_HOST_NUM) &&
+        virIsCapableFCHost(TEST_FC_HOST_PREFIX,
+                           TEST_FC_HOST_NUM_NO_FAB))
         return 0;
 
     return -1;
@@ -148,6 +151,39 @@ test5(const void *data ATTRIBUTE_UNUSED)
     return ret;
 }
 
+/* Test virReadFCHost fabric name optional */
+static int
+test6(const void *data ATTRIBUTE_UNUSED)
+{
+    const char *expect_wwnn = "2002001b32a9da4e";
+    const char *expect_wwpn = "2102001b32a9da4e";
+    char *wwnn = NULL;
+    char *wwpn = NULL;
+    int ret = -1;
+
+    if (!(wwnn = virReadFCHost(TEST_FC_HOST_PREFIX, TEST_FC_HOST_NUM_NO_FAB,
+                               "node_name")))
+        return -1;
+
+    if (!(wwpn = virReadFCHost(TEST_FC_HOST_PREFIX, TEST_FC_HOST_NUM_NO_FAB,
+                               "port_name")))
+        goto cleanup;
+
+    if (virReadFCHost(TEST_FC_HOST_PREFIX, TEST_FC_HOST_NUM_NO_FAB,
+                      "fabric_name"))
+        goto cleanup;
+
+    if (STRNEQ(expect_wwnn, wwnn) ||
+        STRNEQ(expect_wwpn, wwpn))
+        goto cleanup;
+
+    ret = 0;
+ cleanup:
+    VIR_FREE(wwnn);
+    VIR_FREE(wwpn);
+    return ret;
+}
+
 static int
 mymain(void)
 {
@@ -169,6 +205,8 @@ mymain(void)
         ret = -1;
     if (virTestRun("test5", test5, NULL) < 0)
         ret = -1;
+    if (virTestRun("test6", test6, NULL) < 0)
+        ret = -1;
 
  cleanup:
     VIR_FREE(fchost_prefix);