[libvirt] [PATCH v2 3/3] conf: Fix vHBA checkParent logic for pool creation

[John Ferlan]

https://bugzilla.redhat.com/show_bug.cgi?id=1458708

When originally designed in commit id '42a021c1', providing the
'parent' attribute to the <adapter type='fc_host' wwnn='vHBA_wwnn'
wwpn='vHBA_wwpn'/> was checked to make sure that the "parent" of
the wwnn/wwpn matched that of the provided parent "just in case"
someone created the node device first, then defined the storage
pool using that node device afterwards. The result is to not
perform the vport_create call when the scsi_host represented by
the wwnn/wwpn already exists since it would fail.

Eventually someone came up with the brilliant idea to provide
wwnn/wwpn of an HBA instead of a vHBA, e.g. <adapter type='fc_host'
wwnn='HBA_wwnn' wwpn='HBA_wwpn'/>. This is the same as creating a
storage pool backed to the HBA that just happens to also be vport
(vHBA) capable. The logic to bypass the vport_create call was the
same as the vHBA code since the wwn's already exist. Once that was
determined to work, adding in the 'parent' attribute caused a problem
for the DeleteVport code, which was fixed by commit id '2c8e30ee7e'.

The next test tried was providing a valid pair of wwns that would
find the scsi_host HBA, but providing the wrong name for the 'parent'
attribute. This caused a different failure because at DeleteVport
time if a parent is provided it was assumed valid especially since
the CreateVport code would check that by calling virVHBAPathExists.

So alter the checkParent code to first ensure that the provided
parent_name is a valid HBA/vHBA, then check if the found scsi_host
is an HBA or a vHBA and make the appropriate check against the
parent_name similar to the check made in virNodeDeviceDeleteVport.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/storage/storage_backend_scsi.c | 47 ++++++++++++++++++++++++++++++++------
 1 file changed, 40 insertions(+), 7 deletions(-)

diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
index 365ab77..d225e4f 100644
--- a/src/storage/storage_backend_scsi.c
+++ b/src/storage/storage_backend_scsi.c
@@ -220,6 +220,7 @@ checkParent(virConnectPtr conn,
             const char *name,
             const char *parent_name)
 {
+    unsigned int host_num;
     char *scsi_host_name = NULL;
     char *vhba_parent = NULL;
     bool retval = false;
@@ -230,20 +231,52 @@ checkParent(virConnectPtr conn,
     if (!conn)
         return true;
 
-    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
+    if (virSCSIHostGetNumber(parent_name, &host_num) < 0) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       _("parent '%s' is not properly formatted"), name);
         goto cleanup;
+    }
 
-    if (!(vhba_parent = virNodeDeviceGetParentName(conn, scsi_host_name)))
+    if (!virVHBAPathExists(NULL, host_num)) {
+        virReportError(VIR_ERR_XML_ERROR,
+                       ("parent '%s' is not a vHBA/HBA"), parent_name);
         goto cleanup;
+    }
 
-    if (STRNEQ(parent_name, vhba_parent)) {
-        virReportError(VIR_ERR_XML_ERROR,
-                       _("Parent attribute '%s' does not match parent '%s' "
-                         "determined for the '%s' wwnn/wwpn lookup."),
-                       parent_name, vhba_parent, name);
+    if (virAsprintf(&scsi_host_name, "scsi_%s", name) < 0)
+        goto cleanup;
+
+    if (virSCSIHostGetNumber(scsi_host_name, &host_num) < 0) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("host name '%s' is not properly formatted"), name);
         goto cleanup;
     }
 
+    /* If scsi_host_name is vport capable, then it's an HBA, thus compare
+     * only against the parent_name; otherwise, as long as the scsi_host_name
+     * path exists, then the scsi_host_name is a vHBA in which case we need
+     * to compare against it's parent. */
+    if (virVHBAIsVportCapable(NULL, host_num)) {
+        if (STRNEQ(parent_name, scsi_host_name)) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("parent HBA '%s' doesn't match the wwnn/wwpn "
+                             "scsi_host '%s'"),
+                           parent_name, scsi_host_name);
+            goto cleanup;
+        }
+    } else {
+        if (!(vhba_parent = virNodeDeviceGetParentName(conn, scsi_host_name)))
+            goto cleanup;
+
+        if (STRNEQ(parent_name, vhba_parent)) {
+            virReportError(VIR_ERR_XML_ERROR,
+                           _("parent vHBA '%s' doesn't match the wwnn/wwpn "
+                             "scsi_host '%s' parent '%s'"),
+                           parent_name, scsi_host_name, vhba_parent);
+            goto cleanup;
+        }
+    }
+
     retval = true;
 
  cleanup:
-- 
2.9.4