[libvirt] [PATCH v2 3/5] storage: Don't use a stack copy of the adapter

[John Ferlan]

https://bugzilla.redhat.com/show_bug.cgi?id=1160926

Passing a copy of the storage pool adapter to a function just changes the
copy of the fields in the particular function and then when returning to
the caller those changes are discarded.  While not yet biting us in the
storage clean-up case, it did cause an issue for the fchost storage pool
startup case, createVport.  The issue was at startup, if no parent is found
in the XML, the code will search for the 'best available' parent and then
store that in the in memory copy of the adapter.  Of course, in this case
it was a copy, so when returning to the virStorageBackendSCSIStartPool that
change was discarded (or lost) from the pool->def->source.adapter which
meant at shutdown (deleteVport), the code assumed no adapter was passed
and skipped the deletion, leaving the vHBA created by libvirt still defined
requiring an additional stop of a nodedev-destroy to remove.

Adjusted the createVport to take virStoragePoolDefPtr instead of the
adapter copy. Then use the virStoragePoolSourceAdapterPtr when processing.
A future patch will need the 'def' anyway, so this just sets up for that.

Signed-off-by: John Ferlan <jferlan at redhat.com>
---
 src/conf/storage_conf.c            | 16 ++++++++--------
 src/conf/storage_conf.h            |  1 +
 src/storage/storage_backend_scsi.c | 32 ++++++++++++++++----------------
 3 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/src/conf/storage_conf.c b/src/conf/storage_conf.c
index afd6cd4..52656e5 100644
--- a/src/conf/storage_conf.c
+++ b/src/conf/storage_conf.c
@@ -343,15 +343,15 @@ virStorageVolDefFree(virStorageVolDefPtr def)
 }
 
 static void
-virStoragePoolSourceAdapterClear(virStoragePoolSourceAdapter adapter)
+virStoragePoolSourceAdapterClear(virStoragePoolSourceAdapterPtr adapter)
 {
-    if (adapter.type == VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_FC_HOST) {
-        VIR_FREE(adapter.data.fchost.wwnn);
-        VIR_FREE(adapter.data.fchost.wwpn);
-        VIR_FREE(adapter.data.fchost.parent);
-    } else if (adapter.type ==
+    if (adapter->type == VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_FC_HOST) {
+        VIR_FREE(adapter->data.fchost.wwnn);
+        VIR_FREE(adapter->data.fchost.wwpn);
+        VIR_FREE(adapter->data.fchost.parent);
+    } else if (adapter->type ==
                VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_SCSI_HOST) {
-        VIR_FREE(adapter.data.scsi_host.name);
+        VIR_FREE(adapter->data.scsi_host.name);
     }
 }
 
@@ -380,7 +380,7 @@ virStoragePoolSourceClear(virStoragePoolSourcePtr source)
     VIR_FREE(source->devices);
     VIR_FREE(source->dir);
     VIR_FREE(source->name);
-    virStoragePoolSourceAdapterClear(source->adapter);
+    virStoragePoolSourceAdapterClear(&source->adapter);
     VIR_FREE(source->initiator.iqn);
     virStorageAuthDefFree(source->auth);
     VIR_FREE(source->vendor);
diff --git a/src/conf/storage_conf.h b/src/conf/storage_conf.h
index 1276ac2..a9b5bdb 100644
--- a/src/conf/storage_conf.h
+++ b/src/conf/storage_conf.h
@@ -177,6 +177,7 @@ typedef enum {
 VIR_ENUM_DECL(virStoragePoolSourceAdapter)
 
 typedef struct _virStoragePoolSourceAdapter virStoragePoolSourceAdapter;
+typedef virStoragePoolSourceAdapter *virStoragePoolSourceAdapterPtr;
 struct _virStoragePoolSourceAdapter {
     int type; /* virStoragePoolSourceAdapterType */
 
diff --git a/src/storage/storage_backend_scsi.c b/src/storage/storage_backend_scsi.c
index 5220292..41ea67a 100644
--- a/src/storage/storage_backend_scsi.c
+++ b/src/storage/storage_backend_scsi.c
@@ -644,24 +644,25 @@ checkVhbaSCSIHostParent(virConnectPtr conn,
 
 static int
 createVport(virConnectPtr conn,
-            virStoragePoolSourceAdapter adapter)
+            virStoragePoolDefPtr def)
 {
+    virStoragePoolSourceAdapterPtr adapter = &def->source.adapter;
     unsigned int parent_host;
     char *name = NULL;
 
-    if (adapter.type != VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_FC_HOST)
+    if (adapter->type != VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_FC_HOST)
         return 0;
 
     /* If a parent was provided, then let's make sure it's vhost capable */
-    if (adapter.data.fchost.parent) {
-        if (virGetSCSIHostNumber(adapter.data.fchost.parent, &parent_host) < 0)
+    if (adapter->data.fchost.parent) {
+        if (virGetSCSIHostNumber(adapter->data.fchost.parent, &parent_host) < 0)
             return -1;
 
         if (!virIsCapableFCHost(NULL, parent_host)) {
             virReportError(VIR_ERR_XML_ERROR,
                            _("parent '%s' specified for vHBA "
                              "is not vport capable"),
-                           adapter.data.fchost.parent);
+                           adapter->data.fchost.parent);
             return -1;
         }
     }
@@ -670,34 +671,34 @@ createVport(virConnectPtr conn,
      * using the wwnn/wwpn, then a nodedev is already created for
      * this pool and we don't have to create the vHBA
      */
-    if ((name = virGetFCHostNameByWWN(NULL, adapter.data.fchost.wwnn,
-                                      adapter.data.fchost.wwpn))) {
+    if ((name = virGetFCHostNameByWWN(NULL, adapter->data.fchost.wwnn,
+                                      adapter->data.fchost.wwpn))) {
         int retval = 0;
 
         /* If a parent was provided, let's make sure the 'name' we've
          * retrieved has the same parent
          */
-        if (adapter.data.fchost.parent &&
-            !checkVhbaSCSIHostParent(conn, name, adapter.data.fchost.parent))
+        if (adapter->data.fchost.parent &&
+            !checkVhbaSCSIHostParent(conn, name, adapter->data.fchost.parent))
             retval = -1;
 
         VIR_FREE(name);
         return retval;
     }
 
-    if (!adapter.data.fchost.parent &&
-        !(adapter.data.fchost.parent = virFindFCHostCapableVport(NULL))) {
+    if (!adapter->data.fchost.parent &&
+        !(adapter->data.fchost.parent = virFindFCHostCapableVport(NULL))) {
         virReportError(VIR_ERR_XML_ERROR, "%s",
                        _("'parent' for vHBA not specified, and "
                          "cannot find one on this host"));
          return -1;
 
-        if (virGetSCSIHostNumber(adapter.data.fchost.parent, &parent_host) < 0)
+        if (virGetSCSIHostNumber(adapter->data.fchost.parent, &parent_host) < 0)
             return -1;
     }
 
-    if (virManageVport(parent_host, adapter.data.fchost.wwpn,
-                       adapter.data.fchost.wwnn, VPORT_CREATE) < 0)
+    if (virManageVport(parent_host, adapter->data.fchost.wwpn,
+                       adapter->data.fchost.wwnn, VPORT_CREATE) < 0)
         return -1;
 
     virFileWaitForDevices();
@@ -815,8 +816,7 @@ static int
 virStorageBackendSCSIStartPool(virConnectPtr conn,
                                virStoragePoolObjPtr pool)
 {
-    virStoragePoolSourceAdapter adapter = pool->def->source.adapter;
-    return createVport(conn, adapter);
+    return createVport(conn, pool->def);
 }
 
 static int
-- 
1.9.3