[libvirt] [PATCH 02/11] storage: Introduce new XMLs for stable SCSI host addressing

Osier Yang jyang at redhat.com
Fri Jun 7 17:03:40 UTC 2013


The SCSI host number is not stable on Linux platform, the number
can be changed after a system rebooting or scsi kernel modules
reloaded. To have a stable address for the scsi_host adapter of
scsi pool, this introduces new XMLs like:

  <adapter type='scsi_host' parent='pci_0000_00_1f_2' unique_id='5'/>

Where "parent" is the parent device of the scsi host, it should be
consistent with the name style what node device driver uses (Either
udev backend style or HAL backend style), or the PCI address in format
"domain:bus:slot:function" format. "unique_id" is the number exposed
by sysfs. E.g:

% cat /sys/bus/pci/devices/0000:00:1f.2/ata5/host4/scsi_host/host4/unique_id
5

The attribute "parent" is required, attribute "unique_id" is optional,
if it's omitted, the scsi host which has smallest unique_id under the
"parent" device will be used.

"parent" and the old "name" attribute are exclusive, since they are both to
indicate scsi host number.

This only supports to parse and format the XMLs. Later patch will
add code to find out the scsi host number via "parent" and "unique_id";
---
 docs/schemas/basictypes.rng                        | 20 ++++++--
 src/conf/storage_conf.c                            | 57 +++++++++++++++++++---
 src/conf/storage_conf.h                            |  3 ++
 .../pool-scsi-type-scsi-host-stable.xml            | 15 ++++++
 .../pool-scsi-type-scsi-host-stable.xml            | 18 +++++++
 tests/storagepoolxml2xmltest.c                     |  1 +
 6 files changed, 104 insertions(+), 10 deletions(-)
 create mode 100644 tests/storagepoolxml2xmlin/pool-scsi-type-scsi-host-stable.xml
 create mode 100644 tests/storagepoolxml2xmlout/pool-scsi-type-scsi-host-stable.xml

diff --git a/docs/schemas/basictypes.rng b/docs/schemas/basictypes.rng
index 34c2254..3bdf923 100644
--- a/docs/schemas/basictypes.rng
+++ b/docs/schemas/basictypes.rng
@@ -347,9 +347,23 @@
               <value>scsi_host</value>
             </attribute>
           </optional>
-          <attribute name='name'>
-            <text/>
-          </attribute>
+          <choice>
+            <group>
+              <attribute name='name'>
+                <text/>
+              </attribute>
+            </group>
+            <group>
+              <attribute name='parent'>
+                <text/>
+              </attribute>
+              <optional>
+                <attribute name='unique_id'>
+                  <ref name='unsignedInt'/>
+                </attribute>
+              </optional>
+            </group>
+          </choice>
         </group>
         <group>
           <attribute name='type'>
diff --git a/src/conf/storage_conf.c b/src/conf/storage_conf.c
index a44e021..d7901af 100644
--- a/src/conf/storage_conf.c
+++ b/src/conf/storage_conf.c
@@ -320,6 +320,7 @@ virStoragePoolSourceAdapterClear(virStoragePoolSourceAdapter adapter)
     } 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.parent);
     }
 }
 
@@ -613,6 +614,8 @@ virStoragePoolDefParseSource(xmlXPathContextPtr ctxt,
     source->dir = virXPathString("string(./dir/@path)", ctxt);
 
     if ((adapter_type = virXPathString("string(./adapter/@type)", ctxt))) {
+        int rc;
+
         if ((source->adapter.type =
              virStoragePoolSourceAdapterTypeTypeFromString(adapter_type)) <= 0) {
             virReportError(VIR_ERR_XML_ERROR,
@@ -633,23 +636,47 @@ virStoragePoolDefParseSource(xmlXPathContextPtr ctxt,
                    VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_SCSI_HOST) {
             source->adapter.data.scsi_host.name =
                 virXPathString("string(./adapter/@name)", ctxt);
+            source->adapter.data.scsi_host.parent =
+                virXPathString("string(./adapter/@parent)", ctxt);
+
+            if ((rc = virXPathUInt("string(./adapter/@unique_id)", ctxt,
+                                   &source->adapter.data.scsi_host.unique_id)) < -1) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("Invalid unique_id for scsi source adapter"));
+                goto cleanup;
+            } else if (rc == 0) {
+                source->adapter.data.scsi_host.has_unique_id = true;
+            }
         }
     } else {
         char *wwnn = NULL;
         char *wwpn = NULL;
         char *parent = NULL;
+        bool has_unique_id = false;
+        int rc;
+
+        rc = virXPathUInt("string(./adapter/@unique_id)", ctxt,
+                          &source->adapter.data.scsi_host.unique_id);
+
+        if (rc < -1) {
+            virReportError(VIR_ERR_XML_ERROR, "%s",
+                           _("Invalid unique_id for scsi source adapter"));
+            goto cleanup;
+        } else if (rc == 0) {
+            has_unique_id = true;
+        }
 
         wwnn = virXPathString("string(./adapter/@wwnn)", ctxt);
         wwpn = virXPathString("string(./adapter/@wwpn)", ctxt);
         parent = virXPathString("string(./adapter/@parent)", ctxt);
 
-        if (wwnn || wwpn || parent) {
+        if (wwnn || wwpn || parent || has_unique_id) {
             VIR_FREE(wwnn);
             VIR_FREE(wwpn);
             VIR_FREE(parent);
             virReportError(VIR_ERR_XML_ERROR, "%s",
-                           _("Use of 'wwnn', 'wwpn', and 'parent' attributes "
-                             "requires the 'fc_host' adapter 'type'"));
+                           _("Use of 'wwnn', 'wwpn', 'parent' and 'unique_id' "
+                             "attributes requires the adapter 'type' specified"));
             goto cleanup;
         }
 
@@ -927,9 +954,19 @@ virStoragePoolDefParseXML(xmlXPathContextPtr ctxt)
                 goto error;
         } else if (ret->source.adapter.type ==
                    VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_SCSI_HOST) {
-            if (!ret->source.adapter.data.scsi_host.name) {
+            if (!ret->source.adapter.data.scsi_host.name &&
+                !ret->source.adapter.data.scsi_host.parent) {
+                virReportError(VIR_ERR_XML_ERROR, "%s",
+                               _("Either 'name' or 'parent' must be specified "
+                                 "for 'scsi_host' adapter"));
+                goto error;
+            }
+
+            if (ret->source.adapter.data.scsi_host.name &&
+                ret->source.adapter.data.scsi_host.parent) {
                 virReportError(VIR_ERR_XML_ERROR, "%s",
-                               _("missing storage pool source adapter name"));
+                               _("'name' and 'parent' are exclusive "
+                                 "for 'scsi_host' adapter"));
                 goto error;
             }
         }
@@ -1084,8 +1121,14 @@ virStoragePoolSourceFormat(virBufferPtr buf,
                               src->adapter.data.fchost.wwpn);
         } else if (src->adapter.type ==
                  VIR_STORAGE_POOL_SOURCE_ADAPTER_TYPE_SCSI_HOST) {
-            virBufferAsprintf(buf," name='%s'/>\n",
-                              src->adapter.data.scsi_host.name);
+            if (src->adapter.data.scsi_host.name) {
+                virBufferAsprintf(buf," name='%s'/>\n",
+                                  src->adapter.data.scsi_host.name);
+            } else {
+                virBufferAsprintf(buf," parent='%s' unique_id='%u'/>\n",
+                                  src->adapter.data.scsi_host.parent,
+                                  src->adapter.data.scsi_host.unique_id);
+            }
         }
     }
 
diff --git a/src/conf/storage_conf.h b/src/conf/storage_conf.h
index 823d5af..801e41c 100644
--- a/src/conf/storage_conf.h
+++ b/src/conf/storage_conf.h
@@ -239,6 +239,9 @@ struct _virStoragePoolSourceAdapter {
     union {
         struct {
             char *name;
+            char *parent;
+            unsigned int unique_id;
+            bool has_unique_id;
         } scsi_host;
         struct {
             char *parent;
diff --git a/tests/storagepoolxml2xmlin/pool-scsi-type-scsi-host-stable.xml b/tests/storagepoolxml2xmlin/pool-scsi-type-scsi-host-stable.xml
new file mode 100644
index 0000000..fdf4002
--- /dev/null
+++ b/tests/storagepoolxml2xmlin/pool-scsi-type-scsi-host-stable.xml
@@ -0,0 +1,15 @@
+<pool type="scsi">
+  <name>hba0</name>
+  <uuid>e9392370-2917-565e-692b-d057f46512d6</uuid>
+  <source>
+    <adapter type='scsi_host' parent='scsi_host' unique_id="5"/>
+  </source>
+  <target>
+    <path>/dev/disk/by-path</path>
+    <permissions>
+      <mode>0700</mode>
+      <owner>0</owner>
+      <group>0</group>
+    </permissions>
+  </target>
+</pool>
diff --git a/tests/storagepoolxml2xmlout/pool-scsi-type-scsi-host-stable.xml b/tests/storagepoolxml2xmlout/pool-scsi-type-scsi-host-stable.xml
new file mode 100644
index 0000000..49d1cec
--- /dev/null
+++ b/tests/storagepoolxml2xmlout/pool-scsi-type-scsi-host-stable.xml
@@ -0,0 +1,18 @@
+<pool type='scsi'>
+  <name>hba0</name>
+  <uuid>e9392370-2917-565e-692b-d057f46512d6</uuid>
+  <capacity unit='bytes'>0</capacity>
+  <allocation unit='bytes'>0</allocation>
+  <available unit='bytes'>0</available>
+  <source>
+    <adapter type='scsi_host' parent='scsi_host' unique_id='5'/>
+  </source>
+  <target>
+    <path>/dev/disk/by-path</path>
+    <permissions>
+      <mode>0700</mode>
+      <owner>0</owner>
+      <group>0</group>
+    </permissions>
+  </target>
+</pool>
diff --git a/tests/storagepoolxml2xmltest.c b/tests/storagepoolxml2xmltest.c
index 0376e63..a9d36c5 100644
--- a/tests/storagepoolxml2xmltest.c
+++ b/tests/storagepoolxml2xmltest.c
@@ -97,6 +97,7 @@ mymain(void)
     DO_TEST("pool-iscsi-multiiqn");
     DO_TEST("pool-iscsi-vendor-product");
     DO_TEST("pool-sheepdog");
+    DO_TEST("pool-scsi-type-scsi-host-stable");
 
     return ret==0 ? EXIT_SUCCESS : EXIT_FAILURE;
 }
-- 
1.8.1.4




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