[Xen-tools] [PATCH] fix xend block-create crash

[Dan Smith <danms@xxxxxxxxxx>]

This patch fixes a crash in xend when adding a block device by doing
an "xm block-create" operation:

  # xm block-create foobar phy:/dev/hdb1 hda1 ro
  Traceback (most recent call last):
    File "/usr/sbin/xm", line 10, in ?
      main.main(sys.argv)
    File "/usr/lib/python/xen/xm/main.py", line 721, in main
      handle_xend_error(argv[1], args[0], ex)
    File "/usr/lib/python/xen/xm/main.py", line 162, in handle_xend_error 
      raise ex
  xen.xend.XendProtocol.XendError: Internal server error

This stack trace is a result of the new blkif xenstore setup code
returning None, instead of a device object with a getConfig() method.
The fix implemented is to resume creating a Blkif object, but without
sending the event channel setup messages.  This also results in a
functioning block-list xm command.

Signed-off-by: Dan Smith <danms@xxxxxxxxxx>

diff -r 8af8ddf91078 tools/python/xen/xend/XendDomainInfo.py
--- a/tools/python/xen/xend/XendDomainInfo.py   Wed Aug 31 14:53:43 2005
+++ b/tools/python/xen/xend/XendDomainInfo.py   Wed Aug 31 11:10:26 2005
@@ -414,21 +414,25 @@
             db['backend-id'] = "%i" % backdom.id
 
             backdb['frontend'] = db.getPath()
-            (type, params) = string.split(sxp.child_value(devconfig, 'uname'), 
':', 1)
-            node = Blkctl.block('bind', type, params)
+            (vbdtype, params) = string.split(sxp.child_value(devconfig, 
'uname'), ':', 1)
+            node = Blkctl.block('bind', vbdtype, params)
             backdb['frontend-id'] = "%i" % self.id
             backdb['physical-device'] = "%li" % blkdev_name_to_number(node)
             backdb.saveDB(save=True)
 
             # Ok, super gross, this really doesn't belong in the frontend db...
-            db['type'] = type
+            db['type'] = vbdtype
             db['node'] = node
             db['params'] = params
             db.saveDB(save=True)
-            
-            return
-
-        if type == 'vif':
+
+            ctrl = self.findDeviceController(type)
+            device = ctrl.createDevice(devconfig, recreate=self.recreate,
+                                       change=change)
+            device.setNode(node)
+            return device
+
+        elif type == 'vif':
             backdom = domain_exists(sxp.child_value(devconfig, 'backend', '0'))
 
             log.error(devconfig)
@@ -457,9 +461,10 @@
             db.saveDB(save=True)
 
             return
-        
-        ctrl = self.findDeviceController(type)
-        return ctrl.createDevice(devconfig, recreate=self.recreate,
+
+        else:
+            ctrl = self.findDeviceController(type)
+            return ctrl.createDevice(devconfig, recreate=self.recreate,
                                  change=change)
 
     def configureDevice(self, type, id, devconfig):
diff -r 8af8ddf91078 tools/python/xen/xend/server/blkif.py
--- a/tools/python/xen/xend/server/blkif.py     Wed Aug 31 14:53:43 2005
+++ b/tools/python/xen/xend/server/blkif.py     Wed Aug 31 11:10:26 2005
@@ -255,12 +255,6 @@
         return self.config
 
     def attach(self, recreate=False, change=False):
-        if recreate:
-            pass
-        else:
-            node = Blkctl.block('bind', self.type, self.params)
-            self.setNode(node)
-            self.attachBackend()
         if change:
             self.interfaceChanged()
 
@@ -351,7 +345,6 @@
         self.destroyed = True
         log.debug("Destroying vbd domain=%d id=%s", self.frontendDomain,
                   self.id)
-        self.send_be_vbd_destroy()
         if change:
             self.interfaceChanged()
         self.unbind()
@@ -362,36 +355,6 @@
         """
         self.getBackend().interfaceChanged()
 
-    def attachBackend(self):
-        """Attach the device to its controller.
-
-        """
-        self.getBackend().connect()
-        self.send_be_vbd_create()
-        
-    def send_be_vbd_create(self):
-        msg = packMsg('blkif_be_vbd_create_t',
-                      { 'domid'        : self.frontendDomain,
-                        'blkif_handle' : self.backendId,
-                        'pdevice'      : self.device,
-                        'dev_handle'   : self.dev_handle,
-                        'vdevice'      : self.vdev,
-                        'readonly'     : self.readonly() })
-        msg = self.backendChannel.requestResponse(msg)
-        
-        val = unpackMsg('blkif_be_vbd_create_t', msg)
-        status = val['status']
-        if status != BLKIF_BE_STATUS_OKAY:
-            raise XendError("Creating vbd failed: device %s, error %d"
-                            % (sxp.to_string(self.config), status))
-
-    def send_be_vbd_destroy(self):
-        msg = packMsg('blkif_be_vbd_destroy_t',
-                      { 'domid'                : self.frontendDomain,
-                        'blkif_handle'         : self.backendId,
-                        'vdevice'              : self.vdev })
-        return self.backendChannel.writeRequest(msg)
-        
 class BlkifController(DevController):
     """Block device interface controller. Handles all block devices
     for a domain.

--
Dan Smith
IBM Linux Technology Center
Open Hypervisor Team
email: danms@xxxxxxxxxx


_______________________________________________
Xen-tools mailing list
Xen-tools@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-tools