storage: Handle guest collision checking

This pattern is already used in two places. Formalize and centralize
it

virtManager/addhardware.py

@@ -1524,10 +1524,8 @@ class vmmAddHardware(vmmGObjectUI):
                  for c in self.vm.xmlobj.devices.controller])):
             controller_model = "virtio-scsi"
 
-        collidelist = [d.path for d in self.vm.xmlobj.devices.disk]
-
         disk = self.addstorage.build_device(self.vm.get_name(),
-            collidelist=collidelist, device=device)
+            collideguest=self.vm.xmlobj, device=device)
 
         used = []
         disk.bus = bus

virtManager/addstorage.py

@@ -142,7 +142,7 @@ class vmmAddStorage(vmmGObjectUI):
             use_storage.set_sensitive(True)
         storage_area.set_tooltip_text(storage_tooltip or "")
 
-    def get_default_path(self, name, collidelist=None):
+    def get_default_path(self, name, collideguest=None):
         pool = self.conn.get_default_pool()
         if not pool:
             return
@@ -151,15 +151,9 @@ class vmmAddStorage(vmmGObjectUI):
         suffix = virtinst.StorageVolume.get_file_extension_for_format(fmt)
         suffix = suffix or ".img"
 
-        # Sanitize collidelist to work with the collision checker
-        newcollidelist = []
-        for c in (collidelist or []):
-            if c and os.path.dirname(c) == pool.get_target_path():
-                newcollidelist.append(os.path.basename(c))
-
         path = virtinst.StorageVolume.find_free_name(
-            pool.get_backend(), name,
-            suffix=suffix, collidelist=newcollidelist)
+            self.conn.get_backend(), pool.get_backend(), name,
+            suffix=suffix, collideguest=collideguest)
 
         return os.path.join(pool.xmlobj.target_path, path)
 
@@ -167,10 +161,10 @@ class vmmAddStorage(vmmGObjectUI):
         return self.widget("storage-create").get_active()
 
     def build_device(self, vmname,
-            path=None, device="disk", collidelist=None):
+            path=None, device="disk", collideguest=None):
         if path is None:
             if self.is_default_storage():
-                path = self.get_default_path(vmname, collidelist or [])
+                path = self.get_default_path(vmname, collideguest=collideguest)
             else:
                 path = self.widget("storage-entry").get_text().strip()
 

virtManager/createvol.py

@@ -160,6 +160,7 @@ class vmmCreateVolume(vmmGObjectUI):
         ret = ""
         try:
             ret = StorageVolume.find_free_name(
+                self.conn.get_backend(),
                 self._parent_pool.get_backend(),
                 hint, suffix=suffix)
             if ret and suffix:

virtinst/cli.py

@@ -2738,15 +2738,9 @@ def _get_default_image_format(conn, poolobj):
 
 
 def _generate_new_volume_name(guest, poolobj, fmt):
-    collidelist = []
-    for disk in guest.devices.disk:
-        if (disk.get_vol_install() and
-            disk.get_vol_install().pool.name() == poolobj.name()):
-            collidelist.append(os.path.basename(disk.path))
-
     ext = StorageVolume.get_file_extension_for_format(fmt)
     return StorageVolume.find_free_name(
-        poolobj, guest.name, suffix=ext, collidelist=collidelist)
+        guest.conn, poolobj, guest.name, suffix=ext, collideguest=guest)
 
 
 class ParserDisk(VirtCLIParser):

virtinst/kernelupload.py

@@ -76,7 +76,7 @@ def _upload_file(conn, meter, destpool, src):
     # Build placeholder volume
     size = os.path.getsize(src)
     basename = os.path.basename(src)
-    name = StorageVolume.find_free_name(destpool, basename)
+    name = StorageVolume.find_free_name(conn, destpool, basename)
     if name != basename:
         logging.debug("Generated non-colliding volume name %s", name)
 

virtinst/storage.py

@@ -535,11 +535,29 @@ class StorageVolume(_StorageObject):
         return "." + fmt
 
     @staticmethod
-    def find_free_name(pool_object, basename, **kwargs):
+    def find_free_name(conn, pool_object, basename, collideguest=None, **kwargs):
         """
         Finds a name similar (or equal) to passed 'basename' that is not
         in use by another volume. Extra params are passed to generate_name
+
+        :param collideguest: Guest object. If specified, also check to
+        ensure we don't collide with any disk paths there
         """
+        collidelist = []
+        if collideguest:
+            pooltarget = None
+            poolname = pool_object.name()
+            for poolxml in conn.fetch_all_pools():
+                if poolxml.name == poolname:
+                    pooltarget = poolxml.target_path
+                    break
+
+            for disk in collideguest.devices.disk:
+                if (pooltarget and disk.path and
+                    os.path.dirname(disk.path) == pooltarget):
+                    collidelist.append(os.path.basename(disk.path))
+
+        kwargs["collidelist"] = collidelist
         StoragePool.ensure_pool_is_running(pool_object, refresh=True)
         return generatename.generate_name(basename,
                                   pool_object.storageVolLookupByName,