feat(LVHDSR): add a way to modify config of LVMs (#56)

With this change the driver supports a "lvm-conf" param on "other-config".
For now The configuration is only used by "remove" calls from LVMCache.

Example to issue discards after a lvremove command:

> xe sr-param-set uuid=<SR_UUID> other-config:lvm-conf=issue_discards=1

And to remove the param:

> xe sr-param-remove uuid=<SR_UUID> param-name=other-config param-key=lvm-conf

Signed-off-by: Ronan Abhamon <[email protected]>

drivers/LVHDSR.py

@@ -161,14 +161,24 @@ def load(self, sr_uuid):
         self.path = os.path.join(lvhdutil.VG_LOCATION, self.vgname)
         self.mdpath = os.path.join(self.path, self.MDVOLUME_NAME)
         self.provision = self.PROVISIONING_DEFAULT
+
+        self.other_conf = None
+        has_sr_ref = self.srcmd.params.get("sr_ref")
+        if has_sr_ref:
+            self.other_conf = self.session.xenapi.SR.get_other_config(self.sr_ref)
+
+        self.lvm_conf = None
+        if self.other_conf:
+            self.lvm_conf = self.other_conf.get('lvm-conf')
+
         try:
-            self.lvmCache = lvmcache.LVMCache(self.vgname)
+            self.lvmCache = lvmcache.LVMCache(self.vgname, self.lvm_conf)
         except:
             raise xs_errors.XenError('SRUnavailable', \
                         opterr='Failed to initialise the LVMCache')
         self.lvActivator = LVActivator(self.uuid, self.lvmCache)
         self.journaler = Journaler(self.lvmCache)
-        if not self.srcmd.params.get("sr_ref"):
+        if not has_sr_ref:
             return # must be a probe call
         # Test for thick vs thin provisioning conf parameter
         if self.dconf.has_key('allocation'):
@@ -178,7 +188,6 @@ def load(self, sr_uuid):
                 raise xs_errors.XenError('InvalidArg', \
                         opterr='Allocation parameter must be one of %s' % self.PROVISIONING_TYPES)
 
-        self.other_conf = self.session.xenapi.SR.get_other_config(self.sr_ref)
         if self.other_conf.get(self.TEST_MODE_KEY):
             self.testMode = self.other_conf[self.TEST_MODE_KEY]
             self._prepareTestMode()

drivers/cleanup.py

@@ -2565,7 +2565,12 @@ def __init__(self, uuid, xapi, createLock, force):
         SR.__init__(self, uuid, xapi, createLock, force)
         self.vgName = "%s%s" % (lvhdutil.VG_PREFIX, self.uuid)
         self.path = os.path.join(lvhdutil.VG_LOCATION, self.vgName)
-        self.lvmCache = lvmcache.LVMCache(self.vgName)
+
+        sr_ref = self.xapi.session.xenapi.SR.get_by_uuid(self.uuid)
+        other_conf = self.xapi.session.xenapi.SR.get_other_config(sr_ref)
+        lvm_conf = other_conf.get('lvm-conf') if other_conf else None
+        self.lvmCache = lvmcache.LVMCache(self.vgName, lvm_conf)
+
         self.lvActivator = LVActivator(self.uuid, self.lvmCache)
         self.journaler = journaler.Journaler(self.lvmCache)
 

drivers/lvmcache.py

@@ -59,10 +59,11 @@ class LVMCache:
     """Per-VG object to store LV information. Can be queried for cached LVM
     information and refreshed"""
 
-    def __init__(self, vgName):
+    def __init__(self, vgName, config=None):
         """Create a cache for VG vgName, but don't scan the VG yet"""
         self.vgName = vgName
         self.vgPath = "/dev/%s" % self.vgName
+        self.config = config
         self.lvs = dict()
         self.tags = dict()
         self.initialized = False
@@ -115,7 +116,7 @@ def create(self, lvName, size, tag = None):
     @lazyInit
     def remove(self, lvName):
         path = self._getPath(lvName)
-        lvutil.remove(path)
+        lvutil.remove(path, self.config)
         for tag in self.lvs[lvName].tags:
             self._removeTag(lvName, tag)
         del self.lvs[lvName]