feat(LargeBlock): read the VG device to attach, detach and delete

Signed-off-by: Damien Thenot <[email protected]>

drivers/LargeBlockSR.py

@@ -64,12 +64,17 @@ def load(self, sr_uuid):
 
     def attach(self, sr_uuid):
         if not self.is_deleting:
+            vg_device = self._get_device()
+            self.dconf["device"] = ",".join(vg_device)
             self._create_emulated_device()
             if not self._is_vg_connection_correct(): # Check if we need to redo the connection by parsing `vgs -o vg_name,devices self.vgname`
                 self._redo_vg_connection() # Call redo VG connection to connect it correctly to the loop device instead of the real 4KiB block device
         super(LargeBlockSR, self).attach(sr_uuid)
 
     def detach(self, sr_uuid):
+        vg_device = self._get_device()
+
+        self.dconf["device"] = ",".join(vg_device)
         super(LargeBlockSR, self).detach(sr_uuid)
         if not self.is_deleting:
             self._destroy_emulated_device()
@@ -89,6 +94,7 @@ def create(self, sr_uuid, size):
             self._destroy_emulated_device(base_devices)
 
     def delete(self, sr_uuid):
+        self.dconf["device"] = ",".join(self._get_device())
         base_devices = self.dconf["device"].split(",")
 
         self.is_deleting = True
@@ -152,18 +158,44 @@ def _get_loopdev_from_device(device):
                     lpdevs.append(loopdev)
         return lpdevs
 
+    @staticmethod
+    def _get_device_from_loopdev(loopdevs):
+        devices = []
+        output = util.pread2(["losetup", "--list"]).rstrip()
+        if output:
+            for line in output.split("\n"):
+                line = line.split()
+                lpdev = line[0]
+                dev = line[5]
+                if lpdev in loopdevs:
+                    devices.append(dev)
+        return devices
+
     def _get_device_from_vg(self):
         devices = []
         output = util.pread2(["vgs", "--noheadings", "-o", "vg_name,devices", self.vgname]).splitlines()
         for line in output:
             line = line.split()
-            devices.append(line[1].split("(")[0])
+            dev = line[1].split("(")[0]
+            if os.path.islink(dev):
+                dev = os.path.realpath(dev)
+            devices.append(dev)
         return devices
 
+    def _get_device(self):
+        vg_device = self._get_device_from_vg()
+        for dev in vg_device:
+            if re.match(r"(.*\.512)|(/dev/loop[0-9]+)", dev):
+                lpdev = os.path.realpath(dev)
+                realdev = self._get_device_from_loopdev(lpdev)[0]
+                vg_device.remove(dev)
+                vg_device.append(realdev)
+
+        return vg_device
+
     def _is_vg_connection_correct(self):
         output = util.pread2(["vgs", "--noheadings", "-o", "vg_name,devices", self.vgname]).split()
-        if self.vgname == output[0]:
-            output[1] = output[1].split("(")[0]
+        output[1] = output[1].split("(")[0]
         return bool(re.match(r"(.*\.512)|(/dev/loop[0-9]+)", output[1]))
 
     def _redo_vg_connection(self):