Merge pull request #1205 from vojtechtrefny/3.9-devel_fix-btrfs-mount…

…point-check

Fix getting subvolumes for mounted btrfs volumes

blivet/devices/btrfs.py

@@ -357,7 +357,7 @@ def _get_any_btrfs_mountpoint(self):
 
         # now try every possible mountpoint with any subvolspec in our cache
         parents = [p.name for p in self.parents]
-        mount_spec = next(((dev, subvol) for dev, subvol in mounts_cache.mountpoints if dev in parents), None)
+        mount_spec = next(((dev, subvol) for dev, subvol in mounts_cache.mountpoints if udev.resolve_devspec(dev) in parents), None)
         if mount_spec:
             try:
                 return mounts_cache.get_mountpoints(devspec=mount_spec[0],