[fs.Linux] Allow dev without /dev/loop... when loop in mnt_options

This commit let Linux automatically handle the loop device creation/deletion during mount/umount

So Now following resource is allowed:
    [fs#1]
    type = ext4
    dev = /loopfile1
    mnt = /data1
    mnt_opt = loop,rw

Signed-off-by: Cyril Galibern <cyril.galibern@opensvc.com>

opensvc/drivers/resource/fs/linux.py

@@ -153,6 +153,8 @@ def is_up(self):
             backfile = utilities.devices.linux.loop_to_file(self.device)
             if backfile and self.mounts.has_mount(backfile, os.path.realpath(self.mount_point)):
                 return True
+        elif os.path.isfile(self.device) and "loop" in self.mount_options.split(","):
+            return self.mounts.has_mount(self.device, os.path.realpath(self.mount_point))
 
         # might be a mount by label or uuid
         for dev in self.sub_devs():