Add ALUA supported method

Passthrough backends like pscsi and user do not support ALUA
managment through configfs. You can create groups, but writing
to files can cause the kernel crashes.

This adds a alua_supported method that backends can override
and return False to indicate they do not support ALUA.

Signed-off-by: Mike Christie <mchristi@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/rtslib/utils.py b/rtslib/utils.py
index 969d2d7..1a5315e 100644
--- a/rtslib/utils.py
+++ b/rtslib/utils.py
@@ -37,6 +37,12 @@ class RTSLibError(Exception):
     '''
     pass
 
+class RTSLibALUANotSupported(RTSLibError):
+    '''
+    Backend does not support ALUA.
+    '''
+    pass
+
 class RTSLibBrokenLink(RTSLibError):
     '''
     Broken link in configfs, i.e. missing LUN storage object.