Re: PATCH: do not run multipath stuff when not nescessary

[Jeremy Katz <katzj redhat com>]

On Tuesday, February 03 2009, Hans de Goede said:
> While working on dmraid I noticed that the multipath stuff gets run when 
> it shouldn't, this is because the test changed in the patch below assumes 
> that not has a lower precedence then and, which it has not, so the not 
> only applies to one part of the and, making the test wrong.

We don't want to return immediately if mpList is None, though -- that means 
that we haven't been through startMpath() before and thus haven't set 
things up.  Maybe more clear would be

> diff --git a/partedUtils.py b/partedUtils.py
> index 2fc553c..cf18324 100644
> --- a/partedUtils.py
> +++ b/partedUtils.py
> @@ -584,7 +584,7 @@ class DiskSet:
>      def startMPath(self):
>          """Start all of the dm multipath devices associated with the DiskSet."""
>
> -        if not DiskSet.mpList is None and DiskSet.mpList.__len__() > 0:
> +        if DiskSet.mpList is None or DiskSet.mpList.__len__() == 0:
+ if DiskSet.mpList is not None and DiskSet.mpList.__len__() > 0:
>              return
>
>          log.debug("starting mpaths")

Jeremy