[dm-devel] Missing DM event ?

[goggin, edward]

On Thu, 28 Jul 2005 16:25:33 +0200
Christophe Varoqui <christophe.varoqui at free.fr> wrote

> I played with the "rename" multipath feature in 
> /sbin/multipath and noticed it doesn't trigger a DM event to 
> the old devmap listeners. Which is quite annoying if we want 
> the daemon to rely on this event to catch a rename initiated 
> by /sbin/multipath.
> 
> Don't know if it is expected behaviour ...
> Anyway, I finaly went the easy way and did the thing with a 
> remove/add sequence.

I missed this when I submitted the patch for the dmsetup remove
and remove_all subcommands.  This is definitely a problem since
the device-mapper user space utilities like multipath use the
dm device name to identify a particular mapped device.
  
I think the fix is for dm_hash_rename to be calling dm_table_event.
I don't have a working host now so I can't include a tested patch.
I will later this week.

Do you want to change multipathd to recognize that a simple name
change occurred to a map for which it already knows about or simply
have it do an implicit remove/add sequence as I suspect it is already
doing in this case?