On Thu, 2008-05-15 at 11:46 +0200, Hannes Reinecke wrote: > Hi Chandra, > > Chandra Seetharaman wrote: > > What is the purpose of this feature ? > > > > With dh_state functionality, one could associate a handler to a new > > device and then if one does "multipath", the hardware handler would be > > associated with the multipath device. What are we achieving by this ? > > > This allows multipath to override the device tables build into > the device handler. Reason here is that multipath has a configuration > file which allows the user to override the build-in defaults. > And this includes the hardware handler, so we need to make sure that > the hardware handler is indeed attached. Hardware handler's existence is currently been verified during parsing (by doing a request_module() followed by scsi_dh_handler_exist() in parse_hw_handler()). Hardware handler module is attached to the device itself (thru try_module_get() in attach), so, the module will exist as long as the device exists. Hence, there is no need to attach it again from the multipath layer. Or, I am missing something totally :) <snip> -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
