Re: [PATCH]qla4xxx:Add support for Async Message PDUs [REPOST with fixes]

[Mike Christie <michaelc@cs.wisc.edu>]

David C Somayajulu wrote:
> +		}
> +		if (sshdr.asc == 0x3f && sshdr.ascq == 0x0e) {
> +			/* induce rescan */
> +			iscsi_block_session(ddb_entry->sess);
> +			iscsi_unblock_session(ddb_entry->sess);
> +		}

I think I was wrong off list. We could actually just call 
iscsi_unblock_session, but we do not know the state of the session do 
we? If we got a event that indicated the session was failed could we 
have a block queued up and this would reverse it by accident?

I was thinking that because qla4xxx_process_aen is called before this we 
could just check the ddb state, but we can call iscsi_block_session from 
the interrupt handler to queue up a block so I think that could race 
with the unblock call here.

I think you really just want to separate that code. It might also be 
better to make a more generic framework. If we got this in the scsi 
command sense we want to rescan too. And the problem is that celerra or 
centerra and cisco mds will send the iscsi asyn pdu, but netapp and 
other boxes do not (probably even across EMC boxes we will not see the 
same thing :( ). These other boxes send the sense in the scsi command, 
so eventually we have to handle it both places to make our masters happy :)