Re: fc_remote_port_delete and returning SCSI commands from LLD

[Christof Schmitt <christof.schmitt@de.ibm.com>]

On Tue, Oct 20, 2009 at 04:40:27PM +0200, Christof Schmitt wrote:
> If the remote_port status is not BLOCKED, this will trigger the SCSI
> midlayer error handling which cannot do much during the interruption
> to the hardware and will mark the SCSI devices 'offline'. In order to
> prevent this, the rule would be: First call fc_remote_port_delete to
> set the remote port (or in the case of an HBA interruption all remote
> ports) to BLOCKED, and only after this step call scsi_done to pass the
> SCSI commands back to the upper layers.

I just stumbled across a loop that blocks the SCSI error handling
thread:

	spin_lock_irqsave(shost->host_lock, flags);
	while (rport->port_state == FC_PORTSTATE_BLOCKED) {
		spin_unlock_irqrestore(shost->host_lock, flags);
		msleep(1000);
		spin_lock_irqsave(shost->host_lock, flags);
	}
	spin_unlock_irqrestore(shost->host_lock, flags);

This seems to be popular among FC drivers. Is this the preferred way
to synchronize the FC transport class state changes with the SCSI
midlayer error recovery?

Christof