Re: [PATCH 6/9] fc class: add fc queueing helper

[Michael Reed <mdr@sgi.com>]

michaelc@cs.wisc.edu wrote:
> From: Mike Christie <michaelc@cs.wisc.edu>
> 
> Add a queueing helper which will return SCSI_MLQUEUE_TARGET_BUSY
> if we are transitioning because there is no need to call into
> the driver anymore at that point.
> 
> Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
> ---
>  include/scsi/scsi_transport_fc.h |   33 +++++++++++++++++++++++++++++++++
>  1 files changed, 33 insertions(+), 0 deletions(-)
> 
> diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
> index 4769efd..62a6a74 100644
> --- a/include/scsi/scsi_transport_fc.h
> +++ b/include/scsi/scsi_transport_fc.h
> @@ -29,6 +29,7 @@
>  
>  #include <linux/sched.h>
>  #include <scsi/scsi.h>
> +#include <scsi/scsi_cmnd.h>
>  #include <scsi/scsi_netlink.h>
>  
>  struct scsi_transport_template;
> @@ -640,6 +641,38 @@ struct fc_function_template {
>  	unsigned long	disable_target_scan:1;
>  };
>  
> +/**
> + * fc_remote_port_queue_ready - called to validate the remote port state
> + * @rport: remote port to be checked
> + *
> + * Returns 0 if IO can be queued or if there the cmd should be

Remove "there" from the comment.

> + * completed by a call to cmd->scsi_done. Caller must check cmd->result.
> + * Returns SCSI_MLQUEUE value if IO cannot be queued temporarily.

How 'bout: "Returns a SCSI_MLQUEUE value if the IO cannot be queued due
to an rport state transition." ?

> + **/
> +static inline int
> +fc_remote_port_queue_ready(struct fc_rport *rport, struct scsi_cmnd *cmd)
> +{
> +	int result = 0;
> +
> +	cmd->result = 0;
> +	switch (rport->port_state) {
> +	case FC_PORTSTATE_ONLINE:
> +		if (rport->roles & FC_PORT_ROLE_FCP_TARGET)
> +			result = 0;
> +		else if (rport->flags & FC_RPORT_DEVLOSS_PENDING)
> +			result = SCSI_MLQUEUE_TARGET_BUSY;
> +		else
> +			cmd->result = DID_NO_CONNECT << 16;
> +		break;
> +	case FC_PORTSTATE_BLOCKED:
> +		result = SCSI_MLQUEUE_TARGET_BUSY;
> +		break;
> +	default:
> +		cmd->result = DID_NO_CONNECT << 16;
> +		break;
> +	}
> +	return result;
> +}
>  
>  /**
>   * fc_remote_port_chkready - called to validate the remote port state