Re: [PATCH 11/20] qla2xxx: Add TAS detection for kernel 3.15 n newer

[Hannes Reinecke <hare@suse.de>]

On 12/08/2015 01:48 AM, Himanshu Madhani wrote:
> From: Quinn Tran <quinn.tran@qlogic.com>
> 
> For kernel 3.15 and newer with TCM API change, add detection
> for TCM support of TAS.  Instead of default command terminate
> for LUN/TARGET reset error handling, allow SCSI status to go
> out if we know sequece Initiative is own by FW (cmd_sent_to_fw=0)
> 
> Signed-off-by: Quinn Tran <quinn.tran@qlogic.com>
> Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
> ---
>  drivers/scsi/qla2xxx/qla_target.c  |   36 +++++++++++++++++-------------------
>  drivers/scsi/qla2xxx/tcm_qla2xxx.c |   20 ++++++++++++++++++++
>  2 files changed, 37 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
> index 4d42b79..5fca846 100644
> --- a/drivers/scsi/qla2xxx/qla_target.c
> +++ b/drivers/scsi/qla2xxx/qla_target.c
> @@ -3239,36 +3239,34 @@ int qlt_abort_cmd(struct qla_tgt_cmd *cmd)
>  	struct qla_tgt *tgt = cmd->tgt;
>  	struct scsi_qla_host *vha = tgt->vha;
>  	struct se_cmd *se_cmd = &cmd->se_cmd;
> -	unsigned long flags,refcount;
> +	unsigned long flags, refcount;
>  
>  	ql_dbg(ql_dbg_tgt_mgt, vha, 0xf014,
>  	    "qla_target(%d): terminating exchange for aborted cmd=%p "
>  	    "(se_cmd=%p, tag=%llu)", vha->vp_idx, cmd, &cmd->se_cmd,
>  	    se_cmd->tag);
>  
> -    spin_lock_irqsave(&cmd->cmd_lock, flags);
> -    if (cmd->aborted) {
> -        spin_unlock_irqrestore(&cmd->cmd_lock, flags);
> +	spin_lock_irqsave(&cmd->cmd_lock, flags);
>  
> -        /* It's normal to see 2 calls in this path:
> -         *  1) XFER Rdy completion + CMD_T_ABORT
> -         *  2) TCM TMR - drain_state_list
> -         */
> -        refcount = atomic_read(&cmd->se_cmd.cmd_kref.refcount);
> -        ql_dbg(ql_dbg_tgt_mgt, vha, 0xffff,
> -               "multiple abort. %p refcount %lx"
> -               "transport_state %x, t_state %x, se_cmd_flags %x \n",
> -               cmd, refcount,cmd->se_cmd.transport_state,
> -               cmd->se_cmd.t_state,cmd->se_cmd.se_cmd_flags);
> +	if (cmd->aborted) {
> +		spin_unlock_irqrestore(&cmd->cmd_lock, flags);
> +		/* It's normal to see 2 calls in this path:
> +		 *  1) XFER Rdy completion + CMD_T_ABORT
> +		 *  2) TCM TMR - drain_state_list
> +		 */
> +		refcount = atomic_read(&cmd->se_cmd.cmd_kref.refcount);
> +		ql_dbg(ql_dbg_tgt_mgt, vha, 0xffff,
> +		    "multiple abort. %p refcount %lx"
> +		    "transport_state %x, t_state %x, se_cmd_flags %x \n",
> +		    cmd, refcount, cmd->se_cmd.transport_state,
> +		    cmd->se_cmd.t_state, cmd->se_cmd.se_cmd_flags);
>  
> -        return EIO;
> -    }
> +		return EIO;
> +	}
>  
>  	cmd->aborted = 1;
>  	cmd->cmd_flags |= BIT_6;
> -    spin_unlock_irqrestore(&cmd->cmd_lock, flags);
> -
> -	qlt_send_term_exchange(vha, cmd, &cmd->atio, 0, 1);
> +	spin_unlock_irqrestore(&cmd->cmd_lock, flags);
>  
>  	return 0;
>  }
> diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
> index 842fcca..2e9c194 100644
> --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
> +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
> @@ -617,6 +617,26 @@ static int tcm_qla2xxx_queue_status(struct se_cmd *se_cmd)
>  				struct qla_tgt_cmd, se_cmd);
>  	int xmit_type = QLA_TGT_XMIT_STATUS;
>  
> +	if (se_cmd->transport_state & CMD_T_ABORTED) {
> +		/* For TCM TAS support n kernel >= 3.15:
> +		 * This cmd is attempting to respond with "Task Aborted Status".
> +		 */
> +		if (cmd->aborted) {
> +			return 0;
> +		} else if ((cmd->state == QLA_TGT_STATE_NEED_DATA) &&
> +		    cmd->cmd_sent_to_fw) {
> +			qlt_abort_cmd(cmd);
> +			return 0;
> +		} else if (cmd->state == QLA_TGT_STATE_PROCESSED) {
> +			if (cmd->cmd_sent_to_fw) {
> +				qlt_abort_cmd(cmd);
> +				return 0;
> +			} else {	/* about to be free */
> +				return 0;
> +			}
> +		}
> +	}
> +
>  	cmd->bufflen = se_cmd->data_length;
>  	cmd->sg = NULL;
>  	cmd->sg_cnt = 0;
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
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