> On Jun 23, 2017, at 12:10 AM, Johannes Thumshirn <[email protected]> wrote:
> 
> In qla2xx_start_scsi_mq() and qla2xx_dif_start_scsi_mq() we grab the
> qpair->qp_lock but do access members of the qpair before having the lock.
> Re-order the locking sequence to have all read and write access to qpair
> members under the qpair->qp_lock.
> 
> Signed-off-by: Johannes Thumshirn <[email protected]>
> ---
> drivers/scsi/qla2xxx/qla_iocb.c | 23 +++++++++++++----------
> 1 file changed, 13 insertions(+), 10 deletions(-)
> 
> Changes to v1:
> * Use __qla2x00_marker() instead of qla2x00_marker which is fit to be called
>  with the qp_lock held (John)
> * Don't protect qpair->online and qpair->difdix_supported as it's not
>  needed (Hannes)
> 
> diff --git a/drivers/scsi/qla2xxx/qla_iocb.c b/drivers/scsi/qla2xxx/qla_iocb.c
> index 8404f17f3c6c..c64036ddd365 100644
> --- a/drivers/scsi/qla2xxx/qla_iocb.c
> +++ b/drivers/scsi/qla2xxx/qla_iocb.c
> @@ -1770,6 +1770,9 @@ qla2xxx_start_scsi_mq(srb_t *sp)
>       struct qla_hw_data *ha = vha->hw;
>       struct qla_qpair *qpair = sp->qpair;
> 
> +     /* Acquire qpair specific lock */
> +     spin_lock_irqsave(&qpair->qp_lock, flags);
> +
>       /* Setup qpair pointers */
>       rsp = qpair->rsp;
>       req = qpair->req;
> @@ -1779,15 +1782,14 @@ qla2xxx_start_scsi_mq(srb_t *sp)
> 
>       /* Send marker if required */
>       if (vha->marker_needed != 0) {
> -             if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> -                 QLA_SUCCESS)
> +             if (__qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> +                 QLA_SUCCESS) {
> +                     spin_unlock_irqrestore(&qpair->qp_lock, flags);
>                       return QLA_FUNCTION_FAILED;
> +             }
>               vha->marker_needed = 0;
>       }
> 
> -     /* Acquire qpair specific lock */
> -     spin_lock_irqsave(&qpair->qp_lock, flags);
> -
>       /* Check for room in outstanding command list. */
>       handle = req->current_outstanding_cmd;
>       for (index = 1; index < req->num_outstanding_cmds; index++) {
> @@ -1942,6 +1944,8 @@ qla2xxx_dif_start_scsi_mq(srb_t *sp)
>                       return qla2xxx_start_scsi_mq(sp);
>       }
> 
> +     spin_lock_irqsave(&qpair->qp_lock, flags);
> +
>       /* Setup qpair pointers */
>       rsp = qpair->rsp;
>       req = qpair->req;
> @@ -1951,15 +1955,14 @@ qla2xxx_dif_start_scsi_mq(srb_t *sp)
> 
>       /* Send marker if required */
>       if (vha->marker_needed != 0) {
> -             if (qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> -                 QLA_SUCCESS)
> +             if (__qla2x00_marker(vha, req, rsp, 0, 0, MK_SYNC_ALL) !=
> +                 QLA_SUCCESS) {
> +                     spin_unlock_irqrestore(&qpair->qp_lock, flags);
>                       return QLA_FUNCTION_FAILED;
> +             }
>               vha->marker_needed = 0;
>       }
> 
> -     /* Acquire ring specific lock */
> -     spin_lock_irqsave(&qpair->qp_lock, flags);
> -
>       /* Check for room in outstanding command list. */
>       handle = req->current_outstanding_cmd;
>       for (index = 1; index < req->num_outstanding_cmds; index++) {
> -- 
> 2.12.3
> 

Looks Good. 

Acked-By: Himanshu Madhani <[email protected]>


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