Re: [PATCH 14/17] target/qla2xxx: Simplify the code for handling aborted commands

["Madhani, Himanshu" <Himanshu.Madhani@cavium.com>]

Hi Bart, 

Apologies for long delay

> On Sep 17, 2018, at 2:35 PM, Bart Van Assche <bvanassche@acm.org> wrote:
> 
> External Email
> 
> Since the target core waits anyway until a target driver has
> finished processing a command, remove similar waiting code from
> the tcm_qla2xxx driver. With this change applied command abortion
> works as follows:
> * tcm_qla2xxx receives an ABTS and calls target_submit_tmr().
> * The target core calls core_tmr_abort_task(). That function
>  sets the CMD_T_ABORTED flag and next calls transport_wait_for_tasks().
> * If CMD_T_ACTIVE is still set, __transport_wait_for_tasks() sets
>  CMD_T_STOP and waits for t_transport_stop_comp.
> * When tcm_qla2xxx_handle_data_work() gets called, it either invokes
>  transport_generic_request_failure() or target_execute_cmd().
> * Both functions start with calling __transport_check_aborted_status()
>  and return 1 if CMD_T_ABORTED was set. Otherwise the command that
>  is being executed is completed and target_complete_cmd() completes
>  t_transport_stop_comp.
> * Once transport_wait_for_tasks() returns the target core considers
>  the TMF as finished.
> 
> Signed-off-by: Bart Van Assche <bvanassche@acm.org>
> Cc: Himanshu Madhani <himanshu.madhani@cavium.com>
> Cc: Quinn Tran <quinn.tran@cavium.com>
> Cc: Nicholas Bellinger <nab@linux-iscsi.org>
> Cc: Mike Christie <mchristi@redhat.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.de>
> ---
> drivers/scsi/qla2xxx/tcm_qla2xxx.c | 26 +++++---------------------
> 1 file changed, 5 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
> index e03d12a5f986..2cedfd4f15a3 100644
> --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
> +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
> @@ -414,21 +414,14 @@ static int tcm_qla2xxx_write_pending(struct se_cmd *se_cmd)
> static int tcm_qla2xxx_write_pending_status(struct se_cmd *se_cmd)
> {
>        unsigned long flags;
> -       /*
> -        * Check for WRITE_PENDING status to determine if we need to wait for
> -        * CTIO aborts to be posted via hardware in tcm_qla2xxx_handle_data().
> -        */
> +       bool wp;
> +
>        spin_lock_irqsave(&se_cmd->t_state_lock, flags);
> -       if (se_cmd->t_state == TRANSPORT_WRITE_PENDING ||
> -           se_cmd->t_state == TRANSPORT_COMPLETE_QF_WP) {
> -               spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
> -               wait_for_completion_timeout(&se_cmd->t_transport_stop_comp,
> -                                               50);
> -               return 0;
> -       }
> +       wp = se_cmd->t_state == TRANSPORT_WRITE_PENDING ||
> +               se_cmd->t_state == TRANSPORT_COMPLETE_QF_WP;
>        spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
> 
> -       return 0;
> +       return wp;
> }
> 
> static void tcm_qla2xxx_set_default_node_attrs(struct se_node_acl *nacl)
> @@ -508,15 +501,6 @@ static void tcm_qla2xxx_handle_data_work(struct work_struct *work)
> 
>        cmd->qpair->tgt_counters.qla_core_ret_ctio++;
>        if (!cmd->write_data_transferred) {
> -               /*
> -                * Check if se_cmd has already been aborted via LUN_RESET, and
> -                * waiting upon completion in tcm_qla2xxx_write_pending_status()
> -                */
> -               if (cmd->se_cmd.transport_state & CMD_T_ABORTED) {
> -                       complete(&cmd->se_cmd.t_transport_stop_comp);
> -                       return;
> -               }
> -
>                switch (cmd->dif_err_code) {
>                case DIF_ERR_GRD:
>                        cmd->se_cmd.pi_err =
> --
> 2.18.0
> 

Patch Looks good. 

Acked-by: Himanshu Madhani <himanshu.madhani@cavium.com>

Thanks,
- Himanshu