On Mon, 2019-10-07 at 15:57 +0200, Hannes Reinecke wrote:
> From: Hannes Reinecke <hare@xxxxxxxx>
>
> Some arrays are not capable of returning RTPG data during state
> transitioning, but rather return an 'LUN not accessible, asymmetric
> access state transition' sense code. In these cases we
> can set the state to 'transitioning' directly and don't need to
> evaluate the RTPG data (which we won't have anyway).
>
> Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
> ---
> drivers/scsi/device_handler/scsi_dh_alua.c | 21 ++++++++++++++++--
> ---
> 1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c
> b/drivers/scsi/device_handler/scsi_dh_alua.c
> index 4971104b1817..f32da0ca529e 100644
> --- a/drivers/scsi/device_handler/scsi_dh_alua.c
> +++ b/drivers/scsi/device_handler/scsi_dh_alua.c
> @@ -512,6 +512,7 @@ static int alua_rtpg(struct scsi_device *sdev,
> struct alua_port_group *pg)
> unsigned int tpg_desc_tbl_off;
> unsigned char orig_transition_tmo;
> unsigned long flags;
> + bool transitioning_sense = false;
>
> if (!pg->expiry) {
> unsigned long transition_tmo = ALUA_FAILOVER_TIMEOUT *
> HZ;
> @@ -572,13 +573,19 @@ static int alua_rtpg(struct scsi_device *sdev,
> struct alua_port_group *pg)
> goto retry;
> }
> /*
> - * Retry on ALUA state transition or if any
> - * UNIT ATTENTION occurred.
> + * If the array returns with 'ALUA state transition'
> + * sense code here it cannot return RTPG data during
> + * transition. So set the state to 'transitioning'
> directly.
> */
> if (sense_hdr.sense_key == NOT_READY &&
> - sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a)
> - err = SCSI_DH_RETRY;
> - else if (sense_hdr.sense_key == UNIT_ATTENTION)
> + sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) {
> + transitioning_sense = true;
> + goto skip_rtpg;
> + }
> + /*
> + * Retry on any other UNIT ATTENTION occurred.
> + */
> + if (sense_hdr.sense_key == UNIT_ATTENTION)
> err = SCSI_DH_RETRY;
> if (err == SCSI_DH_RETRY &&
> pg->expiry != 0 && time_before(jiffies, pg-
> >expiry)) {
> @@ -666,7 +673,11 @@ static int alua_rtpg(struct scsi_device *sdev,
> struct alua_port_group *pg)
> off = 8 + (desc[7] * 4);
> }
>
> + skip_rtpg:
> spin_lock_irqsave(&pg->lock, flags);
> + if (transitioning_sense)
> + pg->state = SCSI_ACCESS_STATE_TRANSITIONING;
> +
> sdev_printk(KERN_INFO, sdev,
> "%s: port group %02x state %c %s supports
> %c%c%c%c%c%c%c\n",
> ALUA_DH_NAME, pg->group_id, print_alua_state(pg-
> >state),
This makes sense to me and has affected recovery timeouts in the past.
Code looks correct to me.
Reviewed-by: Laurence Oberman <loberman@xxxxxxxxxx>
