[24/24] libsas: poll for ata device readiness after reset

Use ata_wait_after_reset() to poll for link recovery after a reset.
This combined with sas_ha->eh_mutex prevents expander rediscovery from
probing phys in an intermediate state.  Local discovery does not have a
mechanism to filter link status changes during this timeout, so it
remains the responsibility of lldds to prevent premature port teardown.
Although once all lldd's support ->lldd_ata_check_ready() that could be
used as a gate to local port teardown.

The signature fis is re-transmitted when the link comes back so we
should be revalidating the ata device class, but that is left to a future
patch.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/scsi/libsas/sas_ata.c      |  104 +++++++++++++++++++++++++-----------
 drivers/scsi/libsas/sas_expander.c |   10 ++-
 drivers/scsi/libsas/sas_internal.h |    3 +
 include/scsi/libsas.h              |    1 
 4 files changed, 83 insertions(+), 35 deletions(-)


--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

I test the patchset ,it works ok.
You can add my tested-by if needed.

Jack

[PATCH 24/24] libsas: poll for ata device readiness after reset
> 
> Use ata_wait_after_reset() to poll for link recovery after a reset.
> This combined with sas_ha->eh_mutex prevents expander rediscovery from
> probing phys in an intermediate state.  Local discovery does not have a
> mechanism to filter link status changes during this timeout, so it
> remains the responsibility of lldds to prevent premature port teardown.
> Although once all lldd's support ->lldd_ata_check_ready() that could be
> used as a gate to local port teardown.
> 
> The signature fis is re-transmitted when the link comes back so we
> should be revalidating the ata device class, but that is left to a future
> patch.
> 
> Cc: Tejun Heo <tj@kernel.org>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/scsi/libsas/sas_ata.c      |  104
> +++++++++++++++++++++++++-----------
>  drivers/scsi/libsas/sas_expander.c |   10 ++-
>  drivers/scsi/libsas/sas_internal.h |    3 +
>  include/scsi/libsas.h              |    1
>  4 files changed, 83 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
> index 773e010..a5a7184 100644
> --- a/drivers/scsi/libsas/sas_ata.c
> +++ b/drivers/scsi/libsas/sas_ata.c
> @@ -267,39 +267,84 @@ static bool sas_ata_qc_fill_rtf(struct
ata_queued_cmd
> *qc)
>  	return true;
>  }
> 
> -static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
> -			       unsigned long deadline)
> +static struct sas_internal *dev_to_sas_internal(struct domain_device
*dev)
> +{
> +	return to_sas_internal(dev->port->ha->core.shost->transportt);
> +}
> +
> +static int smp_ata_check_ready(struct ata_link *link)
>  {
> +	int res;
> +	u8 addr[8];
>  	struct ata_port *ap = link->ap;
>  	struct domain_device *dev = ap->private_data;
> -	struct sas_internal *i =
> -		to_sas_internal(dev->port->ha->core.shost->transportt);
> -	int res = TMF_RESP_FUNC_FAILED;
> -	int ret = 0;
> +	struct domain_device *ex_dev = dev->parent;
> +	struct sas_phy *phy = sas_find_local_phy(dev);
> 
> -	if (i->dft->lldd_I_T_nexus_reset)
> -		res = i->dft->lldd_I_T_nexus_reset(dev);
> +	res = sas_get_phy_attached_sas_addr(ex_dev, phy->number, addr);
> +	/* break the wait early if the expander is unreachable,
> +	 * otherwise keep polling
> +	 */
> +	if (res == -ECOMM)
> +		return res;
> +	if (res != SMP_RESP_FUNC_ACC || SAS_ADDR(addr) == 0)
> +		return 0;
> +	else
> +		return 1;
> +}
> 
> -	if (res != TMF_RESP_FUNC_COMPLETE) {
> -		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);
> -		ret = -EAGAIN;
> +static int local_ata_check_ready(struct ata_link *link)
> +{
> +	struct ata_port *ap = link->ap;
> +	struct domain_device *dev = ap->private_data;
> +	struct sas_internal *i = dev_to_sas_internal(dev);
> +
> +	if (i->dft->lldd_ata_check_ready)
> +		return i->dft->lldd_ata_check_ready(dev);
> +	else {
> +		/* lldd's that don't implement 'ready' checking get the
> +		 * old default behavior of not coordinating reset
> +		 * recovery with libata
> +		 */
> +		return 1;
>  	}
> +}
> 
> +static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
> +			      unsigned long deadline)
> +{
> +	int ret = 0, res;
> +	struct ata_port *ap = link->ap;
> +	int (*check_ready)(struct ata_link *link);
> +	struct domain_device *dev = ap->private_data;
> +	struct sas_phy *phy = sas_find_local_phy(dev);
> +	struct sas_internal *i = dev_to_sas_internal(dev);
> +
> +	res = i->dft->lldd_I_T_nexus_reset(dev);
> +
> +	if (res != TMF_RESP_FUNC_COMPLETE)
> +		SAS_DPRINTK("%s: Unable to reset ata device?\n", __func__);
> +
> +	if (scsi_is_sas_phy_local(phy))
> +		check_ready = local_ata_check_ready;
> +	else
> +		check_ready = smp_ata_check_ready;
> +
> +	ret = ata_wait_after_reset(link, deadline, check_ready);
> +	if (ret && ret != -EAGAIN)
> +		ata_link_err(link, "COMRESET failed (errno=%d)\n", ret);
> +
> +	/* XXX: if the class changes during the reset the upper layer
> +	 * should be informed, if the device has gone away we assume
> +	 * libsas will eventually delete it
> +	 */
>  	switch (dev->sata_dev.command_set) {
> -		case ATA_COMMAND_SET:
> -			SAS_DPRINTK("%s: Found ATA device.\n", __func__);
> -			*class = ATA_DEV_ATA;
> -			break;
> -		case ATAPI_COMMAND_SET:
> -			SAS_DPRINTK("%s: Found ATAPI device.\n", __func__);
> -			*class = ATA_DEV_ATAPI;
> -			break;
> -		default:
> -			SAS_DPRINTK("%s: Unknown SATA command set: %d.\n",
> -				    __func__,
> -				    dev->sata_dev.command_set);
> -			*class = ATA_DEV_UNKNOWN;
> -			break;
> +	case ATA_COMMAND_SET:
> +		*class = ATA_DEV_ATA;
> +		break;
> +	case ATAPI_COMMAND_SET:
> +		*class = ATA_DEV_ATAPI;
> +		break;
>  	}
> 
>  	ap->cbl = ATA_CBL_SATA;
> @@ -311,8 +356,7 @@ static int sas_ata_soft_reset(struct ata_link *link,
> unsigned int *class,
>  {
>  	struct ata_port *ap = link->ap;
>  	struct domain_device *dev = ap->private_data;
> -	struct sas_internal *i =
> -		to_sas_internal(dev->port->ha->core.shost->transportt);
> +	struct sas_internal *i = dev_to_sas_internal(dev);
>  	int res = TMF_RESP_FUNC_FAILED;
>  	int ret = 0;
> 
> @@ -350,8 +394,7 @@ static int sas_ata_soft_reset(struct ata_link *link,
> unsigned int *class,
>   */
>  static void sas_ata_internal_abort(struct sas_task *task)
>  {
> -	struct sas_internal *si =
> -
to_sas_internal(task->dev->port->ha->core.shost->transportt);
> +	struct sas_internal *si = dev_to_sas_internal(task->dev);
>  	unsigned long flags;
>  	int res;
> 
> @@ -421,8 +464,7 @@ static void sas_ata_post_internal(struct
ata_queued_cmd
> *qc)
>  static void sas_ata_set_dmamode(struct ata_port *ap, struct ata_device
> *ata_dev)
>  {
>  	struct domain_device *dev = ap->private_data;
> -	struct sas_internal *i =
> -		to_sas_internal(dev->port->ha->core.shost->transportt);
> +	struct sas_internal *i = dev_to_sas_internal(dev);
> 
>  	if (i->dft->lldd_ata_set_dmamode)
>  		i->dft->lldd_ata_set_dmamode(dev);
> diff --git a/drivers/scsi/libsas/sas_expander.c
> b/drivers/scsi/libsas/sas_expander.c
> index fd77ea3..5e1eec9 100644
> --- a/drivers/scsi/libsas/sas_expander.c
> +++ b/drivers/scsi/libsas/sas_expander.c
> @@ -125,7 +125,11 @@ static int smp_execute_task(struct domain_device
*dev,
> void *req, int req_size,
>  		    task->task_status.stat == SAS_DATA_OVERRUN) {
>  			res = -EMSGSIZE;
>  			break;
> -		} else {
> +		}
> +		if (task->task_status.resp == SAS_TASK_UNDELIVERED &&
> +		    task->task_status.stat == SAS_DEVICE_UNKNOWN)
> +			break;
> +		else {
>  			SAS_DPRINTK("%s: task to dev %016llx response: 0x%x
"
>  				    "status 0x%x\n", __func__,
>  				    SAS_ADDR(dev->sas_addr),
> @@ -1648,8 +1652,8 @@ static int sas_get_phy_change_count(struct
> domain_device *dev,
>  	return res;
>  }
> 
> -static int sas_get_phy_attached_sas_addr(struct domain_device *dev,
> -					 int phy_id, u8 *attached_sas_addr)
> +int sas_get_phy_attached_sas_addr(struct domain_device *dev, int phy_id,
> +				  u8 *attached_sas_addr)
>  {
>  	int res;
>  	struct smp_resp *disc_resp;
> diff --git a/drivers/scsi/libsas/sas_internal.h
> b/drivers/scsi/libsas/sas_internal.h
> index 5879e72..dde4f29 100644
> --- a/drivers/scsi/libsas/sas_internal.h
> +++ b/drivers/scsi/libsas/sas_internal.h
> @@ -74,7 +74,8 @@ int sas_smp_get_phy_events(struct sas_phy *phy);
> 
>  struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
>  struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int
> phy_id);
> -
> +int sas_get_phy_attached_sas_addr(struct domain_device *dev, int phy_id,
> +				  u8 *attached_sas_addr);
>  void sas_hae_reset(struct work_struct *work);
> 
>  void sas_free_device(struct kref *kref);
> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
> index a8159f9..42110f9 100644
> --- a/include/scsi/libsas.h
> +++ b/include/scsi/libsas.h
> @@ -605,6 +605,7 @@ struct sas_domain_function_template {
>  	int (*lldd_clear_task_set)(struct domain_device *, u8 *lun);
>  	int (*lldd_I_T_nexus_reset)(struct domain_device *);
>  	int (*lldd_ata_soft_reset)(struct domain_device *);
> +	int (*lldd_ata_check_ready)(struct domain_device *);
>  	void (*lldd_ata_set_dmamode)(struct domain_device *);
>  	int (*lldd_lu_reset)(struct domain_device *, u8 *lun);
>  	int (*lldd_query_task)(struct sas_task *);
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

On Mon, Dec 19, 2011 at 10:18 PM, Jack Wang <jack_wang@usish.com> wrote:
> I test the patchset ,it works ok.
> You can add my tested-by if needed.
>
> Jack
>

Thank you Jack.

Very much appreciated.

I will need to refresh the patches to address Tejun's comments about
drain_workqueue(), I'll get them re-posted shortly.
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html