Commit 36a39947 authored by Dan Williams's avatar Dan Williams Committed by James Bottomley
Browse files

[SCSI] 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.

Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarJames Bottomley <JBottomley@Parallels.com>
parent 50824d6c

drivers/scsi/libsas/sas_ata.c

+73 −31
Original line number Diff line number Diff line
@@ -272,39 +272,84 @@ static bool sas_ata_qc_fill_rtf(struct ata_queued_cmd *qc) 
	return true;

}



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 domain_device *ex_dev = dev->parent;

	struct sas_phy *phy = sas_find_local_phy(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;

}



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_internal *i =

		to_sas_internal(dev->port->ha->core.shost->transportt);

	int res = TMF_RESP_FUNC_FAILED;

	int ret = 0;

	struct sas_phy *phy = sas_find_local_phy(dev);

	struct sas_internal *i = dev_to_sas_internal(dev);



	if (i->dft->lldd_I_T_nexus_reset)

	res = i->dft->lldd_I_T_nexus_reset(dev);



	if (res != TMF_RESP_FUNC_COMPLETE) {

		SAS_DPRINTK("%s: Unable to reset I T nexus?\n", __func__);

		ret = -EAGAIN;

	}

	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;

	}



	ap->cbl = ATA_CBL_SATA;
@@ -316,8 +361,7 @@ 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;
@@ -355,8 +399,7 @@ 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;
@@ -425,8 +468,7 @@ 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);

drivers/scsi/libsas/sas_expander.c

+7 −3
Original line number Diff line number Diff line
@@ -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;

drivers/scsi/libsas/sas_internal.h

+2 −1
Original line number Diff line number Diff line
@@ -89,7 +89,8 @@ 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);

include/scsi/libsas.h

+1 −0
Original line number Diff line number Diff line
@@ -615,6 +615,7 @@ 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 *);

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