[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: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 4beca66728b47c9d72eb59d74f4757589c8c8522..5fdb63ad94b7564d84cfb979c59e2f23ae7bfa96 100644 (file)
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -272,39 +272,84 @@ 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;
@@ -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);

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 7c59f97c02872d127a6e8ba0ad7e705bceec8b00..32e417e6c2f7e2099cd9c6f6fbfba8c56242de94 100644 (file)
--- 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 9e960b2d535ad6140162feb2d4489bcbc2fb23ce..a9a3bb94c1bcb4263d9d599201052432a87c2b45 100644 (file)
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -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);

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 18704a2e4f071a538924eccf6ff87ab3bfcd4430..2079b18467a14f85ee120d17c7aca7dfcbac0dd0 100644 (file)
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -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 *);