8 files changed, 158 insertions, 16 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 2fc5a3961ca6..4b6365c6410f 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -758,6 +758,35 @@ static int sas_discover_sata_pm(struct domain_device *dev)
         return -ENODEV;
 }
 
+void sas_probe_sata(struct work_struct *work)
+{
+        struct domain_device *dev, *n;
+        struct sas_discovery_event *ev =
+                container_of(work, struct sas_discovery_event, work);
+        struct asd_sas_port *port = ev->port;
+
+        clear_bit(DISCE_PROBE, &port->disc.pending);
+
+        list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node) {
+                int err;
+
+                spin_lock_irq(&port->dev_list_lock);
+                list_add_tail(&dev->dev_list_node, &port->dev_list);
+                spin_unlock_irq(&port->dev_list_lock);
+
+                err = sas_rphy_add(dev->rphy);
+
+                if (err) {
+                        SAS_DPRINTK("%s: for %s device %16llx returned %d\n",
+                                    __func__, dev->parent ? "exp-attached" :
+                                                            "direct-attached",
+                                    SAS_ADDR(dev->sas_addr), err);
+                        sas_unregister_dev(port, dev);
+                } else
+                        list_del_init(&dev->disco_list_node);
+        }
+}
+
 /**
  * sas_discover_sata -- discover an STP/SATA domain device
  * @dev: pointer to struct domain_device of interest
@@ -794,10 +823,15 @@ int sas_discover_sata(struct domain_device *dev)
                 break;
         }
         sas_notify_lldd_dev_gone(dev);
-        if (!res) {
-                sas_notify_lldd_dev_found(dev);
-                res = sas_rphy_add(dev->rphy);
-        }
+
+        if (res)
+                return res;
+
+        res = sas_notify_lldd_dev_found(dev);
+        if (res)
+                return res;
+
+        sas_discover_event(dev->port, DISCE_PROBE);
 
         return res;
 }
@@ -805,6 +839,17 @@ int sas_discover_sata(struct domain_device *dev)
 void sas_ata_strategy_handler(struct Scsi_Host *shost)
 {
         struct scsi_device *sdev;
+        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(shost);
+
+        /* it's ok to defer revalidation events during ata eh, these
+         * disks are in one of three states:
+         * 1/ present for initial domain discovery, and these
+         *    resets will cause bcn flutters
+         * 2/ hot removed, we'll discover that after eh fails
+         * 3/ hot added after initial discovery, lost the race, and need
+         *    to catch the next train.
+         */
+        sas_disable_revalidation(sas_ha);
 
         shost_for_each_device(sdev, shost) {
                 struct domain_device *ddev = sdev_to_domain_dev(sdev);
@@ -816,6 +861,8 @@ void sas_ata_strategy_handler(struct Scsi_Host *shost)
                 ata_port_printk(ap, KERN_DEBUG, "sas eh calling libata port error handler");
                 ata_scsi_port_error_handler(shost, ap);
         }
+
+        sas_enable_revalidation(sas_ha);
 }
 
 int sas_ata_timed_out(struct scsi_cmnd *cmd, struct sas_task *task,
diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 32e011766046..7e8fdcb202b7 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -148,9 +148,14 @@ static int sas_get_port_device(struct asd_sas_port *port)
         port->disc.max_level = 0;
 
         dev->rphy = rphy;
-        spin_lock_irq(&port->dev_list_lock);
-        list_add_tail(&dev->dev_list_node, &port->dev_list);
-        spin_unlock_irq(&port->dev_list_lock);
+
+        if (dev_is_sata(dev))
+                list_add_tail(&dev->disco_list_node, &port->disco_list);
+        else {
+                spin_lock_irq(&port->dev_list_lock);
+                list_add_tail(&dev->dev_list_node, &port->dev_list);
+                spin_unlock_irq(&port->dev_list_lock);
+        }
 
         return 0;
 }
@@ -255,14 +260,43 @@ static void sas_unregister_common_dev(struct asd_sas_port *port, struct domain_d
         sas_put_device(dev);
 }
 
-void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
+static void sas_destruct_devices(struct work_struct *work)
 {
-        if (dev->rphy) {
+        struct domain_device *dev, *n;
+        struct sas_discovery_event *ev =
+                container_of(work, struct sas_discovery_event, work);
+        struct asd_sas_port *port = ev->port;
+
+        clear_bit(DISCE_DESTRUCT, &port->disc.pending);
+
+        list_for_each_entry_safe(dev, n, &port->destroy_list, disco_list_node) {
+                list_del_init(&dev->disco_list_node);
+
                 sas_remove_children(&dev->rphy->dev);
                 sas_rphy_delete(dev->rphy);
                 dev->rphy = NULL;
+                sas_unregister_common_dev(port, dev);
+
+                sas_put_device(dev);
+        }
+}
+
+void sas_unregister_dev(struct asd_sas_port *port, struct domain_device *dev)
+{
+        if (!test_bit(SAS_DEV_DESTROY, &dev->state) &&
+            !list_empty(&dev->disco_list_node)) {
+                /* this rphy never saw sas_rphy_add */
+                list_del_init(&dev->disco_list_node);
+                sas_rphy_free(dev->rphy);
+                dev->rphy = NULL;
+                sas_unregister_common_dev(port, dev);
+        }
+
+        if (dev->rphy && !test_and_set_bit(SAS_DEV_DESTROY, &dev->state)) {
+                sas_rphy_unlink(dev->rphy);
+                list_move_tail(&dev->disco_list_node, &port->destroy_list);
+                sas_discover_event(dev->port, DISCE_DESTRUCT);
         }
-        sas_unregister_common_dev(port, dev);
 }
 
 void sas_unregister_domain_devices(struct asd_sas_port *port)
@@ -271,6 +305,8 @@ void sas_unregister_domain_devices(struct asd_sas_port *port)
 
         list_for_each_entry_safe_reverse(dev, n, &port->dev_list, dev_list_node)
                 sas_unregister_dev(port, dev);
+        list_for_each_entry_safe(dev, n, &port->disco_list, disco_list_node)
+                sas_unregister_dev(port, dev);
 
         port->port->rphy = NULL;
 
@@ -335,6 +371,7 @@ static void sas_discover_domain(struct work_struct *work)
                 sas_rphy_free(dev->rphy);
                 dev->rphy = NULL;
 
+                list_del_init(&dev->disco_list_node);
                 spin_lock_irq(&port->dev_list_lock);
                 list_del_init(&dev->dev_list_node);
                 spin_unlock_irq(&port->dev_list_lock);
@@ -353,16 +390,28 @@ static void sas_revalidate_domain(struct work_struct *work)
         struct sas_discovery_event *ev =
                 container_of(work, struct sas_discovery_event, work);
         struct asd_sas_port *port = ev->port;
+        struct sas_ha_struct *ha = port->ha;
+
+        /* prevent revalidation from finding sata links in recovery */
+        mutex_lock(&ha->disco_mutex);
+        if (test_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state)) {
+                SAS_DPRINTK("REVALIDATION DEFERRED on port %d, pid:%d\n",
+                            port->id, task_pid_nr(current));
+                goto out;
+        }
 
         clear_bit(DISCE_REVALIDATE_DOMAIN, &port->disc.pending);
 
         SAS_DPRINTK("REVALIDATING DOMAIN on port %d, pid:%d\n", port->id,
                     task_pid_nr(current));
+
         if (port->port_dev)
                 res = sas_ex_revalidate_domain(port->port_dev);
 
         SAS_DPRINTK("done REVALIDATING DOMAIN on port %d, pid:%d, res 0x%x\n",
                     port->id, task_pid_nr(current), res);
+ out:
+        mutex_unlock(&ha->disco_mutex);
 }
 
 /* ---------- Events ---------- */
@@ -414,6 +463,8 @@ void sas_init_disc(struct sas_discovery *disc, struct asd_sas_port *port)
         static const work_func_t sas_event_fns[DISC_NUM_EVENTS] = {
                 [DISCE_DISCOVER_DOMAIN] = sas_discover_domain,
                 [DISCE_REVALIDATE_DOMAIN] = sas_revalidate_domain,
+                [DISCE_PROBE] = sas_probe_sata,
+                [DISCE_DESTRUCT] = sas_destruct_devices,
         };
 
         disc->pending = 0;
diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index e5035aa4c2a6..933d757499b5 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -81,6 +81,32 @@ int sas_drain_work(struct sas_ha_struct *ha)
 }
 EXPORT_SYMBOL_GPL(sas_drain_work);
 
+void sas_disable_revalidation(struct sas_ha_struct *ha)
+{
+        mutex_lock(&ha->disco_mutex);
+        set_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state);
+        mutex_unlock(&ha->disco_mutex);
+}
+
+void sas_enable_revalidation(struct sas_ha_struct *ha)
+{
+        int i;
+
+        mutex_lock(&ha->disco_mutex);
+        clear_bit(SAS_HA_ATA_EH_ACTIVE, &ha->state);
+        for (i = 0; i < ha->num_phys; i++) {
+                struct asd_sas_port *port = ha->sas_port[i];
+                const int ev = DISCE_REVALIDATE_DOMAIN;
+                struct sas_discovery *d = &port->disc;
+
+                if (!test_and_clear_bit(ev, &d->pending))
+                        continue;
+
+                sas_queue_event(ev, &d->pending, &d->disc_work[ev].work, ha);
+        }
+        mutex_unlock(&ha->disco_mutex);
+}
+
 static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event)
 {
         BUG_ON(event >= HA_NUM_EVENTS);
diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index f33d0c9911c4..e45b259dac4c 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -704,9 +704,7 @@ static struct domain_device *sas_ex_discover_end_dev(
 
                 child->rphy = rphy;
 
-                spin_lock_irq(&parent->port->dev_list_lock);
-                list_add_tail(&child->dev_list_node, &parent->port->dev_list);
-                spin_unlock_irq(&parent->port->dev_list_lock);
+                list_add_tail(&child->disco_list_node, &parent->port->disco_list);
 
                 res = sas_discover_sata(child);
                 if (res) {
@@ -756,6 +754,7 @@ static struct domain_device *sas_ex_discover_end_dev(
         sas_rphy_free(child->rphy);
         child->rphy = NULL;
 
+        list_del(&child->disco_list_node);
         spin_lock_irq(&parent->port->dev_list_lock);
         list_del(&child->dev_list_node);
         spin_unlock_irq(&parent->port->dev_list_lock);
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index 572b943d7603..52cd11d76664 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -104,6 +104,7 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
 {
         int error = 0;
 
+        mutex_init(&sas_ha->disco_mutex);
         spin_lock_init(&sas_ha->phy_port_lock);
         sas_hash_addr(sas_ha->hashed_sas_addr, sas_ha->sas_addr);
 
@@ -168,6 +169,7 @@ int sas_unregister_ha(struct sas_ha_struct *sas_ha)
         sas_drain_work(sas_ha);
 
         sas_unregister_ports(sas_ha);
+        sas_drain_work(sas_ha);
 
         if (sas_ha->lldd_max_execute_num > 1) {
                 sas_shutdown_queue(sas_ha);
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 948ea64cc2eb..ebe9b81ddef5 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -56,6 +56,8 @@ enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *);
 int  sas_init_queue(struct sas_ha_struct *sas_ha);
 int  sas_init_events(struct sas_ha_struct *sas_ha);
 void sas_shutdown_queue(struct sas_ha_struct *sas_ha);
+void sas_disable_revalidation(struct sas_ha_struct *ha);
+void sas_enable_revalidation(struct sas_ha_struct *ha);
 
 void sas_deform_port(struct asd_sas_phy *phy, int gone);
 
@@ -138,6 +140,7 @@ static inline struct domain_device *sas_alloc_device(void)
         if (dev) {
                 INIT_LIST_HEAD(&dev->siblings);
                 INIT_LIST_HEAD(&dev->dev_list_node);
+                INIT_LIST_HEAD(&dev->disco_list_node);
                 kref_init(&dev->kref);
         }
         return dev;
diff --git a/drivers/scsi/libsas/sas_port.c b/drivers/scsi/libsas/sas_port.c
index d88e55f9732b..2980bde4e34a 100644
--- a/drivers/scsi/libsas/sas_port.c
+++ b/drivers/scsi/libsas/sas_port.c
@@ -277,6 +277,8 @@ static void sas_init_port(struct asd_sas_port *port,
         memset(port, 0, sizeof(*port));
         port->id = i;
         INIT_LIST_HEAD(&port->dev_list);
+        INIT_LIST_HEAD(&port->disco_list);
+        INIT_LIST_HEAD(&port->destroy_list);
         spin_lock_init(&port->phy_list_lock);
         INIT_LIST_HEAD(&port->phy_list);
         port->ha = sas_ha;
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 9d9330ae4213..9421bae8af1a 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -1603,6 +1603,20 @@ sas_rphy_delete(struct sas_rphy *rphy)
 EXPORT_SYMBOL(sas_rphy_delete);
 
 /**
+ * sas_rphy_unlink  -  unlink SAS remote PHY
+ * @rphy:       SAS remote phy to unlink from its parent port
+ *
+ * Removes port reference to an rphy
+ */
+void sas_rphy_unlink(struct sas_rphy *rphy)
+{
+        struct sas_port *parent = dev_to_sas_port(rphy->dev.parent);
+
+        parent->rphy = NULL;
+}
+EXPORT_SYMBOL(sas_rphy_unlink);
+
+/**
  * sas_rphy_remove  -  remove SAS remote PHY
  * @rphy:       SAS remote phy to remove
  *
@@ -1612,7 +1626,6 @@ void
 sas_rphy_remove(struct sas_rphy *rphy)
 {
         struct device *dev = &rphy->dev;
-        struct sas_port *parent = dev_to_sas_port(dev->parent);
 
         switch (rphy->identify.device_type) {
         case SAS_END_DEVICE:
@@ -1626,10 +1639,9 @@ sas_rphy_remove(struct sas_rphy *rphy)
                 break;
         }
 
+        sas_rphy_unlink(rphy);
         transport_remove_device(dev);
         device_del(dev);
-
-        parent->rphy = NULL;
 }
 EXPORT_SYMBOL(sas_rphy_remove);