[SCSI] libsas: Add SAS_HA state flags to avoid queueing events while unloading

Track sas_ha_struct state so that we ignore events that come in while
we're shutting things down.

Signed-off-by: Malahal Naineni <malahal@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

5 files changed, 31 insertions, 6 deletions

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 21f538e4a0b5..b6ba0e053d1a 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -753,7 +753,7 @@ int sas_discover_event(struct asd_sas_port *port, enum discover_event ev)
         BUG_ON(ev >= DISC_NUM_EVENTS);
 
         sas_queue_event(ev, &disc->disc_event_lock, &disc->pending,
-                        &disc->disc_work[ev].work, port->ha->core.shost);
+                        &disc->disc_work[ev].work, port->ha);
 
         return 0;
 }
diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index d83392ee6823..9db30fb5caf2 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -31,7 +31,7 @@ static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event)
         BUG_ON(event >= HA_NUM_EVENTS);
 
         sas_queue_event(event, &sas_ha->event_lock, &sas_ha->pending,
-                        &sas_ha->ha_events[event].work, sas_ha->core.shost);
+                        &sas_ha->ha_events[event].work, sas_ha);
 }
 
 static void notify_port_event(struct asd_sas_phy *phy, enum port_event event)
@@ -41,7 +41,7 @@ static void notify_port_event(struct asd_sas_phy *phy, enum port_event event)
         BUG_ON(event >= PORT_NUM_EVENTS);
 
         sas_queue_event(event, &ha->event_lock, &phy->port_events_pending,
-                        &phy->port_events[event].work, ha->core.shost);
+                        &phy->port_events[event].work, ha);
 }
 
 static void notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
@@ -51,7 +51,7 @@ static void notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
         BUG_ON(event >= PHY_NUM_EVENTS);
 
         sas_queue_event(event, &ha->event_lock, &phy->phy_events_pending,
-                        &phy->phy_events[event].work, ha->core.shost);
+                        &phy->phy_events[event].work, ha);
 }
 
 int sas_init_events(struct sas_ha_struct *sas_ha)
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index 4df73d69bb3c..965698c8b7bf 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -87,6 +87,9 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
         else if (sas_ha->lldd_queue_size == -1)
                 sas_ha->lldd_queue_size = 128; /* Sanity */
 
+        sas_ha->state = SAS_HA_REGISTERED;
+        spin_lock_init(&sas_ha->state_lock);
+
         error = sas_register_phys(sas_ha);
         if (error) {
                 printk(KERN_NOTICE "couldn't register sas phys:%d\n", error);
@@ -127,6 +130,15 @@ Undo_phys:
 
 int sas_unregister_ha(struct sas_ha_struct *sas_ha)
 {
+        unsigned long flags;
+
+        /* Set the state to unregistered to avoid further
+         * events to be queued */
+        spin_lock_irqsave(&sas_ha->state_lock, flags);
+        sas_ha->state = SAS_HA_UNREGISTERED;
+        spin_unlock_irqrestore(&sas_ha->state_lock, flags);
+        scsi_flush_work(sas_ha->core.shost);
+
         sas_unregister_ports(sas_ha);
 
         if (sas_ha->lldd_max_execute_num > 1) {
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 137d7e496b6d..a78638df2018 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -80,7 +80,7 @@ void sas_hae_reset(struct work_struct *work);
 static inline void sas_queue_event(int event, spinlock_t *lock,
                                    unsigned long *pending,
                                    struct work_struct *work,
-                                   struct Scsi_Host *shost)
+                                   struct sas_ha_struct *sas_ha)
 {
         unsigned long flags;
 
@@ -91,7 +91,12 @@ static inline void sas_queue_event(int event, spinlock_t *lock,
         }
         __set_bit(event, pending);
         spin_unlock_irqrestore(lock, flags);
-        scsi_queue_work(shost, work);
+
+        spin_lock_irqsave(&sas_ha->state_lock, flags);
+        if (sas_ha->state != SAS_HA_UNREGISTERED) {
+                scsi_queue_work(sas_ha->core.shost, work);
+        }
+        spin_unlock_irqrestore(&sas_ha->state_lock, flags);
 }
 
 static inline void sas_begin_event(int event, spinlock_t *lock,
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index c83426344e8f..ca393929c10b 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -323,12 +323,20 @@ struct sas_ha_event {
         struct sas_ha_struct *ha;
 };
 
+enum sas_ha_state {
+        SAS_HA_REGISTERED,
+        SAS_HA_UNREGISTERED
+};
+
 struct sas_ha_struct {
 /* private: */
         spinlock_t       event_lock;
         struct sas_ha_event ha_events[HA_NUM_EVENTS];
         unsigned long    pending;
 
+        enum sas_ha_state state;
+        spinlock_t        state_lock;
+
         struct scsi_core core;
 
 /* public: */