[SCSI] pm8001: Fix for sata io circular lock dependency.

This patch fix for sata IO circular lock dependency. When we call task_done
for SATA IO, we have got pm8001_ha->lock ,and in sas_ata_task_done, it will
get (dev->sata_dev.ap->lock. then cause circular lock dependency .So we
should drop pm8001_ha->lock when we call task_done for SATA task.

Signed-off-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Lindar Liu <lindar_liu@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 35 insertions, 5 deletions

diff --git a/drivers/scsi/pm8001/pm8001_hwi.c b/drivers/scsi/pm8001/pm8001_hwi.c
index a3de306b9045..68695b72e1ef 100644
--- a/drivers/scsi/pm8001/pm8001_hwi.c
+++ b/drivers/scsi/pm8001/pm8001_hwi.c
@@ -1901,7 +1901,7 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
 {
         struct sas_task *t;
         struct pm8001_ccb_info *ccb;
-        unsigned long flags;
+        unsigned long flags = 0;
         u32 param;
         u32 status;
         u32 tag;
@@ -2040,7 +2040,9 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
                         ts->stat = SAS_QUEUE_FULL;
                         pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                         mb();/*in order to force CPU ordering*/
+                        spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                         t->task_done(t);
+                        spin_lock_irqsave(&pm8001_ha->lock, flags);
                         return;
                 }
                 break;
@@ -2058,7 +2060,9 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
                         ts->stat = SAS_QUEUE_FULL;
                         pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                         mb();/*ditto*/
+                        spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                         t->task_done(t);
+                        spin_lock_irqsave(&pm8001_ha->lock, flags);
                         return;
                 }
                 break;
@@ -2084,7 +2088,9 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
                         ts->stat = SAS_QUEUE_FULL;
                         pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                         mb();/* ditto*/
+                        spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                         t->task_done(t);
+                        spin_lock_irqsave(&pm8001_ha->lock, flags);
                         return;
                 }
                 break;
@@ -2149,7 +2155,9 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
                         ts->stat = SAS_QUEUE_FULL;
                         pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                         mb();/*ditto*/
+                        spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                         t->task_done(t);
+                        spin_lock_irqsave(&pm8001_ha->lock, flags);
                         return;
                 }
                 break;
@@ -2171,7 +2179,9 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
                         ts->stat = SAS_QUEUE_FULL;
                         pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                         mb();/*ditto*/
+                        spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                         t->task_done(t);
+                        spin_lock_irqsave(&pm8001_ha->lock, flags);
                         return;
                 }
                 break;
@@ -2200,11 +2210,20 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
                         " resp 0x%x stat 0x%x but aborted by upper layer!\n",
                         t, status, ts->resp, ts->stat));
                 pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
-        } else {
+        } else if (t->uldd_task) {
                 spin_unlock_irqrestore(&t->task_state_lock, flags);
                 pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                 mb();/* ditto */
+                spin_unlock_irqrestore(&pm8001_ha->lock, flags);
+                t->task_done(t);
+                spin_lock_irqsave(&pm8001_ha->lock, flags);
+        } else if (!t->uldd_task) {
+                spin_unlock_irqrestore(&t->task_state_lock, flags);
+                pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
+                mb();/*ditto*/
+                spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                 t->task_done(t);
+                spin_lock_irqsave(&pm8001_ha->lock, flags);
         }
 }
 
@@ -2212,7 +2231,7 @@ mpi_sata_completion(struct pm8001_hba_info *pm8001_ha, void *piomb)
 static void mpi_sata_event(struct pm8001_hba_info *pm8001_ha , void *piomb)
 {
         struct sas_task *t;
-        unsigned long flags;
+        unsigned long flags = 0;
         struct task_status_struct *ts;
         struct pm8001_ccb_info *ccb;
         struct pm8001_device *pm8001_dev;
@@ -2292,7 +2311,9 @@ static void mpi_sata_event(struct pm8001_hba_info *pm8001_ha , void *piomb)
                         ts->stat = SAS_QUEUE_FULL;
                         pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
                         mb();/*ditto*/
+                        spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                         t->task_done(t);
+                        spin_lock_irqsave(&pm8001_ha->lock, flags);
                         return;
                 }
                 break;
@@ -2401,11 +2422,20 @@ static void mpi_sata_event(struct pm8001_hba_info *pm8001_ha , void *piomb)
                         " resp 0x%x stat 0x%x but aborted by upper layer!\n",
                         t, event, ts->resp, ts->stat));
                 pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
-        } else {
+        } else if (t->uldd_task) {
                 spin_unlock_irqrestore(&t->task_state_lock, flags);
                 pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
-                mb();/* in order to force CPU ordering */
+                mb();/* ditto */
+                spin_unlock_irqrestore(&pm8001_ha->lock, flags);
+                t->task_done(t);
+                spin_lock_irqsave(&pm8001_ha->lock, flags);
+        } else if (!t->uldd_task) {
+                spin_unlock_irqrestore(&t->task_state_lock, flags);
+                pm8001_ccb_task_free(pm8001_ha, t, ccb, tag);
+                mb();/*ditto*/
+                spin_unlock_irqrestore(&pm8001_ha->lock, flags);
                 t->task_done(t);
+                spin_lock_irqsave(&pm8001_ha->lock, flags);
         }
 }