[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>

diff --git a/drivers/scsi/pm8001/pm8001_hwi.c b/drivers/scsi/pm8001/pm8001_hwi.c
index a3de306b9045486985c4ed4ccaf9d3b543ea122f..68695b72e1eff6efff380feedf2b29eb6d3f8a5f 100644 (file)
--- 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);
        }
 }