[SCSI] libsas: fix deref before check in commit 70b25f890ce

commit 70b25f890ce9f0520c64075ce9225a5b020a513e
Author: Tejun Heo <tj@kernel.org>
Date:   Thu Apr 15 09:00:08 2010 +0900

    [SCSI] fix locking around blk_abort_request()

Introduced a reference before check problem, fix this by moving the
lock shorthand code to be right at the point of actual use.

Reported-by: Dan Carpenter <error27@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Cc: Stable Tree <stable@kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

2 files changed, 11 insertions, 10 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 88f744672576..8c496b56556c 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -395,12 +395,13 @@ int sas_ata_init_host_and_port(struct domain_device *found_dev,
 void sas_ata_task_abort(struct sas_task *task)
 {
         struct ata_queued_cmd *qc = task->uldd_task;
-        struct request_queue *q = qc->scsicmd->device->request_queue;
         struct completion *waiting;
-        unsigned long flags;
 
         /* Bounce SCSI-initiated commands to the SCSI EH */
         if (qc->scsicmd) {
+                struct request_queue *q = qc->scsicmd->device->request_queue;
+                unsigned long flags;
+
                 spin_lock_irqsave(q->queue_lock, flags);
                 blk_abort_request(qc->scsicmd->request);
                 spin_unlock_irqrestore(q->queue_lock, flags);
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 822835055cef..53849f21ad42 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -1030,8 +1030,6 @@ int __sas_task_abort(struct sas_task *task)
 void sas_task_abort(struct sas_task *task)
 {
         struct scsi_cmnd *sc = task->uldd_task;
-        struct request_queue *q = sc->device->request_queue;
-        unsigned long flags;
 
         /* Escape for libsas internal commands */
         if (!sc) {
@@ -1043,13 +1041,15 @@ void sas_task_abort(struct sas_task *task)
 
         if (dev_is_sata(task->dev)) {
                 sas_ata_task_abort(task);
-                return;
-        }
+        } else {
+                struct request_queue *q = sc->device->request_queue;
+                unsigned long flags;
 
-        spin_lock_irqsave(q->queue_lock, flags);
-        blk_abort_request(sc->request);
-        spin_unlock_irqrestore(q->queue_lock, flags);
-        scsi_schedule_eh(sc->device->host);
+                spin_lock_irqsave(q->queue_lock, flags);
+                blk_abort_request(sc->request);
+                spin_unlock_irqrestore(q->queue_lock, flags);
+                scsi_schedule_eh(sc->device->host);
+        }
 }
 
 int sas_slave_alloc(struct scsi_device *scsi_dev)