[SCSI] fix locking around blk_abort_request()

blk_abort_request() expects queue lock to be held by the caller.
Grab it before calling the function.

Lack of this synchronization led to infinite loop on corrupt
q->timeout_list.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 2660e1b4569a..822835055cef 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -1030,6 +1030,8 @@ 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) {
@@ -1044,7 +1046,9 @@ void sas_task_abort(struct sas_task *task)
                 return;
         }
 
+        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);
 }