1 files changed, 41 insertions, 24 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1344553afe70..621d841d819a 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1153,6 +1153,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 	cmd->sense_buffer = buf;
 	cmd->prot_sdb = prot;
 	cmd->flags = flags;
+	INIT_LIST_HEAD(&cmd->eh_entry);
 	INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
 	cmd->jiffies_at_alloc = jiffies_at_alloc;
 	cmd->retries = retries;
@@ -1184,8 +1185,6 @@ static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
 	}
 
 	cmd->cmd_len = scsi_req(req)->cmd_len;
-	if (cmd->cmd_len == 0)
-		cmd->cmd_len = scsi_command_size(cmd->cmnd);
 	cmd->cmnd = scsi_req(req)->cmd;
 	cmd->transfersize = blk_rq_bytes(req);
 	cmd->allowed = scsi_req(req)->retries;
@@ -2665,6 +2664,40 @@ scsi_target_resume(struct scsi_target *starget)
 }
 EXPORT_SYMBOL(scsi_target_resume);
 
+static int __scsi_internal_device_block_nowait(struct scsi_device *sdev)
+{
+	if (scsi_device_set_state(sdev, SDEV_BLOCK))
+		return scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
+
+	return 0;
+}
+
+void scsi_start_queue(struct scsi_device *sdev)
+{
+	if (cmpxchg(&sdev->queue_stopped, 1, 0))
+		blk_mq_unquiesce_queue(sdev->request_queue);
+}
+
+static void scsi_stop_queue(struct scsi_device *sdev, bool nowait)
+{
+	/*
+	 * The atomic variable of ->queue_stopped covers that
+	 * blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue.
+	 *
+	 * However, we still need to wait until quiesce is done
+	 * in case that queue has been stopped.
+	 */
+	if (!cmpxchg(&sdev->queue_stopped, 0, 1)) {
+		if (nowait)
+			blk_mq_quiesce_queue_nowait(sdev->request_queue);
+		else
+			blk_mq_quiesce_queue(sdev->request_queue);
+	} else {
+		if (!nowait)
+			blk_mq_wait_quiesce_done(sdev->request_queue);
+	}
+}
+
 /**
  * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
  * @sdev: device to block
@@ -2681,24 +2714,16 @@ EXPORT_SYMBOL(scsi_target_resume);
  */
 int scsi_internal_device_block_nowait(struct scsi_device *sdev)
 {
-	struct request_queue *q = sdev->request_queue;
-	int err = 0;
-
-	err = scsi_device_set_state(sdev, SDEV_BLOCK);
-	if (err) {
-		err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK);
-
-		if (err)
-			return err;
-	}
+	int ret = __scsi_internal_device_block_nowait(sdev);
 
 	/*
 	 * The device has transitioned to SDEV_BLOCK.  Stop the
 	 * block layer from calling the midlayer with this device's
 	 * request queue.
 	 */
-	blk_mq_quiesce_queue_nowait(q);
-	return 0;
+	if (!ret)
+		scsi_stop_queue(sdev, true);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
 
@@ -2719,25 +2744,17 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
  */
 static int scsi_internal_device_block(struct scsi_device *sdev)
 {
-	struct request_queue *q = sdev->request_queue;
 	int err;
 
 	mutex_lock(&sdev->state_mutex);
-	err = scsi_internal_device_block_nowait(sdev);
+	err = __scsi_internal_device_block_nowait(sdev);
 	if (err == 0)
-		blk_mq_quiesce_queue(q);
+		scsi_stop_queue(sdev, false);
 	mutex_unlock(&sdev->state_mutex);
 
 	return err;
 }
 
-void scsi_start_queue(struct scsi_device *sdev)
-{
-	struct request_queue *q = sdev->request_queue;
-
-	blk_mq_unquiesce_queue(q);
-}
-
 /**
  * scsi_internal_device_unblock_nowait - resume a device after a block request
  * @sdev:	device to resume