1 files changed, 73 insertions, 64 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 0226c9279cef..ad9afae49544 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -122,11 +122,9 @@ static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd, unsigned long msecs)
 		WARN_ON_ONCE(true);
 	}
 
-	if (msecs) {
-		blk_mq_requeue_request(rq, false);
+	blk_mq_requeue_request(rq, false);
+	if (!scsi_host_in_recovery(cmd->device->host))
 		blk_mq_delay_kick_requeue_list(rq->q, msecs);
-	} else
-		blk_mq_requeue_request(rq, true);
 }
 
 /**
@@ -165,7 +163,8 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
 	 */
 	cmd->result = 0;
 
-	blk_mq_requeue_request(scsi_cmd_to_rq(cmd), true);
+	blk_mq_requeue_request(scsi_cmd_to_rq(cmd),
+			       !scsi_host_in_recovery(cmd->device->host));
 }
 
 /**
@@ -453,6 +452,7 @@ static void scsi_run_queue(struct request_queue *q)
 	if (!list_empty(&sdev->host->starved_list))
 		scsi_starved_list_run(sdev->host);
 
+	blk_mq_kick_requeue_list(q);
 	blk_mq_run_hw_queues(q, false);
 }
 
@@ -503,6 +503,9 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
 
 static void scsi_run_queue_async(struct scsi_device *sdev)
 {
+	if (scsi_host_in_recovery(sdev->host))
+		return;
+
 	if (scsi_target(sdev)->single_lun ||
 	    !list_empty(&sdev->host->starved_list)) {
 		kblockd_schedule_work(&sdev->requeue_work);
@@ -578,11 +581,6 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
 	return false;
 }
 
-static inline u8 get_scsi_ml_byte(int result)
-{
-	return (result >> 8) & 0xff;
-}
-
 /**
  * scsi_result_to_blk_status - translate a SCSI result code into blk_status_t
  * @result:	scsi error code
@@ -595,17 +593,19 @@ static blk_status_t scsi_result_to_blk_status(int result)
 	 * Check the scsi-ml byte first in case we converted a host or status
 	 * byte.
 	 */
-	switch (get_scsi_ml_byte(result)) {
+	switch (scsi_ml_byte(result)) {
 	case SCSIML_STAT_OK:
 		break;
 	case SCSIML_STAT_RESV_CONFLICT:
-		return BLK_STS_NEXUS;
+		return BLK_STS_RESV_CONFLICT;
 	case SCSIML_STAT_NOSPC:
 		return BLK_STS_NOSPC;
 	case SCSIML_STAT_MED_ERROR:
 		return BLK_STS_MEDIUM;
 	case SCSIML_STAT_TGT_FAILURE:
 		return BLK_STS_TARGET;
+	case SCSIML_STAT_DL_TIMEOUT:
+		return BLK_STS_DURATION_LIMIT;
 	}
 
 	switch (host_byte(result)) {
@@ -803,6 +803,8 @@ static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
 				blk_stat = BLK_STS_ZONE_OPEN_RESOURCE;
 			}
 			break;
+		case COMPLETED:
+			fallthrough;
 		default:
 			action = ACTION_FAIL;
 			break;
@@ -1985,6 +1987,8 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost)
 	tag_set->flags = BLK_MQ_F_SHOULD_MERGE;
 	tag_set->flags |=
 		BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);
+	if (shost->queuecommand_may_block)
+		tag_set->flags |= BLK_MQ_F_BLOCKING;
 	tag_set->driver_data = shost;
 	if (shost->host_tagset)
 		tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED;
@@ -2152,6 +2156,7 @@ EXPORT_SYMBOL_GPL(scsi_mode_select);
  *	@sdev:	SCSI device to be queried
  *	@dbd:	set to prevent mode sense from returning block descriptors
  *	@modepage: mode page being requested
+ *	@subpage: sub-page of the mode page being requested
  *	@buffer: request buffer (may not be smaller than eight bytes)
  *	@len:	length of request buffer.
  *	@timeout: command timeout
@@ -2163,7 +2168,7 @@ EXPORT_SYMBOL_GPL(scsi_mode_select);
  *	Returns zero if successful, or a negative error number on failure
  */
 int
-scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
+scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage,
 		  unsigned char *buffer, int len, int timeout, int retries,
 		  struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr)
 {
@@ -2183,6 +2188,7 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage,
 	dbd = sdev->set_dbd_for_ms ? 8 : dbd;
 	cmd[1] = dbd & 0x18;	/* allows DBD and LLBA bits */
 	cmd[2] = modepage;
+	cmd[3] = subpage;
 
 	sshdr = exec_args.sshdr;
 
@@ -2728,24 +2734,16 @@ void scsi_start_queue(struct scsi_device *sdev)
 		blk_mq_unquiesce_queue(sdev->request_queue);
 }
 
-static void scsi_stop_queue(struct scsi_device *sdev, bool nowait)
+static void scsi_stop_queue(struct scsi_device *sdev)
 {
 	/*
 	 * 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.
+	 * The caller needs to wait until quiesce is done.
 	 */
-	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->tag_set);
-	}
+	if (!cmpxchg(&sdev->queue_stopped, 0, 1))
+		blk_mq_quiesce_queue_nowait(sdev->request_queue);
 }
 
 /**
@@ -2772,19 +2770,19 @@ int scsi_internal_device_block_nowait(struct scsi_device *sdev)
 	 * request queue.
 	 */
 	if (!ret)
-		scsi_stop_queue(sdev, true);
+		scsi_stop_queue(sdev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
 
 /**
- * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
+ * scsi_device_block - try to transition to the SDEV_BLOCK state
  * @sdev: device to block
+ * @data: dummy argument, ignored
  *
- * Pause SCSI command processing on the specified device and wait until all
- * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
- *
- * Returns zero if successful or a negative error code upon failure.
+ * Pause SCSI command processing on the specified device. Callers must wait
+ * until all ongoing scsi_queue_rq() calls have finished after this function
+ * returns.
  *
  * Note:
  * This routine transitions the device to the SDEV_BLOCK state (which must be
@@ -2792,17 +2790,26 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
  * is paused until the device leaves the SDEV_BLOCK state. See also
  * scsi_internal_device_unblock().
  */
-static int scsi_internal_device_block(struct scsi_device *sdev)
+static void scsi_device_block(struct scsi_device *sdev, void *data)
 {
 	int err;
+	enum scsi_device_state state;
 
 	mutex_lock(&sdev->state_mutex);
 	err = __scsi_internal_device_block_nowait(sdev);
+	state = sdev->sdev_state;
 	if (err == 0)
-		scsi_stop_queue(sdev, false);
+		/*
+		 * scsi_stop_queue() must be called with the state_mutex
+		 * held. Otherwise a simultaneous scsi_start_queue() call
+		 * might unquiesce the queue before we quiesce it.
+		 */
+		scsi_stop_queue(sdev);
+
 	mutex_unlock(&sdev->state_mutex);
 
-	return err;
+	WARN_ONCE(err, "%s: failed to block %s in state %d\n",
+		  __func__, dev_name(&sdev->sdev_gendev), state);
 }
 
 /**
@@ -2885,36 +2892,35 @@ static int scsi_internal_device_unblock(struct scsi_device *sdev,
 	return ret;
 }
 
-static void
-device_block(struct scsi_device *sdev, void *data)
-{
-	int ret;
-
-	ret = scsi_internal_device_block(sdev);
-
-	WARN_ONCE(ret, "scsi_internal_device_block(%s) failed: ret = %d\n",
-		  dev_name(&sdev->sdev_gendev), ret);
-}
-
 static int
 target_block(struct device *dev, void *data)
 {
 	if (scsi_is_target_device(dev))
 		starget_for_each_device(to_scsi_target(dev), NULL,
-					device_block);
+					scsi_device_block);
 	return 0;
 }
 
+/**
+ * scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state
+ * @dev: a parent device of one or more scsi_target devices
+ * @shost: the Scsi_Host to which this device belongs
+ *
+ * Iterate over all children of @dev, which should be scsi_target devices,
+ * and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for
+ * ongoing scsi_queue_rq() calls to finish. May sleep.
+ *
+ * Note:
+ * @dev must not itself be a scsi_target device.
+ */
 void
-scsi_target_block(struct device *dev)
+scsi_block_targets(struct Scsi_Host *shost, struct device *dev)
 {
-	if (scsi_is_target_device(dev))
-		starget_for_each_device(to_scsi_target(dev), NULL,
-					device_block);
-	else
-		device_for_each_child(dev, NULL, target_block);
+	WARN_ON_ONCE(scsi_is_target_device(dev));
+	device_for_each_child(dev, NULL, target_block);
+	blk_mq_wait_quiesce_done(&shost->tag_set);
 }
-EXPORT_SYMBOL_GPL(scsi_target_block);
+EXPORT_SYMBOL_GPL(scsi_block_targets);
 
 static void
 device_unblock(struct scsi_device *sdev, void *data)
@@ -2942,11 +2948,20 @@ scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
 }
 EXPORT_SYMBOL_GPL(scsi_target_unblock);
 
+/**
+ * scsi_host_block - Try to transition all logical units to the SDEV_BLOCK state
+ * @shost: device to block
+ *
+ * Pause SCSI command processing for all logical units associated with the SCSI
+ * host and wait until pending scsi_queue_rq() calls have finished.
+ *
+ * Returns zero if successful or a negative error code upon failure.
+ */
 int
 scsi_host_block(struct Scsi_Host *shost)
 {
 	struct scsi_device *sdev;
-	int ret = 0;
+	int ret;
 
 	/*
 	 * Call scsi_internal_device_block_nowait so we can avoid
@@ -2958,20 +2973,14 @@ scsi_host_block(struct Scsi_Host *shost)
 		mutex_unlock(&sdev->state_mutex);
 		if (ret) {
 			scsi_device_put(sdev);
-			break;
+			return ret;
 		}
 	}
 
-	/*
-	 * SCSI never enables blk-mq's BLK_MQ_F_BLOCKING flag so
-	 * calling synchronize_rcu() once is enough.
-	 */
-	WARN_ON_ONCE(shost->tag_set.flags & BLK_MQ_F_BLOCKING);
-
-	if (!ret)
-		synchronize_rcu();
+	/* Wait for ongoing scsi_queue_rq() calls to finish. */
+	blk_mq_wait_quiesce_done(&shost->tag_set);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(scsi_host_block);