1 files changed, 54 insertions, 18 deletions

diff --git a/block/blk-exec.c b/block/blk-exec.c
index 9bceff7674f..f4d27b12c90 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -5,6 +5,8 @@
 #include <linux/module.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/blk-mq.h>
+#include <linux/sched/sysctl.h>
 
 #include "blk.h"
 
@@ -16,14 +18,13 @@
 /**
  * blk_end_sync_rq - executes a completion event on a request
  * @rq: request to complete
- * @error: end io status of the request
+ * @error: end I/O status of the request
  */
 static void blk_end_sync_rq(struct request *rq, int error)
 {
 	struct completion *waiting = rq->end_io_data;
 
 	rq->end_io_data = NULL;
-	__blk_put_request(rq->q, rq);
 
 	/*
 	 * complete last, if this is a stack request the process (and thus
@@ -41,25 +42,54 @@ static void blk_end_sync_rq(struct request *rq, int error)
  * @done:	I/O completion handler
  *
  * Description:
- *    Insert a fully prepared request at the back of the io scheduler queue
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution.  Don't wait for completion.
+ *
+ * Note:
+ *    This function will invoke @done directly if the queue is dead.
  */
 void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 			   struct request *rq, int at_head,
 			   rq_end_io_fn *done)
 {
 	int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+	bool is_pm_resume;
+
+	WARN_ON(irqs_disabled());
 
 	rq->rq_disk = bd_disk;
-	rq->cmd_flags |= REQ_NOMERGE;
 	rq->end_io = done;
-	WARN_ON(irqs_disabled());
+
+	/*
+	 * don't check dying flag for MQ because the request won't
+	 * be resued after dying flag is set
+	 */
+	if (q->mq_ops) {
+		blk_mq_insert_request(rq, at_head, true, false);
+		return;
+	}
+
+	/*
+	 * need to check this before __blk_run_queue(), because rq can
+	 * be freed before that returns.
+	 */
+	is_pm_resume = rq->cmd_type == REQ_TYPE_PM_RESUME;
+
 	spin_lock_irq(q->queue_lock);
-	__elv_add_request(q, rq, where, 1);
-	__generic_unplug_device(q);
-	/* the queue is stopped so it won't be plugged+unplugged */
-	if (blk_pm_resume_request(rq))
-		q->request_fn(q);
+
+	if (unlikely(blk_queue_dying(q))) {
+		rq->cmd_flags |= REQ_QUIET; 
+		rq->errors = -ENXIO;
+		__blk_end_request_all(rq, rq->errors);
+		spin_unlock_irq(q->queue_lock);
+		return;
+	}
+
+	__elv_add_request(q, rq, where);
+	__blk_run_queue(q);
+	/* the queue is stopped so it won't be run */
+	if (is_pm_resume)
+		__blk_run_queue_uncond(q);
 	spin_unlock_irq(q->queue_lock);
 }
 EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
@@ -72,7 +102,7 @@ EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
  * @at_head:    insert request at head or tail of queue
  *
  * Description:
- *    Insert a fully prepared request at the back of the io scheduler queue
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution and wait for completion.
  */
 int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
@@ -81,12 +111,7 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	char sense[SCSI_SENSE_BUFFERSIZE];
 	int err = 0;
-
-	/*
-	 * we need an extra reference to the request, so we can look at
-	 * it after io completion
-	 */
-	rq->ref_count++;
+	unsigned long hang_check;
 
 	if (!rq->sense) {
 		memset(sense, 0, sizeof(sense));
@@ -96,11 +121,22 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 
 	rq->end_io_data = &wait;
 	blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
-	wait_for_completion(&wait);
+
+	/* Prevent hang_check timer from firing at us during very long I/O */
+	hang_check = sysctl_hung_task_timeout_secs;
+	if (hang_check)
+		while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
+	else
+		wait_for_completion_io(&wait);
 
 	if (rq->errors)
 		err = -EIO;
 
+	if (rq->sense == sense)	{
+		rq->sense = NULL;
+		rq->sense_len = 0;
+	}
+
 	return err;
 }
 EXPORT_SYMBOL(blk_execute_rq);