block_abort_queue (blk_abort_request) racing with scsi_request_fn

Commit Message

Mike Christie Nov. 10, 2010, 7:09 a.m. UTC

None

Patch

diff --git a/block/blk-core.c b/block/blk-core.c
index f0834e2..92279d4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -981,6 +981,9 @@  EXPORT_SYMBOL(blk_make_request);
  */
 void blk_requeue_request(struct request_queue *q, struct request *rq)
 {
+	if (test_bit(REQ_ATOM_TIMEDOUT, &rq->atomic_flags))
+		return;
+
 	blk_delete_timer(rq);
 	blk_clear_rq_complete(rq);
 	trace_block_rq_requeue(q, rq);
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
index ee9c216..e0a8d11 100644
--- a/block/blk-softirq.c
+++ b/block/blk-softirq.c
@@ -156,8 +156,10 @@  void blk_complete_request(struct request *req)
 {
 	if (unlikely(blk_should_fake_timeout(req->q)))
 		return;
-	if (!blk_mark_rq_complete(req))
+	if (!blk_mark_rq_complete(req)) {
+		blk_clear_rq_timedout(req);
 		__blk_complete_request(req);
+	}
 }
 EXPORT_SYMBOL(blk_complete_request);
 
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 4f0c06c..afc6e5f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -97,6 +97,7 @@  static void blk_rq_timed_out(struct request *req)
 		 * and we can move more of the generic scsi eh code to
 		 * the blk layer.
 		 */
+		blk_mark_rq_timedout(req);
 		break;
 	default:
 		printk(KERN_ERR "block: bad eh return: %d\n", ret);
@@ -104,6 +105,25 @@  static void blk_rq_timed_out(struct request *req)
 	}
 }
 
+/**
+ * blk_requeue_timedout_request - put a request that timedout back on queue
+ * @q:		request queue where request should be inserted
+ * @rq:		request to be inserted
+ *
+ * Description:
+ *	If a module has returned BLK_EH_NOT_HANDLED from its
+ *	rq_timed_out_fn and needs to requeue the request this
+ *	function should be used instead of blk_requeue_request.
+ *
+ *	queue_lock must be held.
+ */
+void blk_requeue_timedout_request(struct request_queue *q, struct request *req)
+{
+	blk_clear_rq_timedout(req);
+	blk_requeue_request(q, req);
+}
+EXPORT_SYMBOL_GPL(blk_requeue_timedout_request);
+
 void blk_rq_timed_out_timer(unsigned long data)
 {
 	struct request_queue *q = (struct request_queue *) data;
diff --git a/block/blk.h b/block/blk.h
index 2db8f32..ad93258 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -30,6 +30,7 @@  void __generic_unplug_device(struct request_queue *);
  */
 enum rq_atomic_flags {
 	REQ_ATOM_COMPLETE = 0,
+	REQ_ATOM_TIMEDOUT = 1,
 };
 
 /*
@@ -46,7 +47,15 @@  static inline void blk_clear_rq_complete(struct request *rq)
 	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
 }
 
-/*
+static inline int blk_mark_rq_timedout(struct request *rq)
+{
+	return test_and_set_bit(REQ_ATOM_TIMEDOUT, &rq->atomic_flags);
+}
+
+static inline void blk_clear_rq_timedout(struct request *rq)
+{
+	clear_bit(REQ_ATOM_TIMEDOUT, &rq->atomic_flags);
+}/*
  * Internal elevator interface
  */
 #define ELV_ON_HASH(rq)		(!hlist_unhashed(&(rq)->hash))
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 1de30eb..06df25a 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1680,7 +1680,11 @@  void scsi_eh_flush_done_q(struct list_head *done_q)
 							  " retry cmd: %p\n",
 							  current->comm,
 							  scmd));
-				scsi_queue_insert(scmd, SCSI_MLQUEUE_EH_RETRY);
+				printk(KERN_ERR "scmd %p %p %p\n", scmd,
+					scmd->eh_entry.next, scmd->eh_entry.prev);
+
+				scsi_queue_insert(scmd,
+						SCSI_MLQUEUE_EH_TIMEDOUT_RETRY);
 		} else {
 			/*
 			 * If just we got sense for the device (called
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index eafeeda..cef49b2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -158,7 +158,10 @@  static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
 	 * and plugs the queue appropriately.
          */
 	spin_lock_irqsave(q->queue_lock, flags);
-	blk_requeue_request(q, cmd->request);
+	if (reason == SCSI_MLQUEUE_EH_TIMEDOUT_RETRY)
+		blk_requeue_timedout_request(q, cmd->request);
+	else
+		blk_requeue_request(q, cmd->request);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 
 	scsi_run_queue(q);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5027a59..e56f28e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -205,7 +205,10 @@  typedef int (dma_drain_needed_fn)(struct request *);
 typedef int (lld_busy_fn) (struct request_queue *q);
 
 enum blk_eh_timer_return {
-	BLK_EH_NOT_HANDLED,
+	BLK_EH_NOT_HANDLED,	/* If this is returned the module must
+				 * call blk_requeue_timedout_request to
+				 * requeue it
+				 */
 	BLK_EH_HANDLED,
 	BLK_EH_RESET_TIMER,
 };
@@ -653,6 +656,8 @@  extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 extern struct request *blk_make_request(struct request_queue *, struct bio *,
 					gfp_t);
 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
+extern void blk_requeue_timedout_request(struct request_queue *,
+					 struct request *);
 extern void blk_requeue_request(struct request_queue *, struct request *);
 extern void blk_add_request_payload(struct request *rq, struct page *page,
 		unsigned int len);
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 216af85..5bde952 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -442,6 +442,7 @@  static inline int scsi_is_wlun(unsigned int lun)
 #define SCSI_MLQUEUE_DEVICE_BUSY 0x1056
 #define SCSI_MLQUEUE_EH_RETRY    0x1057
 #define SCSI_MLQUEUE_TARGET_BUSY 0x1058
+#define SCSI_MLQUEUE_EH_TIMEDOUT_RETRY	0x1059
 
 /*
  *  Use these to separate status msg and our bytes