From c82765d3af0fb4c76376294aae0250f1742ab64e Mon Sep 17 00:00:00 2001
From: t_jeang <devnull@localhost>
Date: Tue, 6 Jan 2009 12:06:01 +0000
Subject: [PATCH] Wakeup blktap thread once frontend is connected -- in case
 there are already pending requests.  Do same for blkback.

---
 drivers/xen/blkback/blkback.c |  2 +-
 drivers/xen/blkback/common.h  |  2 ++
 drivers/xen/blkback/xenbus.c  | 13 ++++++++-----
 drivers/xen/blktap/blktap.c   |  6 +++---
 drivers/xen/blktap/common.h   |  2 ++
 drivers/xen/blktap/xenbus.c   | 13 ++++++++-----
 6 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/drivers/xen/blkback/blkback.c b/drivers/xen/blkback/blkback.c
index 4b8b5ba6..1652edf9 100644
--- a/drivers/xen/blkback/blkback.c
+++ b/drivers/xen/blkback/blkback.c
@@ -282,7 +282,7 @@ static int end_block_io_op(struct bio *bio, unsigned int done, int error)
  * NOTIFICATION FROM GUEST OS.
  */
 
-static void blkif_notify_work(blkif_t *blkif)
+void blkif_notify_work(blkif_t *blkif)
 {
 	blkif->waiting_reqs = 1;
 	wake_up(&blkif->wq);
diff --git a/drivers/xen/blkback/common.h b/drivers/xen/blkback/common.h
index 663bfeef..425d8cd6 100644
--- a/drivers/xen/blkback/common.h
+++ b/drivers/xen/blkback/common.h
@@ -133,6 +133,8 @@ void blkif_xenbus_init(void);
 irqreturn_t blkif_be_int(int irq, void *dev_id, struct pt_regs *regs);
 int blkif_schedule(void *arg);
 
+void blkif_notify_work(blkif_t *blkif);
+
 int blkback_barrier(struct xenbus_transaction xbt,
 		    struct backend_info *be, int state);
 
diff --git a/drivers/xen/blkback/xenbus.c b/drivers/xen/blkback/xenbus.c
index ece7d84f..9d95137f 100644
--- a/drivers/xen/blkback/xenbus.c
+++ b/drivers/xen/blkback/xenbus.c
@@ -375,13 +375,16 @@ static void frontend_changed(struct xenbus_device *dev,
 		/* Ensure we connect even when two watches fire in 
 		   close successsion and we miss the intermediate value 
 		   of frontend_state. */
+		if (dev->state != XenbusStateConnected) {
+			err = connect_ring(be);
+			if (err)
+				break;
+			update_blkif_status(be->blkif);
+		}
+
 		if (dev->state == XenbusStateConnected)
-			break;
+			blkif_notify_work(be->blkif);
 
-		err = connect_ring(be);
-		if (err)
-			break;
-		update_blkif_status(be->blkif);
 		break;
 
 	case XenbusStateClosing:
diff --git a/drivers/xen/blktap/blktap.c b/drivers/xen/blktap/blktap.c
index 512c4563..6d014083 100644
--- a/drivers/xen/blktap/blktap.c
+++ b/drivers/xen/blktap/blktap.c
@@ -1013,7 +1013,7 @@ static int blktap_read_ufe_ring(tap_blkif_t *info)
  * NOTIFICATION FROM GUEST OS.
  */
 
-static void blkif_notify_work(blkif_t *blkif)
+void tap_blkif_notify_work(blkif_t *blkif)
 {
 	blkif->waiting_reqs = 1;
 	wake_up(&blkif->wq);
@@ -1021,7 +1021,7 @@ static void blkif_notify_work(blkif_t *blkif)
 
 irqreturn_t tap_blkif_be_int(int irq, void *dev_id, struct pt_regs *regs)
 {
-	blkif_notify_work(dev_id);
+	tap_blkif_notify_work(dev_id);
 	return IRQ_HANDLED;
 }
 
@@ -1360,7 +1360,7 @@ static void make_response(blkif_t *blkif, u64 id,
 
 	spin_unlock_irqrestore(&blkif->blk_ring_lock, flags);
 	if (more_to_do)
-		blkif_notify_work(blkif);
+		tap_blkif_notify_work(blkif);
 	if (notify)
 		notify_remote_via_irq(blkif->irq);
 }
diff --git a/drivers/xen/blktap/common.h b/drivers/xen/blktap/common.h
index 87c6ea2e..e1c304ba 100644
--- a/drivers/xen/blktap/common.h
+++ b/drivers/xen/blktap/common.h
@@ -120,4 +120,6 @@ struct tap_blkif *associate_blkif(domid_t domid, int xenbus_id,
 				  blkif_t *blkif);
 void signal_tapdisk(int idx);
 
+void tap_blkif_notify_work(blkif_t *blkif);
+
 #endif /* __BLKIF__BACKEND__COMMON_H__ */
diff --git a/drivers/xen/blktap/xenbus.c b/drivers/xen/blktap/xenbus.c
index e2761383..0ab00f80 100644
--- a/drivers/xen/blktap/xenbus.c
+++ b/drivers/xen/blktap/xenbus.c
@@ -386,13 +386,16 @@ static void tap_frontend_changed(struct xenbus_device *dev,
 		/* Ensure we connect even when two watches fire in 
 		   close successsion and we miss the intermediate value 
 		   of frontend_state. */
+		if (dev->state != XenbusStateConnected) {
+			err = connect_ring(be);
+			if (err)
+				break;
+			tap_update_blkif_status(be->blkif);
+		}
+
 		if (dev->state == XenbusStateConnected)
-			break;
+			tap_blkif_notify_work(be->blkif);
 
-		err = connect_ring(be);
-		if (err)
-			break;
-		tap_update_blkif_status(be->blkif);
 		break;
 
 	case XenbusStateClosing:
-- 
2.39.5