From: Laszlo Ersek <lersek@redhat.com>
Date: Mon, 16 May 2011 12:26:45 +0000 (+0100)
Subject: xenbus: fix xenbus_transaction_start() hang caused by double xenbus_transaction_end()
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=aed3bdd642c2f05e557025cce7e1f329bff777fc;p=legacy%2Flinux-2.6.18-xen.git

xenbus: fix xenbus_transaction_start() hang caused by double xenbus_transaction_end()

vbd_resize() up_read()'s xs_state.suspend_mutex twice in a row via
double xenbus_transaction_end() calls. The next down_read() in
xenbus_transaction_start() (at eg. the next resize attempt) hangs.

See RHBZ#618317.

Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Acked-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/drivers/xen/blkback/vbd.c b/drivers/xen/blkback/vbd.c
index 802b7868..5677e86c 100644
--- a/drivers/xen/blkback/vbd.c
+++ b/drivers/xen/blkback/vbd.c
@@ -156,6 +156,7 @@ again:
 		goto again;
 	if (err)
 		printk(KERN_WARNING "Error ending transaction");
+	return;
 abort:
 	xenbus_transaction_end(xbt, 1);
 }