dm: use non reentrant workqueues if equivalent

kmirrord_wq, kcopyd_work and md->wq are created per dm instance and
serve only a single work item from the dm instance, so non-reentrant
workqueues would provide the same ordering guarantees as ordered ones
while allowing CPU affinity and use of the workqueues for other
purposes.  Switch them to non-reentrant workqueues.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/include/linux/dm-ioctl.h b/include/linux/dm-ioctl.h
index e453e11..78bbf47 100644
--- a/include/linux/dm-ioctl.h
+++ b/include/linux/dm-ioctl.h
@@ -268,8 +268,8 @@
 
 #define DM_VERSION_MAJOR	4
 #define DM_VERSION_MINOR	19
-#define DM_VERSION_PATCHLEVEL	0
-#define DM_VERSION_EXTRA	"-ioctl (2010-10-14)"
+#define DM_VERSION_PATCHLEVEL	1
+#define DM_VERSION_EXTRA	"-ioctl (2011-01-07)"
 
 /* Status bits */
 #define DM_READONLY_FLAG	(1 << 0) /* In/Out */