kblockd: use flush_work

Switch the kblockd flushing from a global flush to a more specific
flush_work().

(akpm: bypassed maintainers, sorry.  There are other patches which depend on
this)

Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <axboe@suse.de>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index d99d402..c059767 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -1712,7 +1712,6 @@
 void blk_sync_queue(struct request_queue *q)
 {
 	del_timer_sync(&q->unplug_timer);
-	kblockd_flush();
 }
 EXPORT_SYMBOL(blk_sync_queue);
 
@@ -3632,11 +3631,11 @@
 
 EXPORT_SYMBOL(kblockd_schedule_work);
 
-void kblockd_flush(void)
+void kblockd_flush_work(struct work_struct *work)
 {
-	flush_workqueue(kblockd_workqueue);
+	flush_work(kblockd_workqueue, work);
 }
-EXPORT_SYMBOL(kblockd_flush);
+EXPORT_SYMBOL(kblockd_flush_work);
 
 int __init blk_dev_init(void)
 {