Both R1BIO_Barrier and R1BIO_Returned are 4 !!!!
This means that barrier requests don't get returned (i.e.  b_endio called)
because it looks like they already have been.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
  * with failure when last write completes (and all failed).
  * Record that bi_end_io was called with this flag...
  */
-#define        R1BIO_Returned 4
+#define        R1BIO_Returned 6
 
 #endif