block: kill QUEUE_ORDERED_BY_TAG

Nobody is making meaningful use of ORDERED_BY_TAG now and queue
draining for barrier requests will be removed soon which will render
the advantage of tag ordering moot.  Kill ORDERED_BY_TAG.  The
following users are affected.

* brd: converted to ORDERED_DRAIN.
* virtio_blk: ORDERED_TAG path was already marked deprecated.  Removed.
* xen-blkfront: ORDERED_TAG case dropped.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

1 files changed, 1 insertions, 16 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 015375c7d031..7077bc0d6138 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -470,12 +470,7 @@ enum {
          * DRAIN        : ordering by draining is enough
          * DRAIN_FLUSH  : ordering by draining w/ pre and post flushes
          * DRAIN_FUA    : ordering by draining w/ pre flush and FUA write
-         * TAG          : ordering by tag is enough
-         * TAG_FLUSH    : ordering by tag w/ pre and post flushes
-         * TAG_FUA      : ordering by tag w/ pre flush and FUA write
          */
-        QUEUE_ORDERED_BY_DRAIN          = 0x01,
-        QUEUE_ORDERED_BY_TAG            = 0x02,
         QUEUE_ORDERED_DO_PREFLUSH       = 0x10,
         QUEUE_ORDERED_DO_BAR            = 0x20,
         QUEUE_ORDERED_DO_POSTFLUSH      = 0x40,
@@ -483,8 +478,7 @@ enum {
 
         QUEUE_ORDERED_NONE              = 0x00,
 
-        QUEUE_ORDERED_DRAIN             = QUEUE_ORDERED_BY_DRAIN |
-                                          QUEUE_ORDERED_DO_BAR,
+        QUEUE_ORDERED_DRAIN             = QUEUE_ORDERED_DO_BAR,
         QUEUE_ORDERED_DRAIN_FLUSH       = QUEUE_ORDERED_DRAIN |
                                           QUEUE_ORDERED_DO_PREFLUSH |
                                           QUEUE_ORDERED_DO_POSTFLUSH,
@@ -492,15 +486,6 @@ enum {
                                           QUEUE_ORDERED_DO_PREFLUSH |
                                           QUEUE_ORDERED_DO_FUA,
 
-        QUEUE_ORDERED_TAG               = QUEUE_ORDERED_BY_TAG |
-                                          QUEUE_ORDERED_DO_BAR,
-        QUEUE_ORDERED_TAG_FLUSH         = QUEUE_ORDERED_TAG |
-                                          QUEUE_ORDERED_DO_PREFLUSH |
-                                          QUEUE_ORDERED_DO_POSTFLUSH,
-        QUEUE_ORDERED_TAG_FUA           = QUEUE_ORDERED_TAG |
-                                          QUEUE_ORDERED_DO_PREFLUSH |
-                                          QUEUE_ORDERED_DO_FUA,
-
         /*
          * Ordered operation sequence
          */