block: reorganize QUEUE_ORDERED_* constants

Separate out ordering type (drain,) and action masks (preflush,
postflush, fua) from visible ordering mode selectors
(QUEUE_ORDERED_*).  Ordering types are now named QUEUE_ORDERED_BY_*
while action masks are named QUEUE_ORDERED_DO_*.

This change is necessary to add QUEUE_ORDERED_DO_BAR and make it
optional to improve empty barrier implementation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 33 insertions, 26 deletions

diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index 6e72d661ae42..1d7adc72c95d 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -24,8 +24,8 @@
 int blk_queue_ordered(struct request_queue *q, unsigned ordered,
                       prepare_flush_fn *prepare_flush_fn)
 {
-        if (ordered & (QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH) &&
-            prepare_flush_fn == NULL) {
+        if (!prepare_flush_fn && (ordered & (QUEUE_ORDERED_DO_PREFLUSH |
+                                             QUEUE_ORDERED_DO_POSTFLUSH))) {
                 printk(KERN_ERR "%s: prepare_flush_fn required\n", __func__);
                 return -EINVAL;
         }
@@ -134,7 +134,7 @@ static void queue_flush(struct request_queue *q, unsigned which)
         struct request *rq;
         rq_end_io_fn *end_io;
 
-        if (which == QUEUE_ORDERED_PREFLUSH) {
+        if (which == QUEUE_ORDERED_DO_PREFLUSH) {
                 rq = &q->pre_flush_rq;
                 end_io = pre_flush_end_io;
         } else {
@@ -167,7 +167,7 @@ static inline struct request *start_ordered(struct request_queue *q,
         blk_rq_init(q, rq);
         if (bio_data_dir(q->orig_bar_rq->bio) == WRITE)
                 rq->cmd_flags |= REQ_RW;
-        if (q->ordered & QUEUE_ORDERED_FUA)
+        if (q->ordered & QUEUE_ORDERED_DO_FUA)
                 rq->cmd_flags |= REQ_FUA;
         init_request_from_bio(rq, q->orig_bar_rq->bio);
         rq->end_io = bar_end_io;
@@ -181,20 +181,20 @@ static inline struct request *start_ordered(struct request_queue *q,
          * there will be no data written between the pre and post flush.
          * Hence a single flush will suffice.
          */
-        if ((q->ordered & QUEUE_ORDERED_POSTFLUSH) && !blk_empty_barrier(rq))
-                queue_flush(q, QUEUE_ORDERED_POSTFLUSH);
+        if ((q->ordered & QUEUE_ORDERED_DO_POSTFLUSH) && !blk_empty_barrier(rq))
+                queue_flush(q, QUEUE_ORDERED_DO_POSTFLUSH);
         else
                 q->ordseq |= QUEUE_ORDSEQ_POSTFLUSH;
 
         elv_insert(q, rq, ELEVATOR_INSERT_FRONT);
 
-        if (q->ordered & QUEUE_ORDERED_PREFLUSH) {
-                queue_flush(q, QUEUE_ORDERED_PREFLUSH);
+        if (q->ordered & QUEUE_ORDERED_DO_PREFLUSH) {
+                queue_flush(q, QUEUE_ORDERED_DO_PREFLUSH);
                 rq = &q->pre_flush_rq;
         } else
                 q->ordseq |= QUEUE_ORDSEQ_PREFLUSH;
 
-        if ((q->ordered & QUEUE_ORDERED_TAG) || q->in_flight == 0)
+        if ((q->ordered & QUEUE_ORDERED_BY_TAG) || q->in_flight == 0)
                 q->ordseq |= QUEUE_ORDSEQ_DRAIN;
         else
                 rq = NULL;
@@ -237,7 +237,7 @@ int blk_do_ordered(struct request_queue *q, struct request **rqp)
             rq != &q->pre_flush_rq && rq != &q->post_flush_rq)
                 return 1;
 
-        if (q->ordered & QUEUE_ORDERED_TAG) {
+        if (q->ordered & QUEUE_ORDERED_BY_TAG) {
                 /* Ordered by tag.  Blocking the next barrier is enough. */
                 if (is_barrier && rq != &q->bar_rq)
                         *rqp = NULL;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e9bb73ff1d64..5c92b4432399 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -523,22 +523,29 @@ enum {
          * TAG_FLUSH    : ordering by tag w/ pre and post flushes
          * TAG_FUA      : ordering by tag w/ pre flush and FUA write
          */
-        QUEUE_ORDERED_NONE      = 0x00,
-        QUEUE_ORDERED_DRAIN     = 0x01,
-        QUEUE_ORDERED_TAG       = 0x02,
-
-        QUEUE_ORDERED_PREFLUSH  = 0x10,
-        QUEUE_ORDERED_POSTFLUSH = 0x20,
-        QUEUE_ORDERED_FUA       = 0x40,
-
-        QUEUE_ORDERED_DRAIN_FLUSH = QUEUE_ORDERED_DRAIN |
-                        QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
-        QUEUE_ORDERED_DRAIN_FUA = QUEUE_ORDERED_DRAIN |
-                        QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
-        QUEUE_ORDERED_TAG_FLUSH = QUEUE_ORDERED_TAG |
-                        QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_POSTFLUSH,
-        QUEUE_ORDERED_TAG_FUA   = QUEUE_ORDERED_TAG |
-                        QUEUE_ORDERED_PREFLUSH | QUEUE_ORDERED_FUA,
+        QUEUE_ORDERED_BY_DRAIN          = 0x01,
+        QUEUE_ORDERED_BY_TAG            = 0x02,
+        QUEUE_ORDERED_DO_PREFLUSH       = 0x10,
+        QUEUE_ORDERED_DO_POSTFLUSH      = 0x40,
+        QUEUE_ORDERED_DO_FUA            = 0x80,
+
+        QUEUE_ORDERED_NONE              = 0x00,
+
+        QUEUE_ORDERED_DRAIN             = QUEUE_ORDERED_BY_DRAIN,
+        QUEUE_ORDERED_DRAIN_FLUSH       = QUEUE_ORDERED_DRAIN |
+                                          QUEUE_ORDERED_DO_PREFLUSH |
+                                          QUEUE_ORDERED_DO_POSTFLUSH,
+        QUEUE_ORDERED_DRAIN_FUA         = QUEUE_ORDERED_DRAIN |
+                                          QUEUE_ORDERED_DO_PREFLUSH |
+                                          QUEUE_ORDERED_DO_FUA,
+
+        QUEUE_ORDERED_TAG               = QUEUE_ORDERED_BY_TAG,
+        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