[PATCH] rbtree: support functions used by the io schedulers

They all duplicate macros to check for empty root and/or node, and
clearing a node. So put those in rbtree.h.

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 5 insertions, 8 deletions

diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index e5bccaaed563..4469dd84623c 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -159,9 +159,6 @@ deadline_find_drq_hash(struct deadline_data *dd, sector_t offset)
 /*
  * rb tree support functions
  */
-#define RB_EMPTY(root)  ((root)->rb_node == NULL)
-#define ON_RB(node)     (rb_parent(node) != node)
-#define RB_CLEAR(node)  (rb_set_parent(node, node))
 #define rb_entry_drq(node)      rb_entry((node), struct deadline_rq, rb_node)
 #define DRQ_RB_ROOT(dd, drq)    (&(dd)->sort_list[rq_data_dir((drq)->request)])
 #define rq_rb_key(rq)           (rq)->sector
@@ -220,9 +217,9 @@ deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
                         dd->next_drq[data_dir] = rb_entry_drq(rbnext);
         }
 
-        BUG_ON(!ON_RB(&drq->rb_node));
+        BUG_ON(!RB_EMPTY_NODE(&drq->rb_node));
         rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
-        RB_CLEAR(&drq->rb_node);
+        RB_CLEAR_NODE(&drq->rb_node);
 }
 
 static struct request *
@@ -496,7 +493,7 @@ static int deadline_dispatch_requests(request_queue_t *q, int force)
          */
 
         if (reads) {
-                BUG_ON(RB_EMPTY(&dd->sort_list[READ]));
+                BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[READ]));
 
                 if (writes && (dd->starved++ >= dd->writes_starved))
                         goto dispatch_writes;
@@ -512,7 +509,7 @@ static int deadline_dispatch_requests(request_queue_t *q, int force)
 
         if (writes) {
 dispatch_writes:
-                BUG_ON(RB_EMPTY(&dd->sort_list[WRITE]));
+                BUG_ON(RB_EMPTY_ROOT(&dd->sort_list[WRITE]));
 
                 dd->starved = 0;
 
@@ -668,7 +665,7 @@ deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
         drq = mempool_alloc(dd->drq_pool, gfp_mask);
         if (drq) {
                 memset(drq, 0, sizeof(*drq));
-                RB_CLEAR(&drq->rb_node);
+                RB_CLEAR_NODE(&drq->rb_node);
                 drq->request = rq;
 
                 INIT_HLIST_NODE(&drq->hash);