[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>

4 files changed, 24 insertions, 32 deletions

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 56c99fa037df..1ec5df466708 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -347,9 +347,6 @@ static struct request *as_find_arq_hash(struct as_data *ad, 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_arq(node)      rb_entry((node), struct as_rq, rb_node)
 #define ARQ_RB_ROOT(ad, arq)    (&(ad)->sort_list[(arq)->is_sync])
 #define rq_rb_key(rq)           (rq)->sector
@@ -418,13 +415,13 @@ static void as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
 
 static inline void as_del_arq_rb(struct as_data *ad, struct as_rq *arq)
 {
-        if (!ON_RB(&arq->rb_node)) {
+        if (!RB_EMPTY_NODE(&arq->rb_node)) {
                 WARN_ON(1);
                 return;
         }
 
         rb_erase(&arq->rb_node, ARQ_RB_ROOT(ad, arq));
-        RB_CLEAR(&arq->rb_node);
+        RB_CLEAR_NODE(&arq->rb_node);
 }
 
 static struct request *
@@ -545,7 +542,7 @@ static struct as_rq *as_find_next_arq(struct as_data *ad, struct as_rq *last)
         struct rb_node *rbprev = rb_prev(&last->rb_node);
         struct as_rq *arq_next, *arq_prev;
 
-        BUG_ON(!ON_RB(&last->rb_node));
+        BUG_ON(!RB_EMPTY_NODE(&last->rb_node));
 
         if (rbprev)
                 arq_prev = rb_entry_arq(rbprev);
@@ -1122,7 +1119,7 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
         struct request *rq = arq->request;
         const int data_dir = arq->is_sync;
 
-        BUG_ON(!ON_RB(&arq->rb_node));
+        BUG_ON(!RB_EMPTY_NODE(&arq->rb_node));
 
         as_antic_stop(ad);
         ad->antic_status = ANTIC_OFF;
@@ -1247,7 +1244,7 @@ static int as_dispatch_request(request_queue_t *q, int force)
          */
 
         if (reads) {
-                BUG_ON(RB_EMPTY(&ad->sort_list[REQ_SYNC]));
+                BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_SYNC]));
 
                 if (writes && ad->batch_data_dir == REQ_SYNC)
                         /*
@@ -1271,7 +1268,7 @@ static int as_dispatch_request(request_queue_t *q, int force)
 
         if (writes) {
 dispatch_writes:
-                BUG_ON(RB_EMPTY(&ad->sort_list[REQ_ASYNC]));
+                BUG_ON(RB_EMPTY_ROOT(&ad->sort_list[REQ_ASYNC]));
 
                 if (ad->batch_data_dir == REQ_SYNC) {
                         ad->changed_batch = 1;
@@ -1591,7 +1588,7 @@ static int as_set_request(request_queue_t *q, struct request *rq,
 
         if (arq) {
                 memset(arq, 0, sizeof(*arq));
-                RB_CLEAR(&arq->rb_node);
+                RB_CLEAR_NODE(&arq->rb_node);
                 arq->request = rq;
                 arq->state = AS_RQ_PRESCHED;
                 arq->io_context = NULL;
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 940364edf2b9..e25223e147a2 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -60,11 +60,6 @@ static DEFINE_SPINLOCK(cfq_exit_lock);
 /*
  * rb-tree defines
  */
-#define RB_EMPTY(node)          ((node)->rb_node == NULL)
-#define RB_CLEAR(node)          do {    \
-                memset(node, 0, sizeof(*node)); \
-} while (0)
-#define RB_CLEAR_ROOT(root)     ((root)->rb_node = NULL)
 #define rb_entry_crq(node)      rb_entry((node), struct cfq_rq, rb_node)
 #define rq_rb_key(rq)           (rq)->sector
 
@@ -559,7 +554,7 @@ static inline void cfq_del_crq_rb(struct cfq_rq *crq)
 
         rb_erase(&crq->rb_node, &cfqq->sort_list);
 
-        if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY(&cfqq->sort_list))
+        if (cfq_cfqq_on_rr(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
                 cfq_del_cfqq_rr(cfqd, cfqq);
 }
 
@@ -914,7 +909,7 @@ static int cfq_arm_slice_timer(struct cfq_data *cfqd, struct cfq_queue *cfqq)
         struct cfq_io_context *cic;
         unsigned long sl;
 
-        WARN_ON(!RB_EMPTY(&cfqq->sort_list));
+        WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
         WARN_ON(cfqq != cfqd->active_queue);
 
         /*
@@ -1042,7 +1037,7 @@ static struct cfq_queue *cfq_select_queue(struct cfq_data *cfqd)
          * if queue has requests, dispatch one. if not, check if
          * enough slice is left to wait for one
          */
-        if (!RB_EMPTY(&cfqq->sort_list))
+        if (!RB_EMPTY_ROOT(&cfqq->sort_list))
                 goto keep_queue;
         else if (cfq_cfqq_dispatched(cfqq)) {
                 cfqq = NULL;
@@ -1066,7 +1061,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 {
         int dispatched = 0;
 
-        BUG_ON(RB_EMPTY(&cfqq->sort_list));
+        BUG_ON(RB_EMPTY_ROOT(&cfqq->sort_list));
 
         do {
                 struct cfq_rq *crq;
@@ -1090,7 +1085,7 @@ __cfq_dispatch_requests(struct cfq_data *cfqd, struct cfq_queue *cfqq,
                         cfqd->active_cic = crq->io_context;
                 }
 
-                if (RB_EMPTY(&cfqq->sort_list))
+                if (RB_EMPTY_ROOT(&cfqq->sort_list))
                         break;
 
         } while (dispatched < max_dispatch);
@@ -1480,7 +1475,6 @@ retry:
 
                 INIT_HLIST_NODE(&cfqq->cfq_hash);
                 INIT_LIST_HEAD(&cfqq->cfq_list);
-                RB_CLEAR_ROOT(&cfqq->sort_list);
                 INIT_LIST_HEAD(&cfqq->fifo);
 
                 cfqq->key = key;
@@ -1873,7 +1867,7 @@ static void cfq_completed_request(request_queue_t *q, struct request *rq)
         if (cfqd->active_queue == cfqq) {
                 if (time_after(now, cfqq->slice_end))
                         cfq_slice_expired(cfqd, 0);
-                else if (sync && RB_EMPTY(&cfqq->sort_list)) {
+                else if (sync && RB_EMPTY_ROOT(&cfqq->sort_list)) {
                         if (!cfq_arm_slice_timer(cfqd, cfqq))
                                 cfq_schedule_dispatch(cfqd);
                 }
@@ -2059,7 +2053,7 @@ cfq_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
 
         crq = mempool_alloc(cfqd->crq_pool, gfp_mask);
         if (crq) {
-                RB_CLEAR(&crq->rb_node);
+                RB_CLEAR_NODE(&crq->rb_node);
                 crq->rb_key = 0;
                 crq->request = rq;
                 INIT_HLIST_NODE(&crq->hash);
@@ -2151,7 +2145,7 @@ static void cfq_idle_slice_timer(unsigned long data)
                 /*
                  * not expired and it has a request pending, let it dispatch
                  */
-                if (!RB_EMPTY(&cfqq->sort_list)) {
+                if (!RB_EMPTY_ROOT(&cfqq->sort_list)) {
                         cfq_mark_cfqq_must_dispatch(cfqq);
                         goto out_kick;
                 }
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);
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index f37006f21664..8d5382e62c08 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -132,6 +132,10 @@ static inline void rb_set_color(struct rb_node *rb, int color)
 #define RB_ROOT (struct rb_root) { NULL, }
 #define rb_entry(ptr, type, member) container_of(ptr, type, member)
 
+#define RB_EMPTY_ROOT(root)     ((root)->rb_node == NULL)
+#define RB_EMPTY_NODE(node)     (rb_parent(node) != node)
+#define RB_CLEAR_NODE(node)     (rb_set_parent(node, node))
+
 extern void rb_insert_color(struct rb_node *, struct rb_root *);
 extern void rb_erase(struct rb_node *, struct rb_root *);