block/genhd.c: remove useless cast in diskstats_show()
[linux-2.6.git] / block / deadline-iosched.c
index c94de8e..c644137 100644 (file)
@@ -1,19 +1,17 @@
 /*
  *  Deadline i/o scheduler.
  *
- *  Copyright (C) 2002 Jens Axboe <axboe@suse.de>
+ *  Copyright (C) 2002 Jens Axboe <axboe@kernel.dk>
  */
 #include <linux/kernel.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
 #include <linux/elevator.h>
 #include <linux/bio.h>
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/compiler.h>
-#include <linux/hash.h>
 #include <linux/rbtree.h>
 
 /*
@@ -25,14 +23,6 @@ static const int writes_starved = 2;    /* max times reads can starve a write */
 static const int fifo_batch = 16;       /* # of sequential requests treated as one
                                     by the above parameters. For throughput. */
 
-static const int deadline_hash_shift = 5;
-#define DL_HASH_BLOCK(sec)     ((sec) >> 3)
-#define DL_HASH_FN(sec)                (hash_long(DL_HASH_BLOCK((sec)), deadline_hash_shift))
-#define DL_HASH_ENTRIES                (1 << deadline_hash_shift)
-#define rq_hash_key(rq)                ((rq)->sector + (rq)->nr_sectors)
-#define list_entry_hash(ptr)   list_entry((ptr), struct deadline_rq, hash)
-#define ON_HASH(drq)           (drq)->on_hash
-
 struct deadline_data {
        /*
         * run time data
@@ -43,12 +33,11 @@ struct deadline_data {
         */
        struct rb_root sort_list[2];    
        struct list_head fifo_list[2];
-       
+
        /*
         * next in sort order. read, write or both are NULL
         */
-       struct deadline_rq *next_drq[2];
-       struct list_head *hash;         /* request hash */
+       struct request *next_rq[2];
        unsigned int batching;          /* number of sequential requests made */
        sector_t last_sector;           /* head position */
        unsigned int starved;           /* times reads have starved writes */
@@ -60,279 +49,94 @@ struct deadline_data {
        int fifo_batch;
        int writes_starved;
        int front_merges;
-
-       mempool_t *drq_pool;
-};
-
-/*
- * pre-request data.
- */
-struct deadline_rq {
-       /*
-        * rbtree index, key is the starting offset
-        */
-       struct rb_node rb_node;
-       sector_t rb_key;
-
-       struct request *request;
-
-       /*
-        * request hash, key is the ending offset (for back merge lookup)
-        */
-       struct list_head hash;
-       char on_hash;
-
-       /*
-        * expire fifo
-        */
-       struct list_head fifo;
-       unsigned long expires;
 };
 
-static void deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq);
-
-static kmem_cache_t *drq_pool;
-
-#define RQ_DATA(rq)    ((struct deadline_rq *) (rq)->elevator_private)
+static void deadline_move_request(struct deadline_data *, struct request *);
 
-/*
- * the back merge hash support functions
- */
-static inline void __deadline_del_drq_hash(struct deadline_rq *drq)
-{
-       drq->on_hash = 0;
-       list_del_init(&drq->hash);
-}
-
-static inline void deadline_del_drq_hash(struct deadline_rq *drq)
-{
-       if (ON_HASH(drq))
-               __deadline_del_drq_hash(drq);
-}
-
-static inline void
-deadline_add_drq_hash(struct deadline_data *dd, struct deadline_rq *drq)
+static inline struct rb_root *
+deadline_rb_root(struct deadline_data *dd, struct request *rq)
 {
-       struct request *rq = drq->request;
-
-       BUG_ON(ON_HASH(drq));
-
-       drq->on_hash = 1;
-       list_add(&drq->hash, &dd->hash[DL_HASH_FN(rq_hash_key(rq))]);
+       return &dd->sort_list[rq_data_dir(rq)];
 }
 
 /*
- * move hot entry to front of chain
+ * get the request after `rq' in sector-sorted order
  */
-static inline void
-deadline_hot_drq_hash(struct deadline_data *dd, struct deadline_rq *drq)
+static inline struct request *
+deadline_latter_request(struct request *rq)
 {
-       struct request *rq = drq->request;
-       struct list_head *head = &dd->hash[DL_HASH_FN(rq_hash_key(rq))];
-
-       if (ON_HASH(drq) && drq->hash.prev != head) {
-               list_del(&drq->hash);
-               list_add(&drq->hash, head);
-       }
-}
-
-static struct request *
-deadline_find_drq_hash(struct deadline_data *dd, sector_t offset)
-{
-       struct list_head *hash_list = &dd->hash[DL_HASH_FN(offset)];
-       struct list_head *entry, *next = hash_list->next;
-
-       while ((entry = next) != hash_list) {
-               struct deadline_rq *drq = list_entry_hash(entry);
-               struct request *__rq = drq->request;
+       struct rb_node *node = rb_next(&rq->rb_node);
 
-               next = entry->next;
-               
-               BUG_ON(!ON_HASH(drq));
+       if (node)
+               return rb_entry_rq(node);
 
-               if (!rq_mergeable(__rq)) {
-                       __deadline_del_drq_hash(drq);
-                       continue;
-               }
-
-               if (rq_hash_key(__rq) == offset)
-                       return __rq;
-       }
-
-       return NULL;
-}
-
-/*
- * 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
-
-static struct deadline_rq *
-__deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
-{
-       struct rb_node **p = &DRQ_RB_ROOT(dd, drq)->rb_node;
-       struct rb_node *parent = NULL;
-       struct deadline_rq *__drq;
-
-       while (*p) {
-               parent = *p;
-               __drq = rb_entry_drq(parent);
-
-               if (drq->rb_key < __drq->rb_key)
-                       p = &(*p)->rb_left;
-               else if (drq->rb_key > __drq->rb_key)
-                       p = &(*p)->rb_right;
-               else
-                       return __drq;
-       }
-
-       rb_link_node(&drq->rb_node, parent, p);
        return NULL;
 }
 
 static void
-deadline_add_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
 {
-       struct deadline_rq *__alias;
+       struct rb_root *root = deadline_rb_root(dd, rq);
 
-       drq->rb_key = rq_rb_key(drq->request);
-
-retry:
-       __alias = __deadline_add_drq_rb(dd, drq);
-       if (!__alias) {
-               rb_insert_color(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
-               return;
-       }
-
-       deadline_move_request(dd, __alias);
-       goto retry;
+       elv_rb_add(root, rq);
 }
 
 static inline void
-deadline_del_drq_rb(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
 {
-       const int data_dir = rq_data_dir(drq->request);
-
-       if (dd->next_drq[data_dir] == drq) {
-               struct rb_node *rbnext = rb_next(&drq->rb_node);
+       const int data_dir = rq_data_dir(rq);
 
-               dd->next_drq[data_dir] = NULL;
-               if (rbnext)
-                       dd->next_drq[data_dir] = rb_entry_drq(rbnext);
-       }
+       if (dd->next_rq[data_dir] == rq)
+               dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-       BUG_ON(!ON_RB(&drq->rb_node));
-       rb_erase(&drq->rb_node, DRQ_RB_ROOT(dd, drq));
-       RB_CLEAR(&drq->rb_node);
-}
-
-static struct request *
-deadline_find_drq_rb(struct deadline_data *dd, sector_t sector, int data_dir)
-{
-       struct rb_node *n = dd->sort_list[data_dir].rb_node;
-       struct deadline_rq *drq;
-
-       while (n) {
-               drq = rb_entry_drq(n);
-
-               if (sector < drq->rb_key)
-                       n = n->rb_left;
-               else if (sector > drq->rb_key)
-                       n = n->rb_right;
-               else
-                       return drq->request;
-       }
-
-       return NULL;
+       elv_rb_del(deadline_rb_root(dd, rq), rq);
 }
 
 /*
- * deadline_find_first_drq finds the first (lowest sector numbered) request
- * for the specified data_dir. Used to sweep back to the start of the disk
- * (1-way elevator) after we process the last (highest sector) request.
- */
-static struct deadline_rq *
-deadline_find_first_drq(struct deadline_data *dd, int data_dir)
-{
-       struct rb_node *n = dd->sort_list[data_dir].rb_node;
-
-       for (;;) {
-               if (n->rb_left == NULL)
-                       return rb_entry_drq(n);
-               
-               n = n->rb_left;
-       }
-}
-
-/*
- * add drq to rbtree and fifo
+ * add rq to rbtree and fifo
  */
 static void
 deadline_add_request(struct request_queue *q, struct request *rq)
 {
        struct deadline_data *dd = q->elevator->elevator_data;
-       struct deadline_rq *drq = RQ_DATA(rq);
+       const int data_dir = rq_data_dir(rq);
 
-       const int data_dir = rq_data_dir(drq->request);
+       deadline_add_rq_rb(dd, rq);
 
-       deadline_add_drq_rb(dd, drq);
        /*
-        * set expire time (only used for reads) and add to fifo list
+        * set expire time and add to fifo list
         */
-       drq->expires = jiffies + dd->fifo_expire[data_dir];
-       list_add_tail(&drq->fifo, &dd->fifo_list[data_dir]);
-
-       if (rq_mergeable(rq))
-               deadline_add_drq_hash(dd, drq);
+       rq_set_fifo_time(rq, jiffies + dd->fifo_expire[data_dir]);
+       list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
 }
 
 /*
- * remove rq from rbtree, fifo, and hash
+ * remove rq from rbtree and fifo.
  */
-static void deadline_remove_request(request_queue_t *q, struct request *rq)
+static void deadline_remove_request(struct request_queue *q, struct request *rq)
 {
-       struct deadline_rq *drq = RQ_DATA(rq);
        struct deadline_data *dd = q->elevator->elevator_data;
 
-       list_del_init(&drq->fifo);
-       deadline_del_drq_rb(dd, drq);
-       deadline_del_drq_hash(drq);
+       rq_fifo_clear(rq);
+       deadline_del_rq_rb(dd, rq);
 }
 
 static int
-deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
+deadline_merge(struct request_queue *q, struct request **req, struct bio *bio)
 {
        struct deadline_data *dd = q->elevator->elevator_data;
        struct request *__rq;
        int ret;
 
        /*
-        * see if the merge hash can satisfy a back merge
-        */
-       __rq = deadline_find_drq_hash(dd, bio->bi_sector);
-       if (__rq) {
-               BUG_ON(__rq->sector + __rq->nr_sectors != bio->bi_sector);
-
-               if (elv_rq_merge_ok(__rq, bio)) {
-                       ret = ELEVATOR_BACK_MERGE;
-                       goto out;
-               }
-       }
-
-       /*
         * check for front merge
         */
        if (dd->front_merges) {
-               sector_t rb_key = bio->bi_sector + bio_sectors(bio);
+               sector_t sector = bio->bi_sector + bio_sectors(bio);
 
-               __rq = deadline_find_drq_rb(dd, rb_key, bio_data_dir(bio));
+               __rq = elv_rb_find(&dd->sort_list[bio_data_dir(bio)], sector);
                if (__rq) {
-                       BUG_ON(rb_key != rq_rb_key(__rq));
+                       BUG_ON(sector != blk_rq_pos(__rq));
 
                        if (elv_rq_merge_ok(__rq, bio)) {
                                ret = ELEVATOR_FRONT_MERGE;
@@ -343,63 +147,36 @@ deadline_merge(request_queue_t *q, struct request **req, struct bio *bio)
 
        return ELEVATOR_NO_MERGE;
 out:
-       if (ret)
-               deadline_hot_drq_hash(dd, RQ_DATA(__rq));
        *req = __rq;
        return ret;
 }
 
-static void deadline_merged_request(request_queue_t *q, struct request *req)
+static void deadline_merged_request(struct request_queue *q,
+                                   struct request *req, int type)
 {
        struct deadline_data *dd = q->elevator->elevator_data;
-       struct deadline_rq *drq = RQ_DATA(req);
-
-       /*
-        * hash always needs to be repositioned, key is end sector
-        */
-       deadline_del_drq_hash(drq);
-       deadline_add_drq_hash(dd, drq);
 
        /*
         * if the merge was a front merge, we need to reposition request
         */
-       if (rq_rb_key(req) != drq->rb_key) {
-               deadline_del_drq_rb(dd, drq);
-               deadline_add_drq_rb(dd, drq);
+       if (type == ELEVATOR_FRONT_MERGE) {
+               elv_rb_del(deadline_rb_root(dd, req), req);
+               deadline_add_rq_rb(dd, req);
        }
 }
 
 static void
-deadline_merged_requests(request_queue_t *q, struct request *req,
+deadline_merged_requests(struct request_queue *q, struct request *req,
                         struct request *next)
 {
-       struct deadline_data *dd = q->elevator->elevator_data;
-       struct deadline_rq *drq = RQ_DATA(req);
-       struct deadline_rq *dnext = RQ_DATA(next);
-
-       BUG_ON(!drq);
-       BUG_ON(!dnext);
-
-       /*
-        * reposition drq (this is the merged request) in hash, and in rbtree
-        * in case of a front merge
-        */
-       deadline_del_drq_hash(drq);
-       deadline_add_drq_hash(dd, drq);
-
-       if (rq_rb_key(req) != drq->rb_key) {
-               deadline_del_drq_rb(dd, drq);
-               deadline_add_drq_rb(dd, drq);
-       }
-
        /*
-        * if dnext expires before drq, assign its expire time to drq
-        * and move into dnext position (dnext will be deleted) in fifo
+        * if next expires before rq, assign its expire time to rq
+        * and move into next position (next will be deleted) in fifo
         */
-       if (!list_empty(&drq->fifo) && !list_empty(&dnext->fifo)) {
-               if (time_before(dnext->expires, drq->expires)) {
-                       list_move(&drq->fifo, &dnext->fifo);
-                       drq->expires = dnext->expires;
+       if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+               if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
+                       list_move(&req->queuelist, &next->queuelist);
+                       rq_set_fifo_time(req, rq_fifo_time(next));
                }
        }
 
@@ -413,52 +190,47 @@ deadline_merged_requests(request_queue_t *q, struct request *req,
  * move request from sort list to dispatch queue.
  */
 static inline void
-deadline_move_to_dispatch(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_move_to_dispatch(struct deadline_data *dd, struct request *rq)
 {
-       request_queue_t *q = drq->request->q;
+       struct request_queue *q = rq->q;
 
-       deadline_remove_request(q, drq->request);
-       elv_dispatch_add_tail(q, drq->request);
+       deadline_remove_request(q, rq);
+       elv_dispatch_add_tail(q, rq);
 }
 
 /*
  * move an entry to dispatch queue
  */
 static void
-deadline_move_request(struct deadline_data *dd, struct deadline_rq *drq)
+deadline_move_request(struct deadline_data *dd, struct request *rq)
 {
-       const int data_dir = rq_data_dir(drq->request);
-       struct rb_node *rbnext = rb_next(&drq->rb_node);
+       const int data_dir = rq_data_dir(rq);
 
-       dd->next_drq[READ] = NULL;
-       dd->next_drq[WRITE] = NULL;
+       dd->next_rq[READ] = NULL;
+       dd->next_rq[WRITE] = NULL;
+       dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-       if (rbnext)
-               dd->next_drq[data_dir] = rb_entry_drq(rbnext);
-       
-       dd->last_sector = drq->request->sector + drq->request->nr_sectors;
+       dd->last_sector = rq_end_sector(rq);
 
        /*
         * take it off the sort and fifo list, move
         * to dispatch queue
         */
-       deadline_move_to_dispatch(dd, drq);
+       deadline_move_to_dispatch(dd, rq);
 }
 
-#define list_entry_fifo(ptr)   list_entry((ptr), struct deadline_rq, fifo)
-
 /*
- * deadline_check_fifo returns 0 if there are no expired reads on the fifo,
+ * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
  * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
  */
 static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
 {
-       struct deadline_rq *drq = list_entry_fifo(dd->fifo_list[ddir].next);
+       struct request *rq = rq_entry_fifo(dd->fifo_list[ddir].next);
 
        /*
-        * drq is expired!
+        * rq is expired!
         */
-       if (time_after(jiffies, drq->expires))
+       if (time_after(jiffies, rq_fifo_time(rq)))
                return 1;
 
        return 0;
@@ -468,33 +240,25 @@ static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
  * deadline_dispatch_requests selects the best request according to
  * read/write expire, fifo_batch, etc
  */
-static int deadline_dispatch_requests(request_queue_t *q, int force)
+static int deadline_dispatch_requests(struct request_queue *q, int force)
 {
        struct deadline_data *dd = q->elevator->elevator_data;
        const int reads = !list_empty(&dd->fifo_list[READ]);
        const int writes = !list_empty(&dd->fifo_list[WRITE]);
-       struct deadline_rq *drq;
+       struct request *rq;
        int data_dir;
 
        /*
         * batches are currently reads XOR writes
         */
-       if (dd->next_drq[WRITE])
-               drq = dd->next_drq[WRITE];
+       if (dd->next_rq[WRITE])
+               rq = dd->next_rq[WRITE];
        else
-               drq = dd->next_drq[READ];
-
-       if (drq) {
-               /* we have a "next request" */
-               
-               if (dd->last_sector != drq->request->sector)
-                       /* end the batch on a non sequential request */
-                       dd->batching += dd->fifo_batch;
-               
-               if (dd->batching < dd->fifo_batch)
-                       /* we are still entitled to batch */
-                       goto dispatch_request;
-       }
+               rq = dd->next_rq[READ];
+
+       if (rq && dd->batching < dd->fifo_batch)
+               /* we have a next request are still entitled to batch */
+               goto dispatch_request;
 
        /*
         * at this point we are not running a batch. select the appropriate
@@ -502,7 +266,7 @@ 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;
@@ -518,7 +282,7 @@ 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;
 
@@ -533,115 +297,53 @@ dispatch_find_request:
        /*
         * we are not running a batch, find best request for selected data_dir
         */
-       if (deadline_check_fifo(dd, data_dir)) {
-               /* An expired request exists - satisfy it */
-               dd->batching = 0;
-               drq = list_entry_fifo(dd->fifo_list[data_dir].next);
-               
-       } else if (dd->next_drq[data_dir]) {
+       if (deadline_check_fifo(dd, data_dir) || !dd->next_rq[data_dir]) {
                /*
-                * The last req was the same dir and we have a next request in
-                * sort order. No expired requests so continue on from here.
+                * A deadline has expired, the last request was in the other
+                * direction, or we have run out of higher-sectored requests.
+                * Start again from the request with the earliest expiry time.
                 */
-               drq = dd->next_drq[data_dir];
+               rq = rq_entry_fifo(dd->fifo_list[data_dir].next);
        } else {
                /*
-                * The last req was the other direction or we have run out of
-                * higher-sectored requests. Go back to the lowest sectored
-                * request (1 way elevator) and start a new batch.
+                * The last req was the same dir and we have a next request in
+                * sort order. No expired requests so continue on from here.
                 */
-               dd->batching = 0;
-               drq = deadline_find_first_drq(dd, data_dir);
+               rq = dd->next_rq[data_dir];
        }
 
+       dd->batching = 0;
+
 dispatch_request:
        /*
-        * drq is the selected appropriate request.
+        * rq is the selected appropriate request.
         */
        dd->batching++;
-       deadline_move_request(dd, drq);
+       deadline_move_request(dd, rq);
 
        return 1;
 }
 
-static int deadline_queue_empty(request_queue_t *q)
-{
-       struct deadline_data *dd = q->elevator->elevator_data;
-
-       return list_empty(&dd->fifo_list[WRITE])
-               && list_empty(&dd->fifo_list[READ]);
-}
-
-static struct request *
-deadline_former_request(request_queue_t *q, struct request *rq)
-{
-       struct deadline_rq *drq = RQ_DATA(rq);
-       struct rb_node *rbprev = rb_prev(&drq->rb_node);
-
-       if (rbprev)
-               return rb_entry_drq(rbprev)->request;
-
-       return NULL;
-}
-
-static struct request *
-deadline_latter_request(request_queue_t *q, struct request *rq)
-{
-       struct deadline_rq *drq = RQ_DATA(rq);
-       struct rb_node *rbnext = rb_next(&drq->rb_node);
-
-       if (rbnext)
-               return rb_entry_drq(rbnext)->request;
-
-       return NULL;
-}
-
-static void deadline_exit_queue(elevator_t *e)
+static void deadline_exit_queue(struct elevator_queue *e)
 {
        struct deadline_data *dd = e->elevator_data;
 
        BUG_ON(!list_empty(&dd->fifo_list[READ]));
        BUG_ON(!list_empty(&dd->fifo_list[WRITE]));
 
-       mempool_destroy(dd->drq_pool);
-       kfree(dd->hash);
        kfree(dd);
 }
 
 /*
- * initialize elevator private data (deadline_data), and alloc a drq for
- * each request on the free lists
+ * initialize elevator private data (deadline_data).
  */
-static void *deadline_init_queue(request_queue_t *q, elevator_t *e)
+static void *deadline_init_queue(struct request_queue *q)
 {
        struct deadline_data *dd;
-       int i;
-
-       if (!drq_pool)
-               return NULL;
 
-       dd = kmalloc_node(sizeof(*dd), GFP_KERNEL, q->node);
+       dd = kmalloc_node(sizeof(*dd), GFP_KERNEL | __GFP_ZERO, q->node);
        if (!dd)
                return NULL;
-       memset(dd, 0, sizeof(*dd));
-
-       dd->hash = kmalloc_node(sizeof(struct list_head)*DL_HASH_ENTRIES,
-                               GFP_KERNEL, q->node);
-       if (!dd->hash) {
-               kfree(dd);
-               return NULL;
-       }
-
-       dd->drq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
-                                       mempool_free_slab, drq_pool, q->node);
-       if (!dd->drq_pool) {
-               kfree(dd->hash);
-               kfree(dd);
-               return NULL;
-       }
-
-       for (i = 0; i < DL_HASH_ENTRIES; i++)
-               INIT_LIST_HEAD(&dd->hash[i]);
 
        INIT_LIST_HEAD(&dd->fifo_list[READ]);
        INIT_LIST_HEAD(&dd->fifo_list[WRITE]);
@@ -655,40 +357,6 @@ static void *deadline_init_queue(request_queue_t *q, elevator_t *e)
        return dd;
 }
 
-static void deadline_put_request(request_queue_t *q, struct request *rq)
-{
-       struct deadline_data *dd = q->elevator->elevator_data;
-       struct deadline_rq *drq = RQ_DATA(rq);
-
-       mempool_free(drq, dd->drq_pool);
-       rq->elevator_private = NULL;
-}
-
-static int
-deadline_set_request(request_queue_t *q, struct request *rq, struct bio *bio,
-                    gfp_t gfp_mask)
-{
-       struct deadline_data *dd = q->elevator->elevator_data;
-       struct deadline_rq *drq;
-
-       drq = mempool_alloc(dd->drq_pool, gfp_mask);
-       if (drq) {
-               memset(drq, 0, sizeof(*drq));
-               RB_CLEAR(&drq->rb_node);
-               drq->request = rq;
-
-               INIT_LIST_HEAD(&drq->hash);
-               drq->on_hash = 0;
-
-               INIT_LIST_HEAD(&drq->fifo);
-
-               rq->elevator_private = drq;
-               return 0;
-       }
-
-       return 1;
-}
-
 /*
  * sysfs parts below
  */
@@ -709,7 +377,7 @@ deadline_var_store(int *var, const char *page, size_t count)
 }
 
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)                           \
-static ssize_t __FUNC(elevator_t *e, char *page)                       \
+static ssize_t __FUNC(struct elevator_queue *e, char *page)            \
 {                                                                      \
        struct deadline_data *dd = e->elevator_data;                    \
        int __data = __VAR;                                             \
@@ -725,7 +393,7 @@ SHOW_FUNCTION(deadline_fifo_batch_show, dd->fifo_batch, 0);
 #undef SHOW_FUNCTION
 
 #define STORE_FUNCTION(__FUNC, __PTR, MIN, MAX, __CONV)                        \
-static ssize_t __FUNC(elevator_t *e, const char *page, size_t count)   \
+static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)        \
 {                                                                      \
        struct deadline_data *dd = e->elevator_data;                    \
        int __data;                                                     \
@@ -767,11 +435,8 @@ static struct elevator_type iosched_deadline = {
                .elevator_merge_req_fn =        deadline_merged_requests,
                .elevator_dispatch_fn =         deadline_dispatch_requests,
                .elevator_add_req_fn =          deadline_add_request,
-               .elevator_queue_empty_fn =      deadline_queue_empty,
-               .elevator_former_req_fn =       deadline_former_request,
-               .elevator_latter_req_fn =       deadline_latter_request,
-               .elevator_set_req_fn =          deadline_set_request,
-               .elevator_put_req_fn =          deadline_put_request,
+               .elevator_former_req_fn =       elv_rb_former_request,
+               .elevator_latter_req_fn =       elv_rb_latter_request,
                .elevator_init_fn =             deadline_init_queue,
                .elevator_exit_fn =             deadline_exit_queue,
        },
@@ -783,24 +448,13 @@ static struct elevator_type iosched_deadline = {
 
 static int __init deadline_init(void)
 {
-       int ret;
-
-       drq_pool = kmem_cache_create("deadline_drq", sizeof(struct deadline_rq),
-                                    0, 0, NULL, NULL);
+       elv_register(&iosched_deadline);
 
-       if (!drq_pool)
-               return -ENOMEM;
-
-       ret = elv_register(&iosched_deadline);
-       if (ret)
-               kmem_cache_destroy(drq_pool);
-
-       return ret;
+       return 0;
 }
 
 static void __exit deadline_exit(void)
 {
-       kmem_cache_destroy(drq_pool);
        elv_unregister(&iosched_deadline);
 }