1 files changed, 162 insertions, 512 deletions

diff --git a/block/as-iosched.c b/block/as-iosched.c
index 5da56d48fbd..50b95e4c142 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -1,7 +1,7 @@
 /*
  *  Anticipatory & deadline i/o scheduler.
  *
- *  Copyright (C) 2002 Jens Axboe <axboe@suse.de>
+ *  Copyright (C) 2002 Jens Axboe <axboe@kernel.dk>
  *                     Nick Piggin <nickpiggin@yahoo.com.au>
  *
  */
@@ -14,7 +14,6 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/compiler.h>
-#include <linux/hash.h>
 #include <linux/rbtree.h>
 #include <linux/interrupt.h>
 
@@ -93,9 +92,8 @@ struct as_data {
 	struct rb_root sort_list[2];
 	struct list_head fifo_list[2];
 
-	struct as_rq *next_arq[2];	/* next in sort order */
+	struct request *next_rq[2];	/* next in sort order */
 	sector_t last_sector[2];	/* last REQ_SYNC & REQ_ASYNC sectors */
-	struct hlist_head *hash;	/* request hash */
 
 	unsigned long exit_prob;	/* probability a task will exit while
 					   being waited on */
@@ -115,7 +113,6 @@ struct as_data {
 	int write_batch_count;		/* max # of reqs in a write batch */
 	int current_write_count;	/* how many requests left this batch */
 	int write_batch_idled;		/* has the write batch gone idle? */
-	mempool_t *arq_pool;
 
 	enum anticipation_status antic_status;
 	unsigned long antic_start;	/* jiffies: when it started */
@@ -133,8 +130,6 @@ struct as_data {
 	unsigned long antic_expire;
 };
 
-#define list_entry_fifo(ptr)	list_entry((ptr), struct as_rq, fifo)
-
 /*
  * per-request data.
  */
@@ -150,40 +145,14 @@ enum arq_state {
 	AS_RQ_POSTSCHED,	/* when they shouldn't be */
 };
 
-struct as_rq {
-	/*
-	 * rbtree index, key is the starting offset
-	 */
-	struct rb_node rb_node;
-	sector_t rb_key;
-
-	struct request *request;
-
-	struct io_context *io_context;	/* The submitting task */
-
-	/*
-	 * request hash, key is the ending offset (for back merge lookup)
-	 */
-	struct hlist_node hash;
-
-	/*
-	 * expire fifo
-	 */
-	struct list_head fifo;
-	unsigned long expires;
+#define RQ_IOC(rq)	((struct io_context *) (rq)->elevator_private)
+#define RQ_STATE(rq)	((enum arq_state)(rq)->elevator_private2)
+#define RQ_SET_STATE(rq, state)	((rq)->elevator_private2 = (void *) state)
 
-	unsigned int is_sync;
-	enum arq_state state;
-};
-
-#define RQ_DATA(rq)	((struct as_rq *) (rq)->elevator_private)
-
-static kmem_cache_t *arq_pool;
-
-static atomic_t ioc_count = ATOMIC_INIT(0);
+static DEFINE_PER_CPU(unsigned long, ioc_count);
 static struct completion *ioc_gone;
 
-static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq);
+static void as_move_to_dispatch(struct as_data *ad, struct request *rq);
 static void as_antic_stop(struct as_data *ad);
 
 /*
@@ -194,7 +163,8 @@ static void as_antic_stop(struct as_data *ad);
 static void free_as_io_context(struct as_io_context *aic)
 {
 	kfree(aic);
-	if (atomic_dec_and_test(&ioc_count) && ioc_gone)
+	elv_ioc_count_dec(ioc_count);
+	if (ioc_gone && !elv_ioc_count_read(ioc_count))
 		complete(ioc_gone);
 }
 
@@ -230,7 +200,7 @@ static struct as_io_context *alloc_as_io_context(void)
 		ret->seek_total = 0;
 		ret->seek_samples = 0;
 		ret->seek_mean = 0;
-		atomic_inc(&ioc_count);
+		elv_ioc_count_inc(ioc_count);
 	}
 
 	return ret;
@@ -240,9 +210,9 @@ static struct as_io_context *alloc_as_io_context(void)
  * If the current task has no AS IO context then create one and initialise it.
  * Then take a ref on the task's io context and return it.
  */
-static struct io_context *as_get_io_context(void)
+static struct io_context *as_get_io_context(int node)
 {
-	struct io_context *ioc = get_io_context(GFP_ATOMIC);
+	struct io_context *ioc = get_io_context(GFP_ATOMIC, node);
 	if (ioc && !ioc->aic) {
 		ioc->aic = alloc_as_io_context();
 		if (!ioc->aic) {
@@ -253,194 +223,43 @@ static struct io_context *as_get_io_context(void)
 	return ioc;
 }
 
-static void as_put_io_context(struct as_rq *arq)
+static void as_put_io_context(struct request *rq)
 {
 	struct as_io_context *aic;
 
-	if (unlikely(!arq->io_context))
+	if (unlikely(!RQ_IOC(rq)))
 		return;
 
-	aic = arq->io_context->aic;
+	aic = RQ_IOC(rq)->aic;
 
-	if (arq->is_sync == REQ_SYNC && aic) {
+	if (rq_is_sync(rq) && aic) {
 		spin_lock(&aic->lock);
 		set_bit(AS_TASK_IORUNNING, &aic->state);
 		aic->last_end_request = jiffies;
 		spin_unlock(&aic->lock);
 	}
 
-	put_io_context(arq->io_context);
-}
-
-/*
- * the back merge hash support functions
- */
-static const int as_hash_shift = 6;
-#define AS_HASH_BLOCK(sec)	((sec) >> 3)
-#define AS_HASH_FN(sec)		(hash_long(AS_HASH_BLOCK((sec)), as_hash_shift))
-#define AS_HASH_ENTRIES		(1 << as_hash_shift)
-#define rq_hash_key(rq)		((rq)->sector + (rq)->nr_sectors)
-
-static inline void __as_del_arq_hash(struct as_rq *arq)
-{
-	hlist_del_init(&arq->hash);
-}
-
-static inline void as_del_arq_hash(struct as_rq *arq)
-{
-	if (!hlist_unhashed(&arq->hash))
-		__as_del_arq_hash(arq);
-}
-
-static void as_add_arq_hash(struct as_data *ad, struct as_rq *arq)
-{
-	struct request *rq = arq->request;
-
-	BUG_ON(!hlist_unhashed(&arq->hash));
-
-	hlist_add_head(&arq->hash, &ad->hash[AS_HASH_FN(rq_hash_key(rq))]);
-}
-
-/*
- * move hot entry to front of chain
- */
-static inline void as_hot_arq_hash(struct as_data *ad, struct as_rq *arq)
-{
-	struct request *rq = arq->request;
-	struct hlist_head *head = &ad->hash[AS_HASH_FN(rq_hash_key(rq))];
-
-	if (hlist_unhashed(&arq->hash)) {
-		WARN_ON(1);
-		return;
-	}
-
-	if (&arq->hash != head->first) {
-		hlist_del(&arq->hash);
-		hlist_add_head(&arq->hash, head);
-	}
-}
-
-static struct request *as_find_arq_hash(struct as_data *ad, sector_t offset)
-{
-	struct hlist_head *hash_list = &ad->hash[AS_HASH_FN(offset)];
-	struct hlist_node *entry, *next;
-	struct as_rq *arq;
-
-	hlist_for_each_entry_safe(arq, entry, next, hash_list, hash) {
-		struct request *__rq = arq->request;
-
-		BUG_ON(hlist_unhashed(&arq->hash));
-
-		if (!rq_mergeable(__rq)) {
-			as_del_arq_hash(arq);
-			continue;
-		}
-
-		if (rq_hash_key(__rq) == offset)
-			return __rq;
-	}
-
-	return NULL;
+	put_io_context(RQ_IOC(rq));
 }
 
 /*
  * rb tree support functions
  */
-#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
-
-/*
- * as_find_first_arq 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 as_rq *as_find_first_arq(struct as_data *ad, int data_dir)
-{
-	struct rb_node *n = ad->sort_list[data_dir].rb_node;
-
-	if (n == NULL)
-		return NULL;
-
-	for (;;) {
-		if (n->rb_left == NULL)
-			return rb_entry_arq(n);
-
-		n = n->rb_left;
-	}
-}
-
-/*
- * Add the request to the rb tree if it is unique.  If there is an alias (an
- * existing request against the same sector), which can happen when using
- * direct IO, then return the alias.
- */
-static struct as_rq *__as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
-{
-	struct rb_node **p = &ARQ_RB_ROOT(ad, arq)->rb_node;
-	struct rb_node *parent = NULL;
-	struct as_rq *__arq;
-	struct request *rq = arq->request;
-
-	arq->rb_key = rq_rb_key(rq);
-
-	while (*p) {
-		parent = *p;
-		__arq = rb_entry_arq(parent);
-
-		if (arq->rb_key < __arq->rb_key)
-			p = &(*p)->rb_left;
-		else if (arq->rb_key > __arq->rb_key)
-			p = &(*p)->rb_right;
-		else
-			return __arq;
-	}
-
-	rb_link_node(&arq->rb_node, parent, p);
-	rb_insert_color(&arq->rb_node, ARQ_RB_ROOT(ad, arq));
-
-	return NULL;
-}
+#define RQ_RB_ROOT(ad, rq)	(&(ad)->sort_list[rq_is_sync((rq))])
 
-static void as_add_arq_rb(struct as_data *ad, struct as_rq *arq)
+static void as_add_rq_rb(struct as_data *ad, struct request *rq)
 {
-	struct as_rq *alias;
+	struct request *alias;
 
-	while ((unlikely(alias = __as_add_arq_rb(ad, arq)))) {
+	while ((unlikely(alias = elv_rb_add(RQ_RB_ROOT(ad, rq), rq)))) {
 		as_move_to_dispatch(ad, alias);
 		as_antic_stop(ad);
 	}
 }
 
-static inline void as_del_arq_rb(struct as_data *ad, struct as_rq *arq)
-{
-	if (!RB_EMPTY_NODE(&arq->rb_node)) {
-		WARN_ON(1);
-		return;
-	}
-
-	rb_erase(&arq->rb_node, ARQ_RB_ROOT(ad, arq));
-	RB_CLEAR_NODE(&arq->rb_node);
-}
-
-static struct request *
-as_find_arq_rb(struct as_data *ad, sector_t sector, int data_dir)
+static inline void as_del_rq_rb(struct as_data *ad, struct request *rq)
 {
-	struct rb_node *n = ad->sort_list[data_dir].rb_node;
-	struct as_rq *arq;
-
-	while (n) {
-		arq = rb_entry_arq(n);
-
-		if (sector < arq->rb_key)
-			n = n->rb_left;
-		else if (sector > arq->rb_key)
-			n = n->rb_right;
-		else
-			return arq->request;
-	}
-
-	return NULL;
+	elv_rb_del(RQ_RB_ROOT(ad, rq), rq);
 }
 
 /*
@@ -458,26 +277,26 @@ as_find_arq_rb(struct as_data *ad, sector_t sector, int data_dir)
  * as_choose_req selects the preferred one of two requests of the same data_dir
  * ignoring time - eg. timeouts, which is the job of as_dispatch_request
  */
-static struct as_rq *
-as_choose_req(struct as_data *ad, struct as_rq *arq1, struct as_rq *arq2)
+static struct request *
+as_choose_req(struct as_data *ad, struct request *rq1, struct request *rq2)
 {
 	int data_dir;
 	sector_t last, s1, s2, d1, d2;
 	int r1_wrap=0, r2_wrap=0;	/* requests are behind the disk head */
 	const sector_t maxback = MAXBACK;
 
-	if (arq1 == NULL || arq1 == arq2)
-		return arq2;
-	if (arq2 == NULL)
-		return arq1;
+	if (rq1 == NULL || rq1 == rq2)
+		return rq2;
+	if (rq2 == NULL)
+		return rq1;
 
-	data_dir = arq1->is_sync;
+	data_dir = rq_is_sync(rq1);
 
 	last = ad->last_sector[data_dir];
-	s1 = arq1->request->sector;
-	s2 = arq2->request->sector;
+	s1 = rq1->sector;
+	s2 = rq2->sector;
 
-	BUG_ON(data_dir != arq2->is_sync);
+	BUG_ON(data_dir != rq_is_sync(rq2));
 
 	/*
 	 * Strict one way elevator _except_ in the case where we allow
@@ -504,61 +323,58 @@ as_choose_req(struct as_data *ad, struct as_rq *arq1, struct as_rq *arq2)
 
 	/* Found required data */
 	if (!r1_wrap && r2_wrap)
-		return arq1;
+		return rq1;
 	else if (!r2_wrap && r1_wrap)
-		return arq2;
+		return rq2;
 	else if (r1_wrap && r2_wrap) {
 		/* both behind the head */
 		if (s1 <= s2)
-			return arq1;
+			return rq1;
 		else
-			return arq2;
+			return rq2;
 	}
 
 	/* Both requests in front of the head */
 	if (d1 < d2)
-		return arq1;
+		return rq1;
 	else if (d2 < d1)
-		return arq2;
+		return rq2;
 	else {
 		if (s1 >= s2)
-			return arq1;
+			return rq1;
 		else
-			return arq2;
+			return rq2;
 	}
 }
 
 /*
- * as_find_next_arq finds the next request after @prev in elevator order.
+ * as_find_next_rq finds the next request after @prev in elevator order.
  * this with as_choose_req form the basis for how the scheduler chooses
  * what request to process next. Anticipation works on top of this.
  */
-static struct as_rq *as_find_next_arq(struct as_data *ad, struct as_rq *last)
+static struct request *
+as_find_next_rq(struct as_data *ad, struct request *last)
 {
-	const int data_dir = last->is_sync;
-	struct as_rq *ret;
 	struct rb_node *rbnext = rb_next(&last->rb_node);
 	struct rb_node *rbprev = rb_prev(&last->rb_node);
-	struct as_rq *arq_next, *arq_prev;
+	struct request *next = NULL, *prev = NULL;
 
-	BUG_ON(!RB_EMPTY_NODE(&last->rb_node));
+	BUG_ON(RB_EMPTY_NODE(&last->rb_node));
 
 	if (rbprev)
-		arq_prev = rb_entry_arq(rbprev);
-	else
-		arq_prev = NULL;
+		prev = rb_entry_rq(rbprev);
 
 	if (rbnext)
-		arq_next = rb_entry_arq(rbnext);
+		next = rb_entry_rq(rbnext);
 	else {
-		arq_next = as_find_first_arq(ad, data_dir);
-		if (arq_next == last)
-			arq_next = NULL;
-	}
+		const int data_dir = rq_is_sync(last);
 
-	ret = as_choose_req(ad,	arq_next, arq_prev);
+		rbnext = rb_first(&ad->sort_list[data_dir]);
+		if (rbnext && rbnext != &last->rb_node)
+			next = rb_entry_rq(rbnext);
+	}
 
-	return ret;
+	return as_choose_req(ad, next, prev);
 }
 
 /*
@@ -712,8 +528,7 @@ static void as_update_seekdist(struct as_data *ad, struct as_io_context *aic,
 static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
 				struct request *rq)
 {
-	struct as_rq *arq = RQ_DATA(rq);
-	int data_dir = arq->is_sync;
+	int data_dir = rq_is_sync(rq);
 	unsigned long thinktime = 0;
 	sector_t seek_dist;
 
@@ -752,11 +567,11 @@ static void as_update_iohist(struct as_data *ad, struct as_io_context *aic,
  * previous one issued.
  */
 static int as_close_req(struct as_data *ad, struct as_io_context *aic,
-				struct as_rq *arq)
+			struct request *rq)
 {
 	unsigned long delay;	/* milliseconds */
 	sector_t last = ad->last_sector[ad->batch_data_dir];
-	sector_t next = arq->request->sector;
+	sector_t next = rq->sector;
 	sector_t delta; /* acceptable close offset (in sectors) */
 	sector_t s;
 
@@ -813,7 +628,7 @@ static int as_close_req(struct as_data *ad, struct as_io_context *aic,
  *
  * If this task has queued some other IO, do not enter enticipation.
  */
-static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
+static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
 {
 	struct io_context *ioc;
 	struct as_io_context *aic;
@@ -821,7 +636,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
 	ioc = ad->io_context;
 	BUG_ON(!ioc);
 
-	if (arq && ioc == arq->io_context) {
+	if (rq && ioc == RQ_IOC(rq)) {
 		/* request from same process */
 		return 1;
 	}
@@ -848,7 +663,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
 		return 1;
 	}
 
-	if (arq && arq->is_sync == REQ_SYNC && as_close_req(ad, aic, arq)) {
+	if (rq && rq_is_sync(rq) && as_close_req(ad, aic, rq)) {
 		/*
 		 * Found a close request that is not one of ours.
 		 *
@@ -864,7 +679,7 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
 			ad->exit_no_coop = (7*ad->exit_no_coop)/8;
 		}
 
-		as_update_iohist(ad, aic, arq->request);
+		as_update_iohist(ad, aic, rq);
 		return 1;
 	}
 
@@ -891,10 +706,10 @@ static int as_can_break_anticipation(struct as_data *ad, struct as_rq *arq)
 }
 
 /*
- * as_can_anticipate indicates whether we should either run arq
+ * as_can_anticipate indicates whether we should either run rq
  * or keep anticipating a better request.
  */
-static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
+static int as_can_anticipate(struct as_data *ad, struct request *rq)
 {
 	if (!ad->io_context)
 		/*
@@ -908,7 +723,7 @@ static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
 		 */
 		return 0;
 
-	if (as_can_break_anticipation(ad, arq))
+	if (as_can_break_anticipation(ad, rq))
 		/*
 		 * This request is a good candidate. Don't keep anticipating,
 		 * run it.
@@ -926,16 +741,16 @@ static int as_can_anticipate(struct as_data *ad, struct as_rq *arq)
 }
 
 /*
- * as_update_arq must be called whenever a request (arq) is added to
+ * as_update_rq must be called whenever a request (rq) is added to
  * the sort_list. This function keeps caches up to date, and checks if the
  * request might be one we are "anticipating"
  */
-static void as_update_arq(struct as_data *ad, struct as_rq *arq)
+static void as_update_rq(struct as_data *ad, struct request *rq)
 {
-	const int data_dir = arq->is_sync;
+	const int data_dir = rq_is_sync(rq);
 
-	/* keep the next_arq cache up to date */
-	ad->next_arq[data_dir] = as_choose_req(ad, arq, ad->next_arq[data_dir]);
+	/* keep the next_rq cache up to date */
+	ad->next_rq[data_dir] = as_choose_req(ad, rq, ad->next_rq[data_dir]);
 
 	/*
 	 * have we been anticipating this request?
@@ -944,7 +759,7 @@ static void as_update_arq(struct as_data *ad, struct as_rq *arq)
 	 */
 	if (ad->antic_status == ANTIC_WAIT_REQ
 			|| ad->antic_status == ANTIC_WAIT_NEXT) {
-		if (as_can_break_anticipation(ad, arq))
+		if (as_can_break_anticipation(ad, rq))
 			as_antic_stop(ad);
 	}
 }
@@ -984,12 +799,11 @@ static void update_write_batch(struct as_data *ad)
 static void as_completed_request(request_queue_t *q, struct request *rq)
 {
 	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq = RQ_DATA(rq);
 
 	WARN_ON(!list_empty(&rq->queuelist));
 
-	if (arq->state != AS_RQ_REMOVED) {
-		printk("arq->state %d\n", arq->state);
+	if (RQ_STATE(rq) != AS_RQ_REMOVED) {
+		printk("rq->state %d\n", RQ_STATE(rq));
 		WARN_ON(1);
 		goto out;
 	}
@@ -1009,14 +823,14 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
 	 * actually serviced. This should help devices with big TCQ windows
 	 * and writeback caches
 	 */
-	if (ad->new_batch && ad->batch_data_dir == arq->is_sync) {
+	if (ad->new_batch && ad->batch_data_dir == rq_is_sync(rq)) {
 		update_write_batch(ad);
 		ad->current_batch_expires = jiffies +
 				ad->batch_expire[REQ_SYNC];
 		ad->new_batch = 0;
 	}
 
-	if (ad->io_context == arq->io_context && ad->io_context) {
+	if (ad->io_context == RQ_IOC(rq) && ad->io_context) {
 		ad->antic_start = jiffies;
 		ad->ioc_finished = 1;
 		if (ad->antic_status == ANTIC_WAIT_REQ) {
@@ -1028,9 +842,9 @@ static void as_completed_request(request_queue_t *q, struct request *rq)
 		}
 	}
 
-	as_put_io_context(arq);
+	as_put_io_context(rq);
 out:
-	arq->state = AS_RQ_POSTSCHED;
+	RQ_SET_STATE(rq, AS_RQ_POSTSCHED);
 }
 
 /*
@@ -1041,27 +855,27 @@ out:
  */
 static void as_remove_queued_request(request_queue_t *q, struct request *rq)
 {
-	struct as_rq *arq = RQ_DATA(rq);
-	const int data_dir = arq->is_sync;
+	const int data_dir = rq_is_sync(rq);
 	struct as_data *ad = q->elevator->elevator_data;
+	struct io_context *ioc;
 
-	WARN_ON(arq->state != AS_RQ_QUEUED);
+	WARN_ON(RQ_STATE(rq) != AS_RQ_QUEUED);
 
-	if (arq->io_context && arq->io_context->aic) {
-		BUG_ON(!atomic_read(&arq->io_context->aic->nr_queued));
-		atomic_dec(&arq->io_context->aic->nr_queued);
+	ioc = RQ_IOC(rq);
+	if (ioc && ioc->aic) {
+		BUG_ON(!atomic_read(&ioc->aic->nr_queued));
+		atomic_dec(&ioc->aic->nr_queued);
 	}
 
 	/*
-	 * Update the "next_arq" cache if we are about to remove its
+	 * Update the "next_rq" cache if we are about to remove its
 	 * entry
 	 */
-	if (ad->next_arq[data_dir] == arq)
-		ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
+	if (ad->next_rq[data_dir] == rq)
+		ad->next_rq[data_dir] = as_find_next_rq(ad, rq);
 
-	list_del_init(&arq->fifo);
-	as_del_arq_hash(arq);
-	as_del_arq_rb(ad, arq);
+	rq_fifo_clear(rq);
+	as_del_rq_rb(ad, rq);
 }
 
 /*
@@ -1074,7 +888,7 @@ static void as_remove_queued_request(request_queue_t *q, struct request *rq)
  */
 static int as_fifo_expired(struct as_data *ad, int adir)
 {
-	struct as_rq *arq;
+	struct request *rq;
 	long delta_jif;
 
 	delta_jif = jiffies - ad->last_check_fifo[adir];
@@ -1088,9 +902,9 @@ static int as_fifo_expired(struct as_data *ad, int adir)
 	if (list_empty(&ad->fifo_list[adir]))
 		return 0;
 
-	arq = list_entry_fifo(ad->fifo_list[adir].next);
+	rq = rq_entry_fifo(ad->fifo_list[adir].next);
 
-	return time_after(jiffies, arq->expires);
+	return time_after(jiffies, rq_fifo_time(rq));
 }
 
 /*
@@ -1113,25 +927,25 @@ static inline int as_batch_expired(struct as_data *ad)
 /*
  * move an entry to dispatch queue
  */
-static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
+static void as_move_to_dispatch(struct as_data *ad, struct request *rq)
 {
-	struct request *rq = arq->request;
-	const int data_dir = arq->is_sync;
+	const int data_dir = rq_is_sync(rq);
 
-	BUG_ON(!RB_EMPTY_NODE(&arq->rb_node));
+	BUG_ON(RB_EMPTY_NODE(&rq->rb_node));
 
 	as_antic_stop(ad);
 	ad->antic_status = ANTIC_OFF;
 
 	/*
 	 * This has to be set in order to be correctly updated by
-	 * as_find_next_arq
+	 * as_find_next_rq
 	 */
 	ad->last_sector[data_dir] = rq->sector + rq->nr_sectors;
 
 	if (data_dir == REQ_SYNC) {
+		struct io_context *ioc = RQ_IOC(rq);
 		/* In case we have to anticipate after this */
-		copy_io_context(&ad->io_context, &arq->io_context);
+		copy_io_context(&ad->io_context, &ioc);
 	} else {
 		if (ad->io_context) {
 			put_io_context(ad->io_context);
@@ -1143,19 +957,19 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
 	}
 	ad->ioc_finished = 0;
 
-	ad->next_arq[data_dir] = as_find_next_arq(ad, arq);
+	ad->next_rq[data_dir] = as_find_next_rq(ad, rq);
 
 	/*
 	 * take it off the sort and fifo list, add to dispatch queue
 	 */
 	as_remove_queued_request(ad->q, rq);
-	WARN_ON(arq->state != AS_RQ_QUEUED);
+	WARN_ON(RQ_STATE(rq) != AS_RQ_QUEUED);
 
 	elv_dispatch_sort(ad->q, rq);
 
-	arq->state = AS_RQ_DISPATCHED;
-	if (arq->io_context && arq->io_context->aic)
-		atomic_inc(&arq->io_context->aic->nr_dispatched);
+	RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
+	if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+		atomic_inc(&RQ_IOC(rq)->aic->nr_dispatched);
 	ad->nr_dispatched++;
 }
 
@@ -1167,9 +981,9 @@ static void as_move_to_dispatch(struct as_data *ad, struct as_rq *arq)
 static int as_dispatch_request(request_queue_t *q, int force)
 {
 	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq;
 	const int reads = !list_empty(&ad->fifo_list[REQ_SYNC]);
 	const int writes = !list_empty(&ad->fifo_list[REQ_ASYNC]);
+	struct request *rq;
 
 	if (unlikely(force)) {
 		/*
@@ -1185,14 +999,14 @@ static int as_dispatch_request(request_queue_t *q, int force)
 		ad->changed_batch = 0;
 		ad->new_batch = 0;
 
-		while (ad->next_arq[REQ_SYNC]) {
-			as_move_to_dispatch(ad, ad->next_arq[REQ_SYNC]);
+		while (ad->next_rq[REQ_SYNC]) {
+			as_move_to_dispatch(ad, ad->next_rq[REQ_SYNC]);
 			dispatched++;
 		}
 		ad->last_check_fifo[REQ_SYNC] = jiffies;
 
-		while (ad->next_arq[REQ_ASYNC]) {
-			as_move_to_dispatch(ad, ad->next_arq[REQ_ASYNC]);
+		while (ad->next_rq[REQ_ASYNC]) {
+			as_move_to_dispatch(ad, ad->next_rq[REQ_ASYNC]);
 			dispatched++;
 		}
 		ad->last_check_fifo[REQ_ASYNC] = jiffies;
@@ -1216,19 +1030,19 @@ static int as_dispatch_request(request_queue_t *q, int force)
 		/*
 		 * batch is still running or no reads or no writes
 		 */
-		arq = ad->next_arq[ad->batch_data_dir];
+		rq = ad->next_rq[ad->batch_data_dir];
 
 		if (ad->batch_data_dir == REQ_SYNC && ad->antic_expire) {
 			if (as_fifo_expired(ad, REQ_SYNC))
 				goto fifo_expired;
 
-			if (as_can_anticipate(ad, arq)) {
+			if (as_can_anticipate(ad, rq)) {
 				as_antic_waitreq(ad);
 				return 0;
 			}
 		}
 
-		if (arq) {
+		if (rq) {
 			/* we have a "next request" */
 			if (reads && !writes)
 				ad->current_batch_expires =
@@ -1256,7 +1070,7 @@ static int as_dispatch_request(request_queue_t *q, int force)
 			ad->changed_batch = 1;
 		}
 		ad->batch_data_dir = REQ_SYNC;
-		arq = list_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
+		rq = rq_entry_fifo(ad->fifo_list[REQ_SYNC].next);
 		ad->last_check_fifo[ad->batch_data_dir] = jiffies;
 		goto dispatch_request;
 	}
@@ -1282,7 +1096,7 @@ dispatch_writes:
 		ad->batch_data_dir = REQ_ASYNC;
 		ad->current_write_count = ad->write_batch_count;
 		ad->write_batch_idled = 0;
-		arq = ad->next_arq[ad->batch_data_dir];
+		rq = ad->next_rq[ad->batch_data_dir];
 		goto dispatch_request;
 	}
 
@@ -1296,8 +1110,7 @@ dispatch_request:
 
 	if (as_fifo_expired(ad, ad->batch_data_dir)) {
 fifo_expired:
-		arq = list_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
-		BUG_ON(arq == NULL);
+		rq = rq_entry_fifo(ad->fifo_list[ad->batch_data_dir].next);
 	}
 
 	if (ad->changed_batch) {
@@ -1316,70 +1129,58 @@ fifo_expired:
 	}
 
 	/*
-	 * arq is the selected appropriate request.
+	 * rq is the selected appropriate request.
 	 */
-	as_move_to_dispatch(ad, arq);
+	as_move_to_dispatch(ad, rq);
 
 	return 1;
 }
 
 /*
- * add arq to rbtree and fifo
+ * add rq to rbtree and fifo
  */
 static void as_add_request(request_queue_t *q, struct request *rq)
 {
 	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq = RQ_DATA(rq);
 	int data_dir;
 
-	arq->state = AS_RQ_NEW;
+	RQ_SET_STATE(rq, AS_RQ_NEW);
 
-	if (rq_data_dir(arq->request) == READ
-			|| (arq->request->flags & REQ_RW_SYNC))
-		arq->is_sync = 1;
-	else
-		arq->is_sync = 0;
-	data_dir = arq->is_sync;
+	data_dir = rq_is_sync(rq);
 
-	arq->io_context = as_get_io_context();
+	rq->elevator_private = as_get_io_context(q->node);
 
-	if (arq->io_context) {
-		as_update_iohist(ad, arq->io_context->aic, arq->request);
-		atomic_inc(&arq->io_context->aic->nr_queued);
+	if (RQ_IOC(rq)) {
+		as_update_iohist(ad, RQ_IOC(rq)->aic, rq);
+		atomic_inc(&RQ_IOC(rq)->aic->nr_queued);
 	}
 
-	as_add_arq_rb(ad, arq);
-	if (rq_mergeable(arq->request))
-		as_add_arq_hash(ad, arq);
+	as_add_rq_rb(ad, rq);
 
 	/*
 	 * set expire time (only used for reads) and add to fifo list
 	 */
-	arq->expires = jiffies + ad->fifo_expire[data_dir];
-	list_add_tail(&arq->fifo, &ad->fifo_list[data_dir]);
+	rq_set_fifo_time(rq, jiffies + ad->fifo_expire[data_dir]);
+	list_add_tail(&rq->queuelist, &ad->fifo_list[data_dir]);
 
-	as_update_arq(ad, arq); /* keep state machine up to date */
-	arq->state = AS_RQ_QUEUED;
+	as_update_rq(ad, rq); /* keep state machine up to date */
+	RQ_SET_STATE(rq, AS_RQ_QUEUED);
 }
 
 static void as_activate_request(request_queue_t *q, struct request *rq)
 {
-	struct as_rq *arq = RQ_DATA(rq);
-
-	WARN_ON(arq->state != AS_RQ_DISPATCHED);
-	arq->state = AS_RQ_REMOVED;
-	if (arq->io_context && arq->io_context->aic)
-		atomic_dec(&arq->io_context->aic->nr_dispatched);
+	WARN_ON(RQ_STATE(rq) != AS_RQ_DISPATCHED);
+	RQ_SET_STATE(rq, AS_RQ_REMOVED);
+	if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+		atomic_dec(&RQ_IOC(rq)->aic->nr_dispatched);
 }
 
 static void as_deactivate_request(request_queue_t *q, struct request *rq)
 {
-	struct as_rq *arq = RQ_DATA(rq);
-
-	WARN_ON(arq->state != AS_RQ_REMOVED);
-	arq->state = AS_RQ_DISPATCHED;
-	if (arq->io_context && arq->io_context->aic)
-		atomic_inc(&arq->io_context->aic->nr_dispatched);
+	WARN_ON(RQ_STATE(rq) != AS_RQ_REMOVED);
+	RQ_SET_STATE(rq, AS_RQ_DISPATCHED);
+	if (RQ_IOC(rq) && RQ_IOC(rq)->aic)
+		atomic_inc(&RQ_IOC(rq)->aic->nr_dispatched);
 }
 
 /*
@@ -1396,93 +1197,35 @@ static int as_queue_empty(request_queue_t *q)
 		&& list_empty(&ad->fifo_list[REQ_SYNC]);
 }
 
-static struct request *as_former_request(request_queue_t *q,
-					struct request *rq)
-{
-	struct as_rq *arq = RQ_DATA(rq);
-	struct rb_node *rbprev = rb_prev(&arq->rb_node);
-	struct request *ret = NULL;
-
-	if (rbprev)
-		ret = rb_entry_arq(rbprev)->request;
-
-	return ret;
-}
-
-static struct request *as_latter_request(request_queue_t *q,
-					struct request *rq)
-{
-	struct as_rq *arq = RQ_DATA(rq);
-	struct rb_node *rbnext = rb_next(&arq->rb_node);
-	struct request *ret = NULL;
-
-	if (rbnext)
-		ret = rb_entry_arq(rbnext)->request;
-
-	return ret;
-}
-
 static int
 as_merge(request_queue_t *q, struct request **req, struct bio *bio)
 {
 	struct as_data *ad = q->elevator->elevator_data;
 	sector_t rb_key = bio->bi_sector + bio_sectors(bio);
 	struct request *__rq;
-	int ret;
-
-	/*
-	 * see if the merge hash can satisfy a back merge
-	 */
-	__rq = as_find_arq_hash(ad, 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
 	 */
-	__rq = as_find_arq_rb(ad, rb_key, bio_data_dir(bio));
-	if (__rq) {
-		BUG_ON(rb_key != rq_rb_key(__rq));
-
-		if (elv_rq_merge_ok(__rq, bio)) {
-			ret = ELEVATOR_FRONT_MERGE;
-			goto out;
-		}
+	__rq = elv_rb_find(&ad->sort_list[bio_data_dir(bio)], rb_key);
+	if (__rq && elv_rq_merge_ok(__rq, bio)) {
+		*req = __rq;
+		return ELEVATOR_FRONT_MERGE;
 	}
 
 	return ELEVATOR_NO_MERGE;
-out:
-	if (ret) {
-		if (rq_mergeable(__rq))
-			as_hot_arq_hash(ad, RQ_DATA(__rq));
-	}
-	*req = __rq;
-	return ret;
 }
 
-static void as_merged_request(request_queue_t *q, struct request *req)
+static void as_merged_request(request_queue_t *q, struct request *req, int type)
 {
 	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq = RQ_DATA(req);
-
-	/*
-	 * hash always needs to be repositioned, key is end sector
-	 */
-	as_del_arq_hash(arq);
-	as_add_arq_hash(ad, arq);
 
 	/*
 	 * if the merge was a front merge, we need to reposition request
 	 */
-	if (rq_rb_key(req) != arq->rb_key) {
-		as_del_arq_rb(ad, arq);
-		as_add_arq_rb(ad, arq);
+	if (type == ELEVATOR_FRONT_MERGE) {
+		as_del_rq_rb(ad, req);
+		as_add_rq_rb(ad, req);
 		/*
 		 * Note! At this stage of this and the next function, our next
 		 * request may not be optimal - eg the request may have "grown"
@@ -1494,38 +1237,22 @@ static void as_merged_request(request_queue_t *q, struct request *req)
 static void as_merged_requests(request_queue_t *q, struct request *req,
 			 	struct request *next)
 {
-	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq = RQ_DATA(req);
-	struct as_rq *anext = RQ_DATA(next);
-
-	BUG_ON(!arq);
-	BUG_ON(!anext);
-
 	/*
-	 * reposition arq (this is the merged request) in hash, and in rbtree
-	 * in case of a front merge
+	 * if next expires before rq, assign its expire time to arq
+	 * and move into next position (next will be deleted) in fifo
 	 */
-	as_del_arq_hash(arq);
-	as_add_arq_hash(ad, arq);
-
-	if (rq_rb_key(req) != arq->rb_key) {
-		as_del_arq_rb(ad, arq);
-		as_add_arq_rb(ad, arq);
-	}
+	if (!list_empty(&req->queuelist) && !list_empty(&next->queuelist)) {
+		if (time_before(rq_fifo_time(next), rq_fifo_time(req))) {
+			struct io_context *rioc = RQ_IOC(req);
+			struct io_context *nioc = RQ_IOC(next);
 
-	/*
-	 * if anext expires before arq, assign its expire time to arq
-	 * and move into anext position (anext will be deleted) in fifo
-	 */
-	if (!list_empty(&arq->fifo) && !list_empty(&anext->fifo)) {
-		if (time_before(anext->expires, arq->expires)) {
-			list_move(&arq->fifo, &anext->fifo);
-			arq->expires = anext->expires;
+			list_move(&req->queuelist, &next->queuelist);
+			rq_set_fifo_time(req, rq_fifo_time(next));
 			/*
 			 * Don't copy here but swap, because when anext is
 			 * removed below, it must contain the unused context
 			 */
-			swap_io_context(&arq->io_context, &anext->io_context);
+			swap_io_context(&rioc, &nioc);
 		}
 	}
 
@@ -1533,9 +1260,9 @@ static void as_merged_requests(request_queue_t *q, struct request *req,
 	 * kill knowledge of next, this one is a goner
 	 */
 	as_remove_queued_request(q, next);
-	as_put_io_context(anext);
+	as_put_io_context(next);
 
-	anext->state = AS_RQ_MERGED;
+	RQ_SET_STATE(next, AS_RQ_MERGED);
 }
 
 /*
@@ -1553,61 +1280,18 @@ static void as_work_handler(void *data)
 	unsigned long flags;
 
 	spin_lock_irqsave(q->queue_lock, flags);
-	if (!as_queue_empty(q))
-		q->request_fn(q);
+	blk_start_queueing(q);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
-static void as_put_request(request_queue_t *q, struct request *rq)
-{
-	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq = RQ_DATA(rq);
-
-	if (!arq) {
-		WARN_ON(1);
-		return;
-	}
-
-	if (unlikely(arq->state != AS_RQ_POSTSCHED &&
-		     arq->state != AS_RQ_PRESCHED &&
-		     arq->state != AS_RQ_MERGED)) {
-		printk("arq->state %d\n", arq->state);
-		WARN_ON(1);
-	}
-
-	mempool_free(arq, ad->arq_pool);
-	rq->elevator_private = NULL;
-}
-
-static int as_set_request(request_queue_t *q, struct request *rq,
-			  struct bio *bio, gfp_t gfp_mask)
-{
-	struct as_data *ad = q->elevator->elevator_data;
-	struct as_rq *arq = mempool_alloc(ad->arq_pool, gfp_mask);
-
-	if (arq) {
-		memset(arq, 0, sizeof(*arq));
-		RB_CLEAR_NODE(&arq->rb_node);
-		arq->request = rq;
-		arq->state = AS_RQ_PRESCHED;
-		arq->io_context = NULL;
-		INIT_HLIST_NODE(&arq->hash);
-		INIT_LIST_HEAD(&arq->fifo);
-		rq->elevator_private = arq;
-		return 0;
-	}
-
-	return 1;
-}
-
-static int as_may_queue(request_queue_t *q, int rw, struct bio *bio)
+static int as_may_queue(request_queue_t *q, int rw)
 {
 	int ret = ELV_MQUEUE_MAY;
 	struct as_data *ad = q->elevator->elevator_data;
 	struct io_context *ioc;
 	if (ad->antic_status == ANTIC_WAIT_REQ ||
 			ad->antic_status == ANTIC_WAIT_NEXT) {
-		ioc = as_get_io_context();
+		ioc = as_get_io_context(q->node);
 		if (ad->io_context == ioc)
 			ret = ELV_MQUEUE_MUST;
 		put_io_context(ioc);
@@ -1626,23 +1310,16 @@ static void as_exit_queue(elevator_t *e)
 	BUG_ON(!list_empty(&ad->fifo_list[REQ_SYNC]));
 	BUG_ON(!list_empty(&ad->fifo_list[REQ_ASYNC]));
 
-	mempool_destroy(ad->arq_pool);
 	put_io_context(ad->io_context);
-	kfree(ad->hash);
 	kfree(ad);
 }
 
 /*
- * initialize elevator private data (as_data), and alloc a arq for
- * each request on the free lists
+ * initialize elevator private data (as_data).
  */
 static void *as_init_queue(request_queue_t *q, elevator_t *e)
 {
 	struct as_data *ad;
-	int i;
-
-	if (!arq_pool)
-		return NULL;
 
 	ad = kmalloc_node(sizeof(*ad), GFP_KERNEL, q->node);
 	if (!ad)
@@ -1651,30 +1328,12 @@ static void *as_init_queue(request_queue_t *q, elevator_t *e)
 
 	ad->q = q; /* Identify what queue the data belongs to */
 
-	ad->hash = kmalloc_node(sizeof(struct hlist_head)*AS_HASH_ENTRIES,
-				GFP_KERNEL, q->node);
-	if (!ad->hash) {
-		kfree(ad);
-		return NULL;
-	}
-
-	ad->arq_pool = mempool_create_node(BLKDEV_MIN_RQ, mempool_alloc_slab,
-				mempool_free_slab, arq_pool, q->node);
-	if (!ad->arq_pool) {
-		kfree(ad->hash);
-		kfree(ad);
-		return NULL;
-	}
-
 	/* anticipatory scheduling helpers */
 	ad->antic_timer.function = as_antic_timeout;
 	ad->antic_timer.data = (unsigned long)q;
 	init_timer(&ad->antic_timer);
 	INIT_WORK(&ad->antic_work, as_work_handler, q);
 
-	for (i = 0; i < AS_HASH_ENTRIES; i++)
-		INIT_HLIST_HEAD(&ad->hash[i]);
-
 	INIT_LIST_HEAD(&ad->fifo_list[REQ_SYNC]);
 	INIT_LIST_HEAD(&ad->fifo_list[REQ_ASYNC]);
 	ad->sort_list[REQ_SYNC] = RB_ROOT;
@@ -1787,10 +1446,8 @@ static struct elevator_type iosched_as = {
 		.elevator_deactivate_req_fn = 	as_deactivate_request,
 		.elevator_queue_empty_fn =	as_queue_empty,
 		.elevator_completed_req_fn =	as_completed_request,
-		.elevator_former_req_fn =	as_former_request,
-		.elevator_latter_req_fn =	as_latter_request,
-		.elevator_set_req_fn =		as_set_request,
-		.elevator_put_req_fn =		as_put_request,
+		.elevator_former_req_fn =	elv_rb_former_request,
+		.elevator_latter_req_fn =	elv_rb_latter_request,
 		.elevator_may_queue_fn =	as_may_queue,
 		.elevator_init_fn =		as_init_queue,
 		.elevator_exit_fn =		as_exit_queue,
@@ -1806,11 +1463,6 @@ static int __init as_init(void)
 {
 	int ret;
 
-	arq_pool = kmem_cache_create("as_arq", sizeof(struct as_rq),
-				     0, 0, NULL, NULL);
-	if (!arq_pool)
-		return -ENOMEM;
-
 	ret = elv_register(&iosched_as);
 	if (!ret) {
 		/*
@@ -1822,21 +1474,19 @@ static int __init as_init(void)
 		return 0;
 	}
 
-	kmem_cache_destroy(arq_pool);
 	return ret;
 }
 
 static void __exit as_exit(void)
 {
-	DECLARE_COMPLETION(all_gone);
+	DECLARE_COMPLETION_ONSTACK(all_gone);
 	elv_unregister(&iosched_as);
 	ioc_gone = &all_gone;
 	/* ioc_gone's update must be visible before reading ioc_count */
 	smp_wmb();
-	if (atomic_read(&ioc_count))
+	if (elv_ioc_count_read(ioc_count))
 		wait_for_completion(ioc_gone);
 	synchronize_rcu();
-	kmem_cache_destroy(arq_pool);
 }
 
 module_init(as_init);