X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=blobdiff_plain;f=block%2Felevator.c;h=9ad5ccc4c5eeca51408eef4bbfc1da33a7c8d532;hp=d265963d1ed333fc6babce13d5fb4112f74bde12;hb=d5aa407f59f5b83d2c50ec88f5bf56d40f1f8978;hpb=94f6030ca792c57422f04a73e7a872d8325946d3

diff --git a/block/elevator.c b/block/elevator.c
index d265963..9ad5ccc 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -34,8 +34,11 @@
 #include <linux/delay.h>
 #include <linux/blktrace_api.h>
 #include <linux/hash.h>
+#include <linux/uaccess.h>
 
-#include <asm/uaccess.h>
+#include <trace/events/block.h>
+
+#include "blk.h"
 
 static DEFINE_SPINLOCK(elv_list_lock);
 static LIST_HEAD(elv_list);
@@ -45,10 +48,10 @@ static LIST_HEAD(elv_list);
  */
 static const int elv_hash_shift = 6;
 #define ELV_HASH_BLOCK(sec)	((sec) >> 3)
-#define ELV_HASH_FN(sec)	(hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
+#define ELV_HASH_FN(sec)	\
+		(hash_long(ELV_HASH_BLOCK((sec)), elv_hash_shift))
 #define ELV_HASH_ENTRIES	(1 << elv_hash_shift)
-#define rq_hash_key(rq)		((rq)->sector + (rq)->nr_sectors)
-#define ELV_ON_HASH(rq)		(!hlist_unhashed(&(rq)->hash))
+#define rq_hash_key(rq)		(blk_rq_pos(rq) + blk_rq_sectors(rq))
 
 /*
  * Query io scheduler to see if the current process issuing bio may be
@@ -56,8 +59,8 @@ static const int elv_hash_shift = 6;
  */
 static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
 {
-	request_queue_t *q = rq->q;
-	elevator_t *e = q->elevator;
+	struct request_queue *q = rq->q;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_allow_merge_fn)
 		return e->ops->elevator_allow_merge_fn(q, rq, bio);
@@ -68,12 +71,19 @@ static int elv_iosched_allow_merge(struct request *rq, struct bio *bio)
 /*
  * can we safely merge with this request?
  */
-inline int elv_rq_merge_ok(struct request *rq, struct bio *bio)
+int elv_rq_merge_ok(struct request *rq, struct bio *bio)
 {
 	if (!rq_mergeable(rq))
 		return 0;
 
 	/*
+	 * Don't merge file system requests and discard requests
+	 */
+	if (bio_rw_flagged(bio, BIO_RW_DISCARD) !=
+	    bio_rw_flagged(rq->bio, BIO_RW_DISCARD))
+		return 0;
+
+	/*
 	 * different data direction or already started, don't merge
 	 */
 	if (bio_data_dir(bio) != rq_data_dir(rq))
@@ -85,6 +95,12 @@ inline int elv_rq_merge_ok(struct request *rq, struct bio *bio)
 	if (rq->rq_disk != bio->bi_bdev->bd_disk || rq->special)
 		return 0;
 
+	/*
+	 * only merge integrity protected bio into ditto rq
+	 */
+	if (bio_integrity(bio) != blk_integrity_rq(rq))
+		return 0;
+
 	if (!elv_iosched_allow_merge(rq, bio))
 		return 0;
 
@@ -100,9 +116,9 @@ static inline int elv_try_merge(struct request *__rq, struct bio *bio)
 	 * we can merge and sequence is ok, check if it's possible
 	 */
 	if (elv_rq_merge_ok(__rq, bio)) {
-		if (__rq->sector + __rq->nr_sectors == bio->bi_sector)
+		if (blk_rq_pos(__rq) + blk_rq_sectors(__rq) == bio->bi_sector)
 			ret = ELEVATOR_BACK_MERGE;
-		else if (__rq->sector - bio_sectors(bio) == bio->bi_sector)
+		else if (blk_rq_pos(__rq) - bio_sectors(bio) == bio->bi_sector)
 			ret = ELEVATOR_FRONT_MERGE;
 	}
 
@@ -133,6 +149,18 @@ static struct elevator_type *elevator_get(const char *name)
 	spin_lock(&elv_list_lock);
 
 	e = elevator_find(name);
+	if (!e) {
+		char elv[ELV_NAME_MAX + strlen("-iosched")];
+
+		spin_unlock(&elv_list_lock);
+
+		sprintf(elv, "%s-iosched", name);
+
+		request_module("%s", elv);
+		spin_lock(&elv_list_lock);
+		e = elevator_find(name);
+	}
+
 	if (e && !try_module_get(e->elevator_owner))
 		e = NULL;
 
@@ -141,12 +169,13 @@ static struct elevator_type *elevator_get(const char *name)
 	return e;
 }
 
-static void *elevator_init_queue(request_queue_t *q, struct elevator_queue *eq)
+static void *elevator_init_queue(struct request_queue *q,
+				 struct elevator_queue *eq)
 {
 	return eq->ops->elevator_init_fn(q);
 }
 
-static void elevator_attach(request_queue_t *q, struct elevator_queue *eq,
+static void elevator_attach(struct request_queue *q, struct elevator_queue *eq,
 			   void *data)
 {
 	q->elevator = eq;
@@ -161,10 +190,7 @@ static int __init elevator_setup(char *str)
 	 * Be backwards-compatible with previous kernels, so users
 	 * won't get the wrong elevator.
 	 */
-	if (!strcmp(str, "as"))
-		strcpy(chosen_elevator, "anticipatory");
-	else
-		strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
+	strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
 	return 1;
 }
 
@@ -172,20 +198,19 @@ __setup("elevator=", elevator_setup);
 
 static struct kobj_type elv_ktype;
 
-static elevator_t *elevator_alloc(request_queue_t *q, struct elevator_type *e)
+static struct elevator_queue *elevator_alloc(struct request_queue *q,
+				  struct elevator_type *e)
 {
-	elevator_t *eq;
+	struct elevator_queue *eq;
 	int i;
 
-	eq = kmalloc_node(sizeof(elevator_t), GFP_KERNEL | __GFP_ZERO, q->node);
+	eq = kmalloc_node(sizeof(*eq), GFP_KERNEL | __GFP_ZERO, q->node);
 	if (unlikely(!eq))
 		goto err;
 
 	eq->ops = &e->ops;
 	eq->elevator_type = e;
-	kobject_init(&eq->kobj);
-	snprintf(eq->kobj.name, KOBJ_NAME_LEN, "%s", "iosched");
-	eq->kobj.ktype = &elv_ktype;
+	kobject_init(&eq->kobj, &elv_ktype);
 	mutex_init(&eq->sysfs_lock);
 
 	eq->hash = kmalloc_node(sizeof(struct hlist_head) * ELV_HASH_ENTRIES,
@@ -205,14 +230,15 @@ err:
 
 static void elevator_release(struct kobject *kobj)
 {
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
+	struct elevator_queue *e;
 
+	e = container_of(kobj, struct elevator_queue, kobj);
 	elevator_put(e->elevator_type);
 	kfree(e->hash);
 	kfree(e);
 }
 
-int elevator_init(request_queue_t *q, char *name)
+int elevator_init(struct request_queue *q, char *name)
 {
 	struct elevator_type *e = NULL;
 	struct elevator_queue *eq;
@@ -224,15 +250,27 @@ int elevator_init(request_queue_t *q, char *name)
 	q->end_sector = 0;
 	q->boundary_rq = NULL;
 
-	if (name && !(e = elevator_get(name)))
-		return -EINVAL;
+	if (name) {
+		e = elevator_get(name);
+		if (!e)
+			return -EINVAL;
+	}
 
-	if (!e && *chosen_elevator && !(e = elevator_get(chosen_elevator)))
-		printk("I/O scheduler %s not found\n", chosen_elevator);
+	if (!e && *chosen_elevator) {
+		e = elevator_get(chosen_elevator);
+		if (!e)
+			printk(KERN_ERR "I/O scheduler %s not found\n",
+							chosen_elevator);
+	}
 
-	if (!e && !(e = elevator_get(CONFIG_DEFAULT_IOSCHED))) {
-		printk("Default I/O scheduler not found, using no-op\n");
-		e = elevator_get("noop");
+	if (!e) {
+		e = elevator_get(CONFIG_DEFAULT_IOSCHED);
+		if (!e) {
+			printk(KERN_ERR
+				"Default I/O scheduler not found. " \
+				"Using noop.\n");
+			e = elevator_get("noop");
+		}
 	}
 
 	eq = elevator_alloc(q, e);
@@ -248,10 +286,9 @@ int elevator_init(request_queue_t *q, char *name)
 	elevator_attach(q, eq, data);
 	return ret;
 }
-
 EXPORT_SYMBOL(elevator_init);
 
-void elevator_exit(elevator_t *e)
+void elevator_exit(struct elevator_queue *e)
 {
 	mutex_lock(&e->sysfs_lock);
 	if (e->ops->elevator_exit_fn)
@@ -261,53 +298,36 @@ void elevator_exit(elevator_t *e)
 
 	kobject_put(&e->kobj);
 }
-
 EXPORT_SYMBOL(elevator_exit);
 
-static void elv_activate_rq(request_queue_t *q, struct request *rq)
-{
-	elevator_t *e = q->elevator;
-
-	if (e->ops->elevator_activate_req_fn)
-		e->ops->elevator_activate_req_fn(q, rq);
-}
-
-static void elv_deactivate_rq(request_queue_t *q, struct request *rq)
-{
-	elevator_t *e = q->elevator;
-
-	if (e->ops->elevator_deactivate_req_fn)
-		e->ops->elevator_deactivate_req_fn(q, rq);
-}
-
 static inline void __elv_rqhash_del(struct request *rq)
 {
 	hlist_del_init(&rq->hash);
 }
 
-static void elv_rqhash_del(request_queue_t *q, struct request *rq)
+static void elv_rqhash_del(struct request_queue *q, struct request *rq)
 {
 	if (ELV_ON_HASH(rq))
 		__elv_rqhash_del(rq);
 }
 
-static void elv_rqhash_add(request_queue_t *q, struct request *rq)
+static void elv_rqhash_add(struct request_queue *q, struct request *rq)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	BUG_ON(ELV_ON_HASH(rq));
 	hlist_add_head(&rq->hash, &e->hash[ELV_HASH_FN(rq_hash_key(rq))]);
 }
 
-static void elv_rqhash_reposition(request_queue_t *q, struct request *rq)
+static void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
 {
 	__elv_rqhash_del(rq);
 	elv_rqhash_add(q, rq);
 }
 
-static struct request *elv_rqhash_find(request_queue_t *q, sector_t offset)
+static struct request *elv_rqhash_find(struct request_queue *q, sector_t offset)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 	struct hlist_head *hash_list = &e->hash[ELV_HASH_FN(offset)];
 	struct hlist_node *entry, *next;
 	struct request *rq;
@@ -341,9 +361,9 @@ struct request *elv_rb_add(struct rb_root *root, struct request *rq)
 		parent = *p;
 		__rq = rb_entry(parent, struct request, rb_node);
 
-		if (rq->sector < __rq->sector)
+		if (blk_rq_pos(rq) < blk_rq_pos(__rq))
 			p = &(*p)->rb_left;
-		else if (rq->sector > __rq->sector)
+		else if (blk_rq_pos(rq) > blk_rq_pos(__rq))
 			p = &(*p)->rb_right;
 		else
 			return __rq;
@@ -353,7 +373,6 @@ struct request *elv_rb_add(struct rb_root *root, struct request *rq)
 	rb_insert_color(&rq->rb_node, root);
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_add);
 
 void elv_rb_del(struct rb_root *root, struct request *rq)
@@ -362,7 +381,6 @@ void elv_rb_del(struct rb_root *root, struct request *rq)
 	rb_erase(&rq->rb_node, root);
 	RB_CLEAR_NODE(&rq->rb_node);
 }
-
 EXPORT_SYMBOL(elv_rb_del);
 
 struct request *elv_rb_find(struct rb_root *root, sector_t sector)
@@ -373,9 +391,9 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
 	while (n) {
 		rq = rb_entry(n, struct request, rb_node);
 
-		if (sector < rq->sector)
+		if (sector < blk_rq_pos(rq))
 			n = n->rb_left;
-		else if (sector > rq->sector)
+		else if (sector > blk_rq_pos(rq))
 			n = n->rb_right;
 		else
 			return rq;
@@ -383,18 +401,18 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_find);
 
 /*
  * Insert rq into dispatch queue of q.  Queue lock must be held on
- * entry.  rq is sort insted into the dispatch queue. To be used by
+ * entry.  rq is sort instead into the dispatch queue. To be used by
  * specific elevators.
  */
-void elv_dispatch_sort(request_queue_t *q, struct request *rq)
+void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 {
 	sector_t boundary;
 	struct list_head *entry;
+	int stop_flags;
 
 	if (q->last_merge == rq)
 		q->last_merge = NULL;
@@ -404,28 +422,29 @@ void elv_dispatch_sort(request_queue_t *q, struct request *rq)
 	q->nr_sorted--;
 
 	boundary = q->end_sector;
-
+	stop_flags = REQ_SOFTBARRIER | REQ_HARDBARRIER | REQ_STARTED;
 	list_for_each_prev(entry, &q->queue_head) {
 		struct request *pos = list_entry_rq(entry);
 
+		if (blk_discard_rq(rq) != blk_discard_rq(pos))
+			break;
 		if (rq_data_dir(rq) != rq_data_dir(pos))
 			break;
-		if (pos->cmd_flags & (REQ_SOFTBARRIER|REQ_HARDBARRIER|REQ_STARTED))
+		if (pos->cmd_flags & stop_flags)
 			break;
-		if (rq->sector >= boundary) {
-			if (pos->sector < boundary)
+		if (blk_rq_pos(rq) >= boundary) {
+			if (blk_rq_pos(pos) < boundary)
 				continue;
 		} else {
-			if (pos->sector >= boundary)
+			if (blk_rq_pos(pos) >= boundary)
 				break;
 		}
-		if (rq->sector >= pos->sector)
+		if (blk_rq_pos(rq) >= blk_rq_pos(pos))
 			break;
 	}
 
 	list_add(&rq->queuelist, entry);
 }
-
 EXPORT_SYMBOL(elv_dispatch_sort);
 
 /*
@@ -446,12 +465,11 @@ void elv_dispatch_add_tail(struct request_queue *q, struct request *rq)
 	q->boundary_rq = rq;
 	list_add_tail(&rq->queuelist, &q->queue_head);
 }
-
 EXPORT_SYMBOL(elv_dispatch_add_tail);
 
-int elv_merge(request_queue_t *q, struct request **req, struct bio *bio)
+int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 	struct request *__rq;
 	int ret;
 
@@ -466,6 +484,9 @@ int elv_merge(request_queue_t *q, struct request **req, struct bio *bio)
 		}
 	}
 
+	if (blk_queue_nomerges(q))
+		return ELEVATOR_NO_MERGE;
+
 	/*
 	 * See if our hash lookup can find a potential backmerge.
 	 */
@@ -481,9 +502,9 @@ int elv_merge(request_queue_t *q, struct request **req, struct bio *bio)
 	return ELEVATOR_NO_MERGE;
 }
 
-void elv_merged_request(request_queue_t *q, struct request *rq, int type)
+void elv_merged_request(struct request_queue *q, struct request *rq, int type)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_merged_fn)
 		e->ops->elevator_merged_fn(q, rq, type);
@@ -494,10 +515,10 @@ void elv_merged_request(request_queue_t *q, struct request *rq, int type)
 	q->last_merge = rq;
 }
 
-void elv_merge_requests(request_queue_t *q, struct request *rq,
+void elv_merge_requests(struct request_queue *q, struct request *rq,
 			     struct request *next)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_merge_req_fn)
 		e->ops->elevator_merge_req_fn(q, rq, next);
@@ -509,14 +530,14 @@ void elv_merge_requests(request_queue_t *q, struct request *rq,
 	q->last_merge = rq;
 }
 
-void elv_requeue_request(request_queue_t *q, struct request *rq)
+void elv_requeue_request(struct request_queue *q, struct request *rq)
 {
 	/*
 	 * it already went through dequeue, we need to decrement the
 	 * in_flight count again
 	 */
 	if (blk_account_rq(rq)) {
-		q->in_flight--;
+		q->in_flight[rq_is_sync(rq)]--;
 		if (blk_sorted_rq(rq))
 			elv_deactivate_rq(q, rq);
 	}
@@ -526,7 +547,7 @@ void elv_requeue_request(request_queue_t *q, struct request *rq)
 	elv_insert(q, rq, ELEVATOR_INSERT_REQUEUE);
 }
 
-static void elv_drain_elevator(request_queue_t *q)
+void elv_drain_elevator(struct request_queue *q)
 {
 	static int printed;
 	while (q->elevator->ops->elevator_dispatch_fn(q, 1))
@@ -540,13 +561,41 @@ static void elv_drain_elevator(request_queue_t *q)
 	}
 }
 
-void elv_insert(request_queue_t *q, struct request *rq, int where)
+/*
+ * Call with queue lock held, interrupts disabled
+ */
+void elv_quiesce_start(struct request_queue *q)
+{
+	if (!q->elevator)
+		return;
+
+	queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
+
+	/*
+	 * make sure we don't have any requests in flight
+	 */
+	elv_drain_elevator(q);
+	while (q->rq.elvpriv) {
+		__blk_run_queue(q);
+		spin_unlock_irq(q->queue_lock);
+		msleep(10);
+		spin_lock_irq(q->queue_lock);
+		elv_drain_elevator(q);
+	}
+}
+
+void elv_quiesce_end(struct request_queue *q)
+{
+	queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+}
+
+void elv_insert(struct request_queue *q, struct request *rq, int where)
 {
 	struct list_head *pos;
 	unsigned ordseq;
 	int unplug_it = 1;
 
-	blk_add_trace_rq(q, rq, BLK_TA_INSERT);
+	trace_block_rq_insert(q, rq);
 
 	rq->q = q;
 
@@ -571,12 +620,11 @@ void elv_insert(request_queue_t *q, struct request *rq, int where)
 		 *   with anything.  There's no point in delaying queue
 		 *   processing.
 		 */
-		blk_remove_plug(q);
-		q->request_fn(q);
+		__blk_run_queue(q);
 		break;
 
 	case ELEVATOR_INSERT_SORT:
-		BUG_ON(!blk_fs_request(rq));
+		BUG_ON(!blk_fs_request(rq) && !blk_discard_rq(rq));
 		rq->cmd_flags |= REQ_SORTED;
 		q->nr_sorted++;
 		if (rq_mergeable(rq)) {
@@ -625,20 +673,20 @@ void elv_insert(request_queue_t *q, struct request *rq, int where)
 
 	default:
 		printk(KERN_ERR "%s: bad insertion point %d\n",
-		       __FUNCTION__, where);
+		       __func__, where);
 		BUG();
 	}
 
 	if (unplug_it && blk_queue_plugged(q)) {
-		int nrq = q->rq.count[READ] + q->rq.count[WRITE]
-			- q->in_flight;
+		int nrq = q->rq.count[BLK_RW_SYNC] + q->rq.count[BLK_RW_ASYNC]
+				- queue_in_flight(q);
 
 		if (nrq >= q->unplug_thresh)
 			__generic_unplug_device(q);
 	}
 }
 
-void __elv_add_request(request_queue_t *q, struct request *rq, int where,
+void __elv_add_request(struct request_queue *q, struct request *rq, int where,
 		       int plug)
 {
 	if (q->ordcolor)
@@ -661,11 +709,12 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
 		 * this request is scheduling boundary, update
 		 * end_sector
 		 */
-		if (blk_fs_request(rq)) {
+		if (blk_fs_request(rq) || blk_discard_rq(rq)) {
 			q->end_sector = rq_end_sector(rq);
 			q->boundary_rq = rq;
 		}
-	} else if (!(rq->cmd_flags & REQ_ELVPRIV) && where == ELEVATOR_INSERT_SORT)
+	} else if (!(rq->cmd_flags & REQ_ELVPRIV) &&
+		    where == ELEVATOR_INSERT_SORT)
 		where = ELEVATOR_INSERT_BACK;
 
 	if (plug)
@@ -673,10 +722,9 @@ void __elv_add_request(request_queue_t *q, struct request *rq, int where,
 
 	elv_insert(q, rq, where);
 }
-
 EXPORT_SYMBOL(__elv_add_request);
 
-void elv_add_request(request_queue_t *q, struct request *rq, int where,
+void elv_add_request(struct request_queue *q, struct request *rq, int where,
 		     int plug)
 {
 	unsigned long flags;
@@ -685,112 +733,11 @@ void elv_add_request(request_queue_t *q, struct request *rq, int where,
 	__elv_add_request(q, rq, where, plug);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
-
 EXPORT_SYMBOL(elv_add_request);
 
-static inline struct request *__elv_next_request(request_queue_t *q)
-{
-	struct request *rq;
-
-	while (1) {
-		while (!list_empty(&q->queue_head)) {
-			rq = list_entry_rq(q->queue_head.next);
-			if (blk_do_ordered(q, &rq))
-				return rq;
-		}
-
-		if (!q->elevator->ops->elevator_dispatch_fn(q, 0))
-			return NULL;
-	}
-}
-
-struct request *elv_next_request(request_queue_t *q)
+int elv_queue_empty(struct request_queue *q)
 {
-	struct request *rq;
-	int ret;
-
-	while ((rq = __elv_next_request(q)) != NULL) {
-		if (!(rq->cmd_flags & REQ_STARTED)) {
-			/*
-			 * This is the first time the device driver
-			 * sees this request (possibly after
-			 * requeueing).  Notify IO scheduler.
-			 */
-			if (blk_sorted_rq(rq))
-				elv_activate_rq(q, rq);
-
-			/*
-			 * just mark as started even if we don't start
-			 * it, a request that has been delayed should
-			 * not be passed by new incoming requests
-			 */
-			rq->cmd_flags |= REQ_STARTED;
-			blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
-		}
-
-		if (!q->boundary_rq || q->boundary_rq == rq) {
-			q->end_sector = rq_end_sector(rq);
-			q->boundary_rq = NULL;
-		}
-
-		if ((rq->cmd_flags & REQ_DONTPREP) || !q->prep_rq_fn)
-			break;
-
-		ret = q->prep_rq_fn(q, rq);
-		if (ret == BLKPREP_OK) {
-			break;
-		} else if (ret == BLKPREP_DEFER) {
-			/*
-			 * the request may have been (partially) prepped.
-			 * we need to keep this request in the front to
-			 * avoid resource deadlock.  REQ_STARTED will
-			 * prevent other fs requests from passing this one.
-			 */
-			rq = NULL;
-			break;
-		} else if (ret == BLKPREP_KILL) {
-			int nr_bytes = rq->hard_nr_sectors << 9;
-
-			if (!nr_bytes)
-				nr_bytes = rq->data_len;
-
-			blkdev_dequeue_request(rq);
-			rq->cmd_flags |= REQ_QUIET;
-			end_that_request_chunk(rq, 0, nr_bytes);
-			end_that_request_last(rq, 0);
-		} else {
-			printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,
-								ret);
-			break;
-		}
-	}
-
-	return rq;
-}
-
-EXPORT_SYMBOL(elv_next_request);
-
-void elv_dequeue_request(request_queue_t *q, struct request *rq)
-{
-	BUG_ON(list_empty(&rq->queuelist));
-	BUG_ON(ELV_ON_HASH(rq));
-
-	list_del_init(&rq->queuelist);
-
-	/*
-	 * the time frame between a request being removed from the lists
-	 * and to it is freed is accounted as io that is in progress at
-	 * the driver side.
-	 */
-	if (blk_account_rq(rq))
-		q->in_flight++;
-}
-
-EXPORT_SYMBOL(elv_dequeue_request);
-
-int elv_queue_empty(request_queue_t *q)
-{
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (!list_empty(&q->queue_head))
 		return 0;
@@ -800,30 +747,29 @@ int elv_queue_empty(request_queue_t *q)
 
 	return 1;
 }
-
 EXPORT_SYMBOL(elv_queue_empty);
 
-struct request *elv_latter_request(request_queue_t *q, struct request *rq)
+struct request *elv_latter_request(struct request_queue *q, struct request *rq)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_latter_req_fn)
 		return e->ops->elevator_latter_req_fn(q, rq);
 	return NULL;
 }
 
-struct request *elv_former_request(request_queue_t *q, struct request *rq)
+struct request *elv_former_request(struct request_queue *q, struct request *rq)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_former_req_fn)
 		return e->ops->elevator_former_req_fn(q, rq);
 	return NULL;
 }
 
-int elv_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
+int elv_set_request(struct request_queue *q, struct request *rq, gfp_t gfp_mask)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_set_req_fn)
 		return e->ops->elevator_set_req_fn(q, rq, gfp_mask);
@@ -832,17 +778,17 @@ int elv_set_request(request_queue_t *q, struct request *rq, gfp_t gfp_mask)
 	return 0;
 }
 
-void elv_put_request(request_queue_t *q, struct request *rq)
+void elv_put_request(struct request_queue *q, struct request *rq)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_put_req_fn)
 		e->ops->elevator_put_req_fn(rq);
 }
 
-int elv_may_queue(request_queue_t *q, int rw)
+int elv_may_queue(struct request_queue *q, int rw)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 
 	if (e->ops->elevator_may_queue_fn)
 		return e->ops->elevator_may_queue_fn(q, rw);
@@ -850,15 +796,33 @@ int elv_may_queue(request_queue_t *q, int rw)
 	return ELV_MQUEUE_MAY;
 }
 
-void elv_completed_request(request_queue_t *q, struct request *rq)
+void elv_abort_queue(struct request_queue *q)
 {
-	elevator_t *e = q->elevator;
+	struct request *rq;
+
+	while (!list_empty(&q->queue_head)) {
+		rq = list_entry_rq(q->queue_head.next);
+		rq->cmd_flags |= REQ_QUIET;
+		trace_block_rq_abort(q, rq);
+		/*
+		 * Mark this request as started so we don't trigger
+		 * any debug logic in the end I/O path.
+		 */
+		blk_start_request(rq);
+		__blk_end_request_all(rq, -EIO);
+	}
+}
+EXPORT_SYMBOL(elv_abort_queue);
+
+void elv_completed_request(struct request_queue *q, struct request *rq)
+{
+	struct elevator_queue *e = q->elevator;
 
 	/*
 	 * request is released from the driver, io must be done
 	 */
 	if (blk_account_rq(rq)) {
-		q->in_flight--;
+		q->in_flight[rq_is_sync(rq)]--;
 		if (blk_sorted_rq(rq) && e->ops->elevator_completed_req_fn)
 			e->ops->elevator_completed_req_fn(q, rq);
 	}
@@ -868,12 +832,16 @@ void elv_completed_request(request_queue_t *q, struct request *rq)
 	 * drained for flush sequence.
 	 */
 	if (unlikely(q->ordseq)) {
-		struct request *first_rq = list_entry_rq(q->queue_head.next);
-		if (q->in_flight == 0 &&
+		struct request *next = NULL;
+
+		if (!list_empty(&q->queue_head))
+			next = list_entry_rq(q->queue_head.next);
+
+		if (!queue_in_flight(q) &&
 		    blk_ordered_cur_seq(q) == QUEUE_ORDSEQ_DRAIN &&
-		    blk_ordered_req_seq(first_rq) > QUEUE_ORDSEQ_DRAIN) {
+		    (!next || blk_ordered_req_seq(next) > QUEUE_ORDSEQ_DRAIN)) {
 			blk_ordered_complete_seq(q, QUEUE_ORDSEQ_DRAIN, 0);
-			q->request_fn(q);
+			__blk_run_queue(q);
 		}
 	}
 }
@@ -883,13 +851,14 @@ void elv_completed_request(request_queue_t *q, struct request *rq)
 static ssize_t
 elv_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 {
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
 	struct elv_fs_entry *entry = to_elv(attr);
+	struct elevator_queue *e;
 	ssize_t error;
 
 	if (!entry->show)
 		return -EIO;
 
+	e = container_of(kobj, struct elevator_queue, kobj);
 	mutex_lock(&e->sysfs_lock);
 	error = e->ops ? entry->show(e, page) : -ENOENT;
 	mutex_unlock(&e->sysfs_lock);
@@ -900,13 +869,14 @@ static ssize_t
 elv_attr_store(struct kobject *kobj, struct attribute *attr,
 	       const char *page, size_t length)
 {
-	elevator_t *e = container_of(kobj, elevator_t, kobj);
 	struct elv_fs_entry *entry = to_elv(attr);
+	struct elevator_queue *e;
 	ssize_t error;
 
 	if (!entry->store)
 		return -EIO;
 
+	e = container_of(kobj, struct elevator_queue, kobj);
 	mutex_lock(&e->sysfs_lock);
 	error = e->ops ? entry->store(e, page, length) : -ENOENT;
 	mutex_unlock(&e->sysfs_lock);
@@ -925,12 +895,10 @@ static struct kobj_type elv_ktype = {
 
 int elv_register_queue(struct request_queue *q)
 {
-	elevator_t *e = q->elevator;
+	struct elevator_queue *e = q->elevator;
 	int error;
 
-	e->kobj.parent = &q->kobj;
-
-	error = kobject_add(&e->kobj);
+	error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
 	if (!error) {
 		struct elv_fs_entry *attr = e->elevator_type->elevator_attrs;
 		if (attr) {
@@ -945,7 +913,7 @@ int elv_register_queue(struct request_queue *q)
 	return error;
 }
 
-static void __elv_unregister_queue(elevator_t *e)
+static void __elv_unregister_queue(struct elevator_queue *e)
 {
 	kobject_uevent(&e->kobj, KOBJ_REMOVE);
 	kobject_del(&e->kobj);
@@ -957,7 +925,7 @@ void elv_unregister_queue(struct request_queue *q)
 		__elv_unregister_queue(q->elevator);
 }
 
-int elv_register(struct elevator_type *e)
+void elv_register(struct elevator_type *e)
 {
 	char *def = "";
 
@@ -971,8 +939,8 @@ int elv_register(struct elevator_type *e)
 			 !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED)))
 				def = " (default)";
 
-	printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, def);
-	return 0;
+	printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name,
+								def);
 }
 EXPORT_SYMBOL_GPL(elv_register);
 
@@ -1006,9 +974,9 @@ EXPORT_SYMBOL_GPL(elv_unregister);
  * need for the new one. this way we have a chance of going back to the old
  * one, if the new one fails init for some reason.
  */
-static int elevator_switch(request_queue_t *q, struct elevator_type *new_e)
+static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
 {
-	elevator_t *old_elevator, *e;
+	struct elevator_queue *old_elevator, *e;
 	void *data;
 
 	/*
@@ -1028,19 +996,7 @@ static int elevator_switch(request_queue_t *q, struct elevator_type *new_e)
 	 * Turn on BYPASS and drain all requests w/ elevator private data
 	 */
 	spin_lock_irq(q->queue_lock);
-
-	set_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
-
-	elv_drain_elevator(q);
-
-	while (q->rq.elvpriv) {
-		blk_remove_plug(q);
-		q->request_fn(q);
-		spin_unlock_irq(q->queue_lock);
-		msleep(10);
-		spin_lock_irq(q->queue_lock);
-		elv_drain_elevator(q);
-	}
+	elv_quiesce_start(q);
 
 	/*
 	 * Remember old elevator.
@@ -1063,7 +1019,12 @@ static int elevator_switch(request_queue_t *q, struct elevator_type *new_e)
 	 * finally exit old elevator and turn off BYPASS.
 	 */
 	elevator_exit(old_elevator);
-	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+	spin_lock_irq(q->queue_lock);
+	elv_quiesce_end(q);
+	spin_unlock_irq(q->queue_lock);
+
+	blk_add_trace_msg(q, "elv switch: %s", e->elevator_type->elevator_name);
+
 	return 1;
 
 fail_register:
@@ -1074,24 +1035,25 @@ fail_register:
 	elevator_exit(e);
 	q->elevator = old_elevator;
 	elv_register_queue(q);
-	clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags);
+
+	spin_lock_irq(q->queue_lock);
+	queue_flag_clear(QUEUE_FLAG_ELVSWITCH, q);
+	spin_unlock_irq(q->queue_lock);
+
 	return 0;
 }
 
-ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
+ssize_t elv_iosched_store(struct request_queue *q, const char *name,
+			  size_t count)
 {
 	char elevator_name[ELV_NAME_MAX];
-	size_t len;
 	struct elevator_type *e;
 
-	elevator_name[sizeof(elevator_name) - 1] = '\0';
-	strncpy(elevator_name, name, sizeof(elevator_name) - 1);
-	len = strlen(elevator_name);
-
-	if (len && elevator_name[len - 1] == '\n')
-		elevator_name[len - 1] = '\0';
+	if (!q->elevator)
+		return count;
 
-	e = elevator_get(elevator_name);
+	strlcpy(elevator_name, name, sizeof(elevator_name));
+	e = elevator_get(strstrip(elevator_name));
 	if (!e) {
 		printk(KERN_ERR "elevator: type %s not found\n", elevator_name);
 		return -EINVAL;
@@ -1103,17 +1065,23 @@ ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
 	}
 
 	if (!elevator_switch(q, e))
-		printk(KERN_ERR "elevator: switch to %s failed\n",elevator_name);
+		printk(KERN_ERR "elevator: switch to %s failed\n",
+							elevator_name);
 	return count;
 }
 
-ssize_t elv_iosched_show(request_queue_t *q, char *name)
+ssize_t elv_iosched_show(struct request_queue *q, char *name)
 {
-	elevator_t *e = q->elevator;
-	struct elevator_type *elv = e->elevator_type;
+	struct elevator_queue *e = q->elevator;
+	struct elevator_type *elv;
 	struct elevator_type *__e;
 	int len = 0;
 
+	if (!q->elevator)
+		return sprintf(name, "none\n");
+
+	elv = e->elevator_type;
+
 	spin_lock(&elv_list_lock);
 	list_for_each_entry(__e, &elv_list, list) {
 		if (!strcmp(elv->elevator_name, __e->elevator_name))
@@ -1127,7 +1095,8 @@ ssize_t elv_iosched_show(request_queue_t *q, char *name)
 	return len;
 }
 
-struct request *elv_rb_former_request(request_queue_t *q, struct request *rq)
+struct request *elv_rb_former_request(struct request_queue *q,
+				      struct request *rq)
 {
 	struct rb_node *rbprev = rb_prev(&rq->rb_node);
 
@@ -1136,10 +1105,10 @@ struct request *elv_rb_former_request(request_queue_t *q, struct request *rq)
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_former_request);
 
-struct request *elv_rb_latter_request(request_queue_t *q, struct request *rq)
+struct request *elv_rb_latter_request(struct request_queue *q,
+				      struct request *rq)
 {
 	struct rb_node *rbnext = rb_next(&rq->rb_node);
 
@@ -1148,5 +1117,4 @@ struct request *elv_rb_latter_request(request_queue_t *q, struct request *rq)
 
 	return NULL;
 }
-
 EXPORT_SYMBOL(elv_rb_latter_request);